Type B aortic dissections: treating the many to benefit the few?

Early and Late Mortality Predictors in Patients with Acute Aortic Dissection Type B

BACKGROUND/AIM

Despite technological advances in diagnosis and treatment, in-hospital mortality with acute aortic dissection type B is still about 11%. The purpose of this study was to assess the risk factors for early and long-term adverse outcomes in patients with acute aortic dissection type B treated medically or with conventional open surgery.

METHODS

The present study included 104 consecutive patients with acute aortic dissection type B treated in our Center from January 1st, 1998 to January 1st, 2007. Patient demographic and clinical characteristics as well as in-hospital complications were reviewed. Univariate and multivariate testing was performed to identify the predictors of in-hospital (30-day) and late (within 9 years) mortality.

RESULTS

92 (88.5%) patients were treated medically, while 12 (11.5%) patients with complicated acute aortic dissection type B were treated by open surgical repair. In-hospital complications occurred in 35.7% patients, the most often being acute renal failure (28%), hypotension/shock (24%), mesenteric ischemia (12%), and limb ischemia (8%). The in-hospital mortality rate was 15.7% and the 9-year mortality rate was 51.9%. Independent predictors of early mortality in patients with acute aortic dissection type B were uncontrolled hypertension (HR-20.69) and a dissecting aorta diameter >4.75 cm (HR-6.30). Independent predictors of late mortality were relapsing pain (HR-7.93), uncontrolled hypertension (HR-7.25), and a pathologic difference in arterial blood pressure (>20 mmHg) (HR-5.33).

CONCLUSION

Knowledge of key risk factors may help with a better choice of treatment and mortality reduction in acute aortic dissection type B patients.

Conservative management versus endovascular or open surgery in the spectrum of type B aortic dissection

Background

Type B aortic dissection is a life-threatening acute aortic condition often with acute ischemic signs or symptoms. With initial management focusing on alleviating malperfusion and pain, and avoiding propagation of dissection or rupture both systolic blood and pulse pressure should be reduced initially by an aggressive medical approach. In the setting of persistent signs of complications endovascular strategies have replaced open surgery and led to a fourfold increase in early survival and better long-term outcomes.

Methods

An electronic health database search was performed on articles published between January 2006 and July 2017. Publications were included in this review if (I) the index aortic pathology was type B aortic (distal) dissection; (II) when medical management, open surgical replacement or thoracic endovascular aortic repair were among those options; (III) when at least one of all basic outcome criteria such as survival, spinal cord ischemia and cerebrovascular accident was reported; (IV) when ≥15 serial patients were included. A total of 62 studies were eligible and analysed.

Results

Our manuscript has summarized data collected over 12 years on management specific outcomes in the setting of distal aortic dissection and provides an up-to-date interpretation of the published evidence. For complicated cases, treated acutely, the 30-day or in-hospital mortality was 7.3% when managed by endovascular means, whereas the pooled rate for 30-day or in-hospital mortality was 19.0% when subjected to open repair. For acute uncomplicated type B dissection usually treated with blood pressure lowering medications, the pooled 30-day or in-hospital mortality rate was 2.4%. Survival rates at 5 years averaged at 60% (40% mortality). Freedom from any aortic event ranged from 34.0% to 83.9%, underlining an inherent risk of progression and late complications. For chronic complicated type B dissection, the rates of stroke, paraplegia and operative mortality following endovascular repair ranged from 5% to 13%, 2% to 13% and 2 to 13%, respectively, while 5-year survival rates after open repair ranged from 60% to 90%. In chronic uncomplicated type B dissection almost 90% of patients survive initial hospitalization and were subjected to medical management with a 5-year survival of 50-80%. However, up to 20-55% of medically treated patients develop aneurysmal degeneration after 5 years with an unknown risk of rupture.

