Clinical factors associated with ultrashort length of stay in patients undergoing lower extremity bypass for peripheral arterial disease.

BACKGROUND: Length of stay (LOS) is a major driver of cost and resource utilization following lower extremity bypass (LEB). However, the variable comorbidity burden and mobility status of LEB patients makes implementing enhanced recovery after surgery pathways challenging. The aim of this study was to use a large national database to identify patient factors associated with ultrashort LOS among patients undergoing LEB for peripheral artery disease. METHODS: All patients undergoing LEB for peripheral artery disease in the National Surgical Quality Improvement Project database from 2011 to 2018 were included. Patients were divided into two groups based on the postoperative length of stay : ultrashort (≤2 days) and standard (>2 days). Thirty-day outcomes were compared using descriptive statistics, and multivariable logistic regression was used to identify patient factors associated with ultrashort LOS. RESULTS: Overall, 17,510 patients were identified who underwent LEB, of which 2678 patients (15.3%) had an ultrashort postoperative LOS (mean, 1.8 days) and 14,832 (84.7%) patients had a standard LOS (mean, 7.1 days). When compared to patients with a standard LOS, patients with an ultrashort LOS were more likely to be admitted from home (95.9% vs 88.0%; P < .001), undergo elective surgery (86.1% vs 59.1%; P < .001), and be active smokers (52.1% vs 40.4%; P < .001). Patients with an ultrashort LOS were also more likely to have claudication as the indication for LEB (53.1% vs 22.5%; P < .001), have a popliteal revascularization target rather than a tibial/pedal target (76.7% vs 55.3%; P < .001), and have a prosthetic conduit (40.0% vs 29.9%; P < .001). There was no significant difference in mortality between the two groups (1.4% vs 1.8%; P = .21); however, patients with an ultrashort LOS had a lower frequency of unplanned readmission (10.7% vs 18.8%; P < .001) and need for major reintervention (1.9% vs 5.6%; P < .001). On multivariable analysis, elective status (odds ratio , 2.66; 95% confidence interval [CI], 2.33-3.04), active smoking (OR, 1.18; 95% CI, 1.07-1.30), and lack of vein harvest (OR, 1.55; 95% CI, 1.41-1.70) were associated with ultrashort LOS. Presence of rest pain (OR, 0.57; 95% CI, 0.51-0.63), tissue loss (OR, 0.30; 95% CI, 0.27-0.34), and totally dependent functional status (OR, 0.54; 95% CI, 0.35-0.84) were associated negatively with an ultrashort LOS. When examining the subgroup of patients who underwent vein harvest, totally dependent (OR, 0.38; 95% CI, 0.19-0.75) and partially dependent (OR, 0.53; 95% CI, 0.32-0.88) functional status were persistently negatively associated with ultrashort LOS. CONCLUSIONS: Ultrashort LOS (≤2 days) after LEB is uncommon but feasible in select patients. Preoperative functional status and mobility are important factors to consider when identifying LEB patients who may be candidates for early discharge.

Expected Duplex Ultrasound Results in Distal Revascularization and Interval Ligation Conduits.

BACKGROUND: There are no published standards for the expected findings on noninvasive testing following distal revascularization and interval ligation (DRIL). This study evaluated the hemodynamic results and duplex ultrasound characteristics of DRIL. METHODS: A retrospective chart review of patients who underwent DRIL using autogenous vein between 2008 and 2019 was performed. Patients with both preoperative and follow-up noninvasive testing were included. RESULTS: Thirty-eight patients were included in the study. Median time to first follow-up was 30 days (range 1-226 days), where 12 had complete resolution of their symptoms and 26 had partial resolution. Of the 27 patients that had preoperative and postoperative testing, the wrist brachial index improved from 0.56 to 0.90 with the median finger pressure improving from 56 to 73 (P < 0.001). Seventeen patients had a second follow-up (sFU) at a median time from DRIL of 196 days (range 106-843 days). There was no significant difference in wrist brachial index or finger pressures between first follow-up and sFU. Duplex ultrasound of the DRIL conduits (n = 32) showed a very consistent pattern with elevated median velocities proximally (inflow 235 cm/sec, proximal anastomosis 217.7 cm/sec) and distinctly slower median velocities distally (midconduit 46.4 cm/sec, distal anastomosis 78.3 cm/sec, outflow 59.3 cm/sec). The same pattern of velocities was held constant at the sFU (n = 16). CONCLUSIONS: In this study, velocities at the proximal anastomosis were significantly higher than velocities more distal in the DRIL bypass without evidence of stenosis. This may be due to hemodynamic changes in the brachial artery associated with presence of a fistula. Elevated velocities at the proximal anastomosis do not necessarily warrant further evaluation or intervention without other evidence of conduit compromise.

Development of hyperacute high-output heart failure at access creation.

