CLE is diagnosed at birth in about 25% of cases and by 1 month of age in about 50% of cases. The diagnosis is sporadic after 6 months of age [8,9,10,11,12]. Most of the cases reported including the ones in our series had repeated previous admissions, with a low degree of suspicion amongst paediatricians, as the symptoms mimic many medical conditions like upper respiratory tract infections, asthma, viral bronchiolitis, etc. [10,11,12,13,14,15,16]. During these admissions, most of these cases were managed conservatively; however, a few underwent invasive procedures like tracheostomy and bronchoscopies, before being referred for surgical intervention (Table 1) [8,9,10,11,12,13].
There are various reasons described for CLE, and the principal mechanism is that the affected bronchus allows passage of air on inspiration but only limited expulsion of air on expiration leading to over-expansion of the affected lobe [1,2,3,4,5,6,7,8]. This air trapping may be due to (a) dysplastic bronchial cartilages creating a ball valve effect, (b) endobronchial obstruction from mucus plug or extensive mucosal proliferation and infolding, (c) extrinsic compression of bronchi from aberrant cardiopulmonary vasculature or enlarged cardiac chambers, and (d) diffuse bronchial abnormalities which may or may not related to infections [1,2,3,4,5,6,7,8]. However, in approximately 50% of cases, the aetiology is unknown [7,8,9,10,11,12]. The most common lobe involved in CLE is the left upper lobe (40–50%), followed by the right middle lobe (30–40%), right upper lobe (20%), lower lobes (1%), and multiple sites for the remainder [8,9,10,11,12,13,14,15,16]. In the literature reviewed, 5 were bilobar involving the right middle lobe/right lower lobe and 20 were of bilateral, with right middle lobe/left upper lobe involvement being the most common (Table 1) [1,2,3,4,5,6,7,8,9,10,11,12,13].
The severity of the disease is dependent on the magnitude of abnormality, which cannot be quantified in many cases . Conventionally, three vague variables are used to decide whether surgery is required in patients with CLE. They are age at presentation, severity and frequency of symptoms, and radiology [10,11,12,13].
Previous reports have emphasized that children presenting before 2 months of age should be operated and the older age groups should be managed conservatively. The age of presentation can be taken as the reflection of the severity of the disease [10,11,12,13,14,15,16].
Reports also describe that those with severe symptoms should be operated but those who are asymptomatic and mildly symptomatic should be managed conservatively . These reports however do not mention the criteria to differentiate between mild and severe symptoms [10,11,12,13,14,15,16]. They also do not pay any attention to the frequency of these mild symptoms as recurrent mild symptoms can also hamper the quality of life of many patients and can hamper the ultimate growth potential. They further add that patients on conservative treatment can deteriorate and this poses a life-threatening risk even in asymptomatic and mildly symptomatic cases . In an Indian scenario, where a patient may not have access to immediate expert management of these life-threatening scenarios and may not reach the right specialist for mild symptoms, conservative treatment is a dangerous option.
Radiological findings are frequently used to diagnose CLE which actually is a pathological diagnosis [1,2,3,4,5,6,7,8,9,10,11,12,13] (Table 1). Radiology is used to decide which side needs to be operated first in cases of bilateral CLE [8,9,10,11,12,13]. The lobe which is more hyperinflated and thus herniating to the opposite side is the one operated first. Also, the amount of compression of other ipsilateral lobes is one of the radiological criteria defining the side to be operated upon [8,9,10,11,12,13,14,15,16].
A more objective way, however, to ascertain whether a patient with CLE requires operative management or can be observed conservatively can be by bronchoscopic findings [10,11,12,13,14]. Findings during bronchoscopy can also help us appreciate the fate of surgery. If the offending lobe bronchus is collapsed and opens up on giving PEEP during bronchoscopy, it is more likely to be managed conservatively . If on occlusion of the offending lobe bronchus the ABG improves and ventilatory requirements decrease, that means doing lobectomy would be beneficial. Doing bronchoscopy can also make us differentiate between acquired emphysema due to mucus impaction from congenital cases . It can make us differentiate between extraluminal causes and inherent congenital cartilaginous defects . Based on the above criteria, one can also very well decide which lobe needs to be operated first in cases of bilateral CLE. Thus, in many instances, bronchoscopy can give objectivity to our cases of bilateral and unilateral CLE and should routinely find a place in the management protocols.
There are a multitude of surgical scenarios described for cases of bilateral CLE, and they are as follows:
Bilateral lobectomies in the same sitting (6/25 cases; Table 1)
Unilateral lobectomies, conservative or follow-up for contralateral (6/25 cases; Table 1)
Bilateral lobectomies in same admission (7/25 cases; Table 1)
Bilateral lobectomies done months apart (4/25 cases; Table 1)
The surgical scenarios have been described for various courses during the admission. Maiya et al.  recommended two-stage sequential lobectomies as it is practical and less risky and with less post-operative pain, and they believe that an infant tolerates sequential thoracotomies better than simultaneous bilateral thoracotomies. We also recommend the same approach; however, it may not be possible in all cases. In seven cases, there was a need for contralateral lobectomy during the same admission as there was sudden contralateral hyperinflation causing worsening of symptoms and delayed weaning from the ventilator [8, 11,12,13, 15].
Thus, we propose that bronchoscopy should be an essential component in the management of all cases of CLE. It helps in defining pathology, the severity of the disease, and the decision on which side to be operated first and avoids unnecessary simultaneous lobectomies. We recommend case selection on basis of radiological, biochemical, clinical, and bronchoscopy criteria. Based on this, an approach of sequential lobectomies is less risky and should be advocated in most of the patients.