Can Frozen Elephant Trunk Cure Type I Dissection Confined to Thoracic Aorta in Marfan Syndrome?

Genetic Basis, New Diagnostic Approaches, and Updated Therapeutic Strategies of the Syndromic Aortic Diseases: Marfan, Loeys-Dietz, and Vascular Ehlers-Danlos Syndrome

Syndromic aortic diseases (SADs) encompass various pathological manifestations affecting the aorta caused by known genetic factors, such as aneurysms, dissections, and ruptures. However, the genetic mutation underlying aortic pathology also gives rise to clinical manifestations affecting other vessels and systems. As a consequence, the main syndromes currently identified as Marfan, Loeys-Dietz, and vascular Ehlers-Danlos are characterized by a complex clinical picture. In this contribution, we provide an overview of the genetic mutations currently identified in order to have a better understanding of the pathogenic mechanisms. Moreover, an update is presented on the basis of the most recent diagnostic criteria, which enable an early diagnosis. Finally, therapeutic strategies are proposed with the goal of improving the rates of patient survival and the quality of life of those affected by these SADs.

Does preoperative dual antiplatelet therapy affect bleeding and mortality after total arch repair for acute type A dissection?

OBJECTIVES

Data are scarce and mixed regarding the impact of preoperative dual antiplatelet therapy (DAPT) on the surgical outcomes of acute type A aortic dissection (ATAAD). We seek to evaluate the impact of DAPT on bleeding-related events and early- and mid-term mortality after total arch replacement and frozen elephant trunk in such patients.

METHODS

This study comprised 48 ATAAD patients on preoperative DAPT and 418 without DAPT (the whole series, i.e. unmatched cohort), from which 45 matched pairs were selected by propensity score (matched cohort). Bleeding-related events (reoperation for bleeding, bleeding of ≥1500 ml within the first 12 h postoperatively or transfusion of ≥10 units of red blood cell or use of recombinant activated factor VII), operative mortality and mid-term survival were compared in the unmatched and matched cohorts. The impact of preoperative DAPT was evaluated with multivariable analysis.

RESULTS

In the unmatched cohort, bleeding of ≥1500 ml/12 h postoperatively was more common in the DAPT group (18.8% vs 8.4%, P = 0.020); operative mortality was 9.7%, which did not differ with DAPT (12.5% vs 9.3%, P = 0.48). Nor did bleeding-related events (54.2% vs 43.5%, P = 0.16) differ significantly between 2 groups. In the matched cohort, neither were drainage of ≥1500 ml/12 h (20% vs 6.7%, P = 0.063) and bleeding-related events (53.3% vs 42.2%, P = 0.30), nor operative mortality (13.8 vs 8.9%, P = 0.50) and mid-term survival (79.3% vs 76.4%, P = 0.93) significantly different between 2 groups. DAPT was not identified as a predictor for operative mortality [odd ratio (OR) 0.97, 95% confidence interval (CI) 0.31-3.08; P = 0.96; adjusted OR 1.28, 95% CI 0.22-7.20; P = 0.78] and bleeding-related events (OR 1.50, 95% CI 0.76-2.95; P = 0.24; adjusted OR 2.03, 95% CI 0.80-3.66; P = 0.14).

CONCLUSIONS

In patients with ATAAD undergoing total arch replacement and frozen elephant trunk, although preoperative DAPT led to more postoperative bleeding, it did not increase bleeding-related events nor operative mortality nor mid-term death. The results of this study imply that for patients with ATAAD, emergency surgical repair, even if as extensive as total arch repair, should not be contraindicated or delayed simply because of ongoing DAPT.

Mild hypothermic circulatory arrest with selective cerebral perfusion in open arch surgery

Background

This study aimed to evaluate whether the use of mild hypothermic circulatory arrest (HCA) with selective cerebral perfusion (SCP) in open arch procedure provides comparable perioperative results to moderate HCA for patients with dissected or degenerative arch pathologies.

Methods

Between January 2017 and September 2020, a total of 88 consecutive patients (mean age 47±11 years, 71 males) underwent open arch repair under a single surgeon at our institution with mild or moderate systemic hypothermia assisted by unilateral or bilateral SCP. Patients were divided into groups according to the nasopharyngeal temperature at the beginning of HCA: a moderate HCA group (n=47, 53.4%) and a mild HCA group (n=41, 46.6%). The postoperative mortality, morbidity, and visceral organ functions between these groups were analyzed retrospectively.

Results

Compared to the moderate HCA group, the mild HCA group had a significantly higher core temperature (nasopharynx: 24.4±0.8 vs. 28.5±2, P<0.001; bladder 25.9±0.9 vs. 30±1.2, P<0.001), and the incidence of major adverse events (MAE) in this group was markedly lower (21.3% vs. 4.9%, P=0.031). No differences were identified between the two groups refer to in-hospital mortality, permanent neurological deficit (PND), temporary neurological deficit (TND), and paraplegia (8.5% vs. 2.4%, P=0.366; 8.5% vs. 0, P=0.120; 6.4% vs. 7.3%, P=1.0; 4.3% vs. 2.4%, P=1.0, respectively). In the moderate HCA group, 6 patients (12.8%) developed acute renal failure needing replacement therapy, which did not occur in the mild HCA group (P=0.028). The duration of ventilator support and intensive care unit stay was shorter in the mild HCA group, as well as a decreased volume of drainage during the first 24 h and reduced platelet transfusion.

