Endovascular Treatment of Aortic Arch Aneurysms

A meta-analysis on the effect of proximal landing zone location on stroke and mortality in thoracic endovascular aortic repair

BACKGROUND

Thoracic endovascular aortic repair (TEVAR) involving the aortic arch may increase the opportunity for stroke owing to disruption of cerebral circulation and embolization. In this study, a systematic meta-analysis was performed to examine the impact of proximal landing zone location on stroke and 30-day mortality after TEVAR.

METHODS

MEDLINE and Cochrane Library were searched for all original studies of TEVAR reporting outcomes of stroke or 30-day mortality for at least two adjacent proximal landing zones, based on the Ishimaru classification scheme. Forest plots were created using relative risks (RR) with 95% confidence intervals (CI). An I2 of <40% was regarded as minimal heterogeneity. A P value of <.05 was considered significant.

RESULTS

Of the 57 studies examined, a total of 22,244 patients (male 73.1%, aged 71.9 ± 11.5 years) were included in the meta-analysis, with 1693 undergoing TEVAR with proximal landing zone 0, 1931 with zone 1, 5839 with zone 2, and 3089 with zone 3 and beyond. The overall risk of clinically evident stroke was 2.7% for zones ≥3, 6.6% for zone 2, 7.7% for zone 1, and 14.2% for zone 0. More proximal landing zones were associated with higher risks of stroke compared with distal (zone 2 vs ≥3: RR, 2.14; 95% CI, 1.43-3.20; P = .0002; I2 = 56%; zone 1 vs 2: RR, 1.48; 95% CI, 1.20-1.82; P = .0002; I2 = 0%; zone 0 vs 1: RR, 1.85; 95% CI, 1.52-2.24; P < .00001; I2 = 0%). Mortality at 30 days was 2.9% for zones ≥3, 2.4% for zone 2, 3.7% for zone 1, and 9.3% for zone 0. Zone 0 was associated with higher mortality compared with zone 1 (RR, 2.30; 95% CI, 1.75-3.03; P < .00001; I2 = 0%). No significant differences were found in 30-day mortality between zones 1 and 2 (P = .13) and between zone 2 and zones ≥3 (P = .87).

CONCLUSIONS

The risk of stroke from TEVAR is lowest in zone 3 and beyond, increasing significantly as the landing zone is moved proximally. Furthermore, perioperative mortality is increased with zone 0 compared with zone 1. Therefore, risk of stent grafting in the proximal arch should be weighed against alternative surgical or nonoperative options. It is anticipated that the risk of stroke will improve with further development of stent graft technology and implantation technique.

Determining the Optimal Proximal Landing Zone for TEVAR in the Aortic Arch: Comparing the Occurrence of the Bird-Beak Phenomenon in Zone 0 vs Zones 1 and 2

Purpose: To identify the optimal proximal landing zone for thoracic aortic endovascular repair (TEVAR) of aortic arch pathologies so as to avoid the bird-beak phenomenon that leads to type Ia endoleak. Materials and Methods: A retrospective single-center review was conducted of 164 patients (mean age 70.3±10.8 years, range 29–93; 127 men) who underwent repairs of the aortic arch using hybrid TEVAR from April 2008 to March 2017. The patients were divided into 2 groups according to the proximal landing zone: 43 zone 0 patients (26.2%) had total debranching TEVAR (n=18) or total endovascular aortic repair (n=25) while 121 patients (73.8%) had TEVAR landing in zones 1 (n=41) or 2 (n=80). Bird-beak configurations, endoleaks, and stent migrations were assessed on the postoperative and latest computed tomography angiography (CTA) scans. Overall survival and freedom from the bird-beak configuration, aorta-related death, and aortic events were estimated using the Kaplan-Meier method. Hazard ratios (HR) were calculated with the 95% confidence interval (CI). Results: All procedures were successful, without any 30-day mortality. There were 3 early complications (1.8%; all strokes) and 10 early endoleaks (6.1%; no type Ia). On the first postoperative CTA, 42 patients (25.6%) had a bird-beak configuration. The zone 0 patients had significantly fewer (p<0.001), shorter (p<0.004), and less angulated (p<0.001) bird-beak configurations than in zones 1–2. The mean follow-up period was 4.2 years (range 0.5–8.8). There were 18 late deaths (11.0%); only one was related to the aorta (rupture due to a type Ib endoleak in a zone 0 patient). The 5-year freedom from aorta-related death was not significantly different between groups (zone 0: 96.9% vs zones 1–2: 100%, p=0.080). On the latest CTA, 51 (31.0%) patients had a bird-beak configuration; of those, 22 (13.4%) showed >3-mm progression. The freedom from bird-beak configuration estimate was significantly higher in the zone 0 group (95.4%) vs zones 1–2 (57.8%; HR 0.10, 95% CI 0.02 to 0.31, p<0.001). There were 9 late endoleaks (4 type Ia; none in the zone 0 group). The rate of stent-graft migration was significantly lower in the zone 0 group (2.3% vs 14.1% in zones 1–2, p=0.035). Conclusion: Early and most late results in zone 0 TEVAR were equal to those in zones 1 and 2; however, there were no late type Ia endoleaks and fewer bird-beak configurations associated with zone 0 TEVAR, which suggests that zone 0 landing is advantageous for preventing these complications.

