Faculty Bibliography

OBJECTIVE: We optimized a time-resolved 3D contrast-enhanced MR angiography sequence with integrated parallel imaging technique that can provide a large field of view with high temporal and spatial resolution, by which the hemodialysis access and the entire course of the inflow and outflow vessels can be imaged at a single anatomic station. Our objective was to evaluate the feasibility and usefulness of this method in the evaluation of patients referred for possible abnormalities in hemodialysis access. CONCLUSION: Time-resolved contrast-enhanced 3D MR angiography with parallel imaging has the potential to provide a rapid and comprehensive evaluation for the surveillance and diagnosis of hemodialysis access malfunctions. This technique may function as an important complement to conventional digital subtraction angiography and may be able to help guide medical management. The MR angiography protocol we present is a noninvasive, versatile, and time-efficient technique, without the need of direct graft puncture or flow interruption, and can be performed using a single injection of contrast material at a single station

Left renal vein ligation has been used as a technical aid to gain exposure to the perirenal aorta and to control bleeding in abdominal aortic operations. Left renal vein ligation is considered to be well tolerated in patients with 2 functioning kidneys, but has rarely been described in the setting of concomitant right nephrectomy and presents a management challenge. Some reports suggest recovery of renal function may be possible after left renal vein ligation during right nephrectomy, but other suggest that a delay in revascularizing the left renal venous drainage may result in irreversible nephropathy. This article reports the inadvertent division of the left renal vein during right nephrectomy. Renal failure ensued postoperatively. The left renal vein was reconstructed, and renal function was recovered. The inability to reliably predict which patients will have adverse outcome after left renal vein ligation in the setting of a right nephrectomy may necessitate preemptive intervention

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

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

Adult intussusception in the setting of inflammatory bowel disease (IBD) is a rare phenomenon. Giant pseudopolyps, while generally considered benign, may function as lead points for intussusception. Diagnosis and management of intussusception in the setting of IBD can be fraught with hazards. We report the case of a 27-year-old male, recently diagnosed with ulcerative colitis and giant pseudopolyps, who presented with colocolonic intussusception and obstruction. Diagnosis was confirmed using CT imaging and the patient underwent resection of the colocolonic intussusception without reduction. The following case underscores the challenges in managing adult intussusception in the setting of IBD and allows for a review of the literature to date. Resection of non-reduced intussusception, rather than endoscopic or enema reduction, should continue to be definitive treatment of patients presenting with this unusual problem

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

When peripheral vascular injuries present in conjunction with life threatening emergencies, controlling hemorrhage from a peripheral blood vessel may take initial priority, however, sacrificing a limb to preserve life is a well-established dictum. The use of intravascular shunts has allowed arterial and venous injuries to be controlled and temporized while treating other injuries. Typically, intravascular shunts are used for short time periods while orthopedic injuries are repaired or other life threatening injuries are managed. The following case demonstrates the long-term use of an intravascular arterial shunt to treat a traumatic transection of the common femoral artery and vein in a patient with an open pelvic fracture from blunt trauma. A 20-year-old woman fell between a subway platform and an oncoming train. She sustained a crush injury to her lower extremity and pelvis as she was pinned between the train and platform. The patient presented with active hemorrhage from a groin laceration, quickly became hemodynamically unstable, and was brought to the operating room. In addition to a pelvic fracture with massive pelvic hematoma she sustained a complete transection of the bifurcation of the common femoral artery (CFA), the common femoral vein (CFV), and associated orthopedic injuries. Vascular shunts were placed in the common femoral artery and vein. The patient became hypotensive from an expanding retroperitoneal hematoma. Pelvic bleeding was controlled with angioembolization and the venous injury was repaired. At this time the patient became cold, acidotic, and coagulopathic. It was thought unsafe to proceed with the arterial repair and it was elected to keep her arterial shunts in place and perform a planned reexploration in 24 hours after correcting her physiologic status. The patient returned to the operating room for an elective repair of her CFA the following day. Her shunt had remained patent throughout this time. She underwent a reverse saphenous vein graft from her CFA to her SFA. After a prolonged hospital course she was ultimately transferred to a rehabilitation center with intact pulses in both lower extremities. This case demonstrates the effectiveness of prolonged (>6 hours) use of an intravascular shunt as part of damage control surgery for peripheral arterial and venous injuries. In a patient who would otherwise undergo an amputation for their injury, the risk of shunt thrombosis, or infection, during damage control resuscitation may not be a contraindication for placement

