Loss Of Primary Patency Research Articles

Disparities in bile duct injury care.

An international group proposed a standardized terminology to report outcomes after bile duct repair. Data on this surgical complication vary depending on the center and country where patients are treated. The aim of this work is to show disparities in the care process of bile duct injury between patients from two different income-level countries, using a standard terminology of outcomes and clinical reporting. A retrospective review comparing primary repair and re-repaired cases performed in an upper middle-income country (UMIC) versus primary repair cases treated in a high-income country (HIC) was performed. All pertinent data included in the tabular reporting system and outcomes classification were collected. Patients' characteristics were reported by calculating descriptive statistics. A total of 261 patients from UMIC (148 (56%) primary repair and 113 (44%) re-repair) were compared with 122 primary repair from HIC. Open cholecystectomy (55.4% vs 3.3%) and more E4 injuries (37.8% vs 19.7%) were found in the UMIC group. More Accordion 3 and higher complications were present in the UMIC primary and repair groups, as well as more episodes of postoperative acute cholangitis. Eleven patients were listed for liver transplant in the UMIC re-repair group. Primary patency by the end of the index treatment period was present in 217 (83%) of the full UMIC cohort. Median time to loss of primary patency was not reached in the primary repair, and was 3.8years in the re-repair group. Patency was below HIC primary repaired cases. Standardized reporting outcomes after primary repair are applicable to re-repaired patients and are helpful to compare different populations, showing better outcomes in HIC. Measures of surgical access disparities exist among the process of bile duct injury care.

Patients with lower extremity dialysis access have poor primary patency and survival

ObjectiveLower extremity arteriovenous (AV) access is an alternative when upper extremity access options have been exhausted. Our goal was to assess short- and medium-term outcomes of lower extremity hemodialysis access. MethodsThe Vascular Quality Initiative was reviewed for all lower extremity AV hemodialysis cases. Patient and case details were recorded. Multivariable analysis was used to analyze outcomes. ResultsWe identified 463 lower extremity AV access cases in the VQI registry. There were 56 AVF (12.1%) and 407 AVG (87.9%). The mean age was 56 ± 15 years, 46.9% were male, and 40.7% were Caucasian. The majority (90%) had a previous upper extremity AV access and 25.4% had a prior lower extremity access. More than one-half (57.9%) had a tunneled line at the time of the procedure. Patients undergoing an AVF vs AVG creation were younger, more often ambulatory, and less often with peripheral arterial disease. For AVF, the superficial femoral artery was more often used for access inflow (76.8% vs 49.4%; P < .001), compared with AVG, and there was no difference in using femoral vein as the main outflow (78.6% vs 82.6%; P = .466). For AVF, compared with AVG, there was no difference in wound infection (12.5% vs 9.6%; P = .571), ischemic steal (5% vs 2.2%; P = .273), or leg swelling (2.5% vs 3.3%; P = .99) at 6 months. Kaplan-Meier analysis of the overall cohort showed that freedom from loss of primary patency at 6 months was 52.9%, freedom from any reintervention at 6 months was 75.3%, and the 1-year survival was 81.9%. Survival at 5 years was 65.5%. Multivariable analysis showed no significant association of access type (AVF vs AVG) with primary patency loss or death (hazard ratio [HR], 0.74; 95% confidence interval [CI], 0.36-1.5; P = .4), any reintervention or death (HR, 1.65; 95% CI, 0.82-3.33; P = .163), or mortality (HR, 1.94; 95% CI, 0.71-5.33; P = .197). Factors independently associated with primary patency loss or death included peripheral arterial disease (HR, 1.6; 95% CI, 1.06-2.42; P = .03) and obesity (HR, 1.5; 95% CI, 1.1-2.05; P = .01). Any reintervention or death was associated with obesity (HR, 1.67; 95% CI, 1.09-2.56; P = .015). Mortality was associated with congestive heart failure (HR, 1.82; 95% CI, 1.13-2.94; P = .015) and white race (HR, 1.71; 95% CI, 1.08-2.73; P = .023). ConclusionsIn our contemporary multicenter analysis, patients undergoing lower extremity AV access creation have low primary access patency and almost 20% mortality at 1 year. These results should be considered when suggesting a lower extremity dialysis access, as well as other dialysis alternatives when available.

Fish oil and aspirin effects on arteriovenous fistula function: Secondary outcomes of the randomised omega-3 fatty acids (Fish oils) and Aspirin in Vascular access OUtcomes in REnal Disease (FAVOURED) trial.

BackgroundArteriovenous fistulas (AVF) for haemodialysis often experience early thrombosis and maturation failure requiring intervention and/or central venous catheter (CVC) placement. This secondary and exploratory analysis of the FAVOURED study determined whether omega-3 fatty acids (fish oils) or aspirin affected AVF usability, intervention rates and CVC requirements.MethodsIn 567 adult participants planned for AVF creation, all were randomised to fish oil (4g/d) or placebo, and 406 to aspirin (100mg/d) or placebo, starting one day pre-surgery and continued for three months. Outcomes evaluated within 12 months included AVF intervention rates, CVC exposure, late dialysis suitability failure, and times to primary patency loss, abandonment and successful cannulation.ResultsFinal analyses included 536 participants randomised to fish oil or placebo (mean age 55 years, 64% male, 45% diabetic) and 388 randomised to aspirin or placebo. Compared with placebo, fish oil reduced intervention rates (0.82 vs 1.14/1000 patient-days, incidence rate ratio [IRR] 0.72, 95% confidence interval [CI] 0.54–0.97), particularly interventions for acute thrombosis (0.09 vs 0.17/1000 patient-days, IRR 0.53, 95% CI 0.34–0.84). Aspirin significantly reduced rescue intervention rates (IRR 0.45, 95% CI 0.27–0.78). Neither agent significantly affected CVC exposure, late dialysis suitability failure or time to primary patency loss, AVF abandonment or successful cannulation.ConclusionAlthough fish oil and low-dose aspirin given for 3 months reduced intervention rates in newly created AVF, they had no significant effects on CVC exposure, AVF usability and time to primary patency loss or access abandonment. Reduction in access interventions benefits patients, reduces costs and warrants further study.

