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Sarah Alarabi PGY-2
7/28/2009
Cc: low back and right buttock painHPI:
56M brought by ambulance to ED with a two day history of progressive low back pain. Patient has described it as occasionally sharp. He took ibuprofen and tylenol to help alleviate the pain to no avail. On the morning of his presentation, the pain radiated to the right buttock and became very sharp and unbearable enough to come to the ED. He began to feel weak upon his arrival.
PMH: perforated ulcerPSH: ex lap for perforated ulcer with “patch”
repair according to family members
SH:Smokes 1ppdOccassional ETOHNo admitted hx of illicit drug use
Allergies: NKDAMeds: ibuprofen and tylenol
Initial ED course prior to exam:Pt had arrived with bp 60/40BP rose, without resuscitation, to 90/50Pt underwent CT and surgery was called
secondary to resultsPE:
128/90 92 50 afebrileGenerally fatigued appearanceRapid rhythmTachypniec, CTABLDistended, firm abdomen, +BSAFQ, no pulsatile
mass on palpation
Aneurysm is defined as a permanent and irreversible localised dilation of a blood vessel At least 50% increase compared to normal
M aorta 1.4-2.4 cm infrarenal aorta (AAA 3cm<)F 1.2-2.1 cm infrarenal aorta (AAA 2.6cm<)
First described in Ebers Papyrus (2000 BC) in peripheral arteries
Antyllus performed first repair of aneurysm in 2nd century by incising it and evacuating its contents
Hunter “fixed” a popliteal artery on a coachman by ligating it after concluding that the patient had developed enough collateral arteries for the limb to survive (1785)
Cooper (one of Hunter’s pts) performed a similar repair for an iliac artery, but the pt did not survive the aortic ligation for more than 2d.
Matas (from New Orleans) buttressed the vessels and ligated the collaterals, 1906
Carrell won Nobel prize 1912 for anastomoses techniques
Debakey, Hopkins, Vorhess (prosthetic graft) added to the developments
Juan Parodi introduced EVAR (endovascular aortic aneurysm repair)
History
True All 3 layers are involved
False (pseudoaneurysms) not all 3 layers
By morphology Fusiform: symmetrical Saccular: only part of the circumference (higher risk for
rupture)By etiology
Degenerative: by atherosclerotic changes Congenital: rare Other etiologies include mycotic infection, blunt trauma,
iatrogenic (most common site is infrarenal aorta, 65%) (most common site peripherally is the popliteal, 70%)
No single theory has been accepted What we do know is the following:
90% are associated with athersclerosis Elastin and collagen play a key role with respect to their
degeneration Elastases to memorise: MMP-2, 9, and 12 have increased
expression in aneurysmal tissue (they return to normal levels once repair is made)
Histologically you will find a lot of plasma cells in the media & t cells in the adventitia, leading many to believe that cytokine release has a significant role in aneurysm formation
As many as 50% of aortic aneuryms demonstrate chlamydia pneumoniae
Genetics plays a role in 15-25% of pts Enlargement is governed by Laplace’s Law:
T=PR (t=tangential stress, r=radius, p=transmural pressure) This does not take into account wall thickness (where t=pr/gamma)
Pediatric diseases associated include: Tuberous sclerosis, behcet disease, marfan syndrome, ehlers-danlos
syndrome, infection from umbilical artery catheters
Most common in infrarenal regionClassification:
I – infrarenalII – juxtarenalIII – pararenalIV – suprarenal
Iliacs involved in 40% (90% of which are in common iliacs)
Generally increasing in frequency secondary to increasing aging population and increase in diagnostic imaging
Exact cause is unknownAge
Increases in M over 55 (peak at 6% in 80-85)Increase after 70 in F (peak at 4.5% in 90+)• Gender – 4-5:1 b/n 60-70, then 1:1 after 80
Race - Caucasian (2-3:1::C:B)Tobacco use – 78% assoc with tobacco (8:1)Family hx – 11:1 if first degree relative
Only 50% of ruptures arrive alive at the hospital
