Targeted multispectral filter array design for the optimization of endoscopic cancer detection in the gastrointestinal tract.

Significance: Color differences between healthy and diseased tissue in the gastrointestinal (GI) tract are detected visually by clinicians during white light endoscopy; however, the earliest signs of cancer are often just a slightly different shade of pink compared to healthy tissue making it hard to detect. Improving contrast in endoscopy is important for early detection of disease in the GI tract during routine screening and surveillance. Aim: We aim to target alternative colors for imaging to improve contrast using custom multispectral filter arrays (MSFAs) that could be deployed in an endoscopic "chip-on-tip" configuration. Approach: Using an open-source toolbox, Opti-MSFA, we examined the optimal design of MSFAs for early cancer detection in the GI tract. The toolbox was first extended to use additional classification models (k-nearest neighbor, support vector machine, and spectral angle mapper). Using input spectral data from published clinical trials examining the esophagus and colon, we optimized the design of MSFAs with three to nine different bands. Results: We examined the variation of the spectral and spatial classification accuracies as a function of the number of bands. The MSFA configurations tested showed good classification accuracies when compared to the full hyperspectral data available from the clinical spectra used in these studies. Conclusion: The ability to retain good classification accuracies with a reduced number of spectral bands could enable the future deployment of multispectral imaging in an endoscopic chip-on-tip configuration using simplified MSFA hardware. Further studies using an expanded clinical dataset are needed to confirm these findings.

Local hyperthermia mediated by gold nanoparticle-integrated silicone-covered stent: feasibility and tissue response in a rat esophageal model.

BACKGROUND: To assess the feasibility and tissue response of using a gold nanoparticle (AuNP)-integrated silicone-covered self-expandable metal stent (SEMS) for local hyperthermia in a rat esophageal model. METHODS: The study involved 42 Sprague-Dawley rats. Initially, 6 animals were subjected to near-infrared (NIR) laser irradiation (power output from 0.2 to 2.4 W) to assess the in vitro heating characteristics of the AuNP-integrated SEMS immediately after its placement. The surface temperature of the stented esophagus was then measured using an infrared thermal camera before euthanizing the animals. Subsequently, the remaining 36 animals were randomly divided into 4 groups of 9 each. Groups A and B received AuNP-integrated SEMS, while groups C and D received conventional SEMS. On day 14, groups A and C underwent NIR laser irradiation at a power output of 1.6 W for 2 min. By days 15 (3 animals per group) or 28 (6 animals per group), all groups were euthanized for gross, histological, and immunohistochemical analysis. RESULTS: Under NIR laser irradiation, the surface temperature of the stented esophagus quickly increased to a steady-state level. The surface temperature of the stented esophagus increased proportionally with power outputs, being 47.3 ± 1.4 °C (mean ± standard deviation) at 1.6 W. Only group A attained full circumferential heating through all layers, from the epithelium to the muscularis propria, demonstrating marked apoptosis in these layers without noticeable necroptosis. CONCLUSIONS: Local hyperthermia using the AuNP-integrated silicone-covered SEMS was feasible and induced cell death through apoptosis in a rat esophageal model. RELEVANCE STATEMENT: A gold nanoparticle-integrated silicone-covered self-expanding metal stent has been developed to mediate local hyperthermia. This approach holds potential for irreversibly damaging cancer cells, improving the sensitivity of cancer cells to therapies, and triggering systemic anticancer immune responses. KEY POINTS: • A gold nanoparticle-integrated silicone-covered self-expanding metal stent was placed in the rat esophagus. • Upon near-infrared laser irradiation, this stent quickly increased the temperature of the stented esophagus. • Local hyperthermia using this stent was feasible and resulted in cell death through apoptosis.

Characterization of the layer, direction and time-dependent mechanical behaviour of the human oesophagus and the effects of formalin preservation.

