Outcomes of Percutaneous Mechanical Thrombectomy of Arteriovenous Fistulas in Hemodialysis Patients

Thrombus stiffness as an independent predictor of endovascular treatment success in hemodialysis fistulas: a study using ultrasound elastography

PURPOSE

This study aimed to evaluate the prognostic value of thrombus stiffness, measured by strain elastography, in independently predicting the success of endovascular treatment for thrombosed hemodialysis fistulas.

METHODS

The study employed a retrospective observational design. Forty-nine patients with chronic kidney disease undergoing hemodialysis and experiencing fistula dysfunction were included. Various factors were evaluated, including patient age, sex, comorbidities, arteriovenous fistula (AVF) type, use of antiplatelet agents, duration of thrombosed AVF dysfunction, thrombus length, thrombus stiffness, and thrombus strain ratio (SR). Thrombus stiffness was measured using strain ultrasound elastography.

RESULTS

The presence of comorbidities (P=0.018), duration of AVF dysfunction due to thrombosis (P=0.005), thrombus stiffness (P<0.001), and thrombus SR (P<0.001) were statistically significant predictors of treatment success, while other factors were not. Thrombus stiffness and SR, assessed by two independent radiologists with excellent inter-reader agreement, demonstrated high reliability. The optimal SR cut-off for treatment success was 1.4 (sensitivity, 0.947; specificity, 0.901; area under the curve, 0.935). Multivariable logistic regression analysis revealed that both thrombus SR and thrombus stiffness significantly influenced treatment outcomes (P=0.003 and P=0.007, respectively). A 0.1-unit increase in thrombus SR was associated with 9.37% reduction in the likelihood of treatment success, while a smilar increase in thrombus stiffness exhibited an 8.06% reduction, underscoring their importance as prognostic factors in clinical setting.

CONCLUSION

This study demonstrates the utility of strain ultrasound elastography in assessing thrombus stiffness in thrombosed hemodialysis AVFs and its correlation with treatment success.

Comparing Patency Rates of Arteriovenous Dialysis Access following Percutaneous Thrombectomy Using Various Catheter Directed Therapies

BACKGROUND

Arteriovenous fistulas often require frequent interventions to maintain patency for hemodialysis. Interventions may include open or percutaneous thrombectomy with additional targeted interventions as indicated. We evaluated the primary and cumulative functional patency rates following three unique approaches to percutaneous thrombectomy of thrombosed dialysis access.

METHODS

A retrospective review of 236 unique patients who presented with thrombosed hemodialysis access was analyzed over a period of 4 years from 2016 to 2020. We analyzed a total of 413 procedures that utilized 3 separate percutaneous thrombectomy devices to assist with restoring patency. The Indigo System CAT-D Aspiration Thrombectomy Catheter (Penumbra; Alameda, CA), the Arrow-Trerotola Rotational Thrombectomy System (Teleflex; Wayne, PA) and the Angiojet Rheolytic Thrombectomy Catheter (Boston Scientific, Marlborough, MA) devices were compared for primary and cumulative functional patency. Primary patency was defined as time from percutaneous thrombectomy to next intervention (Angioplasty, stenting, and repeat thrombectomy). Cumulative functional patency was defined as time from percutaneous thrombectomy to time of access abandonment. Medical record chart review was utilized to determine patency rates.

RESULTS

A total of 413 percutaneous thrombectomy procedures were performed. Of the procedures performed, 98 utilized Angiojet, 103 utilized Trerotola, and 212 used Penumbra. The mean primary patency rates in (days) for the devices were as follows: Angiojet (194), Trerotola (204), and Penumbra (107). The mean cumulative functional patency rates (in days) for the devices were as follows: rheolytic thrombectomy (450 days), aspiration thrombectomy (292 days), and rotational thrombectomy (475 days). Angiojet versus Penumbra and Trerotola versus Penumbra both showed diminished patency rates when using the Penumbra catheter that were statistically significant (P < 0.05).

CONCLUSIONS

All percutaneous thrombectomy approaches do not result in the same primary or cumulative functional patency rates. Approaches with Trerotola and Angiojet resulted in improved primary and cumulative functional patency rates compared to those using Penumbra.

