SnapSBO - An International Non-randomized Time-bound Prospective Observational Cohort Study Addressing the Epidemiology and Management of Small Bowel Obstruction
Conditions: Small Bowel Obstruction
Sponsor: European Society for Trauma and Emergency Surgery


COHORT STUDY PROTOCOL
An international non-randomized time-bound prospective observational cohort study 
addressing the epidemiology and management of Small Bowel Obstruction
Study period: November 01st 2023 – May 31st 2024
 
ClinicalTrials.gov Registration: NCTxxxxxxx
ESTES Snapshot Audit 2023 SBO 
Protocol version 4.0 (March 2023)

Table of contents
ESTES SnapSBO Study Steering Committee 
 
3
Introduction 
 
4
Scope 
 
5
Key Study Dates 
 
6
Definitions 
 
7
Methods 
 
8
Summary 
 
8
Primary Objective 
 
8
Methods for identifying patients 
 
8
Research Questions 
 
9
Inclusion and Exclusion Criteria 
 
10
Center eligibility 
 
10
Patient follow-up 
 
10
Data completion 
 
11
Missing data and retrospective patient entry 
 
11
Data collection system and information governance 
 
11
Local approvals 
 
11
Authorship 
 
12
Publication of data 
 
12
Data governance 
 
12
Financial arrangements 
 
12
Reference list 
 
13
REDCap® Data Collection Instruments 
 
14
Data Collection Instrument 1 - Patient and Centre Demographics 
 
14
Data Collection Instrument 2 - Patient demographics 
 
14
Data Collection Instrument 3 - Patient past medical history 
 
15
Data Collection Instrument 4 - Patient past surgical history 
 
15
Data Collection Instrument 5 - Patient past SBO history 
 
16
Data Collection Instrument 6  - Current episode Symptoms and signs 
 
16
Data Collection Instrument 7 - Initial Complementary Exams 
 
17
Data Collection Instrument 8 - Current episode, course evolution 
 
18
Data Collection Instrument 9 - Current episode Surgery 
 
19
Data Collection Instrument 10 - Current episode, Final outcome 
19
ESTES Snapshot Audit 2023 SBO 
Protocol version 4.0 (March 2023)

ESTES SnapSBO Study Steering Committee
Name
Country
Center
Email
Isidro Martinez Casas, MD PhD 
FACS hFEBS(Em Surg)
Spain
Hospital Universitario Virgen del Rocio, Sevilla
isidromartinez@me.com
Gary Alan Bass, MD MBA PhD 
FEBS (Em Surg)
USA / 
Ireland
University of Pennsylvania, Philadelphia
gary.bass@pennmedicine.upenn.edu
Shahin Mohseni, MD PhD FACS 
hFEBS(Em Surg)
Sweden/
Orebro University Hospital, Orebro
mohsenishahin@yahoo.com
Hayato Kurihara, MD hFEBS(Em 
Surg)
Italy
Fondazione IRCCS Ca’ Granda Ospedale 
Maggiore Policlinico di Milano
hayato.kurihara@gmail.com
Matteo María Cimino, MD
Italy
Fondazione IRCCS Ca’ Granda Ospedale 
Maggiore Policlinico di Milano
Matteo.cimino@policlinico.mil.it
Lewis J Kaplan, MD FACS FCCM 
FCCP
USA
University of Pennsylvania, Philadelphia;
Corporal Michael J. Cresencz Veterans Affairs 
Medical Center, Philadelphia
Lewis.Kaplan@pennmedicine.upenn.edu
ESTES Snapshot Audit 2023 SBO 
Protocol version 4.0 (March 2023)

Introduction 
Multi-center, ‘snapshot’ cohort studies or audits have the ability to gather large 
patient numbers in short time periods from many hospitals. They allow exploration of 
differences in patients, techniques and management across the cohort to identify 
areas of practice variability that may result in apparent differences in outcome. As 
such, whilst not providing true evidence of efficacy or the impact of a particular 
variable, they can be hypothesis-generating and can identify areas warranting further 
study in future randomized controlled trials1.
The European Society of Trauma and Emergency Surgery has recognized the 
strengths of this form of research, as well as its power in bringing together surgeons 
and emergency surgical units across multiple regions or countries for a common 
research goal, thus strengthening an active network of research participation across 
Europe.
ESTES Snapshot Audit 2023 SBO 
Protocol version 4.0 (March 2023)