High-output heart failure can occur in patients undergoing hemodialysis via permanent access. We have described two cases of hyperacute high-output heart failure. Two patients with multiple previous failed access attempts presented for redo access. Each patient experienced high-output heart failure in the operating room during access placement. A delay in the diagnosis led to the first patient's death, although early recognition led to successful treatment of the second patient. Hyperacute heart failure during access creation is uncommon. Early recognition of this complication is important because timely intervention can be life-saving.

Redo Hemodialysis Access in Elderly Patients has Acceptable Outcomes With Similar Patency of Arteriovenous Fistulas as Compared to Grafts.

OBJECTIVES: Selecting optimal hemodialysis access in elderly patients remains challenging, particularly in those requiring new options after failed initial access. We sought to describe the outcomes of redo hemodialysis access in elderly patients. METHODS: All patients aged ≥65 undergoing hemodialysis access placement from 2014-2019 were retrospectively identified in the electronic medical record. Characteristics and outcomes of those with initial versus redo access were compared. Patency was depicted utilizing Kaplan-Meier methods, with censoring at loss to follow-up or death, and unadjusted Cox regression. RESULTS: Overall, 211 elderly patients undergoing 257 procedures were included in the study. Of these, 116 (45.1%) were redo access procedures. There were no demographic or comorbidity differences between the two groups with the exception of central venous stenosis which was more common in the redo cohort (27.2% vs. 6.4%, P < 0.001). 91.5% of initial, vs. 60.3% of redo, procedures were arteriovenous fistulas (P < 0.001). Distribution of fistula type differed between the two groups with first time and redo procedures of 25.5% vs. 6.9% radiocephalic, 28.4% vs. 7.8% brachiocephalic, and 35.5% vs. 37.1% brachiobasilic respectively (P < 0.001). At 12 and 24 months, 63.6% and 44.0% of first-time accesses remained patent vs. 51% and 29.0% of redo accesses (HR 1.37, 95% CI 1.05-1.80, P = 0.02). However, there was no difference in primary patency between redo grafts and fistulas (48.7% fistulas vs. 55.0% grafts at 12 months, P = 0.47). CONCLUSIONS: These results demonstrate acceptable outcomes of redo access in elderly patients. There is no evidence from this study that prosthetic grafts are preferential, suggesting elderly patients with meaningful life expectancy who require redo access should be offered autogenous options when possible.

Successful bilateral popliteal-plantar bypasses for polyarteritis nodosa induced ischemia.

Polyarteritis nodosa (PAN) is a rare vasculitis that can cause peripheral ischemia. We present the case of a 49-year-old man who developed PAN causing toe gangrene and severe rest pain in one foot and claudication of the contralateral foot. He was treated with immunosuppression and underwent popliteal-plantar artery bypass with resolution of rest pain and subsequent amputation of his mummified toe. Despite remission of PAN, his contralateral foot claudication was lifestyle limiting; thus, 5 years later he underwent contralateral popliteal-plantar bypass with resolution of claudication. This case demonstrates the anatomically symmetric presentation of PAN induced ischemia with successful open revascularization after resolution of inflammatory markers with systemic therapy.

Distal revascularization and interval ligation for dialysis access-related ischemia is best performed using arm vein conduit.

OBJECTIVE: Distal revascularization and interval ligation (DRIL) is an effective approach to the management of hemodialysis access-related ischemia that offers both symptom relief and access salvage. The great saphenous vein (GSV) has been the most commonly used conduit. However, the use of an ipsilateral arm vein will allow for performance of the operation with the patient under regional anesthesia and might result in lower harvest site morbidity than the GSV. We sought to determine the suitability of DRIL using an arm vein compared with a GSV conduit. METHODS: All patients who had undergone DRIL from 2008 to 2019 were retrospectively identified in the electronic medical records. The characteristics and outcomes of those with an arm vein vs a GSV conduit were compared using the Wilcoxon log-rank and χ2 tests. Access patency was examined using Kaplan-Meier methods, with censoring at lost to follow-up or death. RESULTS: A total of 66 patients who had undergone DRIL for hand ischemia were included in the present study. An arm vein conduit was used in 40 patients (median age, 65 years; 25% male) and a GSV conduit in 26 patients (median age, 58 years; 19% male). No significant differences in comorbidities were found between the two groups, with the exception of diabetes mellitus (arm vein group, 78%; GSV group, 50% GSV; P = .02). No difference in the ischemia stage at presentation was present between the groups, with most patients presenting with stage 3 ischemia. Also, no differences in patency of hemodialysis access after DRIL between the two groups were found (P = .96). At 12 and 24 months after DRIL, 86.9% (95% confidence interval [CI], 68.3%-94.9%) and 82.0% (95% CI, 61.3%-92.3%) of patients with an arm vein conduit had access patency compared with 93.8% (95% CI, 63.2%-99.1%) and 76.9% (95% CI, 43.0%-92.2%) of those with a GSV conduit, respectively. All but one patient had symptom resolution. The incidence of wound complications was significantly greater in the GSV group than in the arm vein group (46% vs 11%; P = .003). DRIL bypass had remained patent in all but one patient in each group, with a median follow-up of 18 months (range, 1-112 months) in the arm vein conduit group and 15 months (range, 0.25-105 months) in the GSV conduit group. CONCLUSIONS: DRIL procedures using an arm vein have advantages over those performed with the GSV. In our series, symptom resolution and access salvage were similar but distinctly fewer wound complications had occurred in the arm vein group. Additionally, the use of an arm vein conduit avoids the need for general anesthesia. If an ipsilateral arm vein is available, it should be the conduit of choice when performing DRIL.

