Ultrasound Assessment of Kidney Transplant Blood Flow

Abstract

Renal transplantation is a treatment option for end stage renal failure. It is now also performed in some patients previously unfavourable for transplantation including older patients generally matched with a kidney from older donors, recipients with BMI over 35kg/m2 and recipients with less “well-matched” kidneys. Opportunities for transplantation are limited, due to the lack of suitable donors, so it is most important that outcomes are maximised. Kidney transplantation is a complex surgical procedure and therefore, minimising the risk of early renal transplant graft loss or graft dysfunction is essential.

Early renal transplant graft loss can occur immediately post-operatively and up to day 30,and is caused by technical and surgical issues directly related to the surgery.

Ultrasound is a readily repeatable, non-invasive, reliable investigation, however, knowledge of blood flow in kidney transplants is limited, especially at the time of surgery and in the early peri-operative period.

The aim of this Thesis was to evaluate whether the additional clinical information about transplant blood flow provided by ultrasound improves the outcomes of renal transplantation.

Ultrasound when routinely used intra-operatively, identified surgical or technical complications enabling immediate correction prior to wound closure. The rate of loss of the transplant kidney reduced from the national rate of 1% to zero. Post-operatively, there was demonstrated compression of the renal cortex and deeper vessels from adipose tissue or the weight of the kidney itself, causing reduced perfusion to the kidney. When patients were decubitus or standing the perfusion improved. Data from both studies provided nominal values for transplant blood flow.

In conclusion, routine use of ultrasound provided additional information about kidney transplant blood flow with improved outcomes and avoided graft loss and dysfunction.