The PINCH Study:
Supervised preoperative forearm exercise to increase blood vessel diameter in patients that require an arteriovenous access for hemodialysis

Background: Failure of maturation occurs in 30-50% of creation of AV fistulas for hemodialysis, with highest rates in distal radiocephalic fistulas. This can partially be attributed to initial small blood vessel size with limited blood flow capacity. Forearm exercise has shown potential as stimulus for increasing blood vessel size in patients with end-stage renal disease (ESRD) and may promote maturation of AVFs in the upper limb when applied postoperatively. However, it is presently unknown if forearm exercise increases blood vessel size pre-operatively, which may facilitate more distal AVF creation, and might raise success rates of AVF surgery. This study will investigate these issues.
Methods and results: The PINCH trial is an investigator-initiated, multi-centre, single-blinded randomized controlled trial with 1:1 randomization to perform supervised fore-arm exercises, or no exercise 6 weeks pre-operatively before creation of an AVF. 40 patients receiving an AVF will be included. The main study parameters/endpoints are blood vessel diameter (cephalic or basilic vein and radial and ulnar artery), AVF surgical plan (radiocephalic or brachiobasilic/-cephalic), and three-month (assisted) maturation rate. The burden of the performed fore-arm exercises will be evaluated using Quality of life (KDQOL-SF Dutch version 1.2 ) and exercise specific questionnaires. The PINCH trial will start in June 2017. Enrolment is expected to be completed after two years.

Conclusions: The PINCH study is the first trial to evaluate the effect of pre-operative, supervised forearm exercises on vein diameter and fistula maturation in hemodialysis patients

pre-operative, supervised forearm exercises have a positive influence on vein diameter and therefore might improve fistula maturation in hemodialysis patients

finalisation handgrip trainer coupled e-device may 2017

first inclusion: june 2017

ending enrollment: 2019

Participants will receive a daily program of structured forearm exercises for the arm that is planned for surgery. At home training program adherence is
stimulated and monitored for efficacy and frequency by validated e-devices coupled to a handgrip traìner. Moreover, patients are expected to attend focused physiotherapy group sessions once a week. After six weeks, an additional Duplex ultrasound examination will be executed to compare blood vessel diameters. After the operation, patients are followed up
according to regular protocol. The control group does not undergo forearm exercise prior to AVF surgery, as is standard practice to date. During the study period, all participants will be
asked to fill in the e-questionnaires about quality of life, burden of disease and (study)
treatment, and forearm exercises apart from the study protocol.