Fistula Graft Research Articles

Effect of Transradial Coronary Angiography Procedure on Vascular Diameter and Vasodilator Functions in the Access Site

The present study aimed to investigate the long-term effects of transradial procedures on the radial artery diameter and vasodilator properties. The study included a total of 35 patients (28 males and 7 females) who underwent left transradial coronary angiography with an appropriate indication. The radial artery diameters were measured before and after flow-mediated vasodilation (FMD) and nitrate-mediated vasodilation (NMD). The nonintervened right radial artery served as the control. A marked narrowing in the diameter of the intervened radial artery and impaired FMD response indicating endothelial dysfunction were observed at a mean of 9 months after transradial intervention. Structural and functional changes should be taken into consideration if previously intervened radial artery would be used for interventions, such as arterial bypass graft or dialysis fistula.

Late myocardial ischemia induced by a large fistula between left internal mammary graft and left pulmonary vein system.

A coronary fistula is an extremely rare coronary artery anomaly and its incidence is 0.08–0.4% (1). A fistula between the Left internal mammary graft (LIMA) graft and pulmonary vein after a coronary artery bypass graft (CABG) is a very rare event, which can result in recurrence of anginal symptoms related to coronary steal (2). We present a 57 year old male patient who had coronary bypass surgery 3 years earlier with a fistula between the LIMA graft and left pulmonary vein after CABG surgery. His ECG on admission revealed sinus rhythm with 1 mm ST depression in precordial leads V4 to V6. The patient was complaining of anginal symptoms with minimal exertion under medical care. Myocardial scintigraphy revealed large anteroseptal ischemia. The patient underwent coronary angiography and this revealed a critical stenosis in the middle of the aorto-right coronary bypass graft composed of a severe thrombotic component and critical stenosis of the proximal left anterior descending artery (LAD) with a patent distal runoff. LIMA graft angiography showed a large fistula draining to the left pulmonary vein system and then left atrium, which was causing cutting off of the distal blood supply of the LIMA graft to the LAD (Figure 1 and Video 1). The management of each individual patient who has LIMA graft fistula should depend on the anatomy of the fistula, clinical picture and the presence or absence of associated cardiac conditions. In our case, we decided to use warfarin and clopidogrel therapy for 2 months to decrease the amount of thrombus in the aorto-coronary saphenous graft then percutaneous stenting for the aorto-right coronary graft and the proximal LAD. Figure 1. Large fistula draining from left internal mammary graft to left pulmonary vein system and then left atrium

Radiation Therapy for Dialysis Access Stenosis: Unfulfilled Promise or False Expectations

Hemodialysis vascular access dysfunction is a major cause of morbidity and hospitalization in the hemodialysis population at a cost of well over $1 billion per annum. Venous stenosis (due to venous neointimal hyperplasia [VNH]) is the most common cause of polytetrafluroethylene PTFE) dialysis access graft and arteriovenous fistula (AVF) failure. Despite the magnitude of the clinical problem, however, there are currently no effective therapies for this condition. We and others have previously demonstrated that VNH in PTFE dialysis grafts and AVF is composed of smooth muscle cells/myofibroblasts, endothelial cells within neointimal microvessels, and peri-graft macrophages. Radiation therapy blocks the proliferation and activation of all these cell types. The current review will dissect out the available in vitro, experimental, and clinical data on the use of radiation therapy for vascular stenosis in general, and for dialysis access dysfunction in particular. It is important to try and identify whether there is still a role for radiation therapy in this specific clinical setting. We believe that this is a critically important question to answer in view of the huge unmet clinical need that is currently associated with hemodialysis vascular access dysfunction.

Internal Mammary Artery Graft Fistulae to the Pulmonary Arteries as a cause of Myocardial Ischaemia after Coronary Artery Bypass Graft

Internal mammary artery (IMA) graft fistula to the pulmonary arteries is a cause of myocardial ischaemia after coronary artery bypass grafting (CABG). Surgical and percutaneous interventional treatments are available, both with their inherent risk and benefits. Optimised medical management is therefore essential. A pre CABG IMA angiographic image may assist surgeons to ligate identifiable accessory branches, which may contribute to fistula formation.

