Acute type-B Dissection Research Articles

Thoracic endovascular aortic repair versus open surgery for type-B chronic dissection

An aging population, increased awareness, high-resolution imaging, and improving access to care all mean that more people are being diagnosed with acute aortic dissection. A better understanding of the role of initial medical therapy, improved surgical techniques, and the addition of endovascular approaches to the treatment algorithm, have resulted in more patients surviving the acute phase of disease. During the chronic phase, patients with residual dissection are challenged by the competing risks of reoperation or death. Open repair for chronic type-B dissection can be performed safely but is a relatively morbid operation. For this reason, surgery is often postponed until patients develop very late complications. Despite encouraging results for thoracic endovascular aortic repair of acute type-B dissection, chronic type-B dissection poses unique challenges that make application of endovascular technology more difficult. As our understanding of the disease and its natural history evolves, the ways in which these 2 methods of treatment complement each other need to be better understood. The benefits and limitations of each therapy, and how and when to apply each in the setting of chronic distal dissection, are discussed.

Disección de aorta tipo B no complicada: ¿debe ser todavía el tratamiento médico la mejor opción? Sí, el tratamiento conservador es la mejor opción

Acute type-B dissection is one of the most dreaded diseases that can occur in the aorta. Classically, the preferred medical treatment has been the perfect control of the blood pressure and the pain. However, the advent of endovascular therapy and its successful implementation in complicated aortic dissections (patients with hemodynamic instability, peripheral ischemia, visceral malperfusion or contained rupture) has expanded its use in all cases. This has led to considerable controversy regarding the appropriate treatment of this disease, especially in uncomplicated aortic dissections. To date, endovascular therapy appears to cause more thrombosis of the false lumen and a more favorable remodeling of the aorta during the follow-up, but missing data shows that this approach improves the overall survival of these patients. The authors of these articles analyze the effectiveness of endovascular therapy in uncomplicated dissections of the descending aorta, reviewing the latest evidence for and against its use.

The Complications of Uncomplicated Acute Type-B Dissection: The Introduction of the Penn Classification

Uncomplicated acute type-B aortic dissection (ATBAD) is a misnomer because it has subgroups with excessive mortality risk. The Penn classification has designated these ATBAD presentations as class-A because they initially are characterized by the absence of malperfusion and/or aortic rupture. The Penn classification also has designated class-A high-risk subgroups as type I and low-risk subgroups as type II. The risk factors for Penn class-A type-I presentations relate to medical therapy; aortic anatomy, and dissection extent as outlined by the DeBakey classification. Tight medical therapy significantly protects against aortic complications. Beta-blockade, angiotensin inhibition, and calcium channel antagonists may reduce mortality. The details of optimal medical therapy require further research. The aortic risk factors for type-I presentations include false lumen size and patency, ulcer-like projections, aortic diameter >40 mm, and intimal tear characteristics such as size and proximal location. The prognostic role of dissection extent in ATBAD remains unclear, requiring further investigation to determine its effect on natural history. Future trials in Penn class-A ATBAD should focus on type-I presentations. The Penn classification can serve as a clinical framework for trial design, laying the groundwork for future management advances. It also may provide a common language to facilitate standardized definitions, trial design, and management approaches for this high-risk patient cohort.

Simultaneous endovascular stent and renal stent placement for acute type B aortic dissection with malperfusion of kidney

Acute aortic dissection frequently causes life-threatening organ ischemia. The optimal therapy for acute type-B aortic dissection is still controversial. Surgery for acute dissection with organ malperfusion is known to carry a high morbidity and mortality; however endovascular treatment is becoming an alternative form of treatment. We report a clinical case of emergency percutaneous thoracal aorta endovascular stenting and renal artery stenting in a patient who had renal malperfusion and acute renal failure due to acute type-B dissection. The present case is a fundamental examples of collaboration between the cardiologist and cardiovascular surgeon in a hybrid procedure.

