Biomedical subjects

Steven R DeMeester

Publications and source records attributed to Steven R DeMeester.

27 records · Page 2Linked to original sources

PubMed2003

Barrett's esophagus can and does regress after antireflux surgery: a study of prevalence and predictive features.

BACKGROUND: To investigate the factors leading to histologic regression of metaplastic and dysplastic Barrett's esophagus (BE). STUDY DESIGN: The study sample consisted of 91 consecutive patients with symptomatic Barrett's esophagus. Pre- and posttreatment endoscopic biopsies from 77 Barrett's patients treated surgically and 14 treated with proton pump inhibitors (PPI) were reviewed. An expert pathologist confirmed the presence of intestinal metaplasia (IM) with or without dysplasia. Posttreatment histology was classified as having regressed if two consecutive biopsies taken more than 6 months apart plus all subsequent biopsies showed loss of IM or loss of dysplasia. Clinical factors associated with regression were studied by multivariate analysis, as was the time course of its occurrence. RESULTS: Histopathologic regression occurred in 28 of 77 patients (36.4%) after antireflux surgery and in 1 of 14 patients (7.1%) treated with PPIs alone (p < 0.03). After surgery, regression from low-grade dysplastic to nondysplastic BE occurred in 17 of 25 patients (68%) and from IM to no IM in 11 of 52 (21.2%). Both types of regression were significantly more common in short (< 3 cm) than long (> 3 cm) segment Barrett's esophagus; 19 of 33 (58%) and 9 of 44 (20%) patients, respectively (p = 0.0016). Eight patients progressed, five from IM alone to low-grade dysplasia and three from low- to high-grade dysplasia. All those who progressed had long segment BE. On multivariate analysis, presence of short segment Barrett's and type of treatment were significantly associated with regression; age, gender, surgical procedure, and preoperative lower esophageal sphincter and pH characteristics were not. The median time of biopsy-proved regression was 18.5 months after surgery, with 95% occurring within 5 years. CONCLUSIONS: This study refutes the widely held assumption that once established, Barrett's esophagus does not change. More than one-third of patients with visible segments of Barrett's esophagus undergo histologic regression after antireflux surgery. Regression is dependent on the length of the columnar-lined esophagus and time of followup after antireflux surgery.

Barrett Esophagus↗

PubMed2003

Increasing esophageal length: a comparison of laparoscopic versus transthoracic esophageal mobilization with and without vagal trunk division in pigs.

BACKGROUND: New laparoscopic techniques allow both mediastinal mobilization and performance of a Collis gastroplasty when necessary, and the utility of a transthoracic approach is questioned. The aim of this study was to compare the increase in esophageal length achievable with laparoscopic and transthoracic esophageal mobilization in pigs, and to assess the impact of vagal trunk division on esophageal length. STUDY DESIGN: Baseline esophageal length was obtained in 20 farm pigs by measuring the distance between a stitch placed in the esophagus to a K-wire placed in a vertebral body. Subsequently, laparoscopic and then transthoracic mediastinal mobilization of the esophagus were performed in 15 pigs and the length gain after each procedure recorded. In 7 of 15 animals, the vagal nerve trunks were divided after esophageal mobilization and the increase in esophageal length measured. In five animals, vagal trunk division was performed without earlier esophageal mobilization. RESULTS: Esophageal length gain after laparoscopic mobilization (median 4 mm) was significantly less than that after transthoracic mobilization (median 12 mm, p < 0.0001). Unilateral vagal nerve transection resulted in a median 2.5 mm of esophageal length gain compared with a median of 6.25 mm with division of both vagal trunks. Maximal esophageal lengthening (median 18.5 mm) occurred with a combination of esophageal mobilization and bilateral vagal trunk division. CONCLUSIONS: Esophageal length gain after transthoracic mobilization in normal pigs is significant, and would likely be even greater in patients with gastroesophageal reflux disease with concomitant mediastinal inflammation. Transthoracic mobilization alone likely will allow successful reduction of the gastroesophageal junction below the diaphragm in many patients who might otherwise require a Collis gastroplasty.

Animals↗

PubMed2003

Vascular endothelial growth factor and basic fibroblast growth factor expression in esophageal adenocarcinoma and Barrett esophagus.

