1. Vascular disease of the bowel refers to conditions that affect the blood vessels supplying the intestines, including mesenteric artery disease where plaque builds up in the abdominal arteries. 2. Mesenteric ischemia occurs when there is insufficient blood flow to the intestines, and can be acute or chronic. Acute ischemia presents with sudden severe abdominal pain while chronic ischemia causes gradual pain after eating. 3. Diagnosis involves blood tests, imaging like CT scans, and angiography. Treatment depends on the cause but may include revascularization procedures or bowel resection if tissue has died. Prompt diagnosis and treatment can help avoid poor outcomes.

1. PERM STATE MEDICAL
UNIVERSITY
VASCULAR DISEASES OF
THE BOWEL
-JOISY ALOOR
5TH YEAR

2. DEFINITION
Vascular disease is a class of diseases of the blood vessels –
the arteries and veins of the circulatory system of the body.
Disorders in this vast network of blood vessels, can cause a
range of health problems which can be severe or prove
fatal.

3. MECHANISM
Vascular disease is a pathological state of large and medium
muscular arteries and is triggered by endothelial cell dysfunction.
Because of factors like pathogens, oxidized LDL particles and other
inflammatory stimuli endothelial cells become active.
The process causes thickening of the vessel wall, forming a plaque
that consists of proliferating smooth muscle cells, macrophages and
lymphocytes.
The plaque results in a restricted blood flow which will decrease the
amount of oxygen and nutrients that reach certain organs, the
plaque might rupture causing the formation of clots.

4. 1. MESENTERIC ARTERY DISEASE
Mesenteric (or intestinal) artery disease is a condition that develops
when the arteries in the abdomen that supply the intestines become
narrowed, or blocked, by an accumulation of a fatty substance called
plaque. As plaque builds up inside the artery walls, the arteries can
become hardened and narrowed (a process called atherosclerosis).
As atherosclerosis affects the whole body, people with mesenteric
artery narrowing often have other cardiovascular conditions such as
carotid artery disease and heart disease. In mesenteric artery disease,
the arteries supplying blood to the intestines are narrowed; people
with this condition lose weight and experience severe pain when they
eat.

5. RISK FACTORS AND SYMPTOMS OF
MESENTERIC ARTERY DISEASE
Risk factors for mesenteric artery disease include smoking - the
number one risk factor for all cardiovascular diseases - a family
history of atherosclerosis, high blood pressure, diabetes, high
cholesterol, advanced age, obesity, and a sedentary lifestyle.
In patients with mesenteric artery disease, they can experience
weight loss and severe abdominal pain when they eat. These
patients can also experience other symptoms including vomiting,
dizziness, and low blood pressure due to accumulation of acid (or
acidosis) in the blood.

7. DIAGNOSTIC TESTS
Duplex ultrasound
Angiography
Magnetic resonance angiography (MRA)
CT scan

8. Most patients with an acute occlusion of the superior mesenteric artery require
immediate revascularization to survive. Approximately 20–30% can survive with
bowel resection only, especially with distal embolism. In other cases,
revascularization must be attempted. Whether revascularization or bowel
inspection (with possible resection) should be performed first is controversial.
Data suggest that revascularization should be attempted first, unless there is
serious peritonitis and septic shock.
Another controversy is to determine whether open surgery or endovascular
therapy of the occluded superior mesenteric artery should be attempted as first
choice. Hybrid intervention is an alternative, with retrograde operative
mesenteric stenting, where the superior mesenteric artery is punctured in the
open abdomen, followed by stenting.

9. In the case of embolic occlusion, open and endovascular revascularizations seem to do
equally well, whereas with thrombotic occlusion, endovascular therapy is associated
with lower mortality and bowel resection rates. The principles of damage control
surgery are important to follow when treating these frail patients. This concept focuses
on saving life by restoring normal physiology as quickly as possible, so avoiding
unnecessary time-consuming procedures. Although laparotomy is not mandatory after
endovascular therapy in these patients with acute bowel ischemia, it is often necessary
to inspect the bowel.
In this setting, second-look laparotomy is also indicated after open revascularization.
Intra-arterial catheter thrombolysis of the superior mesenteric artery has been
reported with good results. Severe bleeding complications were uncommon, except
when intestinal mucosal gangrene was present.