Regional Market Competition is Associated with Aneurysm Diameter at the Time of EVAR.

BACKGROUND: Local market competition has been previously associated with more aggressive surgical decision-making. For example, more local competition for organs is associated with acceptance of lower quality kidney offers in transplant surgery. We hypothesized that market competition would be associated with the size of an abdominal aortic aneurysm (AAA) at the time of elective endovascular aneurysm repair (EVAR). METHODS: We included all elective EVARs reported in the Vascular Quality Initiative database (2012-2018). Small AAAs were defined as a maximum diameter <5.5 cm in men or <5.0 cm in women. We calculated the Herfindahl-Hirschman Index (HHI), a measure of physician market concentration (higher HHI = less market competition), for each US census region. Multilevel regression was used to examine the association between the size of AAA at EVAR and HHI, clustering by region. RESULTS: Of 37,914 EVARs performed, 15,379 (40.6%) were for small AAAs. There was significant variation in proportion of EVARs performed for small AAAs across regions (P < 0.001). The South had both the highest proportion of EVARs for small AAAs (44.2%) as well as the highest market competition (HHI 50), whereas the West had the lowest proportion of EVARs for small AAAs (35.0%) and the lowest market competition (HHI 107). Adjusting for patient characteristics, each 10 unit increase in HHI was associated with a 0.1 mm larger maximum AAA diameter at the time of EVAR (95% CI 0.04-0.24 mm, P = 0.005). CONCLUSIONS: Physician market concentration is independently associated with AAA diameter at time of elective EVAR. These data suggest that physician decision-making for EVAR is impacted by market competition.

Complete versus partial excision of infected arteriovenous grafts: Does remnant graft material impact outcomes?

OBJECTIVE: Infected arteriovenous grafts necessitate intervention to obtain source control. However, excising the graft material can be challenging and can lead to complications. Leaving a cuff of graft at the sites of anastomosis allows for the avoidance of potential risks. However, it is unclear whether doing so places patients at risk of recurrent graft infection. The purpose of the present study was to investigate the effect of complete vs partial excision of infected arteriovenous prosthetic dialysis access grafts. METHODS: The data from all patients who had undergone surgical intervention for infected arteriovenous grafts at a single institution were retrospectively reviewed. The patients were grouped according to intervention type: complete excision and partial excision of arteriovenous prosthetic grafts. Partial excisions were further substratified based on whether flow had been restored through the arteriovenous access. The primary outcome was freedom from subsequent intervention for infection, defined as the number of days from excision to subsequent reoperation for reinfection. Freedom from infection was analyzed using the Kaplan-Meier method. RESULTS: A total of 117 patients had undergone surgical intervention for 122 infected arteriovenous grafts from 2003 to 2016. Of these 117 patients, 79 (64.8%) had undergone partial excision of infected arteriovenous grafts, and 43 (35.2%) had undergone complete excision with vascular repair. Within the partial excision cohort, 71 infected arteriovenous grafts (58.2%) were not flow restored and 8 (6.6%) were flow restored using either prosthetic or autogenous interpositions. The median follow-up time was 2.4 years (interquartile range, 0.6-4.5 years). The most common causative organisms included methicillin-resistant Staphylococcus aureus (n = 34; 27.9%), methicillin-sensitive S. aureus (n = 17; 13.9%), and S. epidermidis (n = 15; 12.3%). The recurrent infection rate in the partial excision group was 16.5% (n = 13) compared with 2.3% (n = 1) in the complete excision group. In the flow-restored subcohorts, those with restoration using prosthetic interposition grafts had the greatest reinfection rate at 57.1% (n = 4), and those with restoration using autogenous conduits did not experience reinfection (P = .033). CONCLUSIONS: Incomplete excision of infected arteriovenous prosthetic grafts was associated with a higher rate of reinfection compared with complete graft excision. Complete excision presents technical challenges but could provide superior source control in managing infected dialysis access. Complete excision with vascular reconstruction should be performed when possible to avoid leaving remnant prosthetic material.

Contemporary Outcomes following Redo Autogenous Infrainguinal Bypass.

