Transcript SMSA - Introduction

SUPERIOR
MESENTERIC ARTERY
SYNDROME
Dr. ST Hung
Princess Margaret Hospital
History
F/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
• Cachexic
• Afebrile, BP/ P stable
• Abdomen: 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
• Unknown 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
Etiology
Congenital Causes
•Anatomical variants:
•
•
•
•
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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
Etiology
Acquired Causes
Chronic 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
• Depend on the cause and grade of duodenal compression
• Chronic abdominal complaints with intermittent exacerbation
• Rarely, rapid evolving upper intestinal ileus
• Intermittent 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 criteria
1.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
• Plain radiograph
• Conventional barium studies
• Hypotonic duodenography barium study
• Computed tomography (CT) scan
• Conventional angiography
• 3-Dimensional CT angiography
• Magnetic resonance angiography
• Ultrasonography
• Endoscopy
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 obstruction
e.g. Pancreatic cysts or neoplasms, paraaortic lymphadenopathy, duodenumal tumor, adhesion,
malrotation and Crohn’s disease
Familial neuropathic disease
e.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
• In 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
• Nil by mouth
• Nasogastric tube with regular aspiration
• Correction of fluid and electrolyte balance
• Enteral jejunal tube feeding, parental nutrition
• Posturing maneuvers
• Prokinetic drugs like metoclopramide or cisapride may be used to
enhance stomach emptying by improving motility
Medical Treatment
• No clear time limit for medical treatment
• Relief 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
1.
2.
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 Gastroenterol
1978; 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
• SMAS 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