Article

Wire-Probing Technique to Revascularize Subacute or Chronic Internal Carotid Artery Occlusion

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Abstract

During endovascular revascularization of subacute and chronic occlusion of the cervical internal carotid artery (ICA) it may be difficult to penetrate the lesion. Selecting the appropriate “true lumen”, a remnant of what had been the arterial lumen, at the initial step may facilitate the procedure. Because plaque at the carotid bifurcation is known to propagate from the posterior wall, a gateway to this “true lumen” should exist in the anterior side of the occluded stump. This hypothesis was studied retrospectively in our series of revascularizing ICA subacute and chronic occlusion. Eleven patients underwent endovascular revascularization for symptomatic cervical ICA occlusion. Procedures were performed by initially penetrating the occluded stump with a guidewire, followed by supporting catheter advancement through the occluded segment to secure the distal normal arterial lumen. Cases were analyzed with regard to the location of initial guidewire penetration. Eight patients underwent successful revascularization. In five cases, the entry point to the occluded stump was located at the anterior side, and in three, at the posterior side. Two posterior stump penetration cases were met with resistance in guidewire advancement, whereas penetration was smooth in the anterior cases. In addition, two posterior stump penetration cases resulted in contrast stasis in the posterior ICA wall. In our series of revascularizing cervical ICA subacute and chronic occlusion, initially targeting the anterior side of the occluded stump resulted in favorable results. This may be the result of selecting the “true lumen” at the beginning of the procedure.

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... Endovascular recanalization of chronically occluded ICA was first reported by Terada et al. in 2005 (6). Since then, multiple case reports (7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18) retrospective and prospective cohort studies (19)(20)(21)(22)(23)(24)(25)(26)(27)(28) have been published, most claiming benefit in patients who underwent successful endovascular or hybrid treatment, but no randomized controlled studies are available and society guidelines so far have failed to recommend endovascular therapy for symptomatic CTO of the ICA (29,30). The aim of this systematic review was to investigate patient selection, technical success, periprocedural complications, early and late outcome of endovascular treatment for symptomatic CTO of the ICA. ...
... Several articles were published from the same institution in Taiwan, we selected one of their papers with the largest number (n=138) of patients for our study (24). Data from two additional papers from this institution were also used to identify perioperative (19,20) one from Taiwan (24) and another from the United States (23). ...
... Five of the eight studies reported on stump anatomy, three presented it in detail, most (61.4%) had tapered stump ( Table 2). Only one group favored carotid arteries with blunt stump and penetrated the stump with the guidewire at the anterior side (20). ...
Article
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The management of patients with symptomatic chronic total occlusion (CTO) of the internal carotid artery (ICA) is controversial. The aim of this systematic review was to investigate patient selection, technical success, early and late outcome of endovascular treatment for CTO of the ICA. PubMed/Medline and EMBASE databases were searched until January 2, 2020 for studies on endovascular treatment for CTO of the ICA. A descriptive analysis of demographic, clinical and anatomic data, endovascular technique, perioperative and late outcomes was performed. A total of 1,222 articles were screened, 8 retrospective or prospective cohort studies were reviewed; 276 patients, 18.9% females, mean age: 64.3 years, underwent attempt at endovascular treatment of 278 lesions. Two hundred and thirteen patients (77.2%) had neurological symptoms; the others had evidence of ipsilateral cerebral hypoperfusion. Two hundred and thirty-eight lesions (91.2%) were treated >30 days after diagnosis of occlusion. Technical success was 66.9%. Perioperative mortality was 1.64% (4/243), early stroke rate was 3.3%. Follow-up averaged 23.4 months (range, 0.25-84 months), late mortality was 1.89% (5/265), stroke rate was 3.4% (9/265). Stroke rate was similar after successful stenting (3.57%, 4/112) vs. failed stenting (3.61%, 2/61; P=1.00), stroke/death rates were also similar after successful stenting (5.36%, 6/112) than after failed stenting (3.28%, 2/61; P=0.71). Endovascular treatment of CTO of the ICA in eight cohort studies was safe and feasible with a technical success of 67% and a low rate of early and late neurological complications. Pooled data in this review failed to confirm the benefit of successful stenting on stroke and mortality, but some of the included studies suggest benefit and some also supported improvement in neurocognitive function after successful stenting. Prospective randomized trials to investigate the benefit of endovascular treatment in addition to best medical therapy for symptomatic CTO of the ICA are urgently needed.
... 16,20 Recent efforts have been focused on the utilization of angioplasty and stenting to recanalize the occluded ICA. 14,17,21,24,26,35 Despite the technical difficulty involved, these endovascular interventions in patients with symptomatic COICA have led to improvements in neurological and cognitive function. 14,17 However, the risks associated with these endovascular approaches are significant. ...
... Sixteen studies satisfied our inclusion criteria. 5,6,9,14,17,18,[21][22][23]25,26,31,32,34,35,37 Studies that did not involve endovascular treatment of COICA or did not present data amenable to our comprehensive review were excluded. Table 2 lists the demographics, technical success, and complication rates (overall, major, and minor) of the studies, both individually and aggregately. ...
... 7,22,25 In the Carotid Occlusion Surgery Study (COSS), 29 the 2-year ipsilateral stroke risk in the medically treated arm increased to a staggering 22.7% for COICA causing hemodynamic hemispheric symptoms. While the management of chronic or subacute ICA oc-clusions has been challenging, recent studies have demonstrated the feasibility, safety, and efficacy of endovascular recanalization for COICA 9,14,17,21,22,25,26,34,36,37 with a wide disparity in outcomes. Thus, we aimed to perform a review to carefully evaluate the literature and attempt to identify whether a subpopulation could respond to such intervention. ...
Article
OBJECTIVE Revascularization of a symptomatic, medically refractory, cervical chronically occluded internal carotid artery (COICA) using endovascular techniques (ETs) has surfaced as a viable alternative to extracranial-intracranial bypass. The authors aimed to assess the safety, success, and neurocognitive outcomes of recanalization of COICA using ETs or hybrid treatment (ET plus carotid endarterectomy) and to identify candidate radiological markers that could predict success. METHODS The authors performed a retrospective analysis of their prospectively collected institutional database and used their previously published COICA classification to assess the potential benefits of ETs or hybrid surgery to revascularize symptomatic patients with COICA. Subjects who had undergone CT perfusion (CTP) imaging and Montreal Cognitive Assessment (MoCA) testing, both pre- and postprocedure, were included. The authors then performed a review of the literature on patients with COICA to further evaluate the success and safety of these treatment alternatives. RESULTS The single-center study revealed 28 subjects who had undergone revascularization of symptomatic COICA. Five subjects had CTP imaging and MoCA testing pre- and postrevascularization and thus were included in the study. All 5 patients had very large penumbra involving the entire hemisphere supplied by the ipsilateral COICA, which resolved postoperatively. Significant improvement in neurocognitive outcome was demonstrated by MoCA testing after treatment (preprocedure: 19.8 ± 2.4, postprocedure: 27 ± 1.6; p = 0.0038). Moreover, successful revascularization of COICA led to full restoration of cerebral hemodynamics in all cases. Review of the literature identified a total of 333 patients with COICA. Of these, 232 (70%) showed successful recanalization after ETs or hybrid surgery, with low major and minor complication rates (3.9% and 2.7%, respectively). CONCLUSIONS ETs and hybrid surgery are safe and effective alternatives to revascularize patients with symptomatic COICA. CTP imaging could be used as a radiological marker to assess cerebral hemodynamics and predict the success of revascularization. Improvement in CTP parameters is associated with significant improvement in neurocognitive functions.
... 6,8 Consequently, some centers have employed angioplasty and stenting for the management of these challenging lesions. 4,[9][10][11]13,18,20 The main concern with the endovascular treatment of COICA is the significant risk of perioperative complications such as distal embolization, vessel perforation, pseudoaneurysm formation, vessel dissection, fistula formation, and hyperperfusion syndrome. 11,19 In this report, we propose a new COICA classification that could offer interventionalists guidance on the technical feasibility and safety of endovascular recanalization for symptomatic COICA. ...
... Several reports in the literature have documented the feasibility and safety of endovascular revascularization for COICA. 2,4,5,[8][9][10][11]13,16,19,21,22 In this report, we sought to introduce a radiographic classification of COICA that could be applied to predict the success of revascularization for COICA using endovascular techniques. This classification is based on the radiographic review of 100 consecutive cases of COICA. ...
... Currently, there are a few reports documenting the feasibility and safety of this approach, and most are from Asian institutions. 2,4,6,[8][9][10][11]13,21,22 In the present study, 20/31 (64.52%) patients had subjectively reported improvement in their neurological symptoms at the 2-6 months' follow-up. Although the subjective improvement alone should not be used to assess the clinical success of this procedure since the majority of stroke symptoms improve over time, the combination of this subjective improvement together with the documented revascularization on DSA and the absence of recurrent stroke or TIA points toward the effectiveness of this intervention when revascularization is achieved. ...
