Anesthesia Anesthesia management for management for Abdominal Aortic Abdominal Aortic

AneurysmsAneurysms Dr. Abhijit NairDr. Abhijit Nair

Consultant Anesthesiologist,Consultant Anesthesiologist,

Care Hospital, Hyderabad.Care Hospital, Hyderabad.

Popularly called AAAPopularly called AAA Its a localized dilatation (ballooning)Its a localized dilatation (ballooning)

of the abdominal aorta exceeding of the abdominal aorta exceeding

the normal diameter by more than 50 %the normal diameter by more than 50 % 90% occur infrarenally90% occur infrarenally Can occur suprarenally, pararenallyCan occur suprarenally, pararenally

Causes:Causes: Cigarette smokingCigarette smoking Genetic factors –Genetic factors –

alpha1 antitrypsin deficiency , alpha1 antitrypsin deficiency ,

Marfans syndrome, Marfans syndrome,

Ehler Danlos syndromeEhler Danlos syndrome AtherosclerosisAtherosclerosis Others :Others :

Infection, trauma, Infection, trauma,

arteritis, cystic medial necrosisarteritis, cystic medial necrosis

The prevalence of AAAs (aortic diameter 30 mm) in chronic smokers is > four times that in lifelong non-smokers

the average rate of aneurysm growth in

smokers is 2.8 mm per

year versus 2.5 mm per

year in non-smokers

PathogenesisPathogenesis No unified conceptNo unified concept Genetic, biochemical, Genetic, biochemical,

metabolic, infectious,metabolic, infectious,

mechanical & haemodynamic mechanical & haemodynamic

factorsfactors Adventitial elastin degradation Adventitial elastin degradation

is the primary event leading to is the primary event leading to

connective tissue destruction connective tissue destruction

in the aortic wallin the aortic wall

Guidelines & Guidelines & recommendationsrecommendations

By By Kaiser PermanenteKaiser Permanente for AAA with USG in for AAA with USG in general population:general population:

One-time screening for AAA by USG One-time screening for AAA by USG recommended in men aged 65 to 75 yearsrecommended in men aged 65 to 75 years

Routine screening for AAA in women is not Routine screening for AAA in women is not recommendedrecommended

It is an option to limit AAA screening to men aged It is an option to limit AAA screening to men aged 65 to 75 years who have never smoked65 to 75 years who have never smoked

ct:ct: With family history of AAA:With family history of AAA: For men aged 50 and older with a known positive For men aged 50 and older with a known positive

family history of aortic aneurysm in a first-degree family history of aortic aneurysm in a first-degree relative, AAA screening is recommendedrelative, AAA screening is recommended

The guideline development team makes no The guideline development team makes no recommendation for or against screening women recommendation for or against screening women with a positive family history of AAAwith a positive family history of AAA

(Kaiser Permanente Care Management Institute. (Kaiser Permanente Care Management Institute. Abdominal aortic aneurysm (AAA) Abdominal aortic aneurysm (AAA) screening clinical practice guidelinescreening clinical practice guideline. Oakland, California: Kaiser Permanente Care . Oakland, California: Kaiser Permanente Care Management Institute; Apr 2009:37 p)Management Institute; Apr 2009:37 p)

A clinical practice guidelines by the US Preventive A clinical practice guidelines by the US Preventive Services Task Force recommends one-time Services Task Force recommends one-time screening for AAA by USG in men age 65 to 75 screening for AAA by USG in men age 65 to 75 years who have ever smokedyears who have ever smoked

This is a grade B recommendationThis is a grade B recommendation

In US, effective January 1, 2007, provisions of In US, effective January 1, 2007, provisions of

SAAAVESAAAVE Act ( Act (Screening Abdominal Aortic Screening Abdominal Aortic

Aneurysm Very EfficientlyAneurysm Very Efficiently) provides a free, one-) provides a free, one-

time, USG AAA screening benefit for qualified time, USG AAA screening benefit for qualified

seniorsseniors Men who have smoked at least Men who have smoked at least

100 cigarettes during their life, 100 cigarettes during their life,

and men and women with a and men and women with a

family history of AAA qualifyfamily history of AAA qualify

for one-time USG screeningfor one-time USG screening

History:History: Antyllus, a Greek Surgeon in 2Antyllus, a Greek Surgeon in 2ndnd century AD tried to century AD tried to

treat AAA with proximal & distal ligature, central treat AAA with proximal & distal ligature, central incision & removal of thrombotic material incision & removal of thrombotic material

