Renal function after partial nephrectomy: effect of warm ischemia relative to quantity and quality of preserved kidney.
OBJECTIVE
To evaluate the effects of warm ischemia time (WIT) and quantity and quality of kidney preserved on renal functional recovery after partial nephrectomy (PN). The effect of WIT relative to these other parameters has recently been challenged.


METHODS
We identified 362 consecutive patients with a solitary kidney who had undergone PN using warm ischemia. Multivariate models with multiple imputations were used to evaluate the associations with acute renal failure and new-onset stage IV chronic kidney disease (CKD).


RESULTS
The median WIT was 21 minutes (range 4-55), the median percentage of kidney preserved was 80% (range 25%-98%), and the median preoperative glomerular filtration rate (GFR) was 61 mL/min/1.73 m2 (range 11-133). Postoperative acute renal failure occurred in 70 patients (19%). Of the 226 patients with a preoperative GFR>30 mL/min/1.73 m2, 38 (17%) developed new-onset stage IV CKD during follow-up. On multivariate analysis, the WIT (P=.021), percentage of kidney preserved (P=.009), and preoperative GFR (P<.001) were significantly associated with acute renal failure, and only the percentage of kidney preserved (P<.001) and preoperative GFR (P<.001) were significantly associated with new-onset stage IV CKD during follow-up. Using our previously published cutpoint of 25 minutes, a WIT of >25 minutes remained significantly associated with new-onset stage IV CKD in a multivariate analysis adjusting for the quantity and quality factors (hazard ratio 2.27, P=.049).


CONCLUSIONS
Our results have validated that the quality and quantity of kidney are the most important determinants of renal function after PN. In addition, we have also demonstrated that the WIT remains an important modifiable feature associated with short- and long-term renal function. The precision of surgery, maximizing the amount of preserved, vascularized parenchyma, should be a focus of study for optimizing the PN procedure.
Mayo Medical School and Mayo Clinic, Rochester, Minnesota, USA.
R Houston
RH
Thompson
Brian R
BR
Lane
Christine M
CM
Lohse
Bradley C
BC
Leibovich
Amr
A
Fergany
Igor
I
Frank
Inderbir S
IS
Gill
Michael L
ML
Blute
Steven C
SC
Campbell
D058186:Acute Kidney Injury / Q000453:epidemiology / Q000503:physiopathology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007668:Kidney / Q000503:physiopathology*; D007674:Kidney Diseases / Q000453:epidemiology / Q000503:physiopathology*; D007680:Kidney Neoplasms / Q000601:surgery; D010535:Laparoscopy / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D009392:Nephrectomy / Q000379:methods* / Q000706:statistics & numerical data; D011183:Postoperative Complications / Q000453:epidemiology / Q000503:physiopathology*; D052096:Warm Ischemia / Q000009:adverse effects*; D055815:Young Adult