Postintervention Primary Patency Rates Research Articles

Radial Arterial Approach with Adjunctive Urokinase for Treating Occluded Autogenous Radial-Cephalic Fistulas

There are no data regarding the feasibility and safety of a radial arterial approach with adjunctive urokinase for treating occluded autogenous radial-cephalic fistulas. We retrospectively examined 54 transradial interventions performed to treat occluded autogenous radial-cephalic fistulas within 72 h of occurrence. Urokinase was used in patients with a large thrombus burden. A total of 92 lesions in 54 consecutive patients (27 males, 27 females; mean age, 61.8+/-12.3 years) were treated via radial access. All radial punctures were successful except in one patient. Most thrombotic lesions were located within 1 cm of the radiocephalic anastomosis (79.6%). The mean length of treated thrombotic lesions was 10.3+/-5.4 cm (range, 4-32 cm). Twenty-five patients (46.3%) received urokinase (mean dose, 96,000+/-30,000 U). After transradial intervention, systolic, diastolic, and mean pressures in the radial artery decreased from 179+/-41, 77+/-17, and 111+/-22 mm Hg to 71+/-29, 36+/-15, and 48+/-19 mm Hg (all p's\0.001), respectively. Four radial interventions were unsuccessful. The anatomic and clinical success rates of the radial approach were both 92.6%; postinterventional primary patency rates were 65% at 6 months and 40% at 12 months. Two minor vascular complications were noted, one caused by guidewire-induced contrast extravasation and the other by balloon-induced contrast extravasation. No patient developed clinical signs of pulmonary embolism. In conclusion, the radial approach with adjunctive urokinase is an effective and safe approach to treat occluded autogenous radial-cephalic fistulas.

Radial artery approach for endovascular salvage of occluded autogenous radial-cephalic fistulae

The endovascular salvage of occluded autogenous radial-cephalic fistulae is a more challenging procedure than that for stenotic fistulae. To obtain an access to the fistula is one of the keys to success. Both retrograde venous approach and brachial artery approach have some disadvantages. The radial artery approach has been used in the endovascular therapy of fistula dysfunction, but few data focused on their feasibility and safety for the totally occluded fistulae. We retrospectively reviewed the patients with occluded autogenous radial-cephalic fistulae receiving endovascular salvage via the radial artery approach in our institution. From January 2004 to July 2007, 48 patients fulfilling the above criteria were enrolled. Balloon maceration was used for patients with small clots. Mechanical thrombectomy with an Arrow-Trerotola percutaneous thrombolytic device or an AngioJet rheolytic catheter was used for patients with large clot burden. Outcome variables included anatomic and clinical success, complications and primary and secondary patency. All the transradial punctures were successful. Anatomic and clinical success was achieved in 96% of the cases. The post-interventional primary patency rates were 92%, 77%, 55% and 44% at 1, 3, 6 and 12 months, respectively. The post-interventional secondary patency rates were 96%, 93%, 89% and 89% at 1, 3, 6 and 12 months, respectively. The 12-month primary patency of the short-segment thrombus group was better than that of the long-segment thrombus group (57% versus 19%, P = 0.005). The complication rate was 4%. No puncture-site-related complications were noted, and all the radial arteries were palpable at follow-up. An endovascular intervention through the radial artery approach is a safe and feasible strategy choice for restoring occluded autogenous radial-cephalic fistulae.

Endovascular Dialysis Interventions in the Era of DOQI

The National Kidney Foundation Dialysis Outcomes and Quality Initiative (DOQI) recommends autogenous fistulae as the preferred access for new dialysis procedures. Unfortunately, despite superior patency rates compared to prosthetic grafts, even autogenous access durability is often undermined by venous stenosis due to intimal hyperplasia at the outflow vein or by central venous stenosis due to long-standing central venous catheters. Salvage interventions, in the form of endovascular treatments such as percutaneous transluminal angioplasty (PTA) and/or stenting, are increasingly utilized for access salvage and maintenance. The objective of this study was to evaluate the efficacy of endovascular dialysis interventions in the era of DOQI. A retrospective review of a database of endovascular interventions for dialysis access during 36 months at an academic medical center was performed. Both central venous and access outflow lesions were included in the analysis. Kaplan-Meier curves and log-rank analysis were used to assess and compare time-dependent variables. Forty-five patients with dialysis access underwent 72 endovascular interventions for access maintenance. There were 27 central venous and 32 outflow endovascular interventions with 98% follow-up. Primary and assisted primary patency rates for outflow balloon PTA were 50% and 72% at 12 months, respectively. There were 1.1 reinterventions required per index outflow PTA procedure. Postintervention primary patency rates for central venous PTA were 30% and 9% at 6 and 12 months, respectively. Postintervention assisted patency for central venous PTA was 100% at 12 months, requiring 1.8 reinterventions per index PTA. Central venous and venous outflow interventions extended overall access patency by 38.5 and 33 months, respectively (p < 0.0001). Endovascular interventions are the mainstay of treatment for the malfunctioning dialysis access. Despite the need for multiple reinterventions and close surveillance, catheter-based interventions positively contribute to dialysis access durability in accordance with DOQI guidelines.

