Left subclavian artery coverage during thoracic endovascular aortic repair: A single-center experience

Coverage of the left subclavian artery without revascularization during thoracic endovascular repair is feasible: a prospective study

BACKGROUND

To effectively isolate thoracic aortic lesions in thoracic endovascular aortic repair (TEVAR), an adequate proximal landing zone length is required. The left subclavian artery (LSCA) and other branches of the aortic arch commonly impose limitations on proximal landing zone length, restricting the use of TEVAR. In this study, we investigated the outcomes of LSCA coverage during TEVAR.

METHODS

Between March 2009 and February 2010, we recruited patients with thoracic dissection, aneurysm or trauma from a single center for TEVAR. We categorized patients into 3 groups: full coverage, partial coverage, or noncoverage of the LSCA. We measured pre- and postoperative blood pressures and evaluated complications during follow-up.

RESULTS

We recruited 111 patients for our study: 55 (50%) and 25 (23%) patients had full and partial LSCA coverage, respectively. The upper left arm blood pressures before and after the operations were significantly different between the full-coverage group and the other groups (P < 0.0001). Follow-up occurred between 6 and 20 months, and the mean follow-up time was 10.4 months. Thirteen patients (24%) in the full-coverage group and 2 patients (8%) in the partial-coverage group suffered from simple vertebrobasilar ischemia (VBI). Eleven of the patients with VBI (20%) in the full-coverage group and 2 (8%) patients with VBI in the partial-coverage group had left subclavian steal syndrome at follow-up. No paraplegia or stroke was observed.

CONCLUSIONS

Intentional coverage of the LSCA to obtain an adequate proximal landing zone for TEVAR can be a treatment option for thoracic aortic lesions, although some patients experienced mil complications.

Innovative application of available stent grafts in Japan in aortic aneurysm treatment-significance of innovative debranching and chimney method and coil embolization procedure

OBJECTIVE

We here describe our experience with innovative uses of these devices.

PATIENTS AND METHODS

We reviewed treatment outcomes of 310 endovascular abdominal aortic repair (EVAR) and 83 thoracic endovascular aortic repair (TEVAR) cases performed between August 2007 and February 2012. We separately assessed results in elderly and high-risk patients who had a novel procedure. This group included 94 patients who underwent EVAR with IIA embolization, 10 patients who had EVAR and a renal artery chimney procedure for a short aortic neck, 20 patients who had two de-branching TEVAR or Chimney method for thoracic aortic aneurysms (TAA) and 3 patients who had debranching TEVAR for thoracic abdominal aortic aneurysms (TAAA).

RESULTS

Of the 393 patients given stent grafts (SGs), 3 (0.8%) died in the hospital, including 1 patient with pneumonia who underwent EVAR and IIA embolization and 1 patient with a cerebral infarction who had TEVAR. Four patients (4.3%) who were treated with EVAR with internal iliac artery (IIA) embolization presented with residual buttock claudication 6 months postoperatively, and 3 patients (3.2%) had onset of ischemic enteritis; however, in all 7 patients, the condition resolved without additional intervention. In the 10 patients who had EVAR and a renal artery chimney method, the landing zone (LZ) was ≤10 mm, but neither endoleak nor renal artery occlusion was observed perioperatively or during midterm follow-up. Of the 20 patients who had a 2-debranching TEVAR, including 9 in whom the chimney method was used with the LZ in zone 0, 1 (5%) had a residual endoleak. In 3 patients with TAAA, we used SGs to cover 4 abdominal branches and bypassed the visceral artery; the outcomes were good, with all patients being ambulatory at hospital discharge.

CONCLUSION

Among innovative SGs treatments, the debranching procedure and the chimney method using catheterization and the coil-embolization technique provided good outcomes, as used in addition to surgical procedures. Aortic aneurysm treatment will become increasingly noninvasive with the continuing development of more innovative ways to use the SGs currently available in Japan. (English Translation of Jpn J Vasc Surg 2012; 21: 165-173).

