Visceral Ischemic Visceral Ischemic SyndromesSyndromesNovember 8, 2012November 8, 2012

Vascular AnatomyVascular Anatomy

Celiac axisCeliac axis Found at T12-L1 between diaphragmatic Found at T12-L1 between diaphragmatic

cruracrura Origin encased in median arcuate ligamentOrigin encased in median arcuate ligament Branches include hepatic artery, splenic Branches include hepatic artery, splenic

artery, and left gastric arteryartery, and left gastric artery Variants include Variants include

Right hepatic from SMA in 15%Right hepatic from SMA in 15% Left hepatic from left gastric in 12%Left hepatic from left gastric in 12% Combined celiac-SMA in 1%Combined celiac-SMA in 1%

Vascular AnatomyVascular Anatomy

SMASMA Arises at level of L1-L2Arises at level of L1-L2 Supplies small intestine to mid-transverse Supplies small intestine to mid-transverse

coloncolon Passes behind neck of pancreas, over Passes behind neck of pancreas, over

uncinate process, and over the 3rd portion of uncinate process, and over the 3rd portion of the duodenumthe duodenum

First branch inferior pancreaticoduodenalFirst branch inferior pancreaticoduodenal Most common site of mesenteric arterial Most common site of mesenteric arterial

embolus embolus

Vascular AnatomyVascular Anatomy

IMAIMA Arises at the level of L3 8-10cm distal to SMAArises at the level of L3 8-10cm distal to SMA Supplies remainder of the colon and proximal Supplies remainder of the colon and proximal

rectumrectum Collateral circulationCollateral circulation

CA and SMA communicate via the PDACA and SMA communicate via the PDA SMA and IMA via the Arc of Riolan and SMA and IMA via the Arc of Riolan and

marginal arteries of Drummondmarginal arteries of Drummond

Acute Mesenteric IschemiaAcute Mesenteric Ischemia

EtiologiesEtiologies Embolization (50%)Embolization (50%) Thrombosis (20%)Thrombosis (20%) NOMI (20%)NOMI (20%) Venous thrombosis (10%)Venous thrombosis (10%) Takayasu’sTakayasu’s FMDFMD PANPAN DissectionDissection

EmbolizationEmbolization

Most originate in left atrium, ventricular Most originate in left atrium, ventricular mural thromus, or valvular lesionsmural thromus, or valvular lesions

Most lodge in SMA due to parallel courseMost lodge in SMA due to parallel course 15% remain impacted at the origin15% remain impacted at the origin Most progress 3-10 cm leading to sparing Most progress 3-10 cm leading to sparing

of proximal jejunumof proximal jejunum 10-15% associated with other embolus to 10-15% associated with other embolus to

alternative arterial bedalternative arterial bed

ThrombosisThrombosis

Most patients have historyMost patients have history Food fearFood fear Postprandial painPostprandial pain Weight lossWeight loss

Atherosclerotic plaque usually with origin Atherosclerotic plaque usually with origin thrombosisthrombosis

Dissection can lead to thrombosis Dissection can lead to thrombosis Following CABG mortality is 70%Following CABG mortality is 70%

NOMINOMI

Low-flow stateLow-flow state Can be related to vasospasm after Can be related to vasospasm after

diagnostic or therapeutic studiesdiagnostic or therapeutic studies Radiographic criteria includeRadiographic criteria include

Narrowing of origin of branchesNarrowing of origin of branches String of sausages signString of sausages sign Spasm of mesenteric arcadesSpasm of mesenteric arcades Impaired filling of intramural vesselsImpaired filling of intramural vessels

Venous ThrombosisVenous Thrombosis

Primary--idiopathicPrimary--idiopathic Secondary related to trauma, surgery, Secondary related to trauma, surgery,

cancer, cirrhosis, pancreatitis, or cancer, cirrhosis, pancreatitis, or hypercoagulable stateshypercoagulable states

Insidious onsetInsidious onset CT study of choiceCT study of choice SMV in 70%SMV in 70% 30-day mortality of 25% and 3-year survival 30-day mortality of 25% and 3-year survival

of 35% for acute diseaseof 35% for acute disease

Clinical PresentationClinical Presentation

Often sudden onset of pain out of Often sudden onset of pain out of proportion to physical exam findingsproportion to physical exam findings

Rebound and guarding often absentRebound and guarding often absent Hemoconcentration, leukocytosisHemoconcentration, leukocytosis Amylase, LDH, CPK, and alk phos Amylase, LDH, CPK, and alk phos

elevatedelevated AcidosisAcidosis Most exam findings and lab abnormalities Most exam findings and lab abnormalities

not present until infarction not present until infarction

Radiographic WorkupRadiographic Workup

Plain films normal in 25%Plain films normal in 25% Duplex may be of benefitDuplex may be of benefit CT helpful if arterial contrast used or MVTCT helpful if arterial contrast used or MVT MRA reported in few seriesMRA reported in few series Gold standard is angiography which is Gold standard is angiography which is

contraindicated if acute abdomen on examcontraindicated if acute abdomen on exam NOMI reveals pruning with absent NOMI reveals pruning with absent

submucosal blushsubmucosal blush

TreatmentTreatment

Resuscitation, correction of acidosis, and Resuscitation, correction of acidosis, and antibioticsantibiotics

