Paul A Armstrong

University of South Florida, Tampa, Florida, United States

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Publications (37)53.39 Total impact

  • Aurelia Calero, Paul A. Armstrong
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    ABSTRACT: Venous invasion is a common characteristic of renal cell carcinoma (RCC) manifesting as tumor thrombus with possible extension into the renal vein, and in extensive cases the thrombus can extend from renal vein to the right atrium. Presently, cytoreductive nephrectomy and tumor thrombectomy are the foundation for improving quality of life and survival in the treatment of RCC, therefore there has emerged a role for a vascular specialist to become an integral part of operative planning and therapy.
    Seminars in Vascular Surgery 01/2014; · 1.02 Impact Factor
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    ABSTRACT: To determine whether the formation of an integrated vascular surgery residency (0 + 5) has negatively impacted the case volume and diversity of the vascular surgery fellows (5 + 2) and chief general surgeons at the same institution. Operative data from the vascular integrated (0 + 5), independent (5 + 2), and general surgery residencies at a single institution were retrospectively reviewed and analyzed to determine vascular surgery case volumes from 2006-2012. National operative data (Residency Review Committee) were used for comparison of diversity and volume. Standard statistical methods were applied. During this period, the 5 + 2 fellows at our institution performed on average 741 (range, 554-1002) primary cases and 1091 (range, 844-1479) combined primary and secondary cases for the 2-year fellowship. Our integrated residency began in July 2007. Our fellows' primary case volumes remained relatively stable between 2006 and 2011, with a 4% increase in the number of cases, although their total (primary and secondary) case volumes fell 15%; by comparison, the equivalent national 50th percentile rates rose 16% during this time frame. Our institution's general surgery residents performed an average of 116 (range, 56-221) vascular cases individually during their 5-year residency from 2005-2011. From 2006-2011, the total case volume fell only 5%, while the national 50th percentile rate fell 24%. Across all years, however, resident and fellow volumes both continue to be above Accreditation Council for Graduate Medical Education minimum requirements, and the major vascular case volume at our institution in all groups studied remained statistically greater than or equal to the national 50th percentile of cases. Our first integrated resident to graduate finished in June 2012 with 931 total vascular cases and 249 general surgery cases for a total operative experience of 1180 cases during the 5-year residency. Finally, after an 8-year period (2003-2010) in which none of our general surgery residents pursued vascular training, 1 resident in each of the 2011, 2012, and 2013 graduating years has now done so. At our institution, the introduction of a 0 + 5 vascular residency has correlated with a modest drop (15%) in overall case volume for the 5 + 2 fellows, but the number of primary cases have actually increased slightly and they continue to meet or exceed Accreditation Council for Graduate Medical Education requirements and national 50th percentile rates. General surgery residents' vascular volumes, by contrast, have remained stable, and interest in vascular surgery by residents has increased. Our integrated vascular residents are projected to exceed the fellows' 50th percentile case volume and diversity targets during their residency experience.
    Annals of Vascular Surgery 10/2013; · 0.99 Impact Factor
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    ABSTRACT: Background This report details the experience of a multidisciplinary surgical team in the management of stage III and stage IV renal cell carcinoma (RCC) with concomitant inferior vena cava (IVC) tumor thrombus. Methods A retrospective inquiry of our vascular database from 2003 to 2012 identified 55 surgical cases of stage III (n = 40) and stage IV (n = 15) RCC presenting with IVC tumor thrombus. Tumor characteristics and IVC tumor thrombus were evaluated by clinical staging and postoperative pathology staging. Patient demographics and surgical reconstruction are detailed. Cancer-specific outcomes consisted of oncologic surveillance with computed tomography or magnetic resonance imaging. A Clavien-Dindo classification of early (<30 days) complications and mortality was recorded, including a review of secondary surgical interventions. Results According to the Novick classification of IVC tumor thrombus, there were 10 supradiaphragmatic (level IV), 20 intrahepatic (level III), and 25 infrahepatic (level II or I) tumor thrombi. Vena cava reconstruction was completed in 54 patients (98%), with one patient deemed unresectable. Vena cava control required cardiac bypass (n = 10), venovenous bypass (n = 4), or infrahepatic IVC control (n = 40). Reconstruction of the IVC was completed with two prosthetic interposition grafts for one stage IV thrombus and one stage III thrombus; two patch repairs were done for stage III thrombus, and there were 50 primary IVC repairs. All other IVC reconstructions were patent at a mean follow-up of 23 months. A single asymptomatic patient with primary IVC repair had estimated 30% IVC narrowing but no other measurable stenosis as detected by postoperative imaging. Three patients required reoperation (two for surgical site bleeding, one for small bowel fistula). Early surgical complications included Clavien-Dindo grades I (n = 3), II (n = 6), IIIa (n = 2), IIIb (n = 3), and V (n = 2). Regional retroperitoneal or distant recurrent RCC occurred in 26 patients (48%); a single patient demonstrating recurrent IVC tumor thrombus at 8 months required secondary IVC thrombectomy. All patients with tumor invasion of the IVC wall developed recurrent RCC, and no patient survived beyond 5 years. Early mortality was 3.6% (n = 2), with 27 patients (49%) dying within 24 months, resulting in an overall mortality for the cohort of 80% (n = 44) as established on routine regular postoperative surveillance. Conclusions A multidisciplinary approach for the management of advanced RCC and IVC tumor thrombus helps optimize outcomes. Primary IVC repairs are possible in most patients, and IVC patency is good. Recurrent tumor thrombus rates are low; however, RCC tumor recurrence and mortality are high, especially among patients with advanced cancer with IVC wall invasion.
