A survival guide for endovascular declotting in dialysis access: procedures, devices, and a statistical analysis of 3,000 cases

The role of vacuum-assisted mechanical thrombectomy in the management of acutely thrombosed arteriovenous fistulas and grafts

PURPOSE

The purpose of this study is to evaluate the safety and efficacy of the mechanical thrombectomy with the Indigo System in the treatment of thrombosed arteriovenous fistulas and grafts.

METHODS

A retrospective search of endovascular procedures performed from November 2018 to June 2020 was conducted. Inclusion criteria were: acute arteriovenous fistula or graft thrombosis that underwent endovascular mechanical thrombectomy with Indigo System. The following information was collected from each case: sex, age, fistula modality, fistula location, treatment modality, and outcomes. Endpoints evaluated were: technical and clinical success rates; primary, assisted primary, and secondary patency rates; complication rates.

RESULTS

Twenty-six mechanical thrombectomy procedures for declotting of arteriovenous fistula thrombosis, using the Indigo System, were performed in 22 patients. Technical and clinical success was achieved in 23/26 cases (88%). Mean follow-up was 9 months (range 11-539 days). The 6-month primary, primary assisted, and secondary patency rates were 71%, 86%, 93% and the 12-month primary, primary assisted, and secondary patency rates were 71%, 72%, 80%, respectively. No technical or device-related complications were observed during thrombectomy, however two venous ruptures occurred on the angioplasty of the underlying stenosis.

CONCLUSION

In conclusion, vacuum-assisted thrombectomy of acutely thrombosed arteriovenous fistulas and grafts with Indigo System is safe and effective, providing good short term patency rates.

Single-centre experience with endovascular rotational thrombectomy for single session salvage of thrombosed arteriovenous fistulas and grafts

OBJECTIVES

This paper documents our experience and outcomes of using a relatively new endovascular rotational thrombectomy device for salvage of thrombosed vascular access.

METHODOLOGY

A retrospective study reviewing patients with thrombosed native AVF or AVG who underwent endovascular declotting using a rotational thrombectomy device between November 2018 and May 2020 at a tertiary university hospital in Southeast Asia. We evaluated demographics, procedural data, technical and procedural success, patency rates and complications.

RESULTS

A total of 40 patients underwent single session endovascular declotting of thrombosed vascular access. The mean follow-up period was 21.6 months (range 13.4-31 months). The technical success was 92.5% and clinical success was 80%. About 50% of patients had concomitant thrombolysis for pharmacomechanical thrombectomy. One patient had a myocardial infarction during the post-operative period. There were no other major complications within 30 days. The primary patency was 45.5% at 6 months and 22.7% at 12 months. Assisted primary patency was 68.1% at 6 months and 61.6% at 12 months, which was maintained up to 2 years. The secondary patency was 84.1% at 6 and 12 months.

CONCLUSION

Our study shows that rotational thrombectomy device for single session thrombectomy of thrombosed arteriovenous fistulas and grafts is safe and effective. A high technical and clinical success rate was achieved, with low complication rates and specific advantages compared to other techniques, including reduced length of hospital stay. Our reported mid-term outcomes are reasonable with an assisted primary patency of 62% at 12 and 24 months. The use of newer techniques and novel dedicated thrombectomy devices show promise.

Acute problems of hemodialysis access: Thrombosis, aneurysms, symptomatic high-flow fistulas, and complications related to central lines

Hemodynamic complications frequently affect vascular access and are important causes of morbidity and mortality. We present a review of acute complications affecting vascular accesses, focusing on classical and new treatments. Acute complications in hemodialysis vascular access are often underestimated and undertreated, and can present a challenge for both vascular surgeons and anesthesiologists. Accordingly, we considered different anesthesiologic approaches to both hemorrhagic and nonhemorrhagic patients. A strict collaboration among nephrologists, surgeons, and anesthesiologists can potentially improve prevention and management of acute complications and quality of life.

