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Presentation/Evaluation
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Presenting symptoms in pediatric patients can range from the incidentally found tumor or lesion in the asymptomatic child to the child who presents in extremis with severe hemorrhage or cardiorespiratory collapse from parenchymal or mediastinal compression or invasion. The size, location, number, degree of vascularity, specific tracheobronchial anatomic location, associated organ (heart, great vessels) or structure (trachea) involvement (directly or indirectly), and malignant potential all are factors known to influence the precise constellation of presenting symptoms. Patients presenting with benign tumors are most commonly asymptomatic (24%).3,4 However, when patients with benign tumors do present with symptoms, fever, cough, and pneumonitis have been documented to have the highest reported frequency (~10%) in this cohort. Those pediatric patients who are found to have metastatic lung cancers are also most commonly asymptomatic, as these lesions are generally small, numerous, and peripherally located on staging studies. Seldom does the child with pulmonary metastases present with pulmonary symptoms as the initial physical complaint. Primary malignant tumors in children generally do present with symptoms, however, and two large series found only 6% of children were asymptomatic upon presentation.3,4 In fact, these reports document that one-third of patients present with a refractory cough, and a not so insignificant number (10%–25% per symptom) also present with evidence of fever, pneumonitis, respiratory distress, or hemoptysis.
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As previously stated, however, these symptoms are nonspecific, and definitive diagnosis is almost always delayed. A high index of suspicion with close, diligent follow-up is mandated in all patients who do not respond to appropriate interventions directed at the suspected disease process that could be masking the presence of a mass. An algorithm has been published5 documenting at least one approach that may be used in the treatment of pediatric patients suspected of harboring a pulmonary tumor (Fig. 96-1). Ideally, the patient is evaluated at presentation and a baseline history and physical examination is conducted with acquisition of chest radiographs (two views) and disease-appropriate laboratory evaluations. A close interval follow-up examination (2–4 weeks) is generally recommended to ensure the symptoms have resolved or responded to treatment. For persistent, recurrent, or ongoing symptoms refractory to treatment interventions, a return visit with further studies, including a chest computed tomogram (CT) should be entertained if there is any question on the interpretation of the data collected during the prior visit. Although the risks of secondary malignancies from radiation exposure in children are not trivial,6 missing a tumor is of even more concern since extirpation is always a component of cure and if the lesion is discovered when small, parenchymal preservation approaches with negative margins and reduced rates of lymph node metastases would be expected. Although other imaging modalities, including magnetic resonance imaging and positron emission tomography, have been described in pediatric pulmonary tumors, their widespread application and utility remain unproved. An early referral to a pediatric pulmonologist also may be warranted to provide for another opinion on the child with refractory pulmonary symptoms and to investigate the utility of bronchoscopic evaluation. Again, close-interval follow-up is warranted to ensure symptom resolution. If a lesion is found on chest CT or bronchoscopy and is amenable to resection without undue perioperative morbidity or mortality, then resection is warranted after appropriate staging studies are performed. Preoperative pulmonary function testing also may be desired in cases where pneumonectomy and/or combined chest wall resection may be indicated so as to have a baseline to predict postoperative recovery and function. A biopsy procedure (bronchoscopically, image-guided, or surgical) can be entertained and discussed, especially in the case of large, central, or invasive tumors that are not amenable to upfront resection without significant perioperative risk. One must be careful in this setting, however, since soiling the pleural space with tumor may be detrimental in specific subtypes, and there is a significant risk of peribronchoscopic hemorrhage with mortal outcomes in the setting of endobronchial lesions.7–9 While commonplace in the adult literature, definitive therapeutic bronchoscopically directed strategies are not recommended treatment modalities in children with endobronchial pulmonary tumors because there can be significant technical limitations in small patients and the ability to achieve a wide local resection with negative margins using these techniques is often not possible.
