Faculty Bibliography

Accurate patient selection based on preoperative imaging is imperative to good risk reduction in patients undergoing carotid endarterectomy (CEA). The goal of this study was to assess the accuracy of gadolinium-enhanced magnetic resonance angiography (GE MRA) versus time-of-flight (TOF) MRA in the work-up of patients undergoing CEA. Patients undergoing CEA between 1999 and 2001 were identified from a prospectively maintained institutional database. GE or TOF MRA was obtained on extracranial carotid arteries (n = 319) in patients undergoing CEA. Stenosis on MRA images was graded as moderate (n = 76) or severe (n = 243) by an attending radiologist who was blind to duplex results. Duplex imaging was performed in an Intersocietal Commission for the Accreditation of Vascular Labs (ICAVL) accredited lab, and stenosis was stratified as moderate (50-79%, n = 76) or high (80-99%, n = 243) grade using University of Washington criteria. For each patient, the degree of stenosis as determined by MRA (GE versus TOF) was compared to percent stenosis on duplex. For moderate-grade lesions, GE MRA concurred with duplex in 11.1% (4/36), underestimated in 2.8% (1/36), and overestimated in 86.1% (31/36) of carotid arteries imaged. TOF MRA concurred with duplex in 35% (14/40), underestimated in 0% (0/40), and overestimated in 65% (26/40) of carotid arteries. High-grade lesions demonstrated improved concordance between MRA and duplex. For these lesions, GE MRA concurred with duplex in 95.6% (130/136) of carotid arteries imaged, never overestimated stenosis (0/136), and underestimated in 4.4% (6/136). TOF MRA concurred with duplex 96.3% (103/107), overestimated stenosis as an occlusion in 0.9% (1/107), and underestimated in 2.8% (3/107). In addition to neck visualization, the GE technique allowed simultaneous aortic arch imaging. This was accomplished in 79.1% (136/172) of all GE MRAs. Simultaneous aortic arch imaging was not technically feasible with TOF MRA. For moderate-grade lesions, both MR techniques are inaccurate predictors of degree of carotid stenosis and result in a significant overestimation of stenosis. Each technique demonstrates improved concordance with duplex ultrasound in the setting of severe carotid artery stenoses. The ability of GE MRA to simultaneously image the aortic arch and the neck may allow for detection of occult tandem lesions and other anatomic variations, which may be particularly important in preoperative planning for carotid artery stenting

OBJECTIVES: Patients with diabetes mellitus have been shown to have an increased incidence of complications after elective major vascular surgery. The objective of this study was to evaluate a large series of diabetic patients undergoing carotid endarterectomy (CEA) to determine if outcome differed from nondiabetic patients and to examine predisposing factors of poor outcome among diabetic patients. METHODS: A retrospective review of a prospectively compiled database was performed. From 1992 through 2000, 2151 CEAs were performed at our institution. Of these, 507 were in diabetic patients (23.6%), and the remaining 1644 procedures were in nondiabetic patients (76.4%). RESULTS: Diabetic patients were significantly more likely than nondiabetic patients to have hypertension (70.8% vs 64.5%, P = .01) and cardiac disease (54.6% vs 49.1%, P = .03). They were more likely than nondiabetic patients to be symptomatic before surgery (52.5% vs 47.1%, P = .04) and to have sustained a preoperative stroke (21.3% vs 17.7%, P = .07). No differences were noted in other recorded demographic factors or in intraoperative factors between diabetic and nondiabetic patients. Despite these differences, diabetic patients had similar perioperative outcomes compared with nondiabetic patients, including perioperative myocardial infarction (0.6% vs 0.4%, P = NS), perioperative death (0.8% vs 0.5%, P = NS), and perioperative neurologic events such as transient ischemic attack and stroke (3.2% vs 2.4%, P = NS). Among diabetic patients alone, cigarette smoking, general anesthesia, the use of a shunt, and the lack of clamp tolerance while under regional anesthesia predicted adverse perioperative neurologic outcome, and contralateral occlusion was associated with increased perioperative mortality. CONCLUSIONS: Despite an increased prevalence of cardiac disease and preoperative neurologic symptoms among diabetic patients undergoing CEA, the rates of perioperative cardiac morbidity, mortality, and stroke were equal to nondiabetic patients. In contrast to nondiabetic patients, current cigarette smoking appeared to predict increased adverse neurologic outcomes among diabetic patients, and the presence of contralateral occlusion among diabetic patients appeared to predispose them towards increased perioperative mortality. The use of a general anesthetic appeared to increased perioperative neurologic risk among diabetic patients; however, this may be related to surgeon bias in the selection of anesthetic technique. Although diabetic patients may have an increase in complications after other major vascular surgical procedures, the presence of diabetes mellitus does not appear to significantly increase risk

