SHORT AND INTERMEDIATE TERM FOLLOW UP OF ALL

INFANTS DIAGNOSED WITH PULMONARY ATRESIA AND

VENTRICULAR SEPTAL DEFECT - A FIVE YEAR FOLLOW UP

STUDY

PROJECT REPORT

Submitted during the course of DM Cardiology by

DR. PRIYADARSHINI. A

Trainee

DEPARTMENT OF CARDIOLOGY

Jan 2014 – Dec 2016

SREE CHITRA TIRUNAL INSTITUTE FOR MEDICAL

SCIENCES AND TECHNOLOGY, TRIVANDRUM, KERALA,

DECLARATION

I, Dr. Priyadarshini A, hereby declare that the project in this book, titled

“Short and intermediate term follow up of all infants diagnosed with pulmonary

atresia and ventricular septal defect - A five year follow up study” was

undertaken by me under the supervision of the faculty, Department of

Cardiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology.

Trivandrum Dr Priyadarshini A

3/10/16 DM Cardiology trainee

FORWARDED

The candidate, Priyadarshini A, has carried out the minimum required

project.

Thiruvananthapuram Prof. (Dr )Ajit Kumar VK

3/10/16 Head of Department of Cardiology

CERTIFICATE

This is to certify that this thesis titled “Short and intermediate term follow up of

all infants diagnosed with pulmonary atresia and ventricular septal defect - a

five year follow up study” has been prepared by Dr. Priyadarshini. A, DM

Cardiology Resident, Department of Cardiology at Sree Chitra Tirunal Institute

for Medical Sciences & Technology, Thiruvananthapuram. She has shown keen

interest in preparing this project.

GUIDE

Dr. Krishnamoorthy.K.M

Professor, Department of Cardiology

SCTIMST, Thiruvananthapuram

CO GUIDE

Dr. Deepa S. Kumar

Assistant Professor, Department of Cardiology

SCTIMST, Thiruvananthapuram

Dedicated to my

teachers, family and

friends

TABLE OF CONTENTS

Abstract i

Introduction 1

Aims and Objectives 6

Review of literature 8

Materials and methods 17

Statistical analysis 19

Results 20

Discussion 42

Conclusion 48

Limitation 49

References 50

Annexure 54

ABBREVIATIONS

VSD – Ventricular septal defect

PA – Pulmonary atresia

MAPCA – Major Aorto-pulmonary collaterals

PDA - Patent ductus arteriosus

RVOT – Right ventricular outflow tract

CT – Computed tomography

MRI – Magnetic resonance imaging

TOF – Tetralogy of Fallot

DRPA – Diameter of right pulmonary artery at the hilum

DLPA – Diameter of left pulmonary artery at the hilum

DDTAO- Diameter of descending thoracic Aorta at the diaphragm

i

ABSTRACT:

Introduction: Ventricular septal defect- pulmonary atresia (VSD-PA)

encompasses a spectrum of anomalies ranging from short to long segment

pulmonary atresia and duct dependent or MAPCA dependent pulmonary

circulation or a combination of both. From the therapeutic standpoint, surgical

treatment could vary from as simple as VSD closure with RVOT reconstruction

to as complicated as multi-staged unifocalisation. More over children may

require interim palliative procedures in the form of ductal stenting, Aorto-

pulmonary shunt or Cavo-pulmonary anastomosis. There is paucity of data from

the Indian subcontinent regarding the outcomes in this cohort of patients.

Aim: To study variations in pulmonary anatomy, natural history, time to

intervention, complications, outcomes and determinants of mortality in infants

with VSD-PA.

Methodology: All infants (<1 year) registered at our institute between January

2011 and December 2015 with the diagnosis of VSD-PA were enrolled.

Children with complex anatomy like Single ventricle, transposition, AV canal

defects etc were excluded from the study. Deaths were classified according to

the time period in which attrition occurred, T1- before any palliation (Aorto-

pulmonary shunt, PDA stenting, BDG)/ definitive surgery was done, T2- in the

ii

interstage between palliation and definitive repair, T3- postoperative period and

T4- late after definitive repair

Results: A total of 108 infants were included in the study. There was an almost

equal gender distribution- 51% were male and 49% were female. Mean age at

presentation was 1.65 months (range 0 – 11 months) and mean duration of

follow up was 18.9 months. 73% had confluent pulmonary anatomy and long

segment pulmonary atresia was more common. Majority of patients (55.6%)

had a ductal dependence, 25.9% had MAPCA dependence and 18.5% had a

combination of both. Right arch was seen in 25.9 % of the children. Mean Mc

Goon index was 1.26. 7 patients were diagnosed with Di George syndrome. The

average birth weight was 2.64 kg and 12 % were born preterm. There was

history of maternal diabetes in 17%. The mean lowest saturation on follow up

was 73.4 %. 32.4% required prostaglandin support. Imaging in the form of CT/

MR was required in 52% of the population. Imaging was very useful in

MAPCA dependent pulmonary circulation to plan surgery. 6 required ductal

stenting, 37 required Aorto-pulmonary shunt and 4 required BDG. Average age

at initial palliation was 6.24 months. Average time to palliation after diagnosis

was 4.81 months. Out of the 43 patients, who underwent palliative procedures,

13 (29%) proceeded to definitive repair. There were 32 deaths in toto – 19 in

the T1 period. 2 children were lost in the inter-stage period- T2. ICR was done

in 13 patients with the following concomitant procedures- homograft repair was

iii

done with intracardiac repair in 4 patients, 7 children did not require conduit -

only RVOT reconstruction sufficed and primary unifocalisation with intra

cardiac repair was done in 3 children. 10 children died in the post operative

period and one death was late- 6 months after surgery. Branch PA plasty was

concomitantly done in majority (69.2%) of the patients. Pulmonary anatomy-

length of atresia, was statistically significant as a predictor of mortality

(p=0.023). Survival at 1, 2 and 4 years were 70.3%, 68.2% and 65%

respectively.

Conclusion: Despite early diagnosis, mortality associated with VSD-PA

remains high with most of the deaths occurring in the T1 period, before any

palliation or corrective surgery is done. Surveillance and weekly saturation

monitoring may avert the catastrophes associated with worsening hypoxemia.

Keywords: Ventricular septal defect- pulmonary atresia, natural history,

outcomes, predictors of mortality.

1

INTRODUCTION :

Pulmonary atresia with ventricular septal defect is a rare congenital

anomaly, constitutes about 2% of congenital heart diseases , is considered to be the

most severe form of Tetralogy of Fallot and occurs at a frequency of 0.07 per 1,000

live births ( Baltimore Washington study)(1). Anatomically, the right ventricular

outflow tract ends blindly, right ventricular stroke volume is directed towards the

Aorta through a large ventricular septal defect. Pulmonary arterial architecture is

complex, ranging from duct dependent pulmonary circulation to a pulmonary

arterial tree entirely fed by major Aorto-pulmonary collaterals (MAPCAs).

