Document Detail

Effect of straining on the lower esophageal sphincter: identification of the "straining-esophageal reflex" and its role in gastroesophageal competence mechanism.
MedLine Citation:
PMID:  15371160     Owner:  NLM     Status:  MEDLINE    
The lower esophagus is intra-abdominal and exposed to intra-abdominal pressure (IAP) variations that may lead to gastroesophageal reflux (GER). We investigated the hypothesis that the lower esophageal sphincter (LES) undergoes phasic contraction on IAP increase, with a resulting inhibition of the stress GER. The study comprised 17 subjects (age 42.3 +/- 8.7 SD yr, 10 men, 7 women) who were scheduled for surgical repair of abdominal hernia. The patients had no swallowing problems. The electromyographic (EMG) activity of the LES and pressure within the LES were recorded at rest and during increased IAP (coughing, straining). The recording was repeated after LES anesthetization or saline infiltration. The LES EMG at rest showed regular slow waves (SWs), superimposed on or followed by random action potentials (APs). Coughing or straining induced increase of the SWs parameters and also of the APs; although the increase with straining was less than with coughing, the difference was insignificant. Coughing or straining increased the LES pressure significantly (p < .05, p < .05, respectively). Ten minutes after LES anesthetization, coughing or straining did not produce significant LES EMG or pressure changes, while saline infiltration of LES caused LES response similar to preinjection. Thus, coughing and straining effected an increase of the LES EMG activity and pressure, an action presumably mediated through a reflex that we call the "straining-esophageal reflex." This reflex seems to be evoked during increased intra-abdominal pressure and to effect LES contraction, thus, sharing with other factors in prevention of gastroesophageal reflux.
Ahmed Shafik; Olfat El-Sibai; Ali A Shafik; Randa Mostafa; Ismail Shafik
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Journal of investigative surgery : the official journal of the Academy of Surgical Research     Volume:  17     ISSN:  0894-1939     ISO Abbreviation:  J Invest Surg     Publication Date:    2004 Jul-Aug
Date Detail:
Created Date:  2004-09-16     Completed Date:  2005-01-26     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  8809255     Medline TA:  J Invest Surg     Country:  United States    
Other Details:
Languages:  eng     Pagination:  191-6     Citation Subset:  IM    
Department of Surgery and Experimental Research, Faculty of Medicine, Cairo University, Egypt.
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MeSH Terms
Action Potentials
Anesthetics, Local
Esophageal Sphincter, Lower / physiopathology*
Gastroesophageal Reflux / diagnosis,  physiopathology*
Hernia, Abdominal / diagnosis,  physiopathology
Middle Aged
Reflex / physiology*
Reg. No./Substance:
0/Anesthetics, Local; 137-58-6/Lidocaine

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