Report on the results of thoracic endovascular aortic repair for acute, complicated, type B aortic dissection at 30 days and 1 year from a multidisciplinary subcommittee of the Society for Vascular Surgery Outcomes Committee

Endovascular versus conventional medical treatment for uncomplicated chronic type B aortic dissection

BACKGROUND

Aortic dissection is a potentially life-threatening condition that occurs when a tear forms in the inner lining of the aorta. It has traditionally been treated by blood pressure control (medical treatment) or open surgery, both with high mortality rates. More recently stent-graft repair has been suggested as an alternative.

OBJECTIVES

To identify the best management for uncomplicated (without rupture of the organs or malperfusion of the extremities) subacute or chronic type B aortic dissection.

SEARCH METHODS

The Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched their Specialised Register (last searched May 2012) and CENTRAL (2012, Issue 4). Clinical trials databases were searched for ongoing or unpublished studies.

SELECTION CRITERIA

All randomised controlled trials designed to compare the outcome of uncomplicated (without rupture of the organs or malperfusion of the extremities) chronic (occurring more than two weeks previously) type B aortic dissection when treated by stenting adjunctive to best medical treatment versus best medical treatment alone were included.

DATA COLLECTION AND ANALYSIS

Data on all cause and aorta-related mortality at two years was collected and analysed. In addition, secondary outcome measures were analysed, including morbidity, complications (additional endovascular or open surgery for rupture, expansion or malperfusion) and quality of life.

MAIN RESULTS

A single trial was identified that fulfilled the inclusion criteria (INSTEAD trial). The two-year all cause survival was not statistically significantly different between study groups (95.6% ± 2.5% in the optimised medical therapy (OMT) group and 88.9% ± 3.7% in the thoracic endovascular aneurysm repair (TEVAR) + OMT group; log rank test P = 0.15).

AUTHORS' CONCLUSIONS

Overall, the data at two years were insufficient to make any practice recommendations. However, the data on the anatomic remodeling of dissected aortas observed after TEVAR + OMT is encouraging and future studies should follow up cases for at least five years to see if early endovascular interventions, even in stable initially uncomplicated type B patients, are of long-term benefit.

Aortic dissection and renal failure in a patient with severe hypothyroidism

Acute aortic dissection (AAD) is a life-threatening condition associated with high morbidity and mortality. The most important recognized acquired cause that leads to dissection is chronic arterial hypertension. With respect to the anuria and renal failure, aortic dissection is not something that is always considered and is still not a very common presentation unless both renal arteries come off the false lumen of the dissection. However, when present, preoperative renal failure in patients with acute type B dissection has been noted to be an independent predictor of mortality. Early recognition and diagnosis is the key and as noted by previous studies as well, almost a third of these patients are initially worked up for other causes until later when they are diagnosed with aortic dissection. Here we present a case of a patient presenting with severe hypothyroidism, long-standing hypertension, and anuria. Through the case, we highlight the importance of having aortic dissection as an important differential in patients presenting with anuria who have a long standing history of uncontrolled hypertension. Pathophysiology relating to severe hypothyroidism-induced renal dysfunction is also discussed.

Descending thoracic aortic surgery: update on mortality, morbidity, risk assessment and management

PURPOSE OF REVIEW

The purpose of this review is to summarize the literature on thoracic aortic surgery, as well as key management guidelines in the perioperative period. This is particularly timely, as endovascular techniques continue to evolve and become more available.

RECENT FINDINGS

Endovascular treatment of thoracic aortic disease is expanding in applications and case complexity.

SUMMARY

With the expanded use of endovascular techniques to treat aortic disease, midterm and long-term outcome studies and comparisons to open surgical approach are now being published with increasing frequency. This review analyzes the available literature on preventing adverse outcomes after descending thoracic aortic surgery, with specific attention to mortality, morbidity, risk assessment and management in the perioperative setting.

Midterm outcomes of open surgical repair compared with thoracic endovascular repair for isolated descending thoracic aortic disease

Objective

This study aimed to assess the surgical morbidity and mortality of thoracic endovascular repair (TEVAR) as compared with open surgical repair (OSR) for isolated descending thoracic aortic disease.