Scoop thrombectomy: A declotting technique for the treatment of thrombosed autologous arteriovenous fistula. A single-center retrospective study

BACKGROUND

Thrombosis is one of the main complications leading to the failure of autologous arteriovenous fistula (AVF) for patients with renal failure. Thrombectomy is one of the major therapies to remove thrombi to salvage the AVF and prolong its patency.

MATERIALS AND METHODS

Fifty-six patients with AVF thrombosis at the anastomosis were recruited for this study and underwent thrombectomy procedures. Their clinical variables were collected. The vasculature was accessed at the site of the aneurysmal dilatation. Under ultrasound guidance, a scoop thrombectomy procedure was performed by anterograde and retrograde scooping to remove the thrombus using forceps. Then, a sheath was placed in the direct vertical direction. Angioplasty was performed with a balloon to treat the underlying primary arteriovenous stenosis. Patients were followed up for 12 months after surgery. The procedural success, primary and secondary patency rates, and incidence of procedure-related complications were analyzed.

RESULTS

There were 2 minor (3.6%) and no major complications. Clinical success was achieved in 55 of the 56 procedures (98.2%). No symptomatic pulmonary embolism or arterial embolization was noted. The primary patency rates at 3, 6, and 12 months were 92.9, 83.8, and 73.3%%, respectively, according to the Kaplan-Meier survival analysis.

CONCLUSION

Scoop thrombectomy is a safe procedure with high technical success and a low complication rate, and it is an effective method for patients to receive hemodialysis immediately.

Perioperative and long-term outcomes after percutaneous thrombectomy of arteriovenous dialysis access grafts

OBJECTIVE

Maintenance of functional arteriovenous grafts (AVGs) for dialysis is difficult secondary to low primary patency, need for reinterventions, and limited alternative dialysis access options. We assessed our experience with percutaneous thrombectomy for treatment of occluded AVGs.

METHODS

We performed a retrospective analysis of all percutaneous thrombectomies for AVGs from 2015 to 2017. These were generally performed using mechanical thrombectomy and occasional chemical tissue plasminogen activator thrombolysis, over-the-wire balloon embolectomy for inflow, and adjunctive inflow and outflow interventions as necessary. Perioperative outcomes, long-term patency, reinterventions, and need for new permanent access placement were analyzed.

RESULTS

There were 218 percutaneous thrombectomies performed on 86 AVGs in 77 patients. Approximately half (53.2%) of the patients were male and 68.8% were black. Mean age was 61.1 ± 13.0 years. At the time of thrombectomy, 73.8% underwent venous outflow interventions and 4.5% underwent arterial inflow interventions. Within 30 days, 24.8% of declotted grafts underwent repeated percutaneous thrombectomy, 14.3% required tunneled dialysis catheter placement, 4% developed minor access site or graft infections, and one patient underwent surgical arterial thrombectomy for arm ischemia. There were no venous thromboembolic, cardiopulmonary, or cerebrovascular complications or clinically significant pulmonary embolism. At 1 year and 3 years after percutaneous thrombectomy, freedom from repeated thrombosis was 37% and 18%, respectively, and freedom from new dialysis access placement was 66% and 51%, respectively. Overall patient survival was 82% at 3 years.

CONCLUSIONS

Percutaneous thrombectomy of AVGs is safe and is associated with acceptable patency rates. This minimally invasive method extends AVG use for these high-risk patients with limited dialysis access options.

Vacuum-assisted mechanical thrombectomy in extensively occlusive thrombosis of dialysis arteriovenous grafts with indigo system

PURPOSE

To present a selected series of extensively occlusive thrombosis of arteriovenous graft treated with the Penumbra's Indigo System.

MATERIALS AND METHODS

Ten patients with acute (within 72 h) extensively occlusive thrombosis of arteriovenous graft (mean extension = 30.1 (range = 15-45) cm) were treated at our institution with the Indigo System. Of the 10 cases, thrombosis was extended to venous outflow in 7 cases and to both arterial inflow and venous outflow in 3 cases.

RESULTS

Both anatomic and clinical success were achieved in 8 of the 10 procedures (80.0%). In the 2 cases of technical failure, the patients underwent surgical thrombectomy with the finding of arteriovenous graft exhaustion, which was then replaced. The 6-month primary patency, primary-assisted patency, and secondary patency rates were 37.5% (3/8), 50.0% (4/8), and 62.5% (5/8). We reported 2 complications (one minor and one major adverse event).