    Journal of Vascular Surgery. 12/2012; 56(6):1820.
  • Journal of Vascular Surgery. 12/2012; 56(6):1815–1816.
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    ABSTRACT: What's known on the subject? and What does the study add? Historically, the surgical management of renal tumours with intravascular tumour thrombus has been associated with high morbidity and mortality. In addition, few cases are treated, and typically at tertiary care referral centres, hence little is known and published about the ideal surgical management of such complex cases. The present comprehensive review details how a multidisciplinary surgical approach to renal tumours with intravascular tumour thrombus can optimise patient outcomes. Similarly, we have developed a treatment algorithm in this review that can be used in the surgical planning of such cases. •  To detail the perioperative and technical considerations essential to the surgical management of renal cell carcinoma (RCC) with inferior vena cava (IVC) tumour thrombus, as historically patients with RCC and IVC tumour thrombus have had an adverse clinical outcome. •  Recent surgical and perioperative advances have for the most part optimized the clinical outcome of such patients. •  A comprehensive review of the scientific literature was conducted using MEDLINE from 1990 to present using as the keywords 'renal cell carcinoma' and 'IVC tumor thrombus'. •  In all, 62 manuscripts were reviewed, 58 of which were in English. Of these, 25 peer-reviewed articles were deemed of scientific merit and were assessed in detail as part of this comprehensive review. •  These articles consist of medium to large (≥25 patients) peer-reviewed studies containing contemporary data pertaining to the surgical management of RCC and IVC tumour thrombus. •  Many of these studies highlight important surgical techniques and considerations in the management of such patients and report on their respective clinical outcomes. •  Careful preoperative planning is essential to optimising the outcomes within this patient cohort. High quality and detailed preoperative imaging studies help delineate the proximal extension of the IVC tumour thrombus and possible caval wall direct invasion while determining the potential necessity for intraoperative vascular bypass. •  The surgical management of RCC and IVC tumour thrombus (particularly for level III or IV) often requires the commitment of a multidisciplinary surgical team to optimise patient surgical outcomes. •  Despite significant improvements in surgical techniques and perioperative care, the 5-year overall survival remains only between 32% and 69%, highlighting the adverse prognosis of such locally advanced tumours. •  Important prognostic factors within this patient cohort include pathological stage, nuclear grade, tumour histology, lymph node and distant metastatic status, preoperative performance status, Charlson comorbidity index, and nutritional status. •  The multidisciplinary surgical care of RCC and IVC tumour thrombus (particularly high level thrombi) is pivotal to optimising the surgical outcome of such patients. •  Similarly, important preoperative, perioperative, and postoperative considerations can improve the surgical outcome of patients.
