Diverticular Disease

1. Diverticular Disease 12/1/2010

2. Diverticular Disease • Anatomic and pathophysiologic change • Usually of sigmoid colon • Diverticulum • A sac or pouch in the wall of an organ • Can range from asymptomatic diverticulosis to inflammatory changes and diverticulitis to GI bleed

3. Incidence • Increased dramatically over past 75 years • Estimated risk approximately 5% by age 40 and more than 80% by age 80 • Accounts for nearly • 450,000 hospital admissions • 2 million office visits • 112,000 disability cases • 3000 fatalities

4. Incidence • Increases with age and diet high in red meat, refined sugars, and milled flour but low in whole grain breads, cereals, and fruits and vegetables • Of patients with diverticular disease • 10-20% will develop symptoms of diverticulitis • Only 10-20% of these require hospitalization • 20-50% of these will require operative intervention (<1% of pts with diverticula)

5. Pathophysiology • Associated with high intraluminal pressures • As high as 90 mmHg during peak contraction • 9 x normal • Leads to segmentation • Colon no longer functions as a continuous entity • Pressures predispose herniation of mucosa through muscular defects in the wall where vasa recta brevia penetrate to reach submucosa and mucosa • Occur mostly between mesenteric and anti-mesenteric tinea • Denuded of muscular layer c/w an acquired process or pulsion diverticula

6. Pathophysiology • Laplace’s law explains why sigmoid is most commonly affected • Tension = Radius x Pressure • Sigmoid has slightly smaller radius • Pressures generated result in greater tension on the wall • Both circular and longitudinal muscle wall is thickened in the sigmoid • May also have secondary pericolic fibrosis • Pain associated with muscle spasm or inflammation • Perforation can occur without inflammation

7. Pathophysiology • Malfunction of rectosigmoid relaxation could result in functional obstruction and hypertrophied muscle • Cellular hypertrophy, cellular hyperplasia, and elastosis have been described • Elastosis not found in any other inflammatory process of the colon • Patients without muscular thickening are more likely to have diffuse diverticula and higher incidence of bleeding • May have underlying connective tissue disorder

8. Etiology • Complications do not occur until there is microperforation through the wall of a diverticulum into the pericolonic tissue • Varying degrees of inflammation ensue • Microabscess, phlegmon, large abscess, fistula • Failure of the diverticular neck to obliterate after perforation results in fecal peritonitis • Rupture of a non-communicating abscess may result in purulent peritonitis • Low-grade inflammation of mucosa can affect the enteric nervous system and alter gut function • Some pts have bacterial overgrowth

9. Etiology • Disturbances in cholinergic activity may contribute • Unsynchronized slow waves of relatively low frequency (as opposed to bursts of action potentials in peristalsis) • More cholinergic innervation than normal colon • Less noncholinergic, nonadrenergic inhibitory nerve activity • May contribute to high intraluminal pressures and segmentation

10. Epidemiology • Diet • Diets high in red meat and low in fruits and veggies can increase symptoms threefold • Red meat assoc with heterocyclic amines, factoring in colon mucosal apoptosis • Veggies and brown bread are protective • Fiber protective by increasing stool weight and water content • Decreases segmentation and transit times • Also provides short-chain fatty acids through fermentation

11. Epidemiology • Sex and Age • Younger than 50 have more chronic or recurrent diverticulitis • Men • Higher incidence of bleeding • Younger patients present with fistula • Older patients with bleeding • Female • Present with complications requiring surgery 5 yrs later than males • Younger patients present with perforation • Older patients with chronic disease and stricture

12. Epidemiology • Immunocompromise • Use of steroids associated with higher risk of perforation and more severe inflammatory complications • NSAIDs • Inhibition of cyclooxygenase • Decreased prostaglandin synthesis • Important in maintenance of mucosal blood flow and mucosal barrier • Direct mucosal damage with increased translocation of toxins and bacteria

13. Epidemiology • Opiates • Increase intracolonic pressure and slow transit • Smoking • 3 times the risk of complications • Alcohol • 3 times the risk in females, 2 times in males • May be biased due to dietary and smoking habits associated with alcoholics