.VSD-PA can be classified into 3 types based on source of pulmonary blood flow.

A classification (2) has been proposed by the Congenital Heart Surgeons Society

(CHSS) based on pulmonary blood flow and is detailed below:

Type A: Native PAs present, pulmonary vascular supply through PDA and no APC

/ MAPCAs

Type B: Native PAs and APC/MAPCAs present

Type C: No native PAs, pulmonary blood supply through APC/MAPCAs only.

2

Figure 1

Types of VSD-PA based on source of pulmonary blood flow

Furthermore, pulmonary atresia can be categorized based on the length of

the atretic segment – short or long. Pulmonary arterial anatomy could also be

classified based on the confluence as confluent or non-confluent pulmonary

anatomy.

In VSD-PA, PDA originates in the majority from the undersurface of the

arch (67%) or from the undersurface of the innominate artery (33%). PDA is

associated with confluent PAs, in as high as 80%. When PDA is present, PAs are

confluent in 80% of cases. Most patients with absent PDA, have non confluent

PAs.

3

Majority (65%) of VSD-PA patients present to a cardiac center during

infancy. The remainder presents later because of sufficient pulmonary blood flow

which lead to clinically undetectable cyanosis during the early months of life.

Clinical presentation is in the form of cyanosis (50%), heart failure (25%) or

murmur with mild cyanosis with or without failure to thrive (3). Patients with PA +

VSD, with or without MAPCAs, have been described as having less than a 50%

chance of being alive at 10 years of age. PA + VSD patients with MAPCAs,

instead, have had only a 40% chance being alive at 10 years of age, and a 20%

chance being alive at the age of 30.

Echocardiography is a useful modality for assessment of source of

pulmonary blood flow. It is very useful in delineating central pulmonary anatomy.

Origin of MAPCAs can also be ascertained from echocardiography. But other

modalities of imaging like CT and MRI are useful for making out the exact

anatomy of MAPCAs. Color flow Doppler was accurate in determining the

presence or absence, the side and the origin of the collateral channels in all

patients, with the correct number being determined in 12 (67%) of 18 patients

studied by Acherman et al (4). "Wash-in" to the hilar pulmonary arteries

(retrograde color flow) was seen in 12 (92%) of 13 patients with collateral

channels and confluent pulmonary arteries.

4

Mc Goon ratio is calculated by dividing the sum of the diameters of RPA (at

the level of crossing the lateral margin of vertebral column on angiogram) and

LPA (just proximal to its upper lobe branch), divided by the diameter of aorta at

the level above the diaphragm [DRPA /DDTAO)+( DLPA / DDTAO)]. An

average value of 2.1 was noted in normal subjects. Ratio above 1.2 is associated

with acceptable postoperative RV systolic pressure in Tetralogy of Fallot. Ratio

below 0.8 is deemed inadequate for complete repair of PA – VSD. VSD closure is

deferred in such patients at the time of repair or they underwent Aorto-pulmonary

shunt procedure as first stage (5,6) However, this ratio tends to overestimate the

adequacy of the size of PAs since this is derived using the diameter of descending

thoracic aorta at the level of diaphragm which is frequently smaller in patients with

PA-VSD.

Nakata index was developed to provide prognostication regarding surgical

outcomes in patients with diminutive pulmonary arteries. In tetralogy, all patients

with a PAI (Pulmonary Artery Index) over 100 mm2/BSA could undergo

correction safely (7).Nakata PA index is calculated from the diameter of PAs

measured immediately proximal to the origin of upper lobe branches of the

respective branch PAs. The sum of the cross sectional area (CSA) of right and left

PAs is divided by the body surface area of the patient [Nakata index = CSA of

5

RPA (mm2) + CSA of LPA (mm2)/ BSA (m2)]. A Nakata index of >150 mm2/m2

is acceptable for complete repair without prior palliative shunt (8).

Surgical treatment varies from correction akin to Tetralogy of Fallot- VSD

closure and RVOT reconstruction to complex multi-staged procedures like

unifocalisation. Many children require some intervention in the neonatal period,

especially in the duct dependent group, coinciding in time with closure of ductus.

Palliative procedure for worsening cyanosis could be in the form of ductal stenting

or Aorto-pulmonary shunt. In children older than 3-6 months, a Bidirectional

Glenn could also be performed to improve pulmonary blood flow.

Most of the attrition occurs during the first year of life, with various studies

documenting rates between 25-40%. Non cardiac anomalies could contribute to

death as in the case of Di George syndrome with immunodeficiency. Cyanotic

spells and sudden cardiac death are important causes of mortality apart from the

peri operative deaths.

Overall surgical outcomes are improving over the last few decades (9),with

greater number achieving complete repair. Presence of MAPCA s has been seen in

many studies to be a negative predictive factor for complete repair (10).

6

AIMS AND OBJECTIVES:

VSD - pulmonary atresia commonly referred to as TOF with pulmonary

atresia is a fairly common congenital heart disease with presentation varying from

cyanosis in the neonatal period to later in life. There is paucity of data with regard

to natural history and treatment outcomes of this order from our part of the world,

where percutaneous intervention in the form of ductal stenting is burgeoning.

Initial palliation in the form of ductal stenting or Aorto-pulmonary shunt is usually

required for alleviation of symptoms brought out by ductal closure. But there is a

lot of attrition in this period prior to initial palliation. There are very few centres in

the country which attempt unifocalisation, and the data on outcome of such

procedures is scarce. Compared to the West, where pulmonary rehabilitation is

started at a much earlier age (first 3 months of life), there is a lag in the time to

unifocalisation, whether such delays affect outcomes have not been looked at.

It could be hypothesized that regular saturation monitoring and surveillance

during this period could help improve mortality in this period. MAPCA dependent

pulmonary circulation forms a complicated cohort with respect to surgical

management, where unifocalisation followed by intracardiac repair is warranted

over multiple steps. Some children may require MAPCA coiling when a segment

of lung is supplies by both native pulmonary arteries as well as MAPCAs- dual

blood supply. There is a subgroup of this cohort, where central pulmonary arteries

7

are entirely absent or very atretic, precluding any form of surgical repair and are

left for medical follow up after cardiac imaging.

The real world scenario in our part of the world is enigmatous and a careful

study to observe the natural history and modified history after palliative and

corrective surgery would give us a fair idea as regards to the prognostics and what

to expect regarding outcome in our settings. It would also help us pick up

vulnerable periods in the natural history of this heart disorder so as to strengthen

surveillance to avert mishaps.

