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Ay, but to die, and go we know not where; To lie in cold obstruction and to rot. - William Shakespeare. Bowel Obstruction. Prof A walid elsahzly MD Professor of General Surgery, Colon and rectal Unit, University of Alexandria. Bowel Obstruction - Outline. Small Bowel Obstruction
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Ay, but to die, and go we know not where; To lie in cold obstruction and to rot.- William Shakespeare
Bowel Obstruction Prof A walid elsahzly MD Professor of General Surgery, Colon and rectal Unit, University of Alexandria
Bowel Obstruction - Outline • Small Bowel Obstruction • Adynamic Ileus • Large Bowel Obstruction • Colonic Pseudo-Obstruction • Pediatric Bowel Obstruction
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”.
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)
SBO - Historical Perspective • 350 BC - 1912 AD: Nothing Happens
SBO - Historical Perspective • 1912: Hartwell and Hoguet discover that saline therapy prolongs the life of experimental dogs. (JAMA 59:82 1912) • 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
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.
SBO- Etiology 64-79% 15%
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
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.
SBO - Physical Exam • Later - Tachycardia, low grade fever • Focal tenderness • Tender mass • Peritoneal Signs, guarding, rebound • Heme-positive stool (specific causes)
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
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:-29-303, 1976) • (Arch Surg 85:121-129 , 1962) • Does not show etiology
SBO - Supine KUB • Small Bowel: • smaller diameter • central location • valvulae conniventes occupy transverse diameter of bowel • Dilated loops • Stepladder pattern • May be absent with fluid in bowel
SBO - Upright KUB • Dilated loops • More air if distal • Air/fluid levels • No air in colon • Makes Diagnosis
SBO - Upright KUB • String of Pearls Sign • Coffee-Bean Sign
SBO - Upright KUB • Pseudo-tumor Sign
Air in biliary tree SBO Gallstone Ileus Gallstone
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. 143-44, 1989)
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 158:765-9 1992) • (Radiology 180:313-8 1991) • CT remains the investigation of choice • Thompson Ann. Surg 2002 • Peck, JJ Am J Surg 1999
SBO - CT Scan • Closed Loop Obstruction: • 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 185:769-775, 1992) • Retrospective analysis shows CT no better than Plain film for detecting infarction (poorly controlled) • (AJR 154:99-103, 1990)
SBO - CT Scan • Diagnoses etiology of Obstruction in 78% • (Rad Clin N America 32:5 1994) • Incisional Hernia
SBO - CT Scan • Crohn’s Disease with focal thickening of bowel wall
SBO - CT Scan • Intussusception
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
SBO - Pathophysiology • Gas accumulates proximal to obstruction. • 70% Swallowed Air (Nitrogen not absorbed) • 30% Carbon Dioxide (Bacterial Fermentation)
SBO - Pathophysiology • First 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+
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.
SBO Pathophysiology (Rosen) • Relationship of Physiologic Changes to Clinical Manifestations in Patients with SBO
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.
SBO - Strangulation • Occurs in 10% of cases (5-42%) • (Surgery 89:407-13 1981) • 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.
SBO - Treatment • Aggressive Fluid Replacement • Normal Saline/Lactated Ringers • Bowel Decompression • NG Tube • Antibiotics • Ampicillin/Levo or Gent/Flagyl or Clinda • Surgical
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
SBO - Treatment • Immediate Surgery if: • Fever • Leukocytosis • localized abdominal tenderness • radiographic evidence of necrosis • (tachycardia)
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 24-48 hours - surgery
SBO - Treatment • Operation • Viability of bowel • Resect • 2nd look • Empty bowel • Pelvic loops • Intestinal bypass
SBO - Treatment Intsussption with small bowel leiomyoma intsussuption with Small bowel lymphoma
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.
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
SBO - Treatment A case of band adhesion causing intestinal obstruction that is amenable to laparoscopic resection.
Adynamic Ileus The cessation of intestinal paralysis, in the absence of mechanical obstruction, which results in the dilatation of the entire gastrointestinal tract.
Adynamic Ileus - History • Similar to SBO • Abdominal distention • Constant abdominal discomfort • NO colicky waves of pain • Vomiting (profuse, never feculent) • Obstipation
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)
Adynamic Ileus - KUB • Dilated Loops • Gas diffuse throughout small bowel and colon
Adynamic Ileus - Treatment • Fluid Replacement • Normal Saline/Lactated Ringers • Bowel Decompression • NG Tube • Correct underlying etiology • Symptomatic treatment • Consider Surgical Consultation
Large Bowel Obstruction 53 % 17%
LBO - Etiology • Causes of acute LBO requiring surgery (n=300) Arch Surg 108:470 1974
LBO - Etiology From: Cameron, Advances in Surgery