Dr. ST HungPrincess Margaret Hospital

SUPERIOR MESENTERIC ARTERY SYNDROME

HistoryF/73

Past Health:

Metastatic CA breast ( Lung, Mediastinal LN ), on Femara® (letrozole) since 6/2012 for palliative intent

Admit for repeated bilious vomiting for days•abdominal distension•BO once every 2-3 days•Decrease intake & weight loss

Physical Examinations•C

achexic•A

febrile, BP/ P stable•A

bdomen: grossly distended, succusion splash+, no mass or hernia

•PR: No mass, brownish stool

AXR

CT abdomen & Pelvis with Contrast

OGD

OGD

Superior Mesenteric Artery

Syndrome(

SMAS)

Introduction

•The superior mesenteric artery syndrome is defined as vascular compression of the third part of the duodenum in the angle between the aorta and the superior mesenteric artery.

•First described by Austrian Professor Carl Freiherr von Rokitansky in 1842

•Wilkie published the first comprehensive series of 75 patients, after which the eponym “Wilkie’s Syndrome” emerged

•Other names: arteriomesenteric duodenal compression syndrome, chronic duodenal ileus and cast syndrome

Epidemiology•U

nknown incidence; roughly estimated to be around 0.013 to 0.3% in general population

•Females are more commonly affected, in ratio of 3:2

•About two thirds of patients are in age group between 10-39

•Cases described in preterm male of 23 weeks & 86 years old man

•No racial difference

Related Anatomy

Related Anatomy & Pathogenesis

• Aorto-mesenteric angle ≈ 6° to 16° (Normal: 38-65°)• Aorto-mesenteric distance ≈2mm to 8mm (Normal:10-28mm)

Etiology

Congenital Vs Acquired

EtiologyCongenital Causes•Anatomical variants:• Short or High insertion of Ligament of Treitz• Congenital peritoneal adhesions and Ladd’s bands • Congenital low origin of the SMA• Short Mesenteric Root• Duodenal Malrotation

EtiologyAcquired CausesChronic Wasting Disease e.g. Malignancy, paraplegia, AIDS

Trauma e.g. Polytrauma, burn injury, brain and spinal cord injury

Dietary Disorders e.g. Malabsorption syndrome, anorexia nervosa

Postoperative States e.g. IPAA, scoliosis surgery, Cast syndrome

Local pathology e.g. Neoplastic growth in mesenteric root, dissecting aortic aneurysm

Clinical Features•D

epend on the cause and grade of duodenal compression•C

hronic abdominal complaints with intermittent exacerbation•R

arely, rapid evolving upper intestinal ileus•I

ntermittent or postprandial abdominal pain (59-81%)* followed by bilious vomiting

•Epigastric pain is relieved by a prone, knee-chest, left lateral decubitus position or Hayes maneuver that all reduce small bowel mesenteric tension at aortomesenteric angle

•Early satiety with a sensation of fullness, food intolerance, anorexia that trigger a vicious cycle resulting in weight loss

*Ylinen P, Kinnunen J, Hockerstedt K: Superior mesenteric artery syndrome. A follow up study of 16 operated patients. J Clin Gastroenterol 1989; 11: 386–391.

Complications

Because of the frequent delay in the diagnosis of SMAS, it can result in life threatening complications*•Pancreatitis secondary to abnormal pancreaticoduodenal reflux within the closed intestinal loop•Gastroparesis is frequently encountered after correction surgery for SMAS •Esophageal tear •Peptic ulcer and perforation of stomach•Aspiration pneumonia, cardiovascular collapse, metabolic alkalosis, electrolyte imbalance

*M. T. Mandarry, L. Zhao, C. Zhang, Z. Q. Wei. A comprehensive review of superior mesenteric artery syndrome. Eur Surg (2010) 42/5: 229–236

Investigations and Diagnosis

•Diagnosis is difficult and is often delayed because of incomplete obstruction and non-specific symptoms

•Diagnosis by exclusion; thus requires high index of suspicious

•Rosa Jimenez et al. advocated that the diagnosis should be based on clinical symptoms and radiologic evidences of obstruction*

*U¨ nal B, Aktas A, Kemal G, et al. Superior Mesenteric artery syndrome: CT and ultrasonography findings. Diagn Interv Radiol 2005;11:90–5.

