Breathing and Feeding Woes: A Neonate’s Journey through Vascular Conundrum

Case details:

A baby boy, born via non-consanguineous marriage with a birth weight of 2.78Kg, presented at 11 days of life with respiratory distress. His antenatal course was uneventful, with a foetal echocardiogram showing a right aortic arch and a foetal chromosomal microarray ruling out any genetic issues. He was delivered by caesarean-section at 37 weeks due to non-progression of labour, with appearance, pulse, grimace, activity and respiration (APGAR) scores of 8 and 9 at 1 and 5 minutes, respectively. The immediate postnatal period was uneventful, and he was discharged on the third day.

At home, the baby experienced feeding difficulties, prolonged feeding times, and occasional non-bilious vomiting. He was predominantly breastfed. On the sixth day, fast breathing was noted, without fever or significant cough, and no family history of viral or flu-like illness was reported. He was admitted to another hospital, where he was managed with intravenous (IV) fluids, orogastric feeds, oxygen, IV antibiotics, and Lasix. However, his symptoms persisted, leading to a referral to our hospital for further management on the 11th day of life.

On admission, the baby had a temperature of 36.5°C, respiratory rate of 68/min with intercostal retractions, bilateral crepitations, SpO2 of 86% (Downe’s score 4), heart rate of 138/min, a pan systolic grade 3/6 murmur, well palpable pulses, non invasive blood pressure (NIBP) of 68/40mmHg (mean, 50), and a random blood sugar (RBS) of 70mg/dL. He had good tone and activity, no dysmorphism, and no visible external malformations. Intermittent hoarseness was noted while crying. He was started on continuous positive airway pressure (CPAP) support (6 cm H2O and fraction of inspired oxygen [FiO2] 30%), orogastric feeds, and IV antibiotics pending blood culture results. Initial investigations showed a positive C-reactive protein (CRP) (25 mg/L) with sterile blood and cerebrospinal fluid (CSF) cultures. A chest radiograph showed haziness in the right lower zone, and 2D ECHO revealed a moderate peri-membranous ventricular septal defect (VSD), with a right aortic arch. An upper respiratory panel polymerase chain reaction (PCR) test was negative for common respiratory viruses. The baby was weaned off CPAP on the 15th day as his distress gradually settled. However, on the 16th day, after attempting oral feeds, he developed cough and respiratory distress again, necessitating re-initiation of high flow nasal cannula (HFNC) support and orogastric feeds. There was no tachycardia and no hepatomegaly. Repeat infection markers were negative. Chest radiograph showed increased bilateral infiltrates. Aspiration was considered due to worsening distress with oral feeds and no response to antibiotics. Further evaluation for airway malformations and vascular anomalies was conducted. Flexible upper airway bronchoscopy revealed a 20% lumen compromise due to pulsatile vascular airway compression. Upper gastrointestinal (GI) fluoroscopy showed postero-lateral indention on the contrast filled oesophagus, suggestive of significant oesophageal compression, with contrast aspiration into the right main bronchus (Figure 1).

Figure 1: Upper gastrointestinal (GI) fluoroscopy (oblique view) shows postero-lateral indention on the contrast filled oesophagus (yellow arrow) and aspiration of contrast into right main bronchus (orange arrows).

A plain computed tomography (CT) chest scan identified a right-sided aortic arch with an aberrant left subclavian artery (ALSA) and Kommerell diverticulum, forming a complete vascular ring, causing significant oesophageal compression and aspiration pneumonia (Figure 2).

Figure 2:

CT angiography axial view showing Left common carotid artery arising from right-sided aortic arch coursing anterior to the trachea (yellow arrow); ALSA courses posterior to oesophagus (red arrowhead) on the left side-making a vascular ring.

Discussion

Vascular rings are congenital anomalies of the aortic arch that result in compression of the tracheobronchial tree and or oesophagus, leading to respiratory and GI symptoms.1-3 They can be classified as complete (when both trachea and oesophagus are fully encircled by a vascular anomaly) or incomplete. Vascular rings with significant symptoms are usually complete type.1 Double aortic arch, right aortic arch with aberrant vessel, innominate artery compression syndrome, aberrant left subclavian and pulmonary vascular sling are the major vascular rings.4-6 Kommerell diverticulum is an outpouching that arises from an aberrant subclavian artery, usually in the context of a right aortic arch with an aberrant left subclavian artery.7,8 This diverticulum can cause compression of the oesophagus and trachea, leading to symptoms like those caused by vascular rings. Vascular rings can either be isolated or be associated with other cardiovascular anomalies. Associated non-cardiac anomalies include tracheal stenosis (associated with a pulmonary sling), tracheomalacia, and laryngomalacia.9 Associated genetic abnormalities include CATCH 22 syndrome, Rubinstein-Taybi syndrome, and chromosomal aberrations.10 Vascular rings commonly present with respiratory symptoms which include inspiratory stridor, recurrent respiratory infections, recurrent wheeze, cough, respiratory distress, and recurrent extubation failure.1,4,11 Symptoms indicative of oesophageal compression include dysphagia, choking while feeding, feeding difficulty, reflux, and vomiting.9 In infants experiencing repeated respiratory or oesophageal compressive symptoms, especially when arch anomalies are present, maintaining a high index of suspicion for diagnosing vascular rings is crucial.2 Vascular ring causing oesophageal compression and aspiration in neonates is rare and is sparsely reported in literature. Diagnostic modalities include flexible bronchoscopy, fluoroscopy/ GI contrast study to see for posterior indentation of oesophagus, chest radiograph, CT angiograph/magnetic resonance imaging (MRI) to assess the arch and branching pattern and echocardiography with doppler and colour mapping.5,11 Surgical correction is the mainstay of treatment for symptomatic vascular rings, though not all vascular rings require surgery.1 Asymptomatic babies need no surgical treatment even when the anomalies are found incidentally.2 For infants with mild symptoms careful feeding with soft foods and aggressive treatment of pulmonary infections is required.5 Severe respiratory distress, recurrent pulmonary infections, oesophageal compression causing aspiration pneumonitis, and apnoeic spells are few indications for surgical intervention.8 The timing of surgery depends on the severity of symptoms and is critical, as delaying intervention can lead to progressive airway and oesophageal damage, worsening symptoms, and an increased risk of respiratory infections.1 Surgical approaches vary depending on the specific anatomy of the vascular ring or diverticulum but generally involve division of the vascular structures causing the compression.9 Postoperative complications include chylothorax, transient hypertension, oesophageal stenosis and vocal cord paralysis/paresis.