1. Activity Think back to your Dietetic Internship.
What was one of the most humbling and potentially embarrassing moments?
In a few words, write this moment on a piece of paper, do not put your name on the paper (this will remain anonymous)
Fold the paper and place it in front of you when you are finished

2. Nutritional Implications of Superior Mesenteric Artery Syndrome
Meghan Zook
Sodexo Dietetic Intern

3. Definition of SMAS
Uncommon and potentially fatal cause of small bowel obstruction
Occurs when the 3rd portion of the duodenum becomes closed off due to external pressure from the Superior Mesenteric Artery and the Aortic Artery
Occurs in 0.013%-0.3% of the general population
Occurs in mainly youth and young and slender females

4. Pathophysiology
In a normal adult, the SMA leaves the Aortic artery at the location of the first lumbar vertebra
This creates an angle in which the duodenum passes through
Duodenum is fixed at this point by the ligament of Treitz
Angle normally is degrees*
*no exact definition of what angle is considered “normal”

5. SMA
Mesenteric fat pad
Aorta
3rd portion of the duodenum

6. Pathophysiology cont.

7. Pathophysiology cont.
Symptoms of SMAS begin to occur when the angle is reduced to approx. <25 degrees
Symptoms are due to mechanical compression of the duodenum, not from ischemic insult

8. Pathophysiology cont.

9. Anatomic reasons
Abnormally short ligament of Trietz
Superior mesenteric artery with unusually low origin
Loss of mesenteric fat pad
Eating disorders
Tube-feeding-dependent patients who are underfed
Excessive exercise
Gastric bypass surgery
Wasting/malabsorption diseases
Post-surgical
External compression
Spinal correction surgery
Abdominal surgery
Trauma
Abdominal trauma
Spinal cord injury
Local pathology
Malignancy
Aortic aneurysm
Chronic inflammation and adhesions

10. Other names Wilkie’s Syndrome Nutcracker Syndrome Cast syndrome
Chronic Duodenal Ileus

11. History of SMAS Carl von Rokitansky in 1861 Under-studied until 1927
Series of autopsies on thin young women
All had post-prandial pain and vomiting
Under-studied until 1927
D. P. Wilkie performed first original research
75 patients
Similar symptoms

12. Early Research Further research has remained slim
Limited number of diagnosed cases
Between 1800s and 1985 – 400 cases
Most were children and females
Pre-existing conditions: disordered eating patterns, cancer, other wasting diseases
Controversy existed due to questions about pathology and methods used to diagnose

13. Current Research Body of literature has begun to grow 13 articles
9 case reports (bulk of the literature)
4 observational research studies (multiple patients)
2 studies of pediatric patients

14. Patient Population 67 patients total 47 of these were female (70%)
Mean age of years

15. Past Medical History Included: Intentional dieting (2)
Tuberculosis interstitial nephritis (1)
Traumatic paraplegia (1)
Appendicular perforation (1)
Mild COPD, repair of perforated duodenal ulcer (1)
Several years of disordered eating (3)
Other psychosocial issues
Drug/alcohol abuse (2)
Domestic abuse (1)
*several articles only listed symptoms and not past medical history

16. Disordered Eating Patients
21-year old Japanese female
2 years bulimia nervosa, 6 years anorexia nervosa – vomiting 1-2x per day
47-year old female
“many-year” history of anorexia nervosa
Laxative use and excessive exercise
15-year old girl
History of anorexia nervosa

17. Presenting Symptoms Post-prandial pain and discomfort Bilious emesis
Anorexia
Weight loss

18. Diagnostic Tests Barium upper GI studies – “Gold Standard”
Small bowel follow through and Doppler blood flow assessment
Abdominal ultrasounds
CT scans
Discern the degree between the SMA and Aortic Artery, fat, and dilation of stomach and 1st and 2nd part of the duodenum

19. Abdominal Ultrasound

20. CT Scan

21. Barium Upper GI Series

22. Misdiagnosed Persons Several individuals were first misdiagnosed
Reflux disease
Treated with Proton-Pump Inhibitors
Other possible misdiagnoses:
Peptic ulcer disease
Gall bladder disease
IBS
Duodenitis
Cholelithiasis
Visceral neuropathy
Pancreatitis
Gastroparesis

23. Treatment Options
Conservative – goal is to increase mesenteric fat pad, all patients except 4 were first conservatively treated
Aggressive – surgical relief
Depends on medical staff and surgeon
Depends on acute vs. chronic SMAS

24. Conservatively Treated
Length of treatment
4 days to several weeks
1 study by-passed conservative treatment completely (4)
Nasogastric decompression
Parenteral & Enteral Nutrition
Positioning patient during meals

25. Parenteral & Enteral Nutrition
Goal:
Avoid re-feeding syndrome
Provide enough nutrition for weight gain and to build up the mesenteric fat pad
Total Parenteral Nutrition Advised
May run with Enteral Nutrition
NJ tube treaded past the point of decompression

26. PN and EN Recommendations
No recommendations through ASPEN
1 study, 1 patient (70 Y.O. man) – Chan et al.
Bolus feeds through NJ tube – Ensure by Nestle
50 mL Q4 hours, increased gradually to 250 mL
Study took place in Singapore
*ASPEN recommends continuous feeds if feeding into the duodenum
Use clinical judgment and nutritional status of the patient to determine appropriate calorie and protein needs

