Surgical Treatment of PA with VSD without/with MAPCA Jeong-Jun Park University of Ulsan, Asan Medical Center
Dec 27, 2015
Surgical Treatment of PA with VSD without/with MAPCA
Jeong-Jun Park
University of Ulsan, Asan Medical Center
Pulmonary Atresia with VSD without/with MAPCA
1. Extreme subgroup of Tetralogy of Fallot Extreme subgroup of Tetralogy of Fallot 2. Major clinical problems in the arteries that2. Major clinical problems in the arteries that supply the pulmonary circulationsupply the pulmonary circulation
3. Variable clinical presentations & different 3. Variable clinical presentations & different surgical strategies to that in TOF/PSsurgical strategies to that in TOF/PS
Morphology of PA with VSD
The general morphology of the heart in TOF/PA - Similar to that in simple TOF,
- The differentiating features are :
1. No luminal continuity between RV & PA 2. Pulmonary arterial anomalies 3. Aortopulmonary collaterals
Natural History
Variable depending on the pulmonary blood flow
- At birth, ductus dependent in case of true PAs
- After ductal closure, dependent on the collaterals
1) Excessive pulmonary blood flow : CHF, PVOD 2) Moderate collateral stenosis : Balanced pulmonary blood flow 3) Severe collateral stenosis : hypoxia
Patterns of Pulmonary Arteries
•
Morphology of Pulmonary Artery
1. Confluence of the pulmonary artery
2. Stenosis of the pulmonary artery
3. Distribution of the pulmonary artery
4. Size of the pulmonary artery
5. Abnormal hilar branching
Alternative Sources of PBF
1. MAPCAs 2. Paramediastinal collateral arteries 3. Bronchial collateral arteries 4. Intercostal collateral arteries 5. Collaterals from coronary arteries 6. Iatrogenically aggravated collaterals
Origin of MAPCA
MAPCAs - Variable in size, number, course, origin, arborization &
histologic makeup - Usually large & discrete arteries from 1 to 7 in number
1. Majority from descending thoracic aorta 2. Some cases, from a common aortic trunk3. Finally, from branches of aorta
Influence of MAPCA
1. Chronic shunt & LV volume overload . Decrease LV function . Aortic annular dilatation . Aortic insufficiency
2. Segmental loss of lung parenchyme . In case of collateral stenosis --hypoxia . In unobstructed cases – CHF, PVOD
Histologic Characteristics of MAPCAs
1. Extrapulmonary: muscular artery with well developed muscular media & adventitia
2. Intrapulmonary:medial muscle is gradually replaced by a thin elastic lamina resembling true Pas
3. Unobstructed MAPCAs: PVOD4. Muscular segments of collaterals:
prone to the development of severe stenoses, often progressive
Characteristic Features of MAPCAs
1. Variable in size, number, course, origin, arborization and histologic makeup
2. Various degree of PA hypoplasia , or even absence of the central PAs
3. MAPCAs connect with branches of central PAs, or constitute the only blood supply
4. Congenital or acquired discrete stenosis along the course of MAPCAs
5. PHT and progressive PVOD
* Confluent PA
Unobstructed MAPCA
Long stenotic segment
MAPCA = Dilated Bronchial Arteries - RCH, 2006 - All MAPCAs : anatomy similar to bronchial arteries
- BAs: limited growth potential and vasoreactivity might preclude long-term beneficial effects of unifocalization
Bronchopulmonary shunts
Definitive Repair of PA with VSD
Ultimate goal : Completely separated pulmonary & systemic circulati
on
1. Closure of ventricular septal defect 2. Establish continuity between RV & PA 3. Occlusion of redundant collaterals & shunts / Unif
ocalization
Preparation for Definitive Repair
1. Maximize the pulmonary artery
: The size & distribution
2. Maintain the adequate PBF
3. Avoid the excessive PBF
Suggested Surgical Strategy for
PA with VSD, MAPCA
1. Unifocalization - Staged vs one-stage - Thoracotomy vs sternotomy 2. Establishment of native PA growth - With vs without unifocalization 3. One-stage complete repair 4. Repair without unifocalization
Early Palliative Procedures
Goals 1) Create a balanced PBF 2) Incorporation & growth of PAs
- Ligation- Embolization- Creating stenosis
- Systemic-pulmonary shunt - RV-PA connection : conduit or outflow patch - Unifocalization
Excessive blood flow Inadequate blood flow
Ideal Unifocalization Procedure
1. Incorporation of all the nonredundant collaterals & true Pas
healthy microvasculature of lung2. Use conduit that is growing, large, & minimizi
