Arterial Anatomy of the Anterior Abdominal Wall:Evidence-Based Safe Sites for Instrumentation based on Radiological Analysis of 100 Patients

Introduction: Multiple medical interventions require percutaneous instrumentation of the anterior abdominal wall, all of which carry a potential for vascular trauma. We assessed the presence, position and size of the anterior abdominal wall superior and inferior (deep) epigastric arteries to determine the safest site with respect to vascular anatomy of the rectus sheath. Materials & Methods: In a review of 100 arterial phase, contrast-enhanced abdominal computed tomography scans, anterior abdominal wall arteries were assessed bilaterally at three axial planes: transpyloric, umbilicus and anterior superior iliac spine (ASIS). Results: The mean age of patients was 69.2 years (SD ± 15), with 62 male and 38 female. An artery was visible least frequently at the transpyloric plane (5%), compared to the umbilicus (72-79%) and ASIS (93-96%), on the left (χ (4) = 207.272; p < 0.001) and right (χ (4) = 198.553; p < 0.001), with a moderate strength association (Cramer's V = 0.588 (left) and 0.575 (right)). The arteries were most commonly observed within the rectus abdominis muscle at the level of the umbilicus and ASIS on both sides (62-68%). The inferior epigastric artery was observed to be larger in diameter, start more laterally, and move medially as it travelled superiorly. Discussion: These data suggest that the safest site to instrument the rectus sheath, with respect to vascular anatomy, is at the transpyloric plane. This information on anatomical variation of the anterior abdominal wall vasculature may be of particular interest to anesthetists performing rectus sheath block and surgeons during laparoscopic port insertion. This article is protected by copyright. All rights reserved

A randomized controlled trial of metformin on left ventricular hypertrophy in patients with coronary artery disease without diabetes:the MET-REMODEL trial

Aim We tested the hypothesis that metformin may regress left ventricular hypertrophy (LVH) in patients who have coronary artery disease (CAD), with insulin resistance (IR) and/or pre-diabetes. Methods and results We randomly assigned 68 patients (mean age 65 ± 8 years) without diabetes who have CAD with IR and/or pre-diabetes to receive either metformin XL (2000 mg daily dose) or placebo for 12 months. Primary endpoint was change in left ventricular mass indexed to height1.7 (LVMI), assessed by magnetic resonance imaging. In the modified intention-to-treat analysis (n = 63), metformin treatment significantly reduced LVMI compared with placebo group (absolute mean difference −1.37 (95% confidence interval: −2.63 to −0.12, P = 0.033). Metformin also significantly reduced other secondary study endpoints such as: LVM (P = 0.032), body weight (P = 0.001), subcutaneous adipose tissue (P = 0.024), office systolic blood pressure (BP, P = 0.022) and concentration of thiobarbituric acid reactive substances, a biomarker for oxidative stress (P = 0.04). The glycated haemoglobin A1C concentration and fasting IR index did not differ between study groups at the end of the study. Conclusion Metformin treatment significantly reduced LVMI, LVM, office systolic BP, body weight, and oxidative stress. Although LVH is a good surrogate marker of cardiovascular (CV) outcome, conclusive evidence for the cardio-protective role of metformin is required from large CV outcomes trials

Metformin regresses left ventricular hypertrophy in normotensive patients with coronary artery disease without Type 2 diabetes mellitus—The MET-REMODEL Trial

Background: Left ventricular hypertrophy (LVH) is highly prevalent in patients with coronary artery disease (CAD) and is an independent predictor of cardiovascular mortality. Metformin has been shown to regress LV mass (LVM) in animal models of LVH. We hypothesize that metformin may regress LVH in nondiabetic and normotensive CAD patients with prediabetes and/or insulin resistance. Methods: In this randomized double-blind placebo controlled trial, 68 patients with prediabetes (HbA1c ?39 mmol/mol and less than 48 mmol/mol) and/or insulin resistance (fasting insulin resistance index ? 2.7) were assigned to receive either metformin (2g daily dose) or placebo for 12 months. An intention-to-treat (ITT) and per-protocol analysis was designed to determine the effect of metformin on the following study endpoints: Primary endpoint was change in left ventricular mass indexed to height1.7 (LVMI), assessed by magnetic resonance imaging; other endpoints were changes in LVM, changes in body weight, office blood pressure (BP) and biomarkers. Results: In the ITT analysis (n=61), metformin treatment significantly reduced: LVMI (metformin -2.7 ± 2.3 g/m1.7 vs. placebo -1.4 ± 2.7 g/m1.7; P=0.05), body weight (lowered by 3.6 kgs, p=0.002), office systolic BP (metformin -4.8 ± 15.6 mmHg vs. placebo 4.6 ± 15.7 mmHg; P=0.02) and reduced concentration of thiobarbituric acid reactive substances (TBARs), a biomarker for oxidative stress (p=0.04). In the on-per protocol analysis (n=56), metformin resulted in a greater reduction of LVMI (metformin -3.1 ± 1.9 g/m1.7 vs. placebo -1.2 ± 2.7 g/m1.7; P=0.005), and greater weight reduction of 4.2kgs (p=0.001). Conclusions: Metformin treatment significantly reduced LVMI, office SBP, body weight and oxidative stress. These results reveal a novel mechanism for the cardioprotective effect of metformin and raise the possibility of using metformin in nondiabetic patients with CAD