8

REVIEW OF LITERATURE:

Pulmonary atresia with ventricular septal defect (PA + VSD) has an

incidence between 4.2 and 10 per 100 000 live births (11,12). Anatomically, the

right ventricular outflow tract ends blindly, right ventricular stroke volume is

directed towards the Aorta through a large ventricular septal defect. Pulmonary

arterial architecture is complex, ranging from duct dependent pulmonary

circulation to a pulmonary arterial tree entirely fed by Aorto-pulmonary collaterals.

Maternal diabetes, phenylketonuria, exposure to drugs like retinoic acid and

trimethadone are associated with increased risk of conotruncal defects. Diabetic

women have a 10 -fold increased risk of giving birth to a child with PA-VSD.

Ryan et al, reported strong association between 22q11 deletion and PA-VSD, their

series showed a 10% prevalence of PA-VSD in patients with this deletion(13).

Aortopulmonary collaterals , right aortic arch and aberrant subclavian artery

occurred more commonly in patients with PA-VSD and 22q11 deletion(14). Brach

pulmonary arteries were smaller and hence clinical outcomes were poorer in this

subgroup of patients (15).

In a postmortem study by Liao et al (16), heart and lung specimens in 31

cases of PA-VSD were studied. Main source of pulmonary blood flow could be the

ductus arteriosus, major collateral arteries or diffuse small pleural arterial plexus

coexisting with either ductus arteriosus or major collateral arteries. The ductus

9

arteriosus and major collateral arteries did not coexist in the same lung in these

cases. Confluent central pulmonary arteries were present in 22 (71%) of the 31

cases, involving 7 (58%) of the 12 cases of ductus arteriosus, 14 (70%) of the 20

cases with major collateral arteries and 1 case with an aorticopulmonary window.

The pulmonary trunk (atretic or patent) was identifiable in 24 (77%) of the 31

cases. A lung or lungs that connected to a ductus (or ligamentum) had a complete

and unifocal intrapulmonary arterial distribution (without arborization

abnormalities). Major collateral blood supply was frequently multifocal and

associated with arborization abnormalities. The size of the central pulmonary

arteries was not related to the type of arterial blood source but seemed to be related

to the amount of blood flow actually reaching the vessels.

A combination of high resolution two dimensional echocardiographic

imaging and color flow Doppler study permits good appreciation of both the

mediastinal pulmonary arteries as well as their blood supply in patients with VSD-

PA. In a study by Acherman et al (17), 42 patients aged a few hours to 19 months

were prospectively assessed by echocardiography. A patent arterial duct was

correctly identified as the sole source of pulmonary blood supply in 23 patients,

whereas Aorto-pulmonary collateral channels were detected in 19, with one of

these having a small patent arterial duct and collateral channels. The patent arterial

duct originated from the undersurface of the aorta in 16 (67%) of 24 patients and

10

from the base of the brachiocephalic trunk in 7 (33%) of 24. All patients with a

patent ductus as the sole source of pulmonary blood supply had confluent

pulmonary arteries. Non-confluent pulmonary arteries were present in six patients,

with all but one having Aorto-pulmonary collateral channels as the sole source of

pulmonary flow. Aorto-pulmonary collateral channels were direct in 17 (89%) of

19 patients, whereas in 2 (11%) of 19, both direct and indirect collateral channels

were present. Color flow Doppler study was accurate in determining the presence

or absence, the side and the origin of the collateral channels in all patients, with the

correct number being determined in 12 (67%) of 18.

Imaging in the form of DSCT (dual source computed tomography) has been

evaluated for pick up rate of MAPCAs in comparison to ECHO

(echocardiography) and CA (catheterization) in a study by Yin et al (18) .The

diagnostic rate of the aortopulmonary collateral vessels was 100% (14/14) for

DSCT, 92.9% (13/14) for CA (p = 0.995 in comparison with DSCT), and 35.7%

(5/14) for ECHO (p = 0.001 in comparison with DSCT). Similarly gadolinium

enhanced magnetic resonance angiography (MRA) has been compared with

cathetersation and has been found that it is a simple, fast, and accurate technique

by which to delineate pulmonary arterial anatomy and can be a reliable

noninvasive alternative to cineangiography. MRA can provide required

11

information to plan surgical strategy in infants and children and at times obviate

the need for catheterization (19).

Leonard et al (20), investigated the natural and unnatural history of patients

with pulmonary atresia. 129 cardiac malformations with

congenital pulmonary atresia were identified from 601,635 live births (21.4/100

000): 29 had PA-IVS, 60 had PA-VSD, and 40 had complex pulmonary atresia.

Total mortality was 72/129 (56%), with 15 deaths in the first week and 49 in the

first year. There were 23 surgical deaths, 33 hospital deaths (not related to

surgery), and 16 sudden deaths, 12 of which remained unexplained. The sudden

death rate was 29/1000 patient years of follow up. Of the 57 survivors, 39% have

exercise ability I or II and 61% III or IV. Definitive surgical repair produced better

exercise ability. The authors concluded that early mortality is high in all types

of pulmonary atresia, although survival has improved in recent years. Most

children who have not undergone definitive repair have significant exercise

limitation on follow up.

In a review of 185 patients by Amark et al (21) , 118 patients had simple

PA-VSD and 53 patients had PAVSD with major aortopulmonary collateral

arteries (MAPCAs). Overall survival from initial operation was 71% at 10 years.

Risk factors for death after initial operation included younger age, earlier birth

cohort, fewer bronchopulmonary segments supplied by native pulmonary arteries,

12

and initial placement of a systemic-pulmonary artery (SP) shunt.

Bronchopulmonary arterial supply is an important determinant of mortality,

achievement of definitive repair, and post-repair reoperation.

Treatment strategy in these patients depend on pulmonary blood flow.

Patients with duct dependent circulation usually have well developed confluent

pulmonary arteries and go for biventricular repair akin to patients with Tetralogy

of Fallot. Some centres adopt staged procedures for duct dependent circulation

with systemic pulmonary shunt being a prelude to the intra-cardiac repair. In a

series of 86 patients with duct dependent PA-VSD reported by Alsoufi et al (22),

33% underwent primary repair whereas 67% underwent initial palliation with

systemic pulmonary shunt. Early and late results were compared between the 2

groups. On multivariable analysis, risk factors for mortality were genetic or extra-

cardiac malformations (hazard ratio [HR], 2.8), post-operative extracorporeal

membrane oxygenation (ECMO) (HR, 4.0). Freedom from right ventricular

outflow tract reoperation after achievement of repair was 63.2% at 8 years (52.4%

for BVR versus 70.2% for BTS, p [ 0.170). On multivariable analysis, risk factors

for reoperation were the use of conduit (HR, 8.7) and prematurity (HR, 2.8).

