Faculty Bibliography

OBJECTIVE: The aim of this study was to determine the benefit of lower extremity CT venography (CTV) with pulmonary CT angiography (CTA) for diagnosing thromboembolic (TE) disease. SUBJECTS AND METHODS: Reports of all CTAs and CTVs over a 3-year interval (Group I) and CTAs, CTVs, and lower extremity Doppler ultrasounds (US) over a 1 1/2-year subset (Group II) were reviewed. Patient population was inpatients and emergency department patients who were assessed for pulmonary embolism (PE) and deep venous thrombosis (DVT) at a tertiary care hospital. Reported results for CTA or CTV were categorized as positive (CTA(P), CTV(P)), negative (CTA(N), CTV(N)), or indeterminate for PE or DVT. When CTV and US results were discrepant, medical records were reviewed for clinical management. Additional benefit of CTV was assessed by chi-square analysis. RESULTS: In Group I, 737 (81.1%) of 909 CTAs from combined CTA/CTV studies were negative. The diagnosis rate of TE disease increased from 13.0% to 17.3% with the addition of CTV(P)s (P=.01). Of the 119 cases in Group II undergoing combined CTA, CTV, and US, CTV and US were both positive in eight and both negative in 88. Of the seven discordant CTVs and USs with clinical follow-up, five CTVs were positive while USs were negative, three of which were treated clinically for TE disease, while two were considered falsely positive. As CTA also proved positive in one of the three, CTV therefore affected management in two of these five cases and increased the rate of thromboembolism diagnosis from 21.0% to 22.6%; however, this was not significant (P>.05). Two CTV(N)s were managed as false negatives. CONCLUSIONS: The combined use of CTA and CTV significantly increases the rate of TE disease over CTA alone. In cases in which ultrasound is performed, however, there is no significant advantage to performing combined CTA/CTV studies

Ischemic complications after endovascular abdominal aortic aneurysm repair (EVAR) are well-recognized and have been reported to be as high as 9%. The goal of our study was to examine the incidence, management, and outcome of ischemic complications at our institution after EVAR and to compare complications according to graft type and time period. This is a retrospective review of all EVARs performed at our institution from 1993 through 2005 (n = 430). EVAR was performed in asymptomatic patients in most cases. Follow-up consisted of a computed tomography scan and office visit at 1, 6, and 12 months and yearly thereafter. Ischemic complications after EVAR have decreased significantly with the advent of lower-profile devices with easier delivery systems and supported limbs. Simultaneous coil embolization of internal iliac artery at the time of EVAR implant does not appear to increase the risk of pelvic or lower-extremity ischemia, can be done safely, and does not need to be staged

OBJECTIVE: To compare the 2-dimensional time of flight, the 3-dimensional time-resolved contrast-enhanced magnetic resonance (MR) angiography, and the 3-dimensional 3-station bolus chase contrast-enhanced MR angiography in assessing distal station atherosclerosis. METHODS: Two-dimensional time of flight, 3-dimensional time-resolved contrast-enhanced MR angiography, and 3-dimensional bolus chase contrast-enhanced MR angiography were performed from the knees to the metatarsal heads of 40 patients. Blinded to the patients' identity, 2 readers independently reviewed the 3 sequences in random order; differences were resolved by consensus. Anterior tibial, peroneal, and posterior tibial arterial lengths to the talar dome were scored as follows: 1, greater than 50% of the length of a normal artery; 2, less than 50%; and 3, total occlusion. Stenoses were scored as follows: 1, less than 50%; and 2, greater than 50%. The pedal vessels (dorsalis pedis, posterior tibial, and plantar pedal arch arteries) were scored as follows: 1, less than 50% stenosis; and 2, greater than 50% stenosis. The reference standard was a combined interpretation of all 3 sequences by both readers in consensus. RESULTS: For the 240 calf segments scored for length, concordance with reference assessment was poorer for the time of flight than for either the bolus chase or time-resolved angiography (P = 0.0021 and P = 0.0082, respectively), and the latter two were statistically indistinguishable. For stenosis grading of the 461 calf and pedal segments, the time-resolved and bolus chase methods were superior to the time of flight (P = <0.0001 and P = 0.0041, respectively), and the contrast-enhanced methods were statistically indistinguishable. CONCLUSIONS: Both contrast-enhanced time-resolved and bolus chase MR angiography are superior to the time of flight in diagnosing distal station peripheral vascular disease

