Loop transverse colostomy versus loop ileostomy for defunctioning of colorectal anastomosis: a systematic review, updated conventional meta-analysis, and cumulative meta-analysis.

Defunctioning of colorectal anastomosis either with loop transverse colostomy or ileostomy was evaluated using updated and cumulative meta-analyses. Studies were identified by a systematic search of Embase, PubMed, Cochrane Library, and Google Scholar databases and were selected as per the PRISMA checklist. Both randomised control trials (RCTs) and retrospective studies were included. A sensitivity analysis was performed, and a cumulative meta-analysis was performed to monitor evidence over time. Significantly more male patients underwent loop ileostomy than transverse colostomy [odds ratio (OR) = 0.59 (95% confidence interval (CI) 0.39, 0.90), p < 0.001, I2 = 48%]. Significantly more colostomies were complicated by stoma prolapse than by ileostomies [OR = 6.32 (95% CI 2.78, 14.35), p < 0.001, I2 = 0%). Patients with ileostomy demonstrated a significantly higher complication rate of high-output stoma than patients with colostomies [Peto OR = 0.16 (95% CI 0.04, 0.55), p = 0.004, I2 = 0%]. Patients with colostomies demonstrated significantly more complications related to stoma reversal, such as wound infections and incisional hernias, than patients with ileostomies [OR = 3.45 (95% CI 2.00, 5.95), p < 0.001, I2 = 0%; OR = 4.80 (95% CI 1.85, 12.44), p < 0.001, I2 = 0%, respectively]. Overall complications related to stoma formation and closure did not demonstrate significant differences; however, their I2 values were 82% and 76%, respectively, suggesting high heterogeneity, which may have influenced the results. A subgroup analysis of RCTs showed no discrepancies when compared to the whole sample. In the cumulative meta-analysis, the effect size of each study was non-significant for the entire period. The demonstrated significant differences did not translate in favour of ileostomy when the overall complications of stoma formation and reversal were evaluated. Confounding factors and underpowered samples may have influenced the results. Future multicentre RCTs with homogeneous populations and adequate power may demonstrate more conclusive evidence regarding the superiority of one procedure over the other.

A Consensus for Classification and Pathologic Reporting of Pseudomyxoma Peritonei and Associated Appendiceal Neoplasia: The Results of the Peritoneal Surface Oncology Group International (PSOGI) Modified Delphi Process.

Pseudomyxoma peritonei (PMP) is a complex disease with unique biological behavior that usually arises from appendiceal mucinous neoplasia. The classification of PMP and its primary appendiceal neoplasia is contentious, and an international modified Delphi consensus process was instigated to address terminology and definitions. A classification of mucinous appendiceal neoplasia was developed, and it was agreed that "mucinous adenocarcinoma" should be reserved for lesions with infiltrative invasion. The term "low-grade appendiceal mucinous neoplasm" was supported and it was agreed that "cystadenoma" should no longer be recommended. A new term of "high-grade appendiceal mucinous neoplasm" was proposed for lesions without infiltrative invasion but with high-grade cytologic atypia. Serrated polyp with or without dysplasia was preferred for tumors with serrated features confined to the mucosa with an intact muscularis mucosae. Consensus was achieved on the pathologic classification of PMP, defined as the intraperitoneal accumulation of mucus due to mucinous neoplasia characterized by the redistribution phenomenon. Three categories of PMP were agreed-low grade, high grade, and high grade with signet ring cells. Acellular mucin should be classified separately. It was agreed that low-grade and high-grade mucinous carcinoma peritonei should be considered synonymous with disseminated peritoneal adenomucinosis and peritoneal mucinous carcinomatosis, respectively. A checklist for the pathologic reporting of PMP and appendiceal mucinous neoplasms was also developed. By adopting the classifications and definitions that were agreed, different centers will be able to use uniform terminology that will allow meaningful comparison of their results.