Gas-Bloat Syndrome after Magnetic Sphincter Augmentation: Incidence, Natural History, Risk Factors, and Impact on Surgical Outcomes Over Time

BACKGROUND

The notion that gas-bloat syndrome (GBS) after magnetic sphincter augmentation (MSA) is less detrimental has not been substantiated by data. This study aimed to identify the incidence, natural history, risk factors, and impact on outcomes of GBS after MSA.

STUDY DESIGN

Records of patients who underwent MSA at our institution were reviewed. GBS was defined as a score of 4 or more on the gas bloat-specific item within the GERD health-related quality-of-life (GERD-HRQL) questionnaire. Preoperative clinical and objective testing data were compared between those with and without GBS at 1 year using univariate followed by multivariable analysis. GBS evolution over time and its impact on outcomes were assessed in those with 1- and 2-year follow-up.

RESULTS

A total of 489 patients underwent MSA. At a mean (SD) follow-up of 12.8 (2.1) months, patient satisfaction was 88.8%, 91.2% discontinued antisecretory medications, and 74.2% achieved DeMeester score normalization.At 1 year, 13.3% of patients developed GBS, and had worse GERD-HRQL scores and antisecretory medication use and satisfaction (p < 0.0001). DeMeester score normalization was comparable (p = 0.856). Independent predictors of GBS were bloating (odds ratio [OR] 1.8, p = 0.043), GERD-HRQL score greater than 30 (OR 3, p = 0.0010), and MSA size 14 or less beads (OR 2.5, p = 0.004). In a subgroup of 239 patients with 2-year follow-up, 70.4% of patients with GBS at 1 year had resolution by 2 years. The GERD-HRQL total score improved when GBS resolved from 11 (7 to 19) to 7 (4 to 10), p = 0.016. Patients with persistent GBS at 2 years had worse 2-year GERD-HRQL total scores (20 [5 to 31] vs 5 [3 to 12], p = 0.019).

CONCLUSIONS

GBS affects 13.3% of patients at 1 year after MSA and substantially diminishes outcomes. However, GBS resolves spontaneously with quality-of-life improvement. Patients with preoperative bloating, high GERD-HRQL scores, or small MSA devices are at greatest risk of this complication.

Magnetic Sphincter Augmentation for Laryngopharyngeal Reflux: An Assessment of Efficacy and Predictors of Outcome

INTRODUCTION

Magnetic sphincter augmentation (MSA) is an effective treatment for typical reflux symptoms, but data on its impact on laryngopharyngeal reflux (LPR) is limited. This study aimed to determine the efficacy of MSA for LPR and to identify predictors of outcome.

METHODS

This was a retrospective review of 775 patients who underwent MSA between 2013 and 2021. LPR was defined as presence of atypical reflux symptoms and a reflux symptom index (RSI) score >13. Favorable outcome was defined as primary symptom resolution, freedom from proton pump inhibitors, and five-point improvement or RSI score normalization. Preoperative clinical, high-resolution manometry, and impedance-pH data were analyzed for impact on favorable outcome using univariate followed by multivariable analysis.

RESULTS

There were 128 patients who underwent MSA for LPR. At a mean (SD) follow-up of 13 (5.4) months, favorable outcome was achieved by 80.4% of patients, with median (IQR) RSI score improving from 29 (22-35) to 9 (4-17), (P < 0.001). Independent predictors of favorable outcome on multivariable analysis included LPR with typical reflux symptoms [OR (95% CI): 8.9 (2.3-31.1), P = 0.001], >80% intact swallow on high-resolution manometry [OR (95% CI): 3.8 (1.0-13.3), P = 0.035], upper esophageal sphincter (UES) resting pressure >34 mmHg [OR (95% CI): 4.1 (1.1-14.1), P = 0.027] and short total proximal acid clearance time [OR (95% CI): 1.1 (1.0-1.1), P = 0.031]. Impedance parameters including number of LPR events, full column reflux and proximal acid exposure events were similar between outcome groups (P > 0.05).

CONCLUSION

MSA is an effective surgery for patients with LPR. Patients with concomitant typical reflux symptoms, normal esophageal body motility, and competent UES benefit the most from surgery. Individual impedance-pH parameters were not associated with outcome.

Sitravatinib combined with PD-1 blockade enhances cytotoxic T-cell infiltration by M2 to M1 tumor macrophage repolarization in esophageal adenocarcinoma

Esophageal adenocarcinoma (EAC) is a leading cause of cancer-related mortality. Sitravatinib is a novel multi-gene tyrosine kinase inhibitor (TKI) that targets tumor-associated macrophage (TAM) receptors, VEGF, PDGF and c-Kit. Currently, sitravatinib is actively being studied in clinical trials across solid tumors and other TKIs have shown efficacy in combination with immune checkpoint inhibitors (ICI) in cancer models. In this study, we investigated the anti-tumor activity of sitravatinib alone and in combination with PD-1 blockade in an EAC rat model. Treatment response was evaluated by mortality, pre- and post-treatment MRI, gene expression, immunofluorescence and immunohistochemistry. Our results demonstrated adequate safety and significant tumor shrinkage in animals treated with sitravatinib, and more profoundly, sitravatinib and PD-1 inhibitor, AUNP-12 (P < 0.01). Suppression of TAM receptors resulted in increased gene expression of pro-inflammatory cytokines and decreased expression of anti-inflammatory cytokines, enhanced infiltration of CD8+ T cells, and M2 to M1 macrophage phenotype repolarization in the tumor microenvironment of treated animals (P < 0.01). Moreover, endpoint immunohistochemistry staining corroborated the anti-tumor activity by downregulation of Ki67 and upregulation of Caspase-3 in the treated animals. Additionally, pretreatment gene expression of TAM receptors and PD-L1 were significantly higher in major responders compared with the non-responders, in animals that received sitravatinib and AUNP-12 (P < 0.02), confirming that TAM suppression enhances the efficacy of PD-1 blockade. In conclusion, this study proposes a promising immunomodulatory strategy using a multi-gene TKI to overcome developed resistance to an ICI in EAC, establishing rationale for future clinical development.

