Kevin Casey

Brachial versus basilic vein dialysis fistulas: a comparison of maturation and patency rates.

OBJECTIVES Although the performance of basilic vein transpositions for dialysis access is well established, the utility and patency rates of brachial vein transpositions are poorly characterized. The brachial vein is being used increasingly as an alternative vein for transposition in an effort to increase the percentage of autogenous fistula utilization. The purpose of this study was to review a single-center comparative experience with these fistulas. METHODS A retrospective chart review was performed on 59 patients who received basilic and brachial vein transpositions between January 2000 and December 2006. Patient demographics, comorbidities, mortality, and morbidity were evaluated. Patency rates were calculated using Kaplan-Meier life-table analysis. RESULTS Of 59 vein transpositions, there were 42 basilic (71%) and 17 brachial (29%). The 30-day mortality was 0%. Maturation rates were 74% for basilic vein transpositions and 47% for brachial (P = .049). The mean time to maturation was 11.9 +/- 8.8 weeks. Primary patency rates at 12 months were 50% for basilic vein transpositions vs 40% for brachial (P = .115). The mean vein size was 4.9 +/- 0.9 mm. The mean basilic vein transposition diameter of 4.9 +/- 1.0 mm and brachial vein transposition diameter of 5.0 +/- 0.8 mm were not significant (P = .39). CONCLUSIONS Despite a higher rate of initial maturation in basilic vein transpositions, brachial and basilic vein transpositions had comparable patency rates at 12 months. These preliminary results require further follow-up and a larger cohort of patients for confirmation. Broader use of the brachial vein transposition for dialysis appears justified and can increase the overall percentage of autogenous fistula placement.

Differences in readmissions after open repair versus endovascular aneurysm repair

OBJECTIVE Reintervention rates after repair of abdominal aortic aneurysm (AAA) are higher for endovascular repair (EVAR) than for open repair, mostly due to treatment for endoleaks, whereas open surgical operations for bowel obstruction and abdominal hernias are higher after open repair. However, readmission rates after EVAR or open repair for nonoperative conditions and complications that do not require an intervention are not well documented. We sought to determine reasons for all-cause readmissions within the first year after open repair and EVAR. METHODS Patients who underwent elective AAA repair in California during a 6-year period were identified from the Health Care and Utilization Project State Inpatient Database. All patients who had a readmission in California ≤1 year of their index procedure were included for evaluation. Readmission rates and primary and secondary diagnoses associated with each readmission were analyzed and recorded. RESULTS From 2003 to 2008, there were 15,736 operations for elective AAA repair, comprising 9356 EVARs (60%) and 6380 open repairs (40%). At 1 year postoperatively, the readmission rate was 52.1% after open repair and 55.4% after EVAR (P=.0003). The three most common principle diagnoses associated with readmission after any type of AAA repair were failure to thrive, cardiac issues, and infection. When stratified by repair type, patients who underwent open repair were more likely to be readmitted with primary diagnoses associated with failure to thrive, cardiac complications, and infection compared with EVAR (all P<.001). Those who underwent EVAR were more likely, however, to be readmitted with primary diagnoses of device-related complications (P=.05), cardiac complications, and infection. CONCLUSIONS Total readmission rates within 1 year after elective AAA repair are greater after EVAR than after open repair. Reasons for readmission vary between the two cohorts but are related to the magnitude of open surgery after open repair, device issues after EVAR, and the usual cardiac and infectious complications after either intervention. Systems-based analysis of these causes of readmission can potentially improve patient expectations and care after elective aneurysm repair.