Mini tunelizador moldável: um avanço técnico no acesso vascular para hemodiálise

CONTEXTO: A confecção de fístula para hemodiálise pode envolver a criação de túnel para a acomodação do enxerto - veia autóloga ou prótese sintética. O trajeto e a extensão dependem do local escolhido para a realização das anastomoses e posicionamento do trajeto do enxerto. Na atualidade, os tunelizadores utilizados são constituídos de estruturas cilíndricas metálicas rígidas, que tornam necessário o uso de múltiplos tamanhos e conformações. OBJETIVO: Testar a utilização de um único mini tunelizador universal metálico e moldável na cirurgia de confecção de fístula para hemodiálise. MÉTODOS: Trata-se de um estudo piloto. O tunelizador desenvolvido consiste de uma estrutura cilíndrica e modular composta de fio de aço inoxidável moldável interno, com manopla em extremidade proximal e dupla ponta cônica intercambiável em extremidade distal e bainha cilíndrica externa de polietileno. O tunelizador foi utilizado em dez cirurgias de confecção de fístulas para hemodiálise em membros superiores e inferiores, e o sucesso de sua aplicabilidade e a frequência de complicações precoces foram observados. RESULTADOS: Suas características de maleabilidade e conformibilidade permitiram a utilização do mesmo tunelizador nos diversos tipos de fístulas realizadas. A ponta cônica distal com duplo diâmetro, intercambiável, permitiu que o mesmo aparato fosse aplicado na utilização de veia autógena ou prótese sintética. Todas as cirurgias foram seguidas de sucesso e com baixos índices de complicações precoces. CONCLUSÃO: A versatilidade do mini tunelizador metálico maleável e moldável permitiu sua utilização em todas as fístulas realizadas, independentemente do sítio das anastomoses e o trajeto de acomodação escolhido, sem complicações e com excelente índice de perviedade. Os dados sugerem que o mini tunelizador metálico maleável moldável pode ser utilizado com segurança e vantagens nas cirurgias de confecção de fístula para hemodiálise. Sua versatilidade e baixo custo de produção podem levá-lo a substituir os tunelizadores rígidos utilizados na atualidade e apontam para estudos mais elaborados e com casuística adequada para avaliação do real valor do novo instrumento.

Aortocoronary bypass graft fistula after surgical treatment of circumflex coronary artery fistula: a unique variation of a rare condition successfully treated with percutaneous embolization

Multiple coronary artery fistulae are rare, complications can be life-threatening, and with large or symptomatic fistulae, intervention is mandatory. Both surgical and percutaneous interventions are well-described. We believe this is the first report of the embolization of an acquired fistula following initial surgical treatment of multiple congenital fistulae.

VASCULAR DIALYSIS ACCESS FLOW MEASUREMENT: EARLY INTERVENTION THROUGH EARLY DETECTION

The aim of the project is to determine the effectiveness of using online access flow measurement, thermodilution method (Fresenius BTM), in detecting and predicting thrombosis or stenosis of the haemodialysis fistula, so that early intervention could be instituted. All haemodialysis patients with permanent vascular dialysis access, either arteriovenous fistula (AVF) or arteriovenous fistula graft (AVG), in a large tertiary referral Dialysis Service in Australia were included in this prospective observational quality project, conducted over 12 months. Out of 165 patients studied, 36 patients were found to have poor dialysis access flow, defined as AVF--flow of <200 ml/min or a decrease of 25% from last measurement or AVG--flow of <600 ml/min or a decrease of 25% from last measurement. Doppler ultrasounds were performed, and confirmed findings of significant stenosis, either on the arterial or venous sites, as indicated by poor dialysis access flow results. Thermodilution technique is a reliable and effective method of detecting poor dialysis access flow for patients with permanent vascular access, comparable with other techniques.