Article
OBJECTIVE The overall risk of ischemic stroke from a chronically occluded internal carotid artery (COICA) is around 5%–7% per year despite receiving the best available medical therapy. Here, authors propose a radiographic classification of COICA that can be used as a guide to determine the technical success and safety of endovascular recanalization for symptomatic COICA and to assess the changes in systemic blood pressure following successful revascularization. METHODS The radiographic images of 100 consecutive subjects with COICA were analyzed. A new classification of COICA was proposed based on the morphology, location of occlusion, and presence or absence of reconstitution of the distal ICA. The classification was used to predict successful revascularization in 32 symptomatic COICAs in 31 patients, five of whom were female (5/31 [16.13%]). Patients were included in the study if they had a COICA with ischemic symptoms refractory to medical therapy. Carotid artery occlusion was defined as 100% cross-sectional occlusion of the vessel lumen as documented on CTA or MRA and confirmed by digital subtraction angiography. RESULTS Four types (A–D) of radiographic COICA were identified. Types A and B were more amenable to safe revascularization than types C and D. Recanalization was successful at a rate of 68.75% (22/32 COICAs; type A: 8/8; type B: 8/8; type C: 4/8; type D: 2/8). The perioperative complication rate was 18.75% (6/32; type A: 0/8 [0%]; type B: 1/8 [12.50%]; type C: 3/8 [37.50%], type D: 2/8 [25.00%]). None of these complications led to permanent morbidity or death. Twenty (64.52%) of 31 subjects had improvement in their symptoms at the 2–6 months’ follow-up. A statistically significant decrease in systolic blood pressure (SBP) was noted in 17/21 (80.95%) patients who had successful revascularization, which persisted on follow-up (p = 0.0001). The remaining 10 subjects in whom revascularization failed had no significant changes in SBP (p = 0.73). CONCLUSIONS The pilot study suggested that our proposed classification of COICA may be useful as an adjunctive guide to determine the technical feasibility and safety of revascularization for symptomatic COICA using endovascular techniques. Additionally, successful revascularization may lead to a significant decrease in SBP postprocedure. A Phase 2b trial in larger cohorts to assess the efficacy of endovascular revascularization using our COICA classification is warranted.
... In terms of surgical technique, initial penetration of the occluded stump from the anterior side may provide a maximal chance to access the 'true lumen'. This may be related to the posterior-to-anterior progression of the plaque at the common carotid artery bifurcation (91). ...
... The factor that most prominently affects the success rate of recanalization is the duration of occlusion. For acute and subacute occlusion of the ICA, both interventional surgery and hybrid surgery are relatively straightforward, mainly as the thrombosis in the ICA has not developed in structure and is relatively soft (91,107). Our experience corroborates this finding. ...
Article
At present, there is limited understanding of chronic total occlusion (CTO) of the internal carotid artery (ICA). Therefore, the present report collected related cases from PubMed and reviewed the literature. Cerebral vessels may form collateral circulation immediately or gradually following CTO of the ICA. The natural history of CTO of the ICA includes a variety of outcomes, all of which are biased toward a non‑benign progressive process and are characterized by insufficient cerebral perfusion, embolus detachment and cognitive dysfunction. The majority of cases of CTO of the ICA require treatment. In early studies, the results of external-ICA bypass were unsatisfactory, while recanalization is now considered the only viable option. The current treat­ment indications mainly depend on the degree of injury to the cerebrovascular reserve and the extent to which the oxygen extraction fraction is increased. The length, height and dura­tion of ICA occlusion are also relevant, though more frequently, the condition depends on multiple factors. Endovascular interventional recanalization, carotid endarterectomy (CEA) and hybrid surgery may be conducted in a select group of patients. As novel materials are developed, the success rate of simple recanalization may gradually increase; however, hybrid surgery may be more representative of the current trend, as advanced CEA can remove carotid atherosclerosis plaques, thus reducing the technological demands of the subsequent interventional recanalization. There are many complications that may result from recanalization following CTO of the ICA, including hyperperfusion and technical errors; therefore, the operation must be conducted carefully. If the recanalization is successful, it typically results in a stable improvement of patient condition in the long term. However, despite these conclusions, more studies are required in the future to further improve current understanding of CTO of the ICA.
... It has been successfully used in peripheral and coronary arteries. 3 The recent development of endovascular therapy has enabled the recanalization of carotid occlusion technically although it needs more study to evaluate its efficacy. ...
... Kao,et al. 7 advocated that excessive rotational or drilling motion of the wire was avoided, but successive small penetrate-andadvance steps carefully along the imaginary tract of the occluded vessel segment can pass the occlusion. Namba, et al. 3 suggest that initial penetration of the occluded stump from the anterior side will provide maximal chance to access the "true lumen." Rostambeigi, et al. 8 used ultrasonography to navigate and pass the carotid occlusion. ...
... Although it is difficult to judge the length of the lesion preoperatively, the possibility of distal extension should be considered. Some authors have suggested that the rate of success of recanalization can decrease with longer lesions [10][11][12] . Anzuini et al. stated that reoperation is often effective in cases of thrombosis after CEA, but difficult in cases of dissection because many such lesions extend distally [1] . ...
Article
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During or following carotid endarterectomy, dissection and occlusion of the internal carotid artery can occur. In cases of stenosis or almost complete occlusion, recanalization is relatively easy; however, in cases of complete occlusion, advancing a guidewire into the true lumen may be challenging. Few reports on how to address this problem have been published. Here, we report a case of suction-enabled advancement of the wire into the true lumen during endovascular treatment of an acute occlusion of the internal carotid artery after carotid endarterectomy. An 80-year-old man underwent carotid endarterectomy; the next morning, he exhibited aphasia and right-sided paralysis, and magnetic resonance images showed left cerebral infarction and left internal carotid artery occlusion. The patient was transferred to our hospital for recanalization. Imaging with contrast material showed that the left internal carotid artery was completely occluded. During recanalization, futile attempts were made to advance the wire into the true lumen. The occlusion was aspirated, and angiography then showed an inflow of contrast material into the vessel, which indicated slight distal widening; this widening allowed the wire to move into the true lumen. The occlusion extended distally, and 2 stents were placed over the entire lesion. Good recanalization was eventually achieved.
... DSA can dynamically display the stump condition, occlusion length, distal reflux, and collateral circulation, but it cannot analyze the course or the wall and lumen of occluded vessels. [21][22][23] CTA can reliably demonstrate occlusion length, collateral circulation, and the course of occluded vessels, but it cannot accurately analyze the age of the thrombus, the components of plaque, or the intracranial ICA (because of intervening skull bone). 19,24 Ultrasound is a noninvasive, economical, and highly operator-dependent tool for the evaluation of carotid artery occlusion; it can show the plaque composition but is useful only for analysis of the extracranial ICA. 25 High-resolution MR imaging (HR-MR imaging), which is being increasingly used in the evaluation of intracranial and extracranial vascular diseases, can provide direct visualization of the vessel wall and lumen, composition of the thrombus or plaque, occlusion length, collateral circulation, and the course of the occluded vessels [26][27][28] and can compensate for the weaknesses of other imaging modalities. ...
Article
Background and purpose: Accurate radiologic evaluation of the possibility of successful recanalization in symptomatic chronic ICA occlusion remains challenging. This study aimed to investigate the high-resolution MR imaging characteristics of symptomatic chronic ICA occlusion and their association with successful recanalization. Materials and methods: Consecutive patients with symptomatic chronic ICA occlusion who underwent balloon dilation plus stent implantation were identified retrospectively and divided into 2 groups: a successful recanalization group and an unsuccessful recanalization group. Clinical and high-resolution MR imaging characteristics were compared between the groups. Univariate and multivariate analyses were used to identify the characteristics associated with successful recanalization. Results: A total of 114 patients were included in the study. High-resolution MR imaging characteristics independently associated with unsuccessful recanalization were longer lesion length (OR, 0.41; 95% CI, 0.36-0.55; P = .009) and larger calcification volume (OR, 0.56; 95% CI, 0.37-0.68; P = .002) for proximal occlusion and reversed distal ICA flow at the level of ophthalmic segment or above (OR, 0.14; 95% CI, 0.08-0.48; P = .001). Reversed distal ICA flow at the level of the petrous segment or below (OR, 4.07; 95% CI, 1.65-8.38; P = .001) and lumen area (OR, 1.13; 95% CI, 1.04-1.61; P = .002) for distal occlusion were risk factors of successful recanalization. Conclusions: In symptomatic chronic ICA occlusion, lesion length and calcification volume (for proximal occlusion), the level of reversed distal ICA flow, and the lumen area (for distal occlusion) appear to be predictors of successful recanalization. High-resolution MR imaging can evaluate chronic ICA occlusion and help in clinical decision-making.
