Association between additional operation timing and perioperative outcomes after noncurative endoscopic submucosal dissection for early gastric cancer.

Abstract

To evaluate the impact of noncurative endoscopic submucosal dissection on additional operation and to explore the optimal timing of additional operation. This retrospective study included patients with early gastric cancer, comprising 135 patients who underwent an additional operation after noncurative endoscopic submucosal dissection (additional-operation group) and 582 patients who underwent primary gastrectomy (operation-only group). Within the additional-operation cohort, the association between the time from endoscopic submucosal dissection to additional operation (in days) and intraoperative outcomes was assessed using restricted cubic spline regression, and the onset of plateau was identified using a prespecified slope-based criterion. For exploratory and clinical interpretability, patients were categorized into an earlier-operation group (≤35 days, n = 67) and a late-operation group (>35 days, n = 68). Compared with the operation-only group, the additional-operation group had a longer operation time (240.74 ± 60.44 vs 226.43 ± 57.34 min; P = .010), greater blood loss (59.33 ± 26.24 vs 39.15 ± 18.43 mL; P < .001), and higher rates of postoperative inflammatory marker abnormalities. Restricted cubic spline analyses demonstrated a significant nonlinear relationship between this interval and both operation time and blood loss, with an evident plateau at approximately 35 days. The earlier-operation group had a longer operation time (252.69 ± 64.20 vs 228.97 ± 54.43 min; P = .022) and greater blood loss (72.84 ± 26.79 vs 45.88 ± 17.38 mL; P < .001) than the late-operation group. Additional operation after noncurative endoscopic submucosal dissection was associated with greater intraoperative burden. Performing additional operations more than approximately 35 days after endoscopic submucosal dissection may reduce operation time and blood loss.