Enteroblastic adenocarcinoma of the ampulla of Vater / Adenocarcinoma enteroblástico de la ampolla de Vater

Adenocarcinoma with enteroblastic differentiation is a rare histologic subtype of adenocarcinoma of the gastrointestinal tract that shows unique histologic and immunohistochemical features that resemble fetal intestinal epithelium. This histological subtype has been widely described in the stomach, where it most frequently appears, but, in other locations, it is misdiagnosed because of the poor experience in routine diagnostic setting. Here we present a case of an 87-year-old male with an adenocarcinoma of the ampulla of Vater with enteroblastic differentiation with a literature review of the cases described of this subtype in this location to date. The anatomical peculiarity of the ampulla, joined with the infrequent nature of this histological subtype, makes this case of great interest to aid to better characterize the biological behavior of these tumors. (AU)

El adenocarcinoma con diferenciación enteroblástica es un subtipo histológico poco frecuente de adenocarcinoma gastrointestinal que muestra características histológicas e inmunohistoquímicas únicas que se asemejan al epitelio intestinal fetal. Este subtipo histológico ha sido ampliamente descrito en el estómago, donde aparece con mayor frecuencia, pero en otras localizaciones es mal diagnosticado debido a la poca experiencia en el diagnóstico de rutina. Presentamos un caso de un varón de 87 años con adenocarcinoma de ampolla de Vater con diferenciación enteroblástica, junto a una revisión bibliográfica de los casos descritos de este subtipo en esta localización hasta el momento. La peculiaridad anatómica de la ampolla, sumada al carácter poco frecuente de este subtipo histológico, dotan a este caso de gran interés para ayudar a caracterizar mejor el comportamiento biológico de estos tumores. (AU)

Direct gastric invasion from the liver metastasis of colorectal origin: A case report.

RATIONALE: Colorectal cancer is the third most common cancer diagnosed worldwide. At the time of diagnosis of colorectal cancer, one of the most common metastatic sites is liver. Gastric metastasis from colorectal origin is rare. Moreover, a direct invasion of the stomach, by hepatic metastasis from colorectal cancer, is particularly uncommon. PATIENT CONCERNS: A 56-year-old male patient with hematochezia was referred to our hospital. DIAGNOSIS: The patient was diagnosed with unresectable colorectal cancer because of the presence of >10 metastases involving both lobes of the liver. INTERVENTIONS AND OUTCOMES: After chemotherapy, the metastatic nodules in the liver nearly disappeared, except for a small nodule in segment VI. The patient underwent a radiofrequency ablation for the single lesion in the liver and laparoscopic low-anterior-resection for the primary tumor. Despite receiving various chemotherapy regimens, he experienced 6 recurrences, leading to 5 hepatectomies including a right hemi-hepatectomy, 1 pulmonary wedge resection, and 2 courses of radiation treatments. Lastly, a metastatic lesion in the liver was observed with invasion into the stomach. Subsequently, gastric wedge resection with resection of segments III and IV of the liver was performed. Direct invasion of the liver metastases into the stomach was confirmed histologically. LESSONS: The patient is still alive, with a good quality of life, even after more than 8 years since the initial diagnosis. In the last instance of metastatic recurrence, direct invasion from the liver metastases into the stomach was observed, which is rare, and there are currently no reported cases.

Retrograde jejunoduodenogastric intussusception associated with fully functioning nonballoon nasojejunal feeding catheter: A case report.

RATIONALE: Retrograde jejunoduodenogastric intussusception refers to invagination of distal small intestine into the stomach. It is extremely rare. It is often associated with displaced feeding catheter in which its balloon tip migrates past the gastric pylorus. The intussusception is triggered by retraction of migrated catheter. It is often accompanied by feeding intolerance or catheter malfunction. This report describes a distinctive case of retrograde jejunoduodenogastric intussusception associated with a fully functioning nonballoon nasojejunal tube. PATIENT CONCERN: A 19-year-old female was presented with repeated vomiting and abdominal distension for 5 days. DIAGNOSIS: An abdominal computerized tomography revealed retrograde jejunoduodenogastric intussusception causing air/fluid-filled gastric distension. Immediate endoscopic examination revealed a loop of small intestine, protruding through the pylorus. Progressed ischemia of the migrated small bowel loop was confirmed. INTERVENTIONS: At laparotomy, a jejunal loop migrating into the duodenum and stomach at the level of the ligament of Treitz was noticed. After manual reduction of migrated bowel, 2 segmental resections of necrotic segment were performed. A feeding jejunostomy was constructed in the proximal jejunum. OUTCOMES: Enteral feeding through the surgically constructed feeding jejunostomy was started on the 5th operative day and the patient was discharged on the 16th postoperative day. LESSONS: When a patient under tube feeding exhibits abrupt intractable gastroesophageal reflux with a sign of catheter migration, we must consider the possibility of catheter-related intussusception. Having a fully functioning feeding catheter with nonballoon tip does not preclude retrograde jejunoduodenogastric intussusception.

