Karen Woo

Regional quality groups in the Society for Vascular Surgery® Vascular Quality Initiative

The Society for Vascular Surgery Vascular Quality Initiative (SVS VQI) is designed to improve the quality, safety, effectiveness, and cost of vascular health care. The SVS VQI is uniquely organized as a distributed network of regional quality improvement groups across the United States. The regional approach allows for the involvement of a variety of health care professionals, the pooling of available resources and expertise, and serves as a motivating factor for each participating institution. Regional quality group sizes, administrative structure, and meeting logistics vary according to geography and regional needs. This review describes the process of forming, growing, and maintaining a regional quality improvement group of the SVS VQI.

Use of unconventional dialysis access in patients with no viable alternative.

BACKGROUND Hemodialysis patients who have exhausted all of the conventionally used veins for vascular access, including arteriovenous fistula, arteriovenous graft, and traditional catheter access sites, present a challenge to the treating physician. Transhepatic and translumbar inferior vena cava catheters have been used in these patients who have no other access site option. The objective of the study was to examine our experience with translumbar and transhepatic approach for catheter-based hemodialysis access in patients who have exhausted all other options. METHODS A retrospective review was performed from June 2000 to May 2011 of all patients who underwent transhepatic or translumbar inferior vena cava catheter placement for the purpose of hemodialysis. Data abstracted included previous access procedures, duration of use and patency of dialysis catheters, catheter-related complications, and mortality. RESULTS Seven patients were identified. Four patients underwent transhepatic access and three underwent translumbar access. Five patients were female and two were male. The mean age was 44 years. The etiology of renal failure was diabetes in four patients, congenital hypoplastic kidneys in two patients, and acute glomerulonephritis in one patient. A mean of 14 (range: 11-18) dialysis access procedures were performed before catheter placement by transhepatic/translumbar interventions. The initial device service interval for all patients ranged from 15 to 658 days, with a mean of 295 days and a median of 245 days. Total access site service interval ranged from 15 to 790 days, with a mean of 380 days and a median of 245 days. CONCLUSION Translumbar and transhepatic venous access is a viable long-term alternative route for catheter-based hemodialysis access in patients who have exhausted conventional options.

Vein harvesting technique for infrainguinal arterial bypass with great saphenous vein and its association with surgical site infection and graft patency

OBJECTIVE The objective of this study was to investigate the association of vein harvesting technique (VHT) with surgical site infection (SSI) and graft patency after infrainguinal arterial bypass. METHODS The Vascular Quality Initiative database was used to review VHT of all patients undergoing single-segment great saphenous vein graft infrainguinal arterial bypass from 2003 to 2013. Patients were divided into three groups according to the VHT used (continuous incision, skip incision, and endoscopic). Multinomial logistic regression was performed to estimate propensity scores for each treatment group. Propensity score adjustment was included in multivariable analysis of the primary outcomes: SSI and graft primary patency. RESULTS From 2003 to 2013, 5066 patients underwent single-segment great saphenous vein graft infrainguinal bypass. The VHT was continuous incision in 48.6%, skip incision in 39.7%, and endoscopic in 12.7%. SSI rates did not differ significantly among the groups (continuous, 4.7%; skip, 4.0%; endoscopic, 3.4%; P = .278). On multivariable analysis, there was no difference in discharge primary patency between the three groups. At 1 year, primary patency rates were 69.5% for continuous, 73.0% for skip, and 58.6% for endoscopic (P < .001). After multivariable analysis, endoscopic vein harvest was independently associated with higher 1-year primary patency loss compared with both continuous (hazard ratio [HR], 1.35; 95% confidence interval [CI], 1.05-1.74; P = .020) and skip (HR, 1.53; 95% CI, 1.18-2.00; P = .002). There was no significant difference in 1-year primary patency loss between continuous and skip techniques (HR, 0.88; 95% CI, 0.73-1.05; P = .170). CONCLUSIONS No association between the choice of VHT and the development of SSI after infrainguinal arterial bypass was identified in the Vascular Quality Initiative population. Endoscopic VHT was associated with significantly reduced 1-year primary patency rate compared with both continuous and skip techniques.

