Quality Assessment and Risk of Bias of Systematic Reviews of Prophylactic Mesh for Parastomal Hernia Prevention Using AMSTAR and ROBIS Tools

Use of prophylactic mesh to prevent parastomal hernia formation: a systematic review, meta-analysis and network meta-analysis

PURPOSE

To evaluate the effectiveness of prophylactic mesh placement in reducing the incidence of parastomal hernias following colostomy, ileostomy, and ileal conduit formation.

METHODS

A systematic review identified relevant studies evaluating parastomal hernia incidence with prophylactic mesh use during stoma formation. Pairwise meta-analysis and network meta-analysis using Bayesian modeling were performed.

RESULTS

25 studies, consisting of 16 randomized control trials (RCT), 6 follow up studies, and 3 retrospective cohort studies, were included. Prophylactic mesh led to significantly fewer parastomal hernias beyond 6 months follow-up (OR 0.43, 95% CI 0.33-0.58). Hernias were reduced with mesh for both ileal conduits and colostomies. When analyzing hazard ratios (HRs), only 6 studies were included, and a statistically significant difference was observed among both randomized controlled trials (RCTs) (HR 0.75 [0.53, 0.92], p = 0.01) and non-RCTs (HR 0.57 [0.36, 0.92], p = 0.02). Network meta-analysis found the retromuscular approach with mesh had the lowest hernia rate. Regression was non-significant for variations between study types.

CONCLUSION

This meta-analysis demonstrated prophylactic mesh placement during ostomy creation significantly reduced parastomal hernia risk, more prominently beyond 6 months, consistently across randomized trials and observational studies for urologic and gastrointestinal ostomies. The retromuscular technique was most effective.

Parastomal hernia prevention with an intraperitoneal prophylactic 3D-funnel mesh: review of the technique and middle-term results

PURPOSE

Parastomal hernia (PH) stands out as a prevalent complication following end colostomies, significantly affecting patients' quality of life. Various surgical strategies, predominantly involving prophylactic mesh deployment, have been explored with variable outcomes. This study details our experience and mid-term outcomes utilizing a funnel-shaped mesh.

METHODS

A single-center, prospective, non-randomized, observational study examined consecutive patients undergoing colorectal surgery with end colostomy, incorporating a 3D-funnel mesh from January 2019 to December 2021 (PM group). A historical cohort of patients with end colostomy without prophylactic mesh served as the comparison (C group). Postoperative morbidity within 30 days was documented, and clinical examinations and radiological tests were employed for parastomal hernia diagnosis during follow-up.

RESULTS

Seventy-two patients participated, with thirty-four in the PM group and thirty-eight in the C group. The PM group experienced 16 postoperative complications, unrelated to the mesh, while the C group recorded 20 complications (p = 0.672). Median follow-up was 22.06 months for the PM group and 63.18 months for the C group. The PM group exhibited a lower parastomal hernia incidence during follow-up (8.8%) compared to the C group(68.4%) (p < 0.001).

CONCLUSION

Prophylactic use of a 3D-funnel mesh appears effective in reducing parastomal hernia incidence in the short and mid-term, without an associated increase in postoperative morbidity.

Prophylactic mesh does not prevent parastomal hernia in long-term: Meta-analysis and trial sequential analysis

BACKGROUND

Previous randomized clinical trials, systematic reviews, and meta-analyses evaluating parastomal hernia prevention with mesh placement during end colostomy formation have reported contradictory results. This review aimed to assess the efficacy of this strategy in long-term follow-up according to the latest available data.

METHODS

Medline, EMBASE, Cochrane Library, Web of Science, and Google Scholar were searched. Randomized clinical trials were included if they compared mesh with no mesh during initial end colostomy creation in adult patients to prevent parastomal hernia with a follow-up longer than 2 years. A meta-analysis was performed to evaluate parastomal hernia incidence (primary outcome), parastomal hernia repair rate, and mortality. Subgroup analysis included surgical approach and mesh position, and trial sequential analysis was performed.