Delayed Aortic Stent Collapse in Blunt Traumatic Aortic Injury Repair

Background  Endovascular stent grafting has emerged as an option to treat traumatic aorta injuries with reported significantly low mortality and morbidity. Stent collapse is one of the complications that can occur in this type of treatment. The aim of this article is to analyze the expected cause of stent collapse and to draw attention to the importance of the surveillance follow-up, as this phenomenon may occur late postdeployment.

Methods  A retrospectively collected dataset from the two highest volume trauma centers in Saudi Arabia was analyzed between April 2007 and October 2012. A total of 66 patients received stent grafts for traumatic aortic injury and were included in the study. We apply Ishimaru's anatomical aortic arch zones and Benjamin's aortic injury grading systems. There were 35 patients with aortic injury at zone 2, 26 patients in zone 3, and 5 patients in zone 4. About 96% (63) of the injuries were grades 2 and 3, including large intimal flap or aortic wall pseudoaneurysm with change in wall contour. The technical success rate, as defined by complete exclusion of lesions without leaks, stroke, arm ischemia or stent-related complications, was 90%.

Results  Proximal stent collapse occurred in 4.5% of patients (3 of 66 inserted stents) during follow-up of 4 to 8 years (mean, 6 years). Patients with stent collapse tended to have an acute aortic arch angle with long-intraluminal stent lip, when compared with patients with noncollapsed stents. Intraluminal lip protrusion more than 10-mm increased collapse ( p  < 0.001). Stent-grafts sizes larger than 28 mm also demonstrated a higher collapse rate ( p  < 0.001).

Conclusions  The risk of stent collapse appears related to poor apposition of the stent due to severe aortic arch angulation in young patients and to large stent sizes (>28 mm). Such age groups may have more anatomical and aortic size changes during the growth. Clinical and radiological surveillance is essential in follow-up after stent-graft treatment for traumatic aortic injury.

Type II Endoleaks, Left-Arm Complications, and Need of Revascularization after Left Subclavian Artery Coverage for Thoracic Aortic Aneurysms Endovascular Repair: A Systematic Review

BACKGROUND

The status of the left arm, the need of revascularization, and the occurrence of type II endoleakes from de left subclavian artery (LSA) after intention LSA coverage for thoracic aortic aneurysm endovascular repair need to be better understood. This systematic review was developed for contributing with such issue.

METHODS

Systematic literature review of studies published from January 2000 through December 2015 identified 7 studies comprising 201 patients submitted to elective endovascular repair for thoracic aortic aneurysms requiring intentional LSA coverage. Outcomes of interest included left-arm complications (ischemia, symptoms of claudication, and subclavian steal syndrome [SSS]) requiring postoperative revascularization of LSA, as well as endoleaks from the subclavian artery requiring postoperative embolization of LSA.

RESULTS

Left-arm complication rate was 4.5% (9 patients), requiring postoperative revascularization of LSA in 1 case (0.5%) of SSS. Type II endoleaks from the subclavian artery requiring postoperative embolization of LSA were reported in 2 cases (1.0%).

CONCLUSIONS

Low-quality evidence suggests very low rates of arm complications with need of LSA revascularization and of type II endoleaks requiring embolization in elective endovascular treatment of thoracic aortic aneurysms with intentional coverage of LSA without prophylactic revascularization of LSA.

Results of Thoracic Endovascular Grafting in Different Aortic Segments

Purpose:

To compare the results of thoracic endovascular grafting of different aortic segments performed with commercially available stent-grafts.

Methods:

Between January 1999 and October 2006, 178 patients (150 men; mean age 69.4±10.2 years) underwent endovascular grafting of the thoracic aorta (68 hybrid procedures) with commercially produced stent-grafts from 4 manufacturers. Patients were divided into 3 groups according to the aortic segment involved: 64 aortic arch cases (37 hybrids for supra-aortic trunks revascularization), 100 descending thoracic aorta (DTA) cases (17 hybrid: 12 for access and 5 for associated abdominal aortic aneurysm), and 14 thoracoabdominal aorta (TaA) patients excluded from conventional repair (14 hybrids for renal and splanchnic revascularization).

Results:

The technical success was 93.8% (167/178). Overall 30-day mortality was 5.6% (10/178). There were 10 (5.6%) type I endoleaks. Initial clinical success was 88.2% (157/178). At a mean follow-up of 29.3±21.2 months, the midterm clinical success was 89.9% (160/178). In the arch group, the technical success was 85.9% (55/64). Thirty-day mortality was 6.3% (4/64). There were 8 (12.5%) type I endoleaks. Initial and midterm clinical success rates were 79.7% (51/64) and 85.9% (55/64), respectively. In the 100-patient DTA group, the technical success was 98.0%. Thirty-day mortality was 2.0%. The type I endoleak rate was 2.0%. Clinical success was 96.0% initially and 95.0% at midterm. All 14 of the TaA cases were completed successfully, but 30-day mortality was 28.6% (4/14). There were no type I endoleaks. Clinical success rates initially and at midterm were both 71.4% (10/14).

Conclusion:

Over the last 6 years, synergy between endovascular and surgical procedures allowed treatment of all segments of the thoracic aorta. Overall perioperative and medium-term results were reasonably favorable; however, they were more satisfactory when the descending thoracic aorta alone was involved. Hybrid procedures allowed treatment of all aortic segments, but they decreased the success rates significantly. Endovascular grafting is currently our preferred method of treating pathologies involving the DTA and aortic arch, while our data suggest limiting the use of stent-grafts to high-risk patients or compassionate indications when the thoracoabdominal aorta is involved.

