ESPN 50th Annual Meeting

ESPN 2017


 
Continuous monitoring of kidney transplant perfusion with near infrared spectroscopy
GEORGIA MALAKASIOTI 2 STEPHEN MARKS 1 TOM WATSON 3 NIZAM MAMODE 4 FARIBA WILLIAMS 3 MARIESA TAYLOR-ALLKINS 3 JUSTIN MORGAN 5 WESLEY HAYES 1

1- DEPARTMENT OF PAEDIATRIC NEPHROLOGY, GREAT ORMOND STREET HOSPITAL FOR CHILDREN & UNIVERSITY COLLEGE LONDON, LONDON, UK
2- DEPARTMENT OF PAEDIATRIC NEPHROLOGY, GREAT ORMOND STREET HOSPITAL FOR CHILDREN, LONDON, UK
3- DEPARTMENT OF PAEDIATRIC RADIOLOGY, GREAT ORMOND STREET HOSPITAL FOR CHILDREN, LONDON, UK
4- DEPARTMENT OF TRANSPLANT SURGERY, GUYS AND ST THOMAS NHS FOUNDATION TRUST, LONDON, UK
5- SOUTHMEAD HOSPITAL BRISTOL, NORTH BRISTOL NHS FOUNDATION TRUST, BRISTOL, UK
 
Introduction:

Current reliance on clinical/ laboratory parameters and doppler ultrasound imaging to detect renal allograft thrombosis results in significant delays in recognizing vascular complications that account for up to 35% of early graft losses in children. Near infrared spectroscopy (NIRS) is a real time, non-invasive technique for monitoring oxygenation percutaneously. Validation of NIRS in real time monitoring of renal allograft perfusion by direct comparison to doppler ultrasound has not been reported. The aim of this pilot study is to determine whether tissue oxygenation indices from NIRS can reliably assess blood flow in established renal transplants.

Material and methods:

 Paediatric renal transplant recipients (pRTRs) aged 1 – 18 years with stable allograft function were eligible. Participants underwent routine outpatient renal transplant ultrasound assessment of perfusion as per protocol including resistive index (RI) calculations at upper, and lower poles. NIRS data (Tissue Oxygenation Index- TOI) were recorded for 2 minutes with two NIRS sensors placed on the skin over the transplant poles as previously marked from ultrasound.

Results:

 Thirteen pRTRs with median age 16 years (range 5.3 to 17.8) and median allograft age 44.7 months (range 6.4 to 148.7) were recruited. Fifty- four percent were male and 69% living donor pRTRs. NIRS monitoring was well tolerated by all participants with a 96- 100% rate of valid measurements. Significant negative correlations were observed between TOI recorded with NIRS, and RI from doppler ultrasound for both upper and lower poles (r= -0.7 for both, p=0.01 and 0.02 respectively). TOI measured with NIRS was a significant predictor of doppler ultrasound RI in adjusted linear regression models for upper and lower pole (p= 0.01 and 0.02 respectively)

Conclusions:

 NIRS indices correlate well with doppler ultrasound graft perfusion parameters in established pRTRs. Further studies are warranted to extend NIRS use for continuous real-time monitoring of early post-transplant vascular complications.