1

Dr. Mohamed AlshekhaniProfessor in Medicine

MBChB-CABM-FRCP-EBGH2016

BO5:1• 1. Abdominal pain due to mesenteric ischemia is • A. Rare.• B. Uncommon.• C. Common.• D. Very common.• E. Not uncommon.

BO5:2• 2. The mortality from acute mesenteric ischemia is: • A. Rare.• B. Uncommon.• C. Common.• D. Very common.• E. Not uncommon.

BO5:3• 3. The most common cause of mesenteric ischemia is: • A. Acute throbosis.• B. Acute embolism.• C. Acute dissection.• D. Chronic atherosclerotic occlusion.• E. Venous thrombosis.

BO5:4• 4. The sequence of events in pathophysiology of acute mesenteric

ischemia include all except: • A. Initial Vasospasm.• B. Intestinal bacterial translocation.• C. Systemic inflammatory response.• D. Vasoconstriction.• E. Intestinal infarction.

BO5:5• 5. Mesenteric ischemia differs from other major organs

atherosclerotic ischemias by being: • A. More common.• B. Less lethal.• C. More common in females.• D. Easier to be diagnosis.• E. All of the above.

BO5:6• 6. The abdominal pain of acute mesenteric ischemia have more

similar characteristics to: • A. Acute appendisitis.• B. Acute cholecystitis.• C. Acute pancreatitis.• D. Bud-Chiari syndrome.• E. Splenic infarction.

BO5:7• 7. The abdominal pain of acute mesenteric ischemia is characterized

by being: • A. Proportional to physical findings.• B. Out of proportion to physical findings.• C. Aggravated by movements.• D. Relieved by movements.• E. Associated with fever.

BO5:8• 8. Clues to acute mesenteric ischemia as a cause of acute abdominal

pain is the presence of: • A. DVT.• B. Recent abdominal surgery.• C. AF &AMI.• D. Presence of diagnosed thrombophilia.• E. Male sex.

BO5:9• 9. Clues to the chronic mesenteric ischemia as a cause of chronic

abdominal pain is the presence of all except: • A. Immediate post-prandial pain.• B. 30 mins post-prandial pain.• C. Food fear.• D. Weight loss.• E. Female sex.

BO5:10• 10. The serum marker suggesting severe acute mesenteric ischemia

is: • A. Albumin.• B. Trasferrin.• C. Lactate.• D. CRP.• E. Transthretin.

BO5:10• 10. Duplex ultrasound as diagnostic aid in mesenteric ischemia is

helpful best for: • A. Acute mesenteric ischemia.• B. Proximal disease.• C. Distal disease.• D. Chronic mesenteric ischemia.• E. Obese patients.

BO5:11• 11. The recommended imaging for the diagnosis of mesenteric

ischemic syndromes is: • A. Duplex ultrasouns.• B. CTA.• C. MRA.• D. Catheter angiography.• E. Endoscopy.

BO5:12• 12. The IVF volume requirements is more: • A. Initially.• B. In advanced disease.• C. Before revascularization intervention.• D. After revascularization intervention.• E. None of the above.

BO5:13• 13. Management of acute mesenteric ischemia include all except: • A. IVF.• B. Antibiotics.• C. Vasodilators.• D. Enteral feeding.• E. Paranteral feeding.

BO5:14• 14. The preferred approach for acute mesenteric ischemia is: • A. Conservative management.• B. Interventional radiology.• C. Open surgery.• D. Laproscopy surgery.• E. None of the above.

BO5:15• 15. The preferred approach for chronic mesenteric ischemia is: • A. Conservative management.• B. Interventional radiology.• C. Open surgery.• D. Laproscopy surgery.• E. None of the above.

Introduction:• Mesenteric ischemia is caused by blood flow insufficient to meet

the metabolic demands of the visceral organs. • The severity & the type of organ involved depend on the affected

vessel& the extent of collateral-vessel blood flow.• The most critical factor influencing outcomes is the speed of

diagnosis & intervention. • Although uncommon cause of abdominal pain<1 of/1000 hospital

admissions, inaccurate or delayed diagnosis can result in catastrophic complications & mortality among acute cases of 60-80%.

Types:• 1.Occlusive arterial disease: Arterial obstruction, most common;

acute &chronic forms. • A. Acute mesenteric ischemia constitutes a surgical emergency: • 1.Embolic occlusion in 40-50% of cases• 2.Thrombotic occlusion of a previously stenotic mesenteric vessel in

20 -35% • 3.Dissection or inflammation of the artery in <5%.

