Native Fistula Research Articles

Comparison of Clinical Assessment With Ultrasound Flow for Hemodialysis Access Surveillance

Organized clinical assessment of hemodialysis access is as useful a surveillance tool as ultrasound flow measurements in preventing access thrombosis. Cohort analysis comparing a dialysis unit evaluated using ultrasound flow measurements with another unit evaluated clinically. University-affiliated community program with private and health maintenance organization dialysis units. One hundred patients in each unit were enrolled. Patients who were unavailable for follow-up or died within the first 30 days of enrollment were excluded from further analysis. Angiograms were obtained in the Transonics Doppler ultrasound system (Transonics Systems Inc, Ithaca, New York) cohort if graft flow was less than 600 mL/min, fistula flow was less than 450 mL/min, or flow decreased more than 25%, and in the clinical cohort if there was a change in the access appearance, change in the bruit, or a sharp increase in venous resistance. Primary and secondary patencies of the hemodialysis access were analyzed for each cohort. Subset analysis was obtained for synthetic grafts and native fistulas. Procedures were assessed for each cohort. The patients in the clinical cohort had similar primary patency (1199 days) as in the Transonics cohort (1162 days) (P = .92). Angiographic procedures were also similar, with 56% of all patients having none. The mean number of procedures was 0.56 per patient in the Transonics cohort and 0.48 in the clinical group (P = .48). An organized clinical assessment, using a formal tracking tool, is equal to ultrasound flow measurements as a surveillance method to prevent hemodialysis access thrombosis.

P3-53 COMPARISON OF CUTTING BALLOON VERSUS HIGH-PRESSURE BALLOON ANGIOPLASTY FOR RESISTANT VENOUS STENOSES OF NATIVE DIALYSIS FISTULAS

MATERIALS AND METHODS: The authors retrospectively reviewed 1,220 percutaneous transluminal angioplasty procedures performed to treat dysfunctional native hemodialysis fistulas. Seventy patients with stenoses resistant to conventional balloon angioplasty (up to 24 atm) were included in this study: 35 patients underwent cutting balloon angioplasty from September 2003 through February 2005, and 35 patients underwent high-pressure balloon angioplasty from March 2005 through April 2006. Evaluation included technical success, complications, and postintervention patency rates up to 6 months.

Pharmacomechanical Thrombectomy with the Castañeda Brush Catheter in Thrombosed Hemodialysis Grafts and Native Fistulas

To evaluate the safety and efficacy of the Castañeda brush catheter in the treatment of thrombosed hemodialysis fistulas and grafts. Twenty-six revascularization procedures with the Castañeda brush catheter combined with urokinase were retrospectively analyzed in 21 patients (mean age, 69 years; range, 35-87 y). Hemodialysis shunts were native arteriovenous (AV) fistulas (n=15; 16 procedures) or polytetrafluoroethylene grafts (n=6; 10 procedures). Major outcomes included procedure time, anatomic and clinical success rates, complication rate, and primary, primary assisted, and secondary patency. In 26 procedures, the brush catheter was used in combination with a mean dose of 239,792 IU urokinase (range, 60,000-300,000 IU). Additional angioplasty was performed in all procedures; five procedures (19%) required additional stent implantation. Mean procedure time was 99.2 minutes (range, 49-261 min). Anatomic and clinical success rates were 100% and 96.2%, respectively. Two minor complications (8%) occurred, neither of which was device-related: one case of extravasation treated by balloon tamponade and one hematoma at the distal puncture site without the need for surgery or transfusion. Primary patency rates were 87%, 62%, and 50% at 3, 6, and 12 months, respectively, for AV fistulas, and 50%, 33%, and 17%, respectively, for grafts. Assisted primary patency rates were 93%, 77%, and 70% at 3, 6, and 12 months, respectively, for AV fistulas, and 50%, 33%, and 17%, respectively, for grafts. At 3, 6, and 12 months, secondary patency rates were 93%, 85%, and 80%, respectively, for AV fistulas, and 83%, 67%, and 50%, respectively, for grafts. The Castañeda brush catheter is a safe and effective pharmacomechanical thrombectomy device for the treatment of thrombosed hemodialysis grafts and native fistulas.

