IntestinalIntestinal IschemiaIschemia ChronicChronic MesentericMesenteric IschemiaIschemia

EmoriEmori Bizer,Bizer, M.D.M.D. UniversityUniversity ofof LouisvilleLouisville /HepatologyGastroenterology/ UniversityMarch 27,of 2008 Louisville BoardBoard Question:Question:

An 80 year old woman with CAD complains to PCC that she has had abdominal for the past 4-6 months. Typically, it occurs 30 minutes postprandially and usually resolves in 1-3 hours. The severity of the pain has increased, and she is losing weight. Exam reveals a cachectic woman, but no abnormality is found on abdominal exam. The additional symptom that would be most suggestive of chronic mesenteric is: a. Intermittent and b. Bloating c. Fear of eating resulting in d. UniversityDiarrhea of Louisville IntestinalIntestinal IschemiaIschemia

„ Objectives:Objectives: „ ReviewReview vascularvascular anatomyanatomy ofof GIGI tracttract „ PathophysiologyPathophysiology ofof intestinalintestinal ischemiaischemia „ ReviewReview typestypes ofof intestinalintestinal ischemiaischemia „ DiagnosisDiagnosis ofof intestinalintestinal ischemiaischemia „ ManagementManagement ofof intestinalintestinal ischemiaischemia „ BoardBoard--stylestyle questionsquestions University of Louisville WhoWho cares?cares?

„ MORTALITYMORTALITY „ Mesenteric Ischemia „ Early diagnosis and intervention: 10% „ : 60%-93% „ Colon Ischemia: 50% „ Mesenteric Venous : 20-50% „ "Occlusion of the mesenteric vessels is apt to be regarded as one of those conditions of which the diagnosis is impossible, the prognosis hopeless, and the treatment almost useless" (UniversityCokkinis, 1926). of Louisville IntestinalIntestinal IschemiaIschemia

„ SpectrumSpectrum ofof disordersdisorders „ AcuteAcute vs.vs. ChronicChronic „ ArterialArterial vs.vs. VenousVenous disturbancedisturbance „ SmallSmall IntestineIntestine vs.vs. LargeLarge IntestineIntestine vs.vs. BothBoth „ AcuteAcute isis moremore commoncommon thanthan ChronicChronic „ ArterialArterial diseasedisease isis moremore commoncommon thanthan VenousVenous

University of Louisville Types and Approximate Frequencies of

Frequency, % Type Colon ischemia 70-75 Acute mesenteric ischemia 20-25 Focal segmental ischemia 5 Chronic mesenteric ischemia 5 Mesenteric Included in above[*] * Mesenteric venous thrombosis may manifest as colon ischemia, acute mesenteric ischemia, or as focal segmental ischemia. The frequency of mesenteric venous thrombosis is rising as computed tomography is performed more commonly. University of Louisville CeliacCeliac AxisAxis

„ 33 majormajor branches:branches: leftleft gastric,gastric, commoncommon hepatic,hepatic, andand splenicsplenic arteriesarteries „ ProvidesProvides arterialarterial bloodblood supplysupply to:to: „ STOMACHSTOMACH „ DUODENUMDUODENUM Figure 111-1 Diagram of typical celiac axis anatomy. A, ; AIPD, „ PANCREASPANCREAS anterior inferior pancreaticoduodenal ; ASPD, anterior superior pancreaticoduodenal artery; C, celiac axis; CP, caudal pancreatic artery; DP, dorsal pancreatic artery; GD, gastroduodenal artery; H, common „ LIVERLIVER hepatic artery; LG, left gastric artery; PIPD, posterior inferior pancreaticoduodenal artery; PM, pancreata magna; RGE, right gastroepiploic artery; S, splenic artery; SM, superior mesenteric artery; TP, transverse pancreatic artery. (From Nebesar RA, Kornblith PL, Pollard JJ, UniversityMichels of NA: Celiac andLouisville Superior Mesenteric : A Correlation of Angiograms and Dissections. Boston, Little, Brown, 1969.) SuperiorSuperior MesentericMesenteric ArteryArtery

