title: Subannular perforation of left ventricular outflow tract associated with transcatheter valve implantation: pathophysiological background and clinical implications.
abstract: OBJECTIVE
  Perforation of the subannular left ventricular outflow tract (LVOT) represents an uncommon but almost invariably fatal transcatheter aortic valve implantation (TAVI)-associated complication. The risk factors to predict the occurrence of this devastating complication, particularly in relation to specific LVOT anatomy, have not yet been systematically analysed. We aimed to evaluate the pathophysiological background and possible risk factors for the occurrence of subannular LVOT perforation.
  
  
  METHODS
  A total of 6 (0.7%) consecutive patients (78.8 ± 3.3 years, 83% women) with subannular LVOT perforation complicating TAVI procedure were identified from our institutional TAVI registry, including 900 consecutive patients who underwent TAVI procedure at a single institution between January 2009 and July 2015. Only patients with an intraoperatively confirmed LVOT perforation were included.
  
  
  RESULTS
  The computed tomography (CT)-guided analysis of aortic root/LVOT morphology revealed subannular calcification in close proximity of the anatomically weakest region of muscular LVOT (i.e. in the region of the muscular LVOT between the left fibrous trigone and the left/right commissure) in 5/6 (83%) patients. Moreover, significant annular asymmetry >20% was present in 4/6 (67%) patients and was combined with a severe asymmetric hypertrophy of muscular LVOT.
  
  
  CONCLUSIONS
  Subannular calcification in close proximity of the anatomically unprotected muscular LVOT might represent an important risk factor for the occurrence of subannular LVOT injury. Precise CT-based analysis of patient-specific aortic root anatomy/subannular calcification patterns may be helpful to predict this TAVI-associated complication preoperatively and hence to avoid it in future patients.
authors.affiliation: Department of Cardiovascular Surgery, University Heart Center Hamburg, Hamburg, Germany e.girdauskas@uke.de evagird@centras.lt.
authors.forename: Evaldas
authors.initials: E
authors.lastname: Girdauskas
authors.affiliation: Department of Cardiac Surgery, Central Hospital Bad Berka, Bad Berka, Germany.
authors.forename: Tamer
authors.initials: T
authors.lastname: Owais
authors.affiliation: Department of Radiology, Central Hospital Bad Berka, Bad Berka, Germany.
authors.forename: Beatrix
authors.initials: B
authors.lastname: Fey
authors.affiliation: Department of Cardiac Surgery, Central Hospital Bad Berka, Bad Berka, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Kuntze
authors.affiliation: Department of Cardiology, Central Hospital Bad Berka, Bad Berka, Germany.
authors.forename: Bernward
authors.initials: B
authors.lastname: Lauer
authors.affiliation: Columbia University Medical Center, New York, NY, USA.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Borger
authors.affiliation: Department of Cardiovascular Surgery, University Heart Center Hamburg, Hamburg, Germany.
authors.forename: Lenard
authors.initials: L
authors.lastname: Conradi
authors.affiliation: Department of Cardiovascular Surgery, University Heart Center Hamburg, Hamburg, Germany.
authors.forename: Hermann
authors.initials: H
authors.lastname: Reichenspurner
authors.affiliation: Department of Cardiac Surgery, Central Hospital Bad Berka, Bad Berka, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Kuntze
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001021:Aortic Valve / Q000601:surgery*; D001024:Aortic Valve Stenosis / Q000601:surgery*; D005260:Female; D006335:Heart Injuries / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000293:injuries* / Q000503:physiopathology; D006801:Humans; D008297:Male; D061330:Multidetector Computed Tomography; D011183:Postoperative Complications; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012307:Risk Factors; D065467:Transcatheter Aortic Valve Replacement / Q000009:adverse effects*; D016277:Ventricular Function, Left / Q000502:physiology*
keywords: Annular rupture; Complication; Surgery; TAVI