BACKGROUND: Revascularization after lower extremity bypass failure poses many challenges. Despite nearly 7 decades of experience with lower extremity revascularization, there is little data on the success of redo bypass particularly when autogenous conduit is utilized. The purpose of this study is to review outcomes of redo infrainguinal bypass constructed solely of autogenous vein. METHODS: All patients who underwent redo infrainguinal bypass at a single institution by a single surgeon were retrospectively reviewed. Bypasses were categorized into 3 groups: femoral-popliteal, femoral-distal, and popliteal-distal bypasses. Since the repeat bypasses were all done for limb salvage, freedom from above or below knee amputation (FFA) was primary outcome, which was defined as the number of days from redo bypass to subsequent amputation or the most recent follow-up. RESULTS: From 2006 to 2016, 100 limbs underwent redo bypass. Fifty-nine (59.0%) limbs had undergone one previous bypass while 41 (41.0%) had undergone 2 or more. The redo configurations consisted of 23 (23.0%) femoral-popliteal, 70 (70.0%) femoral-distal, and 7 (7.0%) popliteal-distal bypasses. Ninety-seven (97.0%) underwent redo using autologous vein grafts including 41 (95.5%) of those who had 2 or more previous bypasses. The 3 patients who ultimately underwent prosthetic bypass had bilateral great and small saphenous veins and bilateral basilic and cephalic veins previously harvested. Nine (9.0%) limbs were subsequently amputated: 2 (2.0%) above knee and 7 (7.0%) below knee amputations. Of these, all had had 2 or more previous bypasses and 2 of the 3 patients who ultimately received prosthetic bypasses were in this group. In patients with one previous bypass, FFA was 775 days (IQR: 213-1,626 days). In patients with 2 or more previous bypasses, FFA was 263 days (IQR: 106-1,148 days). No patients with femoral-popliteal bypasses suffered amputation while 7 (10.0%) of the femoral-distal and 2 (28.6%) of the popliteal-distal bypasses suffered subsequent amputations (P = 0.067). CONCLUSIONS: Redo infrainguinal bypass is effective in salvaging threatened lower extremities. Furthermore, once a patient is deemed a bypass candidate, revascularization with autologous vein can be achieved. A significant FFA rate is achieved with redo bypass, although patients with more distal disease are harder to salvage.

Comparison of forearm versus upper arm basilic transposition arteriovenous fistulas demonstrates equivalent satisfactory patency.

OBJECTIVE: In accordance with the Kidney Disease Outcomes Quality Initiative recommendations, attaining autogenous hemodialysis access, specifically via creation of radiocephalic arteriovenous fistulas (AVF), brachial-basilic (BB)-AVF, or brachial-cephalic AVFs, is preferred for mortality and morbidity benefits over catheter access in patients with end-stage renal disease. The aim of this study is to determine the suitability of forearm basilic vein transposition (FBVT) fistulas as an alternative access option by comparing outcomes with those of BB-AVFs. METHODS: All patients who underwent creation of FBVT between 2007 and 2015 were identified retrospectively in the electronic medical record and compared with a sample of patients undergoing BB-AVF placement during this time. Access patency was examined using Kaplan-Meier methods and Cox proportional hazards regression. RESULTS: We included 34 patients with FBVT (median age, 54 years; 67.6% male) and 49 with BB-AVF (median age, 57 years; 42.9% male) in this study. There were no significant differences in comorbid conditions between the two groups, with the exception of hyperlipidemia (29.4% FBVT vs 53.1% BB-AVF; P = .03). Although those with FBVT were more likely to have had previous permanent access attempts (70.6% vs 38.7%; P = .002), and access attempts on the same extremity (44.1% vs 24.4%; P = .04), there were no significant differences in primary patency (46.9% vs 53.3%; P = .6), primary-assisted patency (65.6% vs 73.3%; P = .5), or secondary patency (68.8% vs 82.2%; P = .2) at 1 year when compared with BB-AVF. The risk of loss of patency was not statistically different for FBVT as compared with BB-AVF (hazard ratio, 1.37; 95% confidence interval 0.65-2.88; P = .4). This risk did not vary for those who had previous access on the same arm (interaction P = .8). Four fistulas in each group failed to mature. Only one infectious complication was identified in the FBVT group. CONCLUSIONS: No prior studies have directly compared outcomes of FBVTs with BB-AVFs at 1 year or longer. Despite the increased difficulty of harvesting the forearm basilic vein, particularly in patients who have had prior access attempts, there was no significant difference in patency between FBVTs and BB-AVFs. FBVTs are a reasonable option for hemodialysis access, particularly in patients without adequate cephalic veins or who previously failed radiocephalic fistula attempts.

Practice patterns in arteriovenous fistula ligation among kidney transplant recipients in the United States Renal Data Systems.

