Faculty Bibliography

BACKGROUND: In previous studies, we found that approximately 25% of patients having carotid endarterectomy with general anesthesia (CEA general) develop cognitive dysfunction compared with a surgical control Group 1 day and 1 mo after surgery. In this study, we tested the hypothesis that patients having CEA with regional anesthesia (CEA regional) will develop significant cognitive dysfunction 1 day after surgery compared with a control group of patients receiving sedation 1 day after surgery. We did not study persistence of dysfunction. METHODS: To test this hypothesis, we enrolled 60 patients in a prospective study. CEA regional was performed with superficial and deep cervical plexus blocks in 41 patients. The control group consisted of 19 patients having coronary angiography or coronary artery stenting performed with sedation. A control group is necessary to account for the 'practice effect' associated with repeated cognitive testing. The patients from the CEA regional group were enrolled at New York Medical Center and the control group at Columbia-Presbyterian Medical Center. The cognitive performance of all patients was evaluated using a previously validated battery of neuropsychometric tests. Differences in performance, 1 day after compared with before surgery, were evaluated by both event-rate and group-rate analyses. RESULTS: On postoperative day 1, 24.4% of patients undergoing CEA regional had significant cognitive dysfunction, where 'significant' was defined as a total deficit score > or =2 SD worse than the mean performance in the control group. CONCLUSIONS: Patients undergoing CEA regional had an incidence of cognitive dysfunction which was not different than patients having CEA general as previously published and compared with a contemporaneously enrolled group

PURPOSE: Clinical decision making for carotid surgery depends largely upon stenosis grade. While digital subtraction angiography remains the gold standard for stenosis grading, many physicians use less invasive modalities. The purpose of this study was to compare the results of multidimensional Computed tomography (CTA) with ultrasound (US) grading and peak flow velocity (PSV). METHODS: 37 stenosed carotid arteries were studied retrospectively in 36 consecutive patients. US grading and PSV were compared to multidimensional CTA analysis (diameter, area and volumetric measurements), performed by a medical software company. Calculations of stenosis percentage on CTA were made using the NASCET and ECST methodology. Diameter measurements were also performed by a neuroradiologist. RESULTS: All CTA diameter, area and volume measurements had only modest correlation with PSV (r<0.5) and ultrasound grading (p<0.5). There was concordant classification of stenosis grades in only 40-60% of cases. CTA diameter, area and volume measurements had good correlation (0.69<r<0.87) with one another using ECST methodology. Using NASCET methodology on CTA, correlation between diameter and area was insignificant (r=0.32). CTA volumetric analysis with the NASCET method yielded 27 negative stenosis grades. Repeatability coefficient for selecting the normal distal ICA 20 mm more distally was 20% for diameter and 43% for area. CTA diameter interobserver repeatability coefficients were 22.9% (NASCET) and 17.8% (ECST) and 0.7 mm (lumen) and 1.9 mm (vessel). CONCLUSIONS: All CTA measurements showed moderate correlation with both ultrasound grading and PSV. Selection of the level of the normal distal ICA influences the NASCET calculations and can produce discrepant stenosis grades. Multidimensional CTA analysis seems to have no additional value for stenosis grading, but provides other useful anatomic information

Durable vascular access for hemodialysis remains a critical issue in end-stage renal disease patients. Creation of an autogenous arteriovenous (AV) fistula in the most distal location of the nondominant extremity is the preferred technique and provides superior patency over an AV graft. Others have shown that regional anesthesia in the form of axillary block results in the dilatation of the native veins and allows for their increased utilization in creating AV fistulae. We report on 26 patients undergoing creation of a vascular access for hemodialysis. Regional anesthesia consisting of axillary nerve block was used in all cases. All surgical plans with regard to the site and type of access were made based on the physical exam and ultrasound vein measurements taken prior to surgery. On the day of surgery patients were reevaluated with venous ultrasound using tourniquet before and after administration of the regional block. The previously determined operative plan either remained unchanged or was modified depending on the venous dilatation noted after administration of regional block. Among 26 patients, average vein diameter increased from 0.29 +/- 0.12 cm to 0.34 +/- 0.11 cm (P = 0.008). Twenty-one of 26 patients had no modification in operative plan (group 1). Five had some modification of the original operative plan (group 2): AV graft to a brachial vein transposition (n = 2), AV graft to a Cimino fistula (n = 2), and brachiocephalic to a Cimino (n = 1). The average follow-up for all patients was 82.6 +/- 75.6 days and did not differ between the groups. There was one failure in a patient from group 1, and there was no significant difference in the patency rate between study groups (P = 0.29). Following regional nerve block, operative plans in patients undergoing AV access surgery were modified in 29.4% of patients undergoing creation of an AV access for hemodialysis; either from graft to fistula creation or from the proximal to more distal fistula site. The routine use of regional anesthesia as well as intraoperative ultrasound during AV access surgery can lead to improved site selection and increased opportunity for AV fistula creation