Scope
Small bowel obstruction (SBO) and its complications are frequently seen in patients 
admitted through the Emergency Departments of all acute care hospitals2.
There is variation in the optimal use of imaging, the appropriate timing and duration 
of non-operative management attempts, anti-microbial therapies and the criteria for 
surgical management, which results in heterogeneity in approaches and outcomes 
across international clinical centers. The expected number of SBO cases in most 
clinical centers is predictable, enabling a suitable sized cohort of patients to be 
gathered in the snapshot audit. 
This ‘ESTES snapshot audit’ -a prospective observational cohort study- has a dual 
purpose. Firstly, as an epidemiological study, it aims to uncover the burden of 
disease. Secondly, it aims to demonstrate current strategies employed to diagnose 
and treat these patients. These twin aims will serve to provide a ‘snapshot’ of what 
we are doing now, but will also be hypothesis-generating while providing a rich 
source of patient-level data to allow further analysis of particular clinical question.
ESTES Snapshot Audit 2023 SBO 
Protocol version 4.0 (March 2023)

Key Study Dates
 
06 may 2023
Snapshot Launch at ECTES 2023, Ljubljana.
Center enrolment and local IRB submission
01 november 2023 
- 01 may 2024
Patient enrolment. Ninety (90) consecutive day enrollment 
within this six (6) month window
01 may 2024
Final day for new patient enrolment
31 July 2024
Final day of patient follow-up (60 days from admission on 01 
may 2024)
01 August 2024 - 
01 September 2024
Local data validation, completion, and final upload
01 september 2024
REDCap® database locked; this is the deadline for data 
submission and center inclusion.
ESTES Snapshot Audit 2023 SBO 
Protocol version 4.0 (March 2023)

Definitions
Mechanical small bowel obstruction (SBO): An intrinsic, extrinsic or endoluminal 
process which narrows or occludes the bowel lumen and delays the passage of 
luminal contents.
Ileus: Functional motility disorder characterized by adynamic paralytic bowel, 
leading to many of the same symptoms of mechanical obstruction, but without a 
single site of obstruction demonstrable on imaging. Common causes include recent 
abdominal surgery, medications such as opiates, and electrolyte disturbances2.
Complete SBO: Obstruction with no passage of luminal contents beyond the point 
of obstruction3 (Appendix A).
Partial SBO: Incomplete obstruction with luminal narrowing but some contents 
continue to pass through the intestine. This is distinguished from complete 
obstruction by the continued passage of bowel movements and flatus, and a non-
peritonitic abdominal exam3.
Small bowel dilatation: Luminal diameter of >3 cm.
Transition zone: Short segment area between dilated proximal bowel and 
decompressed distal bowel. Sometimes called a transition point and is radiographic 
evidence of SBO.
Bowel compromise: when there is ischemia or injury that has led to necrosis and/or 
perforation of the bowel wall4.
Adhesions: Fibrous tissue that connects surfaces or organs within the peritoneal 
cavity that are normally separated. Such adhesions are the results of an adaptive 
healing response of the peritoneum upon tissue handling or contact with blood or 
purulence, but also caused by other conditions like radiotherapy, endometriosis, 
inflammation or local response to tumors5. 
Virgin abdomen: abdomen of a patient without prior surgery. Although there is no 
consensus in the literature about radiotherapy, known peritoneal inflammatory 
disease  or primary abdominal wall hernias, in our study we will consider only those 
non-operated inside the definition6.
Water Soluble Oral Contrast (WSOC) challenge: a combined diagnostic study and 
therapeutic intervention utilized in the evaluation and management of small bowel 
obstruction.
ESTES Snapshot Audit 2023 SBO 
Protocol version 4.0 (March 2023)

