Utility of bile acids in large airway bronchial wash versus bronchoalveolar lavage as biomarkers of microaspiration in lung transplant recipients: a retrospective cohort study.

BACKGROUND: Bronchoalveolar lavage (BAL) is a key tool in respiratory medicine for sampling the distal airways. BAL bile acids are putative biomarkers of pulmonary microaspiration, which is associated with poor outcomes after lung transplantation. Compared to BAL, large airway bronchial wash (LABW) samples the tracheobronchial space where bile acids may be measurable at more clinically relevant levels. We assessed whether LABW bile acids, compared to BAL bile acids, are more strongly associated with poor clinical outcomes in lung transplant recipients. METHODS: Concurrently obtained BAL and LABW at 3 months post-transplant from a retrospective cohort of 61 lung transplant recipients were analyzed for taurocholic acid (TCA), glycocholic acid (GCA), and cholic acid by mass spectrometry and 10 inflammatory proteins by multiplex immunoassay. Associations between bile acids with inflammatory proteins and acute lung allograft dysfunction were assessed using Spearman correlation and logistic regression, respectively. Time to chronic lung allograft dysfunction and death were evaluated using multivariable Cox proportional hazards and Kaplan-Meier methods. RESULTS: Most bile acids and inflammatory proteins were higher in LABW than in BAL. LABW bile acids correlated with inflammatory proteins within and between sample type. LABW TCA and GCA were associated with acute lung allograft dysfunction (OR = 1.368; 95%CI = 1.036-1.806; P = 0.027, OR = 1.064; 95%CI = 1.009-1.122; P = 0.022, respectively). No bile acids were associated with chronic lung allograft dysfunction. Adjusted for risk factors, LABW TCA and GCA predicted death (HR = 1.513; 95%CI = 1.014-2.256; P = 0.042, HR = 1.597; 95%CI = 1.078-2.366; P = 0.020, respectively). Patients with LABW TCA in the highest tertile had worse survival compared to all others. CONCLUSIONS: LABW bile acids are more strongly associated than BAL bile acids with inflammation, acute lung allograft dysfunction, and death in lung transplant recipients. Collection of LABW may be useful in the evaluation of microaspiration in lung transplantation and other respiratory diseases.

Bronchoalveolar bile acid and inflammatory markers to identify high-risk lung transplant recipients with reflux and microaspiration.

BACKGROUND: Gastroesophageal reflux disease (GERD) is a risk factor for chronic lung allograft dysfunction. Bile acids-putative markers of gastric microaspiration-and inflammatory proteins in the bronchoalveolar lavage (BAL) have been associated with chronic lung allograft dysfunction, but their relationship with GERD remains unclear. Although GERD is thought to drive chronic microaspiration, the selection of patients for anti-reflux surgery lacks precision. This multicenter study aimed to test the association of BAL bile acids with GERD, lung inflammation, allograft function, and anti-reflux surgery. METHODS: We analyzed BAL obtained during the first post-transplant year from a retrospective cohort of patients with and without GERD, as well as BAL obtained before and after Nissen fundoplication anti-reflux surgery from a separate cohort. Levels of taurocholic acid (TCA), glycocholic acid, and cholic acid were measured using mass spectrometry. Protein markers of inflammation and injury were measured using multiplex assay and enzyme-linked immunosorbent assay. RESULTS: At 3 months after transplantation, TCA, IL-1ß, IL-12p70, and CCL5 were higher in the BAL of patients with GERD than in that of no-GERD controls. Elevated TCA and glycocholic acid were associated with concurrent acute lung allograft dysfunction and inflammatory proteins. The BAL obtained after anti-reflux surgery contained reduced TCA and inflammatory proteins compared with that obtained before anti-reflux surgery. CONCLUSIONS: Targeted monitoring of TCA and selected inflammatory proteins may be useful in lung transplant recipients with suspected reflux and microaspiration to support diagnosis and guide therapy. Patients with elevated biomarker levels may benefit most from anti-reflux surgery to reduce microaspiration and allograft inflammation.

Adaptation of the fundamentals of laparoscopic surgery box for endoscopic simulation: performance evaluation of the first 100 participants.

