Poor runoff and distal coverage below the knee are associated with poor long-term outcomes following endovascular popliteal aneurysm repair.

OBJECTIVE: Reports of good short-term outcomes for endovascular repair of popliteal artery aneurysms have led to an increased use of the technique. However, data are lacking on long-term limb-related outcomes and factors associated with the failure of endovascular repair. METHODS: All patients who underwent endovascular popliteal aneurysm repair (EPAR) at a single institution from January 2006 to December 2018 were included in the study. Demographics, indications, anatomic and operative details, and outcomes were reviewed. Long-term patency, major adverse limb event-free survival (MALE-FS) and graft loss/occlusion were analyzed with multivariable cox regression analysis and Kaplan-Meier curves. RESULTS: We included 117 limbs from 101 patients with a mean follow-up of 55.6 months (range, 0.43-158 months). The average age was 73 ± 9.3 years. Thirty-two patients (29.1%) were symptomatic (claudication, rest pain, tissue loss, or rupture). The stent grafts crossed the knee joint in 91.4% of cases. In all, 36.8% of procedures used one stent graft, 41.0% used two stent grafts, and 22.2% of procedures used more than two stent grafts. The median arterial length covered was 100 mm, with an average length of stent overlap of 25 mm. Tapered configurations were used in 43.8% of cases. The majority of limbs (62.8%) had a three-vessel runoff, 20.2% had a two-vessel runoff, and 17% has a one-vessel runoff. The Kaplan-Meier estimates of graft occlusion at 1 and 3 years were 6.3% and 16.2%, respectively. The 1- and 3-year primary patency rates were 88.2% and 72.6%, and the 1- and 3-year major adverse limb event-free survival (MALE-FS) rates were 82% and 57.4%. The 1- and 3-year survival rates were 92.9% and 76.2%, respectively. On multivariable Cox regression, aneurysm size, one-vessel runoff, and coverage below the knee were associated with a lower 3-year MALE-FS. Coverage below the knee was also associated with a lower 3-year MALE-FS. Other anatomic or technical details were not associated with limb-related events or patency. CONCLUSIONS: This study is the largest single center analysis to describe the predictors of poor outcomes after EPAR. EPAR is a safe and effective way to treat popliteal artery aneurysms. Factors associated with poor MALE-FS after EPAR include single-vessel tibial runoff and coverage below the knee.

Systemic vasoprotection by inhaled carbon monoxide is mediated through prolonged alterations in monocyte/macrophage function.

Carbon monoxide (CO) is anti-inflammatory and protective in models of disease. Its actions in vitro are short-lived but are sustained in vivo. We hypothesize that systemic CO can mediate prolonged phenotype changes in vivo, with a focus on macrophages (Mφs). Mφs isolated from CO treated rats responded to lipopolysaccharide (LPS) with increased IL6, IL10 and iNOS expression but decreased TNF. Conditioned media (CM) collected from peritoneal Mφs isolated from CO treated rats stimulated endothelial cell (EC) proliferation versus CM from Mφs from air treated rats. This effect was mediated by Mφ released VEGF and HMGB1. Inhaled CO reduced LPS induced Mφ M1 inflammatory phenotype for up to 5 days. Mitochondrial oxygen consumption in LPS treated Mφs from CO treated mice was preserved compared to LPS treated Mφs from control mice. Finally, transient reduction of inflammatory cells at the time of inhaled CO treatment eliminated the vasoprotective effect of CO in a rodent carotid injury model. Thus, inhaled CO induces a prolonged mixed phenotype change in Mφs, and potentially other inflammatory cells, that contribute to vasoprotection. These findings demonstrate the ability of inhaled CO to modify Mφs in a sustained manner to mediate its therapeutic actions, supporting the translational potential of inhaled CO.

Meta-analysis of open and endovascular repair of popliteal artery aneurysms.