Surgical revision of complicated false and true vascular access–related aneurysms

This prospective observational study examined the effect of revision surgery in patients who present solely with complicated arteriovenous access (AVA)-related aneurysms. The demographics and comorbid conditions of 44 hemodialysis access patients who presented with complicated true or false AVA-related aneurysms and underwent revision surgery during a 7-year period were prospectively entered into our AVA database. Also recorded were AVA characteristics before and after revision. Arteriovenous access anatomy was evaluated preoperatively using color Doppler ultrasonography, and AVA adequacy was assessed in all patients postoperatively after the first needle puncture and every month thereafter. Postintervention access function and primary patency rates were analyzed. Patency was evaluated using the Kaplan-Meier method and compared between groups of patients with different AVA characteristics before and after revision using the log-rank test. The cases of initial AVA with complicated aneurysms comprised 16 radiocephalic, 8 brachiocephalic, 2 basilic vein transposition, and 18 prosthetic fistulas (7 and 11 of the lower and upper arm, respectively), of which 42 were dysfunctional and 2 had thrombosed early at presentation. Primary indications for revision were danger of aneurysm rupture in 26, duplication in graft aneurysm diameter in 18, painful aneurysm in 12, stenosis due to partial aneurysm thrombosis in 12, shortness of the potential cannulation area in 12, aneurysm enlargement in 4, infected aneurysm in 2, and completely thrombosed aneurysm in 2. The mean postintervention primary patencies were 93%, 82%, 57%, and 32% at 3, 6, 12, and 24 months, respectively. The outcomes was better in autogenous than prosthetic corrections, in true than false aneurysms, in patients with two or fewer than more than 2 previous AVAs on revised arms, and in forearm than upper-arm corrections (P = .0197, P = .004, P = .0022, and P = .0225, respectively). Surgical revision of complicated false and true AVA-related aneurysms reveals acceptable postintervention primary patency rates and therefore is justified. This outcome measure was superior in the following specific groups of corrections: autogenous were better than prosthetic, true aneurysms were better than false aneurysms, patients with one or two previous AVAs in the revised arm were better than those with more than two previous accesses in the revised arm, and finally, forearms were better than those in the upper arm.

Cutting balloon angioplasty for resistant venous stenoses of dialysis access: Immediate and patency results

To evaluate the technical success, safety and patency of cutting balloon angioplasty for the treatment of resistant dialysis access stenoses. Cutting balloon angioplasty has been proposed to be useful in treating resistant dialysis access stenoses. However, they are based on experience with very limited cases and formal patency data is insufficient. The author retrospectively reviewed 896 percutaneous transluminal angioplasty (PTA) procedures for the treatment of dysfunctional or thrombotic dialysis access. Thirty-seven of 623 patients with native fistulas and 23 of 273 patients with synthetic grafts had residual stenoses of more than 30% after conventional PTA at an inflation pressure of 24 atm for 60 sec. In these 60 patients, additional cutting balloon PTA was performed. The overall technical success rate was 96.7% and clinical success rate was 98.3%. Only one patient experienced mild local extravasation. The postintervention primary patency rates for native fistula group (N = 37) were 100%, 86.4%, and 67.5% at 1-month, 3-month, and 6-month; the postintervention primary patency rates for synthetic graft group (N = 23) were 87.0%, 60.9%, and 34.2% at 1-month, 3-month, and 6-month respectively. For resistant venous stenoses of dialysis access, cutting balloon PTA is effective, safe, and seems to provide comparative primary patency as suggested by guidelines.

Angioplasty of Long Venous Stenoses in Hemodialysis Access: At Last an Indication for Cutting Balloon?

To compare the postintervention primary patency rates of cutting balloon angioplasty (CBA) with those of conventional percutaneous transluminal angioplasty (PTA) in the treatment of hemodialysis-related stenoses at least 2 cm long. This retrospective and controlled study included 29 patients with a hemodialysis-related stenosis at least 2 cm long. From August 2002 to August 2003, nine patients (PTA group, six upper-arm and three forearm fistulas) were treated with a conventional balloon (5-8 mm, 4 cm long). From September 2003 to December 2005, 20 patients (CBA group, 12 upper-arm and seven forearm fistulas; one polytetrafluoroethylene hemodialysis graft) were treated with a cutting balloon (5-7 mm, 1 cm long). The median follow-up was 22.1 months for the CBA group and 15.6 months for the PTA group. The Kaplan-Meier method was used to calculate the primary cumulative patency rates, and the log-rank test was used for comparison. Multivariate Cox models were generated by combining three variables: patient age, stenosis length, and treatment type (CBA or PTA). In the CBA group, the postintervention primary patency was 85% +/- 16 at 6 months, 70% +/- 20 at 1 year, and 32% +/- 26 at 18 months. In the PTA group, the postintervention primary patency was 56% +/- 32 at 6 months and 21% (range, 0%-53%) at 1 year. When comparing PTA versus CBA with the log-rank test, there was a statistically significant difference (P = .009). With the multivariate Cox models, treatment was again a statistically significant (P = .007) determinant of primary patency; patient age and stenosis length were not. The use of a cutting balloon as the first-line treatment for stenoses at least 2 cm long significantly improves the postintervention primary patency rate.

