P A Robinson

Charleston Area Medical Center, Charleston, West Virginia, United States

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Publications (43)103.89 Total impact

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    ABSTRACT: Several authorities have recently advocated carotid stenting for recurrent carotid stenosis because of the perception that redo surgery has a higher complication rate than primary carotid endarterectomy (CEA). This study compares the early and late results of reoperations versus primary CEA. All reoperations for recurrent carotid stenosis performed during a recent 7-year period by a single vascular surgeon were compared with primary CEA. Because all redo CEAs were done with polytetrafluoroethylene (PTFE) or vein patch closure, we only analyzed those primary CEAs that used the same patch closures. A Kaplan-Meier life-table analysis was used to estimate stroke-free survival rates and freedom from >/=50% recurrent stenosis. Of 547 primary CEAs, 265 had PTFE or saphenous vein patch closure, and 124 reoperations had PTFE or vein patch closure during the same period. Both groups had similar demographic characteristics. The indications for reoperation and primary CEA were symptomatic stenosis in 78% and 58% of cases and asymptomatic >/=80% stenosis in 22% and 42% of cases, respectively (P<0.001). The 30-day perioperative stroke and transient ischemic attack rates for reoperation and primary CEA were 4.8% versus 0.8% (P=0.015) and 4% versus 1.1%, respectively, with no perioperative deaths in either group. Cranial nerve injury was noted in 17% of reoperation patients versus 5.3% of primary CEA patients; however, most of these injuries were transient (P<0.001). Mean hospital stay was 1.8 days for reoperation versus 1.6 days for primary CEA. Cumulative rates of stroke-free survival and freedom from >/=50% recurrent stenosis for reoperation and primary CEA at 1, 3, and 5 years were 96%, 91%, and 82% and 98%, 96%, and 95% versus 94%, 92%, and 91% and 98%, 96%, and 96%, respectively (no significant differences). Reoperation carries higher perioperative stroke and cranial nerve injury rates than primary CEA. However, reoperations are durable and have stroke-free survival rates that are similar to primary CEA. These considerations should be kept in mind when carotid stenting is recommended instead of reoperation.
    Stroke 12/2001; 32(12):2787-92. · 6.16 Impact Factor
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    ABSTRACT: This study examines the selection of patients for combined femorofemoral bypass (FFB) grafting and iliac balloon angioplasty (IBA) and stenting for bilateral iliac occlusive disease (successively or simultaneously) and the correlation of the length and location of stenoses of the donor iliac artery to the success of FFB grafts. Forty-one patients with long iliac occlusion and significant contralateral iliac stenosis were treated with combined FFB grafting and IBA and stenting, which were performed simultaneously or percutaneously within 1 to 2 days before surgery. Stenting was performed for suboptimal IBAs. IBA/graft patency was evaluated by duplex scanning/ankle-brachial index at 1, 3, 6, and 12 months and every 12 months thereafter. A life-table analysis of patency was performed, according to the length of stenosis as classified by the Society of Cardiovascular Interventional Radiology (group A, < 3 cm and 3-5 cm; group B, > 5 cm). Indications for surgery were limb salvage (22%), rest pain (44%), and claudication (34%). The mean follow-up time was 34.1 months. Perioperative complications were 7% for group A versus 62% for group B (P = .0007) with no perioperative deaths or amputations. Stenting was needed in 12 of 13 patients (92%) in group B versus four of 28 patients (14%) in group A (P < .0001) and in 11 of 12 external iliac artery lesions versus five of 29 common iliac artery lesions (P < .0001). The overall early success rate was 100% for group A and 62% for group B (P = .0028). The primary patency rates at 1, 2, and 3 years were 96%, 85%, and 85% for group A, respectively, and for group B were 46%, 46%, and 31%, respectively (P < .01). The secondary patency rates for group A at 1, 2, and 3 years were 100%, 96%, and 87%, respectively; and for group B were 62%, 54%, and 27%, respectively (P < .001). The overall primary and secondary patency rates for common iliac and external iliac artery lesions were similar (72% and 72% versus 67% and 75%, respectively). The overall limb salvage rates were 96% for group A and 85% for group B. Seven of 13 patients (54%) of group B, in contrast with 0 of 28 patients in group A, had to undergo a revision of the procedure within 30 days (P < .01). Combined use of IBA and stenting and FFB grafting is effective and durable and can be performed simultaneously, if the donor iliac stenosis length is 5 cm or less. Percutaneous transluminal angioplasty/stenting of stenoses of 5 cm or more fail to support FFB grafting in most patients; therefore, their combination should be questioned.
