Coronary endothelial damage during off-pump CABG related to coronary-clamping and gas insufflation.

OBJECTIVE: Although off-pump coronary artery bypass grafting (CABG) has been recognized less invasive than conventional CABG on cardiopulmonary bypass, off-pump CABG may be partly invasive especially to the coronary endothelium. The present study was designed to evaluate the adverse effects of coronary snaring with looped sutures and gas insufflation on the coronary endothelium. The protective efficacies on the coronary endothelium of coronary snaring with elastic sutures or humidified gas insufflation with/without heparin and dipyridamole-added were also tested. METHODS: Thirty-six mongrel dogs were used. After systemic heparinization (150 U/kg), a 5 mm longitudinal coronary incision was made with looped non-elastic monofilament sutures or elastic sutures applied proximally and distally. The incised coronary artery was exposed to non-humidified carbon dioxide, humidified carbon dioxide with lactated Ringer solution, or humidified carbon dioxide with heparin and dipyridamole-added lactated Ringer solution for 10 or 20 min in each group. After gas insufflation, the incised coronary artery was repaired, then, the coronary was reperfused. Perfusion-fixation was done for observation of the coronary endothelium by scanning electron microscopy. The adverse effect on the endothelium was graded as follows: grade 1, appeared normal; grade 2, few blood cells deposited; grade 3, many blood cells deposited; grade 4, few endothelial cells delaminated with blood cells deposited; grade 5, many endothelial cells delaminated with blood cells deposited. RESULTS: Non-elastic looping caused much more endothelial tears than elastic looping (P<0.00001). Non-humidified gas blowing for 20 min caused more endothelial cell damage than humidified gas blowing (P=0.00005). Non-humidified gas blowing for 10 min caused less damage than for 20 min (P=0.00326), but still caused more damage than humidified gas blowing (P=0.00253). Heparin and dipyridamole-added humidification reduced coronary endothelial area mottled by the deposited cells when compared with simple humidification (P=0.00120). CONCLUSIONS: Coronary snaring resulted in coronary endothelial injury, which was ameliorated by using elastic sutures instead of non-elastic sutures. Non-humidified gas insufflation made blood cells deposited and endothelial cells delaminated with time. Humidified gas insufflation attenuated these adverse effects. Heparin and dipyridamole-added humidification had potential advantage in terms of reducing deposited blood cells on the endothelium over simple humidification.

Life-saving strategy for left ventricular free wall rupture after acute myocardial infarction. Infarction-covering repair on the ruptured site under the beating heart.

OBJECTIVE: Left ventricular free wall rupture after acute myocardial infarction is a serious complication with high mortality. For life-saving, it is important how to maintain poor hemodynamics till operation. We have consistently made it our strategy to attach percutaneous cardiopulmonary support system and intra-aortic balloon pumping immediately after the diagnosis regardless of the type of left ventricular free wall rupture and of the hemodynamic conditions, and perform an infarction-covering repair under the beating heart. We have studied the short-term and middle-term results after the operations, and have evaluated the efficacy and problems of this procedure. METHODS: Since September 1994, we have performed this method in six of eight patients with left ventricular free wall rupture. RESULTS: As results, five of the six patients (83%) were saved including two cases of blow-out type. Our strategy for left ventricular free wall rupture showed several advantages for preoperative and intraoperative maintenance of the hemodynamic conditions, and for preservation of some reversible myocardium by the simple technique of infarction-covering repair under the beating heart. These resulted in shortening the operation time, decreasing the incidence of low cardiac output syndrome, and obtaining a satisfactory rate of life-saving. CONCLUSION: We believe that this infarction-covering repair based on our strategy is effective for life-saving during the acute period.

Surgery of the dissecting aneurysm involving a right aortic arch.

A dissecting aneurysm in association with a right aortic arch is extremely rare. However, a 50-year-old male was diagnosed as having a dissecting aneurysm (DeBakey IIIa) with a right aortic arch, right descending aorta and an aberrant retro-esophageal left subclavian artery. A graft replacement of the right descending aorta was successfully performed under right thoracotomy and partial cardiopulmonary bypass. Precise anatomical definition and proper surgical procedure permitted a successful surgical result.