Chameleon™ PTA balloon catheter: A single device in managing thrombosed AV access

Thrombectomy is a common procedure for maintenance of arteriovenous (AV) access and is critical to prolong access life. Techniques for performing thrombectomy are incredibly diverse, ranging from open surgical procedures to percutaneous interventions. Percutaneous interventions include a combination of thrombectomy devices to clear the thrombus and balloon angioplasty to treat the underlying lesion. In this case report we describe a novel technique using a single device, the Chameleon™ PTA balloon catheter (Medtronic, Minneapolis, MN) balloon catheter, to safely and efficiently perform a percutaneous intervention.

[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.

The related factors to the re-thrombosis of hemodialysis arteriovenous graft after endovascular salvage

BACKGROUND

Only a few issues of the related factors to hemodialysis access dysfunction have been evaluated, and the effects of antiplatelets to improve the patency of hemodialysis access remained controversial. Hence, this study aimed to determine the related factors to the re-thrombosis of arteriovenous grafts (AVGs) after endovascular treatment.

METHODS

This retrospective study was conducted at a university-affiliated teaching hospital in Southern Thailand. All patients who underwent hemodialysis with thrombosed AVG, who had pharmacomechanical thrombolysis from January 2016 to December 2018, were enrolled. Post-intervention primary patency was analyzed by the Kaplan-Meier method, and the related factors to the re-thrombosis of AVG were evaluated using logistic regression.

RESULTS

A total of 157 patients with thrombosed hemodialysis AVG were enrolled. The most common graft location and configuration was a forearm loop graft (65%). Post-intervention primary patency rate at 1, 3, and 6 months were 79.0%, 67.1%, and 54.0%, respectively. Diabetes mellitus (DM) was a significant related factor for re-thrombosis (hazard ratio [HR], 1.89; 95% confidence interval [CI], 1.20-2.98; p = 0.006). A single antiplatelet after the procedure was a protective factor for re-thrombosis (HR, 0.58; 95% CI, 0.38-0.89; p = 0.013). The median post-intervention primary patency was 15.7 months in the group of single antiplatelet usage, which was better than that of the non-antiplatelet group (p = 0.012).

CONCLUSION

DM and antiplatelet usage were significant related factors to the re-thrombosis of hemodialysis AVG after endovascular salvage.

Hemodialysis Arteriovenous Fistula Dysfunction: Retrospective Comparison of Post-thrombotic Percutaneous Endovascular Interventions with Pre-emptive Angioplasty

OBJECTIVES

We aimed to compare the clinical outcomes of pre-emptive angioplasty versus post-thrombotic percutaneous endovascular restoration of dysfunctional arteriovenous fistula (AVF).

METHODS

This retrospective study reviewed data from 80 patients who underwent 114 endovascular interventions for a malfunctioning AVF from July 2016 to August 2019. Stenotic AVFs were treated with pre-emptive angioplasty. Thrombosed AVFs were treated with percutaneous pharmacomechanical fibrinolysis with urokinase used only during the operation or continuously infused. The differences in patency rates were evaluated using Kaplan-Meier method. In addition, univariate and multivariate regression Cox models were used to determine influential factors on the post-intervention primary patency.

RESULTS

Post-thrombotic interventions and pre-emptive angioplasty yielded statistically similar rates in clinical success (100% vs 100%), anatomic success (94% vs 89%; p = .52), complication (4% vs 11%; p = .29), as well as postintervention primary, assisted primary and secondary patency (p = .80; .57; .57). The use of pre-emptive angioplasty was associated with reduced total cost (¥25108 vs ¥30833, p< .001). The patients who used urokinase only during the operation prolonged both the primary and assisted primary patency (p = .02; .002), while those with continuous infusion of urokinase had worst patency rates and high costs (¥39275 vs ¥25108 vs ¥27140, p< .001). Compared with the other locations, dysfunction in the anastomotic or juxta-anastomotic segment (HR = .41, p = .001) was associated with prolonged postintervention primary patency.

CONCLUSIONS

No clinical outcome differences was found between the post-thrombotic percutaneous endovascular interventions and pre-emptive angioplasty. However, pre-emptive angioplasty decreased access expenditure.

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.

