Current status of thoracic aortic endograft repair

Transesophageal echocardiography guidance for stent-graft repair of a thoracic aneurysm is facilitated by the ability of partial stent deployment

Transesophageal echocardiography (TEE) is routinely used in our Institution for monitoring correct positioning of thoracic aortic stent grafts. We present a case of successful endovascular repair of three discrete thoracic aortic aneurysms with Zenith TX2 endovascular stent grafts in an 82-year-old female patient. Our focus is on the increased value of TEE guidance because of the ability of partial stent deployment and manipulation during insertion.

Preprocedural planning for endovascular stent-graft placement

Endovascular stent grafts have become a viable treatment for aortic thoracic and abdominal aneurysms in both elective and emergent situations. Computed tomographic (CT) angiography is the primary tool for determining eligibility for this procedure. This article discuses the preprocedural evaluation of an endovascular stent candidate. Evaluation begins with identification of the aneurysm pathology and its relationship to treatment efficacy. The radiologist must evaluate the aneurysm geometry for compatibility with stent hardware. Aneurysm features that suggest a contraindication must be recognized. Procedures that involve a combination of endovascular stenting and surgical revascularization are discussed so that the reader understands the limits of stent eligibility. Vascular access for stent placement must also be evaluated for the ability to accommodate stent delivery. The radiologist also must be familiar with CT imaging protocols and alternative methods of imaging that can evaluate stent feasibility. The utility of three-dimensional processing is discussed.

Current status of thoracic endografting and its adjunctive pharmacology

BACKGROUND

Thoracic endovascular aortic repair is a promising treatment modality. The advantages in the short term include shorter hospital stay, avoidance of lengthy invasive procedures, and decreased anesthesia time. It has made possible the treatment of elderly patients with coexisting comorbidities who otherwise would be difficult candidates for open surgery.

OBJECTIVE

Although the technical aspects of thoracic endovascular procedures have been described in the literature, the adjunct pharmacology has not been discussed. The aim of this study is therefore to review the clinical pharmacology necessary for procedural details in repair of patients with aortic aneurysms and aortic dissection.

METHODS

A literature search was performed using PUBMED by combining relevant Medical Subject Heading key words. The query was subsequently limited to English language, and involving "human". The articles were assessed for their validity, importance, and applicability. The publications were analyzed and clinically important data were collected and incorporated.

RESULTS/CONCLUSION

Thoracic endovascular aortic repair is a complex procedure on a morbid cohort of patients with aortic pathologies. The pharmacotherapy is a crucial component of the procedure: It is aimed at facilitating the endovascular procedure and improving outcomes.

[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.

High-dose adenosine-induced asystole assisting accurate deployment of thoracic stent grafts in conscious patients

Adenosine has been used to induce asystole and assist deployment of endoluminal grafts. However, application of high-dose adenosine in conscious patients has not been described. In this prospective study, we administered high-dose adenosine in patients undergoing thoracic stent grafting. Asystole duration in relationship to the dosage of adenosine, safety, and side effect profiles was investigated. All patients who underwent thoracic stent grafting between 1998 and 2006 were the potential study subjects. They received monitored anesthesia care and local anesthesia unless contraindicated. Adenosine was given via rapid intravenous bolus immediately prior to the deployment of the stent graft. Every patient received a dose of 36 mg. If needed, a second dose of 18 mg was given. Duration of asystole was recorded after each administration. Patients' vital signs before and after administration were also documented. Side effect profiles were collected intra- and postoperatively. A total of 46 patients received adenosine (34 men, 12 women). Mean age was 60.4 +/- 17.5 years. American Society of Anesthesiologists scores were II in one patient (2%), III in six patients (13%), and IV in 39 patients (85%). Eighteen patients received a single dose of 36 mg adenosine, 15 were given a second dose of 18 mg, and 13 received nonstandard dosages. Asystole durations were 18.8 +/- 8.8 and 11.6 +/- 5.5 sec for 36 and 18 mg, respectively. Technical success was achieved in all cases. The differences achieved statistical significance (p = 0.0009). There were no severe cardiac or pulmonary complications. High-dose adenosine can be given safely in conscious patients. The dose-response was predictable and reproducible. The dosages used in our study induce sufficient duration of asystole, which ensured accurate deployment of thoracic stent grafts.