BACKGROUND: Arteriovenous fistulas (AVF) and grafts (AVG) have been associated with significant cardiac morbidity that often improves after ligation. However, AV access ligation after kidney transplant (KT) is controversial due to concern for potential long-term allograft failure. We investigated US trends in AV access ligation after KT and the association between ligation and allograft failure. METHODS: All adult Medicare patients on pretransplant hemodialysis with a functioning AVF or AVG who underwent first-time KT were studied using the United States Renal Data Systems (January 2011 to December 2013). Post-transplant AV access ligation was determined using current procedural terminology codes. The incidence of post-transplant AV access ligation was described, and characteristics for patients undergoing ligation vs no ligation were compared. Kaplan-Meier curves and Cox proportional hazard models were then used to determine the association of AV access ligation with long-term allograft failure and all-cause mortality after accounting for patient characteristics, donor characteristics, and variation in transplant center practices. RESULTS: A total of 16,845 patients with functioning AVF/AVG received a KT during the study period. Of these, 779 (4.6%) underwent post-transplant AV access ligation. The proportion of patients who underwent ligation varied substantially between transplant centers, ranging from 0% (43.0% of centers) to >10% (11.0% of centers). Transplant recipients who underwent access ligation were more likely to be female (40.4% vs 36.6%), had lower median body mass index (27.6 vs 28.4 kg/m2), spent longer on dialysis pretransplant (4.2 vs 4.0 years), and were less likely to have renal failure secondary to diabetes compared with other etiologies (25.0% vs 34.9%) (all, P ≤ .03). Patients who underwent ligation were also more likely to have steal syndrome (77.2% vs 4.1%) and AV access infectious or aneurysmal complications (2.7% vs 0.7%) (both, P < .001). After adjusting for donor and recipient characteristics, increasing age (adjusted hazards ratio [aHR], 1.01; 95% confidence interval [CI], 1.00-1.01), increasing years on dialysis (aHR, 1.06; 95% CI, 1.00-1.13), zero human leukocyte antigen mismatch (aHR, 1.82; [95% CI, 1.09-3.05), and steal syndrome (aHR, 41.00; 95% CI, 34.56-48.64) were associated with post-transplant AV access ligation. Black race (aHR, 0.82; 95% CI, 0.69-0.98) and congestive heart failure (aHR, 0.66; 95% CI, 0.54-0.82) were negatively associated with ligation. Three-year allograft failure occurred in 4.9% ± 1.3% transplant recipients who underwent access ligation vs 9.5% ± 0.5% transplant recipients with functioning access (log-rank, P = .30), and was not significantly different between groups after risk adjustment (aHR, 0.81; 95% CI, 0.47-1.40). There was also no significant association between AV access and all-cause mortality after risk adjustment (aHR, 0.84; 95% CI, 0.46-1.54). CONCLUSIONS: Post-transplant AV access ligation is uncommon and generally reserved for patients with steal syndrome. Importantly, ligation is not associated with post-transplant allograft failure, which occurs in less than 10% of patients at 3 years. There also appears to be no reduction in all-cause mortality with AV access ligation. These data suggest that AV access ligation after KT can likely be reserved for access-related complications because the systemic benefits appear to be minimal.

Feasibility and Outcomes of Femoral Vein Harvest for Dialysis Access and Arterial Reconstruction.

BACKGROUND: We describe the feasibility and long-term outcomes of using femoral vein (FV) for arteriovenous fistula (AVF) and lower extremity bypass (LEB) creation. METHODS: All patients undergoing AVF or LEB using autogenous FV by a single surgeon (April 2006 to September 2013) were reviewed. Perioperative (30-d) complications and long-term outcomes are described. RESULTS: Forty-four patients underwent vascular reconstruction with FV (AVF = 27 and LEB = 17). Perioperative morbidity was 43.2%, including harvest site infection and or seroma in 15.9%. No patients suffered from compartment syndrome or venous thromboembolic event. At median follow-up of 50.0 mon, overall patency was 70.4% for AVF (primary = 37.0% and secondary = 70.3%) and 76.5% for LEB (primary = 70.6% and secondary = 76.5%). Long-term lower extremity swelling occurred in 18.2% of patients. CONCLUSIONS: Perioperative morbidity following FV harvest is high, but long-term patency rates are excellent. FV harvest is feasible and should be considered as a valid conduit in patients without useable great saphenous vein or other more commonly used sources of autogenous vein.

Removal of Noninfected Arteriovenous Fistulae after Kidney Transplantation is a Safe and Beneficial Management Strategy for Unused Dialysis Access.