Elephant trunk technique for hybrid aortic arch repair

The original elephant trunk technique was developed by Borst in 1983 for the treatment of aortic arch aneurysms. This technique reduced operative risks, but was associated with cumulative mortality rates of 6.9 % for the first stage and 7.5 % for the second stage. Patients also waited a long time between two major surgical procedures. Only 50.4 % of patients underwent the second-stage surgery, and there was a significant interval mortality rate of 10.7 %. With the advent of stent-graft techniques, two different hybrid elephant trunk techniques were developed. One technique is first-stage elephant trunk graft placement followed by second-stage endovascular completion. The conventional elephant trunk graft provides a good landing zone for the stent-graft, and endovascular completion is a useful alternative to conventional second-stage surgery. This method has few major complications, and a postoperative paraplegia rate of 1.1 %. The other technique is the frozen elephant trunk technique. This technique eliminates the need for subsequent endovascular completion, and is particularly useful for the treatment of acute type A dissection because it can achieve a secure seal. However, it is associated with a higher rate of spinal cord ischemia than other methods such as the original elephant trunk technique. The left subclavian artery (LSA) is often lost when performing a hybrid elephant trunk procedure. Revascularization of the LSA should be performed to prevent arm ischemia and neurological complications such as paraplegia or stroke, although the level of evidence for this recommendation is low.

Subclavian revascularization in the age of thoracic endovascular aortic repair and comparison of outcomes in patients with occlusive disease

OBJECTIVE

Open surgical revascularization for subclavian artery occlusive disease (OD) has largely been supplanted by endovascular treatment despite the excellent long-term patency of bypass. The indications for carotid-subclavian bypass (C-SBP) and subclavian transposition (ST) have been recently expanded with the widespread application of thoracic endovascular aortic repair (TEVAR), primarily to augment proximal landing zones or treat endovascular failures. This study was performed to determine the outcomes of patients undergoing C-SBP/ST in the context of contemporary endovascular therapies and evolving indications.

METHODS

A prospective database including all procedures performed at a single institution from 2002 to 2012 was retrospectively queried for patients who underwent subclavian revascularization for TEVAR or OD indications. Patient demographics and perioperative outcomes were recorded. Patency was determined by computed tomography angiography in the TEVAR group. Noninvasive studies were used for the OD patients. Life-table methods were used to estimate patency, reintervention, and survival.

RESULTS

Of 139 procedures identified, 101 were performed for TEVAR and 38 for OD. All TEVAR patients underwent C-SBP/ST to augment landing zones (49% preoperative; 41% intraoperative), treat arm ischemia (8% postoperative), or for internal mammary artery salvage (2%). OD patients had a variety of indications, including failed stent/arm fatigue, 49%; asymptomatic >80% internal carotid stenosis with concurrent subclavian occlusion, 18%; symptomatic cerebrovascular OD, 13%; redo bypass, 8%; and coronary-subclavian steal, 5%. Differences in postoperative stroke and death, primary patency, or freedom from reintervention were not significant. The 30-day postoperative stroke, death, and combined stroke/death rates were, respectively, 10.8%, 5.8%, and 13.7% for the entire cohort; 8.9%, 7.1%, and 12.9% in TEVAR patients; and 15.8%, 2.6%, and 15.8% in OD patients. The 1- and 3-year primary patencies were, respectively, 94% and 94% for TEVAR and 93% and 73% for OD patients. Survival was similar between the groups, with an estimated survival rate of 88% at 1 year and 76% at 5 years.

CONCLUSIONS

Stroke risk in this contemporary series of C-SBP/ST performed for TEVAR and OD indications may be higher than previously reported in historical series. In TEVAR patients, this may be attributed to procedural complexity of the TEVAR in patients requiring subclavian revascularization. In OD patients, this is likely due to the changing patient population that requires more frequent concomitant carotid interventions. Despite the short-term morbidity, excellent bypass durability and equivalent long-term patient survival can be anticipated.

