Faculty Bibliography

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

A variety of intraoperative imaging and assessment techniques can be used during carotid endarterectomy (CEA) to evaluate the technical results of the arterial repair. However, the necessity of utilizing these techniques routinely in every case, and the actual ability of these studies to improve the outcomes of the operation, remain areas of controversy. The most commonly used intraoperative assessment techniques include arteriography, duplex ultrasonography, and use of a hand-held continuous-wave Doppler probe. While surgeons who advocate intraoperative imaging presume that it will ultimately improve the technical 'perfection' of the operation by allowing the intraoperative identification and immediate revision of occult technical defects that would likely predispose toward perioperative stroke, there is little comparative data in the literature to support this premise. Proponents of routine intraoperative assessment argue that the identification of technical imperfections will allow their immediate correction prior to a perioperative stroke resulting from thromboembolization. In addition, surgeons who use these techniques believe that the presumed reduction in rate of serious technical errors will also result in a lower rate of recurrent carotid stenosis. However, many experienced vascular surgeons who perform CEA do not routinely utilize any of these intraoperative assessment techniques, and report equally excellent results using meticulous technique alone and clinical inspection of the endarterectomy site and arterial repair. Potential issues that may arise when performing routine intraoperative assessment can include: making a determination of which type of 'imperfections' actually require immediate revision of the arterial repair, and potential vascular injuries or cerebral ischemia associated with reclamping of the artery in order to perform an immediate revision. In an analysis of a large, population-based cohort study of CEAs, the authors have found no compelling evidence that routine use of these imaging techniques confers any advantage in terms of the perioperative outcomes of carotid endarterectomy. Conclusions: the majority of surgeons who perform carotid endarterectomy do not routinely utilize any formal intraoperative completion imaging or assessment technique during CEA, other than clinical inspection of the arterial repair. However, even among vascular surgeons, less than 50% are routinely using intraoperative imaging or assessment. The routine use of intraoperative imaging studies did not appear to significantly improve perioperative outcomes with regard to ipsilateral perioperative stroke, and stroke/death. Considering the increased time and cost of performing these procedures, routine use of intraoperative imaging and assessment techniques during CEA is of questionable value. Selective use of these imaging or assessment techniques when the surgeon has a specific concern regarding the technical outcomes of the operation appears to be a reasonable alternative

OBJECTIVE: Most studies on outcomes of carotid endarterectomy (CEA) have focused on the major complications of death and stroke. Less is known about minor but more common surgical complications such as hematoma, cranial nerve palsy, and wound infection. This study used data from a large, population-based cohort study to describe the incidence of minor surgical complications after CEA and examine associations between minor and major complications. METHODS: The New York Carotid Artery Surgery (NYCAS) study examined all Medicare beneficiaries who underwent CEA from January 1998 to June 1999 in NY State. Detailed clinical information on preoperative characteristics and complications < or =30 days of surgery was abstracted from hospital charts. Associations between minor (cranial nerve palsies, hematoma, and wound infection) and major complications (death/stroke) were examined with chi(2) tests and multivariate logistic regression. RESULTS: The NYCAS study had data on 9308 CEAs performed by 482 surgeons in 167 hospitals. Overall, 10% of patients had a minor surgical complication (cranial nerve (CN) palsy, 5.5%; hematoma, 5.0%; and wound infection, 0.2%). Cardiac complications occurred in 3.9% (myocardial 1.1%, unstable angina 0.9%, pulmonary edema 2.1%, and ventricular tachycardia 0.8%). In both unadjusted and adjusted analyses, the occurrence of any minor surgical complication, CN palsy alone, or hematoma alone was associated with 3 to 4-fold greater odds of perioperative stroke or combined risk of death and nonfatal stroke (P < 0.0001). Patients with cardiac complications had 4 to 5-fold increased odds of stroke or combined risk of death and stroke. CONCLUSION: Minor surgical complications are common after CEA and are associated with much higher risk of death and stroke. Patient factors, process factors, and direct causality are involved in this relationship, but future work will be needed to better understand their relative contributions

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