Preoperative hemoglobin A1c levels and increased risk of adverse limb events in diabetic patients undergoing infrainguinal lower extremity bypass surgery in the Vascular Quality Initiative

BackgroundThe impact of preoperative glycemic control on the risk of adverse perioperative outcomes in diabetic patients undergoing lower extremity bypass (LEB) surgery is not well-understood. We determined whether higher preoperative hemoglobin A1c (HbA1c) levels are associated with an increased risk of major adverse limb events, major adverse cardiovascular events, and mortality in diabetic patients undergoing infrainguinal LEB. MethodsA retrospective review of all infrainguinal LEB surgeries in the Vascular Quality Initiative registry from January 2012 to February 2017 was performed. Only surgeries performed on diabetic patients with complete demographic and clinical data, including HbA1c value at the time of LEB, were included for analysis (n = 7727). Entries were stratified according to the following HbA1c levels: 6 or less (n = 1087), greater than 6 to 7 or less (n = 2137), greater than 7 to 8 or less (n = 1657), and greater than 8 (n = 2846). Multivariate logistic regression was used to determine the association of preoperative HbA1c levels on the risk of in-hospital major adverse limb events (above ankle amputation, loss of primary graft patency), major adverse cardiovascular events (myocardial infarction, stroke, congestive heart failure, cardiac arrhythmia), and mortality. ResultsThe number of surgeries complicated by adverse limb and cardiovascular events were 356 (4.6%) and 1314 (17.0%), respectively. There were 72 in-hospital deaths (0.9%). After adjustment for clinical and demographic variables, patients with high HbA1c values (≥8%) were at an increased risk of adverse limb events (odds ratio [OR], 1.37; 95% confidence interval [CI], 1.01-1.86) compared with those with a normal HbA1c (>6% to ≤7%). High HbA1c values were not associated with an increased risk of cardiovascular events (OR, 1.07; 95% CI, 0.81-1.43) or mortality (OR, 1.57; 95% CI, 0.83-3.03). Patients with low HbA1c values (≤6%) did not experience a significantly higher risk for any of the three outcomes. In a stratified analysis, the association of high HbA1c values with adverse limb events was only present in those presenting without critical limb ischemia (OR 1.82; 95% CI, 1.05-3.16). ConclusionsPoor preoperative glycemic control in diabetic individuals undergoing infrainguinal LEB, particularly in those without critical limb ischemia, is associated with an increased risk of in-hospital limb events. Further study should evaluate whether improved efforts to identify individuals with poorly controlled diabetes and subsequent interventions to better optimize glycemic control during the preoperative period improve limb outcomes after LEB.

Current clinical indications and midterm outcomes of surgical portosystemic shunts in adults

Background: Portosystemic shunts were originally described for the management of bleeding varices due to cirrhosis. However, in the era of transjugular intrahepatic portosystemic shunts and liver transplant, these procedures are increasingly rare. We reviewed indications, operative details and outcomes of patients undergoing surgical portosystemic shunt procedures. Methods: Clinical and procedural details of consecutive patients undergoing creation of a portosystemic shunt from Jan 1997 to August 2018 were reviewed retrospectively. Endpoints were mortality, primary patency, secondary patency and shunt-related complications. Clinical success was defined as postoperative resolution of the primary symptoms for which the shunt was performed. Univariate Cox regression analysis was performed to search for risk factors for graft thrombosis (loss of primary patency). Subsequently, we compared patency and survival in subgroups: Group I: patients with cirrhosis vs those with non-cirrhotic portal hypertension and Group II: patients with computed tomography signs of portomesenteric venous thrombosis (PMVT) vs those without PMVT. Results: Surgical portosystemic shunts were performed in 99 patients (54 female, mean age 46 years). Indications were refractory gastrointestinal bleeding in 75; ascites in 24; secondary to PMVT in 63 (portal n = 46, hepatic n = 15, splenic n = 17, superior mesenteric vein n = 16) and cirrhosis in 36. PMVT was unprovoked in 45 patients (thrombophilia identified in 17). Comorbidities included hypertension (21), diabetes (16), hyperlipidemia (8), coronary artery disease (5) and smoking (16); average MELD score was 8. Shunts were nonselective in 45 (portocaval n = 25, mesocaval n = 17, mesorenal n= 2, rex n = 1) and selective in 50 (distal n = 6, central n = 48). Procedural success was 99%; average length of stay was 8 (3–122) days. Complications occurred in 55% [hematoma (23), bowel ischemia in (3), encephalopathy in (19), new PMVT (10)]. Early mortality was 2% (1 pulmonary embolism, 1 coagulopathy). Early graft thrombosis occurred in 9; 7 underwent re-intervention (1 endovascular, 6 open- patency restored in 3). Symptom relief was not achieved in 6 with early graft thrombosis. It was complete in 76; partial in 6 (3 patent, 2 thrombosed) and recurrent in 3 (graft thrombosis). Therapeutic anticoagulation was prescribed in 35. The median clinical follow-up was 3.2 (1-20) years and imaging follow-up 1 (1–20) years. On Kaplan-Meier analysis, overall survival was 90%, 73% and 49%; primary patency 84%, 82% and 82%; secondary patency 90%, 85% and 82% at 1, 5 and 10 years respectively. The risk of loss of primary patency [HR of 9.22 (95% CI 1.22–70.27, p = 0.032] but not secondary patency was higher in Group II (Fig 1) with no difference in age adjusted survival in either group. No other predictive factors for shunt thrombosis were identified. Conclusion: Surgical portosystemic shunts are safe and effective for symptom relief in selected patients with portal hypertension. The risk of graft thrombosis is 9-times higher in patients with PMVT and is not influenced by use of therapeutic anticoagulation. Overall survival is similar in those with/without cirrhosis or PMVT. Rethrombosis is associated with symptom recurrence; open re-intervention is advisable for symptom relief when suitable targets are available.