Types:• B. Chronic mesenteric ischemia:• 1.>90% related to progressive atherosclerotic disease of the origins

of the visceral vessels; treated with elective revascularization to avert the risk of complications& death associated with the development of acute ischemia.

• 2. Mesenteric venous thrombosis, accounts for 5-15%, results in impaired venous outflow, visceral edema&abdominal pain,caused by primary or idiopathic thrombosis& 90% of cases related to thrombophilia, trauma, or local inflammation as pancreatitis, diverticulitis, or inflammation or infection in the biliary system.

• Patients typically respond to anticoagulation in combination with treatment for underlying local or systemic processes.

• Surgical intervention is reserved for patients who are critically ill or whose condition is deteriorating; it is rarely required.

Types:• 2. Non-occlusive mesenteric ischemia:• it accounts for 5-15% of all cases of mesenteric ischemia,most often

associated with cardiac insufficiency or low-flow states after cardiac surgery or hypovolemia or heart failure& hemodialysis.

• The mesenteric circulation is a high-resistance vascular bed in which impaired regional perfusion owing to vasospasm can develop.

• The incidence of non-occlusive mesenteric ischemia may be decreasing as awareness of the condition increases &supportive therapies improve.

Pathophysiology:• Mesenteric Circulation:• Extremely complex.• 3 primary vessels — the celiac artery, superior mesenteric artery, &

inferior mesenteric artery — interconnect through collateral networks between the visceral & non-visceral circulations.

• These interconnections ensure that the loss of a single vessel does not lead to catastrophic malperfusion of the viscera.

• The acute occlusion of a single vessel (typically the superior mesenteric artery) in acute mesenteric ischemia can result in profound ischemia caused by the loss of blood flow through this key vessel & its collateral vascular network.

• In chronic mesenteric ischemia, additional collateral networks develop over time; symptoms often do not appear until occlusion of two or more primary vessels occurs.

Pathophysiology:• Causes of altered mesenteric circulation:• Often obstruction or diminished blood flow , with resulting hypoxia.• Vasodilatation is the initial response, but prolonged ischemia leads

to vasoconstriction, which can persist even after intestinal blood flow returns to normal.

• This early injury primarily affects the intestinal mucosa&submucosa potentially impairs mechanisms that prevent the translocation of bacteria from the intestinal lumen.

• Sequence of events result in the activation of systemic inflammatory pathways & ultimately worsened vasospasm, further regional ischemia& more extensive injury to the bowel wall.

• Without intervention, the damage can progress to full-thickness injury, infarction & death.

History & PE:• In contrast to other vascular disorders, mesenteric ischemia

primarily affects women; > 70% are female.• The physician should assess the patient’s records& the results of

the examination for any evidence of other atherosclerotic & vascular diseases, including PAD, cerebrovascular,CAD, &renovascular disease.

• Other pulmonary &CV conditions must be identified & managed, since they are often coexisting &may limit the available options for revascularization.

History & PE:• Features of acute mesenteric ischemia:• May initially present with classic “pain out of proportion to

examination,” with an epigastric bruit; many, however, do not. • Others may have tenderness with palpation owing to peritoneal

irritation caused by full thickness bowel injury. • In a patient with abdominal pain of acute onset, it is critical to

assess the possibility of atherosclerotic disease&potential sources of an embolus, including a history of AF &AMI.

• Patient’s description of the history & symptoms can be unclear because of changes in mental status, particularly if elderly.

• Patients with mesenteric venous compared with acute arterial occlusion, present with a less abrupt onset of abdominal pain.

• Risk factors for venous thrombosis: H/O deep venous thrombosis, cancer, CLD or PVT, recent abd surgery, inflammatory disease & thrombophilia.

History & PE:• Features of chronic mesenteric ischemia:• Can present with a variety of symptoms, including abd pain, PP

pain, nausea or vomiting (or both), early satiety, diarrhea or constipation(or both)&weight loss.

• A detailed inquiry into the abd pain &relationship to eating can be enlightening.

• Abdominal pain 30 - 60 minutes after eating is common&often self-treated with food restriction, resulting in weight loss &in extreme situations, fear of eating, or “food fear.”

• PP Pain DD: biliary disease,peptic ulcer disease, pancreatitis, diverticular disease, gastric reflux, irritable bowel syndrome&gastroparesis.

History & PE:• An extensive GE workup, including even cholecystectomy , OGD&

lower endoscopy —often negative ,carried out before the diagnosis. • An important distinction: these alternatives do not involve weight

loss, whereas it is common in cases of mesenteric ischemia.• Since older age &H/O smoking are common in these patients,

cancer is often considered& may delay the identification of chronic mesenteric ischemia.

