Editing Ruptured AAA

== Definitions: ==

* AAA with extra-luminal blood, either on CT or noted at surgery
* Contained rupture - blood outside the aneurysm sac, but confined to the retroperitoneal space
* Free rupture - bleeding directly into peritoneal cavity
* Symptomatic non-ruptured AAA: back pain or tenderness over the aorta on deep palpation, but with an intact aneurysm on CT/surgery
** The pain is thought to be secondary to acute expansion of the wall, intramural haemorrhage, wall degeneration or bleeding into the thrombus and is considered a prelude to rupture
** Much better prognosis than ruptured, but still require urgent management to prevent rupture

== Pathophysiology ==

* RAAA represents failure of the aortic wall to bear the load
* Aortic thrombus plays a role - this impedes blood supply to the wall. Thicker mural thrombus means more likely to rupture.

== Pre-op prognosis ==

* Mortality 80-90% overall (30% if they make it to OT)
* Predictors of mortality:
** Hardman index/Glagow aneurysm score, RAAA-POSSUM, Edinburgh Ruptured Aneurysm Score
** None of those is accurate enough to deny repair
** Loss of consciousness - OR 2.6
** Pre-op cardiac arrest - OR 4.3
** Pre-existing CCF
** Pre-existing renal insufficiency
** Advanced age (>76yo) - OR 5.3
** Female
** Suprarenal clamp - OR 2.4

== Presentation ==

* Classic triad:
** Hypotension
** Abdo/back pain - typically severe and unrelenting
** Pulsatile abdominal mass
* Frequently appears pale and diaphoretic
* Flank ecchymosis is a late sign

== Differential diagnosis ==

* Renal colic
* Diverticulitis
* MI
* Pancreatitis
* GIT bleed
* Perforated ulcer

== Investigation: ==

* AXR
** Enlargement of calcified aortic wall beyond normal limits
** Loss of psoas shadow from retroperitoneal haemorrhage
* USS
** FAST
*** Excellent for identifying AAA in trained hands
*** Not sufficiently accurate to exclude rupture
* CT
** Most accurate method for diagnosis, ideally with contrast, to plan open or EVAR
** Do it if the patient is stable

*

== Management ==

=== Initial management ===

** Immediate vascular consult
** Permissive hypotension - SBP around 80
*** Maintain consciousness, minimise organ ischaemia, prevent ST depression
*** Be very judicious with fluids. Increased fluids increases mortality. Overall risk of harm is low if the diagnosis is wrong.
*** Blood or fluids can be given
** Dual large-bore access
** Art line?
** IDC?
** Crossmatch
** Avoid intubation if they can protect own airway
** CT-A would be very useful if possible - look for periaortic stranding to suggest imminent rupture - however the patient has to be well enough to go to CT
** NGT 

=== Open vs EVAR ===

* '''EVAR is preferred if possible'''
* Need a CTA for EVAR - patient has to be stable
* Anatomy is most important (see open AAA repair page for considerations)
* Overall about half of RAAA patients are suitable for EVAR

=== Operative setup: ===

* Prep, drape THEN intubate
* Consider art line/IDC
* Cell saver
* Avoid hypothermia

=== Open repair: ===

* Proximal aortic control - laparotomy, retract left lobe of liver and stomach to right, divide gastrohepatic ligament, retract oesophagus to left, access aorta and clamp it.
* Dissect infra-renal aortic neck. The clamp can be repositioned here if there is space
* Tube graft is most commonly used
* Close abdomen primarily if possible. Can't close in 25% due to tension. Early mesh closure may be an option.

=== EVAR: ===

* Can be done under local + sedation (maintain sympathetic tone) or GA
* Can be either percutaneous access or cutdown
* Stable patients can have GA and a cutdown
* Can do balloon occlusion first

== Post-op prognosis: ==

== Complications ==

* Often start to go downhill on day 2
* Lower extremity ischaemia
** Either distal embolization or occlusion
** Often kinking or compression of graft if done via EVAR
* Abdominal compartment syndrome
** More common after EVAR, but can also occur after open - esp if significant haemorrhage or oedematous bowel
** Often manifests as renal failure secondary to renal vein compression, or rising peak airway pressures, reduced cardiac output, oliguria
** Decompressive laparotomy for intra-abdominal HTN > 25mmHg
* Ischaemic colitis
** See separate topic under 'open AAA repair'
* Infection
** Graft infection is rare but devastating
** Often requires complete excision of graft
* Groin access complication



[[Category:Vascular]]