Continuous Monitoring of Kidney Transplant Perfusion Using Near Infra-red Spectroscopy

Kidney transplant thrombosis (loss of blood flow) is responsible for up to 35% transplant failures in children. Detection of kidney transplant thrombosis currently relies on recognition of deterioration in parameters such as urine output and blood creatinine levels, which change relatively slowly. Confirmation is then required with an ultrasound scan. There is inherent delay in the above process, during which time some or all of the transplant kidney tissue can die, which can result in failure of the transplant.

Near infrared spectroscopy (NIRS) is a non-invasive technique used in continuous monitoring of oxygen levels in several organ systems including the brain, muscles, gut, liver and native kidneys. We hypothesise that NIRS can be applied to monitor kidney transplant blood flow in real time.

We aim to test the use of NIRS in detecting blood flow in established kidney transplants in children, and to compare it with ultrasound, the current gold standard measurement. Existing NIRS equipment would be used within its CE marked purpose measuring oxygen levels; this mechanistic study would extrapolate measured oxygen levels to determine blood flow. Participating children attending outpatient clinic for routine transplant ultrasound scans will have NIRs monitoring for a 10 minute period. NIRs data will be compared to a validated perfusion score from ultrasound images.

If this study is successful, NIRS could provide continuous monitoring of kidney transplant blood flow in the postoperative period, thus allowing immediate detection of blood flow problems. This has potential to reduce kidney transplant failures from thrombosis.