„ 4 major branches: inferior pancreaticoduodenal, middle colic, right colic, and ileocolic arteries „ Series of jejunal and ileal branches – form ARCADES „ From the terminal arcade, straight vessels enter the intestinal wall „ Supplies: Figure 111-2 Diagram of typical superior mesenteric artery anatomy. A, aorta; AIPD, anterior inferior pancreaticoduodenal „ AND artery; COL, colic branches; I, ileal branches; IC, ileocolic artery; JEJ, jejunal branches; MC, middle colic artery; PIPD, posterior inferior pancreaticoduodenal artery; RC, right colic artery; SM, „ RIGHT HALF OF LARGE superior mesenteric artery. (From Nebesar RA, Kornblith PL, Pollard JJ, Michels NA: Celiac and Superior Mesenteric Arteries: A Correlation of UniversityBOWEL of AngiogramsLouisville and Dissections. Boston, Little, Brown, 1969.) InferiorInferior MesentericMesenteric ArteryArtery

„ Branches include left colic artery, multiple sigmoid branches, and terminates as the superior rectal artery „ Supplies: „ FROM DISTAL TRANSVERSE COLON TO PROXIMAL

„ **The distal rectum is supplied by the internal iliac Figure 111-3 Diagram of typical inferior mesenteric artery anatomy. AOR, arc of artery and its hypogastric Riolan; ASC, ascending branch of the left colic artery; CA, central artery; DSC, descending branch of the left colic artery; IM, inferior mesenteric artery; LMC, artery branch left branch of middle colic artery; MA, marginal artery; MC, middle colic artery; RMC, right branch of middle colic artery; S1, S2, S3, sigmoid branches; SM, University superiorof mesenteric Louisville artery; SR, superior rectal artery. (From Nebesar RA, Kornblith PL, Pollard JJ, Michels NA: Celiac and Superior Mesenteric Arteries: A Correlation of Angiograms and Dissections. Boston, Little, Brown, 1969.) IntestinalIntestinal IschemiaIschemia -- PathophysiologyPathophysiology

„ InnateInnate preventativepreventative measuresmeasures „ Collateral circulation – particularly to stomach, , and rectum, so less likely to have ischemia to these organs „ Splenic flexure and sigmoid colon have fewer collateral vessels, so higher risk for ischemia „ Compensatory mechanisms – 1/5 mesenteric capillaries are open at a time. „ TheThe bowelbowel cancan toleratetolerate aa 75%75% reductionreduction ofof mesentericmesenteric bloodblood flowflow andand oxygenoxygen consumptionconsumption forfor 1212 hourshours withwith nono microscopicmicroscopic changeschanges ofof ischemia.ischemia. University of Louisville IntestinalIntestinal IschemiaIschemia -- PathophysiologyPathophysiology

„ Occlusive vs nonocclusive (NOMI) „ Reversible ischemia to transmural infarction and perforation „ collaterals open distally initially „ Hours of ischemia which reduces collateral flow „ Vasoconstriction is irreversible after a certain period of time „ leads to bowel wall spasm which leads to gut emptying „ Mucosal sloughing leads to GI „ Occlusive: Hemorrhagic infarction is final common pathway „ Disruption of the mucosal barrierbarrier becomesbecomes allowsallows bacteria,bacteria, toxins, and vasoactive substances to be released into the systemic circulationUniversity of Louisville IntestinalIntestinal IschemiaIschemia -- PathophysiologyPathophysiology

„ IschemicIschemic damagedamage fromfrom hypoxiahypoxia andand reperfusionreperfusion „ Brief insult: more damage during reperfusion „ Long insult: more damage from hypoxia „ ReperfusionReperfusion injuryinjury duedue toto reactivereactive oxygenoxygen radicalsradicals „ radicals cause cell lysis and on reperfusion of ischemic tissue „ Xanthine – in nucleic acid degrad. „ Converted to Xanthine Oxidase in ischemia „ Xanthine oxidase (XO) – source of oxygen radicals University of Louisville Non-ischemic Tissue Ischemic Tissue

Nucleic acids XDH XO XDH

Nucleic acid degradation Reactive oxygen products radicals

**Allopurinol inhibits XO = decreased epithelial cell necrosis Reperfusion Universityduring reperfusion of Louisville IntestinalIntestinal IschemiaIschemia -- PathophysiologyPathophysiology

