FRCA Notes

Prostate Surgery

The curriculum asks us to 'describe the anaesthetic management of... urological procedures including TURP'.

TURP featured as a CRQ in 2021 (80% pass rate) and was 'well answered by most candidates'.

This page also contains information on robotic-assisted urological surgery.

Resources

  • Transurethral resection of the prostate (TURP) remains the gold standard for treating BPH
  • It is usually indicated for small (<60g) prostate glands, whereas for large glands or neoplastic aetiologies other prostatic surgical options include:
    • Open prostatectomy
    • Robotic-assisted laparoscopic (radical) prostatectomy (RALP or RARP)
    • Robotic cystoprostatectomy
  • The prostate is a 20g gland encircling the urethra at the base of the bladder
  • It has a rich blood supply and venous drainage via large, thin-walled sinuses adjacent to the capsule
  • This can lead to:
    • High rates of irrigation fluid absorption into the venous sinuses
    • High (>1,000ml) volume blood loss during radical resections

Innervation

  • Innervation is from the prostatic plexus, itself arising via the inferior hypogastric (pelvic) plexus
    • Sympathetic: T11 - L2
    • Parasympathetic: S2 - 4

  • Pain sensation arises from:
    • Prostate, prostatic urethra and bladder mucosa: S2 - 4 sacral nerves
    • Bladder distension: T11-L2 running with sympathetics
  • Therefore if TURP is performed under neuraxial anaesthesia need a spinal block to at least T10 to avoid discomfort from bladder distension


Benefits of robotic prostatectomy
Smaller incision
↓ pain
↓ blood loss
↓ wound infection rates
↓ morbidity and mortality
Faster surgical recovery
Shorter hospital length of stay
Fewer post-operative complications than laparoscopic or open radical prostatectomy

Risks & disadvantages of robotic urological surgery


Anaesthetic Surgical Patient
↓ access to patient Longer positioning time to accurately dock robot Facial oedema
Complete immobility required Visceral or vascular damage Raised ICP & IOP
Positioning increases risk of atelectasis, aspiration & endobronchial intubation Major haemorrhage, which may be insidious inc. retroperitoneal haematoma Risk of gas embolism
Standard sequelae of pneumoperitoneum Reduced renal perfusion ± renal injury
Difficulty communicating from console
Steep learning curve
High up-front costs ± maintenance costs


Perioperative management of the patient undergoing prostate surgery


History and examination

  • Patient cohort is typically elderly (average age 69yrs) and approximately 77% have a significant medical comorbidity
  • Assess for common comorbidities in this age group including:
    • COPD or other pulmonary comorbidities (14.5%)
    • Hypertension
    • Ischaemic heart disease (12.5%)
    • Cardiac dysrhythmia including AF (12.5%)
    • Cerebrovascular disease ± dementia
    • Diabetes mellitus (9.8%)
    • Gastrointestinal comorbidities (13.2%)
    • Renal insufficiency (9.8%)
    • Osteoarthritis or other musculoskeletal issues

  • If robotic surgery is planned ensure no contraindications such as:
    • Raised ICP or IOP
    • Significant respiratory disease which would make ventilating in steep Trendelenburg difficult

Investigations

  • FBC: check Hb
  • U&E: check renal function and electrolytes given potential for chronic obstructive kidney injury
  • Group and save, especially if large (>80g) gland size as potential for greater blood loss
  • ECG
  • Urinalysis to check for UTI; if present increases risk of post-operative sepsis
  • Other investigations as indicated by past history, functional status and nature of surgery e.g. spirometry, TTE, CPET

Monitoring and access

  • AAGBI monitoring as standard
  • For more major surgery including robotic cases:
    • Wide-bore access is ideal as potential for high volume haemorrhage
    • Arterial lines may be indicated by patient comorbidities or need for closer haemodynamic monitoring or blood sampling
    • CVC not usually required unless other indication
  • Temperature probe for longer cases

Anaesthetic technique

Spinal anaesthesia General anaesthesia
Good for those with respiratory pathology Useful in those unable to tolerate lying still
Earlier detection of complications
(TURP syndrome, capsular tears or bladder perforation)		 Necessary in laparoscopic or robotic procedures
↓ intra-operative blood loss No difference in rates of perioperative myocardial ischaemia vs. spinal
Better post-operative analgesia No difference in outcomes vs. spinal anaesthesia
↓ incidence of VTE
Faster return of bowel function
Low risk of PDPH in this cohort
Only need block to T10
Not suitable as a standalone technique for open or laparoscopic/robotic procedures Unable to readily detect complications
Does not prevent erection, which can interfere with surgery No inherent analgesia
Positioning may compromise ventilation