... As the occlusion duration gets longer, the thrombus gradually becomes fibrotic or calcified, and the occluded segments of ICA undergoes atrophy. In this case, the difficulty of wiring through the lesion will increase, so will the risk for development of potential complications, e.g., arterial dissection (19,20). The atherosclerotic lesion typically develops from C1 (5), which marks the bifurcation of the common carotid artery. ...
Article
Full-text available
Background: Revascularization surgery sometimes can achieve recanalization in patients with internal carotid artery occlusion (ICAO). High-resolution vessel wall magnetic resonance imaging (HRVWI) is a feasible technique to give detailed characteristics of the vessel wall, which may help to identify patients that carry higher success rates and more suitable for revascularization surgery. Objective: To examine the association between HRVWI characteristics of ICAO and the success rate of revascularization surgery in ICAO patients. Methods: We conducted a retrospective analysis of 31 ICAO recanalization patients enrolled from October 2017 to May 2019. The clinical data of patients and lesions were collected and analyzed. Results: A total of 31 ICAO patients were enrolled in this study. No significant differences were found between recanalization success and recanalization failure groups with regard to occlusion length, distal end of the occluded segment, and the treatment applied. The ipsilateral-to-contralateral diameter ratios (I/C ratios) of C1 or C2 and the diameter of C7 were positively related to recanalization success. A two-factor predictive model was constructed, and the I/C ratio of C2 < 0.86 and the diameter of C7 < 1.75mm were separately assigned 1 point. The ICAO patients who scored 0, 1, or 2 points had a risk of 5.6% (1/18), 55.6% (5/9), or 100% (4/4) to fail in the recanalization. Conclusions: The I/C ratios of C1 or C2 and the diameter of C7 are predictive factors of a revascularization surgery success in ICAO patients. A risk stratification model involving C2 and C7 was constructed for future clinical applications.
... In basilar artery occlusions, reperfusion at 36 h (136), 50 h (137), and >2 days (138) resulted in fully restored neurologic function, complete functional recovery, and 77% mRS of 0-3, respectively. In internal carotid artery occlusions, recanalization from 1 month up to 27 months resulted in favorable outcomes, with some patients achieving full recovery (139)(140)(141)(142). In basic science research, there is a limited number of studies that have investigated recanalization beyond 24 h. ...
Article
Full-text available
Although many patients do not receive reperfusion therapy because of delayed presentation and/or severity and location of infarct, new reperfusion approaches are expanding the window of intervention. Novel application of neuroprotective agents in combination with the latest methods of reperfusion provide a path to improved stroke intervention outcomes. We examine why neuroprotective agents have failed to translate to the clinic and provide suggestions for new approaches. New developments in recanalization therapy in combination with therapeutics evaluated in parallel animal models of disease will allow for novel, intra-arterial deployment of therapeutic agents over a vastly expanded therapeutic time window and with greater likelihood success. Although the field of neuronal, endothelial, and glial protective therapies has seen numerous large trials, the application of therapies in the context of newly developed reperfusion strategies is still in its infancy. Given modern imaging developments, evaluation of the penumbra will likely play a larger role in the evolving management of stroke. Increasingly more patients will be screened with neuroimaging to identify patients with adequate collateral blood supply allowing for delayed rescue of the penumbra. These patients will be ideal candidates for therapies such as reperfusion dependent therapeutic agents that pair optimally with cutting-edge reperfusion techniques.
... The baseline characteristics and lesion characteristics (except the duration, occlusion length, and level of distal ICA reconstitution) were statistically homogeneous between the two groups (Tables 1, 2). As some literature has reported, it is relatively straightforward to achieve recanalization for acute and subacute ICAO because the thrombus is soft and clot fibrosis does not occur (Namba et al., 2012). The clot develops fibrotic organization and extends gradually over time, which increases the difficulty of recanalization. ...
Article
Full-text available
Background Internal carotid artery occlusion (ICAO) is a relatively uncommon but important cause of transient ischemic attack and cerebral infarction. The majority of cases of symptomatic ICAO requires surgical treatment. In this study we performed an investigation of the efficacy and safety of hybrid surgery which is a surgical method for symptomatic chronic complete ICAO.Methods Fifty-five patients with symptomatic chronic ICAO treated by hybrid surgery from 2016 to 2019 were included. We recorded and analyzed the patients’ clinical characteristics, angiographic data, recanalization rate, complications, and outcomes. Catheter angiography or computed tomography angiography was used to assess the patency of the recanalized ICA during follow-up.ResultsThe total success rate of recanalization was 78.2% (43/55). The occlusions were significantly shorter in the success than failure group (5.40 ± 1.50 vs. 7.56 ± 0.99 cm, respectively; P < 0.001). The median duration of ICA occlusion was significantly shorter in the success than failure group (90 vs. 200 days, respectively). The success rates of distal ICA recanalization at the petrous segment or below, cavernous segment, and clinoid segment or above were 100, 33.3, and 14.3%, respectively (P < 0.001). Multivariate analysis showed that the level of distal ICA reconstitution was the only factor affecting the recanalization success rate. Periprocedural complications included hyperperfusion syndrome (n = 1) and laryngeal nerve injury (n = 1). ICA reocclusion occurred in one patient (2.3%). Significant postoperative improvement in symptoms was observed in the success group, with a median modified Rankin scale score of 0 at the 3-month follow-up compared with before recanalization (median, 1) (P<0.001).Conclusion Hybrid surgery might be safe and effective for patients with symptomatic chronic complete ICAO. The level of distal ICA reconstitution is a predictor of successful recanalization in hybrid operations.
... The mean radiological and clinical follow-up were 14.4 months (median 12, IQR [10][11][12][13][14][15][16][17][18][19], and 17 months (median 14, IQR 12-23), respectively. ...
Article
Background It is debated whether endovascular treatment is indicated for a symptomatic chronically occluded internal carotid artery (COICA). Objective To assess outcomes after endovascular treatment of COICA. Methods We performed a systematic search of three databases (PRISMA guidelines), including endovascular series of COICA. Outcomes were analyzed with random-effects models. Results We included 13 studies and 528 endovascularly treated patients with COICA. Successful recanalization was 72.6% (347/528, 95% CI 65.4% to 79.9%, I ² =68.9%). Complications were 18% (88/516, 95% CI 12.1% to 23.8%, I ² =65%), with 5% (25/480, 95% CI 2% to 7%, I ² =0%) of permanent events, and 9% (43/516, 95% CI 6% to 13%, I ² =34%) of thromboembolisms. Treatment-related mortality was 2% (11/516, 95% CI 0.5% to 2.6%, I ² =0%). Shorter duration of the occlusion was associated with higher recanalization: 80% (11/516, 95% CI 54% to 89%, I ² =0%), 63% (33/52, 95% CI 49% to 76%, I ² =0%), and 51% (18/35, 95% CI to 37% to 88%, I ² =40%) recanalization rates for 1, 3, and >3 months occlusions, respectively. Complications were 6% (3/50, 95% CI 3% to 21%, I ² =0%), 14% (4/27, 95% CI 5% to 26%, I ² =0%), and 25% (13/47, 95% CI 10% to 30%, I ² =0%) for 1, 3, and >3 months occlusions, respectively. Patient aged <70 years presented higher revascularization rates (OR=3.1, 95% CI 1.2 to 10, I ² =0%, p=0.05). Successful reperfusion was higher (OR=5.7, 95% CI 1.2 to 26, I ² =60%, p=0.02) and complications were lower (OR=0.2, 95% CI 0.6 to 0.8, I ² =0%, p=0.03) for lesions limited to the cervical internal carotid artery compared with the petrocavernous segment. Successful recanalization significantly lowered the rate of thromboembolisms (OR=0.2, 95% CI 0.8 to 0.6, I ² =0%, p=0.01) and mortality (OR=0.5, 95% CI 0.1 to 0.9, I ² =0%, p=0.04), compared with conservative treatment. Conclusions Endovascular treatment of COICA gives a 70% rate of successful recanalization, with 5% morbidity. Patients aged <70 years, lesions limited to the cervical internal carotid artery, and a shorter duration of the occlusion decreased the risk of complications. Successful recanalization of symptomatic lesions lowered by about 80% the likelihood of thromboembolisms, compared with medical management.