OBJECTIVE: This study was undertaken to investigate the role of the angiogenic factors vascular endothelial growth factor and basic fibroblast growth factor in the development and progression of Barrett esophagus and adenocarcinomas of the esophagus and gastroesophageal junction. METHODS: Vascular endothelial growth factor and basic fibroblast growth factor messenger RNA expression levels, relative to the control gene encoding beta-actin, were measured by using a quantitative reverse transcription-polymerase chain reaction method (ABI 7700 Sequence Detector system) in specimens of Barrett intestinal metaplasia (n = 16), dysplasia (n = 11), adenocarcinoma (n = l 5), and matching normal squamous esophageal tissues (n = 35). Vascular endothelial growth factor and basic fibroblast growth factor protein expression and CD31(+) microvessel density were assessed by means of immunohistochemistry in 25 tissue sections that included representative areas for each of these Barrett stages. RESULTS: Expression levels were significantly increased in adenocarcinoma compared with in either normal squamous mucosa (P <.0001 for both genes) or intestinal metaplasia (vascular endothelial growth factor, P =.002; basic fibroblast growth factor, P <.0001). Vascular endothelial growth factor levels were also significantly higher in cancer tissues compared with dysplasia tissues (P =.024, Mann-Whitney U test). Basic fibroblast growth factor expression was also significantly increased in Barrett dysplastic mucosa compared with in intestinal metaplasia or normal esophageal mucosa. Microvessel density was generally higher in adenocarcinoma compared with in preneoplastic Barrett tissues. The pattern of vascular endothelial growth factor and basic fibroblast growth factor protein expression was similar to the messenger RNA expression pattern, with the exception that mucin-containing goblet cells stained intensely for vascular endothelial growth factor and only weak vascular endothelial growth factor staining was present in some adenocarcinomas. CONCLUSIONS: Vascular endothelial growth factor and basic fibroblast growth factor messenger RNA expression levels are significantly upregulated in esophageal and gastroesophageal junction adenocarcinomas, suggesting a role for these angiogenic factors in the development of these cancers. Vascular endothelial growth factor and basic fibroblast growth factor messenger RNA expression levels are also increased in some Barrett esophagus tissues, with this increase occurring at an earlier stage for basic fibroblast growth factor than for vascular endothelial growth factor. Basic fibroblast growth factor protein expression pattern is similar to the messenger RNA expression pattern, but unlike the messenger RNA findings, vascular endothelial growth factor protein expression is strongest in goblet cells.

Adenocarcinoma↗

PubMed2002

Excellent quality of life after Nissen fundoplication depends on successful elimination of reflux symptoms and not the invasiveness of the surgical approach.

BACKGROUND: Quality of life, poor in patients with reflux disease, improves significantly after an antireflux operation. The aim of this study was to determine the relative importance of the operative approach used for a fundoplication, as well as the successful elimination of reflux symptoms on long-term quality of life in patients with gastroesophageal reflux disease. METHODS: A questionnaire, including the medical outcome study short-form health survey (SF-36), was completed by 105 patients who had undergone either a laparoscopic Nissen fundoplication (n = 72) or a transthoracic Nissen fundoplication (n = 33); median follow-up was 25 and 31 months, respectively. Patients were classified as completely or incompletely relieved of reflux symptoms based on the frequency of reflux symptoms and the use of acid-suppression medication. RESULTS: Patients selected for transthoracic Nissen fundoplication had significantly worse preoperative gastroesophageal reflux disease based on the presence of a large hiatal hernia, Barrett's esophagus, or stricture. Long-term quality of life was similar for the two approaches, but was significantly decreased in patients with recurrent reflux symptoms. Compared with laparoscopic Nissen fundoplication patients, transthoracic Nissen fundoplication patients were less likely to use acid-suppression medication and tended to be more satisfied with their operation. CONCLUSIONS: Long-term quality of life was independent of the invasiveness of the procedure, but significantly dependent on successful elimination of reflux symptoms and the necessity for acid suppression medication. Patients who underwent a transthoracic Nissen fundoplication, despite having more advanced disease preoperatively, tended to have less reflux symptoms and less long-term acid-suppression medication usage after their procedure. These findings support the continued use of a transthoracic antireflux procedure in patients with advanced gastroesophageal reflux disease.

Female↗

PubMed2002

Vagal-sparing esophagectomy: a more physiologic alternative.

