Thoracic aortic aneurysm repair with an endovascular stent graft: the "first generation"

Research and clinical translation of trilayer stent-graft of expanded polytetrafluoroethylene for interventional treatment of aortic dissection

The aortic dissection (AD) is a life-threatening disease. The transcatheter endovascular aortic repair (EVAR) affords a minimally invasive technique to save lives of these critical patients, and an appropriate stent-graft gets to be the key medical device during an EVAR procedure. Herein, we report a trilayer stent-graft and corresponding delivery system used for the treatment of the AD disease. The stent-graft is made of nitinol stents with an asymmetric Z-wave design and two expanded polytetrafluoroethylene (ePTFE) membranes. Each of inner and outer surfaces of the stent-graft was covered by an ePTFE membrane, and the two membranes were then sintered together. The biological studies of the sintered ePTFE membranes indicated that the stent-graft had excellent cytocompatibility and hemocompatibility in vitro. Both the stent-graft and the delivery system exhibited satisfactory mechanical properties and operability. The safety and efficacy of this stent-graft and the corresponding delivery system were demonstrated in vivo. In 9 canine experiments, the blood vessels of the animals implanted with the stent-grafts were of good patency, and there were no thrombus and obvious stenosis by angiography after implantation for 6 months. Furthermore, all of the 9 clinical cases experienced successful implantation using the stent-graft and its post-release delivery system, and the one-year follow-ups indicated the preliminary safety and efficacy of the trilayer stent-graft with an asymmetric Z-wave design for interventional treatment.

Covered or Not, Here I Come: Stanford Type B Aortic Dissection Repair With a Covered and Uncovered Stent Hybrid Technique

The complications resulting from aortic dissections are often devastating. Historically, when a Stanford B aortic dissection extended into the visceral abdominal aorta, only surgical management was considered to limit visceral organ malperfusion. Complications of surgical management for Stanford B aortic dissections are as high as 50%. The inherently high complication and mortality rate for any acute aortic dissection, in addition to the complication rates resulting from surgical management, have demonstrated poor outcomes. This is especially true when aortic dissections involve the visceral segment, where thoracic endovascular aortic repair (TEVAR) becomes limited or contraindicated. In the last two decades, various approaches for TEVAR have improved in both endograft design and interventional technique. The current literature demonstrates improved outcomes for patients that receive TEVAR for Stanford B aortic dissections, including those that involve the visceral segment. Despite favorable prognostic advancement in TEVAR, the proven management complexity of Stanford B aortic dissections continue to reflect the pitfalls of the endovascular devices that are currently available. We describe a covered and uncovered stent hybrid technique in patients with complicated Stanford B aortic dissections involving the visceral segment, considering these deficiencies. Hundred percent technical success was demonstrated in the short and mid-term surveillance periods.

Validated Computational Model to Compute Re-apposition Pressures for Treating Type-B Aortic Dissections

The use of endovascular treatment in the thoracic aorta has revolutionized the clinical approach for treating Stanford type B aortic dissection. The endograft procedure is a minimally invasive alternative to traditional surgery for the management of complicated type-B patients. The endograft is first deployed to exclude the proximal entry tear to redirect blood flow toward the true lumen and then a stent graft is used to push the intimal flap against the false lumen (FL) wall such that the aorta is reconstituted by sealing the FL. Although endovascular treatment has reduced the mortality rate in patients compared to those undergoing surgical repair, more than 30% of patients who were initially successfully treated require a new endovascular or surgical intervention in the aortic segments distal to the endograft. One reason for failure of the repair is persistent FL perfusion from distal entry tears. This creates a patent FL channel which can be associated with FL growth. Thus, it is necessary to develop stents that can promote full re-apposition of the flap leading to complete closure of the FL. In the current study, we determine the radial pressures required to re-appose the mid and distal ends of a dissected porcine thoracic aorta using a balloon catheter under static inflation pressure. The same analysis is simulated using finite element analysis (FEA) models by incorporating the hyperelastic properties of porcine aortic tissues. It is shown that the FEA models capture the change in the radial pressures required to re-appose the intimal flap as a function of pressure. The predictions from the simulation models match closely the results from the bench experiments. The use of validated computational models can support development of better stents by calculating the proper radial pressures required for complete re-apposition of the intimal flap.

