title: The proper delivery pressure for cardioplegic solution in neonatal cardiac surgery - an investigation of biomechanical and structural properties of neonatal and adult coronary arteries.
abstract: When cardioplegic solution is injected into coronary arteries with a pump in order to ensure myocardial protection, it is necessary to determine the correct delivery pressure to avoid damage of the heart. Biomechanical and structural properties of the neonatal coronary artery wall should be taken into account when determining the delivery pressure. We investigated twelve coronary artery specimens without cardiac pathology retrieved from autopsies of neonates 9.3 ± 9.7 days old and compared them to adult specimens with no detected atherosclerosis. There was a rapid increase in the strain until the inner pressure reached 80 - 100 mmHg, whilst the increase of stress in the wall of the neonatal coronary arteries was less rapid. When the pressure exceeded 100 mmHg, the increase in the strain slowed down, whilst the wall stress and modulus of elasticity began to increase rapidly. Morphologic examination of tensile properties revealed prominent affection of the vascular wall of the neonates, with accentuated redistribution (loosening) of medial myocytes and the adventitial vasa vasorum. Collectively, a raised inner pressure applied to cardioplegic solution injected into the coronary artery of a neonate may increase the risk of structural damage to the vascular wall.
authors.affiliation: Clinic for Pediatric Cardiology, and Cardiac Surgery, Children's University Hospital, Riga Stradins University, Riga LV-1004, Latvia. normundssikora@yahoo.com
authors.forename: N
authors.initials: N
authors.lastname: Sikora
authors.forename: A
authors.initials: A
authors.lastname: Lacis
authors.forename: V
authors.initials: V
authors.lastname: Kasyanov
authors.forename: V
authors.initials: V
authors.lastname: Groma
authors.forename: E
authors.initials: E
authors.lastname: Ligere
authors.forename: V
authors.initials: V
authors.lastname: Ozolins
authors.forename: L
authors.initials: L
authors.lastname: Smits
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D006348:Cardiac Surgical Procedures / Q000379:methods; D002314:Cardioplegic Solutions / Q000008:administration & dosage* / Q000627:therapeutic use*; D002315:Cardiopulmonary Bypass / Q000379:methods; D003331:Coronary Vessels / Q000737:chemistry / Q000473:pathology* / Q000648:ultrastructure*; D006801:Humans; D007231:Infant, Newborn; D011312:Pressure; D013314:Stress, Mechanical
chemical_list: D002314:Cardioplegic Solutions
keywords: biomechanical and structural properties of the vascular wall; cardiopulmonary bypass; delivery pressure for cardioplegic solution; neonatal coronary artery