„ Role of Neutrophils „ Source of reactive oxygen metabolites „ In reperfusion, XO increased production of leukotriene B4 and -activating factor = neutrophil adherence and migration „ Increased microvascular injury by neutrophils causing release of proteases which disrupt endothelial barrier and tight junctions „ In vitro, XO inhibitors and agents that inhibit leukocyte adherence and migration protect organs against Universityreperfusion injury. In vivo, of agents Louisvillemust be given before ischemic insult BoardBoard Question:Question:

A 71 year old woman comes to the ER with severe nausea, vomiting, and determined to be secondary to viral . Her BP is 70/50mmHg. She is given IVF. One day later, she returns to the ER complaining of sudden onset of crampy LLQ pain and passage of bloody diarrhea. Sigmoidoscopy findings indicate her symptoms are due to: a. Recurrence of viral GE b. Superimposed bacterial c. Ulcerative d. Colon ischemia University of Louisville TypesTypes ofof IntestinalIntestinal IschemiaIschemia

„„ AcuteAcute MesentericMesenteric IschemiaIschemia „ ArterialArterial –– ,thrombus, embolusembolus (cardiac),(cardiac), nonocclusivenonocclusive „ MesentericMesenteric VenousVenous ThrombosisThrombosis „ FocalFocal SegmentalSegmental IschemiaIschemia -- VenousVenous „ ColonColon IschemiaIschemia „ ChronicChronic MesentericMesenteric IschemiaIschemia „ VasculitisVasculitis andand AngiopathyAngiopathy ofof SplanchnicSplanchnic CirculationCirculation University of Louisville AcuteAcute MesentericMesenteric IschemiaIschemia

„ Insufficient flow to all or part of the small bowel and may involve the right half of the colon (SMA) „ SMA most often site of embolic AMI due to straighter take-off from Aorta Causes and Approximate Frequencies of Acute Mesenteric Ischemia Frequency, % Cause SMA 50 Nonocclusive mesenteric ischemia 25 SMA thrombosis 10 Mesenteric venous thrombosis 10 FocalUniversity segmental ischemia of Louisville5 AcuteAcute MesentericMesenteric IschemiaIschemia

„ ThromboticThrombotic AMIAMI „ Final cause of ischemia may be sudden drop in cardiac output or ruptured plaque „ Often 2/3 vessels must be occluded for symptoms „ NonocclusiveNonocclusive MesentericMesenteric IschemiaIschemia „ “low flow state” – hypovolemia, cardiogenic or septic „ Failure of autoregulation „ No thrombus or embolus „ Cocaine, digitalis, vasopressin can cause local Universityvasoconstriction of Louisville AcuteAcute MesentericMesenteric IschemiaIschemia „ RiskRisk Factors:Factors: „ ≥50 y/o: CHF, cardiac , recentrecent MI,MI, hypotensionhypotension „ Young: amphetamines, cocaine, triptans, , thrombophilic d/o „ SignsSigns andand Symptoms:Symptoms: „ Early: „ Late: Abdominal distention „ First sign of intestinal infarction „ If rebound tenderness or guarding = think infarction „ GI bleeding „ Recurrent bacteremia s/p cardiopulmonary arrest (gut translocation of bacteria) „ Critically ill patient: intolerance to tube feeds University„ Confusion (especially in elderly) of Louisville AcuteAcute MesentericMesenteric IschemiaIschemia

„ AbdominalAbdominal pain:pain: „ AcuteAcute „ SMAT:SMAT: postprandialpostprandial painpain inin thethe weeksweeks toto monthsmonths precedingpreceding thethe acuteacute onsetonset ofof severesevere painpain „ Late complication of severe atherosclerotic when usually 2/3 vessels occluded. „ SMAE:SMAE: sudden,sudden, severesevere painpain accompaniedaccompanied byby rapid,rapid, forcefulforceful bowelbowel evacuationevacuation „ MVT:MVT: indolentindolent University„ NOMI:NOMI: nono painpain inin 25%25% of Louisville AcuteAcute MesentericMesenteric IschemiaIschemia

