by John R. Ross, MD, and Dion L. Franga, MD

End-stage renal disease (ESRD) affects more than 664,000 patients in the United States.¹ Patients with ESRD face marked, persistent disparities in survival and quality of life compared with the general population, and their treatment incurs an estimated $34.3 billion in US healthcare costs annually.¹

Hemodialysis remains the most common treatment for advanced kidney failure. In 2011, almost 430,000 US patients with ESRD were undergoing dialysis, a 52% increase since 2000.1 Although the Fistula First Breakthrough Initiative has increased the use of autogenous or native arteriovenous (AV) fistulas for hemodialysis, many patients still undergo dialysis through prosthetic hemodialysis AV grafts.2 Forearm or upper arm sites are preferred, with thigh grafts reserved for patients for whom upper-limb options have been exhausted.³ In addition, hemodialysis Reliable Outflow (HeRO) grafts (Hemosphere/CryoLife Inc., Eden Prairie, MN) are used in patients with ESRD and central venous occlusive disease when fistulae or standard grafts are not possible.^4,5 Central venous catheters are used temporarily or as a last resort in patients for whom other options are infeasible.⁶

Stenosis and thrombosis of hemodialysis fistulae and grafts are major barriers to reliable long-term AV access. Prosthetic grafts are especially prone to thrombosis because of the increased risk of intimal hyperplasia with subsequent stenosis.7 In recent decades, percutaneous techniques such as angioplasty, pharmacomechanical thrombolysis, mechanical thrombectomy, and endovascular stenting have gained widespread use for treating thrombosed fistulae and grafts.8 Surgical and percutaneous approaches have comparable rates of technical success and primary patency, but percutaneous techniques have the advantage of conserving native vessel architecture.^8-10

Rotational Thrombectomy

Acute thrombi within grafts tend to be soft and amenable to maceration by means of mechanical thrombectomy, with minimal risk of damaging the vascular endothelium.11 Numerous options for mechanical thrombectomy of grafts and fistulae are available, including rheolytic (hydraulic recirculation) and rotational approaches.^11-13 Rotational thrombectomy has been reported to be significantly more efficient and associated with greater rates of immediate success and secondary patency compared with rheolytic thrombectomy in the treatment of AV thrombosis.¹⁴

The Cleaner™ and Cleaner15^™ Rotational Thrombectomy Systems (Argon Medical Devices Inc., Plano, TX) are single-piece, disposable devices approved for the mechanical declotting of synthetic dialysis access grafts and native vessel dialysis fistulae. Cleaner™ has guide-wire-like construction with a safety locking mechanism designed to optimize maneuverability and safety. Its atraumatic wire tip is S-shaped with a 9-mm amplitude, enabling the sinusoidal wire to conform to various lumen diameters and macerate wall-adherent thrombi around the graft apex and opposing sheath. The drive unit rotates at up to 4,500 rpm. The tip of the outer catheter and sinusoidal wire are radiopaque for fluoroscopic visualization. The 135-cm version of the device has a 3-way sideport and distal side hole to permit infusion of fluids and contrast media.

Cleaner15™ incorporates a larger (0.044 inch) wire and 15 mm amplitude tip to macerate thrombi in larger-diameter grafts and fistulae, and provides increased torque and power for efficient maceration. Cleaner™ was associated with less endothelial damage compared with the Arrow-Trerotola™ PTD (Teleflex, Inc., Research Triangle Park, NC) in a rabbit model.¹⁵

Our Experience

We conducted a single-center evaluation of Cleaner™ and Cleaner15™ devices in hemodialysis patients who underwent rotational thrombectomy of prosthetic polytetrafluoroethylene (PTFE) AV grafts. The study included patients who presented with occluded grafts during a 30-day period in 2013. We defined technical success as the patient’s ability to complete at least one successful hemodialysis session following mechanical declotting with Cleaner™ or Cleaner15™.

Technique

After providing informed consent, patients were taken to the operating room and placed under anesthesia. Sterile technique was used to prep and drape affected extremities. Angioaccess was obtained in AV grafts in both a retrograde and antegrade fashion by means of 7-French short sheaths. The Argon Cleaner™ or Cleaner15™ device was inserted into the antegrade sheath and advanced just beyond the venous anastomosis.