• Particularly in the case of elderly women with a history of weight loss, dietary changes& systemic vascular disease, chronic mesenteric ischemia must be seriously considered&evaluated appropriately.

Lab:• Most useful in acute mesenteric ischemia are the assessment of

fluid, electrolyte, ABB& evaluation for infection. • Many present with acidosis due to dehydration&decreased intake. • Lactic acidosis often indicates at least segmental, severe ischemia or

irreversible bowel injury&not helpful to wait for evidence of increasing serum lactate to proceed with further testing & intervention would occur before lactic acidosis develops, with the goal of saving additional intestine from full-thickness injury.

• A left shift neutrophils or high WBC may indicate full-thickness injury to the bowel wall or ischemia with bacterial translocation.

• S. biomarkers not proved valuable for the early detection&no clinically useful biomarkers, owing to the hepatic metabolism of complex proteins secreted by the intestine.

• Nutritional status; albumin, transthyretin, transferrin, CRP, are the only studies of value in cases of chronic mesenteric ischemia.

Imagings:• Ultrasonography:• Duplex U/S has a high degree of reliability & reproducibility, with

sensitivity/specificity of 85-90%.• It is effective, low-cost, helpful in the assessment of the proximal

visceral vessels, but limited more distally.• It is extremely operator dependent.• Difficult to obtain in patients with obesity, bowel gas,heavy

calcification in the vessels,patients with acute mesenteric ischemia because of the length of the study &abdominal pressure required; so best reserved for the evaluation of patients with chronic mesenteric ischemia& for monitoring after intervention.

Imagings:• CTA: hs 95-100% accuracy, the recommended imaging for the

diagnosis of visceral ischemic syndromes, its benefits:• Imaging origins&length of the vessels obtained rapidly• Indicate extent of stenosis or occlusion.• The relationship to branch vessels.• Aid in the assessment of options for revascularization.• indicate potential sources of emboli.• Shows other intra-abd structures&pathologies as the lack of

enhancement or thickening of bowel wall &mesenteric stranding. • Shows pneumatosis, free intraabdominal air, portal venous gas.• CTA should be performed with IV contrast &reconstruction of

images with thin axial images (1-3 mm). • Sensitivity of CTA is not as high for venous thrombosis,but improved

with two-phase imaging to enhance visceral venous drainage

Imagings:• MRA: attractive option provide information about flow & avoid the

risks of radiation&use of contrast associated with CTA. • It test takes longer to perform than CTA, lacks the necessary

resolution&can overestimate the degree of stenosis.• Currently CTA imaging is almost always the preferred choice&its

advantages outweigh any risks.

Imagings:• Endoscopy: most useful in diagnosing conditions other than

mesenteric ischemia as inflammatory&ischemic changes in the stomach and proximal small bowel, rectum&right colon.

• Does not reach the majority of sections of the small bowel that are most frequently involved in mesenteric ischemia.

• Only sensitive in identifying late changes, including infarction, but lacks sensitivity / specificity in detecting more subtle ischemic changes.

Imagings:• Catheter angiography: usually for therapeutic intervention rather

than for diagnosis. • Revascularization with selective catheterization of mesenteric

vessels, then single or complementary endovascular therapies, including thrombolysis,angioplasty with or without stenting& intraarterial vasodilation combined to restore blood flow.

• Angiography can also be used to confirm the diagnosis before open abd exploration is undertaken.

Management:IVF,Electrolytes• Fluid&Electrolyte Management:• Fluid resuscitation with isotonic crystalloid&blood as needed. • Serial monitoring of electrolytes& acid–base status should be

performed& invasive hemodynamic monitoring should be implemented early especially in acute mesenteric ischemia, in whom severe metabolic acidosis & hyperkalemia can develop as a result of infarction with the potential for rapid decompensation to a SIR or progression to sepsis.

• In hemodynamic instability; carefully adjust fluid volume while avoiding fluid overload &pressor agents only as a last resort.

• The fluid-volume requirement can be very high, especially after revascularization, because of the extensive capillary leakage; as much as 10-20 liters of crystalloid fluid may be required during the first 24 hours after the intervention.

Management:IVF,Electrolytes• Early Medical Therapy:• Heparin should be initiated as soon as possible in patients who have

acute ischemia or an exacerbation of chronic ischemia. • Vasodilators may play a role in care, particularly in combating

persistent vasospasm in patients with acute ischemia after revascularization.

• Bacterial translocation & sepsis develop& the high risk of infection among outweighs the risks of antibiotic use, and therefore broad-spectrum antibiotics should be administered early.

• Oral intake should be avoided in patients with acute mesenteric ischemia, since it can exacerbate intestinal ischemia.