Use of short PTFE segments (

The re-establishment of patency in a stenosed or thrombosed native arteriovenous fistula (AVF) is fundamental to regaining adequate hemodialysis through the same cannulable vein. Many surgeons have been reluctant to use even small segments of synthetic grafts in AVF revisions because of a perception that these would lead to poor results; however, studies comparing various treatment options are scarce. This study compared the use of short (<6 cm) polytetrafluoroethylene (PTFE) segments with pure autologous repair in stenosed or thrombosed native fistulas. The cumulative postintervention primary patency rates of two groups of hemodialysis patients receiving different surgical revision operations of their vascular accesses were prospectively compared. Group I (n = 30) comprised patients who presented with stenosed or thrombosed native fistulas and received short (2 to 6 cm) interposition PTFE grafts placed after the stenosed or thrombosed outflow vein segment was resected. These short PTFE grafts were not used for cannulation. Group II (n = 29) comprised patients who presented with dysfunctional or failed AVFs and underwent various types of pure autogenous corrections. AVF dysfunction or thrombosis was detected with clinical examination and color duplex ultrasound scanning. In all cases, on-table arteriography-fistulography was performed before surgical repair. Access adequacy was assessed in all patients postoperatively after the first puncture and every month thereafter (mean follow up 16.7 months). No statistically significant difference in patency was observed between the two groups. Postintervention cumulative patencies were 100%, 88%, and 82% for group I and 90%, 82%, and 71% for group II at 6, 12, and 18 months, respectively ( P = .8). Short (<6 cm) interposition PTFE segments used for the revision of failing or failed AVFs compare favorably to purely native repair and do not alter the autologous behavior of the initial access. These short PTFE revisions resulted in satisfactory midterm primary patency without further consumption of the venous capital by harvesting segments of vein from other locations and without compromising more proximal access sites. This practice is recommended and is justified as part of an aggressive access salvage policy addressed by many authors so far.

Pulmonary Embolism from PulseSpray Pharmacomechanical Thrombolysis of Clotted Hemodialysis Grafts: Urokinase versus Heparinized Saline

To compare the frequency and extent of pulmonary embolism (PE) occurring during pulse-spray pharmacomechanical thrombolysis (PSPMT) of clotted hemodialysis grafts with use of either urokinase (UK) or heparinized saline (HS). Postintervention primary patency and complication rates were compared for each method of thrombolysis. Twenty-seven patients were enrolled in this prospective, randomized, double-blind study evaluating PE with two PSPMT agents. The doses of heparin were similar between groups. The only variable was that one group of patients received UK and the other received HS. In two cases, the venous anastomosis could not be crossed. Eleven patients were treated with UK and 14 with HS. Nuclear medicine perfusion lung scans were performed before treatment and after graft declotting procedures. Lung perfusion was quantified to 10% of a pulmonary segment (0 = normal perfusion, 1 = segmental perfusion defect), with nine segments counted for each lung. Baseline nuclear medicine perfusion lung scan results were abnormal (> or = 20% segmental perfusion defect) in 19 patients (70.4%). New PE (one or more pulmonary segments) occurred in two patients treated with UK (18.2%) and nine patients treated with HS (64.3%; P = .04). All cases of PE were asymptomatic. Quantitative global pulmonary perfusion analyses revealed that treatment with UK improved flow to 0.2 +/- 2.0 pulmonary segments, whereas treatment with HS decreased perfusion to 1.0 +/- 1.7 segments (P = .16, NS). Although postintervention primary patency rates were similar according to life-table analysis (P = .76, NS), complication rates were higher with use of HS (n = 4, 28.6%) than with use of UK (n = 2, 18.2%) (P = .6, NS). All PE were asymptomatic during PSPMT, but treatment with UK reduced the rate of PE and tended to result in smaller defects in lung scan results. Most patients undergoing hemodialysis have abnormal baseline perfusion scan results, but PSPMT with UK improved many of them. The postintervention primary patency rates were similar between groups, but complications were more frequent after treatment with HS.