Iyer et al (23) , reported intermediate term outcomes of 58 patients with

VSD-PA, hypoplastic pulmonary arteries with arborization defects, and major

aortopulmonary collaterals between 1979-89. A total of 121 staging procedures

13

were performed with an overall mortality of 10.3%. One hundred thirty-four major

collaterals were either ligated or transplanted. Thirty patients eventually underwent

hemodynamic repair with an early mortality of 3.3% and late mortality of 10.0%.

Twenty-six current survivors of repair remain clinically well after a mean follow-

up of 3.6 years.

Patients with MAPCA dependent pulmonary circulation in lieu of

unfavorable anatomy undergo staged repair more often whereas some centres

advocate single stage unifocalisation. Reddy et al (24), analysed early and

intermediate outcomes after unifocalisation in 85 patients with pulmonary atresia,

VSD, and MAPCAs (median age, 7 months). Complete 1-stage unifocalization

and intracardiac repair were performed through a midline approach in 56 patients,

whereas 23 underwent unifocalization in a single stage with the VSD left open, and

6 underwent staged unifocalization through sequential thoracotomies. There were 9

early deaths. During follow-up (1 to 69 months), there were 7 late deaths. Actuarial

survival was 80% at 3 years. Among early survivors, actuarial survival with

complete repair was 88% at 2 years. Reintervention on the neo–pulmonary arteries

was performed in 24 patients.

Kaskinen et al (25), in a recent review of 109 patients over a period of 37

years, observed that achievement of repair and initial size of true central

pulmonary arteries affect survival of patients with PA + VSD. Presence of

14

MAPCAs did not affect survival but reduced the chance at complete repair.

Palliative surgery may have a role in treatment of PA + VSD because the size of

pulmonary arteries increased after placement of Aorto–pulmonary shunt. In

addition, subtotal repair by a RV–pulmonary artery connection and septal

fenestration improved survival over extracardiac palliation.

Shimazaki et al (26), catheterized 21 patients after surgical repair od VSD-

PA and MAPCA dependent pulmonary circulation. They found that the mean and

systolic pulmonary arterial pressure, as well as the pulmonary vasculature

resistance, were abnormally high in 60% of the patients. 33% of the patients were

found to have pulmonary arterial segments that were not connected to the central

and unbranched hilar portions of the right and left pulmonary arteries. The mean

pulmonary artery pressure and the pulmonary vasculature resistance were

correlated (inversely) with the number of centrally connected pulmonary arterial

segments. The pulmonary vasculature resistance per pulmonary arterial segment

was also inversely correlated with the number of centrally connected pulmonary

arterial segments. This highlights the fact that the more the number of pulmonary

segments connected to the RV after unifocalisation, the better are the right sided

pressures.

Twenty-five patients over a period of 6 years between 2003- 08, were

studied by Liava`a et al (27) and analyzed a protocol of neonatal rehabilitation of

15

hypoplastic PAs in the management of VSD-PA and major aortopulmonary

collateral arteries (MAPCAs). This group did not believe in the school of thought

of MAPCA translocation, rather believed in promotion of native PA growth,

promoted by Aorto-pulmonary shunt. At a 18 months follow up, 12 of 20 patients

had undergone complete repair. There was a significant increase in PA growth

after the initial palliative shunt. The median RV/ LV pressure was 0.66. This group

concluded that rehabilitation of hypoplastic native pulmonary arteries by a

neonatal shunting regimen, without MAPCA translocation, for pulmonary atresia,

VSD, and MAPCAs, provides encouraging results with excellent early survival.

A protocol was proposed by Malhotra et al (28), the group which analyzed

462 patients with VSD-PA and MAPCAs over 15 years. Median age at operation

was 7.7 months, ranging from 10 days to 39 years. Complete single-stage

unifocalization was achieved in 76% of patients. Intracardiac repair was possible at

initial operation in 56%. At 5 years, 90% of patients were completely repaired,

indicating that most patients who did not achieve initial intracardiac repair

eventually did. No factor was predictive of mortality apart from the birth cohort in

this study. The following figure is illustrative of the study flow and their protocol.

16

Fig 1

Study flow

Many studies (29-32) have shown that unfavorable long-term outcomes

from staged approaches can be largely attributed to the significant loss of lung

segments, and development of pulmonary vascular disease, as a result of prolonged

uncontrolled flow through collaterals because of delayed or deferred completion

unifocalization. The most important factor in improving the long-term prognosis of

these patients is not the achievement of intracardiac repair alone, but the

achievement of intracardiac repair with a low RV/LV pressure ratio.

17

MATERIAL AND METHODS:

A total of 108 children were enrolled in the study. Infants registered in our

hospital from January 1 st 2011 to December 31 st 2015 were enrolled in the study.

They were followed up until 30 th June 2015. Data of those, who were lost to

follow up before 30 th June 2015 were analysed till the point, they were followed

up either through a hospital visit or telephonic enquiry. Institute Ethics committee

clearance was obtained prior to commencement of the study. Data was collected

using detailed proforma and data collection by telephone was systematically made

when there was a lack of follow up over a prolonged period. In the event of

mortality outside hospital, details regarding the heralding events were obtained bt

telephonic conversation.

Inclusion criteria:

All children < 1 year with a diagnosis of VSD-PA (Ventricular septal defect-

pulmonary atresia), attending the outpatient department at this institute were

enrolled in the study. Children who had undergone intervention outside , but

subsequently registered in our hospital were also included if their age at first

contact with our institute, was less than 1 year.

18

Exclusion criteria:

Pulmonary atresia associated with complex heart disease were excluded –

eg. Transposition, double outlet right ventricle, AV canal defect etc. Any child

beyond beyond the age of one year at the time of first contact were excluded.

Mortality data:

Mortality data were segregated depending on the time interval at which

death occurred and we introduced the following novel nosology to depict the

timeframe in which it occurred.

“T1” is defined as the period prior to any palliative procedure, in a child who has

undergone direct total correction – it is the time before the first surgical procedure.

“T2”is defined as the period between initial palliative procedure and final

corrective procedure, in children who have undergone an initial palliative

procedure

“T3” is defined as a death in the peri procedural period, regardless of whether the

procedure is palliative or definitive. All deaths till discharge following a procedure

were included in this category.

“T4” is defined as a death following a corrective period at any time beyond

hospital discharge after the procedure.

