Cardiovascular surgery (London, England)
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Between October 1979 and January 1993, 85 Chinese neonates in Hong Kong underwent surgical repair for coarctation of the aorta. Their mean (s.e.) age and body weight at operation was 15.6(8.5) days and 3.06(0.56) kg, respectively. Simple coarctation was present in 17 babies, while 36 had additional ventricular septal defect and 31 had associated major complex intracardiac lesions. ⋯ Successful balloon angioplasty was subsequently performed in 11 patients. In an era of echocardiography with prenatal diagnosis and therapeutic catheterization, early recognition of the disease with prompt prostaglandin infusion should prevent collapse of the baby, thus avoiding renal impairment and sever metabolic acidosis. Balloon angioplasty would offer a simple effective treatment of patients who developed aortic re-coarctation.
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From 1967 to 1993, 21 patients underwent surgical repair of aortic left ventricular discontinuity as a result of acute bacterial endocarditis. Repair of the defect between the aorta and left ventricle was usually with interposition of a patch (prosthetic patch or autologous pericardium), using a continuous monofilament suture. Interrupted pledgetted stitches were used when the ventricular tissue appeared friable. ⋯ Of 11 long-term survivors (5 to 61 months (mean 21 months) after operation), nine have had event-free courses. Two cases of recurrent subacute bacterial endocarditis occurred 3 and 52 months after surgery in patients who were intravenous drug abusers, both of whom were managed medically. It is concluded that while aortic left ventricular discontinuity remains a potentially lethal complication of acute bacterial endocarditis, débridement of infected necrotic tissue, patch repair of the defect, and prosthetic valve replacement offer satisfactory immediate and late results.
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Comparative Study
Reperfusion injury in skeletal muscle: controlled limb reperfusion reduces local and systemic complications after prolonged ischaemia.
Previous studies in isolated limbs using crystalloid perfusion solutions have shown that control of the initial reperfusion reduces postischaemic complications. However, no experimental study has been undertaken to evaluate the concept of controlled limb reperfusion experimentally in an in vivo blood-perfused model and to assess the local as well as systemic effects of normal blood reperfusion and controlled limb reperfusion. Of 20 pigs undergoing preparation of the infrarenal aorta and iliac arteries, six were observed for 7.5 h and served as controls; 14 others underwent 6 h of complete infrarenal occlusion. ⋯ Furthermore, controlled limb reperfusion resulted in higher total adenine nucleotides content, less tissue acidosis, markedly reduced creatine kinase release, and potassium release as compared with that of normal blood reperfusion. This study shows that 6 h of acute infrarenal aortic occlusion will result in severe reperfusion injury (postischaemic syndrome) if normal blood at systemic pressure is given in the initial reperfusion phase. In contrast, initial treatment of the ischaemic skeletal muscle by controlled limb reperfusion reduces the metabolic, functional and biochemical alterations.
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Comparative Study
Reperfusion injury in skeletal muscle: interaction of osmotic and colloid-osmotic pressure in the initial reperfusate for oedema prevention.
Previous studies from the authors' laboratory have shown that controlled limb perfusion after prolonged, acute ischaemia minimizes reperfusion injury. The present study was performed to investigate the role of osmotic and colloid-osmotic pressure in the initial reperfusate in order to reduce postischaemic limb oedema and subsequent reperfusion injury. A total of 96 isolated rat hindlimbs were used: 18 were perfused immediately after amputation (no ischaemia; untreated) and 78 limbs were subjected to 4 h of warm ischaemia in a moist chamber. ⋯ Furthermore, colloid-osmotic pressure > 26 mmHg increases the viscosity of the reperfusate (flow decreases to < 50% of control) and does not allow an optimal functional recovery. Macromolecules used to create the colloid-osmotic pressure should be of similar molecular weight to albumin (69,000 Da); those with a smaller molecular weight (e.g. hydroxyethyl starch40,000/0.5) produce excessive limb oedema (184.9(13.5)% control weight; 85.7(1.4)% water content) without functional recovery (0% control contractions). The present data suggest that after prolonged limb ischaemia: (1) addition of mannitol to a crystalloid solution does not prevent oedema; (2) hyperosmotic reperfusates (380-480 mosmol/l) with a colloid-osmotic pressure of 26 mmHg are most effective in preventing limb oedema; and (3) macromolecules used to achieve colloid-osmotic pressure should have a molecular weight similar to albumin.