Endovascular repair of the descending thoracic aorta: evidence for the change in clinical practice

Endovascular approaches and perioperative considerations in acute aortic dissection

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

Hybrid Approach for the Treatment of Thoracic Aortic Arch Aneurysm in a Patient With Chronic Obstructive Lung Disease and Retrosternal Adhesion

A 73-year-old woman with a history of chronic hypertension and severe chronic obstructive pulmonary disease, presented to a district general hospital with thoracic pain in a profound state of shock. She was diagnosed with cardiac tamponade, severe mitral regurgitation, and Stanford type A (Debakey type I) intramural hematoma. Her ascending aorta was of a significant size and therefore emergent repair was done to replace the ascending aorta and mitral valve. After 6 months, an increased aneurysmal size of 6.0 cm was observed in a follow up contrast-enhanced computed tomography angiography. The patient was successfully treated by a staged hybrid procedure involving initial supra-aortic reconstruction.

Endovascular repair of nonruptured thoracic aortic aneurysms: systematic review

Thoracic aortic aneurysms represent a major health problem. Untreated thoracic aortic aneurysms may rupture, which has a dismal outcome. The standard treatment for thoracic aneurysms is open surgical repair, but it is associated with high mortality and morbidity. Endovascular repair provides a less invasive and safer alternative. A systematic review was performed of all published literature on the above subject. Our primary objective was to measure 30-day mortality for nonruptured thoracic aortic aneurysms. Studies describing other pathologies, such as aortic dissection, mycotic aneurysms, penetrating ulcers, traumatic transactions, and pseudoaneurysms, and studies from which independent data for thoracic aortic aneurysm could not be separately extracted were excluded. Case series describing less than 10 patients and all case series describing ruptures or concealed ruptures were excluded as well. Twenty-six case series and one comparative study were identified. This formed a cohort of 1,038 patients. Technical success was possible in more than 97% of patients. The 30-day mortality was calculated to be 5.1% even though the group under study was mostly those who were refused surgery by a surgeon or had a higher surgical risk. The incidence of paraplegia and stroke was 3.1% and 4.7%, respectively. Early endoleak was seen in 16.7% of patients, whereas 11.7% of patients developed late endoleak, but most did not require any additional procedure. The rate of reintervention was 14.9%. The 12-month mortality rate was 14.2%. Endovascular repair shows encouraging short-term results. It is associated with significantly less mortality and morbidity, but long-term results need to be further investigated.

Endovascular approach to acute aortic trauma

Traumatic thoracic aortic injury remains a major cause of death following motor vehicle accidents. Endovascular approaches have begun to supersede open repair, offering the hope of reduced morbidity and mortality. The available endovascular technology is associated with specific anatomic considerations and complications. This paper will review the current status of endovascular management of traumatic thoracic aortic injuries.

Endovascular Management of Traumatic Thoracic Aortic Transection

The conventional treatment of traumatic thoracic aortic transection is open surgical repair but it is associated with high rates of morbidity and mortality, particularly in patients with multiple injuries. We reviewed our experience of endovascular repair of traumatic thoracic aortic transection. Between March 2002 and December 2007, 7 patients (male 6, female 1; mean age 40 years) with multiple injuries secondary to blunt trauma underwent endovascular stenting. One patient required adjunctive surgery to facilitate endovascular stenting. Mean intensive care unit stay was 8.6 days (range, 3–16 days). Arterial access in all patients was obtained by femoral cut-down. The mean operating time was 122 min. Technical success was achieved in all cases. There was no mortality. One patient suffered a right parietal stroke, but none developed procedure-related paralysis. The mean follow-up period was 18.6 months (range, 6–48 months). There was no evidence of endoleak, stent migration, or late pseudoaneurysm formation on follow-up computed tomography. Endovascular stents can be used to treat traumatic thoracic aortic transection, with low rates of morbidity and mortality. Although early and midterm results are promising, the long-term durability of endovascular stenting for traumatic thoracic aortic transection remains unknown.

Current management of traumatic rupture of the descending thoracic aorta

Traumatic rupture of the descending thoracic aorta remains a leading cause of death following major blunt trauma. Management has evolved from uniformly performing emergent open repair with clamp and sew technique to include open repair with mechanical circulatory support, medical management and most recently, endovascular repair. This latter approach appears, in the short term, to be associated with perhaps better outcome, but long term data is still accruing. While an attractive option, there are specific anatomic and physiologic factors to be considered in each individual case.