Edible electronics to treat the brain.

Ingestible electronic pills can be used for targeted noninvasive neuromodulation.

Helicobacter pylori glycan biosynthesis modulates host immune cell recognition and response.

Introduction: The pathogenic bacterium Helicobacter pylori has evolved glycan-mediated mechanisms to evade host immune defenses. This study tests the hypothesis that genetic disruption of H. pylori glycan biosynthesis alters immune recognition and response by human gastric epithelial cells and monocyte-derived dendritic cells. Methods: To test this hypothesis, human cell lines were challenged with wildtype H. pylori alongside an array of H. pylori glycosylation mutants. The relative levels of immune response were measured via immature dendritic cell maturation and cytokine secretion. Results: Our findings indicate that disruption of lipopolysaccharide biosynthesis diminishes gastric cytokine production, without disrupting dendritic cell recognition and activation. In contrast, variable immune responses were observed in protein glycosylation mutants which prompted us to test the hypothesis that phase variation plays a role in regulating bacterial cell surface glycosylation and subsequent immune recognition. Lewis antigen presentation does not correlate with extent of immune response, while the extent of lipopolysaccharide O-antigen elaboration does. Discussion: The outcomes of this study demonstrate that H. pylori glycans modulate the host immune response. This work provides a foundation to pursue immune-based tailoring of bacterial glycans towards modulating immunogenicity of microbial pathogens.

Bridging the gap: understanding Belgian anesthesiologists' proficiency and training demands in gastric point-of-care ultrasound, a case-based survey.

BACKGROUND: Pulmonary aspiration syndrome remains a significant complication of general anesthesia, particularly in unfasted patients. Gastric point-of-care ultrasound (POCUS) allows for both qualitative and quantitative assessment of gastric content, providing a safe and reliable method to assess gastric emptying and reduce the risk of aspiration during general anesthesia. METHODS: The survey was distributed to Belgian certified anesthesiologists and trainees between April 2020 and June 2021. Participants received a simulated clinical case of a patient at risk of gastric aspiration, created and approved by two certified anesthesiologists trained to perform gastric POCUS. The objectives of this study were to assess recognition of high-risk clinical situations for gastric aspiration, awareness of the gastric POCUS and its indications, and knowledge of the technical and practical conditions of the procedure among respondents trained in the technique. Furthermore, the study assessed the state of training in gastric POCUS, the desire for education, and the practical availability of ultrasound equipment. The survey used conditional branching to ensure unbiased responses to POCUS-related questions. It included multiple-choice questions, quantitative variables, and 5-point Likert scales. The margin of error was calculated using Daniel's formula, corrected for a finite population. RESULTS: The survey was conducted among 323 anesthesiologists. Only 20.8% (27) recognized the risk of a full stomach based on the patient's history. Anesthesiologists who recognized the indication for gastric POCUS and were trained in the procedure demonstrated good recall of the practical conditions for performing the procedure and interpreting the results. Only 13.08% (31) of all respondents had received training in gastric POCUS, while 72.57% (172) expressed interest in future training. Furthermore, 80.17% (190) of participants had access to adequate ultrasound equipment and 78.90% (187) supported teaching gastric POCUS to anesthesia trainees. CONCLUSIONS: This survey offers insight into the epidemiology, clinical recognition, knowledge, and utilization of gastric POCUS among Belgian anesthesia professionals. The results emphasize the significance of proper equipment and training to ensure the safe and effective implementation of gastric POCUS in anesthesia practice. Additional efforts should focus on improving training and promoting the integration of gastric POCUS into daily clinical practice.

Convergent gene losses and pseudogenizations in multiple lineages of stomachless fishes.

