Value and limitations of chimney grafts to treat arch lesions

AIM

The endovascular debranching with chimney stents provides a minimally invasive alternative to open surgery with readily available devices and has extended the option of endoluminal therapy into the realm of the aortic arch. But a critical observation at the use of this technique at the aortic arch is important and necessary because of the lack of long-term results and long term patency of the stents. Our study aims to review the results of chimney grafts to treat arch lesions.

METHODS

A systematic health database search was performed in December 2014 according to the Prisma Guidelines. Papers were sought through a meticulous search of the MEDLINE database (National Library of Medicine, Bethesda, MA) using the Pubmed search engine.

RESULTS

Twenty-two articles were eligible for detailed analysis and data extraction. A total of 182 patients underwent chimney techniques during TEVAR (Thoracic Endovascular Aneurysm Repair). A total of 217 chimney grafts were implanted: 36 to the IA, 1 to the RCCA, 91 to the LCCA and 89 to the LSA. The type of stent-graft used for TEVAR was described in 132 patients. The type and name of chimney graft was described in 126 patients. In 53 patients information was limited to the type. Primary technical success, defined as a complete chimney procedure was achieved in 171 patients (98%). In 8 patients it was not clearly reported. The overall stroke rate was 5.3%. The overall endoleak rate, in those papers were it was clearly reported, was 18.4% (31 patients); 23(13,6%) patients developed a type IA endoleak, 1 patient (0.6%) developed type IB endoleak and 7 patients (4.1%) developed a type II endoleak

CONCLUSION

The total endovascular aortic arch debranching technique represent a good option to treat high-risk patients, because it dramatically reduces the aggressiveness of the procedure in the arch. Many concerns are still present, mainly related to durability and material interaction during time. Long-term follow-up is exceptionally important in light of the interactions of the stents, the thoracic endograft, the aortic arch, and every variation in systolic and diastolic pressure. Actually this technique has acceptable short and mid-term results. Long term data are available just from a very small number of patients and more data from a wider number are needed in order to embrace this method as a safe one.

Case report of an endovascular repair of a residual type A dissection using a not CE not FDA-approved Najuta thoracic stent graft system

This report describes an endovascular repair of a residual type A dissection using a medical device that is not marked by european conformity (CE) or Food and Drug Administration (FDA).The patient underwent ascending aortic surgery for acute type A dissection. The 2-year angio-computed tomography demonstrated patency of the residual false lumen with evolution into a 6 cm aneurysm, the extension of the dissection from the aortic arch to the aortic bifurcation with thrombosis of the right common iliac artery. There was no CE- or FDA-marked medical device indicated for this case or any other acceptable therapeutic alternative.We used the Najuta thoracic stent graft and successfully handled the pathology in a multiple-phase treatment.Technology is evolving with specific grafts for the ascending and fenestrated grafts for the aortic arch. In this single case the Najuta endograft, in spite of the periprocedural problems, was a valid therapeutic option.

Endovascular repair of acute uncomplicated aortic type B dissection promotes aortic remodelling: 1 year results of the ADSORB trial

OBJECTIVES

Uncomplicated acute type B aortic dissection (AD) treated conservatively has a 10% 30-day mortality and up to 25% need intervention within 4 years. In complicated AD, stent grafts have been encouraging. The aim of the present prospective randomised trial was to compare best medical treatment (BMT) with BMT and Gore TAG stent graft in patients with uncomplicated AD. The primary endpoint was a combination of incomplete/no false lumen thrombosis, aortic dilatation, or aortic rupture at 1 year.

METHODS

The AD history had to be less than 14 days, and exclusion criteria were rupture, impending rupture, malperfusion. Of the 61 patients randomised, 80% were DeBakey type IIIB.

RESULTS

Thirty-one patients were randomised to the BMT group and 30 to the BMT+TAG group. Mean age was 63 years for both groups. The left subclavian artery was completely covered in 47% and in part in 17% of the cases. During the first 30 days, no deaths occurred in either group, but there were three crossovers from the BMT to the BMT+TAG group, all due to progression of disease within 1 week. There were two withdrawals from the BMT+TAG group. At the 1-year follow up there had been another two failures in the BMT group: one malperfusion and one aneurysm formation (p = .056 for all). One death occurred in the BMT+TAG group. For the overall endpoint BMT+TAG was significantly different from BMT only (p < .001). Incomplete false lumen thrombosis, was found in 13 (43%) of the TAG+BMT group and 30 (97%) of the BMT group (p < .001). The false lumen reduced in size in the BMT+TAG group (p < .001) whereas in the BMT group it increased. The true lumen increased in the BMT+TAG (p < .001) whereas in the BMT group it remained unchanged. The overall transverse diameter was the same at the beginning and after 1 year in the BMT group (42.1 mm), but in the BMT+TAG it decreased (38.8 mm; p = .062).