A Prospective Study on Incidence of Bacterial Infections in Portuguese Dialysis Units

Background: Viral infection has been the main epidemiologic concern in the hemodialysis unit; however, bacterial infection is responsible for more than 30% of all causes of morbidity and mortality in our patients, vascular access infection being the culprit in 73% of all bacteremias. Methods: A prospective multicenter cohort study of bacterial infections incidence, conducted from January to July 2004 in five hemodialysis units, to record and track bacterial infections, using a validated database from CDC’s Dialysis Surveillance Network Program. Results: 4,501 patient-months (P-M) were surveilled, being dialyzed through a native fistula (AVF) in 60.6%, a graft (PTFE) in 31.3%, a tunneled catheter (TC) in 7.6%, and a transient catheter (C) in 0.5%. As target events, we registered 166 hospitalizations – 3.7/100 P-M (2.2/100 P-M in patients with AVF, 4 in PTFE, 9.9 in TC, and 19 in C), and 182 intravenous antibiotic courses. Of these 182 antibiotic treatments, 47.8% included vancomycin, only 30% had blood cultures drawn pretreatment, and only 36% were positive. We recorded 98 infections at the vascular access site 2.18/100 P-M (0.95 in AVF, 1.6 in PTFE, 12.6 in TC, and 42.85 in C) and 2.13 infections/100 P-M at other sites. The isolated microorganisms were Staphylococcus epidermidis in 40.1%, Staphylococcus aureus in 30.1%, Pseudomonas in 13.3%, and Escherichia coli in 3.3%. Although we found a diversity of practice patterns, the number of target events (8.4/100 P-M) and the bacterial infections incidence (4.31/100 P-M) were remarkably homogeneous in the five centers. Conclusion: (1) High incidence of bacterial infections, causing major morbidity; (2) infectious risk is vascular access type-dependent, with dramatic rise in catheters; (3) underutilization of blood cultures to orient diagnosis and therapy, and (4) high rates of vancomycin prescription.

Short-Term Follow-up for Percutaneous Extra-anatomic Intervascular Anastomosis in Salvage of a Thrombosed Native Arteriovenous Fistula

Percutaneous extra-anatomic intervascular anastomosis (PEIA), i.e., the nonsurgical connection of two anatomically unrelated vascular lumina, has rarely been reported in peripheral applications. Chen et al. [1] recently described a PEIA technique applied in peripheral vascular intervention. Using the same technique, the authors successfully salvaged an occluded native arteriovenous (AV) fistula with obliterated outflow veins. The vascular access has been followed up for more than 6 months and access-related complications are reported here. A 54-year-old woman with a failed and diffusely thrombosed native radiocephalic fistula in the right forearm was referred for shunt salvage. The fistula had been used for about 13 years. Informed consent was obtained. The institutional review board was not required for this retrospective report in our hospital. On physical examination, a hard and dilated forearm cephalic vein was noted, terminating as a venous stump not far below the elbow crease. Using local anesthesia, a 7-Fr introducer sheath was inserted in antegrade fashion in the forearm cephalic vein about 4 cm downstream of the AV anastomosis. A 4.1-Fr angiographic catheter was advanced to the venous stump and a small test bolus of contrast material was injected. No outflow vein from the venous stump could be identified on fluoroscopy. Under sonographic guidance, small thrombosed veins were catheterized, but attempts to get access into the dilated venous stump failed (Fig. 1A). During the search for small thrombosed veins around the venous stump, an upper arm basilic vein near and medial to the venous stump was noted. The patent basilic vein was catheterized under sonographic guidance and the venogram revealed no direct anastomosis with the venous stump (Fig. 1B) and the finding was comfirmed by sonography. A new vascular access creation was therefore suggested but the patient refused surgery after a thorough explanation to her and her family. In order to restore sufficient shunt flow, a good outflow drainage tract from the venous stump was required. Therefore, we attempted to salvage the fistula using the technique reported by Chen et al. [1] by stent-graft insertion between the venous stump and an adjacent patent basilic vein. An 8 · 60-mm stent-graft (Wallgraft; Boston Scientific, Natick, MA) was used to bridge the two ends of the fistulous tract. The stent-graft was dilated with an 8mm ·4-cm PTA balloon catheter. Thrombolysis was performed thereafter using 500,000 IU of urokinase. Thromboaspiration was performed with an 8-Fr Desilets-Hoffman sheath (Cook, Bloomington, IN, USA). Before thrombolysis, a bolus of 5000 IU heparin was given through a peripheral intravenous line. The AV fistula was successfully salvaged and the immediate follow-up fistulography showed brisk flow with presumed compression of a segment of the runoff basilic vein by hematoma (Fig. 1C; arrow). No immediate complications were noted and the patient underwent successful hemodialysis the next morning. The patient was called back for a fistulography 1 month after M. C.-Y. Chen (&) R.-H. Wu W.-S. Tzeng S.-C. Chang Department of Diagnostic Radiology, Chi-Mei Medical Center, Yung-Kang Campus, No. 901, Chung Hwa Road, Yung-Kang City, Tainan County 806, Taiwan e-mail: jjychen@gmail.com