A Retrospective Monocenter Review of Simultaneous Pancreas-Kidney Transplantation

Objective Herein we have reviewed a consecutive series of simultaneous pancreas-kidney (SPK) transplantations performed at our institution over a 6-year period. Patients and Methods The study population included 22 patients (15 males and 7 females) who underwent SPK transplantation between 2001 and 2007. The mean recipient age was 47 years (range, 26–63 years). Eighteen patients suffered type 1 and 4 type 2 diabetes mellitus. The mean donor age was 33 years (range, 14–56 years). The mean HLA match was 2.1 (range, 1–5). Immunosuppressive treatment consisted of basiliximab induction followed by tacrolimus, mycophenolate mofetil, and prednisone. Results The mean hospital stay was 20 days (range, 11–52 days). After a mean follow-up of 44 months (range, 17–88 months), patient, kidney, and pancreas graft survivals were 86%, 82%, and 73%, respectively. Two patients died in the immediate postoperative period due to, respectively, disseminated intravascular coagulation and pulmonary embolism. A kidney graft was lost due to early hyperacute rejection. Other early complications associated with the pancreas graft included 2 cases of immediate reperfusion defects that led to early vascular thrombosis in 1 patient and a duodenal graft fistula in the other patient; a third patient developed type 2 diabetes mellitus. Beyond the postoperative period, graft loss was limited to 1 case of noncompliance to the immunosuppressive medications and 1 death secondary to pulmonary infection with a functional allograft after 4 years. Conclusions SPK transplantation is a valid therapeutic option for patients with insulin-dependent diabetes mellitus and renal failure due to diabetic nephropathy. The main complications of SPK transplantation occur in the immediate postoperative period consequent to vascular or rejection processes.

The Natural History of Vascular Access For Hemodialysis: A Single Center Study of 2,422 Patients

Conclusion: With the possible exception of older patients with diabetes, autogenous conduits are preferable for dialysis access. Summary: The Clinical Guidelines for Vascular Access from the National Kidney Foundation Disease Outcomes Quality Initiative recommend radial-cephalic arteriovenous fistulas (AVFs) and brachial-cephalic AVFs as the first and second choices for dialysis access, followed by prosthetic grafts, brachial-basilic AVFs, and venous catheters as secondary choices. These recommendations have been verified by review articles and small prospective trials and small clinical series. The article represents a retrospective review of a very large dialysis access experience in which 2422 consecutive patients underwent 3685 vascular access procedures in a tertiary care hospital. Radial-cephalic, brachial-cephalic, brachial-basilic, and prosthetic graft fistulas were all performed. Maximum follow-up was 20 years, and patency rates were determined by Kaplan-Meier analysis. Median primary patency for radial-cephalic AVFs was 712 days (95% confidence interval [CI], 606-818 days). Median primary patency for brachial-cephalic AVFs was 1009 days (95% CI, 823-1195 days). Median primary patency for PTFE reconstructions was 384 days (95% CI, 273-945 days). Median secondary patency for radial-cephalic fistulas was 1809 days (95% CI, 1692-1582 days). Median primary patency of brachial-basilic AVFs (second or third choice for vascular access) was 1582 days (95% CI, 415-2749 days). The cumulative incidence of clinically important complications in patients receiving radial-cephalic, brachial-cephalic, brachial-basilic, and PTFE dialysis access was 0.25, 0.57, 0.33, and 0.61 per patient-year, respectively. After 2000 days, radial-cephalic AVF patency was superior to brachial-cephalic AVF patency. Ten years after construction, 18% of radial-cephalic AVFs and 12% of brachial-cephalic AVFs were still functional. More than 50% of brachial-basilic arteriovenous fistulas were still patent after 4 years. Comment: The value of this study lies in the large number of patients and the long period of follow-up. Otherwise, the conclusions are really not substantially different from those derived previously. There has, however, been some controversy about the use of prosthetic vs brachial-basilic fistulas as secondary or tertiary access procedures. This study would suggest that a brachial-basilic fistula is far superior to prosthetic access and that brachial-basilic AVF, although more technically demanding, should be the preferred secondary or tertiary access over a prosthetic graft.