Article
Background The optimal management of chronic total carotid artery occlusion (CTO) is still debated. Endovascular treatment is being increasingly used with heterogeneous technical and clinical results. Methods Patients with CTO treated with modern endovascular approaches during the past several years (January 2018–December 2021) were retrospectively reviewed. Results Twenty patients, with a mean age of 63.7 years, were treated during the study period. Indications for treatment were recurrent stroke in 12 (60%), hemodynamic impairment in 4 (20%), and progressive stroke in 4 (20%) patients. In 6 (30%) patients, the occlusion was limited to the cervical portion, in 5 (25%) to the petrous segment, and in 9 (45%) to the cavernous segment. Technical treatment success was achieved in 80% of cases. In patients with successful recanalization, median pretreatment hypoperfusion volumes dropped from 126 mL (25–75 IQR, 33–224 mL) to 0 mL (25–75 IQR, 0–31.5 mL). Symptomatic procedure-related complications were 30% and permanent procedure-related morbidity-mortality was 5%. Early stent occlusion occurred in 5 (25%) cases. Two cases were asymptomatic and were not retreated, 3 cases presented transient symptoms of which two were successfully recanalized. Stent occlusion was not associated with permanent symptoms. In successfully recanalized patients no intraprocedural emboli were observed. Conclusions In the modern endovascular era, revascularization of CTO is a feasible procedure in most cases, and it may be offered in selected patients. However, the high re-occlusion rate is still a limitation of the technique, underlining the need for more research on the technical procedural and periprocedural management.
Article
Background: The risk of ischemic stroke in patients with chronic total occlusion (CTO) of the internal carotid artery (ICA) on best medical treatment has been estimated to be 5.5% per year. The purpose of this study was to assess early and mid-term outcome of patients who underwent an attempt at transfemoral carotid artery stenting (CAS) for CTO of the ICA. Methods: Clinical data of symptomatic patients who underwent attempt at CAS for CTO of the ICA between January 1, 2010 and July 1, 2020 were retrospectively reviewed. Clinical success, perioperative and mid-term stroke and death rates were recorded. Descriptive statistics were used. Results: There were 27 patients, 14 females, 13 males, with a mean age of 66.8 years, range: 57 to 79. All patients had symptoms within 6 months prior to the procedure. 16 had ipsilateral stroke at a mean of 2.8 months, ranges: 1.5-4 months, two had transient ischemic attack (TIA), at 1 week and at 6 months, one had amaurosis fugax at one week, two had chronic ocular ischemia and six had chronic cerebral hypoperfusion. Technical success was 52% (14/27). One patient developed a minor reversible stroke (1/27, 3.7%) there was no early death, for an overall 30-day stroke and death rate of 3.7% (1/27). Two patients had perioperative TIAs. Among 14 patients with successful CAS (group A) one had minor, reversible ipsilateral stroke during a follow-up of 29 months (range: 4-112), two had contralateral stroke. There was no death. One patient developed asymptomatic stent occlusion, three had asymptomatic in-stent restenosis >50%, two had reinterventions. Among patients with unsuccessful attempt at CAS (group B), 31% (4/13) had stroke at 4, 10, 14 and 22 months, respectively. One stroke patient died at 10 months. Conclusions: Transfemoral CAS of symptomatic patients with CTO of the ICA was feasible in half of the patients, with no mortality or major stroke, for an overall early stroke/death rate of 3.7%. Since one third of the patients with unsuccessful stenting developed stroke during follow-up, further studies to investigate the safety, efficacy and durability of CAS for CTO of the ICA are needed.
Article
Objective To evaluate the efficacy and safety of hybrid revascularization by carotid endarterectomy and endovascular intervention in the treatment of chronic internal carotid artery occlusion (ICAO). Methods We performed a retrospective analysis of patients who received hybrid treatment for symptomatic chronic ICAO between December 2016 and December 2018. Fifty-six patients with long-segment ICAO were enrolled and divided into the short duration (1-3 months) and long ICAO duration (>3 months) groups, and their clinical and angiographic data were analyzed. Results The mean duration was 106.8±36.1 days from the date of ICAO diagnosis to revascularization. Totally, 10 patients (17.8%, n=56) in the short duration group while no patients in the long duration group failed recanalization (n=7). Perioperative complications included intraoperative thromboembolism in 1 (1.8%) patient and subarachnoid hemorrhage in 2 (3.6%) patients. Early phase postoperative hypertension was noted in 11 (19.6%) patients and cervical hemorrhage in 1 (1.8%) patient. No severe neurological deficits occurred. Overall, the 6-month modified Rankin score, Mini-mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) scores in patients with successful recanalization significantly improved versus the baseline (P<0.05). After successful recanalization, the long duration group demonstrated more stents for revascularization compared with the short duration group (P<0.05). Five (10.8%) patients had recurrent transient ischemic attack, and 1 (2.2%) patient developed stroke in the successful revascularization group during 6 months of follow-up. ICA restenosis occurred in 5 (8.9%) patients and re-occlusion was noted in 1 (1.8%) patient. Conclusions Hybrid operation may be feasible and effective for patients with symptomatic chronic complete ICAO according to our limited data. The original occlusion site from the carotid bifurcation and the duration of ICAO should be considered as independent indicators for successful recanalization as well as perioperative outcomes.
Article
While the time window for reperfusion after ischemic stroke continues to increase, many patients are not candidates for reperfusion under current guidelines that allow for reperfusion within 24 h after last known well time; however, many case studies report favorable outcomes beyond 24 h after symptom onset for both spontaneous and medically induced recanalization. Furthermore, modern imaging allows for identification of penumbra at extended time points, and reperfusion risk factors and complications are becoming better understood. Taken together, continued urgency exists to better understand the pathophysiologic mechanisms and ideal setting of delayed recanalization beyond 24 h after onset of ischemia.
Aim Symptomatic carotid artery chronic total occlusion (SCACTO) can lead to neurocognitive function decline and carries a high risk or recurrent stroke. The treatment option is limited, endovascular intervention may be an alternative treatment but still controversial. To our knowledge, the staged carotid angioplasty and stenting (SCAS) did not previously reported. The purpose of this study was to report our experiences in this novel technique. Methods In 2017–2018, we attempted the staged carotid angioplasty and stenting (SCAS) approach in 13 patients who received SCACTO treatment. The SCAS approach involves two stages of intervention. The first stage involves initial recanalization and initial small-sized balloon angioplasty. The second stage, which is performed 4–6 weeks later, involves angioplasty and carotid stent placement. Results The success rate of SCAS was 76.9%. At the second stage, the lumen remained patent in all the patients. The mean spontaneous increase in lumen diameter after 4–6 weeks was 51.7%. The median length of the stent was 4.0 cm, and the median number of stents used was 1. One patient had a complication of dissection, with a complication rate of 7.6%. Conclusions SCAS is a novel technique in the endovascular treatment of SCACTO. It is a feasible and safe approach that could reduce the complication rate and number of carotid stents needed.
Article
Objective: To summarize the preliminary experience of hybrid operation for the treatment of symptomatic long-segment chronic internal carotid artery occlusion (CICAO) without stump. Methods: Clinical data of 12 patients of symptomatic long-segment CICAO without stump undergoing hybrid operation treatment from July 2015 to December 2017 were retrospectively analyzed. The safety and efficacy of hybrid operation for the treatment of symptomatic long-segment CICAO without stump were preliminarily assessed. CICAO was defined as occlusion time being more than 4 weeks. The primary outcome was defined as any stroke (including ischemic or hemorrhagic) or deaths from any cause after hybrid operation within 30 days. The secondary outcome was defined as successful revascularization and occurrence of >50% in-stent restenosis during the follow-up period. Results: In this group, the symptomatic long-segment CICAO of 11 patients were successfully recanalized. Technical success rate was 91.7% (11/12). The main complication rate was 8.3% (1/12). This patient encountered iatrogenic internal carotid artery cavernous sinus fistula caused by micro-guide wire in the midway of the hybrid operation, the proximal segment of this internal carotid artery was ligated and the iatrogenic internal carotid artery cavernous sinus fistula disappeared in the following digital subtraction angiography image. No patient encountered hemorrhagic stroke and ischemic stroke. No death complications occurred. In this group 10 patients of them were followed up. The follow-up period ranged from 10 to 32 months [mean, (19±9) months]. During the follow-up period, 1 patients developed in-stent restenosis and improved after reoperation of percutaneous transluminal angioplasty by the right size balloon without stenting treatment. Conclusion: Hybrid operation for the treatment of highly screened patients with symptomatic long-segment CICAO without stump is safe and effective, could reduce the incidence of complications and improve procedural success rate.