Abstract No. 477 Endovascular arteriovenous dialysis fistula intervention: outcomes and factors contributing to fistula failure

To determine post-intervention patency rates and contributing factors for fistula failure in pre-dialysis patients with arteriovenous (AV) dialysis fistulas. Institutional review board approval was obtained for this single-institution retrospective study. All pre-dialysis patients who underwent upper extremity AV fistula creation for anticipated dialysis between October 1995 and January 2015 and who required subsequent endovascular therapy to maintain patency were reviewed. A total of 210 patients were identified. The medical record was queried for patient demographics, procedural details and outcomes. Multiple AV fistula configurations were reviewed: 138 brachiocephalic, 39 radiocephalic, 30 brachiobasilic, 2 ulnocephalic and 1 radiobasilic. Median post-intervention primary patency was 2.7 years, median post-intervention primary-assisted patency was 3.2 years, and median post-intervention secondary patency was 3.6 years. There were 293 initial stenosis treated. This included 5 stenosis in the inflow artery, 50 at the anastomosis, 71 in the juxta-anastomotic segment, 71 in the cannulation zone of the outflow vein, 16 in the noncannulation zone, 10 at the swing point of basilic vein transpositions, 57 in the cephalic arch, and 13 in the central veins. Stenoses in the non-cannulation zone of the outflow vein had the highest rate of target lesion revascularization (TLR) (76.7%), whereas central venous stenosis had the lowest rate of TLR (7.7%). The radiocephalic fistula configuration had better post-intervention primary patency (hazard ratio [HR] 0.58; 95% confidence interval [CI] 0.35-0.96; p=0.034). Conversely, brachiocephalic fistulas had higher risk for loss of post-intervention primary patency (HR 1.90; 95% CI 1.13-3.20; p=0.015). Among predialysis patients who undergo initial endovascular therapy to maintain patency of the AV fistula, the radiocephalic configuration was found to have the best post-intervention primary patency compared to other configurations. While the majority of hemodynamically significant lesions occurred at the anastomosis, lesions in the non-cannulation zone of the outflow vein had the highest rates of TLR.

A relationship of intradialytic blood pressure variability with vascular access outcomes in patients on hemodialysis.

Vascular access dysfunction is a major cause of morbidity in patients with end-stage renal disease (ESRD) on hemodialysis (HD). Thus, identifying risk factors for vascular access failure is important. Patients on HD are routinely exposed to high blood pressure variability (BPV) during HD. However, the impact of intradialytic BPV on vascular access outcomes is unknown. Therefore, we investigated the association of intradialytic BPV with vascular access outcomes in patients on HD. One hundred and thirty patients with ESRD who created vascular access for HD were evaluated. We examined 12 dialysis sessions per patient and recorded BP five times for each session. BPV was assessed using residual standard deviation derived from the linear regression model. The patients were divided into two groups according to a level below or above the median value of intradialytic BPV and compared. The primary outcome was primary unassisted vascular access patency. The median time to loss of primary unassisted patency was significantly longer in low intradialytic BPV group than in high intradialytic BPV group (52 months vs. 21 months, P < 0.001) during the mean follow-up of 3.7 years. After adjustment for other variables, high intradialytic BPV was significantly associated with loss of primary unassisted vascular access patency (hazard ratio, 2.605; 95% confidence interval, 1.462-4.643; P = 0.001). Our study revealed a significant correlation between intradialytic BPV and vascular access patency. Further studies are needed to identify methods for lowering BPV.

Outcomes and predictors of failure of iliac vein stenting after catheter-directed thrombolysis for acute iliofemoral thrombosis