Acute pancreatic graft fistula and peripancreatic fluid collection: demonstration by secretin-stimulated MRI

Peripancreatic fluid collections are among the common post pancreas transplant complications, which are mainly due to leakage from the anastomosis site to bowel and graft pancreatitis. Differentiation between these two entities is important because they are treated differently. In this case, secretin stimulated magnetic resonance cholangiopancreatography revealed gradual intraperitoneal fluid collection and accumulation of fluid in small bowel excluded leakage from the anastomosis of the pancreas to bowel and changed the management from surgery to medical treatment.

Fistula repair after hypospadias surgery using buccal mucosal graft.

The aim of this study was to evaluate the success rate of urethrocutaneous fistula repair using buccal mucosal graft in patients with a previous hypospadias repair. We reviewed records of our patients with urethrocutaneous fistula developed after hypospadias repair in whom buccal mucosal graft fistula repair had been performed. All of the patients had been followed up for 24 postoperative months. A successful surgical operation was defined as no fistula recurrence or urethral stricture. Retrograde urethrography and urethrocystoscopy would be performed in patients who had any history of decreased force and caliber of urine or any difficulty in urination. Fistula repair using buccal mucosa patch graft had been done in 14 children with urethrocutaneous fistula developing after hypospadias reconstruction. The mean age of the children was 8.70 +/- 1.99 years old (range, 4 to 11 years). Seven fistulas were in the midshaft, 4 were in the penoscrotal region, and 3 were in the coronal region. Repair of the fistulas was successful in 11 of 14 patients (78.6%). In the remaining children, the diameter of the fistula was smaller than that before the operation, offering a good opportunity for subsequent closure. Our findings showed that fistula repair using buccal mucosal graft can be one of the acceptable techniques for repairing fistulas developed after hypospadias repair.

The natural history of vascular access for hemodialysis: A single center study of 2,422 patients

Our objective is to provide provision of primary and secondary patency rates data and incidence of complications. Despite the publication of some review articles and small prospective trials about vascular accesses, controversy still exists regarding the choice of the outflow conduit and especially the choice of the fistula to be formed in secondary and tertiary access procedures. This is a retrospective study of 2,422 consecutive patients who underwent 3,685 vascular access procedures in a tertiary care hospital, including radial-cephalic (RCAVF), brachial-cephalic (BCAVF), brachial-basilic (BBAVF), and prosthetic graft (PTFE) fistulas. Maximum follow-up period was 20 years. Actuarial patency rates were obtained by Kaplan-Meier analysis. The median primary patency (days) of the most common 1st choices for vascular access were 712 (95% CI: 606, 818), 1,009 (95% CI: 823, 1,195), and 384 (95% CI: 273, 945) days for RCAVF, BCAVF, and PTFE, respectively. The median secondary patency was 1809 days (95% CI: 1,692, 1,926) for the RCAVF. The median primary patency of BBAVF (2nd or 3rd choice for vascular access) was 1,582 days (95% CI: 415, 2,749). The cumulative incidence of clinically important complications for the patients who received a RCAVF, BCAVF, BBAVF, and u-PTFE was 0.25, 0.57, 0.33, and 0.61 per patient-year, respectively. We advocate maximal use of autogenous conduits, except probably the case of the older diabetic patient, in whom access at the antecubital fossa should be the first choice. BBAVF is an excellent fistula and should probably be constructed before prosthetic graft placement.

An Experience in Arterio-Venous Fistula creation for Chronic Haemodialysis

Obtaining a vascular access for haemodialysis is very vital in the long-term management of patients with end-age renal disease. This is achieved via an autogenous (primary) arteriovenous fistula or a grafted fistula in situations where autogenous fistulas may not function. Complications such as thrombosis and infection are common following graft creation, and they contribute significantly to the cost of dialysis therapy. In a prospective study of the patients who underwent Anterior-venous fistula creation by our team in Lagos, Nigeria from 1995 to December 2002, a protocol was designed and data were collected. The data included their ages, gender, the indications, site and types of fistulae created. We constructed 32 fistulae within the period-21 males and 11 females giving a M:F of 2:1. Brescia cimino fistulae were created 25 (81.3%) of the patients. Polytetrafluorothylene graft fistulae were created in 7(21.95) of the patients. The only indication for surgery was the need for access for haemodialysis in end stage renal disease. Three of the fistulae got thrombosed acutely while others did well. The study aimed at highlighting the surgical methods of vascular access and the possible complications in our environment. We concluded that radio-cephalic arterio-venous fistula provides the best vascular access for chronic haemodialysis NQJHM Vol. 13 (3-4) 2003: pp. 54-55

