Pulmonary sequestration

Study objectives: To review our experience with indications, timing, and results of pulmonary resection in infants.

Design: Retrospective cohort study.

Setting: Thoracic Surgery Department, Chest Diseases Hospital, Kuwait.

Patients and intervention: Forty-seven infants with congenital lung diseases were treated with pulmonary resection from January 1993 to December 2000.

Results: The mean age at the time of diagnosis was 90 days (range, 7 days to 11 months). Thirty-four patients were male (72%). Congenital lobar emphysema, congenital cystic adenomatoid malformation, pulmonary sequestration, and atelectasis were seen in 26, 10, 6, and 5 patients, respectively. The indications for surgery were respiratory distress in 32 patients (68%), respiratory tract infections in 12 patients (26%), and the presence of asymptomatic chest radiographic findings in 3 patients (6%). A lobectomy was performed in 42 patients (89%), bilobectomy in 2 patients (4%), left pneumonectomy in 1 patient (2%), and excision of a mass in 2 patients with extralobar sequestration (4%). An emergency lobectomy was performed in seven patients (15%). Only one postoperative death occurred following a left pneumonectomy for extensive congenital adenomatoid malformation due to pulmonary hypertension. Four patients (9%) had postoperative complications: atelectasis (n = 2), prolonged air leak (n = 1), and pneumothorax (n = 1). Mean follow-up was 4 years (range, 1 to 5 years) for all patients. None of the patients had any physical limitations.

Conclusion: Pulmonary resection is indicated for the majority of patients with congenital lung malformations. In case of severe respiratory distress, an emergency lobectomy can be performed safely.

Key words: congenital lobar emphysema; congenital lung malformation; lobectomy; pulmonary sequestration

Abbreviations: CAM = congenital adenomatoid malformation; CLE = congenital lobar emphysema

**********

Congenital pulmonary malformations can be present at any age. (1) Their clinical appearance can vary from immediately postnatal respiratory distress, to an incidental finding on chest radiography. (1) Clinical recognition of these anomalies is important since their presentation may be life threatening and, therefore, require prompt surgical resection. (2) The indication for and management of pulmonary resections in the first year of life are not well recognized. (3) A retrospective review of all patients with congenital pulmonary malformations that occur in the first year of life was carried out to look for the diagnosis, the indications and timing of surgery, and the results of the treatment.

MATERIALS AND METHODS

This study was conducted at Chest Diseases Hospital, the only center for the surgical treatment of chest disorders in Kuwait. All data from the patients operated on for congenital pulmonary malformations in our center between January 1993 and December 2000 were reviewed. The data obtained included age, sex, type of malformation, presentation, and method of diagnosis. The operative treatment and significant operative findings, including exact anatomic location of the lesion, were evaluated. At follow-up visits after resection, the families were questioned on symptoms, hospital admissions, and general level of activity. Follow-up chest radiographs were obtained of all patients.

RESULTS

A total of 47 infants (age range, 7 days to 11 months) underwent pulmonary resection for congenital pulmonary malformations during the study period. There were 34 male (72%) and 13 female (28%) patients. There were 26 cases of congenital lobar emphysema (CLE), 10 cystic adenomatoid malformations (CAMs), 6 pulmonary sequestrations, and 5 cases of atelectasis.

The presenting signs and symptoms included variable degrees of respiratory distress in 32 patients (68%), respiratory tract infection in 12 patients (26%), cough in 4 patients (9%), and asymptomatic findings in 3 patients (6%). Some patients had more than one symptom.

In 21 patients (45%) [19 patients with CLE, and 2 patients with CAM], plain chest radiographs were the only diagnostic imaging studies performed before the operation. Twenty-four patients (7 patients with CLE, 8 patients with CAM, 5 patients with atelectasis, and 4 patients with sequestration) underwent CT scan, which was diagnostic in 22 patients. Arteriography was done in three patients with sequestration. Radioisotope ventilation-perfusion scans were obtained in three patients with CLE, but they did not contribute to the diagnosis. The associated anomalies consisted of pectus excavatum in one patient with CLE, pulmonary hypoplasia in one patient with CAM, pectus carinatum in another patient with CAM, and ventricular septal defect in one patient with extralobar sequestration. Specific data on the 47 patients are presented in Table 1.

In patients with CLE, the mean age at diagnosis was 58 days (range, 7 to 180 days). The majority of these patients had variable degrees of respiratory distress (n = 23). The most common mode of presentation was mild-to-moderate respiratory distress, in which the most common signs were tachypnea, cyanosis, grunting, and chest wall retractions. Severe respiratory distress was present in five patients, and these patients were receiving positive-pressure ventilation. Three patients had cough and episodic cyanosis, three patients were asymptomatic, and one patient had a respiratory tract infection. Some patients had more than one symptom. The treatment consisted of lobectomy in all cases. In five patients with severe respiratory distress, an emergency thoracotomy and lobectomy was performed. No postoperative deaths occurred. In one patient, a prolonged air leak required pleural drainage for 9 days. One patient had an apical pneumothorax that resolved spontaneously.