ObjectiveIliac vein stenting is recommended to treat venous outflow obstruction after catheter-directed thrombolysis for acute iliofemoral deep venous thrombosis (DVT). Data on the outcome of proximal and distal stent extension are limited. Proximal stent extension to the vena cava may obstruct the contralateral iliac vein, whereas distal extension below the inguinal ligament contradicts common practice for arterial stents. The aim of this retrospective study was to assess outcomes and predictors of failure of iliac vein stents and contralateral iliac vein thrombosis, taking into consideration stent positioning. MethodsConsecutive patients who underwent thrombolysis and stenting for DVT between May 2007 and September 2017 were identified from a prospectively maintained database. The intraoperative venograms were reviewed for proximal stent placement (covering >50% contralateral iliac vein orifice) and distal placement across the inguinal ligament. End points were ipsilateral DVT recurrence, post-thrombotic syndrome (PTS; Villalta score ≥5), and contralateral DVT. Patients with chronic contralateral DVT or contralateral iliac vein stenting at baseline were excluded from the contralateral DVT outcome evaluation. Survival analysis and Cox regression models were used to determine outcomes. ResultsOf 142 patients lysed, 73 patients (12 bilateral DVTs; mean age, 45.8 ± 17.2 years; 46 female patients) were treated with various combinations of thrombolytic techniques and at least one self-expanding iliac stent (77 stented limbs). Thirty-day recurrence developed in nine (12.3%) patients. The 3-year primary patency and secondary patency rates were 75.2% and 82.2%, respectively. The single predictor for loss of primary patency was incomplete thrombolysis (≤50%; hazard ratio [HR], 7.41; P = .002). Overall, 3 of 12 (25%) stents extending below the inguinal ligament occluded at 1 month, 2 months, and 9 months, respectively. The overall rate of PTS (Villalta score ≥5) in the stented cohort was 14.4% at 5 years. This was predicted by incomplete lysis (<50%; HR, 7.09; P = .040), stent extension below the inguinal ligament (HR, 6.68; P = .026), and male sex (HR, 6.02; P = .041). Of the 17 stents that extended into the contralateral common iliac vein and 58 stents that did not, there were 1 (5.9%) and 5 (8.6%) contralateral DVTs (P = .588) at an average follow-up of 27.4 ± 33.7 and 22.2 ± 22.3 months (P = .552), respectively. ConclusionsIliac stenting after thrombolysis for acute DVT guarantees high patency and low PTS rates, provided adequate thrombus resolution has been achieved before stent placement. Stent placement below the inguinal ligament does not affect the patency but may be associated with a higher PTS rate. Stenting proximal to the iliocaval confluence, although a precipitating factor, may not independently increase the likelihood of contralateral DVT.

Impact of calcification and infrapopliteal outflow on the outcome of endovascular treatment of femoropopliteal occlusive disease.

ObjectivesIn this paper, we report the long-term outcomes of the endovascular treatment of femoropopliteal occlusive disease, focusing on the importance of calcification and runoff outflow on limb salvage and patency, and the factors associated with these outcomes at a single center.MethodsThis retrospective cohort study included consecutive patients with femoropopliteal occlusive who underwent femoropopliteal angioplasty at the Division of Vascular and Endovascular Surgery, Hospital do Servidor Público Estadual, São Paulo, Brazil, between January 2015 and July 2017.ResultsIn total, 86 femoropopliteal occlusive angioplasties were performed in 86 patients, with an initial technical success rate of 95.34%. The mean ± standard deviation follow-up time was 880 ± 68.84 days. The analysis was performed at 720 days. Technical failure occurred in four patients, who were excluded from the analysis, leaving 82 patients and 82 femoropopliteal occlusive angioplasties. The estimated primary patency, secondary patency, limb salvage, and overall survival rates at 720 days were 60%, 96%, 90%, and 82.5%, respectively. In univariate and multivariate analyses, Cox regression showed worse primary patency rates in patients with one tibial vessel or isolated popliteal artery runoff (p = 0.005), calcification grade 4 (p = 0.019), calcification grade > 2 (p = 0.017), small vessel diameter < 4 mm (p = 0.03) or primary angioplasty without stenting (p = 0.021). A univariate analysis showed worse limb salvage in patients with one tibial vessel or isolated popliteal artery runoff (p = 0.039).ConclusionsIn this study, the main factors associated with worse outcomes in the endovascular treatment of femoropopliteal occlusive in terms of loss of primary patency were one tibial vessel or isolated popliteal artery runoff, calcification grade 4, or calcification grade > 2, small vessel diameter < 4 mm, and no stents use. One tibial vessel or isolated popliteal artery runoff was also associated with limb loss in a univariate Cox regression analysis.

A national study of autogenous arteriovenous access use and patency in a contemporary hemodialysis population

ObjectiveThe predicted outcomes of autogenous arteriovenous (AV) hemodialysis access creation are predominantly based on historical data; however, both the hemodialysis population and clinical practices have changed significantly during the last decade. This study examined contemporary AV access clinical use and patencies. MethodsA multicenter observational cohort study was performed of all new AV accesses created in Scotland in 2015. The primary end point was efficacy assessed by successful AV access use for a minimum of 30 days and primary, primary assisted, and secondary patency at 1 year. Data obtained included all interventions to maintain or to restore patency. Predictors of patency loss including demographics, comorbid conditions, dialysis status, AV access location, duplex ultrasound surveillance, procedures, prior access, and antiplatelets were assessed. Kaplan-Meier and competing risks analyses were performed to estimate the probability of AV access failure. All patients were followed up for at least 1 year or had a censoring event. ResultsA total of 582 AV accesses were created in 537 patients (mean age, 60 [standard deviation, 14] years; 60% men; 42% with diabetes) in nine adult renal centers. Mean follow-up was 11.8 (standard deviation, 7.6) months. By the end of the follow-up, 322 (55.3%) AV accesses were successfully used for dialysis. At 1 year, 48% (95% confidence interval [CI], 44-52) of AV accesses had primary patency, (95% CI, 63-71) had primary assisted patency, and 69% (95% CI, 65-73) had secondary patency. The leading cause of primary patency loss was primary failure (30%). An average of 0.48 intervention per patient-year was required to maintain patency. On multivariable analysis, patency was better for an upper arm than for a forearm AV access (1-year secondary patency of upper arm vs forearm AV accesses, 74% vs 58%). The cumulative hazard and incident functions for AV access failure were 31% (95% CI, 27-35) and 23% (95% CI, 20-27) at 1 year, respectively. ConclusionsDespite advances in recent years with preoperative vessel assessment and surveillance, patency rates have not improved, with primary failure remaining the major obstacle. Competing events should be taken into consideration; otherwise, biases may occur with overestimation of the probability of AV access failure.