Methods
Summary 
Prospective audit of consecutive patients admitted in Emergency Department for 
mechanical small bowel obstruction over a 3 month period. The audit shall include 
unscheduled patient admissions from November 2023 until May 2024 as outlined in 
‘Key Study Dates’.
As this is an observational cohort audit, no change to normal patient management is 
required.
Primary Objective 
To explore differences in patients, management and outcomes across the entire 
cohort to identify areas of practice variability resulting in apparent differences in 
outcome warranting further study. The outcomes that the study will examine are:
▪
Incidence of small bowel obstruction by etiology.
▪
Differences in clinical presentation.
▪
Diagnostic work-up.
▪
Non-operative management strategies. 
▪
Time to surgery and outcomes.
▪
Complications related to disease and/or therapies within 60 post-operative 
days.
▪
Length of Emergency Department and Hospital stay.
▪
Re-admission within 6 months for related conditions.
Methods for identifying patients 
Multiple methods may be used according to local circumstances/staffing:
1. Daily review of emergency department (non-operative) and operating room 
lists. 
2. Daily review of team handover sheets / emergency admission lists / ward lists.
3. Review of operating room logbooks.
4. Use of electronic systems to flag any readmissions of patients identified and 
treated.
ESTES Snapshot Audit 2023 SBO 
Protocol version 4.0 (March 2023)

Research Questions 
Primary Research Questions
•
What is the global incidence of SBO? 
•
What are the treatment algorithms currently employed in the management 
of these patients? 
•
Proportion of non-operatively managed patients? 
•
Proportion of surgical patients approached laparoscopically? 
•
Recurrence rate within 6 months?  
Secondary Research Questions
•
What is the incidence and etiology of virgin abdomen SBO? 
•
What is the incidence of early postoperative SBO?
•
What is the success rate for non-operative management?
•
What is the prevalence of complications and treatment failure in the non-
operative management of SBO?
•
Proportion of patients that underwent WSOC challenge, and under what 
indications?
•
What are the Patient Related Outcomes results?
ESTES Snapshot Audit 2023 SBO 
Protocol version 4.0 (March 2023)

Inclusion and Exclusion Criteria
Center eligibility 
All hospitals/units performing general surgery are eligible to join this audit. No unit 
size or case throughput stipulations are made. Any clinical center is welcome to 
participate so long as the protocol is adhered to. Countries outside Europe are 
eparticipate in this audit.
All participating centers will be required to register their details with the ESTES 
cohort study office and will be responsible for their own local approvals process prior 
to the start of the data collection period. Inclusion of data sets will be subject to local 
approval from participating clinical Centers. 
Centers should ensure that they have appropriate pathways and manpower to 
include all consecutive eligible patients during the study period and provide >95% 
completeness of data entry before locking of the study REDCap® database on the 
November 1st 2024.
Patient follow-up 
The audit is designed so normal patient follow-up pathways can be used to obtain 
outcome data. No additional visits or changes to normal follow-up should be made. 
However, local investigators should be proactive in identifying post-diagnosis events 
(or lack thereof), within the limits of normal follow-up. These may include reviewing 
the patient notes (paper and electronic) during admission and before discharge to 
note in-hospital complications, reviewing hospital systems to check for re-
attendances or re-admissions, and reviewing post-operative radiology reports.
Inclusion Criteria: 
Adult patients (≥16 years of age) admitted for mechanical small bowel obstruction. 
Example etiologies which should be included:
Adhesions.
Hernias with bowel compromise (incisional/parastomal, ventral, inguinal, femoral, 
obturator, internal).
Malignancy (primary: lymphoma, carcinoid, GIST, adenocarcinoma/metastatic 
disease: colon, ovarian, gastric, pancreatic, melanoma and others).
Enteroliths/gallstones/bezoars/foreign bodies
Radiation. 
Inflammation (Crohn’s disease, mesenteric adenitis, appendicitis, diverticulitis, 
tuberculosis, actinomycosis, ascariasis).
Congenital (malrotation, duplication cysts).
Trauma (hematomas, ischemic strictures).
Exclusion criteria: 
Functional small bowel obstruction (dysmotility or adynamic ileus secondary to 
abdominal operations, peritonitis, trauma or medications).
ESTES Snapshot Audit 2023 SBO 
Protocol version 4.0 (March 2023)

