Article Text

other Versions

Test occlusion of Fontan fenestration: unique contribution of interventional MRI
  1. Aphrodite Tzifa,
  2. Reza Razavi
  1. Correspondence to Dr Aphrodite Tzifa; aphrodite.tzifa{at}

Statistics from

A 24-year old lady with fenestrated Fontan circulation was referred for a combined cardiac MRI and catheterisation procedure to assess her anatomy and suitability for fenestration closure. The patient was considering pregnancy; however, due to low saturations of 83%, successful pregnancy was unlikely.

Under interactive screening, the balloon of a wedge catheter was inflated in the lateral tunnel to render it visible as a dark spot in the bright surrounding blood.1 The balloon was then deflated and advanced through the 4 mm fenestration (panel A) into the atrium. Atrial saturations measured 83% and aortic phase contrast flow images revealed cardiac output of 3.22 l/min. The balloon was then inflated against the atrial wall to completely obstruct the fenestration (panel B). Repeat atrial saturations measured 96% and cardiac output decreased to 2.95 l/min. Lateral tunnel and systemic pressures remained unchanged. The minor drop of the cardiac output with the balloon inflated represented the contribution of the fenestration flow to the total cardiac output.

Panel A

Three-dimensional steady state free precession (SSFP) coronal view of the lateral tunnel showing the Fontan fenestration jet.

Panel B

Under interactive imaging, the balloon of the wedge catheter appeared like a dark circle in the surrounding white blood in the atrium (arrowhead). The balloon was kept inflated against the wall to obstruct the fenestration, while aortic phase contrast flows were performed to measure changes in the cardiac output.

Test occlusion of the Fontan fenestration must always be performed prior to interventional closure. In the catheterisation laboratory this entails measurement of the right atrial, left atrial and aortic pressures, mixed venous and aortic oxygen saturations, measurement of whole-body oxygen consumption, systemic blood flow, systemic oxygen transport and oxygen extraction.2 However, these measurements can be laborious and prone to errors. The clinical case reported is the first description of a more simplified method of assessing those patients, providing more accurate information on cardiac output changes with simultaneous pressure measurements.


View Abstract


  • Competing interests None.

  • Patient consent Obtained.

  • Ethics approval This study was conducted with the approval of the King's College Hospital Research Ethics Committee, 09/H0808/61, 26 June 2009.

  • Provenance and peer review Not commissioned; not externally peer reviewed.

Request permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.