Diverticular Disease (Sawyer, 8/11/2021)

Diverticulitis is. . . 

• the 3rd most common cause of GI illness requiring hospitalization
• the leading cause of elective colon surgery
• a bit unpredictable but often managed medically
• 15% of cases ultimately require surgery 
• surgical indications: medical therapy failure (or not amenable)

Medical management

Medical/conservative treatment of uncomplicated diverticulitis generally involves antibiotics x 7-10 days

Note: there is NO high quality evidence regarding the ideal duration of antibiotics and which abx are superior

Good abx choices include: bactrim DS/flagyl (favorite of Dr. Sawyer), cipro/flagyl, levo/flagyl augmentin, and more

Diet

There is NO high quality evidence for specific dietary management of diverticulitis

Older surgeons prefer clear liquids x72 hours, advancing as tolerated after that (the rationale for this is really about possibility of surgery-- to be better prepared for a bowel prep if a surgery becomes necessary)

Of note, more recently trained surgeons will often let patients eat as tolerated (i.e. ad lib)

Of note, avoiding nuts, popcorn, seeds, corn, tomatoes, strawberries, etc is NOT evidence based and not necessary (JAMA 2008 paper). Do NOT tell patients to avoid these foods to prevent diverticulitis.

Known complications of diverticulitis:

• Perforation
• Fistula
• Obstruction

Perforations that are very small are characterized as microperforations: conservative treatment with abx (oral/IV) is appropriate for microperforations; of note,19% of microperforations go on to form abscesses. Random pearl: diverticulitis as seen on CT often looks "worse" than the patient. 

Classification of perforation

• Microperforation (not included in Hinchey classification system)
• Hinchey I pericolic or mesenteric
• Hinchey II walled off pelvic abscess
• Hinchey III purulent ascites
• Hinchey IV feculent ascites

Hinchey I and II can be managed non-operatively, III and IV should be managed with surgery

4cm abscess is used as the cutoff for IR drain placement

<4 cm diameter, abx alone usually sufficient 

>4cm diameter, IR drain + abx

if an abscess is exactly 4cm, it's at the discretion of the interventionalist/location of the abscess that determines best practice for management

What if it doesn't work?

If patients fail to improve after 48-72 hours of abx (usually repeat imaging is done), the next step is  a bowel preparation (if pt can tolerate it) and a surgical anastomosis. Of note, a "contaminated" peritoneum may require a diversion.

Surgical options:

colon resection w/primary anastomosis: one step, requires well-vascularized, non-edematous bowel, good nutritional status, good immune state (not immunocompromised)

colon resection w/proximal diversion

Hartman's procedure

open vs. minimally invasive: MIS preferred if feasible, shorter hospitalization/ileus and less pain. Long term, outcomes are about equal

Goal of surgical management of diverticulitis:

1. Source control: remove the perforated segment
2. Restore intestinal continuity-- depends on hemodynamics of the patient, degree of contamination, and surgeon preference/comfort

Free perforation (in an unstable patient) requires urgent damage control, which involves limited resection (if possible), peritoneal lavage, and usually a temporary abdominal closure. Alternative is a "Hartman's Procedure" with a limited resection, peritoneal lavage, end colostomy, and temporary closure.

• in a study of 58 patients with generalized peritonitis and perforated diverticulitis, 9% mortality (5 patients). OF the 53 survivors, 44 were stoma free at 2 years (pretty good!)

Stable patient with feculent peritonitis (Hinchey IV) generally requires Hartman's procedure.

• these can be difficult to close (only 50-60% have closure)
• need to wait 6 months to 1 year for all the inflammation to resolve before rehooking

Of note, BOTH require a second look (return to the OR) at 24-48 hours

Fistulas can occur:

colo-vesicular 65%

colo-vaginal 25%

colo-enteric 7%

colo-uterine 3%

Obstruction: if diverticulitis is leading to obstruction, you MUST rule out cancer. Stenting-- while can be helpful in cancer-- is not helpful in diverticulitis

And, finally, the SSRRH Diverticulitis PROTOCOL

• admit with IV abx
• re-image at day 2-3
• if improved on imaging--> abx management (7-14 days)
• if imaging stable OR worse--> 
• if drainable abscess, then IR drain, followed by surgery in 6-8 weeks,
• if abscess NOT drainable, then mechanical bowel prep with surgery in 1-3 days