Abstract
Background:
Partial nephrectomy (PN) has been the main strategy for treating cT1 (≤ 7cm) renal tumors. Previous studies have established PN's safety and effectiveness over radical nephrectomy (RN) for cT1 tumors. However, the efficacy and safety of retroperitoneal PN for larger renal tumors (> 7cm) remained controversial. Through a size-based comparative analysis of cT1 and cT2 tumors undergoing retroperitoneal PN, we explored the impact of renal tumors larger than 7cm on perioperative, oncological, and functional outcomes.
Materials and Methods:
From January 2017 to April 2021, we collected data from 201 patients undergoing retroperitoneal laparoscopic or robot-assisted PN. Of these, 173 (86.1%) had tumors ≤ 7 cm (Group A) and 28 (13.9%) had tumors > 7 cm (Group B). We analyzed demographics (gender, age, Body Mass Index, Charlson Comorbidity Index, preoperative hemoglobin and renal function, tumor location, operative method, RENAL score, and complexity), perioperative (operative time, warm ischemic time, estimated blood loss, hospital stay, surgical margins, complications), and functional outcomes (changes in renal function pre- and postoperatively), along with recurrence rates.
Results:
Mean tumor sizes in Group A and Group B were 3.67 ± 1.56 cm and 9.90 ± 2.97 cm, respectively. RENAL score analysis revealed a significant difference (7.64 vs. 9.21, P < 0.0001), attributed to the Radius and Exophytic/Endophytic property parameters. Furthermore, Group B exhibited significantly higher tumor complexity(P = 0.0009). In perioperative outcomes, Group B had a prolonged warm ischemic time (18.90 vs 22.60 min, P = 0.0486). However, there was no significant difference in estimated blood loss and complication rates. Regarding functional outcomes, only the reduction of estimated glomerular filtration rate on postoperative day 1 was significant (-0.74 vs -8.31, p = 0.016), with no significant differences at 3 months, 6 months, or 1 year postoperatively.
Conclusion:
Retroperitoneal PN for cT2 tumors achieves similar oncological outcomes and long-term renal function preservation for cT1 tumors. Additionally, despite managing larger sizes and higher complexity in cT2 tumors, retroperitoneal PN provided a non-inferior complication rate. Given its effectiveness, safety, and functional preservation, retroperitoneal PN has the potential to be the preferred option for renal tumors larger than 7cm.