Peristaltic regimes in esophageal transport

A FLIP device gives cross-sectional area along the length of the esophagus and one pressure measurement, both as a function of time. Deducing mechanical properties of the esophagus including wall material properties, contraction strength, and wall relaxation from these data are a challenging inverse problem. Knowing mechanical properties can change how clinical decisions are made because of its potential for in-vivo mechanistic insights. To obtain such information, we conducted a parametric study to identify peristaltic regimes by using a 1D model of peristaltic flow through an elastic tube closed on both ends and also applied it to interpret clinical data. The results gave insightful information about the effect of tube stiffness, fluid/bolus density and contraction strength on the resulting esophagus shape through quantitive representations of the peristaltic regimes. Our analysis also revealed the mechanics of the opening of the contraction area as a function of bolus flow resistance. Lastly, we concluded that peristaltic driven flow displays three modes of peristaltic geometries, but all physiologically relevant flows fall into two peristaltic regimes characterized by a tight contraction.

Post-lung transplantation abdominopelvic complications: the role of multimodal imaging

Lung transplantation (LT) is an established method for treating end-stage lung disease. Although most of the post-lung transplant imaging surveillance is focused on chronic lung allograft rejection, abdominopelvic complications have been reported in 7-62% of patients. The reported wide range of post-LT abdominopelvic complications is thought to be secondary to lack of current standardized definitions. These complications encompass a heterogeneous group of disorders including upper and lower gastrointestinal (GI) disorders, inflammatory conditions of solid organs, lymphoproliferative disorders, and neoplasms; each with varying pathophysiology, timing, severity, and treatment. Clinical manifestations of these complications may overlap or be masked by immunosuppression; therefore, imaging plays a paramount role in the early management and treatment.

Vocal cord dysfunction concurrent with a nutcracker esophagus and the role of gastroesophageal reflux disease

BACKGROUND

Psychological disorders were originally thought to be the sole cause of vocal cord dysfunction (VCD). Subsequently, other organic diseases, including structural laryngeal abnormalities, have also been reported to be associated with VCD.

OBJECTIVES

To describe the first patient with VCD concurrent with a nutcracker esophagus and to establish the association between VCD and gastroesophageal reflux disease (GERD) by using the Bernstein test.

METHODS

Symptom assessments, neuropsychiatric evaluations, fiberoptic laryngoscopy, pulmonary function tests, allergic skin prick tests, radiographs of the chest and sinuses, esophageal manometry (including 24-hour ambulatory esophageal pH monitoring), and the Bernstein test were performed.

RESULTS

A 36-year-old woman had dyspnea, hoarseness, chest pain, and wheezes without relief for a decade. Neuropsychiatric evaluations disclosed mild depression. Fiberoptic laryngoscopy showed posterior laryngitis and paradoxical vocal cord adduction with audible inspiratory stridor. Pulmonary function tests showed attenuation of the inspiratory limb with notching in both flow-volume loops and a mid-vital capacity expiratory to inspiratory flow ratio of 4. All the symptoms except chest pain were improved dramatically by speech therapy and empirical treatment for GERD. Esophageal manometry revealed a nutcracker esophagus; 24-hour ambulatory esophageal pH monitoring demonstrated multiple short reflux episodes. The Bernstein test was conducted, and all the manifestations were reproduced with 0.1 N hydrochloric acid but not with isotonic sodium chloride infusion.

CONCLUSIONS

This is the first human case report confirming that GERD can trigger an acute attack of VCD and may induce chest pain as a nutcracker esophagus in patients with VCD. It strengthens this association and expands our knowledge of diverse manifestations of this clinical entity.

The role of esophagogastroduodenoscopy in the diagnosis and management of upper gastrointestinal disorders

Esophagogastroduodenoscopy has revolutionized the clinical management of upper gastrointestinal diseases. Millions of EGDs are performed annually in the United States for many indications, such as gastrointestinal bleeding, abdominal pain, dysphagia, or surveillance of premalignant lesions. Esophagogastroduodenoscopy is very safe, with a low risk of serious complications such as perforation, cardiopulmonary arrest, or aspiration pneumonia. It is a highly sensitive and specific diagnostic test, especially when combined with endoscopic biopsy. Esophagogastroduodenoscopy is increasingly being used therapeutically to avoid surgery. New endoscopic technology such as endosonography, endoscopic sewing, and the endoscopic videocapsule will undoubtedly extend the frontiers and increase the indications for endoscopy.