Hybrid repair of aortic arch pathology

The objective was to evaluate a 13-year single-centre experience of arch endovascular aortic repair using the hybrid approach. Between 1999 and 2013, 491 patients were treated with endografts for thoracic aortic pathologies. The aortic arch was involved in 179 (36.5%) patients (128 men; mean age 70.2 ± 10.8 years, range 27-84). A hybrid approach was performed for all Zone 0 and 1 procedures and in nearly half of Zone 2 procedures. Early and mid-term outcomes were reviewed retrospectively. Overall primary technical success (24 h) was achieved in 162 (90.5%) of the 179 cases; 2 deaths and 15 Type 1 endoleaks were observed. Clinical success at 30 days was achieved in 161 (89.9%) of the 179 patients, with a mortality rate of 4.5% (8/179). Short-term clinical success at 6 months was achieved in 169 (94.4%) of the 179 patients; the rates for the different landing zones did not differ significantly. At a mean follow-up of 27.3 ± 15.7 months (range 1-94), the mid-term clinical success was 165 (92.2%) of the 179 patients; the rates among the different proximal zones did not differ significantly. In selected patients, early and mid-term outcomes of arch endovascular aortic repair using the hybrid approach are promising; however, mortality and morbidity are not negligible. Our results may have practical implications for the ongoing evaluation of the hybrid procedure in the aortic arch, as well as for patients fit for traditional surgery.

Management of a right aberrant subclavian artery during complex hybrid stent-graft procedures: a rare and complex issue

A 76-year-old man with an ascending arch and proximal descending aortic aneurysm underwent a complex aortic replacement through a sternotomy with ligation of a right aberrant subclavian artery (RASA) distal to the right vertebral artery. The second-stage procedure was performed with a stent-graft deployed within the elephant trunk. At 6- and 12-month follow-up, the RASA was opacified by the patent right vertebral artery. Under ultrasound guidance, the patient's RASA stump was occluded by coils. Management of an RASA during complex hybrid stent-graft procedures is discussed.

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.

Relay NBS graft with the plus delivery system to improve deployment in aortic Arch with small radius curve

The purpose of this report is to describe deployment of the Relay NBS Thoracic Stent Graft with the Plus Delivery System (Bolton Medical, Sunrise, FL) in a flexible resin arch model with a 15-mm radius curve as well as our preliminary clinical results. The Relay NBS graft with the Plus Delivery System was evaluated by way of bench testing, which was performed with stent grafts with diameters ranging from 24 to 46 mm and lengths ranging from 100 to 250 mm in flexible resin arch models with a 15-mm arch radius of curvature. The deployment sequence was analyzed. The Relay NBS graft with the Plus Delivery System was deployed in two patients, respectively, having a 6.5-cm penetrating aortic ulcer of the proximal third of the descending thoracic aorta and a DeBakey type-I aortic dissection with chronic false lumen dilatation after surgery due to an entry site at the distal thoracic aorta. Bench tests showed proper conformation and apposition of the Relay NBS graft with the Plus Delivery System in the flexible resin model. This stent graft was deployed successfully into the two patients with a correct orientation of the first stent and without early or late complications. The Relay NBS graft with the Plus Delivery System ensures an optimal conformation and apposition of the first stent in the aortic arch with a small radius of curvature.

Endovascular grafts for treatment of traumatic injury to the aortic arch and great vessels

BACKGROUND

Treatment of traumatic vascular injury using endovascular techniques has evolved as endovascular capabilities have advanced over the past several decades. Several endovascular techniques have been employed to address the challenges of traumatic arterial injury, including coil embolization and the use of stents, which may be either bare metal or covered with graft material. Compared with traditional surgical repair, endovascular stent grafting for the repair of traumatic arterial injury offers the advantage of decreased morbidity because a remote access site may be used, avoiding surgical dissection and lengthy operating times.

METHODS

A Medline (1995-2007) search was performed to find all studies discussing the use of endovascular means to treat supradiaphragmatic arterial trauma.

RESULTS

In this review of 195 studies published between January 1995 and December 2007, the overall technical success rate of endovascular treatment of supradiaphragmatic arterial injury was 96.7%, and the complication rate was 6.4%.

CONCLUSION

The results of this review suggest a potential morbidity and mortality benefit over traditional open repair; however, long-term data are lacking. Long-term follow-up for stent durability is of particular concern in the trauma population, which tends to comprise younger patients with minimal atherosclerotic disease. The success of endovascular techniques is also limited by the availability of skilled interventionalists, properly outfitted angiography suites, and suitable stent graft devices. Despite these challenges, the potential advantages of endovascular stenting make it a welcome addition to the armamentarium of the vascular interventionalist who treats arterial traumatic injuries.

Evaluation of the diameter of the proximal descending thoracic aorta with age: implications for thoracic aortic stent grafting

BACKGROUND

Long-term anatomical changes of the thoracic aorta which may affect long-term outcome of blunt aortic injuries treated with endovascular stent grafts are unknown. The purpose of this study was to examine the natural history of thoracic aortic diameter with progressing age.

METHODS

One thousand consecutive thoracic computed tomographic scans performed for nonthoracic aortic pathology on patients aged 15-99 (mean 59.4) were examined, and thoracic aortic diameter immediately adjacent to the left subclavian artery was measured. Factors possibly influencing diameter, including age by decade of life, race, gender, history of hypertension (HTN), diabetes mellitus (DM), chronic obstructive pulmonary disease (COPD), and tobacco use, were examined. Factors were compared using Student's t-test.