The Results of a Needs Assessment to Guide a Vascular Surgery Skills Simulation Curriculum

BACKGROUND In response to economic and societal pressures, a new integrated model of vascular surgery training has emerged that will condense training into 5 years. These new requirements challenge educators to develop innovative training programs that produce competent surgeons despite time constraints. Surgical skills simulation is a proven effective method to teach and evaluate learners in surgery residency programs. METHODS To determine which skills are the most important to include in a vascular surgical skills training curriculum, a needs assessment survey was administered to all attending surgeons and fellows at vascular surgery training institutions in Southern California. Participants were asked to rank 52 vascular procedures and skills on a Likert scale (with scores ranging from 1 [not necessary] to 5 [essential]) based on perceived need for simulation training. RESULTS Nineteen (48.7%) surveys were returned (6 fellows [60%], 13 attending surgeons [44.8%]). Carotid artery stenting was ranked by both fellows and attendings as the most essential procedure for simulation, with a mean score of 4.26. This was followed by open repair of ruptured infrarenal aortic aneurysm (R-AAA) (3.79), renal angioplasty/stent (3.68), thoracic endovascular aortic aneurysm repair (3.53), and open repair of juxtarenal/suprarenal aortic aneurysm (3.47). In addition, fellows gave a rank of 4 or higher to R-AAA, thoracic endovascular aortic aneurysm repair, mesenteric artery angioplasty/bypass, renal angioplasty/stent, and intravascular ultrasonography. Attendings did not give a mean rank score of 4 or higher to any procedures other than carotid artery stenting. CONCLUSIONS Our needs assessment identified vascular procedures where simulation may be beneficial to improve the skill level of vascular trainees in Southern California. With economic and logistical constraints for simulation at each individual training facility, a potential approach to this educational challenge is a regional Southern California vascular surgery skills simulation center.

Outcomes after abdominal aortic aneurysm repair requiring a suprarenal cross-clamp

OBJECTIVE The objective of this study was to analyze the early and late outcomes of patients who require a suprarenal aortic cross-clamp during elective open repair of an abdominal aortic aneurysm (AAA). METHODS Patients from 1998 to 2012 who required a suprarenal aortic cross-clamp during elective open AAA repair were reviewed. Data abstracted included demographics and comorbidities; preoperative, perioperative, and late renal function; late interventions related to AAA repair; and late mortality. A decrease in renal function was defined as a >30% decline in estimated glomerular filtration rate (eGFR) compared with the preoperative value. Primary outcomes included renal function, intervention-free survival, and overall survival. RESULTS During the study period, 211 patients underwent open elective or urgent AAA repair; 69 required a suprarenal cross-clamp. The mean age was 71 years, and 80% were men. The mean preoperative creatinine concentration was 1.2 mg/dL, and the mean preoperative eGFR was 66 mL/min/1.73 m2. Location of the aortic cross-clamp was suprarenal (37), supramesenteric (21), and supraceliac (11). Perioperatively, 21 patients (30%) experienced a significant decrease in eGFR; four patients required hemodialysis. Six patients had full recovery of renal function by discharge. Perioperative morbidity and mortality were 35% and 4%, respectively. At a mean follow-up of 3 years, seven patients had an eGFR significantly less than the preoperative value. Late interventions related to the AAA repair were required in eight patients. Indications included wound complication (3), anastomotic aneurysm (2), incisional hernia (1), anastomotic graft stenosis (1), and proximal aortic dilation (1). Overall 5-year intervention-free survival was 62% and overall survival 77%. Intervention-free survival was enhanced by antiplatelet use (P = .04), whereas overall survival was decreased by chronic obstructive pulmonary disease (P = .003) and perioperative pneumonia (P = .001). CONCLUSIONS More than a quarter of patients requiring a suprarenal cross-clamp during open AAA repair experience renal dysfunction. Late graft-related complications are few, with preoperative and perioperative pulmonary function negatively affecting overall patient survival.