Endografting of the Aortic Arch

In recent years, endovascular repair with stent-grafts has made great advances as a minimally invasive alternative to conventional open surgery in the treatment of aortic aneurysm and dissection. Although many commercial endograft systems are now used worldwide for the treatment of these pathologies in the abdominal aorta, only a few dedicated stent-grafts have been developed for use in the thoracic aorta. However, these second-generation commercial endografts have almost identical specifications and performance profiles in terms of structure, function, and delivery mechanism as stent-graft systems employed in the abdominal aorta. Thus, endografts have been used in the thoracic aorta with little consideration to the morphological and hemodynamic characteristics specific to the aortic arch and the deployment techniques needed to navigate this curved region of the thoracic aorta. This review will survey the literature on aortic arch stent-graft repair and identify key elements critical to the successful design of an endograft to treat lesions in the aortic arch.

Complications after Endovascular Treatment of Thoracic Aortic Aneurysms

Purpose:

To retrospectively determine the value of stent-graft repair of descending thoracic aortic aneurysms by analyzing the results and complications.

Methods:

From May 1997 to July 2002, 45 patients (33 men; mean age 69 years, range 31–88) received endovascular treatment for thoracic aortic aneurysms. In 11 patients, emergency treatment was necessary for a contained rupture. The medical records of these patients were reviewed to gather data on the procedures, immediate results, complications, mortality, and survival in follow-up.

Results:

In all cases, the stent-grafts were successfully implanted. In 15 (33%) cases, the subclavian artery was covered by the stent-graft without complications. There was no paraparesis/paraplegia; 2 (4.4%) patients suffered a stroke intraoperatively. The in-hospital mortality was 2.2% (n = 1); 3 (6.7%) patients died within 30 days. Primary endoleaks occurred in 8 (17.8%) cases. Procedural success (technical success without endoleak or death) was 80% (93.3% after primary endoleak repair). During follow-up, 2 (4.4%) secondary endoleaks developed. All endoleaks were treated successfully or sealed spontaneously (n = 2). At a mean 24-month follow-up (range 1–62), 84% of patients were alive.

Conclusions:

The endovascular treatment of thoracic aortic aneurysms appears to be safe and effective, with lower morbidity and mortality than in conventional open operations. For these reasons, endovascular treatment should be administered whenever possible.

Stent-Graft Treatment of Penetrating Thoracic Aortic Ulcers

Purpose:

To evaluate the efficacy of stent-graft placement for the treatment of penetrating thoracic aortic ulcers.

Methods:

Ten patients (7 men; mean age 73.8 years, range 69–79) were treated for penetrating thoracic aortic ulcers using Talent or Excluder stent-grafts. Preoperative examinations included computed tomographic angiography (CTA), transesophageal echography, and digital subtraction angiography (DSA). Follow-up included predischarge multimodal imaging and periodic CTA scans after discharge. Endoleaks, aortic diameter changes, and clinical complications were tracked.

Results:

Technical success was achieved in 100%, but 1 major neurological complication led to death 3 months after the procedure. Radiological follow-up detected 4 early endoleaks (3 type I and a type II), all of which spontaneously regressed, and 1 secondary type II endoleak. The mean aortic diameter decreased by 22% over a mean 9-month follow-up.

Conclusions:

Aortic ulcers are potentially lethal lesions. Considering its low morbidity and mortality, endovascular repair could widen the treatment options for these lesions.

