1. Ay, but to die, and go we know not where; To lie in cold obstruction and to rot. - William Shakespeare

2. Prof A walid elsahzly MD
Bowel Obstruction
Prof A walid elsahzly MD
Professor of General Surgery, Colon and rectal Unit, University of Alexandria

3. Bowel Obstruction - Outline
Small Bowel Obstruction
Adynamic Ileus
Large Bowel Obstruction
Colonic Pseudo-Obstruction
Pediatric Bowel Obstruction

4. Bowel Obstruction Defined
Any disorder in which the intestine fails to allow for the regular passage of food or bowel contents.
Thus, mechanical, hypo-peristaltic, or neurological causes are all “obstructions”.

5. SBO - Historical Perspective
350 BC: Praxagoras creates a therapeutic entero-cutaneous fistula.
Praxagoras, the sophist, is also known for the discovery of arteries. He states "We have long known about the existence of veins which carry blood. We now know what carries the air throughout our bodies.” (295 BC)

6. SBO - Historical Perspective
350 BC AD: Nothing Happens

7. SBO - Historical Perspective
1912: Hartwell and Hoguet discover that saline therapy prolongs the life of experimental dogs. (JAMA 59: )
1950’s: Nasogastric tube decompression and antibiotics are advocated for treatment of SBO.
Advances in surgical techniques.
Mortality decreases:
60% in 1900
3-5% in 2000

8. SBO - Epidemiology
20% of all hospital admissions for patients with abdominal pain.
300,000 operations annually.
Causes:
Non-Mechanical/Ileus - Most Common
64-79% - Adhesions
15% - Hernias
10-15% - Cancer
Others - intussusception, gallstones, inflammation, abscess, bezoar.

9. SBO- Etiology
64-79%
15%

10. SBO- Etiology

11. SBO - History Pain: Crampy, diffuse, Spasmodic
(q3-10 min depending on location of obstruction)
Nausea/Vomiting (bilious or feculent)
Distention (may be mild)
Obstipation (once contents have passed)
Presentation within hours or days of onset
Focal, constant pain = strangulation

12. SBO - Physical Exam Early - vital signs normal, afebrile. Distention
Scars
Borborygmi, Singultus
Tympani
High Pitched, musical bowel sounds
Diffuse, mild tenderness
Heme-negative stool, rectal masses.

13. SBO - Physical Exam Later - Tachycardia, low grade fever
Focal tenderness
Tender mass
Peritoneal Signs, guarding, rebound
Heme-positive stool (specific causes)

14. SBO - Laboratory Analysis
Generally not helpful to diagnose strangulation
Mild Leukocytosis with left shift
WBC>20, think necrosis
Hypovolemia, elevated HCT, BUN/Cr
Electrolytes normal until late, then severely deranged, especially hypokalemia
Pre-op labs

15. SBO - Radiology KUB - Supine and upright, Upright CXR
Demonstrate obstruction in 50-60% of cases
Suggest obstruction in 20-30% of cases
Normal or misleading in 10-20%
Failed to diagnose strangulation in 50-85%
(Am J Surg 132: , 1976)
(Arch Surg 85: , 1962)
Does not show etiology

16. SBO - Supine KUB Small Bowel: Dilated loops Stepladder pattern
smaller diameter
central location
valvulae conniventes occupy transverse diameter of bowel
Dilated loops
Stepladder pattern
May be absent with fluid in bowel

17. SBO - Upright KUB Dilated loops More air if distal Air/fluid levels
No air in colon
Makes Diagnosis

18. SBO - Upright KUB
String of Pearls Sign
Coffee-Bean Sign

19. SBO - Upright KUB
Pseudo-tumor Sign

20. Air in biliary tree
SBO
Gallstone
Gallstone Ileus

21. Gummi Bear Bezoar
7 year old male presents to Albert Einstein Hospital in Philadelphia with complaint of vomiting and abdominal pain.
Ill appearing, distended, tender abdomen
Further history reveals that patient had eaten 12 bags of Gummi Bears 6 hours prior to onset of symptoms
(J Emerg Med Vol. 7, pp , 1989)

22. SBO - CT Scan
I+/O+ Scan helpful when KUB suggestive but not diagnostic
Can clarify etiology and strangulation
95% Accurate
94% Sensitive
96% Specific
(AJR 158: )
(Radiology 180: )
CT remains the investigation of choice
Thompson Ann. Surg 2002
Peck, JJ Am J Surg 1999