Investigations and Diagnosis

Radiographic criteria1.Dilatation of the 1st and 2nd part of the duodenum +/- gastric dilatation

2.Abrupt vertical and oblique compression of the mucosal folds

3.Antiperistaltic flow of contrast medium (barium) proximal to obstruction, producing to and fro movements

4.Delay of 4 to 6 hours in gastroduodenojejunal transit time

5.Relief of the obstruction when the patient is placed in a prone, knee-chest or left lateral positions

Dietz UA, Debus ES, Heuko-Valiati L, Valiati W, Friesen A, Fuchs KH, Malafaia O, Thiede A: Aorto-mesenteric artery compression syndrome. Chirurg 2000; 71: 1345–1351.

Hines JR, Gore RM, Ballantyne GH: Superior mesenteric artery syndrome. Diagnostic criteria and therapeutic approaches. Am J Surg 1984; 148: 630–632.

Radiographic Diagnostic Tools •P

lain radiograph•C

onventional barium studies•H

ypotonic duodenography barium study•C

omputed tomography (CT) scan•C

onventional angiography•3

-Dimensional CT angiography•M

agnetic resonance angiography•U

ltrasonography•E

ndoscopy

Radiographic Diagnostic Tools

Conventional barium studies• Classic diagnostic technique; cheap, easy but non-specific• A dilated proximal duodenum with an abrupt linear cut off at

the 3rd part of the duodenum and a collapsed small bowel distal to the crossing SMA • Retention of barium within the duodenum

Hypotonic duodenography barium study• Duodenal peristalsis was suppressed by anti-cholinergics

like propantheline bromide

Radiographic Diagnostic Tools

Computed tomography (CT) scan• can clearly demonstrate the aortomesenteric angle and

distance accurately • the gastric and proximal duodenal dilatation, the duodenal

obstruction (site of vascular compression of the duodenum) • local pathologies e.g. aneurysm or neoplasm, etc.• Provide an overall assessment of the abdominal cavity as

well as the amount of retroperitoneal fat

Radiographic Diagnostic Tools

3-Dimensional CT & MR angiography•Most popular; rapid, non-invasive, eliminate erroneous diagnoses that originate from the angulations of SMA• Calculating the aortomesenteric angle and distance precisely• Can demonstrate the direct pressure of SMA on the entrapped duodenum

Conventional angiography•Gold standard modality in the past• Invasive, time-consuming

Radiographic Diagnostic Tools

Ultrasound color doppler• Advocate for detection of reduced aortomesenteric angle

Upper gastrointestinal endoscopy• To rule out intraluminal obstruction and gastric or duodenal ulcer disease that might be secondary to reflux or as a primary pathology mimicking SMAS• Fluid retention in stomach, a dilated proximal duodenum, a pulsatile mass in the third part of duodenum precluding the passage of the scope•Not indicate the diagnosis

Differential Diagnosis

Mechanical obstructione.g. Pancreatic cysts or neoplasms, paraaortic lymphadenopathy, duodenumal tumor, adhesion, malrotation and Crohn’s disease

Familial neuropathic diseasee.g. megaduodenum

Postoperative paralytic ileus e.g. general anesthesia, analgesic, electrolyte imbalance or greater splanchnic nerve injury during anterior spinal

Recurrent biliary pancreatitis Gastroparesis in Type I Diabetes Psychogenic vomiting Rare causes with decreased peristalsis e.g. dermatomyositis, SLE, myxoedema, amyloidosis, myotonic dystrophy or chronic idiopathic intestinal pseudo-obstruction

Treatment

• Medical Treatment to Surgical Treatment

Medical Treatment•I

n absence of displacement by an abdominal mass, an aneurysm or another pathologic condition that requires immediate surgical exploration, the treatment of the SMAS usually begins with conservative approaches

•Aim: Reversal of weight loss; promote the restoration of retroperitoneal fat tissue which consequently increases the aortomesenteric angle*

*Jawad NH, Al-Sanae A, Al-Qabandi W. Superior mesenteric artery syndrome: An uncommon cause of intestinal obstruction; report of two cases and review of literature. Kuwait Med J 2006; 38:241–4.

