Endovascular Repair of Nontraumatic Ruptured Thoracic Aortic Pathologies

Early Characteristics and Progression of Blunt Traumatic Aortic Injuries at a Single Level I Trauma Center

OBJECTIVES

The most widely accepted grading system for blunt traumatic aortic injury (BTAI) by the Society of Vascular Surgery (SVS) recommends endovascular repair for grade 2 and greater. Non-operative management in grade 2 injuries has been shown to be reasonable in certain circumstances. The natural history of low-grade injuries (1, 2) when managed non-operatively is not well defined.

METHODS

Utilizing our trauma registry, patients from 2013 to 2016 with blunt traumatic injury who underwent initial computed tomography were identified. Aortic pathology was graded and grouped by SVS classification. Clinical courses were reviewed for timing of interventions, repeat imaging, concurrent injuries, and outcomes. Analysis of variance and Chi-square tests of significance were utilized to compare between groups.

RESULTS

Out of 10,178 patients, we identified 32 with BTAI (grade: 1 (n = 13), 2 (n = 5), 3 (n = 3), 4 (n = 11)). High-grade injuries (3, 4) resulted only from motor vehicle, motorcycle, and pedestrian mechanisms. Initially, 9 patients (28%) required intervention, 5 (16%) were treated non-operatively, and 18 (56%) underwent repeat imaging. On repeat imaging, injuries that did not resolve remained stable and no injuries were found to progress. Of these patients, 9 (50%) required delayed intervention and 9 (50%) successfully underwent non-operative management. Patients with low-grade injuries were more likely to have successful non-operative management than those with high-grade injuries (72% vs 7%; p < 0.01).

CONCLUSIONS

While low-grade injuries generally have good outcomes, some ultimately do require delayed intervention, and short-term imaging is not reliable in identifying these cases.

Rapid Pacing for Better Placing: Comparison of Techniques for Precise Deployment of Endografts in the Thoracic Aorta

Purpose:

To investigate the safety, efficacy, impact on positioning, and neurocognitive outcomes of 3 conceptually different methods of avoiding the “windsock” effect during thoracic stent-graft placement.

Methods:

A retrospective review was conducted of 70 patients (48 men; mean age 63 years) who underwent elective or emergency stent-graft placement in the thoracic aorta for various pathologies. Twenty-seven patients (18 men; mean age 64±12 years) had stent-graft positioning during rapid right ventricular (RV) pacing at 180 to 200 beats per minute. Another 27 patients (18 men; mean age 62±12 years) had stent-graft placement under controlled hypotension (≤45 mmHg) achieved with sodium nitroprusside (3 µg/kg/min). Sixteen patients (12 men; mean age 63±14 years) had intermittent cardiac arrest induced by a 0.5-mg/kg adenosine bolus prior to launching the stent-graft. Termination of the endovascular procedure, weaning, and recovery were conducted according to the same routines in all patients. Hemodynamics, landing precision (deviation from planned placement site), cerebral blood flow, and neurocognitive function were compared.

Results:

Rapid RV pacing (median 12 seconds) was conducted without technical difficulty or delayed recovery in any of the 27 patients. Once rapid pacing ceased, blood pressure recovered within 8 seconds from 22±8 mmHg to normal prepacing levels. The level of hypotension was most pronounced in the rapid RV pacing group (20±4 mmHg, p<0.001), and the duration of hypotension was also the shortest (20±10 seconds, p<0.001) at a pacing rate of 190±10 beats per minute. The instantaneous mean flow velocity was lowest (10±4 cm/s, p<0.001) and recovery to normal pressure was quickest (within 1 minute) with rapid pacing. Instrumentation for rapid pacing did not prolong the procedure, but shortened it ∼25 minutes. Moreover, precise positioning at a mean 2±2 mm from the predetermined launch site was observed with rapid pacing (p<0.05). There were no differences in postprocedural neurological assessment among groups.

