Analysis of the hemostatic effect of preset wrapping technique for type A aortic dissection with abnormal coagulation

Background

There are many techniques to reduce anastomotic bleeding for the total arch replacement, but hemostasis is sometimes difficult to achieve after surgery for acute dissection, especially in patients with abnormal coagulation (AC). This study aimed to investigate the hemostatic effect and early efficacy of a pre-set bovine pericardium wrapper in the right heart system shunt for total arch replacement in patients with type A aortic dissection (TAAD) and preoperative AC.

Methods

A retrospective analysis was conducted on 85 patients with TAAD and AC who underwent total arch replacement between January 2018 and December 2022. The patients were divided into two groups: the preset pericardium group (n=30) and the control group (n=55).

Results

There were no significant differences between the two groups in terms of Bentall surgery (ascending aorta replacement with an aortic valve artificial vessel) and cardiac arrest time. However, compared to the control group, the preset pericardium group exhibited a shorter duration of cardiopulmonary bypass (CPB) and operation (P<0.001). Additionally, the preset pericardium group required fewer transfusions of blood products and hemostatic drugs (P<0.05). Moreover, the preset pericardium group had lower 24-hour postoperative mediastinal drainage volume (P<0.001), a lower proportion of bedside hemofiltration (P=0.039), and a shorter duration of mechanical ventilation and stay in the intensive care unit (P=0.014). Although the preset pericardium group showed reductions in in-hospital mortality, re-exploration for bleeding, and neurologic dysfunction, these differences were not statistically significant compared to the control group.

Conclusions

This study represents the first investigation into the application of the preset wrapping technique in total arch replacement for TAAD with AC. The results demonstrate that this method can reduce the duration of CPB and operation, decrease postoperative bleeding, and minimize the need for blood transfusion and hemostatic drugs. Consequently, this technique may contribute to early postoperative recovery.

Preoperative diameters of aorta influence the remodeling after surgery for type A aortic dissection

Background

Although current research revealed the preoperative diameter of the aorta is related to aortic remodeling, prognosis should consider the true lumen (TL) and false lumen (FL) respectively too.

Methods

The cohort of this retrospective analysis included 161 type A aortic dissection (TAAD) patients who underwent surgery at a single institution from September 1, 2017, to September 1, 2018. Computed tomography angiography (CTA) images were reviewed to assess changes of the diameters of the TL, FL and total aorta at the levels of the stented segment, distal end of the stent, celiac trunk, and below the renal artery.

Results

During the study period, positive remodeling was observed in 33 (20.5%) patients. The probability of negative remodeling far from the stent segment was greater than the aorta close to the stent. Only the TL diameter was associated with each levels' changes and underwent significant change (P<0.05). Multivariate analysis identified aortic regurgitation as a risk factor for remodeling in the distal end of the stent. The maximum diameter of the FL was the only risk factor related to the remodeling type (odds ratio =0.10; 95% confidence interval: 0.01-0.51), a maximum diameter of the FL of >1.28 cm was associated with a higher probability of negative remodeling after surgery (specificity =0.994; sensitivity =0.571; area under the receiver operating characteristic curve =0.76).

Conclusions

The TL and FL diameters on preoperative CTA images can be used to assess the risk of negative remodeling after surgery.

Synthesis of multidimensional pathophysiological process leading to type A aortic dissection: a narrative review

Objective

This review aims to synthesize the existing knowledge on the etiological process leading to type A aortic dissection (TAAD) and to clarify the relationship between mechanical, biochemical, and histopathological processes behind the aortic disease.

Background

Extensive research has previously identified several risk factors for TAAD as well as pathological mechanisms leading to TAAD. However, due to the complexity of the pathological process and limited knowledge on the relationships between distinct pathomechanisms leading to TAAD, the ability to identify the patients at high risk for TAAD has been poor.

Methods

PubMed (National Library of Medicine) database was searched for suitable literature. The most relevant articles focusing on anatomy, histopathology, physiology, and mechanics of ascending aorta and aortic diseases were reviewed.

Conclusions

Pathophysiology of the TAAD is related to biochemical and histological as well as mechanical and hemodynamic alterations leading to a degeneration of the aortic wall via inflammatory response. The degradative mechanisms of aortic wall structures and the mechanical forces, to which the wall is predisposed, are interrelated and influence one another. The relativity between the factors influencing aortic wall strength and healing capacity, and factors influencing mechanical stress on the aortic wall suggest that the risk of TAAD is not a linear but rather a dynamic phenomenon. Accounting for the dynamical property of the aortic disease in assessing the need for preventive surgical aortic reconstruction may provide a wider perspective in identifying patients at risk of TAAD and in planning preventive medical therapies.

Predicting in-hospital rupture of type A aortic dissection using Random Forest

Background

This study is to establish prediction tools for in-hospital rupture of type A aortic dissection (TAAD) patients, to better guide emergency surgical triage and patient counselling.

Methods

We retrospectively evaluated 1,133 consecutive patients with TAAD from January 2010 to December 2016. The study population was divided into training and testing datasets in a 70:30 ratio for further analysis using Random Forest.