Thoracic stent graft versus surgery for thoracic aneurysm

BACKGROUND

Thoracic aortic aneurysm (TAA) is an uncommon disease with an incidence of 10.4 per 100,000 inhabitants. It occurs mainly in older individuals and is evenly distributed among both sexes. There are no signs or symptoms indicative of the presence of the disease. Progressive but unpredictable enlargement of the dilated aorta is the natural course of the disease and can lead to rupture. Open chest surgical repair using prosthetic graft interposition has been a conventional treatment for TAAs. Despite improvements in surgical procedures perioperative complications remain significant. The alternative option of thoracic endovascular aneurysm repair (TEVAR) is considered a less invasive and potentially safer technique, with lower morbidity and mortality compared with conventional treatment. Evidence is needed to support the use of TEVAR for these patients, rather than open surgery. This is an update of the review first published in 2009.

OBJECTIVES

This review aimed to assess the efficacy of TEVAR versus conventional open surgery in patients with thoracic aortic aneurysms.

SEARCH METHODS

For this update the Cochrane Vascular Information Specialist searched the Specialised Register (last searched January 2016) and CENTRAL (2015, Issue 12).

SELECTION CRITERIA

Randomised controlled trials in which patients with TAAs were randomly assigned to TEVAR or open surgical repair.

DATA COLLECTION AND ANALYSIS

Two review authors independently identified and evaluated potential trials for eligibility. Excluded studies were further checked by another author. We did not perform any statistical analyses as no randomised controlled trials were identified.

MAIN RESULTS

We did not find any published or unpublished randomised controlled trials comparing TEVAR with conventional open surgical repair for the treatment of thoracic aortic aneurysms.

AUTHORS' CONCLUSIONS

Stent grafting of the thoracic aorta is technically feasible and non-randomised studies suggest reduction of early outcomes such as paraplegia, mortality and hospital stay. High quality randomised controlled trials assessing all clinically relevant outcomes including open-conversion, aneurysm exclusion, endoleaks, and late mortality are needed.

Endovascular repair of Stanford B aortic dissection using two stent grafts with different sizes

OBJECTIVE

The objective of this study was to introduce a novel strategy for thoracic endovascular aortic repair of Stanford B aortic dissection using two-stent graft implantation (TSI), in which the proximal stent and distal stent with different sizes are sequentially deployed, and to summarize our experience with this technique.

METHODS

A retrospective study was conducted of 72 consecutive patients (61 men; mean age, 55 ± 7 years; range, 41-67 years) with Stanford type B aortic dissection who underwent TSI treatment between January 2012 and May 2013. Among all patients, 43 (59.7%) involved the infrarenal aorta and 29 (40.3%) involved the whole thoracic and abdominal aorta; mean aortic involvement length was 226 ± 13 mm (range, 182-312 mm). Eight cases were for acute dissection (within 2 weeks from onset of symptoms), 11 cases were for chronic dissection (>3 months after initial dissection), and 53 cases were for subacute dissection (between 2 weeks and 3 months). Twenty-two cases (30.6%) were uncomplicated type and 50 cases (69.4%) were complicated type. Follow-up was performed postoperatively at 1 month, 6 months, and yearly thereafter. Technique success, aorta morphology, and procedure-related complications were evaluated.

RESULTS

Technical success was achieved in 100%; 72 pairs of stent grafts (144 thoracic stent grafts) and 10 left subclavian artery chimney stents were used. The mean aortic length coverage by the stent grafts was 197.6 ± 20.3 mm, and mean taper diameter span was 7.5 ± 1.8 mm. All patients were followed up from 6 to 16 months (mean, 10 ± 4 months); 95.8% (69 of 72) had a thrombosed false lumen in the aortic coverage, and the true lumen expanded on average 57% ± 11% (23%-100%). No significant changes were found in aortic diameters of the proximal and distal ends of the two stent grafts and the angles between centerlines of the distal end of the stent and the aorta during follow-up. Procedure-related complications included transient paraplegia (coverage of the left subclavian artery without revascularization and extensive coverage of aorta >220 mm) due to acute spinal cord ischemia (n = 1) and malapposition of the distal stent (primary tear closed, true lumen expansion led to oversize rate insufficient in distal stent diameter; n = 1). No death or malperfusion complications were observed during the perioperative period and follow-up.

