AP-NOSES: A Prospective Multicentre Registry of Natural Orifice Specimen Extraction in Minimally Invasive Colorectal Surgery

Official title

AP-NOSES: A Prospective, Multicentre Registry of Natural Orifice Specimen Extraction in Minimally Invasive Colorectal Surgery Across the Asia-Pacific Region

Overview

Natural orifice specimen extraction (NOSE) is a minimally invasive colorectal surgical technique in which the surgical specimen is removed through a natural orifice, including transanal or transvaginal routes, thereby avoiding an abdominal extraction incision. Observational studies suggest that NOSE may reduce wound-related morbidity and improve postoperative recovery, but prospective multicenter data evaluating long-term outcomes remain limited. AP-NOSES is a prospective, multicenter observational registry evaluating clinical, patient-reported, and long-term wound outcomes following minimally invasive colorectal surgery with NOSE or transabdominal specimen extraction. The primary objective is to compare time to incisional hernia within 24 months between NOSE-eligible patients undergoing planned NOSE extraction and NOSE-eligible patients undergoing planned transabdominal extraction. Secondary objectives include evaluation of postoperative complications, extraction-related morbidity, bowel function, urinary and sexual function, oncologic outcomes, and long-term patient-reported and clinical outcomes across participating centers. This study does not alter routine clinical care. Surgical technique, perioperative management, and follow-up are performed according to local institutional practice.

Detailed description

Natural orifice specimen extraction (NOSE) is an established minimally invasive colorectal surgical technique that enables removal of the surgical specimen through transanal or transvaginal routes while avoiding an abdominal specimen extraction incision. Existing retrospective studies and meta-analyses suggest that NOSE may reduce postoperative pain, wound morbidity, and length of hospital stay without compromising oncologic outcomes. However, prospective multicenter data evaluating long-term abdominal wall outcomes and patient-reported outcomes remain limited.

Incisional hernia is a common long-term complication following colorectal surgery and is closely associated with the abdominal extraction site. By avoiding an abdominal extraction incision, NOSE may reduce extraction-site morbidity and long-term incisional hernia risk. AP-NOSES was designed to prospectively evaluate these outcomes in a multicenter setting using predefined eligibility criteria and a concurrent comparator cohort.

AP-NOSES is a prospective observational multicenter registry coordinated by Singapore General Hospital. Consecutive adult patients undergoing elective minimally invasive colorectal resection with planned intact specimen extraction are eligible for enrollment. Participating centers include tertiary colorectal units within the Asia-Pacific region.

The primary comparative analysis is conducted within a predefined NOSE-eligible cohort. Exposure groups are defined according to planned specimen extraction strategy:

1. Planned NOSE extraction (transanal or transvaginal), and 2. Planned transabdominal extraction among patients meeting protocol NOSE eligibility criteria.

Planned and achieved extraction routes, reasons for non-performance of NOSE, operative details, postoperative complications, and oncologic outcomes are prospectively recorded.

The primary outcome is time to incisional hernia within 24 months following index colorectal surgery.

Secondary outcomes include postoperative complications, extraction-site morbidity, surgical site infection, readmission, reoperation, pathologic outcomes, patient-reported quality-of-life and functional outcomes, bowel function, urinary and sexual function in selected patients, and oncologic outcomes including recurrence and disease-free survival.

Patient-reported outcomes are assessed using validated instruments including EQ-5D-5L, Body Image Scale (BIS), Low Anterior Resection Syndrome (LARS) score, International Prostate Symptom Score (IPSS), International Index of Erectile Function-5 (IIEF-5), and Female Sexual Function Index-6 (FSFI-6), where applicable.

This study is observational and does not mandate changes to standard surgical or postoperative management. Data are entered into a secure centralized REDCap database using coded study identifiers.

Interventions

• Procedure Natural Orifice Specimen Extraction
  Specimen extraction through a natural orifice, including transanal or transvaginal extraction, during minimally invasive colorectal surgery.
• Procedure Transabdominal Specimen Extraction
  Specimen extraction through an abdominal incision during minimally invasive colorectal surgery.

Primary outcome measures

• Time to Incisional Hernia Within 24 Months [Time frame: 24 months after index surgery]

Secondary outcome measures (10)

• Overall Postoperative Complications [Time frame: 30 days after surgery]
• Surgical Site Infection [Time frame: 30 days after surgery]
• Extraction-Site Complications [Time frame: 30 days after surgery]
• Length of Hospital Stay [Time frame: From date of surgery until hospital discharge, up to 30 days]
• EQ-5D-5L Score [Time frame: Baseline, 6 months, and 12 months after surgery]
• Body Image Scale (BIS) Score [Time frame: Baseline, 6 months, and 12 months after surgery]
• Low Anterior Resection Syndrome (LARS) Score [Time frame: 6 months and 12 months after surgery]
• Local Recurrence [Time frame: Up to 24 months after surgery]
• Distant Recurrence [Time frame: Up to 24 months after surgery]
• Disease-Free Survival [Time frame: Up to 24 months after surgery]

Eligibility criteria

Inclusion criteria

• Age 21 years or older
• Elective minimally invasive colorectal resection (laparoscopic or robotic intent)
• Planned intact specimen extraction
• Eligible for natural orifice specimen extraction (NOSE) or transabdominal specimen extraction according to study protocol
• Ability to provide informed consent

Exclusion criteria

• Emergency colorectal surgery
• Planned transanal total mesorectal excision (TaTME)
• Planned ultralow anterior resection with planned anastomosis 3 cm or less from the anal verge
• Planned abdominoperineal resection (APR)
• Planned permanent end stoma without restoration of intestinal continuity
• Planned multivisceral resection
• Generalized peritonitis or uncontrolled intra-abdominal sepsis
• Pregnancy
• Pre-existing ventral or incisional hernia at the planned extraction site
• Planned specimen extraction through a prior laparotomy incision containing mesh
• Fixed distal obstruction, severe pelvic stenosis, or other anatomical constraint precluding intact specimen extraction

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Observational model

Cohort

Study locations

Singapore · 1 center

• Singapore General Hospital — Singapore

Publications

• den Hartog FPJ, van Egmond S, Poelman MM, Menon AG, Kleinrensink GJ, Lange JF, Tanis PJ, Deerenberg EB. The incidence of extraction site incisional hernia after minimally invasive colorectal surgery: a systematic review and meta-analysis. Colorectal Dis. 2023 Apr;25(4):586-599. doi: 10.1111/codi.16455. Epub 2023 Jan 5. PMID 36545836
• Chin YH, Decruz GM, Ng CH, Tan HQM, Lim F, Foo FJ, Tai CH, Chong CS. Colorectal resection via natural orifice specimen extraction versus conventional laparoscopic extraction: a meta-analysis with meta-regression. Tech Coloproctol. 2021 Jan;25(1):35-48. doi: 10.1007/s10151-020-02330-6. Epub 2020 Aug 26. PMID 32851500
• Guan X, Liu Z, Longo A, Cai JC, Tzu-Liang Chen W, Chen LC, Chun HK, Manuel da Costa Pereira J, Efetov S, Escalante R, He QS, Hu JH, Kayaalp C, Kim SH, Khan JS, Kuo LJ, Nishimura A, Nogueira F, Okuda J, Saklani A, Shafik AA, Shen MY, Son JT, Song JM, Sun DH, Uehara K, Wang GY, Wei Y, Xiong ZG, Yao HL, Yu G, Yu SJ, Zhou HT, Lee SH, Tsarkov PV, Fu CG, Wang XS; International Alliance of NOSES. Interna PMID 30792863

Identifiers

NCT: NCT07615036 · 2026-0237

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