Conclusion:

Rapid RV pacing is safe in selected patients and in experienced hands. It abbreviates hemodynamic compromise, shortens the endovascular procedure, and may eventually emerge as the preferred method to avoid the windsock effect during stent-grafting. The maneuver, however, requires knowledge of right cardiac anatomy and expertise in selecting patients.

Endovascular Repair of Thoracic Aortic Disease: Overview of Current Devices and Clinical Results

Endovascular repair of thoracic aortic aneurysm has become an important treatment modality in patients who are at increased risk for open surgical repair. Since the US Food and Drug Administration (FDA) approved the clinical application of this technology in the thoracic aorta in 2005, there has been a rapid growth in this treatment modality as numerous endovascular devices have been introduced in the application of thoracic aortic pathology. Although thoracic aortic aneurysm is the only FDA-approved treatment indication for endovascular repair, this technology may lead to a broader clinical applicability in other thoracic pathologies. This article reviews the current endovascular devices designed for the treatment of thoracic aortic pathology. These devices are described, and the current clinical results are discussed.

Call for a new classification system and treatment strategy in blunt aortic injury

OBJECTIVE

The current Society for Vascular Surgery (SVS) classification scheme for blunt aortic injury (BAI) is descriptive but does not guide therapy. We propose a simplified classification scheme based on our robust experience with BAI that is descriptive and guides therapy.

METHODS

Patients presenting with BAI between January 1999 and September 2014 were identified from our institution's trauma registry. We divided patients into eras by time. Era 1: before the first United States Food and Drug Administration (FDA)-approved thoracic endovascular aortic repair (TEVAR) device (1999-2005); era 2: FDA-approved TEVAR devices (2005-2010); and era 3: FDA-approved BAI-specific devices (2010-present). Baseline demographic information, Injury Severity Score, hospital details, and survival were collected and compared. Our classification scheme was minimal aortic injury, SVS grade 1 and 2; moderate aortic injury, SVS grade 3; and severe aortic injury, SVS grade 4.

RESULTS

We identified 226 patients with a diagnosis of BAI: 75 patients in era 1, 84 in era 2, and 67 in era 3. Mean Injury Severity Score was 39.5 (range, 16-75). The BAI-related in-hospital mortality was significantly higher before endovascular introduction in era 1 (14.6% vs 4.8%; P = .03), but was not significantly different between eras 2 and 3 or before and after BAI-specific devices were introduced (P = .43). Of 146 patients (64.6%) who underwent aortic intervention, 91 underwent endovascular repair, and 55 underwent open repair. All but nine patients (94%) had a moderate or severe injury. Survival across all three eras of patients undergoing operative intervention was 80.2%. Survival in eras 2 and 3 was higher than in era 1 (86.4% vs 73.8%) but was not significant (P = .38). Of 47 patients in eras 2 and 3 with minimal aortic injury, 45 (96%) were managed nonoperatively, with no BAI-related deaths. After 2007, follow-up imaging was obtained in 38 patients (80%) with minimal aortic injury, and progression was not observed. Computed tomography scans showed the injury in 13 patients appeared stable, 19 had complete resolution (50%), and 6 had a decreasing size of injury.

CONCLUSIONS

Our experience confirms that BAI-related mortality for patients who survive to presentation is now 5%. From our findings during the past 15 years, we propose simplification of the SVS grading criteria of BAI into minimal, moderate, and severe based on treatment differences among the three groups. Minimal aortic injury can be successfully managed nonoperatively without mandatory follow-up imaging. Moderate aortic injury can be managed semielectively with TEVAR, and severe aortic injury, requires emergency TEVAR.

Tolerance of rapid right ventricular pacing during thoracic endovascular aortic repair

BACKGROUND

The objective of this retrospective study was to evaluate the tolerance of rapid right ventricular pacing (RRVP) compared with that of the traditional methods of hypotension used during thoracic endovascular aortic repair (TEVAR).