CONCLUSIONS

Short-term outcomes showed TSI to be a flexible and effective approach to accurately repair Stanford B aortic dissection that could potentially address the limitations of currently available stent grafts. Further prospective clinical studies are warranted to evaluate its long-term efficacy.

Endovascular aortic injury repair after thoracic pedicle screw placement

Our objective was to describe the management and prevention of thoracic aortic injuries caused by a malposition of pedicle screws in corrective surgery of major spine deformities. Positioning pedicle screws in thoracic vertebras by posterior approach exposes to the risk of injury of the elements placed ahead of the thoracic spine, as the descending thoracic aorta. This complication can result in a cataclysmic bleeding, needing urgent vascular care, but it can also be totally asymptomatic, resulting in the long run in a pseudoaneurysm, justifying the systematic removal of the hardware. We report the case of a 76-year-old woman who underwent spinal correction surgery for thoraco-lumbar degenerative kypho-scoliosis. Immediately after the surgery, a thoracic aortic injury caused by the left T7 pedicle screw was diagnosed. The patient underwent a two-step surgery. The first step was realized by vascular surgeons and aimed to secure the aortic wall by short endovascular aortic grafting. During the second step, spine surgeons removed the responsible screw by posterior approach. The patient was discharged in a rehabilitation center 7 days after the second surgery. When such a complication occurs, a co-management by vascular and spine surgeons is necessary to avoid major complications. Endovascular management of this kind of vascular injuries permits to avoid an open surgery that have a great rate of morbi-mortality in frail patients. Nowadays, technologies exist to prevent this kind of event and may improve the security when positioning pedicle screws.

Thoracic stent graft versus surgery for thoracic aneurysm

BACKGROUND

Thoracic aortic aneurysm (TAA) is an uncommon disease with an incidence of 10.4 per 100,000 inhabitants. It occurs mainly in older individuals and is evenly distributed among both sexes. There are no signs or symptoms indicative of the presence of the disease. Progressive but unpredictable enlargement of the dilated aorta is the natural course of the disease and can lead to rupture. Open chest surgical repair using prosthetic graft interposition has been a conventional treatment for TAAs. Despite improvements in surgical procedures perioperative complications remain significant. The alternative option of thoracic endovascular aneurysm repair (TEVAR) is considered a less invasive and potentially safer technique, with lower morbidity and mortality compared with conventional treatment. Evidence is needed to support the use of TEVAR for these patients, rather than open surgery.

OBJECTIVES

The aim of this review is to assess the efficacy of TEVAR versus conventional open surgery in patients with TAAs.

SEARCH METHODS

For this update the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched March 2013) and CENTRAL (2013, Issue 2).

SELECTION CRITERIA

Randomised controlled trials in which patients with TAAs were randomly assigned to TEVAR or open surgical repair.

DATA COLLECTION AND ANALYSIS

Two review authors independently identified and evaluated potential trials for eligibility. Excluded studies were further checked by another author. We did not perform any statistical analyses as no randomised controlled trials were identified.

MAIN RESULTS

We did not find any published or unpublished randomised controlled trials comparing TEVAR with conventional open surgical repair for the treatment of thoracic aortic aneurysms.

AUTHORS' CONCLUSIONS

Though stent grafting of the thoracic aorta is technically feasible and non-randomised studies suggest reduction of early outcomes such as paraplegia, mortality and hospital stay, high quality randomised controlled trials assessing all clinically relevant outcomes including open-conversion, aneurysm exclusion, endoleaks, and late mortality are needed.

Combined thoracic endovascular aortic repair and neurosurgical intervention for injury due to posterior spine surgery

Aortic injuries represent a rare but life-threatening complication of spinal surgery. Perforation of the aorta due to pedicle screw penetration or misplacement can lead to immediate bleeding with hemodynamic instability or to pseudoaneurysm development with delayed risk of rupture, which can occur weeks to months later. Recently, thoracic endovascular aortic repair (TEVAR) in aortic trauma has contributed to a reduction of both mortality and morbidity. The literature on this subject is reviewed.

