1. Superior mesenteric artery syndrome (SMA syndrome)
12+3 minutes
Slide 12, 24
Joint hospital surgical grandround 19/7/2014
Cheung Hing Fong

2. ` Case presentation Pathophysiology Predisposing conditions
Epidemiology
Diagnosis and imaging finding
Treatment
Summary `

3. Case presentation c/o: increased vomiting and weight loss for 3 months
Phx
Scoliosis with OT done >20years ago
SMA syndrome diagnosed in 2011, on conservative treatment
c/o: increased vomiting and weight loss for 3 months
In hospital care for dehydration
PE: thin body build, BMI 15

4. CTA 10/2013: narrowed aortomesenteric angle(~16
CTA 10/2013: narrowed aortomesenteric angle(~16*) and distance (5mm) with compression over third part of duodenum and left renal vein
Dilated left renal vein

5. CTA: dilated left ovarian veins and pelvic side veins, compatible with Nutcracker syndrome
Dx: SMA and nutcracker syndrome

6. Infrarenal SMA transposition
Infrarenal aorta, SMA/ IMA exposed and sling in preparation for anastomosis

7. Repeated vomiting early post OT
Recovered gradually and tolerated normal diet

8. Case presentation
Pathophysiology
Predisposing conditions
Presentation
Epidemiology
Diagnosis and imaging finding
Treatment
Summary

9. Pathophysiology
Vascular compression of third part of duodenum(D3) by angle formed by SMA and aorta (aortomesenteric angle)

10. Left renal vein Nutcracker syndrome Third part of duodenum
SMA syndrome
Except for the first part of the duodenum,it is retroperitoneal in nature
Between SMA and aorta, there are L renal vein and D3

11. Case presentation
Pathophysiology
Predisposing conditions
Presentation
Epidemiology
Diagnosis and imaging finding
Treatment
Summary

12. Predisposing conditions
1. loss of aortomesenteric fat (catabolic state)
2. Post operative state
ileoanal pouch
bariatric surgery e.g lap roux en Y gastric bypass
spinal surgery
3. local pathology
abdominal aortic aneurysm
Ileoanal pouch (tension and caudal pull of SB mesentery and hence SMA decreased aortomesenteric angle
Case report lap roux en Y gastric bypasss
Bariatric surgery loss of retroperitoneal fat
spinal surgery: relative lengthening of spine post OT

13. Predisposing conditions(local anatomy)
Ligament of Treitz
low origin of SMA
high or short insertion of ligament of Treitz
 cranial displacement of duodenum

14. Case presentation
Pathophysiology
Predisposing conditions
Presentation
Epidemiology
Diagnosis and imaging finding
Treatment
Summary

15. Patient presentation
Post-prandial epigastric pain then bilious vomiting
with prone/ knee chest/ left lateral position
Food fear weight loss and anorexia
Rare benign differentials for GOO

16. Diagnosis is usually delayed
Rare disease
Diseases with similar presentation
anorexia
duodenal/ pancreatic tumour
irritable bowel syndrome
megaduodenum

17. Case presentation
Pathophysiology
Predisposing conditions
Presentation
Epidemiology
Diagnosis and imaging finding
Management
Summary

18. Epidemiology Prevalence: 0.01-0.3% (1 in 330-7690) More affected
female
age 10-39
chronic illness

19. Case presentation
Pathophysiology
Predisposing conditions
Presentation
Epidemiology
Diagnosis and imaging finding
Treatment
Summary

20. CT angiogram (abdomen) Upper endoscopy+/- EUS
Investigations
Barium study
CT angiogram (abdomen)
Upper endoscopy+/- EUS

