27 Ventral Approaches to the Thoracic Spine for Trauma Abstract A ventral approach to the thoracic spine for trauma may be clinically necessary for fractures that require decompression and/or stabilization that cannot be accomplished through the posterior approach alone. Retropulsion of vertebral body fragments into the canal can cause compression of the spinal cord or thecal sac can cause neurologic injury. A ventral approach allows for direct decompression and visualization of these neural elements, and superior ventral neural decompression more than posterior-only approaches. Significant vertebral body comminution also may require a corpectomy and anterior column support that is best accomplished with ventral access. A low anterior cervical approach provides access to the cervicothoracic junction through traditional anterior cervical interval with the addition of a transsternal, transmanubrial, or transclavicular modifications. Thoracotomy provides wide access for thoracic spine fractures. Mobilization and retraction of the scapula with thoracotomy extends the approach cranially to access upper thoracic fractures. Ventral retroperitoneal dissection with takedown of the diaphragm when performed with caudal thoracotomy joins the thoracic and abdominal cavities to expose thoracolumbar fractures. Keywords: cervicothoracic fracture, thoracotomy, thoracic fracture, thoracolumbar fracture Clinical Pearls • Low anterior cervical approach should be limited to when ventral visualization is critical or if a costotrasversectomy is too difficult, the usual indication is primary en bloc tumor resection. • Anterior column support in the upper thoracic spine is rarely indicated for fractures due to robust posterior segmental fixation. • Thoracotomy or thoracoabdominal approaches may be used for thoracic vertebral fractures with spinal canal compromise and neurological deficits. • A double lumen endotracheal tube is rarely needed for thoracotomy as the inflated lung can easily be retracted, causing less trauma than lung deflation. • Care must be taken to close the diaphragm if it is reflected during access to the thoracolumbar spine. • While access to the fractured vertebrae is relatively easy using a minimally invasive surgical approach, instrumentation through these retractors can often be challenging; therefore, a posterior pedicle screw stabilization procedure is often preferred for definitive stabilization. Thoracic spinal fractures may significantly disrupt the architecture of the spine. The anterior column supports up to 80% of the axial load of the spine ( Fig. 27.1 (a) Sagittal CT of a T12 fracture with significant anterior column comminution, kyphotic deformity, and canal retropulsion. (b) Axial image of the fracture with retropulsion of fragments and significant canal compromise. (c) Anterior–posterior radiograph with excellent restoration of height after posterior short segment fixation. (d) Lateral radiograph with excellent restoration of height after posterior short segment fixation. (e) Anterior–posterior radiograph with excellent restoration of height after anterior short segment fixation. (f) Lateral radiograph with excellent restoration of height after anterior short segment fixation. The cervicothoracic junction is generally accepted to be the region from C6 to T3. The biomechanical environment involves transition from cervical lordosis to thoracic kyphosis and can be region of high stress during trauma. Fractures of the cervicothoracic junction are uncommon and account for only 2.4 to 4.5% of all spine fractures.8 As a result, ventral approaches to the upper thoracic spine are most commonly reserved for spinal tumor or debridement of osteomyelitis and discitis. The low anterior cervical approach provides access to C7-T1 vertebra; transsternal and transclavicular modifications can be added to gain access to the T3 vertebra.9,10 We would suggest the assistance of an ear, nose, and throat specialist and/or cardiothoracic surgical team to facilitate the dissection for fractures requiring sternal splitting approach. The low anterior cervical approach to the ventral thoracic spine begins with supine positioning. The shoulders are retracted by placing a towel roll between the scapulae and the arms are tucked at the sides. The shoulders are then taped to the bed to retract caudally, allowing improved fluoroscopic view of the spine intraoperatively. The head is extended and can be turned away from the desired side of approach. The left-sided approach is often favored due to the more predictable course of the left recurrent laryngeal nerve.11 Incision is made along the anterior border of the sternocleidomastoid extending to the suprasternal notch ( Sternum splitting allows for distal extension of the approach. The sternum is exposed subperiosteally. A Gigli or oscillating saw may be used to split the manubrium and proximal sternum longitudinally. A transverse cut is then made in the second and third