Gadolinium-Enhanced Angiography for Diagnosis and Interventional Treatment of Subclavian Artery Stenosis Prior to Fistula Creation

We report the use of gadolinium-based contrast agent for both diagnostic and interventional subclavian angiography in two azotemic patients, presenting with an asymptomatic, high-grade stenosis of the left subclavian artery, ipsilateral to the site of choice for native fistula creation. Angiographic imaging performed with diluted gadolinium-based contrast material was clear enough to perform successful subclavian artery stenting, resulting in normalization of the arterial blood pressure in the afferent artery of the dialysis fistula. Clinically, no decrease in residual renal function and no other complication were noted immediately or a longer period after the interventional treatment.

Does the Surgeon’s Experience Impact on Radiocephalic Fistula Patency Rates?

Establishing successful long-term hemodialysis access remains a major challenge. The primary aims of this study were to determine whether primary success and primary and secondary patency rates of a series of consecutive radio-cephalic fistulae (RCF) were affected by the experience of the surgeon. The secondary aims were to assess complications, and to compare results with patency rates from the literature. All native fistulae (AVF) created in our unit between January 1, 2002 and December 31, 2005 were analyzed retrospectively. The RCF were identified and divided into group A (RCF fashioned by the consultant surgeon), and group B (fashioned by the junior surgeons within the unit). Demographic characteristics, risk factors, primary success rate (patent fistula at discharge), and primary and secondary patency rates were compared between each group using chi-squared test. During this period, 552 AVF were created. Of the 195 RCF, there were 153 fistulae in group A and 42 in group B. Median follow-up was 22 months for both groups. There was no difference with regards to age, sex ratio, prevalence of diabetes, and cardiovascular disease. The primary success rate in group A and B was 94.2% and 81%, respectively (p < 0.01). Primary and secondary patency rates at 22 months were 80%, 93%* and 74%, 81%* in group A and B, respectively (*p < 0.025). Even within group B, these results compare very favorably with the published literature. These results suggest that the placement of a RCF should be performed by the most experienced member of a team dedicated to vascular access creation or at least under his supervision.

Cannulating in haemodialysis: rope-ladder or buttonhole technique?

The standard technique for fistula cannulation, the rope-ladder technique, is problematic for patients with short fistula lengths and for patients in whom the fistula is difficult to cannulate. The buttonhole technique, cannulation of exactly the same site, offers the advantage of an easy cannulation procedure. However, it can be used only in native fistulas and cannulation is preferably executed by a 'single-sticker'. This study was conducted to compare these cannulation techniques using objective parameters. We introduced the buttonhole technique for self-cannulating home haemodialysis patients and compared it with baseline data obtained with the rope-ladder technique. Thirty-three patients with a native arteriovenous fistula were observed prospectively during 18 months on the following parameters: cannulating ease, number of bad sticks, pain, time of compression after cannula removal, bleeding, infectious complications and aneurysm formation. With the buttonhole method, cannulating ease improved distinctly, which was especially favourable in patients with a short fistula vein. Reported cannulation pain did not change significantly. The incidence of bad sticks decreased significantly, as well as time of compression after cannula removal, without increased incidence of bleeding. Three patients developed a local skin infection of their buttonhole during the study, after which the disinfection routine prior to cannulation was changed. Compared with the rope-ladder technique, the buttonhole method offers the advantage of an easier cannulation procedure with less bad sticks, which has a special benefit for patients with limited access cannulation sites or with a fistula which is difficult to cannulate. Prolonged compression times or re-bleeding episodes did not occur, but precautions have to be taken in order to prevent infectious complications. The buttonhole method can contribute considerably to the cannulating ease of self-cannulating patients, thus providing a better quality of life.

