NON-INVASIVE MAPPING OF POST-PANCREATICODUODENECTOMY GASTRIC FUNCTION USING GASTRIC ALIMETRY®

Introduction
Laparoscopic fundoplication in patients with a history of lung transplant has an average length of stay (LOS) of 3 days with a 30-day readmission rate of 25%, which is significantly worse compared to the non-lung transplant population. We investigated if lung transplantation was still a risk factor for poor short-term outcomes in a practice that exclusively uses the robot for hiatal hernia/GERD surgeries.

Methods
We performed a single-center retrospective analyses of the Society of Thoracic Surgery (STS) database for patients who underwent elective hiatal hernia/GERD procedures from 1/5/2018 to 2/6/2021. We identified patient and surgical characteristics, morbidity, LOS, 30-day readmission and mortality. Analysis was conducted using Chi-square and Wilcoxon rank-sum tests, univariable linear regression, and bivariate analysis. A p-value below 0.05 was considered significant.

Results
Among 386 patients who underwent barrier creation, 43 patients had previously undergone a lung transplant, either bilateral (n=28) or single (n=14). The hiatal hernia/GERD procedure was performed for the lung transplant population on an average of 2.5 years post-transplant (SD +/- 2.5). All lung transplant patients underwent robotic-assisted laparoscopic hiatal hernia/GERD surgery. There was no significant difference in post-operative complications (9.3% vs. 5.2%, p=0.29, Figure 1A), median hospital LOS (1 vs. 1 day, p=0.27, Figure 1B), 30-day readmission (7.0% vs. 5.0%, p=0.48, Figure 1C), or 30-day all-cause mortality (0% vs. 0.6%, p=1.0) between lung transplant and non-lung transplant patients. Univariate analysis showed older age (p=0.03), opioid dependence (p=0.02), neurocognitive dysfunction (p<0.001), and dependent functional status (p=0.02) were associated with all post-operative complications. However, lung transplantation was not associated with increased risk of postoperative complications (p=0.28).

Discussion
In this cohort of patients who underwent robot-assisted laparoscopic hiatal hernia / GERD surgery, we found no difference in short-term outcomes between lung transplant and non-lung transplant patients. Robot-assisted surgery may provide improved outcomes for high-risk surgical patients.

Introduction: There is an overall tendency toward more restriction of the final sleeve by using a smaller bougie and leaving a shorter antrum. Few observational cohort and randomized controlled trial studies have compared between different resection distances from the pylorus during sleeve gastrectomy. Our aim was to aggregate the evidence available on sleeve gastrectomy with antral preservation (AP) versus antral resection (AR) by a meta-analysis.

Methods: Literature search was done according to the PRISMA guidelines. Observational cohort studies only were included in the analysis (9 studies). Meta-analysis was done using the RevMen 5.4.1 software. Statistical method used was Mantel-Haenszel. Analysis model used was random effects regardless of the heterogeneity (I²).

Results: There was no significant difference in the excess weight loss percentage (EWL%) at 1 and 3 months, mean differences (MDs) were 0.45 (CI -1.44, 2.35) and 2.72 (CI -2.04, 7.48), respectively. However, significant difference was observed in favor of the AR group in EWL% at 6, 12 and 24 months. MDs were 4.61 (CI 2.01, 7.20), 6.02 (CI 2.42, 9.61), and 8.32 (CI 6.45, 10.20), respectively. There was no significant difference in the total body weight loss % (TBWL%) at 1 month, MD was 0.66 (CI -0.06, 1.37). However, significant differences were observed in favor of the AR group regarding the TBWL% at 6, 12 and 24 months. MDs were 2.64 (CI 1.46, 3.82), 4.50 (CI 0.86, 8.13), and 4.10 (CI 3.29, 4.91), respectively. Significant difference was observed in favor of AP in postoperative leaks (OR 1.19, CI 1.00, 1.42). No significant difference was observed in the total number of postoperative complications (OR 1.12, CI 0.71, 1.76), postoperative bleeding (OR 0.88, CI 0.73, 1.06), length of stay (LOS) in days (MD 1.09, CI -2.22, 4.39), LOS in hours (MD 0.41, CI -3.39, 4.20), operative time (MD 0.72, CI -2.68, 4.12), or wound infections (OR 1.01, CI 0.41, 2.47). No significant difference was observed in complete resolution of type 2 diabetes (OR 1.35, CI 0.58, 3.15), hypertension (OR 1.51, CI 0.54, 4.28), and dyslipidemia (OR 1.17, 0.52, 2.64).

