Creation Of Arteriovenous Access Research Articles

Vascular access surgery training in the United Kingdom is currently perceived (by trainees) to be inadequate.

Vascular access surgery (VAS) involves the creation and maintenance of arteriovenous access to facilitate haemodialysis. The prevalence of haemodialysis is rising despite increases in kidney transplants on a yearly basis. There is currently only one access surgery fellowship accredited by the Royal College of Surgeons of England. We aimed to establish the experience and perceived competence in access surgery of senior vascular surgery trainees. A short questionnaire (SurveyMonkey) was used to survey all senior (ST6-ST8) vascular surgery trainees in Health Education England (HEE) vascular surgery training programmes. The short survey asked trainees to report their: (1) training grade; (2) training deanery; (3) experience of access surgery; and (4) whether senior trainees thought they would be able to independently undertake primary access surgery post-completion of training (post Certificate of Completion of Training). The survey was circulated via HEE deaneries and the vascular surgery trainees' society: the Rouleaux Club. Twenty-eight senior (ST6-ST8) vascular surgery trainees responded to the survey: 29.6% were ST6 level, 33.3% were ST7 and 37.1% were ST8. Deanery respondence was evenly spread, although London was overrepresented (37.1%). In total, 28.6% had been involved in fewer than 10 cases, 35.7% in 10-25 cases, and 35.7% in more than 25 cases. Almost 54% of senior vascular surgery trainees believed they would not be able to undertake independent access surgery once they had completed training. Competence in access surgery is an increasing requirement of a consultant vascular surgeon. More formalised training is required to adequately train the next generation of vascular surgeons.

Vascular access surgery training in the United Kingdom is currently perceived (by trainees) to be inadequate.

Vascular access surgery (VAS) involves the creation and maintenance of arteriovenous access to facilitate haemodialysis. The prevalence of haemodialysis is rising despite increases in kidney transplants on a yearly basis. There is currently only one access surgery fellowship accredited by the Royal College of Surgeons of England. We aimed to establish the experience and perceived competence in access surgery of senior vascular surgery trainees. A short questionnaire (SurveyMonkey) was used to survey all senior (ST6-ST8) vascular surgery trainees in Health Education England (HEE) vascular surgery training programmes. The short survey asked trainees to report their: (1) training grade; (2) training deanery; (3) experience of access surgery; and (4) whether senior trainees thought they would be able to independently undertake primary access surgery post-completion of training (post Certificate of Completion of Training). The survey was circulated via HEE deaneries and the vascular surgery trainees' society: the Rouleaux Club. Twenty-eight senior (ST6-ST8) vascular surgery trainees responded to the survey: 29.6% were ST6 level, 33.3% were ST7 and 37.1% were ST8. Deanery respondence was evenly spread, although London was overrepresented (37.1%). In total, 28.6% had been involved in fewer than 10 cases, 35.7% in 10-25 cases, and 35.7% in more than 25 cases. Almost 54% of senior vascular surgery trainees believed they would not be able to undertake independent access surgery once they had completed training. Competence in access surgery is an increasing requirement of a consultant vascular surgeon. More formalised training is required to adequately train the next generation of vascular surgeons.

Comprehensive Approach to Improve Quality of Life in Hemodialysis Patients by Early Creation of Arteriovenous Access