Anti-phosphorylcholine IgM, an Anti-inflammatory Mediator, Predicts Peripheral Vein Graft Failure: A Prospective Observational Study

One third of infrainguinal vein bypasses may fail within the first 1.5 years. Pro- and anti-inflammatory mechanisms are thought to be involved in these graft stenoses and occlusions. In previous studies, low levels of anti-phosphorylcholine IgM (anti-PC IgM, an innate anti-inflammatory IgM) have been associated with increased cardiovascular events. In this study, the peri-operative dynamics of anti-PC IgM levels were established during leg bypass surgery, and associations assessed between anti-PC IgM levels and primary graft patency. This was a prospective, observational cohort study of infrainguinal autogenous vein bypass for peripheral arterial occlusive disease involving four university affiliated hospitals. Plasma cytokine and anti-PC IgM levels were measured pre- and post-operatively. The outcome of interest was loss of primary graft patency because of occlusion or intervention for graft stenosis. One hundred and forty-two consecutive patients were enrolled: mean age 66 (46-91); 91% white race and male; 72.5% critical limb ischaemia (Fontaine III or IV). Median pre-operative anti-PC IgM levels were 49 units/mL (IQR 32.3-107.7, mean 89.8+101 sd). During follow up of an average of 1.8 years (1 month-7.4 years), 50 (35.2%) grafts lost primary patency. Pre-operative levels of interleukin 6 or C-reactive protein did not predict graft failure. Patients with pre-operative anti-PC IgM values in the lowest quartile had a twofold increased risk of graft failure (multivariable Cox proportional hazard, p=.03, HR 2.11, 95% CI 1.09-4.07), even after accounting for the other significant factors of conduit diameter, distal anastomosis, smoking, and the severity of leg ischaemia. Low levels of anti-PC IgM are associated with vein bypass graft failure. This biological mediator may be a useful marker to identify patients at higher risk, and offers the potential for novel, directed therapies for vascular inflammation and its consequences.

Comparison of one-stage and two-stage upper arm brachiobasilic arteriovenous fistula in the Vascular Quality Initiative

ObjectiveAn upper arm brachiobasilic arteriovenous fistula (BBAVF) is a reliable autogenous hemodialysis access created with a one-stage or two-stage technique. Although both techniques are variably used, the optimal approach is uncertain. In this study, we compared the outcomes of one-stage and two-stage BBAVF procedures. MethodsWe identified 2648 patients who had received BBAVFs within the Vascular Quality Initiative data set (2010-2016) and compared those created using the one-stage and two-stage technique. The primary outcome measures were primary and secondary patency rates at 12 months. Other outcomes assessed were wound infection, steal, and swelling at 3 months. The log-rank test was used to evaluate patency by Kaplan-Meier analysis. Cox proportional hazards models were used to examine the adjusted association between surgical technique and outcomes. ResultsThere were 1234 (47%) one-stage and 1414 (53%) two-stage BBAVFs in the study cohort, including 1848 (70%) patients who were on dialysis at the time of surgery and 1795 (68%) patients with a history of previous access. Patients who underwent a one-stage BBAVF were more likely to be male (54% vs 45%; P < .001), to be white (60% vs 41%; P < .001), and to have a history of coronary artery disease (22% vs 17%; P = .001). Patients undergoing one-stage BBAVFs have larger vein diameters (4.1 vs 3.4 mm; P < .001) and have the procedure in an inpatient setting (21% vs 13%; P < .001) compared with patients undergoing a two-stage procedure. The 12-month primary patency rate was higher for the one-stage BBAVF (49.1% vs 40.4%; P = .005), although the secondary patency rate was comparable (80.0% vs 77.9%; P = .54). Postoperative bleeding (4% vs 1.5%; P < .001), wound infection (1.01% vs 0.4%; P = .047), and arm swelling (2.1 % vs 0.8%; P = .006) were higher for one-stage BBAVFs. In multivariable analysis, although loss of primary patency at 12 months (adjusted hazard ratio [aHR], 1.12; 95% confidence interval [CI], 0.97-1.30; P = .12) and 3-month wound infection (aHR, 0.42; 95% CI, 0.14-1.25, P = .12) were similar between the two approaches, the risk of 3-month arm swelling was significantly lower for two-stage BBAVFs (aHR, 0.35; 95% CI, 0.16-0.77; P = .009). ConclusionsWhereas surgeons were more likely to perform a two-stage BBAVF in patients with a history of previously failed access and smaller basilic vein, our data show no difference in primary or secondary patency of one-stage and two-stage BBAVFs at 12 months.

Primary Stent Placement for Hepatic Artery Stenosis After Liver Transplantation: Improving Primary Patency and Reintervention Rates.

