P1360 - The Esophageal Response to the Alleviation of Distension: A Study Utilizing FLIP Panometry

Monday, October 25, 2021

10:30 AM – 4:15 PM PT

Location: Shoreline Exhibit Hall

Has Audio

Presenting Author(s)

Dustin Carlson, MD

Northwestern University Feinberg School of Medicine
Chicago, IL, United States

Dustin Carlson, MD, Jacqueline E. Prescott, BS, Emma Germond, BS, David Karasik, BS, Bidemi Godo, BS, John E. Pandolfino, MD
Northwestern University Feinberg School of Medicine, Chicago, IL

Introduction: An abnormal esophageal response to distension involving lower esophageal sphincter (LES) contraction can occur during functional luminal imaging probe (FLIP) testing. This may account for reduced esophagogastric junction (EGJ) opening observed among some patients with normal LES relaxation pressures on high resolution manometry (HRM). This study aimed to evaluate the response of EGJ distensibility during alleviation of distension, i.e. emptying of the FLIP, among patients evaluated for esophageal motility disorders, focusing on patients with achalasia or normal motility.

Methods: 135 consecutive adult patients (ages 20-83; 65% female) that completed 16-cm FLIP during endoscopy and HRM were included. Patients with conditions associated with secondary motor findings (e.g. previous foregut surgery) were excluded. EGJ opening was assessed by diameter, pressure, and EGJ-distensibility index (DI) during the standard, stepwise FLIP filling protocol to a maximum fill volume of 70ml, and then again after emptying the FLIP back to 60ml (Figure A). HRM was classified according to the Chicago Classification v4.0 (CCv4.0).

Results: CCv4.0 diagnoses on HRM included 42 (31%) achalasia (18 type I, 17 type II, 7 type III), 38 (28%) normal motility, and 55 (41%) other. Among all patients, achalasia, and normal motility, the EGJ-DI and EGJ diameter were greater during emptying than with standard filling, P-values < 0.001 (Table). The absolute change in EGJ-diameter between emptying and filling was greater in achalasia than normal motility, but other change-metrics were similar. During the filling 60ml, 34/42 (81%) achalasia and 6/38 (16%) normal motility had EGJ-DI < 2.0 mm²/mmHg and 41/42 (98%) achalasia and 15/38 (40%) normal motility had egj diameter < 12mm (Figure B-E). On emptying, an increase in EGJ-DI to >2.0 mm²/mmHg occurred in 15/34 (44%) achalasia and 3/6 (50%) normal motility, while increase in EGJ diameter to >12mm occurred in 2/41 (5%) achalasia and 5/15 (33%) normal motility.

Discussion: Increase in EGJ distensibility metrics occurred with alleviation of distension across the spectrum of esophageal motility disorders and appeared to frequently occur via isobaric relaxation. Increase in EGJ diameter values to >12mm upon alleviation of distension may help identify a subset of patients with normal esophageal motility and a reactive LES response to distension, though the clinical significance of this response warrants future investigation.

Figure: Figure. Esophagogastric junction (EGJ) distensibility in response to distension (filling) and alleviation of distension. The FLIP study protocol is displayed in A and associated distensibility index (DI) and EGJ diameter measures in B-E. Achalasia (subtypes I, II, and III) and normal motility were defined on high-resolution manometry. Median values are represented by the horizontal bars.

	Achalasia	Normal motility	Other CCv4.0¹
n	42	35	55
EGJ-DI, mm²/mmHg	1.4 (0.9-1.9)	3.8 (2.2-7.0)^†	2.7 (1.6-4.1)^†
EGJ diameter, mm	7.2 (6.5-8.6)	13.8 (10.3-19.7)^†	11.2 (9.3 – 14.4)^†
FLIP pressure, mmHg	32 (26-36)	44 (38-48)^†	41 (31-49)^†
Emptying EGJ-DI, mm²/mmHg	1.9 (1.7-2.8)*	4.8 (2.9-7.0)^†,*	3.9 (2.5-5.4)^† *
Emptying EGJ diameter, mm	9.3 (8.2-10.2)*	15.6 (12.0-19.9)^†,*	13.2 (11.6-16.0)^†,*
Emptying FLIP pressure, mmHg	32 (24-37)*	45 (34-49)	37 (31-46)^†,*
Absolute change EGJ-DI, mm²/mmHg	0.8 (0.4-1.1)	0.5 (-0.4 - 1.1)	0.7 (0.2-1.4)^†,*
Absolute change EGJ diameter, mm	2.0 (1.3-2.6)	0.5 (-0.1 - 1.8)^†	1.4 (0.1-2.6)
Absolute change FLIP pressure, mmHg	-2 (-3 - 1)	0 (-5 – 4)	-1 (-4 – 1.3)
Maximum EGJ diameter, mm	10.5 (9.1-11.7)	18.0 (14.9 – 20.7)^†	15.6 (13.6 – 18.3)^†

Table: Table. Esophagogastric junction opening metrics in response to distension (standard filling protocol) and emptying. Values are displayed as median (interquartile range). Absolute changes were calculated as emptying value minus filling value. 1”Other CCv4.0” included 23 manometric EGJ outflow obstruction, 7 absent contractility, 2 hypercontractile esophagus, 1 distal esophageal spasm, and 22 ineffective esophageal motility. *P < 0.05 on paired comparison with standard filling metrics. †P < 0.05 on comparison with achalasia.

Disclosures:

Dustin Carlson: Medtronic – Consultant, Speaker's Bureau.

Jacqueline Prescott indicated no relevant financial relationships.

Emma Germond indicated no relevant financial relationships.

David Karasik indicated no relevant financial relationships.

Bidemi Godo indicated no relevant financial relationships.

John Pandolfino: Given Imaging – Consultant, Speaker's Bureau. Ironwood – Consultant. Medtronic – Consultant, Speaker's Bureau, Other Financial or Material Support, Licensing agreement. Sandhill Scientific – Consultant, Speaker's Bureau. Takeda – Speaker's Bureau. Torax – Consultant, Speaker's Bureau.

Dustin Carlson, MD, Jacqueline E. Prescott, BS, Emma Germond, BS, David Karasik, BS, Bidemi Godo, BS, John E. Pandolfino, MD. P1360 - The Esophageal Response to the Alleviation of Distension: A Study Utilizing FLIP Panometry, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.