BACKGROUND: The paucity of readily accessible, cost-effective models for the simulation, practice, and evaluation of endoscopic skills present an ongoing barrier for resident training. We have previously described a system for conversion of the Fundamentals of Laparoscopic Surgery box (FLS) for flexible endoscopic simulation. Six endoscopic tasks focusing on scope manipulation, and other clinically relevant endoscopic skills are performed within a 5-min time limit per task. This study describes our experience and validation results with the first 100 participants. METHODS: A total of 100 participants were evaluated on the simulator. Thirty individuals were classified as experts (having done over 200 endoscopic procedures), and 70 were classified as trainees (39 individuals reported having no prior endoscopy experience). Of the 100 participants, 55 individuals were retested on the simulator within a period of 4 months. These 55 individuals were also evaluated using the "Global Assessment of Gastrointestinal Endoscopic Skills" (GAGES). T-tests and Pearson correlations were used where appropriate, values less than 0.05 were considered significant. RESULTS: Experts completed all six tasks significantly faster than trainees. For the 55 participants who were retested on the simulator, all tasks demonstrated evidence of test-retest reliability for both experts and trainees who did not practice in between tests. Moderate correlations between lower completion times and higher GAGES scores were observed for all tasks except the clipping task. CONCLUSIONS: The results from the first 100 participants provide evidence for the simulator's validity. Based on task completion times, we found that experts perform significantly better than trainees. Additionally, preliminary data demonstrate evidence of test-retest reliability, as well as GAGES score correlation. Additional studies to determine and validate a scoring system for this simulator are ongoing.

Feasibility of adapting the fundamentals of laparoscopic surgery trainer box to endoscopic skills training tool.

BACKGROUND: The fundamentals of laparoscopic surgery (FLS) training box is a validated tool, already accessible to surgical trainees to hone their laparoscopic skills. We aim to investigate the feasibility of adapting the FLS box for the practice and assessment of endoscopic skills. This would allow for a highly available, reusable, low-cost, mechanical trainer. METHODS: The design and development process was based on a user-centered design, which is a combination of the design thinking method and cognitive task analysis. The process comprises four phases: empathy, cognitive, prototyping/adaptation, and end user testing. The underlying idea was to utilize as many of the existing components of FLS training to maintain simplicity and cost effectiveness while allowing for the practice of clinically relevant endoscopic skills. A sample size of 18 participants was calculated to be sufficient to detect performance differences between experts and trainees using a two tailed t test with alpha set at 0.05, standard deviation of 5.5, and a power of 80%. RESULTS: Adaptation to the FLS box included two fundamental attachments: a front panel with an insertion point for an endoscope and a shaft which provides additional support and limits movement of the scope. The panel also allows for mounting of retroflexion tasks. Six endoscopic tasks inspired by FLS were designed (two of which utilize existing FLS components). Pilot testing with 38 participants showed high user's satisfaction and demonstrated that the trainer was robust and reliable. Task performance times was able to discriminate between trainees and experts for all six tasks. CONCLUSIONS: A mechanical, reusable, low-cost adaptation of the FLS training box for endoscopic skills is feasible and has high user satisfaction. Preliminary testing shows that the simulator is able to discriminate between trainees and experts. Following further validation, this adaptation may act as a supplement to the FES program.

Safety and efficacy of POEM for treatment of achalasia: a systematic review of the literature.

INTRODUCTION: Peroral endoscopic myotomy (POEM) is a novel intervention for the treatment of achalasia, which combines the advantages of endoscopic access and myotomy. The purpose of this study was to perform a systematic review of the literature to evaluate the efficacy and safety of POEM. METHODS: The systematic review was conducted following the PRISMA guidelines. Evidence-Based Medicine Reviews, Cochrane Central Register of Controlled Trials, Ovid MEDLINE (R) including in-process and non-indexed citations were searched for POEM studies using the keywords: esophageal achalasia, POEM, endoscopy, natural orifice surgery, laparoscopic Heller myotomy (LHM), and related terms. Eckardt score, lower esophageal sphincter (LES) pressure, and reported complications were the main outcomes. Two authors reviewed the search result independently. A third reviewer resolved all disagreements. Data abstraction was pilot-tested and approved by all authors. Data were examined for clinical, methodological, and statistical heterogeneity with the aim of determining whether evidence synthesis using meta- analysis was possible. RESULTS: The search strategy retrieved 2894 citations. After removing duplicates and applying the exclusion criteria, 54 studies were selected for full-text review of which a total of 19 studies were considered eligible for further analysis. There were 10 retrospective and 9 prospective studies, including 1299 POEM procedures. No randomized control trial (RCT) was identified. Overall, the pre- and post-POEM Eckardt scores and LES pressure were significantly different. The most frequently reported complications were mucosal perforation, subcutaneous emphysema, pneumoperitoneum, pneumothorax, pneumomediastinum, pleural effusion, and pneumonia. The median follow-up was 13 months (range 3-24). CONCLUSION: POEM is a safe and effective alternative for the treatment of achalasia. However, only short-term follow-up data compared with LHM are available. RCTs and long-term follow-up studies are needed to establish the efficacy and safety of POEM in the management of patients with achalasia.