CONCLUSION

Percutaneous mechanical thrombectomy aspiration with Indigo System is a relatively safe and effective procedure and can be used even in extensively thrombosed arteriovenous graft.

Spanish Clinical Guidelines on Vascular Access for Haemodialysis

Vascular access for haemodialysis is key in renal patients both due to its associated morbidity and mortality and due to its impact on quality of life. The process, from the creation and maintenance of vascular access to the treatment of its complications, represents a challenge when it comes to decision-making, due to the complexity of the existing disease and the diversity of the specialities involved. With a view to finding a common approach, the Spanish Multidisciplinary Group on Vascular Access (GEMAV), which includes experts from the five scientific societies involved (nephrology [S.E.N.], vascular surgery [SEACV], vascular and interventional radiology [SERAM-SERVEI], infectious diseases [SEIMC] and nephrology nursing [SEDEN]), along with the methodological support of the Cochrane Center, has updated the Guidelines on Vascular Access for Haemodialysis, published in 2005. These guidelines maintain a similar structure, in that they review the evidence without compromising the educational aspects. However, on one hand, they provide an update to methodology development following the guidelines of the GRADE system in order to translate this systematic review of evidence into recommendations that facilitate decision-making in routine clinical practice, and, on the other hand, the guidelines establish quality indicators which make it possible to monitor the quality of healthcare.

Stent tunnel technique to save thrombosed native hemodialysis fistula with extensive venous aneurysm

INTRODUCTION AND PURPOSE

The increasing number of patients undergoing hemodialysis and the limited number of access sites have resulted in an increasing number of techniques to maintain vascular access for hemodialysis. Thrombosed arteriovenous (AV) fistulas with large venous aneurysms have poor treatment results, with both endovascular and surgical techniques, leading to a high rate of definitive AV access loss. The purpose of this study was to review the feasibility and initial results of this novel endovascular treatment of thrombosed AV fistulas with large venous aneurysms.

MATERIALS AND METHODS

A novel endovascular treatment technique of inserting nitinol auto-expandable uncovered stents stretching through the whole puncture site area, thus creating a tunnel inside the thrombus, was retrospectively analyzed and described.

RESULTS

A total of 17 stents were placed in 10 hemodialysis fistulas, with a mean venous coverage length of 17.8 cm. In all the cases, 100% technical success was achieved, with complete restoration of blood flow in all patients. There were no procedure-related complications. The mean follow-up was 167 days (range 60-420 days), with a primary and assisted patency of 80% and 100%, respectively. No multiple trans-stent struts-related complications were observed. Three stent fractures were diagnosed with plain films at the site of puncture without consequence in the venous access permeability.

CONCLUSION

The "stent tunnel technique" is a feasible, safe and effective alternative to salvage native hemodialysis access, thus extending the function of the venous access with no signs of stent-related complications and a respectable midterm patency.

Percutaneous treatment of thrombosed hemodialysis arteriovenous fistulas: use of thromboaspiration and balloon angioplasty

Background

Endovascular strategies have been used to manage patients with thrombosed vascular access for hemodialysis. We analyzed primary success rate and patency rates of balloon angioplasty following mechanical thrombectomy for the treatment of thrombosed native arteriovenous fistulas.

Methods

This was a retrospective study of 24 patients with thrombosed native arteriovenous fistulas who were referred for treatment in the intervention unit of the Radiology Department. All patients had been performed percutaneous thrombo-aspiration and balloon angioplasty. Technical and clinical success rates as well as the 6th and 12th months primary and secondary patency of fistulas were evaluated.

Results

Technical and clinical success was 83%. In the 6 of 20 patients, early re-thrombosis were detected. Patent AVF with primary and secondary patency rates at 6 and 12 months was 55%-40%. The secondary patency rates at 6 and 12 months were 75% and 70%.

Conclusion

Mechanical thrombectomy with balloon angioplasty is a minimally invasive and effective procedure for the treatment of thrombosed native arteriovenous fistula. Advantages of this technique are minor complication rates, cost effectiveness, high technical success rate.

