Transthoracic (Thoracotomy) Approach to the Thoracic Spine

The transthoracic thoracotomy approach provides direct anterior access to the thoracic vertebral bodies and discs from approximately T4 to T12. It is the workhorse exposure for anterior corpectomy and reconstruction, thoracic disc herniation, vertebral osteomyelitis, primary and metastatic tumours, and selected deformities. The patient is placed in the lateral decubitus position, almost always left side up. The rib resected is typically two levels cephalad to the target vertebra to achieve perpendicular access to the disc space. After rib resection and transpleural entry the lung is deflated and retracted. Segmental vessels are ligated at the mid-vertebral body level to mobilise the aorta. The artery of Adamkiewicz, thoracic duct, azygos vein, sympathetic chain and intercostal neurovascular bundles are the critical structures at risk. Closure requires a chest tube and layered chest wall repair.

Primary Indications:

• Anterior corpectomy and reconstruction for tumour (primary or metastatic)
• Vertebral osteomyelitis with abscess or instability requiring debridement
• Thoracic disc herniation with myelopathy when anterior decompression needed
• Post-traumatic kyphosis or burst fracture with anterior column deficiency
• Deformity correction requiring anterior release or osteotomy
• Failed posterior surgery with persistent anterior pathology

Why This Approach is Chosen:

The transthoracic approach gives unmatched direct visualisation of the anterior thoracic spine and allows complete corpectomy, decompression of the spinal canal from the front, and reconstruction with strut grafts, cages or vascularised fibula. No other approach provides the same degree of anterior column access without traversing the spinal canal.

Contraindications:

• Severe pulmonary disease precluding single-lung ventilation
• Previous thoracotomy with dense adhesions (relative)
• Active pleural infection or empyema
• Inability to tolerate lateral decubitus position
• High thoracic levels (T1-T3) better accessed via manubrium or sternotomy

Alternative Approaches:

• Posterior transpedicular or costotransversectomy for selected tumours
• Lateral extracavitary approach for thoracolumbar junction
• Endoscopic transthoracic for selected disc herniations
• Combined anterior-posterior staged procedures for complex tumours

Bony Anatomy:

The thoracic spine has twelve vertebrae. The vertebral bodies are heart-shaped with a smaller cross-sectional area than lumbar vertebrae. The pedicles are short and directed posteriorly. The rib head articulates with the costal facet on the vertebral body and the transverse process. The disc space is narrower than lumbar discs. The spinal canal is narrowest in the thoracic region, making cord compression rapidly symptomatic.

Thoracic Wall Layers:

|| Layer | Structures | Clinical Relevance | ||-------|------------|------------------| || Skin and subcutaneous | Intercostal nerves superficial branches | Incision planning | || Muscular | Latissimus dorsi, serratus anterior, intercostal muscles | Split or divide as needed | || Rib | Periosteum, neurovascular bundle in costal groove | Protect during resection | || Pleura | Parietal and visceral | Transpleural entry | || Lung | Visceral pleura, hilum | Deflate and retract |

Neurovascular Anatomy:

|| Structure | Location | Clinical Significance | ||-----------|----------|----------------------| || Intercostal neurovascular bundle | Costal groove on inferior rib border | Protect during rib stripping - runs vein-artery-nerve order | || Segmental arteries | Arise from aorta, enter foramen at mid-body | Ligate at mid-body to mobilise aorta | || Artery of Adamkiewicz | Left T9-T12 in 80 percent of individuals | Major radicular feeder to anterior spinal artery | || Thoracic duct | Right of aorta T5-T6, crosses left at T4-T5 | At risk on left thoracotomy - ligate if injured | || Sympathetic chain | Runs along rib heads anterior to vertebral bodies | Identify and preserve for autonomic function | || Azygos vein | Right paravertebral, crosses midline at T4 | Protect or ligate branches as needed |

Spinal Cord Blood Supply:

The anterior spinal artery supplies the anterior two-thirds of the cord. It is fed by radicular arteries, the largest being the artery of Adamkiewicz. Sacrifice of multiple segmental vessels or injury to Adamkiewicz can produce anterior spinal artery syndrome with flaccid paralysis, loss of pain and temperature sensation, and preserved proprioception.

Deep Internervous Plane:

There is no classical internervous plane in the transthoracic approach because the exposure traverses the chest wall and pleural cavity rather than splitting muscle between two different nerve supplies. The intercostal muscles are innervated segmentally by the intercostal nerves; division of one intercostal space does not denervate significant muscle mass. The approach is therefore described as intercostal or transpleural rather than internervous.