23. SBO - CT Scan Closed Loop Obstruction: Strangulation:
U-Shaped dilated loops
Mesenteric vessels converging
Beak sign, or two adjacent collapsed loops
Strangulation:
circumfrentially thickened loop
High bowel wall attenuation
target sign
pneumatosis
Retrospective analysis of CT diagnosed 8/19 with closed loop, 7/19 with strangulation
(Radiology 185: , 1992)
Retrospective analysis shows CT no better than Plain film for detecting infarction (poorly controlled)
(AJR 154:99-103, 1990)

24. SBO - CT Scan Incisional Hernia
Diagnoses etiology of Obstruction in 78%
(Rad Clin N America 32:5 1994)
Incisional Hernia

25. SBO - CT Scan
Crohn’s Disease with focal thickening of bowel wall

26. SBO - CT Scan
Intussusception

27. SBO - Pathophysiology Three types of mechanical SBO:
Obstruction of the lumen
tumors, intussusception, gallstones, feces, bezoar
Obstruction by intrinsic bowel wall lesions
congenital, strictures, tumors
Obstruction by extrinsic lesions
adhesions, hernias, tumor

28. SBO - Pathophysiology Gas accumulates proximal to obstruction.
70% Swallowed Air (Nitrogen not absorbed)
30% Carbon Dioxide (Bacterial Fermentation)

29. SBO - Pathophysiology First 24 hours: After 24 hours:
Distention decreases absorption of Na+ and H20 from lumen.
After 24 hours:
Active secretion of Na+ and H20 into lumen.
Distention causes reflex vomiting.
further loss of Na+, K+, Cl-, H+

30. SBO - Pathophysiology Luminal Pressure Rises:
Normal 2-4 mmHg
Rises to 8-10 mmHg
Closed Loop Obstruction 30-60mmHg
High Pressure causes rupture of small blood vessels, venous/arterial insufficiency.
Intra-abdominal pressure rises, inhibiting respiration, venous return.

31. SBO Pathophysiology (Rosen)
Relationship of Physiologic Changes to Clinical Manifestations in Patients with SBO

32. SBO - Pathophysiology
Normally nearly sterile small bowel is rapidly overgrown by bacteria.
Bacterial translocation occurs.
(Am J Surgery 159:394, 1990)
70% Mortality from sepsis/shock.

33. SBO - Strangulation Occurs in 10% of cases (5-42%)
(Surgery 89: )
Blood supply to obstructed intestine is impaired
Intraluminal Pressure > Central Venous Pressure
Venous/lymphatic outflow obstructed
(adhesive bands, hernial rings)
Leads to hemorrhage, gangrene, sepsis, perforation - all of these are bad.

34. SBO - Treatment Aggressive Fluid Replacement Bowel Decompression
Normal Saline/Lactated Ringers
Bowel Decompression
NG Tube
Antibiotics
Ampicillin/Levo or Gent/Flagyl or Clinda
Surgical

35. SBO - Treatment Operative Planning:
Minimal metabolic disturbance/co-morbidity
Can go to OR immediately
Marked metabolic disturbance/co-morbidity
Correct these over several hours first

36. SBO - Treatment Immediate Surgery if: Fever Leukocytosis
localized abdominal tenderness
radiographic evidence of necrosis
(tachycardia)

37. SBO - Treatment Conservative Management
75% of Partial SBO will resolve
16-36% of Complete SBO will resolve
Most Likely:
Early Post-Operative, Adhesions, Crohn’s Disease
Least Likely:
Intraluminal Cancer, Intussusception
If no resolution in hours - surgery

38. SBO - Treatment Operation Viability of bowel Resect 2nd look
Empty bowel
Pelvic loops
Intestinal bypass

39. SBO - Treatment Intsussption with small bowel leiomyoma
intsussuption with Small bowel lymphoma

40. SBO - Treatment Laparoscopy
Laparoscopy advantage include lower adhesion formation and quicker post operative recovery.
Safe and feasible
Strickland Surg Endosc 1999
Controversy still exists in the use of laparascopy for acute obstruction.
Some studies have demonstrated the safety and feasibility of lap treatment for SBO, but comparative data is still lacking.

