Sphinkeeper Procedure for Treating Severe Faecal Incontinence-A Prospective Cohort Study

Problems with repairing gut sphincters malfunctions

Correcting a gut sphincter malfunction is a difficult problem. Because each sphincter has two opposite functions, that of closure and opening, repairing one there is a risk of damaging the other. Indeed, widening a narrow sphincter, such as lower esophageal sphincter (LES) and anal sphincter, may cause gastroesophageal reflux and fecal incontinence, respectively, whereas narrowing a wide sphincter, may cause a difficult transit. All the corrective treatments for difficult or retrograde transit concerning LES and anal sphincter with their unwanted consequences have been analyzed and discussed. To overcome the drawbacks of sphincter surgical repairs, researchers have devised devices capable of closing and opening the gut lumen, named artificial sphincters (ASs). Their function is based on various mechanisms, e.g., hydraulic, magnetic, mechanical etc, operating through many complicated components, such as plastic cuffs, balloons, micropumps, micromotors, connecting tubes and wires, electromechanical clamps, rechargeable batteries, magnetic devices, elastic bands, etc. Unfortunately, these structures may facilitate the onset of infections and induce a local fibrotic reaction, which may cause device malfunctioning, whereas the compression of the gut wall to occlude the lumen may give rise to ischemia with erosions and other lesions. Some ASs are already being used in clinical practice, despite their considerable limits, while others are still at the research stage. In view of the adverse events of the ASs mentioned above, we considered applying bioengineering methods to analyze and resolve biomechanical and biological interaction problems with the aim to conceive and build efficient and safe biomimetic ASs.

Endosonographic monitoring of Sphinkeeper® prostheses movements: does physical activity have an impact?

The Sphinkeeper® procedure for treating faecal incontinence (FI) may be associated with potential implant migration (IM) and dislocation (ID), with considerable variations regarding their occurrence and effects on consecutive functional outcome. This study assessed IM and ID following the Sphinkeeper® procedure and its correlation with physical activity. This was a prospective observational clinical study of ten patients undergoing Sphinkeeper® operation due to FI between August 2020 and November 2020 at the Medical University of Vienna. Patients were followed-up after 1, 2, 3 and 6 months and 1 year postoperatively. Each follow-up visit included endosonographic monitoring of protheses location and manometric examinations. Additionally, functional outcome and physical activity were assessed using validated standardized questionnaires. The median number of prostheses implanted was 10 (IQR 9-10). The St. Mark's incontinence (SMS) score improved significantly until the last follow-up (p = 0.049), without observing a significant effect on the physical SF-12 score. The median rate of implants leading to IM and ID was 3 (range 1-4) and 2 (range 1-2) after 3 months of follow-up. A strong association of deltaSMS with number of dislocated prostheses at one month after Sphinkeeper® implantation was observed (r = 0.654, p = 0.078). Physical activity, assessed by the international physical activity questionnaire, did not have an impact on the correct prosthesis placement (1 month: p = 0.527; 2 months: p = 0.886; 3 months: p = 0.180; 6 months: p = 0.111). IM and ID of Sphinkeeper® prostheses occurred frequently early after surgery and affected functional outcome negatively. Physical activity did not have an influence on the implants displacement.

Long-term outcome after SphinKeeper® surgery for treating fecal incontinence-who are good candidates?

PURPOSE

The efficacy of the novel SphinKeeper® procedure for the treatment of fecal incontinence (FI) is not yet well defined. This study aimed to assess long-term functional outcomes after SphinKeeper® surgery.

METHODS

We included 32 patients with FI (28 female), who were operated at a tertiary referral center between August 2018 and September 2021. Functional outcome and quality of life were evaluated prospectively using validated questionnaires before and after surgery. Additionally, endoanal ultrasound and anal manometry were conducted prior and after SphinKeeper® implantation. Predictive parameters for treatment success were defined.