RESULTS

The differences in mean diameters of the thoracic aorta by gender (male=27.1 vs. female=26.0, p=0.87), race (Caucasian=26.6 vs. non-Caucasian=26.3, p=0.10), presence of HTN (yes=25.8 vs. no=24.9, p=0.36), COPD (yes=26.3 vs. no=25.4, p=0.21), DM (yes=26.1 vs. no=25.3, p=0.12), and tobacco use (yes=26.3 vs. no=25.0, p=0.18) were not significant. However, differences in mean diameter increased significantly over time with age. Patients under 40 years old had mean aortic diameters of 22.92 mm compared to 27.09 mm (p<0.001) for patients over 40. The mean aortic isthmus diameter showed an approximately 1cm increase when comparing octogenarians to teenagers.

CONCLUSION

The diameter of the aortic isthmus increases substantially with age. These findings suggest that long-term surveillance is warranted for trauma patients with aortic stent grafts, to monitor the natural history and to assess for possible late complications.

In situ bending of thoracic stent grafts: clinical application of a novel technique to improve conformance to the aortic arch

PURPOSE

A straight thoracic stent graft often complies poorly with the curvature of the aortic arch. We have previously reported an in vitro model of a modified stent graft that can be bent in situ after deployment to improve conformance to the aortic arch. We now report the first clinical experience with this technique in three consecutive patients.

METHODS

Between September 2007 and August 2008, three patients were treated for different pathologies of the aortic arch with a modified thoracic stent graft that was fitted with a sliding self-locking knot and a detachable Bowden cable. Transfemoral traction on the Bowden cable enables controlled shortening of the proximal part of the stent graft at the inner curve after deployment. The stent graft is thereby directed to allow for better apposition to the aortic wall.

RESULTS

The modified thoracic stent grafts were correctly orientated and deployed in all patients. Transfemoral traction on the Bowden cable successfully bent all stent grafts and improved vessel wall apposition without a residual gap on the inner curve. The Bowden cable was successfully released and withdrawn in all patients.

CONCLUSION

In situ bending of thoracic stent grafts with a sliding self-locking knot is feasible and improves proximal apposition of the device at the inner curve of the aortic arch. More data and longer follow-up are required to confirm the applicability of this technique.

Management of left subclavian artery in endovascular stent-grafting for distal aortic arch disease

BACKGROUND

Although the left subclavian artery (LSA) is simply covered to exclude distal aortic arch aneurysm during endovascular stent-grafting, this technique is potentially harmful.

METHODS AND RESULTS

Between January 2001 and April 2005, 40 cases of stent-grafting were performed for distal aortic arch diseases. For all 31 elective cases, the LSA occlusion test using a balloon catheter was preoperatively performed to predict critical complications secondary to LSA coverage by a stent graft and this revealed 2 cases in which the LSA was crucial for brain circulation (6.5%). The LSA was saved by using a hand-made fenestrated stent graft without bypass-grafting to the LSA in 22 cases. Bypass-grafting to LSA was performed in 5 cases. The LSA was simply occluded in 13 cases. Hospital mortality rates for the elective and emergency cases were 3.2% and 30.0%, respectively. One elective patient had a cerebral infarction (2.5%). LSA patency was successfully maintained in all 22 cases using a fenestrated stent graft.

CONCLUSION

The LSA plays an important role in brain circulation in some patients and so a preoperative LSA occlusion test is helpful when aortic stent-grafting is proposed. Fenestrated stent graft saved the LSA in more than 50% of the present cases.

Endovascular treatment of aortic arch aneurysms

BACKGROUND: Endovascular approach to the aortic arch is an appealing solution for selected patients. OBJECTIVE: To compare the technical and clinical success recorded in the different anatomical settings of endografting for aortic arch disease. METHODS: Between June 1999 and October 2006, among 178 patients treated at our institution for thoracic aorta disease with a stent-graft, the aortic arch was involved in 64 cases. According to the classification proposed by Ishimaru, aortic zone 0 was involved in 14 cases, zone 1 in 12 cases and zone 2 in 38 cases. A hybrid surgical procedure of supra-aortic debranching and revascularization was performed in 37 cases. RESULTS: Zone 0. Proximal neck length: 44±6 mm. Initial clinical success was 78.6%: two deaths (stroke), one type Ia endoleak. At a mean follow-up of 16.4±11 months the midterm clinical success was 85.7%. Zone 1. Proximal neck length: 28±5 mm. Initial clinical success was 66.7%: 0 deaths, four type Ia endoleaks. At a mean follow-up of 16.9±17.2 months the midterm clinical success was 75.0%. Zone 2. Proximal neck length: 30±5 mm. Initial clinical success was 84.2%: two deaths (one cardiac arrest, one multiorgan embolization), three type Ia endoleaks, one case of open conversion. Two cases of delayed transitory paraparesis/paraplegia were observed. At a mean follow-up of 28.0±17.2 months the midterm clinical success was 89.5%. CONCLUSIONS: This study and a literature review demonstrated that hybrid procedure for aortic arch pathology is feasible in selected patients at high risk for conventional surgery. Our experience is still limited by the relatively small sample size. We propose to reserve zone 1 for patients unfit for sternotomy or in cases with aortic neck length > 30 mm following left common carotid artery debranching. We recommend to perform complete aortic rerouting of the aortic arch in cases with lesser comorbidities and shorter aortic neck.

In situ bending of a thoracic stent-graft: a proposed novel technique to improve thoracic endograft seal

PURPOSE

To demonstrate the feasibility of a novel technique that modifies the configuration of a thoracic stent-graft after deployment to comply with the arch curvature.