Modified lyse and wait technique for the treatment of dialysis fistula thrombosis: Percutaneous thrombolytic therapy with a 27-G dental needle

BACKGROUND

The lyse and wait technique is a percutaneous endovascular technique in the treatment of thrombosed dialysis fistulas. In this study, our aim was to introduce a more easily applicable modification of the lyse and wait technique and present our results.

METHODS

A total of 84 patients (56 male; 66.6%), with a mean age of 61 years, were included in the study. The treatment was performed in patients presenting with dialysis fistula thrombosis no more than 1 week before the procedure, whose thrombosed segment length was less than 10 cm. A 27-G dental needle was inserted into the thrombosed segment under ultrasonography guidance, and 5 mg of alteplase was injected in a controlled manner. After about 6 to 12 h, the patients were taken to the angiography unit, and balloon angioplasty was performed.

RESULTS

The technical and clinical success of the procedure was 98.8%. Technical and clinical failure occurred in only one patient. The median primary patency duration was 13.5 months. None of the patients had major complications. At the end of 12 months, the primary patency rate was 66.6%, and the secondary patency rate was 80%.

CONCLUSIONS

Our technique has shown to have high technical and clinical success and patency.

Outcomes of Catheter-Directed Thrombolysis for Arteriovenous Fistula Thrombosis in Singapore: Is It Still Relevant Today?

Objective: To review the outcomes of catheter-directed thrombolysis (CDT) for salvage of thrombosed arteriovenous fistula (AVF) in a single centre in Southeast Asia.

Methods: A retrospective study of CDT in AVF between January 2015 and July 2018 at a tertiary university hospital was carried out.

Results: Within the study period, 85 patients underwent CDT for AVF thrombosis. Of these patients, 78% underwent CDT for 24 h and 12% required CDT for 48 h. Moreover, 14% of patients had bleeding during CDT and hence required a decrease in dosing or complete cessation. Incidence of intracranial haemorrhage was 1%, and technical success was 92%. Post CDT, primary patency rates at 12, 24 and 36 months were 87%, 62% and 36%, respectively; assisted primary patency rates at 12, 24 and 36 months were 96%, 82% and 69%, respectively; and secondary patency rates at 12, 24 and 36 months were 99%, 93% and 86%, respectively. Multivariate analysis did not identify any predictive factors for patency post CDT.

Conclusion: Within our study population, CDT for AVF salvage conferred good technical results with low rates of complications. There was good primary patency at 12 months, and the results were sustained up to 36 months. It remains a useful modality for fistula salvage, avoiding surgical intervention.

Comparison between endovascular versus hybrid thrombectomy for arteriovenous graft under complete ultrasound guidance

BACKGROUND

Endovascular treatment of acute thrombosed arteriovenous grafts performed completely under ultrasound guidance has rarely been reported. We compared the efficacy of a new endovascular thrombectomy technique (percutaneous manual thromboaspiration through the introducer sheath) with classical hybrid thrombectomy (minimally invasive surgical thrombectomy combined with high-pressure angioplasty) performed completely under ultrasound guidance, for arteriovenous graft thrombosis.

METHODS

This was a retrospective cohort study involving patients receiving hemodialysis who underwent arteriovenous graft thrombectomy between January 2014 and December 2017. We divided 130 participants into an intervention (endovascular) group (N.=65) and a control (classical hybrid) group (N.=65) according to the thrombectomy technique. The procedural success rate, immediate outcomes and patency were compared between the groups.

RESULTS

There was no significant difference in the procedural success rate (92.31% vs. 89.23%, P=0.55) between the intervention and control groups, respectively. No major complications were noted, but two cases of vessel rupture occurred in the control group and three cases of vessel rupture occurred in the intervention group. The procedure time in the intervention group was significantly shorter than that in the control group (74±14.21 min vs. 109.05±19.20 min, respectively; P<0.05). During the 6-month follow-up, we found no significant difference in the postintervention primary patency rate (48.33% vs. 55.17%; P=0.51) or the postintervention second patency rate (83.33% vs. 84.49%; P=0.79) between the intervention and control groups, respectively. Dialysis clearance and ≥50% stenosis were predictors of postintervention primary patency (hazard ratio, 7.80; 95% confidence interval: 1.75-34.81; P=0.01; and hazard ratio, 6.43; 95% confidence interval: 2.43-17.03; P<0.001), respectively.

