Differential regulation of MMP-2 in the gastrohepatic ligament of the gastroesophageal junction.

INTRODUCTION: Ligamentous attachments maintain the normal anatomic position of the gastroesophageal (GE) junction. Failure of these elastic ligaments through an alteration in collagen synthesis, deposition, and metabolism may be a primary etiology of hiatal hernia formation. Differential expression of zinc-dependent matrix metalloproteinases (MMPs) is largely responsible for collagen remodeling. The purpose of this study was to survey baseline levels of MMPs in supporting ligaments of the GE junction from patients without hiatal hernia. METHODS: Following an institutional review board-approved protocol, plasma and tissue biopsies of the gastrohepatic ligament (GHL), gastrophrenic ligament (GPL), and phrenoesophageal ligament (PEL) were obtained in six patients without a hiatal hernia during laparoscopic anterior esophageal myotomy for achalasia. Total protein extracts from tissue biopsies were analyzed for elastases MMP-2, -9, and -12 and collagenases MMP-1, -3, -7, -8, and -13 using a multiplex profiling kit (R&D Systems, Minneapolis, MN). Data are reported as mean +/- standard deviation. Statistical significance (p < 0.05) was determined using Tukey's test and analysis of variance. RESULTS: In control patients without hiatal hernias, increased levels of MMP-2 (p < 0.02) were detected in the GHL compared with the GPL and PEL, respectively. Tissue levels of MMP-1, -12, and -13 were not detectable. CONCLUSIONS: Gelatinase-A (MMP-2) is present in the GHL and plasma of control patients. The GHL may provide the primary GE junction supporting ligament to compare tissue from patients with type I (sliding) and type III (paraesophageal) hiatal hernias to examine the role of altered collagen metabolism in hiatal hernia formation.

The effectiveness and risks of bariatric surgery: an updated systematic review and meta-analysis, 2003-2012.

IMPORTANCE: The prevalence of obesity and outcomes of bariatric surgery are well established. However, analyses of the surgery impact have not been updated and comprehensively investigated since 2003. OBJECTIVE: To examine the effectiveness and risks of bariatric surgery using up-to-date, comprehensive data and appropriate meta-analytic techniques. DATA SOURCES: Literature searches of Medline, Embase, Scopus, Current Contents, Cochrane Library, and Clinicaltrials.gov between 2003 and 2012 were performed. STUDY SELECTION: Exclusion criteria included publication of abstracts only, case reports, letters, comments, or reviews; animal studies; languages other than English; duplicate studies; no surgical intervention; and no population of interest. Inclusion criteria were a report of surgical procedure performed and at least 1 outcome of interest resulting from the studied surgery was reported: comorbidities, mortality, complications, reoperations, or weight loss. Of the 25,060 initially identified articles, 24,023 studies met the exclusion criteria, and 259 met the inclusion criteria. DATA EXTRACTION AND SYNTHESIS: A review protocol was followed throughout. Three reviewers independently reviewed studies, abstracted data, and resolved disagreements by consensus. Studies were evaluated for quality. MAIN OUTCOMES AND MEASURES: Mortality, complications, reoperations, weight loss, and remission of obesity-related diseases. RESULTS: A total of 164 studies were included (37 randomized clinical trials and 127 observational studies). Analyses included 161,756 patients with a mean age of 44.56 years and body mass index of 45.62. We conducted random-effects and fixed-effect meta-analyses and meta-regression. In randomized clinical trials, the mortality rate within 30 days was 0.08% (95% CI, 0.01%-0.24%); the mortality rate after 30 days was 0.31% (95% CI, 0.01%-0.75%). Body mass index loss at 5 years postsurgery was 12 to 17. The complication rate was 17% (95% CI, 11%-23%), and the reoperation rate was 7% (95% CI, 3%-12%). Gastric bypass was more effective in weight loss but associated with more complications. Adjustable gastric banding had lower mortality and complication rates; yet, the reoperation rate was higher and weight loss was less substantial than gastric bypass. Sleeve gastrectomy appeared to be more effective in weight loss than adjustable gastric banding and comparable with gastric bypass. CONCLUSIONS AND RELEVANCE: Bariatric surgery provides substantial and sustained effects on weight loss and ameliorates obesity-attributable comorbidities in the majority of bariatric patients, although risks of complication, reoperation, and death exist. Death rates were lower than those reported in previous meta-analyses.

Utility of staging laparoscopy in subsets of peripancreatic and biliary malignancies.

OBJECTIVE: To determine the relative benefit of staging laparoscopy in peripancreatic and biliary malignancies. SUMMARY BACKGROUND DATA: Staging laparoscopy has been used in a variety of peripancreatic and biliary malignancies. The utility of the technique in subsets of these types of cancer has not been systematically compared. METHODS: One hundred fifty-seven patients underwent laparoscopy after conventional tumor staging; 89 were also staged with laparoscopic ultrasonography. Diagnostic categories were cancer of the pancreatic head and uncinate process, cancer of the body and tail of pancreas, cancer of the extrahepatic bile duct, cancer of the gallbladder, and cancer of the ampulla of Vater/duodenum. RESULTS: In patients with cancer of the head of the pancreas, metastatic disease or vascular invasion was discovered frequently by laparoscopy (31%), whereas in ampullary/duodenal cancer it was never found. The laparoscopic findings in cancer of the head of the pancreas had an important influence on treatment decisions, whereas in cancer of the ampulla/duodenum, laparoscopy had no effect on clinical decisions. Laparoscopy also substantially influenced the treatment of gallbladder cancer; in other tumor types, results were intermediate. Laparoscopic ultrasonography was valuable in cancer of the head of the pancreas. CONCLUSIONS: The utility of staging laparoscopy depends on diagnosis. It is recommended for continued use in pancreatic head and gallbladder cancers but not in ampullary malignancies.