Further consideration for subclavian revascularization with TEVAR

Management of the left subclavian artery (LSA) during thoracic endovascular aortic repair (TEVAR) continues to be controversial, despite recent guidelines submitted by the Society for Vascular Surgery recommending routine revascularization of the LSA in most circumstances. Up to one third of patients require coverage of the LSA during TEVAR. The LSA provides extensive circulation to the upper extremity, spinal cord, and brain, consequently, sacrifice of this great vessel might not be physiologically tolerated. Studies supporting routine preoperative revascularization of the LSA note increased rates of spinal cord ischemia, strokes, and upper extremity ischemia when the LSA is sacrificed. Other studies supporting a selective revascularization strategy note no difference in neurologic outcomes and recommend expectant management of upper extremity ischemia. In addition, LSA revascularization has associated complications that are avoided by selective revascularization. The purpose of this article is to review and focus the available data in support of routine versus selective LSA revascularization.

Thoracic endovascular aortic repair with the chimney technique for blunt traumatic pseudoaneurysm of the aortic arch in a no-option patient

A 42-year-old man was involved in a motor vehicle collision. Imaging studies revealed the presence of a post-traumatic aortic pseudo-aneurysm (about 34 × 26 cm) arising from the descending thoracic aorta at the level of the left subclavian artery (LSA), prone to rupture. Thoracic endovascular aneurysm repair (TEVAR) was the only feasible option due to his poor overall medical status. In this case, LSA needed to be covered in order to extend the proximal landing zone. Eventually, modified TEVAR was successfully performed by means of the chimney technique to preserve flow to the LSA and to prevent flow into the pseudoaneurysmal sac.

Endovascular repair of growing chronic type B aortic dissection with a vascular plug

We report the successful endovascular repair of a growing chronic type B aortic dissection using an Amplatzer Vascular Plug II. A 44-year-old man, with previous medical history of aortic surgery and stenting complained of vague back pain. An approximately 5-mm entry remained in the stented segment of the aorta on computed tomography (CT). Endovascular closure of the entry with a Vascular Plug was uneventful. A 3-month follow-up CT showed no leak, complete false lumen thrombosis in the thoracic segment, shrinkage of the false lumen, and a reduced diameter of thoracic aorta.

Selective left subclavian ligation in total aortic arch replacement

BACKGROUND

The left subclavian artery (LSA) is usually difficult to manipulate in total aortic arch replacement procedures if it is displaced by huge false lumens in the ascending aorta or right hemiarch. We summarize our experience of selectively ligating the deeply located LSA in total aortic arch replacement and stented "elephant trunk" implantation procedures for Stanford type A aortic dissection.

METHODS

Data of 29 patients with deep LSA undergoing total arch replacement and stented "elephant trunk" implantation from January 2008 to June 2010 were reviewed. The LSA was ligated because of the difficult exposure (21 males, 8 females, age 19 to 55). Collateral circulation of the circle of Willis and bilateral vertebral arteries were assessed thoroughly by preoperative imaging and intraoperative observations. If collateral circulation was sufficient, LSA was ligated; if insufficient, an additional bypass graft was created from the ascending aorta to the left axillary artery.

RESULTS

Twenty-eight patients survived the operation with 1 early death. Postoperative blood pressures were lower in the left arm than in the right (78±17.3 vs 126±3.7 mm Hg, p<0.01), but oxygen saturation, skin temperature, and strength of the left hand were normal. The surviving patients have been followed for 16.6±9.0 months (6 to 36) and none had symptoms of LSA steal syndrome or arm ischemia.

CONCLUSIONS

Ligation of the LSA after strict evaluation of collateral circulation could be safe for type A dissection patients if the exposure is insufficient, and this method can simplify the operation significantly.

Results with a selective revascularization strategy for left subclavian artery coverage during thoracic endovascular aortic repair

BACKGROUND

The need for routine left subclavian artery (LSCA) revascularization when this vessel is covered during thoracic endovascular aortic repair remains controversial. We report our results with a selective LSCA revascularization strategy during thoracic endovascular aortic repair.

METHODS

Between May 2002 and March 2010, 287 thoracic endovascular aortic repair procedures were performed at our institution. LSCA coverage occurred in 145 (51%), which form the basis of this report.

