Diverticulitis

Upto 1/3^rd of the population have diverticulosis by age 50.

25% of these, may experience an epidsode of diverticulitis in their lifetimes.

Pathophysiology:

• Composed of mucosa and submucosa.

• Two types of diverticula: true and pseudodiverticula. True is entire bowel wall involvement. Pseudo is protrusion of mucosa through the muscularis propria of the colon. Pseudo is the most common form of diverticulum affecting the colon. Occurs at the point where vasa rectii (nutrient artery) penetrates through the muscularis propria.

• Develop as herniations through weakness in the muscular layers of the bowel wall, commonly between taenia coli.

• Diverticuli without evidence of inflammation define the condition of diverticulosis.

• Diverticulitis are inflammed diverticuli. Typically inflammation is as a result of obstruction of the diverticulum with fecal material > retention of mucus secretion > bacterial proliferation > inflammatory cascade >>>increasing intraluminal pressure on the edematous diverticular wall > microperforation. The vasa recti is either compressed or eroded, leading to perforation or bleeding. Rupture is typically contained within pericolic tissues but causes inflammation of these tissues, resulting in the clinical form of the disease. Because of the relatively weaker muscular wall, the sigmoid colon is the most frequent site of diverticulosis and therefore diverticulitis. Inflammation extending to adjacent organs (bladder, uterus) may promote fistula formation.

History:

• Abdominal pain – anywhere in the lower abdomen, but common location is LLQ. RLQ disease may mimic acute appendicitis and should be considered in the DDx, particularly for patients over age of 50 presenting with RLQ pain.

• Pain is constant cramp or deep ache.

• Bowel habits may vary, patients may have diarrhea, constipation, or no change at all.

• Tenesmus is a common complaint if diverticulitis involves rectosigmoid.

• Fistula formation involving the bladder may cause pneumaturia or sx of UTI.

• Fever is common, low grade <38°C (<100.4°F). High fever suggests abscess or peritonitis.

• Nausea and vomiting are typically absent but occurs in the presence of paralytic ileus or bowel obstruction from inflammatory narrowing.

• Free perforation is rare but commonly present as acute, localized pain that becomes generalized.

Physical Examination:

VS: low grade fever, HR, BP usually normal. Tachycardia, hypotension suggest septicemia and suggest abscess formation or perforation.

Abdomen: localized tenderness, typically in LLQ. Voluntary guarding and focal rebound tenderness may be appreciated. Mass may be felt.

Diffuse tenderness, rebound tenderness, rigidity, and involuntary guarding suggest peritonitis.

Rectal examination may elicit tenderness, predominantly on the left side.

Diagnosis:

Clinical.

WBC mildly elevated or normal in uncomplicated disease, but may display a bandemia. Counts >15,000 should raise the suspicion of abscess or other sequelae.

UA routinely performed to check UTI, fistula formation (fecal material).

Radiology: Acute abdominal series (plain X-ray), US, and CT (double contrast CT) is the diagnostic test of choice.

Tx:

ABx, IVF, bowel rest, and pain control.

ABx to cover enteric flora, especially gram-negative (E. coli, Klebsiella, Enterobacter) and anaerobic pathogens (Bacteroides fragilis, Peptostreptococcus).

Ciprofloxacin and metronidazole for 10 – 14 days.

Amoxicillin-clavulanic acid may also be used for same duration.

IP, in cases of systemic toxicity: Fluroquinolone or aminoglycoside IV + clindamycin or metronidazole IV

If Pt. d/c f/up in 48 hr with PCP

Uncomplicated disease in patient who are febrile, unable to tolerate by mouth, multiple comorbidities (DM), elderly, poor social support or f/up may be admitted.

Surgical consult for complicated cases. Indicated in diverticular abscess or 2nd cases.

Transcutaneous or open drainage is the typical approach for abscess formation.

Laprotomy with partial colectomy and reanastomosis or diversion in the standard treatment for obstruction and perforation.

20% of patient with diverticulosis will have GIB, hematochezia. Most are self limiting. Lifetime risk of rebleeding is 25%.

C-scopy in mild to moderate bleeding.

Angiography if patients is stable. Mesenteric angiography can localize the bleeding site and occlude the bleeding vessel successfully with a coil in 80% of cases. F/up with C-scopy, if needed to look for evidence of colonic ischemia. Segmental resection of the colon to eliminate risk of further bleeding. Vasopressin infusion given selectively can stop H'ge, but is associated with significant complications like MI and intestinal ischemia. Also 50% rebleed once infusion is stopped. Bleeding is more often seen in right colon. Emergent surgery without localization ends up with total colectomy.

If the patient is unstable or has had a 6 unit of bleed within 24 hr, current recommendations are that surgery should be performed. In patients without severe comorbidities surgical resection can be performed with a primary anastomosis. A higher anastomotic leak rate has been reported in patients who received >10 units of blood.

Uncomplicated diverticular disease: 75%: Abd pain, fever, leukocytosis, anorexa/obstipation

Complicated diverticular disease: 25%: Abscess, perf, stricture, fistula.

DX: CT: sigmoid diverticula, thickened colonic wall >4 mm, and inflammation within the pericolic fat +/- the collection of contrast material or fluid. In 16% patient an abdominal abscess may be present. If suspected diverticular dz does not meet CT criteria, not associated with leukocytosis or fever, then it is unlikely to be diverticular dz.

DDX: IBS, ovarian cyst, endometriosis, acute appendicitis, and PID.

Ba enema and C-scopy not done in acute setting due to risk of perf. Done ~6 weeks after an attack of diverticular disease.

Complicated diverticular disease is defined as diverticular disease associated with an abscess or perforation and less commonly with a fistula

Perforated diverticular disease is staged using the Hinchey classification system. This staging system is used to predict outcomes following the surgical managment of complicated diverticular dz. Fisutla can form cutaneously, vaginal or vesical.

Hinchey classification of diverticulitis:

• • Stage I: perf diverticulitis with a confined paracolic abscess.

  • Stage II: perf diverticulitis that has closed spontaneously with a distant abscess formation.

  • Stage III: non communicating perf diverticulitis with fecal peritonitis (the diverticular neck is closed off and therefore contrast does not freely expel on radiographic images.

  • Stage IV: perf and free communication with the peritoneum, resulting in fecal peritonitis.

Diverticular disease managment:

Asx: 30 g fiber/d (metamucil, fibercon, citrucel is useful supplements). No nuts and no popcorns, which may obstruct the lumen of diverticulum.

Abx: Mild diverticulitis - TMP-SMX 160 mg/800 (DS) PO bid or ciprofloxacin, 500 mg bid, and metronidazole, 500 mg PO bid, for 7 - 10 days, target GNB and anaerobic bacteria. Do not cover enterococci and the addition of ampicillin to this regimen for non-responders is recommended.

Oral Augmentin may be effective.

Course 10 - 14 days. Some 7 days.

Rifaximin (poorly absorbed broad spectrum ABx) given with fiber associated with less frequent recurrent sx.

Surgical management: Preop risk includes higher ASA class and preexisting organ failure.

Low risk (ASA I and ASA II), surgery if patients have had at least 2 documented attacks of diverticulitis requiring hosp or those who do not respond rapidly to medical therapy. It is recommended to do surgery on younger patients who have more aggressive form of dz and all patients who have low risk.