Gastrografin Challenge vs Standard Treatment in ASBO

Martin D. Zielinski

EAST Multicenter Trial Proposal

“Never let the sun rise or set on a

small bowel obstruction”

EAST GG Challenge Trial Background

Mucha P. Surg Clin NA 1987; 67(3):597-620

EAST GG Challenge Trial Background

• Non-op management

• Greater resection risk

if > 24 hours

• Electrolyte and fluid

imbalances

Bickell et al. J Am Coll Surg 2005; 201:847-854

• > 50% of strangulation

obstructions are

misdiagnosed

• Which patients should

undergo operative

treatment?

EAST GG Challenge Trial Background

Sarr et al. AJS 1983; 145(1):176-182.

EAST GG Challenge Trial Optimal Approach

• 1 – provide immediate exploration for

strangulation obstructions

• 2 – facilitate early recognition of

patients who will not resolve without

operative intervention

• 3 – minimize unnecessary operations

EAST GG Challenge Trial GG Challenge

• Gastrografin

• Hyperosmotic

oral contrast agent

• Diagnostic Rx

• Therapeutic Rx

• 55 GG Challenge vs 72 historic controls

• 25% vs 42% surgical exploration

• 13% vs 31% complications

• Equal LOS, strangulation, mortality

EAST GG Challenge Trial GG Challenge vs Standard

EAST GG Challenge Trial GG Meta-analysis

• Diagnostic effects

• 7 RCTs

• 99% PPV, 90% NPV

• 8 hour X-ray ideal

• Therapeutic effects

• 9 RCTs

• Exploration 21% vs 30%; p = .007

• 1.9 day LOS improvement

Branco, BJS 2010

Mixed results among RCTs

• Inconsistent SBO definition

• Lack of blinding

• Non-controlled studies

• Conflicting inclusion / exclusion

• Variable contrast media

• Variable doses

• 4 – 72 hour X-ray

• Variable strangulation reporting

SBO Exploration Prediction Gastrografin Meta-analysis

• Prospective, observational trial

• Institutional standardization

• GG Challenge vs.

• “Standard Management”

• 200 patients total – 100 per arm

• Heavy data collection and protocol compliance

SBO Exploration Prediction Proposal

SBO Exploration Prediction Proposal

• Symptoms consistent with a strangulation obstruction

• Incarcerated external hernia

• Portal-venous gas

• Pneumatosis intestinalis

• Closed loop SBO (two independent transition points)

• Internal hernia

• Small bowel volvulus

• Peritonitis on physical exam

• Hypotension (systolic blood pressure < 90 mm Hg)

• Recent abdominal procedure

SBO Exploration Prediction Proposal

• Primary aim

• 1. To determine, the GG Challenge’s ability to predict resolution of adhesive SBO.

• Outcome - Accuracy of predicting the need for operative exploration (i.e. PPV/NPV)

• Hypothesis – GG will improve the NPV/ PPV for predicting exploration in ASBO

SBO Exploration Prediction Proposal

• Secondary aims:

• 1. To determine the GG Challenge’s ability to treat adhesive SBO.

• Outcome – exploration rate

• Hypothesis – GG will reduce the rate of explorations in ASBO.

• 2. To validate the AAST SBO anatomic score

• Outcome - mortality prediction (AUROC)

• The AUROC of the AAST anatomic score will be greater than 0.80

Patient arrives with signs and

Symptoms of SBO

Page 1

Adhesive Small Bowel Obstruction (SBO) Protocol – Gastrografin Challenge Institutions

Signs of

strangulation

Symptoms

increasing or

recurrent/

persistent by day

3-5

Advance diet

Symptom

resolution

Non-operative trial

Presence of 3 risk factors:

· Obstipation

· Mesenteric edema

· Lack of small bowel feces

sign

Dismiss

Prior abdominal

proceedure

Gastrografin Challenge

Bowel movement

OR contrast

within colon by 8

hours

NO, order CT

YES

NO

NO

YES

NO

YES

YES

YESOperative

exploration

Consider

Operative

exploration

Operative

exploration

Patient arrives with signs and

Symptoms of SBO

Page 1

Adhesive Small Bowel Obstruction (SBO) Protocol – Non-Gastrografin Challenge Institutions

Signs of ischemia

Symptoms

increasing or

recurrent/

persistent by day

4-5

Advance diet

Symptom

resolution

Non-operative trial

Presence of 3 risk factors:

· Obstipation

· Mesenteric edema

· Lack of small bowel feces

sign

Dismiss

Prior abdominal

proceedure

NO, order CT

YES

NO

NO

YES

YES

YES

YESOperative

exploration

Operative

exploration

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http://www.east.org/index_copy(1).asp

http://www.east.org/index_copy(1).asp

• Feb 15 - participating centers identified

• March 15 - IRBs approved

• April 1, 2015 - Study initiation

• January 1, 2016 - Study completion

• Feb 2016 - Data analysis

• EAST submission July 1, 2016

SBO Exploration Prediction Timeline