OBJECTIVE: The optimal timing of carotid endarterectomy (CEA) after ipsilateral hemispheric stroke is controversial. Although early studies suggested that an interval of about 6 weeks after a completed stroke was preferred, more recent data have suggested that delaying CEA for this period of time is not necessary. With these issues in mind, we reviewed our experience to examine perioperative outcome with respect to the timing of CEA in previously symptomatic patients. METHODS: A retrospective review of a prospectively maintained database of all CEAs performed at our institution from 1992 to 2003 showed that 2537 CEA were performed, of which 1,158 (45.6%) were in symptomatic patients. Patients who were operated on emergently <or=48 hours of symptoms for crescendo transient ischemic attacks (TIAs) or stroke-in-evolution were excluded from analysis (n = 25). CEA was considered 'early' if performed <or=4 weeks of symptoms, and 'delayed' if performed after a minimum of a 4-week interval following the most recent symptom. RESULTS: Of nonurgent CEAs in symptomatic patients, in 87 instances the exact time interval from symptoms to surgery could not be precisely determined secondary to the remoteness of the symptoms (>18 months), and these were excluded from further analysis. Of the remaining 1,046 cases, 62.7% had TIAs and 37.3% had completed strokes as their indication for surgery. Among the entire cohort, patients who underwent early CEA were significantly more likely to experience a perioperative stroke than patients who underwent delayed CEA (5.1% vs 1.6%, P = .002). Patients with TIAs alone were more likely to be operated on early rather than in a delayed fashion (64.3% vs 46.7%, P < .0001), likely reflecting institutional bias in selecting delayed CEA for stroke patients. However, even when examined as two separate groups, both TIA patients (n = 656) and CVA patients (n = 390) were significantly more likely to experience a perioperative stroke when operated upon early rather than in a delayed fashion (TIA patients, 3.3% vs 0.9%, P = .05; CVA patients, 9.4% vs 2.4%, P = .003). There were no significant differences in demographics or other meaningful variables between patients who underwent early CEA and those who underwent delayed CEA. CONCLUSIONS: In a large institutional experience, patients who underwent CEA <or=4 weeks of ipsilateral TIA or stroke experienced a significantly increased rate of perioperative stroke compared with patients who underwent CEA in a more delayed fashion. This was true for both TIA and stroke patients, although the results were more impressive among stroke patients. On the basis of these results, we continue to recommend that waiting period of 4 weeks be considered in stroke patients who are candidates for CEA

Physicians in residency training will be the referring physicians of tomorrow. We sought to determine the current surgical and medical trainees' perception of vascular surgery's endovascular qualifications and capabilities. An anonymous survey was sent to all general surgery and internal medicine residents at a single academic institution. Respondents answered the question 'Which specialty is the most qualified to perform (1) inferior vena cava (IVC) filter insertion; (2) angiograms, angioplasty, and stenting of the carotid arteries; (3) renal arteries; (4) aorta; and (5) lower extremity arteries?' For each question, respondents chose one response, either vascular surgery, interventional radiology, interventional cardiology, or do not know. One hundred respondents completed the survey (general surgery, n=50; internal medicine, n=50). There was a significant difference in the attitudes of surgery and medicine residents when choosing the most qualified endovascular specialist (p<0.05). Surgery residents chose vascular surgery as the most qualified specialty for each listed procedure: carotid (80%, n=40), IVC (56%, n=28), aorta (100%, n=50), extremity (86%, n=43), renal (78%, n=39). Medicine residents chose vascular surgery as the most qualified specialty less frequently: carotid (66%, n=33), IVC (6%, n=3), aorta (88%, n=44), extremity (72%, n=36), renal (16%, n=8). There was no significant difference in specialty selection based on postgraduate year. There is a large discrepancy between surgical and medical trainees' perception of vascular surgery's endovascular abilities, particularly regarding IVC placement and renal artery interventions. If our own institution mirrors the nation, each passing year a significant portion of the 21,722 graduating internal medicine residents go into practice viewing vascular surgeons as second-tier endovascular providers. A concerted campaign should be undertaken to educate medical residents regarding the skills and capabilities of vascular surgeons

OBJECTIVES: The diagnosis and treatment of carotid artery disease is an integral part of stroke prevention. However, a population of patients who would benefit from screening for carotid artery stenosis has not been well defined. As part of an institutional stroke-screening program, a modified, rapid duplex scan was developed to evaluate patients for occult carotid stenosis. The goal of this study was to evaluate risk factors predictive of carotid stenosis in a selected population, and to identify patients who would benefit from carotid screening. METHODS: Patients were eligible for the study if they were >60 years of age and had a history of hypertension, heart disease, current smoking, or family history of stroke. A modified carotid duplex scan that had been previously validated against formal duplex scanning was utilized; this involved visualization of the carotid bulb and proximal internal carotid artery where Doppler flow velocities were obtained and recorded. RESULTS: Screening was performed on 394 patients. Thirty-eight patients (9.6%) had either unilateral or bilateral carotid stenosis of > or =50%. Risk factors evaluated included smoking, hypertension, cardiac disease, or hypercholesterolemia. If none of these risk factors was present, the incidence of carotid stenosis was 1.8%. This increased to 5.8% with one risk factor, 13.5% with two risk factors, and 16.7% with three risk factors. Two of three patients with all four risk factors had carotid stenosis (66.7%). Logistic regression and prespecified contrast statements for multiple comparisons were used to assess the relationship between the presence of risk factors and occult carotid artery stenosis. The presence of any one of these risk factors was associated with a statistically significant increase in the presence of occult carotid stenosis (P <.01). This was also statistically significant for the presence of any two risk factors (P <.01) or three risk factors (P <.05). CONCLUSION: The prevalence of carotid stenosis significantly increases with the presence of one or more identifiable demographic risk factors in a selected population. Assuming the diagnosis and treatment of carotid stenosis are fundamental to stroke prevention, screening for carotid artery disease is justified in this group of patients