RESULTS

Left subclavian artery revascularization was performed in 32 patients (22%) through a left common carotid-LSCA bypass. Indications for selective LSCA revascularization included spinal cord protection in 10, patent pedicled left internal mammary artery graft in 9, left arm ischemia after LSCA coverage in 5, origin of the left vertebral artery from the arch in 4, dialysis access in the left arm in 2, and vertebrobasilar insufficiency in 2. There were no instances of dominant left vertebral artery. The revascularized and non-revascularized groups had similar rates of death (6.3% vs 1.8%; p=0.21), stroke (3.1% vs 3.5%; p>0.99), permanent paraplegia or paraparesis (3.1% vs 0%; p=0.22), and type II endoleak (4.3% vs 6.5%; p>0.99). There were no instances of ischemic stroke related to left posterior circulation hypoperfusion. Four complications of carotid-subclavian bypass occurred in 3 patients (9.4%).

CONCLUSIONS

Selective LSCA revascularization is safe and does not appear to increase the risk of neurologic events. Further, subclavian revascularization is not without complications, which should be considered with regards to a nonselective revascularization strategy.

Management of acute complicated and uncomplicated type B dissection of the aorta: focus on endovascular stent grafting

Endovascular repair of aortic dissection is the subject of multiple studies. This article aims to review the current literature on Type B complicated and uncomplicated dissection, including indications for medical therapy, open surgical therapy, and endovascular therapy. The review suggests a benefit for thoracic endovascular aortic repair in complicated dissection and medical therapy for uncomplicated dissection. Upcoming trials may shed more light on this issue.

The effects of operative indication and urgency of intervention on patient outcomes after thoracic aortic endografting

BACKGROUND

Endovascular repair for complex thoracic aortic pathology has emerged over the past decade as an alternative to open surgical repair. Reports suggest lower morbidity and mortality rates associated with endovascular interventions. The purpose of this report was to analyze a large single institution experience in endovascular thoracic aortic repair based on clinical presentation as well as within and outside specific instructions for use.

METHODS

Records of all patients undergoing thoracic aortic endografting at our institution were retrospectively reviewed for demographics, interventional indications and acuity, operative details, and clinical outcomes. Study outcomes were analyzed by clinical presentation (urgent/emergent vs elective) and aneurysm morphology that was within and outside specific instructions for use as recommended by the manufacturer.

RESULTS

Between March 2006 and October 2009, 96 patients underwent thoracic endografting for aneurysm (n = 43), transection (n = 7), penetrating ulcer (n = 11), dissection (n = 19; acute = 9, chronic = 10), pseudoaneurysm (n = 11), or miscellaneous indications (n = 5). Endografting was performed with various endografts (Gore TAG: 59; Medtrontic Talent: 26; Zenith-TX2: 7; Combination: 4.Involvement of the arch (n = 42, 43.75%) was treated with subclavian artery coverage without revascularization in 13 (13.5%), debranching in 20 (20.8%), and fenestration/stenting in 9 (9.38%). Involvement of the visceral vessels (n = 24, 25%) was treated with debranching in 15 (15.6%) or fenestration/stenting in 9 (9.4%). Patients had a mean follow-up of 11.5 ± 10.96 (range: 0-38) months. Overall mortality was 6.25% (n = 6). Mean intensive care unit stay was 6.26 ± 8.55 (range: 1-63, median: 4) days, and hospital stay was 9.97 ± 10.31 (range: 1-65, median: 65) days. Major complications were infrequent and included: spinal cord ischemia (n = 6, 6.25%), stroke (n = 6, 6.25%), myocardial infarction (n = 3, 3.15%), renal failure (n = 6, 6.25%), and wound complications (n = 9, 9.38%). Reoperation was required in 13 (13.54%), with early intervention in 2 (2.1%). The vast majority of patients were discharged directly to home (n = 66, 68.8%). There were no significant differences between death (1/49 [2%] vs 5/47 [10.6%], P = .07), stroke (3/49 [6%] vs 3/47 [6%], P = 1.0), or spinal cord ischemia (3/49 [6%] vs 3/47 [6%], P = 1.0) when comparing urgent/emergent presentation to elective cases, respectively. However, there were significant differences in death (6/58 [10.5%] vs 0/38 [0%], P = .04) and spinal cord ischemia (6/58 [10.5%] vs 0/38 [0%], P = .04) but not stroke (5/58 [8.8%] vs 1/38 [2.5%], P = .24] when procedures were performed outside the specific instructions for use.