„ Diagnosis: and „ Labs – nonspecific; late-stage fixed „ Plain films – normal 70% formless „ Formless fixed loops of SB , SB loop ileus, “thumbprinting” or due to SMAE „ CT –arterial occlusion or venous thrombosis, intramural gas or portal venous gas, focal lack of bowel wall enhancement (sens 64%, spec 92%) „ Dopplers – limited in clinical value „ Visualize proximal portion of vessel, occlusion nondiagnostic, variable blood flow through SMA University„ Spec 92%, sensitivity 70-89% of Louisville AcuteAcute MesentericMesenteric IschemiaIschemia Diagnosis . . . Infarcted „ CTA – sens 71-96% and a spec of 92- loop of 94%, rapid bowel. „ MRA – sens 100%, spec 91%, but time- consuming SMV „ Laparoscopy – less helpful b/c serosa thrombus may look normal when mucosa necrotic and SMA flow decreases with incr pressure „ Laparotomy – use when not available or if signs of „ Mesenteric Angiography – diagnostic and therapeutic, gold standard „ Sens: 90-100%, spec 100% „ Drawbacks: delays , SMA embolus, difficult in critically ill s/p embole- „ Decreased mortality ctomy „ UniversityOnly way to dx NOMI of Louisville AcuteAcute MesentericMesenteric IschemiaIschemia -- ManagementManagement

„ STATSTAT surgicalsurgical consultconsult „ SMAE:SMAE: „ : Laparotomy, and/or resection „ Re-exploration often – may leave abdomen open. „ No peritonitis: Angiography „ “Road map” for „ infusion „ Given through angio directly into SMA „ VASODILATOR: Relieves mesenteric vasoconstriction „ SMAT:SMAT: „ Emergency surgical revascularization University of Louisville AcuteAcute MesentericMesenteric IschemiaIschemia -- ManagementManagement

„ NOMI:NOMI: „ Papaverine infusion into SMA „ Decreased mortality in small case series „ BroadBroad spectrumspectrum antibioticsantibiotics (no(no RCTsRCTs)) „ NoNo anticoagulantsanticoagulants forfor firstfirst 4848 hours,hours, exceptexcept inin MVTMVT

University of Louisville MesentericMesenteric VenousVenous ThrombosisThrombosis

„ 10%10% ofof AcuteAcute MesentericMesenteric IschemiaIschemia „ RiskRisk Factors:Factors: „ Hypercoagulable States „ Estrogen – OCP, HRT, pregnancy „ Malignancy „ DVT – 60% MVT have h/o peripheral DVT „ „ Inflammatory States – , , peritonitis, IBD „ Trauma University„ Decompression Sickness of Louisville MesentericMesenteric VenousVenous ThrombosisThrombosis

„ Location, Location, Location „ Initial thrombus location varies with etiology „ , : Start proximal, extend peripherally „ Hypercoag state: Start peripherally and extend proximally „ Rare intestinal infarction „ : „ Impaired venous drainage leads to congestion and of bowel and thickened bowel wall with intramuintramuralral hemorrhage „ Clinical: acute, subacute, or chronic. Abdominal pain, GI bleed. „ Diagnosis: „ SB wall thickening, thumbprinting „ CT – test of choice University„ Angiography of Louisville „ Laparotomy – serosanguinous peritoneal fluid, blue-black bowel, thrombi MesentericMesenteric VenousVenous ThrombosisThrombosis

„ TreatmentTreatment „ Asymptomatic – 3-6 mos anticoagulation or no therapy „ Peritoneal signs – laparotomy „ Papaverine infusion if viable bowel „ Thrombectomy if possible „ Immediate heparinization for 7-10 days (improves survival) „ No peritoneal signs – 3-6 mos anticoagulation „ Lifelong anticoagulation if hypercoagulable state „ EGD for if chronic MVT University of Louisville FocalFocal SegmentalSegmental IschemiaIschemia

„ Ischemia to a short segment of „ Causes: Atheromatous emboli, strangulated , immune complex disorders/vasculitis, blunt abdominal trauma, segmental venous thrombosis, , OCP’s. „ Clinical: acute abdomen or chronic with chronic SBO from stricture with intermittent abdominal pain and vomiting „ Xray: „ “blind loop” syndrome – bacterial overgrowth of the dilated loop proximal to the SBO. „ Smooth tapered stricture with abrupt change to normal mucosa „ Treatment:University surgical resection ofof involved Louisville bowel TypesTypes ofof IntestinalIntestinal IschemiaIschemia