• In chronic mesenteric ischemia, enteral nutrition (as long as it does not cause pain) or parenteral nutrition should be considered in order to improve perfusion by means of mucosal vasodilation & to provide nutritional&immunologic benefits.

Management:interventions• Acute Mesenteric Ischemia: Endovascular interventions successful

in 87%, in-hospital mortality lower than open surgery (36% v 50%).• This strategy may be most appropriate for patients with ischemia

not severe &those who have severe coexisting conditions that place them at high risk for complications&death with open surgery.

• Most often mechanical thrombectomy or angioplasty & stenting.• Thrombolysis is safe/effective in treating both embolic &

thrombotic occlusions& an adjunct to remove the additional burden of thrombus in patients without peritonitis,especially helpful in restoring perfusion to occluded arterial branches.

• 31% who received endovascular therapy were spared laparotomy. • If endovascular-only therapy is pursued, close monitoring is

compulsory&any clinical deterioration or peritonitis necessitates operative exploration as emergency as 28-59% will ultimately require bowel resection.

Management:interventions• Acute Mesenteric Ischemia: Open Repair• Emboli causing acute occlusion typically lodge within proximal SMA

have good response to surgical embolectomy.• If embolectomy is unsuccessful, arterial bypass may be performed. • If distal perfusion remains impaired, local intraarterial doses of

thrombolytic agents can be administered.• A hybrid option, retrograde open mesenteric stenting, involves local

thromboendarterectomy& angioplasty, followed by retrograde stenting,reduces the extent of surgery while allowing for direct assessment of the bowel

• Short-term mortality after open revascularization ranges from 26- 65%, higher with renal insufficiency, older age, metabolic acidosis, a longer duration of symptoms, and bowel resection at the time of a second-look operation.

Management:interventions• Chronic Mesenteric Ischemia:• Revascularization is indicated for all symptomatic patients. • Now with endovascular repair, used in 70-80% of initial procedures.• Stenting is used most often. • Open repair can be performed with the use of antegrade inflow or

retrograde inflow (from the iliac artery), with either a vein or prosthetic conduit to bypass one or more vessels, depending on the extent of disease.

• Hybrid procedures involving open access to the superior mesenteric artery &retrograde stenting, are also options.

• Endovascular therapy is a very successful,minimally invasive approach that provides initial relief of symptoms in up to 95% & has a lower rate of serious complications than open repair.

Management:interventions• Chronic Mesenteric Ischemia• Despite these advantages, the use of endovascular techniques is

associated with lower rates of long-term patency &shorter time to the return of symptoms,restenosis occurs in 40% & 20 - 50% will require re-intervention.

• Open repair is associated with slower recovery & longer hospital stays than endovascular repair.

• In most centers, endovascular therapy is considered to be first-line therapy, particularly in patients with short, focal lesions,In contrast, open repair may be a preferable option for younger, lower-risk patients with a longer life expectancy.

Management:interventions• Venous Mesenteric Ischemia• Unless such treatment is contraindicated, all patients should initially

receive heparin transitioned to long-term oral coagulation 24 - 48 hours after stabilization of the acute condition.

• 5% deteriorate, need transhepatic & percutaneous mechanical thrombectomy, thrombolysis,open intraarterial thrombolysis.

• Any evidence of peritonitis, stricture, or GIB should trigger an exploratory laparotomy to assess for the possibility of bowel necrosis &need for a second-look operation.

• The long-term mortality is heavily influenced by the underlying cause of thrombosis; 30-day survival is 80%&5-year survival is 70%.

Management:interventions• Nonocclusive Mesenteric Ischemia• The outcomes depend on the management of the underlying cause;

overall mortality is 50-83%. • The initial goal is to address hemodynamic instability to minimize

the use of systemic vasoconstrictors. • Additional treatment may include systemic anticoagulation and the

use of vasodilators in patients who do not have bowel infarction. • Catheter-directed infusion of vasodilatory&antispasmodic agents,

most commonly papaverine hydrochloride, can be used.• Patients should be monitored closely by means of serial abdominal

examinations&open surgical exploration should be performed if there is concern about the possibility of peritonitis.

Management:Follow-up• Long-Term Care:• Aggressive smoking-cessation measures, blood-pressure control&

statin.• Lifelong preventive treatment with aspirin is recommended in all

patients who undergo endovascular or open repair. • Patients who undergo endovascular repair should also receive

clopidogrel for 1 - 3 months after the procedure. • Regardless of the type of repair performed, in patients with atrial

fibrillation, mesenteric venous thrombosis, or inherited or acquired thrombophilia, oral anticoagulant therapy is indicated&should be continued indefinitely or until the underlying cause of embolism or thrombosis has resolved.

