A Nomogram Predicts the Need for Internal Iliac Vein Dissection During Renal Transplantation: A Multicenter Collaborative Study

BACKGROUND: Internal iliac vein dissection (IIVD) can be used for optimal venous anastomosis during renal transplantation; however, it poses a massive bleeding risk. No method has been established yet to identify the need for IIVD during renal transplantation. AIM: To develop a preoperative predictive nomogram that assesses IIVD necessity for safe living-donor renal transplantation. METHODS: Data were retrieved from electronic medical records for 523 consecutive living-donor renal transplant cases at 4 institutions between 2009 and 2024. The key preoperative variables included recipient anatomical factors and donor kidney characteristics. Correlations among variables were examined to avoid multicollinearity. Variables were selected using the step-down method of multiple logistic regression. RESULTS: Eight pediatric transplant patients and 15 patients with renal vein venoplasty were excluded; hence, 500 patients were included in the final analysis. Caudal branch of the internal iliac vein, shallowness of the iliopsoas muscle, laterality of the transplanted pelvis, kidney thickness, and laterality of the transplanted kidney were incorporated into a nomogram. The model demonstrated good accuracy (C-index: 0.79). Internal validation via bootstrap resampling yielded an optimism-corrected C-index of 0.79 and a calibration plot with an intercept of 0.03 and a slope of 0.95, indicating no major overfitting. CONCLUSIONS: Our nomogram can assess IIVD necessity and facilitate surgical planning and intraoperative decision-making to ensure safe living-donor kidney transplantation.