Intraoperative radiofrequency microbipolar coagulation to replace incisions of maze III procedure for correcting atrial fibrillation in patients with rheumatic valvular disease.

OBJECTIVE: Radiofrequency catheter ablation of atrial tachycardias and flutter is an established technique. The same modality in the microbipolar mode is effective in producing full thickness coagulation injury. Cox's maze procedure is highly successful in curing atrial fibrillation (AF) surgically. However, it consumes relatively long cross clamp time and cardiopulmonary bypass time. In this study, radiofrequency microbipolar coagulation was used as an adjunct to corrective valve surgery, as an intraoperative ablative modality to replace Cox's maze III incisions, thus remarkably shortening the procedure. The results of this procedure are compared historically with those of 26 patients who underwent corrective valve surgery alone. METHODS: Radiofrequency microbipolar coagulation was used to produce conduction blocks along the Cox's maze III incision lines as an adjunct to valve surgery in 18 patients in atrial fibrillation undergoing surgery for rheumatic valvular disease. A bayonet type bipolar forceps with an active tip length of 7 mm drawing current from a microbipolar port of Valleylab Force 4 electrosurgical unit (Valleylab, Boulder, CO) was used for microbipolar coagulation. A 3-mm retinal handheld cryoprobe working on nitrous oxide gas was used for cryoablation. RESULTS: A total of 15 survivors in the coagulation maze group were followed from 43 to 224 days (149.7 +/- 73.1 mean +/- S.D.). Twelve of the 15 survivors (80%) converted to normal sinus rhythm (70% confidence limit: 64.7-90.6%). Atrial transport function studies with pulsed wave doppler, showed presence of a wave in all the 12 (100%) patients in tricuspid valve flow and in nine (75%) patients in mitral valve flow. The procedure took 11.62 +/- 3.86 min of elective cardioplegic arrest time for the left atrial portion and 18.71 +/- 4.25 min of cardiopulmonary bypass time during reperfusion for the right atrial portion. Of the 23 survivors out of 26 patients who underwent the valve procedure alone, only one patient (4.3%) converted to normal sinus rhythm (70% confidence limit: 0.6-14%). CONCLUSION: Thus, our modification considerably shortened the time taken for creating the maze in comparison to the Cox's maze procedure and was effective in restoring normal sinus rhythm in 80% of the patients.

Viability testing of homograft valves using methyl thiazol tetrazolium assay.

Viability status before and after treatment with antibiotics was investigated in a total of 104 homograft valves using MTT (3-[4, 5-dimethyl thiazol-2-y1]-2, 5-diphenyl tetrazolium bromide). The valves with warm ischaemic time above 11 hours, were found to be non-viable. Increase in storage time directly decreases cell viability. Methyl thiazol tetrazolium (MTT) assay can be used as a reliable, simple, rapid and economic method for assessing the viability status based on mitochondrial respiration even for homograft valves. Basal media with and without nutrients i.e., DMEM and Hanks BSS showed no difference in viability of the cells.

Blalock Taussig type shunt palliation for cyanotic infants and children.

In a period of ten years from January 1, 1979 to December 31, 1988, 54 cyanotic patients weighing less than 10 kg underwent shunt operations of Blalock Taussig type. The indications were hypercyanotic spells, failure to thrive and pulmonary arteries being too small for safe total collection. The commonest diagnosis was tetralogy of Fallot (63%). Thirty-three (64%) patients were older than 1 year but still weighed less than ten kg. Mortality was 16.67% (70% C.L. 8.94-26.60). During follow-up, there were 4(7%) late deaths. During the same period, 134 patients less than 5 years age came to autopsy without having any cardiological or surgical intervention. Ninety-seven (72.4%) of these deaths were due to cardiac causes. In order to save their lives, early identification is necessary which highlights the importance of parent and primary physician education.

Double-chambered right ventricle with pulmonary valve endocarditis.

A rare case of isolated pulmonary valve endocarditis associated with a double-chambered right ventricle in a nonaddict, was diagnosed on two-dimensional echocardiography and cardiac catheterization and angiography. The patient was successfully operated and the above findings confirmed on the operation table.

Left main coronary block in a nineteen-year-old woman.

A 19-year-old woman had angina on exertion, which had existed for 4 years. An exercise test was strongly positive, and selective coronary angiography showed 95% block of the left main coronary artery at its ostium. The patient underwent a successful aortocoronary bypass to the left anterior descending coronary artery. After 1 year and 10 months, she continues to be asymptomatic.

Anomalous origin of right pulmonary artery from ascending aorta with right ventricular endocardial fibroelastosis.

A case of aortic origin of the right pulmonary artery with right ventricular endocardial fibroelastosis is reported. Its diagnostic features, surgical aspects, and postmortem findings are discussed. This is a rare combination. The relevant literature is reviewed.