A 61 y.o. comes in with a fall from her couch complaining of L sided flank pain.

BP 103/43 Temp 35.7 Pulse 49 Wt 153 kg. The pt is on eliquis.

The patient quickly spikes a temp and becomes hypotensive and septic; what could be wrong?

Our patient presented with what was thought to be a retroperitoneal hematoma. On her CT colonic thickening was noted but no obvious perforation. She was managed conservatively and discharged home but returned with fever, hypotension an hypoxia. She had a large amount of gas in the soft tissue and was taken to the OR with necrotizing fasciitis.

Retroperitoneal infections can be subtle as in the case above but rapidly lead to necrotizing fasciitis.

Retroperitoneal colonic perforations can cause retroperitoneal abscess.  It is life threatening because of its potential to spread rapidly to the perinephric space, the psoas muscle, the lateral abdominal wall and the legs.  Retroperitoneal infections are associated with a 20% mortality. 

While the most common cause of retroperitoneal abscess is diverticular disease.  Abscess of the psoas muscle can also  be caused by a perforated colon cancer,  perforated appendicitis, Crohn’s and tuberculosis.  Since diverticulitis  is one of the most common GI disorders a brief review is in order.

while a diverticulum can be a perforation through the colonic wall, it can also contain fat as in an epiploic outpouching causing epiploic appendagitis

Paiter and Burkitt noted diverticular disease increased in prevalence at the time of the Industrial Revolution with noted differences in Western and Eastern countries.  This led to a hypothesis that a lack of dietary fiber caused the disease by producing hard stools that caused increased colon contractility.    Herniation of the colonic mucosa was thought to occur as a result— through the wall of the colon. More recently.  it has been found to be associated with chronic inflammatory disease.  Studies have shown that obesity,  physical inactivity, Vit D deficiency and diabetes; all thought to influence biomarkers of inflammation, are associated with higher risk for diverticular disease.  A complex interaction of these lifestyle factors and the gut microbiome may be associated with diverticulitis as shown below.

Our patient was taken to the OR for necrotizing fasciitis. A large amount of necrotic tissue : subcutaneous tissue, muscle and fascia was removed from the L flank, L buttock, L anterior abdomen and L back. There was foul smelling dishwater drainage and fascial necrosis. Rectal contrast did not show a perforation and she was managed with antibiotics after debridement. She has since been taken off pressors, extubated and discharged from the ICU.

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