OBJECTIVE: To evaluate the function of the vagal nerves and the gastric reservoir after vagal-sparing esophagectomy. SUMMARY BACKGROUND DATA: Esophagectomy as currently performed includes division of the vagal nerves and surgical alteration of the stomach, with attendant postoperative dumping, diarrhea, reduced meal capacity, and weight loss. Vagal-sparing esophagectomy has been introduced as a technique for removal of the esophagus while preserving the vagal nerves and gastric reservoir. The procedure is touted as having a low morbidity and is applicable to patients with end-stage benign or early malignant disease. METHODS: A random sample of 15 patients at a median of 20 months after a vagal-sparing esophagectomy was compared to 23 asymptomatic normal subjects; 10 randomly selected patients, 29 months after esophagogastrectomy with colon interposition; and 10 randomly selected patients, 47 months after standard esophagectomy with gastric pull-up. Gastric mucosal acidification was tested with Congo red staining. Vagal secretory function was measured by gastric acid output and pancreatic polypeptide response to sham feeding. Vagal motor function was assessed by a technetium gastric emptying scan and a questionnaire to evaluate dumping and diarrhea. Gastric reservoir function was evaluated by measuring meal capacity and postoperative changes in body mass index. RESULTS: Vagal-sparing esophagectomy preserved the function of the vagi, as evident by an increase in gastric acid output, a rise in serum pancreatic polypeptide following sham feeding, and preservation of normal postoperative gastric emptying in 70% of the patients. After vagal-sparing esophagectomy, patients were free of dumping and diarrhea and were analogous to normal subjects in meal capacity but had a slight reduction in the speed of eating. CONCLUSIONS: Vagal-sparing esophagectomy preserves gastric secretory, motor, and reservoir function. Postoperatively, patients have normal alimentation, bowel regulation, and no weight loss. It is an ideal procedure for patients with end-stage benign disease, Barrett's esophagus with high-grade dysplasia, or esophageal carcinoma limited to the lamina propria.

Adult↗

PubMed2002

Cytokeratin and DAS-1 immunostaining reveal similarities among cardiac mucosa, CIM, and Barrett's esophagus.

OBJECTIVE: The normal histology at the gastroesophageal junction, and in particular the nature of cardiac mucosa, remains in dispute. Likewise, the relationship of intestinal metaplasia at the gastroesophageal junction (CIM) to Barrett's and intestinal metaplasia of the stomach (GIM) is unclear. The aim of this study was to assess the immunostaining characteristics of cardiac mucosa and CIM and compare their staining pattern with that of other foregut mucosal types. We hypothesized that the immunostaining patterns of these foregut tissues would provide insight into the nature and etiology of cardiac mucosa and CIM. METHODS: Paraffin-embedded biopsy specimens from 50 patients with normal antral or fundic mucosa, cardiac mucosa, squamous mucosa, CIM, GIM, or Barrett's were obtained and immunostained with a panel of monoclonal antibodies including those for cytokeratins 7 and 20 (CK7/CK20) and DAS-1. RESULTS: Biopsies from normal gastric antral and fundic mucosa and squamous esophageal mucosa all showed a non-Barrett's type CK7/CK20 immunostaining pattern, whereas in 85% of patients, cardiac mucosa had a Barrett's type CK7/CK20 pattern (p < 0.001). A Barrett's type CK7/ CK20 staining pattern was seen in 100% of Barrett's, 78% of CIM, and 0% of GIM patients. Likewise, DAS-1 staining was similar in patients with CIM and Barrett's and significantly different in patients with GIM. CONCLUSIONS: Cytokeratin immunostaining of cardiac mucosa demonstrates significant differences from recognized normal gastric and esophageal mucosa but a similarity to Barrett's. This suggests that cardiac mucosa, like Barrett's, may be acquired. Likewise, immunostaining similarities between CIM and Barrett's biopsies point to the possibility of a reflux etiology for CIM in some patients.

Antibodies↗

PubMedDate not supplied

Preoperative lower esophageal sphincter pressure affects outcome of laparoscopic esophageal myotomy for achalasia.

The primary aim of this study was to identify factors that influence outcome of the surgical treatment of achalasia. A secondary aim was to compare outcomes after laparoscopic Heller myotomy and partial fundoplication using either a Dor or Toupet hemifundoplication. Between 1994 and 2002, a total of 78 patients underwent laparoscopic Heller myotomy and partial fundoplication. Preoperative investigations included esophageal manometry, a videoesophogram, and upper gastrointestinal endoscopy with biopsy. In 64 patients (35 males and 29 females), telephone contact was possible at a median 24 months (IQR 14-34). A Dor fundoplication was performed in 41 patients and a Toupet fundoplication in 23. Symptoms were assessed prior to surgery and at follow-up by an independent physician using standardized definitions to grade the severity of dysphagia, regurgitation, and chest pain. To assess outcome, dysphagia was categorized as persistent or resolved. Persistent was defined as dysphagia that occurred on a weekly or daily basis. Resolved was defined as dysphagia that occurred occasionally or not at all. At follow-up, patients were asked to make a personal evaluation of their outcome as to whether (1) their swallowing was improved by the procedure, (2) they were satisfied with the outcome, and (3) they would undergo surgery again under the same circumstances. There was a significant improvement in dysphagia and regurgitation scores after surgery (P<0.05). The scores for chest pain/heartburn remained unchanged. By physician assessment, dysphagia was resolved in 49 patients (77%) and persisted in 15 (33%). By patient assessment, 62 patients (97%) reported an improvement in the symptom of dysphagia, and 60 (94%) stated that they were satisfied with their improvement and would undergo surgery if they had to make the choice again. On univariate analysis, patients who had resolution of their dysphagia had a significantly higher resting lower esophageal sphincter (LES) pressure prior to myotomy (P=0.01) and on multivariate analysis only a high resting LES pressure prior to surgery was a predictor of resolution of dysphagia (P=0.015). Outcome comparison of patients with Dor and Toupet fundoplications showed no significant differences in physician assessment of postoperative symptom scores and resolution of dysphagia, patient assessment of outcome, or postoperative use of proton pump inhibitors. Ninety-four percent of patients are satisfied with their surgical myotomy for achalasia. By physician assessment dysphagia was resolved in 77% of patients. A high LES resting pressure before surgery predicted resolution of dysphagia.