41. SBO - Treatment
Stickland* found that if the operation could be performed then the laparoscopic approach was cost effective and reduced post operative morbidity and LOS.
Wullstein et al** found that :
treatment of acute adhesive SBO was feasible in half of their patients, who benefited from a low postoperative complication rate, a quicker recovery of bowel function and a shorter hospital stay.
An attempt at laparoscopic management of acute SBO seems justified in patients with fewer than two previous laparotomies but should not be offered to other patients because of the unacceptably high risk of intraoperative bowel perforation.
* Strickland Surg Endosc 1999
** Wullstein, BJS 2003Laparoscopic

42. SBO - Treatment A case of band adhesion causing intestinal obstruction
that is amenable to laparoscopic resection.

43. Adynamic Ileus
The cessation of intestinal paralysis, in the absence of mechanical obstruction, which results in the dilatation of the entire gastrointestinal tract.

44. Adynamic Ileus - History
Similar to SBO
Abdominal distention
Constant abdominal discomfort
NO colicky waves of pain
Vomiting (profuse, never feculent)
Obstipation

45. Adynamic Ileus - Etiology
Surgery
Intestinal distention or ischemia
Trauma (vertebral or rib fractures)
Hemorrhage (especially retro-peritoneal hematoma)
Perforation
Peritonitis
Infection (peritoneal, retro-peritoneal, pelvic, thoracic)
Pancreatitis
Renal/Biliary Colic
Myocardial Infarction
Electrolyte Abnormalities (hypokalemia)

46. Adynamic Ileus - KUB Dilated Loops
Gas diffuse throughout small bowel and colon

47. Adynamic Ileus - Treatment
Fluid Replacement
Normal Saline/Lactated Ringers
Bowel Decompression
NG Tube
Correct underlying etiology
Symptomatic treatment
Consider Surgical Consultation

48. Large Bowel Obstruction
53 %
17%

49. LBO - Etiology Causes of acute LBO requiring surgery (n=300)
Arch Surg 108:

50. From: Cameron, Advances in Surgery
LBO - Etiology
From: Cameron, Advances in Surgery

51. LBO - History/Physical Exam
Abdominal pain (may be sudden or insidious)
Distention (competent ileocecal valve)
Obstipation, change in bowel habits
Vomiting
Feculent smelling breath
Medication use
Altered bowel sounds (small bowel motility)
Fever, tachycardia, peritonitis suggest strangulation

52. LBO - Pathophysiology Increased intraluminal pressure
Transudate and decreased fluid absorption
Hypovolemia
Blood flow to other bowel segments increases
Blood flow to cecum decreases
Wall tension in cecum rises (Laplace’s Law)
Bacterial overgrowth/translocation
39% node culture positive, 43% same organism causing sepsis
(Br J Surg 63:721, 1976)

53. LBO - Radiology Plain Films: Contrast Enema:
Dilated Peripheral loops (small and large bowel)
Plain Films:
84% Sensitive
72% Specific
Contrast Enema:
96% Sensitive
98% Specific
Clin Rad 46:273, 1992

54. LBO - Radiology

55. LBO - Treatment Aggressive Fluid Replacement Bowel Decompression
Normal Saline/Lactated Ringers
Bowel Decompression
NG Tube: does not decompress colon but may aid nausea/vomiting/distention
Antibiotics
Ampicillin/Levo or Gent/Flagyl or Clinda
Surgical

56. LBO - Carcinoma Colorectal Cancer: large bowel decompression/lavage
resection and primary anastomosis
staged resection with colostomy/ileostomy
laser ablation, endoscopic stenting, balloon dilation, tube decompression (palliative)
Mortality 15%

57. LBO - Carcinoma

58. LBO - Carcinoma

59. LBO – Carcinoma Endoscopic Stenting

60. LBO - Volvulus
Twisting or folding of a large bowel segment on its mesentery
5% of colonic obstructions
Location:
65-72% sigmoid
21% cecal
2% transverse
40% Diagnosed on KUB
High incidence of strangulation
Coffee-Bean Sign

61. LBO - Volvulus Volvulus Risks: Bird’s Beak Sign
Prior episodes (40-60%)
Elongated mesentery with narrow base
High fiber diet
Chronic Constipation
Institutionalization
Laxative use
Previous surgery
Pregnancy
African-American
Hirshprung’s disease
Bird’s Beak Sign

62. LBO - Volvulus Sigmoid Volvulus: Early decompression
Colon/Sigmoidoscopy
55-85% successful
(Ann Surg 206:1, 1987)
Rectal Tube
Recurrence in 60-90%
(Surg Gyn Obs 124: )
Elective resection of prepped bowel
Detorsion/colopexy
Bent Inner-Tube Sign

