FRCA Notes

Robotic Surgery

Robotic surgery is in absentia from both core and intermediate curricula.

Nevertheless there was a CRQ on robotic surgery in the September 2022 paper (48% pass rate).

Examiners were displeased with candidates' 'minimal experience' with the latest surgical toy and perceived ignorance of the 'practicalities of positioning patients during this type of surgery'.

Resources

  • Robotic surgery is a minimally-invasive surgical technique which overcomes some of the issues associated with 'classic' minimally invasive i.e. laparoscopic techniques
  • It is being used across an increasing breadth of surgical practice, including head & neck, thoracic, cardiac, urological , gynaecological, upper GI and lower GI surgery

Minimally invasive surgery in general Robotic surgery specifically
↓ pain 3D image visualisation i.e. true depth perception
↓ physiological insult Filtering & removal of natural hand tremor allows ↑ precision
↓ blood loss ↑ instrument mobility i.e. six degrees of freedom vs. four for classic laparoscopy
↓ wound infection rates Improved kinematics; can scale movement allowing precision work
Faster recovery Improved surgical views & access
↓ incidence of complications Ability to magnify imaging
Smaller surgical incision Similar speed to laparoscopic surgery (once surgeon fully trained)
↓ length of stay Low device failure rate (~0.5%)



Robot-related General intra-operative Associated with pneumoperiotneum + Trendelenburg
Limited tactile feedback Patient sliding due to more extreme positioning Risk of ETT movement during Trendelenburg positioning
High up-front cost Pressure injuries Cerebral, ocular, facial and/or laryngeal oedema
Maintenance costs Limited patient access including airway, monitoring & IV lines Negative ventilatory effects (see below)
Steep learning curve ↑ risk of peripheral nerve injuries vs. laparoscopy Regurgitation inc. aspiration, conjunctival chemical injury
Difficulty communicating from console Risk of visceral or vascular damage with patient movement Negative cardiovascular effects (see below)
Bulky equipment needs extra storage space ↑ positioning time Raised ICP, CBF and IOP
Time delay to unlocking robot in case of emergency Well-leg or gluteal compartment syndrome
Risk of VTE ↑ risk of gas embolism
Risk of rhabdomyolysis

Physiological respiratory changes

  • Increased intra-abdominal pressure & abdominal contents shifted towards the thorax
  • Decreased total lung compliance, due to reduced chest wall compliance and reduced lung compliance
  • Decreased FRC and vital capacity
  • Reduced ventilation, particularly in dependent areas
  • Greater lung atelectasis
  • Increased plateau pressure, which persists after pneumoperitoneum is released due to dorsal de-recruitment
  • Impaired gas exchange and V/Q mismatching

Physiological cardiovascular changes

  • Increased SVR
  • Increased myocardial oxygen consumption
  • Increased MAP but reduced renal, portal and splanchnic flow
  • RAAS activation

vs. open surgery

  • Reduced post-operative surgical complications
  • Reduced post-operative medical complications
  • Reduced blood loss & transfusion rates
  • Improved cosmesis
  • Improved recovery rates
  • Reduced length of stay
  • Reduced 30-day complication rate

vs. standard minimally invasive surgical techniques

  • Operating times may be longer, or equivocal only once surgeon fully trained on the system
  • May have particular benefit in the obese and/or elderly patient cohorts
  • Similar length of stay
  • Reduced conversion-to-open rate
  • Reduced blood loss & transfusion rates
  • Similar intra- and post-operative complication rates

Perioperative management of the patient undergoing robotic surgery


History and examination

  • Be mindful of the patient cohort in which robotic surgery is being used, as this will allow tailoring of the pre-operative assessment and subsequent anaesthetic conduct
  • In particular, it may be used for:
    • Obese patients
    • Elderly patients
    • Surgically complex patients
    • Otherwise higher-risk patients

  • Assess for existing comorbidities which may be exacerbated by robotic (extreme) positioning and prolonged surgery, or contraindicate use of the robot:
    • Pulmonary disease
    • Cardiovascular disease in particular RV or biventricular failure, right-to-left shunt
    • Raised IOP e.g. glaucoma
    • Raised ICP
    • Gastro-oesophageal reflux

Optimisation

  • Consider oral antacid prophylaxis in those with high reflux risk to reduce injury associated with gastric regurgitation during surgery

Monitoring and access

  • AAGBI
  • Consider arterial line although for low-risk patients may be unnecessary
  • At least 2 x IV access with extension lines to ensure adequate access and back-up in case of failure
  • Consider depth of anaesthesia monitoring in longer cases, e.g. pEEG, to avoid excessively deep anaesthesia and reduce risk of post-operative cognitive dysfunction
  • Core temperature measurement

Positioning

  • Use appropriate non-slip padding, foot/shoulder supports, beanbags and straps

  • Reduce risk of pressure injury and neuropraxia:
    • Avoiding excess stretch on limbs
    • Gel padding to key areas
    • Pad monitoring lines and IV connectors
    • Ensure upper limb joints abducted <90°
    • Ensure key lower limb pressure areas not compressed and suitably padded e.g. common peroneal nerve at head of fibula

  • Pad eyes thoroughly to ensure protected from gastric content spillage
  • Facial oedema can cause eyelids to open and risks corneal abrasions; ensure taped shut appropriately

  • Reduced risk of well-leg compartment syndrome
    • Avoid compression stockings
    • Periodically level the patient
    • Monitor foot pulses

  • Consider a 'trial of positioning' in high risk patients, where the patient is put in steep Trendelenburg and observed
    • This allows assessment of how the patient's physiology will cope before the robot docks
    • If significant issues arise, can consider alternatives such as laparoscopy, open procedure or abandonment