The regressive evolution of independent lineages often results in convergent phenotypes. Several teleost groups display secondary loss of the stomach, and four gastric genes, atp4a, atp4b, pgc, and pga2 have been co-deleted in agastric (stomachless) fish. Analyses of genotypic convergence among agastric fishes showed that four genes, slc26a9, kcne2, cldn18a, and vsig1, were co-deleted or pseudogenized in most agastric fishes of the four major groups. kcne2 and vsig1 were also deleted or pseudogenized in the agastric monotreme echidna and platypus, respectively. In the stomachs of sticklebacks, these genes are expressed in gastric gland cells or surface epithelial cells. An ohnolog of cldn18 was retained in some agastric teleosts but exhibited an increased non-synonymous substitution when compared with gastric species. These results revealed novel convergent gene losses at multiple loci among the four major groups of agastric fish, as well as a single gene loss in the echidna and platypus.

Metabolomics approach for predicting stomach and colon contents in dead Arctocephalus pusillus pusillus, Arctocephalus tropicalis, Lobodon carcinophaga and Ommatophoca rossii from sub-Antarctic region.

The dietary habits of seals play a pivotal role in shaping management and administration policies, especially in regions with potential interactions with fisheries. Previous studies have utilized various methods, including traditional approaches, to predict seal diets by retrieving indigestible prey parts, such as calcified structures, from intestines, feces, and stomach contents. Additionally, methods evaluating nitrogen and stable isotopes of carbon have been employed. The metabolomics approach, capable of quantifying small-scale molecules in biofluids, holds promise for specifying dietary exposures and estimating disease risk. This study aimed to assess the diet composition of five seal species-Arctocephalus pusillus pusillus, Lobodon carcinophaga, Ommatophoca rossii, and Arctocephalus tropicalis 1 and 2-by analyzing stomach and colon contents collected from stranded dead seals at various locations. Metabolite concentrations in the seal stomach and colon contents were determined using Nuclear Magnetic Resonance Spectroscopy. Among the colon and stomach contents, 29 known and 8 unknown metabolites were identified. Four metabolites (alanine, fumarate, lactate, and proline) from stomach contents and one metabolite (alanine) from colon contents showed no significant differences between seal species (p>0.05). This suggests that traces of these metabolites in the stomach and colon contents may be produced by the seals' gut microbiome or derived from other animals, possibly indicating reliance on fish caught at sea. Despite this insight, the cause of death for stranded seals remains unclear. The study highlights the need for specific and reliable biomarkers to precisely indicate dietary exposures across seal populations. Additionally, there is a call for the development of relevant metabolite and disease interaction networks to explore disease-related metabolites in seals. Ultimately, the metabolomic method employed in this study reveals potential metabolites in the stomach and colon contents of these seal species.

Prospective, randomized study comparing two different regimens of split-dose polyethylene glycol and their effect on endoscopic outcomes.

BACKGROUND: Different split regimens of polyethylene glycol are routinely used and no guidelines are available to select an optimal protocol of ingestion. This study aims to compare the efficacy and side effect profile of two different regimens of polyethylene glycol bowel preparation solution: PEG (3 + 1) vs. PEG (2 + 2). METHODS: 240 patients above the age of 18 years were included in the study between June 1st and November 31st, 2023. Patients were randomly assigned either to Group A, consisting of 115 patients receiving a 3 L of PEG the night before the colonoscopy, and 1 L the same morning of the procedure. Or to group B, where 125 patients ingested 2 L the night before the procedure, and the remaining 2 L the same morning. The cleansing efficacy was evaluated by the attending endoscopist using the Boston Bowel Preparation Scale, through a score assigned for each segment of the colon (0-3). Side effects, tolerability, and willingness to retake the same preparation were listed by an independent investigator using a questionnaire administered before the procedure. RESULTS: A higher percentage of patients had gastric fullness with the 3 + 1 vs. 2 + 2 preparation (58.3% vs. 31.2%; p <.001). A higher Boston bowel preparation score was seen in patients who took the 2 + 2 vs. 3 + 1 preparation (7.87 vs. 7.23). Using the 2 + 2 preparation was significantly associated with higher Boston bowel preparation scores vs. the 3 + 1 preparation (OR = 1.37, p =.001, 95% CI 1.14, 1.64). After adjustment over other variables (age, gender, comorbidities, previous abdominal surgeries, presence of adenoma, and time between last dose and colonoscopy), results remained the same (aOR = 1.34, p =.003, 95% CI 1.10, 1.62). CONCLUSION: While both (2 + 2) and (3 + 1) regimens of polyethylene glycol are a good choice for a successful colonoscopy, we recommend the use of (2 + 2) regimen for its superior efficacy in bowel cleansing.