63. LBO - Volvulus Cecal Volvulus: Presents as SBO
Incomplete fixation of right colon to peritoneum
90% - Ileocolic
10% - cecal bascule
Endoscopy ineffective
Resection/Colopexy

64. LBO
Entero-colic intussusception
20% are colonic

65. Ogilvie’s Syndrome

66. Ogilvie’s Syndrome Colonic Dilation without mechanical obstruction
Autonomic imbalance
(parasympathetic inhibition/sympathetic excitation)
Seriously ill/elderly patients
Symptoms
Abdominal Distention (100%)
Abdominal Pain (83%)
Constipation (51%)
Diarrhea (41%)
Fever (37%)

67. Ogilvie’s Syndrome Causes:
Cardiovascular, trauma, post-operative, inflammatory, respiratory, metabolic, neurological, pharmacological
Treatment:
Bowel Rest
Fluid Re-hydration
Correction of underlying etiology
Colonoscopic decompression (71-93% successful)
(Am J Surg 147:243, 1984) (Ann Surg 197: )
Guanethadine/neostigmine/cisapride/erythromycin
Risk of perforation correlated with duration

68. Pediatric Bowel Obstruction
Atresia and stenosis
Hypertrophic pyloric stenosis
Meconium Ileus
Meckel’s Diverticulum
Intussusception
Malrotation

69. Atresia and Stenosis Surgery to resect involved segment
Neonatal Bowel Obstruction
95% Atretic 5% Stenotic
1:330 infants in USA
Associated with Down’s syndrome
Caused by an intrauterine vascular occlusion
Polyhydraminos, bilious vomiting, distention, jaundice and failure to pass meconium on first day of life.
Surgery to resect involved segment

70. Atresia and Stenosis
Doudenal atresia
oesphageal atresia

71. Hypertrophic pyloric stenosis

72. Meconium Ileus Neonatal SBO (typically ileum)
7-25% of Cystic Fibrosis (1:2000)
Low water content and a gelatinous protein
Distention, bilious vomiting, no stool passed by hours after birth
Soap Bubble appearance on KUB
Hyperosmolar enema (gastrograffin)
Meconium ileus “equivalent” in 10% of older CF patients (inadequate pancreatic enzyme dosage)

73. Meconium Ileus

74. Meconium Ileus

75. Meconium Ileus

76. Meconium Ileus

77. Malrotation Embryology:
Intestine normally rotates 270 degrees counter-clockwise around the SMA
Midgut Volvulus
Duodenal Obstruction by Ladd’s Bands
Double Bubble sign on KUB
Internal Herniation
(non -fixed colon created hernial pouches)

78. Malrotation

79. Malrotation and volvulus

80. Meckel’s Diverticulum
Vittelline Duct remnant
2% of population
2 Years old (45%)
2 Feet from Cecum
2-4% symptomatic
44% Gastric Mucosa
35% asymptomatic
75% symptomatic
5% Pancreatic tissue

81. Meckel’s Diverticulum
Obstruction (35%)
Mechanism:
Intussusception 47%
Lead point of ileoileal obstruction with progress to ileocolic obstruction
Duct Remnants 53%
Herniation (Littre’s hernia)
Bands
Kinking
Volvulus
NG Tube, IVF, Antibiotics

82. Intussusception - History
Well Nourished child with URI/OM symptoms (21%)
<1 year old (65%)
Colicky pain (100%)
Vomiting (80-100%)
Bloody stool (65-95%)
Pallor/diaphoresis
Apathy
Stool - relief of symptoms
Obstipation/diarrhea (7%)
Prior Episodes (5-7%)

83. Intussusception

84. Intussusception Obstruction is complete from beginning
95% begin at ileocecal valve
2-8% have a lead point
(polyp, Meckel’s, lymphoid patch)
Edema produces lymph node enlargement
Fluid, blood and mucus into the lumen
Current Jelly Stool

85. Intussusception - Treatment
NG Tube, IVF, Antibiotics, Surgical Consultation
Hydrostatic Reduction (65%):
Foley inserted into rectum, balloon inflated
Barium run in from 3’6” above patient
Fluoroscopy: meniscus lengthens, reduces
If no free flow into ileum - surgery
(Johns Hopkins series, 1965)
Glucagon?

86. Hirshirprung disease

87. Thank you