Neoadjuvant nivolumab or nivolumab plus LAG-3 inhibitor relatlimab in resectable esophageal/gastroesophageal junction cancer: a phase Ib trial and ctDNA analyses

Gastroesophageal cancer dynamics and drivers of clinical responses with immune checkpoint inhibitors (ICI) remain poorly understood. Potential synergistic activity of dual programmed cell death protein 1 (PD-1) and lymphocyte-activation gene 3 (LAG-3) inhibition may help improve immunotherapy responses for these tumors. We report a phase Ib trial that evaluated neoadjuvant nivolumab (Arm A, n = 16) or nivolumab-relatlimab (Arm B, n = 16) in combination with chemoradiotherapy in 32 patients with resectable stage II/stage III gastroesophageal cancer together with an in-depth evaluation of pathological, molecular and functional immune responses. Primary endpoint was safety; the secondary endpoint was feasibility; exploratory endpoints included pathological complete (pCR) and major pathological response (MPR), recurrence-free survival (RFS) and overall survival (OS). The study met its primary safety endpoint in Arm A, although Arm B required modification to mitigate toxicity. pCR and MPR rates were 40% and 53.5% for Arm A and 21.4% and 57.1% for Arm B. Most common adverse events were fatigue, nausea, thrombocytopenia and dermatitis. Overall, 2-year RFS and OS rates were 72.5% and 82.6%, respectively. Higher baseline programmed cell death ligand 1 (PD-L1) and LAG-3 expression were associated with deeper pathological responses. Exploratory analyses of circulating tumor DNA (ctDNA) showed that patients with undetectable ctDNA post-ICI induction, preoperatively and postoperatively had a significantly longer RFS and OS; ctDNA clearance was reflective of neoantigen-specific T cell responses. Our findings provide insights into the safety profile of combined PD-1 and LAG-3 blockade in gastroesophageal cancer and highlight the potential of ctDNA analysis to dynamically assess systemic tumor burden during neoadjuvant ICI that may open a therapeutic window for future intervention. ClinicalTrials.gov registration: NCT03044613 .

Esophageal body adaptation to Nissen fundoplication: Increased esophagogastric outflow resistance yields delayed and sustained peristaltic contractions without increased amplitude

BACKGROUND

Improvement in lower esophageal sphincter (LES) competency after laparoscopic Nissen fundoplication (LNF) is well established, yet esophageal body physiology data are limited. We aimed to describe the impact of LNF on whole esophagus physiology using standard and novel manometric characteristics.

METHODS

A cohort of patients with an intact fundoplication without herniation and no postoperative dysphagia were selected and underwent esophageal manometry at one-year after surgery. Pre- and post-operative manometry files were reanalyzed using standard and novel manometric characteristics and compared.

KEY RESULTS

A total of 95 patients were included in this study. At 16.1 (8.7) months LNF increased LES overall and abdominal length and resting pressure (p < 0.0001). Outflow resistance (IRP) increased [5.8 (3-11) to 11.1 (9-15), p < 0.0001] with a 95th percentile of 20 mmHg in this cohort of dysphagia-free patients. Distal contractile integral (DCI) also increased [1177.0 (667-2139) to 1321.1 (783-2895), p = 0.002], yet contractile amplitude was unchanged (p = 0.158). There were direct correlations between pre- and post-operative DCI [R: 0.727 (0.62-0.81), p < 0.0001] and postoperative DCI and postoperative IRP [R: 0.347 (0.16-0.51), p = 0.0006]. Contractile front velocity [3.5 (3-4) to 3.2 (3-4), p = 0.0013] was slower, while distal latency [6.7 (6-8) to 7.4 (7-9), p < 0.0001], the interval from swallow onset to proximal smooth muscle initiation [4.0 (4-5) to 4.4 (4-5), p = 0.0002], and the interval from swallow onset to point when the peristaltic wave meets the LES [9.4 (8-10) to 10.3 (9-12), p < 0.0001] were longer. Esophageal length [21.9 (19-24) to 23.2 (21-25), p < 0.0001] and transition zone (TZ) length [2.2 (1-3) to 2.5 (1-4), p = 0.004] were longer. Bolus clearance was inversely correlated with TZ length (p = 0.0002) and time from swallow onset to proximal smooth muscle initiation (p < 0.0001). Bolus clearance and UES characteristics were unchanged (p > 0.05).

CONCLUSIONS & INFERENCES

Increased outflow resistance after LNF required an increased DCI. However, this increased contractile vigor was achieved through sustained, not stronger, peristaltic contractions. Increased esophageal length was associated with increased TZ and delayed initiation of smooth muscle contractions.

The Dubai Definition and Diagnostic Criteria of Laryngopharyngeal Reflux: The IFOS Consensus

OBJECTIVE

The objective of this work was to gather an international consensus group to propose a global definition and diagnostic approach of laryngopharyngeal reflux (LPR) to guide primary care and specialist physicians in the management of LPR.

METHODS

Forty-eight international experts (otolaryngologists, gastroenterologists, surgeons, and physiologists) were included in a modified Delphi process to revise 48 statements about definition, clinical presentation, and diagnostic approaches to LPR. Three voting rounds determined a consensus statement to be acceptable when 80% of experts agreed with a rating of at least 8/10. Votes were anonymous and the analyses of voting rounds were performed by an independent statistician.

RESULTS

After the third round, 79.2% of statements (N = 38/48) were approved. LPR was defined as a disease of the upper aerodigestive tract resulting from the direct and/or indirect effects of gastroduodenal content reflux, inducing morphological and/or neurological changes in the upper aerodigestive tract. LPR is associated with recognized non-specific laryngeal and extra-laryngeal symptoms and signs that can be evaluated with validated patient-reported outcome questionnaires and clinical instruments. The hypopharyngeal-esophageal multichannel intraluminal impedance-pH testing can suggest the diagnosis of LPR when there is >1 acid, weakly acid or nonacid hypopharyngeal reflux event in 24 h.

CONCLUSION

A global consensus definition for LPR is presented to improve detection and diagnosis of the disease for otolaryngologists, pulmonologists, gastroenterologists, surgeons, and primary care practitioners. The approved statements are offered to improve collaborative research by adopting common and validated diagnostic approaches to LPR.

LEVEL OF EVIDENCE

5 Laryngoscope, 134:1614-1624, 2024.

Impact of Change in Sizing Protocol on Outcome of Magnetic Sphincter Augmentation

OBJECTIVE

To evaluate and compare magnetic sphincter augmentation (MSA) device sizing protocols on postoperative outcomes and dysphagia.

SUMMARY BACKGROUND DATA

Among predictors of dysphagia after MSA, device size is the only factor that may be modified. Many centers have adopted protocols to increase device size. However, there is limited data on the impact of MSA device upsizing protocols on the surgical outcomes.

METHODS

Patients who underwent MSA were implanted with 2 or 3-beads above the sizing device's pop-off point (POP). Clinical and objective outcomes >1-year after surgery were compared between patients implanted with POP+2-vs-POP+3 sizing protocols. Multiple subgroups were analyzed for benefit from upsizing. Pre- and postoperative characteristics were compared between size patients received, regardless of protocol.

