Mechanically assisted bidirectional cavopulmonary shunt in neonates and infants: An acute human pilot study.
Poor survival following surgical palliation for hypoplastic left heart syndrome (HLHS) raises the question of the need for a paradigm shift. This is the first human study to investigate the possibility of primary "in-series" palliation in neonates and infants with HLHS in an acute setting with the aid of 2 types of mechanical assist: superior vena cava (SVC)-to-pulmonary artery (PA) pump assist and SVC-to-right atrium (RA) oxygenation assist.



By rearranging the cannula sites and flow rates for modified ultrafiltration, 2 types of mechanically assisted bidirectional cavopulmonary shunt (BCPS) circulation were simulated for 20 minutes. Three neonates undergoing a stage I Norwood procedure were assigned to SVC-PA pump assist, and 3 infants undergoing stage II BCPS were assigned to SVC-RA oxygenation assist. Hemodynamic parameters, blood gas values, and arterial (SaO2) and regional cerebral tissue (rCTO2) saturations were analyzed.



All 6 patients completed the study without hemodynamic compromise. In the SVC-PA pump assist group, a mean arterial pressure >40 mm Hg was maintained. SVC pressure was lower (P = .01) and cerebral perfusion pressure (CPP) was higher (P = .03) during the last 10 minutes of assist compared with Norwood physiology. SaO2>80%, rCTO2>60%, and mixed venous saturation ≥59% were maintained, comparable to values with Norwood physiology. In the SVC-RA oxygenation assist group, with full or 50% support, mean blood pressure >50 mm Hg, SVC pressure <15 mm Hg, mixed venous saturation >50%, and CPP >40 mm Hg were maintained, which were comparable to BCPS physiology.



Two types of mechanical assist to support primary in-series palliation are feasible in the acute setting. Both modes of mechanical assist maintained oxygenation, as well as systemic and cerebral perfusion.
The Labatt Family Heart Centre, The Hospital for Sick Children and The University of Toronto, Toronto, Ontario, Canada.
Osami
O
Honjo
The Labatt Family Heart Centre, The Hospital for Sick Children and The University of Toronto, Toronto, Ontario, Canada.
Sandra L
SL
Merklinger
The Labatt Family Heart Centre, The Hospital for Sick Children and The University of Toronto, Toronto, Ontario, Canada.
John B
JB
Poe
Department of Critical Care Medicine, The Hospital for Sick Children and The University of Toronto, Toronto, Ontario, Canada.
Anne-Marie
AM
Guerguerian
The Labatt Family Heart Centre, The Hospital for Sick Children and The University of Toronto, Toronto, Ontario, Canada.
Hargen
H
Zhang
Department of Anaesthesia, The Hospital for Sick Children and The University of Toronto, Toronto, Ontario, Canada.
Katherine L
KL
Taylor
Division of Cardiovascular Surgery, The Hospital for Sick Children and The University of Toronto, Toronto, Ontario, Canada. Electronic address: glen.vanarsdell@sickkids.ca.
Glen S
GS
Van Arsdell
D000208:Acute Disease; D001243:Assisted Circulation / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D018729:Fontan Procedure / Q000379:methods*; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D018636:Hypoplastic Left Heart Syndrome / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D007231:Infant, Newborn; D008297:Male; D010865:Pilot Projects; D016896:Treatment Outcome
bidirectional cavopulmonary shunt; in-series palliation; mechanical circulatory assist; single-ventricle physiology