An arteriovenous fistula (AVF) is the closest to the ideal model of vascular access. Evidence suggests that people who approach end-stage kidney disease may have an arteriovenous fistula surgically created proactively, enabling the elimination of Permcath insertion for dialysis. Consequently, this proactive action will reduce the risk of bacteremia and admissions to inpatient services for this vulnerable population. The current mean waiting time for AVF creation in King Fahd Armed Forces Hospital, Jeddah (KFAFH), was 172 days. The aim of the project was to decrease the adult Chronic Kidney Disease patient mean waiting time for arteriovenous (AV) access creation from a mean of 172 days to less than 10 days within 12 months. The project was carried out in the Chronic Kidney Disease patient population of King Fahd Armed Forces Hospital, Jeddah. The Plan Do Study Act rapid cycles Quality improvement method was used to implement changes. The interventions include a multidisciplinary approach as the base for the new AVF strategy. Identification of CKD Stage IV patients with impending dialysis was booked for early AVF, thereby reducing the need for Permcath. An additional renal clinic was established to update the patients waiting time for AVF creation and to book patients as Day-surgery through fast track. Daily rounds in the dialysis unit were introduced to address issues of new patients on hemodialysis, and the waiting time for each patient was revised and booked to the new renal clinic for AVF creation. This reduced the referral time to the vascular clinic. Centralized approach by requesting early venogram & venous mappings. The addition of a dedicated inpatient bed for advanced access surgery like AV graft, superficialization, and bridging for patients on anti-coagulation was allotted. Addition of a dedicated operating room for at least daily AVF creation apart from the regular operating list. Addition of 1 more day to existing 1 day per week schedule for Day case procedures with 2 day surgery beds for vascular access. During the 1st PDCA cycle, the mean waiting time for AVF Access decreased to 127.75 days; during the 2nd PDCA cycle, the mean time decreased to 34.25 days, and during the 3rd PDCA cycle the project achieved proactive AVF access with the mean waiting time at -7.2 days. None of the patients with newly created AVF access developed steal syndrome during the project period. AV fistulae have a longer median survival, require less costly and invasive intervention to maintain patency and are less likely to become infected than AV graft or Permcath. A multidisciplinary team approach proved to be successful in reducing the mean AVF waiting time for hemodialysis patients. The interventions enable the team to perform proactive AVF creation in a timely manner eliminating the use of Permcaths for newly admitted Hemodialysis patients. Thus, reducing the CLABSI rate.

Readmissions Following Arteriovenous Access Creation for Haemodialysis in a French National Database

There is a lack of large real world data on arteriovenous (AV) access results. This study aimed to describe the required hospital care during the first year following creation of AV access. Data from all adult patients who underwent creation of AV access performed in 2017 in a public or private facility were collected through the French national hospitalisation database. Patients were classified into two groups ("de novo" and "secondary") according to their history of prior AV access creation. The primary outcome was the proportion of patients with at least one hospital readmission related to the AV access recorded during the first 12 post-operative months. In 2017, 10 476 adult patients underwent AV access creation in France, including 8 690 (83%) de novo creations. An AV fistula was created for 92% of the patients (95% de novo vs. 78% secondary; p < .001). During the first 12 post-operative months, 6 591 (63%) patients recorded at least one related readmission (68% secondary vs. 62% de novo; p < .001). A total of 5 557 (53%) recorded a readmission for surgical/interventional procedure and 2 852 (27%) were observed with a readmission for medical complications. The mean (± standard deviation) number of related readmissions at 12 months was 1.4 ± 1.6 per patient (1.7 ± 1.9 secondary vs. 1.3 ± 1.5 de novo; p < .001). Patients with an AV graft were more frequently readmitted than those with an AV fistula (1.8 ± 2 vs. 1.3 ± 1.5 readmission; p < .001). This study highlights the high frequency of readmissions during the first 12 months following creation of AV access, particularly in patients who had already undergone creation of a previous AV access or had an AV graft implanted. Further research should focus on tailoring AV access strategies to improve patient quality of life and decrease the healthcare cost burden.

