Comparative outcomes of retroperitoneal partial nephrectomy for cT1 and cT2 renal tumors: a single-center experience.

BACKGROUND

Partial nephrectomy (PN) has been the main strategy for treating cT1 (≤ 7 cm) 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 (> 7 cm) 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 7 cm 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. For eGFR changes over time in Group B, declines at postoperative month 3 and postoperative year 1 were noted.

CONCLUSION

Despite higher preoperative RENAL scores and prolonged perioperative warm ischemic time, retroperitoneal PN for tumors > 7 cm demonstrated acceptable functional, oncological, and perioperative outcomes, with no observed gastrointestinal complications. Our findings support its feasibility as a treatment option for patients with > 7 cm or intermediate/high complexity renal tumors.