Clamshell Thoracotomy

In this article, we will discuss Clamshell Thoracotomy (Case report). So, let’s get started.

Schwannomas (neurilemmomas) are benign tumors arising from the Schwann cells of the neural sheath. They are typically well-encapsulated lesions and in the chest they are most commonly seen within the posterior mediastinum, often originating along the intercostal nerves. Several operative approaches have previously been described for the resection of these tumors, including thoracoscopic techniques and posterolateral thoracotomy. We report a case of a massive schwannoma (27 cm, maximum diameter), unresectable by described approaches, which was successfully excised using a clamshell thoracotomy.

Schwannomas are neurogenic tumors arising from the found in association with peripheral nerves throughout the body. Intrathoracic Schwannomas are well-described, typically within the posterior mediastinum. The tumors are well-encapsulated and, although usually benign, may cause significant local symptoms if not resected.

Case report

A 45-year-old man presented to our institution with complaints of progressive dyspnea and productive cough during the course of nearly 10 months. The patient had a persistent supplemental oxygen requirement (4 L/min to 6 L/min). A chest roentgenogram suggested a mass
lesion in the upper right hemithorax. A subsequent chest computed tomographic scan demonstrated a massive, posteriorly-based heterogenous, smoothly-bordered, extrapulmonary mass. This lesion caused extrinsic compression of the right mainstem bronchus and bronchus intermedius, with resultant right upper and middle lobe collapse and significant narrowing of the right pulmonary artery and superior pulmonary vein. No pulmonary embolus or direct cardiac or tracheal compression was evident. Given the significant symptoms, definitive treatment was urgently required. After multidisciplinary discussion, a primary surgical diagnostic approach was chosen because of the concern that a percutaneoucs biopsy would not be adequate for diagnosis. A 4-сm posterolateral thoracotomy incision was made for biopsy, revealing a smoothly-encapsulated mass. An incisional biopsy indicated a tumor of neural origin. As neural tumors are not typically responsive to cytoreductive radiation or chemotherapy, surgical resection often remains the only viable treatment option. Thus, the thoracotomy was extended to the anterior axillary line to facilitate en-bloc resection. However, the lesion could not be safely freed from the chest wall due to dense fibrous adhesions to the parietal pleura. The ditficulty with posterior mobilization of the mass in combination with its sheer sized precluded visualization of the vascular structures of the pulmonary hilum, making safe anterior dissection impossible from this approach. Further attempts at resection were aborted until definitive pathology was available. Just prior to extubation, the patient desaturated, and subsequently cardiopulmonary arrest occurred, which required resuscitation by advanced cardiac life support protocol, and he remained intubated.

Histopathology revealed a fibrous tumor with spindle-cell components strongly positive for S100 and negative for smooth-muscle actin, desmin, CD34, AEI, and AE3, consistent with a benign schwannoma. As this tumor would not be expected to have a measurable response to radiotherapy or chemotherapy for local control, surgical resection remained the only option in this severely symptomatic patient. As the traditional postero-lateral approach did not afford adequate exposure of the hilum, given the location of the mass, further extension of the incision posteriorly was believed to be unlikely to improve hilar visualization. An anterior approach through a clamshell thoracotomy was chosen for its ability to provide excellent exposure of the pulmonary hilum and mediastinum, wherein the mass seemed to arise. The patient was intubated with a double lumen endotracheal tube and was placed in the supine position, with a towel roll placed under the right flank to elevate the right lateral chest wall. The right chest was entered through the fifth interspace at the mid-clavicular line, with the thoracotomy extending posteriorly to the mid-axillary line and medially to the sternum. The internal mammary arteries were ligated bilaterally prior to a transverse sternotomy. The tumor compressed the ectatic right middle lobe, superiorly displacing the collapsed right upper lobe. There was a significant inflammatory reaction at the level of the hilum. The tumor intimately involved both the right mainstem bronchus and the bronchus intermedius, with extrinsic compression of up to one half of the bronchial lumen The right pulmonary artery and superior pulmonary vein were adherent to the capsule of the mass.

The mass was dissected free from the middle and lower pulmonary lobes in a lateral to medial fashion. This allowed lateral mobilization of the mass, which arose from the third and fourth intercostal nerve roots just lateral to the neuroforaminae. The upper pulmonary lobe was freed from the superior border of the mass and excision from the posteromedial chest wall was completed by sharply dividing several fibrous attachments.

Finally, the neural base of the tumor was dissected away from the normal-appearing intercostal nerve roots, allowing extirpation. Double-lung ventilation was resumed and the previously atelectatic upper and middle lobes were well aerated. The thoracotomy closure was performed using traditional pericostal sutures and the transverse sternotomy was reapproximated with vertical wires. Grossly, the tumor measured 27 x 27 x 6.5 cm and weighed 1.34 kg. Final pathologic review confirmed the diagnosis of a schwannoma without evidence of malignant transformation.

The patient’s postoperative course was complicated by alcohol withdrawal and poor baseline nutritional status. Despite the extent of the operation and underlying co-morbidities, the patient was extubated on the second postoperative day. The remainder of the hospital course was unremarkable. The patient was discharged home without supplemental oxygen at 4 weeks after the resection. At his 3-month follow-up, the patient denied any chest pain or dyspnea, and his functional status had improved which allowed him to return to work full time. A chest roentgenogram obtained at that time demonstrated expected postoperative changes without evidence of recurrence.

Source: Clamshell Thoracotomy: A Unique Approach to a Massive Intrathoracic Schwannoma

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