Conclusions

Currently, the less invasive strategy of endovascular repair (as compared to open surgery) provides improved 30-day or in-hospital survival in the setting of complicated acute type B aortic dissection and may seek broad application. Open surgical aortic reconstruction should be left to experienced aortic centres if endovascular management is not an option.

Treatment of serious complications following endovascular aortic repair for type B thoracic aortic dissection

Objective

This study aimed to describe treatment of serious complications after primary thoracic endovascular aortic repair (TEVAR) in type B aortic dissection.

Methods

From June 2008 to March 2016, serious complications occurred in 58 patients without Marfan syndrome who received TEVAR for type B aortic dissection.

Results

Complications included endoleak, distal true lumen collapse, retrograde dissection, stroke, stent–graft (SG) migration and mistaken deployment, lower limb ischaemia, and SG fracture. Treatment included endovascular repair, surgical procedures, or conservative medication. Forty-six patients recovered from complications. Twelve patients were not cured. The median follow-up time was 29.5 months (2–61 months). The overall 30-day mortality rate was 1.7% (1/58) and the total mortality rate following secondary complications was 8.6% (5/58). The causes of death were stroke and aortic rupture.

Conclusion

Some treatments need to be performed after TEVAR because of severe complications. A reduction in these complications can be achieved by optimal evaluation of patients, selection of SGs, and specialized endovascular manipulation.

Management of complicated and uncomplicated acute type B dissection. A systematic review and meta-analysis

BACKGROUND

The management of acute type B dissection represents a clinical challenge. We undertook a systematic review of the available literature regarding medical, surgical and endovascular treatments of acute type B aortic dissection and combined the eligible studies into a meta-analysis.

METHODS

An extensive electronic health database search was performed on all articles published from January 2006 up to November 2013 describing the management of acute type B aortic dissection. Studies including less than 15 patients were excluded.

RESULTS

ACUTE COMPLICATED TYPE B DISSECTION: overall, 2,531 patients were treated with endovascular repair (TEVAR) and the pooled rate for 30-day/in-hospital mortality was 7.3%. The pooled estimates for cerebrovascular events, spinal cord ischemia (SCI) and total neurologic events were 3.9%, 3.1% and 7.3%, respectively. A total of 1,276 patients underwent open surgical repair and the pooled rate for 30-day/in-hospital mortality was 19.0%. The pooled rate for cerebrovascular events was 6.8%, for SCI 3.3% and for total neurologic complications 9.8%. Acute uncomplicated type B dissection: outcome of 2,347 patients who underwent conservative medical management were analyzed. The pooled 30-day/in-hospital mortality rate was 2.4%. The pooled rate for cerebrovascular events was 1%, for SCI 0.8% and for overall neurologic complications 2%.

CONCLUSIONS

Endovascular repair provides a superior 30-day/in-hospital survival for acute complicated type B aortic dissection compared to surgical aortic reconstruction. However, open repair still has a significant role as endovascular repair is not applicable in all patients and there remains concerns regarding the durability of this technique. TEVAR seems to have a more favorable outcome regarding aortic remodeling and the aortic-specific survival rate when compared with medical therapy alone. Randomized controlled trials focusing on the prognostic factors of early and late complications in uncomplicated type B dissections are needed.

Systematic review of outcomes of combined proximal stent-grafting with distal bare stenting for management of aortic dissection

OBJECTIVE

Available data on outcomes of combined proximal stent-grafting with distal bare stenting for management of aortic dissection are limited. The objective of this study was to provide a systematic review of outcomes of this approach.

METHODS

Studies involving combined proximal stent-grafting with distal bare stenting for management of aortic dissection were systematically searched and reviewed through MEDLINE databases.