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STATISTICAL ANALYSIS:

The data was analyzed by the principal investigator. All data was handled

with care to maintain patient confidentiality. Records were maintained in both

computer and paper formats. Data was tabulated in Microsoft excel sheet.

Descriptive summaries are presented as frequencies and percentages, for

categorical data, and as means and standard deviations for continuous variables.

Continuous variables are compared using Student’s t test or Mann-Whitney U test

as appropriate. Discrete variables are compared using Chi- square test. Kaplan-

Meier survival analyses was performed to evaluate differences in mortality among

various sub-groups. Univariate analysis for predictors of mortality was done by

Chi square test and multivariate analysis was done by binary logistic regression

model. Cox proportional hazard model was done for multivariate analysis of

survival and Log rank test was used for univariate analysis of survival. All

statistical analyses were performed using the SPSS statistical software package

(release 17.0, SPSS Inc.; Chicago,Ill).

20

RESULTS:

Baseline demographic data:

Among the 108 children, who were enrolled, 55 (50.9%) were male and 53

(49.1%) were female, suggesting an equal gender preponderance. The mean age at

diagnosis was 1.65 +/- 2.61 months. Infants presented as early as soon after birth

on the first day of life to as late as 11 months. There was tendency to later

diagnosis in MAPCA dependent pulmonary circulation. The mean duration of

follow up was 18.98 +/- 18.54 months (range 0.7 – 66 months).

There was history of maternal diabetes in 17 infants (15.7%). The average

birthweight of the entire cohort was 2.64 +/- 0.46 kg. 13 infants (12%) were born

preterm. 32.4% of the infants required prostaglandin either orally or parenterally

due to desaturation associated with issues in ductal patency. Lowest saturation

during the follow up period on an average was 73.4 +/- 7.8 %. 48.1% (n=52)

infants required some form of intervention on follow up.

21

Table 1:

Demographic data

N = 108

Age at diagnosis (Mean +/ SD)

1.65 +/- 2.61 months

Follow up (Mean +/ SD) 18.98 +/- 18.54 months

Gender Male – 55 (51%)

Female – 53 (49%)

Birth weight (Mean +/ SD)

2.64 +/- 0.46 kg

Prematurity 13 (12 %)

Maternal risk factors Gestational diabetes - 17

Hypertension - 7

Hypothyroidism - 5

Imaging Total – 56 (52%)

CT – 26 (24%)

MRI – 30 (28%)

Lowest oxygen saturation on follow up (Mean +/ SD)

73.4 +/- 7.8 %

Time to saturation nadir All – 6.85 months

Duct dependent - 4.35 months

MAPCA dependent – 9.83 months

Both – 8.62 months

Prostaglandin 35 (32.4 %)

Associated cardiac Situs ambiguous- 5

22

anomalies PAPVC – 4

LPA stenosis – 3

Corrected transposition – 3

Retro aortic innominate vein – 3

Coronary anomalies - 3

Criss cross heart – 1

Interrupted IVC- 1

Aberrant LSCA- 1

Asymmetric septal hypertrophy – 1

Dextrocardia -1

Bovine arch - 1

Associated extra cardiac anomalies

Di George syndrome – 7

Trisomy 21- 1

Anorectal malformation – 2

Renal anomalies- 2

CTEV-1

Cleft palate – 1

Annular pancreas - 1

Associated cardiac and extra cardiac anomalies:

14 children had bilateral SVC. Other common cardiac anomalies seen in

children with VSD pulmonary atresia were situs ambiguous (n=5), partial

anomalous pulmonary venous connection (n=4), branch PA stenosis (n=3),

corrected transposition (n=3) and retro aortic innominate vein (n=3). Other less

23

common anomalies seen in the cohort were criss cross heart, interrupted inferior

vena cava and aberrant left subclavian artery, Seven children were antenatally

diagnosed to have pulmonary atresia.

Di George syndrome was the commonest syndrome observed in this cohort

(n=7). 22 q11 deletion was proven genetically in only in 4 patients, the others had

facies characteristic of the syndrome with or without hypocalcemia and stigmata of

immunodeficiency. Trisomy 21 was the only chromosomal aneuploidy seen in this

study. Other associated extra cardiac anomalies were renal, anorectal or gut

related. Cleft palate and congenital talipes equinovarus were each seen in 1 patient.

Pulmonary blood flow and anatomy:

73.1% (n=79) of the infants had confluent pulmonary arterial anatomy,

whereas 26.9% had non-confluent anatomy. 80 infants (74.1%) had long segment

pulmonary atresia and 28 of them had short segment pulmonary atresia. 36 of the

53 (66%) female infants had confluent pulmonary arterial anatomy and 41 of the

53 (77.3%) had long segment pulmonary atresia, thereby making confluent long

segment atresia the predominant phenotype in the female cohort. 43 of the 55

(78.2%) male infants had confluent anatomy and 39 of the 55 (70.9%) male infants

had long segment pulmonary atresia.

24

29 of the 55 male infants (52.8%) had duct dependent pulmonary circulation, 16

(29%) had collateral dependent pulmonary circulation and 10 (18.2%) had

evidence of both. 31 of the 53 female infants (58.4%) had duct dependent

pulmonary circulation, 12 (22.7%) had collateral dependent circulation and 10

(18.9%) had evidence of both. The mean McGoon index in the male cohort was

1.21 and in the female cohort was 1.26. The mean McGoon index in the children

with duct dependent circulation was 1.30, 1.16 in MAPCA dependent group and

was 1.29 in the presence of both.

80 of the 108 infants (74%) had left sided Aortic arch, whereas 28 (26%)

had right arch. Among the patients with collaterals the prevalence of right arch was

41.7%. In the presence of collateral dependent pulmonary circulation (MAPCAs as

the only source of pulmonary blood flow) 71.4% of the infants had right arch.

There were 7 infants diagnosed with DiGeorge syndrome in the study, of which 5

(71.4%) had right arch.

Pulmonary anatomy was assessed by echocardiography and when there was

ambiguity, imaging by CT/ MRI was performed. Most patients with MAPCA

dependent circulation required an additional modality to delineate the origin of

MAPCAs. Imaging in the form of CT was done in 26 children and MRI was

performed in 30 children. Imaging provided incremental data over echo in 33

25

patients. Incremental data was usually in the form of exact location of MAPCA

and clarify central pulmonary artery anatomy, where it was not clear.

