Differences in In-Hospital and Follow-Up Outcomes Between Non-A Non-B Aortic Dissection and Type B Aortic Dissection Treated by Endovascular Based Treatment

OBJECTIVES

Non-A non-B aortic dissection (AD) is a rare and life-threatening medical emergency, and it has been controversial whether it should be managed as type B aortic dissection (TBAD). The study aims to compare in-hospital and follow-up outcomes between patients with non-A non-B AD and those with TBAD treated by endovascular based treatment (EBT).

METHODS

From January 2017 to December 2021, 96 consecutive patients with non-A non-B AD met the inclusion criteria and underwent EBT. Patients with TBAD were matched to patients with non-A non-B AD at a 1:1 ratio using propensity score matching analysis to correct for baseline confounding factors. The primary endpoint was all-cause mortality. Aortic-related events were defined as dissection-related death, aortic rupture, retrograde type A aortic dissection, reintervention, and type Ia endoleak.

RESULTS

Patients with non-A non-B AD required more TEVAR-related adjunctive procedures compared to TBAD patients during EBT and they required a longer ICU length of stay (36.0 vs 24.0 hours, P < .05) as well as a longer hospitalization (8.0 vs 7.0 days, P < .05) after EBT. There was no statistical difference in overall survival after EBT for patients with TBAD and non-A non-B AD. However, compared to patients with TBAD, non-A non-B AD patients had a higher rate of reintervention and experienced more aortic-related late events during follow-up.

CONCLUSION

Patients with non-A non-B acute AD who are treated with EBT do not have higher in-hospital or follow-up mortality rates compared to patients with type B AD. However, there is an increased risk of reintervention and aortic-related late events after the intervention during follow-up.

Non-A Non-B Acute Aortic Dissection: Is There Some Confusion in the Radiologist's Mind?

BACKGROUND

The aim of this study is to define and determine the rate of acute non-A-non-B aortic dissections, and to evaluate CT angiography findings and possible complications, as well as to discuss management strategies and currently available therapy. Non-A non-B type of aortic dissection is still a grey area in the radiologist's mind, such that it is not entirely clear what should be reported and completed in terms of this disease.

METHODS

A retrospective single-center study including 36 pre-treatment CT angiograms of consecutive patients (mean age: 61 years) between January 2012 and December 2022 with aortic dissection involving the aortic arch with/without the thoracic descending/abdominal aorta (type non-A non-B).

RESULTS

According to the dissection anatomy, we identified three modalities of spontaneous acute non-A-non-B anatomical configurations. Configuration 1 (n = 25) with descending-entry tear and retrograde arch extension (DTA entry). Configuration 2 (n = 4) with Arch entry tear and isolated arch involvement (Arch alone). Configuration 3 (n = 7) with Arch entry and anterograde descending (±abdominal) aorta involvement (Arch entry). CT angiogram findings, management, and treatment options are described.

CONCLUSIONS

Acute non-A non-B dissection represents an infrequent occurrence of aortic arch dissection (with or without involvement of the descending aorta) that does not extend to the ascending aorta. The complete understanding of its natural progression, distinct CT angiography subtypes, optimal management, and treatment strategies remains incomplete. Within our series, patients frequently exhibit a complex clinical course, often necessitating a more assertive approach to treatment compared to type B dissections.

Early and Long-Term Follow-Up for Chronic Type B and Type Non-A Non-B Aortic Dissection Using the Frozen Elephant Trunk Technique

Background: This study aimed to evaluate the early and long-term outcomes of a single center using a frozen elephant trunk (FET) procedure for chronic type B or non-A non-B aortic dissection.

Methods: From February 2009 to December 2019, 79 patients diagnosed with chronic type B or non-A non-B aortic dissection who underwent the FET procedure were included in the present study. We analyzed operation mortality and early and long-term outcomes, including complications, survival and interventions.

Results: The operation mortality rate was 5.1% (4/79). Spinal cord injury occurred in 3.8% (3/79), stroke in 2.5% (2/79), and acute renal failure in 5.1% (4/79). The median follow-up time was 53 months. The overall survival rates were 96.2, 92.3, 88.0, 79.8, and 76.2% at 1/2, 1, 3, 5 and 7 years, respectively. Moreover, 79.3% of patients did not require distal aortic reintervention at 7 years. The overall survival in the subacute group was superior to that in the chronic group (P = 0.047).

Conclusion: The FET technique is a safe and feasible approach for treating chronic type B and non-A non-B aortic dissection in patients who have contraindications for primary endovascular aortic repair. The technique combines the advantages of both open surgical repair and endovascular intervention, providing comparable early and long-term follow-up outcomes and freedom from reintervention.

Non-A non-B aortic dissection: A literature review

Non-A non-B aortic dissections are an infrequent occurrence and represent a small proportion of aortic dissections. Treating this life-threatening medical emergency often requires surgeons to undertake some one of the most challenging surgical or endovascular cases in medicine. This literature review aims to define and classify non-A non-B dissections, describe their epidemiology as well as their pathology. This review also aims to discuss the range of surgical techniques employed in their treatment and management and to investigate the patient outcomes associated with each technique.