Endovascular stent-graft placement in aortic dissection: a meta-analysis

Endovascular stent-graft placement or open surgery for the treatment of acute type B aortic dissection: a meta-analysis

BACKGROUND

Acute type B aortic dissection (ATBAD) is a life-threatening condition. Open chest surgical repair using a prosthetic graft has been a conventional treatment for ATBAD. During the past decade, thoracic endovascular aortic repair (TEVAR), which is considered as a less invasive and potentially safer technique, has been increasingly used to treat this condition. Evidence is needed to support the use of TEVAR for these patients. The aim of this review was to assess the efficacy of TEVAR versus conventional open surgery in patients with ATBAD.

METHODS

For this review, we searched the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library (last searched: 2010, issue 4), MEDLINE, EMBASE, CINAHL, Web of Science, and the Chinese Biomedicine Database for clinical trials until January 18, 2011. Controlled trials in which patients with ATBAD were assigned to TEVAR or open surgical repair were included. For each outcome, we evaluated the quality of the evidence with reference to the Grading of Recommendations Assessments, Development, and Evaluation criteria. At the end, we used RevMan 5.0 software to analyze the datum.

RESULTS

Five trials (318 participants) are included in this review. As determined by the Grading of Recommendations Assessments, Development, and Evaluation approach, the result quality was low for 30-day mortality and very low for other variables. TEVAR can significantly reduce the short-term mortality for ATBAD (Mantel-Haenszel fixed odds ratio [95% confidence interval]: 0.19 [0.09-0.39], P < 0.001). TEVAR cannot significantly improve postoperative complications or long-term mortality.

CONCLUSIONS

TEVAR can be weakly recommended as an alternative for the selective treatment of ATBAD but cannot always be used in case of surgery.

Unusual complications of endovascular repair of the thoracic aorta: MDCT findings

With the development of minimally invasive surgical techniques, endovascular stent-graft placement has become an accepted and widely used alternative to the traditional surgical repair of aortic disease and is gaining acceptance as the treatment of choice. Many studies show that endovascular stent-graft therapy is safe and effective, although complications related to this treatment are also recognised. Although the incidence of major complication is low, neurological sequelae remain the major concern of endovascular repair. With growing experience, however, the spectrum of mid- and long-term complications has broadened to include potentially disastrous events, other than paraplegia or stroke, that require diligent surveillance. Three-dimensional data sets acquired quickly by multidetector computed tomography (MDCT) allow multiplanar reformations and 3D viewing, as well as quantitative assessment of vessel lumens, walls and surroundings. Although a large portion of radiologists will not be involved in the actual endograft deployment, many will be involved in the interpretation of postprocedural surveillance studies. Accordingly, the goal of this report is to summarise our experience with the presentation, diagnostic approach, management and outcomes of these unusual, but potentially catastrophic, postendovascular aortic repair complications to highlight their significance and increase familiarity with them among the imaging community. Increasing awareness of these complications may facilitate rapid diagnosis and/or triage and treatment.

Transapical wire-assisted endovascular repair of thoracic aortic dissection

PURPOSE

To describe a technique for transapical wire-assisted endograft deployment under rapid ventricular pacing for a type B dissection involving the proximal left subclavian artery and extending to the aortic bifurcation.

CASE REPORT

A 58-year-old man presented with a symptomatic thoracic aneurysm as a complication of a chronic type B dissection, with a short proximal neck in zone 1. After arch vessel debranching, the patient underwent endoluminal repair with deployment of a closed web, tapered Valiant thoracic endograft over a through-and-through wire from the left groin to the apex of the left ventricle, using rapid ventricular pacing to reduce cardiac output. The remaining dissected aorta was covered with a second Valiant endograft down to the distal third of the descending thoracic aorta and bare Z stents down to the aortic bifurcation to re-expand the true lumen. A freeflow Valiant endograft was deployed as a proximal extension to treat a proximal type I endoleak. The recovery was complicated by retrograde type A aortic dissection, considered secondary to the bare stent. The complication was repaired surgically; postoperative computed tomography after recovery was unremarkable.

CONCLUSION

Transapical wire-assisted deployment with rapid ventricular pacing is feasible and may provide improved stability for stenting within the aortic arch. The use of a stent-graft with a proximal bare stent is associated with a higher risk of retrograde extension of the dissection and warrants lifelong imaging follow-up.

