Hypertrophy of the Muscularis Propria of the Lower Esophageal Sphincter and the Body lf the Esophagus in Patients With Primary Motility Disorders of the Esophagus

Mittal, Ravinder K.,Kassab, Ghassan,Puckett, James L.,Liu, Jianmin 대한소화관운동학회 2003 Journal of Neurogastroenterology and Motility (JNM Vol.9 No.3

Objectives: Patients with diffuse esophageal spasm (DES) and nutcracker esophagus/high amplitude esophageal contraction (HAEC) have a thicker esophageal muscularis propria than do healthy subjects. The goals of this study were to determine the esophageal muscle cross-sectional area (MCSA), a measure of muscle mass, in patients with achalasia of the esophagus; and to compare it with that in patients with DES, patients with HAEC, and normal subjects. Methods: Using a high-frequency ultrasound probe catheter, concurrent manometry and ultrasound images of the esophagus were recorded in four subject groups: normal volunteers, patients with HAEC, patients with DES, and patients with achalasia of the esophagus. Recordings were obtained from the lower esophageal sphincter (LES) and multiple sites in the esophagus 2, 4, 6, 8, and 10 cm above the LES. Results: The LES and esophageal muscle thickness as well as esophageal MCSA were greater in all three patient groups than in the normal subject group. Muscle thickness and MCSA were observed to be greatest in patients with achalasia, which were greater than in patients with DES, which were greater than in those with HAEC, which in turn were greater than in normal subjects. Conclusions: We propose that an increase in the MCSA is an important feature of patients with primary motility disorders of the esophagus. The degree of increase in muscle mass may be an important determinant of the type and the severity of esophageal motor dysfunction. (Am J Gastroenterol 2003;98:17051712. 2003 by Am. Coll. of Gastroenterology)

Length Tension Function of Puborectalis Muscle: Implications for the Treatment of Fecal Incontinence and Pelvic Floor Disorders

( Ravinder K Mittal ),( Geoff Sheean ),( Bikram S Padda ),( Mahadevan R Rajasekaran ) 대한소화기기능성질환·운동학회 2014 Journal of Neurogastroenterology and Motility (JNM Vol.20 No.4

Background/Aims External anal sphincter (EAS) and puborectalis muscle (PRM) play important role in anal continence function. Based on length-tension measurement, we recently reported that the human EAS muscle operates at short sarcomere length under physiological conditions. Goal of our study was to determine if PRM also operates at the short sarcomere length. Methods Length-tension relationship of the PRM muscle was studied in vivo in 10 healthy nullipara women. Length was altered by vaginal distension using custom-designed probes of 5, 10, 15, 20, 25 and 30 mm diameters as well as by distending a polyethylene bag with different volumes of water. Probes were equipped with a reverse perfuse sleeve sensor to measure vaginal pressure (surrogate of PRM tension). PRM electromyogram (EMG) was recorded using wire electrodes. Three-dimensional ultrasound images were obtained to determine effect of vaginal distension on PRM length. Results Ultrasound images demonstrate distension volume dependent increase in PRM length. Rest and squeeze pressures of vaginal bag increased with the increase in bag volume. Similarly, the change in vaginal pressure, which represents the PRM contraction increased with the increase in the probe size. Increase in probe size was not associated with an increase in EMG activity (a marker of neural drive) of the PRM. Conclusions Probe size dependent increase in PRM contraction pressure, in the presence of constant EMG (neural input) proves that the human PRM operates at short sarcomere length. Surgically adjusting the PRM length may represent a novel strategy to improve treat anal continence and possibly other pelvic floor disorders.

Review : Longitudinal Muscle Dysfunction in Achalasia Esophagus and Its Relevance

( Ravinder K Mittal ),( Su Jin Hong ),( Valmik Bhargava ) 대한소화기기능성질환·운동학회(구 대한소화관운동학회) 2013 Journal of Neurogastroenterology and Motility (JNM Vol.19 No.2

Muscularis propria of the esophagus is organized into circular and longitudinal muscle layers. Goal of this review is to summarize the role of longitudinal muscle in physiology and pathophysiology of esophageal sensory and motor function. Simultaneous manometry and ultrasound imaging that measure circular and longitudinal muscle contraction respectively reveal that during peristalsis 2 layers of the esophagus contract in perfect synchrony. On the other hand, during transient relaxation of the lower esophageal sphincter (LES), longitudinal muscle contracts independently of circular muscle. Recent studies provide novel insights, i.e., longitudinal muscle contraction of the esophagus induces LES relaxation and possibly descending relaxation of the esophagus. In achalasia esophagus and other motility disorders there is discoordination between the 2 muscle layers. Longitudinal muscle contraction patterns are different in the recently described three types of achalasia identified by high resolution manometry. Robust contraction of the longitudinal muscle in type II achalasia causes pan-esophageal pressurization and is the mechanism of whatever little esophageal emptying that take place in the absence of peristalsis and impaired LES relaxation. It may be that preserved longitudinal muscle contraction is also the reason for superior outcome to medical/surgical therapy in type II achalasia esophagus. Prolonged contractions of longitudinal muscles of the esophagus is a possible mechanism of heartburn and “angina like” pain seen in esophageal motility disorders and possibly achalasia esophagus. Novel techniques to record longitudinal muscle contraction are on the horizon. Neuro-pharmacologic control of circular and longitudinal muscles is different, which provides an important opportunity for the development of novel pharmacological therapies to treat sensory and motor disorders of the esophagus.

