Changes in Oesophageal Transit, Macro-Reflux Events, and Gastric Emptying Correlate with Improvements in Gastro-Intestinal Symptoms and Food Tolerance Early Post Sleeve Gastrectomy

Abstract

Purpose: There are significant alterations in gastro-intestinal function, food tolerance, and symptoms following sleeve gastrectomy (SG). These substantially change over the first year, but it is unclear what the underlying physiological basis for these changes is. We examined changes in oesophageal transit and gastric emptying and how these correlate with changes in gastro-intestinal symptoms and food tolerance.

Material and methods: Post-SG patients undertook protocolised nuclear scintigraphy imaging along with a clinical questionnaire at 6 weeks, 6 months, and 12 months.

Results: Thirteen patients were studied: mean age (44.8 ± 8.5 years), 76.9% females, pre-operative BMI (46.9 ± 6.7 kg/m2). Post-operative %TWL was 11.9 ± 5.1% (6 weeks) and 32.2 ± 10.1% (12 months), p-value < 0.0001. There was a substantial increase of meal within the proximal stomach; 22.3% (IQR 12%) (6 weeks) vs. 34.2% (IQR 19.7%) (12 months), p = 0.038. Hyper-accelerated transit into the small bowel decreased from 6 weeks 49.6% (IQR 10.8%) to 42.7% (IQR 20.5%) 12 months, p = 0.022. Gastric emptying half-time increased from 6 weeks 19 (IQR 8.5) to 12 months 27 (IQR 11.5) min, p = 0.027. The incidence of deglutitive reflux of semi-solids decreased over time; 46.2% (6 weeks) vs. 18.2% (12 months), p-value < 0.0001. Reflux score of 10.6 ± 7.6 at 6 weeks vs. 3.5 ± 4.4 at 12 months, (p = 0.049) and regurgitation score of 9.9 ± 3.3 at 6 weeks vs. 6.5 ± 1.7, p = 0.021 significantly reduced.

Conclusions: These data demonstrate that there is an increase in the capacity of the proximal gastric sleeve to accommodate substrate over the first year. Gastric emptying remains rapid but reduce over time, correlating with improved food tolerance and reduced reflux symptoms. This is likely the physiological basis for the changes in symptoms and food tolerance observed early post-SG.

Keywords: Bariatric outcome; Bariatric surgery mechanism; Clinical trial; Food tolerance; Gastric emptying; Gastrointestinal symptoms; Nuclear scintigraphy; Physiology; Reflux; Sleeve.

Fig. 1

Intragastric meal distributions in the study cohort patients observed over time. a–d are illustrative drawings demonstrating nuclear scintigraphy images with presumed anatomy and regions of interest (ROI) as drawn. b proximal IMD c antral IMD and d uniform IMD. Panels e to h illustrate 3D reconstruction volumetric computed tomography of the gastric sleeve. f represents proximal dilated stomach g represents antral dilated stomach h represents uniformly dilated stomach

Fig. 2

Schematic of triggered deglutitive reflux on a 60 s nuclear scintigraphy oesophageal swallow study. Upper dotted line = manubrium, lower dotted line = xiphisternum. a Bolus-induced deglutitive reflux, majority of the radioactive food bolus moved to the mid oesophagus. The red circle represents the start of reflux. b No reflux, majority of the food bolus was seen moving from the proximal oesophagus to the distal oesophagus within 60 s after ingestion

Fig. 3

Nuclear Scintigraphy gastric clearance and intestinal delivery. a–d are schematic representations of proportional emptying of a patient at 6 weeks (a and b) and 12 months (c and d) post sleeve gastrectomy. a illustrates a uniform retained stomach with hyper-acceleration of emptying into the small bowel at T = 2 min (6 week scan). b illustrates most (97.2%) of the meal in the small bowel at T = 90 min (6 week scan). c illustrates proximal retention and little emptying into the small bowel at T = 2 min (12 month scan). d illustrates an increase in meal retention in the stomach and lesser (91.1%) emptying into the small bowel T = 90 min (12 month scan)

Fig. 4

Patient reported outcome measures on adverse symptoms. Responses to a ‘heartburn frequency’, b ‘use of reflux medication’, c ‘regurgitation frequency’, d ‘dysphagia frequency’, e ‘upper abdominal bloating’, and f ‘most significant problem following sleeve gastrectomy’

Fig. 5

Patient-reported outcome measures on food tolerance. Patients’ ability to consume foods of different texture. For each food type listed, patients were asked if when they consumed these foods they ‘never regurgitated’, ‘sometimes regurgitated/always regurgitated’. Responses to a “Water”, b “Soup”, c “Bread”, d “Apple”, e “Steak”