nitinol and Kidney-Failure--Chronic

Early recurrent stenosis of the cephalic arch in autogenous arteriovenous access for hemodialysis is a common problem that requires stenting to prevent thrombosis. Because the results of stenting are unsatisfactory, we compared the efficacy of stent grafts with bare stents in these patients.. All patients who presented with recurrent cephalic arch stenosis >50% within 3 months of successful balloon angioplasty were randomized to have angioplasty and stenting with either a bare nitinol stent or a stent graft. Outcome was assessed by angiography 3 months later. Restenosis was defined as >50% narrowing of the stent lumen or of the vessel margin up to 0.5 cm adjacent to the stent. There were no exclusions.. This report includes data on the outcome of 25 consecutive patients with recurrent cephalic arch stenosis who were treated from April to August 2006. At 3 months, three patients had died and one had undergone a renal transplant. The 21 patients who had angiography at 3 months had patent stents. Restenosis rates were seven of 10 (70%) in the bare stent group and two of 11 (18%) in the stent graft group (P = .024). Life-table analysis at 3 and 6 months showed that primary patency was 82% in the stent graft group and 39% in the bare stent group. One-year primary patency was 32% in the stent graft group and 0% in the bare stent group (P = .0023). During a mean follow-up of 13.7 months, nine patients died, four in the bare stent group and five in the stent graft group. Two patients in the stent graft group had received a renal transplant. The number of interventions per patient-year was 1.9 in the bare stent group and 0.9 in the stent graft group (P = .02).. The use of stent grafts in angioplasty for recurrent cephalic arch stenosis significantly improved short-term restenosis rates and long-term patency compared with the use of bare stents. The significant improvement that emerged during the study caused accrual of patients to be halted for ethical reasons. This study altered our usage of stents for venous stenoses in arteriovenous accesses by eliminating bare nitinol stents in favor of stent grafts.

Topics: Adult; Aged; Aged, 80 and over; Alloys; Angioplasty; Arteriovenous Shunt, Surgical; Blood Vessel Prosthesis; Brachiocephalic Veins; Constriction, Pathologic; Female; Follow-Up Studies; Humans; Kidney Failure, Chronic; Male; Middle Aged; Prospective Studies; Recurrence; Renal Dialysis; Stents; Treatment Outcome; Ultrasonography, Doppler; Vascular Diseases

The native arteriovenous fistula may remain immature despite adequate arterial inflow after formation. This may occur when the puncturable vein segment (cannulation zone) is too small to be reliably punctured, occluded or too deep under the skin for needle access. We performed stenting (stent-assisted maturation) of arteriovenous fistulas with an immature cannulation zone, allowing for a large subcutaneous channel which could then be immediately punctured for dialysis.. We performed a retrospective review of 49 patients (mean age was 58.7 ± 16.09 (12-83) years, mean arteriovenous fistula age of 162.6 ± 27.28 days) with end-stage renal failure who underwent balloon dilatation and bare-metal stent implantation (1.6 ± 0.67 (1-3) stents, median diameter and length of 8 (5-14) mm and 80 (40-150) mm, respectively) through their cannulation zone (forced maturation). Radiocephalic (35 arteriovenous fistulas), brachiocephalic (10 arteriovenous fistulas) and autogenous loop arteriovenous fistulas (4 arteriovenous fistulas) were included with 30 patients (61.2%) having an inadequate cannulation zone venous diameter, 9 patients (18.4%) having an absent cannulation zone and 10 patients (20.4%) having a patent cannulation zone deeper than 1 cm which was not reliably puncturable. The study was conducted over 9 years (January 2008-December 2016) with implantation of the SMART. At 6 months, 12 months and 4 years, respectively, cannulation zone primary patency was 84.4%, 74.4% and 56.1% and access circuit primary patency was 62.2%, 45.3% and 23.2%; however, assisted primary access circuit patency was 95.6%, 91.1% and 83.8%, achieved with an endovascular re-intervention rate of 0.53 procedures/year with only four thrombosed circuits occurring.. Forced maturation using nitinol stents allows for long-term haemodialysis access with a low rate of re-intervention.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Alloys; Angioplasty, Balloon; Arteriovenous Shunt, Surgical; Catheterization; Child; Female; Graft Occlusion, Vascular; Humans; Kidney Failure, Chronic; Male; Middle Aged; Prosthesis Design; Renal Dialysis; Retrospective Studies; Stents; Time Factors; Treatment Outcome; Vascular Patency; Young Adult

