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

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

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

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

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

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

Repeated vomiting early post OT Recovered gradually and tolerated normal diet

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Proximal gastroduodenal dilatation Distended stomach and proximal duodenum

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. 

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

***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

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

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

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

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

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.

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.

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.

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 2010 03;76(3):321-4. Merrett ND, Wilson RB, Cosman P, Biankin AV. Superior Mesenteric Artery Syndrome: Diagnosis and Treatment Strategies. Journal of Gastrointestinal Surgery 2009 02;13(2):287-92. (8 cases of open DJ) ****** shorter recovery time and hospital stay

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

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

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

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

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

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

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

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

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

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