    Journal of Vascular Surgery 02/2001; 33(2 Suppl):S93-9. · 2.88 Impact Factor
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    ABSTRACT: The use of patch angioplasty after carotid endarterectomy (CEA) has been shown to have superior results to CEA with primary closure. Polytetrafluoroethylene (PTFE) patches have been shown to have comparable results to autogenous vein patching; however, PTFE has the disadvantage of prolonged hemostasis time. Therefore, many surgeons are using collagen-impregnated Dacron patches (Hemashield[HP]). We believe this is the first prospective controlled study of the use of HP in carotid endarterectomy. This study included 144 consecutive patients who had 151 CEAs with HP. Postoperative duplex ultrasounds were done at 1 month and every 6 months thereafter. The mean follow-up was 12 months (range: 1-30 months). Indications for CEA included symptomatic (64%) and asymptomatic (36%) stenoses. The overall incidence of ipsilateral stroke was 5% (4% perioperative), with a combined TIA and stroke rate of 12%. Incidence of > or =50% recurrent stenosis was 21% (7% symptomatic TIA/stroke) and > or =80% recurrent stenosis was 9%. Kaplan-Meier analysis showed that at 1 year and 2.5 years freedom from > or =50% recurrent stenosis was 78% and 57%, respectively, freedom from > or =80% recurrent stenosis was 92% and 77%, respectively, and a stroke-free survival rate of 94% and 72%, respectively. Women had a 22% and men a 14% recurrent stenosis rate (p=0.04). There was no correlation between other specific risk factors and recurrent stenosis except for hypertension (33% vs 12%, p=0.003). The authors concluded that CEA with HP had a higher incidence of recurrent stenosis (21%), and a higher perioperative stroke rate (4%) after a mean follow-up of 12 months than previously reported using PTFE or saphenous vein patching (2% and 9% recurrent stenosis rates, respectively, and 1% and 0% perioperative stroke rates, respectively after a mean follow-up of 30 months). This raises the question as to whether this patch is thrombogenic in this location. Therefore, a randomized controlled trial comparing this patch with other patches (PTFE or vein) is warranted.
    Vascular surgery 01/2001; 35(3):167-74.
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    ABSTRACT: In several nonrandomized studies investigators have reported on the value of postoperative carotid duplex surveillance (PCDS) with mixed results; however the type of closure was not analyzed in these studies. In this study we analyze the frequency and timing of postoperative carotid duplex ultrasound scanning according to the type of closure from a randomized carotid endarterectomy (CEA) trial comparing primary closure (PC) versus patching. We randomized 399 CEAs into 135 PCs, 134 polytetrafluoroethylene (PTFE) patch closures, and 130 vein patch closures (VPCs) with a mean follow-up of 47 months. PCDS was done at 1, 6, and 12 months and every year thereafter (a mean of 4.0 studies per artery). Kaplan-Meier analysis was used to estimate the rate of > or = 80% restenosis over time and the time frame of progression from < 50%, to 50%-79% and > or = 80% stenosis. Restenoses of > or =80% developed in 24 (21%) arteries with PC and nine (4%) with patching. Kaplan-Meier estimate of freedom of > or = 80% restenosis at 1, 2, 3, 4, and 5 years was 92%, 83%, 80%, 76%, and 68% for PC, respectively, and 100%, 99%, 98%, 98%, and 91% for patching, respectively, (P <.01). Of 56 arteries with 20% to 50% restenosis, two of 28 patch closures and 10 of 28 PCs progressed to 50% to < 80% restenosis (P =.02); none of the patch closures and six of 28 PCs progressed to > or =80% (P =.03). In PCs, the median time to progression from <50% to 50%-79%, < 50% to > or =80%, and 50%-79% to > or = 80% was 42, 46, and 7 months, respectively. Of the 24 arteries with > or =80% restenosis in PC, 10 were symptomatic. Thus, assuming th symptomatic restenosis would have undergone duplex scan examinations regardless, there were 14 asymptomatic arteries (12%) that could have been detected only with PCDS (estimated cost, $139, 200), and those patients would have been candidates for redo CEA. Of the 9 arteries (3 PTFE closures and 6 VPCs) with > or =80% restenosis with patch closures, 6 asymptomatic (4 VPCs and 2 PTFE closures) arteries (3%) could have been detected with PCDS. In patients with normal duplex scan findings at the first 6 months, only four (2%) of 222 patched arteries (two asymptomatic) developed > or = 80% restenosis versus five (38%) of 13 in patients with abnormal duplex scan examination findings (P<.001). PCDS is beneficial in patients with PC, but is less beneficial in patients with patch closure. PCDS examinations at 6 months and at 1- to 2-year intervals for several years after PC are adequate. For patients with patching, a 6-month postoperative duplex scan examination with normal results is adequate.