RESULTS

Eight randomized clinical trials involving 537 patients met the inclusion criteria. Based on long-term follow-up, the incidence of parastomal hernia was not reduced when a prophylactic mesh was placed (relative risk = 0.68 [95% confidence interval:0.46-1.02]; I2 = 81%, P =.06). The parastomal hernia repair rate was low; however, no difference was found between the groups (relative risk = 0.90 [95% confidence interval:0.51-1.56]; I2 = 0%; P = .70), and no difference was detected between the groups when mortality was assessed (relative risk = 1.03 [95% confidence interval: 0.77-1.39]; I2 = 21%; P = .83). Subgroup analyses did not show differences according to the surgical approach or mesh position used. Regarding trial sequential analysis, an optimal information size was not achieved.

CONCLUSION

Prophylactic mesh placement during end colostomy formation does not prevent parastomal hernia in the long term. The parastomal hernia repair rate and mortality rate did not vary between the included groups. Heterogeneity among the included randomized clinical trials might restrict the reliability of the results.

Definition, harms, and prevention of redundant systematic reviews

BACKGROUND

Along with other types of research, it has been stated that the extent of redundancy in systematic reviews has reached epidemic proportions. However, it was also emphasized that not all duplication is bad, that replication in research is essential, and that it can help discover unfortunate behaviors of scientists. Thus, the question is how to define a redundant systematic review, the harmful consequences of such reviews, and what we could do to prevent the unnecessary amount of this redundancy.

MAIN BODY

There is no consensus definition of a redundant systematic review. Also, it needs to be defined what amount of overlap between systematic reviews is acceptable and not considered a redundancy. One needs to be aware that it is possible that the authors did not intend to create a redundant systematic review. A new review on an existing topic, which is not an update, is likely justified only when it can be shown that the previous review was inadequate, for example, due to suboptimal methodology. Redundant meta-analyses could have scientific, ethical, and economic questions for researchers and publishers, and thus, they should be avoided, if possible. Potential solutions for preventing redundant reviews include the following: (1) mandatory prospective registration of systematic reviews; (2) editors and peer reviewers rejecting duplicate/redundant and inadequate reviews; (3) modifying the reporting checklists for systematic reviews; (4) developing methods for evidence-based research (EBR) monitoring; (5) defining systematic reviews; (6) defining the conclusiveness of systematic reviews; (7) exploring interventions for the adoption of methodological advances; (8) killing off zombie reviews (i.e., abandoned registered reviews); (9) better prevention of duplicate reviews at the point of registration; (10) developing living systematic reviews; and (11) education of researchers.

CONCLUSIONS

Disproportionate redundancy of the same or very similar systematic reviews can lead to scientific, ethical, economic, and societal harms. While it is not realistic to expect that the creation of redundant systematic reviews can be completely prevented, some preventive measures could be tested and implemented to try to reduce the problem. Further methodological research and development in this field will be welcome.

Efficacy of Surgical Masks Versus N95 Respirators for the Prevention of COVID-19 in Dental Settings: A Systematic Review

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2. (SARS-CoV-2). It spreads mainly through saliva droplets or nasal discharge. Dentists are among the professionals with the greatest risk of contracting and transmitting COVID-19. We compared the efficacy of surgical masks versus N95 respirators in preventing COVID-19 infection in dental settings. PubMed, Scopus, Web of Science, and Cochrane Library databases were searched. Search terms corresponded to a predefined PICOS (patient/population, intervention, comparison, and outcomes) question. The risk of bias was evaluated using AMSTAR-2 (A Measurement Tool to Assess Systematic Reviews-2), ROBIS (Risk of Bias in Systematic Reviews), and Health Evidence tools. A total of 191 articles were screened, and nine of them were further evaluated for eligibility, of which five articles (fulfilled the selection criteria) and were included in this study. Two studies concluded that surgical masks could provide equivalent protection to N95 respirators. Another study found that N95 respirators were superior to surgical masks. The fourth study found that better protection can be achieved when using surgical masks by the aerosol source than when the recipient uses an N95 respirator, while the last study concluded that surgical masks or N95 respirators alone do not provide full protection. Thus, according to this systematic review, N95 respirators provide better protection against COVID-19 infection compared to surgical masks.