    BJU International 04/2012; 110(7):926-39. · 3.05 Impact Factor
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    ABSTRACT: To compare the accuracy of inferior vena cava (IVC) filter placement using a bedside technique guided by intravascular ultrasound (IVUS) with a concurrent experience of filter deployment with fluoroscopic venogram imaging. From November 2006 to December 2009, 195 consecutive IVC filters were placed to prevent pulmonary embolism in 120 high-risk patients without lower limb deep vein thrombosis (DVT) and 75 patients with DVT and anticoagulation contraindications. Filter insertion techniques included bedside IVUS-guided (n = 97) and fluoroscopic-guided (n = 98) procedures. Before mid-2008, 2 bedside IVUS-guided protocols were used evolving from a single-puncture, pullback technique (n = 48), in which the measured distance from the venous access site to the IVC landing zone then allowed a calibrated reinsertion of a 7F delivery sheath and filter deployment. After mid-2008, a single puncture 8F sheath technique (n = 48) using IVUS to position the delivery sheath tip within the IVC landing zone without catheter or sheath measurement or reinsertion was used. Venous access was via the right femoral (84 IVUS and 56 fluoroscopy), left femoral (10 IVUS and 16 fluoroscopy), or right internal jugular vein (3 IVUS and 26 fluoroscopy). The 3 filter insertion techniques were compared for "optimal" IVC placement defined as the filter positioning between L1 and L4 vertebrae with tilt <15° based on postprocedure abdominal x-rays or venography. Filter malposition occurred with 6% (6 of 97) bedside IVUS-guided procedures with no malpositions during fluoroscopic imaging. Malposition was lower with the evolved sheath (4%, 2 of 48) compared with the earlier pullback (8%, 4 of 48) insertion technique (P = .03). The incidence of the filter malposition during IVUS-guided deployment was highest using left femoral access (4 of 10) compared with right femoral (2 of 84) or internal jugular (0 of 3) vein access (P < .01). Filter tilt occurred more after IVUS-guided procedure (10 of 97) than fluoroscopic procedure (3 of 98; P = .05) and was most frequent for left femoral access (5 of 10 IVUS and 1 of 16 fluoroscopy; P < .01) and was not related to filter type (P = .13). Our current bedside IVUS-guided IVC filter technique using a single venous puncture and single sheath positioning has improved the placement accuracy. Left femoral venous access should be avoided to minimize the occurrence of filter malpositioning and tilt.
    Vascular and Endovascular Surgery 04/2012; 46(4):293-9. · 0.88 Impact Factor
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    ABSTRACT: The management of a post-chemotherapy retroperitoneal mass secondary to testicular cancer can present a surgical challenge when involving adjacent organs or major vascular structures. We present the first video of a retroperitoneal lymph node dissection (RPLND) with IVC (inferior vena cava) thrombectomy, caval wall resection resulting from metastatic non-seminomatous germ cell testis (NSGCT) cancer. In this surgical video, we highlight important surgical considerations in the management of a postchemotherapy retroperitoneal mass with direct IVC wall invasion and level 2 thrombus in such a patient. A 34 year old man underwent a right inguinal orchiectomy for a mixed NSGCT (embryonal, yolk sac, and teratoma components) and elevated serum tumor markers. He underwent systemic chemotherapy (BEP regimen x 4 cycles) with subsequent near normalization of tumor markers. His post-chemotherapy imaging revealed a 6 cm residual retroperitoneal mass with a level 2 IVC tumor thrombus and suspected direct infrarenal IVC wall invasion from the mass. The patient underwent an open post-chemotherapy RPLND, IVC thrombectomy, IVC resection and grafting. The final pathology report of the retroperitoneal mass revealed teratoma with no viable germ cell tumor elements and negative surgical margins. His intra-operative and post-operative stages were unremarkable with his IVC graft remaining patent and no evidence of disease recurrence at last follow-up. We present the first surgical video of a post-chemotherapy RPLND with IVC thrombectomy, caval wall resection and grafting for metastatic NSGCT. The final pathology report of teratoma with no viable tumor highlights the local vascular invasive potential of such pathology.
    International braz j urol: official journal of the Brazilian Society of Urology 01/2012; 38(1):135; discussion 136.
