대한흉부외과학회 제 35 차 춘계학술대회 2009. 5. 28. Palliative RVOT procedures 양 지 혁 성균관의대 삼성서울병원 흉부외과학교실

대한흉부외과학회 제 35 차 춘계학술대회 2009. 5. 28.

Palliative RVOT Palliative RVOT proceduresprocedures

양 지 혁성균관의대 삼성서울병원

흉부외과학교실


Palliative RVOT procedures

Pulmonary Valvotomy/valvectomyTransannular patch enlargementRV-PA conduit interposition

Right heart obstructive lesion

Pulmonary atresia (PA) Pulmonary stenosis (PS)

intact ventricular septum

Intact ventricular septum

With VSD TOF


Pulmonary valvotomy / valvectomy

Closed pulmonary valvotomy (Brock procedure)


Pulmonary valvotomy / valvectomy

Pulmonary valvotomy w/wo bypass


Why these procedures can be found only in textbook?

Interventional valvotomyNeed for additional procedureExcessive pulmonary blood flowEarly total correction


Transannular patch enlargement


Transannular patch enlargement

PA with ivs

Tricuspid z-value

Definitive repair Initial procedure

> -2 2 ventricle RV decompression

-5 ~ -2 1½ ventricle RV decompression + shunt

-5 > 1 ventricle Shunt only


SMC experience of PAIVS (1997~2006)


Morphologic spectrum of TOF/PA

Major Aorto-Pulmonary Colllateral Arteries; MAPCA


Outcome of systemic-to-PA shunt

(Circulation 2007;116:293-297)


Initial RVOT reconstruction for palliation in TOF/PA, MAPCAs

RV-PA connectionPatch widening

• Piehler et al. (Mayo) 1980• Freedom et al. (Toronto) 1983• Rome et al. (Boston) 1993• Pagani et al. (Michigan) 1995


Rationale for initial RV-PA connection

↑ PA size and angiogenesis of distal microvessels, especially early in lifeNonconfluence in the presence of PA is low (3 ~ 16%)Significant arborization abnormality in the setting of centrally confluent arteries is low

• 80% of patients with confluent central PA have pulmonary blood flow to 15 or more pulmonary segments

• 11.8 segments received blood flow from central PA5.1 segments from aortopulmonary collateral arteries only0.64 segments from a dual source.

Allows access to pulmonary arteries • balloon dilation of peripheral stenotic vessels• precise identification of native pulmonary artery

segmental distribution


Advantage of RV-PA connection

LV volume overload

Pulsatile blood flow to enhance PA

growth

Branch PA distortion, pleural adhesion→ easier staged procedures (unifocalization)


RV-PA connection for hypoplastic PA






Unifocalization and RV-PA for hypoplastic PA


Unifocalization and RV-PA for non-confluence


PA growth after RVOT reconstruction

Piehler et al. (JTCS 1980)


PA growth after RVOT reconstruction

Piehler et al. (JTCS 1980)

• Less PA distortion 18% (vs. 46% of shunt)


How small is too small for true PA

PAI < 90 mm2/m2 (Rome et al.) PA diameter < 3mm (Pagani et al.)

PA diameter < 1.5mm

Melbourne shunt


Selection of Conduit - material

Valved homograft• Advantage

↓ regurgitation → more growth ?↓ bleeding↓ pseudointimal formation

• DisadvantageAneurysmal changeShortage of supply

Valveless conduit (Goretex)• Advantage

Less energy loss

• DisadvantageUnable to maintain distal diastolic PA pressure


Selection of Conduit - size

Sano shunt for HLHS• Non-valved Gore-Tex shunt from RV to PA • 5mm : neonate < 3~3.5 kg• 6mm : neonate > 3~3.5 kg

RV-PA for biventricular repair• Bradley et al. (ATS 2008)• 5mm : < 3 kg• 6mm : 3 ~ 4.5 kg


Selection of Conduit - size

5kg, BSA 0.3 • 25mm ~ 29mm / π =

diameter 8.0 ~ 9.2 mm

– thickness of vessel wall (1mm?)

Internal diameter : 7 ~ 8mm

Trusler’s formula (band circumference) for PAB• noncyanotic, nonmixing lesion 20mm + 1mm/kg Bwt• Mixing lesion 24mm + 1mm/kg Bwt• SV for Fontan 22mm + 1mm/kg Bwt

Z-value > 2 not recommended


Predictors of successful definitive repair

PAI > 150 mm2/m2

Total neopulmonary artery index (TNPAI) > 200mm2/m2

Qp/Qs > 1.5

pRV/LV < 0.8


RV-PA shunt for Norwood op. (Sano)

Advantage• ↑ diastolic pressure• ↓ coronary steal• Pulsatile flow

Disadvantage• RV incision• RV volumeload → TR• ↓ PA growth

Better in low birth weight babiesBetter at smaller centerLower risk of graft thrombosisGreater resistance to physiologic insults such as cardiopulmonary arrest


RV-PA shunt ; technical considerations


RV-PA vs. BT shunt - mathematic model

(JTCS 2008)



3mm BTS vs. 4mm RV-PA3.5mm BTS vs. 5mm RV-PA4mm BTS vs. 6mm RV-PA



RV-PA model exhibited, at similar SaO2

• lower pulse pressure • lower Qp/Qs ratio• lower PAP• lower RV systolic and diastolic pressure• higher coronary perfusion pressure• higher O2 delivery• higher ventricular performance




RV-PA shunt in biventricular repair

Bradley et al. (Ann Thorac Surg 2008;86:183– 8)• 10 infants excluding patients with PA VSD,

MAPCA• Median age : 9 (4~86) days• Median Wt. : 3.0 (1.7 ~ 4.5) kg• Non-valved Gore-Tex shunt from RV to PA


RV-PA shunt in biventricular repair

No hospital deaths1 reoperation

• Revision of shunt d/t distal anastomosis stenosis SpO2 at the discharge : 94 ± 4 %

2 patients with a clipped shunt underwent successful balloon dilation (6 Mo after RV-PA)

Biventricular repair • 8 patients• interval : median 10 (6~17) months• SpO2 : 86 ± 1• Conduit diameter : 14 ~ 16 mm• No early or late deaths


Case 1, M/3Mo

PA, VSD, MAPCAs, hypoplastic central PA (+)


Case 1, M/3Mo

RV-PA connection with homograft femoral vein 7mmLPA angioplasty with GA-fixed autologous pericardium


Case 2, F / 3.7yrs

PA, VSD, MAPCAs, s/p staged unifocalization


Case 2, F / 3.7yrs

6 Mo later, VSD closure (PRV/LV = 0.65)

RV-PA connection with T-shaped homograft


Case 3, F / 6Mo

TGA, VSD, PA, Rt aortic archs/p LMBT shunt, PA angioplasty


Case 3, F / 6Mo

RV-PA connection with femoral vein homograft (composite graft with Goretex 8mm)RPA & LPA angioplastyShunt takedown

Documents

대한흉부외과학회 제 35 차 춘계학술대회 2009. 5. 28. Palliative RVOT procedures 양 지 혁 성균관의대 삼성서울병원 흉부외과학교실