Table 2:

Pulmonary blood supply

Pulmonary anatomy Confluent – 79 (73.1%)

Non confluent – 29

(26.9%)

Atresia length Long segment - 80

(74.1%)

Short segment – 28

(25.9%)

Source of pulmonary

blood flow

Duct – 60 (55.6%)

MAPCA – 28 (25.9%)

Both – 20 (18.5%)

Arch Left – 80 (74.1%)

Right – 28 (25.9%)

Mc Goon ratio

All – 1.26

Duct dependent - 1.30

MAPCA dependent –

1.16

Both – 1.29

26

Procedure data:

51 (47.2%) of the 108 patients underwent some procedure – palliative,

corrective or both. Initial palliation was with ductal stenting in 6 patients, with

Aorto-pulmonary shunt in 37 patients and with Cavopulmonary shunt (BDG) in 1

patient. BDG was performed in children after initial palliation in 3 children. Out of

children in the duct dependent pulmonary circulation group, 10 proceeded to

corrective surgery. Whereas in the MAPCA group, 3 children proceeded to

corrective surgery in the form of unifocalisation. Among the 6 children, who

underwent ductal stenting, 2 underwent BDG and 1 underwent total correction.

Among the children, who underwent Aorto-pulmonary shunt, 1 underwent BDG

and 5 underwent total correction. Of the 108 children, who were enrolled in the

study, only 13 underwent total correction, which is in fact the goal of treatment in

every patient. 10 children were kept on medical follow up and any form of surgical

treatment was deferred in them, in view of poor pulmonary anatomy.

27

Fig 2

Study flow

Among the children, who underwent ductal stenting, the commonest stent

size was 3.5 (n=5) and one child received a size 4 mm bare metal stent. None of

them required more than one stent. There were no peri procedural complications in

this subgroup. Left axillary access was the commonest vascular access chosen in

lieu of the ductal anatomy.

Aorto-pulmonary shunt surgery was performed in 37 patients. The commonest

shunt size used was 3.5 mm (n=18), followed by 3 mm (n=12) and 4 mm shunt

was used 7 children only. Blockage of Aorto-pulmonary shunt was seen on follow

VSD-PA

N = 108

INTERVENED

N = 51

PALLIATION

N = 44

ICR

N = 13

PRIMARY ICR

N = 7

ICR AFTER PALLIATION

N= 6

NOT INTERVENED

N = 56

PLANNED FOR

SURGERY

N = 45

SURGERY DEFFERED -DUE TO UNFAVORABLE

ANATOMY

N = 11

28

up in 3 patients, and among them 1 had an acute shunt blockage requiring revision

on the first post0operative day.

Primary ICR was performed in 7 children whereas it was done after an initial

palliation in 6 patients (1 with prior ductal stenting and 5 with prior Aorto-

pulmonary shunt). Unifocalisation was performed in 3 patients, concomitant

branch PA plasty was required in 9, homograft was placed in 4 and VSD patch

fenestration was required in 2 patients.

Surgical site infection (n=3) and ventilator associated pneumonia (n=3) were

the commonest post-operative complications, among all patients who underwent

surgery.

Table 3:

Procedure data

N = 51

Age at procedure (Mean +/ SD) 5.92 +/- 9.84 months

Average duration of “T1” period

(Mean +/ SD)

4.81 +/- 9.06 months

Ductal stenting N = 6

3.5 mm stent – 5

4 mm stent – 1

Left axillary access – 5

Right femoral access - 1

29

BT shunt N = 37

3 mm shunt- 12

3.5 mm shunt – 18

4 mm shunt - 7

Primary BDG 1

Time to ICR (Mean +/ SD) 15.68 +/- 14.98 months

Primary ICR 7

BDG after initial palliation 3

ICR after initial palliation 6

Concomitant procedure Unifocalisation – 3

Homograft – 4

Branch PA plasty – 9

VSD fenestration - 2

Post procedure complications Blocked Aorto-pulmonary shunt – 3

Branch PA stenosis – 3

Surgical site infection – 3

VAP -3

RV hypertension – 2

Severe TR - 1

30

Mortality:

There were a total of 32 deaths in the entire study population, of which 17

were in the duct dependent group, 8 were in the MAPCA dependent group and 7 in

the group with dual pulmonary blood supply. Of the children who died, 16 were

male and 16 were female. Number of deaths before 3 months of age was 10 and 22

died after 3 months of age.

Fig 3

Flow chart showing survival proportions in subgroups based on pulmonary

anatomy

VSD-PA

N= 108

Duct group

N = 60

Survived

N= 43 (71.7%)

Died

N= 17 (28.3%)

MAPCA group

N = 28

Survived

N= 20 (71.5%)

Died

N= 8 (28.5%)

Both group

N = 20

Survived

N= 13 (65%)

Died

N= 7 (35%)

31

Death prior to any procedure referred to in this study as “ T 1” death

numbered 19, 2 in the “ T 2 “ period , defined as period between palliation and

corrective procedures numbered , in the perioperative period ( within 2 weeks of

surgery or till hospital discharge ) referred to as “ T3 “ numbered 10 and late

deaths numbered 1 and was regarded as “T 4” deaths. T1 period had the maximum

number of deaths. Causes of post-operative deaths were as follows- ventricular

dysfunction in 6, RV hypertension in 2 and sepsis in 2.

Table 4:

Mortality data

N = 32

Age at death (Mean +/ SD) 6.25 +/- 7.73 months

Gender Male – 16 (50%)

Female – 16 (50%)

Pulmonary anatomy Duct dependent – 17 (53.1%)

MAPCA dependent – 8 (25%)

Both – 7 (21.9%)

T1 (prior to any palliation/ corrective

surgery)

19 (59.3 %)

T2 (post palliation, prior to corrective

surgery)

2 (6.2 %)

32

T3 (peri operative) 10 (31.2%)

T4 ( late, after corrective surgery) 1(3.1%)

10 children died in the perioperative period, defined as any death prior to

discharge from hospitalization for an interventional procedure. There were no

deaths following ductal stenting. Among the children, who underwent Aorto-

pulmonary shunts, 6 died and the main cause of mortality was ventricular

dysfunction. Most of the children underwent the above procedure as an emergency

following a spell or worsening cyanosis and hence same could be incriminated to

be the cause of the ventricular dysfunction. The cause of deaths post

unifocalisation was suprasystemic right ventricular pressure, reflecting the inability

the ventricle to handle high pulmonary artery pressure, as a consequence of poorly

developed pulmonary arteries, poor arborisation or onset of pulmonary vascular

obstructive disease (PVOD) prior to the procedure in case of hypertensive MAPCA

s. Post complete repair, 1 child died of sepsis and another because of severe RV

dysfunction.