CONCLUSIONS

Completely ultrasound-guided percutaneous manual thromboaspiration through the introducer sheath can be used for thrombosed arteriovenous grafts. This approach has the advantage of shorter operative time compared with hybrid treatment.

Comparison between bovine carotid artery graft and polytetrafluoroethylene graft for haemodialysis vascular access: A systematic review and meta-analysis

BACKGROUND

There is a renewed interest in using bovine carotid artery grafts for haemodialysis vascular access after recent advances in conduit manufacturing and endovascular management of access-related complications. Our aim was to summarize the results of the recent studies comparing bovine carotid artery grafts with polytetrafluoroethylene grafts as vascular access for haemodialysis.

METHODS

A systematic review was conducted for original articles comparing bovine carotid artery with polytetrafluoroethylene grafts for haemodialysis vascular access published between January 2000 and December 2019 searching the databases of Medline, Scopus, Google Scholar, ClinicalTrials.gov and the Cochrane Central Register of Controlled Trials.

RESULTS

Four studies were included (one prospective randomized controlled trial and three retrospective studies) with 676 patients in total (bovine carotid artery: 395, polytetrafluoroethylene: 281). There was lower graft infection rate per patient-year in bovine carotid artery grafts (mean difference: -0.03, p < 0.0001). Bovine carotid artery grafts required fewer interventions per patient-year to maintain or restore patency (mean difference: -0.81, p = 0.002). No significant difference was detected regarding pseudoaneurysm formation (p = 0.24), steal syndrome (p = 0.11) or patency rates (primary: 1 year: p = 0.15, 2 years: p = 0.69; primary assisted: 1 year: p = 0.18, 2 years: p = 0.54; secondary: 1 year: p = 0.22, 2 years: p = 0.17).

CONCLUSION

Bovine carotid artery and polytetrafluoroethylene grafts have similar short-term and long-term outcomes, with a possible advantage of bovine carotid artery grafts concerning graft infections and number of required interventions. Thus, bovine carotid artery grafts can be a useful alternative modality for haemodialysis vascular access.

Outcomes after endovascular mechanical thrombectomy in occluded vascular access used for dialysis purposes

Purpose

Endovascular mechanical thrombectomy using the AngioJet™ system can be considered to reestablish patency in occluded vascular access. The aim of this study was to review our results for endovascular mechanical thrombectomy using the AngioJet™ system in patients with arteriovenous fistulae (AVF) and arteriovenous grafts (AVG).

Methods

Data collected in a database of patients requiring hemodialysis for renal failure were analyzed. Patients who underwent endovascular mechanical thrombectomy procedures with the AngioJet™ system for occlusion of vascular access were included. Clinical and technical success rates and patency rates were calculated. Multivariate analysis was used to identify factors of influence.

Results

A total of 92 AngioJet™ procedures in 60 patients with thrombosed vascular access were reviewed during a mean follow‐up period of 21.5 months in patients with an AVF and 11.9 months in patients with an AVG. Technical and clinical success was achieved in 92.6% of AVF cases and 92.0 and 90.8% of AVG cases with an AVG, respectively. Significantly higher primary and primary‐assisted patency rates were observed in the AVF group. Multivariate regression analysis indicated that left‐sided vascular access and female sex were independent predictors for failure regarding primary patency in AVG patients. Immunosuppressive drugs and older age were negative predictors for secondary patency in AVG patients.

Conclusions

The AngioJet™ system can be deemed an effective technique to reestablish patency in occluded vascular access with minimal use of central venous catheters for dialysis. Good technical and clinical success rates were achieved with acceptable patency rates, especially in AVF patients.

Factors influencing outcomes of rheolytic thrombectomy on thrombosed dialysis access grafts: Door to angiographic bed time and what else?

BACKGROUND

The aim of this study was to investigate the effect of the time interval from clinical presentation of arteriovenous graft thrombosis and the thrombectomy procedure by the AngioJet system in terms of technical and clinical success and to identify factors influencing success.

