Outcomes after revisional surgery for paraesophageal hernias at a high-volume tertiary care center.

BACKGROUND: Although recurrences after repair of giant paraesophageal hernias (PEH) are common, revisional procedures are challenging and associated with higher complication rates than primary repair. Therefore, repair of recurrent PEH is often avoided except in symptomatic patients. Data describing operative outcomes in these infrequent cases is lacking. Therefore, this study aimed to report and compare peri-operative outcomes of revisional PEH repair to similar patients undergoing primary surgery. METHODS: A single-institution, retrospective cohort study was conducted on all adult patients undergoing primary repair of Type II-IV PEH and any revisional surgery for recurrent hiatal hernia after previous primary PEH repair (2012-2019). Patient and operative characteristics and post-operative outcomes were extracted from medical records. Patients were grouped into revisional (rPEH) and primary repair (pPEH). Coarsened exact matching was performed to create balanced cohorts. RESULTS: A total of 347 cases were identified. The matched cohort included 234 patients (rPEH: 46, pPEH: 188). Patient sex and comorbidities were well balanced, while those who underwent revisions were younger (64 ± 13 vs. 69 ± 11 years; p = 0.01). Median time between primary and rPEH was 40[17-121] months. Incidence of emergency repair were similar among groups (rPEH: 9(15%), pPEH: 14(8%); p = 0.10). All revisional cases commenced laparoscopically with 7(15%) requiring conversion to open. The conversion rate was higher for rPEH than primary surgery (7(15%) vs. 3(2%); p < 0.01), with the most common reasons being adhesions and gastric fundus injury. Intra-operative complications occurred in 12(26%) revisional cases, of which 58% were gastric fundus injuries. Median length of stay was longer for rPEH than pPEH (2[1-5] vs. 1[1-2] day; p = 0.02). Incidence of severe complications (rPEH: 5(11%), pPEH: 11(6%); p = 0.23) and reoperations (rPEH: 2(4%), pPEH: 7(4%); p = 0.84) were similar between groups. There were no peri-operative deaths. CONCLUSION: In a high-volume tertiary care center, repair of recurrent giant paraesophageal hernias can be performed successfully laparoscopically in the majority of cases with acceptable morbidity and peri-operative outcomes in comparison to primary surgery.

A Video-Based Procedure-Specific Competency Assessment Tool for Minimally Invasive Esophagectomy.

Importance: Minimally invasive esophagectomy (MIE) is a complex procedure with substantial learning curves. In other complex minimally invasive procedures, suboptimal surgical performance has convincingly been associated with less favorable patient outcomes as assessed by peer review of the surgical procedure. Objective: To develop and validate a procedure-specific competency assessment tool (CAT) for MIE. Design, Setting, and Participants: In this international quality improvement study, a procedure-specific MIE-CAT was developed and validated. The MIE-CAT contains 8 procedural phases, and 4 quality components per phase are scored with a Likert scale ranging from 1 to 4. For evaluation of the MIE-CAT, intraoperative MIE videos performed by a single surgical team in the Esophageal Center East Netherlands were peer reviewed by 18 independent international MIE experts (with more than 120 MIEs performed). Each video was assessed by 2 or 3 blinded experts to evaluate feasibility, content validity, reliability, and construct validity. MIE-CAT version 2 was composed with refined content aimed at improving interrater reliability. A total of 32 full-length MIE videos from patients who underwent MIE between 2011 and 2020 were analyzed. Data were analyzed from January 2021 to January 2023. Exposure: Performance assessment of transthoracic MIE with an intrathoracic anastomosis. Main Outcomes and Measures: Feasibility, content validity, interrater and intrarater reliability, and construct validity, including correlations with both experience of the surgical team and clinical parameters, of the developed MIE-CAT. Results: Experts found the MIE-CAT easy to understand and easy to use to grade surgical performance. The MIE-CAT demonstrated good intrarater reliability (range of intraclass correlation coefficients [ICCs], 0.807 [95% CI, 0.656 to 0.892] for quality component score to 0.898 [95% CI, 0.846 to 0.932] for phase score). Interrater reliability was moderate (range of ICCs, 0.536 [95% CI, -0.220 to 0.994] for total MIE-CAT score to 0.705 [95% CI, 0.473 to 0.846] for quality component score), and most discrepancies originated in the lymphadenectomy phases. Hypothesis testing for construct validity showed more than 75% of hypotheses correct: MIE-CAT performance scores correlated with experience of the surgical team (r = 0.288 to 0.622), blood loss (r = -0.034 to -0.545), operative time (r = -0.309 to -0.611), intraoperative complications (r = -0.052 to -0.319), and severe postoperative complications (r = -0.207 to -0.395). MIE-CAT version 2 increased usability. Interrater reliability improved but remained moderate (range of ICCs, 0.666 to 0.743), and most discrepancies between raters remained in the lymphadenectomy phases. Conclusions and Relevance: The MIE-CAT was developed and its feasibility, content validity, reliability, and construct validity were demonstrated. By providing insight into surgical performance of MIE, the MIE-CAT might be used for clinical, training, and research purposes.

