Endovascular Management of Complex Renal Artery Aneurysms Using the Multilayer Stent

Endovascular treatment of a wide-necked renal artery aneurysm with a flow diverter stent

Renal artery aneurysm (RAA) is a rare, often asymptomatic disease (0.1% incidence in general population) and can be incidentally diagnosed during an abdominal imaging workup. The traditional, gold standard of treatment is open surgery, carrying with it, however, a high risk of nephrectomy, mortality, and collateral morbidity. The endovascular approach is currently the most valid alternative to treating RAAs reducing, as it does, the risks associated with the surgical approach/open surgery. Herein we report on our experience with a case of wide-necked RAA treated with the Pipeline Vantage (Medtronic) flow diverter stent. Wide-neck aneurysms are defined as having neck diameters greater than 4 mm. Our choice of endovascular treatment was preferred over the surgical option notwithstanding the large size of the neck and the involvement of the branching vessels.

Eighteen cases of renal aneurysms: Clinical retrospective analysis and experience of endovascular interventional treatment

Background

Development of endovascular interventional techniques gradually replaced traditional open surgery and has become the preferred treatment for renal aneurysms. This study aimed to analyze the clinical characteristics of renal artery aneurysm (RAA) and the safety and efficacy of intravascular interventional treatment.

Materials and Methods

We retrospectively analyzed the clinical characteristics and imaging data of 23 aneurysms in 18 patients with RAA. The technical success rate, complication rate, mortality rate, reintervention rate, and use of embolization materials were evaluated.

Results

In 18 patients with RAA (age, 32-72 years, average age, 52.2 ± 11.2 years), a total of 23 aneurysms were found (diameter 0.5-5.5 cm, average diameter 2.2 ± 1.4 cm). Among them, 11 cases (61.1%) were discovered accidentally, and the remaining patients were diagnosed due to the following major complaints: four cases (22.2%) presented low back pain, two (11.1%) were due to high blood pressure, and one (5.5%) had low back pain with gross hematuria. A total of 14 aneurysms in 13 patients received endovascular interventional therapy. The technical success rate of 13 patients with renal aneurysms was 100%. Three of the 18 patients were lost to follow-up, and the remaining were followed up for 4-89 months. There was no recurrence of the aneurysm or displacement of the stent or coil.

Conclusion

Endovascular treatment for RAA has a high success rate, low complication rate, and low reintervention rate. It has the advantage of less trauma and is flexible and more targeted for different types of renal aneurysms.

Coil embolization of a complex renal artery aneurysm using a new scaffold (Comaneci) device – A case report

Advances in endovascular approaches have resulted in increasing utilization of minimally invasive techniques to treat visceral artery aneurysms including renal artery aneurysms (RAAs), with high rates of success. The basic endovascular approach to treating RAAs includes stent graft exclusion or coil embolization. Treatment of RAAs with wide necks or at the bifurcation of the main vessel is facilitated by scaffolding techniques, which have been previously described. These techniques have their limitations and cannot be used in all situations. We describe a scaffolding technique using the Comaneci device (Rapid Medical, Israel), a retrievable mesh device meant for intracranial treatment of wide neck or bifurcation aneurysms that we used to safely and successfully treat a 2 cm RAA.

Packing Technique with or without Remodeling for Endovascular Coil Embolization of Renal Artery Aneurysms: Safety, Efficacy and Mid-Term Outcomes

