Direct Measurement of Clamping Forces in Cardiovascular Surgery

Equipment for measuring the direct tip force of a clamp arm on the vessel wall was designed as an adjustable surgical clamp with strain gauges applied and connected via an amplifier to a computer-based data acquisition system. A mechanical model that incorporates the resistance of tissue against momentary deformations is developed to analyse and justify measured results. In in vivo experiments on rat thoracic aorta, the minimum occlusion force, stationary clamping force and the momentary peak clamping force are measured and observed as an important cause of damages in the endothelial layer of vascular walls. Correspondence should be addressed to Dr. Borut Gersak, tel/fax: ++ 386 61 1334 162, E-mail: [email protected] 1 Introduction The exposition of vascular endothelial surface (inner vascular layer) during cardiovascular surgery needs an occlusion of blood flow through the exposed area. In most cases the occlusion is obtained by mechanical means with surgical clamps (Kuo et..

Comparison of the ST-40ms isointegral maps prior and after aortocoronary revascularisation

In the prospective study we tested the hypothesis that successful aortocoronary by-pass procedure performed in reversible ishemic areas of the cardiac muscle can be documented by the study of ST-40ms isointegral maps prior and after aortocoronary revascularisation with the combination of dipyridamole stress testing. Eight patients (1 female), age from 47 to 72 years were included in the study. The patients with conduction and rhythm disturbances, left main stenosis, and/or unstable angina pectoris were excluded from the study. The body surface potentials were recorded in lying position with unipolar leads referenced to the Wilson central terminal with 32 electrodes (Ag-AgCl disks). Ten seconds intervals of 32 lead ECG were recorded before dipyridamole infusion and 10 minutes after it, both prior and after the operation. J point was determined and ST-40ms isointegral maps were calculated and compared. 1. Introduction The quantitative understanding of the relationship between bioelelec..

Computer Simulation And Spatial Modelling In Heart Surgery

A three dimensional modelling and heat transfer computer simulation of generally-shaped, non-homogenous bodies, is proposed and described in this work. The complexity of the calculation is estimated and the potential use of high performance parallel computers is discussed. The method is focused for applications in medicine. As an example, a numerical algorithm for the parallel computer simulation of heart cooling procedures during surgery is presented, and, on the basis of simulated results, different methods of cooling are compared

Sutureless Aortic Valves

In this discussion filmed at the 2017 STS Annual Meeting in Houston, Texas, two surgeons talk about their experiences using sutureless aortic valves. Dr Tom C. Nguyen of the University of Texas in Houston is joined by Dr Patrick McCarthy of Northwestern Memorial Hospital in Chicago, Illinois, and Dr Borut Gersak of the Ljubljana University Medical Center in Slovenia. The panelists present videos of valve implantation, and they discuss indications for and the benefits of using sutureless valves