    Journal of Vascular Surgery 12/2000; 32(6):1043-51. · 2.88 Impact Factor
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    A F AbuRahma, P A Robinson, T G Jennings
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    ABSTRACT: Since the advent of subclavian artery percutaneous transluminal angioplasty/stenting, several authorities advocate it as the treatment of choice for patients with subclavian artery disease, claiming results equal to or better than those of reconstructive vascular surgery. However, most of their quoted surgical series included patients who may have other brachiocephalic disease who were treated nonuniformly by means of various bypass grafts with different grafts in the same series (eg, Dacron, polytetrafluoroethylene [PTFE], or vein). In this study, we analyze the long-term results of a large series of carotid-subclavian bypass grafts for subclavian artery disease in which PTFE was uniformly used; the study can be used as a future reference to compare the results of subclavian artery percutaneous transluminal angioplasty/stenting. Fifty-one patients with symptomatic subclavian artery disease (40 occlusions and 11 stenoses) who were treated with carotid-subclavian bypass grafts (PTFE [Goretex]) during a 20-year period were analyzed. Graft patency was determined clinically and confirmed with Doppler scanning pressures and duplex ultrasound scanning. The cumulative patency, overall survival, and symptom-free survival rates were calculated with the life table method. Indications for surgery were arm ischemia in 34 patients (67%), vertebrobasilar insufficiency (VBI) in 27 (53%), and symptomatic subclavian steal in 7 (14%). A combination of arm ischemia and VBI occurred in 17 (33%) of these patients. The mean follow-up was 7.7 years with a median of 7.0 years (range, 1-19 years). The 30-day morbidity rate was 6%, with no perioperative stroke or mortality. Immediate relief of symptoms was achieved in 100% of patients; however, four patients (8%) had late recurrent symptoms (three with VBI). The primary patency and secondary patency rates at 1, 3, 5, and 10 years were 100%, 98%, 96%, and 92% and 100%, 98%, 98%, and 95%, respectively. The symptom-free survival rates at 1, 3, 5, and 10 years were 100%, 96%, 82%, and 47%, respectively. The overall survival rates at 1, 3, 5, and 10 years were 100%, 98%, 86%, and 57%. The mean hospital stay was 3.5 days in the late 70s and 80s and 2.1 days in the 90s (P <. 001). Carotid-subclavian bypass grafts with PTFE grafts for subclavian artery disease are safe, effective, and durable and should remain the procedure of choice, particularly in good-risk patients.
    Journal of Vascular Surgery 10/2000; 32(3):411-8; discussion 418-9. · 2.88 Impact Factor
  • A F AbuRahma, P A Robinson
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    ABSTRACT: To analyze changes in the management of effort subclavian vein thrombosis at our institution. Records of 23 patients with effort subclavian vein thrombosis treated over a 10-year period were analyzed to compare the results of conventional therapy (heparin/warfarin) used in the first half of this period to a multimodality treatment strategy (thrombolysis and other adjunctive treatment as indicated, e.g., first rib resection, angioplasty/stenting, and vein reconstruction). Diagnostic testing included duplex ultrasound and venography. All patients had at least 1-year follow-up. Eight patients (7 men; mean age 34 years, range 15-54) had conventional treatment (group A) and 15 patients (14 men; mean age 36 years, range 17-55) had multimodality therapy (group B). Demographics and clinical characteristics were comparable for both groups. Initial thrombolysis was achieved in 14 (93%) group B patients; 10 received adjunctive treatment to relieve external compression or vein stenosis. Four patients had successful first or cervical rib resection and scalenectomy, and first rib resection followed by angioplasty/stenting was successful in 2. However, angioplasty and stenting alone failed in 2 patients, while venous reconstruction was successful in only 1 of 2 cases. Mean follow-up was 72 months in group A patients and 59 months in group B. One (13%) group A patient and 12 (80%) group B patients demonstrated total venous recanalization and symptom resolution (p = 0.003). Overall, clinical resolution (total and partial symptom relief) was achieved in 3 (38%) group A patients and 13 (87%) group B patients (p = 0.026). Initial lytic therapy followed by adjunctive treatment to relieve external venous compression or venous stenosis is effective in treating patients with effort subclavian vein thrombosis.
