甲氧基苯蓝染色被描述为一种改善淋巴结采收的替代方法，相较于传统的触诊和视觉检查方法。本次荟萃分析评估了这种技术在直肠癌手术中的实用性，特别是在新辅助治疗后。从Medline、Embase和Cochrane数据库中筛选比较甲氧基苯蓝染色直肠标本和未染色标本淋巴结采收的随机对照试验(RCTs)，排除非随机研究和仅进行结肠切除的研究。使用Cochrane的偏倚风险工具评估RCTs的质量。计算加权平均差(WMD)以比较染色和未染色标本的总采收量、新辅助治疗后的采收量和转移淋巴结产量。相反，计算风险差(RD)以比较染色和未染色标本的少于12个淋巴结的采收量。研究选择包括七个RCT，无染色组有343名患者，染色组有337名患者。染色标本的总淋巴结采收量和新辅助治疗后的采收量明显高于未染色标本，WMD分别为13.4和10.6，95%置信区间(CI)分别为9.5-17.2和4.8-16.3。染色组的转移淋巴结采收量明显高于未染色组(WMD 1.0，95% CI 0.6-1.4)。未染色组的少于12个淋巴结的采收量明显高于染色组，RD为0.292，95% CI为0.182-0.403。尽管患者数量较少，但本次荟萃分析证实，相较于未染色的标本，采用甲氧基苯蓝染色的手术标本可以提高淋巴结采收量。©2023 Springer Nature Switzerland AG。

Methylene blue staining of the resected specimen has been described as an alternative to the conventional palpation and visual inspection method to improve lymph node harvest. This meta-analysis evaluates the usefulness of this technique in surgery for rectal cancer, particularly after neoadjuvant therapy.Randomized controlled trials (RCTs) comparing lymph node harvest in methylene blue-stained rectal specimens to those of unstained specimens were identified from the Medline, Embase, and Cochrane databases. Non-randomized studies and those with only colonic resections were excluded. The quality of RCTs was assessed using Cochrane's risk of bias tool. A weighted mean difference (WMD) was calculated for overall harvest, harvest after neoadjuvant therapy, and metastatic nodal yield. In contrast, the risk difference (RD) was calculated to compare yields of less than 12 lymph nodes between the stained and unstained specimens.Study selection comprised seven RCTs with 343 patients in the unstained group and 337 in the stained group. Overall lymph node harvest and harvest after neoadjuvant therapy were significantly higher in stained specimens with a WMD of 13.4 and 10.6 and a 95% confidence interval (CI) of 9.5-17.2 and 4.8-16.3, respectively. Harvest of metastatic lymph nodes was significantly higher in the stained group (WMD 1.0, 95% CI 0.6-1.4). The yield of less than 12 lymph nodes was significantly higher in the unstained group with RD of 0.292 and 95% CI of 0.182-0.403.Despite a small number of patients, this meta-analysis confirms improved lymph node harvest in surgical specimens stained with methylene blue compared with unstained specimens.© 2023. Springer Nature Switzerland AG.