Overview
Definition:
Transaxillary first rib resection is a surgical procedure performed through an incision in the axilla (armpit) to remove the first rib
This is primarily done to decompress the neurovascular structures of the thoracic outlet, relieving symptoms of thoracic outlet syndrome (TOS).
Epidemiology:
Thoracic outlet syndrome affects approximately 3-8% of the general population, with symptoms often appearing in young adults (20-40 years)
The transaxillary approach is favored for certain types of TOS, particularly those involving bony anomalies of the first rib or clavicle.
Clinical Significance:
Effective management of thoracic outlet syndrome is crucial as it can lead to chronic pain, upper extremity weakness, and potentially severe vascular complications
Transaxillary first rib resection offers a direct and effective approach for anatomical decompression when conservative measures fail.
Indications
Indications For Surgery:
Failure of conservative management (physical therapy, analgesics, activity modification) for at least 3-6 months
Documented compression of the subclavian artery, subclavian vein, or brachial plexus
Symptomatic bony anomalies or a prominent first rib contributing to TOS
Recurrence of TOS after previous decompression procedures.
Contraindications:
Active infection
Significant systemic illness precluding major surgery
Uncontrolled coagulopathy
Patient refusal or inability to comply with postoperative rehabilitation
TOS secondary to soft tissue causes without bony impingement that can be addressed by rib resection alone.
Preoperative Assessment:
Detailed patient history and thorough physical examination to confirm TOS diagnosis
Diagnostic imaging including chest X-ray, CT scan of the thoracic outlet, MR angiography or conventional angiography to visualize vascular compression, and EMG/NCS for neurological involvement
Thorough cardiovascular and pulmonary assessment.
Preoperative Preparation
Patient Counseling:
Informed consent regarding the procedure, potential risks, benefits, alternatives, and expected outcomes
Discussion of the transaxillary approach and its implications.
Medications:
Discontinuation of anticoagulants and antiplatelet agents as per standard surgical protocols
Optimization of comorbid conditions such as hypertension or diabetes
Prophylactic antibiotics may be administered.
Positioning And Anesthesia:
General anesthesia is typically used
The patient is positioned in a supine position with the arm abducted and externally rotated to provide optimal access to the axilla and thoracic outlet
Careful padding to prevent pressure injuries.
Procedure Steps
Incision:
A curvilinear incision, approximately 5-8 cm long, is made in the axilla, typically along the anterior border of the pectoralis major muscle or following Langer's lines.
Dissection:
The dissection proceeds through subcutaneous tissue and fascia to expose the pectoralis major and minor muscles
The pectoralis minor is often divided to gain access to the thoracic outlet
Care is taken to identify and protect the axillary vessels and nerves.
Exposure Of First Rib:
The scalene muscles are carefully dissected away from the first rib
The subclavian artery and vein, along with the brachial plexus, are identified and gently retracted to expose the anterior and superior aspects of the first rib.
Resection Of First Rib:
The first rib is resected using rib shears or an oscillating saw, typically from the costochondral junction to the costotransverse articulation or beyond, depending on the degree of decompression required
Hemostasis is meticulously achieved.
Closure:
The wound is irrigated, and hemostasis is confirmed
The pectoralis minor may be repaired if divided
Drains are usually placed
The skin and subcutaneous tissues are closed in layers.
Postoperative Care
Pain Management:
Adequate analgesia is essential, often involving patient-controlled analgesia (PCA) or scheduled multimodal pain medications
Nerve blocks may be considered.
Wound Care:
Wound inspection for signs of infection or hematoma
Dressing changes as needed
Drain management and removal typically occur within 24-48 hours postoperatively.
Mobilization And Rehabilitation:
Early mobilization is encouraged
Arm elevation and gentle range-of-motion exercises are initiated to prevent stiffness
Formal physical therapy is crucial for regaining strength and function, and to prevent recurrence.
Monitoring:
Close monitoring of vital signs, respiratory status, and neurovascular status of the affected upper extremity
Assessment for signs of complications such as pneumothorax, bleeding, or nerve injury.
Complications
Early Complications:
Pneumothorax (due to proximity to pleura)
Hemorrhage from intercostal vessels or subclavian vessels
Wound infection or hematoma
Brachial plexus injury causing neurological deficits
Phrenic nerve injury
Air embolism.
Late Complications:
Chronic pain
Recurrence of TOS symptoms
Shoulder dysfunction or stiffness
Thoracic duct injury (rare)
Spinal accessory nerve injury (if dissection is extensive)
Adhesions and fibrosis around neurovascular structures.
Prevention Strategies:
Meticulous surgical technique with careful identification and protection of vital structures
Adequate hemostasis
Careful dissection to avoid pleural injury
Prompt recognition and management of any intraoperative or early postoperative complications
Aggressive postoperative physical therapy.
Prognosis
Factors Affecting Prognosis:
The underlying cause of TOS (e.g., bony anomaly vs
fibrous band)
The severity and chronicity of symptoms prior to surgery
The patient's adherence to postoperative rehabilitation
The presence and extent of neurovascular involvement.
Outcomes:
A significant percentage of patients (often 70-90%) experience substantial symptom relief and functional improvement after successful transaxillary first rib resection
However, some residual symptoms or occasional recurrence may occur
Vascular TOS often has better outcomes than neurogenic TOS.
Follow Up:
Regular follow-up appointments are necessary, particularly in the first 6-12 months postoperatively, to monitor progress, address any persistent symptoms, and ensure compliance with rehabilitation exercises
Long-term follow-up may be required for patients with complex cases or residual issues.
Key Points
Exam Focus:
Transaxillary approach is ideal for bony first rib anomalies
Key structures at risk: subclavian artery/vein, brachial plexus, phrenic nerve, thoracic duct
Complete resection of the first rib, from cartilage to articulation, is critical for decompression.
Clinical Pearls:
Always visualize and protect the neurovascular bundle before rib resection
Consider dividing pectoralis minor for better exposure
Intraoperative neuromonitoring can be valuable for brachial plexus protection
Aggressive early rehabilitation is paramount for optimal outcomes.
Common Mistakes:
Incomplete rib resection leading to persistent compression
Injury to the subclavian vein or artery
Failure to protect the brachial plexus
Inadequate postoperative physical therapy
Misdiagnosis of TOS, leading to unnecessary surgery.