Procedure. The super-Glenn is a procedure that is used to augment flow to the left ventricle (as part of an LV recruitment pathway) or to promote the growth of one of the pulmonary arteries (as part of a single ventricle pathway). The ‘typical’ super-Glenn includes the following components:
- A right superior cavopulmonary (i.e. Glenn) anastomosis may be part of the procedure or maybe in situ from the prior palliation.
- A systemic to pulmonary shunt (typically a BT shunt) to the contralateral PA. Alternatively, a Sano shunt is left in situ. As shown, the shunt may anastomose to the RPA itself but with the majority of flow directed to the LPA. The connection between the RPA and LPA is typically restricted using a fenestrated patch as shown to diminish the pulsatility in the SVC (i.e. cerebral venous drainage). This provides pulsatility to the LPA, which may enhance LPA growth; this may be important for the future candidacy of a patient for the Fontan circulation, as sometimes a Sano conduit favors RPA flow and results in a hypoplastic LPA. Once PBF is completely passive (i.e. following BDG), a hypoplastic PA is difficult to recruit and may result in progressive loss of effective lung perfusion.
- In the Glenn circulation, PBF represents only ~50-60% of systemic blood flow, with the remainder of systemic venous return coming to the RV via the IVC. When the LV is borderline and considered recruitable, the additional flow from the shunt may be directed into the LV using a fenestrated ASD closure. In this setting, it is important to monitor for postoperative LA HTN.