Interview with Dr Greg Nowak

Greg Nowak, MD, PhD

Associate Professor of Transplantation Surgery
Karolinska Institutet
Department for Clinical Science,
Intervention and Technology CLINTEC

Division of Transplantation Surgery
Karolinska University Hospital Huddinge B56
141 86 Stockholm, Sweden

What year and how did you start using microdialysis?
– I started to use microdialysis in 1999 for experimental setting of monitoring the liver graft during transplantation procedure in a pig liver transplantation model. In year 2002 we used microdialysis for the first time in a liver transplanted patient. At that time we monitored the liver graft for three days after the transplantation.

How many liver transplantations do you conduct every year in your hospital?
– Each year we perform around 60 liver transplantations including whole organs, split, domino and living related liver transplantations.

In total how many patients have you monitored with microdialysis?
– Up until today we have used intrahepatic microdialysis monitoring in 56 liver transplanted patients.

Do you treat your patients based on the Microdialysis results and what metabolic pattern and threshold values are of interest after liver transplantation?
– Right now we have an on going multicentre study on using microdialysis in detection of early graft rejection. The study is observational and no therapeutic intervention is planned. I hope that after completing the study, results will confirm our previous observations and we will start treatment protocol based on changes measured with microdialysis. For example, increase in intrahepatic lactate/pyruvate ratio would make us perform additional examinations for diagnosis of the hepatic artery thrombosis; increasing intrahepatic glycerol will make us increase standard immunosupression to high recommended level, etc.

Do you consider Microdialysis monitoring following liver transplantation feasible in a clinical routine setting?
Yes, microdialysis monitoring is of clinical use. Our experience shows that it is feasible for clinical routine use. The microdialysis method permits early identification of primary graft dysfunction or delayed graft function. It also permits detection of early phase of liver graft rejection and vascular complications.

– The method is feasible to use in both children and adults who have received liver transplants. The method is safe for the patient and doesn’t cause any major disturbances to the patient.

How do you see the future use of Microdialysis within Transplant Surgery?
I think there are two major directions for use of microdialysis in transplantation surgery.

1.  To use microdialysis as a tool for evaluation of the organ quality already in the donor and prior transplantation during preservation time.

2. To use microdialysis in posttransplant monitoring of transplanted organ. In my opinion microdialysis will still be used to detect posttransplant vascular complications but the main role of microdialysis is to monitor graft rejection.

– Thanks to microdialysis we will be able to individualize immunosupression protocol for each patient based on monitoring of the effect of used immunosupression on the graft. In the future one will also have to identify more specific and sensitive molecules for monitoring the organs in specific situations. However, the future for microdialysis in transplantation surgery has already started.