Infective Endocarditis Associated Superior Mesenteric Artery Pseudoaneurysm

BACKGROUND Since William Osler first described mycotic aneurysms in the setting of endocarditis in 1885, few pseudoaneurysms (PAs) of the superior mesenteric artery (SMA) have been reported in the literature. We report 2 cases of SMA PA related to infective endocarditis that were managed with open surgery. RESULTS Here we report 2 cases of SMA PAs treated with different surgical techniques. A 59-year-old male with a history of intravenous drug use presented with abdominal pain and was found to have Streptococcus viridans endocarditis and an SMA PA. A laparotomy was performed, and proximal and distal control of the SMA PA was obtained. After ensuring that Doppler signals were still present in the distal mesentery and the entirety of the bowel was viable, the SMA was ligated proximal and distal to the PA. The patient recovered uneventfully. The second case is a 35-year-old female who presented with abdominal pain and was found to have Streptococcos gordonii endocarditis and an SMA PA for which the patient was initially observed. After several weeks, the patients condition deteriorated and the patient underwent open ligation of the SMA, proximal and distal to the PA, with a bypass from the infrarenal abdominal aorta to a distal unnamed SMA branch and resection of 3 ft of ischemic small bowel. The patient continued to have recurrent bowel ischemia over the next several weeks and ultimately died. CONCLUSIONS SMA PAs associated with infective endocarditis are rare, but carry a high risk of rupture and associated morbidity and mortality. Delay in surgical management may increase this risk.

Thoracic aortic stent-grafting for acute, complicated, type B aortic dissections.

BACKGROUND To report a single-center experience of aortic stent-grafting for the treatment of acute, complicated, type B aortic dissections. METHODS A retrospective review was conducted of the data obtained from all patients who underwent endovascular stent-grafting for acute, type B aortic dissection between 2006 and 2009. The primary and secondary endpoints were 30-day mortality and morbidity rates, respectively. RESULTS In all, 104 thoracic endovascular aortic aneurysm repairs were performed during the study period. Nine (8.6%) patients (six men; mean age: 65 years) underwent thoracic endovascular aortic aneurysm repair for acute, complicated, type B aortic dissections. Seven (78%) patients had uncontrolled hypertension on presentation. Visceral branch vessel involvement of the dissection was limited to the celiac axis origin in one patient with no evidence of visceral malperfusion. The indication for repair was aortic rupture in five patients, renal malperfusion in two, and persistent pain in the remaining two. Average time taken from presentation to surgery was 5.5 days. Two patients presenting with aortic ruptures had retrograde extension of the dissection that required replacement of the aortic valve and ascending aorta. The mean length of thoracic aorta covered was 21 cm. Complete coverage of the left subclavian artery was required in three patients and partial coverage in two. On completion angiogram, two type I endoleaks were detected, one of which was resolved by postoperative day 5. The 30-day mortality rate was 22%. One mortality was secondary to aortic rupture. The other mortality was due to multiorgan system failure. Seven patients (78%) had one or more major complications. There were no strokes or paraplegia. CONCLUSION The association of morbidity and mortality with endovascular stent-grafting for acute, complicated, type B aortic dissections is significant, which most likely reflects the lethal nature of the disease. The precise role of endovascular treatment in these patients remains to be defined.

Compliance with Surgical Follow-up Does Not Influence Fistula Maturation in a County Hospital Population

BACKGROUND The purpose of this study is to examine follow-up rates and maturation rates after dialysis access surgery using a fistula-first approach in a county hospital with an indigent population. METHODS A prospectively maintained dialysis access database was queried for cases performed between August 1, 2009 and September 30, 2011. The follow-up period ended on December 31, 2011. An attempt was made to contact patients who did not have complete follow-up data recorded to the point of fistula maturation for arteriovenous fistulas (AVF). Patients were contacted directly or through their dialysis center. Maturation was defined by successful use of the AVF for hemodialysis for at least 2 weeks for patients who are dialysis dependent or by the clinical assessment of an attending vascular surgeon for those not on dialysis. RESULTS Two hundred three dialysis access cases were performed. The mean age was 51.4 years. One hundred twenty-six (62%) were male and 175 (86%) were Hispanic. Of these, 194 (95.6%) were AVF. Three AVF were ligated in the postoperative period for steal. Of the remaining 191 AVF, 94 (49%) patients completed their scheduled follow-up appointments. Sixty-six (35%) patients did not come to clinic but were contacted. Twenty-six (14%) patients were completely lost to follow-up and 5 (2.6%) died. Maturation data was obtained on 160 AVF. Of those, 123 (77%) reached maturation with a mean maturation time of 112 ± 99 days (range, 21-483). Twenty patients who completed follow-up underwent at least 1 additional surgical or endovascular procedure in an attempt to achieve maturation. Seventeen (85%) patients who underwent a secondary procedure went on to achieve maturation. There was no significant difference in maturation between the group that completed follow-up and those who were contacted by phone (69 [73%] vs. 54 [81%], P = not significant). CONCLUSIONS In this indigent population, follow-up does not influence maturation rates of AVF. Despite poor compliance with follow-up in the setting of a public hospital, the maturation rate of an aggressive fistula-first approach is acceptable.