Rudolf Matas performed the 1Rudolf Matas performed the 1stst successful aortic successful aortic ligation in humansligation in humans

He also proposed the theory of He also proposed the theory of endoaneurysmorraphyendoaneurysmorraphy

Albert Einstein was operated Albert Einstein was operated

by Rudolf Nissen in 1949by Rudolf Nissen in 1949 The method : The method :

wrapping of aorta with wrapping of aorta with

polythene cellophane which polythene cellophane which

induced fibrosis and induced fibrosis and

restricted aneurysm growthrestricted aneurysm growth

EVAR was performed in late 1980sEVAR was performed in late 1980s

Classification:Classification:

Crawford classification of thoraco-abdominal Crawford classification of thoraco-abdominal aneurysm :-aneurysm :-

I. Starts below the subclavian artery origin and endsI. Starts below the subclavian artery origin and ends above the renal arteryabove the renal arteryII. Entire descending thoracic aorta up to theII. Entire descending thoracic aorta up to the bifurcationbifurcationIII. Starts at distal thoracic aorta and also involve theIII. Starts at distal thoracic aorta and also involve the abdominal aortaabdominal aortaIV. Confined to upper abdominal aortaIV. Confined to upper abdominal aorta

ManagementManagement Conservative:Conservative:

High risk patientsHigh risk patients, ,

repair carries a high risk of repair carries a high risk of

mortality, in patients where mortality, in patients where

repair is unlikely to improverepair is unlikely to improve

life expectancylife expectancy Surveillance: with a view to eventual repairSurveillance: with a view to eventual repair Repair: if the aneurysm grows more than 1 cm per Repair: if the aneurysm grows more than 1 cm per

year or it is bigger than 5.5 cm , symptomatic AAAyear or it is bigger than 5.5 cm , symptomatic AAA OpenOpen EVAREVAR

Medical management:Medical management:

Aggressive BP control: Beta blockers!Aggressive BP control: Beta blockers! AntiplateletsAntiplatelets StatinsStatins 6 monthly USG6 monthly USG Cessation of smokingCessation of smoking

Evaluation of aneurysmEvaluation of aneurysm

Symptoms of aneurysmSymptoms of aneurysm Site & size of aneurysmSite & size of aneurysm ExtentExtent

Pre-op considerationsPre-op considerations

• • Aortic disease is indicative of other vascular disease Aortic disease is indicative of other vascular disease AAA surgery has high risk of periop myocardial AAA surgery has high risk of periop myocardial

ischemia.. ischemia..

» Coronary artery disease. » Coronary artery disease.

– – MIMI

– – Stable or unstable anginaStable or unstable angina

– – LV dysfunction/CHFLV dysfunction/CHF

– – Atrial fibrillationAtrial fibrillation

– – Arrhythmias; Arrhythmias;

Pacemakers in situ!Pacemakers in situ!

» Peripheral vascular disease» Peripheral vascular disease

» Carotid artery disease:» Carotid artery disease:

always listen for carotid bruits & ask about always listen for carotid bruits & ask about TIA/CVA symptomsTIA/CVA symptoms

Other co morbidities:Other co morbidities:

» COPD» COPD » HTN» HTN » DM » DM perioperative insulin perioperative insulin » Renal dysfunction » Renal dysfunction Often exacerbated by Often exacerbated by periop angiograms,periop angiograms, IV contrastIV contrast NAC may helpNAC may help

Drug issues:Drug issues:» To continue cardiac medications » To continue cardiac medications up to & including day of surgeryup to & including day of surgery

» Continuation of ACE inhibitors » Continuation of ACE inhibitors is controversial; is controversial; associated with severe hypotension associated with severe hypotension during GAduring GA

» Diuretics may be held on the» Diuretics may be held on the morning of surgerymorning of surgery

» withhold morning insulin» withhold morning insulin

» Patients are often taking » Patients are often taking anticoagulation or antiplatelet agentsanticoagulation or antiplatelet agents