VS16P OUTCOMES OF ARTERIOVENOUS FISTULA FOR VASCULAR ACCESS

Introduction Vascular access for chronic haemodialysis persists as a surgical challenge. The development of the radiocephalic arteio venous fistula in 1966 by Brescia was a milestone in vascular access surgery. There has been a move away from the use of prosthetic due to the associated complications.A decision was made at this institution to use autologous vein in all cases recognising the consequence of using marginal veins.Aim To determine the Outcomes of all Radiocephalic, Bracheocephalic and Transposition arterio venous fistulae.Method A retrospective study by review of the case notes was carried out in March 2006.All renal access procedures performed between 6/03 and 6/05 were reviewed.In the new native fistulas formed during this time, the following end points were sought: Primary, secondary and functional patency at 24 hrs. 6 weeks, 6 months and 1 year.Results Life table analysis of the patency outcomes showed that Percentage primary patency rates for Radiocephalic and Bracheocephalic fistulae were 71% and 74% at 1 year respectively. Subgroup analysis of females, diabetics and those with BMI &gt; 30 showed diabetics composed &gt;40% of patients and patients with BMI &gt;30 was 29%. Of these two subgroups primary patency rates were comparable to the whole group.Conclusion The population studied was different to those in other parts of the world. FavourablePrimary patency rates were obtained for this challenging group of patients.

Efficacy of ProLumen in Percutaneous Thrombectomy of Clotted Dialysis Access: A Single-Center Prospective Study

Purpose To prospectively evaluate the efficacy of the ProLumen thrombectomy device for declot of dialysis access. Methods 16 women and 4 men suffering from end-stage renal disease (ESRD) dependent on hemodialysis (mean age, 66.4 years) and presenting with thrombosed dialysis access were enrolled form October 2005 through February 2006. Sixteen patients had synthetic grafts and 4 had native fistulas. Mean age of access was 24.65 months (range, 2 to 96 months). A history of previous intervention was noted for seven patients (6 percutaneous, 1 surgical). Results A mean of 2.7 passes of the ProLumen device were required for the venous limb (range, 1 to 6) and 2.35 passes for the arterial limb (range, 0 to 5). Average procedure time was 48 minutes (range 32–81 minutes). Adjunctive thrombectomy devices were utilized in 5 cases. Good angiographic and clinical results were reported in 19 patients; one patient had a poor result. Dialysis flow rate prior to thrombosis was 425 mL/min (range, 300 to 550). The mean post-thrombectomy flow rate was 380 mL/min (range, 200 to 480; n=19). “Ease of use” of Pro Lumen thrombectomy device was rated good in 17 patients. Maneuverability was good in 14 patients and clot removal around the opposite sheath was rated as good in 18 patients. Conclusions ProLumen is effective in thrombectomy of dialysis access. The device is easy to use, and effectively removes clot around the opposite sheath.

Salvage of Nonmaturing Native Fistulas by Using Angioplasty

To retrospectively review outcomes following angioplasty of nonmaturing autogenous hemodialysis fistulas. Institutional review board exemption was received for this HIPAA-compliant retrospective study; informed consent was waived. During 48 months, 101 patients underwent fistulography for percutaneous salvage of nonmaturing native fistulas. Clinical and technical success, need for secondary interventions, and complications were recorded according to consensus definitions. Patency following angioplasty was estimated with the Kaplan-Meier technique. Patient age, sex, ethnicity, fistula age, fistula type, number of stenoses, maximal angioplastic balloon diameter used, and presence of palpable thrill following angioplasty were examined as predictors of primary patency of the fistula following intervention by using Cox proportional hazards model. Mean patient age was 58 years; 35% were women. Median time from fistula creation to fistulography was 2.5 months. Hemodynamically significant (>50%) stenoses were identified in 88% (89 of 101) of patients; angioplasty was attempted in 96% (85 of 89). Technical success was achieved in 92% (78 of 85) of fistulas following angioplasty; clinical success of normal hemodialysis with total access blood flow of more than 500 mL/min occurred following 88% (75 of 85) of angioplastic interventions. No major and two minor complications occurred. Mean primary unassisted patency at 3, 6, and 12 months was 60%+/-6% (95% confidence interval), 45%+/-6%, and 34%+/-6%, respectively. Additional angioplasty (n=12), stent placement (n=1), or thrombectomy (n=1) during subsequent interventions resulted in mean secondary patency at 3, 6, and 12 months of 82%+/-4%, 79%+/-5%, and 75%+/-6%, respectively. Patients without thrill following angioplasty were more than twice as likely to lose patency as patients with thrill (P=.035). No relationship was seen between primary patency and other predictors examined. Early fistulography enables identification of underlying areas of stenosis in nonmaturing fistulas, which can be safely and effectively treated with angioplasty. With continued surveillance and repeat interventions, functional patency can be sustained in the majority of fistulas.