11. SURGICAL OPTIONS
Endarterectomy: Involves the surgical removal of plaque build-
up on the inner lining of the artery.
Bypass Grafting: Redirects blood flow around an area of
blockage. The procedure creates an alternate channel for blood
flow, bypassing an obstructed or damaged vessel. The graft
may come from a healthy section of the patient's own vein, or
from a synthetic material such as Dacron.

12. ENDOVASCULAR OPTIONS
Balloon Angioplasty and Stenting: A catheter with a small balloon at
the end is inserted through an artery in the groin and guided to the
narrowed segment of the artery. When the catheter reaches the
blockage, the balloon is inflated to widen the narrowed artery
(known as balloon angioplasty).
In some cases, it may be necessary to place a stent (a wire-mesh
tube that expands to hold the artery open). The stent is left
permanently in the artery to provide a reinforced channel for blood
flow.

14. MESENTERIC ISCHEMIA
Mesenteric ischemia is a medical condition in which injury to the
small intestine occurs due to not enough blood supply. It can come
on suddenly, known as acute mesenteric ischemia, or gradually,
known as chronic mesenteric ischemia.
The acute form of the disease often presents with sudden severe
abdominal pain and is associated with a high risk of death. The
chronic form typically presents more gradually with abdominal pain
after eating, unintentional weight loss, vomiting, and fear of eating.

16. RISK FACTORS
Atrial fibrillation
Heart failure
Chronic kidney failure
Being prone to forming blood clots
Previous myocardial infarction.
There are four mechanisms by which poor blood flow occurs: a blood clot from
elsewhere getting lodged in an artery, a new blood clot forming in an artery, a
blood clot forming in the superior mesenteric vein, and insufficient blood flow
due to low blood pressure or spasms of arteries. Chronic disease is a risk factor
for acute disease.

17. EPIDEMIOLOGY
Acute mesenteric ischemia affects about five per hundred thousand
people per year in the developed world.
Chronic mesenteric ischemia affects about one per hundred
thousand people. Most people affected are over 60 years old.
Rates are about equal in males and females of the same age.
Mesenteric ischemia was first described in 1895.
Acute mesenteric ischemia was first described in 1895 while chronic
disease was first described in the 1940s. Chronic disease was initially
known as angina abdominis.

18. SIGNS AND SYMPTOMS
While not always present and often overlapping, three progressive phases of mesenteric
ischemia have been described:
A hyper active stage occurs first, in which the primary symptoms are severe abdominal pain
and the passage of bloody stools. Many patients get better and do not progress beyond this
phase.
A paralytic phase can follow if ischemia continues; in this phase, the abdominal pain becomes
more widespread, the belly becomes more tender to the touch, and bowel motility decreases,
resulting in abdominal bloating, no further bloody stools, and absent bowel sounds on exam.
Finally, a shock phase can develop as fluids start to leak through the damaged colon lining. This
can result in shock and metabolic acidosis with dehydration, low blood pressure, rapid heart
rate, and confusion. Patients who progress to this phase are often critically ill and require
intensive care.

