Randomized trial of thulium laser-assisted tumor bed coagulation versus conventional suture renorrhaphy in laparoscopic partial nephrectomy: impact on perioperative outcomes and fibrosis biomarker response

This study aimed to determine whether thulium laser–assisted tumor bed hemostasis could provide effective bleeding control comparable to conventional suture renorrhaphy while minimizing ischemic exposure, parenchymal trauma, and profibrotic response. Specifically, we compared perioperative outcomes, renal functional preservation, and urinary fibrosis biomarker profiles between the two techniques during laparoscopic partial nephrectomy (LPN). In this prospective randomized trial (March 2024–September 2025), 48 patients with clinical T1 renal masses and a normal contralateral kidney were assigned to thulium laser-assisted LPN (LLPN) or conventional LPN (CLPN). In LLPN, tumor bed hemostasis was achieved with a 2-μm continuous thulium laser followed by cortical closure, while CLPN employed standard medullary and cortical renorrhaphy. Perioperative outcomes, renal function (estimated glomerular filtration rate, eGFR), and urinary fibrosis biomarkers (transforming growth factor-β1 [TGF-β1], monocyte chemoattractant protein-1 [MCP-1]) were assessed preoperatively and on postoperative day 1, and at 1 and 3 months. Forty-three patients (LLPN 23, CLPN 20) were analyzed. Operative time and warm ischemia time were shorter in LLPN than CLPN (95 vs. 121 min, p = 0.001; 13 vs. 17 min, p = 0.037). LLPN required fewer sutures (8 vs. 14, p < 0.001) and resulted in lower blood loss (150 vs. 300 mL, p < 0.001). All complications were low-grade and comparable. eGFR declined significantly in both groups, with partial recovery in LLPN but not CLPN; between-group differences were not significant. Urinary TGF-β1 and MCP-1 increased postoperatively in both groups but were consistently lower in LLPN at all time points (p < 0.05). Thulium laser coagulation during LPN reduces ischemia, blood loss, and suture requirement without compromising safety or short-term renal function. The attenuated rise in fibrosis biomarkers suggests a potential long-term nephron-sparing advantage. The study was registered on ClinicalTrials.gov (Identifier: NCT06322745, registered March 14, 2024).