A systematic review of spinal cord injury and cerebrospinal fluid drainage after thoracic aortic endografting

BACKGROUND

The use of thoracic endovascular aneurysm repair (TEVAR) is increasing. Similar to open repair, TEVAR carries a risk of spinal cord ischemia (SCI). We undertook a systematic review to determine whether preoperative cerebrospinal fluid (CSF) drainage reduces SCI.

METHODS

PubMed, the Cochrane Library, and conference abstracts were searched using the keywords thoracic endovascular aortic repair, cerebrospinal fluid, spinal cord ischaemia, TEVAR, and aneurysm. Studies reporting SCI rates and CSF drain rates for TEVAR patients were eligible for inclusion. SCI rates across studies were pooled using random-effects modeling. Study quality was evaluated using the Downs and Black score.

RESULTS

Study quality was generally poor to moderate (median Downs and Black score, 9). The systematic review identified 46 eligible studies comprising 4936 patients; overall, SCI affected 3.89% (95% confidence interval, 2.95.05%-4.95%). Series reporting routine prophylactic drain placement or no prophylactic drain placement reported pooled SCI rates of 3.2% and 3.47%, respectively. The pooled SCI rate from 24 series stating that prophylactic drainage was used selectively was 5.6%.

CONCLUSIONS

Spinal chord injury is uncommon after TEVAR. The role of prophylactic CSF drainage is difficult to establish from the available literature. High-quality studies are required to determine the role of prophylactic CSF drainage in TEVAR.

Combined endovascular and neurosurgical approach to the removal of an intraaortic pedicle screw

Iatrogenic aortic injuries are a potentially devastating complication of spine surgery. In instrumented cases, injuries may occur in the perioperative period due to iatrogenic vessel injury, or they may occur years later as prominent implants erode or penetrate major vessels. The authors present a case of a 71-year-old man in whom a thoracic pedicle screw was found perforating the thoracic aorta during routine follow-up 6 months after surgery. Due to the risk of future complications, the screw was removed while simultaneously delivering an endovascular aortic stent to gain vascular control. Surgical considerations and potential technical limitations are discussed.

Endovascular versus open treatment of degenerative aneurysms of the descending thoracic aorta: a single center experience

Multiple reports could show a reduced risk for thoracic endovascular aortic repair (TEVAR) compared with open treatment. The aim of this study was to evaluate our twelve-year TEVAR experience for thoracic aortic aneurysms and compare these results with open repair. All patients who had received either open or endovascular surgery for a degenerative aortic aneurysm of the descending thoracic aorta in our center were evaluated retrospectively. N = 53 TEVAR patients (1997–2008) were included and their course was compared with an open-surgery group of n = 24 patients (1992–2002). The percentage of symptomatic patients was 43% (TEVAR) and 42% (open surgery). Endovascular treatment resulted in a significantly reduced 30-day (5.7% versus 25% P = 0.02) and one-year mortality (19% versus 42% P = 0.05) in the entire cohort. Symptomatic patients benefited the most from TEVAR (30-day mortality: 9% versus 40%, P = 0.06; one-year mortality: 27% versus 70%, P = 0.049) whereas the survival of our asymptomatic patients was not significantly different (30-day mortality: 3% versus 14%, P = 0.22; one-year mortality: 13% versus 21%, P = 0.65). Lastly, Kaplan–Meier analysis showed a significantly improved survival after TEVAR ( P = 0.05) and in particular for the symptomatic patients ( P = 0.003). In conclusion, endovascular treatment for patients with degenerative thoracic aortic aneurysms has significant advantages over open surgery.

