Transplant Trial Watch

Exploring the Role of an Implantable Doppler Probe as a Blood Flow-Monitoring Device in Kidney Transplant: A Feasibility Randomized Controlled Trial.

Malik, M. S., et al.

Experimental & Clinical Transplantation: Official Journal of the Middle East Society for Organ Transplantation 2023; 21(11): 860-867.

The aim of this study was to examine whether it was feasible to use an implantable Doppler probe for monitoring blood flow in renal transplant recipients, and assess its effectiveness in preventing early graft loss.

Participants were randomised to either receive an implantable Doppler probe monitoring device or to receive standard care.

60 kidney transplant recipients.

The main surgical outcomes of interest were early vascular complications; departmental ultrasonogram scans requested in the first 24, 48, and 72 hours postoperation; and grafts lost due to vascular complications.

72 hours

CET Conclusions
This single-centre randomised study investigated the feasibility of a trial using an implantable doppler probe to monitor renal artery flow following renal transplantation. 30 transplants were included in each arm of the study. The study is well designed and well described, and the authors succeed in showing the feasibility of their study protocol and the use of the doppler device in a clinical trial setting. The aim of the study was not to demonstrate clinical benefit, and indeed the sample size is too small to demonstrate a difference in a rare outcome such as thrombosis. No statistical analyses are undertaken to compare groups. There were two graft losses in the control group due to EIA dissection – it is not clear how early these were and whether they would have been detected by use of the doppler. It does not appear that any patients in the study group had a complication detected by use of the doppler probe. The authors report that there were fewer early (<24h) ultrasound scans in the doppler group, although overall ultrasound rates remain the same suggesting that use of a doppler may reduce the urgency, rather than frequency of post-operative ultrasound. Ultimately the study shows feasibility, but a larger study would be required to demonstrate any potential clinical benefit.

Jadad score

Data analysis
Strict intention-to-treat analysis

Allocation concealment

Trial registration - NCT05634863

Funding source
No funding received