Surg - Viva - AAA Flashcards
Mortality and morbidity of a AAA
Ruptured - 50% reach hospital alive
50% die before surgery
Further 50% do not survive surgical repair
Risk factors for AAA
Male Age over 65 Smoker Hypertension Myocardial or cerebral vascular disease Familial Genetic - Marfans/Ehlers Danlos
Presentation of a AAA
Majority of AAA rupture in the retroperitoneal cavity
Triad:
Pain - severe in the back
Shocked - circulatory comprimise
Pulsatile abdomen mass
Atypical signs Back pain like renal colic Radiation to legs Chronic back pain suggests a contained rupture Transient lower limb paralysis
GI bleed suggests aorto-enteric fistulae (usually previous graft erosion)
Treatment of AAA
This is an emergency
Transfer for surgery should notbe delayed by Ix or procedures
Manages ABCDE, treat abnormalities as found
- Resus - Two large bore peripheral cannulae
Giving sets with rapid infusors of hand pumps
Crossmatch 6 units, massive transusion protocol
Aim systolic 90mmHg
Analgesia - fentanyil/morphine
Ix - FBC, U&E, Coag, Gas
ECG - MI in case
Imaging
Take to theatre ASAP
Surgical - Open / EVAR
Some evidence of 30 mortality benefit for EVAR but studies ongoing
Contained ruptures need repairing but less acutely
Imaging for AAA
CT - Best if uncertain diagnosis
Detailed extent of aneurysm
Confirm and localise site of rupture
Evaluate the aortic wall and extra aorta structures
BUT
Needs stability
Delays surgery
Contrast media may cause nephrotoxicity
US - rapid demonstrate free fluid, good for unstables
Can detect aneurysm and free fluid
Simple, cheap
BUT Sensitivity 95%
MRI - not appropriate for AAA - takes too long
Costs too much
But Highly specific and sensitive, no contract media
Complications for AAA surgery
Early Graft related: massive transfusion, distal emboli, aortic branch involement, ischaemia e.g. AKI, pancreatitis
Endoleak
Late graft: Infection, graft occlusion
Fistula
Anastomotic pseduoaneurysm
Non graft - early
Rnal failure, MI, paraplegia, hepatic failure, HAP/VAP,
ARDS, Compartment syndrome of abdomen
Ileus
Non graft, late: long resp wean, small bowel obstruction
Incisional hernia
sexual dysfunction
DVT and PE
Prognoistication systems for AAA
Hardman Index - 5 variable, scored 0 or 1
Mortality of 80% when score >2
Glascow Aneurysm score - used in both elective and emergency surgery
5 variables - age in years = points
Score of 84 = mortality of 65%
Point is APACHE II and POSSUM dont capture these patients
Whats the Hardman Index
5 variables point for each Age>65 Creatinine > 190 Hb <90 MI on ECG Hx of LOC after arrival in hospital
Glascow anurysm score
Age in year Shock (17 points_ Myocardial disease 7 CVA including TIA 10 Renal 14
When to do elective repiar
Male with AAA>5.5cm
Female >5
Rapid growth 1cm/year
When would you insert a spinal drain
Aim is to reduce CSF pressure after complex abdominal EVARs where patients are thought to be at risk of spinal cord ischaemia.
Also done as a rescue for delayed paraplegia post op
Reduces ICP Pre intra and post neurosurgery
Monitor CSF chemistry
Provide temporary CSF drainage with patients with infected CSF shunts
Why insert a spinal drain?
Can prevent cord ischaemia
Cord perfusion pressure = MAP - CSF pressure
Draining CSF by catheter in the subarachnoid space between lumbar spinous process, increases perfusion by decreasing CSF pressure
Contraindictations to spinal drains
Absolute
Anticoagulated patietns
Bleeding diathesis
Not recommended:
Non communicating hydrocephalus
Large intracranial mass lesions, tumours etc
Infection in the surrounding area
