Innovations in Aortic Disease: The Ascending Aorta and Aortic Arch

A New Clinically Driven Classification for Acute Aortic Dissection

Objectives: To report a new classification scheme for acute aortic dissection (AAD) that considers the aortic arch as a separate entity and integrates patterns of malperfusion syndrome (MPS). The proposed classification was evaluated retrospectively in a large population.

Materials and Methods: We retrospectively reviewed pre-therapy CT angiograms of 226 consecutive patients (mean ± SD age: 64 ± 12 years) with AAD. AADs were reclassified with a new classification scheme that included three aortic dissection types (A, involving at least the ascending aorta; B, involving exclusively the descending aorta; and C, involving the aortic arch with/without the descending aorta) and four malperfusion grades (0: no MPS; 1: dynamic MPS; 2: static MPS; 3: static and dynamic MPS). AAD features were assessed and correlated to patient outcomes.

Results: According to the new classification, we identified 152 type A dissections (92 A0, 11 A1, 38 A2, 11 A3); 50 type B (38 B0, 5 B1, 6 B2, 1 B3); and 24 type C (17 C0, 6 C2, 1 C3). Type C represented 11% of all AADs. MPS occurred in 39, 24, and 29% in type A, B, and C, respectively. Type C was treated with significantly more endovascular or hybrid interventions (37%) than in types A (3%) and B (20%) (p < 0.001).

Conclusion: The new AAD classification was feasible, and type C was easily identified (“non-A, non-B”). Preliminary findings supported the usefulness of this classification for the decision-making process and subsequent treatments.

Utility of neuromonitoring in hypothermic circulatory arrest cases for early detection of stroke: Listening through the noise

OBJECTIVE

Stroke remains a potentially devastating complication of aortic arch intervention. The value of neurophysiologic intraoperative monitoring (NIOM) in the early identification of stroke is unclear. We evaluated the utility of NIOM for early stroke detection in aortic arch surgery.

METHODS

Across 8 years at our institution, 365 patients underwent aortic arch surgery with hypothermic circulatory arrest, and 224 cases utilized NIOM. One patient was excluded for intraoperative death. In the remaining cohort, we reviewed the incidence, timing, and location of strokes, and the incidence and nature of NIOM alerts.

RESULTS

Hemiarch was performed in 154 patients and total arch replacement in 69 patients. Stroke occurred in 6.3% of all cases (14 out of 223), 15.9% of total arches (11 out of 69), and 2.0% of hemiarches (3 out of 154). There were 33 NIOM alerts (14.8%), and 9 patients had both alerts and stroke. Of these, NIOM deficits plausibly correlated with imaging findings in 7 cases (78%). Of the 5 stroke patients without NIOM alerts, 2 developed neurologic symptoms 3 days or more postoperatively, and infarcts in 3 patients did not result in sensory or motor deficits. Excluding 2 patients with late stroke, the sensitivity of NIOM for stroke detection was 75%, specificity was 88.5%, positive predictive value was 27.3%, and negative predictive value was 97.4%.

CONCLUSIONS

Despite a low positive predictive value requiring a high level of discrimination when interpreting abnormal findings, NIOM has high sensitivity and specificity for the early stroke detection. Furthermore, its high negative predictive valve is reassuring for low risk of stroke in the absence of alerts.

Perioperative transesophageal echocardiography for aortic dissection

PURPOSE

Aortic dissection is an infrequent but serious condition that often requires immediate operative intervention. We explore recent developments in the classification of aortic dissection and perioperative transesophageal echocardiography that assist with quantifying the severity of disease and facilitate its management.

PRINCIPAL FINDINGS

We describe the pivotal role of echocardiography in relation to key surgical considerations such as cannulation, aortic root surgery, perfusion in the aortic arch vessels, stenting in hybrid arch repair, and timing of preventative surgery.

CONCLUSION

Developments in the classification of aortic dissection have improved our perspective and understanding of the key presenting features that affect mortality. Improvements in patient outcome may be achieved in part by appropriately timed echocardiography-guided surgery.

Outcomes after ascending aorta and proximal aortic arch repair using deep hypothermic circulatory arrest with retrograde cerebral perfusion: analysis of 207 patients

OBJECTIVES

Correction of ascending aorta and proximal aortic arch pathology with numerous surgical techniques having been proposed over the years remains a surgical challenge. This study was undertaken to identify risk factors influencing outcome after aortic arch operations, requiring deep hypothermic circulatory arrest (DHCA).

METHODS

Between 1993 and 2010, 207 consecutive patients were operated for ascending aorta and proximal arch correction with the use of deep hypothermic circulatory arrest with retrograde cerebral perfusion. All patients were followed up with regular out-patient clinics, transthoracic echocardiography and, when required, chest computed tomography.

RESULTS

There were 102 (49.3%) emergencies (acute type A dissection) and 105 (50.7%) elective cases. Mean age: 63.5 ± 12 years. Mean circulatory arrest time was 25.4 ± 13 min. Unadjusted analysis of factors associated with 30-day mortality revealed emergency status, preoperative hemodynamic instability, acute dissection, reoperation, increased circulatory arrest time, postoperative bleeding, postoperative creatinine levels and presence of neurological dysfunction. Multi-adjusted analysis revealed duration of circulatory arrest as the only and main factor related to death. Thirty-day mortality was 2.4% for the elective and 7.2% for emergencies cases. Survival during long-term follow-up was 93, 82 and 53% at 1, 5 and 10 years, respectively.

CONCLUSIONS

Ascending aorta and proximal aortic arch replacement with brief duration of deep hypothermic circulatory arrest combined with retrograde cerebral perfusion is a safe method with acceptable short- and long-tem results.