International Multi-center Profile of Emergency Large-Bowel Obstruction Management and Outcomes (IMPEL)

International Multi-center Profile of Emergency Large-Bowel Obstruction Management and Outcomes (IMPEL)

Mechanical large-bowel obstruction is a common and high-risk emergency surgical condition with substantial variation in diagnostic evaluation, operative timing, and management strategies across institutions and healthcare systems. Evidence guiding optimal management remains limited and is largely derived from retrospective or single-center studies.

IMPEL is an international, multicenter, time-bound, prospective observational cohort study designed to characterize real-world presentation, diagnostic pathways, operative and non-operative management, and short-term outcomes in adults presenting with mechanical large-bowel obstruction. By capturing standardized patient-level, radiologic, operative, and outcome data across diverse acute care settings, IMPEL aims to describe contemporary practice patterns, quantify variation in care, and identify factors associated with morbidity, mortality, and stoma-related outcomes.

Study Overview

• Status: Not yet recruiting
• Conditions: Large Bowel Obstruction

Detailed Description

IMPEL is a prospective, non-randomized, observational snapshot audit conducted across international acute care hospitals managing emergency general surgery. Participating centers enroll consecutive adult patients presenting with mechanical large-bowel obstruction during a predefined 90-day inclusion period within a six-month global study window.

Patients are managed according to local standard practice; no interventions are assigned by the study protocol. Data collected include baseline characteristics and comorbidity burden, clinical frailty, diagnostic imaging features, operative and non-operative management strategies (including bridge-to-surgery approaches), perioperative outcomes, and short-term follow-up outcomes. Stoma creation, intent, and reversal status are recorded, with follow-up to six months for stoma outcomes.

The study is structured in accordance with STROBE guidelines for observational research. Analyses addressing comparative or causal questions will follow target trial emulation principles, including explicit definition of eligibility, time zero, treatment strategies, and estimands, without implying interventional assignment.

IMPEL is intended to provide a contemporary international reference standard for the management of large-bowel obstruction, inform future interventional studies, and support quality improvement and guideline development efforts.

• Study Type: Observational
• Enrollment (Estimated): 500

Contacts and Locations

• Study Contact: Name: Matteo M Cimino, MD; Phone Number: +393928811420; Email: cimino.matteo@gmail.com
• Study Contact Backup: Name: Gabriele Bellio, MD; Email: gabrielebellio87@gmail.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

The study population comprises consecutive adults (≥18 years) admitted to participating acute care hospitals with a diagnosis of mechanical large-bowel obstruction, with or without associated large-bowel perforation attributable to obstruction. Patients are enrolled irrespective of management strategy (operative or non-operative), and care is delivered according to local standard practice. Participating sites include international hospitals providing emergency general surgery care. Enrollment occurs during a predefined 90-day consecutive inclusion period selected by each site within a global six-month study window, with follow-up through 30 days for postoperative outcomes and through 6 months for stoma-related outcomes.

Description

Inclusion Criteria:

• Age 18 years or older
• Hospital admission with mechanical large-bowel obstruction, with or without associated perforation
• Managed operatively or non-operatively according to local standard practice

Exclusion Criteria:

• Functional or pseudo-obstruction without a mechanical lesion
• Pediatric patients (<18 years)
• Patients not admitted to hospital
• Isolated large-bowel perforation unrelated to obstruction