„ AcuteAcute MesentericMesenteric IschemiaIschemia „ ArterialArterial –– thrombus,thrombus, embolus,embolus, nonocclusivenonocclusive „ MesentericMesenteric VenousVenous ThrombosisThrombosis „ FocalFocal SegmentalSegmental IschemiaIschemia -- VenousVenous „„ ColonColon IschemiaIschemia „ ChronicChronic MesentericMesenteric IschemiaIschemia „ VasculitisVasculitis andand AngiopathyAngiopathy ofof SplanchnicSplanchnic CirculationCirculationUniversity of Louisville ColonColon IschemiaIschemia „ TheThe MostMost CommonCommon formform ofof IntestinalIntestinal IschemiaIschemia „ Causes:Causes: VastVast andand oftenoften idiopathicidiopathic „ Emboli „ Hematologic d/o – vasculitis, hypercoagulable states „ Infectious – E.coli 0157:H7, HBV, CMV, parasites „ Surgical – includes colonoscopy; moremore oftenoften Aortic,Aortic, CardiacCardiac „ Drugs, Drugs, Drugs – GoLYTELY among many „ NSAIDs, PCN, saline laxatives, cocaine, estrogens, IFN-α, Lotronex „ Shock, Trauma „ Obstructing colon lesions „ Pancreatitis „ Strangulated Hernia University„ Long distance running of Louisville ColonColon IschemiaIschemia

„ CausesCauses andand affectedaffected segments:segments: „ Systemic low-flow states = Right colon „ Local nonocclusive ischemic injury – the watershed area = splenic flexure and rectosigmoid „ Ligation of IMA – sigmoid colon „ Atheromatous emboli - short segments of injury „ Nonocclusive injury – longer portions of colon „ InIn mostmost cases,cases, nono specificspecific causecause isis identifiedidentified University of Louisville ColonColon IschemiaIschemia

Figure 111-12 Schematic of patterns of colon ischemia showing the percentage of involvement of each pattern in a total of 250 cases University of Louisville ColonColon IschemiaIschemia

„ PathologyPathology „ Varies with duration and severity of ischemia „ Mild: mucosal and submucosal hemorrhage and edema +/- partial necrosis and mucosal ulceration „ Moderate: chronic ulcerations, crypt abscesses, pseudopolyps (**MIMICKS IBD) „ Severe: MP replaced by fibrous tissue (stricture formation) „ Very Severe: transmural infarction University of Louisville ColonColon IschemiaIschemia

„ ClinicalClinical „ Sudden, cramping pain, can be mild intensity „ LLQ „ Urgent need to defecate „ within 24 hours (small volume)

University of Louisville ColonColon IschemiaIschemia -- DiagnosisDiagnosis „ UnpreppedUnprepped colonoscopycolonoscopy w/inw/in 4848 hrshrs ifif nono signssigns ofof peritonitisperitonitis „ Do not overdistend the colon –can worsen ischemia „ “Hemorrhagic nodules” = submucosal bleeding „ “thumbprints” on barium enema study „ “Colon single-stripe sign” – single erythematous line with ulceration oriented along longitudinal axis of colon. 75% sensitive. „ Indicates milder dz than if circumferential ulcer „ Rectal sparing „ Segmental disease „ Mucosal „ UniversityMore sensitive than barium enema of Louisville ColonColon IschemiaIschemia -- DiagnosisDiagnosis

„ NoNo MesentericMesenteric AngiographyAngiography unlessunless cannotcannot distinguishdistinguish btwbtw CICI andand AMIAMI (Right(Right coloncolon involvementinvolvement oror severityseverity ofof pain)pain) b/cb/c coloncolon bloodblood flowflow returnsreturns toto normalnormal byby thethe timetime ofof presentationpresentation „ IfIf unclearunclear CICI vsvs AMI,AMI, firstfirst orderorder airair enemaenema „ Will show presence of submucosal edema and hemorrhage of CI „ If no thumbprinting seen or only in the right colon, then order mesenteric angiography University of Louisville ColonColon IschemiaIschemia :: DifferentialDifferential DiagnosisDiagnosis atat EndoscopyEndoscopy

Ischemia or Crohn’s?