The endovascular treatment of renal artery aneurysms (RAAs) has lower morbidity and shorter stay lengths compared to surgical repair. Here, we describe coil packing with or without remodeling and assess outcomes and complications. We retrospectively identified the 19 consecutive preventive endovascular RAA coil embolizations done in 18 patients at our center in 2010-2020. Patient and aneurysm characteristics, technical success rate, complications, and recurrences were recorded. Mean patient age was 63 ± 13 years. The RAA was >1.5 cm in 11 cases, and in four cases, the aneurysm-to-parent artery size ratio was >2. Simple coiling was performed for 11 (57.9%) aneurysms, stent-assisted coiling for seven (36.8%) aneurysms, and balloon-assisted coiling for one (5.3%) aneurysm. Technical success rate was 100%. Complete definitive RAA exclusion was achieved with a single procedure for 17 (89.5%) aneurysms, whereas two (10.5%) aneurysms required a repeat procedure. Four minor complications occurred but resolved with no long-term consequences. No major complications occurred during the mean follow-up of 41.1 ± 29.7 months. Coil embolization by sac packing or remodeling proved very safe and effective. Together with the known lower morbidity and shorter stay length compared to open surgery, these data indicate that this endovascular procedure should become the preventive treatment of choice for RAAs.

Tratamento de aneurismas de artéria esplênica e renal no mesmo tempo operatório: relato de caso e revisão

Resumo Aneurismas de artérias viscerais e renais são raros (0,01 a 2%) e seu risco de ruptura varia entre os diferentes tipos e de acordo com sua anatomia e contexto do paciente (comorbidades, gravidez e histórico de transplante hepático). A mortalidade decorrente da ruptura desses aneurismas é em torno de 25%. Novas técnicas e materiais derivados da neurointervenção parecem alternativas promissoras para o tratamento desses aneurismas. Neste contexto, relatamos um caso de paciente submetida a tratamento endovascular no mesmo procedimento de aneurisma de artéria esplênica e de artéria renal com a utilização de stent Solitaire® (Medtronic, Minneapolis, EUA) e molas de liberação controlada Ruby® (Penumbra, Alameda, EUA). A paciente apresentou boa evolução com ambos aneurismas tratados de forma adequada. Em conclusão, o tratamento endovascular de aneurismas de artéria esplênica e renal no mesmo tempo operatório é exequível e demonstrou segurança e efetividade no caso relatado.

Giant celiac artery aneurysm

Celiac artery aneurysms (CAAs) are rare but potentially devastating lesions. Given the high rates of mortality on rupture at large sizes, they should be treated promptly with either surgical or endovascular interventions in appropriate-risk patients. Several options exist for treatment, including surgical repair and endovascular embolization with or without stent or stent graft placement. Because of their rarity, there are few reports of successfully treated CAA lesions. Herein, we describe successful endovascular treatment of one of the largest CAAs reported in the literature.

Endovascular treatment of true renal artery aneurysms: a single center experience

PURPOSE

We aimed to report a single center's experience on endovascular treatment of true renal artery aneurysms (TRAAs), including treatment techniques and outcomes.

METHODS

This retrospective study was designed to evaluate the treatment and follow-up of TRAAs treated by a variety of endovascular interventional techniques over a period of 6 years. Six patients with nine TRAAs were identified; seven of the TRAAs were treated using different combinations of coil embolization and flow diverter stents. The clinical findings, aneurysm characteristics, endovascular methods and treatment outcomes were reported.

RESULTS

Seven TRAAs of six patients were treated, with a median aneurysm size of 20 mm. Three TRAAs were treated with primary sac occlusion (one with primary coil embolization, one with balloon and stent assisted coil and glue embolization, and one with amplatzer vascular occlusion device and coil embolization). The remaining four TRAAs of three patients were treated with flow diverter stents (Cardiatis, Silk, Pipeline, and Surpass). Immediate clinical success was achieved in patients treated with primary sac embolization (95% CI, 29.2%-100%). Among patients treated with flow diverter stents, one patient required an additional flow diverter at 6-month follow-up. The occlusion time in flow diverters ranged from 1 month to 12 months (median, 3.5 months) taking the repeat procedure into account. In patients treated with flow diverters, the clinical success rate was 100% (95% CI, 29.2%-100%) at one-year follow-up. Long-term follow-up ranged from 3 to 52 months. One intraprocedural complication was encountered with a flow diverter during deployment, which required additional stenting and tirofiban infusion. No other major complication was seen.