METHODS

A total of 60 consecutive patients (35 men and 25 women; mean age = 52 ± 7.89 years) who had undergone percutaneous thrombectomy by the AngioJet device from 2016 to 2019 were retrospectively enrolled. Demographics and fistula data, previous treatments, time from clinical onset of thrombosis to intervention, procedural details and complications were recorded. Technical and clinical success and primary and secondary patency rates were calculated. One-way analysis of variance was performed to test any correlation between patient-related and fistula/procedure-related variables and technical/clinical success. Odds ratio and relative risk were also calculated when necessary.

RESULTS

Technical success and clinical success were 95% and 91.7%, respectively. Post-interventional primary and secondary patency rates at 1 year were 72.5% and 84.3%, respectively. Complication rate was 6.7%. One-way analysis of variance showed that clinical success was higher in patients with no previous treatment (p = 0.015). Furthermore, clinical success was significantly associated with door to angiographic bed time (p = 0.002): p-value for the 24-h and the 72-h cut-off was 0.012 and 0.006, respectively.

CONCLUSION

Percutaneous rheolytic thrombectomy is safe and effective for thrombosed arteriovenous grafts, with acceptable primary and secondary patency rates. Higher clinical success was found in patients never treated before and when the procedure was carried out within 24 h from the clinical onset of thrombosis.

Long-term results of endovascular treatment for arteriovenous dialysis access thrombosis in 143 patients: A single center experience

Objective:

This study aimed to determine the long-term patency duration and rate of thrombosis of autologous arteriovenous fistulas and synthetic grafts treated with endovascular methods in a large patient population.

Methods:

A total of 144 arteriovenous accesses (37 radiocephalic, 51 brachiobasilic, 41 brachiocephalic, and 15 femorofemoral) from 143 patients were included in the study. A total of 304 endovascular thrombolytic treatment procedures were performed for 94 (65%) arteriovenous fistula and 50 (35%) arteriovenous graft accesses.

Results:

The procedural technical success rate was 98.7%. The mean follow-up duration was 32.5 (range, 3–132) months. The primary patency rates for arteriovenous fistulas and arteriovenous grafts were 78% and 78% at 6 months, 66% and 63% at 1 year, and 45% and 0% at 36 months, respectively. The assisted primary patency rates for arteriovenous fistulas and arteriovenous grafts were 82% and 84% at 6 months, 71% and 69% at 1 year, 51% and 29% at 36 months, and 30% and 1% at 60 months, respectively. The secondary patency rates for arteriovenous fistulas and arteriovenous grafts were 94% and 93% at 6 months, 85% and 85% at 1 year, 58% and 59% at 36 months, and 47% and 48% at 60 months, respectively.

Conclusion:

Although the primary patency durations for arteriovenous fistulas were better after endovascular thrombolytic treatment than those for arteriovenous grafts, the long-term outcomes of assisted primary and secondary patency durations after repeated procedures were similar for both types of arteriovenous accesses.

Recent developments in endovascular interventions to sustain vascular access patency in haemodialysis patients

There is amassed evidence regarding the use of endovascular procedures for the treatment of vascular access stenosis and thrombosis. A review was conducted based on available randomized trials, cohort studies and retrospective analyses published after 2000 on endovascular treatment of dysfunctional and thrombosed vascular access, with an aim to illustrate the available device and procedural options. The use of paclitaxel-coated balloons, cutting balloons and covered stents is described in the field of vascular access stenosis. The broad spectrum of available devices and endovascular declotting procedures ranging from thrombolysis to thrombectomy is also discussed. Overall, in this review we demonstrate the increasing role of endovascular procedures in vascular access treatment and the improved patency outcomes provided by the implementation of novel endovascular devices. Moreover, the improvement of post-intervention primary patency rates after endovascular declotting procedures and the shift to more thrombectomy-dependent procedures over time is also highlighted. In conclusion, endovascular treatment of dialysis access stenosis and thrombosis has an established role, owing to the implementation of sophisticated devices, allowing, when needed, the simultaneous treatment of thrombosis and the underlying stenosis.