  • Urology 01/2011; 78(3). · 2.42 Impact Factor
  • Paul A. Armstrong, Dennis F. Bandyk
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    ABSTRACT: An accurate diagnosis of lower extremity peripheral artery disease (PAD) can usually be established based on the clinical history, vascular examination including pulse palpation, and Doppler survey of the femoral and pedal arteries.With the development of symptomatic PAD, i.e., disabling claudication, critical limb ischemia (ischemic rest pain, tissue loss), or peripheral aneurysmal disease, more detailed vascular testing is necessary for disease management. Peripheral arterial testing is best performed in an accredited facility by certified technical personnel and physicians experienced in test interpretation. Measurement of limb blood pressure in conjunction with duplex mapping of the arterial tree should be performed to assess disease location and severity. Duplex ultrasound scanning provides hemodynamic and anatomic information at no risk to the patient and ensures an accurate diagnosis.1–4 Based on disease location and morphology, a decision to proceed with endovascular or surgical intervention is possible.5–9 Other vascular imaging modalities [contrast arteriography, computed tomography (CT) angiography, magnetic resonance angiography (MRA)] do not provide hemodynamic information essential for the evaluation of symptomatic PAD, and formulating an individualized treatment plan.
    03/2010: pages 47-55;
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    Journal of Vascular Surgery - J VASC SURG. 01/2010; 52(6):1734-1735.
  • D F Bandyk, P A Armstrong
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    ABSTRACT: Intravascular ultrasound (IVUS) provides high-resolution vessel imaging and has been shown to improve clinical outcomes when used to assess the technical result of peripheral angioplasty procedures. Our vascular group compared anatomic and clinical outcomes of carotid artery stent-angioplasty (CAS) performed with angiogram monitoring alone, or in combination with IVUS imaging to select stent/balloon diameter and interrogate stent deployment region for residual stenosis. A retrospective review of our carotid stent registry (N=306) identified 220 CAS procedures performed with either a digital C-arm fluoroscopy alone (N=110) or in conjunction with IVUS (N=110) with at least 6-month of clinical follow-up. Outcome measures of procedure time, angioplasty balloon diameter, contrast dye volume, Duplex surveillance testing for recurrent stenosis, and procedure event (death, cardiac, neurologic) rates were compared to assess the risks and benefits of IVUS. All procedures utilized a cerebral protection device deployed prior to IVUS imaging. Procedure times were similar, but IVUS usage resulted in lower (P<0.05) contrast agent volumes due to fewer angiogram runs for stent sizing and verification of adequate stent deployment. IVUS imaging resulted in the use of larger diameter balloons (typically 6 mm) for final stent angioplasty based on distal internal carotid artery (ICA) dia measurements, and identified (P<0.01) more residual stent abnormalities (N=12, 11%) versus CAS with angiogram assessment alone (N=2, 1.8%). No procedural or 30-day cardiac events or deaths occurred. The overall stroke rate was 0.9%; two events (stroke-1; reperfusion injury-1) in the angio+IVUS group (1.8%) and none in the angio alone group. Duplex ultrasound surveillance following CAS demonstrated a higher (P<0.01) incidence of >50% diameter-reducing in-stent stenosis in the angio alone group (11% vs 7% at 1 month ; 24% vs 6% at last surveillance; mean 36 moontha; range: 6-66 months). The quality control of the CAS procedure was enhanced by IVUS imaging which directed stent /balloon sizing and was more accurate than angiography in confirming adequate stent expansion. No IVUS related adverse events occurred. Based on the anatomic information provided by IVUS, larger diameter angioplasty balloons were used which correlated with less residual stenosis after CAS based on duplex ultrasound testing.
    The Journal of cardiovascular surgery 12/2009; 50(6):727-33. · 1.51 Impact Factor
  • Journal of Vascular Surgery - J VASC SURG. 01/2009; 50(6):1545-1545.
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    ABSTRACT: The authors report the microbiology and outcomes following an individualized treatment algorithm for extracavitary (EC) prosthetic graft infection, including the use of graft preservation and in situ graft replacement techniques. A retrospective 8-year review of 87 patients treated for EC prosthetic graft infections was carried out. The treatment algorithm included culture-specific antibiotic therapy, surgical site debridement with antibiotic bead placement, selected graft preservation with muscle flap coverage, or graft excision with in situ conduit replacement. Outcomes measured included death, limb loss, and recurrent infection. It was found that present-day management of EC prosthetic graft infections is associated with lower mortality and morbidity despite changes in microbiology and the increased application of graft preservation and in situ grafting treatments.
