Da Vinci robot-assisted pull-through in secondary megarectum resection after anorectal malformation surgery

Purpose Some children with anorectal malformations (ARMs) acquire secondary megarectum (SMR) following anorectoplasty, leading to intractable constipation and overflow fecal incontinence. Currently, there is no established treatment for this condition. This study aims to characterize the clinical features of SMR following anorectoplasty for ARMs and to evaluate the outcomes of the da Vinci robot-assisted pull-through procedure. Methods Between October 2022 and June 2023, a total of 14 children with recurrent constipation following anorectal malformation surgery presented to our department, of whom 8 were included in this clinical analysis based on the established criteria. Results This cohort included 5 males and 3 females, comprising 3 cases of intermediate-type and 5 cases of low-type ARMs. All patients underwent the da Vinci robot-assisted pull-through procedure to resect the megarectum (MR) due to recurrent constipation following anorectoplasty. The age at the time of surgery ranged from 30.4 to 50.6 months, with a median age of 38.8 months. According to the Krickenbeck classification (2005), postoperative constipation improved significantly in 7 patients, with 5 cases achieving complete resolution from grade 3 and 2 improving from grade 3 to grade 1; one patient, however, remained at grade 3. Preoperatively, 6 patients presented with soiling; postoperatively, this symptom improved in 5 cases, while 1 case remained unchanged at grade 1. Postoperative pathology revealed thickened nerve plexuses, disordered and thickened muscle fibers with degeneration, thickened submucosa in the distal intestinal wall, and increased collagen deposition. No obvious abnormalities were observed in the number or distribution of ganglion cells. Conclusion Resecting MR following anorectal malformation repair significantly alleviates constipation in pediatric patients. The da Vinci robot-assisted pull-through procedure facilitates precise dissection of the abdominal and pelvic anatomy, which minimizes tissue trauma.