TECHNIQUE

The principle of a Bowden cable has been applied to direct a conventional thoracic stent-graft in situ after deployment. A suture placed at the proximal inner curve of a conventional thoracic stent-graft is fitted with a sliding, self-locking knot attached to a line that runs inside a catheter through the central rod of the stent-graft. Traction applied to this line directs the endograft post deployment, which allows for better apposition to the aortic wall. Shortening the inner curve makes the stent-graft bend. The extent of bending is fully controlled by the surgeon and held in place with the sliding knot. A release mechanism allows removal of all luminal components of the mechanism.

CONCLUSION

The described technique of directing a thoracic stent-graft in situ seems feasible and enables better apposition of the stent-graft in a glass model. It may improve the durability of thoracic stent-grafts in the aortic arch.

Stent graft treatment for thoracic and thoracoabdominal aortic disease using a unibody Z-stent that adapts to flexure

Positioning a stent graft (SG) that adapts to the anatomical shape of the aorta is important to prevent complications after SG procedures to treat aortic disease. The Gianturco Z-stent has several benefits, but its rigid structure prevents adaptation to flexure. We improved this stent and studied its ability to adapt in the clinical environment. We positioned SGs and inspected their adaptability to flexure in an aortic arch model. We examined several gap lengths and strut directions, and determined the distance generated between the stent and the aortic wall. We found that adaptation was quite satisfactory with a gap of more than 10 mm or when the struts faced the major flexure or the side of the model aorta. Based on these findings and to facilitate placement, we manufactured the unibody Z-stent with 10-mm gaps. The unibody Z-stent was applied to treat thoracic and thoracoabdominal aortic disease in seven patients. The SG was positioned from the femoral or iliac artery in five patients and from an anastomosed graft to the ascending aorta after median sternotomy and bypass of the arch branches in two patients. A minor endoleak developed in one patient. None of the other six patients developed complications or died during the procedure, although one patient died in the hospital due to cerebral infarction. The unibody Z-stent was applied as a SG that adapts to flexure of the aorta and was easy to apply. The frequency of complications was apparently decreased after clinical application of the unibody Z-stent in SG treatment for thoracic and thoracoabdominal aortic disease.

Thoracic endograft positioning and carotid-subclavian bypass grafting in a patient with a saccular aneurysm at the aortic arch

A 75-year-old man was referred to our hospital because of sudden thoracic pain. A saccular aneurysm of the aortic arch extending on the anterior surface of the aortic arch was found on computed tomographic arteriography. The patient was hemodynamically stable and he was programmed for a staged surgical and endovascular approach (hybrid approach). As a first stage and in order to prevent major cardiac complications due to the overstenting of the left subclavian artery (LSA) with the occlusion of the aortocoronary bypass, the patient underwent a polytetrafluoroethylene bypass graft (GORE-TEX, W.L. Gore & Associates, Flagstaff, AZ) between the LSA and the left carotid artery. Intraoperative arteriography revealed a good patency of the left carotid-subclavian bypass and of the left internal mammary bypass on the left anterior descending artery. As a second stage the endovascular procedure was accomplished 5 days later in the operating room. A Gore TAG stent graft (W.L. Gore & Associates) was deployed in the aortic arch 20 mm proximally to the aneurysmatic segment covering the ostium of the LSA. The postoperative course was uneventful and the patient was discharged on the fifth postoperative day in good general conditions. Hybrid procedures for treatment of aneurysms of the aortic arch or of the descending thoracic aorta are a promising alternative to open surgery especially in high-risk patients, with lower early morbidity and mortality rates. Long-term effectiveness remains to be fully elucidated.

Hybrid repair of an aortic arch aneurysm with complex anatomy: Right aortic arch and anomalous origin of supra-aortic vessels

We performed a one-stage hybrid surgical and endovascular procedure to manage a 6.5-cm right aortic arch aneurysm associated with anomalous origin of the supra-aortic vessels in a 70-year-old man. Complete surgical rerouting of the supra-aortic vessels was followed by the endovascular repair of the right aortic arch aneurysm with a Zenith TX2 stent graft (Cook, Bloomington, Ind) and Z-track plus introducer system. The procedure was successfully completed with exclusion of the aortic arch aneurysm, and the patient was discharged on postoperative day 7. Aortic arch aneurysms with complex anatomy may be successfully treated with a less invasive hybrid approach using new generation devices.

Results of Endografting of the Aortic Arch in Different Landing Zones

INTRODUCTION

Endovascular approach to the aortic arch is an appealing solution for selected patients. Aim of this study is to compare the technical and clinical success recorded in the different anatomical settings of endografting for aortic arch disease.

METHODS

Between June 1999 and October 2006, among 178 patients treated at our Institution for thoracic aorta disease with a stent-graft, the aortic arch was involved in 64 cases. According to the classification proposed by Ishimaru, aortic "zone 0" was involved in 14 cases, "zone 1" in 12 cases and "zone 2" in 38 cases. A hybrid surgical procedure of supraortic debranching and revascularization was performed in 37 cases to obtain an adequate proximal aortic landing zone.