33

Fig 4

Distribution of mortality in the various time intervals

Table 5

Post procedure mortality data:

N=10

Post ductal stenting 0

Post Aorto-pulmonary shunt 6

Ventricular dysfunction – 5

Sepsis- 1

Post BDG 0

Post Unifocalisation + ICR

N = 2

2 ( 66.67%)

Suprasytemic RV pressure - 2

Post ICR 2 (15.38%)

60% 6%

31%

3%

Mortality data of the entire cohort T1

T2

T3

T4

34

N = 13 RV dysfunction – 1

Sepsis, MODS- 1

Among the 44 children, who underwent intervention in the duct dependent

group, 79.5% survived, whereas in the “no intervention” arm only 50% survived.

In the MAPCA dependent group, only one child underwent intervention, in the

form of unifocalisation and that child died, translating into a mortality of 100%.

Despite not undergoing intervention 74.1% of the children in MAPCA dependent

group survived. In the group with dual pulmonary blood supply, 30 % underwent

intervention, of which 50% survived. Among the children with no intervention in

the same group, 71.4% survived.

Figure 5

Flow chart showing survival of various subgroups based on intervention

Total no. of children

n = 108

Duct dependent

n = 60

Intervention

n = 44 (73.3%)

Alive

n = 35 (79.5%)

Died

n = 9(20.5%)

No intervention

n = 16 (26.7%)

Alive

n = 8(50%)

Died

n = 8(50%)

MAPCA dependent

n = 28

intervention

n = 1 (3.5%)

Alive

n = 0

Died

n = 1(100%)

No intervention

n = 27(96.5%)

Alive

n = 20(74.1%)

Died

n = 7(25.9%)

Both

n = 20

Intervention

n =6 ( 30%)

Alive

n = 3 (50%)

Died

n = 3(50%)

No intervention

n = 14 (70%)

Alive

n = 10(71.4%)

Died

n = 4(28.6%)

35

Predictors of mortality:

Analysis was done to assess predictors of mortality. Only length of

pulmonary atresia (long segment) and prematurity were predictive of survival

among the various parameters analysed, with a “p” value of .011 and 0.041

respectively. The other variable nearing significance statistically was prostaglandin

use (p=0.075). Other variables like age at diagnosis, source of pulmonary blood

flow, Mc Goon index, intervention and association with a syndrome were not

predictive of mortality.

Table 6:

Predictors of mortality– univariate analysis

Death

Total χ2 df p Parameter

No Yes

N % N % N %

Gender Male 39 51.3 16 50 55 50.9 0.016 1 0.901 Female 37 48.7 16 50 53 49.1 PA anatomy

Confluent

57

75

22

68.8

79

73.1

0.448

1

0.503

Non confluent 19 25 10 31.3 29 26.9 Long 51 67.1 29 90.6 80 74.1 6.486 1 0.011 Short 25 32.9 3 9.4 28 25.9 Source of PBF

PDA

43

56.6

17

53.1

60

55.6

0.34

2

0.844

MAPCA 20 26.3 8 25 28 25.9 Both 13 17.1 7 21.9 20 18.5 Arch

Right

21

27.6

7

21.9

28

25.9

0.389

1

0.533

Left 55 72.4 25 78.1 80 74.1

36

Prematurity

6

7.9

7

21.9

13

12

4.157 1

0.041

Prostaglandin usage

20 26.3 14 43.8 34 31.5 3.173 1 0.075

Any procedure

38 50 13 40.6 51 47.2 0.794 1 0.373

Palliative procedure

BTS 27 81.8 10 100 37 86 2.113 1 0.146

PDA 6 18.2 0 0 6 14 Intervention vs No intervention

Complete repair 9 11.8 4 12.5 13 12 1.027 2 0.598

Palliation 29 38.2 9 28.1 38 35.2 No intervention 38 50 19 59.4 57 52.8 Mc Goon ratio

<1.2 19 25 9 28.1 28 25.9 0.115 1 0.735

=>1.2 57 75 23 71.9 80 74.1 Age at surgery

<=10 32 84.2 11 84.6 43 84.3 0.001 1 0.972

>10 6 15.8 2 15.4 8 15.7 Associated Syndrome

4 5.3 5 15.6 9 8.3 3.165 1 0.075

In multi variate analysis only long segment pulmonary atresia remained a

significant predictor of death (p = 0.023).

37

Table 7:

Binary logistic regression model for outcome of death as dependent variable

B S.E. Wald df p

Long / short segment

atresia -1.515 .665 5.191 1 .023

Prematurity 1.102 .649 2.888 1 .089

Prostaglandin usage .689 .482 2.044 1 .153

Associated syndrome 1.127 .793 2.018 1 .155

Survival analysis:

Kaplan Meier curves were plotted for the entire cohort and also for various

subgroups like and are shown below. One year survival for the entire cohort was

70.3%, at 2 years it was 68.2% and was 65% at 4 years.

38

Fig 6:

Kaplan Meier curve for survival for the entire population

One year survival for children with duct dependent pulmonary circulation

was 70.9%, in MAPCA dependent circulation was 68.1% and was 67.8% in the

group having both duct and MAPCAs.

39

Fig 7:

Kaplan Meier curve for survival based on source of pulmonary blood flow

Figure showing years of follow up in the x axis and and cumulative survival in the y axis

One year survival in children who underwent Aorto-pulmonary shunt as the

initial palliation was 72.5%, 75.9% in those undergoing any form of palliation

40

(surgical or interventional),76.9 % in those undergoing ICR and 64.6 % in those

not undergoing any form of intervention.

Fig 8:

Survival curves depending on intervention performed

41

0 10 20 30 40 50 60 70 80

Entire cohort

Non MAPCA group

MAPCA group

Complete repair

Palliation group

No intervention group

70

71

68

79

77

65

Key findings - 1 Year survival

42

DISCUSSION:

Both old ((33) (34)) and contemporary (21) series show at MAPCA

dependent circulation occurs in about 25 – 31%. This is in line with our series

where the MAPCA dependent group constituted 25.9 % (n=28)

Data from our study suggests that about three fourths (3/4) of the duct

dependent population required some form of intervention and once intervened,

survival was good, around 80%. On the contrary, in the MAPCA dependent group,

majority of them survived without any intervention. In the mixed group, survival

with intervention was around 50% and without any intervention was 71%. Duct

dependent cohort is the subgroup which needed intervention in infancy to alleviate

worsening cyanosis and the other two subgroups were less vulnerable, though

MAPCA group was better in terms of survival without any intervention, re-

iterating the fact that MAPCA s were a more stable source of pulmonary blood

flow in an infant. The fact that many in the MAPCA group (n= 9) were planned for

an unifocalisation and still had not undergone the same during the period in which,

they were followed up in this study should be borne in mind. In our study,

mortality rate after ICR is 15.38% whereas 2 of the 3 children who underwent

unifocalisation with ICR is 66.67%.

43

As early as 1978, survival data were published for VSD-PA, with necropsy

data and it was published that survival without surgery was 50% at 1 year and 8%

at 10 years ((35)).