[Traumatic thoracic aorta rupture: preclinical assessment, diagnosis and treatment options]

Traumatic aortic rupture is a life-threatening injury which is frequently associated with blunt thoracic trauma or found coincidentally in heavily traumatized patients. Depending on the degree of disruption of the damaged aortic wall, vascular injury is associated with a high primary mortality rate and a significant risk of secondary aortic rupture. Early clinical signs which may indicate a ruptured thoracic aorta are left sided thoracic pain, reduced ventilation, tachycardia and dyspnoe as well as hypotension in the lower extremities. The primary aim for emergency treatment is to maintain vital organ function and to hemodynamically stabilize the patient. Surgical treatment was previously performed by either direct aortic suture or segmental alloplastic graft interposition using the clamp and sew technique with or without extra-anatomic shunts or extracorporeal circulation. However, endovascular stent graft implantation has now become another treatment option for traumatic aortic rupture. According to the reported data and our own experience there is increasing evidence that endovascular aortic repair might become the treatment of choice for patients with traumatic aortic rupture, with the option of an early, less invasive intervention thus avoiding thoracotomy. Regular follow-up is necessary to detect possible stent graft migration or leakage which could require additional endovascular or open surgical re-interventions.

Hybrid Endovascular Repair of an Aneurysmal Chronic Type B Dissection in a Patient with Marfan Syndrome With an Aberrant Right Subclavian Artery

Abnormal aortic arch anatomy is relatively uncommon but most frequently involves an aberrant right subclavian artery. Rarely, it is associated with aneurysmal dilatation of a chronic type B dissection. Under such circumstances, the abnormal anatomy may complicate therapeutics options. Furthermore, controversy exists regarding the use of surgical or endovascular techniques in patients with aortic aneurysms and underlying arteriopathies. The current literature is limited with regard to reporting of the latter. We present a hybrid approach to repair such an aneurysm in a patient with Marfan syndrome. In a 2-stage procedure, involving initial supra-aortic bypass to all aortic arch branches, followed by endovascular stent graft deployment, the aneurysm was successfully excluded. There were no immediate complications and no evidence of endoleak at 3 months postoperatively, with thrombosis of the false lumen in the chest. By adapting hybrid open and endovascular techniques, complex thoracic aneurysms may be successfully treated in the short term in the presence of an underlying arteriopathy.

Endovascular treatment of an intramural aortic haematoma following cardiopulmonary resuscitation for myocardial ischemia with ventricular fibrillation

Cardiopulmonary resuscitation by manual cardiac compression can restore cardiocirculatory function but can also injure patients. Commonly reported are skeletal fractures of the rips and sternum, while injuries to the large thoracic vessels will frequently be lethal. We report the case of a 57-year-old male patient with sudden cardiac arrest because of myocardial ischemia with ventricular fibrillation, successful cardiopulmonary resuscitation, associated with an intramural haematoma (IMH) of the descending thoracic aorta treated by endovascular aortic repair. Secondary coronary angiography revealed a severe three vessel coronary disease with an occlusion of the proximal anterior descending branch and a subtotal stenosis of the first segmental branch of the left coronary artery (LCA) and a high-grade stenosis of the posterolateral segmental branch of the circumflex left coronary artery. Stenotic segments of coronary arteries were treated successfully by implantation of three drug-eluting stents followed by dual antiplatelet therapy. The patients recovered almost completely and was discharged for further rehabilitation after 3 weeks.

Early Results of Endovascular Treatment of the Thoracic Aorta Using the Valiant Endograft

Endovascular repair of the thoracic aorta has been adopted as the first-line therapy for much pathology. Initial results from the early-generation endografts have highlighted the potential of this technique. Newer-generation endografts have now been introduced into clinical practice and careful assessment of their performance should be mandatory. This study describes the initial experience with the Valiant endograft and makes comparisons with similar series documenting previous-generation endografts. Data were retrospectively collected on 180 patients treated with the Valiant endograft at seven European centers between March 2005 and October 2006. The patient cohort consisted of 66 patients with thoracic aneurysms, 22 with thoracoabdominal aneurysms, 19 with an acute aortic syndrome, 52 with aneurysmal degeneration of a chronic dissection, and 21 patients with traumatic aortic transection. The overall 30-day mortality for the series was 7.2%, with a stroke rate of 3.8% and a paraplegia rate of 3.3%. Subgroup analysis demonstrated that mortality differed significantly between different indications; thoracic aneurysms (6.1%), thoracoabdominal aneurysms (27.3%), acute aortic syndrome (10.5%), chronic dissections (1.9%), and acute transections (0%). Adjunctive surgical procedures were required in 63 patients, and 51% of patients had grafts deployed proximal to the left subclavian artery. Comparison with a series of earlier-generation grafts demonstrated a significant increase in complexity of procedure as assessed by graft implantation site, number of grafts and patient comorbidity. The data demonstrate acceptable results for a new-generation endograft in series of patients with diverse thoracic aortic pathology. Comparison of clinical outcomes between different endografts poses considerable challenges due to differing case complexity.

