Biomedical subjects

R E Metreveli

Publications and source records attributed to R E Metreveli.

6 recordsLinked to original sources

PubMed2001

Resection and advancement of esophageal mucosa. A potential therapy for Barrett's esophagus.

BACKGROUND: Barrett's esophagus affects 5-10% of patients with gastroesophageal reflux disease (GERD) and is associated with a 40-fold increased risk of malignant transformation. Ablative therapies may lead to esophageal perforation or stricture formation if applied too liberally and residual glandular tissue and persistent cancer risk if utilized too sparingly. METHODS: Ten pigs underwent gastrotomy. Mucosa below the gastroesophageal (GE) junction was elevated by saline injections, circumferentially incised, and secured to an orogastric tube. By traction, the distal esophageal mucosa was inverted 10 cm proximally, then returned to the gastric lumen. In group A (n = 4), the mucosa (5 cm) was resected and the remnant was allowed to retract. In group B (n = 4), the mucosa was simply sutured back into its native position. In group C (n = 2), the mucosa (5 cm) was resected and the proximal segment was advanced and sutured to the gastric mucosa. At 6 weeks, or sooner if stricture developed, the animals were killed. Stricture formation was determined by ex vivo barium esophagram and gross assessment. The extent of fibrosis and epithelial healing were established histologically. RESULTS: Group A (mucosa resected) developed weight loss and anorexia within 4 weeks. Pathology revealed dense fibrotic stricture without reepithelialization. Group B (mucosa elevated/replaced) gained weight after the operation. Histology demonstrated mucosal healing without significant stricture or fibrosis. Group C (mucosa resected/advanced) also thrived postoperatively. Histology confirmed mucosal healing without evidence of retraction or dense stricture. CONCLUSIONS: Exposure of submucosal tissues causes esophageal stricture. Mucosal coverage minimizes submucosal fibrosis after injury. Mucosal resection and advancement allows healing without stricture and may have therapeutic potential for patients with Barrett's esophagus.

Anastomosis, Surgical↗

PubMed2001

Assessing laparoscopic manipulative skills.

BACKGROUND: The rapid emergence of laparoscopic surgery over the past decade has highlighted the need for teaching and assessing laparoscopic manipulative skills. Most analyses consist of a measurement of the time to complete a specified task and a subjective assessment by an observer. Objective assessments of accuracy in the performance of manipulative skills have been lacking. To quantify both speed and accuracy during laparoscopic skill performance, we have developed a skills assessment device (SAD) using a laparoscopic simulator platform and computer-based skills assessment software that precisely measures an instrument's movement during performance of timed laparoscopic manipulations. STUDY DESIGN: The SAD device measures the time necessary for an operator to complete a task, and the movements of the working end of laparoscopic instruments in three dimensions. Ten nonsurgeons performed 10 repetitions of a standardized laparoscopic manipulation. Data were captured in real time for both hands on a personal computer. Accuracy was determined by calculating the sum of all distances traveled. Duration was measured in seconds. Results are group means. RESULTS: The time necessary to perform defined laparoscopic manipulative skills improved dramatically during the first 3 repetitions and then stabilized. However, accuracy of manipulations continued to improve over all 10 repetitions. CONCLUSIONS: When untrained subjects are learning a laparoscopic manipulative task, measurement of time alone fails to account for the more protracted learning curve for accuracy. Therefore, devices and training programs that fail to consider objective assessments of accuracy may overestimate laparoscopic proficiency.

Clinical Competence↗

PubMed2000

Choice of insufflating gas influences on wound metastasis.