Strategies for prevention and operative treatment of aortic lesions related to spinal interventions

STUDY DESIGN

A retrospective analysis of a case series was performed.

OBJECTIVE

To give recommendations for the prevention and operative treatment of thoracic and thoracoabdominal aortic lesions in association with spinal interventions.

SUMMARY OF BACKGROUND DATA

Aortic lesions after spinal interventions for traumatic vertebral fractures, segmental spondylodiscitis, or vertebral metastasis are fortunately rare, but associated with a high perioperative mortality rate and absolute numbers are unknown. Therefore, preventive strategies to avoid perioperative major vessel injuries and recommendations for the operative treatment of aortic lesions related to spinal surgery are required.

METHODS

The clinical course of 10 patients with an acute aortic hemorrhage or an increased intraoperative risk for aortic injuries in association with primary or secondary spinal interventions is reported. All patients were evaluated before surgery by orthopedic trauma surgeons, vascular surgeons, and diagnostic radiologists.

RESULTS

Five patients had preventive vascular interventions to avoid major aortic injuries during spinal reinterventions, and 5 patients were treated as an emergency for acute intraoperative hemorrhage related to spinal interventions. The operative treatment was performed by direct aortic sutures (n = 3), segmental alloplastic reconstructions (n = 2), or endovascular stent graft implantations (n = 3). Prophylactic banding of the thoracic aorta during thoracotomy or a femoral access for possible aortic balloon blockade was performed in patients with an estimated lower risk for an aortic laceration caused by malpositioned pedicle screws. No perioperative mortality was observed in patients treated by this interdisciplinary concept, but 1 patient treated under emergency condition for spondylodiscitis with an initially unrecognized aortic lesion died.

CONCLUSION

In patients with complex spinal trauma, spondylodiscitis or difficult vertebral reinterventions, and an increased risk of major vessel injury, a preoperative interdisciplinary evaluation is recommended, even under emergency conditions. Endovascular stent graft technique is an additional option for prevention and treatment of suspected or acute aortic injuries of thoracic and infrarenal aortic lesions, whereas injuries to the visceral aortic segment still require advanced vascular reconstructions.

Surgical and endovascular treatment of symptomatic aberrant right subclavian artery (arteria lusoria)

Right aberrant subclavian artery, also called arteria lusoria, is one of the most common intrathoracic arterial anomalies. Although mostly asymptomatic, the retroesophageal and retrotracheal course of the lusorian artery might result in unspecific thoracic pain, dysphagia, dyspnea, arterioesophageal or arteriotracheal fistulae with hematemesis or hemoptysis, and aneurysmal formation with relevant risk of rupture. The purpose was to present our experience with six patients with a symptomatic aberrant right subclavian artery, two patients with dysphagia or dyspnea caused by a nonaneurysmal lusorian artery, and four patients with arteria lusoria aneurysms. The operative procedures performed are described and discussed in view of the data reported in the literature. According to the classification of the lusorian artery pathology, a combined intervention with right subclavian artery transposition, distal or proximal lusorian artery ligation or proximal endovascular occlusion for nonaneurysmal disease, or endovascular thoracic aortic stent graft implantation for lusorian artery aneurysms seems to be an additional and minimally invasive approach with promising midterm results.

Imaging of implants on chest radiographs: a radiological perspective

Endovascular and percutaneous techniques have emerged as alternatives to surgical management in the treatment for a wide range of congenital and acquired cardiac, non-vascular and vascular conditions. Consequently, there has been an increasing use of implants such as closure devices, vascular stents (coronary, aortic, pulmonary and superior vena cava) and non-vascular stents like oesophageal and tracheo-bronchial stents. A large number of percutaneously sited implants are used for treating congenital cardiac anomalies such as atrial septal defects (ASD), ventricular septal defects (VSD), and patent ductus arteriosus (PDA). These implants take many shapes and forms. The aim of this review is to demonstrate the radiographic appearances of the various types of cardiovascular, bronchial and oesophageal implants that are visible on plain films. A brief outline of the aims and indications of various implant procedures, the general appearance of the commonest types of implants, and the radiological procedures are discussed. All radiologists are likely to come across implanted devices in plain film reporting. Imaging can be useful in identifying the device, assessing the position, integrity, and for the identification of complications related directly to the implant.