Ureteral Perigraft Fistula

Ureteral injury following aortic surgery occurs in less than 1% of all cases. Ureteral-arterial fistulae rarely occur in the current literature and only in case reports. This case involves a suspected ureteral aortic graft fistula presenting with acute hematuria with distant history of redo aortic bifemoral graft for aortoenteric fistula. Cystoscopy with retrograde pyelogram was performed and demonstrated what appeared to be a fistula between the left ureter and the aortic graft with a proximal hydroureter and hydronephrosis. After a detailed review of the films, we diagnosed a more benign ureteral perigraft fistula. Multidisciplinary management including urology and vascular surgery suggested conservative management. However, the patient later required more definitive therapy for his illness. This case demonstrates a ureteral perigraft fistula and displays how it appears radiographically. Here we present our experience with this new radiological diagnosis.

Percutaneous Mural Fenestration and Angioplasty for the Treatment of a Refractory Hemodialysis-Related Venous Stenosis

Venous stenoses are the leading cause of dialysis graft and mature dialysis fistula malfunction. We report a simple, inexpensive technique for treating stenoses that are refractory to conventional balloon angioplasty and present a case in which this technique was successfully applied.

Development of a novel catheter preventing the outflow of debris and thrombus on percutaneous transluminal angioplasty for hemodialysis access fistulas

If a large amount of debris or thrombus dislodges from a lesion because of dilation of the stenotic or occluded lesion in the hemodialysis access fistula when angioplasty is performed, it may move into the pulmonary artery via the central vein, resulting in pulmonary embolism. A novel sheath has been developed to prevent the outflow of debris or thrombus to the central vein. The catheter consists of a 5 F sheath introducer and a silicone balloon attached at the tip of the sheath. The silicon balloon is inflated via small inflation lumen on the shaft wall of the sheath. In the case of percutaneous transluminal angioplasty (PTA), the silicone balloon is inflated to block the blood flow by a mixture of contrast medium and physiological saline, and then dilate a stenotic or occluded lesion by PTA balloon. Next, the debris and thrombus are aspirated using the flush-lumen of this device. Finally, the silicone balloon is deflated and the dilation of the lesion is confirmed. A case of hemodialysis access fistula graft with massive thrombotic occlusion was presented. This device enabled Fogarty procedure using PTA balloon and the blood flow of the graft was completely improved and a large amount of thrombus was removed. This novel device is useful to prevent the embolic complication of the intervention for hemodialysis access fistula.

Axillo-iliac Conduit for Haemodialysis Vascular Access

Objectives To describe a series of venous surgical procedures performed to maintain vascular access. Methods We report eight patients with end-stage renal failure (ESRF) who had complex renal access problems. Three patients had central venous occlusion and underwent veno-venous axillo-iliac bypass. In five further patients with a symptomatic central venous obstruction we performed axillo-iliac arterio-venous grafting (AVGs) in order to achieve haemodialysis access. All patients were assessed pre-operatively with duplex ultrasound and venogram of upper and lower limbs. The axillary artery or vein, and iliac vein were approached via infraclavicular and extra-peritoneal groin incisions, respectively. Non-externally-supported polytetrafluoroethylene (PTFE) was used as a conduit in all patients and anti-coagulation regimen were commenced post-operatively. Results Following venous diversion surgery, there was a dramatic improvement in the facial and limb swelling experienced by the patients. There was no significant peri-operative morbidity. The veno-venous graft is still patent at 14 months in patient one, at 10 months in patient two, and 5 months in patient three. In the second group, who had arterio-venous grafts, the mean follow-up was 13.2 (7–20) months with a secondary patency rate of 80% at 6 months. Four patients had patent, usable grafts at 12 months. In two cases, graft occlusion was treated with successful thrombectomy. Conclusion Axillary-iliac veno-venous diversion can overcome the symptoms and complications of superior vena cava and innominate vein obstruction. Although, axillo-iliac arterio-venous graft fistulae formation was previously described it has not been widely used. We have found the procedure to have low morbidity and advocate its use in these complex cases.

