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