Concerted epithelial and stromal changes during progression of Barrett's Esophagus to invasive adenocarcinoma exposed by multi-scale, multi-omics analysis.

Esophageal adenocarcinoma arises from Barrett's esophagus, a precancerous metaplastic replacement of squamous by columnar epithelium in response to chronic inflammation. Multi-omics profiling, integrating single-cell transcriptomics, extracellular matrix proteomics, tissue-mechanics and spatial proteomics of 64 samples from 12 patients' paths of progression from squamous epithelium through metaplasia, dysplasia to adenocarcinoma, revealed shared and patient-specific progression characteristics. The classic metaplastic replacement of epithelial cells was paralleled by metaplastic changes in stromal cells, ECM and tissue stiffness. Strikingly, this change in tissue state at metaplasia was already accompanied by appearance of fibroblasts with characteristics of carcinoma-associated fibroblasts and of an NK cell-associated immunosuppressive microenvironment. Thus, Barrett's esophagus progresses as a coordinated multi-component system, supporting treatment paradigms that go beyond targeting cancerous cells to incorporating stromal reprogramming.

Remoteness from urban centre does not affect gastric cancer outcomes with established care pathway to specialist centre.

BACKGROUND: Patients living in rural communities experience difficulty accessing specialized medical care. Rural patients with cancer present with more advanced disease, have reduced access to treatment and have poorer overall survival than urban patients. This study's aim was to evaluate outcomes of patients with gastric cancer living in rural and remote areas versus urban and suburban communities in the context of an established care corridor to a tertiary care centre. METHODS: All patients treated for gastric cancer at the McGill University Health Centre during 2010-2018 were included. Travel, lodging and cancer care coordination were provided for patients from remote and rural areas and coordinated centrally by dedicated nurse navigators servicing these regions. Statistics Canada's remoteness index was used to categorize patients into a rural and remote group and an urban and suburban group. RESULTS: A total of 274 patients were included. Compared with patients from urban and suburban areas, patients from rural and remote areas were younger and their clinical tumour stage was higher at presentation. The number of curative resections and palliative surgeries and rate of nonresection were comparable (p = 0.96). Overall, disease-free and progression-free survival were comparable between the groups, and having locally advanced cancer correlated with poorer survival (p < 0.001). CONCLUSION: Although patients with gastric cancer from rural and remote areas had more advanced disease at presentation, their treatment patterns and survival were comparable to those of patients from urbanized areas in the context of a publicly funded care corridor to a multidisciplinary specialist cancer centre. Equitable access to health care is necessary to diminish any preexisting disparities among patients with gastric cancer.

Relation between mismatch repair status, chemoresponse, survival and anatomic location in gastroesophageal adenocarcinoma.