Recent studies have reported high rates of reintervention after primary stenting for hepatic artery stenosis (HAS) due to the loss of primary patency. The aims of this study were to evaluate the outcomes of primary stenting after HAS in a large cohort with longterm follow-up. After institutional review board approval, all patients undergoing liver transplantation between 2003 and 2017 at a single institution were evaluated for occurrence of hepatic artery complications. HAS occurred in 37/454 (8%) of patients. HAS was defined as >50% stenosis on computed tomography or digital subtraction angiography. Hepatic arterial patency and graft survival were evaluated at annual intervals. Primary patency was defined as the time from revascularization to imaging evidence of new HAS or reaching a censored event (retransplantation, death, loss to follow-up, or end of study period). Primary stenting was attempted in 30 patients (17 female, 57%; median age, 51 years; range, 24-68 years). Surgical repair of HAS prior to stenting was attempted in 5/30 (17%) patients. Endovascular treatment was performed within 1 week of the primary anastomosis in 5/30 (17%) of patients. Technical success was accomplished in 97% (29/30) of patients. Primary patency was 90% at 1 year and remained unchanged throughout the remaining follow-up period (median, 41 months; interquartile range [IQR], 25-86 months). Reintervention was required in 3 patients to maintain stent patency. The median time period between primary stenting and retreatment was 5.9 months (IQR, 4.4-11.1 months). There were no major complications, and no patient developed hepatic arterial thrombosis or required listing for retransplantation or retransplantation during the follow-up period. In conclusion, primary stenting for HAS has excellent longterm primary patency and low reintervention rates.

Intraoperative Heparin Use during Upper Extremity Arteriovenous Access Creation Does Not Affect Outcomes

There are conflicting data about the effect of heparin use on perioperative outcomes during upper extremity arteriovenous (AV) access creation. Our goal was to assess the effect of the use and degree of intraoperative heparin on perioperative outcomes after AV access creation. All upper extremity AV access cases performed at a tertiary academic medical center between 2014 and 2017 were reviewed. Patient and procedural details including intraoperative heparin use and dosing as well as protamine use were analyzed. Full heparin dose was defined as 80-100 U/kg and partial heparin dose as less than 80 U/kg. Perioperative arterial thrombosis or distal embolism, hematoma, and early loss of primary patency within 30days were evaluated. Multivariate analysis was performed to assess the effect of heparin use. There were 550 AV access cases identified: brachiocephalic (37.5%), brachiobasilic (29.3%), and radiocephalic fistulas (12.9%), and AV grafts (16.9%). Average patient age was 62.6years and 58.9% were male. Full heparinization was used in 21.3%, partial heparinization in 58.7%, and no heparin was used in 20% of cases. Protamine was used in 94.9% of full heparin cases and 51.4% of partial heparin cases. No perioperative arterial thrombosis or distal embolism was observed. Perioperative wound hematoma rate was 3.4%, 3.1%, and 0.9% in full heparin, partial heparin, and no heparin cohorts, respectively (P=0.42). Early loss of primary patency was 11.1%, 7.7%, and 6.4% for full heparin, partial heparin, and no heparin cases, respectively (P=0.39). There were no differences in return to the operating room or perioperative survival. On multivariable analysis, full heparin use (odds ratio [OR] 3.82, 95% confidence interval [CI] 0.41-35.9, P=0.24) and partial heparin (OR 4.03, 95% CI 0.5-32.6, P=0.19) use were not significantly different from no heparin cases with respect to 30-day perioperative hematoma rate. Full heparin (OR 1.76, 95% CI 0.65-4.78, P=0.26) and partial heparin (OR 1.13, 95% CI 0.46-2.75, P=0.79) were not significantly different from no heparin cases with respect to early loss of primary patency. Intraoperative heparin use, at full or partial doses, did not affect perioperative outcomes after AV access creation. Overall complication event rate was low for all groups. AV access can be safely performed without intraoperative heparin use.

Increased warm ischemia time during vessel harvest decreases the primary patency of cryopreserved conduits in patients undergoing lower extremity bypass

ObjectiveAutologous vein is the preferred conduit for lower extremity bypass. However, it is often unavailable because of prior harvest or inadequate for bypass owing to insufficient caliber. Cryopreserved cadaveric vessels can be used as conduits for lower extremity revascularization when autogenous vein is not available and the use of prosthetic grafts is not appropriate. Many studies have shown that donor characteristics influence clinical outcomes in solid organ transplantation, but little is known regarding their impact in vascular surgery. The purpose of this study was to examine the effects donor variables have on patients undergoing lower extremity bypass with cryopreserved vessels. MethodsThe tissue processing organization was queried for donor blood type, warm ischemia times (WITs), and serial numbers of cryopreserved vessels implanted at a single center from 2010 to 2016. The serial numbers were then matched with their respective patients using the institutional Clinical Data Repository and patient data were obtained from the Clinical Data Repository and chart review. Primary outcomes were primary patency of the bypass conduits and limb salvage. Time to loss of patency was evaluated using Kaplan-Meier methods and a Cox proportional hazards model determined risk-adjusted predictors of patency and limb salvage. ResultsSixty patients underwent lower extremity bypass with 65 cryopreserved vessels (23 superficial femoral arteries, 41 saphenous veins, 1 femoral vein). Thirty-eight procedures were reoperations. There were 21 inflow, 44 outflow, and 44 infrainguinal procedures. Preexisting comorbidities did not differ significantly between those who lost patency and those who did not. The mean WIT among the entire cohort was 892.3 ± 389.1 minutes (range, 158.0-1434.0 minutes). The median follow-up was 394 days. Kaplan-Meier analysis demonstrated an overall 1-year primary patency rate of 51%. Primary patency at 1 year was 67% and 41% for inflow and outflow procedures, respectively, and did not differ significantly between the two groups (P = .15). Donor-to-recipient ABO incompatibility was not associated with loss of primary patency. The 1-year amputation-free survival was 74%. Primary patency significantly decreased with each hourly increase in WIT on risk-adjusted analysis (hazard ratio, 1.1; P = .02). ConclusionsHigher cryopreserved vessel WIT was associated with increased risk-adjusted loss of primary patency in this cohort. At 1 year, the overall primary patency was 51% and amputation-free survival was 74%. Vascular surgeons should be aware that WIT may affect outcomes for lower extremity bypass.