BACKGROUND: Renal transplant recipients often maintain their hemodialysis access in the event of future allograft failure. Patients may develop complications related to the unused dialysis access, and it also limits vein availability for phlebotomy. Accordingly, a change in the current paradigm may be warranted. This study evaluates the indications for, and safety of, arteriovenous fistula (AVF) removal in patients after successful renal transplantation. METHODS: All patients who underwent AVF excision at a single institution from 2006 to 2016 were retrospectively reviewed. Within that cohort, those undergoing removal after renal transplantation were included for analysis. Baseline patient characteristics, including renal function at the time of removal, reason for excision, and age of the AVF, were examined. The primary outcome was the need for dialysis after AVF removal. RESULTS: A total of 114 patients, of which 36 (31.6%) were recipients of renal transplants, underwent fistula removal during the study period. Within the transplant cohort, the median fistula age at the time of excision was 1,903 days (interquartile range: 556-3,394 days). The most common indications for excision included aneurysmal degeneration (n = 9, 25%), pain (n = 6, 16.7%), upper extremity steal syndrome (n = 5, 13.9%), thrombosis (n = 5, 13.9%), high cardiac output heart failure (n = 4, 11%), and extremity swelling secondary to venous hypertension (n = 2, 5.6%). Most patients (30, 83.3%) had intact graft function. Average creatinine and eGFR at the time of excision in these patients were 1.6 mg/dL and 52.3 mL/min/m2, respectively. Two of these 30 patients (6.7%), who had creatinine values of 2.0 and 9.7 mg/dL, went on to require dialysis following excision. The remaining 28 have maintained normal renal function with improvement in their preoperative symptomatology. Two patients (5.6%) experienced postoperative complications-a hematoma requiring evacuation and a superficial wound infection requiring oral antibiotics. CONCLUSIONS: Removal of symptomatic, unused AVFs can be performed safely in renal transplant recipients. Considering the morbidity associated with large AVFs (including high output cardiac failure), the current paradigm of maintaining asymptomatic hemodialysis access in patients with normally functioning renal transplants should be reconsidered.

A prospective randomized study of bovine carotid artery biologic graft and expanded polytetrafluoroethylene for permanent hemodialysis access.

OBJECTIVE: Arteriovenous grafts (AVGs) remain reliable substitutes for permanent hemodialysis access in scenarios that preclude the placement of native arteriovenous fistulas (AVFs). The majority of AVGs are constructed of expanded polytetrafluoroethylene (ePTFE), which is relatively inexpensive and readily available, but synthetic AVGs have poor patency rates. On the other hand, biologic grafts confer an advantage by virtue of their inherent similarity to the native human vasculature. However, evidence to support the current preference of synthetic conduits over biologic grafts in clinical practice is scarce. The aim of this protocol is to propose a contemporary re-evaluation and comparison between ePTFE and bovine carotid artery (BCA) grafts. METHODS: This prospective randomized controlled trial is being conducted at an academic hospital center. A total of 100 patients at least 18 years of age and undergoing AVG placement will be recruited and prospectively randomized into two parallel groups with a 1:1 allocation ratio. Patients eligible to receive AVF and those with a known allergic reaction or history of intolerance to any ePTFE or BCA component will not be included in the study. Moreover, patients with a recent active infection at the site of previous AVG placement and patients with a bleeding disorder, an active malignant disease, or a life expectancy <1 year or who refuse blood transfusion and pregnant women will be excluded. Patients will receive either BCA (experimental) or standard ePTFE grafts (control) in compliance with the National Kidney Foundation Kidney Disease Outcomes Quality Initiative guidelines for AVG creation. Primary end points include primary, primary assisted, secondary, and functional patency at 1 year and 2 years after graft placement. Secondary outcomes include complications (pseudoaneurysms, infections, and steal syndrome) and reintervention rates during the first and second postoperative years. Outcomes will be assessed and documented every 6 months. RESULTS: Once the study is completed, analysis of the data will be performed using univariate methods, and Kaplan-Meier and multivariate Cox proportional regression analyses will be employed to evaluate and to compare outcomes between BCA and ePTFE over time. CONCLUSIONS: The creation of a functional and durable dialysis vascular access is crucial in the treatment of patients with end-stage renal disease and is a challenging quest for vascular surgeons. The proposed study compares the outcomes of synthetic and biologic AVG options in patients who are poor candidates for a native AVF. This will help derive contemporary evidence and improve the care of vascular access patients.

Bovine carotid artery biologic graft outperforms expanded polytetrafluoroethylene for hemodialysis access.

