A 57 y.o. male presents with abdominal distention
What do you notice on the CT of the abdomen?
hint the wall of the bowel is abnormal
Our patient has pneumatosis cystoides intestinalis or gas filled cysts in the bowel wall. This was first described in 1730 by DuVernoy during a cadaver dissection. Although the first thing we are taught to rule out is ischemic bowel; the condition is often benign.
It is estimated that 15% of pneumatosis is primary; in 85% of cases there appear to be secondary causes. The causes of pneumatosis include:
traumatic and mechanical- this includes pyloric stenosis where the bowel contracts against an obstruction or bowel surgery which can disrupt the bowel wall layers.
Inflammatory and autoimmue- this includes crohn's disease, NEC, and conditions where steroids are used for treatment. Steroids are thought to cause atrophy of the mucosa and lead to spaces which can fill with gas
Infectious- c diff, HIV and CMV have all been shown to cause pneumatosis
Transplantation probably because of immune suppression, and neoplasm are also associated with pneumatosis.
in pneumatosis the ruptured cysts can cause free intraperitoneal air and yet the bowel wall is intact as shown above.
Often the patient is treated with flagyl but oxygen therapy can be used. it is thought that 350 mm of oxygen increased the oxygen in the cyst to blood diffusion gradient and this will lead to absorption of the cysts. The cysts themselves contain nitrogen and carbon monoxide.
submucosal cysts
Pneumatosis is called the surgeons dilemma because no one wants to perform unnecessary surgery, yet missing ischemic bowel can be devastating. The two things to look for are lactic acidosis and severe abd pain. Our patient had neither and he was managed conservatively with antibiotics. The pneumatosis resolved.
- Brauman C, Menenahosc C, Jacobi C . Pneumatosis intestinalis- a pitfall for surgeons. 2005 Scand Journal of Surg 94(10 47-50.
- Zulke C, Ulbrich S, Graeb C, Hahn J. Pneumatosis cystoides intestinalis following allogenic transplantation. 2002;29(9) 795-798.