Improved patency after axillofemoral bypass for aortoiliac occlusive disease

ObjectiveAxillofemoral bypasses (AxFBs) have been used since 1962 to treat aortoiliac disease. In the past, reported patency rates (37%-76%) for these extra-anatomic grafts have been inferior to those for anatomic aortic grafting. Reported low survival rates after AxFB (40%-50%) have confirmed that these procedures have been used primarily in patients at high risk for complications from aortofemoral bypass. However, modern medical and anesthesia management, preoperative scanning, donor artery preparation, postoperative graft surveillance, and graft technology may improve outcomes after AxFB, possibly supporting expansion of its use. We therefore report our last 15-year experience with AxFB. MethodsRing-reinforced, 8-mm expanded polytetrafluoroethylene grafts were used in all cases. The cross-femoral limb of axillobifemoral bypass (AxBFB) grafts was preconstructed. Heparin was administered intraoperatively, with protamine reversal. Loss of primary patency was defined as graft thrombosis of part or all of the inserted graft. Five-year primary patency rates were calculated by Kaplan-Meier analysis. ResultsBetween February 1991 and June 2016, a total of 161 grafts were inserted (85 AxBFBs and 76 axillounifemoral bypasses [AxUFBs]) in 91 male and 70 female patients (median age, 72.6 years; mean age, 73 years; range, 41-94 years). Indications for treatment were rest pain (49.6%), ischemic lesions (26%), claudication (22.3%), failed prior revascularization (9.3%), infection (3.7%), and dissecting aneurysm (1.2%). Reasons for performing AxFB rather than aortofemoral bypass were hostile aorta (44.1%), high risk (19.2%), prior failed reconstruction (12.4%), advanced age (8.7%), infection (4.3%), hostile abdomen (4.3%), aortic dissection (0.6%), and morbid obesity (0.6%). During follow up, 63 patients died, 17 within the first year; but only 3 patients died within 30 days of surgery (performed to treat an acute aortic occlusion). The 5-year survival rate was 55%. Five-year patency rates were 83.7% for all procedures, 81.8% for AxBFB, and 85.5% for AxUFB; the difference between AxBFB and AxUFB was not significant. ConclusionsOur data indicate that AxBFB and AxUFB performed with the use of modern protocols and technology may render them an acceptable valid primary intervention in patients in whom endovascular treatment has failed or is unlikely to offer long-term success. The simplicity of performing these grafts and their low mortality and morbidity lend their application to surgeons with limited open aortic experience. Because AxUFB and AxBFB have similar patency rates, AxBFB should be reserved for bilateral indications.

Association of early loss of primary functional patency of arteriovenous access with mortality in incident hemodialysis patients: A nationwide population-based observational study.

The long-term survival and life quality of hemodialysis (HD) patients depend on adequacy of dialysis via a well-functioning vascular access. Loss of primary functional patency (PFP) of an arteriovenous access (AVA) eventually happens in HD patients. The association between time to loss of PFP of AVAs and mortality in HD patients remains unclear. The retrospective nationwide population-based cohort study compared the hazards of mortality with time to loss of PFP. We enrolled 1618 adult incident HD patients who received HD via AVAs for at least 90 days between January 1, 2001 and December 31, 2013. They were divided into early (≤1 year) and late (>1 year) loss of PFP according to intervention-free intervals (time from first successful cannulation to percutaneous transluminal angioplasty [PTA]). Patients with early loss of PFP were older; had more clinic visits annually and higher Charlson comorbidity index scores; were associated with higher proportions of diabetes mellitus, coronary artery disease, heart failure, stroke, chronic obstructive pulmonary disease, cancer, and use of arteriovenous graft, diuretic, antidiabetic drugs, and aspirin (all P < .05). Kaplan-Meier analysis revealed the cumulative incidence of mortality was significantly higher in patients with early loss of PFP (log-rank test; P < .01). After adjustment, early loss of PFP was independently associated with a higher risk of mortality (adjusted hazard ratio, 1.21; 95% confidence interval, 1.01-1.45; P = .045). Regarding the impact of time to PTA on mortality, patients with intervention-free intervals of ≤3, 3 to 6, and 6 to 12 months had similar trends of lower survival. Early loss of PFP is an independent risk factor for mortality in chronic HD patients. A comprehensive strategy for maintaining PFP and reducing dysfunctional AVAs may be required.