METHODS

From January 2002 to December 2012, we retrospectively included all the patients treated with TEVAR by comparing the 2 groups: patients operated with RRVP (RRVP+) and those operated without RRVP (RRVP-). The characteristics of the population and the procedures were recorded. The rates of complications were compared up to 1 year.

RESULTS

Sixty-one patients were operated. Treated pathologies were multiple with 19 aneurysms, 14 false aneurysms, 12 isthmic ruptures, 11 dissections, 3 coarctations, and 2 endoleaks. Twenty-four patients were RRVP+ and 37 patients were RRVP-. Mortality rates at 1 month in groups RRVP+ and RRVP- were of 0% and 2.7%, respectively (P = 1), and reintervention rates were 0% and 13.5%, respectively (P = 0.15). Three peroperative rhythm disorders (12.5%) were observed in the RRVP+ group including 2 ventricular fibrillations and 1 atrial fibrillation, both reduced without complications. One pacemaker was implanted for atrioventricular block in the RRVP- group. In the RRVP+ group, 83.3% of the patients presented a rise in troponin Ic (TnI) >0.04 ng/mL in 72 hours compared with 40.5% of the patients in the RRVP- group (P = 0.0013), with a spontaneously favorable evolution. No coronary syndrome was observed at 1 year with a mortality rate of 10.8% in the RRVP- group vs. 0% in the RRVP+ (P = 0.15).

CONCLUSIONS

In spite of a frequent moderate rise of TnI at the time of RRVP, this technique does not present more complications at 1 year than the use of a chemical hypotension. It thus seems an interesting alternative for selected patients, in trained teams.

Gore TAG®Thoracic Endoprosthesis: the first US FDA-approved thoracic endograft

Open surgical repair of thoracic aortic lesions carries a significant risk of complications, including death. Minimally invasive approaches, however, may improve outcomes. Clinical trials of the Gore TAG Thoracic Endoprosthesis device indicate that subjects receiving the graft are less likely to experience major adverse events, less intraprocedural blood loss, shorter intensive care unit and hospital stays, and reduced recovery times than surgical patients. The US FDA approved the device in March 2005. Since then, the device has been used widely, although a 0.30% rate of complications related to infolding or partial compression of the device prompted a 'Dear Doctor' letter in January 2006. This article profiles the TAG device and evaluates endografting technology in general.

Application of rapid artificial cardiac pacing in thoracic endovascular aortic repair in aged patients

OBJECTIVE

To compare the safety, efficacy, and impact on stent graft positioning between rapid artificial cardiac pacing (RACP), induced hypotension and sodium nitroprusside (SNP) induced hypotension during thoracic endovascular aortic repair (TEVAR) for Stanford B aortic dissection.

METHODS

One hundred and sixty-eight patients, who were diagnosed with Stanford B aortic dissection and who underwent selective TEVAR in Guangdong General Hospital and the People's Hospital of Baoan District, Shenzhen, People's Republic of China, were enrolled in this study. Patients were randomly divided into a RACP group (n=77) and a SNP group (n=91). During localization and deployment of the stent graft, hypotension was induced by RACP or intravenous SNP, according to randomization. Hemodynamics, landing precision (deviation from planned placement site), duration of procedure, renal function, neurocognitive function, and incidence of endoleaks and paraplegia/hemiplegia were compared. Except for methods of inducing hypotension, TEVAR was performed according to the same protocol in each group.

RESULTS

RACP was successfully performed in all patients assigned to the RACP group. Compared with the SNP group, blood pressure was significantly lower (43±5 versus 81±6 mmHg, P=0.003) and the restoration time of blood pressure and the operation duration were significantly shorter (7±2 versus 451±87 seconds, P<0.001; 87±15 versus 106±18 minutes, P<0.001, respectively) in the RACP group. Stent graft localization/deployment was more precise in the RACP group (2±1 versus 5±2 mm, P<0.001). Compared to baseline, there was no significant change after TEVAR in either group in regard to renal function, neurocognitive function, and incidence of endoleaks and paraplegia/hemiplegia.