New Trend in Clinical Methodologies of GI Motility : Relationship between Esophageal Muscle Thickness and Intraluminal Pressure in Patients with Esophageal Spasm

( Nonko Pehlivanov ),( Jian Min Liu ),( Ghassan S. Kassab ),( Cheryl Beaumont ),( Ravinder K. Mittal ) 대한소화기학회 2003 SIDDS Vol.7 No.-

Morphology of the Esophageal Hiatus: Is It Different in 3 Types of Hiatus Hernias?

( Dushyant Kumar ),( Ali Zifan ),( Gary Ghahremani ),( David C Kunkel ),( Santiago Horgan ),( Ravinder K Mittal ) 대한소화기 기능성질환·운동학회 2020 Journal of Neurogastroenterology and Motility (JNM Vol.26 No.1

Background/Aims The esophageal hiatus is formed by the right crus of the diaphragm in the majority of subjects. Contraction of the hiatus exerts a sphincter-like action on the lower esophageal sphincter (LES). The aim is to study the hiatal anatomy (using CT scan imaging) and function (using high-resolution manometry [HRM]), and esophageal motor function in patients with sliding and paraesophageal hiatal hernia. Methods We assessed normal subjects (n = 20), patients with sliding type 1 hernia (n = 18), paraesophageal type 2 hernia (n = 19), and mixed type 3 hernia (n = 19). Hernia diagnosis was confirmed on the upper gastrointestinal series. The hiatal morphology was constructed from the CT scan images. The LES pressure and relaxation, percent peristalsis, bolus pressure, and hiatal squeeze pressure were assessed by HRM. Results The CT images revealed that the esophageal hiatus is formed by the right crus of the diaphragm in all normal subjects and 86% of hernia patients. The hiatus is elliptical in shape with a surface area of 1037 mm² in normal subjects. The hiatal dimensions were larger in patients compared to normal subjects. The HRM revealed impaired LES relaxation and higher bolus pressure in patients with paraesophageal compared to the sliding hernia. The hiatal pinch on HRM was recognized in significantly higher number of patients with sliding as compared to paraesophageal hernia. Conclusions Using a novel approach, we provide details of the esophageal hiatus in patients with various kinds of hiatal hernia. Impaired LES relaxation in paraesophageal hernia may play a role in its pathophysiology and genesis of symptoms.

Esophageal Submucosal Injection of Capsaicin but Not Acid Induces Symptoms in Normal Subjects

( Robert H Lee ),( Hariprasad Korsapati ),( Vikas Bhalla ),( Nissi Varki ),( Ravinder K Mittal ) 대한소화기기능성질환·운동학회(구 대한소화관운동학회) 2016 Journal of Neurogastroenterology and Motility (JNM Vol.22 No.3

Background/Aims Transient receptor potential vanilloid-1 (TRPV1) is a candidate for mediating acid-induced symptoms in the esophagus. We conducted studies to determine if the presence of acid in the mucosa/submucosa and direct activation of TRPV1 by capsaicin elicited symptoms in normal healthy subjects. We also studied the presence of TRPV1 receptors in the esophagus. Methods Unsedated endoscopy was performed on healthy subjects with no symptoms. Using a sclerotherapy needle, normal saline (pH 2.0- 7.5) was injected into the mucosa/submucosa, 5 cm above the Z line. In a separate group of healthy subjects, injection of capsaicin and vehicle was also studied. Quality of symptoms was reported using the McGill Pain Questionnaire, and symptom intensity using the visual analogue scale (VAS). Immunohistochemistry was performed on 8 surgical esophagus specimens using TRPV1 antibody. Results Acid injection either did not elicit or elicited mild symptoms in subjects at all pH solutions. Capsaicin but not the vehicle elicited severe heartburn/chest pain in all subjects. Mean VAS for capsaicin was 91 ± 3 and symptoms lasted for 25 ± 1 minutes. Immunohistochemistry revealed a linear TRPV1 staining pattern between the epithelial layer and the submucosa that extended into the papillae. Eighty-five percent of papillae stained positive for TRPV1 with a mean 1.1 positive papillae per high-powered field. Conclusions The mechanism of acid-induced heartburn and chest pain is not the simple interaction of hydrogen ions with afferents located in the esophageal mucosa and submucosa. TRPV1 receptors are present in the lamina propria and their activation induces heartburn and chest pain. (J Neurogastroenterol Motil 2016;22:436-443)