Diversity in vascular surgery

A growing body of literature in vascular surgery demonstrates disparities in the type of health care that racial/ethnic minorities receive in the United States. Numerous recommendations, including those of the Institute of Medicine, have been set forth, which identify increasing the number of minority health professionals as a key strategy to eliminating health disparities. The purpose of this study is to compare the racial/ethnic distribution of the Society for Vascular Surgery (SVS) membership, the SVS leadership, vascular surgery trainees, and medical students. The results demonstrate that the racial/ethnic distribution of the SVS membership reflects a considerable lack of diversity with a paucity of diversity among the SVS leadership. An increasing rate of racial/ethnic diversity among vascular surgery trainees may indicate that the SVS will see an improvement in diversity in the future.

Contemporary outcomes after venography-guided treatment of patients with May-Thurner syndrome.

OBJECTIVE Patients with May-Thurner syndrome (MTS) present with a spectrum of findings ranging from mild left leg edema to extensive iliofemoral deep venous thrombosis (DVT). Whereas asymptomatic left common iliac vein (LCIV) compression can be seen in a high proportion of normal individuals on axial imaging, the percentage of these persons with symptomatic compression is small, and debate exists about the optimal clinical and diagnostic criteria to treat these lesions in patients with symptomatic venous disease. We evaluated our approach to venography-guided therapy for individuals with symptomatic LCIV compression and report the outcomes. METHODS All patients with suspected May-Thurner compression of the LCIV between 2008 and 2015 were analyzed retrospectively. Patients with chronic iliocaval lesions not associated with compression of the LCIV were excluded from analysis. Criteria for intervention included LCIV compression in the setting of (1) leg edema/venous claudication with associated venographic findings (collateralization, iliac contrast stagnation, and contralateral cross cross-filling), or (2) left leg deep venous thrombosis. Outcome measures included presenting Clinical, Etiology, Anatomy, Pathophysiology (CEAP) score, postintervention CEAP score, primary patency, and secondary patency. Technical success was defined as successful stent implantation without intraoperative device complications, establishment of in-line central venous flow, and less than 30% residual LCIV stenosis. RESULTS Of the 63 patients evaluated, 32 (51%) had nonthrombotic MTS and presented with leg edema (100%) or venous claudication (47%). Thirty-one patients (49%) had thrombotic MTS and presented with acute (26%) or chronic (71%) DVT, leg edema (100%), or venous claudication (74%). The mean presenting CEAP score was 3.06 and 3.23 for nonthrombotic and thrombotic MTS, respectively. Forty-four patients (70%) underwent successful intervention with primary stenting (70%) or thrombolysis and stenting (30%); 14 nonthrombotic MTS patients were treated conservatively with compression therapy alone, and 5 thrombotic MTS patients were treated with lysis or angioplasty alone. Clinical improvement and decrease in CEAP score occurred in 95% and 77% of stented patients compared with 58% and 32% of nonstented patients. Complete symptom resolution was achieved in 48% of patients overall, or 64% of stented patients and only 21% of nonstented patients. Complications included two early reocclusions. Primary and secondary 2-year patency rates were 93% and 97% (mean follow-up, 20.3 months) for stented patients. CONCLUSIONS Venography-guided treatment of MTS is associated with excellent 1-year patency rates and a significant reduction in symptoms and CEAP score. Treating symptomatic MTS patients on the basis of physiologically relevant venographic findings rather than by intravascular ultrasound imaging alone results in excellent long-term patency and clinical outcomes but may result in undertreatment of some patients who could benefit from stent implantation.