EP902 - Lessons From a Case Series of Veterans Undergoing Robotic Sigmoid Colectomy using Natural Orifice Specimen Extraction (NOSE)

Purpose/Background: Minimally invasive colorectal resection using transrectal specimen extraction and intracorporeal anastomosis to minimize abdominal incisions has multiple patient benefits including reduced post-operative pain, lower oral morphine equivalents used, and lower hernia rates. Widespread adoption of natural orifice extraction has been limited, with surgeons citing barriers of added operative time and technical difficulty. We report a case series of patients undergoing robotic sigmoid colectomy using natural orifice specimen extraction (NOSE) for non-malignant indications performed at a small VA hospital between 2022-2024 and discuss technical lessons learned.

Methods/Interventions: This is a case series study of patients who underwent elective robotic sigmoid colectomy with NOSE by a single colorectal surgeon. Surgeries were performed using the DaVinci Xi Robot. Colon specimens were extracted using ring forceps through a small 2.5-6cm wound protector within the rectum. To place the wound protector, the rectal stump was first dilated using EEA sizers; then the wound protector was introduced by folding one of the rings. Perioperative patient data was extracted from electronic medical records. Illustrative photos were captured of operating room tools and from operation recordings.

Results/Outcomes: In this small series of six patients, NOSE was achieved in all six procedures and intracorporeal anastomosis was achieved in five patients. Mean specimen extraction time was 40.5 minutes and ranged from 21 to 58 minutes. Specimen morcellation was required in 50% of cases due to chronic inflammation. Median time for return of bowel function was 1.5 days and median LOS was 4 days. While two of the six patients experienced post-operative ileus and one patient had post-operative urinary retention, no major complications occurred (Table 1). Key technical steps that facilitated operative efficiency included 1) Modification of the wound protector device by suturing one end of the ring together using three 0-Vicryl sutures to promote easy passage through the rectum, and 2) Morcellation using Robotic scissors on cutting mode, when morcellation was indicated (Figure 1.)

Conclusion/Discussion: In select patients, NOSE can be achieved safely without significant extension in operative time. Efficiency improved with refinement of the technical steps outlined above. Long Kocher clamps, not currently available at this VA hospital, would be a superior instrument with which to grasp the specimen. When chronic inflammation of the colon is present, morcellation should be anticipated and is best performed using monopolar scissors using the cutting function. This case series demonstrates that NOSE is safe and technically feasible, but additional investigation is needed to assess its impact on clinical outcomes when compared to traditional transabdominal specimen extraction.

Figure 1: NOSE Key Technical Steps – Pearls and Pitfalls
A. Specimen Extraction Instrument Tray. B Modified Wound Protector. C. Insertion of Wound Protector Through Rectum. D. Intact Specimen Removal with Ring Forcep E. Slow Specimen Morcellation with Vessel Sealer. F. Efficient Specimen Morcellation with Monopolar Scissor with Prograsps Holding Tension.

Table 1: NOSE Operative Factors and Patient Outcomes