Ostomy continence devices: a systematic review of the literature and meta‐analysis

Colostomy complication rates range widely from 10% to 70%. The psychological burden on patients, leading to lifestyle changes and decreased quality of life (QoL), is one of the largest factors. The aim of this work was to assess the history and efficacy of ostomy continence devices in improving continence and QoL.


INTRODUC TI ON
An ostomy is a surgically created opening from an internal hollow organ to the outside of the body.The term 'ostomy' is often used interchangeably with the term 'stoma' [1,2].Ostomies are formed by exteriorizing the bowel to the abdominal wall for a variety of gastrointestinal pathologies including colorectal cancer and inflammatory bowel disease.The reported prevalence of individuals in the United States living with an ostomy ranges from 725 000 to 1 000 000.It is estimated that approximately 100 000-150 000 ostomy surgeries are performed each year [3][4][5].Ostomies, while often necessary and lifesaving, are unfortunately associated with a multitude of complications, with complication rates ranging from 10% to 70% [6][7][8].Common complications include peristomal skin complications, hernias, high-output ostomies, ostomy necrosis and ostomy stenosis [9].Additionally, one of the most prominent complications of ostomy creation is the large psychological burden that ostomies place on patients.Patients often live in fear of leakage, flatus and embarrassment from their device and its function.Because of these fears, patients often make significant changes to their daily lives, including limiting their public and social activities [2,10].
Although ostomy-related complications are relatively common, they can be mitigated through various strategies.One of the most common ostomy complications, skin irritation around the ostomy site [6,11], can be addressed through a variety of products including bacterial and antifungal creams as well as skin protectants [12].Furthermore, limiting the changing of the ostomy appliance to every 3-7 days can help prevent skin breakdown [13].
Loss of continence, or the ability to control passage of a bowel movement, places a large psychological burden on patients.
Surgeons have attempted to devise surgical solutions to this problem, starting with continent ileostomy, which was first described by Kock in 1969 [14].This procedure remains viable in select patients for whom ileoanal pouch surgery is not an option or has failed, although it has been noted to have numerous problems that necessitate repeat surgical revisions [15].There have also been efforts to develop external devices that would allow for control of flatus and stool expulsion, referred to as 'colostomy continence' [16].The first device, described in 1953, was a 'valvular colostomy plug' [17].There was a gap in the literature for over 20 years before the next study on ostomy continence devices was published.The aim of the present study was to conduct a systematic review of the literature on the history, evolution and outcomes of ostomy continence devices.

Registrationandreporting
The protocol has been prospectively registered in the PROSPERO register of systematic reviews (CRD42023448348) and is reported according to the PRISMA 2020 guidelines [18].There was no deviation from the registered protocol when reporting this systematic review.

Searchstrategy
A systematic search of PubMed, Scopus and Google Scholar was undertaken by two investigators (ZD, ZG) for all available studies on continence devices for all ostomies up to April 2023.The investigators used the following syntax combination of keywords and Boolean operators 'AND' and 'OR' in the literature search: (device OR plug OR appliance) AND (stoma OR ostomy OR ileostomy).Additionally, clini caltr ials.gov was searched for any ongoing trials.
Conference abstracts without a full text were evaluated for their content, and if the abstract contained sufficient information for this review, the study was included.After exclusion of duplicate reports, a stepwise filtration of all remaining articles was undertaken, firstly by title and abstract followed by full-text review of each article by two authors (SE, JD) to confirm eligibility for inclusion and extract relevant data for the systematic review and meta-analysis.The process of literature review and article selection was under the supervision of the senior author (SDW).

Assessmentofriskofbiasandcertaintyofevidence
Three authors (PR, PA, AW) independently assessed the risk of bias in the studies using the revised tool to assess the risk of bias in nonrandomized studies of interventions (ROBINS-1) for cohort studies [19] and the risk of bias in randomized trials (RoB 2) for randomized trials [20].The certainty of the evidence was graded with the GRADE approach as very low, low, moderate, or high [21].Publication bias was assessed if 10 or more studies met the inclusion criteria.

Dataextractionandstudyoutcomes
Three authors (PR, PA, AW) collected data including publication details (authors, year, location, journal), type of study, number of subjects and the reported outcomes, which included adjuncts used, completeness of continence, episodes of leakage, wearable time range and complications of the device, and patient perception of the device.Data collection was verified by a fourth author (JD).The primary outcomes were continence and improvement in quality of life (QoL) and the secondary outcomes were leakage rate, patient preference for the device and complications.

Whatdoesthispaperaddtotheliterature?
Our study is the first systematic review of ostomy continence devices and includes the only quantitative pooled data comparing the outcomes of these devices.
Additionally, we propose that selective usage of these devices, rather than continuous use, could lead to improved quality of life and continence in patients with ostomies.