    Vascular and Endovascular Surgery 10/2008; 42(6):537-44. · 0.88 Impact Factor
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    ABSTRACT: Controversy regarding the efficacy of duplex ultrasound surveillance after infrainguinal vein bypass led to an analysis of patient and bypass graft characteristics predictive for development of graft stenosis and a decision of secondary intervention. Retrospective analysis of a contemporary, consecutive series of 353 clinically successful infrainguinal vein bypasses performed in 329 patients for critical (n = 284; 80%) or noncritical (n = 69; 20%) limb ischemia enrolled in a surveillance program to identify and repair duplex-detected graft stenosis. Variables correlated with graft stenosis and bypass repair included: procedure indication, conduit type (saphenous vs nonsaphenous vein; reversed vs nonreversed orientation), prior bypass graft failure, postoperative ankle-brachial index (ABI) < 0.85, and interpretation of the first duplex surveillance study as "normal" or "abnormal" based on peak systolic velocity (PSV) and velocity ratio (Vr) criteria. Overall, 126 (36%) of the 353 infrainguinal bypasses had 174 secondary interventions (endovascular, 100; surgery, 74) based on duplex surveillance; resulting in 3-year Kaplan-Meier primary (46%), assisted-primary (80%), and secondary (81%) patency rates. Characteristics predictive of duplex-detected stenosis leading to intervention (PSV: 443 +/- 94 cm/s; Vr: 8.6 +/- 9) were: "abnormal" initial duplex testing indicating moderate (PSV: 180-300 cm/s, Vr: 2-3.5) stenosis (P < .0001), non-single segment saphenous vein conduit (P < .01), warfarin drug therapy (P < .01), and redo bypass grafting (P < .001). Procedure indication, postoperative ABI level, statin drug therapy, and vein conduit orientation were not predictive of graft revision. The natural history of 141 (40%) bypasses with an abnormal first duplex scan differed from "normal" grafts by more frequent (51% vs 24%, P < .001) and earlier (7 months vs 11 months) graft revision for severe stenosis and a lower 3-year assisted primary patency (68% vs 87%; P < .001). In 52 (15%) limbs, the bypass graft failed and 20 (6%) limbs required amputation. The efficacy of duplex surveillance after infrainguinal vein bypass may be enhanced by modifying testing protocols, eg, rigorous surveillance for "higher risk" bypasses, based on the initial duplex scan results and other characteristics (warfarin therapy, non- single segment saphenous vein conduit, redo bypass) predictive for stenosis development.
    Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter 09/2008; 48(3):613-8. · 3.52 Impact Factor
  • Joe P Chauvapun, Paul A Armstrong, Brad L Johnson
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    ABSTRACT: Carotid duplex ultrasound testing provides a safe and accurate method to detect and grade the severity of atherosclerotic internal carotid artery stenosis both before and following carotid intervention. Testing after surgical endarterectomy or stent angioplasty allows assessment of the technical success by excluding residual stenosis. The focus of duplex surveillance after carotid intervention is to identify recurrent stenosis, repair site occlusion, and progression of contralateral internal carotid artery disease. Patients who develop a neurologic event or a duplex-detected >75% diameter-reducing internal carotid artery stenosis with a peak systolic velocity >300 cm/s and end-diastolic velocity >125 cm/s should be further evaluated by angiographic imaging and should be considered for reintervention if an appropriate lesion is confirmed. Duplex surveillance allows the vascular surgeon to evaluate patency of the rendered intervention, its stenosis-free durability, and its effectiveness in stroke prevention.
    Perspectives in Vascular Surgery and Endovascular Therapy 01/2008; 19(4):362-7; discussion 368-9.
  • Paul A Armstrong
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    ABSTRACT: Color duplex ultrasound testing has evolved to be a clinically useful modality to diagnose chronic mesenteric ischemia caused by visceral artery origin atherosclerosis. Testing requires expertise in ultrasound imaging, visceral artery hemodynamics, and duplex scan interpretation. Patient can be accurately screened for severe stenosis or occlusion involving celiac, superior mesenteric, or inferior mesenteric arteries. Duplex testing can also evaluate functional patency following visceral bypass grafting procedures or endovascular stent-angioplasty. The focus of duplex surveillance after visceral artery intervention is to identify severe repair site stenosis, which can develop with symptoms of gut ischemia. Visceral duplex testing of a bypass graft or stent-angioplasty site that shows peak systolic velocities >300 cm/s with end-diastolic velocities >50 to 70 cm/s, or a decreased graft velocity peak systolic velocity <40 cm/s should be considered for interrogation using angiography to confirm or exclude severe (>70%) stenosis. Duplex testing after surgical or endovascular visceral interventions is a screening study, which compliments clinical follow-up by aiding the vascular surgeon in timely identification of visceral repairs that have developed a progressive, high-grade stenosis.
