[Study on the impact of ultrasound-guided bedside hyperthermic intraperitoneal chemotherapy after laparoscopic gastric cancer surgery on the prognosis of patients with positive peritoneal lavage fluid cytology].

<b>Objective:</b> To investigate the impact of bedside ultrasound-guided hyperthermic intraperitoneal chemotherapy (HIPEC) after laparoscopic gastric cancer surgery on the prognosis of patients with only positive peritoneal lavage cytology (CY+) and no other distant metastases. <b>Methods:</b> The clinicopathological data of 49 patients with only positive peritoneal lavage cytology who underwent laparoscopic gastrectomy and D2 lymph node dissection from December 2017 to December 2022 were retrospectively analyzed. The patients were divided into the HIPEC group (27 cases) and the non-HIPEC group (22 cases) based on whether they received postoperative bedside ultrasound-guided HIPEC. The patterns of postoperative recurrence and metastasis and the 3-year survival rates were compared between the two groups. Univariate and multivariate analyses using the Cox proportional hazards model were conducted to determine the prognostic factors. <b>Results:</b> There was no statistically significant difference in all baseline clinicopathological data between the two groups (<i>P</i>>0.05); the median follow-up time for all patients was 31 months (ranging from 13 to 73 months), and the overall recurrence rate for all patients was 55.1% (27/49). Among them, 12 cases (24.5%) had peritoneal metastasis, 7 cases (14.3%) had hematogenous recurrence, 5 cases (10.2%) had distant lymph node metastasis, and 3 cases (6.1%) had local recurrence. The overall recurrence rates of patients in the HIPEC group and the non-HIPEC group were 51.8% (14/27) and 59.1% (13/22), respectively. There was no statistically significant difference (χ²=0.26, <i>P</i>=0.612). The peritoneal metastasis rate of patients in the HIPEC group was 18.5% (5/27), which was lower than that of the non-HIPEC group at 31.8% (7/22). However, there was no statistically significant difference (χ²=1.16, <i>P</i>=0.282). The proportions of local recurrence, hematogenous metastasis, and distant lymph node metastasis were comparable between the two groups (all <i>P</i>>0.05). The cumulative 3-year recurrence rates of the two groups were similar (70.7% vs. 71.3%, <i>P</i>=0.266). In the HIPEC group, the 3-year overall survival rate was 61.1%, which was significantly higher than that of the non-HIPEC group (31.5%). The difference was statistically significant (<i>P</i>=0.014). The disease-free progression survival rates of the two groups were 29.3% and 28.7% respectively, and there was no statistically significant difference between them (<i>P</i>=0.266). Cox multivariate analysis showed that no postoperative HIPEC (HR=5.21, 95%CI:1.90-14.31, <i>P</i>=0.001), poor tumor differentiation (HR=3.78, 95%CI:1.07-13.26, <i>P</i>=0.038), and later N stage (HR=6.18, 95%CI:1.39-7.59, <i>P</i>=0.017) were independent risk factors for the overall survival rate after surgery (<i>P</i><0.05). Later N stage (HR=3.67, 95%CI:1.07-12.55, <i>P</i>=0.038) was an independent risk factor for the disease-free progression survival rate after surgery (<i>P</i><0.05). <b>Conclusion:</b> Bedside ultrasound-guided HIPEC after laparoscopic gastrectomy and D2 lymph node dissection can improve the overall survival of CY+ gastric cancer patients.