Natural history of chronic renal insufficiency after partial and radical nephrectomy

Objectives. To compare the incidence of newly developed chronic renal insufficiency after partial nephrectomy (PN) and radical nephrectomy (RN). Elective PN for renal tumors is intended to preserve renal function; however, studies of transplant donors suggest normal renal function is also maintained after unilateral nephrectomy.

Methods. We retrospectively compared all patients undergoing PN or RN for renal tumors 4 cm or less in the presence of a normal contralateral kidney from 1989 to 2000. Creatinine failure was defined as a serum creatinine value greater than 2.0 mg/dL. Risk factors for renal insufficiency, including diabetes, hypertension, American Society of Anesthesiologists score, age, preoperative creatinine, and history of smoking tobacco, were compared between the two groups. We compared the two groups using the chi-square and Mann-Whitney U tests and the creatinine failure rates using the Kaplan-Meier method.

Results. One hundred seventy-three patients met the criteria for analysis after RN and 117 did so after PN (median follow-up 25 months). The 5-year freedom from recurrence rate was 96.4% and 98.6% for PN and RN, respectively (P >0.05). The mean preoperative serum creatinine was 1.0 mg/dL (range 0.4 to 1.4) and 0.98 (range 0.6 to 1.5) for RN and PN, respectively (P = 0.4, not significant). The incidence of risk factors for renal insufficiency did not differ between the two groups. The mean postoperative serum creatinine in the RN and PN groups was 1.5 mg/dL (range 0.8 to 3.8) and 1.0 mg/dL (range 0.5 to 1.9), respectively (P <0.001). The chance of creatinine failure over time was significantly greater in the RN group (P = 0.008).

Conclusions. When controlled for preoperative risk factors for renal insufficiency, patients undergoing RN are at a greater risk of chronic renal insufficiency than a similar cohort of patients undergoing PN.