Maintaining Vascular Access in Chronic Kidney Disease: Patient Perspectives

Chronic kidney disease affects 16.8% of adults in the United States for which hemodialysis is most commonly used for renal replacement therapy. Although emphasis with the Fistula First Initiative has historically focused on the creation of autogenous arteriovenous access, higher rates of maturation failure and access dysfunction have prompted a reappraisal of this approach in the literature and clinical practice. Often, frail or medically complex patients with dysfunctional access will be subjected to a large number of surgical procedures to maintain or reestablish patency. The influence of arteriovenous fistula (AVF) dysfunction and repetitive reintervention on patient experience and quality of life remains largely unexplored in the contemporary literature. Using a provincial database of renal failure patients, we selected patients who had undergone five or more interventional procedures (open or endovascular) to maintain vascular access within a 20-year period from a single institution. Semistructured interviews were conducted with these patients, and the responses were analyzed qualitatively using the constant comparative approach. Sixteen patients who had met the inclusion criteria were recruited from across British Columbia. The cohort included patients from both genders (10 men; 6 women) aged 52 to 87 years. Four major thematic categories emerged from the interviews: impact of dialysis, treatment values, impact of repeated surgical intervention, and AVF satisfaction. For the impact of dialysis category, loss of independence (13 of 16) was a dominant theme, with the psychological impact secondary. Regarding treatment values, 11 of 16 patients stated survival was of primary importance, with a reduction in dialysis frequency secondary. The dominant theme in the impact of repeated surgical interventions was interruption to daily life (12 of 16), with travel interruptions and fatigue being minor. For AVF satisfaction, failure of the AVF was dominant (14 of 16), with pain associated with using the AVF considered the most common negative factor. Only 7 of 16 expressed satisfaction with their management pathway. Reduced independence and interruption to daily routine were the most cited difficulties regarding dialysis and surgical intervention. As expected, survival was a key treatment value. Recurrent access failure and reintervention were significant causes of impaired quality of life for patients requiring hemodialysis.

Outcomes of Patients Who Have Undergone AV Shunt Procedure at Dr. Zainoel Abidin General Hospital in Banda Aceh

In recent decades, kidney disease has been documented as a global public health problem. The current challenge is about improving the treatment of chronic kidney disease (CKD) patients in order to provide a longer life expectancy for them. In hemodialysis, there has been a considerable development in finding access to the vascular system, one of which developments was the creation of arteriovenous access by Cimino and Brescia (called an AV shunt). Research on the AV shunt is still limited, so the researchers are interested in conducting this descriptive epidemiological survey study on the profile of patients undergoing AV shunt procedures at Dr. Zainoel Abidin General Hospital in Banda Aceh in 2017. Data were obtained retrospectively from the medical records of the Central Surgery Installation Department of Dr.Zainoel Abidin General Hospital in Banda Aceh, and there were 105 patients have undergone AV shunt, 72 men (68.6%) and 33 women (31.4%). The frequency based on the age was the risking age about 45-54 years as many as 30 people (28.6%). Based on the outcomes obtained 95 people (90.48%) who have used the AV shunt for hemodialysis access, consisting of 66 men (62.86%) and 29 women (27.62). Based on the duration of use, AV Shunt is mostly used for 1 year with the number of 48 patients (50.52%) in the proportion of men and women were 38.95% and 11.57%. With an average duration of use of AV Shunt 2,6 years. From the results of this study, we conclude that the result was obtained that the highest cases in patients who have undergone AV Shunt is man as much as 68.6%. Furthermore, Pertaining to this study, it was obtained that the majority of age who undergo Av shunt is 45-54 years. In addition, the result of this study showed that the success rate of surgery AV shunt in Dr. Zainoel Abidin General Hospital in Banda Aceh was high. It is about 90, 48% with an average duration use of Av shunt is 2.6 years.

The Clinical Relevance and Management of High-Flow Arteriovenous Access.

Obtaining an arteriovenous (AV) access for initiation of hemodialysis is considered the gold standard as it reduces risks of infections, hospitalizations, and need for interventions. It is well documented that creation of AV access can cause or aggravate heart failure. Once AV access is created, blood volume, cardiac contractility, and left ventricular end-diastolic volume increase in a nonphysiologic fashion resulting in an overall increase in cardiac output. Left ventricular hypertrophy, diastolic dysfunction, pulmonary hypertension, and high-output cardiac failure can occur. AV accesses that have blood flows greater than 1.5L per minute are of high risk. When access flow exceeds 25% to 30% of cardiac output, the risk of developing high-output heart failure increases. Studies suggest that a blood flow (Qa)/cardiac output (CO) ratio of greater than 0.30 should be used as a screening tool to perform further cardiac testing. Depending on the severity of symptoms, management can range from banding procedure (flow reduction) or need for total abandonment of the AV access. The complications associated with high-flow AV accesses are often overlooked. Nephrologists and vascular access experts should work in tandem to mitigate potential harm to patients on dialysis who are afflicted by this condition.