A review of clinical trials and registries in descending thoracic aortic aneurysms

Aortic disease is a significant pathology, as it represents the 12(th) leading cause of overall death. Aneurysms of the descending thoracic aorta pose a small but significant part of this pathology. Traditional open descending thoracic aortic aneurysm (TAA) repair continues to be performed despite relatively high morbidity and mortality rates. As endovascular therapy to treat vascular disease has evolved, a paradigm shift has occurred such that likely most isolated TAAs are now repaired with an endovascular approach. Multiple, prospective trials have been performed comparing open and endovascular TAA repair with three company sponsored trials documenting clinical equipoise. In these studies, endovascular thoracic aortic aneurysm repair (ETAR) was mostly compared with historic controls or open repair from centers of excellence. While the trials all indicate that 30-day peri-operative morbidity and mortality is lower in the ETAR group, these trials were not designed to determine which patient is best served by an open versus an endovascular approach. In addition, long-term follow-up data is limited. Registry data of patients undergoing ETAR seems to mirror that of the aforementioned clinical trials and indicates acceptable morbidity and mortality profiles when compared to published open TAA repair results. Future prospective studies focused on patient selection likely will never be performed, as most believe the benefits of ETAR outweigh the lack of long term follow up data. This review will focus on repair of TAA, specifically clinical trial and registry data comparing open and endovascular repair.

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.

Endovascular repair of thoracic aortic aneurysm

A thoracic aortic aneurysm (TAA) is a potentially life-threatening condition with structural weakness of the aortic wall, which can progress to arterial dilatation and rupture. Today, both an increasing awareness of vascular disease and the access to tomographic imaging facilitate the diagnosis of TAA even in an asymptomatic stage. The risk of rupture for untreated aneurysms beyond a diameter of 5.6 cm ranges from 46% to 74% and the two-year mortality rate is greater than 70%, with most deaths resulting from rupture. Treatment options include surgical and non-surgical repair to prevent aneurysm enlargement and rupture. While most cases of ascending aortic involvement are subject to surgical repair (partially with valve-preserving techniques), aneurysm of the distal arch and descending thoracic aorta are amenable to emerging endovascular techniques as an alternative to classic open repair or to a hybrid approach (combining debranching surgery with stent grafting) in an attempt to improve outcomes.

Endovascular aortic stent for thoracic and abdominal aortic aneurysm: imaging consequences and complications

Background: Endovascular stent-graft implantation has been used as an alternative to conventional open surgery in treatment of aortic aneurysm. Computed tomographic angiography (CTA) has been requested for follow-up and evaluation of aortic stent complications. Objective: Find the incidence of endovascular aortic stent complications and analyze the CTA features of postendovascular aortic stent consequences. Methods: Two radiologists reviewed CTA images of 635 patients who attended King Chulalongkorn Memorial Hospital between Sep 1, 2003 and Aug 31, 2008. Thirty-eight patients had endovascular aortic stent installation with 95 CTA images. The incidence of endovascular aortic stent complications, the image appearances including consequences and time-interval of endoleak were analyzed. Results: There were 23 thoracic aortic stents, 10 abdominal aortic stents and five combined stents for thoracic and abdominal aortic aneurysms. Twenty-eight cases had aortic stent complications (73.7%). Two cases had immediately post procedural complication of groin hematomas (7.1%). Ten patients had more than one finding. Findings of the stent-graft complications were as follows: 19 endoleaks, 15 stent thrombosis, five stents without covered-dissection, two stent kinkings, two iatrogenic focal aortic dissection, two air within aneurysm after stent installation and one spreading infected aortitis. The most common complication was endoleaks (53.6%), which could progress, be persistent or resolvable. Time-interval to detect endoleak was between 1 and 464 days. Conclusion: CTA can be used as modality of choice in demonstration of stent location, consequences, and complications. The stent complication was still high in the first five-year experience.

Endovascular stent graft placement in patients with type B aortic dissection: a meta-analysis in China

OBJECTIVE

We summarized all published studies for endovascular stent graft placement among patients with type B aortic dissection in China with respect to clinical success, complications, and outcomes.

