Thoracoscopic Lung Biopsies and Resections in Children



Fig. 15.1.
Frontal CT reconstruction of an adolescent boy with right-sided spontaneous pneumothorax and bilateral apical bleb disease (a, arrows). In this case, bilateral apical bleb resection and pleurectomy were performed (b).





Surgical Indications


Pulmonary nodules that are increasing in size or associated with other pathologic findings should be biopsied or resected. Generally, thoracoscopy has been used successfully in children for tissue biopsy of lesions such as neuroblastoma, pulmonary metastasis, and lymphoma, with a low conversion rate under 5 % [14]. Patients with Wilms tumor and pulmonary metastasis on CT may be excellent candidates for thoracoscopic resection [15]. However, recurrence rates were high (over 40 %) when osteosarcoma metastasis was approached thoracoscopically [15, 16]. Therefore, thoracoscopy may be a valuable tool for the resection of a variety of nodules but not indicated in cases of metastatic osteosarcoma when complete resection of all lesions is the goal. Another indication for thoracoscopic lung biopsy is interstitial lung disease. Since the underlying disease is diffuse, a wedge resection of an easily accessible lung portion is usually adequate and easier to perform than finding a specific target lesion. If the macroscopic changes are subtle, separate biopsies at different sites can improve the validity of the histologic analysis.

In cases of recurrent spontaneous pneumothorax with underlying bleb disease, thoracoscopic resection of the blebs or bullae is indicated. The blebs are usually located in the apical lung portions, but the entire lung should be inspected during the procedure for suspicious lesions. A simultaneous bilateral approach decreases the recurrence rate [17, 18], as does concomitant pleurodesis or pleurectomy of the apical parietal pleura.



Technique



Anatomy


Pulmonary lesions may be present in any of the five lobes. Parietal, peripheral nodules are easier to find thoracoscopically than central ones. Since tactile feedback is limited with thoracoscopy, deep parenchymatous lesions may require preoperative image-guided marking by methylene blue, patient blood, or placement of microcoils [19]. For non-peripheral lesions, it is imperative to recapitulate the vascular and bronchial anatomy beforehand in order to avoid any inadvertent injury or ligation of uninvolved structures or lung segments.


Special Considerations


Single-lung ventilation of the contralateral side is helpful but not mandatory, since the lung in children can be collapsed by insufflating carbon dioxide into the pleural cavity at a pressure slightly above positive end-expiratory pressure (PEEP). Double-lumen endotracheal tubes are not available for small children, so single-lung ventilation is achieved by main stem intubation of the contralateral side under bronchoscopic guidance. Alternatively, a Fogarty catheter can be passed into the ipsilateral main stem bronchus and inflated carefully to block the flow of gas. Care must be taken when repositioning the patient after such interventions, since both the endotracheal tube and the Fogarty catheter may easily dislodge with minimal movement of the head, neck, and torso.


Positioning


Generally, the patient is placed in lateral decubitus position for thoracoscopic lung biopsy. An axillary roll is mandatory, as is careful padding of dependent prominences to avoid pressure sores and nerve injury. Depending on the location of the lesion, it may be worth angulating the patient more anteriorly than 90° (for posterior lesions) or posterior (for anterior lesions). During the procedure, it is helpful to shift the bed in Trendelenburg or reverse Trendelenburg position, depending on the location of the lesion or lesions. Therefore, the patient should be well secured to the bed. In small children, rolls should be placed on both sides of the torso. A vacuum beanbag may be useful for older children.

Port positioning depends on the location of the lesion. In general, the surgeon, endoscope, target tissue, and main monitor should be in one line, with the grasping port on the surgeon’s nondominant hand side slightly beyond the optic port and the working port on the opposite side (triangular configuration). The size of the working port must be chosen to accommodate the selected instruments, depending on the method of resection (stapler, endoscopic loop tie, sealing device).


Instruments


Most thoracoscopic biopsies can be achieved in a three-port, triangulated technique. For children, depending on age, between 2 and 5 mm instruments are mostly adequate and include a Maryland dissector, a blunt grasper, a pair of Metzenbaum scissors, and a hook electrocautery. A 30°- or 45°-angled endoscope is useful to obtain a good view of all aspects of the pleural cavity. The lesion can be isolated from the rest of the lung using either an endoscopic stapler (usually 10–12 mm in diameter but recently also available as a 5 mm device), an endoscopic loop tie (usually 5 mm in diameter), or an advanced bipolar sealer (3–5 mm in diameter). Bronchi cannot be sealed effectively and require loop tie or stapled closure.


Operating Room Setup


As described above, the operating room should be set up so that the surgeon, optic, target lesion, and monitor are all in one line. In case of multiple lesions, this may require adjusting the monitor or changing positions during the procedure. It is helpful to have the surgeon and assistant on one side of the patient if only one monitor is used. For apical lesions, the surgeon and assistant may be better positioned on opposite sides, with the monitor or monitors over the head of the patient.

Discreet lung lesions may be difficult to localize. Therefore, having the CT and endoscopic image visible to the surgeon at the same time may help with intraoperative orientation (Fig. 15.2).

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Fig. 15.2.
This setup allows the surgeon to view both the thoracoscopic image and the computed tomography scan simultaneously facilitated with exact localization of the target lesion.


Operative Steps




Oct 25, 2017 | Posted by in PEDIATRICS | Comments Off on Thoracoscopic Lung Biopsies and Resections in Children
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