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Introduction: We reviewed the literature on interventions for patients with medically refractory chronically occluded internal carotid artery (COICA) to assess the risks/benefits after recanalization via endovascular technique (ET) or hybrid surgery (HS, i.e. ET plus carotid endarterectomy). Methods: A systematic search of the electronic databases was performed. COICA patients were classified in 4 different categories according to Hasan et al classification. Results: Eighteen studies satisfied the inclusion criteria. Only 6 studies involved a HS procedure. We identified 389 COICA patients who underwent ET or HS; 91% were males. The overall perioperative complication rate was 10.1% (95%-CI:7.4-13.1%). For type A and B, the successful recanalization rate was 95.4% (95%-CI:86.5%-100%) with a 13.7% (95% CI:2.3%-27.4%) complication rate. For type C, the success rate for ET was 45.7% (95%-CI:17.8%-70.7%) with a complication rate of 46.0% (95%-CI: 20.0%-71.4%) for ET and for the HS technique was 87.6% (95%-CI: 80.9%-94.4%), with a complication rate 14.0% (95%-CI: 7.0%-21.8%). For type D, the success rate of recanalization was 29.8% (95%-CI: 7.8%-52.8%) with a 29.8% (95%-CI:6.1%-56.3%) complication rate. Successful recanalization resulted in a symmetrical perfusion between both cerebral hemispheres, resolution of penumbra, normalization of the MTT and improvement in MoCA score (ΔMoCA = 9.80 points; P=0.004) Conclusion: Type A and B occlusions benefit from ET, especially in the presence of a large penumbra. Type C occlusions can benefit from HS. Unfortunately, we did not identify an intervention to help patients with type D occlusions. A phase 2b randomized controlled trial is needed to confirm these findings.
Article
Background: Reports have emerged describing the successful endovascular recanalization of the chronically occluded internal carotid artery (COICA). The impact this restoration of flow has on the sensitive carotid sinus baroreceptors has not been previously described. In this manuscript, we present the largest COICA surgical series to date, with a specific focus on perioperative heart rate abnormalities. Methods: Patient demographics were obtained, and the COICAs were radiographically classified based on the anatomic distribution of the stenosis and collateral flow. Thirty-six patients had a total of 37 COICA revascularization procedures. Results: A total of 23 patients had intraprocedural bradycardia during balloon angioplasty. Three patients went into transient asystole during the procedure, and 2 of these patients had symptomatic bradycardia with ischemic cerebral changes, 1 of which required permanent pacemaking. All other patients had immediate resolution of their bradycardia, asystole, and neurologic symptoms immediately following balloon deflation and pharmaceutical management. There was a statistically significant difference in the observed proportion of bradycardic patients among COICA classifications (P = 0.014). There was no statistically significant difference in mean age between patients with bradycardia and those without (aged 63.36 vs. 67.71 years, P = 0.2265). Conclusions: Bradycardia associated with angioplasty of the carotid bulb was observed in the majority of patients receiving COICA revascularization. A small percentage of these patients were symptomatic. Our results suggest that carotid sinus baroreceptors remain active while residing in a complete arterial occlusion, and close monitoring is necessary during balloon angioplasty of the proximal COICA.
Article
Background Internal carotid artery occlusion (ICAO) causes transient ischemic attack and cerebral infarction. ICAO management remains clinically challenging. We discuss a hybrid treatment combining carotid endarterectomy and endovascular intervention (E-I) for patients with nontaper or nonstump lesions of symptomatic ICAO. Methods We treated 32 patients with consecutive nontaper or nonstump ICAO with neurological symptoms with hybrid treatment or E-I. We analyzed the epidemiology, symptoms, angiographic morphology, technical success rate, and perioperative complications. Results Of the 32 patients, 17 were treated with hybrid surgery and 15, E-I. The demographic data and lesion characteristics were similar between the 2 groups. The overall recanalization success rate was 71.9%. The rate for hybrid surgery was better than that for E-I (88.2% vs. 53.3%). The postoperative cerebral hyperperfusion rate showed no difference between the 2 groups (11.8% vs. 6.7%). Ipsilateral cerebral perfusion improved after treatment. The mean transition time and time to peak were greater than normal (normal values, <6 seconds and <8 seconds, respectively). Both increased significantly after treatment (mean transition time, 11.30 seconds vs. 7.25 seconds; time to peak, 19.30 seconds vs. 15.50 seconds). The incidence of perioperative complications from hybrid surgery was less than that with E-I (5.9% vs. 40.0%). Recurrent cerebrovascular events (5.9% vs. 13.3%) and the 3-month modified Rankin scale score (2.76 ± 0.66 vs. 2.93 ± 0.70) did not differ between the 2 groups. Conclusions Recanalization of nontaper or nonstump ICAO with hybrid treatment was more successful than that with E-I, with fewer perioperative complications. The carotid endarterectomy procedure enables easier wire crossing across the occlusion and reduces potential technology-related complications by requiring a shorter lesion and fewer dissections and minimizing the effect of calcification.
Article
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Atherosclerosis, the leading cause of death in the developed world and nearly the leading cause in the developing world, is associated with systemic risk factors including hypertension, smoking, hyperlipidemia, and diabetes mellitus, among others. Nonetheless, atherosclerosis remains a geometrically focal disease, preferentially affecting the outer edges of vessel bifurcations. In these predisposed areas, hemodynamic shear stress, the frictional force acting on the endothelial cell surface as a result of blood flow, is weaker than in protected regions. Studies have identified hemodynamic shear stress as an important determinant of endothelial function and phenotype. Arterial-level shear stress (>15 dyne/cm2) induces endothelial quiescence and an atheroprotective gene expression profile, while low shear stress (<4 dyne/cm2), which is prevalent at atherosclerosis-prone sites, stimulates an atherogenic phenotype. The functional regulation of the endothelium by local hemodynamic shear stress provides a model for understanding the focal propensity of atherosclerosis in the setting of systemic factors and may help guide future therapeutic strategies.
Article
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The natural course of symptomatic carotid artery occlusion with hemodynamic impairment is poor. Surgical revascularization may improve the outcome; however, its efficacy has not been established yet. The goal of this study was to characterize the technical and clinical outcomes following endovascular recanalization of the ICA under cerebral circulatory protection. Endovascular recanalization was attempted in 8 patients with symptomatic ICA occlusions. The duration of the occlusion ranged from 7 days to 7 months (mean, 2.5 months), and the mean length of the occlusion was 95 mm. Cerebral hemodynamics ipsilateral to the side of the occlusion were severely impaired in all patients. The endovascular procedure was performed under total cerebral circulatory protection, beginning with proximal protection with a subsequent switch to distal protection after successful guidewire passage. The occlusion was recanalized successfully in 7 of 8 patients (88%), resulting in improvement of ipsilateral cerebral hemodynamics without symptomatic stroke. Small asymptomatic ischemic lesions were detected in 6 of 8 patients (75%) on DWI, and 1 patient developed a mild groin hematoma. Ischemic episodes did not recur during the mean follow-up period of 19 months. However, 1 patient experienced asymptomatic reocclusion, which was re-treated successfully without complications, while another patient developed mild retinal hemorrhage at 3 months after the procedure due to the combination of antiplatelet and anticoagulant therapy. Endovascular revascularization of an ICA occlusion is feasible and well-tolerated in patients with subacute or chronic total occlusion of the ICA.
Article
Full-text available
Atherosclerosis, the leading cause of death in the developed world and nearly the leading cause in the developing world, is associated with systemic risk factors including hypertension, smoking, hyperlipidemia, and diabetes mellitus, among others. Nonetheless, atherosclerosis remains a geometrically focal disease, preferentially affecting the outer edges of vessel bifurcations. In these predisposed areas, hemodynamic shear stress, the frictional force acting on the endothelial cell surface as a result of blood flow, is weaker than in protected regions. Studies have identified hemodynamic shear stress as an important determinant of endothelial function and phenotype. Arterial-level shear stress (>15 dyne/cm2) induces endothelial quiescence and an atheroprotective gene expression profile, while low shear stress (<4 dyne/cm2), which is prevalent at atherosclerosis-prone sites, stimulates an atherogenic phenotype. The functional regulation of the endothelium by local hemodynamic shear stress provides a model for understanding the focal propensity of atherosclerosis in the setting of systemic factors and may help guide future therapeutic strategies.
Article
Full-text available
Patients with hemodynamic impairment ipsilateral to a carotid occlusion are at a high risk of subsequent stroke, and currently 2 surgical options have been studied: extracranial-to-intracranial bypass and direct thromboendarterectomy. We report the successful revascularization of 2 symptomatic chronically occluded carotid arteries with stenting and angioplasty.
