Congenital lobar emphysema: an Otolaryngologic perspective

Congenital lobar emphysema: an Otolaryngologic perspective

International Journal of Pediatric Otorhinolaryngology (2005) 69, 549—554 www.elsevier.com/locate/ijporl CASE REPORT Congenital lobar emphysema: an...

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International Journal of Pediatric Otorhinolaryngology (2005) 69, 549—554

www.elsevier.com/locate/ijporl

CASE REPORT

Congenital lobar emphysema: an Otolaryngologic perspective Michael C. Chao*, Amir M. Karamzadeh, Gupreet Ahuja Division of Pediatric Otolaryngology, Department of Otolaryngology–—Head and Neck Surgery, University of California Irvine Medical Center, 101 The City Drive, B-25 R-81, Orange, CA 92868, USA Received 28 April 2004; received in revised form 15 October 2004; accepted 6 November 2004

KEYWORDS Congenital lobar emphysema; Respiratory distress; Endoscopy; Infant

Summary Congenital lobar emphysema (CLE) is an uncommon but potentially life threatening pulmonary abnormality affecting infants. Patients often present within the first 6 months of life with recurrent respiratory distress as a result of hyperinflation of the affected pulmonary lobe, and resultant near total collapse of normal lung parenchyma. We present a case of a 2-month-old infant with recurrent admissions for respiratory distress. # 2004 Elsevier Ireland Ltd. All rights reserved.

1. Introduction Congenital lobar emphysema (CLE) is a rare cause of airway compromise affecting the pediatric age group. Disease presentation can vary from acute respiratory distress to recurrent bouts of pneumonia. Radiographically, CLE is characterized by hyperinflation of the affected pulmonary lobe. Diagnosing this rare entity amidst the more come common pulmonary and airway pathologies poses a significant challenge. The Otolaryngologist may be consulted to assess the status of the airway and help rule out intraluminal etiologies, such as foreign bodies, which present in a similar fashion. Given the tenuous nature of the airway in certain affected individuals, it is very important to keep this entity in mind before performing bronchoscopy. We present a * Corresponding author. Tel.: +1 714 456 5753; fax: +1 714 456 5747. E-mail address: [email protected] (M.C. Chao).

case of CLE and review the presentation, diagnostic evaluation, and highlight the otolarygologic considerations.

2. Case report We present a 2-month-old male who has a history of two admissions to the pediatric intensive care unit at a community hospital for respiratory distress and pneumonia which required intubation. On the third admission, the patient was found to be in marked respiratory distress and hypoxic, with oxygen saturation in the low 90s, while breathing room air. He was transferred to UC Irvine Medical Center. On physical examination, the patient was noted to have marked substernal retractions and usage of accessory respiratory muscles. Interestingly, the patient’s air exchange and work of breathing improved when placed in the left lateral decubitus position. Chest ro ¨entgenogram on admission sug-

0165-5876/$ — see front matter # 2004 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ijporl.2004.11.017

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Fig. 1

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AP chest ro ¨entgenogram. Note the hyperinflated left lung with the mediastinum shifted to the right.

gested hyperinflation of the left lung and mediastinal deviation to the right (Fig. 1). The Otolaryngology service was consulted to assess the airway. The patient was, subsequently taken to the operating room to undergo diagnostic direct laryngoscopy and bronchoscopy for presumptive left lung and bronchial pathology. Intraoperatively, the patient was noted to have a normal glottis and subglottis with mobile true vocal cords. There was no evidence of laryngomalacia or tracheomalacia. The right mainstem bronchus and bronchioles

were patent and free of abnormality. The left lower lobe bronchus was noted to be dynamically compressed, with critical stenosis on inspiration and complete collapse on expiration (Figs. 2 and 3); no foreign body or intraluminal pathology was noted. The patient was intubated after direct laryngoscopy and bronchoscopy were performed. Subsequent radiographic examinations included computed tomography (CT), magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) of the chest (Figs. 4 and 5). While the CTchest was negative for any intrathoracic masses it did

Fig. 2 Bronchoscopic evaluation of the left main bronchus demonstrating stenotic left lower bronchus on inspiration.

