Surgical management of perianal fistula using an ovine forestomach matrix implant

PURPOSE

Invasive surgical management of cryptoglandular perianal fistulas (PF) is challenging because of high recurrence rates and the potential for injury to the sphincter complex. In the present technical note, we introduce a minimally invasive treatment for PF using a perianal fistula implant (PAFI) comprising ovine forestomach matrix (OFM).

METHODS

This retrospective observational case series highlights 14 patients who had undergone a PAFI procedure at a single center between 2020 and 2023. During the procedure, previously deployed setons were removed and tracts were de-epithelialized with curettage. OFM was rehydrated, rolled, passed through the debrided tract, and secured in place at both openings with absorbable suture. Primary outcome was fistula healing at 8 weeks, and secondary outcomes included recurrence or postoperative adverse events.

RESULTS

Fourteen patients underwent PAFI using OFM with a mean follow-up period of 37.6 ± 20.1 weeks. In follow-up, 64% (n = 9/14) had complete healing at 8 weeks and all remained healed, except one at last follow-up visit. Two patients underwent a second PAFI procedure and were healed with no recurrence at the last follow-up visit. Of all patients that healed during the study period (n = 11), the median time to healing was 3.6 (IQR 2.9-6.0) weeks. No postprocedural infections nor adverse events were noted.

CONCLUSIONS

The minimally invasive OFM-based PAFI technique for PF treatment was demonstrated to be a safe and feasible option for patients with trans-sphincteric PF of cryptoglandular origin.

Advances in Organoid Culture Research

Organoids are powerful systems to facilitate the study of individuals' disorders and personalized treatments because they mimic the structural and functional characteristics of organs. However, the full potential of organoids in research has remained unrealized and the clinical applications have been limited. One of the reasons is organoids are most efficient grown in reconstituted extracellular matrix hydrogels from mouse-derived, whose poorly defined, batch-to-batch variability and immunogenicity. Another reason is that organoids lack host conditions. As a component of the tumor microenvironment, microbiota and metabolites can regulate the development and treatment in several human malignancies. Here, we introduce several engineering matrix materials and review recent advances in the coculture of organoids with microbiota and their metabolites. Finally, we discuss current trends and future possibilities to build more complex cocultures.

Technical Refinements with the Use of Biologic Healing Agents

Soft tissue defects resulting from trauma, vascular disease, burns, and postoncologic resections require reconstructive surgery for appropriate wound coverage and support. Dermal substitutes have been applied to a vast array of reconstructive settings across nearly all anatomical areas with demonstrable success. However, they require meticulous handling and operative technical expertise to optimize management of these soft tissue defects. In this review, we will address three dermal substitutes, their operative techniques, and their surgical applications.

Transvaginal Repair of Complex Rectovaginal Fistulas Using the Porcine Urinary Bladder Matrix as an Augmenting Graft

BACKGROUND

After the US Food and Drug Administration issued a safety warning concerning vaginal mesh implants in 2008, their use in correction of pelvic floor defects have decreased in the United States (http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm479732.htm). However, we are still treating patients who have had complications associated with their use, rectovaginal fistulas (RVFs) being one of them. Rectovaginal fistulas are considered complex if greater than 2.5 cm, recurrent, associated with inflammatory bowel disease, or if they are proximal in location. Various surgical techniques have been described for treating RVFs. Interposition grafts such as Martius, gracilis, omental J flaps, and rectus abdominis flaps have been used extensively in correcting RVFs (Am J Gastroenterol 2014;109(8):1141-1157). However, these techniques may increase morbidity or have poor cosmesis. Pelvic surgeons have chronicled the use of biologic grafts for fistula repair. Of the various biologic grafts in use, there have been no reports describing the use of porcine urinary bladder matrix (UBM) for fistula repair. We report on 2 cases of large, complex RVFs secondary to mesh erosion, which were effectively treated with transvaginal repair using the UBM.

CASES

An 80-year-old woman was referred by the colorectal service to our urogynecology service with complaints of rectal bleeding and vaginal spotting secondary to mesh erosion. Surgical history included hysterectomy with mesh augmented posterior repair with synthetic midurethral sling placement in 2002. Examination revealed a 3-cm mesh exposure located in the middle third of the posterior vaginal wall. On rectovaginal examination, a 3-cm full-thickness RVF with through-and-through mesh erosion was noted between the rectum and vagina.A 65-year-old woman presented to our service with complaints of passage of fecal material through the vagina. Surgical history was significant for hysterectomy in 1988 and prolapse repair with anterior and posterior vaginal mesh in 2009. Subsequently in 2011, she had part of the mesh removed because of exposure. Vaginal examination revealed mesh exposure at the right sulcus of the anterior wall consistent with evidence of prior sling and another mesh exposure on the posterior vaginal wall. Rectovaginal examination revealed palpable mesh in the rectovaginal septum with a 3-cm large and complex fistula. Both of our patients underwent transvaginal excision of mesh, RVF repair, and posterior repair with augmentation with UBM. At 6- and 10-month follow-up, they reported complete resolution of their symptoms with no fistula noted on physical examination.

CONCLUSIONS

Typically, traditional repair with use of muscular advancement flaps is performed for complex RVF closures. Recently, however, various biologic agents have been successfully used to augment RVF repair. In our cases, the use of UBM led to successful follow-up at 6 to 8 months. Despite existing literature, there remains a void in the depth of knowledge regarding the UBM grafts. Larger studies utilizing it for repair of RVFs are warranted to further understand the success and effectiveness of the UBM grafts for RVF repair.