OBJECTIVE: To evaluate the differences in short- and mid-term outcomes for intramural hematoma in the type A distribution (TAIMH) and acute type A aortic dissection (ATAAD) patients treated at a single institution between 2000 and 2020 to provide insight into whether an emergent surgical treatment strategy for TAIMH is an acceptable treatment option. METHODS: Between January 2000 and December 2020, a total of 903 patients were treated for acute aortic syndrome at Stanford Hospital. Baseline characteristics, operative details, short-term postoperative outcomes, mid-term survival, and reoperation rates were examined for this cohort. Cardinality matching was used to control for baseline characteristics and presentation symptoms. Fine balance matching was used to control for cannulation strategy. RESULTS: A total of 187 TAIMH patients were treated surgically and 27 were managed medically. The ATAAD arm included 642 patients who underwent surgery and 47 who were managed nonoperatively. ATAAD operative patients were more commonly male and younger compared to the TAIMH operative patients
however, other baseline medical history was similar in the 2 arms. ATAAD patients presented with higher rates of malperfusion and aortic regurgitation. Cross-clamp and cardiopulmonary bypass times were longer in the ATAAD arm, and these patients underwent more root replacements. Short-term postoperative outcomes were similar in the 2 arms, and there was no significant difference in unadjusted long-term survival and freedom from reoperation. With cardinality matching for preoperative history and presentation symptoms, mid-term survival was better for TAIMH patients. With fine balance matching for cannulation strategy, there was no significant difference between the groups in mid-term survival or stroke. CONCLUSIONS: In conclusion, a surgical management strategy for acute TAIMH results in excellent postoperative outcomes and supports an aggressive emergent operative strategy in aortic centers of excellence.