    Journal of Endovascular Therapy 09/2000; 7(4):302-8. · 2.70 Impact Factor
  • A. F. AbuRahma, P. A. Robinson, B. K. Richmond
    Vascular and Endovascular Surgery - VASC ENDOVASC SURG. 01/2000; 34(4):319-329.
  • A F AbuRahma, P A Robinson, S M Holt
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    ABSTRACT: Although several studies have compared the patency rates of polytetrafluoroethylene (PTFE) and saphenous vein grafts (SVG) for the above knee location, none have compared the 2 grafts when implanted in the same patient with claudication who needs bilateral above knee femoropopliteal bypasses. Forty-three patients (86 limbs) with bilateral disabling claudication who had superficial femoral artery occlusion and above knee reconstitution with 2- to 3-vessel runoff were analyzed. Patients were treated on one side with PTFE and on the other side with SVG. They were sequentially assigned to PTFE-SVG alternating with SVG-PTFE. All patients were followed using duplex ultrasound and ankle/brachial indexes at 1 month and every 6 months thereafer. The perioperative complication rates were 5% for PTFE and 12% for SVG. There was no operative death or perioperative amputation for either procedure. The Kaplan-Meier estimate of primary, assisted primary, and secondary patency rates at 72 months were 68%, 68%, and 77% for PTFE and 76%, 83%, and 85% for SVG. There were no statistically significant differences between primary and secondary patency rates for both grafts; however; the assisted primary patency rates were higher for SVG (P < .05). The crude limb salvage rate at 72 months was 98% for PTFE and 98% for SVG. There were no risk factors identified that had an impact on graft patency. PTFE and SVG for above knee bypasses have comparable patency and limb salvage rates in claudicant patients with bilateral superficial femoral artery occlusion and 2- to 3-vessel runoff This may justify the use of PTFE for above knee locations in these selected patients.
    Surgery 11/1999; 126(4):594-601; discussion 601-2. · 3.37 Impact Factor
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    ABSTRACT: Although several studies have compared the results of carotid endarterectomy (CEA) with primary closure (PC) versus patch closure, none have compared the outcome of bilateral CEAs with patch versus PC performed on the same patient. This prospective randomized study compares the clinical outcome and incidence of recurrent stenosis (>/=80%) for CEA with PC versus patch closure in patients with bilateral CEAs. This study includes 74 patients with bilateral CEAs with PC on one side and patching on the other. Patients were randomized to sequential operative treatment of either patching/PC or PC/patching. Postoperative duplex ultrasounds and clinical follow-up were done at 1, 6, and 12 months and every year thereafter. A Kaplan-Meier analysis was used to estimate the risk of significant restenosis (>/=80%). Demographic characteristics and the mean operative diameter of the internal carotid artery were similar for both PC and patching. The mean follow-up was 29 months (range, 6 to 65 months). The incidence of ipsilateral stroke was 4% for PC versus 0% for patching. PC had a significantly higher incidence of neurological complications (transient ischemic attacks and stroke combined) than patching (12% versus 1%; P=0.02). Operative mortality was 0%. PC had a higher incidence of recurrent stenosis (22% versus 1%; P<0.003) and total internal carotid artery occlusion (8% versus 0%; P=0.04) than patching. Restenoses necessitating a repeated CEA were also higher for PC (14%) than for patching (1%; P=0.01). The Kaplan-Meier analysis showed that patching had a significantly better cumulative patency rate than PC (P<0.01). This analysis also showed that freedom from recurrent stenosis at 24 months was 75% for PC and 98% for patching. Patch closure is less likely than PC to cause ipsilateral stroke, transient ischemic attacks, and recurrent carotid stenosis. The higher rate of unilateral recurrent stenosis may suggest that local factors play a more significant role than systemic factors in the etiology of recurrent carotid stenosis.
