Arterial AneurysmsArterial Aneurysms

Definition Definition

Permanent localized dilatation of the Permanent localized dilatation of the affected artery over the normal diameteraffected artery over the normal diameter~ ~ 50%50% ArteriomegalyArteriomegaly

~~ 100% 100% AneurysmsAneurysms

As the age increases, arteries become As the age increases, arteries become stiffer, wider (aneurysm) and longer stiffer, wider (aneurysm) and longer (tortousity)(tortousity)

Aetiology Aetiology

Most by degenerative disease (atherosclerosis) Most by degenerative disease (atherosclerosis) Structural weakness & Haemodynamic forcesStructural weakness & Haemodynamic forces– Damage to, and loss of intimaDamage to, and loss of intima– Reduction in the elastin and collagen content of the Reduction in the elastin and collagen content of the

media media – Collagen; tensile strength, adventitiaCollagen; tensile strength, adventitia– Elastin; recoil capacity, mediaElastin; recoil capacity, media

Risk factorsRisk factors– smoking, hypertension, hypercholesterolaemiasmoking, hypertension, hypercholesterolaemia

AetiologyAetiology

Laplace’s lowLaplace’s low(Tension varies directly with radius when (Tension varies directly with radius when

pressure is constant)pressure is constant)

– For every increase in the radius there is a For every increase in the radius there is a large increase in tension, leading to further large increase in tension, leading to further enlargement of the aneurysmenlargement of the aneurysm

Rare causes of aneurysmsRare causes of aneurysmsCongenitalCongenital– Marfan’s syndromeMarfan’s syndrome((misfolding of the misfolding of the

protein fibrillin-1)protein fibrillin-1), Berry aneurysms, Berry aneurysmsPost-stenoticPost-stenotic– Coarctation of the aorta, Cervical rib, Popliteal artery Coarctation of the aorta, Cervical rib, Popliteal artery

entrapment syndromeentrapment syndromeTraumaticTraumatic– Gunshot, stab wounds, arterial punctures Gunshot, stab wounds, arterial punctures

InflammatoryInflammatory– Takayaso’s diseaseTakayaso’s disease(( is a form of large  is a form of large

vessel granulomatous vasculitis with massive intimal fibrosis and vessel granulomatous vasculitis with massive intimal fibrosis and

vascular narrowingvascular narrowing, Behcet’s disease, Behcet’s disease ( (is a rare immune-is a rare immune-mediated small-vessel systemic vasculitis that often presents mediated small-vessel systemic vasculitis that often presents with mucous membrane ulceration and ocular problems.with mucous membrane ulceration and ocular problems.

Rare causes of aneurysmsRare causes of aneurysms

MycoticMycotic– Bacterial endocarditis, syphilisBacterial endocarditis, syphilis

Pregnancy associatedPregnancy associated– Splenic, cerebral, aortic, renal, iliac & Splenic, cerebral, aortic, renal, iliac &

coronarycoronary

Classification of aneurysmsClassification of aneurysmsWallWall

■ ■ True True

■ ■ False False

MorphologyMorphology■ ■ Fusiform,Saccular,DissectingFusiform,Saccular,Dissecting

AetiologyAetiology■ ■ Atheromatous, Collagen disease,Traumatic, Atheromatous, Collagen disease,Traumatic,

Mycotic (bacterial rather than fungal)Mycotic (bacterial rather than fungal)

Classification Classification

FalseFalse  is when there is a breach in is when there is a breach in the vessel wall such that blood the vessel wall such that blood leaks through the wall but is leaks through the wall but is contained by the adventitia or contained by the adventitia or surrounding perivascular soft surrounding perivascular soft

tissuetissue..TrueTrue– Dilatation involving all Dilatation involving all

layers of the wall layers of the wall

FusiformFusiform– Spindle-shaped Spindle-shaped

involving whole involving whole circumference circumference

SaccularSaccular– Small segment of wall Small segment of wall

ballooning due to ballooning due to localized weaknesslocalized weakness

Incidence- atherosclerotic Incidence- atherosclerotic

>90% affecting abdominal aorta >90% affecting abdominal aorta

Infra-renal segment in Infra-renal segment in ~~95%95%

Male : Female ratioMale : Female ratio 4:14:1

More common in western countriesMore common in western countries

5% over 50s, 15% over 80s5% over 50s, 15% over 80s

Associated with iliac aneurysms in 30%Associated with iliac aneurysms in 30%

Associated with popliteal aneurysms in 10%Associated with popliteal aneurysms in 10%

Classification of Thoracic Aortic AneurysmClassification of Thoracic Aortic Aneurysm

Anatomy of the abdominal aortaAnatomy of the abdominal aorta

Begins at T12, Ends at L4Begins at T12, Ends at L4Anterior relationsAnterior relations– Splenic vein, pancreas, duodenumSplenic vein, pancreas, duodenumRightRight– Cisterna chyli, IVC, azygos veinCisterna chyli, IVC, azygos veinLeftLeft– Sympathetic trunk Sympathetic trunk Surface anatomySurface anatomy– Just above transpyloric plane in the mid line to a point Just above transpyloric plane in the mid line to a point

left to the midline on the supracristal planeleft to the midline on the supracristal plane

branches of the abdominal aortabranches of the abdominal aorta

Paired visceral branchesPaired visceral branches– Suprarenal, renal, gonadalSuprarenal, renal, gonadal

