Feasibility and necessity of the fourth arm of the da Vinci Si surgical system for robot‐assisted partial nephrectomy

BACKGROUND: To investigate the feasibility of the fourth arm of the da Vinci Si system for robot-assisted partial nephrectomy (RAPN). METHODS: Fifty-eight consecutive patients underwent RAPN with the same port placements. After reviewing the surgical videos and records, 38 patients showing usefulness of the fourth arm were categorized into Group A and those not showing usefulness into Group B. The background data, tumor characteristics, and perioperative outcomes were compared between the groups. RESULTS: Group B had a larger proportion of tumors located on the inner side of the kidney, and the console time was significantly longer. Multivariable logistic regression analysis showed that tumors located on the inner side of the kidney were associated with the non-use of the fourth arm of the da Vinci Si system during RAPN. CONCLUSIONS: Our findings suggested that use of fourth arm in RAPN by da Vinci Si should be considered for each tumor location.