Hiatal Herniation After Transhiatal Esophagectomy: an Underreported Complication.

INTRODUCTION: The incidence and presentation of hiatal hernias after esophagectomy (HHAE) are not well characterized, and may be changing with increased survival from esophageal cancer. The aims of this study were to define the incidence and presentation of HHAE in our population of patients undergoing transhiatal esophagectomy (THE), as it may have implications for management. METHODS: A retrospective cohort study (2004-2013) was performed of esophageal cancer patients who underwent THE. To determine the presence or absence of HHAE independent of the original radiology report, a radiologist sub-specializing in body imaging independently reviewed post-operative computed tomography images. A time-to-event competing risk analysis was performed to estimate the cumulative incidence of HHAE. RESULTS: Among 192 patients, the two-year cumulative incidence of HHAE was 14 % (95 % confidence interval 7.5-21 %). Of the 22 patients determined to have HHAE by independent expert radiologist review, only 11 (50 %) were identified by the original interpreting radiologist. Seven patients were symptomatic, and each underwent hiatal hernia repair (4 via laparotomy, 3 via laparoscopy). CONCLUSION: HHAE is not rare and is often unrecognized. As more patients with esophageal cancer survive, the number of patients becoming symptomatic and requiring repair may also rise. Therefore, it is important to consider this diagnosis when following patients long-term after esophagectomy.

The use of crural relaxing incisions with biologic mesh reinforcement during laparoscopic repair of complex hiatal hernias.

INTRODUCTION: Laparoscopic hiatal hernia repair has a better chance of success if the hiatus is closed without tension. This study attempts to answer the following questions: (1) What is the rate of hiatal hernia recurrence in patients who undergo hiatal closure with diaphragmatic relaxing incisions? (2) Can biologic mesh be safely substituted for synthetic mesh as coverage of the relaxing incisions? METHODS: We identified all patients who underwent laparoscopic hiatal hernia repair at our institution between 2007 and 2013 and reviewed their clinical records. Radiologic recurrence was identified by an experienced radiologist and defined as the presence of any abdominal contents located above the diaphragm on esophagram. Clinical recurrence was defined as little or no improvement in symptoms, the development of a new symptom, or the need for medical, endoscopic, or surgical treatment of postoperative symptoms. RESULTS: A minimum of 6 months of radiologic and clinical follow-up was available for 146 (40 %) patients, including 16 with relaxing incisions. There were 66 (45 %) recurrent hernias detected on esophagram. There was no difference in the rate of recurrent hiatal hernia among the three groups: Primary closure of the hiatus (21/36 [58 %]), primary closure with biologic mesh reinforcement (36/94 [38 %]), and relaxing incision with biologic mesh reinforcement (9/16 [56 %]; p = 0.428). Two reoperations were performed on patients who underwent left relaxing incisions and developed symptomatic diaphragmatic hernias through the left relaxing incisions. There were no complications associated with use of biologic mesh at the hiatus. CONCLUSIONS: Rate of recurrent hiatal hernia is similar between patients who undergo diaphragmatic relaxing incisions and patients who undergo primary hiatal closure. Relaxing incisions can be safely performed on either crus; however, biologic mesh should not be used to patch a left-sided relaxing incision due to the risk of developing a diaphragmatic hernia.

Causes and treatments of achalasia, and primary disorders of the esophageal body.

The following on achalasia and disorders of the esophageal body includes commentaries on controversies regarding whether patients with complete lower esophageal sphincter (LES) relaxation can be considered to exhibit early achalasia; the roles of different mucle components of the LES in achalasia; sensory neural pathways impaired in achalasia; indications for peroral endoscopic myotomy and advantages of the technique over laparoscopic and thorascopic myotomy; factors contributing to the success of surgical therapy for achalasia; modifications to the classification of esophageal body primary motility disorders in the advent of high-resolution manometry (HRM); analysis of the LES in differentiating between achalasia and diffuse esophageal spasm (DES); and appropriate treatment for DES, nutcracker esophagus (NE), and hypertensive LES (HTLES).