Unpaired visceral branchesUnpaired visceral branches– Coeliac, SMA, IMACoeliac, SMA, IMA

Paired abdominal wall branchesPaired abdominal wall branches– Subcostal, inferior phrenic,lumber Subcostal, inferior phrenic,lumber

Clinical features of AAAClinical features of AAA

Asymptomatic in 75%Asymptomatic in 75%– Incidentally discovered during clinical exam.or Incidentally discovered during clinical exam.or

radiographic investigation radiographic investigation

PainPain– Central abdominal radiating to the back Central abdominal radiating to the back – Chronic due to stretching the vessel wall or Chronic due to stretching the vessel wall or

compression/erosion of surrounding compression/erosion of surrounding structuresstructures

– Acute pain due to ruptureAcute pain due to rupture

Clinical features of AAAClinical features of AAA

RuptureRupture– Risk of rupture ~ aneurysm sizeRisk of rupture ~ aneurysm size– Retroperitoneal 80%, back pain, stableRetroperitoneal 80%, back pain, stable– Intraperitoneal 20%, abdo/back/falnk pain, Intraperitoneal 20%, abdo/back/falnk pain,

shock shock – 5-year rupture rate 0% in AAA <5cm5-year rupture rate 0% in AAA <5cm– 5-year rupture rate 25% in AAA >5cm5-year rupture rate 25% in AAA >5cm

Risk of rupture can be predicted by Risk of rupture can be predicted by – High diastolic BP, COADHigh diastolic BP, COAD

Complications of AAAComplications of AAA

Fistulation, rareFistulation, rare– Gut, IVC, left renal veinGut, IVC, left renal vein

Thrombosis, rareThrombosis, rare– Acute lower limb ischaemiaAcute lower limb ischaemia

Distal embolismDistal embolism– Acute ischaemia to small distal areas (trash Acute ischaemia to small distal areas (trash

foot)foot)

Distal obliterationDistal obliteration– Claudication, rest pain, gangreneClaudication, rest pain, gangrene

Investigation Investigation

CXR, PFTCXR, PFT

ECG, EchoECG, Echo

ESRESR

U&EsU&Es

USSUSS

Spiral CT with contrastSpiral CT with contrast

ArteriographyArteriography

CT ScanCT Scan Spiral CTSpiral CT

AngiographyAngiography

Indications for operation of AAAIndications for operation of AAA

AsymptomaticAsymptomatic■ ■ Aneurysm > 55 mm in APAneurysm > 55 mm in AP

■ ■ Patient fit for surgeryPatient fit for surgery

■ ■ Indications for endoluminal are the same Indications for endoluminal are the same

SymptomaticSymptomaticpainful or tenderpainful or tender

distal embolisationdistal embolisation

Management of AAAManagement of AAA

Elective repair for AAA >6cmElective repair for AAA >6cm– Mortality 5%Mortality 5%

Urgent repair for AAA <6cmUrgent repair for AAA <6cm– Developed back painDeveloped back pain– Rate of growth >0.5cm / 6 month Rate of growth >0.5cm / 6 month

Emergency repair for ruptured AAAEmergency repair for ruptured AAA– Mortality 50%Mortality 50%

Elective surgical repairElective surgical repair

6-unit X-matched blood6-unit X-matched bloodMid line or transverse incisionMid line or transverse incisionAneurysm neck defined and controlledAneurysm neck defined and controlledControl of normal vessels distal to AAAControl of normal vessels distal to AAASystemic heparinization, 5000IUSystemic heparinization, 5000IUAAA sac opened and thrombus removedAAA sac opened and thrombus removedBack bleeding from lumber arteries controlled by Back bleeding from lumber arteries controlled by suturessuturesInlay tube or trouser synthetic graftInlay tube or trouser synthetic graftClosure of aneurysm sac over graftClosure of aneurysm sac over graft

Emergency surgical repairEmergency surgical repair

Unstable patient, no investigationUnstable patient, no investigationStable patient, USS/spiral CTStable patient, USS/spiral CT10-unit of x-matched blood10-unit of x-matched bloodUrinary catheter & 2 large-bore i.v. linesUrinary catheter & 2 large-bore i.v. linesResustation to systolic BP Resustation to systolic BP ~100mmHg~100mmHgCrash anaesthetic inductionCrash anaesthetic inductionNo heparinizationNo heparinizationRapid entrance to abdomen & neck controlRapid entrance to abdomen & neck control– If difficult, supra-renal clamp for short period If difficult, supra-renal clamp for short period