    Perspectives in Vascular Surgery and Endovascular Therapy 01/2008; 19(4):386-92; discussion 393-4.
  • Journal of Surgical Research - J SURG RES. 01/2008; 144(2):331-332.
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    ABSTRACT: We sought to describe modes of failure and associated limb loss after infrainguinal polytetrafluoroethylene bypass grafting in patients lacking a saphenous venous conduit and to define specific clinical or hemodynamic factors prognostic for bypass failure. We identified 121 patients (mean age, 67 years; 90 men and 31 women) with determinable outcomes (minimum follow-up, 2 months; mean, 17 months) after 130 prosthetic infrainguinal bypasses between 1997 and 2005. Ischemic presentation was rest pain in 52%, tissue loss in 34%, and disabling claudication and/or popliteal aneurysm in 14%, with 24% of patients requiring a redo bypass. Distal targets were the above-knee (n = 44), distal popliteal (n = 27), or tibial/pedal (n = 59) arteries. Sixty-six (77%) of the below-knee (BK) target (distal popliteal or tibial) bypasses had distal anastomotic adjuncts (vein cuff or patch). Duplex graft surveillance was performed at 1, 4, and 7 months after surgery and twice yearly thereafter, with recording of midgraft velocities and imaging encompassing inflow and outflow vessels. Arteriography and open/endovascular intervention was performed for stenoses identified by duplex scanning (peak systolic velocity >300 cm/s; velocity ratio >3.5). An attempt was made to salvage occluded grafts by using catheter-directed thrombolysis or open techniques. Eighty-six patients (74% of BK bypasses) were placed on chronic warfarin therapy with a target international normalized ratio range between 2 and 3. Prognostic factors were identified by using univariate statistics and multivariate logistic regression analysis. Three-year primary, assisted, and secondary patency rates were 39%, 43%, and 59%, respectively, for all bypasses, with no difference noted between above-knee and BK grafts (P = .5). At 3 years, freedom from limb loss was 75%, and patient survival was only 70%, with no adverse effect on survival imparted by amputation. Sixty-nine total adverse events occurred as a result of thrombotic occlusion (n = 51), duplex scan-detected stenosis (n = 13), or graft infection (n = 5). Forty-nine percent of all initial graft occlusions eventually led to amputation. Twenty-three grafts (27% of 86 patients) in patients maintained on chronic warfarin were subtherapeutic at the time of occlusion. Use of a distal anastomotic adjunct with BK bypasses reduced graft thrombosis (35% with vs 60% without) but did not impart a significant patency advantage (P = .07). Multivariate analysis revealed low graft flow (midgraft velocity < or =45 cm/s; odds ratio [OR], 6.1; 95% confidence interval [CI], 1.9-19.2), use of warfarin (OR, 8.4; 95% CI, 2.1-34.5), and therapeutic warfarin (OR, 24.6; 95% CI, 5.7-106) to be independently predictive for bypass patency. Graft patency was maintained in 89% of grafts remaining therapeutic on warfarin compared with only 55% of subtherapeutic or nonanticoagulated grafts (P < .001). Low-flow grafts (n = 61) occluded more frequently than higher-flow grafts (46% vs 13%; P < .001). Therapeutic warfarin augmented the patency of low-flow (P < .001) but not high-flow (P = .15) grafts. Low graft flow was a more common mode of prosthetic bypass failure than development of duplex scan-detected stenotic lesions during follow-up. Early duplex scanning may be more important for characterizing midgraft velocity and related thrombotic potential and selecting patients for chronic anticoagulation. Maintenance of therapeutic warfarin is paramount in optimizing prosthetic bypass patency and limb preservation.
