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Colorectal NeoplasmsAP-NOSESNCT07615036

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

An observational study of Colorectal Neoplasms and Incisional Hernia, run by Singapore General Hospital at 1 site in Singapore.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
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Trial summary

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. Read more about this study

Who is it for?
Ages 21 years and older
Conditions the study is for
Colorectal Neoplasms, Incisional Hernia
What is being tested?
Natural Orifice Specimen Extraction and Transabdominal Specimen Extraction
Type of treatment
Surgery or procedure
How many people
800 participants
Where
1 siteSingapore
Study dates
5 May 2026to 30 Dec 2033
Phase
Observational
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 21 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Study population: Adult patients undergoing elective minimally invasive colorectal resection with planned intact specimen extraction at participating tertiary colorectal centers in the Asia-Pacific region.

Who may be able to join

  • 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

Who cannot join

  • 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
Show all 11Show fewer
  • 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

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

Isaac Seow-En, MBBS, FRCSEd contact

+6563213853

isaac.seow.en@singhealth.com.sg

Singapore1 site, 1 recruiting
  • Singapore General Hospital

    Singapore, 169608

    Isaac Seow-En, MBBS, FRCSEd, +6563213853, isaac.seow.en@singhealth.com.sg

    Recruiting

Other trials in Singapore

About this study

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

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.

Read more

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.

Read the 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.

Being tested
Natural Orifice Specimen Extraction, Transabdominal Specimen Extraction
Keywords
Natural Orifice Specimen Extraction, NOSE surgery, Minimally invasive colorectal surgery, Incisional hernia, Laparoscopic colorectal surgery, Transanal specimen extraction, Transvaginal specimen extraction, Patient-reported outcomes, Prospective registry
Medical subject headings
Colorectal Neoplasms, Incisional Hernia

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Natural Orifice Specimen ExtractionProcedure or surgery

    Specimen extraction through a natural orifice, including transanal or transvaginal extraction, during minimally invasive colorectal surgery.

  • Transabdominal Specimen ExtractionProcedure or surgery

    Specimen extraction through an abdominal incision during minimally invasive colorectal surgery.

Study groups in NCT07615036
Study groupRoleWhat they receive
Planned NOSE ExtractionPatients undergoing planned natural orifice specimen extraction (NOSE), including transanal or transvaginal extraction, during elective minimally invasive colorectal surgery.
Receives: Procedure: Natural Orifice Specimen Extraction
Planned Transabdominal ExtractionNOSE-eligible patients undergoing planned transabdominal specimen extraction during elective minimally invasive colorectal surgery.
Receives: Procedure: Transabdominal Specimen Extraction

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Time to Incisional Hernia Within 24 Months

    Time from index colorectal surgery to first clinical or radiologic diagnosis of incisional hernia at or adjacent to the specimen extraction site.

    Measured: 24 months after index surgery

Secondary outcomes (10)
  1. Overall Postoperative Complications

    Postoperative complications within 30 days classified according to the Clavien-Dindo grading system.

    Measured: 30 days after surgery

  2. Surgical Site Infection

    Incidence of postoperative surgical site infection following minimally invasive colorectal surgery.

    Measured: 30 days after surgery

  3. Extraction-Site Complications

    Extraction-related morbidity including specimen rupture, contamination, bleeding, fistula, or extraction-site injury.

    Measured: 30 days after surgery

  4. Length of Hospital Stay

    Length of postoperative inpatient hospital stay following index colorectal surgery.

    Measured: From date of surgery until hospital discharge, up to 30 days

  5. EQ-5D-5L Score

    Health-related quality-of-life assessed using the EuroQol 5-Dimension 5-Level (EQ-5D-5L) questionnaire.

    Measured: Baseline, 6 months, and 12 months after surgery

  6. Body Image Scale (BIS) Score

    Body image assessed using the Body Image Scale (BIS).

    Measured: Baseline, 6 months, and 12 months after surgery

  7. Low Anterior Resection Syndrome (LARS) Score

    Bowel function assessed using the Low Anterior Resection Syndrome (LARS) score.

    Measured: 6 months and 12 months after surgery

  8. Local Recurrence

    Incidence of local recurrence following minimally invasive colorectal surgery.

    Measured: Up to 24 months after surgery

  9. Distant Recurrence

    Incidence of distant recurrence following minimally invasive colorectal surgery.

    Measured: Up to 24 months after surgery

  10. Disease-Free Survival

    Time from index colorectal surgery to recurrence or death from any cause.

    Measured: Up to 24 months after surgery

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted29 May 2026
  2. Study start5 May 2026
  3. Primary completion30 Mar 2033 (estimated)
  4. Study completion30 Dec 2033 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Observational
Observational model
Cohort
Time perspective
Prospective
Enrolment
800 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07615036
Sponsor's protocol ID
2026-0237
Acronym
AP-NOSES
Status last verified
May 2026
First submitted
19 May 2026
Last updated
29 May 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Undecided: Individual participant data sharing plans have not yet been finalized. Future sharing of deidentified data may be considered following establishment of multicenter governance, data-sharing agreements, and publication policies.

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.

    PubMed 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.

    PubMed 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. International consensus on natural orifice specimen extraction surgery (NOSES) for colorectal cancer. Gastroenterol Rep (Oxf). 2019 Feb;7(1):24-31. doi: 10.1093/gastro/goy055. Epub 2019 Jan 23.

    PubMed 30792863
  • Seow-En I, Wong KY, Koo CH, Khor SN, Fu CWP, Chang M, Tan MNA, Kitaguchi D, Ng ZQ, Shao YC, Shen MY, Chang SC, Chen WT; AP-NOSES Collaborative. Prospective multicentre observational study of natural orifice specimen extraction in minimally invasive colorectal surgery in the Asia-Pacific: protocol for the AP-NOSES registry. BMJ Open. 2026 Sep 18;16(9):e123140. doi: 10.1136/bmjopen-2026-123140.

    PubMed 42760090

Questions about this trial

What is this clinical trial studying?

An observational study of Colorectal Neoplasms and Incisional Hernia, run by Singapore General Hospital at 1 site in Singapore.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 5 inclusion and 11 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: looking for participants now, as of the sponsor's last update on 29 May 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Singapore. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Isaac Seow-En, MBBS, FRCSEd (+6563213853, isaac.seow.en@singhealth.com.sg), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Time to Incisional Hernia Within 24 Months (time frame: 24 months after index surgery). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT07615036, which also lists 4 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 29 May 2026.

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