Acute Mesenteric IschemiaAcute Mesenteric Ischemia

Scott Q. Nguyen, M.D.Scott Q. Nguyen, M.D.

Celia M. Divino, M.D.Celia M. Divino, M.D.

Mount Sinai School of MedicineMount Sinai School of Medicine

Department of SurgeryDepartment of Surgery

Mrs. MittyMrs. Mitty

• An 83 year-old woman is brought to the ER by ambulance from her nursing home w/ a 4 hour history of severe diffuse abdominal pain and distention..

History

What other points of the history do you want to know?

History, Mrs. MittyHistory, Mrs. Mitty

• Characterization of symptoms

• Temporal sequence• Alleviating /

Exacerbating factors:

• Pertinent PMH, ROS, MEDS.

• Associated signs and symptoms

• Relevant family hx.

Consider the Following

History, Mrs. Mitty

• Characterization of Symptoms:Characterization of Symptoms: Sudden onset diffuse abdominal pain and distention 4

hours ago. Pain not localized to any quadrant.

• Alleviating / Exacerbating factors:Alleviating / Exacerbating factors: Pain is excruciating, it’s the worse she’s ever experienced Nothing alleviates it

• Associated signs/symptoms:Associated signs/symptoms: She vomits 1L of feculent emesis on arrival to ER. Last BM 2 hours ago, loose

Other History

• PMHPMH Atrial Fibrillation - dx’d 1 month ago,

anticoagulation contraindicated with history of massive GI bleed

CHF, CAD, DM

• PSHPSH Cholecystectomy, left hemicolectomy for

diverticular disease

• MEDS digoxin, metoprolol, insulin

Other History

• Social History Occasional wine,

50 pack-yr smoker, quit 2 yrs ago

• Family History Patient unable to give

What is your Differential Diagnosis?

Differential DiagnosisBased on History and Presentation

• Small Bowel Obstruction Obstruction• Acute Mesenteric Acute Mesenteric

IschemiaIschemia• Perforated DiverticulitisPerforated Diverticulitis• Ischemic ColitisIschemic Colitis

• Perforated Peptic Ulcer Disease

• Acute Pancreatitis• Acute Cholecystitis• Gastroenteritis• Acute Appendicitis

Physical Examination

What would you look for?

Physical Examination

• Vital Signs: T = 38.5, P = 103, BP = 140/85, RR = 28

• Appearance: thin , in severe distress, legs pulled up to chest, moaning

• Heart: irregularly irregular

• Lungs: mild rales at bases

• Abdomen: decreased BS, very distended, mildly tender diffusely, no guarding/rebound tenderness, no hernias

• Rectal: loose stool in vault, streaked w/ fresh blood

Remaining Examination findings non-contributory

Would you like to revise your Differential Diagnosis?

Laboratory

What would you obtain?

• LFTs - WNL• Amylase/Lipase - 89/95 - 89/95• PT/PTT - 13.0/33.0PT/PTT - 13.0/33.0• ABG - 7.31/30/69/16 - 7.31/30/69/16• Lactate 7.9 7.9

133 101

4.9 19

14

42405 30

1.2

18 240

Labs ordered, Mrs. Mitty

85 PMN’s 22 Bands

Lab Results, Discussion

• Leukocytosis - - acute processacute process, , possibly infectiouspossibly infectious

• Electrolytes - elevated BUN indicating dehydration or - elevated BUN indicating dehydration or 3rd spacing. 3rd spacing.

• Anion gap acidosis - intravascular depletion, - intravascular depletion, Metabolic acidosis (lactic acidosis)Metabolic acidosis (lactic acidosis)

• Coags –abnormal coags may reflect sepsis. Pt. not on Coags –abnormal coags may reflect sepsis. Pt. not on anticoagulation for Afib.anticoagulation for Afib.

• Normal LFTs/ pancreatic enzymes - no signs of - no signs of hepatic/pancreatic insulthepatic/pancreatic insult

Interventions at this point?

Consider the following Interventions

• Admit to the hospital/ICU• Aggressive resuscitation

• Start IV with isotonic crystalloid solution ( NS or LR)

• Insert Foley catheter• Monitor response to resuscitation

• Administer broad spectrum antibiotics• Likely intra-abdominal septic process

Studies

What further studies would you want at this time?

Studies, Mrs. Mitty• Abdominal X-rays

• Flat / UprightFlat / Upright• Acute Abdominal Series (may include chest at some Acute Abdominal Series (may include chest at some

institutions)institutions)

Studies – Results

• Plain abdominal films Diffuse dilation of small bowel w/ air fluid

levels on upright view. Some air in Left colon and Rectum. NO free air

What is the differential diagnosis at this point?

Revised Differential Diagnosis

1) Acute Mesenteric Ischemia

2)2) Strangulated small bowel obstructionStrangulated small bowel obstruction

3)3) Diverticulitis w/ contained perforation?Diverticulitis w/ contained perforation?

What next?

What next?

