Reverse order of staging in single ventricle palliation out of necessity: Southern Glenn

followed a Northern Fontan

A. Dodge-Khatami, MD, PhDChief of Pediatric and Congenital Heart SurgeryChildren’s Heart CenterProfessor of Surgery, University of Mississippi Medical CenterJackson, MS, USA

Introduction: from animal models to surgical norms

• 1950-58: Dr. Carlon/Italy, Dr. Meshalkin/Russia, Dr. Glenn/Yale had no canine survivors of the IVC-PA connection but success using the SVC. >> historical preference for standard palliation in single ventricle physiology to include a bi-directional Glenn with the SVC-PA anastomosis.

• however, with unfavorable upper body systemic venous anatomy (SVC thrombosis/stenosis), performing single ventricle staging in the usual manner with an initial superior vena cava-PA connection may be precluded or hazardous.

• if a standard SVC-PA Glenn is deemed a poor option, the suboptimal alternative is to leave the patient with shunt-dependent/banded physiology.

• we report a case of reverse staging out of necessity, namely performing a primary inferior cavo-pulmonary (IVC-PA) connection, followed by completion Fontan from above, after adequate SVC growth.

Case Presentation

• in a 6-month old infant with a very small SVC and thrombosed innominate vein, a primary extracardiac (Ø 14mm) inferior cavo-pulmonary connection (“Southern” Glenn) was performed.

• early post-operative extubation, standard low-dose iv. heparin (10U/kg/h) was transitioned to Aspirin.

• uneventful ICU stay (3 days), removal of chest drains and discharge to home on post-operative day 8.

• 3 month angiogram and CT scan: open IVC-PA connection, no veno-venous collaterals, and no hepatic venous congestion: victory?

• unknown outcome: ”Longer follow-up is warranted … whether it leads to an unplanned inter-stage reoperation, will be an ideal set-up for future Fontan completion with the SVC, or results in a final palliative stage not needing any further intervention…”

Dodge-Khatami et al. When the bidirectional Glenn is an unfavorable option: primary extracardiac inferior cavopulmonary connection as an alternative palliation. Cardiol Young 2016;26:1247-9

Case Presentation

• sixteen months later, increasing cyanosis led to the discovery of a veno-venous collateral that was coiled

• an SVC that had grown to larger-than-normal size.

• pre-Fontan angiogram showing the primary IVC-PA connection (“Southern Glenn”).

• despite the coiled collateral, persisting cyanosis led us to plan a fenestrated completion Fontan:

– mean PA 15mmHg– PVR 1.47 Wood/m2.

Surgery

• at 22 months of age, completion Fontan = standard “Northern” bi-directional cavo-pulmonary connection with the superior vena cava, and extracardiac fenestration, was performed.

• intra-operative picture prior to cannulation showing the larger-than-normal superior vena cava (remember the reverse IVC-PA staging was done owing to an initially unusable small SVC)

• the cephalad opening into the PA which will accommodate the SVC anastomosis.

• uneventful hospital course, 10-day intensive care stay requiring iNO, and was discharged to home on day 17, with 1-liter supplemental oxygen and empirical sildenafil.

• current 8 months post-operative follow-up: he (2 ½ years old) is thriving at home, fully saturated (with spontaneous fenestration closure) allowing discontinuation from oxygen.

Discussion

• reverse geographical staging, namely initial partial right heart bypass from below (South), followed by complete right heart bypass from above (North), is feasible in humans, despite it never working in a canine/animal model.

• if faced with unfavorable anatomical conditions for a bi-directional Glenn, reversing the staging order from North to South, namely performing a primary IVC-PA connection, allows earlier ventricular unloading rather than indefinitely leaving a volume-loaded heart with shunt-dependent physiology, or a pressure-loaded heart with a PA band.

• in our patient, following primary IVC-PA connection, altered systemic venous flow patterns or decompressing veno-venous collaterals led to impressive growth of a previously diminutive SVC, allowing completion Fontan with the SVC at 22 months of age, and a good clinical outcome.

• in complex shunt-dependent or banded single ventricle patients, increased experience with reversed staging out of necessity may encourage future protocol flexibility (2nd patient planned for completion Northern Fontan).

Ponderings on Innovation / Courage

• 1958 - Glenn: no canine survivors of the IVC-PA connection but success with the SVC, leading to systematic application of the SVC-PA palliation in humans as we know it today.

• 1968 - Fontan/Kreutzer: no canine survivors of total right heart bypass; the concept was still attempted out of desperation in humans, succeeded, and is now the routine surgical norm.

• animal models don’t necessarily apply to human physiology, or vice versa…

• 1954 - in the context of 7/14 deaths for VSD closure using cross-circulation, and then the first AVSD and TOF repair, “Cardiologist Helen Taussig, of blue-baby operation fame, also condemned Lillehei. Learning of his one success with tetralogy of Fallot, Taussig said, Too bad, now he’ll continue.”

King of Hearts: the true story of the Maverick who pioneered open heart surgery. G. Wayne Miller

Thank Y’All !