C. P. Gyawali
Washington University in St. Louis
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Publication
Featured researches published by C. P. Gyawali.
Gastroenterology | 2016
Qasim Aziz; Ronnie Fass; C. P. Gyawali; Hiroto Miwa; John E. Pandolfino; Frank Zerbib
Functional esophageal disorders consist of a disease category that present with esophageal symptoms (heartburn, chest pain, dysphagia, globus) not explained by mechanical obstruction (stricture, tumor, eosinophilic esophagitis), major motor disorders (achalasia, EGJ outflow obstruction, absent contractility, distal esophageal spasm, jackhammer esophagus), or gastroesophageal reflux disease (GERD). While mechanisms responsible are unclear, it is theorized that visceral hypersensitivity and hypervigilance play an important role in symptom generation, in the context of normal or borderline function. Treatments directed at improving borderline motor dysfunction or reducing reflux burden to sub-normal levels have limited success in symptom improvement. In contrast, strategies focused on modulating peripheral triggering and central perception are mechanistically viable and clinically meaningful. However, outcome data from these treatment options are limited. Future research needs to focus on understanding mechanisms underlying visceral hypersensitivity and hypervigilance so that appropriate targets and therapies can be developed.
Neurogastroenterology and Motility | 2017
Sabine Roman; C. P. Gyawali; Edoardo Savarino; Rena Yadlapati; Frank Zerbib; Justin C. Wu; Marcelo F. Vela; Radu Tutuian; Roger P. Tatum; Daniel Sifrim; Jutta Keller; M. Fox; John E. Pandolfino; A. J. Bredenoord
An international group of experts evaluated and revised recommendations for ambulatory reflux monitoring for the diagnosis of gastro‐esophageal reflux disease (GERD).
Neurogastroenterology and Motility | 2011
C. P. Gyawali; Vladimir M. Kushnir
Background High‐resolution manometry (HRM) can identify obstructive motor features at the esophagogastric junction and abnormalities in esophageal bolus transit. We sought to determine if HRM patterns can differentiate functional from organic mechanical lower esophageal sphincter (LES) obstruction.
Neurogastroenterology and Motility | 2012
C. P. Gyawali
Esophageal manometry assesses pressure phenomena, peristalsis and bolus transit in the esophagus. Older conventional manometry techniques recorded esophageal peristalsis using 5–8 widely spaced water perfused channels in an esophageal motility catheter. Two significant advances in the 1990s, an increase in pressure sensors along the catheter, and use of spatiotemporal plots for data display, led to what is now recognized as high-resolution manometry (HRM). HRM was the concept and innovation of a remarkable esophagologist, researcher and educator, the late Ray Eugene Clouse, MD. HRM has its roots in conventional perfused manometry. Clouse decided that the esophagus was holding secrets between the widely spaced recording points of his conventional manometry catheter. He tested his hypothesis by continuing the pull through maneuver 1 cm at a time till the last recording channels reached the upper esophageal sphincter (UES), obtaining at least one wet swallow at each station. When the swallows were aligned, the jumble of tracings he obtained could not be easily interpreted. It was time for another Clouse innovation – the spatiotemporal contour plot. Clouse, along with Annamaria Staiano, MD, digitized the tracings using a hand held digitizer, and assigned colors to amplitude levels. Software programs provided best fit data points in between the recording sites. The final result was a smooth topographic map of the esophageal peristaltic wave. Since amplitudes were color coded, topographic contours could be viewed from above as a spatiotemporal plot (Fig. 1). We now recognize these plots as a characteristic of HRM. Next, Clouse worked on streamlining the process of data acquisition. Collaboration with Dentsleeve resulted in a 0.4 cm extruded, 21 lumen silicon water perfused catheter, and complementary software was developed by Medical Measurement Systems (MMS, Enschede, Holland). The manometry procedure remained cumbersome, the pull through maneuver had not been eliminated, and only 75–80% of the esophagus could be interrogated at a time. Nevertheless, there were significant advances in our understanding of esophageal peristalsis, which was now shown to consist of a chain of contracting segments
Neurogastroenterology and Motility | 2012
Vladimir M. Kushnir; Gregory S. Sayuk; C. P. Gyawali
Background Multiple rapid swallows (MRS) inhibit esophageal peristalsis and lower esophageal sphincter (LES) tone; a rebound excitatory response then results in an exaggerated peristaltic sequence. Multiple rapid swallows responses are dependent on intact inhibitory and excitatory neural function and could vary by subtype in achalasia spectrum disorders.
Neurogastroenterology and Motility | 2014
J. Vu; Vladimir M. Kushnir; Benjamin Cassell; C. P. Gyawali; Gregory S. Sayuk
Functional gastrointestinal disorders (FGID) patients report poor health‐related quality of life (HRQOL) and experience high rates of psychiatric and extraintestinal functional disorder (EIFD) comorbidity. The independent influence of these comorbidities on HRQOL and symptom burden remains unknown. We sought to determine whether FGID with mood or EIFD comorbidity have poorer HRQOL and greater GI symptom burdens; to determine the influence of comorbidities on HRQOL in FGID independent of bowel symptoms.
Neurogastroenterology and Motility | 2011
R. F. Porter; C. P. Gyawali
Background Botulinum toxin injection into the lower esophageal sphincter (LES) treats dysphagia syndromes with preserved peristalsis and incomplete LES relaxation (LESR). We evaluated clinical and esophageal motor characteristics predicting response, and compared duration of efficacy to similarly treated achalasia patients.
Neurogastroenterology and Motility | 2012
R. F. Porter; N. Kumar; Jesse Drapekin; C. P. Gyawali
Background Esophageal peristalsis consists of a chain of contracting striated and smooth muscle segments on high resolution manometry (HRM). We compared smooth muscle contraction segments in symptomatic subjects with reflux disease to healthy controls.
Neurogastroenterology and Motility | 2016
C. P. Gyawali
Achalasia is defined by esophageal outflow obstruction from abnormal relaxation of the lower esophageal sphincter (LES) due to deranged inhibitory control. In genetically predisposed individuals, an autoimmune response to an unknown inciting agent, perhaps a viral infection, results in inflammation and sometimes loss of myenteric plexus ganglia and neurons. The net result is varying degrees of inhibitory dysfunction, at times associated with imbalanced and exaggerated excitatory function, with manometrically distinct achalasia phenotypes on high resolution manometry. There is new evidence in the current issue of this Journal suggesting that type 1 achalasia, with esophageal outflow obstruction and absent esophageal body contractility, is an end‐stage phenotype from progression of type 2 achalasia, which is characterized by panesophageal compartmentalization of pressure in the untreated patient, and partial recovery of peristalsis after treatment. Esophageal outflow obstruction with premature peristalsis (type 3 achalasia) or intact peristalsis may result from plexitis in the myenteric plexus but can also be encountered in other settings including chronic opioid medication usage and structural processes at the esophagogastric junction and distally. In most instances when idiopathic esophageal outflow obstruction is confirmed, some form of pharmacologic manipulation or disruption of the LES provides durable symptom relief. This review will focus on current understanding of pathophysiology, diagnosis, and principles of management of achalasia in light of emerging literature on the topic.
Neurogastroenterology and Motility | 2016
D. Wang; Amit Patel; M. D. Mello; A. Shriver; C. P. Gyawali
Esophagogastric junction contractile integral (EGJ‐CI) assesses EGJ barrier function on esophageal high resolution manometry (HRM). We assessed EGJ‐CI values in achalasia and gastroesophageal reflux disease (GERD) to determine if postoperative EGJ‐CI changes reflected surgical intervention.