Parastomal hernia prevention with permanent mesh in end colostomy: failure with late follow-up of cohorts in three randomized trials

PURPOSE

Short-term results have been reported regarding parastomal hernia (PH) prevention with a permanent mesh. Long-term results are scarce. The objective was to assess the long-term PH occurrence after a prophylactic synthetic non-absorbable mesh.

METHODS

Long-term data of three randomized controlled trials (RCTs) were collected. The primary outcome was the detection of PH based exclusively on a radiological diagnosis by computed tomography (CT) performed during the long-term follow-up. The Kaplan-Meier method was used for the comparison of time to diagnosis of PH according to the presence of mesh vs. no-mesh and the technique of mesh insertion: open retromuscular, laparoscopic keyhole, and laparoscopic modified Sugarbaker.

RESULTS

We studied 121 patients (87 men, median age 70 years), 82 (67.8%) of which developed a PH. The median overall length of follow-up was 48.5 months [interquartile range (IQR) 14.4-104.9], with a median time until PH diagnosis of 17.7 months (IQR 9.3-49.0). The survival analysis did not show significant differences in the time to development of a PH according to the presence or absence of a prophylactic mesh neither in the overall study population (log-rank, P = 0.094) nor in the groups of each technique of mesh insertion, although according to the surgical technique, a higher reduction in the appearance of PH for the open retromuscular technique was found (log-rank, P = 0.001).

CONCLUSION

In the long-term follow-up placement of a non-absorbable synthetic prophylactic mesh in the context of an elective end colostomy does not seem effective for preventing PH.

Permanent end-colostomy parastomal hernia prevention using a novel three-dimensional mesh

PURPOSE

Prophylactic mesh placement has been proposed to reduce the high occurrence of parastomal hernia (PSH) after stoma formation.

METHODS

This is an observational study comparing two cohorts of patients: a mesh prophylaxis group (who received mesh prevention since introduction at our Institution) and a no mesh prophylaxis group (retrospectively selected from our historical series). Same exclusion criteria were applied for both groups. The study was conducted at a tertiary referral center for colorectal surgery. 43 patients were operated with mesh prophylaxis between May 2015 and may 2019. 45 patients underwent end-colostomy formation without prophylaxis between April 2011 and April 2015. The primary outcome measure was PSH development at 12-month follow up.

RESULTS

Demographic variables and risk factors for PSH were comparable between the two groups. There was no difference between the two cohorts in terms of operative time and main early postoperative outcomes. 37 patients completed the 12-month follow up in each group. PSH occurrence after 12-months was 11% in the mesh prophylaxis group and 54% in the no mesh prophylaxis group (p < 0.0001). There were no differences in long-term complications. 5% of patients who received mesh prophylaxis underwent emergency surgery for bowel occlusion at 7 and 10 months after surgery, with partial or complete mesh removal. At multivariate analysis, mesh prophylaxis was a protective factor for PSH development at 12 months (p < 0.0001).

CONCLUSIONS

Prophylactic intraperitoneal mesh placement appears to be effective in preventing PSH.

The lateral rectus abdominis positioned stoma (LRAPS) in the construction of end colostomies, loop ileostomies and ileal conduits

BACKGROUND

Stomas are traditionally constructed through the belly of the rectus muscle. Parastomal herniation is common with the use of mesh prophylaxis still deliberated.

METHODS

A novel trephine, the lateral rectus abdominis positioned stoma or LRAPS, that minimises damage to the musculature of the anterior abdominal wall, has been used in the construction of end colostomies, loop ileostomies and ileal conduits.

RESULTS

In a cohort of 106 patients with end colostomy, the cumulative rate of parastomal herniation at 1, 2 and 3 years were 6, 10 and 17%, respectively. In 56 patients in whom an ileal conduit was performed, there was no clinical or radiological evidence of parastomal herniation at 1 year.

CONCLUSION

In contrast to a traditional trephine through the belly of the muscle, this technique avoids damage to the rectus abdominis muscle. Early symptomatic parastomal herniation is unusual after LRAPS.