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1.  Sun’s procedure for complex aortic arch repair: total arch replacement using a tetrafurcate graft with stented elephant trunk implantation 
Annals of Cardiothoracic Surgery  2013;2(5):642-648.
The Sun’s procedure is a surgical technique proposed by Dr. Li-Zhong Sun in 2002 that integrates total aortic arch replacement using a tetrafurcated graft with implantation of a specially designed frozen elephant trunk (Cronus®) in the descending aorta. It is used as a treatment option for extensive aortic dissections or aneurysms involving the ascending aorta, aortic arch and the descending aorta. The technical essentials of Sun’s procedure include implantation of the special open stented graft into the descending aorta, total arch replacement with a 4-branched vascular graft, right axillary artery cannulation, selective antegrade cerebral perfusion for brain protection, moderate hypothermic circulatory arrest at 25 °C, a special anastomotic sequence for aortic reconstruction (i.e., proximal descending aorta → left carotid artery → ascending aorta → left subclavian artery → innominate artery), and early rewarming and reperfusion after distal anastomosis to minimize cerebral and cardiac ischemia. The core advantage of Sun’s procedure lies in the use of a unique stented graft, which has superior technical simplicity, flexibility, inherent mechanical durability and an extra centimeter of attached regular vascular graft at both ends. Since its introduction in 2003, the Sun’s procedure has produced satisfactory early and long-term results in over 8,000 patients in China and more than 200 patients in South American countries. In a series of 1,092 patients, the authors have achieved an in-hospital mortality rate of 6.27% (7.98% in emergent or urgent vs. 3.98% in elective cases). Given the accumulating clinical experience and the consequent, continual evolution of surgical indications, the Sun’s procedure is becoming increasingly applied/used worldwide as an innovative and imaginative enhancement of surgical options for the dissected (or aneurysmal) ascending aorta, aortic arch and proximal descending aorta, and may become the next standard treatment for type A aortic dissections requiring repair of the aortic arch.
doi:10.3978/j.issn.2225-319X.2013.09.03
PMCID: PMC3791186  PMID: 24109575
Sun’s procedure; frozen elephant trunk; aortic arch surgery; aortic dissection; aortic aneurysm
2.  Aortic arch/elephant trunk procedure with SiennaTM graft and endovascular stenting of thoraco-abdominal aorta for treatment of complex chronic dissection 
Annals of Cardiothoracic Surgery  2013;2(3):358-361.
Aneurismal dilatation of the remaining thoracic aorta after ascending aortic interposition grafting for type ‘A’ aortic dissection is not uncommon. For such complex cases, one treatment option is total arch replacement and elephant trunk procedure with the SiennaTM collared graft (Vascutek, Inchinnan, UK) technique followed by a staged thoracic endovascular aortic repair (TEVAR). The video illustrates our technique in a 56-year-old man with an extensive aortic arch and descending thoracic aortic dissecting aneurysm. For the ‘open’ procedure femoral arterial and venous cannulation was used along with systemic cooling and circulatory arrest at 22 °C. Upon circulatory arrest, the aortic arch was incised and antegrade cerebral perfusion achieved via selective cannulation to the right brachiocephalic and left common carotid artery, keeping flow rates at 10-15 mL/kg/min and perfusion pressure at 50-60 mmHg. Arch replacement with an elephant trunk component was then performed and after completion of the distal aortic anastomosis antegrade perfusion via a side-arm in the graft was started and the operation completed using a variation of the ‘sequential’ clamping technique to maximize cerebral perfusion. The second endovascular stage was performed two weeks after discharge. Two covered stents were landing from the elephant trunk to the distal descending thoracic aorta, to secure the distal landing a bare stent of was placed to cover the aorta just distal to the origin of the celiac axis. The left subclavian artery was embolised with fibre coils. Post TEVAR angiogram showed no endoleak Although re-operative total arch replacement and elephant trunk procedure and subsequent TEVAR remained a challenging procedure, we believe excellent surgical outcome can be achieved with carefully planned operative strategy.
doi:10.3978/j.issn.2225-319X.2013.05.03
PMCID: PMC3741863  PMID: 23977606
TEVAR; elephant trunk; aortic dissection; arch replacement
3.  Technical Challenges in Endovascular Repair of Complex Thoracic Aortic Aneurysms 
Annals of Vascular Diseases  2012;5(1):21-29.
Background: Endovascular aneurysm repair has gained widespread acceptance, and there has been a significant increase in the number of aneurysms treated with stent grafts. However, the endovascular technique alone is often not appropriate for anatomically complex aneurysms involving the neck branches. We used the TAG stent for thoracic aortic aneurysms (TAA), and report our initial results.
Patients and Results: We deployed 80 TAG stents in 65 patients electively treated with TAA between June 2006 and June 2008. Thoracic endovascular aneurysm repair (TEVAR) was performed in 45 cases of descending aortic aneurysm with no morbidity or mortality. A combination of open surgery and TEVAR was performed in 11 out of 20 cases with aneurysms of the aortic arch. The prior total arch replacement and elephant trunk procedure was performed in 3 cases with dilated ascending aorta, total debranching from ascending aorta with sternotomy in 5, and carotid-carotid artery crossover bypass in 3 cases. Meanwhile, TEVAR with coverage of the left subclavian artery was performed in the remaining 9 distal arch cases. In 3 cases with extremely short necks, a 0.018” guide wire was inserted percutaneously in a retrograde manner through the common carotid artery (CCA) into the ascending aorta to place the stent graft in close proximity to the CCA (wire protection). In 1 of these 3 cases, the TAG stent was deployed through the CCA, and the 0.018” guide wire was used to deliver a balloon-expandable stent in order to restore the patency of the CCA. In arch and distal arch aneurysm cases, perioperative mortality and the incidence of stroke were both 5.0%; dissection of the ascending aorta was seen in one case (5.0%).
