title: Left pulmonary artery kinking caused by outflow tract dilatation after transannular patch repair of tetralogy of Fallot.
abstract: BACKGROUND
  Stenosis of the branch pulmonary arteries after tetralogy of Fallot repair can result from several mechanisms. In patients with free pulmonary regurgitation and right ventricular dilatation after transannular patch repair, we have observed that the pulmonary outflow tract can dilate and elongate craniad and rotate to the left, resulting in kinking and obstruction of the previously normal left pulmonary artery.
  
  
  METHODS
  Ten patients referred for reoperation after tetralogy repair with severe pulmonary regurgitation and right ventricular outflow tract dilatation were found to have left pulmonary artery kinking. In 8 of these patients kinking was the sole or partial cause of left pulmonary artery obstruction, whereas there was no documented obstruction in the other 2. All patients underwent right ventricular outflow tract reconstruction and left pulmonary artery repair with removal of the redundancy at the kink point. Patching alone is not an effective method of repair in this condition, because the mechanism of obstruction is not corrected and the patch material can become redundant and lead to recurrent obstruction.
  
  
  RESULTS
  All patients underwent successful pulmonary outflow tract reconstruction. Left pulmonary artery kinking was corrected in all patients, and relief of obstruction was attained in the 8 patients with stenosis. At follow-up ranging from 9 to 58 months, no patient has evidence of recurrent left pulmonary artery stenosis.
  
  
  CONCLUSIONS
  Left pulmonary artery kinking should be suspected at long-term follow-up after tetralogy repair in patients with significant pulmonary regurgitation and right-sided dilatation, even if previous evaluations showed no evidence of left pulmonary arterial abnormality. Because unilateral obstruction caused by kinking may lead to asymmetric pulmonary flow, it can exacerbate pulmonary regurgitation and right ventricular dilatation, in effect accelerating the processes that led to kinking in the first place. Kinking can be relieved successfully with the techniques described in this report.
authors.affiliation: Division of Cardiothoracic Surgery, University of California, San Francisco, USA.
authors.forename: D B
authors.initials: DB
authors.lastname: McElhinney
authors.forename: A J
authors.initials: AJ
authors.lastname: Parry
authors.forename: V M
authors.initials: VM
authors.lastname: Reddy
authors.forename: F L
authors.initials: FL
authors.lastname: Hanley
authors.forename: P
authors.initials: P
authors.lastname: Stanger
mesh_terms: D000293:Adolescent; D000328:Adult; D001157:Arterial Occlusive Diseases / Q000209:etiology; D002648:Child; D002675:Child, Preschool; D003251:Constriction, Pathologic / Q000209:etiology; D004108:Dilatation, Pathologic / Q000150:complications; D005500:Follow-Up Studies; D006352:Heart Ventricles / Q000473:pathology; D006801:Humans; D007223:Infant; D008137:Longitudinal Studies; D011183:Postoperative Complications / Q000601:surgery; D019919:Prosthesis Implantation / Q000009:adverse effects; D011651:Pulmonary Artery / Q000473:pathology* / Q000601:surgery; D011652:Pulmonary Circulation; D011665:Pulmonary Valve Insufficiency / Q000209:etiology; D012008:Recurrence; D012039:Regional Blood Flow; D012086:Reoperation; D013771:Tetralogy of Fallot / Q000601:surgery*; D014652:Vascular Diseases / Q000473:pathology / Q000601:surgery; D014694:Ventricular Outflow Obstruction / Q000209:etiology / Q000601:surgery