Tailoring surgery for obstructed defecation syndrome to the 'iceberg diagram': Long-term results

Analysis of factors that indicated surgery in 400 patients submitted to a complete diagnostic workup for obstructed defecation syndrome and rectal prolapse using a supervised machine learning algorithm

BACKGROUND

Patient selection is extremely important in obstructed defecation syndrome (ODS) and rectal prolapse (RP) surgery. This study assessed factors that guided the indications for ODS and RP surgery and their specific role in our decision-making process using a machine learning approach.

METHODS

This is a retrospective analysis of a long-term prospective observational study on female patients reporting symptoms of ODS who underwent a complete diagnostic workup from January 2010 to December 2021 at an academic tertiary referral center. Clinical, defecographic, and other functional tests data were assessed. A supervised machine learning algorithm using a classification tree model was performed and tested.

RESULTS

A total of 400 patients were included. The factors associated with a significantly higher probability of undergoing surgery were follows: as symptoms, perineal splinting, anal or vaginal self-digitations, sensation of external RP, episodes of fecal incontinence and soiling; as physical examination features, evidence of internal and external RP, rectocele, enterocele, or anterior/middle pelvic organs prolapse; as defecographic findings, intra-anal and external RP, rectocele, incomplete rectocele emptying, enterocele, cystocele, and colpo-hysterocele. Surgery was less indicated in patients with dyssynergia, severe anxiety and depression. All these factors were included in a supervised machine learning algorithm. The model showed high accuracy on the test dataset (79%, p < 0.001).

CONCLUSIONS

Symptoms assessment and physical examination proved to be fundamental, but other functional tests should also be considered. By adopting a machine learning model in further ODS and RP centers, indications for surgery could be more easily and reliably identified and shared.

Laparoscopic ventral mesh rectopexy vs. transperineal mesh repair for obstructed defecation syndrome associated with rectocele: comparison of selectively distributed patients

PURPOSE

Obstructed defecation syndrome represents 50-60% of patients with symptoms of constipation. We aimed to compare the two frequently performed surgical methods, laparoscopic ventral mesh rectopexy and transperineal mesh repair, for this condition in terms of functional and surgical outcomes.

METHODS

This study is a retrospective review of 131 female patients who were diagnosed with obstructed defecation syndrome, attributed to rectocele with or without rectal intussusception, enterocele, hysterocele or cystocele, and who underwent either laparoscopic ventral mesh rectopexy or transperineal mesh repair. Patients were evaluated for surgical outcomes based on the operative time, the length of hospital stay, operative complications, using prospectively designed charts. Functional outcome was assessed by using the Initial Measurement of Patient-Reported Pelvic Floor Complaints Tool.

RESULTS

Fifty-one patients diagnosed with complex rectocele underwent laparoscopic ventral mesh rectopexy, and 80 patients diagnosed with simple rectocele underwent transperineal mesh repair. Mean age was found to be 50.35 ± 13.51 years, and mean parity 2.14 ± 1.47. Obstructed defecation symptoms significantly improved in both study groups, as measured by the Colorectal Anal Distress Inventory, Constipation Severity Instrument and Patient Assessment of Constipation-Symptoms scores. Minor postoperative complications including wound dehiscence (n = 3) and wound infection (n = 2) occurred in the transperineal mesh repair group.

CONCLUSION

Laparoscopic ventral mesh rectopexy and transperineal mesh repair are efficient and comparable techniques in terms of improvement in constipation symptoms related to obstructed defecation syndrome. A selective distribution of patients with or without multicompartmental prolapse to one of the treatment arms might be the preferred strategy.

A modified myotomy of the puborectalis for anismus

Anismus or non-relaxing puborectalis muscle (PRM) on straining may affect over 40% of patients with obstructed defecation (OD). Management is usually with biofeedback, or botulin toxin injection or partial puborectalis muscle myotomy. Such a procedure can be difficult technically. Bleeding and rectal injury may occur when detaching the PRM from the rectum. A partial modification of surgical technique may avoid these complications. The diagnosis should be confirmed with exclusion of sphincter compromise. Through two cutaneous incisions, an Ellis forceps is advanced through the ischio-rectal space, whilst finger pressure per rectum allows the puborectalis to be visualized and grasped by the forceps. Removal of some ischiorectal fat may be necessary to allow division of half the PRM under direct view. From October 2020 to October 2021, 5 patients underwent the modified technique in our department (4 males, median age 43 years [range 34-58 years], median follow-up 6 months [range 2-12 months]). No patients suffered from injury of the rectum or bleeding during or after surgery. Operative time was 30 min less than conventional PRM division, as the time-consuming "blind dissection" of PRM was avoided. Four patients regained appropriate relaxation of the PRM on straining. One male patient had temporary minor anal incontinence for 2 weeks. One male patient with severe mental distress continued to have with anismus and OD after surgery and refused psychiatric support. This modified procedure is feasible and safe and quicker than our conventional technique. More cases with longer follow-up are needed to confirm its efficacy.