Management:Follow-up• Long-Term Care:• Nutritional status & body weight monitored in all patients who have

undergone an intervention for mesenteric ischemia. • These patients may have prolonged ileus, food fear&require total

parenteral nutrition until full oral intake is possible.• In bowel resection, diarrhea / malabsorption may occur. • Extensive nutritional support, lifelong total parenteral nutrition, or

even evaluation for small-bowel transplantation may be required in patients with persistent short-gut syndrome.

• Assessment:• Lifelong repeated assessment of vascular patency is indicated.

Duplex ultrasonography should be performed every 6 months for the first year after repair, then yearly thereafter.

Conclusion:• Mesenteric ischemia is one of the least common causes of

abdominal pain, but associated with extremely high risk. • Despite the variety of presentations & causes of mesenteric

ischemia, it always presents a diagnostic challenge&has the potential for catastrophic, lifethreatening consequences.

• Early consideration&evaluation of this disease &underlying causes in patients with abdominal pain are critical to timely diagnosis & improved outcomes.

BO5:1• 1. Abdominal pain due to mesenteric ischemia is • A. Rare.• B. Uncommon.• C. Common.• D. Very common.• E. Not uncommon.

BO5:2• 2. The mortality from acute mesenteric ischemia is: • A. Rare.• B. Uncommon.• C. Common.• D. Very common.• E. Not uncommon.

BO5:3• 3. The most common cause of mesenteric ischemia is: • A. Acute throbosis.• B. Acute embolism.• C. Acute dissection.• D. Chronic atherosclerotic occlusion.• E. Venous thrombosis.

BO5:4• 4. The sequence of events in pathophysiology of acute mesenteric

ischemia include all except: • A. Initial Vasospasm.• B. Intestinal bacterial translocation.• C. Systemic inflammatory response.• D. Vasoconstriction.• E. Intestinal infarction.

BO5:5• 5. Mesenteric ischemia differs from other major organs

atherosclerotic ischemias by being: • A. More common.• B. Less lethal.• C. More common in females.• D. Easier to be diagnosis.• E. All of the above.

BO5:6• 6. The abdominal pain of acute mesenteric ischemia have more

similar characteristics to: • A. Acute appendisitis.• B. Acute cholecystitis.• C. Acute pancreatitis.• D. Bud-Chiari syndrome.• E. Splenic infarction.

BO5:7• 7. The abdominal pain of acute mesenteric ischemia is characterized

by being: • A. Proportional to physical findings.• B. Out of proportion to physical findings.• C. Aggravated by movements.• D. Relieved by movements.• E. Associated with fever.

BO5:8• 8. Clues to acute mesenteric ischemia as a cause of acute abdominal

pain is the presence of: • A. DVT.• B. Recent abdominal surgery.• C. AF &AMI.• D. Presence of diagnosed thrombophilia.• E. Male sex.

BO5:9• 9. Clues to the chronic mesenteric ischemia as a cause of chronic

abdominal pain is the presence of all except: • A. Immediate post-prandial pain.• B. 30 mins post-prandial pain.• C. Food fear.• D. Weight loss.• E. Female sex.

BO5:10• 10. The serum marker suggesting severe acute mesenteric ischemia

is: • A. Albumin.• B. Trasferrin.• C. Lactate.• D. CRP.• E. Transthretin.

BO5:10• 10. Duplex ultrasound as diagnostic aid in mesenteric ischemia is

helpful best for: • A. Acute mesenteric ischemia.• B. Proximal disease.• C. Distal disease.• D. Chronic mesenteric ischemia.• E. Obese patients.

BO5:11• 11. The recommended imaging for the diagnosis of mesenteric

ischemic syndromes is: • A. Duplex ultrasouns.• B. CTA.• C. MRA.• D. Catheter angiography.• E. Endoscopy.

BO5:12• 12. The IVF volume requirements is more: • A. Initially.• B. In advanced disease.• C. Before revascularization intervention.• D. After revascularization intervention.• E. None of the above.

BO5:13• 13. Management of acute mesenteric ischemia include all except: • A. IVF.• B. Antibiotics.• C. Vasodilators.• D. Enteral feeding.• E. Paranteral feeding.

BO5:14• 14. The preferred approach for acute mesenteric ischemia is: • A. Conservative management.• B. Interventional radiology.• C. Open surgery.• D. Laproscopy surgery.• E. None of the above.

BO5:15• 15. The preferred approach for chronic mesenteric ischemia is: • A. Conservative management.• B. Interventional radiology.• C. Open surgery.• D. Laproscopy surgery.• E. None of the above.