7% died before surgery17% died during surgery37% died within 30 days of surgeryOverall mortality post op is 45%
Risk Factor Low Risk Avg Risk High Risk
Diameter <5cm 5-6cm >6cm
Expansion <0.3cm/yr 0.3-0.6cm/yr >0.6cm/yr
Smoke/COPD None, mild Mod Sever/steroids
FMH No relatives One rel Many rel’s
HTN n/l bp Controlled Poorly controlled
Shape Fusiform Saccular Very eccentric
Gender Male female
Good Risk Moderate Risk High Risk
>70 years 70-80 years 80 years
Physically active Active Inactive, poor stamina
No clinically overt cardiac disease
Stable coronary disease; remote MI; EF >35%
Sig. CAD, recent MI, freq. angina; CHF; EF <25%
Creatinine 2.0-3.0
n/l anatomy Adverse anatomy or AAA characteristics
Creatinine >3
No adverse AAA characteristics
Liver disease (albumin <2)
Anticipated operative mortality 1%-3%
Anticipated operative mortality, 3%-7%
Anticipated operative mortality, at least 5%-10%; each comorbid condition adding approximately 3%-5% mortality risk
In a consecutive series of 180 pts w/ ruptured AAA, the following factors were independently related to the mortality rate: agesystolic BP < 80 mm
Hghistory of
hypertensionAnginamyocardial infarction
(MI)
In pts who survived surg, causes of death were as follows: Renal /multisystem
failure (32%) Cardiac failure (29%) Resp failure (17%) Coagulopathy (12%) GI hemorrhage (3%) Perf duod ulcer (1.5%) Renal hemorrhage (1.5%) Hemorrhage from graft
anastomosis (1.5%) Stroke (1.5%) Aspiration (1.5%)
"Blue Toe Syndrome"
Livedo
Reticularis:
Atheroemboli
from small
abdominal
aortic
aneurysms
In a series of 226 AAAs in Italy, bleeding occurred into the following regions: Retroperitoneal - 85.3% Peritoneal - 7.1% Inferior vena cava (IVC) or iliac vein - 5.8% Enteric - 1.8%ruptures into the retroperitoneum typically
originate from the L posterior aspect of the AAA
ruptures into the intestine tend to occur from the right anterior aspect
Routine PE Pulsatile mass Radiographic study
Sx Compression by bowel may cause early satiety/n/v Chronic, vague abdominal/back pain Severe/sharp/tearing back pain groin pain syncope, paralysis flank mass
Ruptured Triad: Sudden onset midabdominal/flank pain Shock Presence of a pulsatile abdominal mass The diagnosis may be confused with renal calculus,
diverticulitis, incarcerated hernia, or lumbar spine disease.
PEFirm, pulsatile abdominal mass “eggshell” calcification on plain filmu/sCT with IV contrast is most precise
Screening is encouraged for pts with risk factors due to the fact that 33% will rupture if undiagnosed; screening cuts risk of rupture by 49%
Once found, if AAA is more than 4.5cm, continued monitoring every 6 months is recommended
Abdominal ultrasonography: used as prelim. determination of aneurysm presence,
size, type, & extent. CT scanning: helps define anatomy of aneurysm
& other intra-abdominal pathologies. location of the renal arteries length of the aortic neckcondition of the iliac arteriesanatomic variants (e.g. retroaortic left renal vein or
horseshoe kidney) Enhanced spiral CT of abdomen & pelvis with
multiplanar reconstruction & CT angiography is the test of choice for preop eval for open & endovascular repair
Nonenhanced CT scanning is used to size aneurysms.
Reduce Risk factorsSmoking cessation is of paramount importanceAggressively control HTNInstitute beta-blocker tx, when possible, to
reduce BP & stress on the artery wall.Repair if 5cm or more for men. Female pt
unfortunately do not have a predetermined size for repair, although it is agreed that it is smaller than the size recommended for men.
AAA diametre (cm)
Rupture risk (%/y)
<4 0
4-5 o.5-5
5-6 3-15
6-7 10-20
7-8 20-40
>8 30-50
Transperitoneal Approach:Midabdominal incision is made, pertinent
anatomy retracted, aneurysm opened, and graft sutured in place
Retroperitoneal Approach:For pt’s with hostile abdomens (e.g. too many
adhesions)Incision in 10th costal interspace, then on to
similar procedure to TP approach
Prepare the skin from the nipples to the mid thigh.