Thirty-year trends in aortofemoral bypass for aortoiliac occlusive disease

ObjectiveEndovascular intervention has supplanted open bypass as the most frequently used approach in patients with aortoiliac segment atherosclerosis. We sought to determine whether this trend together with changing demographic and clinical characteristics of patients undergoing aortobifemoral bypass (ABFB) for aortoiliac occlusive disease (AOD) have an association with postoperative outcomes. MethodsUsing a prospectively maintained institutional database, we identified patients who underwent ABFB for AOD from 1985 to 2015. Patients were divided into two cohorts: the historical cohort (HC) included patients who underwent ABFB for AOD from 1985 to 1999 and the contemporary cohort (CC) who underwent ABFB for AOD from 2000 to 2015. Medical and demographic data, procedural information, postoperative complications, and follow-up data were extracted. Cox proportional hazards regression was used to evaluate associations with the end point of primary patency. A similar analysis was performed for major adverse limb events (MALEs; the composite of above-ankle amputation, major reintervention, graft revision, or new bypass graft of the index limb) in the subset of patients with critical limb ischemia. ResultsThere were a total of 359 cases: 226 in the HC and 133 in the CC. The CC had more women (56.4% vs 43.8%; P = .02), smokers (87.2% vs 67.7%; P = .001), and patients who failed prior aortoiliac endovascular intervention (17.3% vs 4.8%; P = .0001), but fewer patients with coronary artery disease (32.3% vs 47.3%; P = .005). Thirty-day mortality was less than 1% in both cohorts, but 10-year survival was higher in the CC (67.7% vs 52.6%; P = .02). Five-year primary, primary-assisted, and secondary patency were higher in the HC (93.3% vs 82.2%; P = .005; 93.8% vs 85.7%; P = .02; 97.5% vs 90.4%; P = .02, respectively). CC membership, decreasing age, prior aortic surgery, and decreasing graft diameter were significant independent predictors of loss of primary patency after adjustment (hazard ratio [HR], 7.03; 95% confidence interval [CI], 2.80-17.63; P < .0001; HR, 0.93; 95% CI, 0.90-0.96; P < .0001; HR, 18.80; 95% CI, 5.94-59.58; P < .0001; and HR, 0.73; 95% CI, 0.55-0.95; P = .02, respectively). Similarly, CC membership, prior aortic surgery, and decreasing graft diameter were significant independent predictors of MALE in the critical limb ischemia cohort after adjustment (HR, 21.13; 95% CI, 4.20-106.40; P = .0002; HR, 40.40; 95% CI, 3.23-505.61; P = .004; and HR, 0.51; 95% CI, 0.30-0.86; P = .01, respectively). ConclusionsCompared with the pre-endovascular era, demographic and clinical characteristics of patients undergoing ABFB for AOD in the CC have changed. Although long-term patency is slightly lower among patients in the CC during which a substantial subset of AOD patients are being treated primarily via the endovascular approach, durability remains excellent and limb salvage unchanged. After adjustment, the time period of index ABFB independently predicted primary patency and MALE, as did graft diameter and prior aortic surgery. These changing characteristics should be considered when counseling patients and benchmarking for reintervention rates and other outcomes.

Medicare Costs Associated With Arteriovenous Fistulas Among US Hemodialysis Patients

An arteriovenous fistula (AVF) is the recommended vascular access for hemodialysis (HD). Previous studies have not examined the resources and costs associated with creating and maintaining AVFs. Retrospective observational study. Elderly US Medicare patients initiating hemodialysis therapy during 2010 to2011. AVF primary and secondary patency and nonuse in the first year following AVF creation. Annualized vascular access costs per patient per year. Among patients with only a catheter at HD therapy initiation, only 54% of AVFs were successfully used for HD, 10% were used but experienced secondary patency loss within 1 year of creation, and 83% experienced primary patency loss within 1 year of creation. Mean vascular access costs per patient per year in the 2.5 years after AVF creation were $7,871 for AVFs that maintained primary patency in year 1, $13,282 for AVFs that experienced primary patency loss in year 1, $17,808 for AVFs that experienced secondary patency loss in year 1, and $31,630 for AVFs that were not used. Similar patterns were seen among patients with a mature AVF at HD therapy initiation and patients with a catheter and maturing AVF at HD therapy initiation. Overall, in 2013, fee-for-service Medicare paid $2.8 billion for dialysis vascular access-related services, ∼12% of all end-stage renal disease payments. Lack of granularity with certain billing codes. AVF failure in the first year after creation is common and results in substantially higher health care costs. Compared with patients whose AVFs maintained primary patency, vascular access costs were 2 to 3 times higher for patients whose AVFs experienced primary or secondary patency loss and 4 times higher for patients who never used their AVFs. There is a need to improve AVF outcomes and reduce costs after AVF creation.

Endovascular treatment of post-thrombotic and non-thrombotic iliofemoral venous outflow obstructions with self-expanding nitinol stents.

The aim of the study was to investigate venous patency and clinical outcomes for endovascular treatment of iliofemoral venous obstruction in patients with post-thrombotic syndrome (PTS) and non-thrombotic iliac vein lesion (NIVL) with dedicated self-expanding nitinol stents. Data were collected from the prospective Swiss Venous Stent Registry, enrolling consecutive patients with a standardized follow-up procedure since January 2008. Patency was evaluated by duplex sonography and clinical outcome by various scores including the Villalta score at baseline, three, six, and 12 months, and then annually after endovascular therapy. Overall, 93 patients (64 PTS, 29 NIVL) were analysed. Mean follow-up time was 20 ± 16 (range 3-70) months. A total of 11 (12 %) patients had a stent occlusion, all of which occurred in the PTS group, and 13 (14 %) patients had a symptomatic stent stenosis. Primary patency was 79 % (95 % CI 68-87 %) at 12 months and 72 % (95 % CI 59-82 %) at 24 months. In PTS patients, primary patency at 12 months was 75 % (95 % CI 61-84 %) vs. 89 % (95 % CI 63-97 %) in NIVL patients (p = 0.10). Secondary patency at 24 months was 94 % (95 % CI 84-98 %) in PTS and 100 % in NIVL, p = 0.19). Overall, 62 (67 %) patients were free from PTS at the latest follow-up with a Villalta score < 5 points. Predictive factors for the loss of primary patency were stents placed below the inguinal ligament (OR 2.59, 95 % CI, 0.99-6.84, p = 0.05). In symptomatic patients with chronic iliofemoral vein obstruction, endovascular therapy with self-expanding nitinol stents was associated with favourable patency rates and clinical improvement in the majority of patients.