Superficial Dissection:

The skin incision is made over the selected rib. The latissimus dorsi and serratus anterior are divided or split in the line of their fibres. The periosteum of the rib is incised and stripped circumferentially with a periosteal elevator, protecting the neurovascular bundle in the costal groove on the inferior surface. The rib is resected from the costotransverse joint to the costochondral junction or as far anteriorly as needed.

Structures at Risk in Each Layer:

|| Layer | Structure | Protection Strategy | ||-------|-----------|-------------------| || Superficial | Intercostal neurovascular bundle | Identify in costal groove before rib resection | || Pleural | Lung parenchyma | Double-lumen tube deflation, gentle retraction | || Deep | Segmental vessels | Ligate at mid-vertebral body with silk ties or clips | || Deep | Aorta | Mobilise gently after segmental ligation | || Deep | Thoracic duct | Identify and protect or ligate if injured | || Deep | Sympathetic chain | Preserve unless tumour involvement requires sacrifice |

Position: Left Lateral Decubitus on Radiolucent Table

Pre-positioning Checklist:

• Double-lumen endotracheal tube confirmed and positioned by anaesthetist
• Arterial line and central venous access established
• Foley catheter placed
• Beanbag or sandbag positioning system prepared
• Axillary roll available
• All pressure points padded (ear, shoulder, hip, knee, ankle)
• C-arm or O-arm access verified from anterior and lateral
• Neuromonitoring leads placed if used (MEP/SSEP)

Positioning Details:

• Patient placed in true lateral decubitus with left side up
• Beanbag inflated after positioning to maintain stability
• Axillary roll placed under dependent axilla to protect brachial plexus
• Upper arm supported on arm board or pillow, abducted less than 90 degrees
• Lower leg flexed at hip and knee, upper leg straight with padding between knees
• Table may be flexed at thoracolumbar junction to increase intercostal space
• Kidney rest elevated if additional flexion required

Alternative Positioning:

• Right lateral decubitus for selected upper thoracic levels (T4-T6)
• Prone position with thoracotomy for combined anterior-posterior procedures (rare)
• Supine with sternotomy for cervicothoracic junction (T1-T3)

Key Bony Landmarks:

• Spinous processes - counted from C7 (vertebra prominens) downward
• Scapula - inferior angle approximately at T7
• Rib count - palpable in thin patients, confirmed with fluoroscopy
• Iliac crest - approximately L4-L5 level for reference

Key Soft Tissue Landmarks:

• Latissimus dorsi - posterior border of incision
• Serratus anterior - anterior border of incision
• Paravertebral muscles - medial limit of exposure

Incision Planning:

• The incision is centred over the rib to be resected, typically two levels cephalad to the target vertebra
• For T7 vertebral body the eighth or ninth rib is commonly resected
• The incision begins at the paravertebral line and extends anteriorly in a gentle curve or hockey-stick shape
• Length is 15-20 cm depending on body habitus and levels required
• Fluoroscopic confirmation of rib level is mandatory before skin incision

Rib Counting Technique:

The surgeon counts ribs from the top or bottom under direct vision after the pleural cavity is entered. The first rib is identified by its articulation with the manubrium and lack of costal groove. The second rib is the first with a costal groove. Intraoperative fluoroscopy or preoperative marking with a radiopaque marker is essential to avoid wrong-level surgery.

Adamkiewicz Injury Management:

• If suspected intraoperatively: maintain blood pressure, consider steroids per protocol, urgent MRI
• Postoperative paraplegia: immediate MRI, maintain mean arterial pressure greater than 85 mmHg, consider CSF drain
• Prevention is paramount - preoperative angiography in elective tumour cases, careful ligation technique, avoid hypotension

Proximal Extension (Cervicothoracic Junction):

For T1-T3 lesions the standard thoracotomy is limited by the scapula and first rib. Options include:

• Extended incision with scapular mobilisation (Paulsen approach)
• Manubrial split or sternotomy with clavicle osteotomy
• Combined cervical and thoracic exposure

Distal Extension (Thoracolumbar Junction):

For T11-L2 the diaphragm must be managed:

• Radial incision of the diaphragm with peripheral detachment
• Circumferential detachment of the diaphragm from the chest wall
• Conversion to formal thoracoabdominal approach
• The psoas muscle is mobilised anteriorly to expose the lumbar vertebral bodies

Combined Anterior-Posterior Procedures:

Staged or same-day anterior decompression and posterior stabilisation is common for tumours and fractures. The anterior approach is performed first, followed by repositioning to prone for posterior instrumentation. Some centres perform both in the lateral position with posterior exposure through a separate incision.