Conclusion: Sleeve gastrectomy with AP had significantly less EWL% and TBWL%, but significantly less incidence of postoperative leaks. Although insignificant, sleeve gastrectomy with AP had higher incidence of postoperative bleeding, and lesser overall resolution of all comorbidities (combined), with p values near the significance cutoff, larger studies may be able to prove significant differences. Larger studies with emphasis on incidence of postoperative denovo GERD are warranted to see if there are significant benefits for sleeve gastrectomy with AP that would justify the lesser weigh loss outcomes. Otherwise, sleeve gastrectomy without AP might be a better option.

Introduction
Pancreaticoduodenectomy (PD) is performed for several indications, including pancreatic and biliary malignancies. A common post-operative complication is delayed gastric emptying (DGE), which may occur acutely and/or chronically. Procedural variations have sought to reduce the incidence of DGE and its associated symptoms of nausea, vomiting and fullness, however the underlying pathophysiology is still poorly understood. Emerging evidence suggests that gastric myoelectrical abnormalities may contribute to DGE. A non-invasive medical device for body surface gastric electrical mapping was recently developed to evaluate gastric electrical activity and function. This study aimed to assess the feasibility of the novel device on the stomach following PD, to identify any changes in gastric activity and their correlation with symptoms.

Methods
PD patients from Auckland, New Zealand between 2017-2022 were recruited. Patients with known mechanical obstructions or recurrent malignancies were excluded. The Gastric Alimetry System® (Auckland, New Zealand) was employed, comprising a stretchable array (8x8 electrodes; 196cm2) and cloud-based analytics platform. Following an overnight fast, 30 minutes of baseline recording was performed, followed by a meal challenge and 4 hours of post-prandial recordings. Symptoms were logged on a validated iPad App. Spectral analysis of Gastric Alimetry data was performed, with quantitative analysis including Principle Gastric Frequency, BMI-adjusted amplitude and Gastric Alimetry Rhythm Index (GA-RI, a measure of rhythm stability), compared to reference intervals from 110 healthy volunteers. Adverse events were recorded.

Results
16 patients were recruited; all had a pylorus-resecting PD with 15/16 having a gastroejejunostomy and 1/16 receiving a Roux-en-Y reconstruction. Gastric Alimetry spectral abnormalities were more common in patients with moderate-severe symptom burdens (3/5 patients) vs mild-minimal symptom burdens (1/11); p=0.029. Abnormalities in symptomatic patients encompassed low GA-RI in 2 patients (<0.25); and low amplitude in 1 patient (<22μV) indicating gastric neuromuscular dysfunction. Gastric Alimetry symptom phenotypes in symptomatic patients were variable; sensorimotor (3), post-gastric (2) and continuous (2); (2 having mixed profiles). There were no adverse events.

Conclusion
Gastric Alimetry is a safe and feasible technique to non-invasively assess gastric function following PD. A third of patients had moderate to severe gastric symptoms chronically after PD, and these showed a higher rate of gastric neuromuscular dysfunction. A range of symptom phenotypes were noted, indicating gastric sensory, post-gastric (i.e. dumping) and continuous (likely neuropathic) contributions. These data indicate a role for Gastric Alimetry testing in evaluating the causes of chronic gastric symptoms after PD.