Results

The Random Forest classification model was developed with the training dataset and 16 variables were confirmed as 'important': age, BMI, gender, syncope, lower limb numbness/pain, acute phase of the TAAD, BP >160 mmHg at admission; acute liver dysfunction, WBC >15×10⁹/L, aortic size, aortic height index (AHI), periaortic hematoma, pleural effusion, brachiocephalic artery involvement, renal artery involvement, and hemopericardium. Validation of the model showed good discrimination with an AUC, sensitivity, specificity, positive predictive value and negative predictive value of 0.994, 1.000, 0.987, 0.998 and 1.000, respectively, in the training dataset, and 0.752, 0.990, 0.514, 0.945 and 0.857, respectively, in the testing dataset.

Conclusions

An easy-to-use tool to predict in-hospital rupture for TAAD patients was developed and validated (http://47.107.228.109/). Periaortic hematoma is the strongest predictor. Simple clinical information such as syncope can be very useful in in-hospital rupture risk stratification.

Treatment with transfemoral bare-metal stent of residual aortic arch dissection after surgical repair of acute type an aortic dissection

Background

Here we evaluate the usefulness of transfemoral uncovered stent implantation to avoid secondary conventional surgery for residual type A aortic dissection (TAAD) of the aortic arch after ascending aorta replacement.

Methods

From June 2009 to April 2015, 11 patients were treated with transfemoral implantation of uncovered stents in the aortic arch after surgical replacement of ascending aorta performed on average 4.7±2.3 years earlier. An enlarged dissected aortic arch or a dangerous median growth of more than 5 mm/yr or impending rupture presenting as chest pain were indications for treatment. The dissected aortic tracts diameter must not exceed 45 mm. Five patients (45.5%) were treated with Djumbodies Dissection System, 6 patients (54.5%) with Jotec E-XL aortic stent.

Results

There were no perioperative deaths or permanent neurologic complications. Primary procedural success was obtained in all patients and the residual TAAD in aortic arch was obliterated, with disappearance of the false lumen. Median intensive care unit (ICU) stay was 24 hours; post-operative hospital stay was 5.2±1.4 days. One death, not aortic related, occurred during follow-up period (mean 5.2±1.9 years). Descending thoracic aorta diameter significantly increased in 3 patients (27.3%): one patient (9.0%) needed a secondary conventional surgery, the other 2 (18.2%) of a distal extension with PETTICOAT approach.

Conclusions

Endovascular approach with uncovered metal bare stent is surely an evolving strategy to perform a purely endovascular treatment, indicated only for treatment of an aortic arch with a diameter of less than 40 or 45 mm, to avoid progressive thoracic aortic dilatation and/or rupture.

Total arch replacement and frozen elephant trunk for type A aortic dissection after Bentall procedure in Marfan syndrome

Background

We seek to report the long-term outcomes of the total arch replacement and frozen elephant trunk (TAR + FET) technique for type A aortic dissection (TAAD) following prior Bentall procedure in patients with Marfan syndrome (MFS).

Methods

Between 2003 and 2015, we performed TAR + FET for 26 patients with MFS who developed TAAD following a prior Bentall procedure. Mean age at FET 36.9±9.7 years and 24 were males. TAAD was acute in 8 (30.8%, all new dissections from precious root aneurysm) and chronic in 18 (69.2%, 15 residual and 3 new). The interval from Bentall procedure to FET averaged 6.4±5.8 years, which was significantly longer in the acute group (10.3±6.3 vs. 4.6±4.9, P=0.021). The early and long-term outcomes were compared between two groups and risk factors identified for late adverse events.

Results

Operative mortality was 11.5% (3/26). Stroke, lower limb ischemia and reexploration for bleeding occurred in 1 patient each (3.8%). Follow-up was complete in 100% (23/23) at mean 5.1±2.3 years (range, 0.9-11.2 years). The maximal diameter (DMax) of distal aorta in the chronic group was significantly greater at the unstented descending aorta [DA, (56.4±15.5 vs. 35.6±12.2 mm, P=0.006)] compared to acute patients. The false lumen was obliterated in 95.7% across the FET and 56.5% in the unstented DA. Distal aortic dilation occurred in 13 patients (11 chronic, 68.8%). Of those 11 patients, 4 underwent an open thoracoabdominal aortic repair and 3 died of distal aortic rupture. Late death occurred in 7 patients at mean 3.9±2.5 years. At 6 years, the incidence was 18% for death, 11% for distal aortic reoperation, and 71% for reoperation-free survival. Survival did not differ between two groups (75.0% vs. 71.3%, P=0.851), while acute patients had significantly higher freedom from late rupture and reoperation at 6 years (100% vs. 61.9%, P=0.046). Hypertension was the sole risk factor for distal aortic dilatation [hazard ratio (HR) =7.271; 95% confidence interval (CI), 1.814-29.143; P=0.005]. Risk factors for late adverse events were hypertension (HR =6.712; 95% CI, 1.201-37.503; P=0.030) and age <35 years (HR =6.760; 95% CI, 1.154-39.587; P=0.034).

Conclusions

The TAR and FET technique was feasible and efficacious for TAAD following previous Bentall procedure in patients with MFS. Early and late survival did not differ with acute and chronic dissections, while freedom from late rupture and reoperation is significantly higher in patients with acute TAAD. Patients with hypertension and aged <35 years are at higher risk for late distal aortic dilation, reoperation and death.