Prognostic significance of collateral vessels detected by preoperative computed tomography in renal tumors: association with surgical, pathological, and radiological parameters

The aim of this study was to evaluate the association between the presence of collateral vessels identified on preoperative computed tomography (CT) scans and tumor biology, surgical complexity, and prognostic parameters in renal cell carcinoma. In this retrospective study, 128 patients who underwent partial or radical nephrectomy for renal cell carcinoma between January 2019 and November 2024 were analyzed. Preoperative contrast-enhanced CT images were evaluated for the presence, number, and diameter of collateral vessels. Patients were compared regarding clinical, surgical, radiological, and pathological parameters, as well as nephrometry and prognostic scoring systems. Appropriate parametric and non-parametric tests and logistic regression analysis were used, including T-stage-adjusted regression models, with p < 0.05 considered statistically significant. Collateral vessels were detected in 48.4% of patients and were significantly associated with larger tumor size and volume, irregular tumor margins, advanced T stage, and high nuclear grade (all p < 0.001). Patients with collateral vessels were more symptomatic, with hematuria and flank pain being more frequent ( p < 0.001). This group also had higher rates of radical nephrectomy and open surgery ( p < 0.001 and p = 0.001, respectively), as well as greater postoperative hemoglobin decrease and complication rates ( p < 0.001 and p = 0.016, respectively). Additionally, lymphovascular invasion ( p < 0.001), perineural invasion ( p = 0.002), and tumor necrosis ( p < 0.001) were more common. Nephrometry (RENAL, PADUA), MAP, SSIGN, and UISS scores were significantly higher in patients with collateral vessels (all p < 0.001); the E-PASS comprehensive risk score was also higher in this group ( p = 0.022). After adjustment for pathological T stage, collateral vessel presence was not independently associated with these outcomes, whereas, among collateral vessel-positive patients, vessel diameter remained associated with RENAL and PADUA scores, tumor size, SSIGN score, and resection extent, but not with perioperative morbidity. Collateral vessel presence was strongly associated with tumor stage and burden, surgical complexity, and prognostic scores, but these associations were largely explained by T stage, and presence provided no independent surgical or prognostic information in this cohort. Among collateral vessel-positive patients, vessel diameter may be a more informative parameter of anatomical tumor complexity and warrants prospective validation.