Development and Implementation of an Introductory Endovascular Training Course for Medical Students

BACKGROUND Endovascular simulation has been promoted as an educational tool for trainees to practice procedures in a safe environment and improve basic technical skills. We sought to determine whether an established endovascular training course for medical students could increase technical proficiency, enhance interest in vascular surgery, and be implemented at another academic institution. METHODS At Center A, medical students participated in an eight-week elective course with a structured curriculum comprised of weekly mentored simulator sessions and didactic teachings. A similar course was developed at Center B to train a similar cohort of students using the same high-fidelity simulator. Demographics and survey data, including interest in vascular surgery, were obtained, and pre- and postcourse graded simulator sessions on renal stent or iliac/superficial femoral artery stent modules were conducted. Performance was assessed by expert observers using a standardized global endovascular rating scale and objective procedural metrics collected from the simulator. RESULTS Seventy-seven medical students (41 at Center A and 36 at Center B; 56 men and 21 women) completed the course from 2007 to 2009. Parameters measured on the standardized global endovascular rating scale, including angiography skills, wire handling, and interventional criteria as well as simulator-generated metrics, significantly improved from pre- to postcourse values for both groups of medical students at the two institutions (p < 0.05). More than 94% of the students agreed or strongly agreed that the simulation course increased their interest in vascular surgery. CONCLUSION A simulation-based endovascular course provides an educational tool that improves basic technical performance and increases interest in vascular surgery among medical students. This simple educational module appears to be transferable and adaptable at another institution with minimal modification to produce similar results.

Safety and efficacy of antiplatelet/anticoagulation regimens after Viabahn stent graft treatment for femoropopliteal occlusive disease.

OBJECTIVE We aimed to determine the safety and efficacy of antiplatelet/anticoagulation regimens after placement of Viabahn stent graft (W. L. Gore & Associates, Flagstaff, Ariz) for the treatment of femoropopliteal occlusive disease. METHODS Clinical, angiographic, and procedural data for patients undergoing endovascular treatment of femoropopliteal occlusive disease using Viabahn covered stent grafts at a single institution between 2006 and 2013 were retrospectively reviewed. Graft patency and freedom from thrombolysis, major adverse limb event, and reintervention were determined by Kaplan-Meier analysis. The influence of relevant variables on clinical outcome was determined through univariate and multivariate Cox proportional hazards analyses. RESULTS Viabahn stent grafts were placed in a total of 91 limbs in 61 patients (66% men; mean age, 69 ± 12 years) during the study period. Indication for intervention was either claudication (n = 59) or critical limb ischemia (n = 32), with the majority (70%) classified as TransAtlantic Inter-Society Consensus II C (n = 33) or D (n = 31) lesions. Mean follow-up was 38.3 months (range, 1-91 months). Postprocedural pharmacologic regimens included aspirin, clopidogrel, and warfarin (47%); indefinite aspirin and clopidogrel (46%); or aspirin and temporary clopidogrel (7%). Primary and secondary patency rates were 60%, 44%, and 36% and 95%, 82%, and 74% at 1 year, 3 years, and 5 years, respectively. Kaplan-Meier analysis demonstrated more aggressive antiplatelet/anticoagulation regimens to be associated with improved primary patency and freedom from reintervention. Cox proportional hazards analysis demonstrated TransAtlantic Inter-Society Consensus II D lesions, tobacco use, coronary artery disease, and smaller stent diameter to be independent risk factors for stent graft failure. Bleeding events were limited to those in the aspirin, clopidogrel, and warfarin group (11.6% [n = 5]; P = .052), although the majority of these events were not life-threatening, and only two cases required blood transfusion. CONCLUSIONS Increasingly aggressive antithrombotic regimens after Viabahn stent graft placement trended toward improved overall clinical outcomes, although the marginal patency benefit observed with the addition of warfarin to dual antiplatelet therapy was tempered by an observed increased risk of bleeding complications. Longer term follow-up and multicenter studies are needed to further define optimal type and duration of antithrombotic therapy after endovascular peripheral interventions.