Initial clinical use of a novel mechanical thrombectomy device, XCOILTM, in hemodialysis graft and fistula declot procedures

PURPOSE

We aimed to evaluate the safety and effectiveness of a novel catheter-based mechanical thrombectomy device, XCOILTM, as a first line therapy to restore patency of thrombosed dialysis grafts and fistulae.

METHODS

In 2010, 18 consecutive/sequential patients (11 male, 7 female; median age, 52 years; age range, 32-69 years) with occluded arteriovenous grafts (n=15) or fistulae (n=3) were treated with XCOILTM (NexGen Medical Systems Inc.) without adjunctive thrombolytic drugs. XCOILTM was advanced distal to the thrombus within the outflow vein as well as distal to the arterial inflow platelet thrombin plug, using a 4F angiographic catheter. The percentage of thrombus cleared, primary patency, procedure time, and XCOILTM performance were documented.

RESULTS

Thrombosis occurred 1-30 days prior to the procedure. Thrombosed segments of graft/fistula measured 10-50 cm. Pre- and postprocedure angiography demonstrated that in 15 of 18 cases (83%) XCOILTM removed 80%-100% of the venous outflow thrombus. In 11 of 14 cases (79%), the platelet thrombin plug was also removed. Thrombectomy procedure time averaged 8 min, with one to three passes with the XCOILTM required. No evidence of distal embolization or graft/vessel injury was found on angiography following clot removal. In four cases in whom patency was not restored with XCOILTM, subsequent use of other clot removal devices also failed to restore patency. In one case with severe venous stenosis, the device failed to deploy and the thrombus was not captured. No intraprocedural complications related to XCOILTM use occurred.

CONCLUSION

XCOILTM is an effective and safe first-line therapy option for the treatment of thrombosed hemodialysis grafts/fistulae. Rapid removal of intact thrombus and platelet thrombin plug can be achieved without adjunctive thrombolytics.

Pharmacomechanical thrombolysis for the treatment of thrombosed native arteriovenous fistula: a single-center experience

Background

Native arteriovenous fistula is one of the important routes for hemodialysis patients because of increased long-term survival and preservation of quality of life. We reported on a single-center experience with using pharmacomechanical thrombolysis for the treatment of thrombosed native arteriovenous fistula.

Material/Methods

This was a retrospective study of 12 hemodialysis patients (8 males and 4 females) with 14 thrombosed distal forearm Brescia-Cimino radiocephalic fistulas who were referred for pharmacomechanical thrombolytic treatment in the intervention unit of the Radiology Department, from 1 January 2010 to 30 December 2011. Demographic data, technical success rates, clinical success rates and complications were evaluated. The patency was evaluated by Kaplan-Meier analysis.

Results

The technical and clinical success was found in 12 thrombosed fistulas. Only 3 procedures had minor complications including small amounts of adjacent soft tissue hematoma. There were no procedure-related major complications. The primary patency rates at 6 and 12 months were 67% and 50%. The secondary patency rates at 6 and 12 months were 75% and 67%.

Conclusions

Pharmacomechanical thrombolysis is a minimally invasive, effective, durable, and safe procedure for the treatment of thrombosed native arteriovenous fistula. This procedure can be considered as an alternative treatment for thrombosed dialysis fistulas.

Central Transposition of the Cephalic Vein in Patients with Brachiocephalic Arteriovenous Fistula and Cephalic Arch Stenosis

Purpose:

Our study aims to evaluate to evaluate clinical outcomes after cephalic vein transposition (CVT) to the axilla in patients with brachiocephalic arteriovenous fistula (BC-AVF) and cephalic arch stenosis (CAS).

Materials and Methods:

Hospital records of 13 patients (median age, 61 years; males, 54%) who received CVT to the proximal basilic/axillary vein due to either dysfunction (n=2) or thrombosis (n=11) between January 2010 and February 2014 were retrospectively reviewed.

