Preoperative Echocardiographic Assessment of Uni-ventricular Repair Salem Deraz, MD Pediatric Cardiologist, Aswan Heart Centre Magdi Yacoub Heart Foundation
Uni-ventricular repair A single or series of surgical procedures that result in: The entire ventricular mass is assigned to the systemic circulation Systemic venous return (pulmonary circulation) drains passively to lung
Usual Steps Decision to proceed with uni-ventricular repair First stage PDA stent Systemic to pulmonary artery shunt (BTS) PA band DKS and BT shunt Norwood (AAO and arch reconstruction + BTS / Sanno) Second stage Glenn shunt (SVC to PA) Third stage Fontan ( adding IVC to PA)
When to consider a uni-ventricular repair Atretic AV valve Atretic TV Atretic MV
When to consider a uni-ventricular repair cont. Hypoplastic ventricle ( even with a patent AV valve) DILV Hypo RV L looped V Hypoplastic LV
When to consider a uni-ventricular repair cont. Difficult septation ( even with good size AV valves and ventricular cavity) DORV with remote VSD Certain types of Shon s complex
Is it a usable single ventricle Good ventricular function No significant AV valve regurgitation
Echo evaluation prior to first stage surgery Type of surgery differ according to UNIV anatomy PAB PDA Stent or BTS Norwood Objectives - Secure an adequate and controlled pulmonary blood flow - Secure a patent UNIV to DAO pass (no UNIV outflow obstruction & no coarctation)
Secure an adequate and controlled pulmonary blood flow 1. Size and morphology of central pulmonary arteries 2. Source and adequacy of pulmonary blood flow 3. Rule out ASD restriction Secure a patent UNIV to DAO pass 1. Evaluate RVOT and LVOT ( Ventricle to AAO) 2. Rule out coarctation
PA s must be appropriate in size & confluent Size and morphology of central pulmonary arteries Non confluent PA s Confluent small PA s
Source & adequacy of Pulmonary blood flow Atretic pulmonary valve Evaluate if PDA stentable Non tortuous Short No branch stenosis no coarctation PDA suitable for stenting Pulmonary stenosis or sub PS Good O 2 sat Wait Low O 2 sat BTS Free unprotected pulmonary flow PA band PDA not suitable for stenting
ASD patency Must be patent to flow with mean pressure gradient of < 3 mmhg Restriction to flow hinder flow before and after surgery HLHS with intact atrial septum Look for vertical vein!!!
Inspect sub-aortic area Restrictive BVF DKS
Echo evaluation prior to second stage surgery Second Stage : SVC connection to ipsilateral PA Cavo- pulmonary anastomosis (Glenn) In interrupted IVC (Kawashima)
Usable ventricle: Good UNIV function No sig AV valve regurgitation Evaluation of first stage s objectives Good size PA s Patent ASD No UNIV to AAO obstruction No COA SVC anatomy In single SVC In bilateral SVC Rule out IIVC ( is it right or left) ( is there a bridging vein) ( Identify the dominant SVC)
Post PA band one should be careful from the newly developed sub AS or restriction of BVF
SVC Anatomy Bilateral SVC Is there a bridging vein In situs solitus or RA isomerism
Rule out IIVC 1. Delaying Glenn (Kawashima) if possible 2. Azygous, hemiazygous will not be tied off 3. Higher incidence of polysplenia needs abdominal US / antibiotics prophylaxis 4. Higher incidence of venovenous malformation after Kawashima early hepatic incorporation
Echo evaluation prior to third stage Third Stage : IVC connection to ipsilateral PA (Fontan) In IIVC: HV connection to ipsilateral PA (Hepatic v incorporation)
Usable ventricle: Good UNIV function No sig AV valve regurgitation Evaluation of first stage objectives Good size PA s Patent ASD No UNIV to AAO obstruction No COA Evaluation of second stage objectives IVC anatomy Patency of Glenn In IIVC ( sidedness of HV and SVC) ( Locate the dominant SVC in bilateral SVC)
Glenn Evaluation SVC to PA stenosis Left Innominate external compression
IVC Anatomy From subcostal long axis Abdominal & Atrial situs indicate the site of the IVC Situs solitus Situs inversus Right IVC Left IVC From subcostal short axis
In interrupted IVC, (s. solitus, LA isom) hepatic segment is absent Azygos vein continuation to SVC. Hemi-Azy continuation to left brachiocephalic From subcostal long axis 4 things to be addressed in IIVC 1- Az or Hem-Az continuation 2- Sidedness of SVC in relation to HV 3- In bilateral SVC identify the dominant SVC 4- Anatomy of hepatic drainage
interrupted IVC Azygos continuation to RSVC 1- Az or Hem-Az continuation interrupted IVC Hemi - Azygos continuation to LSVC From subcostal short axis From subcostal long axis
2- Sidedness of SVC in relation to HV ( in single SVC)
3- Identify the dominant SVC (in bilateral SVC) the SVC receiving the AZ or HAZ is called the dominant SVC
4- Hepatic drainage HV drain together to RA HV drain from two different sites
Thank You
Pike et all. Ann Thorac Surg 2004