RESULTS

"Zone 0" (14 cases). Proximal neck length: 44+/-6mm. Initial clinical success 78.6%: 2 deaths (stroke), 1 type Ia endoleak. At a mean follow-up of 16.4+/-11 months the midterm clinical success was 85.7%. "Zone 1" (12 cases). Proximal neck length: 28+/-5mm. Initial clinical success 66.7%: 0 deaths, 4 type Ia endoleaks. At a mean follow-up of 16.9+/-17.2 months the midterm clinical success was 75.0%. "Zone 2" (38 cases) Proximal neck length: 30+/-5mm. Initial clinical success 84.2%: 2 deaths (1 cardiac arrest, 1 multiorgan embolization), 3 type Ia endoleaks, 1 case of open conversion. Two cases of delayed transitory paraparesis/paraplegia were observed. At a mean follow-up of 28.0+/-17.2 months the midterm clinical success was 89.5%.

CONCLUSIONS

Total debranching of the arch for "zone 0" aneurysms allowed to obtain a longer proximal aortic landing zone with lower incidence of endoleak, however a higher risk of cerebrovascular accident was observed. The relatively high incidence of adverse events in "zone 1" could be associated to a shorter proximal neck, therefore this landing zone is reserved for patients unfit for sternotomy. In case of endoleak, discovered after a satisfactorily positioned endograft in the arch, the rate of spontaneous resolution within the first 6 months is high.

Anatomic factors associated with acute endograft collapse after Gore TAG treatment of thoracic aortic dissection or traumatic rupture

OBJECTIVE

The potentially devastating complication of total or near total thoracic endoprosthesis collapse has been described with the TAG device (W. L. Gore & Associates, Flagstaff, Ariz). This rare complication has resulted in a warning to clinicians and speculation about the etiology of this problem. This report evaluates potential causative anatomic factors that may increase the probability of endoprosthesis collapse in patients undergoing endovascular thoracic aneurysm repair (TEVAR).

METHODS

Preoperative and postoperative computed tomography scans were collected worldwide representing six patients who had experienced radiologically confirmed TAG endoprosthesis collapse. These were compared with a matched cohort of five patients with a TAG endoprosthesis in the same anatomic position in which no collapse occurred. Anatomic variables of aortic arch angulation, apposition, intraluminal lip length, proximal aortic diameter, distal aortic diameter, intragraft aortic diameter, percentage of oversizing, and angle of the proximal endograft to the aortic arch were compared between groups. Differences between groups were determined using the Student t test, with P < .05 considered significant.

RESULTS

The two groups (collapse vs no collapse) were evenly matched demographically, and all underwent endoluminal treatment with the TAG device, with no differences in gender, graft position in the aorta, operative indication, or age (P = NS). Distal sealing zone aortic diameter +/- standard deviation of 18.9 +/- 1.7 mm vs 22.7 +/- 2.7 mm and minimum aortic diameter within the endograft of 18.6 +/- 1.7 mm vs 22.4 +/- 3.1 mm predicted collapse (P < .05). Proximal aortic diameter, apposition, intraluminal lip length, aortic arch angle, and angle of proximal endograft to aortic arch did not predict collapse (P = NS).

CONCLUSION

Thoracic endograft collapse is an exceedingly rare event. In this series, endoprosthesis collapse occurred in patients who were treated outside the manufacturer's instructions for use for minimum required aortic diameter. Although distal aortic diameter and minimum intragraft aortic diameter predicted collapse, other variables may also influence this complication but were not significant owing to potential type II statistical errors. In the future, caution should be exercised when contemplating TEVAR in patients with small (<23 mm) aortic diameters.

The Hybrid Total Arch Repair: Brachiocephalic Bypass and Concomitant Endovascular Aortic Arch Stent Graft Placement

BACKGROUND

Repair of aortic arch aneurysm is technically demanding, requiring complex circulatory management. Very large atherosclerotic saccular aneurysms of the arch are grave markers of extensive arch and brachiocephalic atheromatous disease and represent high surgical risks for perioperative neurologic complications. Operative morbidity and mortality may be prohibitive with traditional surgical intervention. We described our experience with a hybrid procedure for total arch repair with a brachiocephalic bypass with a trifurcated graft followed by concomitant placement of a stent graft in the arch.

METHODS

Since June 2005, we have performed the hybrid total arch repair in eight patients. A retrospective review was performed to evaluate the new technique.

RESULTS

The mean age of the patients was 67 years with a mean aneurysm size of 8 cm (range, 4.4 to 10 cm). Significant comorbidities included carotid stenosis, chronic renal insufficiency, peripheral vascular disease, hypertension, and coronary artery disease. Two patients had previous Abdominal aortic aneurysm (AAA) repairs. Three patients had previous sternotomy for type A dissection, ascending aortic aneurysm repair, and coronary artery bypass grafting. Transesophageal echocardiogram demonstrated grade IV or V atheromatous disease in the arch and ascending aorta. Stent grafts were deployed antegrade directly into the ascending aorta in three patients and retrograde from the femoral artery in five patients. Technical success with complete aneurysmal exclusion was achieved in all patients (100%). At a mean follow-up period of 11.7 months, there was no incidence of endoleak. There was one death resulting from a perioperative myocardial infarction (first patient). Documented perioperative neurologic events (stroke) occurred in two patients, with both patients demonstrating no residual deficit at the time of discharge.

CONCLUSIONS

Saccular arch aneurysms can be technically treated by total arch repair with brachiocephalic bypass and concomitant aortic arch stent graft placement. Hybrid arch repair provides an alternative to patients otherwise considered prohibitively high risk for traditional open arch repair.