Topics: Aged; Alloys; Angioplasty, Balloon; Arteriovenous Shunt, Surgical; Collateral Circulation; Female; Graft Occlusion, Vascular; Humans; Kidney Failure, Chronic; Prosthesis Design; Renal Dialysis; Stents; Treatment Outcome; Upper Extremity; Vascular Patency

Topics: Aged; Alloys; Angioplasty, Balloon; Arteriovenous Shunt, Surgical; Blood Vessel Prosthesis Implantation; Humans; Kidney Failure, Chronic; Male; Phlebography; Prosthesis Design; Recurrence; Renal Dialysis; Self Expandable Metallic Stents; Stents; Superior Vena Cava Syndrome; Treatment Outcome; Vascular Patency

Thrombosis due to anastomotic site stenosis is the most common complication in patients with brachio-axillary arteriovenous graft (AVG). Intravascular stent placement may play a special role in the salvage of dialysis grafts that have been previously performed percutaneous angioplasty or surgical procedure on the graft. Herein, we applied a novel stent named Supera which has a high degree of flexibility and resistance to external compression for treating a patient with recurrent venous anastomotic stenosis of brachio-axillary AVG.. We report a case of the patient with end-stage renal disease who presented with brachio-axillary AVG malfunction.. The patient underwent repeated percutaneous angioplasty with thrombectomy for total graft occlusion, and we placed the Supera stent to salvage the graft.. Postprocedural Doppler ultrasonography did not show any restenosis on the 1- and 3-month follow-up periods, and average flow volume in the stent was >1000 mL/min. And he has been on dialysis for 6 months without any problems after stent placement.. The Supera stent is a useful treatment option of interventional procedure for recurrent venous anastomotic stenosis of brachio-axillary AVG in the clinical practice.

Topics: Aged; Alloys; Angioplasty; Arteriovenous Shunt, Surgical; Axillary Vein; Brachial Artery; Graft Occlusion, Vascular; Humans; Kidney Failure, Chronic; Male; Renal Dialysis; Stents; Thrombectomy; Ultrasonography, Doppler; Vascular Patency

Maintaining vascular access in patients undergoing chronic hemodialysis is a challenging process, especially in patients enduring multiple central line placements and in whom peripheral options have been exhausted.. We present a case of a 60-year-old male without options for peripheral vascular access due to multiple failed arteriovenous fistulas for hemodialysis. Furthermore, bilateral subclavian, brachiocephalic veins and iliac veins were occluded or significantly obstructed. After long segment central vein recanalization, an upper arm loop arteriovenous graft was implanted. The recanalized segment was stented with a 12-mm dedicated venous nitinol stent.. Chronic central vein obstructions demand stents with both high radial force and flexibility. We recommend dedicated venous stents to improve technical success and reduce stent-related complications like early re-occlusion due to fracturing, kinking or straightening.

Topics: Alloys; Arteriovenous Shunt, Surgical; Blood Vessel Prosthesis; Blood Vessel Prosthesis Implantation; Brachiocephalic Veins; Catheterization, Central Venous; Constriction, Pathologic; Humans; Kidney Failure, Chronic; Male; Middle Aged; Phlebography; Prosthesis Design; Renal Dialysis; Stents; Subclavian Vein; Treatment Outcome; Upper Extremity; Vascular Patency

Topics: Adult; Aged; Aged, 80 and over; Alloys; Angioplasty; Arteriovenous Shunt, Surgical; Blood Vessel Prosthesis; Brachiocephalic Veins; Constriction, Pathologic; Female; Graft Occlusion, Vascular; Humans; Kidney Failure, Chronic; Male; Middle Aged; Recurrence; Renal Dialysis; Stents; Treatment Outcome; Ultrasonography, Doppler; Vascular Diseases; Vascular Patency