Horseshoe lung and facio-auriculo-vertebral sequence: A previously unreported association page 1
Horseshoe lung and facio-auriculo-vertebral sequence: A previously unreported association page 2
Horseshoe lung and facio-auriculo-vertebral sequence: A previously unreported association page 3
Horseshoe lung and facio-auriculo-vertebral sequence: A previously unreported association page 4
Horseshoe lung and facio-auriculo-vertebral sequence: A previously unreported association page 5

Horseshoe lung and facio-auriculo-vertebral sequence: A previously unreported association

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Text of Horseshoe lung and facio-auriculo-vertebral sequence: A previously unreported association

  • Pediatric Pulmonology 41:592596 (2006)

    CASE REPORT

    Horseshoe Lung and Facio-Auriculo-VertebralSequence: A Previously Unreported Association

    Lisa DAlessandro, MD,1 Tom Kovesi, MD,2* Sherief Massoud, MD,3 Jane Lougheed, MD,2

    Alasdair Hunter, MD,2,4 and Joseph Reisman, MD2

    Summary. We describe a case of horseshoe lung in an infant with facio-auriculo-vertebral (FAV)

    sequence that included mild hemifacial microsomia, ear anomalies, a missing left rib, left

    hemivertebrae (T2T4), and complex congenital heart disease. Of the approximately 40 cases of

    horseshoe lung described since 1962, most are reported in association with scimitar syndrome,

    and only four reported cases were associated with left lung hypoplasia. None of these cases

    included malformations consistent with a diagnosis of FAV sequence. Pediatr Pulmonol. 2006;

    41:592596. 2006 Wiley-Liss, Inc.

    Key words: Goldenhar syndrome; respiratory system abnormalities; cardiovascular

    abnormality.

    INTRODUCTION

    Goldenhar sequence (oculoauriculovertebral dysplasia)was reported as early as the 1860s, and was described byGorlin et al. in 1963 as including ocular and earmalformations, and vertebral defects.1,2 Over time, it hasbecome apparent that Goldenhar syndrome is part of abroader and heterogeneous spectrum of congenital ano-malies, variously referred to as hemifacial microsomia,facio-auriculo-vertebral (FAV), sequence, and oculoaur-iculovertebral spectrum, all of which are included under164210 in the Online Mendelian Inheritance in Man.3

    Pulmonary malformations, consisting primarily of pul-monary hypoplasia, appear to be relatively common inaffected patients. Horseshoe lung is a rare congenitalmalformation in which the lungs are connected by anisthmus of lung parenchyma posterior to the pericardium.We describe the first reported case of horseshoe lung inassociation with FAV sequence.

    CASE REPORT

    Pregnancy and Birth History

    The subject was female, and the second of monochor-ionic twins born to a 27-year-old gravida 4, abortus 3(G4A3) mother. The twin was unaffected. The motherreported taking levothyroxine for hypothyroidismthroughout the pregnancy, but denied tobacco, alcohol,and drug use. She had recurrent genital herpes, and was

    treated with acyclovir 2 days prior to delivery. She wasrubella-immune, and hepatitis B- and HIV-negative.Complex congenital cardiac malformations were identi-fied prenatally by ultrasound. The infant was born bycesarean section at 37 weeks of gestation, and weighed2,314 g. She cried at birth, and her Apgars were 5 and 9 at1 and 5 min. She was given brief positive-pressureventilation and free-flow oxygen because of bradycardia

    1Department of Pediatrics, Childrens Hospital of Western Ontario,

    London, Ontario, Canada.

    2Department of Pediatrics, Childrens Hospital of Eastern Ontario,

    University of Ottawa, Ottawa, Ontario, Canada.

    3Department of Radiology, Childrens Hospital of Eastern Ontario,

    University of Ottawa, Ottawa, Ontario, Canada.

    4Department of Genetics, Childrens Hospital of Eastern Ontario,

    University of Ottawa, Ottawa, Ontario, Canada.

    *Correspondence to: Tom Kovesi, Department of Pediatrics, Childrens

    Hospital of Eastern Ontario, 401 Smyth Road, Ottawa, ON Canada,

    K1H 8L1. E-mail: kovesi@cheo.on.ca

    Received 1 September 2005; Revised 8 December 2005; Accepted 11

    December 2005.

    DOI 10.1002/ppul.20404

    Published online 14 April 2006 in Wiley InterScience

    (www.interscience.wiley.com).

    2006 Wiley-Liss, Inc.

  • and poor oxygen saturation, andwas placed on continuouspositive airway pressure. A prostaglandin E infusion wasstarted, and she was transferred to the Neonatal IntensiveCare Unit (NICU) at the Childrens Hospital of EasternOntario (CHEO). Physical examination revealed a two-vessel cord. She had skin tags on the left cheek and justanterior to the left tragus, and an overfolded left helix.Therewas mild hypoplasia of the left lower face. The eyeswere normal without choristoma, and no abnormalities ofthe extremities were apparent.