CoumadinCoumadin: : generally discontinued 7 days generally discontinued 7 days prior to procedure; bridge therapy prior to procedure; bridge therapy with LMWH may be necessary depending with LMWH may be necessary depending (eg, DVT, heart valve)(eg, DVT, heart valve)

ASA: ASA: discontinue 5 days prior to surgerydiscontinue 5 days prior to surgery ClopidogrelClopidogrel : : discontinue 7 days prior to surgerydiscontinue 7 days prior to surgery TiclopidineTiclopidine: : discontinue 7 days prior to surgerydiscontinue 7 days prior to surgery

Physical findingsPhysical findings::

Neck: Neck:

Carotid bruits,Carotid bruits,

Increased JVPIncreased JVP

PulmonaryPulmonary : : WheezesWheezes RalesRales RhonchiRhonchi Distant breath soundsDistant breath sounds Barrel chest Barrel chest

Cardiovascular :Cardiovascular :

Check for regular vs irregular rhythmCheck for regular vs irregular rhythm Presence of S3 or S4Presence of S3 or S4 MurmursMurmurs Displaced apical impulseDisplaced apical impulse

» Abdomen » Abdomen BruitsBruits Pulsatile massesPulsatile masses ObesityObesity

» Extremities » Extremities Diminished/absent lower Diminished/absent lower

extremity pulsesextremity pulses Nonhealing ulcersNonhealing ulcers Distal embolic phenomenaDistal embolic phenomena

Work up:Work up: Functional status/ exercise tolerance :Functional status/ exercise tolerance :

severity of cardiopulmonary statusseverity of cardiopulmonary status

ECG ECG TTE, TEETTE, TEE DSEDSE Thallium scanningThallium scanning CAGCAG

Carotid USG Carotid USG

( H/o stroke/ TIA )( H/o stroke/ TIA )

PFT/ ABG :PFT/ ABG :

in pts with moderate to in pts with moderate to

severe pulmonary disease severe pulmonary disease

PFTs may help guide preop PFTs may help guide preop

medical therapy for optimal medical therapy for optimal

pulmonary status & estimate risk pulmonary status & estimate risk

LABSLABS CBCCBC BUN, creatinineBUN, creatinine PT/PTTPT/PTT Electrolytes for pts on diuretics, ACE inhibitors, or Electrolytes for pts on diuretics, ACE inhibitors, or

history of renal insufficiency or failurehistory of renal insufficiency or failure HbAIcHbAIc

Surgeon orders Surgeon orders CT scan with contrast or CT scan with contrast or MRA to evaluate :MRA to evaluate : the extent of the aortic disease,the extent of the aortic disease, position [infra- or suprarenal], position [infra- or suprarenal], diameter, diameter, involvement of mesenteric involvement of mesenteric vesselsvessels

Intra op:Intra op: ECG : II, V5, V6 with ST analysisECG : II, V5, V6 with ST analysis ABP, CVPABP, CVP Two large-bore peripheral IVs Two large-bore peripheral IVs

(or central introducer sheath) (or central introducer sheath) Additional monitors: Additional monitors: TEE, PACTEE, PAC Thromboelastography:Thromboelastography:

demonstrates both hypercoagulability and fibrinolysis, which are frequently

underestimated with conventional coagulation tests

Intraop concerns:Intraop concerns: Maintenance of hemodynamic stability:Maintenance of hemodynamic stability:

» Close titration of IV » Close titration of IV

& inhalation agents : & inhalation agents :

emphasis on hemodynamic emphasis on hemodynamic

stability, not speed of onsetstability, not speed of onset

» Thiopental, propofol, etomidate, » Thiopental, propofol, etomidate,

narcotics, benzodiazepines, narcotics, benzodiazepines,

inhalationals used successfullyinhalationals used successfully

Esmolol & nitroglycerin may be useful for Esmolol & nitroglycerin may be useful for hemodynamic mgt of hypertension/tachycardiahemodynamic mgt of hypertension/tachycardia

Esmolol or opioids may be necessary to blunt the Esmolol or opioids may be necessary to blunt the pt's response to tracheal intubationpt's response to tracheal intubation