A approach of gastric conduit via the anterior of pulmonary hilum route during minimally invasive McKeown esophagectomy.

BACKGROUND: The gastric conduit is the most commonly used replacement organ for reconstruction after minimally invasive McKeown esophagectomy. Although the optimal route of gastric conduit remains controversial, the posterior mediastinal route is physiologically preferable but is not without disadvantages. Here, we report the safety and efficacy of a method of gastric conduit reconstruction via the anterior of the pulmonary hilum route. METHODS: We have used the anterior of the pulmonary hilum route since 2021. This procedure involves pulling the gastric conduit up through a substernal tunnel between the right thoracic cavity and the abdominal cavity and passing it into the neck via the anterior of the pulmonary hilum route. In this retrospective study, we compared the clinical outcomes between 20 patients who underwent this procedure and 20 patients who underwent the posterior mediastinal route from 2021 to 2022. RESULTS: No mortality was reported in either group. No significant differences were observed between the two groups in duration of surgery, blood loss, incidence of postoperative complications, and postoperative hospital stay. As a result of the anterior of the pulmonary hilum route, the primary tumor bed and lymph node drainage area were effectively bypassed, which facilitates postoperative adjuvant radiotherapy or chemoradiotherapy. The distance of the gastric conduit accompanying the airway was significantly shorter in the anterior of the pulmonary hilum route group. CONCLUSIONS: Our method is considered to be a safe and useful technique for the reconstruction of gastric conduit.

[Serum ghrelin changes after bariatric surgery]. / Kak izmenyaetsya uroven' grelina u patsientov, perenesshikh bariatricheskie vmeshatel'stva.

OBJECTIVE: To study the effect of bariatric surgery on serum ghrelin in patients with morbid obesity. MATERIAL AND METHODS: We experimentally analyzed serum ghrelin in 96 rats. Of these, 84 rats underwent sleeve gastrectomy, and 12 rats comprised the control group (no surgery). We measured body weight and serum ghrelin using ELISA method after 1, 3, 7, 14, 21 and 30 days after surgery. Serum ghrelin was studied before and after bariatric surgery in 23 patients with morbid obesity. RESULTS: Baseline serum ghrelin was lower in larger rats and obese patients compared to normal body weight. We found no decrease in serum ghrelin after resection of fundal ghrelin-releasing part of the stomach. CONCLUSION: Stomach volume changes after restrictive bariatric surgery (sleeve resection or gastroplication) are accompanied by mild increase in serum ghrelin. This increment is greater after more significant body weight loss after surgery. Similar researches will help to find new treatment strategies for pathological obesity.

Ovarian serous carcinoma with stomach metastasis: a rare case report and literature review.

Ovarian cancer is a common tumor among women. It is often asymptomatic in the early stages, with most cases already at stage III to IVE at the time of diagnosis. Direct spread and lymphatic metastasis are the primary modes of metastasis, whereas hematogenous spread is rare. An initial diagnosis of ovarian cancer that has metastasized to the stomach is also uncommon. Therefore, clear treatment methods and prognostic data for such metastasis are lacking. In our hospital, we encountered a patient with an initial imaging diagnosis of a gastric tumor and a history of an ovarian tumor with endoscopic abdominal metastasis. Based on the characteristics of the case, the two tumors were considered to be the same. After chemotherapy, a partial response was observed in the stomach and pelvic lesions, suggesting the effectiveness of the treatment. Through three treatments of recurrence, gastroscopy confirmed the stomach to be a metastatic site. Therefore, determining the primary source of advanced tumors is crucial in guiding treatment decisions. Clinicians must approach this comprehensively, relying on thorough evaluation and personal experience.

Role of indocyanine green fluorescence imaging for evaluating blood supply in the gastric conduit via the substernal route after McKeown minimally invasive esophagectomy.

