Biomedical subjects
L K Von Segesser
Publications and source records attributed to L K Von Segesser.
Congenital coronary fistulas in children and adults: diagnosis, surgical technique and results.
Coronary artery fistula is a very rare congenital malformation with abnormal coronary-cameral communication that may involve any chamber and any or all coronary artery branches. We present our experience with 11 consecutive patients [mean age 16.6 years, ranging from 4 to 64 years]; 9 of them were treated surgically, spontaneous closure of the fistula was observed in one patient and one patient is still under observation. Fistulas originated from the right coronary artery in 4 patients and drained either into the right [n=3] or into the left system [n=1]. In 9 patients, the fistulas originated from the left coronary system and the fistulous communication developed with the right cardiac structures only. In 2 patients both coronary arteries were involved in the pathological drainage and 2 patients were demonstrated to have multiple drainage from the left coronary artery. Additional congenital cardiac malformations were found in 2 patients. Surgical closure of the fistula was successful in all operated patients [in one case treatment was possible without cardiopulmonary bypass]. Simple ligation of the fistula was performed in 1 patient, intracardiac closure of the fistula was combined with different reconstructive procedure in the other patients. Neither hospital mortality nor severe complications occurred. Mean follow-up interval was 39.4 months and all patients except one were in NYHA I. In presence of symptoms of congestive heart failure, significant left-to-right shunt and arrhythmias, elective closure of coronary fistula is generally accepted, whereas indication is more controversial in asymptomatic patients.
Sternal cleft associated with vascular anomalies and micrognathia.
Sternal defects combined with craniofacial vascular defects are rare. We report on a 45-year-old woman with a sternal cleft associated with craniofacial and brain hemangiomata, an aneurysm of the aortic arch, anomalous origin of the coronary arteries, a left superior vena cava, micrognathia, supraumbilical midline raphe, and a cervical cyst. The surgical procedure consisted of the resection and replacement of the aortic arch and the innominate artery with reimplantation of the left carotid artery into the graft under circulatory arrest and deep hypothermia. The presence of sternal cleft is an indication for the search for other asymptomatic internal vascular anomalies.
Improved biocompatibility of heparin surface-coated ventricular assist devices.
Heparin surface coated ventricular assist devices (VADs) and cannulas were evaluated in comparison to uncoated VADs in 10 bovine experiments (body weight 77 +/- 6 kg). All systems were primed with cristalloid solution. No systemic heparin was given. Left ventricular assist was started with a blood flow of 4.2 +/- 0.4 l/min and maintained over 6 hours. Besides hemodynamic monitoring, blood samples were taken at regular intervals for blood gas, hematological, biochemical and coagulation studies. All animals in the study group (coated) were assisted for the scheduled 6 hours without device failure. In the control group, however, total occlusion occurred in 1 VAD after 1 hour of left ventricular assist whereas the other 4 VADs remained functional throughout the protocol. Mixed venous oxygens saturation was preassist 56 +/- 12% for coated versus 63 +/- 11% for uncoated and the final value at 60 minutes after weaning was 58 +/- 16% versus 59 +/- 5% (NS). Mean hematocrit dropped from a baseline value of 33 +/- 4% for coated versus 29 +/- 8% for uncoated to 29 +/- 7% versus 30 +/- 5% (NS) after 6 hours of assist. There was no significant difference between the baseline values (5.7 +/- 3.0 mumol/l for coated versus 4.6 +/- 3.1 mumol/l for uncoated) and the 6-hour values (3.8 +/- 3.7 mumol/l versus 7.6 +/- 6.4 mumol/l) for mean plasma hemoglobine. The normalized platelet levels dropped after 10 minutes of assist to 91 +/- 21% for coated versus 94 +/- 49% for uncoated (NS) and 89 +/- 29% versus 65 +/- 44 at 6 hours (NS).(ABSTRACT TRUNCATED AT 250 WORDS)