Radiation Entritis

A 77-year-old comes to the ED with complaints of diarrhea, rectal pain and urgency for 3 days. His History is notable for Ischemic Heart disease, Hyperlipidemia, Hypertension and Prostate cancer. His medications include aspirin, statins, captopril and atenolol. He recently finished a high dose palliative radiotherapy, done in 6 courses of 60 Gy done over the last 6 weeks. His PE is notable for diffused abdominal pain, and an enlarged prostate and traces of cherry red blood in a rectal exam. Laboratory findings include a raised white cell count of 14.4, Hb 13.4, and C-reactive protein of 213mg/l. What is the most likely diagnosis:

A) Ischemic Colitis B) Acute Appendicitis C) Radiation enteritis D) Paraneoplastic Syndrome E) Crohn’s disease

Clinical Vignette

Definition -  Inflammation of the small intestine caused by radiation therapy to the abdomen, pelvis, or rectum. Symptoms include nausea, vomiting, abdominal pain and cramping, frequent bowel movements, watery or bloody diarrhea, fatty stools, and weight loss. Some of these symptoms may continue for a long time. (NCI)

Radiation enteritis

Epidemiology - 5-15% of patients treated with radiotherapy (usually > 4.5Gy) develop radiation enteropathy, the risk is augmented in doses over 10Gy.

Risk Factors – oAdhesions from previous abdominal surgeryo Peritonitis prior to radiation therapyoHigh radiation dose (Over 4.5Gy)oRisk factors for atherosclerosis; hypertension and

diabetes mellitusoChemotherapy 

Acute stage: Concurrent or within 2 months of treatment

Subacute: 2-12 months after treatment Chronic: >12 months after treatment

Classification

In the acute phase, radiation affects bowel mucosa causing cell death with ulceration. It also causes inflammation with mucosal and submucosal edema. In the subacute and chronic phases healing and fibrosis occurs. Additionally radiation induces endarteritis obliterans, which results in a state of chronic mesenteric ischaemia leading to bowel strictures.  

Pathogenesis

Cramping abdominal pain Tenesmus Nausea Vomiting Anorexia Diarrhea Hematochezia Fever

The most common clinical finding is generalized abdominal tenderness without peritoneal signs. Rarely, severe acute enteritis is associated with massive hematochezia or bowel perforation.

Clinical Presentation - Acute

Wave-like abdominal pain. Bloody diarrhea. Frequent urges to have a bowel movement. Greasy and fatty stools. Weight loss. Nausea. Vomiting.

Clinical Presentation - Chronic

Dehydration Anal Fistula Intra – Abdominal Abscess Perforation of colon colon fistula Perforation of rectum Perforation of ileum Bowel Obstruction – relatively rare

Complications

Enteroclysis  CT MRI

Findings – ◦ Bowel wall thickening and

luminal narrowing

◦ Small bowel obstruction

◦ Fistulas between the bowel (especially colon) and the bladder or vagina

Diagnostics

Medical◦ Dietary modification– usually resolves acute

symptoms◦ Hydration◦ Antidiarrheals 

◦ Other measures: 5-ASA Steroids Hyperbaric oxygen therapy – to consider in the treatment

of intractable radiation proctitis, prior to surgical intervention

Treatment

Prevention Complications –

◦ Obstruction – Strictureplasty  Intestinal bypass - Long or multiple stricture segments

◦ Fistula – Primary anastomosis - resection of the involved small bowel up

to healthy margins ostomy 

◦ Perforation -   Primary anastomosis - resection of the area of perforation with

exteriorization of the divided ends of the bowel◦ Hemorrhage –

rarely needs surgical treatment

Treatment - Surgery

Surgical procedures on radiated intestine carry morbidity rates of 12-65% and mortality rates of 2-13%

Almost 50% of patients who survive a laparotomy for radiation bowel injury require further surgery for ongoing bowel damage from radiation.

A mortality rate as high as 25% is reported for patients who require a second surgical procedure.

Prognosis

Authors: Curtis, N.J.1; Bryant, T.2; Raj, S.2; Bateman, A.R.2

; Mirnezami, A.H.2

Source: Annals of The Royal College of Surgeons of England, Volume 93, Number 7, October 2011 , pp. 129E-130E(2)Publisher: The Royal College of Surgeons of England

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