OBJECTIVE: Endovascular popliteal artery aneurysm repair (EPAR) is increasingly used over open surgical repair (OPAR). The purpose of this study was to analyze the available literature on their comparative outcomes. METHODS: The PubMed and Embase databases were searched to identify studies comparing OPAR and EPAR. Studies with only one treatment and fewer than five patients were excluded. Demographics and outcomes were collected. Bias risk was assessed using a modified version of the Newcastle-Ottawa Scale. Results were computed from random-effects meta-analyses using the DerSimonian-Laird algorithm. RESULTS: A total of 14 studies were identified encompassing 4880 popliteal artery aneurysm repairs (OPAR, 3915; EPAR, 1210) during the last decade. OPAR patients were younger (standard mean difference, -0.798 [-0.798 to -1.108]; P < .001) and more likely to have worse tibial runoff (odds ratio [OR], 1.949 (1.15-3.31); P = .013) than EPAR patients. OPAR had higher odds of wound complications (OR, 5.182 [2.191-12.256]; P < .001) and lower odds of thrombotic complications (OR, 0.362 [0.155-0.848]; P < .001). OPAR had longer length of stay (standardized mean difference, 2.158 [1.225-3.090]; P < .001) and fewer reinterventions (OR, 0.275 [0.166-0.454]; P < .001). Primary patency was better for OPAR at 1 year and 3 years (relative risk, 0.607 [P = .01] and 0.580 [P = .006], respectively). There was no difference in secondary patency at 1 year and 3 years (0.770 [P = .458] and 0.642 [P = .073], respectively). CONCLUSIONS: EPAR has a lower wound complication rate and shorter length of hospital stay compared with OPAR. This comes at the cost of inferior primary patency but not secondary patency out to 3 years. Studies reporting long-term outcomes are lacking and necessary.

Contemporary outcomes of open and endovascular popliteal artery aneurysm repair.

OBJECTIVE: The purpose of this study was to evaluate contemporary practice and outcomes of open repair (OR) or endovascular repair (ER) for popliteal artery aneurysms (PAAs). METHODS: Consecutive patients with PAA treated at one institution from January 2006 to March 2014 were reviewed under an Institutional Review Board-approved protocol. Demographics, indications, anatomic characteristics, and outcomes were collected. Standard statistical methods were used. RESULTS: A total of 186 PAAs were repaired in 156 patients (110 ORs, 76 ERs) with a mean age of 71 ± 11 years, and most were male (96%). Mean follow-up was 34.9 ± 28.6 months for OR and 28.3 ± 25.8 months for ER (P = .12). Comorbidities were similar between groups. OR was used in more patients with PAA thrombosis (41.8% vs 5.3%; P < .001), acute ischemia (24.5% vs 9.2%; P = .010), and ischemic rest pain (34.5% vs 6.6%; P < .001). Mean tibial (Society for Vascular Surgery) runoff score was 5.0 for OR vs 3.3 for ER (P = .006). OR was associated with increased 30-day complications (22% vs 2.6%; P < .001) and mean postoperative stay (5.8 vs 1.6 days; P < .001). There was no difference in 30-day mortality (OR, 1.8%; ER, 0%; P = .56) or major amputation rate (OR, 3.7%; ER, 1.3%; P = .65). Primary, primary assisted, and secondary patency rates were similar at 3 years (OR, 79.5%, 83.7%, and 85%; ER, 73.2%, 76.3%, and 83%; P = NS). Among 130 patients presenting electively without acute ischemia or thrombosed PAA (63 ORs and 67 ERs), OR had better 3-year primary patency (88.3% vs 69.8%; P = .030) and primary assisted patency (90.2% vs 73.5%; P = .051) but similar secondary patency (90.2% vs 82%; P = .260). ER thrombosis was noted in 8 of 24 patients treated in 2006-2008 (33%; mean time to failure, 49 months) but in only 4 of 51 patients treated in 2009-2013 (7.8%; mean time to failure, 30 months), suggesting a steep learning curve. CONCLUSIONS: ER is a safe and durable option for PAA, with lower complication rates and a shorter length of stay. OR has superior primary patency in patients treated electively but no difference in midterm secondary patency and amputations.

Arteriovenous grafts are associated with earlier catheter removal and fewer catheter days in the United States Renal Data System population.