Maintaining HR & MAP within 20% of baseline is Maintaining HR & MAP within 20% of baseline is generally appropriate; agents should be readily generally appropriate; agents should be readily available available

Muscle relaxation is necessary for surgical Muscle relaxation is necessary for surgical exposure/ conditionsexposure/ conditions

Obtain baseline ABG & ACTObtain baseline ABG & ACT

Keep blood products in the OR Keep blood products in the OR

in case of significant hemorrhagein case of significant hemorrhage

Avoid hypothermia by Avoid hypothermia by

warming IV fluids & warming IV fluids &

using forced air warmingusing forced air warming

Cross clamp!Cross clamp! Cross-clamping of the aorta : significant cardiac Cross-clamping of the aorta : significant cardiac

stressstress » Acute left ventricular strain produces a major » Acute left ventricular strain produces a major

cardiovascular stress; magnitude is related to clamp cardiovascular stress; magnitude is related to clamp position position

MAP may increase only 2% with infrarenal MAP may increase only 2% with infrarenal 5% with suprarenal5% with suprarenal up to 54% with supraceliac placementup to 54% with supraceliac placement

Preload & afterload may increase Preload & afterload may increase Ejection fraction may decrease.Ejection fraction may decrease. This may lead to myocardial ischemia in pts This may lead to myocardial ischemia in pts

with significant CADwith significant CAD

Mgt of hemodynamic changes with aortic cross-Mgt of hemodynamic changes with aortic cross-clampclamp: :

» NTG, beta blockers and/or sodium nitroprusside » NTG, beta blockers and/or sodium nitroprusside

» Increasing anesthetic depth » Increasing anesthetic depth

» Anticipation of the increase in SVR is important» Anticipation of the increase in SVR is important

» Some vascular surgeons clamp the iliac arteries first to » Some vascular surgeons clamp the iliac arteries first to prevent distal embolization due to the aortic clamp prevent distal embolization due to the aortic clamp

Other changes with aortic cross-clamp :Other changes with aortic cross-clamp : » Ischemia/ hypoperfusion of the kidneys, » Ischemia/ hypoperfusion of the kidneys,

abdominal viscera, spinal cord, limbabdominal viscera, spinal cord, limb » Accumulation of acid metabolites in tissues » Accumulation of acid metabolites in tissues

& vasculature below the level of the clamp& vasculature below the level of the clamp

Anticipation of clamp removal is important. Anticipation of clamp removal is important.

» Prior to clamp removal, increase preload. » Prior to clamp removal, increase preload.

increasing the PCWP (if PAC used) by 3-4 mmHg increasing the PCWP (if PAC used) by 3-4 mmHg above baselineabove baseline

» Discontinue agents such as NTG, nitroprusside & » Discontinue agents such as NTG, nitroprusside & esmolol esmolol

» Don’t decrease anesthetic depth » Don’t decrease anesthetic depth

» Agents such as phenylephrine, ephedrine & » Agents such as phenylephrine, ephedrine & epinephrine can be usedepinephrine can be used

Raising BP 20-30% above baseline with such agents Raising BP 20-30% above baseline with such agents prior to clamp release is often necessary to avoid prior to clamp release is often necessary to avoid significant hypotensionsignificant hypotension

Duration & location of the aortic clamp determine Duration & location of the aortic clamp determine the degree of hypotension observedthe degree of hypotension observed

A supraceliac clamp can result in significant bowel A supraceliac clamp can result in significant bowel & liver ischemia; decrease in SVR & CO after & liver ischemia; decrease in SVR & CO after release of such a clamp can be significantrelease of such a clamp can be significant

• • Upon unclamping, acidic metabolites from the Upon unclamping, acidic metabolites from the ischemic tissues below the clamp are washed back ischemic tissues below the clamp are washed back into the circulation into the circulation

» Make prophylactic ventilatory adjustments to » Make prophylactic ventilatory adjustments to accommodate this increased acid loadaccommodate this increased acid load

» Frequent ABGs» Frequent ABGs » buffer therapy withbicarbonate or THAM ( trome » buffer therapy withbicarbonate or THAM ( trome

Thiamine 0.3M)Thiamine 0.3M) » After unclamping, reverse heparin» After unclamping, reverse heparin

Discuss timing of reversal with surgeon.Discuss timing of reversal with surgeon.

