Introduction

Congenital lobar emphysema is a well-known condition in infants that causes respiratory distress and often requires urgent lobectomy. The diagnosis is made on chest x-ray and computed tomography (CT) by the presence of a hyperinflated lobe with herniation to the opposite side, associated with atelectasis of the ipsilateral normal lung segments. Lobar emphysema is most often seen as an isolated anomaly, even though there are case reports of its association with cystic adenomatoid formation of the lung [1]. To our knowledge, pulmonary sequestration and lobar emphysema in the same infant has not been reported. The following case report illustrates one such infant whose treatment involved some innovative approaches to a persistent pneumothorax after lobectomy.

Case report

A 5-month-old male infant was airlifted to our hospital from a neighboring country. He was on a ventilator and had been diagnosed as having congenital lobar emphysema of the left upper lobe. The infant had had intermittent spells of tachypnea from the age of 4 weeks. A chest x-ray done at a local hospital showed left upper lobe hyperinflation with herniation across the midline (Fig. 1). A CT scan of the chest was reported as consistent with lobar emphysema of the left upper lobe with collapse consolidation of the lower lobe. No other anomaly was detected.

Fig. 1
figure 1

Chest x-ray showing hyperinflation of the left upper lobe with herniation across the midline

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With the diagnosis of congenital lobar emphysema affecting the left upper lobe, the child underwent an emergency thoracotomy after a preliminary bronchoscopy. The left upper lobe was hyperinflated and was removed by a lobectomy. The left lower lobe was unusually firm to feel and was thought to be collapsed and “consolidated.” There were small air leaks from the edges of the lower lobe parenchyma, and these were sutured to control the leak. A bronchoscopy was done again at the end of procedure, and no intraluminal pathology was seen. The chest was closed with an intercostal drainage tube, and the child was sent back to the pediatric intensive care unit.

Over the next 3 weeks, the lower lobe remained incompletely expanded, with a slowly accumulating pneumothorax. Repositioning the chest tubes and additional tubes failed to solve the problem. An echocardiogram was done, as there was a short systolic murmur over the precordium. This did not detect any gross anomaly. A repeat bronchoscopy was done, and this again excluded any intrabronchial pathology. At this point, there was clinical suspicion that the lower lobe may be abnormal, but review of the CT scans failed to show any mass lesion. The histology of the excised upper lobe was consistent with congenital lobar emphysema. As the air leak and pneumothorax persisted, we suggested that the child be reexplored and the lower lobe removed. The parents refused this procedure, and the child was transferred to the Hospital for Sick Children at Great Ormond Street, London.

At admission to that hospital, a repeat Doppler study of the heart was done. This showed a hyperdynamic left atrium and left ventricle. An aberrant artery was seen to be supplying the lower lobe, and this seemed to originate from below the diaphragm. A retrograde aortogram and pulmonary angiogram were then done under general anesthesia. This confirmed a normal left pulmonary artery, a normal pulmonary vein, and a huge aberrant systemic arterial supply to the left lower lobe arising just below the diaphragm from the abdominal aorta (Prof. Andrew Redington). An Amplatzer PDA plug and coil were then used to successfully embolize this artery. This stopped the blood flow through this vessel. Following this procedure, the left lower lobe rapidly reexpanded to fill the hemithorax, with cessation of the air leak and pneumothorax. The chest x-ray became normal.

Six months after this procedure, the child was readmitted with fever. Investigations at our hospital showed that there was partial recanalization of the occluded vessel. Another coil was put into the artery to totally occlude this aberrant supply (Fig. 2). An angiogram once again confirmed a normal pulmonary artery and normal venous drainage. CT scanning has not shown any mass lesion. The child is now 4 years old, is growing up normally, and has no respiratory or cardiac symptoms.

Fig. 2
figure 2

Angiogram showing the aberrant systemic arterial vessel to the lower lobe of the left lung before (a) and after (b) embolization

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Discussion

Congenital lobar emphysema is reported to have an incidence of 1:25,000 live births, with the left upper lobe predominantly affected [2]. It is thought to arise because of either an abnormal parenchyma [3] or an abnormal bronchiole [4]. Hyperinflation secondary to an intraluminal foreign body or mucus plug or extrabronchial vascular compression can mimic true lobar emphysema. Pulmonary sequestration, both intralobar and extralobar, presents as a mass lesion seen on chest x-ray. It is defined as the presence of pulmonary tissue without the normal tracheobronchial connections and is supplied by a systemic arterial supply from the abdominal aorta.

Embryologically, the developing lung bud is supplied by a series of vessels from the primitive aorta. The splanchnic arteries initially supply it. Later the splanchnic supply diminishes, and the 6th aortic arch takes over to develop as the pulmonary artery [5]. The exact stimulus for this is conjectural; some postulate that oligemia of the lung bud is responsible for the development of the pulmonary arterial system. An extremely rare form of sequestration would thus be the presence of only the systemic arterial system without the presence of the “sequestrated” pulmonary tissue. We believe that our case falls into this category. It is possible that during the development of this lung with abnormal vasculature, the bronchial tree was affected, causing lobar emphysema to develop in a part of the lung.

It would be interesting to speculate on the possible events should the lower lobe have a normal pulmonary arterial supply and venous drainage, apart from a huge systemic arterial supply. The lobe would get overperfused with blood and become turgid. The pulmonary venous flow may increase. The lobe would get progressively more congested and then produce hemoptysis. Most of the reported cases—only 16 so far—have presented with hemoptysis as the presenting symptom [6]. A murmur, closely resembling the murmur of patent ductus arteriosus, may be heard in the interscapular location.

Most of the reported cases had lobectomy as treatment [6]. There are also reports of such a case being treated by an anastamosis between the pulmonary artery and the aberrant systemic artery. There has also a recent case report of an infant with aberrant systemic arterial supply to the lung being treated with embolization [7]. Our case is unique in the sense that the upper lobe and lower lobe were pathological, with the upper lobe affected by lobar emphysema and the lower lobe by arterial sequestration. With the upper lobe having been removed, it was imperative that the lower lobe be preserved to avoid the long-term complications of pneumonectomy. Embolization of the aberrant artery resulted in reexpansion of the lower lobe and obviated the necessity for removing this lobe. It also resulted in the rapid sealing of an air leak following lung surgery. Long-term results of this form of treatment of sequestration seem to be encouraging [8].

This case illustrates the following points:

  1. (1)

    Congenital lobar emphysema can be associated with other pathology-like sequestration.

  2. (2)

    A hemodynamic and echocardiographic evaluation is advisable prior to surgery.

  3. (3)

    Nonexpansion of the remaining lobe following surgery would require detailed investigations, including echocardiography and angiography.

  4. (4)

    Anomalous systemic arterial supply to a normal pulmonary segment in an infant can be successfully treated by transcatheter embolization procedures, thus avoiding resectional surgery.