Primary goal of repair

Reduction of the volume work of the single ventricle and a predictable Qp:Qs (pulm:systemic) of 0.6-0.7

Stage 2 Bidirectional Glenn

Description of repair

  • SVC is divided w/ cardiac end oversewn. 
  • Cephalic end is anastomosed end to side w/ ipsilateral PA.
  • Typically done b/w 4-9 months

Important physiology post glenn

  • Pulmonary blood flow is PASSIVE!
  • All SVC return must pass through lungs to reach the heart.
  • Ventricular filling is not absolutely dependent on pulmonary venous return, because IVC still returns blood to single ventricle which maintains preload.
  • Early extubation is key!
  • Pts need anticoagulation to prevent shunt from clotting.

Post operative issues

Elevated SVC pressures

  • Sx: Upper extremity plethora, edema, unexplained fussiness, full anterior fontanelle
  • May have obstruction at anastomosis, distal PA distortion, or marked elevations in PVR.
  • Will limit cerebral blood flow


  • HTN may be caused by pain, catecholamine secretion, or intracranial HTN.
  • Be cautious in lowering too quickly as may decrease cerebral blood flow.
  • Bradycardia may be due to acute reduction in volume load of single ventricle, intracranial HTN, or injury to sinus node.


  • Consider pulm venous desat, decreased pulm blood flow, or low SVO2 (see previous page).
  • Important to consider pulm AV malformations as additional cause of pulm venous desat.
  • Decompressing venous collaterals, baffle leak, or contralateralSVC may also cause decreased pulm blood flow.

Chylothorax/pleural effusions

  • Common post-op problem.  Follow output closely and replacement of lytes and immunoglobulins is key.