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Benign and malignant pediatric pulmonary tumors are rare entities overall, but benign lesions are tenfold more common than malignant ones.10 Metastatic lesions encompass over 80% of all pediatric lung tumors sampled and 95% of all cancerous lesions.10 From two large series on the topic, at least 60% of all primary pediatric lung tumors are malignant with a mortality rate of roughly 30%.3,4 Benign lesions, however, do not necessarily confer significant survival advantage. Depending on the exact anatomical site of origin, these lesions have a collective mortality risk of 8% since they can be locally invasive to the heart, great vessels, and/or other mediastinal structures.3,4 Below we present specific data for each tumor class (malignant [primary, secondary] and benign) and type.
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Technical Considerations
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Primary or secondary pulmonary tumor resections can be performed by a variety of different techniques or approaches. The surgeon should be familiar with all thoracic incisions and operative approaches, since the best oncologic operation, and hence patient outcome, will be facilitated by using the proper incision. Minimally invasive surgical (MIS) approaches (as described in Chapter 52) are acceptable as long as oncologic principles can be maintained and executed without compromising patient safety. The surgeon must also have thorough knowledge of the technical limitations of patient size and equipment availability needed in these techniques. Preoperative patient assessment and determination of suitability for surgery, in addition to perioperative anesthetic and pain and sedation management techniques described elsewhere (see Chapter 5), also apply to pediatric patients.
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For children requiring hemithoracic exploration and extirpation of metastases from osteosarcoma or for the performance of a pneumonectomy (extra- or intrapleural), a sleeve resection, or difficult lobectomy, the authors prefer to use a complete muscle-sparing vertical thoracotomy technique as modified from the initial description by Sir Denis Browne.11 This technique since first described over seven decades ago has been utilized and modified by both adult and pediatric surgeons for the treatment of many intrathoracic conditions and diseases.12–16 The advantages of this approach are numerous, but it is particularly noted for decreasing the risk of musculoskeletal deformities and resultant pulmonary complications commonly found in children who undergo standard antero- or posterolateral thoracotomy.17–20 With younger patients, the chest is far more compliant than in adults, and this incision has proved to be both versatile and simple. The conduct of the operation involves standard lateral positioning (Fig. 96-2) after appropriate lung isolation (double-lumen endotracheal tube vs. use of a bronchial blocker depending on patient age) and placement of central (epidural) or regional (paravertebral) perioperative pain adjuncts have been achieved. The skin incision (Fig. 96-3) is marked with the arm in full abduction to ensure a straight incision. Otherwise, if the incision is made while the arm is flexed, it will curve anteromedially towards the chest. The dermis is incised longitudinally at the medial border of the latissimus dorsi from the inferior axillary line to the ninth interspace. If the border of the latissimus cannot be identified secondary to body habitus, the incision should be placed in the posterior axillary line. Monopolar electrocautery is used to separate the subcutaneous tissues. The medial border of the latissimus (Fig. 96-4) is identified and dissected in the axis of the wound. Care is taken not to damage the underlying neurovascular structures in the axilla, especially the thoracodorsal neurovascular complex and the long thoracic nerve during this dissection. Once identified, the latissimus dorsi muscle is dissected off the underlying serratus anterior muscle back toward the tip of the scapula (Fig. 96-5) without damaging or violating either muscle. The edge of the serratus anterior muscle is then located at its insertion on the tip of the scapula and the fascial plane connecting it to the chest wall is incised sharply (Fig. 96-6). Once this plane is entered, the serratus is dissected off the chest wall medially, rostrally, and caudally until it is completely separated. Caution must be exercised to avoid damage to the muscle or the neurovascular structures in the area, and once free, a blunt dissection can take place to identify the appropriate intercostal space to enter for the proposed operation as is standard for all thoracotomies. Once the chest is entered, the required pulmonary or thoracic operation can be performed as described elsewhere in this text. The wound is closed by reapproximating the intercostal space and all muscle, subcutaneous and dermal layers, with absorbable sutures.
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