27. Fluids and Soft Foods
1 study, 1 patient (47 Y.O female with anorexia nervosa) – Mascolo et al.
Small and frequent liquids
Sitting in knee-chest positioning
On CT scan, this patient was found to have only partial compression of the duodenum
Patient improved and was able to slowly advance her diet

28. Positioning
After meals
Knee-chest position
Left side lying

29. Medications
Controversy over whether or not certain medications should be given during conservative treatment
Medications to increase gastric emptying (Metoclopramide)
Dangerous?
Several reviewed articles used metoclopramide and anti-emetic
Successful conservative treatment outcomes
No recommended regimen for medication

30. Aggressively Treated Normally follows period of conservative treatment
67 patients
Conservative Treatment successful for 56%
If patient does not gain weight and continues to be unable to eat or drink foods, surgery is recommended

31. Surgical Procedures Strong’s Procedure (3) Gastrojejunostomy (1)
Open or Laparoscopic Duodenojejunostomy (13)
Gold Standard

32. Strong’s Procedure Mobilization by division of the ligament of Treitz
Preoperative gastric decompression with NG tube
Dissection allows the 3rd portion of the duodenum to drop lower, relieving pressure
25% rate of failure

33. Gastrojejunostomy

34. Open or Laparoscopic Duodenojejunostomy

35. Recovery
Many patients will require help for existing or developed disordered eating patterns
Chan et al (27 pediatric patients, 8 male)
21 conservatively treated
14 good recovery within weeks
6 underwent surgery (type not listed)
5 had successful surgeries
1 female developed adhesion ileus and needed TPN for 3 weeks until the ileus had resolved

36. Recovery cont. Shin et al (18 pediatric patients, 11 male)
13 responded to conservative treatment
(4 recurrences, 3 recovered again, 1 did not - anorexia nervosa - and was lost to follow-up)
1 female with anorexia nervosa responded to laparoscopic gastrojejunostomy and symptoms were relieved within 2 weeks
Others were lost to follow-up

37. Role of the Clinical Dietitian
Perform assessment to obtain patient nutritional status upon patient admission – document degree of malnutrition
Work with medical team to give opinion as to whether or not patient is able to be conservatively treated or if patient requires immediate surgical attention
If conservative treatment is an option, prescribe calories and protein and take care to avoid re-feeding syndrome
Try to increase patient nutritional status as soon as possible
Use clinical judgment to decide upon enteral formula and feeding rate

38. Conclusions Body of literature leaves much to be desired
Specifically in regards to feeding recommendations
More original research on large groups of subjects
Less focus on case reports
Hopefully in the future we will see recommendations for formula type and how long to conservatively treat

39. Quiz Time!
What are the two arteries that are responsible for compression of the duodenum during SMAS?
What is the name of the surgical procedure that is considered the “Gold Standard” used to treat SMAS?
List something that you did not know before this presentation.

40. Questions?

41. References
Baltazar, U., Dunn, J., Floresguerra, C., Schmidt, L., & Browder, W. (2000). Superior mesenteric artery syndrome: an uncommon cause of intestinal obstruction. Southern medical journal, 93(6),
Gebhart, T. (2015). Superior mesenteric artery syndrome. Gastroenterology Nursing, 38(3),
McCallum R W. Superior mesenteric artery syndrome. Practical Gastroenterology,
Naseem, Z., Premaratne, G., & Hendahewa, R. (2015). “Less is more”: Non operative management of short term superior mesenteric artery syndrome. Annals of Medicine and Surgery, 4(4),
Nutrition care manual website. Accessed on April 29, 2016.
Rabie, M. E., Ogunbiyi, O., Al Qahtani, A. S., Taha, S., El Hadad, A., & El Hakeem, I. (2015). Superior Mesenteric Artery Syndrome: Clinical and Radiological

42. References cont.
Merrett, N. D., Wilson, R. B., Cosman, P., & Biankin, A. V. (2009). Superior mesenteric artery syndrome: diagnosis and treatment strategies. Journal of Gastrointestinal Surgery, 13(2),
Chan, D. K., Mak, K. S., & Cheah, Y. L. (2012). Successful nutritional therapy for superior mesenteric artery syndrome. Singapore medical journal, 53(11), e233-6.
Shin, M. S., & Kim, J. Y. (2013). Optimal duration of medical treatment in superior mesenteric artery syndrome in children. Journal of Korean medical science, 28(8),
Shiu, J. R., Chao, H. C., Luo, C. C., Lai, M. W., Kong, M. S., Chen, S. Y., ... & Wang, C. J. (2010). Clinical and nutritional outcomes in children with idiopathic superior mesenteric artery syndrome. Journal of pediatric gastroenterology and nutrition, 51(2),
Berchi, F. J., Benavent, M. I., Cano, I., Portela, E., & Urruzuno, P. (2001). Laparoscopic treatment of superior mesenteric artery syndrome. Pediatric Endosurgery and Innovative Techniques, 5(3),

43. References cont.
Mascolo, M., Dee, E., Townsend, R., Brinton, J. T., & Mehler, P. S. (2015). Severe gastric dilatation due to superior mesenteric artery syndrome in anorexia nervosa. International Journal of Eating Disorders, 48(5),
Gthrie Jr, R. H. (1971). Wilkie's syndrome. Annals of surgery, 173(2), 290.
Patel, A.H., Joshi, A.H., Shah, N. (2015). A case of superior mesenteric artery syndrome. IJSR. 4(6),