The impact of robotic technology on the learning curve for robot-assisted gastrectomy in the initial clinical application stage.

OBJECTIVE To evaluate the impact of robotic technology on the learning curve for robot-assisted gastrectomy in the initial clinical application stage and to compare RAG with laparoscopic-assisted gastrectomy using a short-term evaluation. METHODS Between September 2016 and December 2018, 111 consecutive distal gastric cancer patients who were candidates for RAG or LAG were prospectively enrolled. Operative findings, morbidity, oncological findings, and the learning curve were analyzed. RESULTS Thirty patients underwent RAG with the da Vinci Si robot system, and eighty-one patients underwent LAG. Blood loss was lower during RAG than during LAG (133.80 ± 95.28 vs. 178.83 ± 98.37, P = 0.046). The operative time for RAG was significantly longer (304.45 ± 42.08 vs. 281.17 ± 32.69, P = 0.015). The number of retrieved lymph nodes (LNs) was greater (37.33 ± 8.25 vs. 32.78 ± 5.98, P = 0.003) with RAG. Notably, RAG had an advantage in the dissection of No. 9 and 11p LNs (3.56 ± 1.76 vs. 2.78 ± 1.30, P = 0.038; 2.48 ± 0.93 vs. 1.99 ± 0.84, P = 0.015, respectively). Severe complications were less frequent in the RAG group (7 (8.6%) vs. 1 (3.3%), P = 0.003). No significant differences in terms of postoperative recovery were found between the two groups. The learning curve for RAG showed that the cumulative sum value decreased from the 10th case, while it decreased from the 28th case in the LAG group. CONCLUSION By means of robotic technology, RAG is better than LAG for the dissection of No. 9 and 11p LNs and for the alleviation of surgical trauma, and the technique is learned more rapidly during the preliminary stage than the LAG technique.