Acute Mesenteric Ischemia

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Acute Mesenteric Ischemia

• Scott Q. Nguyen, M.D.
• Celia M. Divino, M.D.
• Mount Sinai School of Medicine
• Department of Surgery

2
Mrs. 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.

3
History

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

4
History, Mrs. Mitty
Consider the Following

• Characterization of symptoms
• Temporal sequence
• Alleviating / Exacerbating factors

• Pertinent PMH, ROS, MEDS.
• Associated signs and symptoms
• Relevant family hx.

5
History, Mrs. Mitty

• Characterization of Symptoms
• Sudden onset diffuse abdominal pain and
  distention 4 hours ago.
• Pain not localized to any quadrant.
• Alleviating / Exacerbating factors
• Pain is excruciating, its the worse shes ever
  experienced
• Nothing alleviates it
• Associated signs/symptoms
• She vomits 1L of feculent emesis on arrival to
  ER.
• Last BM 2 hours ago, loose

6
Other History

• PMH
• Atrial Fibrillation - dxd 1 month ago,
  anticoagulation contraindicated with history of
  massive GI bleed
• CHF, CAD, DM
• PSH
• Cholecystectomy, left hemicolectomy for
  diverticular disease
• MEDS
• digoxin, metoprolol, insulin

7
Other History

• Social History
• Occasional wine,
• 50 pack-yr smoker, quit 2 yrs ago
• Family History
• Patient unable to give

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What is your Differential Diagnosis?
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Differential DiagnosisBased on History and
Presentation

• Small Bowel Obstruction
• Acute Mesenteric Ischemia
• Perforated Diverticulitis
• Ischemic Colitis

• Perforated Peptic Ulcer Disease
• Acute Pancreatitis
• Acute Cholecystitis
• Gastroenteritis
• Acute Appendicitis

10
Physical Examination

• What would you look for?

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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
12
Would you like to revise your Differential
Diagnosis?
13
Laboratory

• What would you obtain?

14

Labs ordered, Mrs. Mitty
14
30
133
101
405
18
240
42
1.2
4.9
19
85 PMNs 22 Bands

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

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Lab Results, Discussion

• Leukocytosis - acute process, possibly infectious
• Electrolytes - elevated BUN indicating
  dehydration or 3rd spacing.
• Anion gap acidosis - intravascular depletion,
  Metabolic acidosis (lactic acidosis)
• Coags abnormal coags may reflect sepsis. Pt. not
  on anticoagulation for Afib.
• Normal LFTs/ pancreatic enzymes - no signs of
  hepatic/pancreatic insult

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Interventions at this point?

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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

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Studies

• What further studies would you want at this time?

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Studies, Mrs. Mitty

• Abdominal X-rays
• Flat / Upright
• Acute Abdominal Series (may include chest at some
  institutions)

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(No Transcript)
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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

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• What is the differential diagnosis at this
  point?

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Revised Differential Diagnosis

• Acute Mesenteric Ischemia
• Strangulated small bowel obstruction
• Diverticulitis w/ contained perforation?

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What next?

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What next?

• Mesenteric Angiogram or CT Angiogram

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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)

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

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Management

• What should be done next?

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Management

• Pre-operative preparation
• Assure adequate resuscitation
• Monitoring
• Foley Catheter
• Urgent exploration
• Surgical embolectomy
• Assess bowel viability

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Management

• Pre-operative preparation
• Assure adequate resuscitation
• Monitoring
• Non-invasive EKG, BP, Pulse Oximetry, foley
  catheter
• Consider invasive monitoring Central venous
  catheter, PA
  Catheter ? Arterial line?
• Operative Technique/ Urgent exploration
• Midline Laparotomy
• Relevant Anatomy
• Surgical Embolectomy
• Assess bowel viability

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Surgical Embolectomy

• Pack bowel to Right, Expose SMA
• Arteriotomy
• Pass balloon embolectomy catheter
• Assess bowel viability
• Resect if necessary

Necrotic bowel from mesenteric ischemia.
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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.

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Discussion

• The 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)
• Acute venous occlusion - venous thrombosis causes
  cessation of venous outflow from intestines
• Non-occlusive mesenteric ischemia can also be
  seen in low-flow states

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Discussion

• Diagnosis - requires high degree of suspicion.
  Classically presents as pain out of proportion
  to physical exam or severe pain w/o peritoneal
  signs. The history of Cardiac disease, valvular
  disease, or Afib should alert one to an embolic
  disease. Gold standard for diagnosis is
  mesenteric angiogram, but CT angiogram is more
  and more being used.
• Treatment - requires aggressive resuscitation
  and hemodynamic monitoring as patients become
  critically ill very quickly. Urgent surgery w/
  viseral revascularization (embolectomy,
  thrombectomy, endarterectomy, or bypass) is
  required. After this, evaluation of viability of
  bowel segments should be performed with resection
  of any necrotic portions.

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QUESTIONS ??????
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References

• Townsend CM. Sabiston Textbook of Surgery. 17th
  Edition
• Cameron JL. Current Surgical Therapy. 8th
  Edition
• Oldenburg et al. Acute Mesenteric Ischemia.
  Arch Intern Med 1641054-62. 2004

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