HeparinHeparin Arteriogram potentially diagnostic and Arteriogram potentially diagnostic and

therapuetictherapuetic Limited to patients with <8 hours of pain Limited to patients with <8 hours of pain

and no peritoneal irritationand no peritoneal irritation PTA/stent has been reportedPTA/stent has been reported

Treatment - EmbolismTreatment - Embolism

Embolus treated with prompt laparotomyEmbolus treated with prompt laparotomy Transverse colon reflected cephalad and Transverse colon reflected cephalad and

fourth portion of duodenum mobilizedfourth portion of duodenum mobilized SMA controlledSMA controlled Transverse arteriotomy and embolectomy Transverse arteriotomy and embolectomy

with 4 Fogarty proximally and 2 or 3 with 4 Fogarty proximally and 2 or 3 Fogarty distallyFogarty distally

Primary closure of arteriotomyPrimary closure of arteriotomy

Treatment - ThrombosisTreatment - Thrombosis

Longitudinal arteriotomy and attempted Longitudinal arteriotomy and attempted thrombectomy if diagnosis in questionthrombectomy if diagnosis in question Thrombectomy not durableThrombectomy not durable Arteriotomy used for distal anastamosisArteriotomy used for distal anastamosis

Autologous conduit if bowel resectionAutologous conduit if bowel resection Antegrade BypassAntegrade Bypass

Supraceliac AortaSupraceliac Aorta Retrograde BypassRetrograde Bypass

Infrarenal AortaInfrarenal Aorta Iliac VesselsIliac Vessels

Treatment - NOMITreatment - NOMI

Supportive careSupportive care Papaverine administration through direct Papaverine administration through direct

catheter infusioncatheter infusion HeparinHeparin Laparotomy if peritoneal signs developLaparotomy if peritoneal signs develop Survival in some series is 70% at five Survival in some series is 70% at five

yearsyears

Treatment – Venous ThrombosisTreatment – Venous Thrombosis

Fluid resuscitationFluid resuscitation AnticoagulationAnticoagulation Correction of underlying coagulopathyCorrection of underlying coagulopathy Resection of necrotic bowelResection of necrotic bowel Extent of resection more generous than Extent of resection more generous than

other disease processesother disease processes Lytic therapy reportedLytic therapy reported Search for etiologySearch for etiology

Chronic Mesenteric IschemiaChronic Mesenteric Ischemia

Risk factors parallel those of other Risk factors parallel those of other atherosclerosis processesatherosclerosis processes Family historyFamily history SmokingSmoking MIMI ClaudicationClaudication HypertensionHypertension HyperlipidemiaHyperlipidemia

SymptomsSymptoms

Pain 15-45 minutes after mealsPain 15-45 minutes after meals Weight lossWeight loss DiarrheaDiarrhea Nausea and vomitingNausea and vomiting Symptoms may be related to vessels Symptoms may be related to vessels

involvedinvolved Patients often have had a myriad of tests Patients often have had a myriad of tests

and interventions for abdominal painand interventions for abdominal pain

CMICMI

DiagnosisDiagnosis Plain filmsPlain films DuplexDuplex

Celiac PSV 200 cm/sCeliac PSV 200 cm/s SMA PSV 275 cm/sSMA PSV 275 cm/s

ArteriogramArteriogram AP and lateralAP and lateral Occlusion/stenosis of 2/3 vessels necessary for Occlusion/stenosis of 2/3 vessels necessary for

development of CMI development of CMI

TreatmentTreatment

PTAPTA Successful in 80% of casesSuccessful in 80% of cases Relief of pain in majorityRelief of pain in majority Successful weight gainSuccessful weight gain Similar patency to surgical bypass but more Similar patency to surgical bypass but more

frequent recurrence of symptoms with PTAfrequent recurrence of symptoms with PTA Restenosis reported in some series to be 30-Restenosis reported in some series to be 30-

50%50%

TreatmentTreatment

Antegrade bypassAntegrade bypass Transperitoneal approachTransperitoneal approach Supraceliac controlSupraceliac control Left lobe of liver mobilizedLeft lobe of liver mobilized Crura divided and 8-10cm aorta exposedCrura divided and 8-10cm aorta exposed SMA and celiac controlledSMA and celiac controlled 14x7 bifurcated graft and retropancreatic 14x7 bifurcated graft and retropancreatic

tunnel for SMA anastamosistunnel for SMA anastamosis Alternative sequential bypassAlternative sequential bypass

TreatmentTreatment

Retrograde bypassRetrograde bypass Suggested to be less durable than Suggested to be less durable than

antegrade bypassantegrade bypass Used in emergency, inaccesible Used in emergency, inaccesible

supraceliac aorta, severe cardiac disease, supraceliac aorta, severe cardiac disease, or the need for infrarenal aortic or the need for infrarenal aortic reconstructionreconstruction

Celiac revascularization often to hepatic Celiac revascularization often to hepatic arteryartery

OutcomesOutcomes

Mortality of 6%Mortality of 6% Major morbidity 20%Major morbidity 20% Good symptom reliefGood symptom relief Graft patency of 90% at 3 yearsGraft patency of 90% at 3 years Success not different in prosthetic vs Success not different in prosthetic vs

autologous or antegrade vs retrogradeautologous or antegrade vs retrograde Patient survival at 5 years reported to be Patient survival at 5 years reported to be

71%71%