Interval gangrene-necrosis of tissue proximal to a successful distal revascularization procedure-is an exceeding rare complication. To date, only nine cases have been reported in the literature, and all were secondary to traditional open bypass procedures. We report the first case, to our knowledge, of interval gangrene after endovascular stent placement in the superficial femoral artery. We believe that with the increasing utilization of endovascular techniques to treat limb ischemia, the serious complication of interval gangrene must be revisited. Assessment of collateral circulation, precise stent placement, and the appropriate choice of stents and stent grafts will become increasing important as more and more of these lesions are treated with endovascular techniques.

Endovascular intervention can provide an alternative method of treatment for visceral artery aneurysms. We conducted a retrospective review of all patients with visceral artery aneurysms at a single university medical center from 1990 to 2003, focusing on the outcome of endovascular therapy. Sixty-five patients with visceral artery aneurysms were identified: 39 splenic (SAA), 13 renal, seven celiac, three superior mesenteric (SMA), and three hepatic. Eleven patients (16.9%) had symptoms attributable to their aneurysms, which included a total of four ruptures (6.2%): three splenic and one hepatic. Management consisted of 18 (27.7%) endovascular interventions, nine (13.9%) open surgical repairs, and 38 (58.5%) observations. Mean aneurysm diameter for patients treated expectantly was significantly less than for those who underwent intervention (p = 0.001). Endovascular interventions included 15 (83.3%) embolizations (11 SAA, three renal, one hepatic) and three (16.7%) stent grafts (two SMA, one renal). The initial technical success rate of the endovascular procedures was 94.4% (17/18). However, there were four patients (22.2%) with major endovascular procedure-related complications: one late recurrence requiring open surgical repair, two large symptomatic splenic infarcts, and one episode of severe pancreatitis. These four patients had distal splenic artery aneurysms at or adjacent to the splenic hilum. There were no endovascular procedure-related deaths. Reasons for performing open surgical repair included three SAA ruptures diagnosed at laparotomy and complex anatomy not amenable to endovascular intervention (six patients). One surgical patient had a postoperative small bowel obstruction treated nonoperatively; and there was one perioperative death in a patient operated on emergently for rupture. Endovascular management of visceral artery aneurysms is a reasonable alternative to open surgical repair in carefully selected patients. Individual anatomic considerations play an important role in determining the best treatment strategy if intervention is warranted. However, four of 11 (36.4%) patients with distal splenic artery aneurysms treated with endovascular embolization developed major complications. Based on our experience, traditional surgical treatment of SAA with repair or ligation and concomitant splenectomy when necessary may be preferred in these cases