Endovascular Treatment of Descending Thoracic Aortic Aneurysms with the EndoFit Stent-Graft

OBJECTIVE

To evaluate the mid-term feasibility, efficacy, and durability of descending thoracic aortic aneurysm (DTAA) exclusion using the EndoFit device (LeMaitre Vascular).

METHODS

Twenty-three (23) men (mean age 66 years) with a DTAA were admitted to our department for endovascular repair (21 were ASA III+ and 2 refused open repair) from January 2003 to July 2005.

RESULTS

Complete aneurysm exclusion was feasible in all subjects (100% technical success). The median follow-up was 18 months (range 8-40 months). A single stent-graft was used in 6 cases. The deployment of a second stent-graft was required in the remaining 17 patients. All endografts were attached proximally, beyond the left subclavian artery, leaving the aortic arch branches intact. No procedure-related deaths have occurred. A distal type I endoleak was detected in 2 cases on the 1 month follow-up CT scan, and was repaired with reintervention and deployment of an extension graft. A nonfatal acute myocardial infarction occurred in 1 patient in the sixth postoperative month. Graft migration, graft infection, paraplegia, cerebral or distal embolization, renal impairment or any other major complications were not observed.

CONCLUSION

The treatment of DTAAs using the EndoFit stent-graft is technically feasible. Mid-term results in this series are promising.

Fístula aorto-esofágica secundária a fratura de endoprótese torácica: relato de caso

O tratamento endovascular dos aneurismas aórticos torácicos tem se desenvolvido consideravelmente nos últimos anos. No entanto, complicações tardias desta nova modalidade terapêutica apenas agora estão sendo observadas e analisadas. Fístulas aorto-esofágicas são complicações raras do tratamento endovascular dos aneurismas aórticos, sendo encontrados poucos relatos na literatura. O presente caso reporta um paciente com aneurisma aórtico torácico tratado há 4 anos e complicado com fratura da endoprótese. Após nova intervenção endovascular, foi observada extrusão da antiga endoprótese através do esôfago com formação de fístula. Apesar do tratamento realizado, o paciente evoluiu a óbito 9 dias após por hemorragia digestiva maciça. Aspectos técnicos e revisão de literatura são discutidos.

Endovascular treatment of a symptomatic suture aneurysm caused by an aortic isthmus restenosis

After operative treatment of aortic isthmus stenoses, late complications, such as aneurysm formation or aortic restenosis, might occur, with relevant morbidity and mortality rates during open surgical reintervention. We report on the endovascular repair of a symptomatic suture aneurysm caused by an aortic isthmus restenosis by thoracic aortic stent graft implantation and additional intraoperative balloon dilatation. Based on our experience, endovascular repair of thoracic aortic aneuryms caused by native aortic isthmus stenosis or postcoarctation restenosis is a valuable treatment option, especially in symptomatic patients with an imminent risk of rupture or a difficult immediate transthoracic surgical approach. Long-term follow-up is required to assess the durability of the stent graft treatment.

Endovascular Repair of Ruptured Saccular Aneurysms of the Descending Thoracic Aorta

Open repair of ruptured aneurysms of the descending thoracic aorta (DTA) is associated with early mortality rates of 20%-60% and severe morbidity rates exceeding 40%. The present report describes three octogenarian patients and one sexagenarian patient at poor surgical risk admitted with acutely ruptured saccular DTA aneurysms (two of four were anastomotic) unrelated to trauma or infection who underwent successful endovascular therapy, which involved the use of aortic endovascular cuffs in three cases. Mean intensive care unit and total hospital stay durations were 1.75 days (range, 1-4 d) and 6 days (range, 3-13 d), respectively. At 30 days, all patients were alive and free of repeat intervention, with aneurysm exclusion achieved in all cases but one, which featured a marginal type II endoleak. These data support endovascular therapy for ruptured saccular DTA aneurysms enabling short-term outcomes that otherwise would have been unrealistic.