Thrombectomy was then performed under active fluoroscopy. To check for stenoses, we watched for changes in the typical sinusoidal pattern of the tip of the device as the device was slowly withdrawn back to the sheath. Angiography was performed to verify suspected stenoses. Balloon angioplasty was performed if indicated, and the venous limb of the graft was flushed with heparinized saline. Arterial limb embolectomy was then performed through the retrograde sheath and flow was restored through the graft circuit. Decannulation of the AV graft was performed and systemic heparin was administered.

Results

A total of 29 patients with PTFE grafts were treated with the Cleaner™ and Cleaner15™ Rotational Thrombectomy Systems. The median age of patients was 65 years (range, 30-86 years), and 58.6% of patients were female. Graft types included upper arm straight (n=5); upper arm loop (n=11), thigh grafts (n=2), and HeRO (n=11). Duration from detection of clot to intervention ranged from one (41.4%) to two days (17.2%) among the 58.6% of patients for whom this information was available.

Technical success was achieved in 27 of 29 (93%) patients, and median fluoroscopy time was 201.5 seconds. Among the remaining two patients, one was an 86-year-old female with a semi-loop HeRO graft that had completely disintegrated; this damage was unrelated to use of Cleaner™. The graft was removed and a central venous catheter was placed pending graft revision. The second patient, a 59-year-old female with a loop 8-mm x 5-cm hybrid graft, had multiple intravascular and angiographically detected stenoses that precluded successful thrombectomy.

Cleaner™ was used in 28 patients, and Cleaner15™ was used in one patient with a HeRO graft whose case characteristics resembled those of other patients. All procedures involved the venous outflow components; the device was not used in the arterial graft component.

Cleaner™ was the primary thrombectomy device used in 21 (72.4%) patients. The remaining eight patients included six who were successfully treated with Cleaner™ (n=5) or Cleaner15™ (n=1) after treatment with the Angiojet Rheolytic Thrombectomy System™ (Possis Medical, Minneapolis, MN) resulted in residual thrombi. Cleaner™ also was used successfully in a patient after treatment with the Clearway™ RX Therapeutic Infusion Catheter (Atrium Medical Corporation, Hudson, NH). Balloon angioplasty was performed to treat stenoses in 22 (75.9%) patients. Thrombolytic agents were not used, and we identified no adverse outcomes related to the use of Cleaner™ or Cleaner15™.

Conclusion

Ensuring long-term hemodialysis access remains a major clinical problem in the management of patients with ESRD. Recurrent thrombosis threatens reliable, long-term AV access and is especially prevalent in patients with risk factors such as specific inherited polymorphisms, obesity, diabetes, older age and hypertension.^16,17 Patients with grafts are at particular risk for thrombosis secondary to stenosis, which, if left unaddressed, can trigger the development of a recurrent clotting cycle.⁷

We found that Cleaner™ and Cleaner15™ were safe, efficient, and effective for mechanical thrombectomy of prosthetic hemodialysis AV grafts, including loop grafts, grafts in elderly patients, and grafts occluded by large, resistant clots. Median fluoroscopy time was approximately 3.3 minutes, the rate of technical success was 96.5% for patients with intact grafts, and we detected no complications related to the use of Cleaner™. We used Cleaner™ successfully both as the primary device and as a secondary device after rheolytic thrombectomy resulted in residual or hanging clots. We did not observe residual or hanging clots after use of Cleaner™ or Cleaner15™. In addition, we used Cleaner™ to identify regions of stenosis by watching for changes in the normal sinusoidal pattern of the tip of the device during fluoroscopy. The rotational pattern elongated in stenotic regions, enabling us to predict the need for balloon angioplasty even prior to angiography

Cases involved the venous outflow system, reflecting previous reports that 80% of graft stenoses involve the venous anastomosis or the venous outlet.⁷ It is also important to note that the manufacturer of HeRO grafts does not recommend use of mechanical thrombectomy devices with wall contact because of concerns about damaging the venous outflow component and connector.¹⁸ Cleaner™ and Cleaner15™ are wall contact devices, but we successfully used them to thrombectomize all 11 HeRO grafts attempted, with no subsequent complications.

In summary, our research demonstrated that rotational thrombectomy with Cleaner™ and Cleaner15™ was feasible in patients with prosthetic hemodialysis AV grafts, including patients with substantial thrombi that did not respond to other conventional thrombectomy approaches. We recommend further research to confirm these findings, evaluate the long-term patency of PTFE grafts after thrombectomy with Cleaner™, and compare the efficacy and efficiency of Cleaner™ with that of other thrombectomy devices.