Strategy for the Maximal Use of Native Arteriovenous Fistulae for Hemodialysis

The long-term survival and quality of life of patients on hemodialysis is dependent on the adequacy of dialysis via an appropriately placed vascular access. The native arteriovenous fistula (AV fistula) at the wrist is generally accepted as the vascular access of choice in hemodialysis patients due to its low complication and high patency rates. It has been shown beyond doubt that an optimally functioning AV fistula is a good prognostic factor of patient morbidity and mortality in the dialysis phase. Recent clinical practice guidelines recommend the creation of a vascular access (native fistula or synthetic graft) before the start of chronic hemodialysis therapy to prevent the need for complication-prone dialysis catheters. A multidisciplinary approach, including nephrologists, surgeons, interventional radiologists, and nurses should improve the hemodialysis outcome by promoting the use of native AV fistulae. An important additional component of this program is the Doppler ultrasound for preoperative vascular mapping. This approach may be realized without unsuccessful surgical explorations, with a minimal early failure rate, and a high maturation, even in risk groups such as elderly and diabetic patients. Vascular access care is responsible for a significant proportion of health care costs in the first year of hemodialysis. These results also support clinical practice guidelines that recommend the preferential placement of a native fistula.

Proximalization of the arterial inflow: A new technique to treat access-related ischemia

Arteriovenous access-related ischemia is an uncommon but serious and occasionally devastating complication. Distal revascularization-interval ligation (DRIL) has been established as a standard treatment procedure; however, an axial artery is ligated and the distal perfusion is maintained by the construction of an arterial bypass. Because such an approach, in principle, appears undesirable, we developed and applied an alternative technique referred to as proximalization of the arterial inflow (PAI). This procedure converts the arterial supply of the arteriovenous access to a more proximal artery with higher capacity by using a small-caliber polytetrafluoroethylene graft as a feeder. From January 1999 to June 2005, the PAI technique was applied in 30 patients. The indication was seen in patients with severe distal ischemia who had a flow volume rate of <800 mL/min in a native fistula and <1000 mL/min in prosthetic access. Pain was the dominant symptom of ischemia in most patients before surgery. In 37%, a tissue loss was observed. The symptoms of access-related ischemia disappeared completely in 84% of patients and improved significantly in 16%. The significant hemodynamic improvement was confirmed by an increase of the intraoperatively measured mean distal arterial pressure from 32 +/- 9 mm Hg to 63 +/- 8 mm Hg. The digital-brachial index increased from 0.40 +/- 0.10 to 0.83 +/- 0.07. The mean access flow rate was 658 +/- 80 mL/min after PAI and did not differ significantly with the preoperative value (634 +/- 181 mL/min). With a mean follow-up interval of 26.1 +/-19.1 months, the primary and secondary patency rates were, respectively, 87% and 90% at 1 year and 67% and 78% at 3 years. The PAI procedure represents a well-suited alternative to the DRIL technique for the treatment of patients who develop ischemia after creation of an arteriovenous access. Results for access salvage and disappearance of ischemic symptoms are equivalent to the DRIL technique. In contrast to the DRIL procedure, the PAI technique preserves the natural arterial pathway. Hence, PAI is preferable for surgeons who are reluctant to ligate an axial artery and are concerned about potentially disastrous consequences.