RESULTS

The mean follow-up time was 22.62 ± 8.82 months. The St. Mark's incontinence score decreased significantly after surgery (median preoperative = 19 (IQR 17-22) versus median last follow-up = 12 (IQR 8-16), p = 0.001). Similarly, physical short-form health survey showed a significant improvement after SphinKeeper® implantation (p = 0.011). Patients with a higher degree of internal sphincter defect showed an improved objective therapy success (r = 0.633, p = 0.015) after SphinKeeper® operation, whereas the type and severity of FI had no impact on the functional outcome. Notably, a higher number of dislocated prostheses (r = 0.772, p = 0.015) showed a significant correlation with reduced improvement of incontinence.

CONCLUSION

The SphinKeeper® procedure showed a significant long-term functional improvement in over half of the patients. Patients with a higher internal sphincter defect benefited most, whereas dislocation of the prostheses was associated with less favorable results.

Artificial sphincters: An overview from existing devices to novel technologies

Artificial sphincters (ASs) are used to replace the function of the biological sphincters in case of severe urinary and fecal incontinence (UI and FI), and gastroesophageal reflux disease (GERD). The design of ASs is established on different mechanisms, e.g., magnetic forces or hydraulic pressure, with the final goal to achieve a implantable and durable AS. In clinical practice, the implantation of in-commerce AS is considered a reasonable solution, despite the sub-optimal clinical outcomes. The failure of these surgeries is due to the malfunction of the devices (between 46 and 51%) or the side effects on the biological tissues (more than 38%), such as infection and atrophy. Concentrating on this latter characteristic, particular attention has been given to the interaction between the biological tissues and AS, pointing out the closing mechanism around the duct and the effect on the tissues. To analyze this aspect, an overview of existing commercial/ready-on-market ASs for GERD, UI, and FI, together with the clinical outcomes available from the in-commerce AS, is given. Moreover, this invited review discusses ongoing developments and future research pathways for creating novel ASs. The application of engineering principles and design concepts to medicine enhances the quality of healthcare and improves patient outcomes. In this context, computational methods represent an innovative solution in the design of ASs, proving data on the occlusive force and pressure necessary to guarantee occlusion and avoid tissue damage, considering the coupling between different device sizes and individual variability.

Clinical effectiveness and safety of self-expandable implantable bulking agents for faecal incontinence: a systematic review

PURPOSE

The purpose of this systematic review is to evaluate whether self-expandable implantable vs non-self-expandable injectable bulking agents (second-line therapies) are equal/superior in terms of effectiveness (severity, quality of life [QoL]) and safety (adverse events) for faecal incontinence (FI).

METHODS

A systematic review was conducted, and five databases were searched (Medline via Ovid, Embase, Cochrane Library, University of York Centre for Reviews and Dissemination, and International Network of Agencies for Health Technology database). In-/exclusion criteria were predefined according to the PICOS scheme. The Institute of Health Economics risk of bias (RoB) tool assessed studies' internal validity. According to the Grading of Recommendations, Assessment, Development and Evaluation approach, the strength of evidence for safety outcomes was rated. A qualitative synthesis of the evidence was used to analyse the data.

RESULTS

The evidence consists of eight prospective single-arm, before-after studies (166 patients) fulfilling the inclusion criteria for assessing clinical effectiveness and safety of implantable bulking agents. FI severity statistically significantly improved in five of seven studies rated by the Cleveland Clinic FI Score and in three of five studies measured by the Vaizey score. Statistically significant improved disease-related QoL was found in one of five studies measured by the FI QoL Score and in one of two studies rated by the American Medical Systems score. Procedure-related adverse events occurred in 16 of 166 patients (i.e., intraoperative complications, anal discomfort and pain). Device-related adverse events occurred in 48 of 166 patients, including prostheses' dislodgement and removed/extruded prostheses. Studies were judged with moderate/high RoB. The strength of evidence for safety was judged to be very low.

CONCLUSION

Implantable bulking agents might be an effective and safe minimally invasive option in FI treatment if conservative therapies fail. FI severity significantly improved, however, effects on QoL need to be explored in further studies. Due to the uncontrolled nature of the case series, comparative studies need to be awaited.