Fig. 3 Bronchoscopic evaluation of the left main bronchus demonstrating complete collapse of the left lower bronchus on expiration.

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Fig. 4 CT chest with contrast demonstrating hyperinflation of the left lung with resultant collapse of the right lung and mediastinal shift to the right.

demonstrate hyperinflation of the left lower lobe. MRA chest was negative for any vascular anomalies. After reviewing the bronchoscopic findings, along with the radiographic examinations, we arrived at the diagnosis of CLE. Pediatric surgery was then consulted and the patient underwent left lower lobectomy. Post-operatively, the patient did well. He continues to thrive at home and has had no further admissions.

lobe, followed by the right middle lobe and right lower lobe; our case involved the left lower lobe, which is the lobe most rarely affected. Unilateral lesions are the norm, but cases of bilateral lesions have been reported [4]. Approximately, 50% of patients with CLE are diagnosed by 1 month of age and presentation after 6 months of age occurs in less than 5% of cases [2]. No inherited factors have yet been elucidated, though familial cases have been reported [5].

3. Discussion

3.1. Clinical presentation

The pathophysiology of CLE is unclear and in as many as 50% of cases no apparent pathology is identified [1]. However, several mechanisms have been hypothesized, including defective or overly compliant cartilage, mucosal folds creating valve-like obstruction, and bronchial stenosis [2]. Congenitally defective cartilage is the most commonly identifiable cause, accounting for 25% of cases [3]. CLE is found in males more often than females. The most commonly affected lobe is the left upper

Clinical presentation various widely from asymptomatic patients incidentally diagnosed on routine chest ro ¨entgenogram to severe, life-threatening respiratory distress. In general, presentation at an earlier age correlates with more severe symptoms. Patients most commonly present in the first few weeks of life with moderate respiratory distress characterized by declining pulmonary status as the emphysematous lobe gradually compresses healthy lung parenchyma. Less commonly patients

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Fig. 5

MR angiogram showing normal vasculature.

present with mild symptoms associated with recurrent pulmonary infections and cough.

3.2. Diagnosis 3.2.1. Imaging The signs and symptoms, as outlined above, are suggestive, but quite non-specific. Hence, CLE can present a diagnostic challenge. When the newborn presents with respiratory distress the initial workup invariably involves a chest roentgenogram. In CLE, this would demonstrate a hyperlucent and enlarged affected lobe. Based on these plain film findings, the differential diagnosis includes foreign body obstruction, extraluminal compression, and intraluminal lesions. In patients with a history of pneumothorax, infection, or vigorous resuscitation, mucous plugs or exudates may lead to air trapping and an emphysematous picture. In those cases the emphysema is reversible [6]. While foreign body obstruction is uncommon in newborns, it is necessary to exclude from the differential diagnosis as it is potentially fatal. Extraluminal compression could stem from either vascular anomaly, including vascular rings and slings [7,8], or intrathoracic masses, such as an enlarged

thymus causing bronchial compression. Intraluminal lesions, such as mucosal folds, septae, and neoplasms may cause a ball valve effect leading to hyperinflation. Lymphadenopathy, as seen with endobronchial tuberculosis may present similarly in infants. Other imaging modalities include CT, magnetic resonance imaging MRI and nuclear imaging studies, such as VQ scans. A CT scan may delinieate the aberrant anatomy of the lesion, which aids in determining a surgical approach. MRI/MRA will demonstrate any vascular lesions, which might cause extraluminal compression. Nuclear imaging studies, such as a VQ scan will demonstrate perfusion defects in the affected lobe. In newborns, presenting with respiratory complaints and a chest ro ¨entgenogram exhibiting hyperexpansion and hyperlucency of one lung possibly with mediastinal shift to the contralateral side, CLE should be suspected. Based on their experience, Karnak et al. [9] devised an algorithm for work-up and treatment of patients with CLE (Fig. 6). 3.2.2. Bronchoscopy Bronchoscopy is not part of the primary diagnostic evaluation. If the clinical presentation strongly sug-