Strategy for the Maximal Use of Native Arteriovenous Fistulae for Hemodialysis

The long-term survival and quality of life of patients on hemodialysis is dependant on the adequacy of dialysis via an appropriately placed vascular access. The native arteriovenous fistula (AV fistula) at the wrist is generally accepted as the vascular access of choice in hemodialysis patients due to its low complication and high patency rates. It has been shown beyond doubt that an optimally functioning AV fistula is a good prognostic factor of patient morbidity and mortality in the dialysis phase. Recent clinical practice guidelines recommend the creation of a vascular access (native fistula or synthetic graft) before the start of chronic hemodialysis therapy to prevent the need for complication-prone dialysis catheters. A multidisciplinary approach, including nephrologists, surgeons, interventional radiologists, and nurses should improve the hemodialysis outcome by promoting the use of native AV fistulae. An important additional component of this program is the Doppler ultrasound for preoperative vascular mapping. This approach may be realized without unsuccessful surgical explorations, with a minimal early failure rate, and a high maturation, even in risk groups such as elderly and diabetic patients. Vascular access care is responsible for a significant proportion of health care costs in the first year of hemodialysis. These results also support clinical practice guidelines that recommend the preferential placement of a native fistula.

Transradial intervention for native fistula failure

The native radiocephalic (Brescia-Cimino) fistula is usually constructed with an anastomosis of the cephalic vein and radial artery. Catheter interventions for native fistula failure have until now been performed via the transcephalic or transbrachial approach. Transradial intervention for native fistula failure was prospectively evaluated for a selected consecutive 11 patients. Six patients had a single lesion and 5 patients had double lesions. Twelve lesions were stenotic and 4 were occlusive with thrombus. Balloon angioplasty alone was successful in 10 lesions. In thrombosed fistulas, 2 lesions underwent manual catheter-directed thrombo-aspiration and 2 further lesions underwent a combination of catheter-directed thrombo-aspiration and mechanical thrombectomy. Cutting Balloon angioplasty was performed for 3 resistant venous stenoses and for 1 radial artery stenosis. Technical and clinical success were achieved in all patients. No vessel rupture or perforation was observed in this study, nor was distal embolization in the radial artery or symptomatic pulmonary embolism. No radial artery occlusion or fistula infection was seen during the follow-up. The primary patency rates were 82% at 3 months and 64% at 6 months. Transradial intervention for native fistula failure is considered safe and feasible in a selected population; yet requires further validation.

Intra-access Blood Flow in Patients With Newly Created Upper-Arm Arteriovenous Native Fistulae for Hemodialysis Access

Intra-access Blood Flow in Patients With Newly Created Upper-Arm Arteriovenous Native Fistulae for Hemodialysis Access

Prospective Study of Balloon Inflation Pressures and Other Technical Aspects of Hemodialysis Access Angioplasty

Balloon angioplasty is a mainstay in the treatment of failing or thrombosed hemodialysis access grafts and fistulas. A sizable body of outcomes data exists concerning percutaneous transluminal angioplasty (PTA) in hemodialysis access, yet there is a relative paucity of technical information available, especially regarding dilation pressures. The aim of the present study was to compile such information, which can be critical to the choice of devices for PTA and to the design of future clinical trials seeking to improve outcomes in this area. Technical data were collected prospectively for 102 PTA procedures (66 prophylactic PTA procedures and 36 PTA procedures performed during access thrombectomy). Demographic data concerning the access were collected. Technical data were collected individually for each lesion treated, including lesion location; degree of stenosis (in quartiles); lesion length; PTA balloon brand, size, and length; pressure at which the waist of the balloon was effaced; residual stenosis; and reason for additional balloons or inflations if used. Outcomes data other than residual stenosis were not collected, but the endpoint for all interventions was a thrill in the access. A total of 230 lesions were treated. Two (1%) could not be successfully treated with PTA despite the use of "ultra high" pressure (approximately 40 atm); one was treated successfully with parallel wire technique and the other was revised surgically after the use of a cutting balloon also failed. Overall, 55% of lesions required pressures greater than 15 atm to efface the waist. Excluding initial failures, 20% of lesions in native fistulas and 9% in grafts required very high pressure (>20 atm) to efface the waist (P = .02). High pressure was needed less frequently in PTA procedures performed in the setting of thrombectomy procedures than in prophylactic PTA procedures (P = .0001). Residual stenosis was positively correlated with severity of initial stenosis and negatively correlated with duration of inflation. Conventional angioplasty balloons are inadequate for the treatment of most hemodialysis access stenoses. High pressures (>15 atm) are commonly needed for PTA in hemodialysis access. Very high pressures (>20 atm) are more frequently needed in native fistulas.