Materials and Methods

From January 1, 2006 through May 31, 2010, a total of 68 patients with isolated descending thoracic aortic disease were retrospectively reviewed for the presence of perioperative complication, 30-day mortality, and clinical success. The patients were divided into two groups (group 1, OSR, n = 40 vs. group 2, TEVAR, n = 28) and these groups were compared for major variables and late outcomes.

Results

The mean age was 58 years (group I = 54 vs. group II = 63 years, p = 0.011). Significant perioperative complications occurred in 12 patients: 8 (20%) in group I and 4 (13%) in group II (p = 0.3). There were five 30 day mortalities of which 4 occurred in group I and 1 in group II (p = 0.23). Clinical success (effective aortic remodeling and complete false lumen obliteration or thrombosis) was achieved in 20 patients (71%). Mean Kaplan-Meier survival rate at 1 year was similar for both groups (group 1 = 87% vs. group 2 = 80%, p = 0.65).

Conclusion

Thoracic endovascular repair for isolated thoracic aortic disease shows comparable results to OSR. However, the potential for endoleak or rupture remains a challenge that needs to be addressed in the future. Therefore, close follow-up study is needed for the evaluation of satisfactory long-term outcomes.

Volume changes in aortic true and false lumen after the "PETTICOAT" procedure for type B aortic dissection

BACKGROUND

The PETTICOAT (Provisional ExTension to Induce COmplete ATtachment) technique may be employed during endovascular treatment of type B aortic dissection (TBD) using self-expandable bare stents distal to the covered stent graft placed over the proximal entry tear. The aim of this study is to evaluate the volume changes of the true (TL) and false lumen (FL) on computed tomography (CT) scans.

METHODS

Since 2005, 25 selected patients received endovascular treatment for complicated TBD with the PETTICOAT technique employing the Zenith Dissection Endovascular System (William Cook Europe, Bjaerverskov, Denmark). Indications to the use of the PETTICOAT technique were the evidence of clinical manifest dynamic malperfusion in five cases (20%) and/or radiologic evidence of TL collapse in 20 cases (80%). Five patients were treated within 2 weeks from onset, 13 patients between 2 weeks and 3 months, and seven patients over 3 months after the initial acute event. The volumetric analysis of the changes of TL and FL obtained from CT scan performed before endovascular treatment of TBD, postoperatively and yearly thereafter were analyzed using the OsiriX software v 3.9 (Pixmeo sarl, Bernex, Switzerland).

RESULTS

Initial clinical (30 days) and midterm clinical success was observed in 21 cases (84%) and in 23 cases (92%), respectively. The volumes of the aortic TL and FL were evaluated at 30 days and midterm follow-up (mean, 38 ± 17 months). The following TL volumes were recorded: baseline 84 ± 29 cm(3), postoperative 167 ± 31 cm(3) (+98%), 1 year 193 ± 46 cm(3) (+131%), and 2 years 216 ± 54 cm(3) (+140%). The following FL volumes were recorded: baseline 332 ± 86 cm(3), postoperative 286 ± 85 cm(3) (-14%), 1 year 233 ± 81 cm(3) (-30%), and 2 years 248 ± 112 cm(3) (-32%). Progressive remodeling of the TL was recorded over time in both thoracic and abdominal segments with shrinkage of the FL mainly in the thoracic segment.

CONCLUSIONS

These data provide insight into potential therapeutic benefit of the PETTICOAT technique. A significant immediate increase in TL could be achieved with resolution of all cases of dynamic malperfusion and TL collapse. A different behavior of volumes in the thoracic and abdominal segments was observed.

Endovascular approaches and perioperative considerations in acute aortic dissection

Aortic dissections remain complicated management issues both in the acute setting and in the chronic setting. Acute problems revolve around malperfusion syndromes or rupture, whereas chronic issues progress from the development of aneurysms in the residual dissected aorta. Endovascular approaches to dealing with these difficult situations are being used more frequently to treat acute issues in type B dissections and prevent secondary complications in type A dissections that may require significant intervention in the future. This article discusses the endovascular approaches employed in the care of acute dissections with particular attention toward the anesthetic considerations involved in these challenging cases.