Citing the higher perioperative risk of redo carotid surgery, balloon angioplasty and stenting of the carotid artery (CAS) has been advocated for recurrent carotid stenosis (RCS). To examine the impact of CAS on the management and outcome of recurrent stenosis, a retrospective review of a prospectively compiled database was performed. From a registry of patients treated for carotid disease, 105 procedures were performed from 1992 to 2002 for RCS. For comparison, two study groups were examined. Time I consisted of 77 reoperations performed through 1998, before CAS was introduced at our institution. Time II included 12 reoperations and 16 CAS procedures performed for RCS from 1999 through 2002. Using perioperative stroke as a measure of outcome, the results for time II were poorer than for time I (7.2% vs. 5.2%, p = NS). Overall, the risk of perioperative stroke was the same for reoperation (5/89) and CAS (1/16) (5.6% vs. 6.3%, p = NS). Although not statistically significant, there was a trend toward a higher risk of perioperative stroke for patients treated with reoperation during the latter time period (8.3% vs. 5.2%, p = NS). This probably relates to the finding that during time II, CAS was most likely to be used in asymptomatic patients (68.6% vs. 41.7%, p = NS) with early (<3 years) RCS (87.5% vs. 41.7%, p= 0.01). No patient with asymptomatic, early RCS had a perioperative stroke with either surgery or CAS (0/35 cases, 0%). The presence of preoperative neurologic symptoms was significantly predictive of a perioperative stroke among all procedures performed for RCS (13.6% vs. 0%, p = 0.004). Contrary to suggestions that CAS might improve the management of RCS, a review of our data shows the overall risk of periprocedural stroke to be no better since CAS has become available. The bias for using CAS for asymptomatic myointimal hyperplastic lesions, and reoperation for frequently symptomatic late recurrent atherosclerotic disease, makes direct comparisons of the two techniques for treating RCS difficult. It is expected that the overall risk for redo carotid surgery will increase, as fewer low-risk patients will be receiving open procedures. However, the increased risk among symptomatic patients undergoing reoperation suggests that endovascular techniques should be investigated among this group of cases as well

This is a retrospective review of all carotid endarterectomies (CEA) (n=91) done from 1993 to 2002 at an inner-city hospital (Group I). This group was compared to a randomly selected group of patients (n=445) treated at a private hospital (Group II). The same high-volume surgeons performed CEAs at both hospitals. The majority of Group I patients (71.4%) were members of racial minority groups. They were also more likely to be younger (p<0.001), hypertensive (p<0.03), diabetic (p<0.001), and current smokers (p<0.001); have contralateral carotid artery occlusion (p=0.04); and present with stroke (p<0.001) than Group II patients. Despite this, the incidence of postoperative myocardial infarction (2.2% vs 0.2%, p=0.08), stroke (1.1% vs 1.6%, NS), and death (1.1% vs 0%, NS) was comparable between the 2 groups. Aggressive preoperative workup for occult cardiac disease in Group I revealed an incidence of 25.9% (n=15). Of these, 5 (33.3%) were found to have coronary artery disease severe enough to warrant intervention before CEA. In an inner-city population with increased medical comorbidities, more severe cerebrovascular disease, and relatively low volume of carotid surgery, the results of CEA were comparable to those in patients treated at a high-volume private hospital. The presence of high-volume surgeons, operating at the low-volume municipal hospital, may contribute to the low complication rate. Finally, aggressive preoperative cardiac workup in this underserved population revealed a meaningful incidence of occult coronary artery disease requiring intervention before CEA