RESULTS

A total of 388 patients were implanted under POP+2 and 216 under POP+3. At a mean of 14.2(7.9) months pH normalization was 73.6% and 34.1% required dilation, 15.9% developed persistent dysphagia, and 4.0% required removal. Sizing protocol had no impact on persistent dysphagia ( P =0.908), pH normalization ( P =0.822), or need for dilation ( P =0.210) or removal ( P =0.191). Subgroup analysis found that upsizing reduced dysphagia in patients with <80 percent peristalsis (10.3-vs-31%, P =0.048) or DCI >5000 (0-vs-30.4%, P =0.034). Regardless of sizing protocol, as device size increased there was a stepwise increase in percent male sex ( P <0.0001), BMI>30 ( P <0.0001), and preoperative hiatal hernia>3 cm ( P <0.0001), LA grade C/D esophagitis ( P <0.0001), and DeMeester score ( P <0.0001). Increased size was associated with decreased pH-normalization ( P <0.0001) and need for dilation ( P =0.043) or removal ( P =0.014).

CONCLUSIONS

Upsizing from POP+2 to POP+3 does not reduce dysphagia or affect other MSA outcomes; however, patients with poor peristalsis or hypercontractile esophagus do benefit. Regardless of sizing protocol, preoperative clinical characteristics varied among device sizes, suggesting size is not a modifiable factor, but a surrogate for esophageal circumference.

Need for frequent dilations after magnetic sphincter augmentation: an assessment of associated factors and outcomes

BACKGROUND

Dysphagia is the most common complaint after magnetic sphincter augmentation (MSA), with nearly one-third of patients requiring at least one dilation following MSA. A subset of patients require frequent dilations, but there is a paucity of data on the characteristics of this population. This study aimed to identify predictors of the need for frequent dilations within the first year after implant and to assess these patients' outcomes.

METHODS

This is a retrospective review of prospectively collected data of patients who underwent MSA over an 8-year period. Frequent dilations were defined as 2 or more dilations within 1 year of surgery. Patients completed baseline and 1-year postoperative GERD-HRQL questionnaires and objective physiology testing. Baseline demographic, clinical characteristics, and objective testing data were compared between patients who did and did not require frequent dilations.

RESULTS

A total of 697 (62.7% female) patients underwent MSA, with 62 (8.9%) patients requiring frequent dilation. At a mean (SD) of 12.3 (3.4) months follow-up, the frequent dilation group had higher median GERD-HRQL total scores (21.0 vs. 5.0, p < 0.001), PPI use (20.8% vs.10.1%, p = 0.023), dissatisfaction (46.7% vs. 11.6%, p < 0.001), and device removal (25.8% vs. 2.2%, p < 0.001) rates. Acid normalization was comparable (p = 0.997). Independent predictors of frequent dilation included preoperative odynophagia (OR 2.85; p = 0.001), IRP > 15 mmHg (OR 2.88; p = 0.006), and > 30% incomplete bolus clearance (OR 1.94; p = 0.004). At a mean (SD) of 15.7 (10.7) months, 28 (45.1%) patients underwent device removal after frequent dilation. Independent predictors of device removal after frequent dilation within 5 years of surgery were preoperative odynophagia (OR 7.18; p = 0.042), LES resting pressure > 45 mmHg (OR 28.5; p = 0.005), and ≥ 10% failed swallows (OR 23.5; p < 0.001).

CONCLUSIONS

The need for frequent dilations after MSA is a marker for poor symptom control, dissatisfaction, and device removal. Patients with preoperative odynophagia, high LES pressures, and poor esophageal motility should be counseled of their risk for these poor outcomes.

Ineffective esophageal motility: The impact of change of criteria in Chicago Classification version 4.0 on predicting outcome after magnetic sphincter augmentation

BACKGROUND

The most recent update of the Chicago Classification (CCv4.0) attempts to provide a more clinically relevant definition for ineffective esophageal motility (IEM). The impact of this new definition on predicting outcome after antireflux surgery is unknown. The aim of this study was to compare utility of IEM diagnosis based on CCv4.0 to CCv3.0 in predicting surgical outcome after magnetic sphincter augmentation (MSA) and to assess any additional parameters that hold value in future definitions.

METHODS

Records of 336 patients who underwent MSA at our institution between 2013 and 2020 were reviewed. Preoperative manometry files were re-analyzed using both Chicago Classification version 3.0 (CCv3.0) and CCv4.0 definitions of IEM. The utility of each IEM definition in predicting surgical outcome was then compared. Individual manometric components and impedance data were also assessed.

KEY RESULTS

Immediate dysphagia was reported by 186 (55.4%) and persistent dysphagia by 42 (12.5%) patients. CCv3.0 IEM criteria were met by 37 (11%) and CCv4.0 IEM by 18 (5.4%) patients (p = 0.011). CCv3.0 and CCv4.0 IEM were equally poor predictors of immediate (AUC = 0.503 vs. 0.512, p = 0.7482) and persistent (AUC = 0.519 vs. 0.510, p = 0.7544) dysphagia. The predicted dysphagia probability of less than 70% bolus clearance (BC) was 17.4%, higher than CCv4.0 IEM at 16.7%. When BC was incorporated into CCv4.0 IEM criteria, the probability increased significantly to 30.0% (p = 0.0042).

CONCLUSIONS & INFERENCES

The CCv3.0 and CCv4.0 of IEM are poor predictors of dysphagia after MSA. Adding BC to the new definition improves its predictive utility and should be considered in future definitions.

The impact of delayed gastric emptying as measured by gastric emptying scintigraphy on the outcome of magnetic sphincter augmentation

INTRODUCTION

The impact of delayed gastric emptying (DGE) on the outcome of anti-reflux surgery (ARS) is controversial. There is concern that poor gastric emptying diminishes outcomes. Magnetic sphincter augmentation (MSA) may have a comparatively mild impact on gastric physiology, but the relationship between DGE and MSA outcomes is unknown. This study aims to evaluate the relationship between objective DGE and MSA outcomes over time.

METHODS

Patients who completed gastric emptying scintigraphy (GES) prior to MSA between 2013 and 2021 were included. DGE was defined as a 4 h retention > 10% or half emptying time > 90 min on GES. Outcomes were compared between DGE and normal gastric emptying (NGE) groups at 6 months, 1 and 2 years. Sub-analysis of patients with severe (> 35%) DGE and correlation analysis between 4-h retention and symptom and acid-normalization were performed.