    Stroke 07/1999; 30(6):1185-9. · 6.16 Impact Factor
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    A F AbuRahma, P A Robinson, D L Stickler
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    ABSTRACT: Recurrent stenosis after carotid endarterectomy (CEA) has been reported to vary between a few percent and 30%. Regression of recurrent stenosis has been reported sporadically in the literature, but studies analyzing the factors affecting regression are lacking. This study analyzed factors affecting the regression of postoperative stenosis from a prospective randomized trial of CEA comparing primary closure (PC) versus patching. Three hundred ninety-nine CEAs were randomized into three groups: 135 PCs, 135 polytetrafluoroethylene patch closures (PTFE), and 130 vein patch closures (VPC). Postoperative duplex ultrasounds were done at 1, 6, and 12 months, and then yearly. The subgroup of these CEAs that exhibited postoperative stenosis was followed for possible regression of the stenosis. Analyses of various risk factors were examined for possible association with regression of recurrent stenosis. Mean follow-up was 46 months. Of 105 postoperative stenoses, regression was noted in 6/64 (9%) in PC, 6/13 (46%) in PTFE, and 10/28 (36%) in VPC. Overall, 22 recurrent stenoses regressed; 19 regressed to normal and 3 regressed from 50% to 80% stenosis to 20% to <50% stenosis. The mean time to regression was 383 days. Regression was more common in patching than PC. Both VPC and PTFE had significantly more regression than PC. When stenoses of 50% to 80% were analyzed, patching had more regression than PC. None of the recurrent stenoses > or = 80% regressed. There was no association between regression and other factors, including gender, hypertension, diabetes mellitus, coronary artery disease, smoking, internal carotid artery diameter, hyperlipidemia, hypercholesterolemia, or aspirin intake. Regression of recurrent stenosis was associated more strongly with patching than with PC. There was no association between regression and other factors.
    Annals of Surgery 06/1999; 229(6):767-72; discussion 772-3. · 6.33 Impact Factor
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    ABSTRACT: To study the role of duplex ultrasonography in evaluating plaque morphology and its correlation to neurological symptoms and cerebral infarctions on computed tomographic scans. The hospital records of 181 patients (107 males; average age 66 years, range 41 to 89) with > 50% carotid stenosis (29 bilateral lesions) who had undergone duplex ultrasonography, carotid arteriography, and cerebral computed tomography were studied retrospectively. Of 210 duplex examinations, 139 were appropriate for morphological analysis of surface characteristics and echogenicity. Over half of the plaques examined had irregular surfaces (81, 58%) and displayed mixed (i.e., heterogeneous) echogenic patterns (74, 53%). Irregular (68 of 81, 84%) and heterogeneous (65 of 74, 88%) plaques were associated with ipsilateral neurological symptoms (p < 0.0001). Similarly, 44 (54%) of 81 irregular plaques and 42 (57%) of 74 heterogeneous plaques were found in patients with cerebral infarctions in the carotid territory (p < 0.0001). Heterogeneous and/or irregular plaques were more often associated with both neurological symptoms and infarctions than smooth or homogeneous plaques. These findings may have implications in patient selection for endoluminal therapy.
    Journal of Endovascular Surgery 03/1999; 6(1):59-65.
  • Vascular and Endovascular Surgery - VASC ENDOVASC SURG. 01/1999; 33(1):23-32.
  • A F AbuRahma, D L Stickler, P A Robinson
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    ABSTRACT: The long-term risk for recurrent deep venous thrombosis (DVT) and the incidence of post-thrombotic syndrome (PTS) after long-term anticoagulation (LTA) therapy have been widely debated. In this study, we compare the results of short-term anticoagulation therapy versus conventional LTA therapy in patients with DVT of the lower extremity. Baseline assessments of DVT symptoms and risk factors were recorded in 105 patients. Diagnosis was made using duplex ultrasound/venography. Patients were sequentially assigned to 1 of the following treatment protocols: (A) conventional LTA therapy, which included initial intravenous standard heparin followed by warfarin on days 3 to 5 and was continued for 3 months for patients without pulmonary embolism (PE); or (B) short-term therapy, which included the same heparin therapy followed by warfarin on days 2 to 3 and was continued for 6 weeks only. Clinical and duplex ultrasound follow-up was done at 6 weeks, 3 and 6 months, and every 6 months thereafter. Risk factors, location of DVT, and mean age of the 2 groups were comparable. Mean follow-up was 59 months. There were 4 immediate major complications in patients of group A (4 of 54 [7%]; 2 PEs and 2 significant bleeds) and 3 in patients of group B (3 of 51 [6%]; 1 PE and 2 bleeds). On long-term follow-up, 18 of 43 (42%) patients in group A and 20 of 44 (46%) patients in group B had PTS. Similarly, 10 of 43 (23%) patients in group A and 9 of 44 (20%) patients in group B had 1 or more recurrent thromboembolic events (not statistically significant). A significant difference was demonstrated only in patients with cancer; LTA was favored in reducing recurrent DVT and PTS. Two other patients in group A had late significant complications secondary to warfarin (hemorrhage in 1 and coumadin necrosis in the other), with no complications in group B. The mean number of days of hospitalization were fewer for patients in group B (5 versus 8 days), which is mainly due to earlier initiation of warfarin therapy for group B. In this study of our local population, we observed that short-term anticoagulation therapy was as effective as LTA therapy and less costly for use in most patients. It may also carry less risk of long-term warfarin complications, such as bleeding or skin necrosis.
