Novel approach to percutaneous thrombolysis in large caliber clotted vascular access using ultrasound-accelerated thrombolysis

Manual compression technique improves the success rate in the treatment of thrombosed aneurysmal arteriovenous fistula: A single-center experience

OBJECTIVE

Endovascular intervention for thrombosed aneurysmal arteriovenous fistula (AVF) is still a challenge. Manual compression technique (MCT)-assisted angioplasty may be helpful, but there is no evidence or data to support it.

METHODS

From January 2018 to May 2021, patients with thrombosed aneurysmal AVFs were retrospectively enrolled. The patients were separated into the MCT group or the traditional group according to the procedure received. Technical failure, clinical failure, 90-day patency, and safety were analyzed.

RESULTS

A total of 159 cases (64 ± 12 years old, 60% male) were enrolled, of which 87 cases received MCT and 72 underwent traditional angioplasty. No technical failure was observed in the MCT group, while five technical failures were observed in the traditional group (0% vs. 7%, p = 0.02). There were no differences in the clinical failure rate (3% vs. 7%, p = 0.30), 90-day patency rate, or procedure time between the MCT group and the traditional group. There was no symptomatic pulmonary embolism or other complication in the two groups.

CONCLUSION

MCT is a low-cost, less invasive, and safe procedure for thrombosed aneurysmal AVF, and it achieves a higher technical success rate than traditional angioplasty.

[Acute interventions-dialysis shunt recanalization]

BACKGROUND

An arteriovenous fistula is vital for patients who need regular hemodialysis. Continuous patency and sufficient functionality determine quality of life and associated morbidity and mortality of patients.

PROBLEM

Following successful hemodialysis shunt creation, intimal hyperplasia and consecutive thrombosis or complete occlusion may cause different types of shunt dysfunctionality or even critical failure.

OBJECTIVE

Immediate shunt recanalization and revision by using an endovascular-first approach is crucial for long-term survival of hemodialysis fistula. There are several mechanisms available for catheter-based thrombus removal to unmask the typically underlying shunt stenosis.

METHODS

Primary technical recanalization success rates are very similar for clot cleaning. Treatment of intimal hyperplasia is preferably addressed by using drug-coated balloon angioplasty to allow for increased shunt patency compared to plain old balloon angioplasty. Stents and stent grafts are only used for resistant or repeated short-term recurrence of severe stenosis. Finally, surgical revision has a classical role in case of repeated failure of endovascular measures.

Transcatheter Thrombolysis with Percutaneous Transluminal Angioplasty Using a Trans-Brachial Approach to Treat Thrombosed Arteriovenous Fistulas

Background

Arteriovenous fistulas (AVFs) are used to provide vascular access for hemodialysis in patients with end-stage renal failure. However, stenosis and thrombosis can compromise long-term AVF patency. The objective of this study was to evaluate catheter thrombolysis with percutaneous transluminal angioplasty (PTA), using a trans-brachial approach, for acutely thrombosed AVFs.

Material/Methods

This retrospective study examined 30 cases of AVF thrombosis treated between January 1, 2015 and January 1, 2017. All patients received transcatheter thrombolysis with PTA using a trans-brachial approach. AVF patency was assessed after 6 months.

Results

Thrombolysis with PTA was performed at 2 to 72 h after diagnosis of AVF occlusion due to acute thrombosis, and AVF patency was restored in all patients. After 6 months, the primary and secondary patency rates were 76.7% and 93.3%, respectively. For type I stenosis, primary patency was achieved in 10 of 16 patients (62.5%) and secondary patency was achieved in 14 of 16 patients (87.5%). For type II stenosis, primary patency was achieved in 13 of 14 patients (92.9%) and secondary patency was achieved in 14 of 14 patients (100%). Comparing type I and II stenosis, a significant difference was detected in the rates of primary patency (odds ratio=0.909, 95% confidence interval 0.754–1.096, P=0.049), but not secondary patency (P=0.178), after 6 months.

Conclusions

Our study provides preliminary evidence that catheter-directed thrombolysis with PTA using a trans-brachial approach can achieve high patency rates when used to treat acutely thrombosed AVFs.

Maintaining Patency of Vascular Access for Haemodialysis

All types of vascular access, a necessity for haemodialysis, are prone to thrombosis and if untreated this results in failure. Thrombosis results from the combination of impaired blood flow, endothelial and vessel wall injury and a propensity towards pro-coagulative states, either intrinsic or aggravated by dialysis or dehydration. The treatment of access thrombosis relies on removal of the clot (thrombectomy) and treatment of the underlying problem. In most cases this is stenosis secondary to neointimal hyperplasia which can occur early (failure to mature) or later. Pharmacological approaches have largely been shown to be ineffective at prevention of thrombosis. The mainstay of preventing access failure may be in surveillance and detecting stenosis prior to occlusion although the optimal protocol to achieve this remains undefined. Management of thrombosed access is via either surgical and radiological approaches. Multiple techniques and devices are available for thrombectomy and the choice is usually based on local expertise and availability rather than evidence as few trials have been performed to allow robust comparisons. This paper outlines the basis of access thrombosis and discusses the currently available techniques for treatment.