METHODS

A meta-analysis was performed on all published studies of retrograde endovascular stent graft placement encompassing 3 or more patients with type B aortic dissection. Thirty-nine studies, involving a total of 1304 patients from January 2001 to December 2007, were included.

RESULTS

The average patient age was 52 years. Procedural success was reported in 99.2% +/- 0.1% of patients. Major complications were reported in 3.4% +/- 0.1% patients, with the most severe neurologic complications in 0.6%. Periprocedural stroke was encountered more frequently than paraplegia (0.2% vs 0%). The overall 30-day mortality was 2.6% +/- 0.1%. In addition, 1.5% +/- 0.1% of patients died over a mean follow-up period of 27.1 +/- 17.5 months. Life-table analysis yielded overall survival rates of 96.9% at 30 days, 96.7% at 6 months, 96.4% at 1 year, 95.6% at 2 years, and 95.2% at 5 years.

CONCLUSION

Although therapy with traditional medicines still remains the first line of treatment for type B aortic dissection, endovascular stent graft placement has shown its advantages, with a success rate of 99% or greater in a select cohort. The technical survival rate, major complications, and acute and midterm survival rates in the Chinese-language literature appeared to favorably compare with that seen in published literature. This analysis is the first to provide an overview of the currently available literature on endovascular stent graft placement in type B aortic dissection in China.

Transluminal endovascular stent grafting of aortic dissections and aneurysms: a concise review of the major trials

Transluminal endovascular repair of the vascular system is rapidly emerging as a leading therapeutic modality for aortic dissections and aneurysms. The use of transluminal endovascular stent grafting has been used to intervene successfully on the aorta and its major branch vessels. There have been several studies examining transluminal endovascular stent grafting of thoracic aortic aneurysms, dissections, and abdominal aortic aneurysms. This paper reviews some of the major trials of transluminal endovascular stent grafting as well as its major limitation, endoleak.

Thoracic stent graft versus surgery for thoracic aneurysm

BACKGROUND

Thoracic aortic aneurysm (TAA) is an uncommon disease with an incidence of 10.4 per 100,000 inhabitants. It occurs mainly in older individuals and is evenly distributed among both sexes. There are no signs or symptoms indicative of the presence of the disease. Progressive but unpredictable enlargement of the dilated aorta is the natural course of the disease and can lead to rupture. Open chest surgical repair using prosthetic graft interposition has been a conventional treatment for TAAs. Despite improvements in surgical procedures perioperative complications remain significant. The alternative option of thoracic endovascular aneurysm repair (TEVAR) is considered a less invasive and potentially safer technique, with lower morbidity and mortality compared with conventional treatment. Evidence is needed to support the use of TEVAR for these patients, rather than open surgery.

OBJECTIVES

The aim of this review is to assess the efficacy of TEVAR versus conventional open surgery in patients with TAAs.

SEARCH STRATEGY

The Cochrane Peripheral Vascular Diseases Group searched their Trials Register (last searched 10 October 2008), the Cochrane Central Register of Controlled Trials database (CENTRAL) (last searched The Cochrane Library 2008, Issue 4).

SELECTION CRITERIA

Randomised controlled trials in which patients with TAAs were randomly assigned to TEVAR or open surgical repair.

DATA COLLECTION AND ANALYSIS

Two review authors independently identified and evaluated potential trials for eligibility. Excluded studies were further checked by another author. We did not perform any statistical analyses as no randomised controlled trials were identified.

MAIN RESULTS

We did not find any published or unpublished randomised controlled trials comparing TEVAR with conventional open surgical repair for the treatment of thoracic aortic aneurysms.

AUTHORS' CONCLUSIONS

Though stent grafting of the thoracic aorta is technically feasible and non-randomised studies suggest reduction of early outcomes such as paraplegia, mortality and hospital stay, high quality randomised controlled trials assessing all clinically relevant outcomes including open-conversion, aneurysm exclusion, endoleaks, and late mortality are needed.