Conclusion: As treatment for descending aortic aneurysms, TEVAR can replace conventional open repair. However, TEVAR for arch aneurysms has some problems, and further improvement is necessary. (English Translation of Jpn J Vasc Surg 2010; 19: 547-555.)
doi:10.3400/avd.oa.11.01011
PMCID: PMC3595906  PMID: 23555482
Keywordsthoracic aortic aneurysm; endovascular surgery; stent graft
4.  “V” aortoplasty of the proximal descending aorta in the elephant trunk procedure 
Complex pathology of the aorta, especially in patients presenting an aneurysm involving the entire aortic arch and proximal descending aorta has been approached in one or two stages. Surgical management of those with an extremely wide diameter of the proximal descending aorta is not yet well defined. The patient in this case was an asymptomatic 47-year-old female with systemic lupus erythematosus (SLE) associated with aneurysm of the ascending aorta, whose aortic arch and descending aorta had presented only overall weakness (examination by inspection and palpation without histological verification). The imaging identified a giant aorta arising at the level of the sinotubular junction (STJ), ending up immediately below the diaphragm. In the first stage she underwent surgical replacement of the entire ascending aorta, aortic arch and proximal part of the descending aorta by combining the elephant trunk with a new type of aortoplasty. In the second stage an endovascular stent graft was inserted into the elephant trunk in the descending aorta. The patient continues to do well 20 months following the repair. In this manuscript type we describe a novel technique of “V” aortoplasty of the proximal descending aorta in order to facilitate the performing of anastomosis between the Dacron graft and aortic aneurysm.
doi:10.1186/s13019-015-0217-x
PMCID: PMC4318449  PMID: 25637000
Aortic aneurysm; Elephant trunk; Aortoplasty
5.  Endovascular Repair of Descending Thoracic Aortic Aneurysm 
Executive Summary
Objective
To conduct an assessment on endovascular repair of descending thoracic aortic aneurysm (TAA).
Clinical Need
Aneurysm is the most common condition of the thoracic aorta requiring surgery. Aortic aneurysm is defined as a localized dilatation of the aorta. Most aneurysms of the thoracic aorta are asymptomatic and incidentally discovered. However, TAA tends to enlarge progressively and compress surrounding structures causing symptoms such as chest or back pain, dysphagia (difficulty swallowing), dyspnea (shortness of breath), cough, stridor (a harsh, high-pitched breath sound), and hoarseness. Significant aortic regurgitation causes symptoms of congestive heart failure. Embolization of the thrombus to the distal arterial circulation may occur and cause related symptoms. The aneurysm may eventually rupture and create a life-threatening condition.
The overall incidence rate of TAA is about 10 per 100,000 person-years. The descending aorta is involved in about 30% to 40% of these cases.
The prognosis of large untreated TAAs is poor, with a 3-year survival rate as low as 25%. Intervention is strongly recommended for any symptomatic TAA or any TAA that exceeds twice the diameter of a normal aorta or is 6 cm or larger. Open surgical treatment of TAA involves left thoracotomy and aortic graft replacement. Surgical treatment has been found to improve survival when compared with medical therapy. However, despite dramatic advances in surgical techniques for performing such complex operations, operative mortality from centres of excellence are between 8% and 20% for elective cases, and up to 50% in patients requiring emergency operations. In addition, survivors of open surgical repair of TAAs may suffer from severe complications. Postoperative or postprocedural complications of descending TAA repair include paraplegia, myocardial infarction, stroke, respiratory failure, renal failure, and intestinal ischemia.
The Technology
Endovascular aortic aneurysm repair (EVAR) using a stent graft, a procedure called endovascular stent-graft (ESG) placement, is a new alternative to the traditional surgical approach. It is less invasive, and initial results from several studies suggest that it may reduce mortality and morbidity associated with the repair of descending TAAs.
The goal in endovascular repair is to exclude the aneurysm from the systemic circulation and prevent it from rupturing, which is life-threatening. The endovascular placement of a stent graft eliminates the systemic pressure acting on the weakened wall of the aneurysm that may lead to the rupture. However, ESG placement has some specific complications, including endovascular leak (endoleak), graft migration, stent fracture, and mechanical damage to the access artery and aortic wall.
The Talent stent graft (manufactured by Medtronic Inc., Minneapolis, MN) is licensed in Canada for the treatment of patients with TAA (Class 4; licence 36552). The design of this device has evolved since its clinical introduction. The current version has a more flexible delivery catheter than did the original system. The prosthesis is composed of nitinol stents between thin layers of polyester graft material. Each stent is secured with oversewn sutures to prevent migration.
Review Strategy
Objectives
To compare the effectiveness and cost-effectiveness of ESG placement in the treatment of TAAs with a conventional surgical approach
To summarize the safety profile and effectiveness of ESG placement in the treatment of descending TAAs
Measures of Effectiveness
Primary Outcome
Mortality rates (30-day and longer term)
Secondary Outcomes
Technical success rate of introducing a stent graft and exclusion of the aneurysm sac from systemic circulation
Rate of reintervention (through surgical or endovascular approach)
Measures of Safety
Complications were categorized into 2 classes:
Those specific to the ESG procedure, including rates of aneurysm rupture, endoleak, graft migration, stent fracture, and kinking; and
Those due to the intervention, either surgical or endovascular. These include paraplegia, stroke, cardiovascular events, respiratory failure, real insufficiency, and intestinal ischemia.
Inclusion Criteria
Studies comparing the clinical outcomes of ESG treatment with surgical approaches
Studies reporting on the safety and effectiveness of the ESG procedure for the treatment of descending TAAs
Exclusion Criteria
Studies investigating the clinical effectiveness of ESG placement for other conditions such as aortic dissection, aortic ulcer, and traumatic injuries of the thoracic aorta
Studies investigating the aneurysms of the ascending and the arch of the aorta
Studies using custom-made grafts
Literature Search
The Medical Advisory Secretariat searched The International Network of Agencies for Health Technology Assessment and the Cochrane Database of Systematic Reviews for health technology assessments. It also searched MEDLINE, EMBASE, Medline In-Process & Other Non-Indexed Citations, and Cochrane CENTRAL from January 1, 2000 to July 11, 2005 for studies on ESG procedures. The search was limited to English-language articles and human studies.
One health technology assessment from the United Kingdom was identified. This systematic review included all pathologies of the thoracic aorta; therefore, it did not match the inclusion criteria. The search yielded 435 citations; of these, 9 studies met inclusion criteria.
Summary of Findings
Mortality
The results of a comparative study found that in-hospital mortality was not significantly different between ESG placement and surgery patients (2 [4.8%] for ESG vs. 6 [11.3%] for surgery).
Pooled data from case series with a mean follow-up ranging from 12 to 38 months showed a 30-day mortality and late mortality rate of 3.9% and 5.5%, respectively. These rates are lower than are those reported in the literature for surgical repair of TAA.
Case series showed that the most common cause of early death in patients undergoing endovascular repair is aortic rupture, and the most common causes of late death are cardiac events and aortoesophageal or aortobronchial fistula.