Propensity score-matched analysis of open surgical and endovascular repair for type B aortic dissection

Objective. To identify national outcomes of thoracic endovascular aortic repair (TEVAR) for type B aortic dissections (TBADs). Methods. The Nationwide Inpatient Sample database was examined from 2005 to 2008 using ICD-9 codes to identify patients with TBAD who underwent TEVAR or open surgical repair. We constructed separate propensity models for emergently and electively admitted patients and calculated mortality and complication rates for propensity score-matched cohorts of TEVAR and open repair patients. Results. In-hospital mortality was significantly higher following open repair than TEVAR (17.5% versus 10.8%, P = .045) in emergently admitted TBAD. There was no in-hospital mortality difference between open repair and TEVAR (5.6% versus 3.3%, P = .464) for elective admissions. Hospitals performing thirty or more TEVAR procedures annually had lower mortality for emergent TBAD than hospitals with fewer than thirty procedures. Conclusions. TEVAR produces better in-hospital outcomes in emergent TBAD than open repair, but further longitudinal analysis is required.

Volumetric analysis of type B aortic dissections treated with thoracic endovascular aortic repair

BACKGROUND

Type B aortic dissections are being successfully treated by thoracic endovascular aortic repair (TEVAR). Postoperative false lumen patency has been associated with aneurysmal dilatation and rupture of the thoracic aorta, necessitating further intervention. This is the first volumetric analysis of type B aortic dissections comparing patients with and without false lumen thrombosis (FLT) after TEVAR. We hypothesized that a greater increase in postoperative true lumen volume will lead to FLT, and without this change, false lumen patency will result.

METHODS

Preoperative and postoperative computed tomography angiography (CTA) imaging was analyzed using three-dimensional reconstruction to measure the short- and long-axis diameter and cross-sectional area of the true lumen, false lumen, and total aorta. Measurements were taken at 5-cm intervals from the left subclavian artery to the aortic bifurcation. Pre- and postoperative volumetric data were calculated and compared in patients with and without postoperative FLT.

RESULTS

Between 2006 and 2010, 132 patients underwent thoracic aortic stent grafting. Of these, 31 (23%) had thoracic endografting for type B aortic dissection. Pre- and postoperative CTA images were available for analysis in 23 patients with a mean age of 59 ± 14 years treated for acute, complicated (n = 8, 35%), and chronic (n = 15, 65%) indications. Mean follow-up imaging was 9 months (range, 1-39 months). Thirteen patients (56%) had postoperative FLT and 10 (43%) had persistent false lumen patency. The dissections involved the left subclavian artery (n = 12), visceral arteries (n = 14), renal arteries (n = 16), and iliac arteries (n = 15). The left subclavian artery was intentionally covered in 15 patients (65%). There were no significant differences in age, acute vs chronic dissection, branch vessel involvement, coverage of the left subclavian artery, or distal extent of the endograft between patients with and without postoperative FLT. Patients with postoperative FLT had a significantly smaller preoperative maximum thoracic aortic diameter (5.05 ± 1.0 vs 6.30 ± 1.4 cm; P = .02). Volumetric analysis demonstrated significantly smaller preoperative true lumen volume (141.3 ± 68 vs 230.5 ± 92 cm(3); P = .01) in patients with FLT, but no difference in preoperative false lumen volume. Patients with FLT had a significant increase in the volume percentage of the true lumen from 42.7% to 61.7% (P = .02) after stent graft repair, compared with an increase from 46.7% to 47.7% (P = .75) in patients with persistent false lumen patency.

CONCLUSIONS

This volumetric study of type B aortic dissection treated with TEVAR suggests that the ability of the endograft to significantly increase the true lumen volume as a percent of the total aorta most accurately predicts postoperative FLT. This is best demonstrated in a nonaneurysmal dissection regardless of timing since dissection.

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.

Complicated acute type B thoracic aortic dissections: endovascular treatment for visceral malperfusion and pseudoaneurysms

PURPOSE

Morbidity and mortality of acute type B thoracic aortic dissections remain alarmingly high. Endoluminal options are promising.

METHODS

A single-center 5-year review of 17 acute type B aortic dissections complicated by visceral malperfusion (11) or pseudoaneurysm formation (6) treated with endovascular intervention. Interventional techniques included endografting (15) and/or percutaneous fenestration (4). Median follow-up is 28 months (range 0-76 months).