RESULTS

The study population consisted of 26 (19.8%) patients with DGE and 105 with NGE. DGE was associated with more 90-days readmissions (18.5 vs 2.9%, p = 0.009). At 6 months patients with DGE had higher median (IQR) GERD-HRQL total [17.0(10-29) vs 5.5(3-16), p = 0.0013], heartburn [1(1-3) vs 0(0-1), p = 0.0010) and gas-bloat [4(2-5) vs 2(1-3), p = 0.033] scores. Outcomes at 1 and 2 years follow-up were comparable (p > 0.05). From 6 months to 1-year the gas-bloat score decreased from 4(2-5) to 3(1-3), p = 0.041. Total and heartburn scores decreased, but not significantly. Severe DGE (n = 4) patients had lower antiacid medication freedom at 6 months (75 vs 87%, p = 0.014) and 1-year (50 vs 92%, p = 0.046). There were non-significant trends for higher GERD-HRQL scores, dissatisfaction, and removal rates in severe DGE at 6 months and 1-year. There was a weak correlation between 4-h retention and 6-month GERD-HRQL total score [R = 0.253, 95%CI (0.09-0.41), p = 0.039], but not acid-normalization (p > 0.05).

CONCLUSION

Outcomes after MSA are diminished early on in patients with mild-to-moderate DGE, but comparable by 1 year and durable at 2 years. Severe DGE outcomes may be suboptimal.

Chevalier Jackson: father of endoscopic surgery, and champion of women in medicine, social justice, and public health

BACKGROUNDS

Chevalier Jackson (1865-1958) was a pioneering force in the medical world, whose extraordinary contributions to surgery and public health have left an indelible impact. He developed the endoscope and perfected the bronchoscope, and his mastery of these tools enabled him to transform the prognosis of foreign body aspiration from 98% mortality to 98% survival. He was also a passionate advocate of public health chairing the national committee on lye legislation, which culminated in the Caustic Poison Act, responsible for poison and antidote labels. Yet Jackson's accomplishments were not limited to these. The aim of this manuscript was to shed light on Chevalier Jackson's lesser-known contributions to surgical science and culture, and to celebrate and honor the life of this remarkable surgeon.

METHODS

Digital and physical historical records from the National Library of Medicine, Smithsonian Institution, Heinz History Center in Pittsburgh PA, and Sunrise Mill Museum, Montgomery County PA were reviewed for Chevalier Jackson's scientific, cultural, and social contributions to the field of surgery.

RESULTS

Among his lesser-known contributions, Chevalier Jackson was the first to describe erosive esophagitis. He developed the first standardized tracheotomy procedure, still in use today. He was ahead of his time in many ways, pioneering a multidisciplinary approach to medicine, advocating for patient-centered care, and advancing the inclusion of women in the medical profession.

CONCLUSION

Chevalier Jackson's legacy extends far beyond the tools and techniques he invented. He was a champion of social justice, a protector of patients, and an inspiration to medical professionals across the globe.

Magnetic sphincter augmentation and high-resolution manometry: impact of biomechanical properties on esophageal motility and clinical significance for selection and outcomes

Magnetic sphincter augmentation (MSA)was introduced as an alternative to laparoscopic Nissen fundoplication (LNF). This reproducible, outpatient procedure addresses the etiology of gastroesophageal reflux disease by implanting a ring of magnetic beads across the esophagogastric junction (EGJ). MSA is designed to resist effacement of the lower esophageal sphincter (LES) and, similar to LNF, results in restoration of anti-reflux barrier competency by increasing overall length, intraabdominal length and resting pressure of the sphincter. However, the novel use of magnets to augment the physiology of the LES poses unique challenges to the physiology of the EGJ and esophagus. These impacts are best revealed through manometry. The degree of restrictive forces at the EGJ, as measured by intrabolus pressure and integrated relaxation pressure, is higher after MSA compared with LNF. In addition, contrary to the LNF, which retains neurohormonal relaxation capability during deglutition, the magnetic forces remain constant until forcibly opened. Therefore, the burden of overcoming EJG resistance is placed solely on the esophageal body contractile force, as measured by distal contractile integral and distal esophageal amplitude. The main utility of preoperative manometry is in determining whether a patient's esophagus has sufficient contractility or peristaltic reserve to adapt to the challenge of an MSA. Manometric thresholds predictive of MSA outcomes deviate from those used to define named Chicago Classification motility disorders. Therefore, individual preoperative manometric characteristics should be analyzed to aid in risk stratification and patient selection prior to MSA.

Abstract 3374: Circulating cell-free tumor DNA dynamics capture minimal residual disease with neoadjuvant immune checkpoint blockade plus chemoradiotherapy for patients with operable esophageal/gastroesophageal junction cancer

Introduction: There is a critical need to incorporate molecular assessments of minimal residual disease (MRD) during neoadjuvant immunotherapy, in order to identify individuals at high risk for disease recurrence based on analyses of circulating cell-free tumor DNA (ctDNA) landscapes. Here we employed longitudinal liquid biopsies to dynamically assess clinical outcomes with neoadjuvant immuno-chemoradiotherapy in patients with esophageal/gastroesophageal junction (E/GEJ) cancer.

Methods: We utilized targeted error-correction sequencing to perform high-depth ctDNA next-generation sequencing for 141 serial plasma and 32 matched white blood cell (WBC) DNA samples from 32 patients with operable stage II/III E/GEJ cancer that received neoadjuvant immune checkpoint blockade (ICB) with chemoradiotherapy prior to surgery (NCT03044613). ctDNA analyses were performed at baseline, post-ICB induction, after completion of chemoradiotherapy (pre-op), and post-operatively (post-op). Using a tumor-agnostic WBC DNA-informed panel NGS approach we determined the cellular origin of plasma variants, filtering out germline and clonal hematopoiesis (CH) variants and evaluated ctDNA clonal dynamics over time. Molecular MRD was evaluated post-ICB, pre-op and post-op and correlated with recurrence-free (RFS) and overall survival (OS).

Results: Twenty out of 32 patients had detectable ctDNA at any timepoint. Of the 12 patients with undetectable ctDNA, 9 had only CH- and/or germline-derived variants, while 3 patients had no detectable variants of any origin. ctDNA clearance post-ICB was correlated with tumor regression &gt;80% at the time of resection (Fischer’s exact p=0.04). The subset of patients that did not attain complete pathologic response was heterogeneous with respect to ctDNA dynamics; such that ctDNA clearance pre-op identified patients with longer OS despite residual tumor of &gt;0% at the time of resection (log rank p=0.06). Patients with undetectable ctDNA or ctDNA clearance pre-op had a longer RFS (log rank p=0.007) and OS (log rank p=0.03). Molecular MRD was associated with RFS and OS such that patients with ctDNA clearance post-op had longer RFS (log-rank p=0.007) and OS (log-rank p=0.017).

Conclusion: ctDNA clearance post-ICB, pre-op and post-op reflects differential clinical outcomes for patients with E/GEJ cancer receiving neoadjuvant immuno-chemoradiotherapy. Understanding ctDNA dynamics and their relationship with pathological response and long-term outcomes can help identify patients at higher risk for recurrence and open a therapeutic window for future intervention.

