Limited right anterolateral thoracotomy for mitral valve surgery.

OBJECTIVE: There has been great enthusiasm in recent years to perform mitral valve surgery through small multiple incisions with the use of the Port Access technique. The procedure is costly, involves a relatively long training curve and leaves the patient with multiple scars in the chest and groin. We used a mini-thoracotomy technique for mitral valve patients and compared our results with the conventional technique. METHODS: We randomized 100 consecutive patients presenting to our practice for mitral valve surgery between two groups. The first group (test group) consisted of 50 patients in which mitral valve surgery was performed via mini-right anterolateral thoracotomy approach. The control group (50 patients) underwent classical mitral valve surgery through median sternotomy. Standard aortic and bicaval cannulation with antegrade blood cardioplegia was adopted in both groups. RESULTS: There was no statistical difference between the two groups preoperatively regarding their age, pathology, LV function and male/female ratio. Most of the patients had valve replacement except four in the test group and three in the control group. The incision in the test group was 12-15 cm long in the right submammary groove. Direct aortic cannulation, clamping and cardioplegia administration was achieved in all patients easily. The mean bypass time was slightly longer in the test group (64+/-12 min) when compared with the test group (59+/-11 min). The cross-clamp time was lower in the test group (27+/-8 min) when compared with the control group (31+/-9 min). There was no hospital mortality in both groups and there was one morbidity in the form of sternal infection in the control group. The mean hospital stay was similar for both groups (7+/-2 days). CONCLUSION: The cosmetic appearance in the test group was excellent and the patients' wounds were scarcely apparent in the female patients. The study demonstrates the efficacy and safety of this older technique, with excellent cosmetic results and no additional cost or risk to the patients.

Respiratory dysfunction following cardiopulmonary bypass: verification of a non-invasive technique to measure shunt fraction.

Respiratory dysfunction is a well recognized complication of cardiopulmonary bypass. The size of the pulmonary shunt fraction is the best indicator of respiratory dysfunction but its measurement conventionally requires use of a pulmonary artery catheter to measure mixed venous oxygen content. We compared pulmonary shunt fraction, based on a non-invasive technique using a previously described mathematical model, with shunt fraction measured invasively using a pulmonary artery catheter in 22 patients undergoing elective coronary artery surgery. The mean shunt fraction measured by the invasive technique was 19.6 +/- 2.0 (18.8-20.4)% of cardiac output at 24 h (+/- 1 SD and 90% confidence intervals) and 20.9 +/- 2.9 (19.8-22.0)% of cardiac output at 44 h post-surgery. There was good agreement between the two methods of measurement. The mean difference was 0.21 percentage points with 95% confidence interval -0.01 to 0.43. The limits of agreement (-1.17 to 1.59) are small enough to be confident that the non-invasive method can be used to give the same result as that obtained using a pulmonary artery catheter. The values for shunt fractions obtained by the non-invasive technique were 19.7 +/- 2.3 (18.8-20.6)% of cardiac output at 24 h and 20.7 +/- 2.5 (19.7-21.6)% of cardiac output at 44 h. The non-invasive measurement of the shunt fraction provided us with a simple, practical method for following a further ten patients over an extended period of time where prolonged catheterization is impractical.