The impact of obesity on patient survival in liver transplant recipients: a meta-analysis.

BACKGROUND & AIMS: It is controversial if obesity has an impact on overall survival after liver transplantation (LT). The goal of this study was to determine if obesity impacts liver transplant recipient survival. Through subgroup analysis, we also evaluated different body mass index (BMI) thresholds and the confounding effect of ascites on survival. METHODS: A systematic literature search from 1990 until July 2013. The main outcome was to evaluate the impact of obesity on survival in adult LT recipients. Dochotomous outcomes were reported as relative risk (RR) with 95% confidence intervals (CI). RESULTS: Thirteen studies with a total 2275 obese and 72 212 non obese patients were included in the analysis. The combined analysis showed no difference in mortality between control and increased weight patients (RR = 0.97, 95% CI [0.82, 1.13], P = 0.66) at last follow-up. Moreover, no differences in mortality were noted in subgroup analysis comparing different BMI thresholds. There was also no differences in survival when BMI was adjusted for ascites or in studies where the liver disease severity was similar. Obese patients had worse survival than nonobese patients in pooled analysis of studies which had similar causes of liver disease (RR = 0.69, 95% CI [0.52, 0.92], P = 0.01). CONCLUSION: The results of our pools analysis suggest that BMI does not specifically impact patient survival. However, obese patients have worse survival when analysis was performed in studies whose cohorts of obese and nonobese patients had similar causes of liver disease.

Evaluation of fully covered self-expanding metal stents in benign biliary strictures and bile leaks.

AIM: To investigate the use of fully covered metal stents in benign biliary strictures (BBS) and bile leaks. METHODS: We studied 17 patients, at Harbor-UCLA Medical center (Los Angeles), with BBS (n = 12) and bile leaks (n = 5) from July 2007 to February 2012 that had received placement of fully covered self-expanding metal stents (FCSEMs). Fourteen patients had endoscopic placement of VIABIL(®) (Conmed, Utica, New York, United States) stents and three had Wallflex(®) (Boston Scientific, Mass) stents. FCSEMS were 8 mm or 10 mm in diameter and 4 cm to 10 cm in length. Patients were followed at regular intervals to evaluate for symptoms and liver function tests. FCSEMS were removed after 4 or more weeks. Resolution of BBS and leak was documented cholangiographically following stent removal. Stent patency can be defined as adequate bile and contrast flow from the stent and into the ampulla during endoscopic retrograde cholangiopancreatography (ERCP) without clinical signs and/or symptoms of biliary obstruction. Criterion for bile leak resolution at ERCP is defined as absence of contrast extravasation from the common bile duct, cystic duct remanent, or gall bladder fossa. Rate of complications such as migration, and in-stent occlusion were recorded. Failure of endoscopic therapy was defined as persistent biliary stenosis or continuous biliary leakage after 12 mo of stent placement. RESULTS: All 17 patients underwent successful FCSEMS placement and removal. Etiologies of BBS included: cholecystectomies (n = 8), cholelithiasis (n = 2), hepatic artery compression (n = 1), pancreatitis (n = 2), and Whipple procedure (n = 1). All bile leaks occurred following cholecystectomy. The anatomic location of BBS varied: distal common bile duct (n = 7), common hepatic duct (n = 1), hepaticojejunal anastomosis (n = 2), right intrahepatic duct (n = 1), and choledochoduodenal anastomatic junction (n = 1). All bile leaks were found to be at the cystic duct. Twelve of 17 patients had failed prior stent placement or exchange. Resolution of the biliary strictures and bile leaks was achieved in 16 of 17 patients (94%). The overall median stent time was 63 d (range 27-251 d). The median stent time for the BBS group and bile leak group was 62 ± 58 d (range 27-199 d) and 92 ± 81 d (range 48-251 d), respectively. All 17 patients underwent successful FCSEMS removal. Long term follow-up was obtained for a median of 575 d (range 28-1435 d). Complications occurred in 5 of 17 patients (29%) and included: migration (n = 2), stent clogging (n = 1), cholangitis (n = 1), and sepsis with hepatic abscess (n = 1). CONCLUSION: Placement of fully covered self-expanding metal stents may be used in the management of benign biliary strictures and bile leaks with a low rate of complications.

Gastrointestinal pH profile in subjects with irritable bowel syndrome.

AIM: To investigate the small bowel pH profile and small intestine transit time (SITT) in healthy controls and patients with irritable bowel syndrome (IBS). METHODS: Nine IBS patients (3 males, mean age 35 yr) and 10 healthy subjects (6 males, mean age 33 yr) were studied. Intestinal pH profile and SITT were assessed by a wireless motility pH and pressure capsule (Smart Pill). Mean pH values were measured in the small intestine (SI) and compared both within and between groups. Data presented as mean or median, ANOVA, P <0.05 for significance. RESULTS: We found the pH for the first (Q1), second (Q2), third (Q3), and fourth quartile (Q4) of the SI in healthy versus IBS patients was 5.608 ± 0.491 vs. 5.667 ± 0.297, 6.200 ± 0.328 vs. 6.168 ± 0.288, 6.679 ± 0.316 vs. 6.741 ± 0.322, and 6.884 ± 0.200 vs. 6.899 ± 0.303, respectively. We found no significant group difference in pH per quartile (P=0.7979). The proximal SI was significantly more acidic, compared to distal segments, in both healthy subjects and IBS patients (P<0.0001). We found no significant difference in the measured SITT between IBS and control groups with a mean SITT of 218.56 ± 59.60 min and 199.20 ± 82.31 min, respectively (P=0.55). CONCLUSION: This study shows the presence of a gradient of pH along the SI, in both IBS and healthy subjects, the distal being less acidic. These finding may be of importance in small bowel homeostasis.

The effect of eating on lower esophageal sphincter electrical activity.

Electrical activity of the lower esophageal sphincter (LES) has been recorded mainly in vitro and in anesthetized animals. Swallowing produces relaxation of the LES, followed by its contraction. These changes should be associated with changes in LES electrical activity. To determine whether changes in LES electrical activity can be used to recognize the beginning of a meal, four dogs were implanted with two electrodes in the longitudinal axis of the LES. The electrodes were connected to an implantable device for recording of electrical activity. After recovery, dogs underwent two experiments: 1) combined recordings of LES electrical activity and esophageal manometry to test the effect of dry swallows, water, and solid food swallows on LES electrical activity and 2) telemetric recording of LES electrical activity during a standard meal. All amplitudes were in mV, means+/-SD, ANOVA, P<0.05. In experiment 1, an increase in the amplitude of LES electrical activity was associated with the substance being swallowed, i.e., at rest: 0.31+/-0.06; dry swallows: 0.6+/-.0.1; water: 0.67+/-0.12; solid food: 1.06+/-0.17, P<0.001. In experiment 2, there was a pronounced and characteristic increase in amplitude of LES electrical activity during feeding, 0.26+/-0.1; during fasting, 0.99+/-0.23; while eating, 0.31+/-0.1 postprandial, P<0.001. In conclusion, the beginning and duration of a meal are identified by distinct, easily recognizable changes in the amplitude of LES electrical activity. These changes depend on the type of the substance being swallowed and are most prominent with solid food. Changes in LES electrical activity can potentially be used for automatic eating detection.