[Direct angioplasty of the left main coronary artery with a pericardium flap].

Surgical treatment of stenosis of the left main coronary artery (LMCA) is a special problem, a number of questions of surgical strategy for this lesion still remain unsolved. The question of direct plasty dilatation of LMCA has not lost its actuality. Operations were made on 6 patients in whom direct plasty dilatation of LMCA with a flap from autopericardium was performed for local, not lengthy constriction which was located in the initial and middle part of LMCA. The operations were made under conditions of extracorporeal circulation, moderate general hypothermia (about 32 degrees C), pharmacohypothermic cardioplagia with external cooling of the heart. In all cases there was good restoration of cardiac activity and the absence of myocardium ischemia at the postoperative period. The restoration of the anatomical lumen of LMCA by this method facilitated sufficient blood flow along LMCA. Five years later all the patients are alive, one patient has external angina of the 11 functional class.

[Technique of endarterectomy from pulmonary artery in chronic thromboembolic pulmonary hypertension].

The article gives detailed description of a technique of pulmonary endarterectomy in chronic thromboembolic pulmonary hypertension. The method is based on the experience of the world leader in surgical treatment of this disease--the clinic of California, San Diego headed by Stuart Jamieson, cardiothoracal clinic Papworth Hospital in the only center in Great Britain, where PE is performed and on the experience obtained by the collective of the Department of hospital surgery of the medical department of the St. Petersburg state University and the City multi-field hospital.

Regulation of hepatic microcirculation in stepwise liver resection.

BACKGROUND: After liver resection a small-for-size syndrome may result from the reduction of liver volume and additional liver damage caused by hepatic hyperperfusion. Therefore the influence of the extent of liver resection on liver perfusion is investigated. MATERIAL AND METHODS: A stepwise liver resection (removal of 30%, 70%, 90%, 95% and 97% of the liver) was performed under inhalation anaesthesia with isoflurane in 6 male Lewis rats. Besides systemic arterial and venous blood pressure the portal pressure and flow was measured and the sinusoidal perfusion was visualized. Sinusoidal diameter, intersinusoidal diameter and functional capillary density were determined. RESULTS AND CONCLUSIONS: A decrease in the portal flow but an increase in the portal pressure was observed. Sinusoidal diameter showed a steady but low increase when up to 70% of the liver was removed but a high increase after 90% or more of the liver was resected. This indicates a decompensation of a regulatory mechanism of sinusoidal perfusion.

Deleterious effects of oxygen during extracorporeal circulation for the microcirculation in vivo.

OBJECTIVE: Clinical complications arising from extracorporeal circulation (ECC) have been linked to disturbances in the microcirculation. Hyperoxia, a mainstay of supportive treatment, is clinically used for a variety of pathological states. In previous in vivo animal experiments we found increased leukocyte/endothelial (L/E) cell interaction following ECC due to oxygen derived free radicals. This study was carried out to investigate the link between arterial pO2 during ECC and the potential damage to the microcirculation, supposedly caused by oxygen derived radicals. METHODS: Intravital fluorescence microscopy was used on the dorsal skinfold chamber preparation in syrian golden hamsters. ECC was introduced via a micro-rollerpump (0.7 ml/min) and a 60 cm silicon tube (1 mm inner diameter) shunted between the carotid artery and the jugular vein after application of 300 IE Heparin/kg/bw. Experiments were performed in chronically instrumented, awake animals (age: 10-14 weeks, weight: 65-75 g). Control inspired room air, experimental group 1 inspired 100% oxygen, group 2 received 100% oxygen and 2000 IE of Heparin i.v. (n=7/group), that releases endothelial bound superoxide dismutase, a natural scavenger of oxygen derived free radicals in the hamster. RESULTS: Normobaric inhalation of 100% oxygen increased arterial pO2 from 64+/-8.1 mmHg to 512+/-124 mmHg (P<0.05 vs. baseline). ECC under 100% oxygen reduced functional capillary density (FCD) to 70% of baseline values 8 h after ECC (P<0.05). Adherent leukocytes in postcapillary venules and arterioles increased significantly (P<0.05). 2000 IE Heparin prevented the reduction in FCD and decreased the number of adherent leukocytes. CONCLUSIONS: Reduction in FCD, increased leukocyte adherence to the microvascular endothelium of postcapillary venules and arterioles under hyperoxia compared to ECC under room air conditions, demonstrates harmful effects of oxygen during ECC in vivo. A high dose of Heparin enhances functional capillary density, thus attenuating the microvascular dysfunction/damage in the period after ECC.