Subtle abdominal aortic injury after blunt chest trauma

This case report describes a patient with an intimal flap of the abdominal aorta after a motor vehicle crash. The patient was an unrestrained driver with minimal anterior chest wall pain. This is a rare injury and one that is difficult to find due to its rarity. The lower cut of the chest CT scan found the injury. Its treatment with endovascular stenting is discussed.

Endovascular Repair of Thoracic Aortic Lesions Using Infrarenal Devices: Lessons Learned and Continued Applications

The application of endovascular devices for the treatment of a variety of thoracic aortic lesions has flourished worldwide over the past decade. Until physicians become facile with recently approved thoracic devices and these devices are immediately available even in emergency situations, the use of endovascular abdominal components offers physicians more options in managing thoracic lesions. We evaluated the safety, efficacy, and outcomes of commercially available, infrarenal endovascular graft components for managing lesions of the thoracic aorta. Nineteen patients were treated outside of a clinical trial using commercially available endovascular devices. The indications for treatment included acute traumatic lesions (n = 7), symptomatic ulcers (n = 4), focal aneurysms or pseudoaneurysms (n = 7), and symptomatic type B dissection (n = 1). The endovascular components included Excluder Aortic Cuffs (n = 9), AneuRx Aortic Cuffs (n = 5), Zenith Aortic Cuffs (n = 2), Zenith Aortic Tube Grafts (n = 2), and graft combinations (n = 1). Seventeen patients (89%) underwent successful endovascular treatment of their thoracic lesion. One patient required elective surgical conversion, and a second patient had a dissection that was not completely sealed endovascularly. There was no periprocedural mortality, and the major complication rate was 16% (3/19). Two patients had asymptomatic troponin leaks, and one patient developed an iliac rupture at the device introduction site, hypotension, and paraplegia. At a mean follow-up of 12.3 months, all successfully treated patients continue to have complete exclusion of the treated lesion. Infrarenal endovascular graft components can be very useful in the treatment of selected patients with amenable thoracic lesions until thoracic devices are available in all necessary sizes, readily accessible to treating physicians, and cost-effective.

The results of catheter-based therapy compared with surgical repair of adult aortic coarctation

A review was performed to compare the results of endovascular therapy (stenting and angioplasty) with surgical techniques to repair adult aortic coarctation. The immediate improvement in hypertension and the morbidity were similar across all groups. Surgical therapy was associated with a very low risk of restenosis and recurrence, whereas endovascular therapy had a much higher incidence of restenosis and the need for repeat interventions. The long-term outcome of endovascular approaches will need to be assessed in the future.

Endograft exclusion of acute and chronic descending thoracic aortic dissections

OBJECTIVES

To analyze the results of endograft exclusion of acute and chronic descending thoracic aortic dissections (Stanford type B) with the AneuRx (n = 5) and Talent (n = 37) thoracic devices and to compare postoperative outcomes of endograft placement acutely (<2 weeks) and for chronic interventions.

METHODS

Patients treated for acute or chronic thoracic aortic dissections (Stanford type B) with endografts were included in this study. All patients (n = 42) were enrolled in investigational device exemption protocols from August 1999 to March 2005. Three-dimensional computed tomography reconstructions were analyzed for quantitative volume regression of the false lumen and changes in the true lumen over time (complete >95%, partial >30%).

RESULTS

Forty-two patients, all of whom had American Society of Anesthesiologists (ASA) risk stratification > or =III and 71% with ASA > or = IV, were treated for Stanford type B dissections (acute = 25, chronic = 17), with 42 primary and 18 secondary procedures. All proximal entry sites were identified intraoperatively by intravascular ultrasound (IVUS). The procedural stroke rate was 6.7% (4/60), with three posterior circulation strokes. Procedural mortality was 6.7% (4/60). The left subclavian artery was occluded in 11 patients (26%) with no complaints of arm ischemia, but there was an association with posterior circulation strokes (2/11) (18%). No postoperative paraplegia was observed after primary or secondary intervention. Complete thrombosis of the false lumen at the level of endograft coverage occurred in 25 (61%) of 41 patients < or =1 month and 15 (88%) of 17 patients at 12 months. Volume regression of the false lumen was 66.4% (acute) and 91.9% (chronic) at 6 months. Lack of true lumen volume (contrast) increase and increasing false lumen volume (contrast) suggests continued false lumen pressurization and the need for secondary reintervention. Thirteen patients (31%) required 18 secondary interventions for proximal endoleaks in 6, junctional leaks in 3, continued perfusion of the false lumen from distal re-entry sites in 3, and surgical conversion in 4 for retrograde dissection.