The mechanical characterization of the oesophagus is essential for applications such as medical device design, surgical simulations and tissue engineering, as well as for investigating the organ's pathophysiology. However, the material response of the oesophagus has not been established ex vivo in regard to the more complex aspects of its mechanical behaviour using fresh, human tissue: as of yet, in the literature, only the hyperelastic response of the intact wall has been studied. Therefore, in this study, the layer-dependent, anisotropic, visco-hyperelastic behaviour of the human oesophagus was investigated through various mechanical tests. For this, cyclic tests, with increasing stretch levels, were conducted on the layers of the human oesophagus in the longitudinal and circumferential directions and at two different strain rates. Additionally, stress-relaxation tests on the oesophageal layers were carried out in both directions. Overall, the results show discrete properties in each layer and direction, highlighting the importance of treating the oesophagus as a multi-layered composite material with direction-dependent behaviour. Previously, the authors conducted layer-dependent cyclic experimentation on formalin-embalmed human oesophagi. A comparison between the fresh and embalmed tissue response was carried out and revealed surprising similarities in terms of anisotropy, strain-rate dependency, stress-softening and hysteresis, with the main difference between the two preservation states being the magnitude of these properties. As formalin fixation is known to notably affect the formation of cross-links between the collagen of biological materials, the differences may reveal the influence of cross-links on the mechanical behaviour of soft tissues.

Prevention of esophageal lesions during atrial fibrillation catheter ablation using esophageal temperature monitoring: A systematic review and meta-analysis.

INTRODUCTION: The use of esophageal temperature monitoring (ETM) for the prevention of esophageal injury during atrial fibrillation (AF) ablation is often advocated. However, evidence supporting its use is scarce and controversial. We therefore aimed to review the evidence assessing the efficacy of ETM for the prevention of esophageal injury. METHODS: We performed a meta-analysis and systematic review of the available literature from inception to December 31, 2022. All studies comparing the use of ETM, versus no ETM, during radiofrequency (RF) AF ablation and which reported the incidence of endoscopically detected esophageal lesions (EDELs) were included. RESULTS: Eleven studies with a total of 1112 patients undergoing RF AF ablation were identified. Of those patients, 627 were assigned to ETM (56%). The overall incidence of EDELs was 9.8%. The use of ETM during AF ablation was associated with a non significant increase in the incidence of EDELs (12.3% with ETM, vs. 6.6 % without ETM, odds ratio, 1.44, 95%CI, 0.49, 4.22, p = .51, I2 = 72%). The use of ETM was associated with a significant increase in the energy delivered specifically on the posterior wall compared to patients without ETM (mean power difference: 5.13 Watts, 95% CI, 1.52, 8.74, p = .005). CONCLUSIONS: The use of ETM does not reduce the incidence of EDELs during RF AF ablation. The higher energy delivered on the posterior wall is likely attributable to a false sense of safety that may explain the lack of benefit of ETM. Further randomized controlled trials are needed to provide conclusive results.

Chronic stridor in a toddler after ingestion of a discharged button battery: a case report.

BACKGROUND: Button battery (BB) ingestions (BBI) are increasingly prevalent in children and constitute a significant, potentially life-threatening health hazard, and thus a pediatric emergency. Ingested BBs are usually charged and can cause severe symptom within 2 h. Discharged BBs ingestion is very rare and protracted symptom trajectories complicate diagnosis. Timely imaging is all the more important. Discharged BBs pose specific hazards, such as impaction, and necessitate additional interventions. CASE PRESENTATION: We present the case of a previously healthy 19-month-old girl who was admitted to our pediatric university clinic in Germany for assessment of a three-month history of intermittent, mainly inspiratory stridor, snoring and feeding problems (swallowing, crying at the sight of food). The child's physical examination and vital signs were normal. Common infectious causes, such as bronchitis, were ruled out by normal lab results including normal infection parameters, negative serology for common respiratory viruses, and normal blood gas analysis, the absence of fever or pathological auscultation findings. The patient's history contained no evidence of an ingestion or aspiration event, no other red flags (e.g., traveling, contact to TBC). Considering this and with bronchoscopy being the gold standard for foreign body (FB) detection, an x-ray was initially deferred. A diagnostic bronchoscopy, performed to check for airway pathologies, revealed normal mucosal and anatomic findings, but a non-pulsatile bulge in the trachea. Subsequent esophagoscopy showed an undefined FB, lodged in the upper third of the otherwise intact esophagus. The FB was identified as a BB by a chest X-ray. Retrieval of the battery proved extremely difficult due to its wedged position and prolonged ingestion and required a two-stage procedure with consultation of Ear Nose Throat colleagues. Recurring stenosis and regurgitation required one-time esophageal bougienage during follow-up examinations. Since then, the child has been asymptomatic in the biannual endoscopic controls and is thriving satisfactorily. CONCLUSION: This case describes the rare and unusual case of a long-term ingested, discharged BB. It underscores the need for heightened vigilance among healthcare providers regarding the potential hazards posed by discharged BBIs in otherwise healthy children with newly, unexplained stridor and feeding problems. This case emphasizes the critical role of early diagnostic imaging and interdisciplinary interventions in ensuring timely management and preventing long-term complications associated even to discharged BBs.