Single-center Experience with the Arrow-Trerotola Percutaneous Thrombectomy Device in the Management of Thrombosed Native Dialysis Fistulas

The present study sought to evaluate the performance of the Arrow-Trerotola Percutaneous Thrombolytic Device (PTD) in the treatment of native fistula thrombosis in a U. S. hemodialysis population. Specifically, the technical success, clinical success, complication rate and type, primary and secondary patency rates, effect of adjunctive thrombolytic therapy, and any variables that affected outcomes of procedures in which this device was used were analyzed. Forty-two patients with 44 thrombosed native fistulas (17 radiocephalic, 10 brachiocephalic, 10 transposed or superficialized, five graft/fistula hybrids, and two leg fistulas) were treated with 62 mechanical thrombolysis procedures with use of the PTD. All patients had large clot burden. The device type was recorded in 43 procedures: standard (n = 21), over-the-wire (OTW; n = 19), or both (n = 3). No device was used in two cases because of inability to cross the anastomosis. Adjunctive therapies (n = 18) included the use of tissue plasminogen activator (tPA; n = 16) and deployment of the AngioJet device with (n = 1) or without tPA (n = 1). Stents were inserted in four procedures. Outcome variables included technical and clinical success, complications, and primary and secondary patency. Cox proportional-hazards regression and Kaplan-Meier analyses were performed. The technical success rate was 87% (54 of 62) and the clinical success rate was 79% (49 of 62). Percutaneous transluminal angioplasty was performed in all but two procedures. Complications occurred in 13% of procedures (n = 8); three resulted in technical failure. The primary patency rates were 38% at 6 months and 18% at 12 months; secondary patency rates were 74% and 69%, respectively. Outcomes were not affected by adjunctive techniques, fistula type, age of fistula, device type (ie, OTW vs standard), or patient sex. Secondary patency was superior when no residual clot or stenosis was present (P = .003). The PTD is effective for percutaneous treatment of thrombosed hemodialysis fistulas, with good short- and long-term outcomes in a U.S. population. Within the limitations of a retrospective study with a small sample size, use of an adjunctive thrombolytic agent did not appear to improve results compared with the use of the device alone.

Mechanical Thrombectomy of Occluded Hemodialysis Native Fistulas and Grafts Using a Hydrodynamic Thrombectomy Catheter: Preliminary Experience

The purpose of this study was to evaluate the efficacy and safety of a new hydrodynamic percutaneous thrombectomy catheter in the treatment of thrombosed hemodialysis fistulas and grafts. Twenty-two patients (median age: 47 years; range: 31-79 years) underwent mechanical thrombectomy for thrombosed hemodialysis fistulas or polytetrafluoroethylene (PTFE) grafts. In all cases, an Oasis hydrodynamic catheter was used. Five patients had native fistulas and 17 had PTFE grafts. Six patients required repeat procedures. All patients with native fistulas and 15 of the 17 with PTFE grafts also underwent angioplasty of the venous limb following the thrombectomy. Major outcome measures included technical success, clinical success, primary and secondary patency, and complication rates. Twenty-eight procedures were performed in total. The technical success rate was 100% and 90% and clinical success was 86% and 76% for native fistulas and grafts, respectively. The primary patency at 6 months was 50% and 59% for fistulas and grafts, respectively, and the secondary patency at 6 months was 75% and 70% for fistulas and grafts, respectively. Two patients died of unrelated causes during the follow-up period. The Oasis catheter is an effective mechanical device for the percutaneous treatment of thrombosed hemodialysis access. Our initial success rate showed that the technique is safe in the treatment of both native fistulas and grafts.

Vascular Access for Hemodialysis: Arteriovenous Fistula

The long-term survival and quality of life of patients on hemodialysis (HD) is dependant on the adequacy of dialysis via an appropriately placed vascular access. The optimal vascular access is unquestionably the autologous arteriovenous fistula (AVF), with the most common method being the conventional radio-cephalic fistula at the wrist. Recent clinical practice guidelines recommend the creation of native fistula or synthetic graft before the start of chronic HD therapy to prevent the need for complication-prone dialysis catheters. This could also have a beneficial effect on the rapidity of worsening kidney failure. A multidisciplinary approach (nephrologists, surgeons, radiologists and nurses) should improve the HD outcome by promoting the use of AVF. An important additional component of this program is the Doppler ultrasound for preoperative vascular mapping. Such an approach may be realized without unsuccessful surgical explorations, with a minimal early failure rate and a high maturation, even in patients with diabetes mellitus.