Rectovaginal fistulas (RVFs) and anovaginal fistulas are abnormal communications between the rectum/anus and the vagina. They are most often secondary to obstetric injury, occurring in approximately 0.1% of vaginal births [1]. Other causes include infections, inflammatory and neoplastic conditions, and iatrogenic injuries. Despite their rarity, RVFs are an important problem, resulting in significant morbidity with demonstrable negative impacts on patients’ quality of life [1,2]. Despite numerous treatment modalities that have evolved over time, RVFs remain difficult problems to manage, and many patients fail several attempts at repair [1]. The procedure of choice for a simple RVF is an endorectal advancement flap, with reported success rates in the range of 41%-78% [2]. Recurrent and complex RVFs may require other surgical techniques, including fecal diversion, sphincteroplasty, muscle flaps, or even rectal resections (Multimedia Appendix 1) [3]. The variety of different techniques utilized in the surgical management of RVFs illustrates the complexity of this problem.

A buccal mucosal graft (BMG) is an oral mucosal tissue harvested from the inner cheek or lower lip. It is frequently used for the repair of urethral defects, including rectourethral and vesicovaginal fistulae [4-8]. This technique was popularized after 1992 and is the first-choice graft tissue for urethroplasty in the repair of male urethral strictures [4,9] The use of oral mucosa is favored by urologists because of its similarities and compatibility with the mucosa of the urethral tract. The buccal mucosa is a nonkeratinized tissue, and its thick epithelium with vascular lamina propria gives it strength and adaptability to withstand the shearing forces in the mouth as well as defend against the microbial environment of the oral cavity [10]. Complications from BMGs are rare. A systematic review found a 4% complication rate occurring at the buccal donor site—most commonly scarring and contracture. Bleeding and hematoma formation occurred in <1% of cases. Patients can expect to have mild pain and discomfort for up to 4 weeks postoperatively. Patients may have limited range of jaw opening, but most return to preoperative range within 4 weeks [10].

A systematic review of the literature was undertaken to identify whether BMGs have previously been used in the repair of RVFs. The electronic databases of Ovid MEDLINE, Embase, Cochrane Library (Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials), and CINAHL (all years) were systematically searched for studies reporting on BMGs used for RVFs. The following medical subject heading terms were used: rectovaginal fistula, rectovaginal fistul* or recto-vaginal fistul* or anorectal vaginal fistul* or rectoneovaginal fistul* or recto-neovaginal fistul* or RVF or ARVF or AVF. All studies reporting on the use of BMGs for RVFs were considered eligible, and no restrictions were applied. Two case reports were identified:

These 2 reports demonstrated the successful use of buccal mucosa as a graft repair for an RVF. To our knowledge, these are the only such published accounts. Additional details from these case reports can be found in Table S2 of Multimedia Appendix 2.

This protocol is modelled from the IDEAL (Idea, Development, Exploration, Assessment, Long-term follow-up) framework for surgical innovation, which describes the stages of optimal surgical innovation: idea, development, exploration, assessment, and long-term follow-up [13]. The goal of this framework is to improve the quality of research in surgical and interventional procedures.

We hypothesize that an autologous BMG can successfully repair an RVF. Our objective is to validate the findings of the aforementioned case reports while also reporting on the safety, short-term outcomes, and technical details of the procedure (in keeping with the IDEAL framework for surgical innovation [13]).

This study is a prospective single-surgeon case series.

This study has been approved by the Conjoint Health Research Ethics Board at the University of Calgary (REB20-1123).

Patients will be recruited by a colorectal surgeon from a university-affiliated academic tertiary care hospital in Calgary, Alberta (Canada). Given the rarity of RVFs, the estimated recruitment is between 3 and 5 patients. The inclusion criteria are as follows: (1) female patients with a clinical or imaging diagnosis of a rectovaginal or anovaginal fistula; (2) fistula resulting from obstetrical injury, infection, inflammatory bowel disease, or radiation; (3) any number of recurrent fistulas; (4) fistula ≤2.5 cm diameter; and (5) adults ≥18 years of age. The exclusion criteria are as follows: (1) fistula resulting from neoplasia and (2) fistula >2.5 cm. Patients who meet the inclusion criteria and none of the exclusion criteria will be offered the opportunity to participate in this study. They will be provided with all the relevant information for informed consent verbally and in writing. If they decide to participate, they will be asked to sign informed consent.

The variables for data collection and analysis are described in Textbox 1.