CONCLUSION

RACP can be safely applied to patients undergoing TEVAR for Stanford B dissection. RACP can shorten the operation duration and facilitate precise graft localization/deployment.

The chimney graft, a systematic review

BACKGROUND

Approximately 20% to 30% of the patients are considered not eligible for standard endovascular aneurysm repair because of aortic neck morphology. Most of these patients have an aortic neck situated in the vicinity of the aortic side branches, requiring extensive open surgery. The introduction of fenestrated and branched stent grafts has made endovascular branch preservation possible, but these procedures are time-consuming and expensive. The chimney procedure offers a readily available endovascular alternative for the treatment in patients with acute aneurysms and challenging anatomy. We conducted a systematic review to evaluate the short- and long-term results of the chimney procedure.

METHODS

A comprehensive literature search for studies describing the chimney procedure was performed using MEDLINE and Excerpta Medica Database. All articles were critically appraised and included, based on relevance, validity, and outcome measures. Patient characteristics, details of the surgical intervention, and short- and long-term outcomes were studied.

RESULTS

A total of 75 patients were included who underwent a chimney procedure for the preservation of a total of 96 branches. Used operating techniques differed considerably between all studies, with an overall technical success rate of 98.9%. Three perioperative deaths were reported, of which one patient died from intervention-related complication. The follow-up duration ranged from 2 days to 54 months. Late complications included three deaths, none of which was device or aneurysm related. Three chimney grafts occluded during follow-up, of which two required reintervention.

CONCLUSION

The chimney procedure appears as an acceptable alternative for patients in an emergency setting, although data regarding long-term follow-up are not yet available.

A novel approach using pulmonary artery catheter-directed rapid right ventricular pacing to facilitate precise deployment of endografts in the thoracic aorta

OBJECTIVE

Controlled hypotension is critical for precise deployment of endografts in the thoracic aorta and for safe balloon dilation after deployment. We describe a novel approach to rapid right ventricular pacing using a pulmonary artery catheter (PAC) that is placed during the procedure for hemodynamic monitoring.

METHODS

The study included 27 patients (20 men and seven women), with a mean age of 74 years, who underwent endograft placement in the thoracic aorta with PAC-directed rapid right ventricular pacing. Hemodynamic parameters, accuracy of deployment, complications related to rapid right ventricular pacing and PAC placement, presence of endoleaks, and postoperative complications were evaluated.

RESULTS

PAC-directed rapid right ventricular pacing was performed during endograft deployment and balloon dilation after deployment without technical difficulty. Each patient underwent a median of two pacing episodes (range, 1-4). The length of each pacing episode was a mean of 11 seconds (range, 8-14 seconds). Mean pacing rate was 170 ± 15 beats/min, which achieved an average mean arterial pressure (MAP) of 42 ± 8 mm Hg. After pacing cessation, the recovery time of MAP to prepacing levels was <5 seconds (mean, 2 seconds) in all but one patient. All endografts were precisely deployed at a mean of 2 mm from the intended placement site, and there was no unintentional branch vessel coverage. One patient with severe valvular heart disease died. There were nine endoleaks, one postoperative stroke (4%), and one access wound hematoma (4%).

CONCLUSIONS

PAC-directed rapid right ventricular pacing is an effective method of inducing hypotension, enabling precise thoracic endograft deployment and safe balloon dilation after deployment. However, despite these advantages, the technique may be contraindicated in patients with severe valvular or ischemic heart disease.

