Overview
Definition:
Subclavian venous cutdown is a surgical technique used to establish central venous access when percutaneous cannulation methods have failed or are contraindicated
It involves a small incision over the subclavian vein, followed by blunt dissection to expose the vein and then cannulation
This method provides a reliable, though more invasive, route for administering fluids, medications, and monitoring central venous pressure.
Epidemiology:
Indications for subclavian venous cutdown are often emergent or when standard venous access is difficult due to patient anatomy, prior interventions, or critical illness
It is considered a salvage procedure, thus specific epidemiological data on its incidence is limited
however, it is employed in situations of severe hemodynamic instability or when large-bore venous access is urgently required.
Clinical Significance:
This procedure is crucial for surgical residents to understand as it represents a vital, albeit last-resort, method for achieving life-saving venous access in critically ill patients
Proficiency in this technique can directly impact patient outcomes in emergent scenarios, organ transplantations, major trauma, and complex surgeries where rapid fluid resuscitation or hemodynamic monitoring is paramount
It is a key competency tested in surgical training and examinations.
Indications
Absolute Indications:
Failure of multiple attempts at percutaneous central venous catheterization
Need for immediate, large-bore venous access in profoundly hypotensive or pulseless patients
Emergent placement of pulmonary artery catheters when other routes fail
Severe coagulopathy where percutaneous risk is deemed higher than surgical cutdown.
Relative Indications:
Difficult anatomy for percutaneous access (e.g., obesity, prior surgery, congenital abnormalities)
Need for long-term central venous access when tunneled catheters are not immediately available
Specific surgical procedures requiring reliable central venous access
Cases where rapid initiation of vasopressor therapy is critical.
Contraindications:
Active infection at the proposed incision site
Ipsilateral subclavian vein thrombosis or occlusion
Significant ipsilateral upper extremity vascular disease
Patient refusal
Uncorrected coagulopathy may be a relative contraindication, requiring careful consideration and management.
Preoperative Preparation
Patient Assessment:
Thorough assessment of airway, breathing, and circulation
Evaluation of coagulation status (PT/INR, aPTT)
Identification of any anatomical variations or prior surgical history in the chest and neck region
Informed consent, emphasizing the risks and benefits of this invasive procedure.
Equipment Setup:
Sterile surgical tray including scalpels, forceps, retractors, scissors, vascular clamps, and suture materials
Central venous catheters of appropriate size (e.g., 7-14 French)
Local anesthetic (e.g., lidocaine with epinephrine)
Antiseptic solution (e.g., chlorhexidine or povidone-iodine)
Sterile drapes and gown
ECG monitoring, pulse oximetry, and capnography.
Positioning And Anesthesia:
Patient placed in supine position with the ipsilateral arm abducted to 90 degrees and externally rotated
A small sandbag or rolled towel may be placed under the shoulder to enhance clavicular prominence
Local anesthesia infiltrated along the planned incision line and around the subclavian vein area
Sedation may be administered as needed for patient comfort, especially in conscious patients.
Procedure Steps
Incision And Dissection:
A transverse or oblique incision approximately 3-5 cm long is made just inferior to the midpoint of the clavicle
The incision is carried down through the subcutaneous tissue and platysma
Blunt dissection with a hemostat or dissecting scissors is then used to separate the fibers of the pectoralis major muscle and to identify the clavipectoral fascia
Careful dissection superiorly and medially allows for exposure of the subclavian vein.
Vein Identification And Ligation:
Once the subclavian vein is identified, it is carefully dissected free from surrounding connective tissue
It is crucial to avoid injury to the adjacent subclavian artery and pleura
Two stay sutures or vascular tapes are placed around the vein to provide proximal and distal control, allowing for temporary occlusion during catheter insertion and for ligation if necessary.
Catheter Insertion:
A small venotomy is made in the anterior wall of the isolated subclavian vein
A pre-selected central venous catheter is then carefully advanced through the venotomy into the lumen of the vein
The catheter is advanced to the desired depth, typically to the level of the superior vena cava or the cavoatrial junction, confirmed by ECG monitoring for arrhythmias or ST-segment changes indicative of right ventricular contact
The stay sutures are then tied to secure the catheter and ligate the vein distally to the insertion site to prevent hemorrhage.
Wound Closure And Dressing:
The proximal stay suture is tied to ensure adequate hemostasis
The skin incision is closed with interrupted sutures
A sterile occlusive dressing is applied over the insertion site
A chest X-ray is mandatory post-procedure to rule out pneumothorax, hemothorax, or malposition of the catheter.
Postoperative Care
Monitoring:
Continuous ECG monitoring for arrhythmias
Frequent vital sign assessment (heart rate, blood pressure, respiratory rate, oxygen saturation)
Monitoring for signs of bleeding, infection, or air embolism at the insertion site
Central venous pressure (CVP) monitoring if indicated.
Catheter Care:
Strict aseptic technique for all procedures involving the catheter (e.g., fluid administration, blood draws, medication infusion)
Regular dressing changes as per institutional protocol
Patency of the catheter maintained with appropriate flushing protocols.
Complication Surveillance:
Close observation for signs of pneumothorax (dyspnea, chest pain, decreased breath sounds), hemothorax (hypotension, chest pain, bruising), air embolism (dyspnea, cyanosis, neurological deficits, hypotension), infection (fever, local signs of inflammation), and thrombosis
Prompt management of any identified complications.
Complications
Early Complications:
Hemorrhage from the venotomy site or surrounding vessels
Pneumothorax or hemothorax due to pleural puncture
Arterial injury (subclavian artery laceration)
Air embolism if the catheter becomes dislodged or the venotomy is not adequately sealed
Nerve injury (e.g., brachial plexus)..
Late Complications:
Catheter-related bloodstream infection (CRBSI)
Deep vein thrombosis (DVT) in the subclavian vein
Catheter occlusion or migration
Stenosis or occlusion of the subclavian vein
Pseudoaneurysm formation at the venotomy site.
Prevention Strategies:
Meticulous surgical technique with clear visualization of anatomical structures
Careful blunt dissection to avoid inadvertent puncture of adjacent arteries or pleura
Secure ligation of the vein proximally and distally to the venotomy
Immediate post-procedure chest X-ray to detect pneumothorax
Strict aseptic technique for catheter handling and dressing changes
Regular assessment for signs of infection or thrombosis.
Key Points
Exam Focus:
Understand the indications, contraindications, and critical steps of subclavian venous cutdown
Be prepared to discuss common complications and their management
Differentiate this procedure from percutaneous central venous access techniques.
Clinical Pearls:
Always ensure proximal and distal control of the vein before making the venotomy
Consider the relationship of the subclavian vein to the subclavian artery and the pleura
A chest X-ray is mandatory post-procedure
Adequate patient positioning is critical for ease of access.
Common Mistakes:
Mistaking the subclavian artery for the vein
Inadvertent pleural puncture leading to pneumothorax
Inadequate ligation leading to persistent bleeding
Failure to obtain adequate venous control, increasing the risk of air embolism or hemorrhage
Poor catheter securement leading to dislodgement.