ng the risk of thrombosis3. Easily accessible from the mediastinum
at the time of definitive repair
Timing of Unifocalization
1. At any age, when collaterals are large to allow tec
hnical ease without risk of thrombosis
2. Variable depending on collateral size, usually old
er than 2~3 months
3. Staged procedures may be required for the bila
teral aortopulmonary collaterals
Techniques of Unifocalization
1. Procedures for collaterals 1) Ligation
2) Patch enlargement3) Direct anastomosis
2. Interposition grafts1) Synthetic graft2) Homograft3) Xenograft 4) Autologous tissue: pericardium, azygos v.
• Ligation
• Angioplasty
• Anastomosis
Unifocalization Procedures
• Interposition
• Additional PA creation
• Central PA creation
Unifocalization Procedures
End-to side Side -to side
- Offbypass during dissection - Maximal use of native tissue - Avoid circumferential use of non-viable conduits for growth potential
Surgical technique of unifocalization
Aortic button : several MAPCAs from the same location
Surgical technique of unifocalization
Surgical technique of unifocalization
RV-PA Conduit
Advantages of RV - PA Connection
1. Reduction of LV volume overload
2. Pulsatile blood flow to enhance PA growth
3. Facilitating the catheter access for the later evaluation & intervention
** CIx d/t
1) aneurysm and pseudoaneurysm
2) pulmonary flow and pressure is completely uncontrolled
Melbourne Shunt
Central end-to-side Aortopulmonary shunt Diminutive central pulmonary arteries
Modified Central Shunt
Criteria for VSD closure: 2 Dimensional Anatomic Data
- Central PA area 50% of predicted normal
- by Puga, 1989
- Predicted pRV/pLV 0.7, No MAPCAs remain
More than 2/3 lung segments are centralized
- by Iyer and Mee, 1991
- Nakata Index > 150mm2/M2 BSA -by Metras, 2001
- TNPAI 200 mm2/m2 - by Hanley, 1997
- 15 out of 20 bronchopulmonary segments(1 & 1/2 lungs) are connected to confluent pulmonary artery
- by Baker, 2002
Functional Intraoperative Pulmoanry Blood Flow Study
* Post-repair RVSP: most reliable predictor of favorable outcome
* Data of functionality of the entire pul. vasculature
Hanley - m PAP < 25mmHg at a full flow(2.5L/min/m2) predicts RV/LV pressure ratio < 0.5
Toronto, 2009- Close the VSD for a mPAP of <30mmHg- Predict postop. Physiology better than standard anatomic measures
Functional Intraoperative PBF Study
- RCH, 2009- Unifocalization brings no long-term benefits . Unifocalization: sufficient to allow a safe repair but, failed to achieve adequate growth . Dilated BAs: limited growth potential & unstable Growth of the native PA rather than recruitment of MAPCAs- Multi-stage approach . 4~6wks: Modified central shunt . 4~6months: RV-PA conduit . 3rd : complete repair or 2nd conduit- 18 pts enrolled in this protocol (No Unifocalization) . 7 : complete repair, RVP 59% of systemic . 8 : awaiting repair . 4 MAPCAs in 17 pts: ligated
Repair without Unifocalization
Advantages of One-stage Complete Repair
1. Eliminate the need for multiple operations
2. Eliminate the use of prosthetic materials
3. Establish the normal physiology early in life 1) Growth of respiratory & PA system 2) Avoid cyanosis & volume overload 3) Prevent the PVOD
Disadvantages of Multistage Approach
1. The final repair is achieved on an old age
2. Mediastinum & hilar regions are significantly
scarred, increasing surgical risks
3. Prolonged cyanosis & previous operation cause
secondary collaterals, risks of bleeding
