Acute diverticulitis: Hinchey, CT staging and management from no antibiotics to Hartmann’s

Terms that are often confused

Diverticulosis

The presence of diverticula, usually found incidentally and without symptoms.

Diverticular disease

Symptoms, such as intermittent lower abdominal pain and altered bowel habit, attributed to diverticula without acute inflammation.

Acute diverticulitis

Inflammation, usually from a microperforation of a diverticulum, with pain, tenderness, fever and raised inflammatory markers.

Complicated diverticulitis

Diverticulitis with abscess, perforation, fistula, obstruction or stricture. Diverticular bleeding is a separate problem.

Colonic diverticula are pulsion (false) diverticula: mucosa and submucosa herniate through the circular muscle where the vasa recta penetrate it, between the mesenteric and antimesenteric taeniae. In Western populations the sigmoid colon is affected in most patients; right-sided disease is commoner in Asian populations. NICE advises exercise, weight loss and stopping smoking to reduce the risk of diverticulitis.

Diagnosis and imaging

The typical patient has left iliac fossa pain and tenderness, fever and a raised CRP. NICE NG147 asks for referral for same-day hospital assessment when uncontrolled pain comes with features of a complication: an abdominal mass or perirectal fullness suggesting an abscess; rigidity and guarding suggesting perforation; signs of sepsis; faecaluria, pneumaturia or faeces per vagina suggesting a fistula; or colicky pain, distension, vomiting and absolute constipation suggesting obstruction.

When complicated diverticulitis is suspected and inflammatory markers are raised, NICE asks for a contrast-enhanced CT within 24 hours of admission. If contrast is contraindicated, a non-contrast CT, MRI or ultrasound can be used, depending on local expertise.

Classification

Hinchey’s 1978 classification described the findings at operation for perforated disease. The modified Hinchey classification (Wasvary, 1999) adds stages for disease seen on CT, and the WSES classification (2015, retained in the 2020 update) is based entirely on CT findings.

Uncomplicated diverticulitis

Two randomised trials changed practice. In AVOD (Chabok, BJS 2012) antibiotics neither sped recovery nor prevented complications or recurrence in CT-confirmed uncomplicated diverticulitis. In DIABOLO (Daniels, BJS 2017) observation without antibiotics gave a similar time to recovery to antibiotic treatment.

• Systemically well. NICE NG147 suggests considering a no-antibiotic strategy, with simple analgesia such as paracetamol and advice to return if symptoms persist or worsen.
• Systemically unwell, immunosuppressed or with significant comorbidity. Offer antibiotics. The first-choice oral regimen in the NICE prescribing guidance is co-amoxiclav 500/125 mg three times a day for 5 days.
• Admitted with suspected complicated disease. Intravenous antibiotics, reviewed within 48 hours or after the scan, stepping down to oral treatment when possible. If CT shows uncomplicated diverticulitis, review the need for antibiotics and plan discharge.
• After recovery. NICE does not recommend aminosalicylates or antibiotics to prevent recurrence.

Diverticular abscess

Small abscesses (under 3 cm) usually resolve with antibiotics, switched to oral treatment where possible. For larger abscesses NICE suggests considering percutaneous drainage, if anatomically feasible, or surgery, and asks for drained pus to be sent for culture so that antibiotics can be matched to sensitivities. The NICE prescribing guidance allows up to 14 days of antibiotics in total for a CT-confirmed abscess. Failure to improve despite drainage is an indication for surgery.

Perforation and peritonitis

Generalised peritonitis needs resuscitation, intravenous antibiotics and an operation. NICE NG147 recommends offering either laparoscopic lavage or resection after discussing the risks and benefits, and proceeding to resection if faecal peritonitis is found. For resection, NICE suggests either primary anastomosis, with or without a defunctioning stoma, or Hartmann’s procedure, taking account of the patient’s age, comorbidities and performance status, and resecting back to compliant bowel.

• Primary anastomosis or Hartmann’s. In LADIES (Lambrichts, Lancet Gastroenterol Hepatol 2019), sigmoidectomy with primary anastomosis and a defunctioning ileostomy gave better stoma-free survival at 12 months than Hartmann’s procedure for Hinchey III and IV disease in stable, selected patients, without more short-term morbidity or mortality.
• Laparoscopic lavage. The LOLA arm of LADIES (Vennix, Lancet 2015) and SCANDIV (Schultz, JAMA 2015) did not show lavage to be superior to resection for purulent peritonitis, and some patients needed further intervention for persisting sepsis. NICE notes that lavage avoids a stoma but is less likely to relieve pain than resection, and that any effect on mortality is uncertain.
• The septic, unstable patient. Damage control: resection, a closed blind end, temporary abdominal closure and a planned second look once the patient has been resuscitated.
• The distal margin. The resection should extend onto the upper rectum, where the taeniae coalesce; leaving distal sigmoid behind is associated with recurrence.

After the acute episode

• Excluding cancer. Most guidance advises colonoscopy or CT colonography a few weeks after complicated diverticulitis, and after an uncomplicated episode in patients with atypical features or no recent assessment of the colon.
• Elective resection. NICE suggests considering open or laparoscopic resection for patients who have recovered from complicated diverticulitis but still have symptoms, for example from a stricture or fistula. In DIRECT (van de Wall, Lancet Gastroenterol Hepatol 2017), elective sigmoidectomy improved quality of life more than conservative care in patients with recurrent or persisting symptoms.
• Number of episodes. The old rule of resection after two attacks has been abandoned. The decision rests on symptoms, complications, immunosuppression and the patient’s wishes.
• Colovesical fistula is the commonest fistula and presents with pneumaturia, faecaluria and recurrent urinary infection. It is treated by elective resection with repair of the bladder.