21. Barium study 1. dilatation of D1 and D2 +/- gastric dilatation
2. abrupt vertical and oblique compression of mucosal folds
3. antiperistaltic flow of contrast proximal to the obstruction
4. delay in transit of 4-6hours through the gastroduodenal region
5. relief of obstruction in prone, knee-chest or left lateral decubitus position
Contrast in stomach duodenum
Here location where SMA lie anterior to duodenum
Here we see to and for movement of contrast in D2, appreciate difficulty of contrast to pass across location of SMA
Lastly, there is pooling of contrast in d2 and there is reflux vomiting
Proximal dilatation, abrupt cut off, antiperistaltic flow, delay transit, relief with postural change

22. Aortomesenteric angle <22-25* Aortomesenteric distance <8mm
CT finding
Aortomesenteric angle <22-25*
(43% sensitivity, 100% specificity)
Aortomesenteric distance <8mm
(100% sensitivity and specificity)
for at least one symptom of SMA syndrome respectively
Rule out other causes of compression
E.g. neoplasia or aneurysm or annular pancreas
Angle <22-25*(43% sensitivity, 100% specificity)
Distance <8mm(100% sensitivity and specificity)
for at least one symptom of SMA syndrome respectively

23. Proximal gastroduodenal
dilatation
Distended stomach and proximal duodenum

24. Endoscopy finding pulsatile D3 obstruction
proximal duodenal dilatation
gastric retention with reflux esophagitis
Rule out structural lesion
EUS: similar finding and demonstrate loss of aortomesenteric fat
third portion of the duodenum with superior mesenteric artery clearly bulging (arrow) and narrowing the lumen. 

25. Case presentation
Pathophysiology
Predisposing conditions
Presentation
Epidemiology
Diagnosis and imaging finding
Treatment
Summary

26. ***medical treatment***
Gastroduodenal decompression
Correction of fluid and electrolyte
Nutritional support
High caloric enteral nutrition via feeding tube (jejunum)
Parenteral nutrition
Positive response: 83% (majority)
Restore aortomesenteric fat tissue
Following scoliosis surgery, most recover from conservative managment

27. Surgery is only indicated when medical treatment fail
Usually for patients with chronic course (persistent symptom/ deterioration after medical treatment)
No clear time limit
1978
Journal 6

28. Roux en Y duodenojejunal Bypass Surgery
Duodenojejunostomy
bypass
Gastrojejunostomy
Type
Gastrointestinal
Others
Strong’s OT
Roux en Y duodenojejunal Bypass
Surgery
open
Approach
Duodenal
circular drainage
lap
Vascular
Infrarenal
SMA transposition
Anterior transposition
of D3

29. Duodenojejunostomy(DJ)
Anastomosis
GI content
Side to side anastomosis between dilated proximal duodenum and jejunum

30. Strong’s procedure division of ligament of Treitz
duodenum was separated from pancreas and posterior retroperitoneal attachment
D4 became intra-peritoneal structure
 caudal displacement of duodenum away from the aortomesenteric angle

31. DJ Pros Success rate 80-90% Cons
Blind loop (modification: division of 4th part of duodenum; to eliminate blind loop)
Most frequently performed
Superior result than GJ and strong’s OT
Series of 146 patient (lee and mangla): DJ better result in severe case and significant better than GJ and strong
In 1963
Modified DJ: division and mobilisation of D4
Proximal J passed via right part of mesocolon accomplished side to side DJ
facilitating the growth of bacteria to the point that problems in nutrient absorption occur.

32. GJ DJ Pros Success rate 80-90% Common GI procedure Cons
Blind loop (modification: division of 4th part of duodenum; to eliminate blind loop)
Fail to relieve duodenal obstructionbile reflux, peptic ulcer and blind loop
Some need further OT, DJ
Most frequently performed
Superior result than GJ and strong’s OT
Severe dilated stomach and duodenum
Duodenal ulcer
Series of 146 patient (lee and mangla): DJ better result in severe case and significant better than GJ and strong
In 1963
Modified DJ: division and mobilisation of D4
Proximal J passed via right part of mesocolon accomplished side to side DJ
facilitating the growth of bacteria to the point that problems in nutrient absorption occur.