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort
All IMPEL patients; All enrolled participants with mechanical large-bowel obstruction managed according to local standard-of-care practices.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
30 day morbidity	Occurrence of postoperative complications within 30 days of hospital day zero (baseline) or date of surgery, graded using the Clavien-Dindo classification.	From hospital admission date or date of surgery (whichever is later) to 30 days later.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
30 day mortality	All-cause mortality occurring within 30 days of date of hospital admission (day zero) for mechanical large-bowel obstruction, irrespective of management strategy.	30 days
Stoma creation	Creation of any intestinal stoma during the index admission for mechanical large-bowel obstruction, including stoma type and intended purpose (defunctioning anastomosis; bridge to definitive resection; non-restorative/palliative; or damage-control).	From hospital day 0 (baseline) to 90 days.
Stoma reversal	Number of reversal (closure) of any diverting or end stoma, created during the index admission, within 6 months of hospital discharge, assessed through routine clinical follow-up and medical record review.	from hospital discharge (baseline) to 6 months
Length of hospital stay	Duration of the index hospital admission day 0 (baseline) to discharge of the patients from the hospital. The event dischage is defined as the day when the patients quit the hospital of the index admission, for these reasons: he's sent home, he's sent to another hospital, he dies dies. This measure in expressed in days.	From hospital day 0 (baseline) to dischagre in a time frame of 90 days.
Association of admitting specialty and on-call model with clinical outcomes and care processes.	Clinical outcomes and care processes, including 30-day major morbidity (Clavien-Dindo grade ≥III), 30-day mortality, time (in hours) from hospital admission(baseline, day zero) to definitive intervention, and stoma creation, will be evaluated in Association to admitting specialty (emergency surgery vs colorectal surgery vs other) and the hospital's out-of-hours emergency general surgery coverage model (dedicated emergency surgery service vs elective subspecialty rota).	From index admission (day 0) to 30 days (for 30-day outcomes).
Use of minimally invasive surgical approach	Use of a minimally invasive surgical approach (laparoscopic, robotic, or hybrid), including conversion to open surgery where applicable, during operative management of large-bowel obstruction.	Index surgical procedure
Number of participants with self expanding metallic stents.	Use of self expanding metallic stent before surgical resection in patients with colonic obstruction.	From hospital day 0 (baseline) up to 90 days
Unplanned readmission	Unplanned hospital readmission related to complications or sequelae of large-bowel obstruction or its management.	From initial inpatient hospitalization (baseline) up to 90 days
Patient-reported assessment of gastrointestinal recovery	Patient-Reported Outcomes of Gastrointestinal Recovery (PRO-diGI) will be used to assess appetite, oral intake, bowel function, nausea/vomiting, abdominal pain, fatigue, and overall gastrointestinal wellbeing using ordered categorical items and a 0-100 visual analogue scale (0=worst, 100=best). Where feasible within routine workflows, PRO-diGI will be administered at prespecified time points.	From day 0 (baseline) up to 30 days.

Collaborators and Investigators

• Sponsor: European Society for Trauma and Emergency Surgery
• Collaborators: University of Pennsylvania; American Society of Colon and Rectal Surgeons; European Society of Coloproctology; Association of Surgeons of Great Britain and Ireland
• Investigators: Study Director: Gary A Bass, MD, PhD, University of Pennsylvania

Study record dates

Study Major Dates

• Study Start (Estimated): July 1, 2026
• Primary Completion (Estimated): June 30, 2027
• Study Completion (Estimated): July 31, 2027

Study Registration Dates

• First Submitted: February 4, 2026
• First Submitted That Met QC Criteria: March 4, 2026
• First Posted (Actual): March 9, 2026

Study Record Updates

• Last Update Posted (Actual): March 9, 2026
• Last Update Submitted That Met QC Criteria: March 4, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: stoma; observational cohort; colonic obstruction; Large-bowel obstruction; bridge to surgery; snapshot audit
• Other Study ID Numbers: IMPEL

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: De-identified individual participant data (IPD) underlying published analyses from this study may be made available to qualified researchers on reasonable request, subject to approval by the IMPEL Steering Committee and compliance with applicable data protection regulations. Shared IPD will be limited to the minimum dataset necessary to address the approved research question and will exclude all direct identifiers. Data sharing will occur only after publication of the primary study results and under a data use agreement specifying the scope of use, authorship expectations, and data security requirements.
• IPD Sharing Time Frame: 5 years
• IPD Sharing Access Criteria: By reasonable request to PI
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF; CSR

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No