Introduction

To evaluate the perioperative, functional, and oncologic outcomes of partial nephrectomy (PN) in renal tumors with concomitant venous tumor thrombosis (VTT) of renal vein branches.

Methods

Data of open, laparoscopic or robotic PN with concomitant VTT removal was collected retrospectively in a multi-center study and compared to radical nephrectomy (RN) performed in the same centers for tumors of comparable diameter and VTT. Demographics, perioperative complications, functional, and oncologic outcomes were compared between the two groups. Mean, median, standard deviation, and interquartile range (IQR) were used to report continuous variables, as appropriate. Survival analysis were used to assess recurrence free survival (RFS), cancer specific survival (CSS) and overall survival (OS). Univariable (UVA) and multivariable (MVA) analyses were used to evaluate variables predicting complications, OS, CSS and RFS, and end-stage renal disease (ESRD, eGFR<30).

Results

Overall, 63 cases and 176 control were enrolled in the study. VTT was unsuspected pre-operatively in 46 (73%) of PN cases. Any grade and high grade postoperative complications were recorded in 41.9% and 22.2% for PN patients, respectively, and in 21.7% and 7.9% for RN patients, respectively (p values <0.05). Once adjusted for covariates, PN was associated with a significantly higher risk of any grade postoperative complications (OR 0.4; p=0.026), whereas only a non-significant trend was identified for high grade complications (OR 0.3; p=0.05). Median follow-up duration of the patients alive and disease free was 26.6 mo (IQR 8.7-39 mo) and 30 mo (IQR 13 - 64 mo) in the PN and RN group, respectively (p=0.5). The two-year RFS, CSS and OS survival estimates were 91.8%, 94.0%, 88.1%, for PN, respectively, and 95.8%, 94.6%, 92.9% for RN, respectively. PN site of recurrence were: local in 3 (4,9%), nodal in 3 (4,9%) and distant in 11 (18%). No differences in RFS, CSS and OS survival estimates were found between PN and RN, both in UVA and MVA analyses, where only the classic pathological variables were independent predictors of RFS, CSS, and OS. Preoperative eGFR was similar in both groups, with roughly 3% of the patients presenting with ESRD at initial diagnosis. At follow-up, eGFR was similar in both groups, whereas the prevalence of ESRD was significantly higher in the PN group (32.7% vs 13.2%, p<0.01). However, in MVA analyses, baseline eGFR was the only independent predictor of ESRD (HR 1.0; p<0.01), whereas only a non-significant trend was identified for the type of surgery (HR 0.5; p=0.07).

Conclusions

PN in tumors with concomitant intraparenchymal vein branches thrombosis is feasible but it is associated with higher risk of complications. RFS, CSS and OS were similar in the two groups. Finally, we found a non-statistically significant trend in favor of PN for ESRD prevention.

Funding

None