The Endovascular Approach to Acute Aortic Trauma

Endovascular repair of the traumatically injured thoracic aorta has emerged as an exceptionally promising modality that is typically quicker than open repair, with a reduced risk of paralysis. There are a specific set of anatomic criteria that need to be applied, which can be rapidly assessed by the CT angiogram. The enthusiasm for endovascular repair must be tempered by recognition of the complications and lack of long-term follow-up, particularly in younger patients. Surgeons who are skilled in open aortic repair must not only be involved, but should take on a leadership role during the planning, deployment, and follow-up of these patients. Familiarity with all of the available devices expands treatment options. As more specific devices become available, and more follow-up is accrued, the role of endovascular stents will continue to grow.

Complex thoracoabdominal aortic aneurysms: endovascular exclusion with visceral revascularization

OBJECTIVE

We review our ongoing experience with a transabdominal stent repair of complex thoracoabdominal aneurysms (Crawford type I, II, and III) with surgical revascularization of visceral and renal arteries.

METHODS

A retrospective review was conducted of prospectively collected data from 29 consecutive patients who underwent an attempted visceral hybrid procedure between January 2002 and April 2005. Twenty-two patients were elective, four were urgent (symptomatic), and three were emergent (true rupture). The median patient age was 74 years (range, 37 to 81 years). The aneurysms were Crawford type I in 3, type II in 18, type III in 7, and type IV in 1. Previous aortic surgery had been performed in 13 (45%) of 29 and included aortic valve and root replacement in 3, TAA repair in 1, type I repair in 1), type IV repair in 3, type B dissection in 2, infrarenal aneurysm in 5, and right common iliac aneurysm in 1. Severe preoperative comorbidity was present in 23 (80%) of 29: chronic renal impairment in 5, severe chronic obstructive pulmonary disease in 6, myocardial disease in 11 at New York Heart Association grade II (6) and grade III (5), and Marfan's syndrome in 6. Twenty-six patients (90%) had a completed procedure. In two patients, myocardial instability prevented completion of the procedure despite extensive preoperative cardiac assessment, and in one, poor flow in the true lumen of a chronic type B dissection prevented anastomosis of the revascularization grafts. Exclusion of the full thoracoabdominal aorta was achieved in all 26 completed procedures and extended to include the iliac arteries in four, with revascularization of coeliac in 26, superior mesenteric artery in 26, left renal artery in 21, and right renal artery in 21).

RESULTS

There was no paraplegia < or =30 days or during inpatient admission, and elective and urgent mortality was 13% (3/23). All of the patients with ruptured thoracoabdominal aneurysms died < or =30 days. Major complications included prolonged respiratory support (>5 days) in 9, inotropic support in 4, renal impairment requiring temporary support in 2 and not requiring support in 2, prolonged ileus in 2, resolved left hemispheric stroke in 1, and resection of an ischemic left colon in 1. Median blood loss was 3.9 liters (range, 1.2 to 13 liters). The median ischemia time was 15 minutes (range, 13 to 27 minutes) for the superior mesenteric and coeliac arteries and 15 minutes for the renal arteries (range, 13 to 21 minutes). The median hospital stay was 27 days (range, 16 to 84 days). Follow-up was a median of 8 months (range, 2 to 31 months), with 92 of 94 grafts patent. Six patients were found to have a type I endoleak. In four, this was a proximal leak, and stent extension in three reduced, but did not cure, the endoleak. One patient with a distal type I endoleak was successfully treated by embolization. Four type II endoleaks resolved without intervention, and one was treated by occlusion coiling of the origin of the left subclavian artery. A single late type III endoleak was found.

CONCLUSION

Early results of visceral hybrid stent-grafts for types I, II, and III thoracoabdominal aneurysms are encouraging, with no paraplegia in this particularly high-risk group of patients. These results have encouraged us to perform the new procedure, in preference to open surgery, in Crawford type I, II, and III thoracoabdominal aortic aneurysms.