Ultrasound of Haemodialysis Radiocephalic Fistula: A Pictorial Essay

Regular vascular access for haemodialysis requires a good calibre vein with high flow. This is typically achieved by anastomosing the radial artery to the cephalic vein at the wrist, the classic Brescia–Cimino arteriovenous fistula (AVF). Alternatives include brachial artery to cephalic/basilic vein and bridge graft fistulas. Ultrasound provides an inexpensive and non-invasive method of monitoring fistula effectiveness, confirming clinical suspicion of stenosis/occlusions and steal. It informs the vascular radiologist regarding the optimal approach to angioplasty and provides rapid assessment of anomalies of the AVF, including diagnosis of aneurysms, thrombus and post-operative fluid collections. This article is intended as an illustrative guide to performing a duplex examination and to clarify some of the problems which may arise.

Analysis of Surgical technique of A-V fistula formation in patients of ESRD

Objective: The study's aim was to analyse the current method of Arteriovenous fistula operation and to find the proper method of operation.Methods: A retrospective study of 44 Arteriovenous fistula operation for hemodialysis at Cheju National Hospital between April 2002 and November 2003.Results: Thirty six autogenous fistula, 8 prosthetic graft were available for evaluation. The incidence of Prosthetic graft was 18%. There are 25 radiocephalic fistula, 9 brachiocephalic or brachiocubital fistula and 2 ulnobasilic fistulas. 38 patients were successful and used for dialysis, but 3 lost in follow-up, I clotted in immediate postoperative period, 1 died before dialysis and 1 failed to mature.Conclusions: The proper selection of patients and method of artiovenous fistula operation can be reduce the incidence of artificial graft fistulas and increase the patency rate.

Non-Invasive Contrast Enhanced Electron Beam Tomography: A Three Dimension Imaging Adjunctive Test To Detect Renal Vascular and A-V Fistula Graft Abnormalities.

Electron beam tomography (EBCT) is a relatively new technology with several potential advantages over traditional CT such as fast acquisition time, less exposure to radiation, less sedation and volume of dye, and better 3D visualization. A retrospective study was done to assess the use of 3D EBCT to detect renal vascular abnormalities and patency of arteriovenous-fistula (A-VF) and arteriovenous-graft (A-VG). EBCT was done in 7 children (age 3–18 year, mean age 10.8 years). All had hypertension (> 95%) and high rennin levels. Four of the patients (group I) had normal renal function. One patient (group II) was 20 days post enblock renal transplantation with ascites, hypertension and renal dysfunction. Two patients (group III) had end-stage renal disease, hypertension, and AV-F and AV-G. One of these patients had SLE and difficult IV access. In group I, 2/4 had left ventricular hypertrophy, eye and CNS changes. MAG-3 renal scan (RSC) and renal ultrasound (RUS) were normal in 2/4 group I patients. In group I, 2/4 EBCT showed unilateral renal artery stenosis: one of these children had decreased velocity in one kidney by RUS and the other child had possible renal artery stenosis by RSC. One child in group I with abnormal RUS suggestive of RAS did not have RAS by EBCT and traditional angiography. In group II, patient with transplant, EBCT showed normal renal vasculature and ureterovesicle anastomoses without RAS or leak respectively. In group III, the SLE patient had thrombosis of the inferior vena cava and renal veins and the other patient had patent A-VF with dilated vessels contrary to US finding of thrombosis. In conclusion, EBCT with its non invasive, maximum intensity projection and 3D images, less radiation and acquisition time is a useful adjunct test to detect RAS and AV-F, AV-G and transplant vascular thrombosis/stenosis in children.