BACKGROUND: Anastomotic leakage (AL) is a determining factor of morbidity and mortality after esophagectomy. Adequate perfusion of the gastric conduit is crucial for AL prevention. This study aimed to determine whether intraoperative angiography using indocyanine green (ICG) fluorescence improves the incidence of AL after McKeown minimally invasive esophagectomy (MIE) with gastric conduit via the substernal route (SR). METHODS: This retrospective cohort study included 120 patients who underwent MIE with gastric conduit via SR for esophageal cancer between February 2019 and April 2023. Of 120 patients, 88 experienced intraoperative angiography using ICG (ICG group), and 32 patients experienced intraoperative angiography without ICG (no-ICG group). Baseline characteristics and operative outcomes, including AL as the main concern, were compared between the 2 groups. In addition, the outcomes among patients in the ICG group with different levels of fluorescence intensity were compared. RESULTS: The ICG and no-ICG groups were comparable in baseline characteristics and operative outcomes. There was no significant difference between the 2 groups regarding the rate of AL (31.0% vs 37.5%; P = .505), median dates of AL (9 vs 9 days; P = .810), and severity of AL (88.9%, 11.11%, and 0.0% vs 66.7%, 16.7%, and 16.7% for grades I, II, and III, respectively; P = .074). Patients in the ICG group with lower intensity of ICG had higher rates of leakage (24.6%, 39.3%, and 100% in levels I, II, and III of ICG intensity, respectively; P = .04). CONCLUSION: The use of ICG did not seem to reduce the rate of AL. However, abnormal intensity of ICG fluorescence was associated with a higher rate of AL, which implies a predictive potential.

A clinical consensus paper on jejunal tube feeding in children.

BACKGROUND: Feeding problems are common in children with complex medical problems or acute critical illness and enteral nutrition may be required. In certain situations, gastric tube feeding is poorly tolerated or may not be feasible. When feed intolerance persists despite appropriate adjustments to oral and gastric enteral regimens, jejunal tube feeding can be considered as an option for nutrition support. METHODS: A multidisciplinary expert working group of the Australasian Society of Parenteral and Enteral Nutrition was convened. They identified topic questions and five key areas of jejunal tube feeding in children. Literatures searches were undertaken on Pubmed, Embase, and Medline for all relevant studies, between January 2000 and September 2022 (n = 103). Studies were assessed using National Health and Medical Research Council guidelines to generate statements, which were discussed as a group, followed by voting on statements using a modified Delphi process to determine consensus. RESULTS: A total of 24 consensus statements were created for five key areas: patient selection, type and selection of feeding tube, complications, clinical use of jejunal tubes, follow-up, and reassessment. CONCLUSION: Jejunal tube feeding is a safe and effective means of providing nutrition in a select group of pediatric patients with complex medical needs, who are unable to be fed by gastric tube feeding. Appropriate patient selection is important as complications associated with jejunal tube feeding are not uncommon, and although mostly minor, can be significant or require tube reinsertion. All children receiving jejunal tube feeding should have multidisciplinary team assessment and follow-up.

[Circulatory failure after bupropion overdose]. / Allt fler allvarliga förgiftningar med preparatet bupropion.

A case of massive overdose of sustained release bupropion tablets is described. The patient presented with GCS 3, tachycardic and in vasoplegic shock. ECHO and EKG were initially normal. The hemodynamic situation was stabilised with vasopressors, but 18 h after presentation the patient deteriorated with wide complex arrhythmias rapidly progressing to cardiac arrest. The patient was put on VA-ECMO after 35 minutes of CPR. Circulation could be stabilized and ECMO was discontinued after 36 h. The patient was extubated on day 6 and made a complete recovery on discharge two weeks after presentation. At 34h, with ongoing ECMO, 236 tablets (with visible print identifying them as bupropion) were evacuated from the patient's stomach by gastroscopy. The tablets were analysed by NMR (nuclear magnetic resonance) but no longer contained any active substance. Blood levels of bupropion and hydroxybupropion at 36h were 790 and 1300 µg/l. The case illustrates a worrying surge in serious bupropion poisonings as noted by the Swedish Poisons Information Centre during the last 5 years.

Bioinformatic Study of Possible Acute Regulation of Acid Secretion in the Stomach.