Medical Treatment•N

il by mouth•N

asogastric tube with regular aspiration•C

orrection of fluid and electrolyte balance•E

nteral jejunal tube feeding, parental nutrition•P

osturing maneuvers •P

rokinetic drugs like metoclopramide or cisapride may be used to enhance stomach emptying by improving motility

Medical Treatment•N

o clear time limit for medical treatment•R

elief of symptoms has been observed from 2 to 12 days; nevertheless, it has been also reported up to 169 days* and even up to 7 months in different cases

*Lee CS, Mangla JC: Superior mesenteric artery compression syndrome. Am J Gastroenterol 1978; 70: 141–150.

Surgical Treatment

Indications for surgical intervention (Berner and Sherman, 1963) are:•Failed conservative treatment•Longstanding disease with progressive weight loss and duodenal dilatation with stasis•Complicated peptic ulcer disease and pancreatitis secondary to biliary stasis and reflux•Local pathology requiring laparotomy•Patients’ preference

Surgical Procedures

•Duodenojejunostomy

•Gastrojejunostomy

•Strong’s operation

•Laparoscopic duodenojejunostomy

•Robotic assisted intestinal bypass surgery

•Anterior transposition of the third part of duodenum

•Transposition of the SMA to the infrarenal aorta

•Duodenal circular drainage

Surgical Procedure

Strong’s procedure•Mobilization of the duodenum by division of the ligament of Trietz, allowing the duodenum to fall away from the aorta•Avoids anastomosis thus, is less invasive, quicker, safer procedure, and with early postoperative recovery•Failure rate of 25%* presumably due to

• Short branches of the inferior pancreaticoduodenal artery not permitting the duodenum to fall inferiorly

• Adhesion resulting in difficult dissection

*Lee CS, Mangla JC: Superior mesenteric artery compression syndrome. Am J

Gastroenterol 1978; 70: 141–150 .

Surgical Procedure

Gastrojejunostomy •Adequate gastric decompression •Fail to completely release duodenal obstruction leading to persistence of symptoms that necessitated duodenojejunostomy in some cases*•Persisting obstruction may lead to blind loop syndrome, gastric bile reflux and ulceration**

*Lee CS, Mangla JC: Superior mesenteric artery compression syndrome. Am J Gastroenterol 1978; 70: 141–150.**Geer MA. Superior mesenteric artery syndrome. Mil Med 1990;155:321–323

Surgical Procedure

Duodenojejunostomy•Was first performed by Stavely in 1910 •The most frequent surgical procedure with a success rate of about 90% *•Lee and Mangla * concluded after reviewing 146 cases operated after 1963 that duodenojejunostomy revealed the best results in severe cases and was significantly better compared to gastrojejunostomy and Strong’s procedure

*Lee CS, Mangla JC: Superior mesenteric artery compression syndrome. Am J Gastroenterol1978; 70: 141–150.

Surgical Procedure

Laparoscopic duodenojejunostomy•Gersin and Heniford reported the first successful laparoscopic duodenojejunostomy case in 1998•Small series have reported success rates of 75-100% with laparoscopic division of the ligament of Treitz or laparoscopic duodenojejunostomy using a retrocolic stapled anastomosis.

Surgical Procedure

Others•World’s first robotically assisted intestinal bypass surgery for SMAS: was reported in July 2008 at London Health Services Centre•Anterior transposition of the third part of duodenum•Billroth II gastrectomy•Transposition of the SMA to the infrarenal aorta•Duodenal circular drainage

Conclusion•S

MAS is a very rare entity which has been associated with a wide range of predisposing factors, presenting with features of upper GIT obstruction and a recent abrupt weight loss.

•An early recognition of the condition, institution of the appropriate conservative measures and proper timely selection of a definite surgical method are critical to prevent the development of severe complications.

M. T. Mandarry et al. A comprehensive review of superior mesenteric artery syndrome. Eur Surg (2010) 42/5: 229–236

Thank You