P2046 - The 4-Hour Gastric Scintigraphy Emptying Study Identifies a Treatable Diagnosis in Most Patients Being Evaluated for Previously Unexplained Upper Gastrointestinal Post-Prandial Symptoms

Monday, October 25, 2021

10:30 AM – 4:15 PM PT

Location: Shoreline Exhibit Hall

Presenting Author(s)

PL

Priyadarshini Loganathan, MD

Texas Tech University Health Sciences Center at El Paso
El Paso, TX, United States

Priyadarshini Loganathan, MD, Jesus Diaz, MD, DABR, Andrew J. Ortega, DO, Richard McCallum, MD
Texas Tech University Health Sciences Center at El Paso, El Paso, TX

Introduction: The 4-hour (h.) gastric emptying scintigraphy (GES) protocol is the gold standard for assessing GE. Given its noninvasive nature and physiologic methodology, this study has become the optimal means to measure gastric emptying (GE), thereby diagnosing gastroparesis (delayed gastric empty, DGE) with the presence of gastric retention >60% at 2h. and >10% at 4h; dumping syndrome (classic rapid gastric emptying, RGE) with >30% gastric contents emptied by 30 minutes and >65% emptied at 1h. and >80% at 2h. As well as the new entity late-onset rapid emptying (LRGE). Which is a subset of RGE, based on criteria where hourly gastric emptying decrements exceed 49% between 2-3 h., and 28% between 3-4h.

We aimed to determine the percentage of patients diagnosed with an abnormal gastric emptying test who had unexplained postprandial gastrointestinal (GI) symptoms and previously had an extensive negative upper GI workup.

Methods: A retrospective review was conducted analyzing the GES results from a standardized 4h. radioisotope-labeled eggbeater meal (255 kilocalories) performed at an academic tertiary care referral center in patients with a spectrum of postprandial GI symptoms (nausea, vomiting, abdominal pain, fullness, urge to go the bathroom, and diarrhea) between Jan 2015 and March 2020 in the setting of having had extensive negative upper GI workup including CT abdomen, upper GI series, and endoscopies.

Results: In total, 828 initial GES were reviewed for analysis. 334 (40.3%) had DGE, and 182 (22%) had RGE (see Table 1). In both categories, females were predominant. Diabetes was present in 50.5% of DGE and 41.2% of RGE. 4% of patients had LRGE and 37.6% had a normal GES (see Table 1).

Discussion: (1) Utilizing a 4h. GE test, 62.3% of patients with unexplained postprandial upper GI symptoms were identified with either DGE or RGE and hence received appropriate treatment to address their symptoms. (2) Dumping syndrome presenting with RGE is an underestimated diagnosis being identified in 22% of our patients. (3) LRGE identified in 4% of our patients, is a new entity for explaining postprandial symptoms when the GES would have been interpreted as normal.

Figure: Figure 1: Images from Gastric Emptying Scintigraphy studies with 99m-Tc sulfur colloid labeling standardized meal.
(A) Illustrates NGE with <10% retention at 4 hours.
(B) Illustrates RGE with <70% retention at 30 minutes.
(C) Illustrates DGE with >10% at 4 hours.

GES Result	Number of cases	Average age in years	Female	Diabetes
Delayed	334 (40.3%)	51.4	260 (77.8%)	168 (50.3%)
Rapid	182 (22%)	54.1	127 (70%)	75 (41.2%)
Normal	312 (37.7%)	50.0	199 (63.8%)	119 (38.1%)

Table: Table 1: Results of 4-h gastric emptying scintigraphy (GES)

Disclosures:

Priyadarshini Loganathan indicated no relevant financial relationships.

Jesus Diaz indicated no relevant financial relationships.

Andrew Ortega indicated no relevant financial relationships.

Richard McCallum indicated no relevant financial relationships.

Priyadarshini Loganathan, MD, Jesus Diaz, MD, DABR, Andrew J. Ortega, DO, Richard McCallum, MD. P2046 - The 4-Hour Gastric Scintigraphy Emptying Study Identifies a Treatable Diagnosis in Most Patients Being Evaluated for Previously Unexplained Upper Gastrointestinal Post-Prandial Symptoms, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.