title: Right ventricular outflow tract reconstructive model in adult sheep.
abstract: Patients born with congenital right ventricular outflow tract lesions are faced with invasive procedures to establish hemodynamic and physiological stability. Commonly, multiple subsequent surgical procedures are required due to deterioration of a previous repair. These procedures carry additive risks of mortality and morbidity. Less aggressive procedures with accompanying lower risk is ideal. Success in percutaneously placing a transcatheter valve has previously been reported; however, continued safety and efficacy of any technique needs continual assessment. We developed a model for preclinical evaluation of a percutaneous placement of a pulmonic transcatheter valve in adult sheep, including preoperative, surgical, and postoperative techniques for long-term evaluation. Adult sheep were assessed and determined to be acceptable for study enrollment. Perioperative antibiotics and analgesics were given prior to a left thoracotomy. A Medtronic, Hancock 1 valve conduit was inserted for reconstruction of the right ventricular outflow tract. The Hancock 1 valve conduit alone represented the control group and the test animals comprised the addition of a Melodytrade mark transcatheter pulmonary valve (TPV), within the Hancock 1 valve conduit. Fifteen adult sheep survived the surgical implant procedure with no perioperative mortality. There were four early postoperative deaths, three due to infection and one due to heart failure, secondary to intraoperative heart block. The remaining 11 animals remained healthy, gained weight, and survived to termination at 5 months. An initial definite-sized valve conduit was implanted, followed by inserting a single size TPV, which allowed a more accurate physiological assessment of any chosen valve. Our developed adult sheep model for percutaneous TPV implantation for right ventricular outflow tract lesions was successful for long-term assessment by utilizing our preoperative, surgical, and postoperative techniques.
authors.affiliation: Physiological Research Laboratories, Medtronic, Inc., Minneapolis, Minnesota, USA.
authors.forename: Nancy
authors.initials: N
authors.lastname: Rakow
authors.forename: Noah
authors.initials: N
authors.lastname: Barka
authors.forename: Dale
authors.initials: D
authors.lastname: Nelson
authors.forename: Nan
authors.initials: N
authors.lastname: Allen
authors.forename: Robyn
authors.initials: R
authors.lastname: Gringaard
authors.forename: Phillip
authors.initials: P
authors.lastname: Falkner
authors.forename: Phil
authors.initials: P
authors.lastname: Wahlberg
authors.forename: Jack
authors.initials: J
authors.lastname: Lemmon
authors.forename: Lynette
authors.initials: L
authors.lastname: Phillips
authors.forename: Tina
authors.initials: T
authors.lastname: Billstrom
authors.forename: Alex
authors.initials: A
authors.lastname: Hill
authors.forename: Linda M
authors.initials: LM
authors.lastname: Shecterle
authors.forename: J A
authors.initials: JA
authors.lastname: St Cyr
mesh_terms: D000818:Animals; D006328:Cardiac Catheterization; D005260:Female; D006330:Heart Defects, Congenital / Q000601:surgery*; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000295:instrumentation / Q000379:methods*; D008297:Male; D023421:Models, Animal; D011183:Postoperative Complications / Q000000981:diagnostic imaging; D011664:Pulmonary Valve; D011859:Radiography; D019651:Plastic Surgery Procedures / Q000295:instrumentation / Q000379:methods*; D012756:Sheep; D015996:Survival Rate; D014694:Ventricular Outflow Obstruction / Q000601:surgery*