CONCLUSIONS

Results of this single-institution report suggest that endovascular thoracic aortic repair is a safe and effective treatment option for a variety of thoracic pathology including both elective and emergent cases. However, off-label usage of the devices is associated with a significantly higher risk of mortality and spinal cord ischemia, but the risk still appears acceptable given the majority of cases were emergent.

Endovascular repair of extent I thoracoabdominal aneurysms with landing zone extension into the aortic arch and mesenteric portion of the abdominal aorta

Thoracic endovascular aortic repair (TEVAR) has emerged as an alternative for patients at prohibitive risk for open thoracic or thoracoabdominal surgery, decreasing perioperative morbidity and mortality. Aneurysms that involve both the left subclavian artery (LSA) proximally and the celiac artery (CA) distally present a unique challenge to the use of TEVAR. We report a series of six high-risk patients presenting with extent I thoracoabdominal aortic aneurysms who were successfully treated with TEVAR including coverage of the LSA and the CA.

Endovascular repair of a type B aortic dissection with a ventricular septal defect occluder

We report a successful endovascular repair of a type B aortic dissection (TB-AD) with a ventricular septal defect (VSD) occluder. In a 39-year-old male patient with TB-AD, the proximal entry tear was 5 mm distal to the orifice of the left subclavian artery (LSA). Ascending aorta-left common carotid artery (LCCA)-LSA bypass was performed, followed by obliterating the proximal entry tear with a VSD occluder endovascularly. One-month follow-up computed tomography angiography showed optimal position of the VSD occluder, absence of leak, complete false lumen thrombosis in the thoracic segment, expansion of the true lumen, and shrinkage of the false lumen.

Coverage of the celiac artery during TEVAR: is it ever appropriate?

Adequate seal at the proximal and distal extent of stent grafts in the aorta is paramount to the success of thoracic endovascular aortic repair (TEVAR). Thoracoabdominal aneurysms pose a formidable challenge given their extension into the arch branches proximally and the visceral segment distally. Extension of the landing zone of even 3 to 5 mm can possibly increase the durability of the stent graft and may decrease the chances of future migration or collapse. Although coverage of the subclavian artery to extend the proximal landing zone has been met with initial success, the outcome of coverage of the celiac axis in order to extend the distal landing zone has not been as well studied. Because of the abundance of rich collateral vessels in the foregut, it has been perceived as a potentially safe practice. However, careful angiographic anatomic delineation and patient selection is vital to determine whether concomitant revascularization procedures are warranted.

Thoracic aortic transection treated by thoracic endovascular aortic repair: predictors of survival

BACKGROUND

We reviewed all patients presenting to our institution with a traumatic thoracic aortic injury (TTAI) between January 2006 and May 2007. Age, gender, injury severity score (ISS), location of injuries, surgical intervention, and length of stay were assessed to determine what characteristics might be predictive of survival. Of the 56 patients who were identified, 23 (41%) were dead on arrival, 15 (20%) died on that admission, and 18 (32%) survived to discharge. Injury severity score was elevated in mortalities (57) compared to survivors (34). Penetrating and blunt aortic injuries had 89% and 58% mortality rates, respectively. Female gender was associated with increased survival (P = .032), as was receiving surgical intervention (P = .03). Patients with a prolonged ICU stay demonstrated increased survival. All eight patients who received thoracic endovascular aortic repair survived to discharge. Injury severity score, mechanism, thoracic endovascular aortic repair (TEVAR), female gender, and surgical treatment were associated with survival after TTAI.