Article
Patients with chronic carotid artery occlusion face a significant risk of stroke. It is believed that treatment is indicated if medical therapy fails or even as prophylaxis in high-risk patients. Direct surgical repair with carotid endarterectomy has a considerable failure rate and significant associated risks. Indirect repair with an extracranial-to-intracranial bypass has become the mainstay of surgical treatment. In this case study, the authors assess the feasibility of direct endovascular recanalization in the setting of chronic carotid occlusion, and discuss technical nuances and indications in comparison with the world literature and alternative options. Two patients presented with symptomatic, chronic, complete occlusion of the proximal carotid artery. The duration of documented occlusion exceeded 3 years in one patient and 6 months in the other. Endovascular recanalization was attempted using extracranial and intracranial stenting with proximal protection (flow arrest/reversal). Both patients had an excellent radiographic result, improving from Thrombolysis in Cerebral Infarction (TICI) grade 0 (no perfusion) to grade 3 (complete perfusion). The first patient's clinical symptoms resolved. The second patient remained unchanged with a mild facial droop. These preliminary results show potential for the endovascular management of this complicated disease. Long-term results and more data will determine the ultimate place of endovascular recanalization for symptomatic chronic carotid occlusion among other therapies.
Article
Patients with chronic cervical internal carotid artery occlusion (ICAO) and cerebral ischemia may benefit from revascularization. The feasibility of endovascular recanalization for chronic ICAO has been reported recently, but its safety is still unproven. We report the follow-up results of 54 chronic ICAO patients who underwent endovascular recanalization, focusing on potential vascular complications and corresponding management. Endovascular recanalization for chronic ICAO was attempted in 54 consecutive patients (48 men; 69.2 + or - 9.8 years old) with either recurrent neurological deficit or objective ipsilateral hemisphere ischemia. Mean duration from occlusion documentation to the procedure was 237 + or - 327 days (range, 56 to 1424 days). Adverse events while in the hospital and during the 3-month follow-up were recorded. Successful recanalization was achieved in 35 of 54 patients (65%). Three-month cumulative stroke and death rate was 4% (2 of 54), including 1 in-hospital fatal nonipsilateral stroke and 1 in-hospital minor ipsilateral stroke secondary to systemic hypotension. Vascular complications developed in 3 of 54 patients (6%), including 1 late pseudoaneurysm formation 3 months after recanalization, 1 immediate carotid-cavernous fistula after recanalization, and 1 minor extravasation at carotid bifurcation after failed recanalization. However, no clinical sequela was noted with close follow-up and adequate management. Certain immediate or delayed vascular complications may develop during or after the endovascular recanalization for chronic ICAO. Although periprocedural death and stroke rate is limited in our study, further study combining neuroimaging tools and cognitive function evaluation is mandatory to assess its utility and appropriateness in patients with chronic ICAO.
Article
The efficacy and pitfalls of endovascular recanalization were evaluated in cases of internal carotid artery (ICA) occlusion in the subacute to chronic stage. Fourteen cases (15 lesions) of symptomatic ICA occlusion with hemodynamic compromise or recurrent symptoms were treated at the subacute to chronic stage using an endovascular technique. The Parodi embolic protection system was used during the recanalization procedure to prevent embolic stroke by reversing the flow from the distal ICA to the common carotid artery. Recanalization of the occluded ICA was possible in 14 of 15 lesions. The occlusion points were 10 cervical ICAs and 4 petrous/cavernous ICAs in successfully recanalized cases. Ischemic symptoms disappeared completely after the treatment, and new ischemic symptoms did not appear related to the treated lesion. Single photon emission computed tomography findings demonstrated the improvement of hemodynamic compromise in all cases. One case showed right middle cerebral artery branch occlusion during the procedure, but this patient's neurological symptoms were stable due to preexisting hemiparesis. Endovascular recanalization was possible and effective in improving hemodynamic compromise. However, there are still several problems with this technique, such as hyperperfusion syndrome after recanalization, cerebral embolism during treatment, durability after treatment, and identification of the occlusion point before treatment. Endovascular recanalization using an embolic protection device can be considered as an alternative treatment for symptomatic ICA occlusion with hemodynamic compromise or refractoriness to antiplatelet therapy, even in the subacute to chronic stage of the illness.
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The success rate of percutaneous coronary intervention (PCI) for chronic total coronary occlusion (CTO) lesions varies depending on the guidewire manipulation skills of the operator. The standardization of guidewire technique is very important. A new technique with a new tapered wire (Conquest, Confianza Pro) was tested to verify effectiveness for higher initial success rates and standardization of PCI for CTO. A prospective, multicenter registry was conducted at 6 investigational sites. In the CONQUEST trial, The CTO lesions were treated by using an intermediate guidewire to cross the lesion. If it did not cross, the guidewire was changed to the Conquest guidewire. If it did not cross, "seesaw-wiring" or the "parallel-wire technique" was performed. The primary endpoint was the initial procedural success rate. A total of 110 patients representing 116 CTO lesions were treated from July 2003 through March 2004. The procedural success rate was 86.2% on the first try, and 88.8% on the second try, respectively. The guidewire success rate on the second try was 90.5% during the hospital stay; no deaths, or acute myocardial infarctions were confirmed. Two patients deteriorated into tamponade, and surgical or percutaneous drainage was performed in each patient without any sequelae. A guidewire technique in PCI for CTOs that starts with the intermediate guidewire and moves to the Confianza Pro tapered guidewire, either alone or by performing a see-saw or parallel-wire technique, can achieve a high initial success rate with an acceptably low major complication rate.
Article
Percutaneous transluminal angioplasty was performed in 8 symptomatic patients with proximal occlusion of the left subclavian artery. Technical and short-term clinical success was achieved in 7 cases. Nonoccluding embolization to the distal subclavian artery and stenosis of the brachial artery after a combined femoral/brachial approach occurred as complications in 2 patients. Three patients are asymptomatic with a patent subclavian artery 25, 28, and 37 months after angioplasty. Reobstructions in 4 patients occurring after 8, 12, and 16 months were retreated by angioplasty (3 patients) and stent implantation (1 patient with a second restenosis) with good technical and clinical success. Long-term patency was less than 50%, but successful retreatment is feasible. Therefore, we consider percutaneous transluminal angioplasty a reasonable therapeutic option in patients who are not surgical candidates.
Article
We studied the adaptive response of the arterial wall and intimal thickening under conditions of increased flow in an atherogenic model. Blood flow was increased by construction of an arteriovenous fistula between the right iliac artery and vein in six cynomolgus monkeys fed a diet containing 2% cholesterol and 25% peanut oil. The left iliac artery served as the control. Serum cholesterol increased from 135 +/- 22 mg/dl to 880 +/- 129 mg/dl during the experiment. After 6 months, blood flow in the right iliac artery (420 +/- 95 ml/min) was 10 times greater than in the left iliac artery (44 +/- 9 ml/min, p less than 0.005). Flow velocity in the right iliac artery (31 +/- 6 cm/sec) was more than twofold greater than in the left (12 +/- 1 cm/sec, p less than 0.05). Despite the marked difference in blood flow and flow velocity, calculated wall shear stress was the same in both the right (16 +/- 4 dynes/cm2) and left iliac vessels (15 +/- 2 dynes/cm2) because of a twofold increase in lumen diameter (p less than 0.001) of the right iliac artery. Shear stress in the aorta was also normal (12 +/- 2 dynes/cm2). There was no difference in plaque deposition or mean intimal thickness between the right and left iliac arteries. In the right iliac artery there was a twofold increase in media cross-sectional area (p less than 0.001) but no change in media thickness or total wall thickness. Tangential wall tension and tangential wall stress were two times greater on the right than on the left (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)
Article
The distribution of nonstenosing, asymptomatic intimal plaques in 12 adult human carotid bifurcations obtained at autopsy was compared with the distribution of flow streamline patterns, flow velocity profiles, and shear stresses in corresponding scale models. The postmortem specimens were fixed while distended to restore normal in vivo length, diameter, and configuration. Angiograms were used to measure branch angles and diameters, and transverse histological sections were studied at five standard sampling levels. Intimal thickness was determined at 15 degrees intervals around the circumference of the vessel sections from contour tracings of images projected onto a digitizing plate. In the models, laser-Doppler anemometry was used to determine flow velocity profiles and shear stresses at levels corresponding to the standard specimen sampling sites under conditions of steady flow at Reynolds numbers of 400, 800, and 1200, and flow patterns were visualized by hydrogen bubble and dye-washout techniques. Intimal thickening was greatest and consistently eccentric in the carotid sinus. With the center of the flow divider as the 0 degree index point, mid-sinus sections showed minimum intimal thickness (0.05 +/- 0.02 mm) within 15 degrees of the index point, while maximum thickness (0.9 +/- 0.1 mm) occurred at 161 +/- 16 degrees, i.e., on the outer wall opposite the flow divider. Where the intima was thinnest, along the inner wall, flow streamlines in the model remain axially aligned and unidirectional, with velocity maxima shifted toward the flow divider apex. Wall shear stress along the inner wall ranged from 31 to 600 dynes/cm2 depending on the Reynolds number. Where the intima was thickest, along the outer wall opposite the flow divider apex, the pattern of flow was complex and included a region of separation and reversal of axial flow as well as the development of counter-rotating helical trajectories. Wall shear stress along the outer wall ranged from 0 to -6 dynes/cm2. Intimal thickening at the common carotid and distal internal carotid levels of section was minimal and was distributed uniformly about the circumference. We conclude that in the human carotid bifurcation, regions of moderate to high shear stress, where flow remains unidirectional and axially aligned, are relatively spared of intimal thickening. Intimal thickening and atherosclerosis develop largely in regions of relatively low wall shear stress, flow separation, and departure from axially aligned, unidirectional flow. Similar quantitative evaluations of other atherosclerosis-prone locations and corresponding flow profile studies in geometrically accurate models may reveal which of these hemodynamic conditions are most consistently associated with the development of intimal disease.