Data completion 
This research is an observational and non-interventional audit that collects  data 
along the usual course patient pathway. The Data Collection Instrument (DCI) has 
been designed to reflect common parameters. We envisage that participating clinical 
Centers will identify a team of 4-5 members; one Consultant (clinical ‘lead’ of the 
study), trainee surgeons or data administrators who will undertake the logistical roles 
as well as co-ordinate data entry.
DCI 2 (patient demographics), DCI 3, 4, 5 (past medical and surgical history) and 
DCI 8 and 10 (follow-up information) can be completed by any suitably qualified 
member of the local team. DCI 6 (Current episode emergency details) and F7 (Initial 
complementary exams) must be completed by or in direct conjunction with an 
admitting staff surgeon who was present, as DCI 9 (operation details) by a staff 
surgeon also present itself. It should ideally be completed as close to the end of 
surgery as feasible, to ensure data accuracy and completeness.
Missing data and retrospective patient entry 
The online database has been designed to allow sites to securely access an 
individual patient’s data throughout the study period. This means that any missing or 
erroneous data can be altered by the local investigators whilst the data collection 
period is ongoing. In order to maximize data completion and emphasize its 
importance to collaborators, participating Centers with >5% missing data in 
mandatory fields (i.e. less than 95% data completeness) will be excluded from the 
study.
The study design means that sites may retrospectively identify eligible patients that 
were missed primarily and for whom contemporaneous patient and operation data 
was not entered. 
Data collection system and information governance 
Data will be recorded on a dedicated, secure server running on the REDCap® web 
application. REDCap® allows for secure upload and storage of data, in compliance 
with European Union General Data Protection Regulation 2018 (GDPR) and the 
Health Insurance Portability and Accountability Act of 1996 (HIPAA) legislation. 
Registered local investigators will have individual password-protected access to their 
unit’s data entered on to REDCap®. During the running of the audit, only local data 
will be visible to individual investigators; other sites’ data will not be accessible. It is 
the responsibility of each participating Center to ensure their own records comply 
with local data governance legislation, GDPR or HIPAA, as applicable.
 Local approvals 
All data collected will measure current practice, with no changes made to normal 
treatment. As such, this study should be registered as an audit of current practice at 
each participating Center. It is the responsibility of the local team at each site to 
ensure that local audit approval (or equivalent) is completed for their Center. 
Participating Centers will be asked to confirm that they have gained formal approval 
at their site. 
ESTES Snapshot Audit 2023 SBO 
Protocol version 4.0 (March 2023)

Authorship 
Investigators from each individual site will be included as formal co-investigators in 
this research, and will be PubMed searchable and citable. The output from this 
research will be published by the steering group on behalf of a single corporate 
authorship – e.g “ESTES SnapSBO Group.”
Publication of data 
The report of this audit will be prepared in accordance with guidelines set by the 
STROBE (strengthening the reporting of observational studies in epidemiology) 
statement for observational studies8, (appendix C) Data will be published as a pool 
from all participating units. Subgroup analyses by disease, technique or outcome 
variables may be presented, but no hospital-level or surgeon-level data will be 
published whereby an individual patient, unit or surgeon could be identified. If local 
investigators would like a breakdown of their own unit’s data for benchmarking 
purposes and local presentation/discussion, this can be made available after the end 
of the study; however, it will not be possible or permissible to de-anonymise patient 
data stored in REDCap®, in strict compliance with GDPR and HIPAA.
Data governance 
The ESTES Cohort Studies Committee welcomes the use of the data for further 
research that benefits patients. Requests can be submitted to the ESTES Cohort 
Studies Committee. Data sharing is subject to ESTES approval and the appropriate 
safeguarding as determined by the ESTES. Any future sub-projects should also 
comply with our policy of a single corporate authorship e.g. “ESTES SnapSBO 
Group” or similar. However, authors’ contributions will be highlighted in accordance 
with the recommendations for the conduct, reporting, editing, and publication of 
scholarly work in medical journals.
Financial arrangements 
This study is undertaken voluntarily by participating institutions under the co-
ordination of the Emergency Surgery Cohort Study Steering Committee. It is not 
anticipated that participating Centers would bear any costs. Similarly, no financial 
reimbursement will be made to units or investigators. 
ESTES Snapshot Audit 2023 SBO 
Protocol version 4.0 (March 2023)