Objective We compared the physiologic effect of selective atropine administration for bradycardia with routine prophylactic administration, before balloon inflation, during carotid angioplasty and stenting (CAS). We also compared the incidence of procedural bradycardia and hypotension for CAS in patients with primary stenosis vs those with prior ipsilateral carotid endarterectomy (CEA). Methods A total of 86 patients were treated with CAS at 3 institutions. Complete periprocedural information was available for 75 of these patients. The median degree of stenosis was 90% (range, 60%-99%). Indications for CAS were severe comorbidities (n = 49), prior CEA (n = 21), and prior neck radiation (n = 5). Twenty patients with primary lesions were treated selectively with atropine only if symptomatic bradycardia occurred (nonprophylactic group). Thirty-four patients with primary lesions received routine prophylactic atropine administration before balloon inflation or stent deployment (prophylactic group). The 21 patients with prior CEA received selective atropine treatment only if symptomatic bradycardia occurred (prior CEA group) and were analyzed separately. Mean age and cardiac comorbidities did not vary significantly either between the prophylactic and nonprophylactic atropine groups or between the primary and prior CEA patient groups. Outcome measures included bradycardia (decrease in heart rate >50% or absolute heart rate <40 bpm), hypotension (systolic blood pressure <90 mm Hg or mean blood pressure <50 mm Hg), requirement for vasopressors, and cardiac morbidity (myocardial infarction or congestive heart failure). Results The overall incidence of hypotension and bradycardia in patients treated with CAS was 25 (33%) of 75. A decreased incidence of intraoperative bradycardia (9% vs 50%; P < .001) and perioperative cardiac morbidity (0% vs 15%; P < .05) was observed in patients with primary stenosis who received prophylactic atropine as compared with patients who did not receive prophylactic atropine. CAS after prior CEA was associated with a significantly lower incidence of perioperative bradycardia (10% vs 33%; P < .05), hypotension (5% vs 32%; P < .05), and vasopressor requirement (5% vs 30%; P < .05), with a trend toward a lower incidence of cardiac morbidity (0% vs 6%; not significant) as compared with patients treated with CAS for primary carotid lesions. There were no significant predictive demographic factors for bradycardia and hypotension after CAS. Conclusions The administration of prophylactic atropine before balloon inflation during CAS decreases the incidence of intraoperative bradycardia and cardiac morbidity in primary CAS patients. Periprocedural bradycardia, hypotension, and the need for vasopressors occur more frequently with primary CAS than with redo CAS procedures. On the basis of our data, we recommend that prophylactic atropine administration be considered in patients with primary carotid lesions undergoing CAS

Gluteal compartment syndrome is an uncommon entity that has been described in the literature after drug overdose and orthopedic procedures. We describe the first case of bilateral gluteal compartment syndrome that followed pelvic revascularization after the repair of an abdominal aortic aneurysm with bilateral common and internal iliac aneurysms. The patient was treated with aggressive fluid hydration and bilateral gluteal fasciotomies with resolution. The bilateral gluteal compartment syndrome was likely caused by increased pressure on the gluteal muscles, secondary to increased patient weight combined with a period of local ischemia to the watershed areas during iliac cross-clamp

BACKGROUND: To evaluate whether abdominal aortic aneurysm (AAA) growth in individual patients can be characterized as continuous or discontinuous (staccato). STUDY DESIGN: From 1996 to 2002, 609 patients presented with unruptured AAAs. Of these, 278 underwent prompt repair and 331 were observed. In this study, we included 52 patients (16% of the latter group) who had at least four CT scans and were observed for 18 months or longer without any intervention. AAA growth was defined as any increase in diameter of >/= 3 mm over any observation period(s). AAA nongrowth was defined as absence of growth for at least 6 months. Staccato growth was defined as at least one period of nongrowth combined with at least one period of growth. RESULTS: The 52 patients had a mean age of 75 +/- 8 (SD) years. The mean observation period was 42 +/- 20 months and the mean AAA diameter growth rate was 3.6 +/- 2.4 mm/y. Only 12 of these 52 patients (23%) demonstrated continuous growth. Staccato growth occurred in 34 patients (65%). Six patients (12%) showed no growth at all over 18 to 57 months (mean 30 months). No correlation was observed between initial diameter of AAAs and a patient's individual growth rate during the whole observation period (R = 0.04, p = 0.46). CONCLUSIONS: Individual AAA behavior is usually characterized by periods of nongrowth alternating with periods of growth, ie, staccato growth. Some aneurysms may have long periods of nongrowth. Accordingly, management decisions cannot be based on the presumption that observed growth rates of AAAs can be extrapolated to predict future growth rates