Endovascular stent placement for acute type-B aortic dissection with malperfusion - an intentional surgical delay and a possible 'bridging therapy'

Acute aortic dissection frequently causes life-threatening organ ischemia. The optimal therapy for acute type-B aortic dissection is still controversial. Early surgery for acute dissections with organ malperfusion is known to carry a high morbidity and mortality. Endovascular treatment, such as stent placement for branch stenosis, percutaneous balloon fenestration for compression of the true channel and aortic stent placement to support collapsed true channel, is becoming an alternative form of treatment. However, it is not clear whether endovascular intervention alone is effective in the long term. We herein report a case of emergency percutaneous endovascular stenting with intentional surgical delay in a patient who had visceral and lower extremity malperfusion due to acute type-B dissection. A 10x57 mm bare metal stent was inserted into the obliterated true channel of the thoracoabdominal aorta 3 h after onset of symptoms. It immediately relieved the abdominal and lower limb ischemic symptoms. The advantage of small-sized stent placement is its easiness and being gentle to fragile intima. The small-sized stent placement for patients with acute aortic dissection with visceral organ ischemia may be a promising 'bridging therapy' before they undergo traditional central repair.

Endovascular Repair of Acute Type B Aortic Dissection: Long-Term Follow-Up of True and False Lumen Diameter Changes

The aim of this study was to determine the technical success after endovascular treatment of acute type B aortic dissections and to evaluate true and false lumen diameter changes at long-term follow-up. Twenty-eight patients with acute type B-dissection who were treated by stent graft repair presented with rupture (n = 1), contained rupture (n = 2), compromised branch vessels (n = 14), pleural effusion (n = 11), rapid aortic diameter progression (n = 5), persistent pain (n = 3), refractory hypertension (n = 10), and an aortic diameter of more than 4 cm (n = 4). Taking into account the perfusion status of the false lumen, diameter changes were monitored in the thoracic aorta at the level of the stented segment (L1), distal to the stent graft (L2), and at the level of the celiac trunk (L3). Severe complications in 9 patients (32%) resulted in 3 deaths for a 30-day mortality rate of 10.7%. Primary sealing of the entry tear was achieved in 86%. At all levels, the true lumen diameter increased significantly after stent graft placement. At the 1-year follow-up, the false lumen in L1 was thrombosed in 90% and the mean difference of diameter reduction was highly significant. In L2, complete false lumen thrombosis occurred in 60% with a significant diameter decrease. In L3, the false lumen thrombosed in only 22%, and the mean difference of false lumen diameter increase reached significance at the 2-year follow-up. Ninety percent of patients were treated successfully with thrombosis of the false lumen in the stented segment. False lumen perfusion distal to the stent graft resulted in diameter increase in several patients leaving these segments an area of concern.

Impact of blood coagulation and fibrinolytic system changes on early and mid term clinical outcome in patients undergoing stent endografting surgery

Blood coagulation and fibrinolytic system changes after endovascular repair (EVAR) of aortic pathologies are of great interest. We have examined the risk for consumption coagulopathy and its clinical implications early, and at a mid-term follow-up, in a prospective study. From June 2002 to June 2004, 41 patients for abdominal aortic aneurysm (AAA), 16 for thoracic aortic aneurysm (TAA) and 13 for acute type-B dissection underwent EVAR. Plasminogen, fibrin degradation products (FDP) and D-dimer were monitored as markers of fibrinolysis. Platelet count, fibrinogen, antithrombin III and prothrombin were assayed as markers of coagulation. The aortic diameters were assessed by computed tomography (CT) scan. FDP and D-Dimer levels significantly increased, while plasminogen values significantly decreased, on postoperative day 1 and 5, coagulation parameters significantly decreased on postoperative day 1 and 5. All parameters recovered on the 1st month of follow-up, except fibrinogen levels that showed a significant increase on month 1 and 6. We did not observe clinical complications related to coagulative disorders. There was no correlation between the preoperative diameter and the coagulative and fibrinolysis variations in the AAA and TAA group. Type-B dissection patients showed a significant correlation between the preoperative presence of a large false lumen and a high level of fibrinolysis. EVAR leads to changes in coagulation and fibrinolysis, with characteristic developments. These latter have no clinical relevance and have no effect on early outcome and on mid-term follow-up.