Results:

Operation was performed under local anesthesia in all cases. There was no technical failure. Concomitant inflow procedure (banding or aneurysmorrhaphy) was performed in 5 patients (38%). During follow-up (1 to 50 months, median 17 months), 3 patients died with functioning AVF and one was successfully transplanted. Two patients suffered from recurrent symptomatic stenosis of AVF and received percutaneous balloon angioplasty. Another 2 patients experienced AVF occlusion treated with interposition graft and manual fragmentation. Overall primary, assisted primary, and secondary patency rates were 77.5%, 92.3%, and 100% at 6 months and 66.1%, 92.3%, and 100% at 1 year, respectively.

Conclusion:

Although most patients presented with BC-AVF occlusion, technical success and access patency rates after CVT were favorable compared with historical data for interventional treatment. CVT should be considered as an appropriate option in selected patients with CAS.

Vascular access for hemodialysis: postoperative evaluation and function monitoring

Vascular access (VA) survival is a crucial issue associated with morbidity and mortality of patients undergoing maintenance hemodialysis. The development of stenosis is the major factor that leads to VA failure. Strategies for early detection of lesions within a VA system before serious complications arise are therefore crucial. The implementation of a VA surveillance program could lead to timely detection of VA dysfunction and referral for correction, reduction in central venous catheter use and decrease in hospitalization and VA-related cost. Suggested methods for arteriovenous fistulae and grafts surveillance include blood flow measurement, static pressure evaluation and duplex ultrasonography. Physical examination is an accepted method in contrast to nonstandardized dynamic pressure measurement for grafts. Access recirculation (not urea based) and dynamic pressure measurements are accepted methods for fistulae. Decreasing URR or Kt/V (otherwise unexplained) and increased (negative) arterial pressure in the dialysis machine are methods of limited sensitivity and specificity for both fistulae and grafts. Measurement of access blood flow has been proposed as the gold standard for the screening of all types of VA. Access flow can be measured by various techniques which are direct or indirect. Several studies about VA surveillance programs have demonstrated conflicting results. Larger, randomized controlled trials need to be carried out in order to clarify whether surveillance programs are necessary and which is the best surveillance strategy for each type of VA.

Cardiac Arrest Secondary to Bilateral Pulmonary Emboli following Arteriovenous Fistula Thrombectomy: A Case Report with Review of the Literature

Number of patients with End Stage Renal Disease (ESRD) is growing worldwide. Hemodialysis remains the main modality of renal replacement therapy for ESRD patients. A patent hemodialysis access (arteriovenous fistula or arteriovenous graft) plays a key role in successful delivery of hemodialysis. Common vascular access issues encountered by patients and nephrologists are thrombosis and infection. The thrombosed access is declotted by various percutaneous techniques these days by multiple outpatient access centers in a timely fashion. Thrombolysis can give rise to various complications, a few of which can be life threatening. A young hemodialysis patient underwent percutaneous thrombolysis of his clotted arteriovenous fistula. Outpatient access thrombectomy was complicated immediately afterwards with cardiac arrest requiring cardiac resuscitation in the recovery room. The patient was admitted to intensive care unit after life sustaining care. Work up revealed multiple pulmonary emboli to both lung fields on CT scan of the chest. Patient was anticoagulated and discharged from the hospital. Thrombolysis of clotted hemodialysis access is associated commonly with occurrences of pulmonary embolic which are usually asymptomatic. Massive pulmonary embolization due to access thrombolysis is rare. Nephrologists and radiologists should be aware of this dangerous complication particularly in patients with preexisting cardiopulmonary disease.

Hybrid surgery versus percutaneous mechanical thrombectomy for the thrombosed hemodialysis autogenous arteriovenous fistulas

Purpose

For the successful treatment of thrombosed autogenous arteriovenous fistula (AVF), we designed and performed a hybrid surgery. Its clinical outcomes were compared with those of percutaneous mechanical thrombectomy, retrospectively.

Methods

Forty cases of thrombosed autogenous AVFs underwent hybrid surgery, whereas 19 cases received percutaneous mechanical thrombectomy. Hybrid surgery consisted of surgical thrombectomy, balloon angioplasty and/or additional surgical angioplasty. Percutaneous mechanical thrombectomy included catheter-introduced thrombus aspiration, balloon angioplasty and/or stenting. Procedure related outcomes such as technical success rates and primary patency rates were analyzed, retrospectively.