BACKGROUND: It has recently been reported that mismatch repair (MMR) status and microsatellite instability (MSI) status in gastroesophageal carcinomas predict surgical, chemotherapeutic and immunotherapeutic outcomes; however, there is extensive variability in the reported incidence and clinical implications of MMR/MSI status in gastroesophaegal adenocarcinomas. We characterized a Canadian surgical patient cohort with respect to MMR status, clinicopathologic correlates and anatomic tumour location. METHODS: We investigated MMR and BRAF V600E status of gastroesophaegal adenocarcinomas in patients who underwent gastrectomy or esophagectomy with extended (D2) lymphadenectomy at a single centre between 2011 and 2019. We correlated patterns of MMR expression in the overall cohort and in anatomic location-defined subgroups with treatment response and overall survival using multivariate analysis. RESULTS: In all, 226 cases of gastroesophaegal adenocarcinoma (63 esophageal, 98 gastroesophageal junctional and 65 gastric) were included. The MMR-deficient (dMMR) immunophenotype was found in 28 tumours (12.3%) (15 junctional [15.3%], 13 gastric [20.0%] and none of the esophageal). The majority (25 [89%]) of dMMR cases showed MLH1/PMS2 loss without concurrent BRAF V600E mutation. Two MSH2/ MSH6-deficient gastric tumours and 1 MSH6-deficient junctional tumour were detected. The pathologic response to preoperative chemotherapy was comparable in the dMMR and MMR-proficient (pMMR) cohorts. However, dMMR status was associated with significantly longer median overall survival than pMMR status (5.8 yr v. 2.4 yr, hazard ratio [HR] 1.91, 95% confidence interval [CI] 1.06-3.46), particularly in junctional tumours (4.6 yr v. 1.9 yr, HR 2.97, 95% CI 1.27-6.94). CONCLUSION: Our study shows that MMR status has at least prognostic value, which supports the need for biomarker testing in gastroesophageal adenocarcinomas, including junctional adenocarcinomas. This highlights the clinical significance of determining the MMR status in all adenocarcinomas of the upper gastrointestinal tract. Response to induction chemotherapy, however, was not influenced by MMR status.

Neutrophil Extracellular Traps in Cancer Therapy Resistance.

Neutrophils and their products are increasingly recognized to have a key influence on cancer progression and response to therapy. Their involvement has been shown in nearly every aspect of cancer pathophysiology with growing evidence now supporting their role in resistance to a variety of cancer therapies. Recently, the role of neutrophils in cancer progression and therapy resistance has been further complicated with the discovery of neutrophil extracellular traps (NETs). NETs are web-like structures of chromatin decorated with a variety of microbicidal proteins. They are released by neutrophils in a process called NETosis. NET-dependent mechanisms of cancer pathology are beginning to be appreciated, particularly with respect to tumor response to chemo-, immuno-, and radiation therapy. Several studies support the functional role of NETs in cancer therapy resistance, involving T-cell exhaustion, drug detoxification, angiogenesis, the epithelial-to-mesenchymal transition, and extracellular matrix remodeling mechanisms, among others. Given this, new and promising data suggests NETs provide a microenvironment conducive to limited therapeutic response across a variety of neoplasms. As such, this paper aims to give a comprehensive overview of evidence on NETs in cancer therapy resistance with a focus on clinical applicability.

Overall Volume Trends in Esophageal Cancer Surgery Results From the Dutch Upper Gastrointestinal Cancer Audit.

