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Query: UMLS:C0154059 (Esophagus)
 2,950 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

There is substantial experimental and anatomic evidence suggesting that the human lower esophageal sphincter is not a muscular ring but has its correlate in the arrangement of the so-called muscular clasps and oblique sling fibers at the gastroesophageal junction. We assessed the mode of action of these distinct muscle units in a mechanical model. The arrangement of the clasp and sling fibers at the gastroesophageal junction was simulated with two elastic bands placed perpendicularly around the gastroesophageal junction of four pig specimens. Rapid pullback manometry with four radially oriented pressure transducers was performed in each specimen. The opening pressure was determined, and three-dimensional pressure images were constructed based on the manometric readings. The elastic bands established a competent high-pressure zone at the level of the gastroesophageal junction. The three-dimensional pressure images matched those usually observed in vivo in normal human volunteers. The vector volume of the high-pressure zone correlated with the opening pressure while individual resting pressure values and length of the high-pressure zone were not sufficient to estimate the competence of the gastroesophageal junction in the model. This model supports the contention that the combined action of the clasp and sling fibers establishes the manometric lower esophageal sphincter in humans.
Dis Esophagus 1997 Apr
PMID:Gastroesophageal sphincter: a model. 917 79


Dis Esophagus 1997 Apr
PMID:Comparison of anterior, posterior and total fundoplication using a viscera model. 917 80

The Angelchik prosthesis appears to be effective in preventing gastroesophageal reflux, although its precise mechanism of action remains controversial. In a unique in vitro model, 10 freshly harvested canine esophagogastric specimens were tested for their ability to remain competent against challenges of intragastric pressure under controlled conditions of intra-abdominal pressure, longitudinal esophageal tension, lower esophageal sphincter pressure and overall length and circumference of the cardia (measure of gastric dilatation). Competency of the specimen was assessed by stepwise variation in the overall length of the sphincter, while keeping constant intraabdominal pressure (20 cm H2O), intragastric pressure (20 cm H2O), esophageal tension (physiologic), lower esophageal sphincter pressure (15 cm H2O) and degree of gastric dilatation (3 cm). With each specimen serving as its own control, the effect produced by the application of an Angelchik prosthesis was evaluated. Results consistently demonstrated that at any lower esophageal sphincter length the percent of competency was increased when the prosthesis was applied (P < 0.01). The findings indicate that the Angelchik prosthesis controls reflux by preventing unfolding of the lower esophageal sphincter when challenged by intragastric pressure.
Dis Esophagus 1997 Apr
PMID:Mechanical effect of the Angelchik prosthesis on the competency of the gastric cardia: pathophysiologic implications and surgical perspectives. 917 81


Dis Esophagus 1997 Apr
PMID:Lower esophageal sphincter or upper gastric sphincter? 917 82

Absence of the peristaltic contractions in the esophageal body and the failure of the lower esophageal sphincter (LES) post-deglutitive relaxation are the major motor disturbances in patients with achalasia. These alterations are usually evidenced by means of stationary esophageal manometry, which is able to record changes over a brief period. The aim of this work has been to study the circadian esophageal motor activity of the esophageal body in patients with achalasia, using a non-perfused ambulatory manometry system. Ten patients with untreated esophageal achalasia (dilatation < or = 5 cm) had a 24-hour ambulatory esophageal manometry. The portable recording system consisted of a computerized data logger and a probe with four microtransducers 5 cm apart, the distal one being positioned 5 cm above the LES. A microtransducer, positioned 1 cm below the upper esophageal sphincter, recorded the swallow activity. Contractions frequency (n/min), mean amplitude (mmHg), mean duration of contraction (sec), percentage of contraction > 7 sec, percentage of multipeaked, repetitive and isolated contractions, and percentage of peristaltic and simultaneous sequences were evaluated and analysed during the following periods: meal-time (MT); upright (UP); supine night-time (NT). On the basis of the relationship with swallows the contraction events were classified as post-deglutitive or spontaneous. The data out of a group of 65 normal subjects were used as control. Student's t-test and Wilcoxon's rank-sum test were used for statistical analysis. Peristaltic sequences were detected in all patients, 27.8 +/- 12.6% of the total, and the 19.5 +/- 11.06% of these were complete. Moreover primary peristaltic sequences were present in 33.1 +/- 23.4% of all peristaltic sequences. In contrast to current trends, our results show surprisingly the presence of peristaltic activity in patients with achalasia (27.9% MT; 26.9% UP; 28.1% NT). We believe these results are related both to the use of an ambulatory system, which allows 24-hour monitoring and to the use of microtransducers, which are able to detect motor events with great accuracy. These motor events are usually not detectable by stationary perfused systems.
Dis Esophagus 1997 Apr
PMID:24-hour esophageal ambulatory manometry in patients with achalasia of the esophagus. 917 83