The gastric H+,K+-ATPase is an integral membrane protein which derives energy from the hydrolysis of ATP to transport H+ ions from the parietal cells of the gastric mucosa into the stomach in exchange for K+ ions. It is responsible for the acidic environment of the stomach, which is essential for digestion. Acid secretion is regulated by the recruitment of the H+,K+-ATPase from intracellular stores into the plasma membrane on the ingestion of food. The similar amino acid sequences of the lysine-rich N-termini α-subunits of the H+,K+- and Na+,K+-ATPases, suggests similar acute regulation mechanisms, specifically, an electrostatic switch mechanism involving an interaction of the N-terminal tail with the surface of the surrounding membrane and a modulation of the interaction via regulatory phosphorylation by protein kinases. From a consideration of sequence alignment of the H+,K+-ATPase and an analysis of its coevolution with protein kinase C and kinases of the Src family, the evidence points towards a phosphorylation of tyrosine-7 of the N-terminus by either Lck or Yes in all vertebrates except cartilaginous fish. The results obtained will guide and focus future experimental research.

Gastrointestinal Bezoars in Paediatrics: Case Series and Literature Review.

BACKGROUND: Bezoars are indigestible lumps which are usually found in stomach. Types of bezoar include phytobezoar, trichobezoar, lithobezoar, pharmacobezoar, plasticobezoar, lactobezoar and metal bezoar. Trichobezoars mostly affect females in 20s and 30s with a rarity in paediatrics. Unexplained complaints with a palpable mass are commonly found in these patients. Treatment involves retrieval of mass with searching for others. The purpose of this study was to present data and surgical management of cases with trichobezoars. MATERIALS AND METHODS: We documented a retrospective review of trichobezoars done in our hospital between 2016 and 2022. All demographic data collected included gender and age of cases, composition and extent of bezoar, clinical presentation, imaging modalities, endoscopic trial, surgical approach and outcome. RESULTS: Five cases of gastrointestinal tract (GIT) trichobezoars underwent surgery. All cases were females between (13 and 16 years). Trichobezoars were three gastric, one ileal and one of combined gastric and colonic. Complaints were abdominal pain, vomiting, weight loss and halitosis. Three cases had a palpable abdominal mass. Different radiological modalities were performed. Endoscopic retrieval was tried in one patient and the laparoscopic approach in another one, but the first route failed. Laparotomy followed by gastrotomy, enterotomy and colotomy was done without complications. CONCLUSIONS: Trichobezoars should be suspected in any child with unexplained abdominal complaints or with a palpable abdominal mass, especially in girls. Imaging can be done in different modalities for diagnosis. Endoscopic retrieval could be tried; however, its failure is common, necessitating laparotomy, which has an excellent outcome.

An externally validated guide to anatomical interpretation using a direct-vision ('IRIS') feeding tube.

BACKGROUND & AIMS: Most of the 11.5 million feeding tubes placed annually in Europe and the USA are placed 'blind'. This carries a 1.6% risk that these tubes will enter the lung and 0.5% cause pneumothorax or pneumonia regardless of whether misplacement is identified prior to feeding. Tube placement by direct vision may reduce the risk of respiratory or oesophageal misplacement. This study externally validated whether an 'operator guide' would enable novice operators to differentiate the respiratory and alimentary tracts. METHODS: One IRIS tube was placed in each of 40 patients. Novice operators interpreted anatomical position using the built-in tube camera. Interpretation was checked from recorded images by consultant gastroenterologists and end-of-procedure checks using pH or X-ray checked by Radiologists and a consultant intensivist. RESULTS: The 40 patients were a median of 68y (IQR: 56-75), 70% male, mostly medical (65%), conscious (67.5%) and 70% had no artificial airway. Three tubes were removed due to failed placement. In the remaining 37 placements, novice operators identified the airway in 17 (45.9%) and airway + respiratory tract in 19 (51.4%), but redirected all these tubes into the oesophagus. By using direct vision to reduce the proportion of tubes near the airway or in respiratory tract from 0.514 to 0, operator discrimination between the respiratory and alimentary tracts was highly significant (0.514 vs 0: p < 0.0001, power >99.9% when significance = 0.05). In addition, organ boundaries (respiratory tract vs oesophagus, oesophagus vs stomach, stomach vs intestine) were identified in 100%. CONCLUSIONS: Novice operators, trained using the guide, identified all respiratory misplacements and accurately interpreted IRIS tube position. Guide-based training could enable widespread use of direct vision as a means to prevent tube-related complications.