Minimally Invasive Variants:

• Video-assisted thoracoscopic surgery (VATS) for selected disc herniations and biopsies
• Mini-thoracotomy with tubular retractors and endoscopic assistance
• These reduce pulmonary morbidity but limit the extent of reconstruction

Intra-operative Complications:

|| Complication | Prevention | Management | ||--------------|------------|------------| || Wrong-level surgery | Fluoroscopic confirmation, rib counting, preoperative marking | Immediate re-exploration if recognised | || Adamkiewicz injury | Preoperative angiography, careful ligation | Maintain MAP greater than 85 mmHg, CSF drain | || Aortic injury | Gentle mobilisation, adequate exposure | Immediate vascular repair, shunt if needed | || Thoracic duct injury | Identify and protect | Ligate proximally and distally | || Intercostal nerve injury | Protect bundle during rib resection | Local anaesthetic, neuropathic pain management | || Lung injury | Careful retraction, single-lung ventilation | Repair laceration, chest tube |

Post-operative Complications:

|| Complication | Incidence | Prevention | Treatment | ||--------------|-----------|------------|-----------| || Atelectasis / pneumonia | 10-20 percent | Early mobilisation, incentive spirometry | Chest physiotherapy, antibiotics | || Chylothorax | 1-3 percent | Identify duct, ligate if injured | Conservative (drain, TPN) or surgical ligation | || Wound infection | 2-5 percent | Prophylactic antibiotics, meticulous closure | Irrigation, debridement, antibiotics | || Hardware failure | 3-8 percent | Adequate reconstruction, anterior-posterior construct | Revision surgery | || Neurological deterioration | 1-5 percent | Careful decompression, maintain perfusion | MRI, blood pressure management, re-exploration | || Post-thoracotomy pain syndrome | 10-30 percent | Intercostal nerve protection, multimodal analgesia | Neuropathic agents, nerve blocks |

Immediate Post-operative (0-48 hours):

• Chest tube management: Maintain on underwater seal, monitor output and air leak. Obtain daily chest radiographs. Remove when output less than 100 mL per day and lung fully expanded.
• Pain control: Multimodal - PCA, intercostal blocks, NSAIDs, paracetamol. Avoid excessive opioids that suppress respiration.
• Pulmonary toilet: Incentive spirometry every hour while awake, early mobilisation to chair, chest physiotherapy.
• Neurological monitoring: Hourly neurovascular checks for first 24 hours. Document lower limb power, sensation and reflexes.
• DVT prophylaxis: Mechanical (IPC) plus pharmacological (LMWH) once haemostasis secure.

Weight Bearing and Mobilisation:

• Mobilise to chair on postoperative day 1 if stable
• Ambulation as tolerated once chest tube removed and pain controlled
• Brace or TLSO if posterior elements are deficient or instrumentation is marginal
• No heavy lifting or bending for 6-12 weeks

Follow-up Schedule:

• 2 weeks: Wound check, chest radiograph, neurological assessment
• 6 weeks: Radiographs, assess fusion/healing, progress activity
• 3 months: CT or radiographs to confirm reconstruction stability
• 6 months: Functional assessment, return to work planning
• 1 year: Final clinical and radiographic review

The transthoracic approach is used worldwide for anterior thoracic spine pathology. Principles are consistent across FRCS, FRACS, EBOT, ABOS and other examination systems: careful patient selection, preoperative imaging to identify Adamkiewicz when possible, meticulous segmental vessel ligation at mid-body, and mandatory chest tube drainage.

Side-by-side principles:

|| Body | Position on transthoracic approach | ||------|----------------------------------| || AO Spine | Anterior approach indicated for tumours, infection and selected deformities; preoperative vascular imaging recommended for elective cases; combined anterior-posterior constructs for instability | || NASS / AAOS | Transthoracic approach appropriate for thoracic disc herniation with myelopathy when posterior access is high risk; chest tube management protocol essential | || NICE (UK) | Multidisciplinary team approach for spinal tumours; anterior decompression considered when cord compression is primarily anterior | || BOA / BASS | High-volume centres should offer transthoracic expertise; transfer protocols for complex thoracic spine pathology |

Registry evidence:

• AO Spine Tumour Registry and similar databases show anterior reconstruction improves local control and neurological outcomes in selected thoracic metastases.
• Pulmonary complication rates of 10-20 percent are consistently reported; aggressive perioperative pulmonary care is the key modifiable factor.

Global practice variation:

In high-resource settings, navigation, intraoperative angiography and advanced reconstruction implants are routine. In resource-limited settings the same principles apply using standard rib resection, silk ties for vessels, and autograft from the resected rib. Chest tube management remains mandatory everywhere.

Consent (globally applicable):

Discuss paraplegia risk from Adamkiewicz injury (1-3 percent in experienced hands), chylothorax (1-3 percent), pulmonary complications (10-20 percent), wound infection (2-5 percent), post-thoracotomy pain, and the need for chest tube drainage for several days postoperatively.