RESULTS

Median age was 55 years; 30-day death, stroke, and paraplegia rates were 0%, 17.6%, and 5.9%. Success reversing visceral ischemia or sealing a pseudoaneurysm was 100%. Cross-sectional imaging demonstrated that the false lumen was thrombosed in 9 patients, partially thrombosed in 6 patients. Late events include 1 delayed proximal type I endoleak, 1 delayed rupture of the thoracic aorta requiring successful emergent open surgical repair, and 2 unrelated late deaths.

CONCLUSION

Endovascular approaches to type B dissections presenting with visceral malperfusion and/or pseudoaneurysm can achieve acceptable early results.

Endovascular treatment of thoracic dissection

Type A aortic dissection remains fatal if untreated. Although classical medical therapy for type B dissection is considered the therapy of choice in uncomplicated cases, the paradigm is changing as greater experience is accrued with endovascular treatments and technical advances improve the long-term outlook. Diagnosis is also becoming more sophisticated, allowing greater appreciation of the anatomy of dissections and improving the knowledge base as their natural history is assessed.

Thoracic aortic aneurysms and dissections: endovascular treatment

The treatment of thoracic aortic disease has changed radically with the advances made in endovascular therapy since the concept of thoracic endovascular aortic repair was first described 15 years ago. Currently, there is a diverse array of endografts that are commercially available to treat the thoracic aorta. Multiple studies, including industry-sponsored and single-institution reports, have demonstrated excellent outcomes of thoracic endovascular aortic repair for the treatment of thoracic aortic aneurysms, with less reported perioperative morbidity and mortality in comparison with conventional open repair. Additionally, similar outcomes have been demonstrated for the treatment of type B dissections. However, the technology remains relatively novel, and larger studies with longer term outcomes are necessary to more fully evaluate the role of endovascular therapy for the treatment of thoracic aortic disease. This review examines the currently available thoracic endografts, preoperative planning for thoracic endovascular aortic repair, and outcomes of thoracic endovascular aortic repair for the treatment of both thoracic aortic aneurysms and type B aortic dissections. Mt Sinai J Med 77:256-269, 2010. (c) 2010 Mount Sinai School of Medicine.

Management of acute complicated and uncomplicated type B dissection of the aorta: focus on endovascular stent grafting

Endovascular repair of aortic dissection is the subject of multiple studies. This article aims to review the current literature on Type B complicated and uncomplicated dissection, including indications for medical therapy, open surgical therapy, and endovascular therapy. The review suggests a benefit for thoracic endovascular aortic repair in complicated dissection and medical therapy for uncomplicated dissection. Upcoming trials may shed more light on this issue.

How to manage the left subclavian artery during endovascular stenting for thoracic aortic dissection? An assessment of the evidence

BACKGROUND

Despite the publication of recent guidelines for management of the left subclavian artery (LSA) during endovascular stenting procedures of the thoracic aorta, specific management for those presenting with dissection remains unclear. This systematic review attempts to address this issue.

METHODS

Systematic assessment of the published data on thoracic aorta dissection was performed identifying 46 studies, which incorporated 1,275 patients. Primary outcomes included the prevalence of left arm ischemia, stroke, spinal cord ischemia, endoleak, stent migration, and mortality. Outcomes were compared between patients with and without LSA coverage and revascularization incorporating factors such as the number of stents used, length of aorta covered, urgency of intervention, and type of dissection (acute or chronic). Statistical pooling techniques, χ(2) tests, and Fisher's exact testing were used for group comparisons.

RESULTS

As compared with other outcomes, LSA coverage without revascularization in the presence of aortic dissection is much more likely to be complicated by left arm ischemia (prevalence increased from 0.0% to 4.0% [p = 0.021]), stroke (prevalence increased from 1.4% to 9.0% [p = 0.009]), and endoleak (prevalence increased from 4.0% to 29.3% [p = 0.001]). However, revascularization was not shown to reverse these effects. Longer aortic coverage (≥ 150 mm) was associated with an increased prevalence of spinal cord ischemia (from 1.3% to 12.5% [p = 0.011]) and mortality (from 1.3% to 15.6% [p = 0.003]).

CONCLUSION

In patients undergoing endovascular stenting for thoracic aortic dissection, in cases where LSA coverage is necessary, revascularization should be considered before the procedure to avoid complications such as left arm ischemia, stroke, and endoleak, and where feasible, an appropriate preoperative assessment should be carried out.

