Metallic stent placement in hemodialysis graft patients after insufficient balloon dilation

Stent Grafts Across the Elbow Joint for Access Salvage

PURPOSE

Covered stent grafts (SGs) are currently being used in a wide variety of situations to maintain function and patency of hemodialysis access circuits. Stent grafts are rarely placed across the elbow joint (EJ), however, due to fear of stent fracture. This study reports on the experience and patency rates with SGs across the EJ.

MATERIALS AND METHODS

From April 2020 to August 2023, all procedures with SGs placed across the EJ were retrospectively analyzed. A total of 21 patients with SGs placed across the EJ were included in the study. The Covera Vascular Covered Stent (BD, Franklin Lakes, New Jersey, USA) was used in all cases. Of these, 18 were arteriovenous (AV) fistulae, and 3 were AV grafts. Stent grafts were placed for various pathologies, including residual stenosis, perforation, aneurysm, and thrombosis. Follow-up outcomes were obtained from angiographic images on follow-up angiography and included primary patency, primary assisted patency, and secondary patency.

RESULTS

The primary patency of the target lesion was 85% (CI=70%-100%) and 85% (CI=70%-100%) at 6 and 12 months, respectively. The primary assisted patency was 85% (CI=70%-100%) and 85% (CI=70%-100%) at 6 and 12 months, respectively. Secondary patency of the access circuit was 95% (CI=86%-100%) at 6 months and 89% (CI=75%-100%) at 12 months. The average follow-up duration was 393 days (range=27-768 days). There were no instances of stent fracture during follow-up.

CONCLUSIONS

Stent grafts should be placed across the EJ for good short-term and mid-term patency rates.

CLINICAL IMPACT

The placement of stent grafts across the elbow joint in hemodialysis patients for access salvage is controversial due to the fear of stent fracture or occlusion. This retrospective study evaluated the placement of stent grafts for access salvage in 21 patients for various etiologies. Good patency rates were seen out to 12 months and no stent fractures were observed. Although longer term data is needed, stent grafts should be considered an acceptable option for access salvage when treating lesions that cross the elbow joint.

A prospective randomized study of stent graft placement after balloon angioplasty versus balloon angioplasty alone for the treatment of hemodialysis patients with prosthetic graft outflow stenosis

BACKGROUND

Hemodialysis graft outflow stenosis is a significant complication occurring in hemodialysis patients with prosthetic grafts for vascular access. Balloon angioplasty remains the first-line endovascular treatment of this complication, although covered stent graft implantation after balloon angioplasty also appears to be an effective and promising treatment. The aim of this study was to evaluate the efficacy and durability of stent graft placement after balloon angioplasty in comparison to balloon angioplasty alone for the treatment of graft outflow stenosis in hemodialysis patients.

METHODS

We conducted a prospective randomized study of 98 patients with clinically significant dialysis graft outflow stenosis treated in the vascular surgery section of a tertiary medical center. The patients were randomized into two groups; 49 patients were treated with stent graft placement after balloon angioplasty, and 49 patients were treated with balloon angioplasty alone. All patients underwent angiography of the graft site at 3 and 6 months after intervention, and restenosis rates were compared between the two groups. In addition, the duration of postintervention primary patency in the two groups was recorded and analyzed.

RESULTS

The postintervention restenosis rate of the stent graft placement group was superior to that seen in the balloon angioplasty alone group (9% vs 69% at 3 months [P < .0001] and 29% vs 72% at 6 months [P < .0001]). The mean postintervention primary patency duration was 380.22 ± 28.54 days for the stent graft placement group and 151.08 ± 16.79 days for the balloon angioplasty alone group (P < .0001).

CONCLUSIONS

The use of stent grafts in hemodialysis patients with graft outflow stenosis yielded superior results compared with the results seen in hemodialysis patients treated with balloon angioplasty alone. Patients treated with stent grafts after balloon angioplasty had a lower restenosis rate and a longer duration of postintervention primary patency. The placement of a stent graft after balloon angioplasty appears to be an optimal therapeutic approach for the treatment of hemodialysis patients with graft outflow stenosis.

Balloon angioplasty vs nitinol stent placement in the treatment of venous anastomotic stenoses of hemodialysis grafts after surgical thrombectomy

OBJECTIVE

Most arteriovenous hemodialysis grafts fail ≤18 months after implantation, most commonly due to intimal hyperplasia at the venous anastomosis. This open prospective study compared balloon angioplasty vs nitinol stent placement in the treatment of venous anastomotic stenosis after thrombectomy of prosthetic brachial-axillary accesses.

METHODS

Between February 2007 and December 2010, 61 patients with an initial thrombosis of a prosthetic brachial-axillary access were admitted to our hospital. Of these patients, 28 (46%), treated before June 2008, underwent thrombectomy plus balloon angioplasty of the venous anastomosis (group A), whereas the remaining 33 (54%) patients, who were treated after July 2008, underwent graft thrombectomy plus angioplasty with self-expanding nitinol stent placement (group B). Primary, primary-assisted, and secondary patency rates were calculated using Kaplan-Meier analysis and compared between the two groups with the log-rank test.

RESULTS

Primary patency was 32% at 3 months, 24% at 6 months, and 14% at 12 months in group A, and the respective values were 85%, 63% and 49% in group B. Primary patency was significantly better in group B than in group A (P < .001; log-rank test). Cumulative median patency was 60 days in group A and 260 days in group B. Patient age, sex, comorbidities, graft material, and graft age did not have prognostic significance. Primary-assisted and secondary patency rates were significantly higher in group B.