Datasynthesis
A meta-analysis was conducted using the open-source, crossplatform software for advanced meta-analysis, openMeta [Analyst]™ version 12.11.14.A proportional meta-analysis was conducted to assess the weighted mean rates and 95% confidence interval (CI) of continence, patient preference, leakage, QoL and complications.
Statistical heterogeneity was assessed using the inconsistency (I 2 ) statistic (low if I 2 < 25%, moderate if I 2 = 25%-75%, high if I 2 > 75%).A fixed-effect meta-analysis was used if I 2 < 25% and a random-effect analysis was used if I 2 ≥ 25%.In case of moderate or high heterogeneity a leave-one-out sensitivity analysis was performed to assess for the source of heterogeneity.

RE SULTS
After screening 9754 articles and abstracts, 22 articles and abstracts were ultimately included (Figure 1).There were 21 studies that were classified as a cohort or case series and one prospective randomized study.Thirteen studies were single-centre and nine were multicentric (Table 1, Figure 2).There were no ongoing clinical trials registered.Other findings from the papers included were outside the scope of this systematic review and therefore excluded.
Ostomy continence devices were broadly classified as historical devices, currently available devices and those devices under development in animal models.Overall, the articles were divided into two groups according to the type of continence device: ball-valve devices and plug-based devices.Within the plug devices there were two main products that were studied in the literature, the Conseal (Coloplast S.p.A., Bologna, Italy) colostomy plug system and the Vitala™ Continence Control Device (CCD) (Convatech, London, UK).

Ball-valvedevices
The first description in the literature of a device for colostomy continence was by Wulff in 1953 [17].Subsequently, Heilblum and Cordoba investigated an implantable silastic balloon that created a valve effect in six patients [22].Five patients achieved continence and none of the patients experienced ischaemia of their ostomy.However, one device was removed because of infection.
The method shifted to external devices.In 1983, Pemberton et al. evaluated a balloon-based occlusion device with a valve and found that occlusion of 5-8 h was well tolerated by four patients who achieved continence without impairing intestinal function [23].Similarly, a study by Hadidi [24]

Plugdevices
As with ball-valve devices, there was an initial interest in implantable devices with plug systems.Goligher et al. described their treatment of 22 patients with an implantable magnetic ostomy device which utilized a plug system [25].Of the 13 patients they assessed, only three (23.1%)achieved improvements in continence.
The effect of the Vitala CCD on improving QoL was supported by Swan [35] who combined two case studies with the above study by Durnal et al. [37] in a pooled analysis.Additionally, Hoch et al.
[36] compared the Vitala CCD with traditional pouching over a 3month period in 165 patients.Seventy patients (42%), with a mean age of 62.5 years and with 61.2% being male, used the CCD.It was established that Vitala™ users had a higher health-related QoL score when utilizing the EQ-5D (p = 0.013) and Stoma Appliance-specific Questionnaire (p = 0.001).No difference was found in the Stoma Quality of Life Scale.More Vitala users reported 'no problems' on all five EQ-5D domains (p = 0.01), and indicated that they enjoyed life most of the time (p = 0.043) when compared with those having a traditional ostomy.

Devices under investigation in humans
There were two studies investigating new devices in human models.
Strigård et al. tested a titanium transcutaneous implant evacuation system (TIES), which consisted of a titanium cylinder with a mesh and plastic cap [38], in four patients with inflammatory bowel disease who were having ostomy relocation or pouch excision.Two of the four patients needed minor corrective surgery.There were no device-related complications or safety concerns; however, only two patients were satisfied at 18 months, with one using an ostomy bag over the TIES for extra security.Additionally, Lehur et al. tested a two-piece appliance with a base plate and capsule cap that allowed patient-controlled release of a folded bag in the cap to collect stool [39].Twenty-three patients completed the 2-week trial: 85.3% of appliance changes were associated with no leakage whereas there were 69 incidents of leakage; 58.6% of the cap removals associated with increased pressure were manual and 41.06% were spontaneous.
Adverse events were recorded in 30% of patients, some of which resolved spontaneously.However, in 13.3% of cases there was skin and subcutaneous tissue reaction which required study discontinuation.
There was no difference in QoL compared with normal pouching systems and 43% said they would be willing to use it in the future.

Devices under development in animal models
Three studies addressed the development of additional continence devices in animal models.Zhang et al. developed an experimental model in miniature Tibetan pigs with the application of different sizes of silicone closure devices (3.0, 3.5 and 4.0 cm) [40].They found that an occlusion diameter of 0.5-1 cm larger than the colostomy diameter has the best balance of occlusion while limiting infection, ischaemia and necrosis of the ostomy.The second study, by Chen et al., reviewed the efficacy of a pressure-sensing colostomy plug in reduction of faecal leakage in nine miniature Tibetan pigs [41].They were divided into 5, 10 or 15 mmHg pressure-sensing settings.This device attempts to allow real-time feedback to the user on the pressure within the ostomy as it relates to stool burden and the need for emptying.It was found that at 15 mmHg there was the highest sensitivity for detecting stool with no significant leakage after the first postoperative week.The final study, by Johansson et al., was specific to reservoir ileo-and urostomies and utilized a soft-tissue-anchored percutaneous port in a dog model [42].
Despite subcutaneous portion integration, the study was terminated due to adverse events related to the lack of implant-skin and implantintestine integration.There were also issues of recurrent superficial infection surrounding the port.Vitala™ CCD 0.341 (−0.099 to 0.780) N/a 0.693 (0.605-0.782) 0.038 (0.002-0.075)N/a 6.8-11 Note: All values except for wear time presented as a pooled rate (95% confidence interval).
Abbreviations: CCD, continence control device; QoL, quality of life.