Ischemia or Neoplasm? University of Louisville ColonColon IschemiaIschemia -- ManagementManagement

„ If no peritonitis, conservative „ Bowel rest, IVF, ABx „ Rectal tube prn colon distention „ Monitor labs, xrays „ Signs of infarction = to OR „ Worsening abdominal tenderness or rebound, guarding, fever

University of Louisville PLC: protein-losing colopathy TypesTypes ofof IntestinalIntestinal IschemiaIschemia

„ AcuteAcute MesentericMesenteric IschemiaIschemia „ ArterialArterial –– thrombus,thrombus, embolus,embolus, nonocclusivenonocclusive „ MesentericMesenteric VenousVenous ThrombosisThrombosis „ FocalFocal SegmentalSegmental IschemiaIschemia -- VenousVenous „ ColonColon IschemiaIschemia „„ ChronicChronic MesentericMesenteric IschemiaIschemia „ VasculitisVasculitis andand AngiopathyAngiopathy ofof SplanchnicSplanchnic CirculationCirculationUniversity of Louisville ChronicChronic MesentericMesenteric IschemiaIschemia

„ ““IntestinalIntestinal AnginaAngina”” „ Prevalence:Prevalence: lessless thanthan 5%5% ofof intestinalintestinal ischemiaischemia „ RiskRisk factors:factors: „ coronarycoronary oror peripheralperipheral vascularvascular diseasedisease „ 75%75% ofof ptspts withwith CMICMI havehave h/oh/o smokingsmoking

University of Louisville ChronicChronic MesentericMesenteric IschemiaIschemia

„ Pathophysiology:Pathophysiology: „ AlmostAlmost alwaysalways causedcaused byby mesentericmesenteric atherosclerosisatherosclerosis „ NewNew Theory:Theory: IschemiaIschemia ofof thethe smallsmall bowelbowel duedue toto preferentialpreferential bloodblood supplysupply toto stomachstomach uponupon foodfood ingestioningestion „ OldOld Theory:Theory: LimitedLimited bloodblood supplysupply toto thethe smallsmall intestineintestine duringduring digestiondigestion University of Louisville ChronicChronic MesentericMesenteric IschemiaIschemia

„ Symptoms:Symptoms: ABDOMINALABDOMINAL PAINPAIN && WEIGHTWEIGHT LOSSLOSS „ AbdominalAbdominal Pain:Pain: „ Starts within 30 minutes of food ingestion „ Increases in severity „ Resolves over 1-3 hours acutely „ Progressively increases in severity over time and may become continuous, unassociated with food intake „ BAD SIGN = INFARCTION IMINENT „ FearFear ofof eating,eating, resultingresulting inin weightweight lossloss University„ “sitophobia” of Louisville ChronicChronic MesentericMesenteric IschemiaIschemia

„ OtherOther Symptoms:Symptoms: „ Nausea,Nausea, bloatingbloating „ EpisodicEpisodic diarrheadiarrhea „ ConstipationConstipation „ MalabsorptionMalabsorption

University of Louisville ChronicChronic MesentericMesenteric IschemiaIschemia

„ UncommonUncommon presentations:presentations: „ AntralAntral ulcersulcers thatthat dodo notnot healheal withwith PPIPPI „ GastroparesisGastroparesis (reversible(reversible withwith revascularization!!)revascularization!!) „ AcalculousAcalculous cholecystitischolecystitis

University of Louisville ChronicChronic MesentericMesenteric IschemiaIschemia

„ PhysicalPhysical Exam:Exam: „ OverallOverall benignbenign „ CachexiaCachexia ifif significantsignificant weightweight lossloss „ AbdomenAbdomen isis NONNON--TENDERTENDER eveneven ifif havinghaving painpain „ Pain out of proportion to physical exam „ CouldCould havehave abdominalabdominal distentiondistention „ AbdominalAbdominal bruitbruit maymay bebe presentpresent University of Louisville ChronicChronic MesentericMesenteric IschemiaIschemia

„ DiagnosisDiagnosis „ NoNo specificspecific diagnosticdiagnostic testtest –– dxdx ofof exclusionexclusion „ XX--RayRay andand CTCT –– normalnormal oror vascularvascular calcificationscalcifications „ EndoscopyEndoscopy –– maymay havehave antralantral ulcersulcers notnot assocassoc withwith H.pyloriH.pylori „ BariumBarium –– normalnormal oror motilitymotility d/od/o oror malabsorptionmalabsorption „ GastricGastric EmptyingEmptying TestTest –– maymay bebe delayeddelayed „ ProvocativeProvocative balloonballoon tonometrytonometry –– evaluatesevaluates thethe Universityphysiologicalphysiological adequacyadequacy ofof intestinalintestinal Louisville bloodblood flowflow ChronicChronic MesentericMesenteric IschemiaIschemia