OBJECTIVE: In the pursuit of quality improvement, this study aimed to investigate volume-outcome trends in oncologic esophagectomy in the Netherlands. SUMMARY OF BACKGROUND DATA: Concentration of Dutch esophageal cancer care was dictated by introducing an institutional minimum of 20 resections/yr. METHODS: This nationwide cohort study included all esophagectomy patients registered in the Dutch Upper Gastrointestinal Cancer Audit in 2016-2019 from hospitals currently still performing esophagectomies. Annual esophagectomy hospital volume was assigned to each patient and categorized into quartiles. Multivariable logistic regression investigated short-term surgical outcomes. Restricted cubic splines investigated if volume-outcome relationships eventually plateaued. RESULTS: In 16 hospitals, 3135 esophagectomies were performed. First volume quartile hospitals performed 24-39 resections/yr; second, third, and fourth quartile hospitals performed 40-53, 54-69, and 70-101, respectively. Compared to quartile 1, in quartiles 2 to 4, overall/severe/technical complication, anastomotic leakage, and prolonged hospital/intensive care unit stay rates were significantly lower and textbook outcome and lymph node yield were higher. When raising the cut-off from the first to second quartile, higher-volume centers had less technical complications [Adjusted odds ratio (aOR): 0.82, 95% confidence interval (CI): 0.70-0.96], less anastomotic leakage (aOR: 0.80, 95% CI: 0.66-0.97), more textbook outcome (aOR: 1.25, 95% CI: 1.07-1.46), shorter intensive care unit stay (aOR: 0.80, 95% CI: 0.69-0.93), and higher lymph node yield (aOR: 3.56, 95% CI: 2.68-4.77). For most outcomes the volume-outcome trend plateaued at 50-60 annual resections, but lymph node yield and anastomotic leakage continued to improve. CONCLUSION: Although this study does not reflect on individual hospital quality, there appears to be a volume trend towards better outcomes in high-volume centers. Projects have been initiated to improve national quality of care by reducing hospital variation (irrespective of volume) in outcomes in The Netherlands.

FLOT-regimen Chemotherapy and Transthoracic en bloc Resection for Esophageal and Junctional Adenocarcinoma.

BACKGROUND AND AIMS: The FLOT4-AIO trial established the FLOT regimen as a compelling option for gastric, junctional and esophageal adenocarcinoma. Data on FLOT with en-bloc transthoracic esophagectomy (TTE) are limited. This study explored operative complications, tolerance, toxicity, physiological impact, and oncologic outcomes. STUDY DESIGN: An observational cohort study on consecutive patients at 3 tertiary centers undergoing FLOT and TTE. Toxicity, operative complications (per ECCG definitions), tumor regression grade (TRG), recurrences and survival were documented, as well as pre and post FLOT assessment of sarcopenia and pulmonary physiology. RESULTS: 175 patients (cT2-4a, Nany) commenced treatment, 84% male, median age 65, 94% cT3/T4a, 73% cN+. 89% completed 4 preoperative cycles, and 35% all cycles. Grade 3/4 toxicities included neutropenia (12%), diarrhoea (13%), and infection (15%). Sarcopenia increased from 18% to 37% (P = 0.020), and diffusion capacity (DLCO) decreased by 8% (-34% + 25%; P < 0.010). On pathology, ypT3/4 was 59%, and ypN+54%, with 10% TRG 1, 14% TRG 2, and 76% TRG3-5, and R0 95%. 161 underwent TTE, with an in-hospital mortality of 0.6%, 24%-pneumonia, 11%-anastomotic leak, and Clavien Dindo ≥III in 27%. At a median follow up of 12 months (1-85), 33 relapsed, 8 (5%) locally, and 3yr survival was 60%. CONCLUSION: FLOT and en bloc TTE was safe, with no discernible impact on operative complications, with 24% having a major pathologic response. Caveats include a limited pathologic response in the majority, and negative impact on muscle mass and lung physiology, and low use of adjuvant cycles. These data may provide a real-world benchmark for this complex care pathway.

Esophageal cancer after sleeve gastrectomy: a population-based comparative cohort study.

