title: Hidden (end-on) patent ductus arteriosus: recognition and device closure.
abstract: BACKGROUND
  Sometimes, it is difficult to visualize a patent ductus arteriosus and deploy a device in the standard lateral view because of an end-on orientation. The right anterior oblique view may be helpful by separating the ductus arteriosus from the aorta. This study was undertaken to evaluate the incidence of end-on patent ductus arteriosus and the utility of the right anterior oblique view during device closure.
  
  
  METHODS
  Aortography was performed in lateral and right anterior oblique views before, during, and after successful device deployment in 117 consecutive patients. When a ductus arteriosus was not clearly visible in the lateral view due to overlapping by the aorta, it was termed "right anterior oblique view useful".
  
  
  RESULTS
  The types of patent ductus arteriosus were A, B, C, and E in 86 (73.5%), 20 (17.1%), 4 (3.4%), and 7 (6.0%) patients, respectively. An end-on ductus arteriosus was present in 24 (20.5%) patients (14 type B, 10 type A). The right anterior oblique view was useful during device closure in 15 (12.8%) cases (all end-on type). Among all cases of end-on patent ductus arteriosus, it was useful in 62.5% (most type B and a few type A). In all of these, the device appeared obliquely oriented and foreshortened in the lateral view but fully profiled in the right anterior oblique view.
  
  
  CONCLUSIONS
  Recognizing an end-on patent ductus arteriosus and utilizing the right anterior oblique view simplified device closure. For ducts well-profiled in the lateral view, the right anterior oblique view is unnecessary and avoidable.
authors.affiliation: Department of Cardiology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India navgarg@sgpgi.ac.in.
authors.forename: Naveen
authors.initials: N
authors.lastname: Garg
authors.affiliation: Department of Cardiology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India.
authors.forename: Bevunahalli Kantharaj
authors.initials: BK
authors.lastname: Madan
mesh_terms: D000293:Adolescent; D000328:Adult; D001027:Aortography; D006328:Cardiac Catheterization / Q000295:instrumentation*; D002648:Child; D002675:Child, Preschool; D004373:Ductus Arteriosus / Q000000981:diagnostic imaging*; D004374:Ductus Arteriosus, Patent / Q000000981:diagnostic imaging* / Q000628:therapy*; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011474:Prosthesis Design; D055989:Septal Occluder Device; D016896:Treatment Outcome; D055815:Young Adult
keywords: Aortography; Cardiac catheterization; Ductus arteriosus; Vascular closure devices