Objective  To assess the role of the arterial based complexity (ABC) scoring system in predicting clinically relevant outcomes of minimally invasive partial nephrectomy (MIPN).

  Methods  A retrospective review of 161 renal cell carcinoma patients who underwent MIPN at Tianjin Medical University Cancer Institute and Hospital from June 2016 to January 2018 was performed. The ABC score, including grades 1, 2, 3S, and 3H, were based on the patients' enhanced preoperative abdominal CT images. The reproducibility of the ABC scoring system was evaluated, and the relationship between the ABC score and patients' pathological features, surgery-related variables, postoperative complications, and renal function was analyzed.

  Results  Patients in grades 1, 2, 3S, and 3H in this study accounted for 20.5% (33/161), 60.2% (97/161), 11.8% (19/161), and 7.5% (12/161), respectively. The average Kappa value of the physician's score was 0.523, and the average exact match percentage was 70.2%. The ABC score was significantly associated with operative time, warm ischemia time (WIT), estimated blood loss (EBL), and tumor size (P < 0.001 for all) and was not associated with postoperative hospital stay, postoperative complications, preoperative estimated glomerular filtration rate (eGFR), and eGFR at 3 and 6 months postoperatively (P>0.05 for both).

  Conclusions  The ABC score is a scoring system with good repeatability and has certain predictive significance for the complexity of MIPN. However, further research is needed for its clinical application.