Article
To elucidate the connection between blood flow and the localized genesis and development of atherosclerosis and thrombosis at the human carotid artery bifurcation, detailed studies of the flow patterns and distributions of fluid velocity and wall shear rate in this region were carried out using a transparent segment of the carotid artery, prepared from a human subject postmortem, and cinemicrographic techniques. It was found that a recirculation zone which consisted of a pair of complex spiral secondary flows, symmetrical about the common median plane of the bifurcation, was formed in the carotid sinus over wide ranges of inflow Reynolds numbers, Re0, and flow rate ratios, Q1/Q0 (internal/common). The formation and the size of the recirculation zone were largely dependent on Q1/Q0, as well as on Re0. The size of the recirculation zone increased from approximately 4 mm at Re0 = 300 to a maximum of approximately 9 mm at Re0 greater than 800. The results suggest that, under physiological conditions (Re0 approximately 600, Q1/Q0 approximately 0.7), a standing recirculation zone exists in the carotid sinus, thereby affecting local mass transfer and interactions of blood cells with the vessel wall, which may lead to the incidence of atherosclerosis and thrombosis in this region.
Article
This study investigated whether stenting improves long-term results after recanalization of chronic coronary occlusions. Restenosis is common after percutaneous transluminal coronary angioplasty (PTCA) of chronic coronary occlusions. Stenting has been suggested as a means of improving results, but its use has not previously been investigated in a randomized trial. We randomly assigned 119 patients with a satisfactory result after successful recanalization by PTCA of a chronic coronary occlusion to 1) a control (PTCA) group with no other intervention, or 2) a group in which PTCA was followed by implantation of Palmaz-Schatz stents with full anticoagulation. Coronary angiography was performed before randomization, after stenting and at 6-month follow-up. Inguinal bleeding was more frequent in the stent group. There were no deaths. One patient with stenting had a myocardial infarction. Subacute occlusion within 2 weeks occurred in four patients in the stent group and in three in the PTCA group. At follow-up, 57% of patients with stenting were free from angina compared with 24% of patients with PTCA only (p < 0.001). Angiographic follow-up data were available in 114 patients. Restenosis (> or = 50% diameter stenosis) developed in 32% of patients with stenting and in 74% of patients with PTCA only (p < 0.001); reocclusion occurred in 12% and 26%, respectively (p = 0.058). Minimal lumen diameter (mean +/- SD) at follow-up was 1.92 +/- 0.95 mm and 1.11 +/- 0.78 mm, respectively (p < 0.001). Target lesion revascularization within 300 days was less frequent in patients with stenting than in patients with PTCA only (22% vs. 42%, p = 0.025). Stent implantation improved long-term angiographic and clinical results after PTCA of chronic coronary occlusions and is thus recommended regardless of the primary PTCA result.
Article
It is known that atherosclerosis does not involve both carotid arteries to the same extent. Pathological investigations have demonstrated that lesions develop in regions of low wall shear stress. The aims of the present study were to verify the degree of carotid atherosclerosis asymmetry in a population-based study and to evaluate whether wall shear stress is lower in carotids with atherosclerotic lesions than in carotids without lesions. Participants in a cardiovascular disease prevention campaign (n = 1166) were screened for carotid atherosclerosis by echo-Doppler examination. Of these, 23 subjects who presented plaque in the common carotid or bulb of one side and no plaque in the contralateral carotid tree were enrolled for common carotid wall shear stress measurement. Shear stress was calculated according to the following formula: Shear Stress = Blood Viscosity x Blood Velocity/Internal Diameter. Of the 1166 subjects screened, 400 (34%) had plaque and/or stenosis in the carotids. Ninety subjects had lesions exclusively in the right carotid, 111 had lesions exclusively in the left, 70 had lesions in both carotids but with different degrees of severity, and only 129 had similar lesions in both carotids. In the 23 subjects in whom wall shear stress was measured, peak shear stress was 18.7 +/- 4.1 and 15.3 +/- 4.0 dynes.cm-2 (mean +/- SD) (P < .0001) in the side without and the side with plaque, respectively. Mean shear stress yielded similar results. The present results demonstrate that the atherosclerotic involvement of carotid arteries is usually asymmetrical and that wall shear stress is lower in the carotid arteries where plaques are present than in plaque-free arteries. These findings provide in vivo evidence for a strong association between shear stress and atherosclerotic lesions.
Article
The aim of the study was to investigate the feasibility and clinical safety of vibrational angioplasty in the treatment of chronic total coronary occlusions and evaluate the clinical and angiographic factors that are predictive of the procedural success and complications of the procedure. Seventy-eight patients with chronic total occlusions (>3 months) resistant to conventional techniques were treated by vibrational angioplasty using a variety of conventional guidewires. Lesions were successfully crossed in 67 (85.9%) cases and antegrade flow was achieved in 59 (75.5%). Major complications (myocardial infarction and tamponade) occurred in two (2.5%) patients, but no fatalities ensued. Angiographically detectable dissections were seen in 23 (29.5%) patients but only resulted in vessel compromise and reclosure in 5 cases. Multiple stepwise logistic regression analysis identified the duration (<6 months, P = 0.008) and the length of the occlusion (<15 mm, P = 0.03) as independent predictors of final success and the age of the patient (<55 years, P = 0.006) as the only independent predictor of procedural complications. Vibrational angioplasty is a safe technique useful in the treatment of chronic coronary occlusive disease. Patients in whom the procedure is likely to prove most successful may be easily identified by clinical and angiographic features (duration and length of occlusion).
Article
A randomized trial was performed to assess the safety and efficacy of a laser guidewire, in the treatment of chronic coronary occlusions. In 18 European centres, 303 patients with a chronic coronary occlusion were randomized to treatment with either the laser guidewire (n=144) or conventional guidewires (mechanical guidewire, n=159). The primary end-point of the study was treatment success, defined as reaching the true lumen distal to the occlusion by the allocated wire within 30 min of fluoroscopic time: laser guidewire vs mechanical guidewire; 52.8% (n=76) vs 47.2% (n=75), P=0.33. Serious adverse events following the initial guidewire attempt were 0% (laser guidewire) and 0.6% (mechanical guidewire), respectively. Angioplasty (performed following successful guidewire crossing) was successful in 179 patients (91%, laser guidewire n=79, mechanical guidewire n=100), followed by stent implantation in 149 (79%). At the 6-month angiographic follow-up, the difference in binary restenosis rate (laser guidewire vs mechanical guidewire; 45.5% vs 38.3 %, P=0.72) or reocclusion rate (25.8% vs 16.1%, P=0.15) did not reach statistical significance. At 1, 6 and 12 months, angina and event-free survival were 69%, 35% and 24% (laser guidewire) vs 74%, 40% and 31% (mechanical guidewire). Although laser guidewire technology was safe, the increase in crossing success did not reach statistical significance.
Article
To evaluate our experience of selective iliac artery stenting for total occlusions, a prospective observational study of 25 patients with an occluded iliac artery was designed to run from January 1996-May 1997. Exclusion criteria were an occlusion extended to the femoral artery, claudication Grade III or IV, according to the standards for reports dealing with lower extremity ischemia, and vascular (bypass) surgery in the past. Complete recanalization and selective stent placement was possible in all patients. No complications occurred. In one patient re-stenosis happened inside the stent after a year. Percutaneous reintervention was performed with success. The mean ankle-brachial pressure increased from 0.46 before the procedure to 0.95 after the procedure. After two years of follow-up, the mean ankle-brachial pressure is 0.93. The clinical stage improved by at least one grade to Grade 0 (Rutherford classification). The overall probability of patency for occluded iliac arteries in this study was 95% after two years. Recanalization, followed by percutaneous transluminal angioplasty (PTA) in the treatment of iliac artery occlusions, is our first choice of intervention, considering the absence of complication and satisfactory patency rates in patients with claudication Grade I or II.
