FRCA Notes

Video-Assisted Thoracic Surgery

This topic was a question in the September 2023 CRQ paper (43% pass rate).

The examiners noted: 'the practicalities of a robotic VATs procedure were not well answered possibly because not many trainees have seen such procedures'.

It's the second year in a row in which there has been a CRQ on robotic surgery.

Resources

  • Minimally invasive thoracic surgery (MITS) aims to avoid thoracotomy and its sequelae, including thoracotomy pain
  • MITS techniques include:
    • Video-assisted thoracic surgery (VATS)
    • Robot-assisted thoracic surgery (RATS)
  • There is a growing use of MITS, accounting for over 50% of lobectomy and sub-lobectomy procedures in 2017
Benefits of minimally invasive thoracic surgery (VIOLET study, 2022)
↓ wound size
Less physiological insult
Less impaired pulmonary function
↓ post-operative complications
↓ analgesia requirements
Lower readmission rate
Better physical function at 5 weeks post-op.
  • The benefits may be more pronounced in those with poorer pre-operative lung function, and it may be the preferred approach in those with poorer cardiorespiratory reserve
  • Issues with MITS include:
    • No difference in physical function vs. thoracotomy at 1yr
    • Higher incidence of air leak and vascular injury prolonging hospital stay
    • No significant difference in length of stay
    • No differences in cancer progression-free or overall survival

Indications

  • The approach aims to avoid rib spreading and thoracotomy wounds, and is usually performed via one (uniportal) or multiple (3-4) ports
Diagnostic Therapeutic
Pleural biopsy Pleurodesis & decortication
Thoracocentesis Lobectomy, segmentectomy and wedge resections
Biopsy of parenchymal tissue Lung-volume reduction surgery/bullectomy
Biopsy of mediastinal tissue inc. pericardium Mediastinal resections inc. thymectomy, chylothorax
Oesophagectomy, oesophageal myotomy
Sympathectomy

Contraindications

  • Adhesions due to prior surgery or radiotherapy
  • Extensive pleural disease
  • Large tumours (>6cm)
  • Difficult anatomical abscess
  • Inability to tolerate one-lung ventilation for prolonged periods

  • Surgeries generally still performed using thoracotomy include pneumonectomy, tracheal resections and sleeve lobectomies

  • All procedures performed by VATS can be performed by RATS, and some surgeries may be easier using this approach

Anaesthetic considerations

  • Limited space
    • Severely restricted patient access, especially airway
    • Generally less space and more thought-out equipment/lines positioning required to accommodate robot

  • Carbon dioxide insufflation of the thoracic cavity (5-10cmH2O)
    • Improves lung deflation and surgical access
    • Affect cardiovascular stability, particularly those with existing cardiac compromise
    • Contribute to hypercapnoea with negative sequelae on PVR and acid-base status

  • Involuntary movements of the patient, including coughing, can be catastrophic
  • Need to ensure adequate positioning, securing of the patient, depth of anaesthesia and neuromuscular blockade

  • Longer operative times, especially in early phase of learning
    • Meticulous positioning
    • VTE prophylaxis
    • Urinary catheter insertion (not usually required for VATS)

  • Delayed management of emergencies, particularly surgical vascular injury or other haemorrhage, due to need for:
    • Safe removal of the robot
    • Surgeon to re-scrub

  • Similar analgesic requirements to VATS as, despite smaller instruments, uses 4-5 ports in a single intercostal space

Perioperative management of the patient undergoing minimally invasive thoracic surgery


Monitoring and access

  • AAGBI
  • Larger gauge IV access due to risk of haemorrhage with delayed control
  • Arterial line for longer cases
  • CVC less commonly needed than open surgery and use should be based on patient factors

Positioning

  • Lateral decubitus positioning with extreme lateral flexion to open intercostal spaces
  • Must ensure adequate positioning to:
    • Prevent pressure injury in a patient population with risk factors such as low body weight, smoking, cardiovascular and peripheral vascular disease
    • Ensure no movement occurs whilst the robotic is in situ
  • Must check DLT position after position as tendency to be displaced during positioning

Anaesthetic technique

  • Neither TIVA nor volatile maintenance robustly proven to be superior, although TIVA may be associated with reduced incidence of unplanned ICU admission
  • Rocuronium/sugammadex is associated with faster post-operative chest drain removal and ↓ incidence of POPCs than cisatracurium/neostigmine (BJA, 2022)

  • Reduce risk of POPC by using
    • Lung-protective ventilatory strategy when using one-lung ventilation
    • Judicious fluid management
    • Minimising one-lung ventilation time

Lung isolation

  • Encouraging maximal lung deflation prior to surgical incision can:
    • Reduced pleural retraction pressure
    • Reduced risk of direct lung injury during port insertion

  • This can be achieved with:
    • Ventilating lungs with 100% FiO2 prior to isolation to denitrogenate operative lung
    • Applying suction to the operative lung

  • The technique for OLV is similar, although application of CPAP to the non-ventilated lung can interfere with surgical exposure and should be the final step in managing hypoxia

Alternative techniques

  • Other techniques include:
    • Spontaneously breathing VATS without intubation
    • Awake VATS under regional anaesthesia + local anaesthesia + sedation
  • These have putative benefits of avoiding the negative sequelae of positive pressure and one-lung ventilation, or of GA entirely
  • Not currently recommended by guidelines

  • Overall rate of complications is ~9%
  • Shares many of the complications with open thoracotomy
Complications of MITS
Haemorrhage
Conversion to open
Hypercarbia and VAE from CO2 insufflation
Tumour dissemination from instrument insertion
Air leaks and recurrent pneumothoraces
Post-operative pulmonary complications (7.4%)

Conversion to open

  • Often due to intra-operative haemorrhage
  • Poor visualisation of structures
  • Difficult anatomy e.g. pleural adhesions
  • Oncological (upstaging of tumours, unexpected chest wall involvement)

Analgesia

  • Pain from both VATS and RATS is less severe than thoracotomy although a moderate sized wound is still required for specimen removal
  • Post-operative pain can still be severe and inadequate analgesia is associated with higher rates of POPCs
  • It is still associated with high rates of chronic pain (25%), although less so than thoracotomy
  • A multi-modal approach is required, including use of paravertebral or erector spinae blocks as first line regional techniques