CONCLUSION

Endovascular treatment is an effective and safe method offering high success rates and low morbidity in the treatment of TRAAs and may supplant surgery as the primary therapy. Current experience in the use of flow diverter stents in TRAAs is limited to individual case reports with one brand of flow diverter device. Our small numbered series of four TRAAs shows our experience regarding endovascular treatment with different flow diverter brands.

A clinical review of early outcomes from contemporary flow modulation versus open, fenestrated and branch technologies in the management of thoracoabdominal aortic aneurysm

Traditional therapeutic options for complex thoracoabdominal aneurysm include open repair, hybrid repair or endovascular repair (involving fenestrated or branched endografts). The Streamliner Multilayer Flow Modulator has been available for treatment of thoracoabdominal aneurysms since 2010. Its design permits blood flow to perfuse through the mesh in a modus that preserves collateral branch patency, while modulating turbulent to laminar flow within the device. The flow then stagnates over time within the surrounding aneurysm sac. Significant complications, including paraplegia, renal failure and cerebrovascular accident, are much lower with Streamliner Multilayer Flow Modulator treatment. Application of the Streamliner Multilayer Flow Modulator to complex aortic pathologies presents a novel solution to an, as of yet, unmet clinical need, and has resulted in promising clinical outcomes when compared to existing solutions. The Streamliner Multilayer Flow Modulator offers potential for treatment of thoracoabdominal aortic pathologies in patients and is not just confined to those with complexity that dictates no other management options. While current literature illustrates that there is a decreased risk of mortality and associated complications when this new disruptive technology is utilised, there is still a need for prospective, long-term clinical trials, as well as comparative trials to accurately assess outcomes of Streamliner Multilayer Flow Modulator treatment that are both precise and reproducible. This article is a review of current clinical literature regarding contemporary flow modulating technology compared with open, branched and fenestrated managements, presenting early outcomes.

Three-Year Outcomes With the Multilayer Flow Modulator for Repair of Thoracoabdominal Aneurysms

Purpose: To evaluate midterm outcomes of endovascular repair of types II and III thoracoabdominal aortic aneurysms (TAAA) using the Multilayer Flow Modulator (MFM) in patients unsuitable for open surgery or fenestrated stent-grafts. Methods: In the prospective, multicenter, nonrandomized STRATO trial (EudraCT registration: 2009-013678-42; ClinicalTrials.gov identifier NCT01756911), 23 patients (mean age 75.8 years; 19 men) with Crawford type II and III TAAA (mean diameter 6.5 cm) were implanted between April 2010 and February 2011. Outcomes included all-cause mortality and stable aneurysm thrombosis with associated branch vessel patency. Results: Through 36 months, there were 7 deaths (none confirmed as aneurysm-related), and no cases of spinal cord injury, device migration or fracture, or respiratory, renal, or peripheral complications. Three patients were lost to follow-up and 2 devices were explanted. The device was patent in the 11 remaining patients at 3 years. Stable aneurysm thrombosis was achieved for 15 of 20 patients at 12 months, 12 of 13 at 24 months, and 10 of 11 at 36 months. The rate of branch patency was 96% at 12 months (primary patency), 100% at 24 months, and 97% at 36 months. Nine patients suffered from endoleaks (attachment site or device overlap); 9 patients underwent 11 reinterventions (3 surgical). Maximum aneurysm diameter was stable for 18 of 20 patients at 12 months, 11 of 13 at 24 months, and 9 of 11 at 36 months. For 10 patients with computed tomography at 36 months, the mean ratio of aneurysm flow volume to total volume had decreased by 83%; the mean ratio of thrombus volume to total volume increased by 159%. Conclusion: Through 3 years, endovascular repair with the MFM appears to be safe and effective while successfully maintaining branch vessel patency.