Patients with human immunodeficiency virus infection do not have inferior outcomes after dialysis access creation

ObjectiveDespite improvements in treating human immunodeficiency virus (HIV) infection and acquired immunodeficiency syndrome (AIDS), the risk of end-stage renal disease and need for long-term arteriovenous (AV) access for hemodialysis remain high in HIV-infected patients. Associations of HIV/AIDS with AV access creation complications have been conflicting. Our goal was to clarify short- and long-term outcomes of patients with HIV/AIDS undergoing AV access creation. MethodsThe Vascular Quality Initiative registry was queried from 2011 to 2018 for all patients undergoing AV access creation. Documentation of HIV infection status with or without AIDS was recorded. Data were propensity score matched (4:1) between non-HIV-infected patients and HIV/AIDS patients. Subsequent multivariable analysis and Kaplan-Meier analysis were performed for short- and long-term outcomes. ResultsThere were 25,711 upper extremity AV access creations identified: 25,186 without HIV infection (98%), 424 (1.6%) with HIV infection, and 101 (.4%) with AIDS. Mean age was 61.8 years, and 55.8% were male. Patients with HIV/AIDS were more often younger, male, nonwhite, nonobese, and current smokers; they were more often on Medicaid and more likely to have a history of intravenous drug use, and they were less often diabetic and less likely to have cardiac comorbidities (P < .05 for all). There was no significant difference in autogenous or prosthetic access used in these cohorts. Wound infection requiring incision and drainage or explantation within 90 days was low for all groups (0.6% vs 1.9 vs 0%; P = .11) of non-HIV-infected patients vs HIV-infected patients vs AIDS patients. Kaplan-Meier analysis showed no significant difference in 1-year freedom from primary patency loss (43.9% vs 46.3%; P =.6), 1-year freedom from reintervention (61% vs 60.7%,; P = .81), or 3-year survival (83% vs 83.8%; P = .57) for those with and without HIV/AIDS, respectively. Multivariable analysis demonstrated that patients with HIV/AIDS were not at significantly higher risk for access reintervention (hazard ratio [HR], 0.97; 95% confidence interval [CI], 0.76-1.24; P = .81), occlusion (HR, 1.06; 95% CI, 0.86-1.29; P = .6), or mortality (HR, 1.08; 95% CI, 0.83-1.43; P = .57). ConclusionsPatients with HIV/AIDS undergoing AV access creation have outcomes similar to those of patients without HIV infection, including long-term survival. Patients with HIV/AIDS had fewer traditional end-stage renal disease risk factors compared with non-HIV-infected patients. Our findings show that the contemporary approach for creation and management of AV access in patients with HIV/AIDS should be continued; however, further research is needed to identify risk factors in this population.

Hyper-Acute Presentation of Access Based Cardiac Disease

Fifty years after the creation of the first arteriovenous access, little is known about the deleterious cardiac effects of this pathological circuit. Understanding the pathophysiology of Access Based Cardiac Disease (ABCD) is critical, given the fact that cardiac abnormalities are the leading cause of morbidity and mortality in end stage kidney disease patients on dialysis. However, this has been a challenge, as many of hemodialysis patients have preexisting cardiac disease, they invariably have volume overload from salt and water retention, and many heart failure symptoms can be masked by regular efficient dialysis. ABCD can be hyper-acute (minutes to hours), acute (days to weeks), or chronic (months to years). In this manuscript, authors will focus on the hyper-acute form.