14. Clinical Patterns • Diverticulosis • Asymptomatic disease • Applies to vast majority of patients (80-90%) • Diverticulitis • Noninflammatory • Acute (simple or complicated) • Chronic (atypical or recurring/persistent) • Complex

15. Noninflammatory Disease • Symptoms of diverticulitis without associated inflammation • Never develop criteria to be called acute diverticulitis • Usually diagnosed at surgery by lack of inflammatory changes grossly and microscopically • 15-35% of resections • 88% become pain free on 12 month follow-up

16. Acute Diverticulitis • Heralded by signs and symptoms of acute inflammation • Simple: fever, leukocytosis • Complicated: tachycardia, hypotension

17. Hinchey classification

18. Chronic Diverticulitis • Remain symptomatic despite standard treatment • Atypical if systemic signs never develop • Recurring, intermittent episodes of acute disease • Persistent, symptomatic low-grade disease • Frequently associated with a phlegmon • Evidence of inflammatory changes in the specimen

19. Complex Diverticular Disease • Manifest sequelae of chronic inflammation • Fistula • Stricture • Obstruction

20. Natural History • Most first episodes are asymptomatic until 1 month prior to presentation • Most respond to bowel rest and antibiotics as outpatients • Up to 10% will develop recurrent or persistent symptoms requiring hospitalization • Median of 5 years between events • Inpatients may be more likely to develop recurrence (10-20%) • After 2nd admission, up to 70% have persistent symptoms, >50% will require 3rd admission in 1 yr

21. Presenting symptoms • Classically left lower quadrant pain • Redundant sigmoid colon can sometimes cause right sided pain • Pain is constant, not colicky • Radiation to back, flank, groin or down leg • May be accompanied by either constipation or diarrhea • Nausea/vomiting unusual in the absence of obstruction • Can occur with secondary ileus

22. Presenting symptoms • Bleeding uncommon and should prompt investigation into alternate diagnosis • Dysuria and urgency may imply bladder involvement • Pneumaturia and fecaluria suggest colovesical fistula • Passage of gas and stool per vagina may occur with colovaginal fistula • Fever is common and proportional to amount of inflammation • High fever suggests perforation with abscess or peritonitis

23. Presenting symptoms • Unusual presentations include • Lower extremity joint infections (hip) • Female adnexal masses • Inflammation/necrosis of perineum and genitalia (complex anal fistula and Fournier’s gangrene) • Subcutaneous emphysema of lower extremities, neck, and abdominal wall • Isolated hepatic abscesses • Brain abscesses • Cutaneous lesions mimicking pyoderma gangrenosum

24. Pyoderma Gangrenosum

25. Physical Findings • Tender to palpation in LLQ and iliac region • Rigidity or localized guarding • Mass in LLQ • Positive psoas or obturator signs if retroperitoneal and/or pelvic involvement

26. Complications • Perforation • Abscess • Fistula • Stricture • Obstruction • Ureteral obstruction • Phlegmon

27. Treatment—Medical/dietary • Asymptomatic: dietary fiber • 25-30 g per day • Acute diverticulitis: bowel rest and antibiotics • Low residue or clear liquids until resolved, then high fiber • Coverage for gram-negatives and anaerobes

28. Treatment—Surgical management • Primary resection with anastomosis (proximal diversion) • Resection with proximal colostomy, oversewn rectal stump (Hartmann’s procedure) or mucus fistula (Mikulicz operation) • Simple diversion with drainage of the affected segment • Diversion with oversewing perforation site • Subtotal colectomy

29. Indications for surgery--acute • Failure to respond to nonoperative management • Persistent phlegmon • Failure of perc or transrectal drainage • Increasing fever • Leukocytosis • Tachycardia • Hypotension • Signs of sepsis • Worsening physical exam • Free perforation with peritonitis • Obstruction not resolving with conservative therapy

30. Indications for surgery--chronic • Multiple, recurrent episodes • Should be considered after one or two well-documented attacks depending on severity, age, and medical fitness • Complicated episodes can be considered for resection after one attack • Increased risk of poor outcome from medical management • Abscess • Extraluminal air • Extraluminal contrast

31. Predictors of complications • Advanced age • Two or more comorbid conditions • Obstipation at initial exam • Use of steriods • Sepsis • Obesity • Emergent resection