WITHDRAWN: A novel approach using pulmonary artery catheter-directed rapid right ventricular pacing to facilitate precise deployment of endografts in the thoracic aorta

The Publisher regrets that this article is an accidental duplication of an article that has already been published, doi: 10.1016/j.jvs.2011.10.003. The duplicate article has therefore been withdrawn.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Real-world experience with type I endoleaks after endovascular repair of the thoracic aorta

Endoleaks are a frequent complication of thoracic endovascular aortic repair (TEVAR) and will likely increase in incidence with application of the technique to more complicated aortic anatomy and a wider range of thoracic aortic pathologies. Management generally consists of aggressive repair of Type I endoleaks; however, the natural history of Type I endoleaks after TEVAR remains largely unknown. The purpose of this study was to examine the incidence and characteristics of Type I endoleaks and to evaluate clinical outcomes of patients with Type I endoleaks after TEVAR. A single-center retrospective review was performed on all patients who underwent TEVAR over a 4-year period. Type I endoleaks were detected in 21 per cent (27 of 129) of patients on post-deployment aortography or CT angiography. During a mean follow-up of 750.63 +/- 483 days, 59 per cent (16 of 27) closed spontaneously; 30 per cent (eight of 27) required secondary endovascular intervention; and 11 per cent (three of 27) have persisted with no increase in maximum aortic diameter. No patients have died or required open surgical conversion as a result of their Type I endoleak. Although accurate predictors of spontaneous resolution of Type I endoleaks have yet to be definitively characterized, our initial results suggest that it may be safe to observe small Type I endoleaks given that a large percentage resolve spontaneously and no endoleak-related deaths have occurred.

Endografts for thoracic aortic pathologies--uncontested benefits in patient care

Medical and surgical treatment of thoracic aortic pathologies have been associated with considerable morbidity and mortality. Conversely, thoracic aortic endografting is proving to be extremely useful for correcting a variety of lesions with few complications. Endovascular intervention avoids sternotomy or thoracotomy, chest tubes, respirators and general anesthesia, and blood loss is limited. Complications such as paraplegia, renal failure and cardiac and pulmonary difficulties are minimized; hospital and rehabilitation times are also reduced. Selection of patients on the basis of favorable anatomy and pathology for a specific device is critical to procedural success. In addition, hybrid procedures combining endovascular and surgical techniques may extend the uses of available devices. Branched and fenestrated grafts are now being developed and are more accessible in Europe and Australia for use in thorac-abdominal aneurysm exclusion; they may be used in the arch and proximal descending thoracic aorta. However, at present, grafting in these regions has been associated with a significant incidence of stroke.

Endoleaks after endovascular repair of thoracic aortic aneurysms

OBJECTIVE

Endoleaks are one of the unique complications seen after endovascular repair of thoracic aortic aneurysms (TEVAR). This investigation was performed to evaluate the incidence and determinants of endoleaks, as well as the outcomes of secondary interventions in patients with endoleaks, after TEVAR.

METHODS

Over a 6-year period, 105 patients underwent TEVAR in the context of pivotal Food and Drug Administration trials with the Medtronic Talent (n = 64) and Gore TAG (n = 41) devices. The medical and radiology records of these patients were reviewed for this retrospective study. Of these, 69 patients (30 women and 39 men) had follow-up longer than 1 month and were used for this analysis. The patients were evaluated for the presence of an endoleak, endoleak type, aneurysm expansion, and endoleak intervention.

RESULTS

The mean follow-up in this patient cohort was 17.3 +/- 14.7 months (range, 3-71 months). Endoleaks were detected in 29% (20/69) of patients, of which 40% (8/20) were type I, 35% (7/20) were type II, 20% (4/20) were type III, and 5% (1/20) had more than one type of endoleak. Patients without endoleaks experienced greater aneurysm sac regression than those with endoleaks (-2.89 +/- 9.1 mm vs -0.13 +/- 7.2 mm), although this difference was not statistically significant (P = .232). All but 2 endoleaks (90%; 18/20) were detected on the initial postoperative computed tomographic scan at 30 days. Two endoleaks (10%; 2/20) developed late. The endoleak group had more extensive aneurysms with significantly larger aneurysms at the time of intervention (69.4 +/- 10.5 mm vs 60.6 +/- 11.0 mm; P = .003). Factors predictive of endoleak included male sex (P = .016), larger aneurysm size (P = .003), the length of aorta treated by stent grafts (P = .0004), and an increasing number of stents used (P < .0001). No open conversions were performed for treatment of endoleaks. Four (50%) of the eight type I endoleaks were successfully repaired by using endovascular techniques. None of the type II endoleaks was treated by secondary intervention. During follow-up, the maximum aneurysm diameter in the type II endoleak patients increased a mean of 2.94 +/- 7.2 mm (range, -4.4 to 17 mm). Spontaneous thrombosis has occurred in 29% (2/7) of the type II endoleaks. Patients with type III endoleaks experienced a decrease in mean maximal aneurysm diameter of 0.78 +/- 3.1 mm during follow-up.