Technical Success Rate
Technical success rates reported by case series are 55% to 100% (100% and 94.4% in 2 studies with all elective cases, 89% in a study with 5% emergent cases, and 55% in a study with 42% emergent cases).
Surgical Reintervention
In the comparative study, 3 (7.1%) patients in the ESG group and 14 (26.5%) patients in the surgery group required surgical reintervention. In the ESG group, the reasons for surgical intervention were postoperative bleeding at the access site, paraplegia, and type 1 endoleak. In the surgical group, the reasons for surgery were duodenal perforation, persistent thoracic duct leakage, false aneurysm, and 11 cases of postoperative bleeding.
Pooled data from case series show that 9 (2.6%) patients required surgical intervention. The reasons for surgical intervention were endoleak (3 cases), aneurysm enlargement and suspected infection (1 case), aortic dissection (1 case), pseudoaneurysm of common femoral artery (1 case), evacuation of hematoma (1 case), graft migration (1 case), and injury to the access site (1 case).
Endovascular Revision
In the comparative study, 3 (7.1%) patients required endovascular revision due to persistent endoleak.
Pooled data from case series show that 19 (5.3%) patients required endovascular revision due to persistent endoleak.
Graft Migration
Two case series reported graft migration. In one study, 3 proximal and 4 component migrations were noted at 2-year follow-up (total of 5%). Another study reported 1 (3.7%) case of graft migration. Overall, the incidence of graft migration was 2.6%.
Aortic Rupture
In the comparative study, aortic rupture due to bare stent occurred in 1 case (2%). The pooled incidence of aortic rupture or dissection reported by case series was 1.4%.
Postprocedural Complications
In the comparative study, there were no statistically significant differences between the ESG and surgery groups in postprocedural complications, except for pneumonia. The rate of pneumonia was 9% for those who received an ESG and 28% for those who had surgery (P = .02). There were no cases of paraplegia in either group. The rate of other complications for ESG and surgery including stroke, cardiac, respiratory, and intestinal ischemia were all 5.1% for ESG placement and 10% for surgery. The rate for mild renal failure was 16% in the ESG group and 30% in the surgery group. The rate for severe renal failure was 11% for ESG placement and 10% for surgery.
Pooled data from case series show the following postprocedural complication rates in the ESG placement group: paraplegia (2.2%), stroke (3.9%), cardiac (2.9%), respiratory (8.7%), renal failure (2.8%), and intestinal ischemia (1%).
Time-Related Outcomes
The results of the comparative study show statistically significant differences between the ESG and surgery group for mean operative time (ESG, 2.7 hours; surgery, 5 hours), mean duration of intensive care unit stay (ESG, 11 days; surgery, 14 days), and mean length of hospital stay (ESG, 10 days; surgery, 30 days).
The mean duration of intensive care unit stay and hospital stay derived from case series is 1.6 and 7.8 days, respectively.
Ontario-Based Economic Analysis
In Ontario, the annual treatment figures for fiscal year 2004 include 17 cases of descending TAA repair procedures (source: Provincial Health Planning Database). Fourteen of these have been identified as “not ruptured” with a mean hospital length of stay of 9.23 days, and 3 cases have been identified as “ruptured,” with a mean hospital length of stay of 28 days. However, because one Canadian Classification of Health Interventions code was used for both procedures, it is not possible to determine how many were repaired with an EVAR procedure or with an open surgical procedure.
Hospitalization Costs
The current fiscal year forecast of in-hospital direct treatment costs for all in-province procedures of repair of descending TAAs is about $560,000 (Cdn). The forecast in-hospital total cost per year for in-province procedures is about $720,000 (Cdn). These costs include the device cost when the procedure is EVAR (source: Ontario Case Costing Initiative).
Professional (Ontario Health Insurance Plan) Costs
Professional costs per treated patient were calculated and include 2 preoperative thoracic surgery or EVAR consultations.
The professional costs of an EVAR include the fees paid to the surgeons, anesthetist, and surgical assistant (source: fee service codes). The procedure was calculated to take about 150 minutes.
The professional costs of an open surgical repair include the fees of the surgeon, anesthetist, and surgical assistant. Open surgical repair was estimated to take about 300 minutes.
Services provided by professionals in intensive care units were also taken into consideration, as were the costs of 2 postoperative consultations that the patients receive on average once they are discharged from the hospital. Therefore, total Ontario Health Insurance Plan costs per treated patient treated with EVAR are on average $2,956 (ruptured or not ruptured), as opposed to $5,824 for open surgical repair and $6,157 for open surgical repair when the aneurysm is ruptured.
Conclusions
Endovascular stent graft placement is a less invasive procedure for repair of TAA than is open surgical repair.
There is no high-quality evidence with long-term follow-up data to support the use of EVAR as the first choice of treatment for patients with TAA that are suitable candidates for surgical intervention.
However, short- and medium-term outcomes of ESG placement reported by several studies are satisfactory and comparable to surgical intervention; therefore, for patients at high risk of surgery, it is a practical option to consider. Short- and medium-term results show that the benefit of ESG placement over the surgical approach is a lower 30-day mortality and paraplegia rate; and shorter operative time, ICU stay, and hospital stay.
PMCID: PMC3382300  PMID: 23074469
6.  Circumferential and Longitudinal Cyclic Strain of The Human Thoracic Aorta: Age-Related Changes 
Objective
We developed a novel method using the anatomical markers along the thoracic aorta to accurately quantify both longitudinal and circumferential cyclic strain in the thoracic aorta. We have applied this method to quantify circumferential and longitudinal cyclic strain in non-diseased thoracic aortas over the cardiac cycle and to compute age-related changes of the human thoracic aorta.
Methods
Changes in thoracic aorta cyclic strains were quantified using the 4D cardiac-gated CT image data of fourteen patients; aged 35-80, with no visible aortic pathology (aneurysms or dissection). We measured the diameter and circumferential cyclic strain in the arch and descending thoracic aorta (DTA), the longitudinal cyclic strain along the DTA, and changes in arch length and motion of the ascending aorta relative to the DTA. Diameters were computed distal to the left coronary artery, proximal and distal to the brachiocephalic trunk, and distal to the left common carotid, left subclavian, and the first and seventh intercostal arteries (ICoA). Cyclic strains were computed using the Green-Lagrange strain tensor. Arch length was defined along the vessel centerline from the left coronary artery to the first ICoA. The length of the DTA was defined along the vessel centerline from the first to seventh ICoA. Longitudinal cyclic strain was quantified as the difference between the systolic and diastolic DTA lengths divided by the diastolic DTA length Comparisons were made between seven young (age 41±7 yrs, 6M, 3F) and seven older (age 68±6 yrs, 6M, 3F) patients.
