3. DEFINITION :
Gastro-vascular disorder
Third and final portion of the duodenum is
compressed between the abdominal aorta (AA)
and the overlying superior mesenteric artery
(SMA).
Rare
Potentially life-threatening syndrome
Caused by an angle of 6°–25° between the AA and
the SMA,
in comparison to the normal range of 38°–56°,
Aortomesenteric distance is 2–8 millimeters,
4. OTHER NAMES TO THE
SYNDROME :
1. Wilkie's syndrome
2. Cast syndrome
3. Mesenteric root syndrome
4. Chronic duodenal ileus
5. Intermittent arterio-mesenteric occlusion
It is distinct from nutcracker syndrome, which is
the entrapment of the left renal vein between the
AA and the SMA, although it is possible to be
diagnosed with both conditions.
5.
6.
7. ETIOLOGY
•Any condition involving:
1. an insubstantial cushion and
2. narrow mesenteric angle.
•It can present in two forms:
1.Chronic/Congenital or
2.Acute/Induced.
8. ETIOLOGY CONTINUED…
1. Chronic/congenital form of SMA syndrome
•lengthy or even lifelong history of abdominal complaints
•intermittent exacerbations depending on the degree of
duodenal compression.
Predisposition is easily aggravated
by any of the following:
poor motility of the digestive tract,
retroperitoneal tumors,
loss of appetite,
malabsorption, cachexia,
exaggerated lumbar lordosis,
visceroptosis,
abdominal wall laxity,
peritoneal adhesions,
abdominal trauma,
rapid linear adolescent growth
spurt,
weight loss,
starvation,
catabolic states (as
9. 2.Acute form of SMA syndrome
develops rapidly after traumatic
incidents that forcibly hyper-extend
the SMA across the duodenum,
inducing the obstruction, or sudden
weight loss for any reason.
Causes include :
prolonged supine bed rest,
scoliosis surgery,
left nephrectomy,
ileo-anal pouch surgery.
10. CLINICAL PRESENTATION
1. In Children and Adults:
• Early satiety,
• Nausea,
• Bilious and semidigested vomiting,
• Extreme "stabbing" postprandial abdominal pain
(due to both the duodenal compression and the
compensatory reversed peristalsis),
• Abdominal distention/distortion,
• Burping,
• External hypersensitivity or tenderness of the abdominal
area,
11. 2. In infants, feeding difficulties and poor weight gain
are also frequent symptoms.
3. Cycle of worsening symptoms – severe malnutrition –
Wasting – Duodenal compression
4. Fear of eating is a commonly seen among those with the
chronic form of SMA syndrome.
5. For many, symptoms are partially relieved when in
the left lateral decubitus
or knee-to-chest position,
or in the prone (face down) position.
6. A. Hayes maneuver, which corresponds to applying
pressure below the umbilicus in cephalad and dorsal
direction, elevates the root of the SMA, also slightly
12. DIAGNOSIS
Is very difficult, and usually one of exclusion.
Diagnosis may follow X-ray examination revealing duodenal
dilation followed by abrupt constriction proximal to the
overlying SMA.
Standard diagnostic exams include
• abdominal and pelvic CT scan with oral and IV contrast,
• upper gastrointestinal series (UGI), and,
• for equivocal cases, hypotonic duodenography.
Criteria in CT scan : is aortomesenteric angle of
<22 degree and distance of < 10-8 mm.
In children, an angle of less 20 degree.
The reason for the persistence of gastrointestinal symptoms
even after surgical correction in some cases has been
traced to the remaining prominence of reversed peristalsis in
contrast to direct peristalsis.
16. TREATMENT
•According to a number of recent sources, at least
70% of cases can typically be treated with
medical treatment, while the rest require surgical
treatment.
•In some cases, emergency surgery is necessary
upon presentation.
•Treatment includes :
1. Medical management
2. Surgical management
17. MEDICAL MANAGEMENT
•A 6 week trial of medical treatment is
recommended in pediatric cases.
•The goal of medical treatment is resolution of
underlying conditions and weight gain.
•Medical treatment may involve
1. nasogastric tube placement for duodenal and gastric
decompression,
2. mobilization into the prone or left lateral decubitus
position,
3. the reversal or removal of the precipitating factor
with proper nutrition and replacement of fluid
and electrolytes, either by
1.surgically inserted jejunal feeding tube,
2.nasogastric intubation,
18. SURGICAL MANAGEMENT
•The most common operation for SMA syndrome,
duodenojejunostomy.
•Less common surgical treatments for SMA syndrome
include
1. Roux-en-Y duodenojejunostomy,
2. gastrojejunostomy,
3. anterior transposition of the third portion of the duodenum,
4. intestinal derotation,
5. division of the ligament of Treitz (Strong's operation), and
6. transposition of the SMA.
Both transposition of the SMA and lysis of the
duodenal suspensory muscle have the advantage that
they do not involve the creation of an intestinal
19.
20. SUMMARY
Caused by an angle of 6°–25° between the AA and the SMA,
in comparison to the normal range of 38°–56°,
Aortomesenteric distance is 2–8 millimeters,
as opposed to the typical 10–20 at the level of L3
Occurs due to a lack of retroperitoneal and visceral fat (mesenteric fat).
•two forms:
• Chronic/Congenital or
• Acute/Induced.
•Criteria in CT scan : is aortomesenteric angle of <22 degree and distance of < 10-8
mm. In children, an angle of < 20 degree.
•At least 70% of cases can typically be treated with medical
treatment, while the rest require surgical treatment
•most common operation for SMA syndrome, duodenojejunostomy
