Intraoperative conversion from partial to radical nephrectomy at a single institution from 2003 to 2008.

PURPOSE

Little information exists on conversion from partial to radical nephrectomy. We assessed the intraoperative reasons and predictive factors for conversion in a contemporary series of patients undergoing partial nephrectomy.

MATERIALS AND METHODS

We identified all patients at our institution who underwent open or laparoscopic partial nephrectomy with conversion to radical nephrectomy between 2003 and 2008. Renal function was assessed by the glomerular filtration rate using the modification of diet in renal disease equation. We used logistic regression analysis to determine whether tumor site, tumor size, body mass index, American Society of Anesthesiologists score, age or gender was associated with the conversion risk.

RESULTS

The rate of conversion to radical nephrectomy was 6% (61 of 1,029 patients). In the open partial nephrectomy group 59 of 865 cases (7%, 95% CI 5-9) and in the laparoscopic partial nephrectomy group 2 of 164 (1.2%, 95% CI 0.01-4) were converted. The most common reasons for conversion were invasion of hilar structures, size discrepancy and insufficient residual kidney. Patients with conversion were more likely to have larger tumors (per 1 cm increase OR 1.41, 95% CI 1.24-1.59), a central site (central vs peripheral OR 7.74, 95% CI 3.98-15) and a lower preoperative glomerular filtration rate (per 10 ml/minute/1.73 m(2) OR 0.78, 95% CI 0.67-0.91), and present with symptoms (any vs none OR 2.78, 95% CI 1.54-5.04) than those without conversion. The median postoperative glomerular filtration rate was 46 vs 61 ml/minute/1.73 m(2) in patients with vs without conversion.

CONCLUSIONS

Conversion to radical nephrectomy was rare in patients undergoing partial nephrectomy in this series. Increasing tumor size, central site, lower preoperative glomerular filtration rate and symptoms at presentation were associated with an increased risk of conversion, which increases the likelihood of chronic kidney disease postoperatively.