33. Strong’s OT DJ GJ Pros Success rate 80-90% Common GI procedure
No anastomosis
Less invasive
OT time decreased
Faster recovery
Cons
Blind loop (modification: division of 4th part of duodenum; to eliminate blind loop)
Fail to relieve duodenal obstructionbile reflux, peptic ulcer and blind loop
Some need further OT, DJ
-adhesion
-branches of inferior pancreatico-duodenal artery
25% fail to achieve caudal displacement of duodenum
Most frequently performed
Superior result than GJ and strong’s OT
Severe dilated stomach and duodenum
Duodenal ulcer
Limited by local anatomy
Series of 146 patient (lee and mangla): DJ better result in severe case and significant better than GJ and strong
In 1963
Modified DJ: division and mobilisation of D4
Proximal J passed via right part of mesocolon accomplished side to side DJ
facilitating the growth of bacteria to the point that problems in nutrient absorption occur.

34. Laparoscopic approach
Both DJ and Strong’s OT reported to be done under laparoscopic approach
Lap DJ
systematic review of 9 papers; total 13 cases
Length of stay 4.5days10 days (open DJ)
1 case(7%) trocar site bleeding reoperation
no case in open approach need reoperation
Munene G, M.D., Knab M, B.S.C., Parag B, M.D. Laparoscopic Duodenojejunostomy for Superior Mesenteric Artery Syndrome. Am Surg ;76(3):321-4.
Merrett ND, Wilson RB, Cosman P, Biankin AV. Superior Mesenteric Artery Syndrome: Diagnosis and Treatment Strategies. Journal of Gastrointestinal Surgery ;13(2):
(8 cases of open DJ)
****** shorter recovery time and hospital stay

35. Vascular surgery--Infrarenal SMA transposition
A therapeutic procedure for chronic mesenteric ischemia
Not a common surgery for SMA syndrome
caudal transposition of compressing SMA to infrarenal aorta compression over D3

36. Infrarenal transposition of SMA
Omentum and transverse colon retracted cranially
SB retracted to right
Division of ligament of Treitz and mobilize D4 and DJ flexure to right
Infrarenal aorta was exposed with the transperitoneal approach

37. Infrarenal transposition of SMA
Infrarenal aorta cross clamp after iv heparin
End to side anastomosis between SMA and infrarenal aorta with 5/0 prolene

38. Infrarenal transposition of SMA
Far less common than GI surgery
Only one case report (Germany)
data regarding its outcome not available
Merit
no bowel anastomosis
treat concomitant Nutcracker syndrome
Higher risk compared with GI surgery
Anastomotic break downBleeding
Bowel ischemia
Embolism
Only one case report describe
Treated by one single procedure
Like in the case presented in the beginning of presentation

39. In the case presented
Before proceed to SMA transposition
Other alternatives: conservative, GI bypass and left renal vein stenting
She opted for SMA transposition
GI complications like bowel anastomotic leaks, blind loop syndrome
treat both SMA and Nutcracker syndrome by a single operation

40. Despite surgery Postulations
Small number--developed persistent symptom after surgery
Postulations
duodenal atony after massive dilatation
strong reverse peristalsis after prolong obstruction

41. Case presentation
Pathophysiology
Predisposing conditions
Presentation
Epidemiology
Diagnosis and imaging finding
Treatment
Summary

42. Different treatment options
Points to note
Diagnosis not to miss
Vicious cycle starving
Different treatment options
Depend on patients’ condition
Selection of optimal treatment
Dfficult to dx becoz it is not common
Dx not to miss,
Patient starve to death

43. GI bypass surgery—DJ First line: Medical treatment unless with DU
Strong’s OT: mainly pediatric patients
Likely due to congenital anatomic predispositon
High risk of failure(1/4)
Phx surgery of upper abd (e.g. bariatric surgery) due to adhesion
After the review of literature
My approach toward mx of SMA syndrome would be

44. END