Citation Format: Blair V. Landon, Ronan J. Kelly, Ali H. Zaidi, Archana Balan, Jenna V. Canzoniero, Gavin Pereira, Zineb Belcaid, Russell K. Hales, K Ranh Voong, Richard J. Battafarano, Blair A. Jobe, Stephen C. Yang, Stephen Broderick, Jinny Ha, Kellie N. Smith, Elizabeth Thompson, Fyza Y. Shaikh, James R. White, Cynthia L. Sears, Eun J. Shin, Ali I. Amjad, Benny Weksler, Josephine L. Feliciano, Chen Hu, Vincent K. Lam, Valsamo Anagnostou. Circulating cell-free tumor DNA dynamics capture minimal residual disease with neoadjuvant immune checkpoint blockade plus chemoradiotherapy for patients with operable esophageal/gastroesophageal junction cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3374.

The Impact of Ineffective Esophageal Motility on Patients Undergoing Magnetic Sphincter Augmentation

OBJECTIVE

To evaluate and characterize outcomes of MSA in patients with IEM.

SUMMARY BACKGROUND DATA

MSA improves patients with gastroesophageal reflux and normal motility. However, many patients have IEM, which could impact the outcomes of MSA and discourage use.

METHODS

An international, multi-institutional case control study of IEM patients undergoing MSA matched to normal patients was performed. Primary outcomes were new onset dysphagia and need for postoperative interventions.

RESULTS

A total of 105 IEM patients underwent MSA with matching controls. At 1 year after MSA: GERD-Health Related Quality of Life was similar; DeMeester scores in IEM patients improved to 15.7 and 8.5 in controls ( P = 0.021); and normalization of the DeMeester score for IEM = 61.7% and controls = 73.1% ( P = 0.079).In IEM patients, 10/12 (83%) with preop dysphagia had resolution; 11/66 (17%) had new onset dysphagia and 55/66 (83%) never had dysphagia. Comparatively, in non-IEM patients, 22/24 (92%) had dysphagia resolve; 2/24 (8%) had persistent dysphagia; 7/69 (10%) had new onset dysphagia, and 62/69 (90%) never had dysphagia.Overall, 19 (18%) IEM patients were dilated after MSA, whereas 12 (11%) non-IEM patients underwent dilation ( P = 0.151). Nine (9%) patients in both groups had their device explanted.

CONCLUSIONS

Patients with IEM undergoing MSA demonstrate improved quality of life and reduction in acid exposure. Key differences in IEM patients include lower rates of objective GERD resolution, lower resolution of existing dysphagia, higher rates of new onset dysphagia and need for dilation. GERD patients with IEM should be counselled about these possibilities.

Predictors of favorable outcome after pyloroplasty for gastroparesis: should response to pyloric dilation or Botox injection be used as a marker of surgical outcome?

INTRODUCTION

Pyloroplasty and gastric peroral endoscopic myotomy (G-POEM) are effective surgeries for gastroparesis. The primary aim of this study was to evaluate outcomes of pyloroplasty and G-POEM in patients with gastroparesis and determine factors associated with favorable outcome. The secondary aim was to assess the utility of clinical response to preoperative pyloric dilation or botulinum toxin injection (Botox) on surgical outcome, a factor conventionally used as a favorable marker.

METHODS

There were 204 patients who underwent pyloroplasty (n = 177) or G-POEM (n = 27) for gastroparesis at our institution from 2014 to 2021. Demographic and clinical parameters were analyzed to assess their impact on surgical outcome. A subgroup of patients who had pyloric dilation or Botox injection were assessed separately. Favorable outcome was defined as patient reported complete resolution of the predominant gastroparesis symptom.

RESULTS

Favorable outcome was achieved in 78.4% of patients (pyloroplasty: 79.7% and G-POEM: 70.4%, p = 0.274). Among 61 patients where pre- and postoperative gastric emptying studies (GES) were available, mean 4-hour retention significantly improved from 33.5 to 15.0% (p < 0.001) and 77.0% of patients achieved normalization. Favorable outcome was not significantly impacted by etiology of gastroparesis (p = 0.120), GERD (p = 0.518), or primary gastroparesis symptom (p = 0.244). Age ≥ 40 was a significant predictor of favorable surgical outcome on multivariate analysis [OR: 2.476 (1.224-5.008), p = 0.012]. Among the patients who had preoperative dilation (n = 82) or Botox injection (n = 46), response to these interventions was not a predictor of favorable surgical outcome (p = 0.192 and 0.979, respectively). However, preoperative Botox injection, regardless of response to injection, was associated with favorable surgical outcome [OR: 3.205 (CI 1.105-9.299), p = 0.032].

CONCLUSION

Symptomatic improvement after pyloroplasty or G-POEM is independent of etiology of gastroparesis, GERD, and primary symptom. Response to dilation or Botox are not markers of response to surgery. However, patients who receive Botox are 3.2 times more likely to improve postoperatively.

Impact of Objective Colonic and Whole Gut Motility Data as Measured by Wireless Motility Capsule on Outcomes of Antireflux Surgery

BACKGROUND

Studies show higher rates of dissatisfaction with antireflux surgery (ARS) outcomes in patients with chronic constipation. This suggests a relationship between colonic dysmotility and suboptimal surgical outcome. However, due to limitations in technology, there is no objective data available examining this relationship. The wireless motility capsule (WMC) is a novel technology consisting of an ingestible capsule equipped with pH, temperature, and pressure sensors, which provide information regarding regional and whole gut transit times, pH and motility. The aim of this study was to assess the impact of objective regional and whole gut motility data on the outcomes of ARS.

STUDY DESIGN

This was a retrospective review of patients who underwent WMC testing before ARS. Transit times, motility, and pH data obtained from different gastrointestinal tract regions were used in analysis to determine factors that impact surgical outcome. A favorable outcome was defined as complete resolution of the predominant reflux symptom and freedom from antisecretory medications.

RESULTS

The final study population consisted of 48 patients (fundoplication [n = 29] and magnetic sphincter augmentation [n = 19]). Of those patients, 87.5% were females and the mean age ± SD was 51.8 ± 14.5 years. At follow-up (mean ± SD, 16.8 ± 13.2 months), 87.5% of all patients achieved favorable outcomes. Patients with unfavorable outcomes had longer mean whole gut transit times (92.0 hours vs 55.7 hours; p = 0.024) and colonic transit times (78.6 hours vs 47.3 hours; p = 0.028), higher mean peak colonic pH (8.8 vs 8.15; p = 0.009), and higher mean antral motility indexes (310 vs 90.1; p = 0.050).

CONCLUSIONS

This is the first study to demonstrate that objective colonic dysmotility leads to suboptimal outcomes after ARS. WMC testing can assist with preoperative risk assessment and counseling for patients seeking ARS.