Clinical anatomy of pulmonary connections in young people.

OBJECTIVE: Aim: To study the clinical anatomy of the pulmonary ligaments of young people. PATIENTS AND METHODS: Materials and Methods: The study was carried out when performing 28 autopsies of young people aged 25 to 44 years. Methods of dissection of chest organocomplexes, macro-microscopy, morphometry and planimetry, and statistical processing were used. The shape and topography of the pulmonary ligaments was assessed, their area, the localization of lymph nodes was examined. RESULTS: Results: The pulmonary ligament is an anatomical formation, which is formed as a result of a combination of leaves of the mediastinal pleura, which, covering the surfaces of the roots of the lungs, descend towards the diaphragm and are located between the mediastinal organs and the lungs. Pulmonary connections on both sides have a few edges: the inner, outer and lower free. The pulmonary ligaments with lower free edges do not pass to the diaphragmatic surface of the pleura, but only with inner ones, which are located on the right along the esophagus, and on the left along the aorta. Pulmonary ligaments on both sides pass into the mediastinal part of the pleura, covering the pericardium. CONCLUSION: Conclusions: There are individual differences between the shape and size of the right and left pulmonary ligaments in males and females. There is no significant difference between the sizes of the right and left pulmonary ligaments, but such dimensions as: the width, the angle of inclination and the ratio of their lower free edge to the lower edge of the lungs are not found in all cases.

Long-gap esophageal atresia: gastric transposition or esophageal lengthening with delayed primary anastomosis? A systematic review.

PURPOSE: This study aims to evaluate different surgical approaches to long-gap esophageal atresia (LGEA) with or without tracheoesophageal fistula (TEF) is unclear. METHODS: A systematic literature review was done comparing gastric transposition versus esophageal lengthening with delayed primary anastomosis in infants with LGEA+/-TEF. The primary outcome was time to full oral feeds. Secondary outcomes were time to full enteric feeds, need for further surgery, growth, mortality, and postoperative adverse events. RESULTS: No comparative studies were found. However, the literature was re-interrogated for non-comparative studies. Four hundred thirty-eight articles were identified and screened, and 18 met the inclusion criteria. All were case series. Forty-three infants underwent gastric transposition, and 106 had esophageal lengthening with delayed primary anastomosis. One study on gastric transposition reported time to full oral feeds, and one study in each group reported growth. Time to full enteric feeds was reported in one study in each group. 30% of infants had further surgery following gastric transposition, including hiatus hernia repair (5/43, 12%) and esophageal dilation (7/43, 16%). Following esophageal lengthening, 62/106 (58%) had anti-reflux surgery, 58/106 (55%) esophageal dilatation and 11/106 (10%) esophageal stricture resection. Anastomotic complications occurred in 13/43 (30%), gastrointestinal in 16/43 (37%), respiratory in 17/43 (40%), and nerve injury in 2/43 (5%) of the gastric transposition group. In the esophageal lengthening group, anastomotic complications occurred in 68/106 (64%), gastrointestinal in 62/106 (58%), respiratory in 6/106 (6%), and none sustained nerve injury. Each group had one death due to a cause not directly related to the surgical procedure. CONCLUSIONS: This systematic review highlights the morbidity associated with both surgical procedures and the variety in reporting outcomes.

Purinergic inhibitory regulation of esophageal smooth muscle is mediated by P2Y receptors and ATP-dependent potassium channels in rats.