CONCLUSIONS

Uncomplicated AD can be safely treated with the Gore TAG device. Remodelling with thrombosis of the false lumen and reduction of its diameter is induced by the stent graft, but long term results are needed.

Endovascular treatment of extracranial vertebral artery aneurysm and aberrant right subclavian artery aneurysm

We report an endovascular approach that used to treat a symptomatic extracranial vertebral artery aneurysm associated to an asymptomatic aberrant right subclavian artery aneurysm. A 54-year-old man presented with neck pain, vertigo and loss of balance. The computed tomography (CT) scan demonstrated a left extracranial vertebral artery aneurysm that compressed and eroded the C5 vertebra associated to an aberrant right subclavian artery aneurysm. Endovascular exclusion of the vertebral aneurysm using a covered stent and a hybrid treatment of the aberrant subclavian artery aneurysm were performed. The 13th month follow-up CT scan confirmed the stent-grafts and supra-aortic vessels patency. The endovascular treatment represents a good option for these complex pathologies with excellent immediate results, reduces the complication rate and the hospital stay if compared to open repair. Long-term follow-up is necessary. To our knowledge this is a unique case in the literature.

Percutaneous endovascular aneurysm repair with the ultra-low profile Ovation Abdominal Stent-Graft System

AIM

Aim of the study was to report our single-center experience of the ultra-low profile OvationTM Abdominal Stent-Graft System with totally percutaneous endovascular aneurysm repair (PEVAR).

METHODS

Between December 2010 and March 2013 we electively treated 35 patients (male: 89%, mean age: 73±7 years) with abdominal aortic aneurysm (AAA) using bilateral PEVAR with the OvationTM endograft. Most (77%) cases were characterized by challenging femoral artery anatomy. Patients returned for follow-up visits at 1, 3, 6 months and annually thereafter.

RESULTS

Technical success was 97.1%. One type Ia endoleak was identified on final angiography, which was treated with an extension cuff. No groin complications were observed, including lymphocele, hematoma, pseudoaneurysm, dehiscence, or wound infection. Mean follow-up was 10 months (range 1-24 months). No death was registered. One type Ia endoleak was identified at the 12-month follow-up, which resolved with placement of a Palmaz balloon-expandible stent. No type II, III, or IV endoleaks were identified. No migration, AAA enlargement, AAA rupture, or conversion to open surgery was reported. Two patients (5.7%) developed monolateral iliac limb occlusion at 58 and 72 days of follow-up, respectively. In one case a limb kinking was observed and treated with iliac kissing stent. The other limb occlusion was due to external iliac artery severe stenosis and was treated with thrombolysis and iliac artery stenting.

CONCLUSION

PEVAR with the OvationTM endograft is feasible and safe in patients with unfavorable anatomy.

Temporal approach: a good way to provide cerebral protection for proximal carotid stenosis, the last chance for trackability in CAS

AIM

The aim of this study was to evaluate the usefulness of the temporal approach during coronary artery stenosis (CAS) to overcome tortuosity in case of difficult arch anatomy or tortuous common carotid artery, and to provide cerebral protection of proximal lesions of the supra-aortic trunks during stenting.

METHODS

The superficial temporal artery is exposed through a small incision right in front of the ear and is cannulated. A guidewire is used to descend in the external and common carotid artery and in the arch if needed. Between the end of March 2007 and May 2008 9 patients were treated with the temporal approach: in 5 cases of stenosis of the internal carotid artery with difficult arch anatomy to obtain a through and through guide from the temporal to the femoral artery, in 3 of the supra-aortic trunks to obtain cerebral protection during the procedure and in one case of tandem lesion of the left common and internal carotid artery.

RESULTS

The procedure was successful in all 9 cases and there were no complications.

CONCLUSIONS

The temporal approach proved to be feasible and at low risk; it represents a new possibility to increase the feasibility of carotid artery stenting in patients with difficult anatomy but, above all, it is a good way to obtain cerebral protection during endovascular treatment of proximal lesions of the supra-aortic vessels.

Carotid endarterectomy in diabetic patients

OBJECTIVE

The purpose of the current study was to identify the possible short- and long-term effects of diabetes on the outcome of carotid endarterectomy.

METHODS

Medical records were reviewed for 781 carotid endarterectomies (in 734 patients) performed by the same vascular surgeon in a university medical center between January 1994 and December 1998. Patients were divided two groups: those with diabetes (n = 181 patients; 193 operations) and those without diabetes (n = 553; 588 operations). The two groups were similar with respect to mean age, male-female ratio, and contralateral lesions. The only significant differences were a higher prevalence of peripheral vascular disease and dyslipidemia in the diabetic group and a higher prevalence of hemispheric transient ischemic attacks among the nondiabetic patients. Carotid color duplex ultrasound scan had been performed in all patients, and in 56 patients from the diabetic group and 56 patients from the nondiabetic group (matched for age, sex, and contralateral lesions), the distal extension of the lesion from the carotid bifurcation had also been defined. Both of these subgroups were fully representative of their respective groups of origin. Carotid endarterectomy was performed after the induction of general anesthesia; electroencephalographic monitoring was continuous.

