Minimally invasive aortic valve replacement.

During a consecutive 12-month period from January 1996 to January 1997 inclusive, 108 aortic valve replacements were performed by one group of surgeons in two community hospitals The majority of the valve replacements were done in combination with other procedures or were redo surgeries. Thirty-one patients had primary isolated aortic valve replacement. Fourteen patients underwent aortic valve replacement via a standard sternotomy, and seventeen patients underwent aortic valve replacement using a minimally invasive parasternal approach, as described by Dr. Cosgrove. There were no operative deaths in either group; however there was one hospital death in each of the two groups. Blood loss and postoperative pain were less in the minimally invasive group. Although the cross-clamp times were longer in the minimally invasive group, with a mean of 82.7 min as compared with 63.1 min in the standard group, the length of stay was shortened, with a median of 5 days in the minimally invasive group as compared to 7 days in the sternotomy group. In the follow-up which ranges from 4-15 months, all patients in the minimally invasive group were New York Heart Class I or II. Patients with the parasternal incisions are permitted to return to work much earlier than those with a standard sternotomy incision. The decreased blood loss and postoperative pain, combined with the anticipated ease of re-entry via a median sternotomy in the future (should redo aortic valve replacement become necessary), make this approach our procedure of choice in isolated primary aortic valve replacement.

Cardiac operation with associated pulmonary resection.

From February 1988 to May 1992, a total of 11 patients aged 52 to 81 years underwent concomitant cardiac operation and pulmonary resection for bronchogenic carcinoma at our institution. All pulmonary lesions were incidental findings on preoperative chest x-ray films. Diagnosis was obtained in six patients before resection. The operation was performed through a midline sternotomy with all patients requiring cardiopulmonary bypass. Pulmonary procedures included two wedge resections, seven lobectomies, and two double lobectomies. Seven patients underwent lobectomy while supported by bypass, with the lungs collapsed, during rewarming. Total bypass time for these patients averaged 143 minutes. Pathologic examination showed all lesions to be non-small-cell malignant tumors; four adenocarcinomas, four squamous cell carcinomas, two bronchoalveolar carcinomas, and one undifferentiated carcinoma. Nine were stage I and two were stage II. One of the wedge resections showed malignant disease involving the surgical margin that later required completion lobectomy. There were no operative deaths and no major postoperative complications. Postoperative hospital stays ranged from 6 to 17 days (mean 10 days) except for one patient who required a prolonged hospitalization because of a complication after thoracentesis on the side opposite the pulmonary resection. Concomitant cardiac operations with lobectomy can be safely performed during cardiopulmonary bypass without significantly prolonging pump time. Our observations suggest that concomitant cardiac surgery with pulmonary resection is a safe and effective technique with minimal morbidity and short hospital stay.

Anomalous origin of the left anterior descending artery from the pulmonary artery.

An extremely rare congenital abnormality is reported in which the anterior descending coronary artery (LAD) originates from the pulmonary trunk. The clinical presentation, angiographic findings, and surgical treatment are discussed. This is the only reported case where surgical treatment included ligation of the LAD with internal mammary artery bypass grafting.

Non-small cell lung cancer in autogenous subcutaneous bronchial grafts in dogs.

The progression of preneoplasia into lung cancer can be serially studied in a new canine model that is simpler and more cost effective than previously reported methods of orthotopic endobronchial carcinogenesis. Short segments of bronchus, obtained by pneumonectomy, were placed on the back of 10 dogs in the form of subcutaneous bronchial autografts. These autografts (12 to 14 per dog) became vascularized and lined with normal respiratory epithelium. Four to 12 weeks after autograft implantation, 10% methylcholanthrene in crystalline form was put into 57 autografts and 10% methylcholanthrene in a silicone polymer sustained-release implant was placed into 54 autografts. Ten autografts without carcinogen (one per dog) served as controls. Serial samplings of each autograft during 9 to 97 weeks of carcinogen exposure showed the neoplastic progression from normal bronchial cells to invasive cancer through stages such as atypical squamous metaplasia and carcinoma in situ. To date, cancers have been histologically proved in 60 autografts; 36 were induced by implants and 24 by the crystalline form. Thirty-nine cancers were epidermoid, and the remainder were either adenocarcinomas (n = 3) or poorly differentiated spindle cell cancers (n = 18). The sustained-release implant method resulted in larger autografts with a greater tendency to progress to cancer than the crystalline carcinogens (p greater than 0.025). Therefore, the sustained-release implant is now considered the preferred method. Measurement of nuclear deoxyribonucleic acid by image analysis of nine histologic cancers demonstrated hyperploidy. Deoxyribonucleic acid from the L1 repeated sequence family was demonstrably hypomethylated in spindle cell tumors. Curettement of individual autografts yielded sheets of respiratory epithelium from which 43.5 to 409.5 micrograms of deoxyribonucleic acid was isolated. For the first time, deoxyribonucleic acid from each stage of the neoplastic progression in non-small cell lung cancer is available in adequate quantities for serial biochemical and therapeutic analysis.