Results

There were no statistically significant differences between the two groups in terms of demographic data of the patients including age, gender, diabetes status, and frequency of antiplatelet use, as well as the characteristics of thrombosed autogenous AVFs such as access age, site, type, and length of time between thrombosis and AVF creation (P > 0.05). Technical success rates (92.5% vs. 68.4%, P = 0.005, respectively) and primary patency rates (85.9% vs. 36.8% at 6 months, 81.1% vs. 26.3% at 12 months, 81.1% vs.21.1% at 18 and 24 months respectively, log-rank test, (P < 0.001) were significantly higher in the hybrid surgery group. In terms of cost analysis, supply cost was not different (P = 0.065), but total cost was statistically lower in the hybrid surgery group (P = 0.019).

Conclusion

Hybrid surgery showed better technical success rates and patency rates in the salvaging of thrombosed autogenous AVFs than in percutaneous mechanical thrombectomy.

Percutaneous treatment of thrombosed arteriovenous fistulas: clinical and economic implications

BACKGROUND AND OBJECTIVES

Maintenance of previously thrombosed arteriovenous fistulas (AVFs) as functional vascular accesses can be highly expensive, with relevant financial implications for healthcare systems. The aim of our study was to evaluate the costs and health outcomes of vascular access care in hemodialysis patients with AVF thrombosis.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A retrospective, controlled cohort study was performed among local hemodialysis patients with completely thrombosed AVFs between August 1, 2007, and July 1, 2008. Detailed clinical and demographic information was collected and a comprehensive measure of total vascular access costs was obtained. Costs are reported in 2009 U.S. dollars.

RESULTS

A total of 63 consecutive hemodialysis patients with thrombosed AVFs were identified--a cohort of 37 patients treated with percutaneous thrombectomy and a historic cohort of 25 patients with abandoned thrombosed AVFs. The mean cost of all vascular access care at 6 months was $2479. Salvage of thrombosed AVFs led to a near two-fold reduction in access-related expenses, per patient-month at risk ($375 versus $706; P = 0.048). The costs for access-related hospitalizations ($393 versus $91; P = 0.050), management of access dysfunction ($106 versus $28; P = 0.005), and surgical interventions ($35 versus $6; P = 0.001) were also significantly lower in the percutaneous treatment group. At 6 months, most of these patients had a functional AVF as permanent vascular access (91% versus 33%, P = 0.0001).

CONCLUSIONS

Salvage of thrombosed AVF is a highly efficient procedure; therefore, intensive efforts should be undertaken to universalize these interventions.

Comparison of radiocephalic fistulas placed in the proximal forearm and in the wrist

Non-maturation is a common problem in patients receiving an arteriovenous fistula. The first vascular access choice is a distal radiocephalic fistula (dRCF) at the wrist. Patients with a failed dRCF or with vessels unsuitable for dRCF, the recommendation is to place a brachiocephalic fistula in the upper arm. Proximal forearm radiocephalic fistulas (pRCF) are created infrequently, but may permit a second forearm fistula before proceeding to the upper arm. The goal of the present study was to compare the outcomes of them. We retrospectively analyzed a computerized access database to compare the outcomes of 19 RCF and 39 dRCF placed during a 6-month period. The baseline characteristics were similar, except those with a pRCF were more likely to have previous access and be male. Primary failure (non-maturation) was lower for pRCF than dRCF (32 vs. 59%, p = 0.05); and excluding secondary failures, cumulative fistula survival was similar (92 vs. 86% at 1 year and 74 vs. 76% at 2 years, p = 0.56). pRCF may be an attractive alternative to a brachiocephalic fistula in patients who cannot receive a dRCF. pRCF has a lower non-maturation rate than that of a dRCF, and a comparable cumulative survival once it is used successfully for dialysis.

Fistula salvage by endovascular therapy

Fistulas are considered superior to synthetic grafts as a hemodialysis vascular access; however, fistulas are not without problems. To maximize the number of fistulas being used in prevalent patients, it is important to have a program designed to salvage early failures or fistulas that fail to mature and those that become dysfunctional during the course of usage. Endovascular techniques have proven to be very effective in the management of both of these problems. These fistulas should be aggressively evaluated and treated because treatment carries with it a high expectation of successful salvage of what would have otherwise been an abandoned access.