Presentation
Two days of severe left lower quadrant pain with intermittent fevers, hypotension, and tachycardia.
Patient Data
Retroperitoneal lymphadenopathy. Florid fat stranding surrounding a thick-walled sigmoid colon with multiple diverticula represents acute sigmoid diverticulitis. No clear abscess or perforation.
Poor contrast enhancement of the portal vein and its branches without filling defect. The splenic vein appears patent. Significant fat stranding surrounding the inferior mesenteric vein (IMV), with a locule of intraluminal gas visible just inferior to the splenic vein confluence (axial, coronal). This is concerning for septic IMV thrombosis (pylephlebitis).
A soft tissue tract appears to extend from the posterior sigmoid colon to the left seminal vesicle, with a small locule of gas inside, which is concerning for a fistula. The tract can be seen extending on the axial slices.
There is soft tissue stranding and loss of the normal fat plane separating the sigmoid colon and urinary bladder without convincing intravesical gas. This may be suspicious for colo-vesical fistula in the right clinical context (e.g. pneumaturia, recurrent UTI, feculent urine).
Case Discussion
This is a 40-year-old male with a history of obesity, IV drug use, eradicated hepatitis C, and diverticulosis. He initially underwent supportive therapy for acute diverticulitis, but then deteriorated with intermittent hemodynamic instability and fevers.
CT of the abdomen and pelvis confirmed acute sigmoid diverticulitis but also demonstrated fat stranding and intraluminal gas in the IMV, raising concern for IMV pylephlebitis. The poor portal venous enhancement is likely due to alteration of flow dynamics by the occlusive IMV thrombus.
The patient underwent an emergency Hartmann's procedure with high ligation of the IMV. The diagnosis was confirmed microbiologically by culture of Enterococcus faecium bacteria from the intraoperative thrombus specimen. There was no ischemic gut.
The intermittent fevers and hemodynamic instability were thought to be related to septic showers from the IMV thrombus. The patient recovered well and completed four weeks of intravenous vancomycin and six weeks of oral apixaban without further complications. His stoma was successfully reversed 12 months later.
Mesenteric vein thrombosis (MVT) is a rare entity in itself, with an incidence of 2.7 per 100,000 people 1. IMV thrombosis is the rarer form of MVT accounting for just 6% of cases 2, with the SMV accounting for 94%. Risk factors include acute diverticulitis, acute pancreatitis, inflammatory bowel disease, and clotting disorders. Consequences of IMV thrombosis include superimposed infection (pylephlebitis or thrombophlebitis), seeding of liver abscess, acute mesenteric ischemia, and bacteremia.
Fistula formation between the sigmoid colon and seminal vesicles is very rare. Only 3 cases have been reported in the literature to date 3. There is very limited data on their incidence, though all have been in the context of diverticular disease.
This case demonstrates two rare complications of acute diverticulitis.
Case courtesy of A/Prof Douglas Stupart and Dr Kirk Underwood.
Unable to process the form. Check for errors and try again.