OBJECTIVE: Arteriovenous fistulas (AVFs) are associated with improved long-term outcomes but longer maturation times and higher primary failure rates compared with arteriovenous grafts (AVGs). The Fistula First Breakthrough Initiative has recently emphasized tunneled dialysis catheter (TDC) avoidance. We sought to characterize the relationship of AVFs and AVGs to the use of TDCs as well as secondary procedures. METHODS: Using the United States Renal Data System (USRDS) database, we identified incident hemodialysis (HD) patients in 2005 that started HD with a TDC and survived at least 1 year. We then monitored them through 2008. Access creation, TDC removal, TDC placement, and secondary procedures were identified by Current Procedural Terminology codes (American Medical Association, Chicago, Ill). Multivariate logistic regression was used to identify risk factors for the primary end points. RESULTS: In 2005, HD was initiated in 56,495 patients, 74% with a TDC. Of these, 6286 had an access procedure ≤3 months and 1 year of follow-up (AVF, 4634; AVG, 1652). Mean age was 67.7 years (AVF, 67.3; AVG, 68.7 years; P < .001), 53.3% were men (AVF, 58.1%; AVG, 40.5%; P < .001), and 33.8% were obese (AVF, 33.6%; AVG, 34.4%; P = not significant). AVG placement was associated with a higher TDC removal at 1 (7.9% vs 3.1%; P < .001), 3 (47.8% vs 17.8%; P < .001), and 6 (60.6% vs 47.2%; P < .001) months. There was no difference at 9 months (AVG, 64.9% vs AVF, 62.3%; P = .06). The median time to TDC removal was lower in the AVG group (70 days vs 155 days; P < .001). Multivariable model found AVFs were associated with decreased odds of TDC removal at 3 (odds ratio, 0.22; P < .001) and 6 months (odds ratio, 0.54; P < .001). AVGs required more secondary procedures than AVFs at all time points up to 1 year and specifically had increased thrombectomy procedures (39.8% vs 11.5%; P < .001). CONCLUSIONS: In patients starting dialysis with a TDC, AVGs are associated with increased TDC removal and fewer catheter days compared with AVFs at up to 6 months. However, AVGs require more secondary procedures at all time points up to 1 year.

Prophylactic distal revascularization with interval ligation and simultaneous arteriovenous fistula creation in high-risk patients.

Dialysis access-related ischemic steal syndrome is a well-recognized dialysis access complication. When severe, manifestations include rest pain, hand dysfunction, and tissue loss. Dialysis access attempts on the affected extremity are usually abandoned after a diagnosis of steal syndrome, and patients are often left catheter-dependent. Prophylactic distal revascularization with interval ligation has been described in patients at high-risk for steal syndrome. We present our experience with prophylactic distal revascularization with interval ligation performed simultaneously with arteriovenous fistula creation to prevent the recurrence in five patients and review the current body of literature supporting its use.

Management and outcomes of dialysis access-associated steal syndrome.

OBJECTIVE: Dialysis access-associated steal syndrome (DASS) complicates arteriovenous access surgery. We describe a 10-year experience with the surgical management of DASS. METHODS: DASS operations were retrospectively reviewed from July 2003 to July 2013 from a single academic institution. Demographics, symptoms, surgical details, and outcomes were collected. RESULTS: A total of 201 patients had 218 episodes of DASS. Mean age was 65 years, and 62% were women. DASS was caused by 175 arteriovenous fistulas (80%), 41 upper extremity prosthetic grafts (19%), and two thigh grafts (1%); 87% were brachial artery based. A portion (22%) were referred for DASS from outside practices. All patients had grade 2 (48%) or grade 3 (52%) DASS; 92% (185) were available for follow-up, with a median time to first follow-up of 23 days. Surgical procedures included ligation (73), distal revascularization with interval ligation (DRIL) (59), revision using distal inflow (RUDI) (21), banding (38), proximalization of arterial inflow (12), and distal radial artery ligation (13). There were no differences in preoperative comorbidities between treatment groups. The 30-day complications included continued steal, thrombosis, bleeding, infection, and mortality. Ligation and DRIL were performed most often for grade 3 steal. Ligation and banding were performed most acutely (median time to intervention after access creation of 39 and 24 days vs DRIL and RUDI at 97 and 100 days). Fistula preservation was 0% for ligation, 100% for DRIL, 95% for RUDI, and 89% for banding (P < .01). Improvement of symptoms ranged from 75% (banding) to 98% (DRIL) (P = .005). Women were less likely to have DRIL but more likely to have ligation (P = .001). Complications were highest in the banding (49%) and RUDI (37%) groups. Average mortality was 3.5%, with no significant differences among groups. During the study period, 3287 access procedures were performed, and access volume steadily increased (2003-2008, 1312 access creations; 2008-2013, 1975). Percentage of fistulas (79% vs 86%), incidence of steal (4% vs 6%), and percentage of DRILs (25% vs 28%) were consistent across the two study periods. CONCLUSIONS: DRIL and ligation were performed in patients with the most severe symptoms. Compared with ligation, DRIL has equal symptom resolution, no increase in complications, and fistula preservation. Compared with banding, DRIL resulted in superior fistula preservation and fewer complications. DRIL should be considered the preferred procedure for management of DASS in patients with a functioning autologous fistula who can tolerate a major operation.

Perceptions of society for vascular surgery members and surgery department chairs of the integrated 0 + 5 vascular surgery training paradigm.

