Thoracoscopic Lobectomy in Infants Less Than 10 kg with Prenatally Diagnosed Cystic Lung Disease

Introduction

Congenital bronchopulmonary malformations include a heterogeneous group of lesions such as bronchogenic cysts, bronchopulmonary sequestrations (BPS), congenital cystic adenomatoid malformation (CCAM), and congenital lobar emphysema (CLE). Clinically, these lesions may cause acute respiratory distress in the newborn period, may harbor infections throughout childhood, or can remain asymptomatic and undiagnosed until later in life. Most surgeons agree that complete resection, usually by anatomic lobectomy, remains the standard treatment, in an effort to avoid the recurrent infections and due to an association of cystic lesions with rare malignancies. Minimally invasive techniques now allow this to be done with much less pain and morbidity and long-term consequence for the infant or child.

With increasing frequency, these lesions are identified in the prenatal period on screening ultrasound. These new opportunities for prenatal consultation and planning have sparked some debate regarding the timing of these often prophylactic operations in asymptomatic newborns. ¹ Rarely, the discovery of very extensive lesions resulting in hydrops leads to consideration for fetal intervention. ² More commonly, sonography points out a cystic lesion and/or a systemic feeding vessel of unclear significance. There appears to be a significant number of cases of spontaneous resolution during gestation, in that they are undetectable by postnatal computed tomography scan. However, there is currently no evidence that lesions present after birth will regress later. We have learned through experience that lobectomies done before infection are technically easier and well-tolerated. This review describes this experience with thoracoscopic lobectomy in infancy.

Materials and Methods

From January 2001 to January 2010, 75 patients under 1 year of age in whom a congenital lung lesion had been identified by ultrasound underwent planned thoracoscopic lobectomy. Patient age ranged from 2 days to 11 months of age (mean 18 weeks) and weight from 3.1 to 10 kg (mean 7.2 kg). The most common lesion was CCAM-52, followed by BPS-20, and CLE-3. In all patients, the presumptive diagnosis was confirmed by computed tomography scan before surgery.

Technique

Thoracoscopic lobectomies were performed with the patient in lateral decubitus position. Single-lung ventilation was isolated by mainstem intubation of the contralateral side or bronchial occlusion. Three to four valved ports, ranging from 3 to 5 mm, were used. In the majority of cases, the Ligasure (Covidien Energy Devices, Boulder, CO), a 5-mm curved dissector and bipolar sealing device, was the primary mode of vessel ligation. It also was used to seal and divide lung parenchyma where an incomplete fissure was found.

The operating room setup is shown in Figure 1. The surgeon and assistant are at the patient's front with the monitor at the patient's back. The thorax was initially insufflated with a Veress needle to further aid in lung collapse. A flow of 1 L/min and pressure of 4 to 6 mm Hg are maintained and usually well tolerated during the case. The first port is placed in the mid to anterior axillary line in the fifth or sixth interspace to determine the position of the major fissure and evaluate the lung parenchyma. The location of the fissure should then guide the placement of the other ports to facilitate work in the fissure, as the most difficult dissection occurs in this plane. The exact procedure varied in each case depending on the lobe resected and the pathology encountered. For lower lobectomies, the first step is mobilization of the inferior pulmonary ligament. During this maneuver, care is taken to identify a potential systemic vessel arising from the aorta in cases of sequestration. When encountered, the vessel is ligated with the ligasure or endoscopic clips and divided. The inferior pulmonary vein is dissected out but not ligated at this point. Pulmonary vein ligation before division of the pulmonary artery can lead to congestion in the lobe, which can significantly reduce work space, especially in the smaller infant. The fissure is then approached from anterior to posterior. The pulmonary artery to the lower lobe is isolated and ligated at its main trunk or at the segmental level, depending on the anatomy of the artery and the fissure. Creating two separate seals with the ligasure and slowly dividing the vessel between the sealed points allow for recovery if one seal is incomplete. The inferior pulmonary vein branches are then sealed and divided, leaving the bronchus to the lower lobe isolated. The bronchus is closed with a 5-mm endoscopic clip or sharply cut and sutured with 3-0 monofilament, absorbable suture. The specimen is then brought out through a slightly enlarged trocar site, either whole or piecemeal. Upper and middle lobe resections were carried out using similar principles, with some variation. For upper lobe resections, dissection starts with isolation and division of the superior pulmonary artery at the segmental level. Occasionally, it is necessary to divide branches of the superior pulmonary vein to better expose the main pulmonary artery trunk. The middle lobe was approached by first completing the minor fissure, which safely exposed the pulmonary artery. A chest tube was left in all cases.

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FIG. 1.

Room set-up: thoracoscopic lung resection.