Conclusions

The preliminary results of the mild HCA group with SCP applied in open arch repair, mainly in total arch replacement (TAR) and stented elephant trunk (SET) implantation for aortic dissection, were satisfactory. Furthermore, comparable inferior outcomes were obtained with mild HCA compared with that of the conventional moderate HCA strategy. These encouraging surgical and postoperative results favor this more aggressive hypothermia strategy in open arch repair.

Management of acute type A aortic dissection during COVID-19 outbreak: Experience from Anzhen

OBJECTIVES

We seek to report our management protocol and early outcomes of acute type A aortic dissection (ATAAD) repair during the early phase of coronavirus disease 2019 (COVID-19).

METHODS

From January 23 to April 30, 2020, we performed ATAAD repair for 33 patients, including three with pregnancy-related TAADs. Confirmation of COVID-19 depended on the results of two nucleic acid tests and pulmonary computed tomography scan. Based on testing results and hemodynamic stability, patients were triaged to an isolated intensive care unit or negative pressure operating room for emergency surgery.

RESULTS

Mean age 50.2 ± 13.3 years and 20 were male (60.1%) and 8 patients were febrile (>37.3°C; 24.2%) and 17 were lymphopenic (51.5%). No patient was excluded from COVID-19 infection preoperatively. Extensive aortic repair with total arch replacement (TAR) was performed in 24 (72.7%), and limited proximal repair in 9 patients (27.3%). Cardiopulmonary bypass and cross-clamp times averaged 177 ± 34 and 88 ± 20 min for TAR, and 150 ± 30 and 83 ± 18 min for hemiarch, respectively. The mean operation time was 410 ± 68.3 min. Operative mortality was 6.1% (2/33). Complications included reintubation in four (12.1%), acute kidney failure in two (6.1%), and cerebral infarction in one (3.0%). No paraplegia nor re-exploration for bleeding occurred. COVID-19 was excluded in 100% eventually. No nosocomial infection occurred. Nor did any patient/surgical staff develop fever or test positive during the study period.

CONCLUSIONS

The results of this study show that our management protocol based on testing results and hemodynamic stability in patients with ATAAD during the COVID-19 pandemic was effective and achieved favorable early surgical outcomes.

Is the frozen elephant trunk technique justified for chronic type A aortic dissection in Marfan syndrome?

Background

Chronic type A aortic dissection (cTAAD) in Marfan syndrome (MFS) is rare. Surgical experience is limited and the role of frozen elephant trunk (FET) technique remains undefined. We seek to evaluate the safety and efficacy of the total arch replacement (TAR) and FET technique for cTAAD in MFS.

Methods

The clinical data of sixty-eight patients with MFS undergoing FET and TAR for cTAAD were analyzed.

Results

Mean age was 35.8±9.7 years and thirty-nine were male (57.4%). Operative mortality was 10.3% (7/68). Stroke occurred in one (1.5%), re-exploration for bleeding in five (7.3%), low cardiac output in four (5.9%), and acute renal failure in two (2.9%). Follow-up was complete in 100% (61/61) at mean 7.3±4.0 years. The false lumen was obliterated in 73.5% across FET and 50.0% in unstented descending aorta (DAo). Distal dilation occurred in twenty patients, six of whom underwent thoracoabdominal aortic replacement, one abdominal aortic replacement and one thoracic endovascular aortic repair (TEVAR). Late death occurred in five. At ten years, 59.8% were free from distal aortic dilation, and the incidences were 23.2% for death, 14.4% for distal reoperation, and 62.4% for reoperation-free survival. Predictors for operative mortality were extra-anatomic bypass [odds ratio (OR), 229.592; P=0.036], preoperative maximal size (DMax) of aortic sinuses (mm) (OR, 1.134; P=0.032) and cardiopulmonary bypass (CPB) time (minute) (OR, 1.061; P=0.041). Risk factors for aortic dilatation included patent false lumen at diaphragmatic hiatus [hazard ratio (HR), 5.374; P=0.008], preoperative DMax (mm) of proximal DAo (HR, 1.068; P=0.001) and renal arteries (HR, 1.102; P=0.005) which also predicted distal reoperation (HR, 1.149; P=0.001). The time from onset to operation (day) (HR, 1.002; P=0.004) and CPB time (minute) (HR, 1.032; P=0.036) predicted late death.

Conclusions

This study shows that the TAR and FET technique is a safe and durable approach to cTAAD in patients with MFS. The operation should be performed as early as possible to optimize clinical outcomes.