Reference list
1. Bass GA, Kaplan LJ, Ryan ÉJ, Cao Y, Lane-Fall M, Duffy CC, et al. The snapshot 
audit methodology: design, implementation and analysis of prospective 
observational cohort studies in surgery. Eur J Trauma Emerg S. 2022;1–11.
2. Detz DJ, Podrat JL, Castro JCM, Lee YK, Zheng F, Purnell S, et al. Small bowel 
obstruction. Curr Prob Surg. 2021;58(7):100893. 
3. Hernandez MC, Haddad NN, Cullinane DC, Yeh DD, Wydo S, Inaba K, et al. The 
American Association for the Surgery of Trauma Severity Grade is valid and 
generalizable in adhesive small bowel obstruction. J Trauma Acute Care. 
2018;84(2):372–8.
4. Vercruysse G, Busch R, Dimcheff D, Al-Hawary M, Saad R, Seagull FJ, et al. 
Evaluation and Management of Mechanical Small Bowel Obstruction in Adults. 
[internet] Ann Arbor (MI): Michigan Medicine University of Michigan; 2021 Apr. 
PMID: 34314126. 
5. Broek RPG ten, Krielen P, Saverio SD, Coccolini F, Biffl WL, Ansaloni L, et al. 
Bologna guidelines for diagnosis and management of adhesive small bowel 
obstruction (ASBO): 2017 update of the evidence-based guidelines from the world 
society of emergency surgery ASBO working group. World J Emerg Surg. 
2018;13(1):24.
6. Amara Y, Leppaniemi A, Catena F, Ansaloni L, Sugrue M, Fraga GP, et al. 
Diagnosis and management of small bowel obstruction in virgin abdomen: a 
WSES position paper. World J Emerg Surg. 2021;16(1):36.
7. Dindo D, Demartines N, Clavien PA. Classification of surgical complications: a 
new proposal with evaluation in a cohort of 6336 patients and results of a survey. 
Annals of Surgery. 2004 Aug 1;240(2):205–13.
8. Vandenbroucke JP, Elm E von, Altman DG, Gøtzsche PC, Mulrow CD, Pocock SJ, 
et al. Strengthening the Reporting of Observational Studies in Epidemiology 
(STROBE): Explanation and elaboration. Int J Surg. 2014; 12(12): 1500–24.
9. Mellor K, Hind D, Lee MJ. A systematic review of outcomes reported in small 
bowel obstruction research. J Surg Res. 2018; 229: 41–50. 
ESTES Snapshot Audit 2023 SBO 
Protocol version 4.0 (March 2023)

REDCap® Data Collection Instruments
Data Collection Instrument 1 - Patient and Centre Demographics
*will be filled once for each center
 Data Collection Instrument 2 - Patient demographics 
ESTES Snapshot Audit 2023 SBO 
Protocol version 4.0 (March 2023)

Data Collection Instrument 3 - Patient past medical history 

Data Collection Instrument 4 - Patient past surgical history 
ESTES Snapshot Audit 2023 SBO 
Protocol version 4.0 (March 2023)

 Data Collection Instrument 5 - Patient past SBO history 

 Data Collection Instrument 6  - Current episode Symptoms and signs 
ESTES Snapshot Audit 2023 SBO 
Protocol version 4.0 (March 2023)

Data Collection Instrument 7 - Initial Complementary Exams 
ESTES Snapshot Audit 2023 SBO 
Protocol version 4.0 (March 2023)

Data Collection Instrument 8 - Current episode, course evolution 
ESTES Snapshot Audit 2023 SBO 
Protocol version 4.0 (March 2023)

Data Collection Instrument 9 - Current episode Surgery
Data Collection Instrument 10 - Current episode, Final outcome
ESTES Snapshot Audit 2023 SBO 
Protocol version 4.0 (March 2023)