超音波検査技術

Purpose: The purpose of this study was to analyze the temporal changes in ultrasound (US) signals in patients with spontaneous isolated superior mesenteric artery dissection (SISMAD).

Subjects and methods: Out of the first 21 cases diagnosed with SISMAD, 10 male patients were included in this study using US at our hospital between March 2013 and January 2020 (mean age 48.2±3.9 years).

The calculated parameters included the maximum outer diameter, minimum inner diameter, maximum stenosis rate, and mean stenosis rate. All parameters were measured retrospectively in distinct phases categorized into the day of onset, approximately three days after, approximately one week after, approximately one month after, and approximately three months after the onset. Subsequently, we analyzed the respective change over time from the day of onset.

Results: The rate of change of maximum stenosis rate was ＋3.8% approximately three days and ＋16.0% after approximately one week after onset, respectively. Stenosis gradually progressed and reached a peak of ＋26.3% after approximately one month. In contrast, the rate of change of mean stenosis rate was initially improved slightly to −3.3% approximately three days after the onset, however, it subsequently reversed to ＋9.0% after one week, and peaked at ＋22.5% approximately one month later. Furthermore, the rates of change of maximum outer diameter and minimum inner diameter after one month were ＋9.8% and −31.4%, respectively. All parameters reached their maximum values after approximately three months post onset.

Conclusions: Based on time-lapse US image analysis in SISMAD, we identified that stenosis tended to become worse after approximately one week and continued to worsen for approximately one month. Despite these US findings, conservative treatment may be expected by focusing on clinical findings such as aggravated abdominal pain.