intercostal space ( Closure begins with sternal wiring or nonabsorbable suturing of the sternum and manubrium. A drain may be placed deep to the sternum. The clavicle is then fixed into placed if removed. The strap muscles and then the sternocleidomastoid is reapproximated to their distal attachments on the clavicle. The platysma and wound are then closed in layered fashion. Fig. 27.2 (a) Incision is made along the anterior border of the sternocleidomastoid muscle to the sternal notch, then extends longitudinally to the level between the second and third ribs. (b) Median sternotomy extends 2 cm distal to the sternal angle with transverse cut in the second intercostal space. (Reproduced with permission from Liu et al.9) The most frequent complication of the ventral approach to the cervicothoracic junction is dysphagia from esophageal retraction. Injury to the recurrent laryngeal nerve may also occur, causing vocal cord paralysis12,13 with incidence up to 16.67%. Other complications include sternal/manubrial nonunion, great vessel injury, carotid sheath injury, damage to sympathetic chain, and tracheal/esophageal injury. An infrequent, but serious complication is chyle leak from thoracic duct damage.9 A modified thoracotomy provides excellent access to the upper thoracic spine and is indicated for anterior exposure for fractures from T1 to T4. A double lumen endotracheal intubation may be used for selective lung isolation. Chest tube placement is often required and should be anticipated. Most injuries in this location can be addressed with a costotransversectomy if bony fragments need to be removed from the ventral spinal cord. A contraindication for this procedure is significant lung trauma that would preclude single lung ventilation. The approach also involves the mobilization of the scapula for the approach. A transpleural or retropleural approach can be used for vertebral column access. The patient is positioned in the lateral decubitus position. The laterality of approach is determined by fracture and vertebral level. A right-sided approach avoids the heart, aorta, and great vessels when accessing upper thoracic spine. The arms are abducted and forward flexed. The arm on the operative side can be placed on stacked towels or a padded mayo stand. The knees and elbows are placed into a slightly flexed position to relax any neural tension. A soft roll is placed beneath the axilla. A double lumen endotracheal tube is used for lung isolation. A hockey stick incision is made from the T1 spinous process along the medial and inferior border of the scapula ( The lung may be selectively deflated prior to dissection into the chest. The ribs are counted down internally to the operative level, either the second or third rib. Intraoperative fluoroscopy can be used to verify the location. Subperiosteal dissection is used to free the rib of intercostal muscles. Care is taken to protect the neurovascular bundle that runs along the inferior surface of the rib. A rib cutter is used to resect the rib as far anterome-dially and posterolaterally as possible. The resected rib can be used for bone graft for fracture fixation. The sharp ends are smoothed with a rasp and bone wax is applied to the ends. For the transpleural approach to the spine, the pleural cavity is entered by dividing the endothoracic fascia and parietal pleura in the rib bed. A rib spreader is used for retraction. A malleable retractor with a lap sponge is used for protection of the lung during the approach. The spine is visible at the deep portion of the incision once the pleural cavity is entered. The sympathetic chain, intercostal arteries, and veins are found within the endothoracic fascia overlying the vertebral column.14 The parietal pleura overlying the vertebral column is incised longitudinally along the axis of the spine. The endothoracic fascia and periosteum are divided sharply. The intervening intercostal arteries and veins are ligated and divided. Full access is the gained to the fractured vertebra and intervertebral disc. Closure is performed in stepwise fashion beginning with the parietal pleura. The lung is reinflated prior to closure of the chest wall for visual confirmation. The resected rib defect can be closed with wire or nonabsorbable suture taking care to avoid the neurovascular bundle. A chest tube is placed in the ninth intercostal space and set to water seal. Retropleural thoracotomy as described by McCormick15 proceeds in similar fashion as transpleural thoracotomy up through the rib resection. However, for a retropleural thoracotomy, the endothoracic fascia is divided in the rib bed, exposing the parietal pleura. The neurovascular bundle inferior to the rib is isolated and protected. The parietal pleura is bluntly dissected from the endothoracic fascia. The exposure is carried down to the level of the rib articulation. The parietal pleura is then dissected to the vertebral column; any tears in the pleura are repaired with suture.
