Discussion
The surgical complications of Crohn's disease include bowel obstruction, fistulation, ulceration, anal fissures and cancer. The pathological severity of this condition derives from a combination of inherited factors and environmental triggers that lead to gut inflammation and local microvascular ischaemia. The vascular component of Crohn's disease has been primarily associated with arterial and venous thrombotic events that can lead to mesenteric ischaemia, venous congestion and bowel perforation. There is an association between patients with Crohn's disease who suffer from intramural bowel haematomas, bleeding diatheses and anticoagulation therapy. To the best of our knowledge, we report the first case in the literature of spontaneous jejunal mesenteric (mesojejunal) haematoma.
Spontaneous mesenteric haematoma (SMH) is a rare condition that occurs due to localized bleeding in the mesenteric vascular tree of a bowel segment with unknown aetiology. It can be clinically distinguished from the related disease pathology of spontaneous mesenteric intraperitoneal haemorrhage (abdominal apoplexy) that occurs due to the spontaneous rupture of a specific mesenteric vessel likely from undiagnosed mesenteric arterial dissection and perivascular pseudo aneurysms. In these cases there is evidence of both intraperitoneal and retroperitoneal haemorrhage. SMH can be managed conservatively if there is no associated haemorrhage and although the patient in this case underwent surgery for intestinal stenosis, the concurrent mesenteric haematoma was successfully managed conservatively.
Patients with isolated SMH typically present with non-specific symptoms of generalised abdominal pain and as a result the haematoma is usually identified on imaging modalities such as CT. Although the cause is unknown, the disease process may be associated with unidentified anticoagulation mismanagement or even undiagnosed connective tissue disease.
Our case demonstrates the presence of localised mid-jejunal mesenteric fat haematoma. Localised visceral inflammation is a recognised contributor to confined microvascular bleeding so that the inflammatory exacerbation of Crohn's disease in this case may have resulted in severe mesenteric fat inflammation to initiate localised capillary leakage and subsequent haematoma.
Mesenteric fat has been recently recognised an essential location for the generation of Crohn's gastrointestinal inflammation. Here bacterial translocation associated with immunoregulation through nucleotide-binding oligomerization domains (NOD1 and 2) and Toll-like receptors (TLRs 2 and 4) result in an increase in local inflammatory mediators including C-reactive-protein (CRP). The powerful inflammatory role of the bowel mesentery might be a contributory factor in the association between Crohn's exacerbation and mesenteric haematoma in this case.
Our intraoperative findings of mesojejunal haematoma reflect the current underestimation of Crohn's ileitis, demonstrating explicit involvement of the mesenteric fat with an associated mesenteric haematoma. This case also highlights how mesenteric abnormalities such as SMH may explain refractoriness or recurrence of symptoms despite intensifying steroid therapy. Indeed, it is possible that ileal compression caused by a mesenteric mass such as this may explain many of the symptoms accredited to Crohn's strictures. As a result, we believe that an increased awareness of the role of the bowel mesentery may give new insights into Crohn's disease pathogenesis. Furthermore, assessment for mesenteric abnormalities may guide future clinical and radiological assessment of unexplained symptoms in patients suffering form this multi-systemic inflammatory process, and identify rare differential diagnoses such as SMH.