To evaluate the biological significance of esophageal squamous cell carcinoma that is associated with contiguous intraepithelial carcinoma, we analyzed 95 patients with operated esophageal carcinoma. Of these 95 patients, eight had in situ carcinoma. Among 87 cases in which the tumo had invaded more deeply than the lamina propria, there were 42 cases (48.3%) of contiguous intraepithelial carcinoma associated with the main tumor. The biological characteristics (proliferative activity of cells, as revealed by immunostaining with the Ki-67 monoclonal antibody) of 45 tumors without contiguous intraepithelial carcinoma (group A) were compared with those of 42 tumors with contiguous intraepithelial carcinoma (group B). The more advanced was the main lesion, the lower was the incidence of contiguous intraepithelial carcinoma. The mean Ki-67 score of the main tumors in group A was 51.6% and that of the main tumors in group B was 45.9%. The mean Ki-67 score of the main tumors in group B was very similar to that of the contiguous intraepithelial carcinomas that were associated with the main tumors (44.4%, P = 0.682). Furthermore, the mean Ki-67 score of contiguous intraepithelial carcinomas associated with main tumors was very similar to that of carcinomas in situ (41.2%, P = 0.529). From our results, it is suggested that tumors with high proliferative activity may be assumed to grow rapidly and, as a result, the region of intraepithelial carcinoma may develop into an invasive tumor. By contrast, tumors with low proliferative activity may grow slowly and, in such cases, the carcinoma may remain in the epithelium around the invasive tumor.
Dis Esophagus 1997 Apr
PMID:Biological characteristics of esophageal squamous cell carcinoma associated with contiguous intraepithelial carcinoma. 917 84

We retrospectively analyzed the clinicopathologic findings, treatment and outcome of 22 patients with synchronous or metachronous carcinomas of the esophagus and head and neck. The patients with metachronous cancers in whom esophageal cancer occurred first had either an early-stage esophageal carcinoma or only one positive lymph node. Similarly, five of 10 patients with metachronous cancers in whom head and neck cancer was the first tumor had early-stage esophageal carcinomas. The esophageal lesion was mucosal carcinoma in four patients which was found by endoscopy with the iodine dye method. In the patients with synchronous cancers either one or both carcinomas were advanced, and the prognosis of these patients was poor compared with those of patients with metachronous carcinomas. Accordingly, endoscopic surveillance for early detection of metachronous lesions are encouraged.
Dis Esophagus 1997 Apr
PMID:Synchronous and metachronous carcinomas of the esophagus and head and neck. 917 85


Dis Esophagus 1997 Apr
PMID:A patient with seven primary tumors of the upper aerodigestive tract: the process of field cancerization versus distant monoclonal expansion. 917 87


Dis Esophagus 1997 Apr
PMID:Clonality of esophageal carcinomas: genetic and epigenetic events leading to loss of genomic stability. 917 86

Prior irradiation to a site is a relative and often absolute contraindication to further irradiation because the tolerance dose of normal tissues is usually exceeded and therefore the risk of serious long-term side-effects is high. This case report describes radical salvage chemoradiation for an esophageal carcinoma in a patient who had prior high-dose neck and chest wall irradiation for the management of a breast cancer 19 years previously.
Dis Esophagus 1997 Apr
PMID:Carcinoma of the esophagus treated with radical chemoradiation 19 years after irradiation for recurrent breast cancer. 917 88


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