Results
For the seven locations analyzed, the diameters of the thoracic aorta increased, on average, by 14% with age from the young (mean age 41 years) to the older (mean age 68 years) group. The circumferential cyclic strain of the thoracic aorta decreased, on average, by 55% with age from the young to the older group. The longitudinal cyclic strain decreased with age by 50% from the young to older group (2.0 ± 0.4% versus 1.0 ± 1%, p=0.03). The arch length increased by 14% with age from the young to the older group (134 ± 17mm versus 152 ± 10mm, p=0.03).
Conclusions
The thoracic aorta enlarges circumferentially and axially and deforms significantly less in the circumferential and longitudinal directions with increasing age. This represents the first quantitative description of in vivo longitudinal cyclic strain and length changes for the human thoracic aorta, creating a foundation for standards in reporting data related to in vivo deformation, and may have significant implications in endo-aortic device design, testing and stability.
doi:10.1016/j.jvs.2008.11.056
PMCID: PMC2695673  PMID: 19341890
age-related; cyclic deformation; cyclic strain; longitudinal strain; circumferential strain; biomechanics; thoracic aorta; wall motion
7.  Interrupted Aortic Arch in an Adult 
Texas Heart Institute Journal  2002;29(2):118-121.
Interrupted aortic arch is a rare congenital malformation of the aortic arch that occurs in 3 per million live births. Defined as a loss of luminal continuity between the ascending and descending portions of the aorta, this anomaly entails a very poor prognosis without surgical treatment. To our knowledge, the world medical literature contains only 12 reports of isolated interrupted aortic arch diagnosed in adults. Nine of these patients underwent successful surgical repair, but 1 died during the early postoperative period. We describe a 10th successful surgical repair, which involved a 42-year-old woman who had an asymptomatic type B interrupted aortic arch (characterized by interruption between the left subclavian and left carotid arteries). We performed a single-stage extra-anatomic repair by placing a 16-mm extra-anatomic Dacron graft between the ascending and descending portions of the thoracic aorta and by interposing a 7-mm extra-anatomic Dacron graft between the 16-mm graft and the left subclavian artery. The patient recovered uneventfully and continued to do well 6 months later. (Tex Heart Inst J 2002;29:118–21)
PMCID: PMC116738  PMID: 12075868
Anastomosis, surgical, extra-anatomic; aorta, thoracic/abnormalities/surgery; blood vessel prosthesis; female; heart defects, congenital/surgery; human
8.  Innominate truncal and arch blowout with left hemiparesis and right hemothorax followed by delayed cheese-wire perforation of innominate graft 
We present the case of a 68 year old Caucasian woman, in extremis, with left hemiparesis and right hemothorax, in hypovolemic shock, secondary to a blow-out of a large penetrating ulcer at the junction of innominate trunk and aortic arch. She underwent interposition graft replacement of innominate trunk and repair of aortic arch, on cardiopulmonary bypass, employing total circulatory arrest and selective antegrade cerebral perfusion and had total resolution of hemiparesis. She, however, represented, 6 months later, with threatened exsanguination after a sternal wire cheese-wired through the sternum and perforated the anteriorly lying innominate graft. Following successful repair, she was found to have an old intramural hematoma of distal arch and descending thoracic aorta and changes suggestive of chronic dissection of the whole of abdominal aorta. This was managed conservatively.
We believe this patient’s presentation initially with a spontaneous innominate blow-out, cardiogenic shock, hemothorax and hemiparesis, and later with cheese-wire perforation of the innominate graft is unique. Her surgical rescue at both presentations was equally unusual, and without surgical precedent to the best of our knowledge. Was the initial innominate blow-out the result of localised innominate dissection, or more unusually, part of retrograde descending thoracic dissection with skip penetration of innominate artery and sparing of the intervening arch? Was it secondary to the minor fall she had sustained 1 week prior to the event, resulting in a false aneurysm or a contained hematoma next to the innominate artery? More intriguingly, did diffuse aortopathy underpin these diverse etiologies and result in penetrating intimal ulcer with blow out in the innominate artery, intramural hematoma in the arch and descending thoracic aorta and dissection in abdominal aorta at different points in time?
We review the current literature for these unusual afflictions of innominate trunk and its origin from the arch of aorta.
doi:10.1186/1749-8090-8-109
PMCID: PMC3652732  PMID: 23618057
Innominate artery blow-out; Innominate graft perforation; Hemothorax; Hemiparesis
9.  Management of Intramural Hematoma of the Ascending Aorta and Aortic Arch 
Texas Heart Institute Journal  2003;30(4):325-327.
We present the case of a 57-year-old woman who had an intramural hematoma of the ascending aorta and aortic arch. After initial blood pressure control and imaging studies, the patient underwent limited surgical repair that consisted of ascending aortic replacement. One week postoperatively, the aortic arch hematoma progressed to a full dissection that extended into the proximal descending aorta. Emergent aortic arch replacement was required.
Current world medical literature regarding thoracic aortic intramural hematoma is presented. This case supports the treatment of intramural hematomas of the ascending aorta and arch by surgical replacement of both segments with a Dacron graft, with the patient under deep hypothermic circulatory arrest. (Tex Heart Inst J 2003;30:325–7)
PMCID: PMC307723  PMID: 14677748
Aneurysm, dissecting/complications/surgery; aortic aneurysm; blood vessel prosthesis; hematoma/complications/surgery
10.  Cannulation in the Diseased Aorta 
Texas Heart Institute Journal  2006;33(3):353-355.
The Seldinger technique is a method of femoral cannulation that has been used to establish cardiopulmonary bypass. Reports of cannulation of the ascending aorta for antegrade perfusion using the Seldinger method are anecdotal. To the best of our knowledge, the approach described herein for direct cannulation of the ascending aorta with use of the Seldinger technique for antegrade perfusion has not been previously described in the English-language medical literature. This method is helpful when the surgeon is treating a patient who has a calcified ascending aorta, complicated aortic dissection, calcified femoral vessels, or a diseased thoracoabdominal aorta. In such cases, retrograde perfusion has been associated with severe complications as a result of atheromatous embolization from the descending thoracic aorta.
