Video Assisted Thoracic Surgery (VATS)

Lobectomy remains the most commonly carried out lung resection procedure but there is a definite shift in the surgical approach towards minimal access (VATS) surgery. Provisional figures for 2013–2014 in the UK show 30% of lobectomies for lung cancer were carried out using a VATS approach (increasing from 23% in 2012–2013). The adoption of VATS techniques in thoracic surgery has driven improved patient outcomes including survival, reduced complications and a shorter recovery. However, as a result, increasingly complex surgical procedures are now being performed on older and sicker patients.

Pleural Drainage

Advances in chest drain technology and the understanding of the management of pleural spaces has greatly advanced. There has been an introduction of chest drains with digital quantification of leaks and pleural pressures, the use of miniature dry suction chambers with one-way valves which have improved safety and allow easy early mobilisation with a shoulder strap. The avoidance of suction and early removal have allowed earlier discharge. In the case of prolonged air leaks, discharge with a chest drain in situ, reviewed 2–4 weeks later, has decreased length of stay and reoperation rate.

Following pneumonectomy, the space within the pneumonectomised hemithorax gradually fills with fluid over a period of days to weeks (see Figure 43.1). In the immediate postoperative period close clinical and radiological monitoring is required for signs of accumulation of blood or air and for mediastinal shift, i.e. movement of the mediastinal contents from their midline position as a result of changes in intrathoracic pressure. This cavity can be managed with:

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  No drainage

  
  
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  Underwater seal drain clamped and released intermittently to allow assessment of blood loss and release any trapped air

  
  
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  Balanced pleural drainage (injection/aspiration of air to limit mediastinal shift).

Figure 43.1 Sequential chest X-rays from a post-pneumonectomy patient demonstrating normal filling of the left hemithorax. (a) Day of surgery, (b) day 1, (c) day 4, (d) day 8.

The use of balanced pleural drainage may be associated with a lower incidence of mediastinal shift and postoperative ARDS. This may be because limitation of movement of the heart and pulmonary vessels from their usual position reduces changes in transpulmonary vascular pressures in the remaining lung and so decreases the propensity for the development of pulmonary oedema. Or it may be that maintenance of the mediastinal contents in their midline position reduces the mechanical stresses on the residual lung caused by over-distension or compression.

Enhanced Recovery

The adoption of enhanced recovery programmes for thoracic surgery has served to increase throughput and decrease hospital length of stay. The enhanced recovery programme aims to institute a number of evidence-based interventions in order to assess and optimise the patients preoperatively, reduce the stress associated with the surgery and promote recovery and restoration of normal function. These programmes have led to a decrease in complications and ICU admissions, as well as a reduction in hospital length of stay. The enhanced recovery programme recommendations for thoracic surgery are listed in Table 43.1.

Within the enhanced recovery programme, the aim of preoperative assessment and optimisation is to identify patients at risk of complications and where possible take measures to prevent such complications from arising. Specific risk factors have been identified in the development of postoperative complications:

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  Age >75

  
  
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  Male sex

  
  
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  Smoker or ex-smoker

  
  
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  COPD

  
  
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  Interstitial lung disease

  
  
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  Concurrent cardiac disease

  
  
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  Lung function FEV1 <60%, TLCO <50%.

Analgesia

Thoracotomy ranks amongst the most painful of surgical procedures. The constant motion of respiration and coughing compounds the pain from muscles that have been transected or overstretched and torn, and ribs that have been partially excised or fractured during thoracotomy. The surgical technique can be modified to reduce the severity of pain, for example by avoiding rib fracture or resection or performing the procedure by VATS rather than thoracotomy.

Pain relief after thoracic procedures can be achieved in many ways, including systemic analgesics, epidural analgesia, paravertebral or intercostal blocks, intrapleural regional anaesthesia or cryoanalgesia. Ineffective analgesia often results in poor chest expansion and expectoration, leading to atelectasis and chest infection. Multimodal analgesia combining systemic non-opioid and opioid analgesics together with some form of nerve block is regarded as the most effective means of rendering the patient comfortable, but without over-sedation.

Thoracic epidural analgesia has been the mainstay of thoracic anaesthetic practice for many years and provides arguably the best postoperative pain relief. Although epidural infusions have been shown to reduce the incidence of chest infection, large numbers of complications have been attributed to epidural insertion and to the management of epidural infusions. Serious complications include nerve injury, epidural abscess and haematoma – the routine use of low molecular weight heparin for thromboprophylaxis and burgeoning use of novel oral anticoagulant agents making the latter a significant concern. Other significant disadvantages are hypotension due to concomitant sympathetic block, requiring the use of intravenous fluids or vasopressors, and delay in patient mobility and, therefore, recovery and discharge.

These factors have led to the search for alternative safer techniques of regional block. The most commonly used techniques today are paravertebral block, or intercostal nerve block. The analgesic efficacy of these techniques may often not be as great as that provided by an epidural infusion, but complications are certainly reduced and the patient is able to mobilise quicker and can be discharged sooner. Paravertebral blocks can be placed either as single shot blocks at multiple levels or via placement of a catheter with an infusion of local anaesthetic for longer or more complex procedures. Paravertebral catheters may be placed by the anaesthetist at the beginning of the procedure, or placed directly by the surgeon at the end of the procedure. Multilevel intercostal nerve blocks are also commonly utilised and are effective at controlling acute pain, but usually are only effective for up to 4–6 hours.

Thromboprophylaxis

Evaluation of venous thromboembolic risk in all patients and the routine use of pharmacological and non-pharmacological prevention has significantly decreased the incidence of morbidity and death from thromboembolic disease in thoracic surgical patients.