OBJECTIVES: Postoperative infection is one of the most dreaded complications associated with use of synthetic patches for carotid endarterectomy. Although polyester patches were used extensively for carotid patch angioplasty throughout the last decade, few reports detail cases of deep patch infection. We describe our experience with polyester patch infections after carotid endarterectomy.Patients and methods From January 1996 through December 2001 we treated polyester patch infections after carotid endarterectomy in 10 patients. RESULTS: The interval from primary carotid endarterectomy to presentation with infection ranged from 11 days to 30 months. All patients underwent repeat operation that involved tissue debridement, excision of the polyester patch, and either interposition grafting or patch angioplasty with autologous vein. No perioperative stroke or death occurred; however, 1 patient had transient hoarseness, and in 1 patient a pseudoaneurysm developed that required additional surgical repair with a saphenous vein interposition graft. All patients remain well and free of infection with follow-up as long as 56 months. CONCLUSIONS: Infection is a serious and rare complication of carotid patch angioplasty with polyester material. Nonetheless, it can be treated successfully with good results and acceptable morbidity with soft tissue debridement, prosthetic patch excision, and either patch angioplasty or interposition grafting with autologous vein

OBJECTIVE: Total occlusion of the contralateral internal carotid artery has often been considered to be a predictor of poor outcome after carotid endarterectomy (CEA) of ipsilateral carotid stenosis. Data from both the North American Symptomatic Carotid Endarterectomy Trial and the Asymptomatic Carotid Atherosclerosis Study have suggested this to be true. However, each of these trials had relatively few patients with contralateral occlusion in the surgical arms of the studies. Recently, advocates of carotid angioplasty and stenting have suggested that this technique may be preferable in patients with a contralateral occlusion because of the perceived poor outcome with surgery. The purpose of this study was to review a large series of CEAs performed in patients with contralateral occlusion to see whether results differed from patients with patent contralateral arteries and to determine whether the presence of preoperative symptoms was an important factor in outcome in these cases. PATIENTS AND METHODS: A review was conducted of a prospectively compiled database of all primary CEAs performed at our institution from 1985 to 1999. Surgery was performed on 2420 patients, of whom 338 (14.0%) had contralateral total occlusion. RESULTS: Patients with contralateral total occlusion were more likely to be symptomatic (65.7% versus 60.1%; P =.1), male (70.9% versus 58%; P <.001), and hypertensive (63.9% versus 58.4%; P =.07) with a positive smoking history (42.6% versus 31.4%; P <.001) than patients with patent contralateral carotid artery. No significant difference was seen in the rates of perioperative neurologic events between patients with contralateral occlusion (3.0%) and those without (2.1%; P =.34). Among the total of 913 asymptomatic patients, of whom 115 had contralateral occlusion, no difference was seen in the rate of perioperative neurologic events (1.8% for contralateral occlusion cases; 1.9% for cases without contralateral occlusion). Among the total of 1507 symptomatic patients, of whom 223 had contralateral occlusion, no significant difference was seen in the rate of perioperative neurologic events (3.7% for contralateral occlusion cases; 2.2% for cases without contralateral occlusion; P =.2). CONCLUSION: The presence of contralateral occlusion does not appear to increase the perioperative risk of CEA. Although the risk of CEA in symptomatic patients with contralateral occlusion may be slightly increased, this must be weighed against the risk with medical treatment alone. CEA can be performed safely in patients with contralateral occlusion, which should not necessarily be considered a high-risk condition for surgery in favor of angioplasty and stenting

Since the Food and Drug Administrations' approval of endovascular devices for abdominal aortic aneurysm (AAA) repair, clinicians have been relaxing the strict inclusion criteria present during the clinical trials. Although the long-term natural history of endoleaks remains unclear, attachment site leaks (type I) are believed to represent an ongoing risk for future rupture. We reviewed our experience with endovascular AAA repair to elucidate factors that predispose toward the development of endoleaks and found that larger AAAs are significantly more likely to have a short proximal neck and severe proximal angulation. These factors likely contribute to the significantly increased rate of type I endoleaks that occurred after endovascular repair of large AAAs. Small AAAs (<5) had the lowest rate of endoleaks overall (8.3%) and of type I endoleaks in particular (0%). We conclude that AAA size and morphology can be used to predict which aneurysms will experience attachment site endoleaks in their course; AAAs from 4.5 to 5 cm in diameter may be particularly well suited for endovascular repair in this regard