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

A Cost-Effective Approach to Resistant AV Fistula Stenosis: Successful Treatment Using Coronary OPN NC® Balloon in a Low-Income Setting

Stenosis in the anastomotic site or venous limb of an arteriovenous fistula (AVF) is the most frequent cause of AVF failure. Percutaneous angioplasty with a standard or high-pressure balloon is the first-line treatment for AVF stenosis due to its higher technical success rate (90%) and lower complication rate (4%). Almost 20% of stenosis cases are resistant or undilatable by regular-pressure balloon angioplasty due to fibrosis, leading to technical failure or restenosis. Alternative therapies, such as atherectomy devices or cutting balloons, are expensive and difficult to obtain in low-income developing countries. We successfully treated resistant AVF stenosis with a coronary OPN-NC® ultra-high-pressure balloon and produced a good angiographic result with technical success. Coronary hardware is easily available and relatively cheaper compared to dedicated peripheral balloons or devices in our country due to reuse, which can be a boon in such type of cases. According to the standard hospital protocol, Cathlab hardware was reused.

Endovascular Management of Thrombosed Dialysis Vascular Circuits

A functional hemodialysis vascular access is the lifeline for patients with end-stage kidney disease and is considered a major determinant of survival and quality of life in this patient population. Hemodialysis therapy can be performed via arteriovenous fistulas, arteriovenous grafts, and central venous catheters (CVCs). Following dialysis vascular access creation, the interplay between several pathologic mechanisms can lead to vascular luminal obstruction due to neointimal hyperplasia with subsequent stenosis, stasis, and eventually access thrombosis. Restoration of the blood flow in the vascular access circuit via thrombectomy is crucial to avoid the use of CVCs and to prolong the life span of the vascular access conduits. The fundamental principles of thrombectomy center around removing the thrombus from the thrombosed access and treating the underlying culprit vascular stenosis. Several endovascular devices have been utilized to perform mechanical thrombectomy and have shown comparable outcomes. Standard angioplasty balloons remain the cornerstone for the treatment of stenotic vascular lesions. The utility of drug-coated balloons in dialysis vascular access remains unsettled due to conflicting results from randomized clinical trials. Stent grafts are used to treat resistant and recurrent stenotic lesions and to control extravasation from a ruptured vessel that is not controlled by conservative measures. Overall, endovascular thrombectomy is the preferred modality of treatment for the thrombosed dialysis vascular conduits.

Cephalic Arch Stenosis in Autogenous Brachiocephalic Hemodialysis Fistulas: Results of Cutting Balloon Angioplasty

Purpose

Cephalic arch stenosis is a known cause of hemodialysis access failure in patients with brachiocephalic fistulas (BCFs). Outcomes of endovascular treatment are affected by resistance of the stenosis to balloon dilation, a high vein rupture rate and the development of early restenosis. The purpose of this retrospective study was to report outcomes after cutting balloon angioplasty (CBA) of cephalic arch stenosis.

Methods

In our vascular access database we identified 74 dysfunctional BcFs of which 30 (41%) were caused by cephalic arch stenosis. Seventeen fistulas in 17 patients (13 males and four females; median age 62 yrs; range 52–86) were treated with CBA (June 2005 to January 2008). Twenty-five procedures were performed. In 15 procedures, a cutting balloon was used alone and in 10 procedures CBA was followed by standard or high-pressure balloon angioplasty. Restenosis rates were calculated and patency rates were estimated with the Kaplan-Meier method.

Results

Primary patency rates (±SEE) at 3, 6, 12 and 15 months were 94% (±6%), 81% (±10%), 38% (±14%) and 22% (±15%), respectively. Assisted primary patency rates (±SEE) at the same intervals were 100% (±0%), 94% (±6%), 77% (±12%) and 63% (±13%), respectively. The mean interval between radiological interventions was 13 months (SD=8) and the mean number of interventions required per patient-year of dialysis was 0.9.

Conclusion

Treatment of cephalic arch stenosis with CBA did not improve patency compared to published results of conventional PTA, but our results indicate that CBA may lower the frequency of required re-interventions.

Timely thrombectomy can improve patency of hemodialysis arteriovenous fistulas

OBJECTIVE

The urgency with which salvage of thrombosed vascular accesses for dialysis should be attempted remains unknown. We examined the effect of a timely thrombectomy approach on vascular access outcomes for dialysis.