Herein, we describe our approach to cannulation for cardiopulmonary bypass, which entails insertion of an aortic cannula into the ascending aorta by means of the Seldinger technique. A soft-tip guidewire is inserted through an arterial entry catheter that has been used to puncture a hole in the wall of the vessel. Then the aortic cannula is introduced into the vessel, sliding along the guidewire. Guided by transesophageal echocardiography, the tip of the cannula is positioned carefully and is then advanced into the descending aorta. This positioning of the cannula decreases the chance of arterial embolization, thereby improving cerebral protection. If cannulation of the ascending aorta is not feasible, the transverse aortic arch or proximal descending aorta can be used.
PMCID: PMC1592270  PMID: 17041694
Aorta, thoracic; cardiopulmonary bypass/adverse effects/methods; catheterization/methods; cerebral protection; intraoperative complications
11.  Is total debranching a safe procedure for extensive aortic-arch disease? A single experience of 27 cases 
OBJECTIVE
Thoracic, arch, and proximal descending thoracic aorta diseases are still considered an enormous challenge. The hybrid approach developed in recent years (supra-aortic trunks debranching and thoracic endovascular repair aortic repair; TEVAR) may improve the morbidity and mortality of the population at risk. The aim of this study was to analyze retrospectively our experience in the hybrid treatment of aortic-arch aneurysms and dissections.
METHOD
We carried out a retrospective review of 27 patients who required a surgical debranching of the supra-aortic trunks and a TEVAR in the management of the aortic arch and proximal descending thoracic aortic disease. The aortic lesions included 18 degenerative arch-aortic aneurysms, four complicated aortic dissections, two subclavian artery aneurysms, and three penetrating atherosclerotic ulcers. Technical success was achieved in all patients.
RESULTS
The 30-day mortality rate was 11.1% (3/27). Mean follow-up was 16.7 months (range, 1–56), and the survival rate was 77.8%. The endoleaks’ rate was 3.7% (1/27), due to a stent-graft migration.
CONCLUSION
Hybrid approaches may represent an alternative option in the treatment of complex aortic lesions involving the arch and the proximal descending thoracic aorta in high-risk patients and emergency cases. However, the promising early results need to be confirmed by longer follow-up and larger comparative series.
doi:10.1016/j.ejcts.2011.05.058
PMCID: PMC3241089  PMID: 21820909
Aortic arch; Stent graft; Hybrid procedure; Aneurysm; Endovascular treatment
12.  Body Perfusion in Surgery of the Aortic Arch 
Texas Heart Institute Journal  2007;34(1):23-29.
We propose a new cannulation and perfusion technique for aortic arch surgery, in order to achieve continuous antegrade total-body perfusion under moderate hypothermia.
The heart and the aortic arch are exposed through a median sternotomy. Cardiopulmonary bypass is established from the right atrium to the right axillary artery. At 26 °C of body temperature, the supra-aortic vessels are clamped, the ascending aorta and the aortic arch are incised, and a cuffed endotracheal cannula, connected to an arterial line geared by a separate roller pump, is inserted into the descending thoracic aorta. Perfusion is started in the distal body, while the brain is perfused through the right axillary artery. Once the aortic arch has been replaced with a Dacron graft and the supra-aortic vessels have been reimplanted on the graft, the arterial line in the descending thoracic aorta is clamped and removed. The supra-aortic vessel clamps are removed, the proximal part of the Dacron graft is clamped, and systemic cardiopulmonary bypass is resumed via the right axillary artery.
From January 2002 through December 2005, this technique was used in 12 consecutive patients on an emergency basis, due to acute aortic dissection that required total arch replacement. Within the first 30 postoperative days, 1 patient (8.3%) died, and no patient had permanent neurologic deficits.
This simple technique ensures a full-flow antegrade total-body perfusion during all phases of the surgical procedure, thereby eliminating ischemia–reperfusion syndrome and yielding excellent clinical results.
PMCID: PMC1847933  PMID: 17420789
Aortic aneurysm, thoracic/surgery; aneurysm, dissecting/surgery; aortic arch; blood flow velocity; blood vessel prosthesis implantation; brain ischemia/prevention & control; cardiopulmonary bypass/methods; cerebral protection; hypothermia, induced/adverse effects; ischemia/reperfusion; perfusion/methods
13.  Clinical Results of Ascending Aorta and Aortic Arch Replacement under Moderate Hypothermia with Right Brachial and Femoral Artery Perfusion 
Background
Selective antegrade perfusion via axillary artery cannulation along with circulatory arrest under deep hypothermia has became a recent trend for performing surgery on the ascending aorta and aortic arch and when direct aortic cannulation is not feasible. The authors of this study tried using moderate hypothermia with right brachial and femoral artery perfusion to complement the pitfalls of single axillary artery cannulation and deep hypothermia.
Materials and Methods
A retrospective analysis was performed on 36 patients who received ascending aorta or aortic arch replacement between July 2005 and May 2010. The adverse outcomes included operative mortality, permanent neurologic dysfunction and temporary neurologic dysfunction.
Results
Of these 36 patients, 32 (88%) were treated as emergencies. The mean age of the patients was 61.9 years (ranging from 29 to 79 years) and there were 19 males and 17 females. The principal diagnoses for the operation were acute type A aortic dissection (31, 86%) and aneurysmal disease without aortic dissection (5, 14%). The performed operations were ascending aorta replacement (9, 25%), ascending aorta and hemiarch replacement (13, 36%), ascending aorta and total arch replacement (13, 36%) and total arch replacement only (1, 3%). The mean cardiopulmonary bypass time was 209.4±85.1 minutes, and the circulatory arrest with selective antegrade perfusion time was 36.1±24.2 minutes. The lowest core temperature was 24±2.1℃. There were five deaths within 30 post-op days (mortality: 13.8%). Two patients (5.5%) had minor neurologic dysfunction and six patients, including three patients who had preoperative cerebral infarction or unconsciousness, had major neurologic dysfunction (16.6%).
Conclusion
When direct aortic cannulation is not feasible for ascending aorta and aortic arch replacement, the right brachial and femoral artery can be used as arterial perfusion routes with the patient under moderate hypothermia. This technique resulted in acceptable outcomes.
doi:10.5090/kjtcs.2011.44.3.215
PMCID: PMC3249305  PMID: 22263154
Aorta, surgery; Cardiopulmonary bypass; Cerebral protection; Hypothermia
14.  New Technique for Single-Staged Repair of Aortic Coarctation and Coexisting Cardiac Disorder 
Texas Heart Institute Journal  2011;38(4):404-408.