BACKGROUND: Sleeve gastrectomy (SG) is the most common bariatric surgery; however, this approach may induce gastroesophageal reflux disease (GERD). Both obesity and GERD are independent risk factors for esophageal cancer, however the impact of SG on risk of esophageal cancer remains unknown. OBJECTIVE: To evaluate the risk of esophageal cancer after reflux-prone bariatric surgery. SETTING: Population-level, provincial administrative healthcare database, Quebec, Canada. METHODS: We identified a population-based cohort of all patients with obesity who underwent reflux-prone surgery (SG and duodenal switch [DS]) or reflux-protective Roux-en-Y gastric bypass (RYGB) during 01/2006-12/2012 in Quebec, Canada. For every surgical patient, 2-3 nonsurgical controls with obesity matched for age, sex, and geography were also identified. Crude incidence rate ratios (IRRs) for esophageal cancer were calculated using person-time analysis. Hazard ratios (HRs) were obtained using multivariate cox regression. RESULTS: A total of 4121 patients had reflux-prone procedures and 852 underwent RYGB. At a mean follow-up of 7.6 years, 8 cases of esophageal cancer were identified after bariatric surgery. Compared with RYGB, IRR for esophageal cancer in reflux-prone group was 1.45 (95%CI: .19-65.5) and HR = .83 (95%CI: .10-7.27). The crude incidence rate of esophageal cancer in the reflux-prone group was higher than that of nonsurgical controls (n = 12,159; IRR = 3.46, 95%CI: 1.00-12.5), but after adjustment the difference disappeared (HR = 2.47, 95%CI: .82-7.45). CONCLUSIONS: Long-term incidence of esophageal cancer after reflux-prone bariatric surgery is not greater than RYGB. While crude incidence of esophageal cancer after reflux-prone surgery is higher than in nonsurgical patients with obesity, such difference disappears after accounting for confounders. Given the low incidence of esophageal cancer and slow progression of dysplastic Barrett esophagus, studies with longer follow-up are needed.

Early diagnosis is associated with improved clinical outcomes in benign esophageal perforation: an individual patient data meta-analysis.

BACKGROUND: Time of diagnosis (TOD) of benign esophageal perforation is regarded as an important risk factor for clinical outcome, although convincing evidence is lacking. The aim of this study is to assess whether time between onset of perforation and diagnosis is associated with clinical outcome in patients with iatrogenic esophageal perforation (IEP) and Boerhaave's syndrome (BS). METHODS: We searched MEDLINE, Embase and Cochrane library through June 2018 to identify studies. Authors were invited to share individual patient data and a meta-analysis was performed (PROSPERO: CRD42018093473). Patients were subdivided in early (≤ 24 h) and late (> 24 h) TOD and compared with mixed effects multivariable analysis while adjusting age, gender, location of perforation, initial treatment and center. Primary outcome was overall mortality. Secondary outcomes were length of hospital stay, re-interventions and ICU admission. RESULTS: Our meta-analysis included IPD of 25 studies including 576 patients with IEP and 384 with BS. In IEP, early TOD was not associated with overall mortality (8% vs. 13%, OR 2.1, 95% CI 0.8-5.1), but was associated with a 23% decrease in ICU admissions (46% vs. 69%, OR 3.0, 95% CI 1.2-7.2), a 22% decrease in re-interventions (23% vs. 45%, OR 2.8, 95% CI 1.2-6.7) and a 36% decrease in length of hospital stay (14 vs. 22 days, p < 0.001), compared with late TOD. In BS, no associations between TOD and outcomes were found. When combining IEP and BS, early TOD was associated with a 6% decrease in overall mortality (10% vs. 16%, OR 2.1, 95% CI 1.1-3.9), a 19% decrease in re-interventions (26% vs. 45%, OR 1.9, 95% CI 1.1-3.2) and a 35% decrease in mean length of hospital stay (16 vs. 22 days, p = 0.001), compared with late TOD. CONCLUSIONS: This individual patient data meta-analysis confirms the general opinion that an early (≤ 24 h) compared to a late diagnosis (> 24 h) in benign esophageal perforations, particularly in IEP, is associated with improved clinical outcome.

Transition from open to minimally invasive en bloc esophagectomy can be achieved without compromising surgical quality.