BACKGROUND: Laparoscopic cancer surgery is limited by concerns about port-site metastasis. No study has definitively addressed the behavior and growth of tumor cells after the use of specific laparoscopic gases. METHODS: In athymic rats, 10,000 colon cancer cells were injected intraperitoneally. The rats received either no pneumoperitoneum (pneumo) or pneumo (8 mmHg, 10 min) with carbon dioxide (CO(2)), nitrous oxide (N(2)O), or air. Two full-thickness incisions were made and closed in the upper abdomen of each animal. After 4 weeks, implants were identified grossly at necropsy, and invasiveness was scored according to penetration through the layers of the abdominal wall. RESULTS: Rats receiving pneumo had more frequent implants (p < 0.01) with deeper penetration (p < 0.001) than rats not receiving pneumo. Implants were more common after air pneumo than after CO(2) (p < 0.05) or N(2)O (p = 0.07) pneumo, and were less penetrating after CO(2) pneumo than after air (p < 0.001) or N(2)O (p < 0.05) pneumo. CONCLUSIONS: Carbon dioxide gas may limit the viability and invasiveness of free intraperitoneal tumor cells, as compared with air or N(2)O.

Abdominal Muscles↗

PubMed1999

Fundoplications resist reflux independent of in vivo anatomic relationships.

BACKGROUND: Antireflux operations restore lower esophageal sphincter (LES) function and hiatal anatomy; however, the relative contributions are unclear. METHODS: We measured the competency of fundoplications, exclusive of in vivo variables, in gastroesophageal explants from 8 cadavers. Using a multichannel manometer, esophageal, LES, and intragastric pressures were recorded during transpyloric distension. Data were compared at baseline, and after Nissen (360 degrees) and Toupet (270 degrees) fundoplications. RESULTS: Before fundoplication, stomachs refluxed immediately upon distension. Nissen fundoplications never refluxed before gastric rupture (46.8 +/- 15.0 mm Hg). LES pressure averaged 2.0 +/- 0.5 times intragastric pressure during distension. Toupet fundoplications refluxed at intragastric pressure <2 mm Hg, then became competent until gastric rupture (49.9 +/- 15.0 mm Hg). LES pressure averaged 2.4 +/- 1.0 times intragastric pressure during distension. CONCLUSIONS: Nissen and Toupet fundoplications increase LES pressure linearly at 2 to 2.5 times intragastric pressure, independent of in vivo variables. Toupet fundoplication lacks the competency of Nissen fundoplication at low intragastric pressures.

Aged↗

PubMed1999

Fundoplication provides effective and durable symptom relief in patients with Barrett's esophagus.

BACKGROUND: Columnar-lined esophagus with intestinal metaplasia (IM), also called Barrett's esophagus, is a manifestation of severe gastroesophageal reflux (GER) and may predict poor symptom relief and high failure rate after fundoplication. We compared symptom scores and reoperation rates in GER patients with and without Barrett's esophagus. METHODS: Between July 1992 and July 1997, 646 patients underwent fundoplication (626 laparoscopic). Of 150 endoscopic biopsies of suspected columnar-lined esophagus, 80 confirmed IM, 50 identified cardiac or fundic epithelium, and 20 revealed only esophagitis. Typical GER symptoms were scored by patients preoperatively and postoperatively (0 to 4 scale). We compared symptom response (Wilcoxon rank sum test) and failure rates (t test) in patients with IM and GER controls without IM. Preoperative data were available for 74 IM patients and 496 controls. One-year follow-up was available in 45 IM patients and 301 controls. Intermediate follow-up (2 to 5 years) was available in 20 IM patients and 99 controls. RESULTS: Preoperatively and postoperatively, patients with IM reported heartburn, regurgitation, and dysphagia scores similar to controls. Procedure failure, requiring redo fundoplication, appeared more likely in IM patients than controls (6.3% versus 2.5%), but this difference did not reach statistical significance (P = 0.061). CONCLUSION: Fundoplication provides equivalent symptom relief for patients with and without IM.

Barrett Esophagus↗

PubMed1990

[Treatment of acute destructive pancreatitis].

The authors analyse observations over 113 patients (1978-1988) with destructive pancreatitis; there were 54 males and 59 females, whose ages ranged from 18 to 85 years. Complex nonoperative treatment was effective only in 17 patients. Cholecystectomy, cholecystostomy or choledochotomy was performed in 7 patients after their condition had improved. Eighty-eight patients underwent operation in the acute period. Total lethality was 71.6%. In summarizing the results the authors came to the conclusion that operative interventions should be postponed in clinical practice. The optimal time for the operation is 6-9 days after the onset of the disease.

Acute Disease↗