The obstructive defecation syndrome (ODS) is a common condition of the pelvic floor or rectum that can lead to a significant impairment of quality of life [1 - 5]. The causes of ODS are multifactorial and can be morphological or functional in nature. Accurately assigning symptoms and findings, as well as choosing the right therapy, is therefore a challenge.
One of the most common morphological findings in ODS is the rectocele, a bulging of the rectal wall. The ventral rectocele is the most common form. The symptoms of a rectocele often include a feeling of incomplete or fragmented stool evacuation, followed by renewed urge to defecate and attempts at evacuation. However, the size of the rectocele does not always correlate with the severity of the symptoms. The primary therapy for rectocele is conservative, and surgical therapy should only be considered if conservative therapy is unsuccessful [5].
Deciding whether the rectocele is the cause of ODS symptoms ("symptomatic rectocele") is often difficult, as the rectocele usually occurs in combination with other pelvic floor dysfunctions [3, 5, 6]. Conservative therapy is always indicated, and surgical indication should only be made for "symptomatic" rectoceles [7 - 10].
The surgical therapy concepts include conventional, laparoscopic, or robot-assisted transabdominal procedures (e.g., resection rectopexy, rectopexy), as well as transanal, transperineal, and transvaginal operations (e.g., STARR, Delorme operation, posterior colporrhaphy). The principle of all surgical procedures is either the positive influence or elimination of a morphologically induced stool evacuation disorder by reducing the rectal reservoir (transanal or transperineal procedures) or by eliminating morphological "obstructions" using transabdominal procedures. Despite exhaustive conservative treatment and strict patient selection, surgical correction of "pathological" morphological findings is not a priori associated with an expected functional success. This applies to all surgical procedures [11 – 14].
In principle, the surgical therapy options for rectocele are controversially discussed, with the focus on a rectocele as a singular cause of evacuation disorder often not leading to therapeutic success [3, 13, 14]. Transanal rectocele resections are based on the assumption that the rectocele is decisive for the symptoms. Thus, many working groups consider transanal rectocele correction as an effective therapy option, although a generally valid recommendation is not possible due to the limited data situation [13]. Numerous studies report high functional success rates after transanal rectocele correction in a rectocele associated with ODS, with the surgical procedures differing.
Most commonly, a modified Delorme operation is performed, where a primary horizontal mucosal incision is made approximately 1–2 cm proximal to the dentate line. This is followed by a submucosal or mucosal dissection proximally, followed by a semicircular muscular "wall duplication" in a longitudinal direction to achieve stabilization of the rectovaginal space. Finally, the redundant rectal mucosa is partially resected and closed with absorbable suture material. However, the surgical procedure "transanal rectocele correction" has no standardization, and several individual or modified surgical techniques are described, differing in various details [15, 16, 17]. Abbas et al. report high functional success rates in their experiences with the "ventral Delorme operation" for the elimination of stool evacuation disorder and improvement of continence in long-term follow-up [18]. Furthermore, some authors recommend a transanal rectocele resection with the stapler in the sense of a full-thickness anterior wall resection ("transanal repair of rectocele and rectal mucosectomy with one circular Stapler", TRREMS; [19]). The results are promising, but there are no generally valid standards that allow validated assessment.
In evaluating the surgical therapy for stool evacuation disorder – and this applies particularly to the rectocele – it remains to be emphasized that especially with the ventral rectocele, the question ultimately remains unanswered whether the rectocele is the cause of the symptoms of stool evacuation disorder or merely an epiphenomenon, i.e., just the "tip of the iceberg" [8, 20]. This diagnostic and therapeutic dilemma in stool evacuation disorder in general and in rectocele in particular has not yet been clarified and has led to the surgical indication for symptomatic rectocele being extremely reserved [21, 22, 23].