Long-term clinical and functional results of magnetic sphincter augmentation

Magnetic sphincter augmentation (MSA) was introduced in 2007 as an alternative surgical procedure for patients with gastroesophageal reflux disease (GERD). The majority of data since MSA's introduction has focused on short and intermediate-term results, demonstrating safety and high efficacy in terms of reflux symptom control, freedom from proton pump inhibitor use and normalization of distal esophageal acid exposure. However, GERD is a chronic condition that demands a long-term solution. Limited available data from studies reporting outcomes at 5 years or later following MSA demonstrate that the promising short- and mid-term efficacy and safety profile of MSA remains relatively constant in the long term. Compared with Nissen fundoplication, MSA has a much lower rate of gas-bloat and inability to belch at a short-term follow-up, a difference that persists in the long-term. The most common complaint after MSA at a short-term follow-up is dysphagia. However, limited data suggest dysphagia rates largely decrease by 5 years. Dysphagia is the most common indication for dilation and device removal in both early- and long-term studies. However, the overall rates of dilation and removal are similar in short- and long-term reports, suggesting the majority of these procedures are performed in the short-term period after device implantation. The indications and standard practices of MSA have evolved over time. Long-term outcome data currently available are all from patient cohorts who were selected for MSA under early restricted indications and outdated regimens. Therefore, further long-term studies are needed to corroborate the preliminary, yet encouraging long-term results.

Abstract B60: Sitravatanib enhances immune checkpoint blockade in a de novo esophageal adenocarcinoma model

Background: Esophageal adenocarcinoma (EAC) is a leading cause of cancer-related mortality. Sitravatinib is a small molecule spectrum-selective tyrosine kinase inhibitor (TKI) that targets TAM receptors (AXL, MERTK and TYRO3), VEGF, PDGF, and c-Kit. Previously, dual inhibition of TAM and VEGF receptors has shown to successfully modulate the tumor immune microenvironment towards a less immunosuppressive state, by depletion of MDSCs and repolarization of TAMs towards a proinflammatory M1 phenotype. In clinical trials, TKIs have shown to improve patient outcomes, alone or in combination with immune checkpoint inhibitors, in multiple solid tumors. In the present study, the antitumor activity of sitravatinib alone and in combination with PD-1 blockade was investigated in a de novo EAC rat model. Methods: Ninety-six rats underwent an end-to-side esophagojejunostomy to induce gastroesophageal reflux, resulting in EAC carcinogenesis. At 32 weeks post-operatively, tumor bearing animals were randomized to a dose of 10mg/kg of sitravatanib (S) or vehicle control (VC), for a total of three 14 day cycles. A PD-1 inhibitor, AUNP-12 (IO), was administered at a dose of 3mg/kg or placebo, on day 12 of each cycle. At 38 weeks post-operatively animals were euthanized. Safety and efficacy was evaluated by on-treatment mortality, MRI, immunofluorescence and qRT PCR. Results: The S+/-IO groups demonstrated a higher mortality when compared to the control groups (p&lt;0.001). Pre- to post-treatment, mean MRI tumor volume decreased by 32% and 73% in the S-IO and S+IO and increased by 90% and 160% in the VC+IO and VC-IO, respectively (p&lt;0.001). Enhanced CD3+CD8+ T-cell densities were observed in the treatment groups when compared to the control groups (p&lt;0.001). Additionally, a higher CD86/CD206 ratio was observed in the S-IO and S+IO groups than in the control groups (p&lt;0.001), indicating a repolarization from M2 to M1 macrophage phenotype. Gene expression analysis of post treatment samples demonstrated upregulation of pro-inflammatory cytokines TNF-α, IFN-γ, IL-1β, IL-6, IL-12 and downregulation of anti-inflammatory cytokines including TGF-β, IL-4, IL-10, and IL-13 in the treated versus control animals (p&lt;0.05). Pre- to post-treatment qRT-PCR levels demonstrated significant inhibition of pathway genes, AXL, AKT, MERTK and PI3K, in the treated animals (p=&lt;0.001). Moreover, pre-treatment AXL levels were significantly higher in major responders (&gt;80% tumor reduction n=8) compared to the non-responders (&lt;25% tumor reduction/progression n=6), in the merged S +/- IO group (p=0.009). Lastly, increased apoptosis and decreased proliferation were confirmed through Cas-3 and Ki-67, respectively, in both treatment groups (p&lt;0.001). Conclusion: This study establishes a promising combination strategy using the multi-gene TKI sitravatinib to overcome PD-1/PD-L1 resistance and potentiate immune checkpoint inhibition in an EAC model.

Citation Format: Ryan W. Sweeney, John T. Fitzpatrick, Ashten N. Omstead, Ping Zheng, Anastasia Gorbunova, Patrick L. Wagner, Juliann E. Kosovec, Blair A. Jobe, Ronan J. Kelly, Ali H. Zaidi. Sitravatanib enhances immune checkpoint blockade in a de novo esophageal adenocarcinoma model [abstract]. In: Proceedings of the AACR Special Conference: Tumor Immunology and Immunotherapy; 2022 Oct 21-24; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2022;10(12 Suppl):Abstract nr B60.

Prognostic and predictive biomarkers for response to neoadjuvant chemoradiation in esophageal adenocarcinoma

Background

Esophageal adenocarcinoma is a lethal disease. For locally advanced patients, neoadjuvant chemoradiotherapy followed by surgery is the standard of care. Risk stratification relies heavily on clinicopathologic features, particularly pathologic response, which is inadequate, therefore establishing the need for new and reliable biomarkers for risk stratification.

Methods

Thirty four patients with locally advanced esophageal adenocarcinoma were analyzed, of which 21 received a CROSS regimen with carboplatin, paclitaxel, and radiation. Capture-based targeted sequencing was performed on the paired baseline and post-treatment samples. Differentially mutated gene analysis between responders and non-responders of treatment was performed to determine predictors of response. A univariate Cox proportional hazard regression was used to examine associations between gene mutation status and overall survival.

Results

A 3-gene signature, based on mutations in EPHA5, BCL6, and ERBB2, was identified that robustly predicts response to the CROSS regimen. For this model, sensitivity was 84.6% and specificity was 100%. Independently, a 9 gene signature was created using APC, MAP3K6, ETS1, CSF3R, PDGFRB, GATA2, ARID1A, PML, and FGF6, which significantly stratifies patients into risk categories, prognosticating for improved relapse-free (p = 4.73E-03) and overall survival (p = 3.325E-06). The sensitivity for this model was 73.33% and the specificity was 94.74%.

Conclusion

We have identified a 3-gene signature (EPHA5, BCL6, and ERBB2) that is predictive of response to neoadjuvant chemoradiotherapy and a separate prognostic 9-gene classifier that predicts survival outcomes. These panels provide significant potential for personalized management of locally advanced esophageal cancer.