    Journal of Vascular Surgery 11/1998; 28(4):630-7. · 2.88 Impact Factor
  • A F AbuRahma, P D Kyer, P A Robinson, R S Hannay
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    ABSTRACT: This study examined the importance of ultrasonic plaque morphology and its correlation to the presence of intraplaque hemorrhage and clinical implications. One hundred fifty-two carotid plaques associated with > or = 50% internal carotid artery stenoses in 135 patients who had carotid endarterectomies were characterized ultrasonographically into irregular/ulcerative, smooth, heterogeneous, homogeneous, or not defined. All plaques were examined pathologically for the presence of intraplaque hemorrhage. The ultrasonic morphology of the plaques included 63 with surface irregularity (41%), 48 smooth (32%), 59 heterogeneous (39%), 52 homogeneous (34%), and 41 not defined (27%). Intraplaque hemorrhage was present in 57 of 63 (90%) irregular plaques and 53 of 59 (90%) heterogeneous plaques, in contrast to 13 of 48 (27%) smooth plaques and 17 of 52 (33%) homogeneous plaques (P < .001). Fifty-three of 63 (84%) irregular plaques and 47 of 59 (80%) heterogeneous plaques had transient ischemic attack (TIA)/stroke symptoms, in contrast to 9 of 48 (19%) for smooth plaques and 15 of 52 (29%) for homogeneous plaques (P < .001). Irregular and/or heterogeneous carotid plaques are more often associated with intraplaque hemorrhage and neurologic events. Therefore, ultrasonic plaque morphology may be helpful in selecting patients for carotid endarterectomy.
    Surgery 10/1998; 124(4):721-6; discussion 726-8. · 3.37 Impact Factor
  • A F AbuRahma, B K Richmond, P A Robinson
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    ABSTRACT: No prior studies have explored the etiology of peripheral arterial thromboembolic events (PATE) in younger patients. Therefore, we analyzed the sources of these events in patients <50 years of age over a recent 10-year period. Diagnostic and work-up strategies will be proposed based on the presence of cardiac or atherosclerotic risk factors. The sources of emboli were classified as (1) conventional (cardiac or arterioarterial), (2) unconventional, or (3) unknown. A statistical analysis of risk factors that, if absent, would suggest an unconventional cause was performed. Risk factors included those for cardiac and atherosclerotic disease: coronary artery disease (CAD), valvular disease, smoking, arrhythmia, hypertension, or diabetes mellitus. Overall, 51 patients were identified. Twenty-nine patients (57%) had unconventional causes (8 paradoxical emboli, 4 possible paradoxical emboli, 12 hypercoagulable states, 3 white clot syndromes, and 2 cervical ribs), 17 (33%) had conventional causes, and 5 (10%) were unknown. When the number of cardiac risk factors was < or =1, excluding smoking, the probability of a conventional source was zero, in contrast to 100% if the number of risk factors was >1. When the following risk factors were absent, there were significantly more unconventional than conventional sources of emboli (P < 0.001): smoking (100% versus 0%), CAD (93% versus 7%), arrhythmias (83% versus 17%), hypertension (93% versus 7%), and diabetes mellitus (81% versus 19%). Patients with a conventional source were significantly older (44 versus 38 years). The "unconventional" causes of PATE were responsible for a higher percentage of cases in young patients. An analysis of the number of risk factors was useful in predicting which patients suffered embolic events from conventional sources, with the critical number being >1 (excluding smoking). Therefore, when younger patients present with PATE, and are found to have < or =1 identifiable cardiac risk factor, their work-up should be directed toward the unconventional sources first.