OBJECTIVE: Arteriovenous grafts remain reliable substitutes for permanent hemodialysis access in patients without a suitable autogenous conduit. Advances in conduit design and endovascular management of access-related complications question the preference for synthetic conduits over biologic grafts in contemporary practice. In this study, we compared outcomes between a bovine carotid artery (BCA) biologic graft and expanded polytetrafluoroethylene (ePTFE) grafts for hemodialysis access in a recent cohort of patients. METHODS: This was a single-institution retrospective review of 120 consecutive grafts placed in 98 patients between January 1, 2011, and June 30, 2014. Univariate methods (χ2, analysis of variance, t-test) were used to compare demographic and medical characteristics of patients who received each graft type. Kaplan-Meier, log-rank tests, univariate and multivariate logistic analyses, and Cox regression analyses were used to evaluate patency and graft complications. Outcomes were defined and analyzed according to reporting guidelines published by the Society for Vascular Surgery. RESULTS: Of the 120 grafts studied, 52 (43%) were BCA and 68 (57%) were ePTFE. Successful graft use for dialysis was 96% (95% confidence interval [CI], 90%-100%) for BCA and 84% (95% CI, 74%-93%) for ePTFE (P = .055). Comparing BCA vs ePTFE, estimates for primary patency were 30% vs 43% at 1 year and 16% vs 29% at 2 years (P = .27). Primary assisted patency was 36% vs 45% at 1 year and 24% vs 35% at 2 years (P = .57). Secondary patency was 67% vs 48% at 1 year and 67% vs 38% at 2 years (P = .05). There were no differences in primary (hazard ratio [HR], 0.70; 95% CI, 0.40-1.28; P = .25) and primary assisted (HR, 0.87; 95% CI, 0.46-1.65; P = .67) patency for BCA compared with ePTFE. However, secondary patency was higher for BCA compared with ePTFE (HR, 2.92; 95% CI, 1.29-6.61; P = .01). Graft infection rates during the study period were 15.4% for BCA and 20.6% for ePTFE (P = .47). The significant predictors of graft failure were higher body mass index (HR, 1.06; 95% CI, 1.00-1.11; P = .04) and hyperlipidemia (HR, 2.94; 95% CI, 1.27-6.76; P = .01). CONCLUSIONS: In this study of a recent cohort of patients who received arteriovenous grafts, primary and primary assisted patencies were similar between BCA and ePTFE grafts. However, secondary patency was higher for BCA, indicating better durability for the biologic graft than for ePTFE grafts in patients whose anatomy preclude placement of an arteriovenous fistula.

Outcomes after open infrainguinal bypass in patients with scleroderma.

BACKGROUND: There are limited reports of outcomes after infrainguinal bypass surgery in patients with scleroderma. This study evaluated the long-term outcome after lower extremity bypass in these patients. METHODS: The study included all patients with systemic sclerosis who underwent infrainguinal bypass surgery for severe peripheral arterial disease at our institution from January 1, 2007, to August 31, 2014. Kaplan-Meier and Cox regression analyses were used to evaluate graft failure and limb salvage. These outcomes were compared with those of nonscleroderma patients who underwent infrainguinal bypass surgery during the same period. Outcomes were defined and evaluated by Society for Vascular Surgery standards. RESULTS: There were 18 autogenous grafts (6% femoral-popliteal, 11% femoral-tibial, 72% popliteal-tibial, 11% tibial-tibial) placed in 18 limbs from 12 patients with systemic sclerosis. Mean ± standard deviation age was 71 ± 9.5 years, and most of the patients were women (83%) and white (78%). All patients presented with critical limb ischemia. History of hypertension and coronary artery disease were 94% and 61%, respectively. All grafts used were autogenous, continuous, and harvested from the lower extremity (nonreversed great saphenous in 61% and reversed great saphenous in 39%). Mean follow-up duration was 2.3 ± 1.6 years. Graft failure was significantly higher in scleroderma patients than in nonscleroderma patients who underwent bypass in the same study period (hazard ratio, 7.2; 95% confidence interval, 1.44-41.4; P = .02). The limb salvage rate was 72%. CONCLUSIONS: Long-term outcomes after open infrainguinal bypass surgery in scleroderma patients are significantly worse than those in nonscleroderma patients. Careful consideration of their inherently poor outcomes should be made when reaching a decision for revascularization.

Management of infected vascular grafts.

Infections of vascular grafts are associated with significant mortality and morbidity risk and cost an estimated $640 million annually in the United States. Clinical presentation varies by time elapsed from implantation and by surgical site. A thorough history and physical examination in conjunction with a variety of imaging modalities is often essential to diagnosis. For infected aortic grafts, there are several options for treatment, including graft excision with extra-anatomic bypass, in situ reconstruction, or reconstruction with the neo-aortoiliac system. The management of infected endovascular aortic grafts is similar. For infected peripheral bypasses, graft preservation techniques can be utilized, but in cases where it is not possible, graft removal and revascularization through uninfected tissue planes is necessary. Infected dialysis access can be surgically treated by complete or subtotal graft excision. Diagnosis, general management, and surgical approaches to infected vascular grafts are discussed in this review.

Contemporary Outcomes for Open Infrainguinal Bypass in the Endovascular Era.

