Usefulness of Turbo-FLASH dynamic MR imaging of dissecting aneurysms of the thoracic aorta

Efficacy of thoracic endovascular stent repair for chronic type B aortic dissection with aneurysmal degeneration

BACKGROUND

The Food and Drug Administration has approved devices for endovascular management of thoracic endovascular aortic aneurysm repair (TEVAR); however, limited data exist describing the outcomes of TEVAR for aneurysms attributable to chronic type B aortic dissection (cTBAD). This study was undertaken to determine the results of endovascular treatment of cTBAD with aneurysmal degeneration.

METHODS

A retrospective analysis of all patients treated for cTBAD with aneurysmal degeneration at the University of Florida from 2004 to 2011 was performed. Computed tomograms with centerline reconstruction were analyzed to determine change in aortic diameter, relative proportions of aortic treatment lengths, and false lumen perfusion status. Reintervention and mortality were estimated using life-tables. Cox regression analysis was completed to predict mortality.

RESULTS

Eighty patients underwent TEVAR for aneurysm due to cTBAD (mean age [± standard deviation], 60 ± 13 years [male, 87.5%; n = 70]; median follow-up, 26 [range, 1-74] months). Median time from diagnosis of TBAD to TEVAR was 16 (range, 1-72) months. Prior aortic root/arch replacement had been performed in 29% (n = 23) at a median interval of 28.5 (range, 0.5-312) months. Mean preoperative aneurysm diameter was 62.0 ± 9.9 mm. In 75% (n = 60) of cases, coverage was proximal to zone 3, and 24% (n = 19) underwent carotid-subclavian bypass or other arch debranching procedure. Spinal drains were used in 78% (pre-op 71%, n = 57; post-op 6%, n = 5). Length of stay was 6.5 ± 4.7 days with a composite morbidity of 26% and in-hospital mortality of 2.5% (n = 2). Overall neurologic event rate was 17% (spinal cord ischemia 10% [n = 8], with a permanent deficit observed in 6.2% [n = 5]; stroke 7.5%). Aneurysm diameter reduced or stabilized in 65%. The false lumen thrombosed completely within the thoracic aorta in 52%, and reintervention within the treated aortic segment was required in 16% (n = 13).One- and 3-year freedom from reintervention (with 95% confidence interval [CI]) was 80% (range, 68%-88%) and 70% (range, 57%-80%), respectively. Survival at 1 and 5 years was 89% (range, 80%-94%) and 70% (range, 55%-81%) and was not significantly different among patients requiring reintervention or experiencing favorable aortic remodeling. Multivariable analysis identified coronary artery disease (hazard ratio [HR], 6.4; 95% CI, 2.3-17.7; P < .005), prior infrarenal aortic surgery (HR, 8.6; 95% CI, 2.3-31.7; P = .001), and congestive heart failure (HR, 11.9; 95% CI, 1.9-73.8; P = .008) as independent risk factors for mortality. Hyperlipidemia was found to be protective (HR, 0.2; 95% CI, 0.05-0.6; P = .004). No significant difference in predictors of mortality were found between patients who underwent reintervention vs those who did not (P = .2).

CONCLUSIONS

TEVAR for cTBAD with aneurysmal degeneration can be performed safely but spinal cord ischemia rates may be higher than previously reported. Liberal use of procedural adjuncts to reduce this complication, such as spinal drainage, is recommended. Reintervention is common, but long-term survival does not appear to be impacted by remediation.

