Thermal Resistance Anastomosis Device for the …

1 CLINICAL STUDYT hermal Resistance Anastomosis Devicefor the percutaneous Creation ofArteriovenous Fistulaefor HemodialysisJeffrey E. Hull, MD, Guillermo Elizondo-Riojas, MD,Wendy Bishop, BHSc, RVT, and Yesenia L. Voneida-Reyna, MDABSTRACTP urpose:To evaluate the safety and efficacy of arteriovenousfistula (AVF) creation with a Thermal Resistance anastomosisdevice (TRAD).Materials and Methods:From January 2014 to March 2015, 26 patients underwent ultrasound (US)-guided percutaneouscreation of proximal radial artery to perforating vein AVFs with a TRAD that uses heat and pressure to create a fusedanastomosis. Primary endpoints werefistula creation, patentfistula by Doppler US, two-needle dialysis at the prescribed rate,and Device -related :Technical success rate offistula creation was 88% (23 of 26).

2 Procedure time averaged minutes (range, 5 34 min),and 96% of anastomoses (22 of 23) were fused. At 6 weeks, 87% of AVFs (20 of 23) were patent, 61% (14 of 23) had 400-mL/minbrachial arteryflow, 1 patient was receiving dialysis, 2fistulae had thrombosed, and 1 patient had died unrelated to the percent (16 of 20), 70% (14 of 20), and 60% (12 of 20) of patients were receiving dialysis at 3, 6, and 12 months; 4 patientsdied, 3fistulae failed, and one patient was lost to follow-up. Overall, 87% of AVFs (20 of 23) had an additional procedure at amean of 56 days (range, 0 239 d), including balloon dilation in 43% (n 10), brachial vein embolization in 26% (n 6), basilicvein ligation in 17% (n 4), venous transposition in 30% (n 7), and valvulotomy in 4% (n 1).

3 There were no majorcomplications related to the : percutaneous AVFs created with a TRAD met the safety endpoints of this study. Midterm follow-up demonstratedintact anastomoses andfistulae suitable for , TRAD= Thermal Resistance Anastomosis deviceThe arteriovenousfistula (AVF) is the preferred accessfor hemodialysis in the United States and throughout theworld (1 3). The predominant method of creating anAVF with a sutured Anastomosis has remained unchan-ged since the original description by Brescia et al in 1966(4). Minimally invasive methods for AVF creation haverecently been developed. A two-catheter electrosurgicalradiofrequency Anastomosis Device that cuts preciselyaligned linear incisions has successfully created ulnarartery to ulnar veinfistulae in the interventional suitewith promising initial results (5).

4 The Thermal resistanceanastomosis Device (TRAD) was designed as a single-catheter venous access system to create percutaneousfis-tulae under ultrasound (US) guidance. This anastomosisdevice uses applied pressure and Thermal resistanceenergy (ie, direct heat) to fuse artery and vein adventitiaFrom the Richmond Vascular Center ( , ), 173 Wadsworth Dr., NorthChesterfield, VA 23236; and Department of Radiology, ( , ),Hospital Universitario, Monterrey, Mexico. Received July 28, 2016;finalrevision received and accepted October 29, ; receives personal fees from and is a stockholder in Avenu Medical (SanJuan Capistrano, California) and has a patent issued for the creation ofarteriovenousfistulae. receives grants and clinical study support fromAvenu Medical.

5 Receives personal fees from Avenu Medical. support for training from Avenu 1is available online , 2016. This is an open access article under the CC BY-NC-ND license( ).J Vasc Interv Radiol 2017; 28:380 387 and then cut an elliptical Anastomosis betweenthe proximal radial artery and perforating vein. Thepresent report prospectively evaluates the initial safety ofthe use of a TRAD in a 6-week study with 12 AND METHODSThe study was a single-arm prospective 6-week evaluation ofthe Ellipsys Vascular Access System (Avenu Medical, SanJuan Capistrano, California) for the creation of AVFs forhemodialysis access ( : NCT02816398).The primary efficacy endpoints were (i)creationofafistulawith the TRAD Device and (ii)fistula patency by DopplerUS examination.