Purines such as ATP are regulatory transmitters in motility of the gastrointestinal tract. The aims of this study were to propose functional roles of purinergic regulation of esophageal motility. An isolated segment of the rat esophagus was placed in an organ bath, and mechanical responses were recorded using a force transducer. Exogenous application of ATP (10-100 µM) evoked relaxation of the esophageal smooth muscle in a longitudinal direction under the condition of carbachol (1 µM) -induced precontraction. Pretreatment with a non-selective P2 receptor antagonist, suramin (500 µM), and a P2Y receptor antagonist, cibacron blue F3GA (200 µM), inhibited the ATP (100 µM) -induced relaxation, but a P2X receptor antagonist, pyridoxal phosphate-6-azophenyl-2,4-disulfonic acid (50 µM), did not affect it. A blocker of ATP-dependent potassium channels (KATP channels), glibenclamide (200 µM), inhibited the ATP-induced relaxation and application of an opener of KATP channels, nicorandil (50 µM), produced relaxation. The findings suggest that ATP is involved in inhibitory regulation of the longitudinal smooth muscle in the muscularis mucosae of the rat esophagus via activation of P2Y receptors and then opening of KATP channels.

An analytical and comparative study of swallowing in a tumor-infected oesophagus: a mathematical model.

This study discusses non-steady effects encountered in peristaltic flows in oesophagus. The purpose of this communication is to evolve a mechanism to diagnose tumor in an oesophagus mathematically. The tumor is modelled by generic bump function of certain height and width. The method of solution follows long wavelength and low-Reynolds number approximations for unsteady flow, while integrations have been performed numerically in order to plot graphs, which reveal various characteristics of the flow. The goal is to assess how pressure varies across the tumor's width. The spatial, as well as temporal, dependence of pressure has been studied in the laboratory frame of reference. The pressure distribution for tumor-infected oesophagus is compared with that of normal oesophagus. An intensified pressure is obtained in the presence of tumor. The interruption while swallowing through benign oesophageal tumor is confirmed by an abrupt pressure rise across the tumor's width. Tumor position also plays a significant role whether it is at contraction or relaxation of walls. Additionally, wall-shear-stress, volumetric flow rate and streamlines have also been described and compared with that without tumor growth. The expressions corresponding to all the physical quantities are computed numerically. Further, this model may also be implemented to the two-dimensional channel flow for an industrial application.

Proactive esophageal cooling during laser cardiac ablation: A computer modeling study.

BACKGROUND AND OBJECTIVES: Laser ablation is increasingly used to treat atrial fibrillation (AF). However, atrioesophageal injury remains a potentially serious complication. While proactive esophageal cooling (PEC) reduces esophageal injury during radiofrequency ablation, the effects of PEC during laser ablation have not previously been determined. We aimed to evaluate the protective effects of PEC during laser ablation of AF by means of a theoretical study based on computer modeling. METHODS: Three-dimensional mathematical models were built for 20 different cases including a fragment of atrial wall (myocardium), epicardial fat (adipose tissue), connective tissue, and esophageal wall. The esophagus was considered with and without PEC. Laser-tissue interaction was modeled using Beer-Lambert's law, Pennes' Bioheat equation was used to compute the resultant heating, and the Arrhenius equation was used to estimate the fraction of tissue damage (FOD), assuming a threshold of 63% to assess induced necrosis. We modeled laser irradiation power of 8.5 W over 20 s. Thermal simulations extended up to 250 s to account for thermal latency. RESULTS: PEC significantly altered the temperature distribution around the cooling device, resulting in lower temperatures (around 22°C less in the esophagus and 9°C in the atrial wall) compared to the case without PEC. This thermal reduction translated into the absence of transmural lesions in the esophagus. The esophagus was thermally damaged only in the cases without PEC and with a distance equal to or shorter than 3.5 mm between the esophagus and endocardium (inner boundary of the atrial wall). Furthermore, PEC demonstrated minimal impact on the lesion created across the atrial wall, either in terms of maximum temperature or FOD. CONCLUSIONS: PEC reduces the potential for esophageal injury without degrading the intended cardiac lesions for a variety of different tissue thicknesses. Thermal latency may influence lesion formation during laser ablation and may play a part in any collateral damage.

Comparison of Laryngeal Mask Airway Seal Between Anesthesiologists and Individuals Without Previous Airway Experience.

