Surgery – Principles

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  • An extensive discussion of every surgical procedure is beyond the scope of this website
  • For non-surgeons, the important considerations are the conditions and typical indications which suggest surgery is warranted
  • Being able to manage minor complications is reasonable but recognition of major complications should be referred directly to the surgeon
  • Advanced knowledge includes some familiarity with contraindications to surgery to prevent unnecessary referral

Purpose of surgery

  • Repair e.g. laceration
  • Reconstruct e.g. breast reconstruction, cleft lip
  • Renew e.g. ulcer debridement
  • Relieve [fluid/gas accumulations, obstruction] e.g. haemothorax, abscess
  • Replace e.g. joint replacement, organ transplant
  • Remove / Resect e.g. neoplasia
Typical surgical problems (by surgical sieve)
  • Degenerative e.g. osteoarthritis > replace
  • Neoplastic (benign and malignant) e.g. bowel cancer, melanoma > resect/remove
  • Vascular e.g. peripheral vascular disease >. revascularise
  • Congenital (malformations) e.g. cleft palate > repair/reconstruct
  • Infection e.g. appendicitis > remove
  • Traumatic e.g. femoral fracture > repair

Surgical Pathologies

Mucocutaneous and epithelial surfaces

  • Traumatic disruption – Abrasions, penetrations, lacerations, incisions, degloving, burns
  • Ulceration (e.g. loss of epithelial layer)

Swellings – solid and cystic

  • Solid organs (e.g. liver, bone)
  • Local compression

Traumatic – laceration, fracture, avulsion, amputation
Hollow organs (e.g. gallbladder, bowel) or external orifices (e.g. nose, vagina)

  • Distension
  • Rupture / Perforation e.g. perforated ulcer, ruptured aneurysm
  • Obstruction – extra-luminal, luminal, intra-luminal
  • Torsion e.g. testicular torsion
  • Fistulas

Tissue planes

  • Herniation (organ protrudes through tissue plane)
  • Sinuses (blind ending sacs)
  • Fistulas (abnormal connection between epithelialised surfaces e.g. hollow organ-hollow organ, hollow organ-skin)
  • Ectopia (displacement or malposition of normal tissue)
  • Metastases (distant spread of neoplastic tissue)


  • Ischaemic / Obstruction/ Torsion
  • Distension / Rupture / haemorrhage

Cavity (e.g. intracranial, intrathoracic, intra-abdominal)

  • Fluid accumulations – exudate, transudate, blood, digestive juice, lymphatic
  • Gas accumulations
  • Fibrosis / Obliteration

Conditions can be congenital, developmental or acquired
Treatment indications


  • Organ / Physiological dysfunction with significant symptoms OR life/limb threatening pathology

Surgical vs Non-surgical treatment

Failure, non-candidate or unfeasible for:

  • Medical treatment e.g. NSAIDS for disc prolapse
  • Minimally invasive intervention e.g. cystoscopic removal of renal calculi
  • Interventional radiology e.g. angiographic embolisation of bleeding

Treatment contra-indications

  • High anaesthetic risk (see below)
  • Extreme bleeding risk e.g. warfarinised [but can be reversed]
  • High complication risk (see below) e.g. tumour encasement of IVC
  • Technically not feasible e.g. diffuse coronary artery disease
  • Incurable or irreversible disease e.g. metastatic cancer
  • Poor life expectancy

Role of interventional radiology

  • Vascular – ischaemia (angioplasty/stent), bleeding / tumour de-bulking (angioembolisation)
  • Shunts / Stents – e.g.  porto-systemic hepatic shunt, biliary stent
  • Drainage – e.g. CT guided abscess drainage, nephtostomy for obstructed kidney

Surgical complications

Early / Mid

  • Infection
  • Bleeding / haemorrhage (+ embolisation in vascular procedures)
  • Damage to proximal structures – nerves, vessels, ducts [e.g. uroma, biloma], organs
  • Treatment failure

Late (complications of wound healing / disease recurrence)

  • Chronic infection e.g. chronic osteomyelitis
  • Impaired wound healing e.g. dehiscence, fracture non-union, hernias
  • Abnormal passages / connections e.g. fistulas, sinuses
  • Fibrosis / Scarring – e.g. obstructed viscus/adhesions
  • Recurrence of disease e.g. hernias, malignancy

Anaesthetic complications

  • Cardiac – ischaemia, infarction, arrhythmia
  • Circulatory – hypotension
  • Respiratory – infection, aspiration
  • Airway damage / Dental damage
  • Awareness

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