Post op:Post op: ICU care, intubated & careful cardiac monitoringICU care, intubated & careful cardiac monitoring RewarmingRewarming Watch for bleedingWatch for bleeding Urine output!Urine output!

Aggressive pain management:Aggressive pain management: Epidural LA &/or narcotics,Epidural LA &/or narcotics, IV Narcotics,IV Narcotics, Avoid NSAIDs please!Avoid NSAIDs please! PCAPCA

* increased pain & anxiety * increased pain & anxiety catecholamine release catecholamine release increased myocardial oxygen demand & ischemia increased myocardial oxygen demand & ischemia

With good pain relief, recovery of pulmonary function With good pain relief, recovery of pulmonary function is improved is improved

Epidural Analgesia Reduces Postoperative Myocardial Infarction: A Meta-Analysis

(Beattie WS et al., Anesthesia analgesia 2001, 93 (4)853-8)

Renal insufficiency:Renal insufficiency: Incidence : 20-25%Incidence : 20-25% Renal medulla more susceptibleRenal medulla more susceptible

The pathogenesis is multifactorial:The pathogenesis is multifactorial: Preoperative renal functionPreoperative renal function The use of nephrotoxic drugs, The use of nephrotoxic drugs,

contrast mediumcontrast medium EmbolicEmbolic

HypotensionHypotension Ligation of the left renal vein during the Ligation of the left renal vein during the

procedureprocedure Temporary suprarenal aortic clamping Temporary suprarenal aortic clamping renal ischemia, renal ischemia, if limb ischemia if limb ischemia muscle necrosis and muscle necrosis and

myoglobinuria myoglobinuria acute tubular necrosisacute tubular necrosis

Renal protectionRenal protection Maintain adequate intravascular volumeMaintain adequate intravascular volume Maintain COMaintain CO Use endovascular techniqueUse endovascular technique Avoid nephrotoxinsAvoid nephrotoxins

NSAIDs, aminoglycosides, NSAIDs, aminoglycosides,

ACE inhibitors, ARBsACE inhibitors, ARBs Cross clamp time <50 minCross clamp time <50 min Other techniquesOther techniques

Mannitol, loop diuretics, Mannitol, loop diuretics,

Fenoldopam,low dose dopamine!?Fenoldopam,low dose dopamine!?

Myocardial protection:Myocardial protection: Preop use of β-BlockerPreop use of β-Blocker Preop statinsPreop statins Endovascular vs open techniqueEndovascular vs open technique Reduce blood pressure before X clampReduce blood pressure before X clamp SNP to unload heart & reduce wall tensionSNP to unload heart & reduce wall tension

Ruptured AAA!Ruptured AAA! Very fatalVery fatal overall mortality rate : 65%overall mortality rate : 65% Mortality rate for patients Mortality rate for patients

who survive to reach hospital who survive to reach hospital

& undergo emergency surgery : 36%,& undergo emergency surgery : 36%, 6% for elective repair6% for elective repair

Mortality if ruptured:

Before reaching the hospital : 27 – 50% In hospital mortality before operation: 24 – 58% Perioperative mortality : 42 – 80% Overall mortality about 80%

The risk of spontaneous rupture depends on aneurysm size

<1% per annum for AAA <55 mm diameter >17% per annum for aneurysms >60 mm diameter

Distribution sites of AAA rupture:Distribution sites of AAA rupture:

Right lateral wall - 28% Right lateral wall - 28% Pelvic arteries - 22% Pelvic arteries - 22% Posterior wall - 19% Posterior wall - 19% Left lateral wall - 17% Left lateral wall - 17% Anterior wall - 10% Anterior wall - 10% Suprarenal - 4%Suprarenal - 4% (Stavropoulos SW, Charagundla SR. Imaging techniques for detection and (Stavropoulos SW, Charagundla SR. Imaging techniques for detection and

management of endoleaks after endovascular aortic aneurysm management of endoleaks after endovascular aortic aneurysm repair. repair. RadiologyRadiology. Jun 2007;243(3):641-55. Jun 2007;243(3):641-55 ) )