Administer general anesthesia (with or without epidural anesthesia).
Cell Saver use has become popular.
Place nasogastric tube.T & C blood.
Administer prophylactic antibiotics (cefazolin, 1 g IVPB)
Foley catheterLarge-bore IV access Monitor CVP or
establish Swan-Ganz catheterization (if indicated)
Depending pt's anatomy, the aorta can be reconstructed with:tube graftaortic iliac bifurcation graftAortofemoral bypass
proximal infrarenal control:identify the L renal (patients may have a
retroaortic vein, <5%). Division of L renal vein is usually required to clamp above the renal arteries
inferior mesenteric artery is sacrificedTo prevent colon ischemia, restore at least one
hypogastric (internal iliac) artery perfusionIf hypogastric arteries are sacrificed (associated
aneurysms), reimplant the inferior mesenteric artery
Identification of the ureters is important
Pt is heparinized (5000 U IV) prior to aortic cross-clamping. If significant intraluminal debris, juxtarenal thrombus,
or prior peripheral embolization is present, the distal arteries are clamped first, followed by aortic clamping.
Before restoring lower extremity blood flow, both forward flow (aortic) and back flow (iliac) are allowed to remove debris.
The graft is also irrigated to flush out debris.Before the patient leaves the OR, determine lower
extremity circulation. If a clot was dislodged at the time of aortic clamping,
it can be removed with a Fogarty embolectomy catheter. Heparin reversal is not usually required.
By CatheterisationIntraoperative angiogram performedVery successfulVery low riskBut has distinct complications…
Requires CVP and vent placementCXR to confirm placement of above24 hrs of beta-blockade to keep HR below 80
bpmPeri-operative Abx should be stopped within
the first 24 hrs
Event Percentage of Patients Affected, %
Case Fatality Rate, %
Respiratroy failure 48 34
Tracheostomy 14 44
Renal Failure 29 76
Sepsis 24 45
MI/CHF 24 66
Bleeding 17 90
Stroke 6 50
Ischemic colitis 5 67
Lower extremity ischemia
3 17
Paraplegia/paraparesis
2 50
Death - 50% if ruptured
Pneumonia - 5% MI - 2-5% Groin infxn - <5% Graft infxn - <1% Colon ischemia - 15-
20% if ruptured Blue toe syndrome
and cholesterol embolization to feet
Renal failure related to preoperative creatinine level, intraoperative cholesterol embolization, & hypotension
Incisional hernia - 10-20%
Bowel obstruction
Amputation from major arterial occlusion Impotence in males - Erectile dysfunction and
retrograde ejaculation (>30%) Paresthesias in thighs from femoral exposure
(rare) Lymphocele in groin - Approximately 2% Late graft enteric fistula
Type Causes Tx options
I Inadequate seal of proximal or distal end of endograft
Balloon dilationPlacement of additional stents or cuffsOpen conversion
II Flow from backbleeding aaPt lumbar, mid sacral, inf mesenteric, hypogastric, accessory renal aa
ObservationCoil embolisation or glueLaparoscopic ligationOpen conversion
III Fabric disruption or tearModule disconnection
Placement of additional stents or cuffsSecondary endograft
IV Flow from fabric porosity
observation
Types of aortic
stent grafts and
their locations
for use
Ali Azizzadeh; Martin A. Villa; Charles C. Miller III; Anthony L. Estrera; Sheila M. Coogan; Hazim J. Safi, 11/2008
Thirty-four publications representing 1,200 patients with RAAA analysed. Of the 1,200 patients531 (44.3%) underwent endovascular aneurysm
repair (EVARaverage age was 74 years13% were femaleAortouni-iliac grafts were used in 49.4% of patients50.6% received bifurcated graftstechnical success rate was 94.9%The mortality rate following EVAR of RAAA is 30%3.8% reduction in mortality was found for each 10%
increase in the percentage of ruptures repaired endovascularly at each center
Baseline CT obtained at 3 months postThen 6, 12, and 18 monthsIf leak is more than 5mm, then reintervention
should be considered.
The long-term prognosis is related to associated comorbidities. Long-term survival is shortened by CHF &
COPD.Rupture of assoc. thoracic aneurysms also
causes late death.