[Acute aortic syndrome and endovascular treatment: good indications of stent-graft, stent and aortic fenestration]

Acute aortic syndrome of the descending aorta can be treated with stent-graft thanks to technical and material development. Ruptured aneurysms, aortic dissection, wall hematoma and penetrating ulcers can be treated with stent-graft. According to the type of initial lesion, and the clinical tolerance, the emergency of treatment can be different. Non covered stent and aortic fenestration are used in case of visceral ischemia in aortic dissection, according to the type of ischemia.

Staged Hybrid Repair of Thoracoabdominal Aortic Aneurysm after Chronic Type B Aortic Dissection

The purpose of this study was to evaluate clinical outcomes of combined endovascular and open techniques to eradicate false lumen dilatation in the visceral aortic segment after type B aortic dissection associated with aortic aneurysm. We reviewed eight patients with distal thoracic and abdominal false lumen dilatation treated with a staged procedure. These included arch debranching as needed, proximal thoracic endovascular repair, and open surgical correction with abdominal aortic replacement of the visceral and infrarenal aorta. False lumen eradication was successful in all patients. There were no operative deaths, and paraplegia or paraparesis occurred in two patients. During a mean follow-up of 30 months, no complications or secondary interventions were necessary. The thoracic false lumen remained thrombosed in all patients, with no evidence of aortic dilatation or stent graft complications. Complete thrombosis and eradication of the false lumen can be achieved through a three-stage repair of chronic type B aortic dissection with aneurysmal dilatation. A prospective randomized trial is needed to establish the viability of this approach versus standard open repair of type II thoracoabdominal aortic aneurysms.

[Management of aortic dissection. Stent grafts for who?]

Acute aortic syndrome (AAS) describes several life threatening aortic pathologies. Acute aortic syndrome include intramural haematoma, penetrating aortic ulcer and acute aortic dissection. Advances in both imaging and endovascular treatment has led to an increase in diagnosis and improved management of these often catastrophic pathologies. The current place of stent-grafts for the AAS management is defined on the basis of the most recent literature.

Midterm results after endovascular treatment of acute, complicated type B aortic dissection

BACKGROUND

The purpose of this study was to assess the efficacy and midterm results of endovascular treatment of acute, complicated type B aortic dissection.

METHODS

Between January 2001 and February 2010, 32 patients (7 women, 25 men) with acute, complicated type B aortic dissection (mean age, 56 years; range, 35 to 83 years), defined as either aortic rupture, malperfusion, intractable pain, or uncontrolled hypertension, underwent endovascular stent graft placement with either the Gore Excluder/TAG device (n = 11), Medtronic Talent/Valiant device (n = 16), Bolton Relay (n = 2), or a combination of these stents (n = 3). Follow-up was 94% complete and averaged 26 ± 23 months.

RESULTS

Technical feasibility and success with deployment proximal to the entry tear was 87%, requiring partial or total coverage of the left subclavian artery (LSA) in 9 patients (28%). Hospital mortality was 12% ± 11% (95% confidence limit) with 2 late deaths (17 and 98 months after implant). Causes of hospital death included rupture in 2, retrograde type A dissection in 1, and multiorgan failure in 1 patient. Three patients (11%) experienced new neurologic complications (2 paraparesis and 1 hemiparesis). Six patients with malperfusion required branch vessel stenting. Furthermore, 2 had an early type Ia endoleak. Actuarial survival at 1 and 5 years was 81% and 76%, respectively. Freedom from treatment failure at 1 and 5 years (including reintervention, aortic rupture, device-related complication, and aortic related death) was 78% and 61%, respectively.

CONCLUSIONS

Endovascular stent-graft placement in acute, complicated type B aortic dissection proves to be a promising alternative therapeutic treatment modality in this relatively difficult patient cohort. Refinements, especially in stent design and application, may further improve the prognosis of patients in this life-threatening situation.

Open and endovascular repair of type B aortic dissection in the Nationwide Inpatient Sample

BACKGROUND

The use of stent grafts and mortality of stent graft repair of type B thoracic aortic dissection (T(B)AD) is not well defined. We sought to determine national estimates for the use and mortality of thoracic endovascular aortic repair (TEVAR) for T(B)AD in the United States.