Estimated Annual rupture riskEstimated Annual rupture risk

Risk stratification:Risk stratification: Several scoring systems availableSeveral scoring systems available scoring systems have their limitations scoring systems have their limitations should only be used to supplement clinical judgmentshould only be used to supplement clinical judgment May be used to compare results from different May be used to compare results from different

centrescentres POSSUMPOSSUM ( ( PPhysiological & hysiological & OOperative perative SSeverity everity

SScore for encore for enUUmeration of meration of MMorbidity & orbidity & MMortality )ortality ) APACHE IIAPACHE II Hardman IndexHardman Index Glasgow Aneurysm scoreGlasgow Aneurysm score

Hardman Index!Hardman Index!

PointsPoints

11 Age> 76Age> 76

11 Creat > 190 umol/LCreat > 190 umol/L

11 Hb < 9gm%Hb < 9gm%

11 MI on ECGMI on ECG

11 H/o LOC on hospital arrivalH/o LOC on hospital arrivalHardman index: 1 point is assigned for each preoperative variable present, so the possible score ranges from 0–5. A total score of 2 is consistent with a mortality rate of 80%.

Glasgow Aneurysm Score(GAS)Glasgow Aneurysm Score(GAS)

PointsPoints

Age of patientAge of patient

( point= no. of yrs)( point= no. of yrs)

1717 ShockShock

77 Myocardial diseaseMyocardial disease

1010 Cerebrovascular diseaseCerebrovascular disease

1414 Renal diseaseRenal disease

Recent data suggest that the GAS is useful in Recent data suggest that the GAS is useful in predicting postoperative mortality in both elective predicting postoperative mortality in both elective and emergency AAA repairand emergency AAA repair

postoperative mortality was 1.4% in patients with a postoperative mortality was 1.4% in patients with a GAS of 78.8 and 8.7% in those with a GAS of 78.8 GAS of 78.8 and 8.7% in those with a GAS of 78.8 following elective repairfollowing elective repair

(Biancari F, Leo E, Ylo¨nen K, Vaarala MH, Rainio P, Juvonen T. Value of the Glasgow Aneurysm Score in (Biancari F, Leo E, Ylo¨nen K, Vaarala MH, Rainio P, Juvonen T. Value of the Glasgow Aneurysm Score in predicting the immediate and longterm outcome after elective open repair of infrarenal abdominal aortic predicting the immediate and longterm outcome after elective open repair of infrarenal abdominal aortic aneurysm. Br J Surg 2003; 90: 838–44)aneurysm. Br J Surg 2003; 90: 838–44)

Predictors of early mortalityPredictors of early mortality

Loss of consciousness in hospital,Loss of consciousness in hospital, Cardiac arrest,Cardiac arrest, Systolic BP < 80 mm hgSystolic BP < 80 mm hg

Surgical complicationsSurgical complications

lumbar muscle rhabdomyolysis,lumbar muscle rhabdomyolysis, anastomotic bleeding, anastomotic bleeding, coagulopathy, coagulopathy, renal dysfunction/failure, renal dysfunction/failure, visceral ischemia & infarction, ileusvisceral ischemia & infarction, ileus lower extremity ischemia/emboli, lower extremity ischemia/emboli, spinal cord ischemia/injury spinal cord ischemia/injury

The incidence of spinal cord injury is reported to be The incidence of spinal cord injury is reported to be 0.15% in unruptured AAA repair 0.15% in unruptured AAA repair

The artery of Adamkiewicz arises from above L3 in The artery of Adamkiewicz arises from above L3 in most people most people

clamping at or above this level increases the risk of clamping at or above this level increases the risk of spinal cord injury spinal cord injury

Spinal cord protection:Spinal cord protection: Paraplegia results from : prolonged spinal cord ischemia, disruption or embolization of radicular blood supply during aneurysm repair ( usually TAA/ TAAA)

Prevention: Steroids, magnesium, intrathecal papaverine injection,epidural cooling, systemic hypothermia

Most common :- Most common :- LUMBAR DRAIN!LUMBAR DRAIN!