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

Determination of degree of carotid artery stenosis is of critical importance when deciding whether a patient warrants surgical intervention. While angiography is still considered by some to be the true reference standard for imaging the internal carotid artery (ICA), physicians rely most commonly on duplex imaging when planning for endarterectomy. It is noninvasive, safe, and overall reliable for grading stenosis but is nevertheless user-dependent and can be limited in cases of severe calcification. Moreover, a lack of consensus for duplex criteria can be confounding. In recent years, magnetic resonance angiography (MRA) and computed tomographic angiography (CTA) have assumed a more prominent role in the preoperative planning for treatment of carotid stenosis. Improved resolution and faster acquisition times for both of these imaging modalities have allowed for accurate depictions of degree of stenosis, as well as plaque characterization. CTA and MRA may have special relevance in the era of carotid stenting, since challenging arch anatomy and identification of a high-risk vulnerable plaque may be useful when deciding whether to perform a stent procedure or endarterectomy

Approval for this HIPAA-compliant study was obtained from the institutional review board; informed consent was not required for retrospective review of patient studies that had been performed for clinical evaluation. The purpose of this study was to retrospectively compare the accuracy of intrastent luminal diameter, as measured on transverse computed tomographic (CT) angiograms and virtual angioscopic views, with the manufacturer's specifications for phantom diameter and with digital subtraction angiographic (DSA) measurements of stent diameter obtained in patients. Intrastent diameter was measured by using standard and stent-optimized reconstruction kernels with three window settings. Endoluminal virtual angioscopic views of the stent-containing vessels were also generated. Measurements at CT angiography were compared with known specifications for the phantom and with DSA measurements in patients. Erroneous measurements of intrastent diameter occurred when a standard kernel and nonoptimized window settings were used. A set of parameters that minimized error relative to measurements obtained at DSA was also identified. Virtual angioscopy helped demonstrate morphologic aspects of stenosis that were otherwise difficult to appreciate

Lower extremity wounds resulting from ischemia are increasingly becoming a common indication for surgical revascularization. Techniques in minimally invasive vascular surgery for the treatment of lower extremity chronic ischemia have expanded rapidly in recent years. The current standard of care with which all new modalities should be compared is the restoration of arterial flow via direct arterial revascularization using the autogenous reversed saphenous vein that can yield limb salvage rates of approximately 95%. Percutaneous transluminal angioplasty and stenting (PTA/S), cryoplasty, catheter-directed atherectomy, laser-assisted PTA/S, drug-eluting stents, and subintimal angioplasty are emerging minimally invasive modalities used for the treatment of lower extremity ischemia. Early success rates using many of these techniques have been promising. The outcomes of randomized controlled trials with long-term follow-ups are needed to make confident remarks about the effectiveness of these techniques

Partial foot amputations have become increasingly prevalent among long-lived diabetic patients. These patients have lower extremity neuropathy and are prone to ulceration at their amputation site. These ulcers are difficult to heal, and they place a significant financial and resource burden on the healthcare system. We examined the efficacy of total-contact casts (TCC) in diabetic amputees with nonhealing partial foot amputation site neuropathic ulcers. Data were collected retrospectively on all patients with amputations who were treated with a total-contact cast between December 2000 and December 2003. Seventeen patients (13 men, 4 women) with amputation site ulceration were identified. All patients were diagnosed with neuropathy secondary to diabetes and none had wound healing compromised by ischemia. The initial ulcer averaged 1,169 mm(2) with a depth of 2.77 mm. Patients were treated with an average of 7.9 cast applications over 8.4 weeks; 47% (8/17) of ulcers healed, but 29% (5/17) of patients were unable to complete their recommended treatment course secondary to complications from the TCC. Of the patients who were able to complete their treatment course, the healing rate was 66.7% (8/12). The recurrence rate for healed ulcers was 63% (5/8). Partial foot amputations with neuropathic ulcers present a very difficult problem to the vascular surgeon. Patient compliance and underlying medical comorbidities limit the success rate. In patients who can complete a TCC treatment course, good short term results can be expected. However, recurrence rates are high following discontinuation of mechanical TCC off-loading

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