BACKGROUND: Tracheal intubation is the gold standard for airway management in emergency medicine, but more difficult to apply for inexperienced individuals than laryngeal mask airway (LMA). OBJECTIVE: The aim of our study was to investigate if inexperienced individuals are able to secure the airway with the help of LMA after a short introduction. A second aim was to evaluate Thiel-fixed specimens against unfixed ones. METHODS: In a body donor model, LMA application was evaluated between medical students without previous airway experience and anesthesiologists by comparing the sealing of the larynx using a water column applied to the esophagus. RESULTS: LMAs were successfully applied in 46 out of 55 (83.6%) attempts by medical students and in 30 out of 39 (76.9%) attempts by anesthesiologists. Among medical students, 14.1% of all LMA applications were primarily leaky, compared with 18.8% in anesthesiologists. Esophageal sealing was better in Thiel-fixed specimens (leakage 10.9%) compared with unfixed specimens (leakage 22.9%). Our data showed no significant difference between anesthesiologists and medical students in terms of sealing of LMA. Therefore, we conclude that medical students without previous airway experience can quickly learn to apply LMA sufficiently and thus, achieve aspiration protection similar to anesthesiologists. CONCLUSION: Medical students without previous airway experience can successfully insert LMAs after a short introduction. Thiel-fixed specimens are suitable for studies as well as for training in LMA application.

Cronkhite-Canada syndrome with esophagus involvement and six-year follow-up: A case report.

BACKGROUND: Cronkhite-Canada syndrome (CCS) is a rare, noninherited disease characterized by gastrointestinal polyposis with diarrhea and ectodermal abnormalities. CCS polyps are distributed through the whole digestive tract, and they are common in the stomach and colon but very uncommon in the esophagus. CASE SUMMARY: Here, we present a case of a 63-year-old man with skin hyperpigmentation accompanied by diarrhea, alopecia, and loss of his fingernails. Laboratory data indicated anemia, hypoalbuminemia, hypocalcemia, hypokalemia, and positive fecal occult blood. Endoscopy showed numerous polyps scattered throughout the digestive tract, including the esophagus. He was treated with nutritional support and glucocorticoids with remission of his symptoms. CONCLUSION: Comprehensive treatment led by hormonal therapy can result in partial or full remission of clinical symptoms. Treatment should be individualized for each patient according to their therapy response. Surveillance endoscopy is necessary for assessing mucosal disease activity and detecting malignant transformation.

Proximal esophageal impedance baseline increases the yield of impedance-pH and is associated with response to PPIs in chronic cough patients.

BACKGROUND: Chronic cough significantly impairs the quality of life. Although various studies focused on MNBI as assessed in the distal esophagus, scarce data are available on the clinical value of proximal measurements. AIM: To investigate the role of proximal MNBI in the workup of patients with chronic cough and its ability to predict PPI response. METHODS: Demographic, clinical, endoscopy findings, impedance-pH and HRM tracings from consecutive cough patients were evaluated. MNBI was calculated at proximal and distal esophagus. RESULTS: One hundred and sixty four patients were included. In addition to traditional variables, when considering also the PSPW index or MNBI at 3 cm or 15 cm, the proportion of patients with pathological impedance-pH monitoring significantly increased. 70/164 patients were responders, while 94 (57.3%) were non-responder to double PPI dose (p < 0.05). Patients with pathologic MNBI at 3 cm and/or 15 cm as well as those with pathologic PSPW index were characterized by a significantly higher proportion of responders than that observed among patients with normal impedance-pH variables (p < 0.001). The proportion of responders with pathological MNBI at 15 cm was significantly higher than the proportion of responders with pathological MNBI at 3 cm (82.8% vs. 64.3%, p < 0.05). At multivariable model, pathological MNBI at both 3 cm and 15 cm as well as PSPW index were associated with PPI responsiveness. The strongest association with PPI response was observed for MNBI at 15 cm. CONCLUSIONS: The assessment of MNBI at proximal esophagus increases the diagnostic yield of impedance-pH monitoring and may represent a useful predictor of PPI responsiveness in the cumbersome clinical setting of suspected reflux-related cough.

