TV atresia

Question 1

Gross path lesions/histo

Answer 1

• Absence of connection btw morphologic RA and RV
  o Fibrofatty tissue interposed btw muscular RA floor and parietal wall of ventricular mass in 95% of cases
  o Imperforated TV membrane in 5% of cases

Question 2

Pathophys

Answer 2

systemic venous return → RA → ASD → LA → mixes w pulmonary venous return → single AV valve → LV → systemic and pulmonary circulations
o Functionally univentricular heart

Question 3

Anatomic features always present w/ TV atresia

Answer 3

 Absence of connection btw physiologic RA and RV
 Hypoplasia of morphologic RV
 Interatrial communication: PFO or ASD
 Morphologic LV w morphologic MV

Question 4

Anatomic features sometimes present w/ TV atresia

Answer 4

 Transposition of GAs
 Pulmonary stenosis
 Size of coexisting VSD: need communication btw systemic and pulmonary circulation
* Occasionally PDA with pulmonary atresia

Question 5

Goal of sx correction

Answer 5

separation of systemic and pulmonary circuits
 Provide adequate pulmonary blood flow → ↓ hypoO2
 Prevent pulmonary overcirculation/PH → can lead to LV failure
 Preserve PA anatomy for later sx

Question 6

Sx correction if no concurrent TGA

Answer 6

 Systemic to pulmonary shunt performed at 6-8wks
 Primary bidirectional Glenn procedure in older children
* Classic Glenn’s shunt = CrVC → RPA
* No volume/pressure overload of single ventricle compared to systemic-PA shunting
* Provide venous flow to lungs for oxygenation and improve O2 saturation

Question 7

Sx correction if concurrent TGA

Answer 7

 Early palliation
* Pulmonary artery banding → ↓ pulmonary blood flow
* Norwood stage 1 procedure if severe stenosis and hypoplastic Ao
 Fontan procedure: only if good ventricular fct, unobstructed systemic blood flow and minimal AV valve regurgitation
* Diversion of systemic venous return → PA bypassing RV
* Definitive palliative sx tx if biventricular repair is not possible
* Ideally: younger, ↓PVR/PAP, adequate PA diameter, normal RA, systemic venous connections, sinus rhythm
o If ↑ venous or RAP → ↑ mean PAP → pleural effusion
o If ↑PVR/PAP → ↓ forward flow → ↓ L side filling → ↓ CO
 Fenestrations btw systemic venous atrium (RA) and pulmonary venous atrium (LA) = safety valve to ensure adequate LV filling
 Total cavopulmonary anastomosis
* Tunnel in RA directing caval blood → PA through anastomosis on underside RPA
* Eliminate diated systemic venous reservoir w ↑ RAP