Internal Hernia – a brief review of its clinical features and management
Surgical Grand Round
22nd Oct, 2011; UCH
C C Chan; TMH
Hernia
• Hernia: protrusion of part or whole of a viscus through an abnormal opening in the walls of its containing cavity (Bailey & Love’s 25th)
• internal: herniation confined to peritoneal cavity
• external: herniation through defect in wall of abdomen or pelvis
Internal Hernia
• congenital or acquired • overall incidence < 1% (1)
• 0.6 - 5.8% of small-bowel obstruction (SBO)(1)
• incidence has been increasing (2)
(1) Newsom BD, Kukora JS. Congenital and acquired internal hernias: unusual causes of small bowel obstruction. Am J Surg 1986; 152:279–284
(2) Higa KD, Ho T, Boone KB. Internal hernias after laparoscopic Roux-en-Y gastric bypass: Incidence, treatment and prevention. Obes Surg 2003;13(3):350–4
Clinical features
• symptoms & signs usually indistinguishable from band obstruction
• mortality could be 50% (1)
• usually diagnosed intra-op• ddx: external hernia, adhesion,
intussusception, gall stone ileus
(1) Mock CJ, Mock HE Jr. Strangulated internal hernia associated with trauma: Arch Surg 1958; 77:881–886
Internal HerniaA = paraduodenal
B = foramen of Winslow
C = intersigmoid
D = pericecal
E = transmesenteric, transomental, and transmesocolic
F = retroanastomotic
g = falciform ligament
h = supravesical and pelvic
Anatomic predisposition to transmesenteric hernia with biliary-enteric anastomosis
a) antecolic Roux-en-Y loop b) retrocolic Roux-en-Y loop
Retroanastomotic Hernia after partially gastrectomy
Retrocolic gastrojejunostomy Antecolic gastrojejunostomy
Internal hernia defects after bariatric surgery
A = mesocolic
B = Petersen’s
C = mesomesenteric
Common symptoms
• non-specific
• asymptomatic
• intermittent attacks of vague epigastric discomfort
• colicky periumbilical pain
• nausea, vomiting
Ever-changing severity
• relates to duration and reducibility of hernia, presence or absence of incarceration and strangulation
• may be altered by changes in posture
Imaging
• plain X ray abdomen
• USG abdomen
• barium enhanced studies / enteroclysis
• CT abdomen
Usual CT findings
• crowded, distended bowel in abnormal location and arrangement
• segmental dilatation and prolonged stasis within the herniated loops
• stretched, displaced, crowded, and engorged mesenteric vessels
• displacement of other bowel segments• (propensity to spontaneously reduce)
M/68
• Hx: CA splenic flexure, L hemicolectomy good recovery
• readmitted Day 13 post-op for abdominal distension and pain
CT scan
Management
• depends on stability of patient
• history is important
• know that it occurs, prevent it from happening
• blood tests and imaging are adjunct only
Management
• prompt surgical intervention:
assessment of bowel viability, reduction and closure of all internal hernia defects
• hernial ring should not be incised liberally
• reduction of the hernia may be accomplished by enterostomy, followed by closure of the ring
F/44
• acute LUQ pain with vomiting BO dailyno UTI, gyn symptoms
• afebrile
vitals stableabdomen - LUQ tenderness, no mass
• CXR - no free gasAXR - no dilated bowel
• Hb: 8.2, L/RFT: normal
CT scan
laparotomy
• small bowel herniated through a small defect in round ligatment
• bowel loop reduced
• viability confirmed
• defect repaired
• good post-op recovery
M/67
• RIIH with mesh repair done • generalized severe abdominal pain for 1 day• fever with tachycardia, BP stable
tenderness & guarding at right side of abdomen
• ANC:17
Hb, R/LFT, amylase: normalCXR: no free gas
Emergency laparotomy
• herniation of a segment of terminal ileum into a defect in mesosigmoid with gangrenous changes
• limited right hemicolectomy done
• post-op ICU care and smooth recovery
TMH dataJuly 07’ to July 11’
• 17 internal hernia diagnosed and operated• female to male: 4(23.5%) to 13(76.5%)• age: 22 to 83, mean: 58.3• previous surgery: 70.6%
Types of internal hernia
• transmesenteric type: 10 (58.8%) hernia neck was congenital fibrous band:
3 (17.6%) paraduodenal: 1 (5.88%) intersigmoid: 1 (5.88%) round ligament: 1 (5.88%) retroanastomotic: 1 (5.88%)
Clinical features
• non-specific
• X-ray may not show I/O
• all end up in surgery
Hx of Abd surgery
Abd pain/ distension
Vomiting XR I/O peritonitissignificant
acidosisCT before
OTType of internal hernia
Ischemia/Perforation
Bowel resection
30 day post-op mortality
0 1 1 1 1 1 0 Congenital fibrous band 1 1 1
0 1 0 1 1 0 0 Intersigmoid 1 1 0
1 1 1 1 0 0 0 Transmesenteric 0 0 0
1 1 1 1 0 0 0 Transmesenteric 0 0 0
1 1 1 1 0 0 0 Transmesenteric 0 0 0
0 1 0 1 1 0 0 Transmesenteric 1 1 0
1 0 1 1 0 n/a 0 Transmesenteric 0 0 0
1 1 0 1 1 1 0 Transmesenteric 0 1 1
1 1 0 1 1 0 0 Transmesenteric 1 1 0
0 1 1 0 1 1 0 Congenital fibrous band 0 0 0
1 1 0 0 0 1 0 Transmesenteric 1 1 0
1 1 0 0 0 0 1 Transmesenteric 0 0 0
1 1 1 0 0 0 1 Round ligament 0 0 0
1 1 0 0 0 0 1 Retroanastomotic 1 0 1
0 1 1 0 0 0 1 Paraduodenal 0 0 0
1 1 0 0 0 0 1 Transmesenteric 1 0 0
0 1 1 1 0 1 1 Congenital fibrous band 1 1 0
• pre-op CT: 6/17 (33.3%)
• comparing CT group to non-CT group:• 0% vs 63.6% peritonitis• 17% vs 36% significant acidosis (p=0.58%)(*)
• 16.7% vs 54.5% bowel resection (P=0.22)(*)
• 16.7% vs 18.2% mortality (P=0.49)(*)
*Fisher’s Exact Test
Lesson to learn
• know it occurs • CT might be valuable if the patient is not in
distress clinically, having no clues from baseline Ix and might be expected to operate on +ve imaging results
• laparoscopic repair possible
(1) B Palmar, R Palmar. Laparoscopic management of left paraduodenal
hernia. J Minimal Access Surgery: 2010; 6:122-24
Thank You
Special thanks to
Dr C C Cheung for inspiration and guidance& Dr K K Li for data framework