  • Epidurals may be used alongside GA for cystoprostatectomies, where their use is associated with:
    • Lower peak inspiratory pressures
    • Better dynamic compliance
    • Better oxygenation
    • Lower lactate levels
    • Reduced post-operative systemic opioid use
    • Reduced rate of GI complications such as ileus or constipation
    • Reduced rate of VTE

Maintenance

  • Volatile or TIVA techniques both valid
  • For robotic surgery, the patient coughing or move can have disastrous consequences so absolute stillness is required
  • This makes remifentanil TCI a favourable technique, although intermittent doses of NMBA can also suffice

  • Intra-operative fluid should be restricted to:
    • Avoid exacerbating fluid overload caused by absorption of irrigating fluid during TURP
    • Reduce facial and airway oedema during robotic procedures
    • Allow an unimpaired visual field during urethral anastomosis during cystoprostatectomy by reducing urine output temporarily

Ventilation

  • The combination of steep Trendelenburg and pneumoperitoneum during robotic cases causes increased intra-abdominal pressure and diaphragmatic splinting leading to:
    • Increased risk of regurgitation/aspiration; pad eyes appropriately
    • Risk of migration of the ETT endobronchially; ensure tied at an appropriate length and check ventilation once positioned
    • ↓ FRC and compliance with associated atelectasis, hypoxia & ↑ ventilatory pressures; PCV is associated with ↓ peak inspiratory pressure and better dynamic compliance than VCV

Haemodynamics

  • Spinal anaesthesia may cause hypotension during TURP
  • This is best managed with vasoconstrictors to both treat the underlying pathophysiological mechanism and reduced further exogenous fluid ingress
  • Lithotomy position may mask hypotension due to added venous return from the lower limbs, which becomes apparent at the end of the procedure

Care bundle

  • Appropriate antibiotics e.g. gentamicin
  • VTE prophylaxis e.g. intermittent pneumatic compression stockings
  • Temperature control and warming as standard
  • NG tube not required and associated with increased risk of ileus in robotic prostatectomy

Extubation

  • If patient has had prolonged surgery in steep Trendelenburg it is prudent to ensure a cuff leak due to risk of laryngeal oedema

  • Disposition for TURP often to a ward-based setting but larger resections e.g. cystoprostatectomy often benefit from HDU care
  • Enhanced recovery should be encouraged; early mobilisation, removal of drains/lines/catheters, early enteral route
  • A three-lumen catheter is inserted and irrigation is continued for up to 24 h after operation

Analgesia

  • Requirements after TURP are often modest
  • Deep pelvic pain can be more of an issue in larger minimally invasive procedures, especially if no regional techniques have been used

  • A multimodal approach with regular simple analgesia and PRN opioids usually suffices
  • NSAIDs are often contraindicated due to either pre-existing comorbidities and/or risk of perioperative renal injury
  • Local anaesthesia infiltration to wounds, TAP blocks or other regional techniques should be used e.g. epidural analgesia for cystoprostatectomy

General

  • TURP syndrome

  • Myocardial ischaemia (up to 25%) or outright myocardial infarction (1 - 3%)

  • Haemorrhage
    • ∽ 500ml blood loss is typical from TURP although radical resections may be associated with greater levels of blood loss (e.g. >1,000ml)
    • Typical blood loss is in the realm of 2.4 - 4.6ml/minute
    • Raw prostatic tissue may release urokinase, further contributing to bleeding by provoking fibrinolysis

      • Factors associated with higher risk of bleeding during prostatic surgery
      Larger prostate gland size
      More extensive resection
      Co-existing UTI
      Prolonged surgery >1hr
      Urinary catheter present pre-operatively

  • Hypothermia; exacerbated by spinal sympathetic blockade and cold irrigation fluids
  • Post-operative cognitive impairment distinct from TURP syndrome
  • Ileus (particularly following larger robotic cases)
  • AKI due to reduced intra-operative perfusion, haemorrhage or obstruction (e.g. clot retention)
  • Well-leg compartment syndrome from prolonged lithotomy or steep Trendelenburg, especially if there's been hypotension
  • Deep vein thrombosis

Urological

  • For large (>100g) glands, TURP is associated with higher complication rates than open prostatectomy, with morbidity ranging from 18 - 26%

  • Catheter pain; lidocaine gel can help
  • Bladder (1.1%), prostatic capsule (10%) or urethral perforation
  • Clot retention; can cause bladder overdistension leading to pain and profound vagal stimulus
  • Penile erection

  • Bladder spasm
    • Anti-muscarinics (hyoscine butylbromide, oxybutynin or tolteridine) can help although increase risk of delirium
    • Other options such as benzodiazepines or sub-hypnotic doses of ketamine (250μg/kg) also risk deranged cognition