Objective: It is yet to be clarified whether pylorus-preserving gastrectomy (PPG) for early gastric cancer will bring the risk of radical tumor resection, whether it will increase the incidence of postoperative complications, and how much is the benefit of the quality of life for patients after surgery, these issues are not clear. This meta-analysis aims to evaluate the efficacy and safety of pylorus-preserving gastrectomy (PPG) for early middle gastric cancer. Methods: The Chinese and English literatures about PPG and distal gastrectomy (DG) for early gastric cancer were searched from PubMed, Embase, The Cochrane Library, Web of Science, CNKI net and Wanfang database. Literature inclusion criteria: (1) Prospective or retrospective cohort study of PPG and DG for early middle-third gastric cancer published publicly; (2) Patients with early middle-third gastric cancer; (3) The enrolled literatures include at least one of the following outcome indicators: the efficacy indicators include gallstone, residual gastritis, bile reflux, delayed gastric emptying, dumping syndrome, reflux esophagitis and overall complication; the long-term prognostic indicators include 5-year survival rate and 5-year tumor recurrence. Literature exclusion criteria: (1) Reviews, case reports, conference summaries and other non-control studies; (2) Repeated published studies, incomplete studies and unextractable studies; (3) The depth of tumor invasion exceeding submucosa. The search time ended in July 2020. The basic information and evaluation indicators included in the article were extracted. The retrospective study was evaluated using Newcastle-Ottawa literature quality evaluation scale. The prospective randomized controlled study was evaluated using Jadad modified scale. Meta-analysis was performed using Review Manager 5.3. Publication bias was assessed using funnel map. Publication bias was tested using Egger tools. Results: A total of 717 literatures were retrieved, and 17 literatures were enrolled finally, including 2 randomized controlled trials and 15 retrospective studies. A total of 2427 patients were enrolled, including 948 in PPG group and 1479 in DG group. The meta-analysis of the efficacy indicators showed that there were significant differences in gallstones incidence (OR=0.42, 95% CI: 0.28-0.65, P<0.001), residual gastritis incidence (OR=0.50, 95% CI: 0.32-0.77,P=0.002), bile reflux incidence (OR=0.30, 95% CI: 0.20-0.45, P<0.001), delayed gastric emptying incidence (OR=2.40, 95% CI:1.67-3.45, P<0.001), and postoperative dumping syndrome incidence (OR=0.28, 95% CI: 0.15-0.51, P<0.001), while there were no significant differences in postoperative overall complications (OR=0.97, 95% CI: 0.69-1.35, P=0.840), reflux esophagitis incidence (OR=0.79, 95% CI: 0.39-1.61, P=0.520) between the two groups. The meta-analysis of the long-term prognostic indicators showed that no significant differences of 5-year survival (OR=1.02, 95% CI: 0.61-1.71, P=0.940) or 5-year tumor recurrence (OR=0.77, 95% CI: 0.36-1.68, P=0.520) were observed between the two groups. Conclusion: The incidences of gallstone, residual gastritis, dumping syndrome, bile reflux are lower after PPG in early gastric cancer, while the postoperative overall complications and long-term survival are comparable between PPG and DG, indicating that PPG is quite safe and feasible.
目的： 保留幽门胃切除术（PPG）治疗早期胃癌，是否会带来肿瘤根治性上的风险，是否会增加术后并发症的发生率，且术后患者生活质量的获益程度尚不明确。本Meta分析旨在评价PPG治疗胃中部癌的有效性和安全性。 方法： 检索Pubmed、Embase、Cochrane Library、Web of Science、中国知网及万方数据库公开发表的有关早期胃中部癌行保留幽门胃切除术（PPG）和远端胃切除术（DG）的中英文文献。文献纳入标准：（1）公开发表的关于早期胃中部癌行PPG和DG的前瞻性或回顾性队列研究；（2）研究对象为早期胃中部癌；（3）纳入文献必须至少包含以下一项指标：疗效指标包括胆囊结石、残胃炎、胆汁反流、胃排空延迟、倾倒综合征、反流性食管炎、整体并发症；远期预后指标包括5年生存率和5年肿瘤复发率。文献排除标准：（1）综述、病例报告、会议摘要和其他非对照研究的文献资料；（2）重复发表的研究以及数据提取不完整或无法提取的研究；（3）肿瘤浸润深度超过黏膜下层。检索时间截至2020年7月。提取纳入文章的基本信息及评价指标，分别采用卡斯尔-渥太华（NOS）、Jadad改良文献质量评价量表对回顾性研究和前瞻性随机对照研究进行文献质量评估。采用Review Manager 5.3软件制作森林图进行Meta分析，采用漏斗图评估发表偏倚，采用Egger检测是否存在发表偏倚。 结果： 共检索出717篇文献，最终共纳入17篇文献，其中2篇为随机对照研究，15篇为回顾性临床研究，共纳入计2 427例患者，其中PPG组948例，DG组1 479例。对纳入指标进行Meta分析，疗效指标比较显示：胆囊结石发生率（OR=0.42，95% CI：0.28~0.65，P<0.001）、残胃炎发生率（OR=0.50，95% CI：0.32~0.77，P=0.002）、胆汁反流发生率（OR=0.30，95% CI：0.20~0.45，P<0.001）、胃排空延迟发生率（OR=2.40，95% CI：1.67~3.45，P<0.001）和术后倾倒综合征发生率（OR=0.28，95% CI：0.15~0.51，P<0.001）的比较，差异均有统计学意义（均P<0.05）；但术后整体并发症（OR=0.97，95% CI：0.69~1.35，P=0.840）、反流性食管炎发生率（OR=0.79，95% CI：0.39~1.61，P=0.520）方面比较，两组差异均无统计学意义。在远期预后方面，两组5年生存率（OR=1.02，95% CI：0.61~1.71，P=0.940）和5年肿瘤复发率（OR=0.77，95% CI：0.36~1.68，P=0.520）比较，差异均无统计学意义。 结论： PPG术后胆囊结石、残胃炎、胆汁反流、倾倒综合征的发生率更低，但术后并发症及远期疗效与DG相近，说明PPG手术具有一定的安全性和可行性。.
Keywords: Distal gastrectomy; Meta-analysis; Pylorus-preserving gastrectomy; Stomach neoplasms, middle-third; Stomach neoplasms,early.