Acute mesenteric ischemia

Presenter: R 蔡逸文

Method

Literature review. MEDLINE/PubMed MeSH term keyword: “mesenteric

ischemia”, “bowel ischemia”, and “bowel infarction”

Exclusion: Isolated colonic ischemia and focal segmental ischemia secondary to adhesions, hernias or other forms of extrinsic compression.

Level of evidence

Classification system used to determine strength of evidence

Presentation and clinical diagnosis etiology

Diagnosis Image

Treatment Vascular procedure Damage control surgery prevention

Which clinical factors should arouse suspicion of AMI in the acute abdomen?

Presentation and clinical diagnosis

Which clinical factors should arouse suspicion of AMI in the acute abdomen?

Acute abdominal pain is disproportionate to the physical examination findings

Early: Nausea, vomiting and initial forced

evacuation

Late if transmural infarction: Fever, bloody diarrhea and shock

Are there any clinical features to distinguish the

etiology of AMI?

Presentation and clinical diagnosis

Arterial thrombosis (TAMI): 25%

Arterial Embolic (EAMI): 45%

Non-occlusive (NOMI): 20%

Venous thrombosis (VAMI): 10%

Embolic MI

CHARACTERISTICS The sudden onset of

severe pain spontaneous

emptying of the bowel (vomiting and diarrhea)

no significant physical findings(40-80%)

RISK FACTOR Atrial fibrillation Rheumatic heart

disease Myocardial infarction Prosthetic valve Ventricular aneurism

Arterial thrombosis MI

CHARACTERISTICS Acute episode, may

be recurrent Prodromal symptoms

of mesenteric angina postprandial abdominal

pain Nausea weight loss

RISK FACTOR Atherosclerosis Dyslipidemia History of other

vascular events, previous vascular surgery

Venous thrombosis MI

CHARACTERISTICS Subacute abdominal

pain Vague complaints Younger population

Thromboembolic AMI in the over 60s

VAMI in the over 40s

RISK FACTOR Hypercoagulability states Abdominal trauma Acute pancreatitis Malignancy Nephrotic syndrome, portal hypertension or

cirrhosis or splenomegaly

Oral contraceptives Pregnancy and the

puerperium

Non-occlusive MI

CHARACTERISTICS Critically ill, sedated

and artificially ventilated Vague complaints

Acute or insidious pain (without defecation)

Mesenteric hypoperfusion secondary to circulatory shock or vasoactive drugs

RISK FACTOR Shock, hypovolemia,

hypotension Digitalis Diuretics beta-blockers, alpha-

adrenergics Enteral nutrition, Critical care support

Can we predict prognosis at presentation, to help

the decision making process?

Presentation and clinical diagnosis

Risk factor for mortality Older age Bandemia, Elevated serum aspartate

aminotransferase, Increased blood urea nitrogen, Metabolic acidosis

Significant co-morbidities and poor performance status

Intestinal necrosis Increased elapsed time to laparotomy(24hr) When the colon was involved

Aliosmanoglu I et al. Int Surg. 2013

Huang HH, et al. Chin Med Assoc. 2005

Gupta PK et al. Surgery. 2011

What is the most sensitive and specific test for the

detection of AMI?

Presentation and clinical diagnosis

Multi-detector computerized tomography scanning (MDCT) with intravenous contrast (LOE: III)

Percutaneous angiography for suspected NOMI (LOE:III)

Radiological features associated with AMI

Pneumatosis intestinalis + hepatic portal or portomesenteric venous gas

↑the likelihood of transmural bowel infarction

Lisa M. Ho, et al. American Journal of Roentgenology. 2007Melanie S. Morris, et al .The American Journal of Surgery. 2008

Is there a role for vasopressor drugs?

Treatment

Vasopressor drugs should be avoided in AMI.

Minimal effect on the splanchnic circulation Dobutamine, low dose dopamine, or milrinone

Cardiac glycosides should not be used as first line treatment of atrial fibrillation/flutter in AMI (LOE: IV).

What is the specific treatment for AMI?

Treatment

Arterial embolism (EAMI)Treatment

Open embolectomy Endovascular embolectomy

percutaneous mechanical aspiration or thrombolysis

percutaneous transluminal angioplasty (PTA) with or without stenting

Arterial thrombosis (TAMI)Treatment-1

Endovascular procedure PTA and stenting Percutaneous aspiration thrombectomy,

local fibrinolysis or intra-arterial drug perfusion

Retrograde open mesenteric stenting After resection of ischemic bowel Failed percutaneous treatment

Arterial thrombosis (TAMI)Treatment-2 Bypass procedures

Antegrade bypass from supraceliac aorta to superior mesenteric trunk

Retrograde bypass from the infra-renal aorta and iliac arteries

Non‑occlusive mesenteric ischemia (NOMI)Treatment

Correcting the underlying cause Improving mesenteric perfusion by

direct infusion of vasodilators. Prostaglandin E1 (alprostadil): 20 mcg

bolus followed by 60–80 mcg/24 h infusion;

papaverine (30–60 mg/h) Infarcted bowel resection(LOE: III)

Venous ischemia (VAMI)Treatment

Systemic anticoagulation (LOE: III) Vascular

Failed medical therapy Transjugular intrahepatic portosystemic

shunting (TIPS) with mechanical aspiration thrombectomy and direct thrombolysis

Percutaneous transhepatic thrombolysis Indirect thrombolysis via the SMA

How should a patient with peritonitis secondary to

AMI be managed?