Airway

  • Cuffed ETT is essentially mandatory owing to high airway pressures from pneumoperitoneum/positioning and risk of aspiration
  • Ensure ETT securely fastened and check tube after positioning
  • Avoid excessively tight tube ties (or tape tube instead) as may cut skin if facial oedema occurs
  • Enough cuff pressure to protect airway from aspiration of gastric contents
  • Monitor face periodically

Ventilation

  • Mode of ventilation
    • PCV may be preferable to VCV, as it is associated with lower peak pressure, greater compliance and better CO2 control
    • PCVVG also causes lower mean and peak airway pressure than VCV although this doesn't necessarily improve gas exchange

  • Tidal volume: 6-8ml/kg

  • I:E ratio
    • A lower I:E ratio (e.g. 1:1, 2:1) may improve CO2 clearance by reducing the dead space fraction

  • PEEP
    • Use of PEEP reduces post-operative atelectasis, enhances dorsal ventilation & improves homogeneity of distribution of ventilation
    • The optimal level varies depending on the patient and the literature is inconsistent in its recommendations for PEEP levels
    • Use of higher PEEP is associated with more positive fluid balance and greater vasopressor use
    • Individualised PEEP levels are recommended, although overall one should avoid zero PEEP (ZEEP) or high (>10cmH2O) levels

  • Recruitment manoeuvres
    • Use if evidence of hypoxaemia, deteriorating respiratory mechanics or once pneumoperitoneum released
    • Use associated with hypotension, barotrauma and alveolar overdistension so need to be selective about timing and frequency of use
    • May improve intra-operative respiratory mechanics and gas exchange, and reduce post-operative pulmonary complication rate (atelectasis, need for oxygen therapy)

Maintenance

  • TIVA may prove beneficial in cancer surgery although limited evidence to suggest a difference in outcomes between volatile and TIVA anaesthetic for robotic surgery overall

  • Ensure patient won't move during surgery as this risks visceral or vascular damage; this can be achieved through either maintenance of muscle paralysis or remifentanil infusion
  • If NMBA used to maintain a still patient:
    • Compared to moderate block (ToF 1-2), deep neuromuscular block (post-tetanic count of 1 or 2) is associated with better operating conditions at lower intra-abdominal pressure, less post-operative pain and reduced haemodynamic upset
    • Consider infusion of short-acting agent e.g. cisatracurium

Fluids

  • Patients may be relatively euvolaemic owing to a move towards reduced fasting times, carbohydrate loading and avoidance of bowel prep as part of ERAS protocols
  • Judicious use of IV fluids when in steep Trendelenburg to reduce oedema of the airway (occurs in up to 26%), eyes, face and intracerebrally
  • Treat hypotension, unless obviously related to hypovolaemia, with vasopressors initially
  • Consider loading with IV fluids prior to levelling to reduce risk of sudden hypotension when patient levelled off
  • Overall aim for neutral fluid balance, acknowledging that urine drainage may be poor while in steep Trendelenburg

Analgesia

  • A major advantage of minimally-invasive surgery is the reduced incision size and degree of tissue injury
  • This means analgesic requirements are often more modest
  • A multi-modal, opioid-sparing analgesic regimen is optimal

  • Consider a neuraxial technique (e.g. spinal) containing long-acting opioids, as evidence suggests this improves post-operative pain management
  • Epidurals, however, may be unwarranted as they are associated with ↓ mobilisation, ↑ IV fluid requirements, prolonged time to return of bowel function and ↑ length of stay
  • Other local anaesthetic techniques include TAP blocks

  • Regular post-operative paracetamol
  • Regular post-operative NSAID unless contraindicated
  • PRN opioids for breakthrough pain
  • The evidence base for adjuncts such as IV lidocaine, ketamine and gabapentinoids is less consistent

Care bundle

  • Consider NG tube to help gastric drainage and prevention of aspiration or gastric content spilling onto face, particularly for long cases
  • Catheter for longer cases
  • Temperature management e.g. warming blanket, fluid warmer
  • Appropriate perioperative antibiotics prophylaxis
  • VTE prophylaxis e.g. TEDS

Emergence & extubation

  • Adequate reversal of NMBA
  • Consider cuff leak testing ± laryngoscopy prior to extubation
  • If concern over significant laryngeal oedema, options include:
    • Extubate over airway exchange catheter
    • Remain intubated overnight ± dexamethasone to allow oedema to settle

  • Multi-modal anti-emesis; pneumoperitoneum associated with higher rates of PONV
  • Multi-modal opioid-sparing analgesia
  • Follow ERAS protocol
  • Consider HDU/ICU for high-risk patients
  • Early return to oral fluid intake
  • Consider permissive oliguria (0.3ml/kg/hr) in absence of clinical signs of hypovolaemia as this may be a natural response to surgery (due to increased ADH release)

  • Overall complication rate is low
  • Older age, increased intra-operative blood loss and prolonged surgical duration are associated with more complications

Respiratory complications

  • Airway oedema (26%)
  • Post-operative pulmonary complications (19%)
  • Delayed extubation (3.5%)
  • Need for re-intubation (0.7%)
  • Pneumothorax
  • Venous air embolism

Surgical complications

  • Structural damage during access to the peritoneal cavity
    • Small bowel (25% of cases where damage occurs)
    • Iliac artery (19%) or vein (9%)
    • Colon (12%)
  • Major haemorrhage, which may be insidious due to mesenteric or retroperitoneal haemorrhage
  • Ileus, which may be due to pelvic haematoma or anastomotic leakage
  • Anastomotic leak

Robotic system

  • Device failure (0.5%)
  • Uncontrolled movements
  • Spontaneous powering off
  • Arcing from diathermy causing burns outside the surgeons field of view