    Journal of Vascular Surgery 12/2007; 46(6):1160-6. · 2.88 Impact Factor
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    ABSTRACT: A duplex ultrasound (DUS) surveillance algorithm used after carotid endarterectomy (CEA) was applied to patients after carotid stenting and angioplasty (CAS) to determine the incidence of high-grade stent stenosis, its relationship to clinical symptoms, and the outcome of reintervention. In 111 patients who underwent 114 CAS procedures for symptomatic (n = 62) or asymptomatic (n = 52) atherosclerotic or recurrent stenosis after CEA involving the internal carotid artery (ICA), DUS surveillance was performed <or=30 days and every 6 months thereafter. High-grade stenosis (peak systolic velocity [PSV] >300 cm/s, diastolic velocity >125 cm/s, internal carotid artery stent/proximal common carotid artery ratio >4) involving the stented arterial segment prompted diagnostic angiography and repair when >75% diameter-reduction stenosis was confirmed. Criteria for >50% CAS stenosis was a PSV >150 cm/s with a PSV stent ratio >2. All 114 carotid stents were patent on initial DUS imaging, including 90 (79%) with PSV <150 cm/s (94 +/- 24 cm/s), 23 (20%) with PSV >150 cm/s (183 +/- 34 cm/s), and one with high-grade, residual stenosis (PSV = 355). During subsequent surveillance, 81 CAS sites (71%) exhibited no change in stenosis severity, nine sites demonstrated stenosis regression to <50% diameter reduction, and five sites developed velocity spectra of a high-grade stenosis. Angiography confirmed >75% diameter reduction in all six CASs with DUS-detected high-grade stenosis, all patients were asymptomatic, and treatment consisted of endovascular (n = 5) or surgical (n = 1) repair. During the mean 33-month follow-up period, three patients experienced ipsilateral, reversible neurologic events at 30, 45, and 120 days after CAS; none was associated with severe stent stenosis. No stent occlusions occurred, and no patient with >50% CAS stenosis on initial or subsequent testing developed a permanent ipsilateral permanent neurologic deficit or stroke-related death. DUS surveillance after CAS identified a 5% procedural failure rate due to the development of high-grade in-stent stenosis. Both progression and regression of stent stenosis severity was observed on serial testing, but 70% of CAS sites demonstrated velocity spectra consistent with <50% diameter reduction. The surveillance algorithm used, including reintervention for asymptomatic high-grade CAS stenosis, was associated with stent patency and the absence of disabling stroke.
    Journal of Vascular Surgery 09/2007; 46(3):460-5; discussion 465-6. · 2.88 Impact Factor
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    ABSTRACT: Outcome data documenting safety for observation of small abdominal aortic aneurysms (AAA 4.0 to 5.4 cm) are lacking outside of large clinical trials but requires near perfect patient compliance. This study describes a clinical pathway for AAA surveillance using a prospective database utilizing a nurse practitioner oversight to provide efficient use of clinic visits while maintaining a high level of patent participation. Over a 7-year period (June 1999 through June 2006), 334 patients were enrolled in an AAA surveillance pathway at our academic veterans hospital. To minimize patient travel, clinic visitation was reserved for an initial examination with patient education and for discussion of intervention options in patients demonstrating AAA growth (>5.4 cm or expansion >1 cm/yr) during follow-up. Biannual ultrasound or CT imaging was scheduled and results discussed (after physician review) via telephone or "same day" direct patient contact. An electronic database was used to update patient information and plan follow-up. Compliance with the AAA surveillance pathway was achieved in 98.5% of patients, with only three patients (0.9%) lost to follow-up and two others (0.6%) choosing early repair at civilian institutions. At a mean interval of 29 months (+/-20 mo), surgical repair was performed in 225 (67%) patients by open (n = 143) or endovascular (n = 82) techniques for AAA growth to >5.4 cm (n = 219) or expansion by >1cm/yr (n = 6). One hundred six patients currently remain in surveillance. A single AAA rupture resulting in death occurred during surveillance (0.3%) and perioperative mortality (<60 days) was 0.9% in patients needing intervention for AAA growth. Cumulative aneurysm-related mortality was 0.9% for patients compliant with the AAA surveillance pathway. Use of a prospectively-maintained surveillance database managed by a non-physician provider with a reliance on telephone contact resulted in a high degree of patient compliance, reduced unnecessary patient travel, and provided practical clinic use. Limited additional resources were needed to implement our pathway and a similar approach may prove useful for large volume hospital, clinic, or practice systems.
    Journal of Vascular Surgery 09/2007; 46(2):190-5; discussion 195-6. · 2.88 Impact Factor

Publication Stats

406 Citations
53.39 Total Impact Points


  • 2004–2014
    • University of South Florida
      • • Division of Vascular and Endovascular Surgery
      • • Department of Urology
      Tampa, Florida, United States
  • 2012
    • Tampa General Hospital
      Tampa, Florida, United States
  • 2008
    • West Virginia University
      • Division of Vascular and Endovascular Surgery
      Morgantown, WV, United States