BACKGROUND: En bloc esophagectomy results in higher lymph node (LN) retrieval than standard esophagectomy. Minimally invasive esophagectomy (MIE) has gained traction due to improved short-term outcomes, but many large series report LN yields well below the international benchmark of 23. We sought to determine if an established approach to open en bloc resection can be safely transferred to MIE using LN yield as a quality benchmark. METHODS: An open approach to en bloc esophagectomy (OE) was established over 5 years (~ 300 cases) before en bloc MIE was introduced in 2010. Patients undergoing curative-intent en bloc Ivor-Lewis and McKeown esophagectomy for cancer from 2010 to 2019 by a single surgeon with formal minimally invasive surgery training were identified from a prospectively collected database. Mann-Whitney U and χ2 tests and cumulative sum analysis were used for statistical analysis. "Failure" was defined as LN yield less than AJCC's 8th edition guidelines: 10 LNs for pT1 cancers, 20 for pT2 and 30 for pT3-4. RESULTS: A total of 269 esophageal resections met inclusion criteria [193(72%) OE; 76(28%) MIE]. Age, sex, BMI and comorbidities were comparable between groups. Tumors were larger and more often locally advanced in OE. Median LN retrieval was sufficient by international standards in both groups [OE:34(27-46); MIE:28(22-39); p = 0.01]. "Failures" occurred in 33(17%) of OE and 12(16%) MIE cases (p = 0.63). No learning effect was observed for LN yield. R0 resection rate was comparable [OE:191(99%); MIE:73(96%); p = 0.90]. Operative time was longer for MIE [275(246-300)] than OE [240(210-270) minutes], p < 0.0001, while estimated blood loss (OE:350(250-500)mL; MIE:300(200-400)mL; p = 0.02] and length of stay [OE:8(6-13); MIE7(6-9) days; p = 0.02] were higher for OE. Morbidity and mortality were comparable between groups and LN yield did not impact survival. CONCLUSIONS: Under appropriate conditions, an established approach to open en bloc esophagectomy can be safely transferred to MIE without compromising surgical quality.

The Effect of Preoperative Anemia and Perioperative Transfusion on Surgical Outcomes After Gastrectomy for Gastric Cancer.

BACKGROUND: The aim of this study is to examine the interaction between preoperative anemia and perioperative transfusions with postoperative morbidity and mortality among patients undergoing gastrectomy for cancer. MATERIALS AND METHODS: The American College of Surgeons National Surgical Quality Improvement Program database was queried from 2005 to 2016. Restricted cubic splines modeled the nonlinear relationship between preoperative hematocrit (Hct) and 30-day overall morbidity, sepsis, and mortality. Preoperative Hct was categorized based on cut points for the three models. Multiple regression modeling examined the interactive effect of preoperative anemia and postoperative transfusion on surgical outcomes. RESULTS: Among 9936 included patients, complication incidence was 38.9% (sepsis 12.7%; mortality 6.0%). Preoperative Hct cut points were identified at 29 and 42. Hct <29 was associated with higher risk of morbidity (OR 2.47, 95%CI 2.10-2.93). Postoperative transfusion was associated with lower risk of morbidity for Hct <29 (OR 0.56, 95%CI 0.43-0.73) but increased risk between 29 and 42 (OR 1.59, 95%CI 1.21-2.08). Similar relationships were found for sepsis and mortality. CONCLUSIONS: Preoperative Hct <29 is associated with an increased risk of surgical complications after gastrectomy for cancer and perioperative transfusions appear to be beneficial for Hct <29 only. There may be a role for better optimization of red cell mass among high-risk patients before gastrectomy for cancer.

Model-based analysis of sample index hopping reveals its widespread artifacts in multiplexed single-cell RNA-sequencing.

Index hopping is the main cause of incorrect sample assignment of sequencing reads in multiplexed pooled libraries. We introduce a statistical model for estimating the sample index-hopping rate in multiplexed droplet-based single-cell RNA-seq data and for probabilistic inference of the true sample of origin of hopped reads. We analyze several datasets and estimate the sample index hopping probability to range between 0.003-0.009, a small number that counter-intuitively gives rise to a large fraction of phantom molecules - the fraction of phantom molecules exceeds 8% in more than 25% of samples and reaches as high as 85% in low-complexity samples. Phantom molecules lead to widespread complications in downstream analyses, including transcriptome mixing across cells, emergence of phantom copies of cells from other samples, and misclassification of empty droplets as cells. We demonstrate that our approach can correct for these artifacts by accurately purging the majority of phantom molecules from the data.

Neutrophil Extracellular Trap-Associated CEACAM1 as a Putative Therapeutic Target to Prevent Metastatic Progression of Colon Carcinoma.