Ten patients underwent pulmonary resection for CAMs. The mean age at diagnosis was 44 days (range, 11 to 90 days). The presenting symptoms were mild-to-moderate respiratory distress (n = 5), severe respiratory distress with patients receiving positive-pressure ventilation (n = 2), recurrent respiratory tract infection (n = 2), and cough with cyanotic attacks (n = 1). Surgical treatment consisted of lobectomy in seven cases, bilobectomy in two cases, and left pneumonectomy for extensive CAM in one case. In two patients with severe respiratory distress, an emergency thoracotomy and lobectomy was performed. Recovery was uneventful in nine patients. There was one death in this group due to pulmonary hypertension requiring a left pneumonectomy for an extensive CAM. The diagnosis of pulmonary hypertension was made by an echocardiographic demonstration of high pulmonary artery pressure and tricuspid regurgitation. This patient was treated with positive-pressure ventilation, inotropic support, and vasodilators. The patient died 22 h postoperatively. Pathologic examination of the left lung revealed CAM in the upper lobe and pulmonary hypoplasia (decrease volume of the lobe and decrease in the number of airways, vessels, and alveoli) in the left lower lobe.

Six patients were treated for pulmonary sequestration. The mean age at intervention was 11 weeks (range, 13 to 43 weeks). The presenting symptoms were recurrent respiratory tract infections in the intralobar (n = 4) and respiratory distress in the extralobar sequestration (n = 2). Intralobar sequestration was seen in four patients, and extralobar sequestration was seen in two patients. Surgical treatment consisted of lobectomy in four patients and resection in two patients with extralobar sequestration. No postoperative deaths occurred. One patient had atelectasis postoperatively and required bronchoscopy and mechanical ventilation for 2 days.

Five patients underwent lobectomy for atelectasis. The mean age at intervention was 36 weeks (range, 17 to 47 weeks). The presenting symptom was recurrent pneumonia in all patients. Three patients had evidence of failure to thrive, and two patients had feeding intolerance. These patients were admitted to the hospital at least two or three times each month. The chest radiographs and CT scan showed a persistent lobar atelectasis in all patients. A bronchoscopic examination revealed no intrinsic obstruction. Four patients had culture-proven bacterial pneumonias: Streptococcus pneumoniae in two patients, Staphylococcus aureus in one patient, and Pseudomonas aeruginosa in one patient. Repeated medical treatment using systemic antibiotics, bronchodilators, and chest physiotherapy was done to treat these patients. Operative therapy was indicated for severe localized symptomatic atelectasis and a poor response to medical treatment. No postoperative deaths occurred. One patient had atelectasis postoperatively and required bronchoscopy.

All patients were followed up in the outpatient department. The mean follow-up duration was 4 years (range, 1 to 5 years) for all patients. All patients are alive, with no subsequent limitation in their growth or physical activity and no further hospital admissions.

DISCUSSION

Congenital malformations of the lung frequently presented with dramatic symptoms resulting in the need for prompt diagnosis and treatment. (1,4) Cystic adenomatoid malformation and CLE usually present in infancy with significant respiratory distress. This prompts an expeditious diagnosis and treatment (5); however, atelectasis and intralobar pulmonary sequestration usually present beyond infancy with recurrent attacks of chest infection. (5,6) Extralobar pulmonary sequestration is usually present as an asymptomatic intrathoracic mass but may be also associated with respiratory distress because of airway compression. (5-7) All these disease entities ultimately require surgical resection before the age of 1 year. (1-3) Early diagnosis and prompt surgical treatment, especially in infants with progressive respiratory failure associated with CLE and CAM, remain the approaches of choice to achieve an optimum outcome. (6)

In infants with CLE or CAM who are asymptomatic or have mild symptoms, observation can be done, although this remains controversial. The recommendation from the literature is that surgical excision of the affected lobe should be done as soon as possible in all infants < 2 months old and in infants > 2 months old who present with moderate-to-severe respiratory distress. (8) The majority of symptoms worsen as the emphysematous lobe gradually enlarges in CLE. Conservative management can be performed in older children who present with mild symptoms or asymptomatic children, with a close follow-up of the patients (8); however, further studies are required to determine the long-term effects of conservative management. Pulmonary resection in infants with significant respiratory symptoms is necessary to avoid morbidity and mortality. Infants with severe respiratory distress sometimes require emergency thoracotomy and lobectomy. (5) This was done in seven patients (five patients with CLE, and two patients with CAM) in our series.

Pulmonary resection in the first year of life may occasionally be indicated for lung atelectasis. (3) Chronic atelectatic portions of the lung are susceptible to recurrent bacterial infections and interfere with the patient's growth; therefore, surgical resection is a worthwhile option in selected patients who have severe localized symptomatic atelectasis and a poor response to medical treatment. However, every effort should be made to effect a cure by other methods. The mechanism of atelectasis in five patients in this review, according to the Fraser and Pare classification, is likely to be resorption atelectasis. (9) Although large central airways were patent, atelectasis occurred because of obstruction of small peripheral airways and consolidation of lung parenchyma.