BACKGROUND: The role of infrainguinal bypasses in this era of increasing endovascular interventions remains the subject of significant debate. In this study, we evaluate contemporary long-term outcomes of lower-extremity open revascularization for peripheral arterial disease (PAD). METHODS: We evaluated all patients who underwent infrainguinal bypass with autogenous vein conduits for claudication or critical limb ischemia in our institution between January 1st, 2007 and July 31st, 2014. Kaplan-Meier and Cox regression analyses were used to evaluate graft failure and identify its predictors. Outcomes were defined per the Society for Vascular Surgery standards. RESULTS: There were 428 autogenous vein grafts (femoro-popliteal: 32%, femoro-tibial: 39%, popliteo-tibial: 27%, and tibio-tibial: 2%) placed in 368 patients (mean age of 67 ± 11.4 years). Most patients were male (59%), white (73%), and presented with critical limb ischemia (81%). Sixty-five cases (15%) were redo bypasses. Arm veins and spliced vein conduits were used in 15% and 14% of cases, respectively. Primary patency at 1, 3, and 5 years was 66%, 59%, and 55%, respectively. Primary-assisted patency was 78%, 69%, and 64% at 1, 3, and 5 years, respectively. Secondary patency was 88%, 84%, and 82% at 1, 3, and 5 years, respectively. Patency was higher for grafts harvested from the lower versus upper extremities and for proximal versus distal bypass (all P < 0.05). Limb salvage rate was 88% after a mean follow-up of 2 ± 1.8 years. Significant predictors of graft failure were younger age, diabetes mellitus, and hyperlipidemia (all P < 0.05). CONCLUSIONS: In this contemporary cohort of patients, we have demonstrated that infrainguinal bypass for lower-extremity revascularization has good long-term outcomes in patients with symptomatic PAD. Patency and limb salvage rates are optimized with careful selection of autogenous conduits, close monitoring of high-risk groups and management of comorbidities.

Vascular access modifies the protective effect of obesity on survival in hemodialysis patients.

BACKGROUND: The protective effect of obesity on the survival of patients undergoing hemodialysis (HD) for end-stage renal disease (ESRD), described as the obesity paradox, has been established previously. Survival benefits also have been ascribed to permanent modes of HD access (fistula/graft) compared with catheter at first HD. The purpose of this study is to evaluate the impact of incident HD access type on the obesity paradox. METHODS: A retrospective study of all patients with ESRD in the US Renal Database System who initiated HD between 2006 and 2010 was carried out. Multivariate logistic, Cox regression, and propensity score matched analyses were used to evaluate the association between body mass index (BMI), modes of HD access (fistula/graft vs catheter), and mortality. RESULTS: There were 501,920 dialysis initiates studied; 83% via catheter, 14% via fistula, and 3% via grafts. Mortality was lesser for patients initiating hemodialysis with permanent forms of access compared with catheter (adjusted odds ratio 0.68, 95% confidence interval 0.67-0.69, P < .001). High body mass index (BMI) was associated with lower mortality. Patients with high BMI were more likely to initiate hemodialysis via permanent modes of access compared with patients with normal BMI. CONCLUSION: The highly popularized protective effect of increased BMI on survival in HD patients is significantly influenced by the method of hemodialysis access. There is greater use of permanent access among patients with high BMI compared with patients with normal BMI. There remains a critical need to increase permanent access utilization at incident hemodialysis so as to improve survival irrespective of BMI status.

Lessons Learned in the Surgical Treatment of Neurogenic Thoracic Outlet Syndrome Over 10 Years.

OBJECTIVE: To evaluate our extensive experience over a decade in the treatment of patients with neurogenic thoracic outlet syndrome (NTOS) who underwent first rib resection and scalenectomy (FRRS). METHODS: Patients treated with FRRS for NTOS from 2003 to 2013 were retrospectively reviewed using a prospectively maintained database. RESULTS: Over 10 years, 286 patients underwent 308 FRRS. During the first 5-year period, 127 FRRS were performed (96 F, 31 M), with an average age of 36.9 years. During the second 5-year period, 181 FRRS were performed (143 F, 38 M), with an average age of 33 years. A total of 24 children (age ≤18 years) underwent FRRS, 9 during the first 5 years and 15 during the second 5 years. When comparing the second 5-year period to the first 5-year period, patients were younger (P = .066), reported a significantly shorter length of preoperative symptoms (35.4 vs. 52.1 months, P < .01), prior narcotic use decreased from 31.5% to 23.8% (P < .05), and a history of prior surgical intervention on the ipsilateral side (head, neck, and shoulder) increased from 30.1% to 51.9% (P < .01). Use of lidocaine blocks as a diagnostic tool (57%-35.4%, P = .06) and Botox blocks as a therapeutic tool (29.1%-12.7%, P < .01) decreased in the second 5 years with similar positive results. Improved or fully resolved symptoms following FRRS increased from 89% in the first 5 years to 92.8% in the second 5 years. Average length of follow-up over the 10-year period was 13.4 months. CONCLUSION: Excellent results were seen in this surgical series reported for NTOS. Younger patients with shorter duration of symptoms with less narcotic use led to even better FRRS results in the second 5 years of surgical intervention. An established vascular practice for referrals for NTOS resulted in an increased number of appropriate patients for surgical intervention, requiring fewer lidocaine and/or Botox injections preoperatively.