Invasive thymoma with intracaval growth extending and directly invading the right atrium.

We report an extremely rare case of an invasive thymoma with intracaval growth extending and directly invading the right atrium. Enbloc excision of the tumor with lobectomy and combined resection of the right atrium, and graft replacement of the superior vena cava were successfully performed during cardiopulmonary bypass. Invasive thymoma with this type of intracaval and intra-atrial progression is extremely rare.

Clinical evaluation of the centrifugal pump in open heart surgery: a comparative study of different pumps.

The centrifugal pump is now widely used in open heart surgery for its clinical benefits related to the blood elements and the coagulation system. The purpose of this study was to compare the clinical performances of and the outcomes offered by 4 types of centrifugal pumps. For each pump, we investigated the effects on the blood elements, coagulation system, complements, and immunoglobulins during open heart surgery. Four types of centrifugal pumps were used: the HPM-15 (Nikkiso Co.), the Capiox (Terumo Co.), the Lifestream (St. Jude Medical Co.), and the BP-80 (Medtronic, BioMedicus Co.). The platelet count, lactate dehydrogenase (LDH), antithrombin III (AT III), thrombin-antithrombin complex (TAT), complements (C3, C4, and CH50), and immunoglobulins (IgG, IgA, and IgM) were measured before and after cardiopulmonary bypass (CPB). The platelet count was decreased more significantly by the HPM-15 than by any of the other pumps. The other parameters showed no difference among the 4 pumps. In clinical use, each of the 4 types of centrifugal pumps was safe.

[A case of total arch replacement for traumatic aortic arch rupture].

We report a case of aortic arch rupture due to blunt chest trauma. A 64-year-old woman was crushed under a wood when she was working. On her arrival to our hospital, she was in shock state due to cardiac tamponade. Her chest roentogenogram showed fracture of her right-sided ribs and mediastinal widening. Her chest CT revealed hematoma around the aortic arch. Her transesophageal echography (TEE) demonstrated an intimal flap in the aortic arch. An emergency operation was performed immediately under the hypothermic circulatory arrest with a selective cerebral perfusion. As the intimal disruption was found to be extended to three fourths of the circumference of aortic arch, total arch replacement was performed. In this case, the TEE was useful for the immediate diagnosis of the aortic rupture. This was the first successful case of total arch replacement for a traumatic arch rupture.

Clinical use of centrifugal pumps and the roller pump in open heart surgery: a comparative evaluation.

Centrifugal pumps have been used widely as the main pump in open heart surgery to reduce damage to blood elements and to reduce the activation of the coagulation system. The purpose of this study was the evaluation and comparison of the effects of two types of centrifugal pumps and of one type of roller pump on blood elements, the coagulation system, complements, and immunoglobulins. Two types of centrifugal pumps (Lifestream; St. Jude Medical, Chelmsford, Massachusetts; and BP-80: Medtronic, BioMedicus, Inc., Eden Prairie, Minnesota, U.S.A.) and one roller pump (Mera Co.) were used separately as the main pump for cardiopulmonary bypass (CPB) in 29 patients. Platelet counts, lactate dehydrogenase, antithrombin III, thrombin-antithrombin complex (TAT), complements (C3, C4, and CH50) and immunoglobulins G, A, and M values were measured before and after CPB and compared. Values, except those for TAT, showed no significant difference among the three groups. The TAT values increased less in each of the centrifugal pump groups than in the roller pump group. This finding suggests that thrombin synthesis might be suppressed by the use of a centrifugal pump.

[Ventricular septal perforation following acute myocardial infarction in an 85-year-old woman].

An 85-year-old woman who experienced sudden severe chest and back pains was admitted to our hospital. On admission a pansystolic murmur was audible and the ECG showed an acute antero-septal myocardial infarction. Right heart catheterization revealed increased oxygen from the right atrium to the right ventricle, leading to the diagnosis of ventricular septal perforation (VSP). Hemodynamics of the patient were stabilized using only a low dosage of dopamine. However the heart weakened progressively, an operation was performed on the 13th day after the onset of the perforation. The post-operative course was uneventful. She is the oldest patient with VSP which has been successfully operated in Japan.