    The American Journal of Surgery 09/1998; 176(2):158-61. · 2.52 Impact Factor
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    ABSTRACT: Current duplex ultrasound criteria for internal carotid artery (ICA) stenosis (1%-15%, 16%-49%, 50%-69%, 70%-99%) may not be applicable to threshold stenoses used in symptomatic (North American Symptomatic Carotid Endarterectomy Trial [NASCET], Veterans' Administration [VA]) and asymptomatic (Asymptomatic Carotid Atherosclerosis Study, VA) carotid endarterectomy (CEA) trials. This, along with increasing reports advocating CEA based on duplex results alone, prompted us to identify (1) new velocity criteria consistent with threshold stenoses used by these trials, and (2) velocity criteria with a high positive predictive value (PPV) (> 95%) and accuracy for detecting > or = 60% and > or = 70% ICA stenoses. This is the first study to propose criteria which can be used for all current CEA trials. The color duplex ultrasound (CDU) and arteriogram results of 462 ICAs were analyzed in blind fashion. Angiographic stenosis was calculated as in NASCET. Three velocity criteria (peak systolic velocity [PSV] of the ICA, end diastolic velocity [EDV] of the ICA, and the ratio of the PSV of the ICA/common carotid artery) were recorded and subjected to receiver operator characteristic curves (ROC) analysis to determine optimum criteria for identifying ICA stenoses of > or = 30%, > or = 50%, > or = 60%, and > or = 70%-99%. For > or = 30% stenosis (st): PSV > or = 120 cm/sec had an overall accuracy (OA) of 87%, sensitivity (sen.) of 93%, specificity (spec.) of 67%, PPV of 90%, and negative predictive value (NPV) of 77%; for > or = 50% st: PSV > or = 140 cm/sec had an OA of 93%, sen. of 92%, spec. of 95%, PPV of 97%, and NPV of 89%; for > or = 60% st: PSV > or = 150 cm/sec and an EDV of > or = 65 had an OA of 90%, sen. of 82%, spec. of 97%, PPV of 96%, and NPV of 86%; for > or = 70%-99% st: PSV > or = 150 cm/sec and an EDV of > or = 90 had an OA of 92%, sen. of 85%, spec. of 95%, PPV of 91%, and NPV of 92%. An ICA-PSV and EDV of 150, 65, and 150, 110 had the best PPV (> or = 95%) in detecting > or = 60% and > or = 70% st, respectively. When these new criteria are used, CDU can accurately detect threshold stenoses used by various CEA trials. Selected velocities with a high PPV (> 95%) may be used as the sole preoperative imaging.
    Annals of Vascular Surgery 07/1998; 12(4):349-58. · 0.99 Impact Factor
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    ABSTRACT: This study examines the long-term clinical outcome and the incidence of recurrent stenosis (> or = 50%) after carotid endarterectomy (CEA) with primary closure (PC) versus vein patch closure (VPC), saphenous (SVP), and jugular vein (JVP) and polytetrafluoroethylene patch closure (PTFE-P). A total of 399 CEAs were randomized into the following groups: 135 PC, 134 PTFE-P, and 130 VPC (SVP alternating with JVP). Postoperative duplex ultrasound scans were performed at 1, 6, and 12 months and every year thereafter. The mean follow-up was 30 months with a range of 1 to 62 months, and demographic characteristics were similar in all groups. Kaplan-Meier analysis was used to estimate the risk of restenosis and the stroke-free survival. The incidence of ipsilateral stroke was 5% (seven of 135) for PC, 1% (one of 134) for PTFE-P, and 0% for VPC (PC vs VPC, p = 0.008; PC vs PTFE-P, p = 0.034). Seven strokes occurred in the perioperative period. All three groups had similar mortality rates. The cumulative stroke-free survival rate at 48 months was 82% for PC, 84% for PTFE-P, and 88% for VPC (p < 0.01 for PC vs PTFE-P or VPC). PC had a higher incidence of recurrent stenosis and occlusion (34%) than PTFE-P (2%) and VPC (9%) (SVP 9%, JVP 8%) (p < 0.001). PTFE-P had a lower recurrent stenosis rate than VPC (p < 0.045). Restenoses necessitating a redo CEA were also higher for PC (11%) than for PTFE-P (1%) and VPC (2%) (p < 0.001). Women with PC had a higher recurrent stenosis rate than men (46% vs 23%, p = 0.008). Kaplan-Meier analysis showed that freedom from recurrent stenosis at 48 months was 47% for PC, 84% for VPC, and 96% for PTFE-P (p < 0.001). The SVP and JVP results were comparable. The mean operative diameter of the internal carotid artery was similar in patients with or without restenosis. Significantly more late internal carotid artery dilatations occurred in the VPC group compared with the PC group. Patch closure (VPC or PTFE-P) is less likely than PC to cause perioperative stroke. Patching was also superior in lowering the incidence of late recurrent stenoses, especially in women.