6 The secondary endpoints were brachialarteryflow volume4400 mL/min and/or three sessions oftwo-needle dialysis at the prescribed rate. The safetyendpoints were (i) less than a 50% incidence of minorcomplications and (ii) less than a 1% incidence of majordevice-related complications as defined in vascular accessreporting standards (6,7). Additional complications eval-uated included electrical shock causing tissue injury andsignificant embolization in a previously uninvolved arterialterritory with associated tissue ischemia. Inclusion andexclusion criteria are listed inTable 1. Continued follow-up of the 20 patients with patentfistulae after the initial6-week evaluation was performed by review of dialysisrecords, Doppler US examination results, and additionalprocedures for a period of 12 months or PopulationThe present study complies with Declaration of Helsinkiguidelines for research in human subjects.

7 The initial 6-week protocol and the extended follow-up data collec-tion had regulatory approval from the Federal Commis-sion for the Protection against Health Risks and hospitalinvestigational review board approval. Between January2014 and March 2015, patients eligible for a surgicalfistula were evaluated for the study. Screening resulted in26 of 45 patients being enrolled as meeting inclusioncriteria for the study. All patients enrolled had anassessment of medical history and a physical examina-tion, laboratory studies, and Doppler US examination,and signed informed consent. All patients were Hispanic,38% were male, 62% were female, and all were under-going catheter hemodialysis. Patient demographics aresummarized inTable 2.

8 The pre- and postproceduralDoppler US vein-mapping examination was performedwith a SonoSite M-Turbo linear 5 13-MHz transducer(SonoSite, Bothell, Washington) according to a modifi-cation of the Society of Vascular US guidelines aspreviously described (8).The TRAD consists of three main components: anaccess needle, an over-the-wire tissue fusion and cuttingcatheter, and a power controller. The TRAD catheterhas a 6-F proximal diameter with opposing activesurfaces between the base and the coned 5-F distal tip(Figs 1, 2c). The power controller delivers direct currentto the catheter heating element that is controlled withfeedback from two temperature sensors and a gap sensordetecting the temperature and the opening distance ofthe catheter.

9 A thumb tab in the handle of the devicecontrols the catheter opening and closing and the fusionpressure. The combination of time, temperature, andpressure results in tissue fusion and cutting of anelliptical 1. Inclusion and Exclusion CriteriaInclusion Criteria1. Age418 y ando80 y2. Patients diagnosed with CKD classification stage IV/V3. Adequate quality vein based on preoperative assessmenta. Adjacent vein diameter mm at targetanastomosis siteb. Confirmed adequate outflow quality radial artery based on preoperativeassessmenta. Arterial lumen diameter mm at targetanastomosis site5. Adequate collateral arterial perfusion6. Negative Allen test results for ulnar Criteria1. Pregnancy or patients currently breast feeding2.

10 Diagnosed hypercoagulable state3. Acute or active infection4. Use of immunosuppressive medication5. History of organ transplantation6. Upper-extremity arterial stenosis (420 mm/Hgsystolic BP difference between arms)7. Radial artery adjacent vein mmBP blood pressure; CKD chronic kidney 2. Demographic Characteristics of Study PatientsCharacteristicValueHispanic race26 (100)Sex (M/F)10/16 Age (y) (kg/m2) *7 (27)IDDM11 (42)NIDDM6 (23)Hypertension24 (92)Left armfistula24(93)Previous AVF2 (8)Previous catheter26 (100)Note Values presented as mean standard deviation whereapplicable. Values in parentheses are arteriovenousfistula; BMI body mass index; HTN hypertension; IDDM insulin-dependent diabetes mellitus;NIDDM non insulin-depended diabetes mellitus.