Coverage of the left subclavian artery during thoracic endovascular aortic repair

BACKGROUND

Thoracic aortic stent grafts require proximal and distal landing zones of adequate length to effectively exclude thoracic aortic lesions. The origins of the left subclavian artery and other aortic arch branch vessels often impose limitations on the proximal landing zone, thereby disallowing endovascular repair of more proximal thoracic lesions.

METHODS

Between October 2000 and November 2005, 112 patients received stent grafts to treat lesions involving the thoracic aorta. The proximal aspect of the stent graft partially or totally occluded the origin of at least one great vessel in 28 patients (25%). The proximal attachment site was in zone 0 in one patient (3.6%), zone 1 in three patients (10.7%), and zone 2 in 24 patients (85.7%). Patients with proximal implantation in zones 0 or 1 underwent debranching procedures of the supra-aortic vessels before stent graft repair. In one patient who underwent zone 1 deployment, the left subclavian artery was revascularized before stent graft deployment. Among patients who underwent zone 2 deployment with partial or complete occlusion of the left subclavian artery, none underwent prior revascularization. Patients were assessed postoperatively and at follow-up for development of neurologic symptoms as well as symptoms of left upper extremity claudication or ischemia.

RESULTS

Mean follow-up was 7.3 months. Among the 24 patients with zone 2 implantation, 10 (42%) had partial left subclavian artery coverage at the time of their primary procedure. A total of 19 patients experienced complete cessation of antegrade flow through the origin of the left subclavian artery without revascularization at the time of the initial endograft repair as a result of a secondary procedure or as a consequence of left subclavian artery thrombosis. Left upper extremity symptoms developed in three (15.8%) patients that did not warrant intervention, and rest pain developed in one (5.3%), which was treated with the deployment of a left subclavian artery stent. Two primary (type IA and type III) endoleaks (7.1%) and one secondary endoleak (type IA) (3.6%) were observed in patients who underwent zone 2 deployment. Three cerebrovascular accidents were observed. Thoracic aortic lesions were successfully excluded in all patients who underwent supra-aortic debranching procedures.

CONCLUSION

Intentional coverage of the origin of the left subclavian artery to obtain an adequate proximal landing zone during endovascular repair of thoracic aortic lesions is well tolerated and may be managed expectantly, with some exceptions.

Complications after endovascular stent-grafting of thoracic aortic diseases

Background

To update our experience with thoracic aortic stent-graft treatment over a 5-year period, with special consideration for the occurrence and management of complications.

Methods

From December 2000 to June 2006, 52 patients with thoracic aortic pathologies underwent endovascular repair; there were 43 males (83%) and 9 females, mean age 63 ± 19 years (range 17–87). Fourteen patients (27%) were treated for degenerative thoracic aortic aneurysm, 12 patients (24%) for penetrating aortic ulcer, 8 patients (15%) for blunt traumatic injury, 7 patients (13%) for acute type B dissection, 6 patients (11%) for a type B dissecting aneurysm; 5 patients (10%) with thoraco-abdominal aortic aneurysms were excluded from the analyses. Fifteen patients (32%) underwent emergency treatment. Overall, mean EuroSCORE was 9 ± 3 (median 15, range 3–19). All procedures were performed in the theatre under general anesthesia. All complications occurring during hospitalisation were recorded. Follow-up protocol featured CT-A, and chest X-rays 1, 4 and 12 months after intervention, and annually thereafter.

Results

Primary technical success was achieved in all patients; procedures never aborted because of access difficulty. Conversion to standard open repair was never required. Mean duration of the procedure was 119 ± 75 minutes (median 90, range 45–285). Mean blood loss was 254 mL (range 50–1200 mL). The mean length of the aorta covered by the SGs was 192 ± 21 mm (range 100–360). The LSA was over-stented in 17 cases (17/47, 36%). Overall 30-day operative mortality was 6.4% (3/47). Major complications included pneumonia (n = 9), cerebrovascular accidents (n = 4), arrhythmia (n = 4), acute renal failure (n = 3), and colic ischemia (n = 1). Overall, endoleak rate was 14%.

Conclusion

Although this report is a retrospective and not comparative analysis of thoracic aortic repair, the combined minor and major morbidity rate was lower than previous reported to results of either electively and emergency performed conventional repair.

Emergency endovascular stent-graft treatment for acute thoracic aortic syndromes

OBJECTIVE

We report the results of our ongoing experience of urgent and emergency stent-graft implantation in acute thoracic aortic syndromes.

METHODS AND RESULTS

In the last 5-years, 19 patients were treated for acute thoracic aortic syndromes. Traumatic rupture was diagnosed in 7 patients, complicated acute type B dissection was present in 5 patients, penetrating ulcer in 4, and symptomatic thoracic aortic aneurysm in 3 patients. There were 17 male patients with a mean age of 54 +/-26 years (range 18-87 ; median 63). Patients were treated in the theatre suite under general anesthesia. Stent-graft placement was technically successful in all patients. The early postoperative mortality was 10.5 %. Neurological events or upper arm ischemia due to overstenting of the left subclavian artery were not observed. Average intensive care unit and hospital stay were 18 and 21 days, respectively. Major complications occurred in 6 patients. Follow-up ranged between 3 and 60 months (mean 25) and included clinical examinations and serial CT-angiography at 1, 4 and 12 months, and every year thereafter. Only one type II endoleak was detected and treated by coil embolization of the left subclavian artery.

CONCLUSIONS

Our experience suggests emergency stent-graft repair in patients with acute thoracic aortic syndromes is a less-invasive attractive alternative, showing encouraging early and mid-term results.