    Journal of Vascular Surgery 02/1998; 27(2):222-32; discussion 233-4. · 2.88 Impact Factor
  • A.F. AbuRahma, B.K. Richmond, P.A. Robinson
    The American Journal of Surgery 01/1998; 176(2). · 2.52 Impact Factor
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    ABSTRACT: Color duplex ultrasound has been advocated as an alternative to arteriography before carotid endarterectomy. However, one limitation of color duplex ultrasound is that it sometimes fails to differentiate high-grade stenosis from total carotid occlusion. This study was done to determine (1) the accuracy of carotid duplex ultrasound in diagnosing total carotid occlusion, and (2) when angiography is necessary. Carotid duplex ultrasound and angiography results were compared for 520 carotid arteries, and 103 of these had a duplex diagnosis of total carotid occlusion or suspected almost total-to-total occlusion. The diagnosis of total carotid occlusion was primarily based on the absence of flow in the internal carotid artery as visualized on B-mode imaging for at least 1 inch beyond the bifurcation (optimal study). If the internal carotid artery was not optimally seen beyond the bifurcation, but secondary criteria were present, such as dampening of the common carotid signal and internalization of the external carotid artery, a diagnosis of suspected subtotal to total occlusion was made (limited study). In the optimal studies, 91 arteries had total carotid occlusions and of these, 87 were confirmed by angiography. The accuracy of carotid duplex ultrasound in diagnosing total carotid occlusion was 97% with a positive predictive value of 96%, negative predictive value of 98%, sensitivity of 91%, and specificity of 99%. Twelve arteries were diagnosed as suspected subtotal to total occlusion (limited studies), and of these, three were occluded on angiography, eight had stenoses ranging from 90% to 99%, and one had 80% stenosis. A carotid duplex ultrasound study is an acceptable method for predicting total carotid occlusion when the study is optimal, and angiography is unnecessary in asymptomatic patients. Angiography is recommended for patients who are surgical candidates with a limited duplex study.
    The American Journal of Surgery 09/1997; 174(2):185-7. · 2.52 Impact Factor
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    ABSTRACT: Although a fever of unknown origin (FUO) is most often due to other causes, the few caused by pulmonary emboli, pelvic thrombophlebitis, or lower extremity venous thrombosis (DVT) present a diagnostic challenge. The purpose of this study was to evaluate the role of venous duplex imaging of the lower extremity in evaluating a large series of patients with FUO. This has not been reported previously in the English-language literature. Medical records were analyzed of patients with FUO who were referred to the vascular laboratory for venous duplex imaging of the lower extremities to rule out DVT as a cause of their fever. A FUO was defined as a temperature of greater than 38.3 degrees C on several occasions for at least 3 weeks' duration that defied 1 week of hospital evaluation. DVT was considered as a probable cause of FUO if the following criteria were met: (1) a positive venous duplex image for acute DVT, (2) subsequent fever resolution within 7 days of anticoagulation therapy, and (3) a fever that was resistant to prior treatment. A total of 114 duplex examinations, gathered during a 2-year period, were analyzed. The 89 patients had a mean age of 58 years. Infections were the most common cause of FUO (57 of 89, 64%), and unknown causes constituted 19%. There were seven cases of DVT (8%), five (6%) of whom met the criteria for probable cause of FUO. The overall cost of venous duplex imaging examinations was $51,300 ($450 x 114 tests), with an average cost of $10,260 for each case of DVT detected as probable cause of FUO. Consistent with the literature, infections remain the most common cause of FUO; however, DVT was found to be a more common cause of FUO in our present series (6%). The cost of venous duplex imaging of the lower extremities in establishing DVT as a probable cause of FUO should be borne in mind when the work-up of these patients is planned.
    Surgery 05/1997; 121(4):366-71. · 3.37 Impact Factor

Publication Stats

772 Citations
103.89 Total Impact Points

Institutions

  • 1990–2001
    • Charleston Area Medical Center
      Charleston, West Virginia, United States
  • 1996
    • Boehringer Ingelheim
      Ingelheim, Rheinland-Pfalz, Germany