27.1 Introduction
Fig. 27.1a, b). For most fractures of the thoracic spine, posterior stabilization is the preferred approach. Posterior modern instrumentation allows for rigid fixation, fracture reduction, and stabilization of the posterior elements (
Fig. 27.1c, d). The ventral approach only becomes clinically necessary in several scenarios wherein the posterior approach prevents sufficient access for either stabilization or decompression. A comminuted vertebral body may necessitate corpectomy and structural bone graft or titanium cage to reestablish the integrity of the anterior column.1 Retropulsion of the fractured vertebral body fragments into the canal compresses the anterior spinal cord or thecal sac and may cause neurological deficits. Posterior segmental instrumentation and ligamentotaxis is not always sufficient to provide sufficient decompression of the spinal cord. The anterior approach allows for direct decompression and visualization of neural elements (
Fig. 27.1e, f). The load sharing classification of spine fractures first introduced by McCormick et al develops a scoring system and provides a rationale to predict the need for anterior, or long posterior stabilization for operative thoracic and thoracolumbar fractures.2 The key features of the classification are comminution, kyphosis, and amount of spread or separation of the fragments. One to three points, depending on the severity are assigned each for vertebral body comminution, the degree of kyphosis corrected and the apposition of fracture fragments. Fractures that scored seven points or more were found to have an increased risk of failure of the posterior only construct and the need for anterior stabilization. In studies comparing anterior-only versus posterior-only fixation of thoracolumbar fractures, anterior instrumentation demonstrated better maintenance, and correction of angular deformity3 with greater loss of sagittal correction at follow-up with posterior fixation.4 In a series of 150 patients with thoracolumbar burst fractures with neurological deficit, Kaneda et al found a fusion rate of 93% with anterior decompression, grafting and instrumentation at a mean of 8 years postoperative. Ninety-five percent of patients in the series improved at least one Frankel grade, with 72% achieving complete neurologic recovery.5 A multicenter fracture study showed that bladder function improved significantly with anterior versus posterior decompression and fusion.6 Delayed fracture presentation can interfere with indirect decompression through ligmentotaxis with posterior approach, necessitating anterior approach for hematoma evacuation and direct anterior column stabilization. Generally accepted indications for a ventral approach for spine fractures include retropulsed fragments that reduce the canal by greater than 67% of total area, comminution of the anterior column with associated kyphosis of greater 30%, and a delay in surgery by more than 4 days.7
27.2 Cervicothoracic Spine
27.2.1 Low Anterior Cervical Approach
Fig. 27.2a). The incision is extended along the midsagittal plane of the sternum to the level between the second and third ribs if reaching T2-3. The skin is incised through subcutaneous tissue and the platysma is divided. The manubrial and clavicular insertions of the sternocleidomastoid are identified. The sternocleidomastoid is removed by subperiosteal dissection and reflected laterally. The sternohyoid and sternothyroid muscles are then dissected in similar fashion and reflected medially. If necessary, clavicular osteotomy can be accomplished with saw or osteotome at either the middle or medial third. The sternoclavicular joint is then disarticulated.
Fig. 27.2b). Care must be taken not to disarticulate the ribs from the sterum, as this will lead to chronic pain. A self-retaining retractor is used for deeper exposure through the manubrium and sternum. The thymus and retrosternal structures are mobilized bluntly and protected. The trachea and esophagus are then gently retracted medially while the carotid sheath and jugular are retracted laterally. Care should be taken to protect the thoracic duct and the recurrent laryngeal nerve as the prevertebral fascia is dissected to reveal the vertebral bodies from C6 to T3.
27.2.2 Complications
27.3 Upper Thoracic Spine
27.3.1 Modified Thoracotomy Approach
Fig. 27.3). The trapezius and latissimus are divided from their attachments and the scapula is rotated superiorly.
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