Overview
Definition:
The supraclavicular approach to the subclavian artery involves surgically exposing this major vessel through an incision made just superior to the clavicle
This approach provides direct access to the proximal subclavian artery and its branches.
Epidemiology:
Indications for subclavian artery exposure arise from trauma, aneurysmal disease, occlusive disease, and the need for vascular access or reconstruction
Its epidemiology is linked to the incidence of these underlying conditions, with increased prevalence in patients with atherosclerosis and trauma.
Clinical Significance:
Accurate and safe exposure of the subclavian artery is critical for managing a variety of life-threatening conditions
It is essential for procedures such as subclavian artery repair, bypass grafting, aneurysm excision, embolization, and management of iatrogenic injuries during central venous catheterization
Proficiency in this exposure is vital for surgical residents preparing for DNB and NEET SS examinations.
Indications
Direct Arterial Repair:
Repair of traumatic injuries (e.g., lacerations, transection) to the subclavian artery
Reconstruction of atherosclerotic occlusive disease or stenosis
Excision of subclavian artery aneurysms.
Vascular Access Procedures:
Placement of prosthetic grafts or shunts for hemodialysis access
Insertion of specialized endovascular devices requiring direct arterial control.
Diagnostic Procedures:
Occasionally required for challenging angiography or other diagnostic interventions directly at the vessel origin.
Management Of Iatrogenic Injury:
Immediate surgical control and repair following complications from central venous catheterization or other procedures in the supraclavicular region.
Anatomy And Relationships
Key Anatomical Landmarks:
The subclavian artery arises from the aortic arch (left) or brachiocephalic trunk (right)
It courses laterally, passing between the anterior and middle scalene muscles
It lies inferior to the clavicle and superior to the first rib.
Relations To Adjacent Structures:
Crucially, the subclavian vein lies anterior and inferior to the artery
The brachial plexus lies posterior to the artery, within the interscalene triangle
The phrenic nerve also courses in close proximity, typically anterior to the anterior scalene muscle.
Vascular Branching:
Major branches include the vertebral artery, internal mammary artery (thoracic artery), and the thyrocervical trunk
Understanding these branching patterns is crucial for dissection and control.
Preoperative Preparation
Patient Assessment:
Thorough cardiovascular assessment, including history of claudication, stroke, or systemic embolization
Review of previous imaging and medical records
Assessment of bleeding risk and coagulopathy.
Imaging Studies:
Doppler ultrasound, CT angiography (CTA), or MR angiography (MRA) to delineate the extent of disease, identify aneurysms, or characterize injury
Chest X-ray to evaluate for mediastinal abnormalities.
Anesthesia Considerations:
General anesthesia is typically used
Close anesthetic monitoring is required due to the proximity of major vascular structures and potential for hemodynamic compromise
Careful attention to fluid management and blood product availability.
Surgical Team And Equipment:
Surgical team experienced in vascular and thoracic surgery
Availability of vascular instruments, clamps, grafts, and appropriate anastomotic materials
Transesophageal echocardiography (TEE) may be considered for intraoperative assessment.
Surgical Technique Supraclavicular Approach
Incision And Dissection:
A transverse or slightly oblique incision is made in the supraclavicular fossa, typically 2-3 cm above and parallel to the clavicle
The platysma and superficial fascia are divided
The sternocleidomastoid muscle is retracted or divided
The omohyoid muscle may also be divided for better exposure.
Identification And Mobilization Of Artery:
The anterior scalene muscle is identified and carefully dissected
The subclavian artery is encountered posterior to the anterior scalene muscle
Careful dissection is paramount to avoid injury to the subclavian vein anteriorly and the brachial plexus posteriorly
The vertebral artery origin should be identified and protected.
Vascular Control:
Proximal and distal control of the subclavian artery is achieved using vascular tapes or vessel loops
Gentle retraction is applied to avoid intimal injury or spasm
In cases of significant atherosclerotic disease or calcification, careful mobilization and clamping are essential.
Reconstruction Or Repair:
Depending on the indication, vascular clamps are applied, and the damaged segment is repaired, bypassed with a graft (e.g., autologous vein, synthetic graft), or excised
Anastomoses are performed using fine non-absorbable sutures
Careful attention to meticulous hemostasis is required.
Postoperative Care
Monitoring:
Continuous hemodynamic monitoring, including arterial blood pressure and heart rate
Serial neurological assessments of the upper extremity
Vigilant observation for signs of bleeding, hematoma formation, or flap necrosis.
Pain Management:
Adequate analgesia is provided
Regional blocks may be considered in conjunction with systemic analgesics
Management of incisional pain and potential nerve irritation.
Fluid And Electrolyte Balance:
Careful fluid management to maintain adequate perfusion and avoid overload
Electrolyte levels are monitored and corrected as necessary
Blood glucose control is important, especially in diabetic patients.
Wound Care:
Standard wound care principles
Dressings are inspected for drainage
Early mobilization as tolerated to prevent venous stasis and pulmonary complications
Antibiotic prophylaxis may be administered.
Complications
Early Complications:
Hemorrhage (primary or secondary), hematoma formation, nerve injury (brachial plexus, phrenic nerve), pneumothorax, air embolism, arterial thrombosis or occlusion, myocardial infarction, stroke, wound infection.
Late Complications:
Graft occlusion, pseudoaneurysm formation at anastomotic sites, chronic limb ischemia, thoracic outlet syndrome (aggravated or newly formed), chronic pain, persistent paresthesias.
Prevention Strategies:
Meticulous surgical technique with precise anatomical dissection, adequate hemostasis, and appropriate graft selection
Careful patient selection and optimization
Preoperative imaging to identify anatomical variations and comorbidities
Postoperative vigilance and prompt management of any signs of complication.
Key Points
Exam Focus:
Understand the anatomical relationships of the subclavian artery to the subclavian vein, anterior and middle scalene muscles, brachial plexus, and phrenic nerve
Differentiate right vs
left subclavian artery origins
Be familiar with indications for supraclavicular exposure and potential complications like pneumothorax and nerve injury.
Clinical Pearls:
Always identify the sternocleidomastoid and anterior scalene muscles first
Protect the brachial plexus and subclavian vein meticulously during dissection
Use vascular tapes for control before definitive clamping
Consider the vertebral artery origin during proximal control
Ensure adequate distal runoff before completing anastomoses.
Common Mistakes:
Injury to the subclavian vein due to anterior dissection
Brachial plexus neuropraxia or transection from posterior dissection
Inadvertent injury to the phrenic nerve
Incomplete proximal or distal control leading to uncontrolled hemorrhage
Inadequate mobilization of atherosclerotic segments leading to clamp failure or graft kinking.