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Fig. 6 Algorithm for evaluation and treatment of congenital lobar emphysema. Adapted from Karnak et al., J. Pediatr. Surg. 34 (9) 1999.

gests CLE, the next appropriate step would be to obtain the appropriate imaging study. Direct laryngoscopy and bronchoscopy are performed to help rule out other potential causes of the patient’s respiratory distress as discussed above. Given the non-specific and varied presentation of CLE, bronchoscopy is often necessary. There are no pathognomonic endoscopic characteristics to diagnose CLE intraoperatively. However, the presence of diffuse narrowing of a unilateral second-generation bronchus is suggestive. The hyperinflation of the affected lobe pulls and stretches the bronchus resulting in narrowing of the lumen. Further, this phenomenon can be positional. When the patient is rotated to the lateral decubitus position of the affected side the hyperinflated lobe settles back and results in less tension on the bronchus. Hence, less narrowing and potentially improved air exchange, as noted in our patient. It is also this dynamic process that further exacerbates air trapping. This process was directly visualized intraoperatively. Bronchoscopy is not appropriate in all cases. If the infant’s pulmonary status is severely compromised and history and chest ro ¨entgenogram suggest CLE, undergoing bronchoscopy may actually worsen the patient’s respiratory state [10]. It is possible that this results from increased air trapping in the affected lobe during the procedure.

3.3. Treatment Definitive therapy of CLE is resection of the affected lobe. This is the mainstay of therapy for patients

presenting with severe respiratory distress. However, as outlined in Fig. 6, patients presenting with mild to moderate respiratory symptoms may not need surgery. In these patients, with chest ro ¨entgenogram demonstrating only mild hyperaeration and bronchoscopy, reveals no abnormality, conservative management with close follow up is appropriate [9].

4. Conclusion In the case presented, the Otolaryngology service was consulted early to assess the patient’s airway. Bronchoscopic evaluation provided valuable diagnostic information, which initiated further workup and led to a rapid diagnosis and subsequent treatment. Given the relative lack of published studies pertaining to this pathology in the Otolaryngologic literature, we hope to raise clinical suspicion when presented with findings suggestive of CLE.

References [1] P.G.L. Stovin, Congenital lobar emphysema, Thorax 14 (1959) 254—262. [2] D.M. Orenstein, Empysema and overinflation, in: R.E. Behrman (Ed.), Nelson Textbook of Pediatrics, 16th ed. WB Saunders, Philadelphia, 2000, p. 1303. [3] J.G. Pardes, Y.H. Auh, K. Blumquist, et al. CT diagnosis of congenital lobar emphysema, J. Comput. Assist. Tomogr. 7 (1983) 1095—1097. [4] S. Ekkelkamp, A. Vos, Successful treatment of a newborn with bilateral congenital lobar emphysema, J. Pediatr. Surg. 22 (1987) 1001—1002.

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[5] P.A. Roberts, A.J. Holland, R.J. Halliday, et al. Congenital lobar emphysema: like father, like son, J. Pediatr. Surg. 37 (2002) 799—801. [6] N.T. Berlinger, D.P. Porto, T.R. Thompson, Infantile lobar emphysema, Ann. Otol. Rhinol. Laryngol. 96 (1987) 106—111. [7] R.B. McLaughlin, R.F. Wetmore, M.A. Tavill, et al. Vascular anomalies causing symptomatic tracheobronchial compression, Laryngoscope 109 (1999) 312—319. [8] M. Lierl, Noninfections disorders of the respiratory tract, in: B.C. Hilman (Ed.), Pediatric Respiratory Disease: Diagnosis

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and Treatment, WB Saunders, Philadelphia, 1993, pp. 457— 497. [9] I. Karnak, M.E. Senocak, A.O. Ciftci, et al. Congenital lobar emphysema: diagnostic and therapeutic considerations, J. Pediatr. Surg. 34 (1999) 1347—1351. [10] P.V. Bailey, T. Tracy Jr., R.H. Connors, et al. Congenital bronchopulmonary malformations. Diagnostic and therapeutic considerations, J. Thorac. Cardiovasc. Surg. 99 (1990) 597—603.