Intraoperative Arterial Biopsy in Incident Hemodialysis Patients: Differences Observed

Introduction: Arterial calcification (AC) is a common complication in chronic kidney disease (CKD) patients that starts to develop before these patients need renal replacement therapy. In these patients, calcification can involve tunica intima or tunica media. This study has looked for the prevalence, severity, and distribution of arterial wall calcification in incident hemodialysis patients through intraoperative arterial biopsy obtained during creation of arteriovenous vascular access for hemodialysis. Methodology: One hundred and seventy-two stage 5 CKD adults (98 male and 74 female) were included. Beside histopathology of the obtained arterial samples, all these cases were tested for serum calcium (Ca), phosphorus (P), alkaline phosphatase, uric acid, parathormone (PTH), fibroblast growth factor 23 (FGF23), and 25 hydroxy vitamin D. Results: Eighty six (50%) of the cases had AC (group I); 29 (17%) as intimal (subgroup Ii), 36 (21%) as medial (subgroup Im), while 21 (12%) had both intimal and medial calcification (subgroup Iim). Eighty-six patients (50%) were devoid of calcification (group II). Apart from the significantly higher serum level of PTH in group I, statistical analysis failed to disclose significant difference in any of the other studied parameters between the 2 groups. On the other hand, there were significant differences in serum P, Ca × P product, serum PTH, and FGF23 between patients according to intensity of calcification. Conclusion: Half of incident hemodialysis CKD patients have developed AC mainly in tunica media. Discrepancy in serum P can have an impact on calcification intensity.

Predictors of Steal in Hemodialysis Access

Pathological steal is an uncommon but devastating complication after the creation of arteriovenous access for hemodialysis. In this study, we sought to assess predictors of clinically significant steal syndrome and to further evaluate the outcome of differing surgical treatment approaches. A retrospective analysis was performed of 282 consecutive patients undergoing hemodialysis access at a single center from November 2014 to April 2016. Adequate follow-up to assess for the development of steal was obtained in 237 patients. One hundred and fifty-seven (66%) patients were male, 152 (64%) Hispanic, and 164 (69%) had diabetes. Forty-three (18%) had prior access procedures. Autologous fistula was created in 218 patients (92%). Pathologic steal occurred in 15 patients (6.7%). On univariate analysis, significant predictors of steal included female sex [P = 0.03, odds ratio (OR) = 3.3, CI [1.1-9]), no systemic heparin at operation (P = 0.02, OR = 5.0, CI [1.4-10]), use of angiotensin-converting enzyme inhibitor (P = 0.003, OR = 5.6, CI [1.7-18.6]), and increased vein size (3.1 vs 4.1 mm P = 0.01). Twelve patients had steal managed with an intervention, but only one patient received distal revascularization. Furthermore, we identify key predictors of clinically significant steal syndrome while demonstrating that distal revascularization and/or fistula ligation are rarely indicated treatment modalities.

Effect of a rapid clinical protocol to the conversion from central venous hemodialysis catheter to arteriovenous access.

Evaluation of the rapid conversion protocol that includes an ambulatory dialysis access center (DAC), and a three-step clinical pathway, to the conversion rate from central venous hemodialysis (HD) catheter to functioning arteriovenous (AV) access. Prospective data were collected on 97 consecutive catheter-dependent HD patients. DAC is defined as an ambulatory unit, able to accommodate clinic visits, ultrasound examinations, surgical, interventional and hybrid procedures. Step I: initial evaluation, vein mapping and creation of AV access. Step II: clinical evaluation in two weeks and if failure identified, secondary procedure to restore function. Step III: evaluation in four weeks after creation, and additional procedure to promote maturation if indicated. The success rate, time to conversion and time to catheter removal were recorded. From the 97 consecutive referred patients, eight patients were excluded. From the remaining 89 patients, 99% were successfully converted to AV access. Seventy-three percent of the patients were converted to native arteriovenous fistulae and 27% of the patients to prosthetic arteriovenous shunts. The median time from creation to HD catheter removal was 63 (SD 41) days. Fifty-two percent of the patients required at least one additional secondary procedure to accomplish successful conversion. High rates of timely conversion from catheter to AV access, primarily AV fistulae, can be accomplished within the context of the rapid conversion protocol.

Mobilization of Endothelial Progenitor Cells Following Creation of Arteriovenous Access in Patients with End-Stage Renal Disease.