Neutrophils promote tumor growth and metastasis at multiple stages of cancer progression. One mechanism through which this occurs is via release of neutrophil extracellular traps (NETs). We have previously shown that NETs trap tumor cells in both the liver and the lung, increasing their adhesion and metastasis following postoperative complications. Multiple studies have since shown that NETs play a role in tumor progression and metastasis. NETs are composed of nuclear DNA-derived web-like structures decorated with neutrophil-derived proteins. However, it is unknown which, if any, of these NET-affiliated proteins is responsible for inducing the metastatic phenotype. In this study, we identify the NET-associated carcinoembryonic Ag cell adhesion molecule 1 (CEACAM1) as an essential element for this interaction. Indeed, blocking CEACAM1 on NETs, or knocking it out in a murine model, leads to a significant decrease in colon carcinoma cell adhesion, migration and metastasis. Thus, this work identifies NET-associated CEACAM1 as a putative therapeutic target to prevent the metastatic progression of colon carcinoma.

Activation of the pattern recognition receptor NOD1 augments colon cancer metastasis.

While emerging data suggest nucleotide oligomerization domain receptor 1 (NOD1), a cytoplasmic pattern recognition receptor, may play an important and complementary role in the immune response to bacterial infection, its role in cancer metastasis is entirely unknown. Hence, we sought to determine the effects of NOD1 on metastasis. NOD1 expression in paired human primary colon cancer, human and murine colon cancer cells were determined using immunohistochemistry and immunoblotting (WB). Clinical significance of NOD1 was assessed using TCGA survival data. A series of in vitro and in vivo functional assays, including adhesion, migration, and metastasis, was conducted to assess the effect of NOD1. C12-iE-DAP, a highly selective NOD1 ligand derived from gram-negative bacteria, was used to activate NOD1. ML130, a specific NOD1 inhibitor, was used to block C12-iE-DAP stimulation. Stable knockdown (KD) of NOD1 in human colon cancer cells (HT29) was constructed with shRNA lentiviral transduction and the functional assays were thus repeated. Lastly, the predominant signaling pathway of NOD1-activation was identified using WB and functional assays in the presence of specific kinase inhibitors. Our data demonstrate that NOD1 is highly expressed in human colorectal cancer (CRC) and human and murine CRC cell lines. Clinically, we demonstrate that this increased NOD1 expression negatively impacts survival in patients with CRC. Subsequently, we identify NOD1 activation by C12-iE-DAP augments CRC cell adhesion, migration and metastasis. These effects are predominantly mediated via the p38 mitogen activated protein kinase (MAPK) pathway. This is the first study implicating NOD1 in cancer metastasis, and thus identifying this receptor as a putative therapeutic target.

Modern era surgical outcomes of elective and emergency giant paraesophageal hernia repair at a high-volume referral center.

INTRODUCTION: Repair of giant paraesophageal hernia (PEH) has historically been associated with significant morbidity and mortality such that elective repair is only offered to symptomatic patients. Recent reports suggest modern era outcomes have improved such that elective repair may now be safer than historically thought. Furthermore, the morbidity of emergency surgery may still be significant. These changes may have important implications for patient selection for elective repair. The objectives of this study were to determine and compare modern era surgical outcomes after elective and emergency repair of giant PEHs at a high-volume tertiary care center. METHODS: A retrospective review was conducted for all Type II-IV giant PEH repairs performed between 1 January 2012 and 31 December 2017. Type 1 hiatal hernias, fundoplication for reflux, and any co-surgery other than cholecystectomy were excluded from the final analysis. Baseline patient demographics, operative details, postoperative complications within 30 days and in-hospital or 30-day mortality were tabulated from the electronic medical record. Data were reported as median (interquartile range) unless otherwise specified. RESULTS: A total of 352 cases were reviewed, of which 204 met inclusion criteria (18 emergency, 186 elective). Eight had Type II PEH, 146 had Type III, and 50 had Type IV. Median length of stay was shorter in the elective group [1 (1) day elective vs. 5 (7) days emergency, p < 0.0001], and emergency patients were less likely to return directly to their original residence at discharge (13, 72% emergency vs 185, 99.4% elective, p < 0.0001). There were significantly more major complications (Clavien-Dindo score ≥ 3) in the emergency group (5, 28% emergency vs. 10, 5% elective, p = 0.005). There were no perioperative deaths in either group. Morbidity and mortality in both groups were less than historically reported. CONCLUSIONS: Informed consent discussions and patient selection for repair of giant PEHs should reflect modern era and institution-specific outcomes.

