"We found that on average, [a] patient went into surgery with a GFR of about 55, and came out with a GFR of about 44," says Steven Campbell, MD, PhD.
In this video, Steven Campbell, MD, PhD, highlights findings from the study, “Functional recovery after partial nephrectomy in a solitary kidney,” which will be presented at the 2023 Annual American Urological Association conference held in Chicago, Illinois. Campbell is a professor of surgery and urology at the Cleveland Clinic in Cleveland, Ohio.
This is a clinical model – this renal mass in a solitary kidney – which is the ideal model for studying functional recovery, because since there is no contralateral kidney there, we get to see the full impact of the ischemia on the recovery of the kidney both short- and long-term. Most of these cases were done as clamped partial nephrectomy with either hypothermia or warm ischemia. A very small number were done with what we call zero ischemia, unclamped partial. What we did in this study was we focused on how much function was being recovered with each one of these cases. We found that on average, the average patient went into surgery with a GFR of about 55, and came out with – after they recovered – a GFR [or] glomerular filtration rate of about 44. So, the average patient lost about 10 or 11 GFR units. Long-term, almost all the patients with that were able to stay off of dialysis.
We further studied this because we know that the most important factor that determines the functional recovery is how much parenchymal mass we save with the case. We found that the amount of parenchymal mass loss during the procedure, between removing the nephrons next to the tumor and reconstructing the kidney, that amount of parenchymal mass loss accounted for 70% of the total loss of function with the procedure. Then we studied secondary factors like ischemia [and] comorbidities. Some of these secondary factors were also correlated with functional recovery, although all together, their impact was much smaller. All together, those secondary factors only accounted for about 30% of the functional loss with the procedure, or only about 3 GFR units.
In the past, when we've studied this, we always have found that the amount of parenchymal volume loss is the most important factor. But in the past, we quite often could not see an impact of the secondary factors. But with this study, we measured the volume with semi automated software, which is much more accurate and subjective. I think what happened was with that in place, we were able to tease out exactly how much parenchymal volume was lost, and we were then able to see the impact of the secondary factors.
This transcription has been edited for clarity.