CONCLUSIONS

Graft thrombectomy plus angioplasty with self-expanding nitinol stent placement provides significantly higher patency rates compared with thrombectomy plus plain balloon angioplasty of the venous anastomosis.

Efficacy of SMART Stent Placement for Salvage Angioplasty in Hemodialysis Patients with Recurrent Vascular Access Stenosis

Vascular access stenosis is a major complication in hemodialysis patients. We prospectively observed 50 patients in whom 50 nitinol shape-memory alloy-recoverable technology (SMART) stents were used as salvage therapy for recurrent peripheral venous stenosis. Twenty-five stents each were deployed in native arteriovenous fistula (AVF) and synthetic arteriovenous polyurethane graft (AVG) cases. Vascular access patency rates were calculated by Kaplan-Meier analysis. The primary patency rates in AVF versus AVG at 3, 6, and 12 months were 80.3% versus 75.6%, 64.9% versus 28.3%, and 32.3% versus 18.9%, respectively. The secondary patency rates in AVF versus AVG at 3, 6, and 12 months were 88.5% versus 75.5%, 82.6% versus 61.8%, and 74.4% versus 61.8%, respectively. Although there were no statistically significant difference in patency between AVF and AVG, AVG showed poor tendency in primary and secondary patency. The usefulness of SMART stents was limited in a short period of time in hemodialysis patients with recurrent vascular access stenosis.

Percutaneous intervention in axillary loop-configured arteriovenous grafts for chronic hemodialysis patients

Objective

The purpose of this study was to evaluate the fistulographic features of malfunctioning axillary loop-configured arteriovenous grafts and the efficacy of percutaneous interventions in failed axillary loop-configured arteriovenous grafts.

Materials and Methods

Ten patients with axillary loop-configured arteriovenous grafts were referred for evaluation of graft patency or upper arm swelling. Fistulography and percutaneous intervention, including thrombolysis, percutaneous transluminal angioplasty and stent placement, were performed. Statistical analysis of the procedure success rate and the primary and secondary patency rates was done.

Results

Four patients had graft related and subclavian venous stenosis, two patients had graft related stenosis and another four patients had subclavian venous stenosis only. Sixteen sessions of interventional procedures were performed in eight patients (average: 2 sessions / patient) until the end of follow-up. An interventional procedure was not done in two patients with central venous stenosis. The overall procedure success rate was 69% (11 of 16 sessions). The post-intervention primary and secondary patency rates were 50% and 63% at three months, 38% and 63% at six months and 25% and 63% at one year, respectively.

Conclusion

Dysfunctional axillary loop-configured arteriovenous grafts almost always had subclavian venous and graft-related stenosis. Interventional treatments are helpful to overcome this and these treatments are expected to play a major role in restoring and maintaining the axillary loop-configured arteriovenous loop grafts.

Stent placement in hemodialysis access: historical lessons, the state of the art and future directions

Vascular access stenosis in patients undergoing chronic hemodialysis is a major issue that is associated with increased morbidity, mortality, and cost of medical care. Recent data have emphasized that endovascular stents could be used in the treatment of central as well as peripheral stenotic lesions. In general, a peripheral or central vein lesion that is elastic or recurs within a three-month period after an initially successful balloon angioplasty or a stenosis where surgical revision is not possible are some indications for intravascular stent placement. Recent reports have expanded the role of stents in the management of pseudoaneurysms associated with dialysis access. In this context, the utilization of these devices must take into account a fair comparison with the traditional (surgical) approaches regarding effectiveness as well as costs. This report describes the role of stents in arteriovenous dialysis access. In addition, some of the recent advances in the structure and complicating issues such as stent fracture, migration, and infection, as well cannulation through the stent, are discussed.

Endovascular treatment for iliac vein compression syndrome: a comparison between the presence and absence of secondary thrombosis

Objective

To evaluate the value of early identification and endovascular treatment of iliac vein compression syndrome (IVCS), with or without deep vein thrombosis (DVT).

Materials and Methods

Three groups of patients, IVCS without DVT (group 1, n = 39), IVCS with fresh thrombosis (group 2, n = 52) and IVCS with non-fresh thrombosis (group 3, n = 34) were detected by Doppler ultrasonography, magnetic resonance venography, computed tomography or venography. The fresh venous thrombosis were treated by aspiration and thrombectomy, whereas the iliac vein compression per se were treated with a self-expandable stent. In cases with fresh thrombus, the inferior vena cava filter was inserted before the thrombosis suction, mechanical thrombus ablation, percutaneous transluminal angioplasty, stenting or transcatheter thrombolysis.

Results

Stenting was performed in 111 patients (38 of 39 group 1 patients and 73 of 86 group 2 or 3 patients). The stenting was tried in one of group 1 and in three of group 2 or 3 patients only to fail. The initial patency rates were 95% (group 1), 89% (group 2) and 65% (group 3), respectively and were significantly different (p = 0.001). Further, the six month patency rates were 93% (group 1), 83% (group 2) and 50% (group 3), respectively, and were similarly significantly different (p = 0.001). Both the initial and six month patency rates in the IVCS patients (without thrombosis or with fresh thrombosis), were significantly greater than the patency rates of IVCS patients with non-fresh thrombosis.

Conclusion

From the cases examined, the study suggests that endovascular treatment of IVCS, with or without thrombosis, is effective.