Comparison of two surgical approaches for acute type A aortic dissection: hybrid debranching versus total arch replacement

Automatic Segmentation of Type A Aortic Dissection on Computed Tomography Images Using Deep Learning Approach

PURPOSE

Type A aortic dissection (TAAD) is a life-threatening aortic disease. The tear involves the ascending aorta and progresses into the separation of the layers of the aortic wall and the occurrence of a false lumen. Accurate segmentation of TAAD could provide assistance for disease assessment and guidance for clinical treatment.

METHODS

This study applied nnU-Net, a state-of-the-art biomedical segmentation network architecture, to segment contrast-enhanced CT images and quantify the morphological features for TAAD. CT datasets were acquired from 24 patients with TAAD. Manual segmentation and annotation of the CT images was used as the ground-truth. Two-dimensional (2D) nnU-Net and three-dimensional (3D) nnU-Net architectures with Dice- and cross entropy-based loss functions were utilized to segment the true lumen (TL), false lumen (FL), and intimal flap on the images. Four-fold cross validation was performed to evaluate the performance of the two nnU-Net architectures. Six metrics, including accuracy, precision, recall, Intersection of Union, Dice similarity coefficient (DSC), and Hausdorff distance, were calculated to evaluate the performance of the 2D and 3D nnU-Net algorithms in TAAD datasets. Aortic morphological features from both 2D and 3D nnU-Net algorithms were quantified based on the segmented results and compared.

RESULTS

Overall, 3D nnU-Net architectures had better performance in TAAD CT datasets, with TL and FL segmentation accuracy up to 99.9%. The DSCs of TLs and FLs based on the 3D nnU-Net were 88.42% and 87.10%. For the aortic TL and FL diameters, the FL area calculated from the segmentation results of the 3D nnU-Net architecture had smaller relative errors (3.89-6.80%), compared to the 2D nnU-Net architecture (relative errors: 4.35-9.48%).

CONCLUSIONS

The nnU-Net architectures may serve as a basis for automatic segmentation and quantification of TAAD, which could aid in rapid diagnosis, surgical planning, and subsequent biomechanical simulation of the aorta.

Hemiarch versus extended arch repair for acute type A dissection: Results from a multicenter national registry

OBJECTIVE

We compared perioperative outcomes of patients with acute type A aortic dissection undergoing hemiarch (HA) versus extended arch (EA) repair with or without descending aortic intervention.

METHODS

Nine hundred twenty-nine patients underwent acute type A aortic dissection repair (2002-2021, 9 centers) including open distal repair (HA) with or without additional EA repair. EA with intervention on the descending aorta (EAD) included elephant trunk, antegrade thoracic endovascular aortic replacement, or uncovered dissection stent. EA with no descending intervention (EAND), included unstented suture-only methods. Primary outcomes were in-hospital mortality, permanent neurologic deficit, computed tomography malperfusion resolution, and a composite. Multivariable logistic regression was also performed.

RESULTS

Mean age was 66 ± 18 years, 30% (278 out of 929) were women, and HA was performed more frequently (75% [n = 695]) than EA (25% [n = 234]). EAD techniques included: dissection stent (39 out of 234 [17%]), thoracic endovascular aortic replacement (18 out of 234 [7.7%]), and elephant trunk (87 out of 234 [37%]). In-hospital mortality (EA: n = 49 [21%] and HA: n = 129 [19%]; P = .42), and neurological deficit (EA: n = 43 [18%] and HA: n = 121 [17%]; P = .74) were similar. EA was not independently associated with death (EA vs HA odds ratio, 1.09; 95% CI, 0.77-1.54; P = .63) or neurologic deficit (EA vs HA odds ratio, 0.85; 95% CI, 0.47-1.55; P = .59). Composite adverse events differed significantly (EA vs HA odds ratio, 1.47; 95% CI, 1.16-1.87; P = .001). Malperfusion resolved more frequently after EAD (EAD: n = 32 [80%], EAND: n = 18 [56%], HA: n = 71 [50%]; P = .004), although multivariable analysis was not significant (EAD vs HA odds ratio, 2.17; 95% CI, 0.83-5.66; P = .10).

CONCLUSIONS

Extended arch interventions pose similar perioperative mortality and neurologic risks as Hemiarch. Descending aortic reinforcement may promote malperfusion restoration. Extended techniques should be approached with caution in acute dissection due to increased risk of adverse events.

Outcomes of two-stage type II hybrid aortic arch repair in elderly patients with acute type A aortic dissection

Acute type A aortic dissection (a-TAAD) is a severe disease characterized by high mortality, which can be fatal in elderly patients. The objective of this study was to investigate the safety and efficacy of two-stage type II hybrid aortic arch repair (HAR) in elderly patients with acute type A aortic dissection (a-TAAD). This was a single-center, retrospective study involving 119 patients with a-TAAD, including 82 males and 37 females, aged 22-81 years old. Eighty-eight patients underwent total aortic arch replacement (TAR) with frozen elephant trunk (FET) implantation (TAR with FET group) and 31 patients underwent two-stage type II HAR (HAR group). Propensity score matching was applied to adjust for preoperative data, and match 25 pairs. The preoperative, perioperative, postoperative and follow-up data were recorded. Fifteen patients died during the perioperative period; 13 cases were in the TAR with FET group and 2 cases were in the HAR group. The age, body mass index, cerebral infarction, renal insufficiency were significantly higher, and the 24-h fluid drainage, the incidence of acute liver injury, acute kidney injury and pulmonary infection were lower in the HAR group (all P < 0.05). Moreover, the mechanical ventilation time, intensive care unit time, hospital stay time were shorter in the HAR group (all P < 0.05). The follow-up period ranged from 12 to 54 months, with 7 deaths (9.3%) in the TAR with FET group and 2 deaths (6.9%) in the HAR group. The true lumen of the aortic arch and the middle descending thoracic aorta were larger and the false lumen thrombosis rates of the middle descending thoracic aorta and renal artery level were higher in the HAR group (all P < 0.05). Two-stage type II HAR is a safe and effective method for the treatment of elderly patients with a-TAAD. It may be a good choice for elderly patients with a-TAAD and comorbidities.

Cardiac Surgery 2022 Reviewed

PubMed displayed almost 37,000 hits for the search term "cardiac surgery AND 2022." As before, we used the PRISMA approach and selected relevant publications for a results-oriented summary. We focused on coronary and conventional valve surgery, their overlap with interventional alternatives, and briefly assessed surgery for aorta or terminal heart failure. In the field of coronary artery disease (CAD), key manuscripts addressed prognostic implications of invasive treatment options, classically compared modern interventions (percutaneous coronary intervention [PCI]) with surgery (coronary artery bypass grafting [CABG]), and addressed technical aspects of CABG. The general direction in 2022 confirms the superiority of CABG over PCI in patients with anatomically complex chronic CAD and supports an infarct-preventative effect as underlying mechanism. In addition, the relevance of proper surgical technique to achieve durable graft patency and the need for optimal medical treatment in CABG patients was impressively illustrated. In structural heart disease, the comparisons of interventional and surgical techniques have been characterized by prognostic and mechanistic investigations underscoring the need for durable treatment effects and reductions of valve-related complications. Early surgery for most valve pathologies appears to provide significant survival advantages, and two publications on the Ross operation prototypically illustrate an inverse association between long-term survival and valve-related complications. For surgical treatment of heart failure, the first xenotransplantation was certainly dominant, and in the aortic surgery field, innovations in arch surgery prevailed. This article summarizes publications perceived as important by us. It cannot be complete nor free of individual interpretation, but provides up-to-date information for decision-making and patient information.