Outcomes after Long-Term Follow-Up of Combat-Related Extremity Injuries in a Multidisciplinary Limb Salvage Clinic

BACKGROUND Although the incidence of casualties from the Global War on Terror is decreasing, there remains a focus on the long-term sequelae from injuries sustained in the combat. Patients with prior significant limb injuries remain at risk of future complications. This study examines our institutions experience with a multidisciplinary team approach toward this challenging patient population. METHODS A retrospective review was performed on all patients treated in a single institution Limb Preservation Clinic over a 2-year period. Those patients who sustained a combat-related injury in theater were examined. Patient demographics, mechanism of injury, amputation rates, time to amputation, and reasons for failure were examined. RESULTS Ninety-four patients were evaluated in our multidisciplinary Limb Preservation Clinic over a 2-year period. Twenty patients (21%) were seen for combat-related injuries. Sixteen patients were evaluated and treated for chronic complications at a median of 13 months from their injury. All 16 patients were male with a median age of 24 years (range, 20-35). Ten patients sustained injuries secondary to a dismounted improvised explosive device (IED). All 16 patients had extensive soft tissue injuries and associated fractures. Only 2 patients sustained a vascular injury. The median number of prior surgeries to the affected limb was 8 (range, 3-19). The limb salvage rate of 37% was lower than our noncombat cohort (47%). The most common reasons for delayed amputation included chronic pain, osteomyelitis, and soft tissue infections. CONCLUSIONS The high secondary amputation rates seen in this cohort underscores the need for long-term follow-up. Despite successful initial outcomes, many patients eventually progress to limb loss. Patients who sustain a dismounted IED are at greatest risk for a delayed amputation. Identifying and addressing those factors which lead to delayed amputation should be a priority for returning war veterans and focus of future studies.

Hypogastric Artery Preservation During Aortoiliac Aneurysm Repair

Hypogastric artery (HA) embolization with iliac limb extension is often performed for patients with concomitant aorta and common iliac artery aneurysms at the time of standard endovascular aneurysm repair. However, symptomatic pelvic ischemia following HA exclusion can be debilitating. In this study, we described two cases of HA preservation using commercially available stent grafts. The techniques that we described enable patients with concurrent aorta and iliac aneurysms to undergo endovascular aneurysm repair without increasing the risk of pelvic ischemia. Although the long-term durability of these trifurcated graft configurations remains to be determined, the short-term results are superb. Technical considerations of these two different approaches have also been compared.

Hybrid Treatment of Celiac Artery Compression (Median Arcuate Ligament) Syndrome

A 53-year-old woman presented with severe, post-prandial generalized abdominal pain and a 50-pound unintentional weight loss over a 3-month period. There had been a prior chronic history of this discomfort, but it had never reached this level of severity and it had not been associated with weight loss. Over the previous 3 months, her symptoms worsened to the point that she could not tolerate anything beyond clear liquids. Her prior surgical history included three cesarean sections, a total abdominal hysterectomy, a laparoscopic cholecystectomy, laparoscopic lysis of adhesions on three separate occasions, and a rectocele repair. Her last operation was 11 years prior to this presentation. Her past medical history was significant for fibromyalgia, chronic fatigue syndrome, narcotic analgesic dependence, anxiety, and hyperlipidemia. She has smoked a half of a pack of cigarettes per day for the past 30 years. She denied any alcohol or illicit drug use and her family history was noncontributory. Upon physical examination, her weight was 116 pounds, down from a weight of 165 pounds 3 months prior. She exhibited temporal wasting. Her abdominal exam was notable for intermittent diffuse mild tenderness and a scaphoid abdomen. Auscultation revealed no abdominal bruit. She had normal peripheral pulses. Extensive gastrointestinal evaluation including colonoscopy, upper endoscopy, and small bowel follow-through radiography were all normal. A CT-angiogram to rule out mesenteric vascular compromise revealed compression of the celiac artery by the median arcuate ligament (MAL), post-stenotic dilation, and characteristic ‘‘fish-hook’’ appearance (Fig. 1). Duplex ultrasound confirmed 70% stenosis of the proximal celiac artery by two-dimensional compression, changing with breathing patterns, as well as elevated velocities of 360 cm/s in the proximal celiac orifice. Post-stenotic turbulence was also noted in the hepatic and splenic arteries. Based on the patient’s clinical and radiographic findings, the diagnosis of MAL syndrome was considered. We planned for a potential hybrid approach with part-laparoscopic and part-endovascular methods to relieve her obstruction. She was taken to the operating room for laparoscopic MAL release (Fig. 2). Significant scarring and fibers were carefully dissected off the celiac trunk and allowed full release/relaxation of the compressed celiac vessel. Postoperatively, her abdominal pain improved dramatically, she denied any further postprandial digestive difficulties and she was discharged home tolerating a regular diet. Her post-operative duplex ultrasound showed resolution of the velocity increase (down to 120 cm/s) and improved caliber of the celiac origin. However, her characteristic post-prandial abdominal pain returned about 1 month later. Although she had been able to gain several pounds of weight and eat despite the symptoms over the course of the first 2 weeks after discharge, she began losing weight again. A repeat duplex ultrasound now revealed an increase in her celiac artery velocity to 253 cm/s. Because of this, the decision was made to proceed with celiac artery angiography and stenting. Angiography showed residual narrowing and delayed filling of the celiac artery (Fig. 3a). A balloon-expandable stent was placed O. P. Palmer M. Tedesco K. Casey J. T. Lee G. A. Poultsides (&) Divisions of General and Vascular Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, CA, USA e-mail: gpoultsides@stanford.edu