CONCLUSIONS

Endoleaks are not uncommon after TEVAR. Many type I endoleaks may be treated successfully by endovascular means. Short-term follow-up suggests that observational management of type II endoleaks is associated with continued sac expansion, and these patients should be monitored closely.

Combined Staged Procedures for the Treatment of Thoracoabdominal Aneurysms

PURPOSE

To examine the efficacy of a staged approach for the treatment of thoracoabdominal aneurysms, with open visceral revascularization followed by aortic endografting, in selected patients not considered candidates for conventional surgical repair.

METHODS

A retrospective review was conducted of 13 consecutive patients (8 women; mean age 64 years, range 33-77) who underwent visceral bypass followed by endovascular thoracoabdominal stent-graft implantation since 1999. Three patients presented with symptomatic aneurysms and 2 with rupture. Two patients had connective tissue disorders. All patients were deemed unfit for conventional thoracoabdominal repair due to comorbid conditions. The procedures were tailored to the pathology and specific patient anatomical situation: 5 aortic dissections with aneurysmal degeneration and 8 aneurysms (5 Crawford type II, 2 type III, and 1 type IV).

RESULTS

The patients underwent retrograde visceral bypass (11 iliovisceral and 2 infrarenal aortic to visceral artery) followed by endovascular aortic relining with Zenith TX2 devices (n=7), homemade endografts (n=5), or a Talent thoracic endograft (n=1). Six patients required either a proximal or distal direct aortic repair (2 infrarenal reconstructions, 3 arch elephant trunk grafts, and 1 ascending aortic repair), while 3 patients also underwent left carotid-subclavian bypass grafting. Two patients developed paraplegia (1 following a ruptured aneurysm), and 2 patients had transient paraparetic events. Two patients had acute renal failure requiring short-term dialysis. Three patients died within 30 days; 2 late aneurysm-related deaths were noted. Three patients developed endoleaks during follow-up. Mean lengths of stay were 13 days (7-30) for the visceral bypass and 12 (3-25) for the endovascular stent-graft. In addition, remaining procedures in 8 patients required a mean of 7 days (0-14) in hospital.

CONCLUSION

Staged endovascular and open procedures are feasible for thoracoabdominal aneurysms in patients at prohibitive risk for open thoracoabdominal reconstruction. However, this approach still carries a significant risk of perioperative mortality and morbidity. The potential for less invasive alternatives should be investigated.

Rapid Ventricular Pacing to Lower Blood Pressure During Endograft Deployment in the Thoracic Aorta

Controlled hypotension is critical to the accurate deployment of aortic endografts and safe balloon post-dilation. We describe the use of rapid ventricular pacing during 15 aortic stenting procedures. An immediate and sustained reduction in both phasic and mean blood pressure was achieved in all patients. This procedure has advantages over pharmacologic or other methods of blood pressure reduction.

Update on Thoracic Aortic Endovascular Grafting Using the Medtronic Talent Device

This article provides a brief update on the current status of the treatment of thoracic aortic pathology using the Medtronic Talent device. Preoperative evaluation and selection criterion along with study design are described for the recently completed Phase II VALOR Trial (Evaluation of the Medtronic AVE Talent Thoracic Stent Graft System for the Treatment of Thoracic Aneurysms). In addition, the results of several recent series for the treatment of degenerative aneurysm and more complex aortic pathology such as transection, rupture and acute and chronic dissection are reviewed.