RESULTS

Except for the significantly higher prevalence of calcified plaques in the diabetic patients (P <.0001), the characteristics of the carotid disease in the two groups were similar. In the 56-member subgroups, 73.2% of the diabetic and 35.7% of the nondiabetic patients (P <.0001) had lesions extending more than 2 cm beyond the carotid bifurcation. Mean length of plaque beyond the bifurcation was 2.3 +/- 0.09 cm for the diabetic and 1.7 +/- 0.08 cm for the nondiabetic patients (P <.0001). Diabetes was the only factor significantly correlated with plaque length. In the diabetic subgroup, surgery was characterized by significantly longer carotid arteriotomies (P =.03) and clamp times (P <.003). Operative mortality was 1.5% in the diabetic group (2 myocardial infarctions + 1 stroke) and 0.5% in the nondiabetic group (1 myocardial infarction + 2 strokes; P value not significant); stroke rates were 1.5% (3 major strokes) and 0.5% (2 major strokes + 1 minor stroke), respectively (P = not significant). Long-term survival (5 years) was not significantly lower among the diabetic patients.

CONCLUSIONS

Diabetes mellitus does not seem to significantly increase the surgical risk for carotid endarterectomy. The presence of more extensive plaques has no significant effect on the results of surgery.

[Update on cerebral monitoring and protective methods]

Clamping ischaemia is responsible for the 20-30% of the neurological complications during carotid surgery. It is impossible at present to determine preoperatively for certainty the patients who are at risk and the ones who are not at risk for clamping ischemia. Intraoperative monitoring is mandatory in all the cases to point out cerebral ischemia and to prevent neurological deficit with an adequate brain protection. Methods used to predict brain ischaemia include local anesthesia, EEG, SEP, stump pressure measurement, transcranial doppler, regional cerebral blood flow measurement and evaluation of venous blood gases from the internal jugular vein. Local anesthesia is a safe and simple method of assessing cerebral ischemia during carotid clamping but has some limits particularly in case of brain ischaemia for the technical difficulties to install an indwelling shunt in an awake and often troubled patient. Moreover the only possibility of cerebral protection under local anesthesia is an increase in systemic blood pressure with a resulting growth in cardiac morbidity and mortality. For these reasons operation should be performed under general anesthesia to assure a better farmacogical brain protection when preoperative evaluation demonstrates a reduction of cerebral vasoreactivity, with a consequent high risk of clamping ischemia. At present EEG is one of the most used technique of cerebral monitoring under general anesthesia with a sensibility and specificity in the diagnosis of brain ischaemia that is about 90%. The best cerebral protection is obtained with a selective shunting. Burst suppression, with high dose thiopentone, has recently demonstrated its reliability alone or in association with an indwelling shunt in patients at high risk for clamping ischaemia. Of course a systematic cerebral protection together with an accurate control of the blood pressure is necessary in all the patients. This behaviour allowed us to obtain good results in the last 500 patients with a morbidity and mortality respectively of 1% and 1.6% with no significant differences between patients who tolerated carotid clamping and those with clamping ischaemia.

Cerebral haemodynamics during carotid cross-clamping

Carotid artery cross-clamping ischaemia during carotid endarterectomy (CEA) causes 5-30% of perioperative neurological deficits. This study was performed to identify possible clinical situations at higher risk for carotid cross-clamping ischaemia. 606 consecutive patients underwent CEA and were retrospectively studied; they were grouped according to risk factors, presence of associated vascular diseases, clinical pattern, angiographic and CT scan findings. Stump pressure measurement was provided in all patients, perioperative monitoring during CEA was performed by electroencephalogram (EEG) in 469 (77%) and somatosensorial evoked potentials (SEP) in 137 (23%). Local anaesthesia was used in 88 (14.5%) patients. Ischaemic changes during carotid cross-clamping were registered in 118 patients (19.5%). The incidence of cross-clamping ischaemia was then related to different factors; it affected 5.6% of asymptomatics, 25.4% of patients with fixed stroke and 38.5% of those with stenosis and contralateral occlusion. Angiographic and clinical correlation showed that patients with more severe lesions are mostly affected by clamping ischaemia (up to 55% in those with stroke and stenosis with contralateral occlusion). Age, hypertension and diabetes do not significantly affect incidence of ischaemic changes. Positive CT scan increased this risk; statistical relevance was found in regard to patients with unilateral or bilateral stenosis and in those with transient ischaemic attacks. A higher risk can be expected for subjects with more severe clinical and instrumental findings, even if no patients can be considered completely at risk or risk free. Perioperative monitoring is always mandatory and is of great importance in detecting ischaemic changes and preventing cerebral damage using a temporary intraluminal shunt.