Riskofbiasandcertaintyofevidence
Bias analyses were completed using the ROBINS-1 and RoB 2 tools (Figures S1 and S2).Two studies had a low risk of bias, 11 studies had moderate risk of bias, eight had serious risk of bias and one did not have enough information to assess bias.Certainty of evidence was very low for all outcomes assessed (Tables S1 and S2).

DISCUSS ION
There have been no previous comprehensive reviews of ostomy continence devices.The present review found that, within the history of ostomy continence devices, two major devices were assessed in several studies that allowed pooling of their outcomes.The Conseal device, developed by Coloplast, was studied over a 24-year period between 1986 and 2010, followed by the Vitala™ CCD, developed by ConvaTec, between 2010 and 2013.The Conseal device is the only device currently available.
Our analysis found that after the advent of ball-valve devices, which did not have much success, the focus transitioned to plug-based devices.When comparing the pooled outcomes of the two main plug-based devices, the Conseal device showed an acceptably low rate of leakage and complications, with rates of continence, device preference and QoL improvement ranging from 67.4% to 73.9%.Additionally, the Conseal device had much fewer complications when compared with the Vitala CCD (13.7% vs. 34.1%).This analysis showed that, when properly used, the Conseal device could provide benefit to ostomy patients with an acceptable risk profile.
It has been shown that leakage is the criterion among ostomy patients that has the highest impact on QoL [43].Worrying about leakage and changing lifestyle and reported wellbeing has been well documented in ostomy patients [44,45].Leakage is prevalent, in that the percentage of patients who report not having episodes of leakage with traditional appliances is <20% [45].In traditional ostomy patients the Ostomy Life Study showed that 65% of ostomy patients experience leakage outside the baseplate at least once a year and 26% experience it at least monthly [46].Additionally, they found that only 14% of patients had a leakage event less than once a year [46].Our analysis showed that the Conseal device was able to reduce the leakage rate down to 10% while maintaining continence, which could represent an advantage.
Among patients with ostomies, a relationship has been shown between frequency of changing the appliance and increased skin complications [13].It has also been shown that increased worry about leakage leads to more device usage [46].These two facts, together with the fact that peristomal skin complications occur with an incidence of up to 43% [47], imply a need for a low-leakage device that improves patients' QoL.As previously stated, skin complications are limited with reduced leakage and when ostomy appliances are changed ideally every 3-7 days [13].The combination of these factors makes the selection of patients who will benefit from continence devices an important consideration that is likely to have led to their lack of widespread adoption.
The Conseal device showed a good combination of improved QoL and preference over a traditional appliance with wear times of 8-16.5 h, low leakage, and low rates of complications.The authors of this study suggest that continence devices, specifically the Conseal device, could be best utilized in patients with low-output ostomies on an as-needed basis for life events that require increased continence and discretion to improve QoL.However, the daily usage of this device is not recommended after our review, as frequent changes could increase skin complications.
Five experimental devices have been investigated since 2011 in both human and animal models.Both human models utilized an implantable baseplate and a plug system with two animal models using a plug system and one ball-valve system.None of these experimental devices reached optimal satisfaction or complication rates.This result further emphasizes that ostomy continence is relevant to patient care and QoL but a durable and reliable solution is not available.
The limitations of our study are the high heterogeneity, low certainty of evidence and the moderate to serious risk of bias in the included studies.As only one study was a randomized trial, the retrospective and descriptive nature of the studies included, in addition to the large time span over which they were performed, probably accounts for these limitations.To minimize the heterogeneity, leaveone-out analyses were performed.The increased continence after the exclusion of the study by Soliani [31] is probably because this study reported continence over a 48-h period rather than per device usage as reported in the other studies.This led the authors to conclude that the possible increase in continence is more pronounced with shorter wear and selective rather than continuous usage.
The increased complications after the exclusion of the studies by Burcharth et al. [26] and Codina Cazador et al. [33] is probably because these studies reported no complications.

CON CLUS ION
Ostomy continence has been a long-standing goal without a reliable daily solution.We propose that the selective and short-term usage of continence devices could potentially lead to improved continence and QoL in patients with ostomies.Further research is needed to develop a reliable daily device for ostomy continence.In addition, continence for ileostomates also requires investigation.
Abbreviations: CCD, continence control device; QoL, quality of life.

F I G U R E 2
Evolution of continence devices.PRISMA 2020 flow diagram for new systematic reviews which included searches of databases and registers only.