Acknowledgments: The authors thank Dr. Amy Karon for her contributions to this manuscript.

John R. Ross, MD, is the Medical Director of the Dialysis Access Institute at the Regional Medical Center in Orangeburg, South Carolina. He has disclosed that he receives research funding from Argon Medical Devices, Inc. Dr. Ross may be reached at (803) 533-7544; [email protected].

Dion L. Franga, MD, is with the Dialysis Access Institute at the Regional Medical Center in Orangeburg, South Carolina. He has disclosed that he receives research funding from Access Connections, LLC.

*The product referred to as Cleaner in this article includes the Cleaner Rotational Thrombectomy System and Cleaner15 Rotational Thrombectomy System.

1. U.S. Renal Data System. USRDS 2013 annual data report: atlas of end-stage renal disease in the United States. National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD (2013)
2. Vassalotti JA, Jennings WC, Beathard GA, et al. Fistula first breakthrough initiative: targeting catheter last in fistula first. Semin Dial. 2012;25:303-310.
3. Ong S, Barker-Finkel J, Allon M. Long-term outcomes of arteriovenous thigh grafts in hemodialysis patients: a comparison with tunneled dialysis catheters. Clin J Am Soc Nephrol. 2013;8:804-809.
4. Gage SM, Katzman HE, Ross JR, et al. Multi-center experience of 164 consecutive Hemodialysis Reliable Outflow [HeRO] graft implants for hemodialysis treatment. Eur J Vasc Endovasc Surg. 2012;44:93-99.
5. Steerman SN, Wagner J, Higgins JA, et al. Outcomes comparison of HeRO and lower extremity arteriovenous grafts in patients with long-standing renal failure. J Vasc Surg. 2013;57:776-783.
6. Schmidt RJ, Goldman RS, Germain M. Pursuing permanent hemodialysis vascular access in patients with a poor prognosis: juxtaposing potential benefit and harm. Am J Kidney Dis. 2012;60:1023-1031.
7. Maya I D, Oser R, Saddekni S, et al. Vascular access stenosis: comparison of arteriovenous grafts and fistulas. Am J Kidney Dis. 2004;44:859–865.
8. Van Ha T. Percutaneous management of thrombosed dialysis access grafts. Semin Intervent Radiol. 2004;21:77-81.
9. Bush RL, Lin PH, Lumsden AB. Management of thrombosed dialysis access: thrombectomy versus thrombolysis. Semin Vasc Surg. 2004;17:32-39.
10. Vesely TM, Williams D, Weiss M, et al. Comparison of the angiojet rheolytic catheter to surgical thrombectomy for the treatment of thrombosed hemodialysis grafts. Peripheral AngioJet Clinical Trial. J Vasc Interv Radiol. 1999;10:1195-1205.
11. Vesely TM. Mechanical thrombectomy devices to treat thrombosed hemodialysis grafts. Tech Vasc Interv Radiol. 2003;6:35-41.
12. Littler P, Cullen N, Gould D, et al. AngioJet thrombectomy for occluded dialysis fistulae: outcome data. Cardiovasc Intervent Radiol. 2009;32:265-270.
13. Horsch AD, van Oostayen J, Zeebregts CJ, et al. The Rotarex® and Aspirex® mechanical thrombectomy devices. Surg Technol Int. 2009;18:185-192.
14. Yang CC, Yang CW, Wen SC, et al. Comparisons of clinical outcomes for thrombectomy devices with different mechanisms in hemodialysis arteriovenous fistulas. Catheter Cardiovasc Interv. 2012;80:1035-1041.
15. Vega, F. Safety comparison of CleanerTM Rotational Thrombectomy System versus Arrow PTDTM in native vessel. San Carlos, CA: Isis Services, LLC; 2010.
16. Gagliardi GM, Mancuso D, Falbo E, et al. Anthropometric parameters of nutritional assessment as predictive factors of arteriovenous fistula malfunction in patients undergoing hemodialysis. J Vasc Access. 2012;13:475-481.
17. Montagnana M, Meschi T, Borghi L, et al. Thrombosis and occlusion of vascular access in hemodialyzed patients. Semin Thromb Hemost. 2011;37:946-954.
18. Hero Graft. Thrombectomy guidelines. Available at: http://www.herograft.com/thrombectomyguidelines/Accessed December 26, 2013.