The surgical treatment of choice is complete lobectomy for patients with CLE, CAM, and intralobar pulmonary sequestration. (1,5,8,10) In the case of extralobar pulmonary sequestration, resection is often possible. (1,7) Segmental resection for CAM and intralobar sequestration carries a high complication rate, with prolonged air leak or recurrent infection requiring re-operation for completion of lobectomy. (4,11) However, occasionally CAM may involve more than one lobe or the entire lung, (12) as occurred in three patients in our series. Two patients had involvement of both the right middle lobe and the right upper lobe, and one patient had involvement of the entire left lung. The two patients did not have any compromise of pulmonary function following bilobectomy. The patient who underwent a left pneumonectomy in our series had severe pulmonary hypertension postoperatively. This condition resulted in death. Several authors (5,12-14) have reported the involvement of more than one lobe or both thoracic cavities with congenital lung disease, both of which were resected. The surgical treatment in infants with lobar atelectasis is complete lobectomy; however, there are some infants with atelectasis who would require segmentectomy if the disease involves an anatomic subdivision of a lobe.

CONCLUSION

In the majority of cases, pulmonary resection is indicated as soon as the diagnosis of congenital pulmonary malformation is made. Emergency surgery in patients with severe respiratory distress is necessary to achieve an optimum outcome.

REFERENCES

(1) Evrard V, Ceulemans J, Coosemans w, et al. Congenital parenchymatous malformations of the lung. World J Surg 1999; 23:1123-1132

(2) Bailey PV, Tracy T Jr., Connors RH, et al. Congenital bronchopulmonary malformations: diagnostic and therapeutic consideration. J Thorac Cardiovasc Surg 1990; 99:597-603

(3) Pierce WS, deParedes CG, Raphaely RC, et al. Pulmonary resection in infants younger than one year of age. J Thorac Cardiovasc Surg 1971; 61:875-881

(4) Buntain WL, Isaacs H, Payne VC, et al. Lobar emphysema, cystic adenomatoid malformation, pulmonary sequestration, and bronchogenic cyst in infancy and children: a clinical group. J Pediatr Surg 1974; 9:85-93

(5) Coran AG, Drongowski R. Congenital cystic disease of the tracheobronchial tree in infants and children: experience with 44 consecutive cases. Arch Surg 1994; 129:521-527

(6) Schwartz MZ, Ramachandran P. Congenital malformations of the lung and mediastinum: a quarter century of experience from a single institution. J Pediatr Surg 1997; 32:44-47

(7) Piccione W, Burt ME. Pulmonary sequestration in the neonate. Chest 1990; 97:244-246

(8) Karnak I, Senocak ME, Ciftci AO, et al. Congenital lobar emphysema: diagnostic and therapeutic considerations. J Pediatr Surg 1999; 34:1347-1351

(9) Fraser RS, Muller NL, Colman N, et al. Radiologic signs of chest disease: atelectasis. In: Fraser and Pare's diagnosis of diseases of the chest. 4th ed. Philadelphia, PA: WB Saunders, 1999; 513-562

(10) Neilson IR, Russo P, Laberge JM, et al. Congenital adenomatoid malformation of the lung: current management and prognosis. J Pediatr Surg 1991; 26:975-981

(11) Mentzer SJ, Filler RM, Phillips J. Limited pulmonary resections for congenital adenomatoid malformation of the lung. J Pediatr Surg 1992; 27:1410-1413

(12) Cloutier MM, Schaeffer DA, Hight D. Congenital cystic adenomatoid malformation. Chest 1993; 103:761-764

(13) Cass DL, Crombleholme TM, Howell LJ, et al. Cystic lung lesions with systemic arterial blood supply: a hybrid of congenital cystic adenomatoid malformation and bronchopulmonary sequestration. J Pediatr Surg 1997; 32:986-990

(14) Jeanfaivre T, Afi M, L'hoste P, et al. Simultaneous discovery of bilateral intralobar and extralobar pulmonary sequestrations. Ann Thorac Surg 1997; 63:1171-1173

* From the Departments of Surgery (Dr. Ayed) and Pediatrics (Dr. Owayed), Faculty of Medicine, Kuwait University, Safat, Kuwait.

Manuscript received June 13, 2002; revision accepted October 23, 2002.

Correspondence to: Adel K. Ayed, MD, FCCP, Associate Professor, Department of Surgery, Faculty of Medicine, Kuwait University, PO Box 24923, 13110, Safat, Kuwait; e-mail: Adel@hsc.kuniv.edu.kw

COPYRIGHT 2003 American College of Chest Physicians
COPYRIGHT 2003 Gale Group