• Mesenteric Angiogram or CT Angiogram

Discussion

• With the sudden onset of symptoms, h/o Afib, and “pain out of proportion to physical exam,” acute mesenteric ischemia should be high on the Differential Diagnosis

• A mesenteric angiogram will allow visualization of the visceral vessels (celiac, SMA, IMA)

Mesenteric AngiogramMesenteric Angiogram

Note complete lack of contrast in mesenteric vessels in AP view (left). The occluded origins of the celiac axis and superior mesenteric artery are demonstrated

in the Lateral view (right).

CT AngiogramCT Angiogram

Note complete occlusion and lack of IV contrast filling the superior mesenteric artery from its origin from the aorta (Arrows).

Other studies

CT angiogram / MR angiogram

• sensitivity 75%, specificity 100% for emboli• additionally can detect thickened, distended

bowel loops• more sensitive for Mesenteric Venous

Thrombosis

Management

What should be done next?

Management

• Pre-operative preparationPre-operative preparation• Assure adequate resuscitationAssure adequate resuscitation• MonitoringMonitoring• Foley CatheterFoley Catheter

• Urgent explorationUrgent exploration• Surgical embolectomySurgical embolectomy• Assess bowel viabilityAssess bowel viability

Management• Pre-operative preparation

• Assure adequate resuscitationAssure adequate resuscitation• MonitoringMonitoring

• Non-invasive: EKG, BP, Pulse Oximetry, foley catheterNon-invasive: EKG, BP, Pulse Oximetry, foley catheter• Consider invasive monitoring: Central venous catheter, Consider invasive monitoring: Central venous catheter,

PA Catheter ? Arterial line?PA Catheter ? Arterial line?

• Operative Technique/ Urgent exploration• Midline LaparotomyMidline Laparotomy• Relevant AnatomyRelevant Anatomy• Surgical EmbolectomySurgical Embolectomy• Assess bowel viability Assess bowel viability

Surgical EmbolectomySurgical Embolectomy

• Pack bowel to Right, Pack bowel to Right, Expose SMAExpose SMA

• ArteriotomyArteriotomy

• Pass balloon embolectomy Pass balloon embolectomy cathetercatheter

• Assess bowel viabilityAssess bowel viability

• Resect if necessaryResect if necessary

Necrotic bowel from mesenteric ischemia.

Discussion

Acute mesenteric ischemia is a vascular emergency with overall mortality 60-80%. There are four main pathophysiologic processes which have the same common endpoint, bowel necrosis, abdominal sepsis, and death. Mesenteric arterial anatomy is notable for rich collateral flow between the celiac trunk, superior mesenteric artery, and inferior mesenteric artery. Gradual occlusion of 2 of the 3 vessels is tolerable as rich collateral branches form between these. Acute occlusion of any of the vessels or their branches causes acute intestinal ischemia and necrosis..

DiscussionThe four processes:1) Acute arterial embolus -usually from cardiogenic embolus

in pts w/ Afib or valvular disorders. SMA is the common vessel affected as it has a less acute take off from aorta

2) Acute arterial thrombosis - chronic atherosclerotic plaque at origin of vessel acutely thromboses

3) Chronic mesenteric ischemia - atherosclerosis of visceral vessels results in abdominal pain (intestinal angina) during times of increased blood demand (digestion)

4) Acute venous occlusion - venous thrombosis causes cessation of venous outflow from intestines

*Non-occlusive mesenteric ischemia can also be seen in low-flow states

DiscussionDiscussion

DiagnosisDiagnosis - - requires high degree of suspicion. Classically presents as requires high degree of suspicion. Classically presents as “pain out of proportion to physical exam” or severe pain w/o peritoneal “pain out of proportion to physical exam” or severe pain w/o peritoneal signs. The history of Cardiac disease, valvular disease, or Afib should signs. The history of Cardiac disease, valvular disease, or Afib should alert one to an embolic disease. Gold standard for diagnosis is alert one to an embolic disease. Gold standard for diagnosis is mesenteric angiogram, but CT angiogram is more and more being used.mesenteric angiogram, but CT angiogram is more and more being used.

TreatmentTreatment - - requires aggressive resuscitation and hemodynamic requires aggressive resuscitation and hemodynamic monitoring as patients become critically ill very quickly. Urgent surgery monitoring as patients become critically ill very quickly. Urgent surgery w/ viseral revascularization (embolectomy, thrombectomy, w/ viseral revascularization (embolectomy, thrombectomy, endarterectomy, or bypass) is required. After this, evaluation of viability endarterectomy, or bypass) is required. After this, evaluation of viability of bowel segments should be performed with resection of any necrotic of bowel segments should be performed with resection of any necrotic portions.portions.

QUESTIONS ??????

References

• Townsend CM. Sabiston Textbook of Surgery. Townsend CM. Sabiston Textbook of Surgery. 17th Edition17th Edition

• Cameron JL. Current Surgical Therapy. 8th Cameron JL. Current Surgical Therapy. 8th EditionEdition

• Oldenburg et al. Acute Mesenteric Ischemia. Oldenburg et al. Acute Mesenteric Ischemia. Arch Intern Med 164:1054-62. 2004Arch Intern Med 164:1054-62. 2004

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