Symptomatic collapse of a thoracic aorta endoprosthesis

We present the case of a 40-year-old man who underwent aortic endoprosthesis implantation for a traumatic lesion of the thoracic aorta (Gore TAG, 26 x 100 mm, after the instructions for use for a thoracic aorta of 22-24 mm). At 6 months, he came to the emergency room for a hypertensive crisis and acute pulmonary edema. The chest radiograph and thoracoabdominal computed tomographic angiography study showed collapse of the endoprosthesis and a type I proximal leak. A second TAG graft was inserted within the previously collapsed device, and re-expansion was achieved, with resolution of the initial symptoms. At 3 and 6 months, the patient remained asymptomatic, and there were no new findings on computed tomographic angiography.

Intentional coverage of the left subclavian artery during endovascular stent graft repair for thoracic aortic disease

BACKGROUND

Surgical revascularization of the left subclavian artery (LSA) has been performed to warrant arm perfusion and to prevent paraplegia during thoracic stent graft (SG) procedures. We retrospectively investigated the outcome after intentional occlusion of the left subclavian artery during SG repair for thoracic aortic diseases.

METHODS

From December 2000 to June 2005, 11 patients (mean age, 57 +/- 19 years) with a short (<1 cm) proximal aspect of a thoracic aortic lesion underwent intentional LSA coverage to expand the proximal landing zone for SG fixation. Three patients were treated in the emergency setting. We did not perform a prophylactic revascularization of the LSA prior to SG implantation. A preliminary balloon occlusion test of the LSA was not performed in this series. The SG was positioned so that its covering was immediately distal to the left common carotid artery.

RESULTS

SG implantation was technically successful in all patients. Intraoperative mortality was not observed; no patient suffered any impairment of left carotid artery flow. Aortography after SG implantation showed no direct flow in the LSA and refilling of the LSA via the ipsilateral vertebral artery. After the intervention, mean systolic pressure in the left arm decreased by 38 +/- 17 mmHg. The stented length of the aorta was 171 +/- 73 (median, 150). During hospitalization, no patient showed any signs of left arm malperfusion. Paraplegia was not observed. One patient developed transient ischemic attack. During a mean follow-up of 19 +/- 8 months (range, 3-36), all patients were completely asymptomatic and had no functional deficit or temperature differential between arms. No leakage was detected.

CONCLUSION

Intentional LSA occlusion seems to be well tolerated. Prophylactic surgical maneuvers may be relegated to an elective measure after an endovascular aortic intervention when intolerable signs or symptoms of ischemia occur.

Endovascular repair of a proximal aortic arch aneurysm: A novel approach of supra-aortic debranching with antegrade endograft deployment via an anterior thoracotomy approach

Although open surgical repair continues to be the standard therapy for thoracic aortic aneurysms, endovascular intervention has evolved into an acceptable strategy for patients who have prohibitive risks for conventional surgical treatments. Aortic arch aneurysm, in particular, is associated with substantial surgery-related morbidities, yet is typically not suitable for endovascular intervention. We describe a combined technique of supra-aortic trunk debranching through an anterior thoracotomy followed by endovascular repair of a large proximal arch aneurysm in an 82 year-old man 8 years after an ascending aortic aneurysm repair.

Spinal cord ischemia after elective stent-graft repair of the thoracic aorta

OBJECTIVES

Neurologic deficit after endovascular treatment of the thoracic aorta is a complication reported with variable frequency that may be associated with severe morbidity and mortality. The mechanism of spinal cord ischemia appears to be multifactorial and remains ill-defined. We reviewed our experience to investigate the determinants of paraplegia after stent-graft repair of the thoracic aorta, identify patients at risk, and assess the effectiveness of ancillary techniques.

METHODS

Over a 5-year period (June 1999 to December 2004), 103 patients underwent elective endovascular repair of the thoracic aorta at a university referral center. Indications for treatment were atherosclerotic aneurysms in 88 patients, chronic type B dissection in 10 patients, and penetrating aortic ulcer in 5 patients. Four of the 103 patients affected with thoracoabdominal aortic aneurysms had hybrid procedures and were excluded from the cumulative analysis. Twelve patients with zone 0 and zone 1 aortic arch aneurysms were operated on with synchronous or staged surgical aortic debranching. Preoperative cerebrospinal fluid (CSF) drainage was instituted in seven selected patients. Neurologic deficits were assessed by an independent neurologist and classified as immediate or delayed. Patient demographics and perioperative factors related to the endovascular procedure were evaluated by using univariate statistical analyses.

RESULTS

A primary technical success was achieved in 94 patients (94.9%). At a mean follow-up of 34 +/- 14 months, a midterm clinical success was obtained in 90 patients (90.9%). Four patients (4.04%) had delayed neurologic deficit that completely resolved after the institution of CSF drainage, steroids administration, and arterial pressure pharmacologic adjustment. None of the four patients who underwent hybrid procedures for thoracoabdominal aortic aneurysms had paraplegia or paraparesis. Univariate analyses identified only a perioperative lowest mean arterial pressure (MAP) of <70 mm Hg as a significant risk factor (P < .0001).

CONCLUSION

Perioperative hypotension (MAP <70 mm Hg) was found to be a significant predictor of spinal cord ischemia; hence, careful monitoring and prompt correction of arterial pressure may prevent the development of paraplegia. When the latter occurred, reduction of the CSF pressure by drainage was useful. Patients with a previous or synchronous abdominal aortic repair may also benefit from CSF drainage as a perioperative adjunct.