A blood-based circulating microbial metagenomic panel for early diagnosis and prognosis of oesophageal adenocarcinoma

BACKGROUND

Emerging evidence indicates the potential clinical significance of specific microbial signatures as diagnostic and prognostic biomarkers, in multiple cancers. However, to date, no studies have systematically interrogated circulating metagenome profiling in oesophageal adenocarcinoma (EAC) patients, particularly as novel non-invasive, early detection, surveillance and prognostic classifiers.

METHODS

Metagenome sequencing was performed on 81 serum specimens collected across EAC spectrum, with sequencing reads classified using Bracken and MetaPhlAn3. Followed by the Linear Discriminant Analysis effect size (LEfSe) method to identify microbial profiles between groups. Logistic regression and Kaplan-Meier analyses were used to build classifiers.

RESULTS

A significant loss of alpha and beta diversity was identified in serum specimens from EAC patients. We observed a shift in microbial taxa between each group-at the phylum, genus, and species level-with Lactobacillus sakei as the most prominent species in gastroesophageal reflux (GERD) vs other patient groups. Interestingly, LEfSe analysis identified a complete loss of Lactobacillus (L. Sakei and L. Curvatus), Collinsella stercoris and Bacteroides stercoris but conversely a significant increase in Escherichia coli in patients with EAC. Finally, we developed a metagenome panel that discriminated EAC from GERD patients with an AUC value of 0.89 (95% CI: 0.78-0.95; P < 0.001) and this panel in conjunction with the TNM stage was a robust predictor of overall survival (≥24 months; AUC = 0.84 (95% CI: 0.66-0.92; P = 0.006)).

CONCLUSION

This study firstly describes unique blood-based microbial profiles in patients across EAC carcinogenesis, that are further utilised to establish a novel circulating diagnostic and prognostic metagenomic signature for EAC.

TRANSLATIONAL RELEVANCE

Accumulating data indicates the clinical relevance of specific microbial signatures as diagnostic and prognostic biomarkers, in multiple cancers. However, to date, no studies have systematically interrogated circulating metagenome profiling in patients with oesophageal adenocarcinoma (EAC). Herein, we performed metagenome sequencing in serum specimens from EAC patients 81 collected across EAC spectrum and observed a significant loss of alpha and beta diversity, with a shift in microbial taxa between each group-at the phylum, genus, and species level-with Lactobacillus sakei as the most prominent species in gastroesophageal reflux (GERD) vs other patient groups. Interestingly, LEfSe analysis identified a complete loss of Lactobacillus (L. Sakei and L. Curvatus), Collinsella stercoris and Bacteroides stercoris but conversely a significant increase in Escherichia coli in patients with EAC. Finally, we developed a metagenome panel that discriminated EAC from GERD patients with an AUC value of 0.89 and this panel, in conjunction with the TNM stage, was a robust predictor of overall survival. This study for the first time describes unique blood-based microbial profiles in patients across EAC carcinogenesis, that are further utilised to establish a novel circulating diagnostic and prognostic metagenomic signature for EAC.

Abstract 1973: Patients with operable esophageal cancer and improved responses to combined chemoradiotherapy and immunotherapy display distinct microbiome profiles enriched in multiple Bacteroides species

Background: Preclinical and clinical data indicate that neoadjuvant chemoradiotherapy (CRT) may prime an anti-tumor immunological response in esophageal cancer driven by intratumoral CD8+ T cells and PD-L1 expression. LAG-3 is also highly expressed in esophagogastric cancers. The microbiome, a novel and potentially modifiable, biomarker of IO response, has not yet been examined in the neoadjuvant setting in esophageal cancer and is the goal of our study.

Methods: Fecal samples were collected from patients with stage II/III esophageal or gastroesophageal junction carcinoma eligible for curative resection treated with the standard of care regimen of carboplatin paclitaxel (50mg/m2), radiation 50.4 Gy in 28 fractions and an Ivor-Lewis esophagectomy 6-10 weeks after last CRT and immunotherapy (IO) dose. Patients on arm A (n=11) received 2 cycles of induction with nivolumab plus 3 additional cycles on week 1, 3 and 5 of CRT. Patients on arm B (n=8) received nivolumab plus relatlimab on the same schedule (Clinical trial: NCT03044613). We examined longitudinal fecal samples from n=19 patients across both arms (n=90 samples) using 16S rRNA amplicon sequencing. Patients were classified based on pathological response: complete response (CR) and grades 1, 2, and 3 (G1, G2, G3) with increasing residual tumor visible in the resected specimen. Sequencing data was trimmed and filtered for contaminants, followed by high-resolution taxonomic assignment and normalization of reads across all samples. Analysis was performed using multiple metrics for alpha diversity and beta-diversity, with principal coordinates analysis/PERMANOVA, and pathway analysis using Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt).

Results: Patients with improved response in the neoadjuvant setting (CR/G1 vs G2/G3) grouped in distinct clusters using Bray-Curtis (p &lt; 0.001). Patients with CR had higher alpha diversity, using both measures of richness and evenness, compared to patients with a G3 responses (p &lt; 0.03). Specifically, family Bacteroidaceae and genus Bacteroides were enriched in patients with CR vs G3 (p &lt; 0.02). At the species level, B. finegoldii, B. ovatus, and B. uniformis were enriched in patients with CR vs G3 (p &lt; 0.02). In contrast, genus Klebsiella and Clostridium termitidis were enriched in patients with a poor response, G3 (p &lt;0.001, both). Pathway analysis found two metabolic pathways enriched in patients with CR: secondary bile acid biosynthesis (p=0.005) and lysine biosynthesis (p=0.02).

Conclusions: Patients with operable esophageal cancer and improved responses to combined CRT and IO had distinct microbiome profiles enriched in multiple Bacteroides species. Further analyses and validation efforts are underway to confirm metabolomic pathways.

Citation Format: Fyza Y. Shaikh, James R. White, Ronan J. Kelly, Ali H. Zaidi, Jenna V. Canzoniero, Josephine L. Feliciano, Russell K. Hales, K Ranh Voong, Richard J. Battafarano, Blair A. Jobe, Stephen C. Yang, Stephen Broderick, Jinny Ha, Kellie N. Smith, Elizabeth Thompson, Eun J. Shin, Ali I. Amjad, Patrizia Guerrieri, Benny Weksler, Chen Hu, Valsamo Anagnostou, Vincent K. Lam, Cynthia L. Sears. Patients with operable esophageal cancer and improved responses to combined chemoradiotherapy and immunotherapy display distinct microbiome profiles enriched in multiple Bacteroides species [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1973.