CONCLUSIONS

Preliminary experience with endografts to treat acute and chronic dissections is associated with a reduced risk of paraplegia and lower mortality compared with open surgical treatment, the results of medical treatment alone, or a combination.

Aortic neck morphology after endovascular repair of descending thoracic aortic aneurysms

BACKGROUND

Endovascular repair has emerged as a less-invasive treatment for descending thoracic aortic (DTA) aneurysms. However, the durability of this procedure relies on the stability of proximal and distal fixation sites. This study analyzes 3 years of computed tomography (CT) data on aortic neck morphology after endovascular DTA aneurysm repair.

METHODS

Between 1999 and 2001, 139 patients underwent successful endovascular DTA repair as part of a prospective, multicenter clinical trial investigating the Gore TAG thoracic endoprosthesis. Contrast-enhanced, high-resolution CT scans were obtained at 1 (baseline), 12, 24, and 36 months and submitted to an independent core laboratory for image analysis. The aorta was carefully measured by using computerized planimetry and a standardized protocol. Neck diameter was measured at 10-mm intervals for 2 cm above and below the aneurysm and correlated with graft migration and endoleak.

RESULTS

The mean proximal neck diameter increased from a baseline of 30.2 +/- 4.6 mm to 32.0 +/- 4.3 mm at 36 months (P <.05), and the annual diameter increase was 0.8, 0.4, and 0.6 mm at 12, 24, and 36 months. The mean distal neck diameter increased from 29.4 +/- 3.8 mm to 32.1 +/- 5.0 mm at 36 months (P <.05), and the annual diameter increase was 1.1, 0.4, and 1.2 mm at 12, 24, and 36 months. At 36 months, freedom from neck dilation of > or =5 mm was 87%, and freedom from migration of > or =10 mm was 83%. An endoleak was present in 11 (9%) of 122 patients at baseline, 7 (7%) of 96 at 12 months, 6 (9%) of 68 at 24 months, and 1 (3%) of 33 at 36 months. Neck dilation was not associated with graft migration or endoleak.

CONCLUSIONS

Three years after endovascular repair of DTA aneurysms, there is progressive enlargement of the proximal and distal aortic necks. Although uncommon for patients to develop significant neck dilation, when it does occur, it is not associated with graft migration or endoleak. Continued surveillance of aortic neck morphology after descending thoracic aneurysm endografting is recommended.

Endovascular Stent-Graft Treatment of Thoracic Aortic Disease

Aneurysmal diseases of the thoracic aorta are life-threatening conditions. In such cases, stent-graft treatment has been proposed as an alternative to surgery. The morbidity and mortality associated with endovascular repair are significantly lower than those associated with open surgery. In the largest surgical series, the mortality ranged from 5% to 20%. In studies of endovascular repair, the 30-day mortality was 0%-20% and the periprocedural stroke rate was 0%-7%. Often, open surgery is prohibited in patients with these high-risk lesions; thus, in many cases endovascular treatment is the only alternative. Thoracic aortic diseases that can be treated with endovascular stent-graft placement include aneurysms, dissection, traumatic rupture, traumatic pseudoaneurysms, intramural hematoma, penetrating atherosclerotic ulcers, and aortic rupture. Thorough preprocedure imaging is essential for selecting patients, choosing the stent-graft devices, and planning the intervention. Prerequisites for endovascular stent-graft placement are an adequate neck for graft attachment and adequate vascular access. When the ascending aorta or aortic arch is involved, surgical and endovascular procedures can be combined and performed simultaneously, allowing treatment of a wider range of cases. An experienced interdisciplinary team is needed to manage such cases.