4. The risk of drop-off before the final repair
Disadvantages of Earlier Repair
1. Increased pulmonary morbidity
1) Contusion & congestion
2) Bronchospasm
3) Phrenic nerve injury
2. Magnitude of operation
3. Technically more demanding
4. Unknown ideal age
Conclusion
- MAPCAs: Wide spectrum of pul. vascualr morphology and physiology, Ranging 1) from pts on the favorable end : true PAs with collaterals simply contributing systemic flow into the pul. vasculature 2) to pts on the unfavorable end : with completely absent native PAs and all of the pulmonary blood supply from collaterals
Management: complex and must be individualized according to their anatomy and clinical situations
Predictors of Successful Definitive Repair
1. McGoon Ratio > 12. Nakata Index > 150mm2/M2 BSA(Metras, 2001)
추가하자3. TNPAI > 200mm2/M2 BSA4. Ideal Age : Not known , but usually more than 2-3years old for conduit repair5. 15 out of 20 bronchopulmonary segments(1 & 1/2 lungs)
are connected to confluent pulmonary artery: Baker EJ. 2002
Selection for Final Repair
1. Central combined Rt. & Lt. PA area : At least 50~75% of predicted normal
2. Distribution of unobstructed confluent PAs : Equivalent to at least one whole lung
3. Presence of a predominant Lt. to Rt. shunt without restrictive RV-PA connection
Representative Data
Approach Age(range)
VSD closure
Mortality(early)
Mee RBB(’91)
Multiple 2.6mo(1d ~ 39yr)
52%(30/55
)
10%
Hanley FL(’95)
Anterior 2yr(2mo ~ 37yr)
90%(9/10) -
Hanley FL(’97)
Anterior 4mo(10d ~ 11mo)
63%(17/27
)
7%
Hanley FL(’98)
Anterior 7.3mo(14d ~ 37yr)
64%(46/72
)
11%
Lofland GK(’00)
Anterior 3mo(5d ~
5.5mo)
91%(10/11)
9.1%
Cherian KM(’02)
Anterior 36mo(6mo ~ 23yr)
51%(26/51
)
16%
Midline One-stage Unifocalization
Staged Unifocalization & RV-PA Connection
One-stage Unifocalization & RV-PA Connection
RVOT Reconstruction with Valved Conduit
RVOT Reconstruction with Outflow Patch
RVOT Reconstruction with PA Reimplantation
RVOT Reconstruction with LA Appendage
RVOT Reconstruction with PA Flap
RV-PA Connection & Unifocalization
RV-PA Connection with Unifocalization
Midline One-stage Repair
Midline One-stage Repair
Staged Unifocalization Staged Unifocalization
• M / 20 Mo, 10.6 kg Postop. 7 Mo
One-stage Unifocalization
One-stage Unifocalization
• M / 46 Mo, 13 kg Post-op. 8 Mo
RV-PA Connection RV-PA Connection
• F / 3 Mo, 4.6 kg Post-op. 3 Mo
RV-PA Connection with Unifocalization
RV-PA Connection with Unifocalization
• F / 15 Mo, 7.5kg Post-op. 11 Mo
One-stage Total Correction
One-stage Total Correction
• M / 7 Mo, 6.4kg Post-op. 1 Mo
Surgical Results of PA with VSD,MAPCAs
Yang Gie Ryu, Jeong-Jun Park,Tae Jin Yoon, Dong Man Seo
Dept. of Thoracic and Cardiovascular SurgeryAMC, University of Ulsan
- Anterior approach - Anterior approach --
Representative Data
Approach Age(range)
VSD closure
Mortality(early)
Mee RBB(’91)
Multiple 2.6mo(1d ~ 39yr)
52%(30/55
)
10%
Hanley FL(’95)
Anterior 2yr(2mo ~ 37yr)
90%(9/10) -
Hanley FL(’97)
Anterior 4mo(10d ~ 11mo)
63%(17/27
)
7%
Hanley FL(’98)
Anterior 7.3mo(14d ~ 37yr)
64%(46/72
)
11%
Lofland GK(’00)
Anterior 3mo(5d ~
5.5mo)
91%(10/11)
9.1%
Cherian KM(’02)
Anterior 36mo(6mo ~ 23yr)
51%(26/51
)
16%
Criteria for VSD closure
- Central PA area 50% of predicted normal (by Puga, 1989)
- Predicted pRV/pLV 0.7 No MAPCAs remain More than 2/3 lung segments are centralized (by Iyer and Mee, 1991)
- TNPAI 200 mm2/m2 (by Hanley, 1997)
- ? Unprotected large MAPCA
Patient Profile
Period Jan. 1997 ~ Jul.