METHODS

Records of the Nationwide Inpatient Sample (NIS) database between 2005 and 2007 were examined. International Classification of Diseases, 9th edition (ICD-9) diagnosis codes were used to select patients who underwent open or TEVAR with a stent graft for a diagnosis of thoracic aortic dissection or thoracoabdominal aortic dissection. We excluded patients with a diagnosis code for aortic aneurysm and those with procedure codes for cardioplegia or for operations on heart vessels or valves, which were considered type A dissections (T(A)AD). The remaining patients were considered as T(B)AD. We compared demographics and comorbidities, as well as adjusted complications and mortality rates, between patients undergoing TEVAR vs open repair.

RESULTS

We identified an estimated 10,466 repairs for dissection of the thoracic or thoracoabdominal aorta (open, 8659; TEVAR, 1818). Of these, 464 had a diagnosis of aortic aneurysm, and 5002 patients were considered T(A)AD. Of nonaneurysmal dissections, 5000 repairs were considered T(B)AD (open, 3619; TEVAR, 1381). The endovascular patients were older and had greater comorbidities, although only cardiac disease, renal failure, hypertension, and peripheral vascular disease were statistically significant. In-hospital mortality was 19% for open repair vs 10.6% for TEVAR (odds ratio [OR], 2.24; 95% confidence interval [CI], 1.36-3.67; P < .01). In-hospital mortality was significantly higher with open repairs coded as emergent admissions (20.1% vs 13.1%; P = .03), but did not reach statistical significance for elective admissions (12.3% vs 4.8%; P = .09). Cardiac complications (12.4% vs 4.9%, P < .01), respiratory complications (7.7% vs 4.3%, P = .02), genitourinary complications (9.0% vs 2.5%, P < .01), hemorrhage (14.0% vs 2.8%, P < .01), and acute renal failure (32.1% vs 17.2%, P < .01) were more frequent in the open repair group. Median length of stay was greater in the open repair group (10.7 vs 8.3 days, P < .01).

CONCLUSION

For patients with a diagnosis of T(B)AD who undergo repair, the endovascular approach is being used for older patients with greater comorbidities, yet has reduced morbidity and in-hospital mortality. The use of endovascular stent graft repair for type B thoracic aortic dissection merits further longitudinal analysis.

Impact of New Development of Ulcer-Like Projection on Clinical Outcomes in Patients With Type B Aortic Dissection With Closed and Thrombosed False Lumen

Background— The purpose of this study was to investigate the clinical importance of newly developed ulcer-like projection (ULP) in patients with type B aortic dissection with closed and thrombosed false lumen (AD with CTFL), which is better known as aortic intramural hematoma.

Methods and Results— A total of 170 patients with acute type B AD with CTFL were admitted to our institution from 1986 to 2008 and treated initially with medical therapy. There were 31 late deaths, including 9 cases of aortic rupture. The actuarial survival rates of all patients were 99%, 89%, 83% at 1, 5, and 10 years, respectively. A total of 62 (36%) patients showed new ULP development within 30 days from the onset. Patients who had ULP showed significantly poorer survival rates than patients who did not have ULP ( P =0.037). Development of ULP was also associated with a significant increase in adverse aorta-related events ( P <0.001). In addition, patients with ULP in the proximal descending thoracic aorta (PD) showed significantly higher aorta-related event rates than patients without ULP in the PD ( P <0.001). Initial aortic diameter (hazard ratio, 3.55; P <0.001) and development of ULP in PD (hazard ratio, 3.79; P =0.003) were the strongest predictors of adverse aorta-related events.

Conclusions— Initial aortic diameter and development of ULP in the PD are both strong predictors of adverse aorta-related events in patients with type B AD with CTFL. Patients with newly developed ULP should be more carefully followed up with close surveillance imaging than those without ULP.

Current strategy of endovascular aortic repair for thoracic aortic aneurysms

Thoracic aortic aneurysms are extremely burdensome to treat owing to their surgical complexity. In particular, major postoperative complications lower significantly patients' quality of life. Surgical treatment has recently shifted to thoracic endovascular aortic repair (TEVAR) to respect the patients' needs and improve postoperative quality of life. This procedure is radical and innovated for thoracic aortic pathology, but the devices and the delivery systems are immature because only a little over a decade and a half has passed since starting to use them. Ready-made stent-grafts were originally indicated only for degenerated aortic aneurysms, but aortic dissection and traumatic aortic transection will become the next targets for TEVAR. This review addresses the history and changes in TEVAR as well as the current TEVAR strategy. Finally, we describe a new trial of TEVAR for aortic dissections, traumatic aortic transections, and aortic arch aneurysms.