Ja Hutter

Posterior pericardiotomy reduces the incidence of supra-ventricular arrhythmias following coronary artery bypass surgery.

A prospective study of 100 patients undergoing coronary artery bypass surgery was performed to demonstrate the effectiveness of a posterior pericardiotomy in reducing the incidence of pericardial effusions and, consequently, reducing the incidence of supraventricular arrhythmias in the post-operative period. Pericardial effusion occurred in 4 of 50 patients following a posterior pericardiotomy, whereas effusion occurred in 20 of 50 patients in whom a pericardiotomy was not created (P < 0.0005). Supra-ventricular arrhythmias occurred in 4 patients in the pericardiotomy group and 18 in the group treated without pericardiotomy (P < 0.005). No complications resulted from this procedure. We conclude that pericardiotomy is a simple, safe and effective method for reducing the incidence or pericardial effusion and thereby post-operative supra-ventricular arrhythmias.

Effect of ischaemia and reperfusion on the intracellular concentration of taurine and glutamine in the hearts of patients undergoing coronary artery surgery.

Taurine and glutamine are the most abundant intracellular free amino acids in mammalian hearts where changes in their intracellular concentrations are likely to influence a number of cellular activities. In this study we investigated the effects of ischaemia and reperfusion on the intracellular concentrations of taurine and glutamine in the hearts of patients undergoing coronary artery bypass surgery using cold crystalloid or cold blood cardioplegic solutions. Ischaemic arrest (30 min), using cold crystalloid cardioplegic solution (n = 19), decreased the intracellular concentrations (micromol/g wet weight) of taurine (from 9.8 +/- 0.8 to 7.7 +/- 0.7, P < 0.05) and glutamine (8.7 +/- 0.5 to 7.2 +/- 0.6). After 20 min of normothermic reperfusion the fall in taurine and glutamine was maintained (7.5 +/- 0.5 and 7.4 +/- 0.7 for taurine and glutamine respectively). Myocardial ischaemic arrest with cold blood cardioplegic solution (n = 16) did not cause a significant fall in tissue taurine or glutamine. However, on reperfusion there was a marked fall in the intracellular concentrations of taurine (9.4 +/- 0.5 to 6.5 +/- 0.7) and glutamine (8.0 +/- 0.7 to 5.8 +/- 0.4). The fall in amino acids was associated with a fall in ATP and a rise in tissue lactate. This work demonstrates that irrespective of the cardioplegic solution used to arrest the heart, there is a marked fall in tissue taurine and glutamine which may influence the extent of recovery following surgery. The fall in taurine is largely due to efflux whereas changes in glutamine are due to both transport and metabolism. Ischaemia, hypothermia and changes in the transmembrane concentration gradients are the likely factors responsible for the changes in tissue amino acids.

The evolution of training in Off-Pump coronary surgery in a single institution

BACKGROUND This study analyses the development of off-pump coronary artery bypass (OPCAB) surgery training at a single institution, and compares the early and midterm clinical outcomes of OPCAB and conventional coronary artery bypass grafting (CABG) procedures performed by trainees with or without direct consultant cardiothoracic surgeon supervision. METHODS Analysis was undertaken on data prospectively recorded on a computer database (Patient Analysis and Tracking System). Of the 2,422 CABG operations performed between January 1999 and December 2001, 969 (40%) were carried out by trainees either off pump (422) or on pump (547). RESULTS Although the total number of CABG operations performed by trainees remained constant, there was a significant increase in the number of OPCAB operations during the study period compared with conventional CABG, as well as an increase in the average number of grafts per patient in the OPCAB group (both p < 0.05). Furthermore, a significant trend towards using two or more arterial conduits in the OPCAB group was observed in the study period. The number of OPCAB operations performed by trainees as independent operators without direct consultant supervision also increased significantly (p < 0.05). Early and midterm clinical outcomes were similar between patients operated by trainees on pump or off pump as independent operators versus under direct consultant supervision. CONCLUSIONS The significant increase in OPCAB operations performed by trainees as independent operators or under direct consultant supervision, as well as the increase in the number of grafts per patient and arterial conduits used for myocardial revascularization, demonstrate a progression of training in beating heart surgery for cardiothoracic trainees. Improvements in the techniques have made it safe to teach trainees off-pump multivessel coronary artery revascularization.