The management of adults with aortic coarctation and a coexisting cardiac disorder is still a surgical challenge. Single-staged procedures have lower postoperative morbidity and mortality rates than do 2-staged procedures. We present our experience with arch-to-descending aorta bypass grafting in combination with intracardiac or ascending aortic aneurysm repair.
From October 2004 through April 2010, 5 patients (4 men, 1 woman; mean age, 45.8 ± 9.4 yr) underwent anatomic bypass grafting of the arch to the descending aorta through a median sternotomy and concomitant repair of an intracardiac disorder or an ascending aortic aneurysm. Operative indications included coarctation of the aorta in all cases, together with severe mitral insufficiency arising from damaged chordae tendineae in 2 patients, ascending aortic aneurysm with aortic regurgitation in 2 patients, and coronary artery disease in 1 patient. Data from early and midterm follow-up were reviewed.
There was no early or late death. Follow-up was complete for all patients, and the mean follow-up period was 34.8 ± 18 months (range, 18 mo–5 yr). All grafts were patent. No late graft-related sequelae or reoperations were observed.
For single-staged repair of aortic coarctation with a coexistent cardiac disorder, we propose arch-to-descending aorta bypass through a median sternotomy as an alternative for selected patients.
PMCID: PMC3147212  PMID: 21841869
Aneurysm, ascending aortic; aorta, ascending/surgery; aorta, thoracic/surgery; aortic coarctation/surgery; aortic valve insufficiency; blood vessel prosthesis; cardiovascular surgical procedures; coronary artery disease; mitral valve insufficiency; spinal cord injuries/prevention & control; treatment outcome
15.  Two-Stage Elephant Trunk Reconstruction for Aneurysm of an Aberrant Right Subclavian Artery in Association with Aneurysmal Distal Aortic Arch and Descending Thoracic Aorta 
Texas Heart Institute Journal  2000;27(4):412-413.
Surgical treatment of the combination of aneurysms of an aberrant right subclavian artery, distal aortic arch, and descending thoracic aorta requires control of structures in both the right and the left hemithorax. We report a 2-stage surgical approach. The 1st stage, performed through a median sternotomy, consists of an elephant trunk reconstruction and an interposition graft to the ligated aberrant right subclavian artery. The 2nd stage, performed through a left thoracotomy, is an interposition graft from the elephant trunk to the distal descending thoracic aorta.
PMCID: PMC101115  PMID: 11198319
Aneurysm, anomalous right subclavian artery; aortic aneurysm; blood vessel prosthesis; subclavian artery/abnormalities; vascular surgical procedures/methods
16.  Ruptured Anterior Spinal Artery Aneurysm Associated with Coarctation of Aorta 
Interventional Neuroradiology  2004;8(3):285-292.
Summary
A 39-year-old man presented with acute headache and neck pain, followed by quadriparesis and quadriparesthesia, accompanied by urinary and bowel incontinence. Lumbar puncture showed subarachnoid haemorrhage. Angiogram via a right axillary approach revealed severe coarctation of the aorta, between the left common carotid artery and left subclavian artery. Multiple collateral circulation including an enlarged anterior spinal arterial axis bridging the stenosed arch provided collateral circulation to the abdominal aorta. A small lobulated aneurysm was seen at the radiculomedullary-anterior spinal artery junction from the right ascending cervical artery. This patient underwent successful surgical clipping of the aneurysm. Pathogenesis of the spinal arterial aneurysm associated with coarctation of the aorta is likely to result from the haemodynamic stress from collateral circulation through the anterior spinal axis rather than segmental arterial disease or angiodysplastic disease. Aneurysms of the spinal artery are rare but can be unusually found in association with SCAVMs, coarctation of aorta, Klippel-Trenaunay syndrome or more rarely with aortic arch interruption.
PMCID: PMC3572481  PMID: 20594486
anterior spinal artery aneurysm, coarctation of aorta and collateral circulation, spinal subarachnoid haemorrhage
17.  Total Arch Replacement with Stented Elephant Trunk in DeBakey Type I Acute Aortic Dissection 
A 67-year-old female patient was treated with conventional total arch replacement and insertion of a stented elephant trunk (SET) graft into the descending thoracic aorta for acute DeBakey type I aortic dissection at one time. She had been treated with right coronary artery stent insertion for acute myocardial infarct 4 days earlier, and at that time, she was diagnosed with acute DeBakey type I aortic dissection from the ascending aorta to the suprarenal artery based on trans-esophageal echocardiography and aorta computed tomography. Through a median sternotomy, we inserted the SET graft through the opened aorta to the descending aorta. We also performed anastomosis between the proximal stented graft and the distal aortic arch, and then performed total arch replacement. For acute DeBakey type I aortic dissection, we report total arch replacement with insertion of a SET graft as a combination of conventional surgery and the interventional technique.
doi:10.5090/kjtcs.2013.46.1.68
PMCID: PMC3573169  PMID: 23423554
Aorta surgery; Aortic dissection
18.  Arch-First Technique Used with Commercial T-Graft 
Texas Heart Institute Journal  2002;29(1):26-29.
Staged repair of extensive thoracic aortic aneurysms puts certain patients at risk of rupture. We report the case of a patient with Marfan syndrome who presented with subacute type-A aortic dissection and a large descending aortic aneurysm. We used the arch-first technique with a commercially available Dacron T-graft. A clamshell incision was used for exposure. A button of arch vessels was anastomosed to the T-graft. Antegrade cerebral perfusion was established through the side branch. The distal end of the graft was anastomosed to the descending aorta and the proximal end to a composite graft. The duration of cerebral ischemia was 30 minutes; antegrade cerebral perfusion lasted 52 minutes. The patient experienced no neurologic dysfunction and was discharged with no major deficit. This technique shortens brain-ischemia time and is a good option if the risk of rupture of the descending component of an extensive thoracic aortic aneurysm is high.
To the best of our knowledge, this is the 1st reported case in which the arch-first technique has been used with a commercially available T-graft to treat subacute type-A aortic dissection in a patient with Marfan syndrome. (Tex Heart Inst J 2002;29:26–9)
PMCID: PMC101264  PMID: 11995844
Aorta, thoracic/surgery; aortic aneurysm/surgery; aneurysm, dissecting/surgery; blood vessel prosthesis implantation/methods; brain ischemia/prevention & control; case report; female; Marfan syndrome/complications; methods; vascular surgical procedures/methods
19.  Observations on the treatment of dissection of the aorta. 
Postgraduate Medical Journal  1976;52(613):671-677.