19. Symptoms of mesenteric ischemia vary and can be acute (especially if embolic), sub acute, or chronic.
Case series report prevalence of clinical findings and provide the best available, yet biased, estimate
of the sensitivity of clinical findings. In a series of 58 patients with mesenteric ischemia due to mixed
causes:
abdominal pain was present in 95% (median of 24 hours duration). The other three patients
presented with shock and metabolic acidosis.
nausea in 44%
vomiting in 35%
diarrhea in 35%
heart rate > 100 in 33%
rectal bleeding in 16% (not stated if this number also included occult blood – presumably not)
constipation in 7%

21. DIAGNOSIS
It is difficult to diagnose mesenteric ischemia early. One must also differentiate ischemic colitis,
which often resolves on its own, from the more immediately life-threatening condition of acute
mesenteric ischemia of the small bowel.
BLOOD TESTS:
In a series of 58 patients with mesenteric ischemia due to mixed causes:
White blood cell count >10.5 in 98% (probably an overestimate as only tested in 81% of patients)
Lactic acid elevated 91% (probably an overestimate as only tested in 57% of patients)
In very early or very extensive acute mesenteric ischemia, elevated lactate and white blood cell
count may not yet be present. In extensive mesenteric ischemia, bowel may be ischemic but
separated from the blood flow such that the byproducts of ischemia are not yet circulating.

22. ENDOSCOPY:
Findings on gastroscopy may include edematous gastric mucosa, and hyper peristalsis.
Finding on colonoscopy may include: fragile mucosa, segmental erythema, longitudinal ulcer,
and loss of haustrations.
PLAIN X-RAY:
Plain X-rays are often normal or show non-specific findings.

23. COMPUTED TOMOGRAPHY:
Computed tomography (CT scan) is often used. The accuracy of the CT scan depends on whether
a small bowel obstruction (SBO) is present.
Early findings on CT scan include:
Mesenteric edema
Bowel dilatation
Bowel wall thickening
Mesenteric stranding
Evidence of adjacent solid organ infarctions to the kidney or spleen, consistent with a cardiac
embolic shower phenomenon

24. In embolic acute mesenteric ischemia, CT-Angiography can be of great value for diagnosis and
treatment. It may reveal the emboli itself lodged in the superior mesenteric artery, as well as the
presence or absence of distal mesenteric branches.
Late findings, which indicate dead bowel, include:
Intramural bowel gas
Portal venous gas
Free abdominal air
ANGIOGRAPHY:
As the cause of the ischemia can be due to embolic or thrombotic occlusion of the mesenteric vessels
or nonocclusive ischemia, the best way to differentiate between the etiologies is through the use of
mesenteric angiography. Though it has serious risks, angiography provides the possibility of direct
infusion of vasodilators in the setting of nonocclusive ischemia.

26. TREATMENT
The treatment of mesenteric ischemia depends on the cause, and can be medical or surgical.
However, if bowel has become necrotic, the only treatment is surgical removal of the dead
segments of bowel.
In non-occlusive mesenteric ischemia, where there is no blockage of the arteries supplying the
bowel, the treatment is medical rather than surgical. People are admitted to the hospital for
resuscitation with intravenous fluids, careful monitoring of laboratory tests, and optimization of
their cardiovascular function. NG tube decompression and heparin anticoagulation may also be
used to limit stress on the bowel and optimize perfusion, respectively.
Surgical revascularization remains the treatment of choice for mesenteric ischemia related to an
occlusion of the vessels supplying the bowel, but thrombolytic medical treatment and vascular
interventional radiological techniques have a growing role.

27. If the ischemia has progressed to the point that the affected intestinal segments are
gangrenous, a bowel resection of those segments is called for. Often, obviously dead segments
are removed at the first operation, and a second-look operation is planned to assess segments
that are borderline that may be savable after revascularization.
METHODS FOR REVASCULARIZATION:
Open surgical thrombectomy
Mesenteric bypass
Trans-femoral antegrade mesenteric angioplasty and stenting
Open retrograde mesenteric angioplasty stenting
Trans-catheter thrombolysis

28. PROGNOSIS
The prognosis depends on prompt diagnosis (less than 12–24 hours and before
gangrene) and the underlying cause:
Venous thrombosis: 32% mortality
Arterial embolism: 54% mortality
Arterial thrombosis: 77% mortality
Non-occlusive ischemia: 73% mortality.
In the case of prompt diagnosis and therapy, acute mesenteric ischemia can be
reversible.