Article
The Safe-Cross radiofrequency guidewire (IntraLuminal Therapeutics, Carlsbad, California) combines 3 capabilities: (1) steerability of a conventional 0.014-in intermediate-stiffness guidewire, (2) optical coherence reflectometry to warn the operator when the wire tip approaches within 1 mm of the vessel wall, and (3) delivery of radiofrequency energy pulses to the wire tip to facilitate passage through an occluded segment. The Guided Radio Frequency Energy Ablation of Total Occlusions Registry was a prospective, nonrandomized, multicenter registry that enrolled 116 patients who had long-term coronary total occlusions and in whom a >10-minute good-faith attempt to cross the occlusion using conventional guidewires had failed. The median known duration of occlusion was 22 months (32%; >1 year), and the median length of the occluded segment was 25 mm (25%; >30 mm). Device success was achieved in 63 of 116 of patients (54.3%), and major adverse events occurred in 6.9%, consisting predominantly of isolated increases in cardiac enzymes with no procedure-related deaths, Q-wave myocardial infarctions, or emergency bypass operations. Clinical perforation occurred in 2.6% of patients; of these, perforation in only 1 patient (0.9%) was adjudicated to be directly related to the Safe-Cross radiofrequency wire rather than to the stiff and/or hydrophilic wires used after an inability to advance with the Safe-Cross. Based on these data, the device has been approved in Europe and was recently (January 2004) granted 510K clearance by the Food and Drug Administration.
Article
A symptomatic internal carotid artery (ICA) occlusion with hemodynamic compromise was treated at its chronic stage by using an endovascular technique. An embolic protection system was used during the recanalization procedure to prevent stroke by reversing the flow from the distal ICA to the common carotid artery. The totally occluded ICA was completely recanalized through percutaneous transluminal angioplasty and stent placement. The patient's symptom (transient ischemic attack) disappeared completely after treatment with no new neurological deficit. Single-photon emission computerized tomography findings confirmed improvement of the hemodynamic compromise, and no new high-intensity spots appeared on diffusion-weighted magnetic resonance imaging after treatment. This case shows that endovascular recanalization by using an embolic protection device can be considered as an alternative treatment for symptomatic ICA occlusion with hemodynamic compromise and refractoriness to antiplatelet therapy, even in the chronic stage of the illness.
Article
Carotid angioplasty and stenting can be used in stroke prevention in high-risk patients. As embolic complications can occur during carotid angioplasty and stenting, a device was developed to protect from cerebral embolization. Between September 1999 and May 2002, carotid angioplasty and stenting was performed in 100 patients (84 men; mean age, 69.2 years) with symptomatic (26%) or asymptomatic (74%) severe carotid artery stenosis. Wallstents were used in all cases with selective pre-dilatation. Cerebral protection devices (Parodi Anti-Emboli System [PAES], ArteriA, San Francisco, Calif) were used in all patients. All patients were evaluated by a neurologist, both before and after the procedure. According to the criteria set forth by the large trials, the occurrence of minor, major or fatal stroke and myocardial infarction (end points) within 30 days and follow-up were determined as end points. Data were collected prospectively. The overall perioperative stroke and death rate was 3% (1 noncorresponding minor stroke, 1 hemorrhagic stroke, and 1 cardiac event). Four patients developed postoperative transient neurologic events (three related to hemodynamic instability and the fourth due to postoperative embolization). The overall technical success rate for carotid angioplasty (protection device placed in position percutaneously) was 99%. The efficacy and safety of carotid angioplasty and stenting with PAES are confirmed. This innovative protection device may prevent the debris released by angioplasty from entering the cerebral circulation. Further investigation is warranted.
Article
This study sought to report technical details and clinical results of the first series of endovascular recanalization for cervical internal carotid artery (ICA) occlusion. Cervical ICA occlusion is associated with impaired cerebral perfusion, which may lead to ischemic cerebral symptoms and hemodynamic infarcts. Neither surgical nor endovascular revascularization has been shown to benefit this population. Endovascular recanalization was attempted in 30 patients with ICA occlusions (27 men; age 72.1 +/- 8.0 years, range 48 to 85 years). Recurrent neurologic deficit or cerebral ischemia by perfusion study, after known ICA occlusion, was noted in all patients. Strategies and devices for coronary occlusion intervention were applied, including microcatheter-supported tapered-tip stiff coronary guidewires. Contralateral ICA stenosis was found in 9 patients (30%). All patients underwent independent neurologic and duplex ultrasound follow-up. The overall technical success rate was 73% (22 of 30). No neck hematoma, intracranial hemorrhage, or hyperperfusion was noted. One (3.3%) fatal brainstem infarction occurred 1 day after a successful ICA procedure, with angiographically proven acute basilar artery occlusion and patent ICA stent. Baseline ophthalmic artery flow was reversed in 15 of the 22 successfully recanalized patients, and was normalized in 12 after the procedure. There was no new cerebral ischemic event or neurologic death for a mean follow-up of 16.1 +/- 18.5 months. Endovascular recanalization for cervical ICA occlusion is feasible with acceptable midterm clinical results.
Article
Retrograde approach through the collateral channels has been recently proposed and has the potential to improve the success rate of percutaneous coronary intervention (PCI) in chronic total occlusion (CTO) lesions of the coronary arteries. The author performed retrograde approach for CTO lesions in 45 patients from January 2006 to January 2007 at different medical institutions worldwide. The details of the techniques were examined retrospectively. The septal branch route was used in 93% of the cases. The author classified the strategies into six types after the successful crossing of a guidewire into the target artery distal to the CTO lesion through the collateral channels. Among them, "Just landmark," "Controlled antegrade and retrograde subintimal tracking," and "Proximal true lumen puncture" strategies were used most frequently (32, 27, and 30%, respectively). The retrograde guidewires could be successfully passed distal to the CTO lesion in 37 patients (82%), among them the final PCI success was achieved in 31 patients, yielding the PCI success by pure retrograde approach of 69%. The final success rate among 45 patients including 42 patients with previous failed attempts was 84% (38 patients). There were no serious complications related to the retrograde approach. Retrograde approach with different strategies, mainly through septal arteries, can provide a high success rate with PCI, as shown in 83% of patients with previous failed attempts at traditional PCI for CTO lesions, with there being no serious complications. More experience of this technique and its refinement are required for further improvement of PCI techniques for CTO lesions.
Article
The aim of this study was to review the feasibility, safety and long-term results of subclavian artery (SA) angioplasty. Over 14 years, 237 patients (males: 135; mean age: 64+/-12 years) underwent percutaneous treatment for SA occlusive disease. Indications for treatment were upper limb ischemia (n=125), vertebrobasilar insufficiency (n=128), coronary steal (n=11) and anticipated coronary bypass surgery in asymptomatic patients (n=26). A total of 192 arteries were stenosed and 45 occluded. Mean percentage stenosis was 81.9+/-7.6% and mean lesion length was 23.8+/-8.8 mm. Percutaneous techniques included retrograde femoral (n=163), brachial artery (n=47) access or both (n=14) and in 4 cases the ''pull through technique''. An isolated balloon angioplasty was performed in 59 cases. We implanted 132 balloon expandable stents and 32 self-expandable stents. Technical success was obtained in 223 lesions (94%). Only 31 occlusions were recanalized (69%). Four periprocedural events occurred (1.2%), 1 major (fatal) stroke, 1 transient ischemic attack and 2 arterial thromboses. At follow-up (mean follow-up: 65.8+/-33.5 months), we had 27 restenoses (12%). Thirteen occurred following angioplasty alone (18.8%) and 14 following angioplasty and stent implantation (8.4%). Primary (PI) and secondary (PII) patencies on an intention to treat basis at 10-year follow-up were 78.1% and 84.5%, respectively. In patients without initial stent placement, the rates were 67.5% and 75.5%, while in those with stents the rates rose to 89.7% and 96.9% (P<0.01). PI for all recanalized lesions were 84.6%, 79.1% without stent, 89.7% with stent (P<0.04) and PII 91.6%, 88.5%, 96.9%, respectively (P<0.02). Percutaneous transluminal angioplasty is currently the treatment of choice for SA lesions. It is a safe and effective procedure associated with low risks and good long-term results. Stents seem to limit the restenosis rate and improve long-term results.
MD Department of Endovascular Surgery Jichi Medical university 3311-1 yakushiji
  • Katsunari Namba
Katsunari Namba, MD Department of Endovascular Surgery Jichi Medical university 3311-1 yakushiji Shimotsuke, Tochigi 329-0498, Japan Tel.: +81-285-58-7373 Fax: +81-285-44-5147