Objectives Limb and pelvic ischemia are known complications after endovascular abdominal aortic aneurysm repair (EVAR). The objective of this paper is to present our experience with the incidence, presentation, and management of such complications. Methods Over 9 years 311 patients with aortic aneurysms underwent EVAR. A retrospective review identified 28 patients (9.0%) with ischemic complications. Results Among 28 patients with ischemic complications, 21 had lower extremity ischemia and 7 had pelvic ischemia: colon (n = 4), buttock (n = 2), and spinal cord (n = 2). Of the 21 patients with lower extremity ischemia, 15 had limb occlusions (71.4%), 3 due to embolization (14.7%) and 3 the result of common femoral artery thromboses (14.7%). Limb occlusions were manifested as severe acute arterial ischemia (n = 6), rest pain (n = 3), intermittent claudication (n = 5), and decreased femoral pulse (n = 1). Limb occlusions were managed with thrombectomy and stent placement (n = 4), femorofemoral bypass (n = 7), eventual explantation because of persistent endoleak (n = 1), and expectant management (n = 3). The 3 patients with occlusions managed expectantly all had intermittent claudication, which has subsequently improved. In the 6 patients with lower extremity ischemia due to embolization or common femoral artery injury presentation was acute, and embolectomy was performed, followed by femoral artery endarterectomy and patch angioplasty or placement of an interposition graft. One patient who had a prolonged postoperative course including cardiac arrest subsequently required distal bypass and ultimately above- knee amputation. Among the 7 patients with pelvic ischemia, 2 patients had unilateral hypogastric artery embolization before the original surgery. Among the patients with colonic ischemia, 3 were seen immediately postoperatively, and required colectomy and colostomy. Two patients who required urgent colectomy subsequently had multiple organ failure, and died in the perioperative period. One patient had abdominal pain 1 week after surgery, which was managed with bowel rest, with subsequent improvement. In 2 patients spinal cord ischemia developed immediately after surgery, w hich resulted in persistent paraplegia. Buttock ischemia developed in 2 patients, 1 of whom required fasciotomy because of gluteal compartment syndrome, and had transient renal failure. Conclusions Ischemic complications are not uncommon after EVAR, and may exceed the incidence with open surgical repair. Limb ischemia is most often a result of limb occlusion, and can be successfully managed with standard interventions. Pelvic ischemia often results from atheroembolization despite preservation of hypogastric arterial circulation. Colonic and spinal ischemia are associated with the highest morbidity and mortality