The results are presented of treatment in twenty-three patients with dissection of the thoracic aorta, in four of whom it was acute (less than 14 days' duration), and in nineteen chronic (more than 14 days' duration). Sixteen patients had Type I and II dissection (involving the ascending aorta) and five Type III (descending aorta at or distal to the origin of the left subclavian artery); in two, dissection complicated coarctation of the aorta in the usual site. Thirteen patients had aortic regurgitation. Three of the patients with acute dissection were treated medically; two, both with Type I dissection, died, and the third, with Type III, survived. The remaining acute patient was treated surgically and also died. Of the patients with chronic dissection, eight were treated medically and eleven surgically. None of the medical group died in hospital; three died between 3 months and 1 year, and five have survived from periods of 12-72 months. Eleven patients with chronic dissection were treated surgically; four died in hospital at or shortly after operation; and the remaining seven lived for periods of 12-84 months. The presentation, indications for surgical treatment and results are discussed. It is concluded that surgical treatment of chronic dissection may carry a higher initial mortality than medical, but that there may be slightly better overall long term results in the former. As this series was not selected randomly, because patients with complications were selected for surgery, and there are only a few patients in each group, the results do not permit firm conclusion regarding the relative merits of medical and surgical treatment. It is suggested that all patients should initially be treated medically but that surgical treatment should be considered if the dissection continues, if aortic regurgitation is severe, if an aneurysm develops or enlarges, if cardiac tamponade develops or there is evidence of progressive involvement of the branches of the aorta. Attention is drawn to the important syndrome of chronic dissecting aneurysm of the ascending aorta with severe aortic regurgitation which requires definitive surgical treatment and aortic valve replacement. The importance of adequate visualization of the origin and extent of the dissection as a preliminary to surgical treatment is stressed.
PMCID: PMC2496339  PMID: 1012993
20.  Endarterectomy and External Prosthetic Grafting of the Ascending and Transverse Aorta under Hypothermic Circulatory Arrest 
Texas Heart Institute Journal  1989;16(2):76-80.
A 78-year-old woman presented with acute pulmonary edema, a blood pressure of 250/160 mmHg, and a 4/6 diastolic murmur of probable aortic origin. Aortography revealed 4+ aortic regurgitation, left ventricular dysfunction, a right coronary artery with good distal run-off but complete proximal occlusion, a fusiform aneurysm of the ascending and transverse aorta (with a transverse dissection in the left anterolateral wall of the upper ascending aorta, but no evidence of intramural lumen), and milder, isolated dilatation of the descending thoracic aorta. Upon operation, on 8 September 1987, I discovered an incompetent aortic valve, advanced atherosclerosis in the ascending and transverse aorta, and a loose intimal flap—but no false lumen—in the upper ascending aorta. After valve replacement and construction of a vein graft to the distal right coronary artery, I decided against replacement of the diseased segment of the ascending and transverse aorta and chose, instead, aortic endarterectomy reinforced by external grafting, as a simpler, quicker, and safer procedure for this patient. Safety was further enhanced by use of profound hypothermia (16°C) to induce total circulatory arrest during the brief period (15 minutes) required for endarterectomy of the arch and approximation of the flap. The patient was discharged 19 days after surgery and continues well and asymptomatic to the present, 21 months after surgery; her milder dilatation of the descending thoracic aorta, which was not treated, is stable and is being monitored. (Texas Heart Institute Journal 1989;16:76-80)
Images
PMCID: PMC324854  PMID: 15227217
Aorta; aorta, thoracic; aortic aneurysm/aneurysm, dissecting; atherosclerosis; blood vessel prosthesis/poly-ethylene terephthalate; total circulatory arrest
21.  The Effect of LVAD Aortic Outflow-Graft Placement on Hemodynamics and Flow 
Texas Heart Institute Journal  2005;32(3):294-298.
Axial-flow ventricular assist devices (VADs) can be implanted either through a left thoracotomy with outflow-graft anastomosis to the descending thoracic aorta or through a midline sternotomy with anastomosis to the ascending aorta. Each method has advantages and disadvantages. Because these VADs produce nonpulsatile flow, their hemodynamic characteristics differ from those of pulsatile devices. These differences may have important clinical consequences, particularly in relation to the outflow-graft configuration. We describe a computer-generated flow model that we created to illustrate the flow dynamics and possible clinical consequences of each method.
The simulations indicate that the location of the anastomosis has important qualitative effects on flow in the ascending aorta and aortic arch. At high VAD outputs (≥75%), native cardiac output cannot supply the carotid and subclavian arteries. With a descending aortic anastomosis, net backward flow occurs in the descending aorta to supply these branches. Consequently, the aortic arch has a region with almost no net flow, where fluid particles stagnate over many cardiac cycles, possibly causing thrombogenesis. With an ascending aortic anastomosis, the arch has no stagnant region, although flow turbulence still occurs.
When the aortic valve remains closed, so that the total output occurs through the VAD, the aortic root has a region of nearly stagnant flow. With an ascending aortic anastomosis, a small degree of recirculatory flow may prevent complete stagnation at the aortic root. With the descending aortic anastomosis, however, no recirculation occurs.
These results help delineate the complex flow dynamics and the advantages and drawbacks of each technique.
PMCID: PMC1336698  PMID: 16392208
Aorta; anastomosis; axial flow; computer simulation; heart-assist devices; heart failure; hemodynamic processes/physiology; nonpulsatile flow; outflow graft; regional blood flow
22.  Total aortic arch replacement: current approach using the trifurcated graft technique 
Annals of Cardiothoracic Surgery  2013;2(3):347-352.