Pathophysiology, diagnosis, and management of aortic dissection

Aortic dissection is an uncommon but potentially fatal disease with catastrophic complications. A high level of suspicion is required for successful diagnosis as presenting symptoms are so variable that dissection may be overlooked in up to 39% of cases. It most commonly presents in the elderly population with a history of chronic hypertension. Rapid intervention is necessary as delay leads to higher mortality. Despite advances in diagnostic and therapeutic techniques, morbidity and mortality remains high. Advances in diagnostic imaging have raised the awareness of variants of aortic dissection, including intramural hemorrhage and penetrating aortic ulcer. This distinction is important as the clinical course of these variants differs from that of classical aortic dissection, and thus treatment may also differ. Understanding of these variants has also led to the recognition of markers that may help predict progression to classical aortic dissection and thus warrant closer vigilance in selected patient populations. The recognition that rapid diagnosis is required for management of aortic dissection has led to the investigation of serum tests as diagnostic aids. Serum smooth muscle myosin heavy chain, d-dimer, and serum soluble elastin fragments are promising tests that may help raise suspicion for the diagnosis of acute aortic dissection. The high mortality associated with surgical therapy has led to investigation of alternative approaches. Endovascular therapy has emerged as a viable option in patients with type B dissection who are too unstable for surgery. However, long-term follow up is required to validate this procedure.

Descending Thoracic Aortic Dissection: Evaluation and Management in the Era of Endovascular Technology

Acute aortic dissection is a relatively uncommon but highly lethal condition. Without proper treatment, devastating consequences can occur due to aortic rupture, cardiac tamponade, or irreversible ischemia involving the spinal cord or the visceral organs. The treatment strategy of this condition is in part influenced by the location and the severity of aortic dissection as immediate surgical intervention is necessary in acute ascending aortic dissection, whereas medical therapy is the initial treatment approach in uncomplicated descending aortic dissection. Recent advances of endovascular technology have broadened the potential application of this catheter-based therapy in aortic pathologies, including descending thoracic aortic dissection. In this article, the etiology, pathogenesis, and classification of this condition are discussed. The diagnostic benefits of various imaging modalities for descending aortic dissection are also discussed. Current treatment strategies, including medical, surgical, and catheter-based interventions, are reviewed. Lastly, clinical experiences of endovascular treatment for descending aortic dissection and various endovascular devices potentially applicable for this condition are discussed.

Clinical, diagnostic, and management perspectives of aortic dissection

The incidence of aortic dissection ranges from 5 to 30 cases per million people per year, depending on the prevalence of risk factors in the study population. Although the disease is uncommon, its outcome is frequently fatal, and many patients with aortic dissection die before presentation to the hospital or prior to diagnosis. While pain is the most common symptom of aortic dissection, more than one-third of patients may develop a myriad of symptoms secondary to the involvement of the organ systems. Physical findings may be absent or, if present, could be suggestive of a diverse range of other conditions. Keeping a high clinical index of suspicion is mandatory for the accurate and rapid diagnosis of aortic dissection. CT scanning, MRI, and transesophageal echocardiography are all fairly accurate modalities that are used to diagnose aortic dissection, but each is fraught with certain limitations. The choice of the diagnostic modality depends, to a great extent, on the availability and expertise at the given institution. The management of aortic dissection has consisted of aggressive antihypertensive treatment, when associated with systemic hypertension, and surgery. Recently, endovascular stent placement has been used for the treatment of aortic dissection in select patient populations, but the experience is limited. The technique could be an option for patients who are poor surgical candidates, or in whom the risk of complications is gravely high, especially so in the patients with distal dissections. The clinical, diagnostic, and management perspectives on aortic dissection and its variants, aortic intramural hematoma and atherosclerotic aortic ulcer, are reviewed.

Crack-cocaine-associated aortic dissection in early pregnancy--a case report

Even though uncommon in pregnancy, aortic dissection is a potentially catastrophic vascular complication, occurring mainly in the late stages of pregnancy. Vascular events, including aortic dissection are recognized complications of crack-cocaine use. The authors report a case of aortic dissection in early pregnancy related to crack-cocaine use. They believe that the combined effects of pregnancy and crack cocaine on the vasculature create the requisite milieu potentiating such catastrophic events as aortic dissection. This paper reviews the possible underlying pathophysiologic mechanisms and the available diagnostic, therapeutic, and management options.

Intermittent cocaine use associated with recurrent dissection of the thoracic and abdominal aorta

Acute aortic dissection has been reported with the use of cocaine. We report a case of intermittent cocaine use spanning nearly 5 years and leading to recurrent dissection and extension of the false lumen. The patient repeatedly declined surgical correction. Management involved aggressive pharmacologic blood pressure control, close monitoring, and encouragement to enter drug rehabilitation.