Technological advancements have lead to dramatic improvements in stentgraft device design resulting in more trackable delivery systems and transrenal uncovered stents and barbs for better fixation. Transrenal bare-stents may limit stentgraft migration, particularly in patients with short or flared proximal aortic necks. However, potential disadvantages might be in worsening renal function, particularly in patients with preexisting renal insufficiency. We retrospectively analyzed our recent 7 year experience of patients undergoing endovascular aneurysm repair (EVAR) using a variety of stentgrafts with and without transrenal bare-stent fixation. Patients were divided into 2 groups; infrarenal fixation (IRF) vs transrenal fixation (TRF), or patients with preoperative serum Cr values that were normal (=/<1.5 mg/dl) vs slightly elevated (1.6-2 mg/dl), vs markedly elevated (2.1- 3.5 mg/dl). The exclusion criteria included patients with chronic renal insufficiency (CRI) on hemodialysis, and preoperative high-grade renal artery stenoses requiring angioplasty and stenting. Of 705 patients that underwent EVAR, 496 (IRF: 385 [78%], and TRF: 111 [22%]) were available with routine evaluations of serum Cr and CT scans. Preexisting comorbidities, mean procedure contrast volume, and postprocedure follow-up were similar in both groups. In the immediate postoperative period, mean serum Cr did not change significantly in either the IRF group (1.3+/-0.7 mg/dl to 1.2+/-0.9 mg/dl) or the TRF group (1.3+/-0.5 mg/dl to 1.3+/-0.6 mg/dl). Mean serum Cr did, however, significantly increase over longer follow-up in both groups: 1.4+/-0.8 mg/dl for IRF (P<0.03), and 1.5 +/- 0.8 mg/dl for TRF (P<0.01). Cr clearance was similarly unchanged in the immediate postoperative period (58+/-23 to 61+/-25 ml/min/1.73 m(2) for IRF group, 53+/-17 to 55+/-17 ml/min/1.73 m(2) for TRF group), but was significantly decreased in longer follow-up (53+/-23 ml/min/1.73 m(2) for IRF, p<0.02: and 48+/-16 ml/min/1.73 m(2) for TRF, P<0.01). There were no significant differences in serum Cr increase (p=0.19) or Cr clearance decrease (p=0.68) between the IRF and TRF groups. Small renal infarcts were noted in 6 patients (1.6%) in the IRF group, and in 8 patients (7%) in the TRF group (p=0.37). Of patients with normal preoperative renal function, renal dysfunction developed in 7.7% of IRF group and 6.1% of TRF group (p=0.76). In patients with preexisting CRI, renal dysfunction developed in 18.2% of IRF group, and 17.1% of TRF group (p=0.95). Eight patients with postoperative renal dysfunction, 5 (1.3%) from IRF group and 3 (2.7%) from TRF group subsequently required hemodialysis, and this difference was not statistically significant (p=0.91). We also analyzed 200 consecutive patients undergoing EVAR with intra-arterial contrast agents with and without preexisting CRI not on dialysis. The groups were identified on the basis of preprocedure serum Cr: group 1 (n=108), Cr less than 1.5 mg/dL (normal range); group 2 (n=65), Cr 1.5 to 2.0 mg/dL; group 3 (n=27), Cr 2.1 to 3.5 mg/dL. Routine precautions in patients with CRI included preoperative intravenous hydration with 2 L of normal saline solution, discontinuation of all nephrotoxic drugs, intraoperative administration of mannitol (0.5 g/kg intravenously), and use of nonionic, low osmolar intra-arterial contrast agent (Omnipaque 350). One-hundred and eight patients had normal renal function (group 1), and 92 patients had preexisting CRI with baseline Cr 1.5 to 2.0 mg/dL (group 2, n=65) or 2.1 to 3.5 mg/dL (group 3, n=27). Comorbid conditions included coronary artery disease (group 1, 51%; group 2, 49%; group 3, 59%), hypertension (group 1, 39%; group 2, 46%; group 3, 52%), and diabetes mellitus (group 1, 25%; group 2, 35%; group 3, 48%). In groups 1, 2, and 3, the mean volume of low osmolar contrast agent used was 210 cc, 160 cc, 130 cc, respectively; hemodynamic instability developed in 3, 1, and 1 patient, respectively. The incidence of postoperative complications between the 3 study groups was not statistically different. In grications between the 3 study groups was not statistically different. In group 1 a transient increase in serum Cr (>30% over baseline and >1.4 mg/dL) was noted in 3 patients (2.7%), 2 of whom (1.9%) required temporary hemodialysis and 1 (0.9%) who died of renal failure. In group 2 a transient increase in serum Cr was noted in 2 patients (3.1%); both patients (3.1%) required temporary hemodialysis, and 1 patient (1.5%) died of renal failure. In group 3 a transient increase in serum Cr was noted in 2 patients (7.4%); 1 patient (3.7%) required temporary hemodialysis, and 1 patient (3.7%) died of renal failure. Perioperative hypotension significantly increased the risk for elevated serum Cr and death (p<0.05), and larger contrast volume was associated with an increase in serum Cr (p<0.05) during the postoperative period. Following EVAR renal function declines slightly with both IRF and TRF. Our data show no overall difference between patients with IRF and TRF with respect to infarcts, decline in renal function, or onset of dialysis. There were a slightly greater number of renal infarcts in the TRF group, but these infarcts were clinically inconsequential. In patients with CRI, EVAR with intra-arterial radiographic contrast agents is believed to impair renal function, and CRI is considered a relative contraindication to the procedure. Results of our investigation indicate that risk for worsening renal insufficiency, dialysis, and death is only slightly and not significantly greater in patients with CRI compared with patients with normal renal function. With appropriate precautions of avoiding perioperative hypotension and limiting the volume of nonionic contrast agents, CRI need not be a contraindication for EVAR with intra-arterial contrast agents