Operative Experience of Esophageal Surgery among General Surgery Residents in the United States: An Analysis of ACGME Operative Case Logs.

INTRODUCTION: Esophageal surgery is an essential component of general surgery training and encompasses several types of cases that are logged by general surgery residents. There is a scarcity of data on the quality and volume of esophageal surgery experience during surgical residency in the United States. We analyzed trends for 9 different esophageal procedure categories logged by residents in the United States, with the aim to identify areas for improvement in training. METHODS: We conducted a retrospective analysis of operative case logs of all general surgery residents graduating from programs accredited by the ACGME over a fourteen-year period from 2009 to 2023. Data on mean esophageal cases reported by graduates, including mean in each procedure subcategory were retrieved. Cases were categorized as either surgeon chief or surgeon junior for each procedure category. Mann-Kendall trend test was used to obtain tau statistics and p-value for trends in mean operative surgical volume for the total number of cases in each operative category over the study period. Trends in surgeon chief and surgeon junior cases were also investigated for each operative category. RESULTS: The mean number of all esophageal procedures performed per resident during their training increased significantly from 10.5 in 2009 to 16 in 2022 (τ = 0.833, p < 0.001). This trend observed among all esophageal procedures during this 14-year study can be largely attributed to the steady increase in the number and proportion of laparoscopic esophageal antireflux procedures performed (τ = 0.950, p < 0.001). Additionally, esophagectomy procedures had a statistically significant, but modest, increase during the study period (τ = 0.505, p = 0.023), from a mean of 1 case during training in 2009 to a peak of 1.3 in 2020. Although the general trend of esophagus procedures increased during the study period, most categories (7 out of 9) either decreased or did not significantly change. Esophagogastrectomy volume decreased significantly by 30%, from 1 per resident during their training in 2009 to 0.7 in 2022 (τ = -0.510, p = 0.018), esophageal diverticulectomy procedures decreased by 50% from 0.2 to 0.1 (τ = -0.609, p = 0.009), and operations for esophageal stenosis decreased by 75% from 0.4 to 0.1 (τ = -0.734, p = 0.001). Mean number of esophageal bypasses (τ = -0.128, p = 0.584), repair of perforated esophageal disease (τ = -0.333, p = 0.156), and other major esophagus procedures (τ = 0.416, p = 0.063) did not significantly change. CONCLUSION: The operative volume of esophageal surgery that general surgery residents in the United States are exposed to has significantly risen over the past 14 years, largely driven by the increase in laparoscopic antireflux procedures. However, given the recent advances and the resultant heterogeneity in both esophageal surgery, the increase in resident operative volume is still inadequate to ensure the training of safe and adept esophageal surgeons, necessitating postresidency specialized training for trainees interested in esophageal surgery.

Bovine Aortic Arch with an Aberrant Left Vertebral Artery in a 3-Year-Old Boy with VACTERL Association: A Case Report.

BACKGROUND The VACTEREL association is an acronym that includes vertebral malformations (V), anal atresia (A), cardiac defects (C), tracheoesophageal fistula (TE), renal defects (R), and limb malformations (L). The aortic arch is the section between the ascending aorta and the descending aorta, where some variants have been described, such as the right aortic arch and bovine aortic arch, among others. A rare presentation in the Natsis classification is the "type X" where a bovine aortic arch and anomalous origin of the left vertebral artery are present. Several structural cardiac malformations have been described in the VACTEREL association. Still, there is no bovine arch or an anomalous left vertebral artery. CASE REPORT Our patient was a 3-year-old boy with a diagnosis of VACTEREL association (type III esophageal atresia, congenital hip dislocation, scoliosis, bilateral clubfoot, and grade IV biliary ureteral reflux). Echocardiographic findings showed changes in the aortic arch, and angiotomography and magnetic resonance angiography showed a bovine aortic arch and an anomalous left vertebral artery. At the time of diagnosis, there were no clinical manifestations or complications due to the anomalous origin of the left vertebral artery. CONCLUSIONS This is the first description of a bovine type X arch according to the Natsis classification in a VACTEREL association. In general, knowledge of the anatomical variants of the aortic arch and the origin and course of the vertebral arteries is of great clinical and interventional importance, mainly because of the risk of cerebral ischemia.