A patent arteriovenous (AV) fistula induces activation of regional vascular endothelium and vascular shear force. Shear stress is an important physiological force in mobilizing endothelial progenitor cells (EPCs). This study aimed to explore the perioperative changes of circulating EPC levels for patients who require hemodialysis and underwent radiocephalic fistula operation. This prospective cohort study included patients who received a radiocephalic fistula surgery when they were between 25 and 65 years of age. The subjects were followed for 90 days postoperatively for any stenotic events or immaturity of the fistula. Blood samples were obtained on the day before surgery and at postoperation day (POD) 3 and 30. CD133+/KDR+ cells, defined as EPCs, were analyzed using flow cytometry. Blood flow of the fistula was followed on POD 3 and 30. A total of 30 patients were enrolled in the study from July 2009 to December 2011. One patient dropped out of the study and seven patients developed a stenotic (or immature) AV fistula (7/29, 24.1%). There were positive linear relationships between EPC numbers and shear rate postoperatively, which were more significant on POD 30. In addition, postoperative mobilization of EPCs was significantly higher in patients who developed a stenotic fistula than those without. The mobilization of circulating EPCs correlated with a compromised arteriovenous fistula. The biological significance of increased EPC numbers need to be determined in future studies. Arteriovenous fistula; Endothelial progenitor cells.

Bariatric Surgery Is Associated with a Reduction in Major Macrovascular and Microvascular Complications in Moderately to Severely Obese Patients with Type 2 Diabetes Mellitus

Bariatric surgery (BAR) has been established as an effective treatment for type 2 diabetes mellitus (T2DM) in obese patients. However, few studies have examined the mid- to long-term outcomes of bariatric surgery in diabetic populations. Specifically, no comparative studies have broadly examined major macrovascular and microvascular complications in bariatric surgical patients vs similar, nonbariatric surgery controls. We conducted a large, population-based, retrospective cohort study of adult obese patients with T2DM, from 1996 to 2009, using UB-04 administrative data and vital records. Eligible patients undergoing bariatric surgery (BAR [n = 2,580]) were compared with nonbariatric surgery controls (CON [n = 13,371]) for the outcomes of any first major macrovascular event (myocardial infarction, stroke, or all-cause death) or microvascular event (new diagnosis of blindness, laser eye or retinal surgery, nontraumatic amputation, or creation of permanent arteriovenous access for hemodialysis), assessed in combination and separately, as well as other vascular events (carotid, coronary or lower extremity revascularization or new diagnosis of congestive heart failure or angina pectoris). Bariatric surgery was associated with favorable unadjusted 5-year event-free survival estimates for the combined primary outcome (95% ± 1% vs 81% ± 1%, log-rank p < 0.01) and each secondary outcome (log-rank p < 0.01). Multivariate-adjusted and propensity-based relative risk estimates showed BAR to be associated with a 60% to 70% reduction (adjusted hazard ratio [HR] 0.36, 95% CI 0.27 to 0.47) in the combined primary outcome and 60% to 80% risk reductions for each secondary outcome (macrovascular events [adjusted HR 0.39, 95% CI 0.29 to 0.51]; microvascular events [adjusted HR 0.22, 95% CI 0.09 to 0.49]; and other vascular events [adjusted HR 0.25, 95% CI 0.19 to 0.32]). Bariatric surgery is associated with a 65% reduction in major macrovascular and microvascular events in moderately and severely obese patients with T2DM.

Cardiovascular Implantable Electronic Device Leads in CKD and ESRD Patients: Review and Recommendations for Practice

Cardiovascular implantable electronic devices (CIEDs) are frequently utilized for management of cardiac dysrhythmias in patients with chronic kidney disease or end-stage renal disease receiving hemodialysis. The survival benefit from use of implantable cardioverter defibrillators in patients with CKD or ESRD is not as clear as in the general population, particularly when used for primary prevention of sudden cardiac death. Transvenous CIED leads are associated with central vein stenosis resulting in significant adverse consequences for existing or future arteriovenous access. Venous hypertension from CIED lead-related central vein stenosis is a challenging clinical problem and may require repeated percutaneous interventions, replacement of the CIED, or creation of alternative arteriovenous access. Infections associated with transvenous CIED leads are more frequent and associated with worse outcomes in patients with renal disease. Epicardial CIED leads or other nontransvenous devices may reduce complications of both central venous stenosis and endovascular infection in these vulnerable patients. Consensus recommendations are offered for avoidance and management of complications arising from the use of CIEDs and arteriovenous hemodialysis access.

