Surgical treatment of stomal prolapse: A systematic review and meta‐analysis of the literature

This study aimed to assess success, recurrence, and overall complication rates among different surgical procedures for stomal prolapse.


INTRODUC TI ON
Stomal prolapse is one of the complications of stomas with an incidence that ranges according to the follow-up duration between 7% and 26% [1][2][3][4]. Stomal prolapse may interfere with patients' quality of life and may result in peristomal dermatitis, bleeding, and difficulty in stoma appliance application [5][6][7].
Several risk factors for stomal prolapse have been recognized.
Uncomplicated stomal prolapse is usually conservatively managed with the application of osmotic agents and manual reduction; nonetheless, these options are just a temporary solution until reversal of the stoma [12,13]. However, the scenario is obviously different when the stoma is permanent.
Although several surgical techniques and approaches have been described, there are still insufficient data to support the choice of technique. Therefore, we conducted this systematic review of the literature in order to assess the success and complication rates of different surgical approaches and determine the risk factors of recurrence.

Review registration
This study has been registered in the PROSPERO register of systematic reviews (CRD42022335908). The present review was reported according to the PRISMA 2020 guideline [14]. This study was not submitted for ethics approval due to its nature as a systematic review wherein patient data were not accessed.

Search strategy and databases searched
A systematic search of PubMed, Scopus, and Google Scholar was independently performed by two authors (ZG, SM) from the inception of each database through March 2022. The terms "prolapse", "stoma", "enterostomy", "ileostomy", "colostomy", and "ostomy", were used combined with the Boolean operators AND/OR in order to recognize all available studies on surgical treatment of stoma prolapse (see search strategy in Appendix S1). The reference lists of the articles retrieved were also searched to look for further eligible studies.
Following removal of duplicate studies, the abstract list generated by the above search was independently screened by two authors (ZG, SM) for potentially relevant studies. After excluding irrelevant papers, a full-text evaluation of all remaining studies was undertaken for eligibility and completeness of data, according to the predefined exclusion criteria. Any ensuing disagreements were resolved by a third reviewer (SDW).

Article selection criteria
Cohort and randomized studies that fulfilled the following PICO criteria were eligible for inclusion: Studies reporting the treatment of paediatric patients <18 years of age, studies with unavailable full-text, reviews, editorials, clinical vignettes, case reports and animal studies were excluded from the analysis. Furthermore, studies without an English full text, studies including <10 patients, and those that reported nonsurgical treatments of stoma prolapse were also excluded.

Assessment of risk of bias
The risk of bias across nonrandomized studies was independently assessed by two authors (ZG and SM) using the ROBINS-1 tool [15] and the robvis tool to create the risk of bias plots [16]. Any conflicts of interpretation among the two authors were resolved by a third author (SDW).

Data extraction
Data of interest included the type of study and year of publication, number and sex of involved patients, comorbidities, aetiology of index operation, type of stoma, details of surgical treatment, type of anaesthesia, complications, recurrence, and time of follow-up.
After thorough full-text evaluation of the included studies, data of interest were extracted to excel spreadsheets (Microsoft) and were subsequently crosschecked by two authors (ZG, SM) for discrepancies.

Study outcomes
The primary outcome of this review was the stomal prolapse recurrence rate following surgical repair. The secondary outcomes were short-term complications and re-operation. Short-term complications were defined as those that occurred within 30 days postoperatively.

Statistical analysis
An open-source, cross-platform software for advanced metaanalysis "openMeta [Analyst]" version 12.11.14 was used to conduct the meta-analysis of data. A proportional meta-analysis was undertaken to assess the weighted mean rate of recurrence across the studies. Statistical heterogeneity was assessed using the p-value of the Cochrane Q test and the Inconsistency (I 2 ) statistics (low if I 2 < 25%, moderate if I 2 = 25%-75%, and high if I 2 > 75%). A randomeffect meta-regression analysis of the risk factors of recurrence was performed weighing the studies by their within-study variance and the degree of heterogeneity. The statistical significance of each examined variable was expressed using slope coefficient (SE) and pvalue. p-value < 0.1 was considered statistically significant.

Study and patient characteristics
Six studies published between 1988 and 2021 were included. The studies incorporated 111 patients (Table 1) [17][18][19][20][21][22]. The process of the literature search and article selection is shown in Figure 1. Of 111 patients, 103 were male and 25 were female, with a median age ranging between 51 and 79 years.

Author
Year of publication Number

BMI in kg/m 2 Indication
Allen-Mersh and Thomson [

Prolapse operation
The majority (n = 93, 83.7%) of the surgical procedures were elective (

Complications
Only three studies reported short-term complications. Serious pain (CD class 1) was the only complication reported in 10 patients who underwent the mesh strip procedure. No other complications were reported in the other two studies assessing the modified Altemeier and the stapled local repair technique.

Assessment of risk of bias
All studies had a serious overall risk of bias ( Figure 4). The results are demonstrated via the robvis tool [16].

DISCUSS ION
Despite the advances in surgical techniques, stomas are still associated with high morbidity [23]. Stoma complications are recorded in 20%-70% of patients with stomal prolapse occurring in 7%-26% [1,11,24,25]. Stomal prolapse might result in difficulties with stoma management and function, thus impacting patients' quality of life [26][27][28]. Colostomies are more prone to prolapse than ileostomies according to a previous report [29], which was supported by the finding of our study as 78.3% of patients had a prolapsed colostomy requiring surgical treatment versus 21.7% with a prolapsed ileostomy. Although uncomplicated stomal prolapse is usually conserva-  to stoma prolapse are discussed in textbooks and narrative review articles, the details, advantages of, and indications for each procedure are not clearly explained [5,[33][34][35]. This is the first systematic review and meta-analysis of surgical repairs of stoma prolapse that attempted to shed light on the optimal approach for this challenging problem.
We acknowledge that there are several limitations of our review.
First, the heterogeneity, small number of studies included and without specifics on stoma prolapse classification and types. Second, the lack of comparative studies renders comparisons difficult and possibly imprecise. Third, this review does not include all available techniques for stomal prolapse, only those described in case series with >10 patients. Lastly, the follow-up period was relatively short ranging between 7 months and 2.5 years, with the period of follow-up ending sometimes at the stoma reversal procedure.

CON CLUS ION
Several surgical techniques are available to treat stomal prolapse.
Local stoma reconstruction may be associated with high rates of recurrence while the stapled local repair and modified Altemeier procedure has relatively low recurrence. Further larger studies are needed to compare the efficacy of these techniques.

FU N D I N G I N FO R M ATI O N
None.

CO N FLI C T O F I NTER E S T S TATEM ENT
None of the authors reports any relevant conflict of interest.

DATA AVA I L A B I L I T Y S TAT E M E N T
Data available upon request.

E TH I C S S TATEM ENT
This study was not submitted for ethics approval due to its nature as a systematic review wherein patient data were not accessed.