Outcomes of open transverse abdominis release for ventral hernias- A systematic review, meta-analysis and meta-regression of factors affecting them

Objectives The primary objectives were to evaluate Surgical Site Occurrences (SSO) and Surgical Site Occurrences requiring procedural Intervention (SSOPI) after open transversus abdominis release and to study various factors affecting it. Secondary objectives were to evaluate Surgical Site Infections (SSI), recurrence rates and overall complications after transversus abdominis release (TAR) and the factors responsible for those. Methods We searched PUBMED, SCOPUS and Cochrane databases with keywords “transversus abdominis release” or “TAR” OR “Surgical Site Occurrences” OR “posterior component separation AND “outcomes” as per PRISMA 2020 and MOOSE guidelines. Full texts and English literature studies were included, studies mentioning outcomes for open transversus abdominis release for ventral hernia were included and studies with robotic transversus abdominis release were excluded. Percentage occurrences of SSO, SSOPI, SSI, recurrence and overall complications after TAR were evaluated. Random effect meta-analysis with restricted maximum likehood methods was used for meta-analysis. Heterogeneity was analysed using I 2 statistics. Publication bias with eager’s test and funnel plots. Meta0regression analysis was done to evaluate factors affecting the heterogeneity. JASP 0.16.2 software was used for meta-analysis. Results Twenty two studies including 5284 patients who underwent TAR for ventral hernia were included in systematic review and meta-analysis. Overall pooled SSO, SSOPI, Overall Complications, SSI and recurrence rates were 21.72% [95% C.I 17.18-26.27%], 9.82% [95% C.I 7.64 −12%], 33.34% [95% C.I. 27.43-39.26%], 9.13% [95% 6.41-11.84] and 1.6% [0.78-2.44] respectively. Heterogeneity was significant in all the analysis. Age (p<0.001),sex (p<0.001), BMI (p<0.001),presence of comorbidities (p<0.001), prior recurrence, defect size (p<0.001) and current or past history of tobacco exposure were associated with SSO in multivariate meta-regression analysis. Defect size (p=0.04) was associated with SSOPI. Age (p=0.011), BMI (p=0.013), comorbidities (p<0.01), tobacco exposure (p=0.018),prior recurrence (p <0.01) and sex (p < 0.01) were associated with overall complications. Conclusion Open transversus abdominis release is associated with high rates of SSO, SSOPI, SSI and overall complications but recurrence rates are low. Various preoperative factors mentioned may be responsible for heterogeneity across studies.