Complications of aortic surgeryComplications of aortic surgery

Haemorrhage, DICHaemorrhage, DICCVACVAColonic ischaemia spinal cord ischaemiaColonic ischaemia spinal cord ischaemiaAorto-enteric fistulaAorto-enteric fistulaGraft thrombosisGraft thrombosisMyocardial ischaemiaMyocardial ischaemiaRenal failure, ARDS, MODSRenal failure, ARDS, MODSFalse anastomotic aneurysmFalse anastomotic aneurysmDistal embolism (trash foot)Distal embolism (trash foot)

Endovascular repair of AAAEndovascular repair of AAA

Patient unfit for surgical repair Patient unfit for surgical repair – severe cardio-pulmonary co-morbidities, hours shoe severe cardio-pulmonary co-morbidities, hours shoe

kidney, Inflammatory AAA, hostile abdo.kidney, Inflammatory AAA, hostile abdo.

Anatomical suitabilityAnatomical suitability– Neck diameter & length Neck diameter & length – Iliac arteries diameter & tortousity Iliac arteries diameter & tortousity

Morbidity Morbidity – Endoleak, migration, kink, thrombosisEndoleak, migration, kink, thrombosis

Mortality Mortality ~5%~5%

Flow-up & durabilityFlow-up & durability

Inflammatory AAAInflammatory AAA

Marked fibrosis of the aneurysm wall extending to the Marked fibrosis of the aneurysm wall extending to the surrounding structuressurrounding structures

It involve the anterior and lateral aspects onlyIt involve the anterior and lateral aspects only

It associated with inflammatory cell infiltrate of T- , B-It associated with inflammatory cell infiltrate of T- , B-lymphocytes & plasma cellslymphocytes & plasma cells

The fibrosis may compress the ureters leading to renal The fibrosis may compress the ureters leading to renal failurefailure

Rupture is less common and usually posteriorRupture is less common and usually posterior

Pt. presents with abdo. pain, weight loss, raised ESRPt. presents with abdo. pain, weight loss, raised ESR

Difficult surgery, therefore conservative/endovascularDifficult surgery, therefore conservative/endovascular

popliteal aneurysmspopliteal aneurysms

Second most common site of atherosclerotic Second most common site of atherosclerotic aneurysms (70 % peripheral, 2/3 B/L)aneurysms (70 % peripheral, 2/3 B/L)

C/FC/F– pulsatile swellingpulsatile swelling– aneurysm thrombosis aneurysm thrombosis or or distal distal emboliemboli

USS/CT/Arteriography to confirm diagnosisUSS/CT/Arteriography to confirm diagnosis

40% of pts with PA aneurysms have an AAA40% of pts with PA aneurysms have an AAA

IndicationIndication– ComplicationComplication– Asymptomatic Size > 25 mm Asymptomatic Size > 25 mm

RxRx– Surgical repair, resection/ligation and vein Surgical repair, resection/ligation and vein

bypassbypass

Femoral aneurysmsFemoral aneurysms

Can occur in isolation but usually part of Can occur in isolation but usually part of generalized arteriomegalygeneralized arteriomegaly

Often symptomless and rarely ruptureOften symptomless and rarely rupture

Distal emboli & thrombosis may occurDistal emboli & thrombosis may occur

Surgical repair by using vein or synthetic graft Surgical repair by using vein or synthetic graft

Splenic aneurysmsSplenic aneurysms

Male : female 1 : 4Male : female 1 : 4

It present in child bearing periodIt present in child bearing period

Usually symptomless unless rupturedUsually symptomless unless ruptured

Rupture rate 25% in the third trimesterRupture rate 25% in the third trimester

Surgical treatment is indicated if the Surgical treatment is indicated if the aneurysm diameter >3cm or patient is aneurysm diameter >3cm or patient is pregnantpregnant

1- AAA1- AAA

A- is 4 time more common in malesA- is 4 time more common in males

B- incidence is falling in western countriesB- incidence is falling in western countries

C- may safely observed if asymptomatic and C- may safely observed if asymptomatic and >5.5cm in diameter>5.5cm in diameter

D- is rarely amenable to endoluminal stentingD- is rarely amenable to endoluminal stenting

E- is less common than popliteal aneurysms E- is less common than popliteal aneurysms

2- AAA2- AAA

A- may cause embolisation to lower limbsA- may cause embolisation to lower limbs

B- is more common in malesB- is more common in males

C- can almost always be treated by C- can almost always be treated by endovascular stentingendovascular stenting

D- can be detected by screeningD- can be detected by screening

E- should be operated upon when it is 5.5 cm E- should be operated upon when it is 5.5 cm longlong

3- AAA3- AAA

A- typically rupture at 4cm diameterA- typically rupture at 4cm diameter

B- extends above the renal artery in 20% of B- extends above the renal artery in 20% of casescases

C- is invariably visible on abdominal X-rayC- is invariably visible on abdominal X-ray

D- is associated with coronary artery diseaseD- is associated with coronary artery disease

E- has an association with smokingE- has an association with smoking

answersanswers

1- A1- A

2- ABD2- ABD

3- DE3- DE