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Page 4 of 17 Shaker et al. Mini-invasive Surg. 2025;9:27 https://dx.doi.org/10.20517/2574-1225.2024.105

Overall, the impact of LSG on factors driving reflux reflects a complex interplay of multiple mechanisms
[Table 1], occurring in the context of weight loss, which can reduce the gastroesophageal pressure gradient.
Additionally, the surgery itself may affect gastric motility, potentially in a protective manner, through
increased gastric emptying, while other surgical effects such as disruption of the anti-reflux barrier and
decrease in gastric compliance may be refluxogenic.

PREVALENCE AND RISK OF GERD AFTER LSG
Numerous studies have examined the development of GERD or worsening of preoperative GERD after SG.
However, data on the prevalence of new-onset or aggravated GERD post-LSG remain somewhat conflicting.
Some studies have reported the development of de novo GERD , while other studies have shown
[24]
[25]
improvement in GERD symptoms . These studies have been limited by a number of methodological
differences, including the definition of GERD (defined by symptoms, endoscopic findings, and/or pH
studies, often with different diagnostic cut-offs), number of patients, duration of follow-up, BMI of the
patients who underwent LSG, and primary and secondary outcomes assessed.

A retrospective review of a longitudinal database of 4,832 patients who underwent LSG between 2007 and
2010 reported preexisting GERD in 44.5% of patients scheduled for SG, 84.1% with persistent GERD
symptoms postoperatively, resolution of GERD symptoms in 15.9%, and 8.6% with de novo GERD
symptoms postoperatively . The incidence of pre- and postoperative GERD was also evaluated in a study
[26]
of 162 SG patients, using questionnaires, PPI use, and upper endoscopy. GERD symptoms (68% vs. 34%, P <
0.0001) and PPI use (57% vs. 19%, P < 0.0001) increased postoperatively. Increases in Grade B (33% vs. 8%, P
< 0.00901), and Grade C esophagitis (12% vs. 4%, P = 0.04) were found, with GERD symptoms in only 33%,
and Grade D esophagitis were increased (9% vs. 0%, P = 0.0016) with symptoms in 57% of patients, post vs.
[16]
pre-SG. Additionally, there was a significant increase in non-dysplastic BE (17% vs. 0%, P < 0.0001) .

Overall, de novo GERD has been reported to occur in 7.4% to 58% of patients following LSG . A systematic
[27]
review and meta-analysis of 33 studies reported the prevalence of GERD symptoms (11 studies using
standardized questionnaires), the use of anti-reflux medications (4 studies), and findings from esophageal
function testing (3, 7, and 2 studies reported results of 24-hour pH testing, esophageal manometry, and
combined pH-impedance, respectively) following LSG. A pooled risk difference for GERD before and after
LSG was 4.3%. Changes in the use of anti-reflux medication could not be pooled, as some studies reported a
marked increase in PPI use, while others found no change or even a decrease. Secondary outcome measures
included the prevalence of new-onset GERD (reported in 24 studies) and esophagitis (4 studies). The pooled
incidence of new-onset GERD was 20%, and the incidence of new-onset esophagitis ranged widely from
6.3% to 63.3%. Overall, these studies were characterized by high heterogeneity, and esophageal function
[28]
testing was inconsistent .
A prospective study utilized 24-hour transnasal pH monitoring before and after LSG to define GERD
(esophageal pH < 4 for at least 4.2% of total recorded time). Preoperatively, 29 patients had normal pH
studies, 86% of whom had no GERD symptoms, while 21 patients had positive pH studies, 62% of whom
reported GERD symptoms. Postoperatively, 69% of patients developed a newly positive pH study, including
24% (n = 7) who remained asymptomatic. Among those with preexisting positive pH studies, there was no
significant change in total time pH < 4 with LSG (5.9% vs. 7.7%, P = 0.296), according to the percent time
[29]
cut-off criteria utilized for the study. Endoscopic findings in these patients were not reported . Of note,
GERD diagnosis is not based solely on the results of pH studies, and the significance of a positive pH study
[11]
in an asymptomatic patient without evidence of mucosal injury is unclear .