Multicenter phase I/II trial of the safety of allogeneic endothelial cell implants after the creation of arteriovenous access for hemodialysis use: The V-HEALTH study

Multicenter phase I/II trial of the safety of allogeneic endothelial cell implants after the creation of arteriovenous access for hemodialysis use: The V-HEALTH study

Multicenter phase I/II trial of the safety of allogeneic endothelial cell implants after the creation of arteriovenous access for hemodialysis use: The V-HEALTH study

Vascular access dysfunction is the major cause of morbidity in patients on hemodialysis to treat end stage renal disease. Preclinical studies have demonstrated that the perivascular placement of implants containing allogeneic aortic endothelial cells (Vascugel) reduces thrombosis, inflammation, stenosis and increases lumen diameter in porcine models of arteriovenous fistulae (AVF) and arteriovenous grafts (AVG). We conducted a phase I/II clinical study to investigate the safety of Vascugel placement around the surgical anastomotic sites of newly constructed dialysis accesses. From July 2006 to August 2006, eight patients (4 AVG, 4 AVF) were treated with two Vascugel sponges at the venous anastomosis in the open-label phase I trial. From January 2007 to August 2007 57 patients (30 AVG and 27 AVF) were randomized in a 2:1 fashion to receive either Vascugel or control matrices (placebo) at surgery. The phase II AVG patients had sponges placed at both the venous and arterial anastomoses. All patients were followed for 24 weeks. The primary objective of the study was to demonstrate the safety (incidence of infection, intervention, and thrombosis) of Vascugel compared with placebo within 30 days post-surgery. Secondary endpoints included assessments of patency, lumen diameter, and immunologic sensitization to human leukocyte antigens (HLA) determined by measurement of panel reactive antibodies (PRA). There was no difference in early complication rates between the Vascugel and placebo groups at 4 weeks (10.9% vs 21.1%, respectively). There were no statistically significant differences in primary or assisted primary patency between the intent to treat groups at 24 weeks. Vascugel treated AVG had a primary patency rate of 38% and an assisted primary patency rate of 72% (vs 23% and 58%, respectively, for placebo). Vascugel treated AVF had a primary patency rate of 60% at 24 weeks and an assisted primary patency rate of 96% (vs 62% and 88%, respectively, for placebo). A greater than 30% increase in PRA was detected in 9 of the 46 (19.5%) Vascugel treated patients and one of the 19 (5.2%) placebo patients (P = .26) and was not associated with any evidence of local or systemic complications. Targeted local therapy with perivascular, allogeneic endothelial cells is a safe and novel therapeutic approach that may be ideally suited to control the response to injury at surgical anastomoses. Larger randomized trials are needed to determine if Vascugel can prolong AVG or AVF patency.

Regional Nerve Block Allows for Optimization of Planning in the Creation of Arteriovenous Access for Hemodialysis by Improving Superficial Venous Dilatation