    Investigations in the NICU

    An admission chest x-ray revealed an opacified lefthemithorax obscuring the left heart border, and a normalright lung (Fig. 1). Therewere segmentation abnormalitiesin the upper thoracic spine, with hemivertebrae from T2T4, and an associated scoliosis convex to the right, and theleft first rib was absent. An echocardiogram revealedlevocardia, a double-outlet right ventricle, a hypoplasticleft ventricle, and mitral valve atresia. The great arteriesarose side-by-side, with a normal aortic valve and mildpulmonary valve stenosis. The left pulmonary artery wasabsent, and there was a large patent ductus arteriosus andnormal-sized right pulmonary artery. The right pulmonaryveins drained normally, but the left pulmonary veinsappeared small. There was a right aortic arch with aretroesophageal aberrant left subclavian artery.A computerized tomographic (CT) scan of the chest

    showed that the mediastinal structures were shiftedslightly to the left. A small left main-stem bronchus wasobserved, and a band of lung tissue with associated bloodvessels was seen crossing from right to left behind the

    heart, which is consistent with horseshoe lung. A pleuralreflection in the midanterior portion of the medial side ofthe right lungwas suggestive of an accessory azygous lobe(Fig. 2).A head ultrasound was normal except for a mildly

    dilated left lateral ventricle. An abdominal ultrasounddemonstrated normal liver, spleen, and kidneys. Hearingwas assessed as normal.A medical genetics consultation concluded that the

    mild left facial microsomia, skin tags, complex congenitalheart disease, missing left rib and left hemivertebrae,and pulmonary malformations were consistent with adiagnosis of FAV sequence. Shewas discharged at 14 daysof age.

    Subsequent Course

    The patient was admitted at 5.5 weeks of age withcongestive heart failure. She underwent cardiac catheter-ization, followed by main pulmonary artery banding. Herrecovery was complicated by multiple episodes of apneaand bradycardia that required cardiopulmonary resuscita-tion, intubation, and ventilation. A magnetic resonancescan (MRI) of the brain revealed no abnormality apartfrom a thin but intact corpus callosum. An MRI of theheart showed no evidence of a vascular ring, and a secondMRI of the chest (Figs. 3, 4) revealed an inferior vena cavainterrupted in the porta hepatis below the diaphragm, andone hepatic vein draining directly into the right atrium.Bronchoscopy demonstrated that a tracheal bronchus waspresent, and the left main-stem bronchus was hypoplasticwith no visible branches, although it was difficult to enterthis bronchus. Gastroesophageal reflux was diagnosed on

    Fig. 1. Chest radiograph. Antero-posterior view of chest shows

    left hemithorax to be almost completely opacified, obscuring

    heart outline. Right lung is well-aerated and is clear. There are

    segmentation abnormalities of upper thoracic spine, with right

    convex scoliosis.

    Fig. 2. Computerized tomographic (CT) scan of lungs. Axial CT

    cut of thorax demonstrates a band of lung with vessels crossing

    from right side to left side of chest (arrow) On other views (not

    included), right pulmonary artery was identified, but left

    pulmonary artery could not be demonstrated.

    Horseshoe Lung and FAV Sequence 593

  • the basis of an abnormal pH probe study. Physiotherapywas prescribed for torticollis. The karyotype was 46,XX.The patientwas subsequently readmitted to hospital at 4

    months of age with an acute respiratory infection due toinfluenza A, a right upper lobe collapse, and feedingdifficulties. A repeat bronchoscopy confirmed the earlierfindings, and also demonstrated tracheomalacia with abulging posterior membranous portion of the trachea, andpulsatile compression of the anterior trachea. Malacia of

    the right middle and lower lobe bronchi were alsoobserved.

    DISCUSSION

    Facio-auriculo-vertebral sequence is an asymmetricdisorder of first and second branchial arch developmentthat has an increased rate of concurrent vertebral, cardiac(1447%), and tracheoesophageal anomalies.2 The bran-chial arch anomalies include variable microtia, preauri-cular tags and fistulae, hypoplasia of the lower face, andunilateral macrostomia. The subgroup of patients withchoritomas are considered to have Goldenhar sequence(oculoauriculovertebral dysplasia). FAV sequence isconsidered to be a causally heterogeneous sequence ofbirth defects. In a thorough review of cases of lungagenesis and ipsilateral malformations, Cunningham andMann hypothesized that a disruption in dorsal aortic archbloodflow inweek 4 of gestation (a stagewhen the embryohas paired aortic arches) could selectively interfere withthe development of the lung, limbs, and derivatives of thefirst and second branchial arches, leading to a patternof ipsilateral malformations.4 A vascular cause for thedisruption of asymmetry in FAV has been suggestedrepeatedly in the literature.2,5,6 The finding of a greater-than-expected rate of some of the component anomalies ofFAV among relatives of patients with FAV sequencesuggests there may be a genetic contribution to itsetiology, and it was suggested that there may be geneticfactors involved in the vascular pathogenesis.7,8 A numberof patients have had chromosomal aberrations, but noconsistent karyotypic anomaly has been found.3 Disrup-tion of blastogenesis during weeks 14 of gestation, whenasymmetric development begins, is another commonlycited etiology, especially considering the many cases ofdiscordant Goldenhar syndrome among monozygotictwins.5,6 Recent systematic analysis showed a relationshipbetween the anomalies seen in FAV and those