test 6 double outlet right ventricle (DORV)

Question 1

Double Outlet Right Ventricle (DORV)

Answer 1

■ The Aorta and Pulmonary Artery both originate from the RV
■ Blood from the LV passes across a VSD into the RV to reach the great arteries.
– May experience significant pulmonary overcirculation
■ The majority of cases occur with pulmonary stenosis and VSD, behaving as a severely cyanotic Tetralogy of Fallot.

Question 2

Double Outlet Right Ventricle (DORV) classified into 4 main categories based on VSD location

Answer 2

– Subaortic VSD
– Subpulmonary VSD
– Doubly Committed VSD
– Noncommitted VSD
- The conal tissue (CT) can separate the outflow tracts

Question 3

Double Outlet Right Ventricle (DORV) symptomology

Answer 3

■ Baby tires easily, especially when feeding
■ Bluish skin color (the lips may also be blue)
■ Clubbing (thickening of the nail beds) on toes and fingers
■ Failure to gain weight and grow
■ Peripheral edema
■ Dyspnea

Question 4

Complications from DORV may include

Answer 4

■ Congestive heart failure (CHF)
■ Pulmonary hypertension
• Irreversible damage to the lungs due to untreated high blood pressure in the lungs

Question 5

Sub-aortic VSD: (DORV)

Answer 5

■ This variant is most common.
■ Pathophysiology depends on the degree of PS. With PS, the pulmonary blood flow is decreased with variable cyanosis like a TOF.
■ In the absence of PS, the pulmonary blood flow is increased, resulting in CHF like a VSD

Question 6

Sub-pulmonary VSD (Taussig-Bing): DORV

Answer 6

■ VSD is located sub-pulmonary
■ Transposed great arteries
■ The PA preferentially receives LV oxygenated blood
■ Desaturated blood from the RV streams to the aorta
■ Similar to TGA.

Question 7

Doubly Committed VSD: DORV

Answer 7

■ The infundibular septum is absent leaving both aortic and pulmonary valves equally related to the VSD.
■ Clinical features depend on the presence or absence of pulmonary stenosis.

Question 8

Non-committed VSD: DORV

Answer 8

■ The non-committed VSD is remote from the aortic and pulmonary valves.
■ Most patients with non-committed VSD undergo single ventricular w/ palliative strategies.

Question 9

Surgical Considerations for DORV

Answer 9

■ ANATOMIC repair, which restores a circulation with two ventricles
- Divide the Ventricles and keep the aorta on the LV side
- remove section of the pulmonary outflow tract and attach a graft from the newly cut portion of the PA and attach it to the new RV with RV to PA graft
■ UNIVENTRICULAR repair, in which only one ventricle is functional.

Question 10

Surgery: DORV with Sub-aortic VSD

Answer 10

■ Intra-ventricular tunnel (LV→VSD→ Ao)
        – Fancy VSD patch (bovine pericardium, GoreTex, etc.) that corresponds to the circumference of the aorta. 
■ Low risk
■ Age 6 months
■ Rastelli procedure for PS

Question 11

Surgery: DORV with Sub-pulmonary VSD (Taussig-Bing Heart)

Answer 11

■ Complex intra-ventricular tunnel to Ao or PA
■ With infundibular resection
■ Close VSD to PA plus arterial switch procedure

Question 12

Surgery: DORV with Doubly Committed VSD

Answer 12

■ Intra-ventricular tunnel (LV→VSD→Aorta)
■ PS or obstruction of the RVOT due to the tunnel may necessitate the creation of a right ventricle outflow patch or even a Rastelli.
■ The VSD, which is typically large, usually does not create difficulty in channeling left ventricular blood to the aorta with an intra-ventricular tunnel.

Question 13

Surgery: DORV with non-committed VSD

Answer 13

■ Most difficult to correct
■ univentricular repair
■ Complex intra-ventricular tunnel to Ao or PA patch/baffle
■ May use of combined atrial and ventricular approaches
■ Fontan procedure ultimately

Question 14

CPB Considerations

Answer 14

■ Incision: Median sternotomy
■ Cannulation:
        ■ Arterial: Aortic
        ■ Venous: Bicaval
■ Hypothermia: Mild to Moderate
■ Cardioplegia: Antegrade (multiple doses due to Ao-pulmonary collateral circulation)

Question 15

CPB case notes

Answer 15

■ These cases are amazingly variable in length, severity, and can be difficult post-op in pressure regulation.
■ Will resemble pump runs for TOF
■ Univentricular repairs will be of the Fontan procedure nature
■ Depending on pre-op lung damage and pulmonary hypertension – ECMO again may be warranted
■ Make sure you know how you are going to deal with high hematocrits in severe cyanotic conditions (pull off volume)
■ Be careful with MUF since it will be easy to get the hct at 50%+ (most likely will add volume pulled off when your warming)