A case of spontaneous mesenteric hematoma successfully diagnosed and treated with aggressive imaging

Introduction: Spontaneous mesenteric hematoma is an uncommon syndrome triggered by bleeding localized in the mesenteric vascular tree of a bowel segment for no apparent underlying reason. We herein report a surgical patient with an extremely rapidly growing spontaneous mesenteric hematoma that we successfully diagnosed using careful radiologic examination. Presentation of case: A 56-year-old old male presenting sudden onset lower abdominal pain was referred to our emergency department. At the time of admission, his physical examination revealed stable vital signs without radiological abnormality. On the following day, the patient suddenly presented hypotension, tachycardia, and increased abdominal pain. Contrast-enhanced computed tomography examination showed a mass with both high- and low-density areas with a 130 mm maximum diameter bordering the transverse colon. Since interventional radiologists were not available, we decided to perform emergency exploratory laparotomy. On laparotomy, a 13 × 8 cm hematoma was found in the mesentery of the transverse colon. As bleeding was noted from the branches of the middle colic artery and gastrocolic artery, these responsible vessels were ligated. The patient was finally given the diagnosis of spontaneous mesenteric hematoma. Discussion and conclusion: The present case, initially diagnosed as enterocolitis, suddenly manifested hypovolemic shock. Close monitoring for any signs of further deterioration, as well as aggressive imaging diagnosis, enabled us to avoid delays in treatment. Early diagnosis and treatment of mesenteric hematomas are essential to prevent them from rupturing and triggering life-threatening adverse events

Dwarf Novae in the Shortest Orbital Period Regime: I. A New Short Period Dwarf Nova, OT J055717+683226

We report the observation of a new dwarf nova, OT J055717+683226, during its first-ever recorded superoutburst in December 2006. Our observation shows that this object is an SU UMa-type dwarf nova having a very short superhump period of 76.67+/- 0.03 min (0.05324+/-0.00002 d). The next superoutburst was observed in March 2008. The recurrence time of superoutbursts (supercycle) is, hence, estimated to be ~480 d. The supercycle is much shorter than those of WZ Sge-type dwarf novae having supercycles of >~ 10 yr, which are a major population of dwarf novae in the shortest orbital period regime (<~85 min). Using a hierarchical cluster analysis, we identified seven groups of dwarf novae in the shortest orbital period regime. We identified a small group of objects that have short supercycles, small outburst amplitudes, and large superhump period excesses, compared with those of WZ Sge stars. OT J055717+683226 probably belongs to this group.Comment: 14 pages, 11 figures, accepted for publication in PAS