Since the pioneering work of DeBakey, Cooley, and colleagues more than 50 years ago, surgical treatment of aneurysms involving the transverse aortic arch has been associated with substantial morbidity and mortality. Over the past 15 years, techniques for replacing the diseased aortic arch have evolved substantially. Previously, our approach to these operations involved femoral cannulation, profound-to-deep hypothermic circulatory arrest and retrograde cerebral perfusion, and the island technique for reattaching the brachiocephalic vessels. In contrast, we currently use innominate artery cannulation, deep-to-moderate hypothermic circulatory arrest with antegrade cerebral perfusion, bilateral cerebral monitoring with near-infrared spectroscopy, and the trifurcated graft (Y-graft) technique for reattaching the arch branches. Cannulating the innominate artery to provide an inflow site for cardiopulmonary bypass has facilitated the use of antegrade cerebral perfusion as a cerebral protection strategy; the left common carotid artery is additionally perfused to provide bilateral cerebral perfusion. Despite having a systemic circulatory arrest time that often exceeds 60 minutes, these improved perfusion strategies make it possible to consistently avoid cerebral circulatory arrest all together. A moderate temperature target of between 18 and 23 °C is now used; this appears to reduce the risk of hypothermic coagulopathy and improve hemostasis. Y-graft techniques, such as the trifurcated graft approach, have the advantages of eliminating residual aortic arch tissue and being easily tailored to the needs of the individual patient. This report describes total aortic arch replacement in patients with aneurysms that are confined to the ascending aorta and transverse aortic arch.
doi:10.3978/j.issn.2225-319X.2013.05.02
PMCID: PMC3741858  PMID: 23977604
Aortic arch surgery; total arch replacement; trifurcated graft
23.  Endovascular treatment of descending thoracic aneurysms 
Introduction
Current strategies for repair of descending thoracic aortic aneurysms consist of open repair with surgical graft replacement or thoracic endovascular aortic repair. We review and update our overall experience in aortic thoracic diseases and specifically analyzed our outcomes with thoracic endovascular aortic repair in patients with descending thoracic aortic aneurysms.
Methods
From 1993 to present a total of 1144 patients were treated in our Center for pathology involving the thoracic aorta. Since 1998, 322 patients underwent thoracic endovascular aortic repair, and among this group, in 188 cases the descending aorta was involved. In 74% of patients treated for a descending thoracic aortic lesion, a degenerative aneurysm was observed.
Results
In patients with descending thoracic aortic aneurysms receiving thoracic endovascular aortic repair, our technical success rate, i.e. deployment of endograft with complete exclusion of the lesion/minimal endoleak, was 99.5% (one case required emergent open conversion) with a perioperative mortality of 2.6% (five patients). The rate of spinal cord ischemia, manifesting either as paraplegia or paraparesis, was 4.7%. Delayed onset spinal cord ischemia ameliorated with adequate arterial pressure and cerebrospinal fluid drainage.
Conclusions
Our experience of selected patients undergoing thoracic endovascular aortic repair of descending thoracic aorta aneurysms is satisfactory with very low mortality and morbidity. A large use of thoracic endovascular aortic repair is foreseen in the next future.
PMCID: PMC3484596  PMID: 23439690
thoracic aortic aneurysm; endovascular aortic repair; aortic endoprostheses; thoracic aortic aneurysms; type B aortic dissection
24.  Hybrid Endovascular and Off-Pump Open Surgical Treatment for Synchronous Aneurysms of the Aortic Arch, Brachiocephalic Trunk, and Abdominal Aorta 
Texas Heart Institute Journal  2004;31(3):283-287.
A 71-year-old patient was admitted for synchronous aneurysms of the aortic arch, brachiocephalic trunk, and juxtarenal abdominal aorta involving the iliac arteries. The patient first underwent open surgical repair of the juxtarenal abdominal aortic aneurysm by means of aorto-bifemoral bypass. Three months later, he underwent off-pump surgical repair of the aneurysm of the brachiocephalic trunk and bypass grafting from the ascending aorta to the brachiocephalic trunk and the left common carotid artery, followed by successful exclusion of the aneurysm of the aortic arch by deployment of a Zenith TX1 custom-made endograft, inserted through a limb of the aorto-bifemoral graft.
Combined endovascular and open surgical treatment is an appealing new alternative to open surgical repair for complex aortic diseases. Debranching of the aortic arch enables endovascular grafting in this area, thereby avoiding cardiopulmonary bypass and circulatory arrest. Staged and simultaneous procedures should be considered for the treatment of complex aortic diseases even in poor-risk patients; however, due to the investigative characteristics of these procedures, patient selection and postoperative follow-up should be carried out with utmost attention.
PMCID: PMC521773  PMID: 15562851
Aortic aneurysm, abdominal/surgery; aortic aneurysm, thoracic/surgery; aortic diseases/therapy; blood vessel prosthesis implantation/methods; brachiocephalic trunk; carotid arteries; stents; vascular surgical procedures/methods
25.  Image quality and diagnostic accuracy of unenhanced SSFP MR angiography compared with conventional contrast-enhanced MR angiography for the assessment of thoracic aortic diseases 
European Radiology  2009;20(6):1311-1320.
Objectives
The purpose of this study was to determine the image quality and diagnostic accuracy of three-dimensional (3D) unenhanced steady state free precession (SSFP) magnetic resonance angiography (MRA) for the evaluation of thoracic aortic diseases.
Methods
Fifty consecutive patients with known or suspected thoracic aortic disease underwent free-breathing ECG-gated unenhanced SSFP MRA with non-selective radiofrequency excitation and contrast-enhanced (CE) MRA of the thorax at 1.5 T. Two readers independently evaluated the two datasets for image quality in the aortic root, ascending aorta, aortic arch, descending aorta, and origins of supra-aortic arteries, and for abnormal findings. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were determined for both datasets. Sensitivity, specificity, and diagnostic accuracy of unenhanced SSFP MRA for the diagnosis of aortic abnormalities were determined.
Results
Abnormal aortic findings, including aneurysm (n = 47), coarctation (n = 14), dissection (n = 12), aortic graft (n = 6), intramural hematoma (n = 11), mural thrombus in the aortic arch (n = 1), and penetrating aortic ulcer (n = 9), were confidently detected on both datasets. Sensitivity, specificity, and diagnostic accuracy of SSFP MRA for the detection of aortic disease were 100% with CE-MRA serving as a reference standard. Image quality of the aortic root was significantly higher on SSFP MRA (P < 0.001) with no significant difference for other aortic segments (P > 0.05). SNR and CNR values were higher for all segments on SSFP MRA (P < 0.01).
Conclusion
Our results suggest that free-breathing navigator-gated 3D SSFP MRA with non-selective radiofrequency excitation is a promising technique that provides high image quality and diagnostic accuracy for the assessment of thoracic aortic disease without the need for intravenous contrast material.
doi:10.1007/s00330-009-1672-3
PMCID: PMC2861759  PMID: 20013276
SSFP MR angiography; Unenhanced MRA; Thoracic aorta; Contrast; Enhanced MRA; Steady state free precession

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