Flap coverage outcomes following vascular injury and repair: chronicling a decade of severe war-related extremity trauma.

Background: Combat-related extremity injuries frequently require vascular repair within the combat theater before undergoing definitive reconstruction. This study examines the outcomes of early vascular repair with secondary soft-tissue extremity reconstruction over the past decade of war trauma. Methods: War-related extremity injuries necessitating a downrange vascular procedure followed by a definitive limb reconstruction were reviewed. Patient demographics, type and location of vascular injuries, vascular intervention, and soft-tissue reconstruction procedures were examined. Outcomes of vascular repair, tissue transfer, and limb salvage were analyzed. Results: From 2003 to 2012, 79 extremities in 78 patients had a vascular injury requiring in-theater intervention followed by 87 staged flap reconstructions performed distal to the vascular repair. Of the 74 arterial injuries requiring intervention, 27 were proximally located, with 73 percent requiring bypass. The early primary patency rate was 66 percent and the early primary-assisted patency rate was 93 percent for proximal artery repair procedures. The flap complication rate was 31 percent. Overall complications were examined by subtype and were not significantly different compared with flaps performed without a proximal vascular injury in the same limb. The flap success rate (93 percent) and the limb salvage rate (81 percent) were similar to the comparison cohort. Conclusions: This represents one of the largest series of traumatic extremity injuries requiring secondary limb reconstruction with tissue transfer following a vascular intervention. The authors identified no significant difference in outcomes related to flap coverage or limb salvage for patients with or without vascular injuries. Reconstructive options in combat extremity trauma are not limited by proximal vascular injury. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

Medical Management of Intermittent Claudication

The symptoms of intermittent claudication (IC) lead sufferers to seek medical attention, potentially leading to substantial workup and invasive testing. However, only a minority of people with IC develop limb-threatening ischemia or symptoms of significant lifestyle-limiting claudication. Patients with IC have a substantial risk of concomitant cardiovascular and cerebrovascular disease. Assessment of co-morbidities and control of risk factors reduce the cardiovascular risk of these patients. A multitude of drugs have been developed and tested in numerous trials for the symptoms of IC. Although no drug alone offers a “cure” to IC, some are used as adjuvant therapy to reduce claudication symptoms.

Tortuous axillary artery aneurysm causing median nerve compression.

Axillary artery aneurysms are rare entities that warrant surgical intervention. Reported complications include thrombosis, distal embolization, and debilitating neurologic symptoms caused by median nerve compression. Common etiologies include trauma or repetition injuries. Less recognized associations include atherosclerotic, connective tissue, or mycotic processes. We report a case of a rare tortuous axillary artery aneurysm causing neurologic symptoms in a woman with an unused arteriovenous fistula.