{Reference Type}: Journal Article {Title}: Simultaneous laparoscopic colectomy and liver metastasectomy with natural orifice specimen extraction: A proof-of-concept study. {Author}: Seow-En I;Koh YX;Tan EK;Tan EK; {Journal}: Heliyon {Volume}: 10 {Issue}: 12 {Year}: 2024 Jun 30 {Factor}: 3.776 {DOI}: 10.1016/j.heliyon.2024.e33065 {Abstract}: Background, Natural orifice specimen extraction (NOSE) via the anus or vagina is an alternative to conventional transabdominal specimen extraction in laparoscopic colorectal cancer surgery. NOSE has been shown to be safe and effective, resulting in decreased postoperative pain, analgesia use, and improved recovery, without oncological compromise. We aimed to demonstrate the feasibility of NOSE for combined colectomy with liver metastasectomy. Methods, From July 2022 to April 2024, all cases of laparoscopic colorectal cancer resection and synchronous liver metastasectomy with NOSE were included in the study. Selection criteria included a maximum specimen diameter of less than 5 cm and patient body mass index of less than 35 kg/m2. Results, Over the 22-month duration, four consecutive patients (two males, two females) underwent combined resection with NOSE. Mean age and BMI were 74.8 (range 63-81) years and 20.9 (range 19.5-22.3) kg/m2 respectively. Patient A and D underwent anterior resection for sigmoid cancer, Patient B underwent D3 right hemicolectomy for cecal cancer, and Patient C underwent subtotal colectomy for synchronous cecal and descending colon cancer. All patients underwent liver metastasectomy at the same sitting. Patient A and D had transanal NOSE while Patients B and C underwent transvaginal NOSE. Mean operative time and blood loss was 416 (range 330-535) minutes and 338 (range 50-500) ml respectively. All patients recovered gastrointestinal function within the first two postoperative days. Infected seroma of the liver bed occurred in one patient requiring percutaneous drainage. The average maximum colon tumor diameter was 2.9 (range 1.3-4.0) cm. All resection margins were clear. Mean duration of follow-up was 7.5 (range 2-12) months. Conclusions, Simultaneous colectomy and liver metastasectomy with NOSE for colorectal cancer is feasible and safe in highly selected patients, resulting in good postoperative outcomes. This proof-of-concept analysis paves the way for larger studies to draw definitive conclusions.