Case-Control Studies↗

PubMedDate not supplied

Absence of gastroesophageal reflux disease in a majority of patients taking acid suppression medications after Nissen fundoplication.

Recent studies have shown that many patients use acid suppression medications after antireflux surgery. The aim of this study was to determine the frequency of gastroesophageal reflux disease in a cohort of surgically treated patients with postoperative symptoms and a high prevalence of acid suppression medication use. The study group consisted of 86 patients who had symptoms following Nissen fundoplication that were sufficient to merit evaluation with 24-hour distal esophageal pH monitoring. All completed a detailed symptom questionnaire. The mean postoperative follow-up period was 28 months (median 18 months). Thirty-seven patients (43%) were taking acid suppression medications after fundoplication. Only 23% (20 of 86) of all the patients and only 24% (9 of 37) of those taking acid suppression medications had abnormal esophageal acid exposure on the 24-hour pH study. Heartburn and regurgitation were the only symptoms that were significantly associated with an abnormal pH study. Endoscopic assessment of the fundoplication was the most significant factor associated with an abnormal pH study. Multivariable logistic regression analysis showed that patients with a disrupted, abnormally positioned fundoplication had a 52.6 times increased risk of abnormal esophageal acid exposure. Most patients who use acid suppression medications after antireflux surgery do not have abnormal esophageal acid exposure, and the use of these medications is thus often inappropriate. Because of the limited predictive power of symptoms, objective evidence of reflux disease should be obtained before prescribing acid suppression medication for patients who have undergone antireflux surgery.

Adult↗

PubMedDate not supplied

Physiologic mechanism and preoperative prediction of new-onset dysphagia after laparoscopic Nissen fundoplication.

The aim of this study was to determine whether preoperative physiologic factors can account for and be used to predict the development of postoperative dysphagia after laparoscopic Nissen fundoplication. One hundred sixty-three patients with gastroesophageal reflux disease underwent laparoscopic Nissen fundoplication with a median follow-up of 14 months (range 6 to 81 months). Preoperative dysphagia was present in 37% (60 of 163) and was relieved in all but five patients (92%). Female sex (P = 0.01) and the presence of a stricture (P = 0.02) were the only preoperative variables associated with the presence of preoperative dysphagia. Eight percent (8 of 103) of patients without preoperative dysphagia developed new-onset dysphagia, and of these 63% (5 of 8) had a normal lower esophageal sphincter (LES) (pressure >6 mm Hg; length >2 cm; abdominal length >1 cm). New-onset dysphagia was significantly more common in patients with a normal LES (22% [5 of 23] vs. 4% [3 of 80], P = 001). Patients with a normal LES had almost a sixfold increase in the risk of developing dysphagia as those with an abnormal LES (relative risk = 5.8). Only a preoperative normal LES (P = 0.02) or mean LES pressures (P = 0.04) were positively associated with the development of postoperative dysphagia. The severity of this dysphagia also showed a strong positive trend of increasing with mean preoperative LES pressures (P = 0.07). Finally, preoperative LES pressure significantly correlated with postoperative LES pressure (r = 0.48, P = 0.01) and with mean residual LES (nadir) pressure (r = 0.33, P = 0.05) offering insight into the mechanism of this dysphagia. In conclusion, preoperative LES parameters play a role in the development of dysphagia after laparoscopic Nissen fundoplication. Patients with a normal LES or high mean LES pressures are at increased risk for developing this complication and should be informed of this before laparoscopic Nissen fundoplication.

Adolescent↗