METHODS

A before-and-after study was conducted with patients on hemodialysis who had undergone endovascular thrombectomy. A timely thrombectomy initiative (ie, salvage within 24 hours of thrombosis diagnosis) was started in July 2015 at our institution. Data about thrombectomy procedures, performed within 1 year before and after the initiative was introduced, were abstracted from an electronic database. Immediate outcomes and patency outcomes were compared between the preinitiative (control) and postinitiative (intervention) groups.

RESULTS

During the study period, 329 patients were enrolled, including 165 cases before and 164 cases after the initiative. The intervention group had more thrombectomy procedures performed within 24 hours (93% vs 55%; P < .01) and within 48 hours (97% vs 79%; P < .01) than the control group. No between-group differences in procedural success or clinical success rates were found. At 3 months, the intervention group had a higher postintervention primary patency rate than the control group, although this did not reach statistical significance (58% vs 48%; P = .06). After stratification into native or graft accesses, the patency benefit was observed in the native access group (68% vs 50%; P = .03) but not in the graft access group (50% vs 46%; P = .65). After adjusting for potential confounders, timely thrombectomy remained an independent predictor of postintervention primary patency (hazard ratio, 0.449; 95% confidence interval, 0.224-0.900; P = .02) for native dialysis accesses.

CONCLUSIONS

Our results suggest that a timely thrombectomy approach, in which salvage is attempted within 24 hours of thrombosis diagnosis, improves postintervention primary patency of native but not graft accesses for dialysis.

Efficacy of a modified pharmacomechanical thrombolysis technique for endovascular treatment of thrombosed prosthetic arteriovenous grafts

Objective

We applied a modified pharmacomechanical thrombolysis (PMT) technique to endovascular treatment of thrombosed arteriovenous (AV) grafts without the use of any mechanical thrombectomy devices. The aim of this study was to evaluate the efficacy of the PMT technique in the treatment of thrombosed AV grafts by analyzing the long-term patency.

Materials and Methods

Eighty-two patients with thrombosed AV grafts were treated with the PMT technique. AV graft surveillance to detect failing/failed access was followed by endovascular treatment.

Results

The technical and clinical success rates were 95% and 95%, respectively. The total number of thrombolysis sessions was 279. A post-intervention primary patency rate was 45% and 22% at 12 and 24 months, respectively. The secondary patency rate was 96% and 91% at 12 and 24 months, respectively. No major complications were noticed.

Conclusion

The modified PMT technique is effective in endovascular treatment of thrombosed AV grafts.

Duplex Scanning–Derived Access Volume Flow: Novel Predictor of Success Following Endovascular Repair of Failing or Nonmaturing Arteriovenous Fistulae for Hemodialysis

The objective of this study was to evaluate the feasibility of duplex scanning–derived access volume flow (DAVQ) to predict the success or failure of arteriovenous fistulae (AVF) after interventions. Eighty-eight DAVQ measurements were available for 60 AVF in 59 patients. In 25 cases, physical examination findings or inadequate dialysis suggested failing (11) or nonmaturing (14) AVF. Outflow stenoses (1–4; mean 1.2 ± 0.8) were confirmed by contrast fistulograms in 23 cases (17 peripheral; 6 central). These 23 cases underwent successful endovascular repair (17 balloon angioplasty; 6 stents) and had pre- and postintervention DAVQ measurements within 2 weeks of the procedure. Each was measured three times in a nontortuous venous segment with laminar flow, and mean values were used for comparison. The overall mean DAVQ for 65 functioning AVF was 1,199 ± 485 mL/min, whereas it was 652 ± 438 mL/min (range 150–1,840 mL/min) for the remaining 23 failing or nonmaturing cases ( p < .0001). Postintervention, the latter values changed to 867 ± 517 mL/min (range 257–2,020 mL/min), with a p < .13. Of these, 11 were still nonfunctional after endovascular procedures and had a mean DAVQ of 404 ± 111 mL/min (range 257–652 mL/min). The remaining 12 cases had a mean DAVQ of 1,280 ± 382 mL/min (range 762–2,020 mL/min) and were functional and usable for at least 6 months of follow-up ( p < .0001). It is interesting to note that none of the AVF cases with postintervention DAVQ < 700 mL/min became functional and usable, whereas all cases with a higher DAVQ underwent successful hemodialysis treatments. This early experience suggests that DAVQ can be used to predict the success or failure of an AVF following endovascular procedures. To our knowledge, this is the first such report.