RESULTS

A TOTAL OF FOUR STUDIES WERE INCLUDED: 108 patients treated for management of acute (n=54) and chronic (n=54) aortic dissection. The technical success rate was 95.3% (range, 84-100%). The 30-day mortality rate was 2.7% (range from 0% to 5%). The morbidity rate occurring within 30 days was 51.8% (range from 0% to 65%) and included stroke (2.7%), paraplegia (2.7%), retrograde dissection (1.8%), renal failure (14.8%), severe cardiopulmonary complications (5.5%) and bowel ischemia (0.9%). The incidence of type I endoleak was 9.2% (10/108). During follow-up, 5 (4.6%) deaths were related to aortic rupture or aortic repair. Mean re-intervention rate was 12.9%. Two cases (1.9%) of delayed retrograde type A dissection and one case of aortobronchial fistula (0.9%) were reported. The most common delayed complication was thoracic stent-graft migration (4.7%). The rate of device failure was 9.2%. Favorable aortic remodeling was observed: studies reporting midterm follow-up of the true lumen demonstrated a high rate of both false lumen regression and true lumen expansion. At 12 months, complete false lumen thrombosis was observed at the thoracic level in 70.4% and at the abdominal level in 13.5% of patients.

CONCLUSIONS

Combined proximal stent-grafting with distal bare stenting appears to be a feasible approach for the management of Type B aortic dissection. Although this approach clearly improved true lumen perfusion and diameter, it failed to completely suppress false lumen patency. However, it should be acknowledged that contemporary data on this approach is limited to small studies with variable results.

Nationwide Comparative Impact of Thoracic Endovascular Aortic Repair of Acute Uncomplicated Type B Aortic Dissections

Objective:

Thoracic endovascular aortic repair (TEVAR) for acute uncomplicated type B aortic dissection (TBAD) remains controversial. This study aims to evaluate the impact of TEVAR on mortality, morbidity, length of stay (LOS), and discharge status in patients with acute uncomplicated TBAD.

Methods:

We analyzed the National Inpatient Sample from 2009 and 2010. Patients were categorized according to the type of treatment: TEVAR or medical management. Outcomes, including mortality, stroke, myocardial infarction (MI), acute renal failure, discharge disposition, and LOS, were compared between the treatment groups.

Results:

We identified 4706 patients with TBAD. Mean age was 67 years and 55% were male. Treatment options included TEVAR in 504 and medical management in 4202. The overall adjusted in-hospital mortality was similar for both the groups (8.5% for TEVAR vs 10.3% for medical management, P = .224). The TEVAR carried higher risk of stroke (odds ratio [OR] = 1.61, 95% confidence interval [CI] = [1.14-2.27]; P = .0073). The TEVAR was associated with prolonged LOS (12 vs 5.6 days, P < .0001) and patients were less likely to be discharged home (OR 0.73, 95% CI 0.54-0.99; P = .013). When stratified by age, all outcomes were similar between the 2 groups, with the exception of longer LOS with TEVAR.

Conclusions:

Thoracic endovascular aortic repair for acute uncomplicated TBAD was associated with similar in-hospital mortality, MI, and renal failure as compared to medical management. The TEVAR had higher rate of stroke up to the age 70 years and longer LOS. Because extending TEVAR to less complicated patients could only decrease TEVAR mortality rates, these findings support the more widespread use of TEVAR to treat patients with uncomplicated TBAD.

Single-stage repair of a complex type B aortic dissection associated with a pressurized infrarenal abdominal aortic aneurysm

The decision-making involved in managing type 2 aortic dissections remains challenging despite the advances in endovascular technology. We report a challenging case of a patient presenting with a type 2 aortic dissection and false lumen extension into an infrarenal abdominal aortic aneurysm (AAA). Severe back pain and hypertension were the patient's initial complaints, and dynamic magnetic resonance angiography revealed 1-way pulsatile flow into the AAA sac from the false lumen. This patient underwent endovascular repair with a thoracic and infrarenal aortic endograft, successfully excluding the false lumen and decompressing the infrarenal aneursymal sac. This is a unique presentation of total endovascular repair of a symptomatic type B aortic dissection with a pressurized infrarenal AAA sac from false lumen flow into the sac.