Comparison of Dor and Nissen fundoplication after laparoscopic paraesophageal hernia repair.

BACKGROUND: Fundoplication is performed routinely during laparoscopic repairs of a paraesophageal hernia, but the degree of fundoplication remains controversial. The purpose of this study is to assess postoperative dysphagia and reflux after a Dor versus a Nissen fundoplication in patients undergoing laparoscopic repair of giant paraesophageal hernias. METHODS: We performed a retrospective cohort study of all patients undergoing laparoscopic repair of giant paraesophageal hernias with Nissen or Dor fundoplication between January 2012 and December 2017 at a high-volume center, excluding revisional and emergency cases. Primary outcomes were reflux and dysphagia at 1 and 6 months. Severe dysphagia was defined as intolerance to liquids. Balanced cohorts were created using coarsened exact matching. RESULTS: A total of 106 patients were included, and 87 were matched (Dor = 48, Nissen = 58). Baseline characteristics were well balanced between matched groups. Mean follow-up duration was 17.7 months (standard deviation 16.4). The incidence of severe dysphagia at 1 month was less in the Dor group (0 of 48 vs 8 of 58, P = .02) with similar reflux symptoms. There was no difference in severe dysphagia and reflux symptoms at 6 months and at the latest visit. CONCLUSION: Dor fundoplication is associated with less severe, early postoperative dysphagia. Future studies assessing the relative importance of dysphagia and reflux on quality of life should be conducted to tailor the operative technique and optimize patient satisfaction.

Gram-Negative Pneumonia Augments Non-Small Cell Lung Cancer Metastasis through Host Toll-like Receptor 4 Activation.

INTRODUCTION: Surgery is essential for cure of early-stage non-small cell lung cancer (NSCLC). Rates of postoperative bacterial pneumonias, however, remain high, and clinical data suggests that post-operative infectious complications confer an increased risk for metastasis. Toll-like receptors (TLRs) mediate the inflammatory response to infection by recognizing evolutionarily conserved bacterial structures at the surface of numerous pulmonary cell types; yet, little is known about how host TLR activation influences NSCLC metastasis. TLR4 recognizes gram-negative bacterium lipopolysaccharide activating the innate immune system. METHODS: C57BL/6 and TLR4 knockout murine airways were inoculated with Escherichia coli or lipopolysaccharide. Hepatic metastasis assays and intravital microscopy were performed. Bronchoepithelial conditioned media was generated through coincubation of bronchoepithelial cells with TLR4 activating Escherichia coli or lipopolysaccharide. Subsequently, H59 NSCLC were stimulated with conditioned media and subject to various adhesion assays. RESULTS: We demonstrate that gram-negative Escherichia coli pneumonia augments the formation of murine H59 NSCLC liver metastases in C57BL/6 mice through TLR4 activation. Additionally, infected C57BL/6 mice demonstrate increased H59 NSCLC in vivo hepatic sinusoidal adhesion compared with negative controls, a response that is significantly diminished in TLR4 knockout mice. Similarly, intratracheal injection of purified TLR4 activating lipopolysaccharide increases in vivo adhesion of H59 cells to murine hepatic sinusoids. Furthermore, H59 cells incubated with bronchoepithelial conditioned medium show increased cell adhesion to in vitro extracellular matrix proteins and in vivo hepatic sinusoids through a mechanism dependent on bronchoepithelial TLR4 activation and interleukin-6 secretion. CONCLUSION: TLR4 is a viable therapeutic target for NSCLC metastasis augmented by gram-negative pneumonia.