INTRODUCTION: As the first generation of integrated (0 + 5) vascular surgery (VS) residents enter the job market, this survey sought to understand how the surgical community perceives this training paradigm. METHODS: An anonymous online survey was e-mailed to surgery chairpersons (n = 193) and Society for Vascular Surgery (SVS) members (n = 2193) in the United States/Canada with 26% (n = 38) and 14% (n = 309) response rates, respectively. Respondents were asked about their practice background, residency program, hiring patterns, and perceptions of the 0 + 5 training. RESULTS: Response rates were 26% (n = 38) and 14% (n = 309) for surgery chairpersons and SVS members, respectively. SVS respondents were from academic (62%) and private (38%) practices and included staff surgeons (62%), program directors (15%), and division chiefs (22%). Only 33% had a 0 + 5 program, and 57% had a VS fellowship. Overall, 94% were likely to hire a new vascular surgeon in the next 5 years. In some categories, SVS respondents believed 0 + 5 residents would be less prepared than 5 + 2 residents. Only 32% thought that 0 + 5 residents have the same level of surgical maturity, and 36% thought that they have the same level of open operative skills as 5 + 2 trainees. Another 34% thought 0 + 5 residents will need additional fellowship training in open surgery. However, there was also a general perception from SVS respondents that 0 + 5 residents would be prepared for clinical practice (67%) and would have equal endovascular skills to 5 + 2 trainees (92%). The chairpersons had similar perceptions as SVS members. Both SVS members (88%) and chairpersons (86%) would consider interviewing a 0 + 5 graduate for faculty position; 83% and 72%, respectively, would consider hiring. Moreover, 93% of SVS respondents who currently have a 0 + 5 program and 86% of SVS respondents who do not would consider hiring a 0 + 5 graduate. Both SVS members (62%) and chairpersons (50%) believed the 0 + 5 paradigm is essential for the advancement of VS. CONCLUSIONS: Overall perceptions of 0 + 5 graduates were positive and indicated their likely acceptance into the VS workforce. Although there were some reservations regarding the 0 + 5 graduates' maturity level and open operative skills, the surgical community was willing to interview and hire these trainees for staff positions. Further follow-up will be required to evaluate their performance in clinical practice.

Retrograde open mesenteric stenting for acute mesenteric ischemia is a viable alternative for emergent revascularization.

OBJECTIVES: Significant comorbidities and an exhausted physiologic reserve lead to high mortality rates during operations for acute mesenteric ischemia. We present our experience with retrograde open mesenteric stenting. METHODS/RESULTS: A total of 3 female patients (mean age = 74.1 years) with acute mesenteric ischemia underwent exploratory laparotomy. Operative technique included isolating the superior mesenteric artery for cannulation and retrograde endovascular angioplasty and stenting. One required small bowel resection. All 3 patients survived. Mean follow-up was 8.4 months (range: 1.2-16.6). All remain with a 100% primary patency rate. CONCLUSION: Retrograde open mesenteric stenting for acute mesenteric ischemia is a viable alternative to bypass.

Should fistulas really be first in the elderly patient?

BACKGROUND: The Kidney Disease Outcomes and Quality Initiative (K/DOQI) has developed guidelines from available data suggesting that arteriovenous fistulas (AVF) be performed in the majority of patients. Patient demographics were not included nor suggested in their recommendations. The purpose of this study is to analyze the outcomes of elderly patients, age greater than 70, undergoing first-time permanent access surgery. METHODS: A retrospective review of consecutive patients undergoing new, first time access procedures from January 2005 through December 2005 was performed. Patients with previous attempts at permanent Arteriovenous (AV) access were removed from analysis. Standard statistical methods were used and patency was determined with Kaplan-Meier curves. RESULTS: One hundred and sixty eight patients underwent first time AVF, 48 of whom were older than 70 years of age. Comparing elderly patients to younger ones, the 12 month primary assisted patency was 35% and 67%, respectively (p=0.002) and secondary patency was 36% and 67%, respectively (p=0.004). Of the 48 elderly patients, 48% had died in the subsequent follow up period as compared to just 20% of the 120 patients younger than 70. The 18-month survival for the elderly group was 50% versus 74% for the younger patients (p=0.004). Of the elderly group who died, the average time to death was 13.1 months and only 8 AVF were able to be accessed. Similar intervention rates per year were seen in both groups. DISCUSSION: With an aging population, more patients older than 70 are being evaluated for permanent vascular access. This group poses a difficult dilemma for surgeons attempting to adhere to K/DOQI guidelines. In light of the increased mortality and decreased patency of AVF, this data questions which form of permanent access should be first-line treatment in this subgroup of patients. CONCLUSION: This data suggest in the elderly patients, autogenous fistulas may not be the best option for this set of patients.