2002
Number 25 (M : F = 12 : 13)
Age(mo), median 8 (3 ~ 190)
Weight(kg), median 6.8 (2.9 ~ 62)
Follow-up(mo), median 16 (3 ~ 150)
PA,VSD,MAPCAs(n=25)
PA,VSD,MAPCAs(n=25)
Gr Ia One stage total
(n=11)
Gr Ib Staged total
(n=8)Group II (n=6)
VSD closed (n=19,76%)
VSD open (n=6,24%
)
Group Ia (VSD closed)
Group Ib(VSD closed)
Group II( VSD open )
No. of
pts(%)11(44) 8(32) 6(24)
Age(mo) Median Range
83 ~ 11
10.54 ~ 190
10.55 ~ 58
Weight(kg) Median Range
6.72.9 ~ 8.1
8.055 ~ 62
7.95.1 ~ 15.8
Demographic Data
MAPCAs & True PAs
Group Ia(VSD closed)
Group Ib(VSD closed)
Group II(VSD
open)
No. of MAPCAs Mean Range
3.6 1.21 ~ 5
3.3 1.31 ~ 5
3.6 0.53 ~ 4
True PAs Present Absent
74
71
60
Operation
Group Ia(VSD closed)
Group Ib(VSD closed)
Group II(VSD open)
Total
Surgical approach Median sternotomy Sternotomy + thoracotomy
74
62
42
178
RV-PA conduit Homograft Pericardial roll Transannular patch
821
512
311
1644
Detail of Group Ia (n=11)
Pt Confluency of PA Neo-McGoon ratio No. of MAPCAs Age
1 - < 2.0 5 4m
2 + Hypoplastic > 2.0 4 8m
3 + Hypoplastic > 2.0 4 6m
4 - > 2.0 4 12m
5 + Good > 2.0 3 6m
6 + Hypoplastic < 2.0 5 10m
7 + Good > 2.0 5 8m
8 + Good > 2.0 1 4m
9 + Good < 2.0 3 4m
10 - > 2.0 3 8m
11 - > 2.0 3 9m
# Neo-McGoon ratio = (True PA + each MAPCA) / descending aorta
Detail of Group Ib (n=8)Pt Confluency of PA Neo-McGoon r
atioNo. of MAPCA
1st Op(Age)
2nd Op(Age)
1 + Hypoplastic < 1.5 3 RV-PA conduit 11m
Total 16m
2 + Hypoplastic < 2.0 3 Lt.unif 8m
Rt.unif 22m
3 - > 2.0 5 Rt.unif 13m
Total 6y 6m
4 + Hypoplastic > 2.0 4 RVOT relieve 5m
Total 10m
5 + Hypoplastic > 2.0 4 RVOT relieve,unif 8m
Total 18m
6 + Hypoplastic AP window
> 2.0 1 RV-PA conduit,unif 9m
Total 10m
7 + Hypoplastic > 2.0 3 RV-PA conduit,unif 16m
Total 3y 1m
8 + > 2.0 1 RV-PA conduit,unif 15y 10m
Total 24y 1m
Detail of Group II (n=6)
Pt Confluency of PA Neo-McGoon ratio
No. of MAPCAs
Op name(Age) Outcome
1 + Hypoplastic
< 2.0 3 Bilat.unif,Central shunt,RV-PA conduit
Cath F/U
2 + Hypoplastic < 2.0 4 RV-PA conduit 6m
Poor growth of PA->death
3 + Hypoplastic
> 2.0 4 RV-PA continuity 10m
Waiting
4 + Hypoplastic < 1.0 4 RV-PA conduit,unif 3y 2m
Waiting
5 - < 1.5 3 Bilat.unif 6m
Observ.
6 + Hypoplastic > 2.0 1 RMBT,cetral shuntRV-PA conduit(9m)
Death
Gr Age Anatomy Cause of death
Ia 4m PA,VSD, 5 MAPCA Respiratory failureBronchial stenosis
Ia 6m PA, VSD, 4 MAPCA Pulmonary Hemorrhage *
Ia 6m PA,VSD, 4 MAPCA Pulm. Hypertensive crisis *
Ia 12m PA,VSD, 4 MAPCA Bronchus compression
II 6m PA,VSD, 4 MAPCA Poor growth of PAs
II 4y 11m
PA, VSD, 1 MAPCA PVOD *
Cases of Mortality (n=6)
* Pulmonary hypertension related
Total correction 76% (19/25)
One stage total correction 44% (11/25)
Early mortality 16% (4/25)
Late mortality 9% (2/21)
Results
Conclusion
Anterior approach 는 수술의 완성도를 높일 수 있는 술식이다 (>80%).
Too small or unprotected large MAPCA를
recruit 하기 위해서는 적절한 시기에 수술이 필요하다 .
PVR 이 높을 것으로 의심되는 경우는 staged op. 이 reasonable 하겠다 .
Conclusion
Just now we are ready
to manage this group of patients properly
in technique and hemodynamic understanding.