Durable vascular access for hemodialysis remains a critical issue in end-stage renal disease patients. Creation of an autogenous arteriovenous (AV) fistula in the most distal location of the nondominant extremity is the preferred technique and provides superior patency over an AV graft. Others have shown that regional anesthesia in the form of axillary block results in the dilatation of the native veins and allows for their increased utilization in creating AV fistulae. We report on 26 patients undergoing creation of a vascular access for hemodialysis. Regional anesthesia consisting of axillary nerve block was used in all cases. All surgical plans with regard to the site and type of access were made based on the physical exam and ultrasound vein measurements taken prior to surgery. On the day of surgery patients were reevaluated with venous ultrasound using tourniquet before and after administration of the regional block. The previously determined operative plan either remained unchanged or was modified depending on the venous dilatation noted after administration of regional block. Among 26 patients, average vein diameter increased from 0.29 +/- 0.12 cm to 0.34 +/- 0.11 cm (P = 0.008). Twenty-one of 26 patients had no modification in operative plan (group 1). Five had some modification of the original operative plan (group 2): AV graft to a brachial vein transposition (n = 2), AV graft to a Cimino fistula (n = 2), and brachiocephalic to a Cimino (n = 1). The average follow-up for all patients was 82.6 +/- 75.6 days and did not differ between the groups. There was one failure in a patient from group 1, and there was no significant difference in the patency rate between study groups (P = 0.29). Following regional nerve block, operative plans in patients undergoing AV access surgery were modified in 29.4% of patients undergoing creation of an AV access for hemodialysis; either from graft to fistula creation or from the proximal to more distal fistula site. The routine use of regional anesthesia as well as intraoperative ultrasound during AV access surgery can lead to improved site selection and increased opportunity for AV fistula creation.

Noninvasive Vascular Testing with the Surgeon Present in Planning and Maintenance of Arteriovenous Hemodialysis Access

Background The goal of the study was to determine the incidence of upper extremity noninvasive vascular findings in guiding anatomic site and management strategies in the creation and maintenance of arteriovenous (AV) access for hemodialysis. All studies were performed with the surgeon present. Methods An ICAVL-accredited vascular laboratory database of upper extremity noninvasive vascular studies performed during a 12-month period was reviewed. The study group consisted of 152 end stage renal disease patients who received Doppler ultrasound and/or noninvasive physiologic testing for the purpose of assisting in planning or maintenance of hemodialysis access. The study group yielded a total of 252 exams as follows: (1) preoperative evaluation to determine site and suitability for use in AV access creation (n = 133); (2) existing AV access (AV fistula or graft) with clinical symptoms indicating malfunction and need for identifying the location and/or nature of the problem (n = 98); (3) finger arterial pressures and wave forms (with and without access compression) in patients with clinical symptoms of steal syndrome (n = 21). Results Of the 133 preoperative evaluations, 67 (51%) resulted in creation of an AV graft and 66 (49%) in an AV fistula. AV graft was chosen over fistula because of duplex findings of inadequate (&lt;2 mm in diameter) or deep (&gt;7 mm below skin level) veins. In all cases, the site and arm were determined by duplex findings and were marked preoperatively by the surgeon. In 72 (73.5%) of the 98 malfunctioning AV accesses, the etiology and site were identified by duplex ultrasound. These included thrombosing/failing access (n = 18, 25%), outflow venous stenosis (n = 16, 22.2%), inflow arterial stenosis (n = 15, 20.8%), anastomotic stenosis (n = 9, 12.5%), and miscellaneous causes (n = 14, 19.5%). Again, sites were marked by the access surgeon to guide intraoperative management. Steal was confirmed to be present in 11 (52%) of 21 patients and the surgeon determined the degree of arterial banding based on intraoperative changes in digital pressures. Conclusions Preoperative duplex scanning of upper extremity vasculature with the access surgeon present allows for accurate and precise planning in the creation of AV access. This has the potential to improve compliance with K/DOQI guidelines. Success in rescuing failing angioaccess is also enhanced by non-invasive testing in the presence of the operating surgeon.

AN INTEGRATED VASCULAR MANAGEMENT PROGRAMME

This paper discusses the development of an integrated approach for the creation and maintenance of arteriovenous access (AVA), under the direction of a dedicated vascular access surgeon in close cooperation with the haemodialysis staff, involving pre-operative imaging, anaesthetic and surgical techniques together with a post-operative graft surveillance programme, in order to maximize autogenous arteriovenous access (AAVA) construction (the preferred access for haemodialysis patients with end-stage renal disease), and to improve patency rates for AAVA and prosthetic arteriovenous access (PAVA).