Esophageal retention cyst: Esophagogastric junction outflow obstruction (EGJOO) as a potential etiology and management with endoscopic mucosal resection (EMR)

INTRODUCTION AND IMPORTANCE

Esophageal retention cysts are acquired cysts with no known etiology. They are characterized by dilation of the submucosal glands. Symptomatic cysts are traditionally managed by surgical resection.

CASE PRESENTATION

We present a case of progressive dysphagia and chest pain secondary to esophageal retention cysts in the mid and distal esophagus with associated esophagogastric junction outflow obstruction (EGJOO) and jackhammer esophagus on high resolution manometry (HRM). The patient underwent staged endoscopic mucosal resection (EMR) with subsequent improvement in her symptoms. However, EGJOO persisted after resection, suggesting it was the primary pathology and not a consequence of the obstruction from the cysts.

CLINICAL DISCUSSION

Esophageal retention cysts are rarely reported in the literature with most descriptions coming from incidental post-mortems. The presented case suggests EGJOO as a potential etiology of retention cysts. The proposed mechanism is that a significant rise in esophageal intraluminal pressure creates a state of stasis in the esophagus, ideal for the development of these cysts. Symptomatic or malignant retention cysts should be resected. We demonstrate the feasibility of EMR as an alternative to surgical resection.

CONCLUSION

Esophageal retention cyst is a rare entity, which may arise as a result of EGJOO. The natural history and malignant potential of these cysts are unknown, and no formal guidelines have been established for follow-up for patients with asymptomatic retention cysts. Endoscopic mucosal resection can be used to successfully manage these cysts.

CSF-1R inhibitor, pexidartinib, sensitizes esophageal adenocarcinoma to PD-1 immune checkpoint blockade in a rat model

Esophageal adenocarcinoma (EAC) is a leading cause of cancer deaths. Pexidartinib, a multi-gene tyrosine kinase inhibitor, through targeting CSF-1R, down modulates macrophage mediated pro-survival tumor signaling. Previously, CSF-1R inhibitors have successfully shown to enhance antitumor activity of PD-1/PD-L1 inhibitors by suppressing tumor immune evasion, in solid tumors. In this study, we investigated the antitumor activity of pexidartinib alone or in combination with blockade of PD-1 in a de novo EAC rat model. Here, we showed limited toxicity with significant tumor shrinkage in pexidartinib treated animals compared to controls, single agent and in combination with a PD-1 inhibitor, AUNP-12. Suppression of CSF-1/CSF-1R axis resulted in enhanced infiltration of CD3+CD8+ T cells with reduced M2 macrophage polarization, in the tumor microenvironment (TME). Endpoint tissue gene expression in pexidartinib treated animals demonstrated upregulation of BAX, Cas3, TNFα, IFNγ and IL6 and downregulation of Ki67, IL13, IL10, TGFβ and Arg1 (p<0.05). Additionally, among the pexidartinib treated animals responders compared to non-responders demonstrated a significant upregulation of pre-treatment CSF-1 gene, confirming that tumor associated macrophage suppression directly translates to clinical benefit. Moreover, a post-treatment serum cytokine assay exhibited similar systemic trends as the gene expression in the TME, depicting increases in pro-inflammatory cytokines and decreases in anti-inflammatory cytokines. In conclusion, our study established a promising combinatorial strategy using a CSF-1R inhibitor to overcome resistance to PD-1/PD-L1 axis blockade in an EAC model, providing the rationale for future clinical strategies.

Acquired Morgagni hernia following coronary artery bypass graft (CABG) with successful robotic repair of hernia

INTRODUCTION AND IMPORTANCE

Morgagni hernia is an uncommon type of diaphragmatic hernia and commonly presents as a congenital disease. Acquired Morgagni hernias following open cardiac surgery are exceedingly rare and only reported in the pediatric population.

CASE PRESENTATION

The patient is a 70-year-old female who presented with complaints of shortness of breath and cough one year following a coronary artery bypass graft (CABG). A chest CT scan showed a large Morgagni type diaphragmatic hernia with herniated transverse colon occupying the anterior mediastinum as well as the right hemi-thorax. This hernia was successfully repaired using transabdominal robotic approach with complete resolution of patient's symptoms.

CLINICAL DISCUSSION

This is the first reported case of acquired Morgagni type diaphragmatic hernia in an adult following open cardiac surgery. The potential etiologies for this hernia include distal extension of the median sternotomy and involvement of the anterior diaphragm, iatrogenic injury to the attenuated anterior diaphragm during pericardial window creation, or pericardial drain placement. Operative repair is the mainstay of treatment and is usually performed with a transabdominal approach since it is thought to be less challenging and allows for evaluation of the entire abdominal cavity. If primary repair cannot be achieved, then synthetic mesh may be needed to obtain a tension free and durable repair.

CONCLUSION

We present a case of acquired Morgagni type diaphragmatic hernia in an adult following open cardiac surgery that was successfully repaired using a transabdominal robotic approach.

Outcomes after totally minimally invasive versus hybrid and open Ivor Lewis oesophagectomy: results from the International Esodata Study Group

BACKGROUND

Large studies comparing totally minimally invasive oesophagectomy (TMIE) with laparoscopically assisted (hybrid) oesophagectomy are lacking. Although randomized trials have compared TMIE invasive with open oesophagectomy, daily clinical practice does not always resemble the results reported in such trials. The aim of the present study was to compare complications after totally minimally invasive, hybrid and open Ivor Lewis oesophagectomy in patients with oesophageal cancer.

METHODS

The study was performed using data from the International Esodata Study Group registered between February 2015 and December 2019. The primary outcome was pneumonia, and secondary outcomes included the incidence and severity of anastomotic leakage, (major) complications, duration of hospital stay, escalation of care, and 90-day mortality. Data were analysed using multivariable multilevel models.

RESULTS

Some 8640 patients were included between 2015 and 2019. Patients undergoing TMIE had a lower incidence of pneumonia than those having hybrid (10.9 versus 16.3 per cent; odds ratio (OR) 0.56, 95 per cent c.i. 0.40 to 0.80) or open (10.9 versus 17.4 per cent; OR 0.60, 0.42 to 0.84) oesophagectomy, and had a shorter hospital stay (median 10 (i.q.r. 8-16) days versus 14 (11-19) days (P = 0.041) and 11 (9-16) days (P = 0.027) respectively). The rate of anastomotic leakage was higher after TMIE than hybrid (15.1 versus 10.7 per cent; OR 1.47, 1.01 to 2.13) or open (15.1 versus 7.3 per cent; OR 1.73, 1.26 to 2.38) procedures.

CONCLUSION

Compared with hybrid and open Ivor Lewis oesophagectomy, TMIE resulted in a lower pneumonia rate, a shorter duration of hospital stay, but higher anastomotic leakage rates. Therefore, no clear advantage was seen for either TMIE, hybrid or open Ivor Lewis oesophagectomy when performed in daily clinical practice.