Robotic transanal minimally invasive rectal mucosa harvest

Buccal mucosal grafts (BMG) are traditionally used in urethral reconstruction. There may be insufficient BMG for applications requiring large grafts, such as urethral stricture after gender-affirming phalloplasty. Rectal mucosa in lieu of BMG avoids oral impairment, while potentially affording less postoperative pain and larger graft dimensions. Transanal minimally invasive surgery (TAMIS) using laparoscopic instruments has been described. Due to technical challenges of harvesting a sizable graft within the rectal lumen, we adopted a new robotic approach. We demonstrate the feasibility and safety of a novel technique of Robotic TAMIS (R-TAMIS) in the harvest of rectal mucosa for the purpose of onlay graft urethroplasty.

Six patients (ages 28-60) presenting with urethral stricture and one vaginal stricture underwent robotic rectal mucosal harvest. The procedure, which was first studied on an inanimate bovine colon model, was performed under general anesthesia in lithotomy position using the GelPOINT^TM Path Transanal Access. Mucosa was harvested robotically after submucosal hydrodissection. Graft size harvested correlated with surface area needed for urethral or vaginal reconstruction. Following specimen retrieval, flexible sigmoidoscopy confirmed hemostasis. The graft was placed as an onlay for urethroplasty.

There were no intraoperative or postoperative complications. Mean graft size was 11.4 × 3.0 cm. All reconstructions had excellent graft take. All patients recovered without morbidity or mortality. They reported minimal postoperative pain and all regained bowel function on postoperative day one. Patients with prior BMG harvests subjectively self-reported less postoperative pain and greater quality of life. There have been no long-term complications at a median follow-up of 17 months.

To our knowledge, this is the first use of R-TAMIS for rectal mucosa harvest. Our preliminary series indicates this approach is feasible and safe, constituting a promising minimally invasive technique for urethral reconstruction. Prospective studies evaluating graft outcomes and donor site morbidity with more long-term follow-up are needed.