DOI: 10.1097/mph.0000000000003264 ISSN: 1077-4114

Beyond Tumor Size: Hilar-to-Central Vessel Distance as a Complementary Safety Metric for Laparoscopic Nephrectomy in Wilms Tumor

Bianca R. Rosa, Rodrigo C. Ribeiro, Mauricio G. Ieiri Yamanari, Fernanda M. Pereira Souza, Carlos E. Bezerra Cavalcante, Raniela F. Faria, Leticia Semissato dos Santos, Wilson Elias de Oliveira Junior

Background:

Laparoscopic nephrectomy for Wilms tumor remains controversial despite growing evidence supporting its feasibility. This study analyzed surgical and oncological outcomes according to the SIOP criteria and evaluated the hilar-to-central vessel distance as a potential selection parameter.

Methods:

Retrospective analysis of 50 children with unilateral Wilms tumor treated between 2014 and 2020. Patients underwent open (ON=38) or laparoscopic (LN=12) nephrectomy following SIOP protocols. Laparoscopic selection required: tumor confined to the kidney, not crossing vertebral border, no venous thrombus, volume ≤300 mL, and adequate chemotherapy response. CT/MRI measurements included tumor volume and the distance between the hilar vessels and the aorta/vena cava. Outcomes included operative time, complications (Clavien-Dindo classification), conversion rate, lymph node yield, recurrence, and survival.

Results:

Groups differed significantly in staging (stage I: LN 83.3% vs. ON 26.3%, P =0.003). Mean tumor volume after chemotherapy was lower in the LN group (87.81 vs. 394.72 cm 3 , P <0.001). Hilar-to-central vessel distance after chemotherapy was greater in the LN group (10.83 vs. 5.42 mm, P =0.005). Conversion rate was 16.7% (2/12) due to bleeding. No intraoperative tumor spillage occurred in the LN group, compared with 3 in the ON group. Postoperative complications occurred only in the ON group (4/38, 10.5%). Average LOS was 2.42 days (LN) versus 4.53 days (ON). Five-year event-free survival was 91.7% (LN) and 84.2% (ON).

Conclusion:

Laparoscopic nephrectomy for carefully selected Wilms tumor patients treated according to SIOP protocols demonstrated favorable perioperative outcomes consistent with appropriate patient selection. The hilar-to-central vessel distance showed statistical association with surgical approach at the group level, but did not discriminate conversion risk at the individual level. Integration of this metric should be studied as a potential adjunct to comprehensive assessment by experienced surgical teams, with prospective multicenter validation required before clinical implementation.

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