Results

Seventy-four of 75 lobectomies were thoracoscopically completed. There was one conversion for bleeding during right upper lobectomy. There were 16 upper lobes, 1 middle, and 58 lower lobectomies. Operative time ranged from 45 to 225 minutes. Chest tube duration averaged 1.2 days. Length of stay ranged from 1 to 5 days (mean 2.4 days). A subset of 26 patients had elective surgery <3 months of age and <5 kg, despite not being in any significant respiratory distress at birth. In this group, the operative time averaged 90 minutes, and mean length of stay was 1.5 days. There were no significant post-operative complications, and average follow-up has been 48 months. All pathologic samples were reviewed by the surgeons after pathologic examination. Without exception, there was evidence of CCAM, BPS, CLE, or some “hybrid” lesion.

Discussion

Complete excision of congenital lung malformations remains the gold standard treatment in pediatric surgery. Thoracoscopic lobectomy in children for such lung disease has been established and well-described.^3–7 Most surgeons agree on the benefits of a thoracoscopic approach over traditional thoracotomy, including less pain, shorter hospital stay, and decreased long term morbidity, including chest wall complications. Lawal et al. compared 62 infants and children undergoing thoracoscopy or thoracotomy, have objectively a higher incidence of chest wall asymmetry, shoulder girdle weakness, and scoliosis in patients undergoing open thoracotomy. ⁸ Comparing our patients with our historical controls, it is clear that discharge from the hospital in 1 or 2 days, quite routine with thoracoscopic lobectomy, was rare or impossible with thoracotomy. Thus, the logical next question seems to be, When is the optimal time for elective surgery?

The neonate with respiratory compromise requires an operation immediately, but this represents a minority of patients. In extreme cases, an emergency thoracotomy with decompression of the chest cavity can be a life-saving maneuver, followed by emergency lobectomy. However, in the majority of neonatal cases (especially with the increased incidence of prenatal diagnosis), the baby is asymptomatic or can overcome mild symptoms to allow for a semielective resection.

Albanese and colleagues were the first to describe a series of asymptomatic children who were diagnosed prenatally and subsequently underwent elective, thoracoscopic lobectomy. ⁹ The patients in this small series (n = 14) ranged in age from 3 to 15 months (mean of 6 months) at the time of surgery. The authors concluded that early resection is feasible, safe, and avoids the potential long-term complications such as infection and malignant transformation.

Minimally invasive techniques can be more challenging once the child has already suffered a clinical chest infection. Kanenko et al. documented a higher complication rate with thoracoscopic lobectomy compared with those diagnosed prenatally who underwent surgery before any clinical infections. ¹⁰ Garrett-Cox and others found that 83% of patients requiring conversion to open had had a previous chest infection. ¹¹

We have also noted during our procedures that many of the patients who were clinically asymptomatic likely had subclinical infections before surgery. Evidence of varying degrees of inflammation include enlarged, adherent lymph nodes adjacent to the vessels, adhesions, and even completely fused fissures, all of which made surgery more difficult and dangerous in our older patients.

In addition to the increased risk of developing infection and the added challenges of operating after inflammatory change, there is little evidence to suggest that delaying resection benefits the child in any significant way. In this series, we conclude that early operation is not only safe but also preferable. In fact, our results with patients <5 kg, who had an average operative time of 90 minutes and hospital stay <2 days, further support early operative intervention. Further, a number of patients travelling significant distances to one of our centers were safely operated on during the first week of life to obviate a return trip.

There are technical difficulties related to operating thoracoscopically in the small space of the neonate's chest. The advent of excellent 3-mm instrumentation and small scopes have made maneuvering in the chest in the tiny ribspaces of neonates possible and more ergonomic. Refining our standardized approach has made these operations more routine. The lack of inflammation, as previously mentioned, has actually made the surgery technically easier despite the patients' small size. We believe that the greatest current limitation is the lack of an effective 3-mm device to safely seal and divide the pulmonary vessels. Suture ligating in this small environment can be very technically demanding, and 5-mm endoclips are both too large and too easily dislodged in these smaller patients. The 5-mm sealing device used in this study was adequate, but its relatively large size occasionally made dissection cumbersome (Fig. 2). In fact, the single conversion to open in this series was during an upper lobectomy in a smaller patient, in which the size of the instrument prevented adequate dissection of the pulmonary artery branches, resulting in a failed seal.

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FIG. 2.

An example of the Ligasure device sealing a segmental vessel to the right upper lobe.

In summary, thoracoscopic lobectomy for prenatally diagnosed congenital cystic lung disease is effective, safe, and has clear benefits over thoracotomy with less pain, quicker recovery, and improved cosmesis. Operating early on younger patients seems to help avoid the inflammatory changes associated with both clinically apparent and subclinical infections, even in patients weighing <5 kg. This can make the procedures much more technically easy and may result in lower complication and conversion rates.