One year survival in our series is 70.3 %. This conforms with other studies,

which also show a similar high rate of attrition in the first year of life. 47.2%

children underwent some form of intervention, whereas 39.8% underwent initial

palliation with ductal stenting or Aorto-pulmonary shunt. Primary ICR rate was 6.4

% (7 among 108 patients). Only 13.6 % of patients, who underwent initial

palliation underwent corrective surgery on follow up of 18 months. Children who

underwent initial palliation (ductal stenting/ Aorto-pulmonary shunt), on an

average underwent corrective surgery in mean period of 15.29 months. On the

other hand, children without any palliation underwent corrective surgery in 16.02

months after their initial diagnosis. The average time to initial palliation was 2.71

months.

In a landmark paper by Amark et al, evaluating the factors associated with

mortality and predicting complete repair, 220 children with ventricular septal

defect and pulmonary atresia, diagnosed over a period of 30 years were followed

up. In their series, definitive repair was attained in 75%. Systemic pulmonary

artery shunt was done in 57%, complete primary repair was done in 31% and RV

ventricular outflow reconstruction in 12 %. After initial palliative shunt, 68.5% of

44

patients underwent complete repair. Risk factors for death after initial operation

included younger age at repair, earlier birth cohort, fewer broncho-pulmonary

segments supplied by native pulmonary arteries, and placement of an Aorto-

pulmonary shunt. 10 - year survival rate in this series after initial surgery was 71%.

Only 15.9% of children in their series did not undergo any form of intervention.

Nearly half of them (n=105) underwent an initial Aorto-pulmonary shunt. They

also found that higher rates of initial complete repair occurred in later birth cohorts

as opposed to earlier ones. 38 children underwent 47 re-operations and 56 patients

underwent 104 catheter based interventions. Catheter based interventions were

more common in the MAPCA group and were done sooner after complete repair at

a median gap of 1.1 years after surgery.

Mortality in the MAPCA group in this series was 39.6%, 55.56 % without

intervention, 33.33 % after unifocalisation and 30.43% in the initially palliated

group.

The above data suggests that though rates of initial palliation with Aorto-

pulmonary shunts in our series is similar to the western data, rates of primary

repair and corrective surgery after initial palliation were much lesser in our cohort,

though our follow up was relatively short term and many children were awaiting

surgical procedures. In our study, we could not find strong predictors of mortality

other than length of pulmonary atresia and prematurity. Since our complete repair

45

rates were low, no meaningful survival analysis of this subgroup was done. No

child in our study, underwent a repeat surgical procedure or catheter based

intervention primarily because of low ICR rates and secondarily due to shorter

follow up compared to historical cohorts. Whereas the population in the series by

Amark et al, represents the modified natural history of VSD-PA; Our study was a

combination of both unmodified and modified natural history in view of lower

rates of complete repair.

In a French study (36), 52 patients with VSD-PA were followed up over a

period of 8.6 years, 26 (50%) were duct dependent and the rest were MAPCA

dependent. Corrective surgery was performed in 14 (53.8%) in the former group

and 9 (34.6%) in the latter group. After a mean follow up of 8.6 years, 71% were

alive, 39 % were corrected and 11.5% were deemed inoperable.

When MAPCA dependent and MAPCA + PDA group are pooled together in

our study, they constitute about 44.5% of the study population, which is similar to

the above population. 18.7% of children the mixed group as described above were

deemed unsuitable for any form of repair in view of poor pulmonary anatomy.

Rates of cardiac catheterization are very low in our study – only 2 patients had

undergone cardiac catheterisation for delineation of MAPCAs. This may be due to

improvement in echo techniques and deployment of additional modalities of

imaging, when clarity was not achieved with echocardiography alone.

46

Though there is debate regarding the approach to managing children with

VSD-PA and MAPCAs, with some groups advocating single stage repair with

unifocalisation and some advocating staged repair with initial Aorto-pulmonary or

RV-PA conduit to promote the growth of PAs, we have only attempted 3 cases of

unifocalisation with intracardiac repair in a single stage procedure. Two of the 3

children aged 7 and 37 months, where unifocalisation with ICR was done died due

to suprasystemic RV pressures despite fenestration.

Among the patients, who died in the T1 period, 10 had sudden death. In 4

children, there is history cyanosis/ spell. Two died of lower respiratory tract

infections and 2 died due to issues related to prematurity. In the T2 period, one

died of lower respiratory tract infection and the other death was sudden.

In another surgical series from India, Murthy et al ((37)) have reported

outcomes of single stage unifocalisation in 124 patients over 13 years. Of these

patients during the initial procedure, 60% underwent complete repair, 21%

underwent only RV-PA conduit and the VSD was left behind whereas in the

remaining 19% only Aorto-pulmonary shunt was accomplished. There were 16

early deaths and 3 late deaths in this series amounting to a total mortality of 15.3%.

The authors concluded that single-stage unifocalization performed at an early age

achieves normalization of physiology with correction of cyanosis or pulmonary

hypertension and attendant complications. Early single-stage unifocalization

47

decreases the number of subsequent surgeries and hospitalizations, and thereby, is

cost effective also compared to a multi staged procedure.

The deaths post single staged unifocalisation with intra cardiac repair in our

series was due to RV hypertension and mandated fenestration of the VSD patch. It

is difficult to conclude at this point in time if a staged unifocalisation would have

been a better option versus an earlier rehabilitation of pulmonary arteries.

48

CONCLUSION:

Survival in a child with VSD-pulmonary atresia in our setting can be

estimated to be around 70% at 12 months

Duct dependent infants are more vulnerable to worsening hypoxemia and

warrant palliative intervention in early infancy

Death most commonly occurs in the ‘T1’ period, prior to any palliation

Only 12% of patients in our study proceeded to complete repair

Only length of pulmonary atresia was a predictor of mortality

Meticulous monitoring of saturation at nearby points of health care may lead

to prompt referral and improve mortality data as majority of deaths happen

before any palliation

49

LIMITATIONS:

The current study is a retrospective analysis of data, some patients were lost

to follow up and hence follow up data are limited to the last hospital visit or

telephonic enquiry.

The average duration of follow up was 18.9 months, which only indicates

the intermediate term follow up of these patients. Long term data remain elusive.

Since it is a medium term follow up, true data of intervention on branch pulmonary

arteries is not represented. Many patients were awaiting unifocalisation or ICR at

the end of study, hence percentage of children undergoing procedure may be an

under-estimate. Longer follow up would give us the true numerator of percentage

of children proceeding to complete repair.

50

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Data collection sheet

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Master chart

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Pliagarism check

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