„ DiagnosisDiagnosis „ DuplexDuplex USNUSN –– elevatedelevated peakpeak systolicsystolic velocityvelocity inin SMASMA ofof 275275 cm/seccm/sec andand CACA ofof 200200 cm/seccm/sec suggestssuggests 70%70% stenosisstenosis ofof thesethese vessels,vessels, butbut doesdoes notnot establishestablish diagnosisdiagnosis ofof CMICMI „ MRAMRA oror mesentericmesenteric angiogrpahyangiogrpahy –– showshow anatomicanatomic limitationslimitations ofof splanchnicsplanchnic bloodblood flowflow butbut cannotcannot diagnosediagnose intestinalintestinal ischemiaischemia „ AngiographyAngiography ––atat leastleast 22 ofof 33 splanchnicsplanchnic vesselsvessels shouldshould bebe severelyseverely stenosedstenosed oror occludedoccluded University of Louisville ChronicChronic MesentericMesenteric IschemiaIschemia

„ SurgicalSurgical RevascularizationRevascularization vsvs PTMAPTMA (percutaneous(percutaneous transluminaltransluminal mesentericmesenteric angioplasty)angioplasty) „ Literature with varied criteria to define outcomes „ Initial success at revascularization similar „ Surgical approach – bypass grafts, aortic reimplantation of SMA, and endarterectomy „ improved duration of graft patency but increased perioperative mortality „ PTMA with decreased perioperative mortality but increased recurrence of symptoms and . Stenting improves these outcomes. „ ManagementManagementUniversity basedbased onon surgicalsurgical of riskriskLouisville ChronicChronic MesentericMesenteric Ischemia:Ischemia: ManagementManagement

Figure 111-19 Algorithim for the management of chronic mesenteric ischemia. Solid lines indicate accepted management plan; dashed line indicates alternative management plan. CTA, computed tomographic angiogram; MRA, magnetic resonance angiography. (From Brandt LJ, Boley SJ: AGA technicalUniversity review on intestinal ischemia: American of Gastrointestinal Louisville Association. Gastroenterology 118:954, 2000.) TypesTypes ofof IntestinalIntestinal IschemiaIschemia

„ AcuteAcute MesentericMesenteric IschemiaIschemia „ ArterialArterial –– thrombus,thrombus, embolus,embolus, nonocclusivenonocclusive „ MesentericMesenteric VenousVenous ThrombosisThrombosis „ FocalFocal SegmentalSegmental IschemiaIschemia -- VenousVenous „ ColonColon IschemiaIschemia „ ChronicChronic MesentericMesenteric IschemiaIschemia „„ VasculitisVasculitis andand AngiopathyAngiopathy ofof SplanchnicSplanchnic CirculationCirculation University of Louisville VasculitisVasculitis

„ Many types „ Segmental ischemia „ Clinical symptoms similar to other causes of ischemia „ Abdominal pain, fever, bloody diarrhea, intestinal obstruction „ Ulceration and strictures common; perforation uncommon „ Pathophysiology: „ Immune complex deposition in the vascular walls leads to complement activation, inflammatory reaction; then aneurysaneurysmsms form which can rupture. Vascular occlusion, thrombosis, and fibrosis ensue. „ Treatment: steroids, immunosuppressants University of Louisville IntestinalIntestinal IschemiaIschemia

„ AA veryvery basicbasic algorithmalgorithm fromfrom thethe 20002000 AGAAGA technicaltechnical reviewreview onon intestinalintestinal ischemiaischemia forfor thethe diagnosisdiagnosis andand treatmenttreatment ofof intestinalintestinal ischemia.ischemia. .. ..

University of Louisville University of Louisville ReferencesReferences

„ Sleisenger and Fortran’s Gastrointestinal and . 8th edition. Chapter 111. „ AGA Technical Review, Gastroenterology. May 2000. „ Mesenteric thrombectomy associated with intestinal resection in extended venous mesenteric infarction – case report. AVRAM J., MOCANU N., TOMA DIDINA, SĂNDESC www.jmed.ro/images/Frame92_(5).JPG

„ emedicine.com. Chat Dang, MD.. Acute Mesenteric Ischemia. University of Louisville