Upload
denis-charles
View
261
Download
7
Embed Size (px)
Citation preview
Superior mesenteric artery syndrome(SMA syndrome)
Joint hospital surgical grandround 19/7/2014
Cheung Hing Fong
1. Case presentation
2. Pathophysiology
3. Predisposing conditions
4. Presentation
5. Epidemiology
6. Diagnosis and imaging finding
7. Treatment
8. Summary
Case presentation 41/F 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*) and distance (5mm) with compression over third part of duodenum and left renal vein
CTA: dilated left ovarian veins and pelvic side veins, compatible with Nutcracker syndromeDx: SMA and nutcracker syndrome
Infrarenal SMA transposition
Repeated vomiting early post OT
Recovered gradually and tolerated normal diet
1. Case presentation
2. Pathophysiology
3. Predisposing conditions
4. Presentation
5. Epidemiology
6. Diagnosis and imaging finding
7. Treatment
8. Summary
Pathophysiology
Vascular compression of third part of duodenum(D3) by angle formed by SMA and aorta (aortomesenteric angle)
Third part of duodenum
SMA syndrome
Left renal vein
Nutcracker syndrome
1. Case presentation
2. Pathophysiology
3. Predisposing conditions
4. Presentation
5. Epidemiology
6. Diagnosis and imaging finding
7. Treatment
8. 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
Ligament of Treitz
Predisposing conditions(local anatomy)
low origin of SMA high or short
insertion of ligament of Treitz cranial
displacement of duodenum
1. Case presentation
2. Pathophysiology
3. Predisposing conditions
4. Presentation
5. Epidemiology
6. Diagnosis and imaging finding
7. Treatment
8. Summary
Post-prandial epigastric pain then bilious vomiting
with prone/ knee chest/ left lateral position
Food fear weight loss and anorexia
Patient presentation
Diagnosis is usually delayed Rare disease
Diseases with similar presentation anorexia duodenal/ pancreatic tumour irritable bowel syndrome megaduodenum
1. Case presentation
2. Pathophysiology
3. Predisposing conditions
4. Presentation
5. Epidemiology
6. Diagnosis and imaging finding
7. Management
8. Summary
Epidemiology
Prevalence: 0.01-0.3% (1 in 330-7690)
More affected female age 10-39 chronic illness
1. Case presentation
2. Pathophysiology
3. Predisposing conditions
4. Presentation
5. Epidemiology
6. Diagnosis and imaging finding
7. Treatment
8. Summary
Investigations
Barium studyCT 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
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
Proximal gastroduodenal dilatation
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
1. Case presentation
2. Pathophysiology
3. Predisposing conditions
4. Presentation
5. Epidemiology
6. Diagnosis and imaging finding
7. Treatment
8. Summary
Treatment
***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)
Surgery is only indicated when medical treatment failUsually for patients with chronic
course (persistent symptom/ deterioration after medical treatment)
No clear time limit
Surgery
Gastrointestinal
Vascular
Type
Approach
bypass
open
lap
Infrarenal SMA transposition
Strong’s OT
Others
Gastrojejunostomy
Duodenojejunostomy
Anterior transposition of D3
Roux en Y duodenojejunal Bypass
Duodenal circular drainage
Duodenojejunostomy(DJ)
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
DJPros Success rate 80-90%
Cons Blind loop (modification: division of 4th part of duodenum; to eliminate blind loop)
Most frequently performedSuperior result than GJ and strong’s OT
DJ GJPros 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 obstructionbile reflux, peptic ulcer and blind loopSome need further OT, DJ
Most frequently performedSuperior result than GJ and strong’s OT
Severe dilated stomach and duodenumDuodenal ulcer
DJ GJ Strong’s OTPros Success rate 80-
90%Common GI procedure
No anastomosis Less invasiveOT time decreasedFaster recovery
Cons Blind loop (modification: division of 4th part of duodenum; to eliminate blind loop)
Fail to relieve duodenal obstructionbile reflux, peptic ulcer and blind loopSome need further OT, DJ
-adhesion
-branches of inferior pancreatico-duodenal artery
25% fail to achieve caudal displacement of duodenum
Most frequently performedSuperior result than GJ and strong’s OT
Severe dilated stomach and duodenumDuodenal ulcer
Limited by local anatomy
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 4.5days10 days (open DJ) 1 case(7%) trocar site bleeding reoperation no case in open approach need reoperation
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 transposition of SMA Infrarenal aorta
cross clamp after iv heparin
End to side anastomosis between SMA and infrarenal aorta with 5/0 prolene
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 downBleeding Bowel ischemia Embolism
Infrarenal transposition of SMA
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
Small number--developed persistent symptom after surgery
Postulations duodenal atony after massive dilatation strong reverse peristalsis after prolong
obstruction
1. Case presentation
2. Pathophysiology
3. Predisposing conditions
4. Presentation
5. Epidemiology
6. Diagnosis and imaging finding
7. Treatment
8. Summary
Points to note
Diagnosis not to missVicious cycle starving
Different treatment options Depend on patients’ condition Selection of optimal treatment
First line: Medical treatment GI bypass surgery—DJ
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
END