Patients are particularly prone to developing intra-Patients are particularly prone to developing intra-abdominal hypertension (intra-abdominal pressure abdominal hypertension (intra-abdominal pressure > 12 mmHg) and abdominal compartment syndrome > 12 mmHg) and abdominal compartment syndrome (ACS, defined as IAP 20 mmHg)(ACS, defined as IAP 20 mmHg)

Factors causing ACS:Factors causing ACS:

prolonged hypotension,prolonged hypotension, cardiopulmonary resuscitation,cardiopulmonary resuscitation, hypothermia,hypothermia, severe acidosis (base deficit < 14 mEq),severe acidosis (base deficit < 14 mEq), Aggressive fluid resuscitation Aggressive fluid resuscitation Prolonged ileusProlonged ileus

Consider laparastoma or mesh closure of the Consider laparastoma or mesh closure of the abdominal wall with delayed secondary surgical abdominal wall with delayed secondary surgical closure after 2–3 daysclosure after 2–3 days

Mesh closure : reduces the incidence of multiorgan Mesh closure : reduces the incidence of multiorgan failure when compared with patients who require a failure when compared with patients who require a second operation for ACS in the postoperative second operation for ACS in the postoperative periodperiod

Monitoring of IAP should be considered in all Monitoring of IAP should be considered in all patients and consideration given to parenteral patients and consideration given to parenteral nutrition if ileus is prolongednutrition if ileus is prolonged

Surgical concernsSurgical concerns

• • Aneurysm rupture prior to cross-clamp Aneurysm rupture prior to cross-clamp placementplacement

Aneurysmal involvement of renal or Aneurysmal involvement of renal or mesenteric arteriesmesenteric arteries

Duration of cross-clamping & consequent Duration of cross-clamping & consequent ischemiaischemia

Renal ischemia & consequent dysfunctionRenal ischemia & consequent dysfunction Spinal cord ischemiaSpinal cord ischemia

Advantages & disadvantages of Advantages & disadvantages of EVAREVAR

Anesthetic technique in EVAR:Anesthetic technique in EVAR: LA,LA, GA ( LMA, ETT),GA ( LMA, ETT), Regional ( SAB, Epidural, CSE )Regional ( SAB, Epidural, CSE ) There is no evidence to suggest that outcome is There is no evidence to suggest that outcome is

better/ worse with any of the type of anesthesia better/ worse with any of the type of anesthesia managementmanagement

Complication of EVAR:Complication of EVAR:( device related )( device related )

Graft migration,Graft migration, Graft kinking,Graft kinking, EndoleakEndoleak STABLE PROXIMAL FIXATION :STABLE PROXIMAL FIXATION :

key to prevent above complicationkey to prevent above complication

Procedure relate EVAR Procedure relate EVAR complications:complications:

Dissection, Dissection, malpositioning, malpositioning, renal failure, renal failure, thromboembolizaton, thromboembolizaton, Ischemic colitis, Ischemic colitis, Groin hematoma, Groin hematoma, wound infection wound infection

Systemic complications of EVAR:Systemic complications of EVAR:

Myocardial infarction,Myocardial infarction, congestive heart failure,congestive heart failure, arrhythmias,arrhythmias, respiratory failure,respiratory failure, renal failurerenal failure

StatisticsStatistics Conversion of EVAR to open: 1.9 - 4.8%Conversion of EVAR to open: 1.9 - 4.8% Periop mortality in EVAR: 1.2%Periop mortality in EVAR: 1.2%

in open : 4.8%in open : 4.8% Late mortality:Late mortality:

rupture with EVAR : 1.8%rupture with EVAR : 1.8%

in open : 0.5%in open : 0.5% Laparotomy related complications:Laparotomy related complications:

in EVAR : 8.1%in EVAR : 8.1%

in open : 14.2%in open : 14.2%(Endovascular vs open repair of AAAs in Medicare population. Schermerhan etal. N Engl J Med 2008; 358: 464-74.)

ConclusionConclusion As compared with open repair, EVAR of AAA is

associated with lower short-term rates of death and complications

The survival advantage is more durable among older patients

Late reinterventions related to AAA are more common after endovascular repair

but are balanced by an increase in laparotomy-related reinterventions and hospitalizations after open surgery

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