Treatment

Immediate surgery if comorbidities and clinical condition make curative treatment possible (LOE: III)

Patients considered unsalvageable should have palliative care (LOE: IV)

What is the role of Damage Control Surgery in

AMI?

Treatment

Laparotomy with resection of ischemic bowel (and no anastomosis or stoma)

open thrombectomy (if indicated) A temporary abdominal closure via a

negative pressure wound therapy

ICU and continue resuscitation

scheduled ‘second-look’ procedure within 48 h (LOE: III)

How should bowel viability be assessed at operation?

Treatment

Reassessed after adequate fluid resuscitation and revascularization.

Intra-operative assessment: Doppler ultrasound of the vascular arcade,

fluorescein angiography, indocyanine angiography

A second-look procedure for the doubts of viability of the bowel(LOE: IV).

What limits should be observed in extensive

bowel resection?

Treatment

What limits should be observed in extensive bowel resection?

Restoration of bowel continuity following extensive resection (LOE: III). Improve functional results May avoid the need for long term TPN

Short bowel syndrome often occurs when residual small bowel length <200 cm

The following minimum remaining intestinal lengths must be respected : 100 cm for terminal jejunostomy (colon

removed) 65 cm for jejunocolic anastomosis (colon

retained) 35 cm for jejunoileal anastomosis with retention

of the ileocecal region.Messing B, et al. Gastroenterology.1999

In the elderly patients and in those with significant co-morbidities Significant risk of resection

In younger patients Long term parenteral nutrition The option of subsequent intestinal

transplantation

When is the most appropriate time to

perform an anastomosis in a patient with AMI who needs bowel resection?

Treatment

Anastomosis should be avoided in patients with shock or multiple organ

dysfunction. (LOE: III)

Stoma avoid risks of anastomotic failure and permit easy examination

of the bowel by inspection or endoscopy

What is the role of second‑look laparotomy

Treatment

Access bowel viability after revascularization and resuscitation

possible progression of bowel ischemia? If doubt about the viability of the bowel,

resection of it (LOE: IV).

Bowel anastomosis(LOE: III). Close the wound

Can we improve outcomes in terms of mortality and

morbidity?

Treatment

Symptoms >24hr=> Mortality increases dramatically

Symptoms <12hr=> lowest mortality

Gut viability 100% when <12h 56% when 12~24hr 18% when >24hr

Aliosmanoglu I et al. Int Surg. 2013

Lobo Martinez E , et al. Rev Esp Enferm Dig. 1993

Revascularization performed within 12 h from the onset of symptoms. (LOE: III)

Resection of non-viable bowel should be performed without delay. (LOE: III)

Is there a role for prevention?

Treatment

~60% TAMI have previous symptoms of chronic mesenteric ischemia

~30% EAMI have inadequately treated atrial fibrillation at presentation

Edwards MS, et al. Ann Vasc Surg. 2003

Edwards MS, et al. Ann Vasc Surg. 2003

Elective revascularization for patients with proven CMI (LOE: IV)

Anticoagulants or antiplatelet therapy and statin therapy for patients with mesenteric artery thrombosis (LOE: IV). High risk of coronary thrombosisBj ¨ ornsson S, et al. J Gastrointest Surg 2013

Cho JS, et al. J Vasc Surg. 2002

Life-long anticoagulation, unless contraindicated, for EAMI, prevent recurrence (LOE: IV).

A minimum of 6 months of anticoagulation and survey for thrombophilia or hypercoagulability for VAMI. (LOE: III). Klempnauer J, Surgery.

1997

Daniel G. et al. N Engl J Med 2016

Acosta S, et al. Br J Surg 2008;

Take home message

History, physical examination prompt diagnosis should be achieved

and revascularization performed within 12 h from the onset of symptoms.

Resection of non-viable bowel should be performed without delay

Are there sensitive and specific laboratory tests

for early detection of AMI?

Presentation and clinical diagnosis

Routine laboratory tests reflect disease progression in AMI (LOE: III). Leukocytosis, metabolic acidosis with high anion

gap High level of Lactate, amylase, AST(GOT), lactate

dehydrogenase(LDH) and creatine phosphokinase(CPK)

A normal serum lactate level does not exclude AMI and not be used for diagnosis (LOE: III).