Long-Term Survival After Open Repair of Chronic Distal Aortic Dissection

Optimal treatment for patients with chronic Stanford type B aortic dissection: endovascularly, surgically or both?

OBJECTIVES

Patients with chronic Stanford type B aortic dissections (TBAD) are traditionally treated medically, but some of the affected thoracic and thoracoabdominal aortic segments progress to large aneurysms with a significant risk of rupture. The purpose of this study is to retrospectively evaluate, with an 'all-comers' approach, the survival and the outcome of patients following thoracic endovascular aortic repair (TEVAR) or conventional open surgery for chronic TBAD as a first-line therapy or a secondary option after failed medical treatment.

METHODS

Between January 2000 and May 2010, 80 consecutive patients (59 males, median age 63, inter-quartile range (IQR) 55-69) suffering from chronic TBAD were treated at our institution. Thirty-three were treated medically (Group A, median age: 65, IQR: 58.5-71.5), 32 received TEVAR (Group B, median age: 62, IQR: 54-67.5) and 15 patients underwent conventional open surgery (Group C, median age: 61, IQR: 54-66). The median follow-up was 42 months (range: 0.1-124.7) and 100% complete.

RESULTS

There were no significant differences with regard to age, gender and associated comorbidities between the treatment groups. The overall hospital mortality for chronic TBAD was 6.3% (n = 5); in-hospital mortalities for Groups A, B and C were 3.0, 6.2 and 13.4%, respectively. The incidence of major complications, such as paraplegia, malperfusion, renal failure and cardiac arrhythmia, did not significantly differ between the three groups. Postoperative stroke occurred more often after conventional open surgery (Group C: 13.3%; P = 0.07). Reintervention for TBAD pathology was required in Groups A, B and C in 12.1, 28.1 and 0%, respectively (P = 0.03). Secondary open surgery post-TEVAR was required in 7 cases (21.8%) with no postoperative paraplegia.

CONCLUSIONS

Open surgery for extensive thoracic and thoracoabdominal repair in chronic TBAD may be performed with acceptable early and mid-term outcomes. TEVAR for aortic complications in patients with chronic dissection may be successfully performed as a first-stage procedure in order to stabilize the patient and serve as a 'bridge' to secondary open surgery. However, close surveillance is mandatory for the timely detection of aneurysm enlargement, malperfusion or impending rupture after TEVAR.

Endovascular management of acute aortic syndromes

The term "acute aortic syndrome" (AAS) refers to a spectrum of life-threatening thoracic aortic pathologies including intramural hematoma, penetrating atherosclerotic ulcer, and aortic dissection. Clinically, patients often present with characteristic aortic pain. AAS often leads to aortic rupture. Therefore, recognition of this condition, its prompt diagnosis, and timely treatment is crucial to obtain clinical success and improved overall survival. The management of AAS, however, remains a therapeutic challenge. Endovascular strategies have gained wide acceptance and now represent a minimally invasive alternative to traditional open surgery. Several studies have shown endovascular repair of varying thoracic aortic pathologies to be technically feasible with fewer complications than open surgery. In this review, the authors discuss AAS pathology and its management, with particular attention to the current role of endovascular aortic repair and its treatment.

A systematic review of mid-term outcomes of thoracic endovascular repair (TEVAR) of chronic type B aortic dissection

OBJECTIVE AND DESIGN

The role of Thoracic Endovascular Repair (TEVAR) in chronic type B aortic dissection remains controversial and its mid-term success as an alternative to open repair or best medical therapy remains unknown. The aim of the present study was to provide a systematic review of mid-term outcomes of TEVAR for chronic type B aortic dissection.

MATERIALS AND METHODS

Medline, trial registries, conference proceedings and article reference lists from 1950 to January 2011 were searched to identify case series reporting mid-term outcomes of TEVAR in chronic type B dissection. Data were extracted for review.

RESULTS

17 studies of 567 patients were reviewed. The technical success rate was 89.9% (range 77.6-100). Mid-term mortality was 9.2% (46/499) and survival ranged from 59.1 to 100% in studies with a median follow-up of 24 months. 8.1% of patients (25/309) developed endoleak, predominantly type I. Re-intervention rates ranged from 0 to 60% in studies with a median follow-up of 31 months. 7.8% of patients (26/332) developed aneurysms of the distal aorta or continued false lumen perfusion with aneurysmal dilatation. Rare complications included delayed retrograde type A dissection (0.67%), aorto-oesophageal fistula (0.22%) and neurological complications (paraplegia 2/447, 0.45%; stroke 7/475, 1.5%).

CONCLUSION

The absolute benefit of TEVAR over alternative treatments for chronic B-AD remains uncertain. The lack of natural history data for medically treated cases, significant heterogeneity in case selection and absence of consensus reporting standards for intervention are significant obstructions to interpreting the mid-term data. High-quality data from registries and clinical trials are required to address these challenges.

Midterm results with thoracic endovascular aortic repair for chronic type B aortic dissection with associated aneurysm

OBJECTIVE

Thoracic endovascular aortic repair for chronic type B aortic dissection with associated descending thoracic aneurysm remains controversial. Concerns include potential ischemic complications due to branch vessel origin from the chronic false lumen and continued retrograde false lumen/aneurysm sac pressurization via fenestrations distal to implanted endografts. The present study examines midterm results with thoracic endovascular aortic repair for chronic (>2 weeks) type B aortic dissection with associated aneurysm to better understand the potential role of thoracic endovascular aortic repair for this condition.

METHODS

Between March 2005 and December 2009, 51 thoracic endovascular aortic repair procedures were performed at a single institution for management of chronic type B dissection. The indication for thoracic endovascular aortic repair was aneurysm in all cases. A subset of 7 patients (14%) underwent placement of the EndoSure wireless pressure measurement system (CardioMEMS, Inc, Atlanta, Ga) in the false lumen adjacent to the primary tear for monitoring aneurysm sac/false lumen pulse pressure after thoracic endovascular aortic repair.

RESULTS

Mean patient age was 57±12 years (range, 30-82 years); 14 patients (28%) were female. Mean aortic diameter was 6.2±1.4 cm. There were no in-hospital/30-day deaths, strokes, or permanent paraplegia/paresis. There were no complications related to compromise of downstream branch vessels arising from the false lumen. Two patients (3.9%) who had preexisting ascending aortic dilation had retrograde acute type A aortic dissection; both were repaired successfully. Median postoperative length of stay was 4 days. Mean follow-up is 27.0±16.5 months (range, 2-60 months). Actuarial overall survival is 77.7% at 60 months with an actuarial aorta-specific survival of 98% over this same time period. Actuarial freedom from reintervention is 77.3% at 60 months. All patients with the EndoSure wireless pressure measurement system exhibited a decrease in aneurysm sac/false lumen pulse pressure indicating a depressurized false lumen. The aneurysm sac/false lumen pulse pressure ratio decreased from 52%±27% at the predischarge measurement to 14%±5% at the latest follow-up reading (P=.029).

CONCLUSIONS

Thoracic endovascular aortic repair for chronic type B dissection with associated aneurysm is safe and effective at midterm follow-up. Aneurysm sac/false lumen pulse pressure measurements demonstrate a significant reduction in false lumen endotension, thus ruling out clinically significant persistent retrograde false lumen perfusion and provide proof of concept for a thoracic endovascular aortic repair-based approach. Longer-term follow-up is needed to determine the durability of thoracic endovascular aortic repair for this aortic pathology.