Multilayer Flow Modulator Treatment of Abdominal and Thoracoabdominal Aortic Aneurysms With Side Branch Coverage: Outcomes From a Prospective Single-Center Moroccan Registry

PURPOSE

To evaluate endovascular repair of thoracoabdominal aortic aneurysms (TAAA) and abdominal aortic aneurysms (AAA) using the Multilayer Flow Modulator (MFM) in high-surgical-risk patients with at least one covered branch vessel.

METHODS

In this prospective single-center nonrandomized trial, 18 patients (mean age 61.1 years; 16 men) with TAAA (n=10, mean diameter 74.4 mm) and AAA (n=8, mean diameter 67.8 mm) were treated with the MFM between June 2009 and September 2012. The primary safety endpoints were all-cause mortality at 30 days and 12 months and neurological complications. The primary efficacy endpoint was overall procedure success, defined as patency of covered branch vessels, reductions in aneurysm diameter, and sac thrombus formation.

RESULTS

The technical success rate was 100% (53 study devices implanted, mean stented length 273 mm). Through mean follow-up of 13.4 months, all 61 covered branch vessels remained patent; there were no neurologic complications, ruptures, or instances of device migration, kinking, or fracture. Three patients died, 2 of unrelated causes and one of an undetermined cause. Only one reintervention with an additional MFM implanted at 5 years was required for a type I endoleak in a young patient with natural growth. Carefully planned and executed diameter and volume measurements demonstrated aneurysm shrinkage and progressive sac thrombus formation for both patient groups.

CONCLUSION

Through midterm follow-up, treatment of high-surgical-risk TAAA and AAA patients with the MFM appears to be safe and effective, maintaining branch vessel patency and reducing rupture risk through reduction of aneurysm diameter and modulation of flow dynamics. Longer term follow-up is needed.

Endovascular management of renal artery aneurysms using the multilayer flow modulator

OBJECTIVE

Our aim was to describe our experience of the Multilayer Flow Modulator (MFM, Cardiatis, Isnes, Belgium) used in the treatment of type III renal artery aneurysms (RAA).

METHODS

This is a single-centre study. 3 patients (2 men and 1 woman; mean age 59 years; range 41-77 years) underwent treatment of a type III renal artery aneurysm using the MFM. The indications were a 23.9 mm type III RAA at the bifurcation of the upper and lower pole vessels, with 4 side branches; a 42.4 mm type III saccular RAA at the renal hilum; and a 23 mm type III RAA at the origin of the artery, supplying the upper pole.

RESULTS

Patients had a mean follow-up of 27 months, and were assessed by perioperative renal function tests, and repeat postoperative CT scan. There were no immediate postoperative complications or mortality. The first patient's aneurysm shrank by 8.6 mm, from 23.9 to 15.3 mm over 19 months, with all 4 side branches remaining patent. The largest aneurysm at 42.4 mm completely thrombosed, while the renal artery remained patent to the kidney. The final patient refused to have any follow-up scans but had no deterioration in renal function below 30 mL/min, and no further symptoms reported.

CONCLUSIONS

The MFM is safe and effective in the management of patients with complex renal artery aneurysms. The MFM can be used to treat branched or distal renal artery aneurysms with exclusion of the aneurysm from the circulation, while successfully preserving the flow to the side branches and kidney. Initial results are promising, however, longer follow-up and a larger cohort are required to prove the effectiveness of this emerging technology.

Endovascular Management of True Renal Arterial Aneurysms: Results from a Single Centre

PURPOSE

To report a single centre's experience of the endovascular treatment of renal arterial aneurysms, including techniques and outcomes.

MATERIALS AND METHODS

This is a retrospective analysis of true renal arterial aneurysms (TRAAs) treated using endovascular techniques over a period of 12 years and 10 months. The clinical presentations, aneurysm characteristics, endovascular techniques and outcomes are reported.

RESULTS

There were nine TRAA cases with a mean aneurysm size of 21.0 mm, located at the main renal arterial bifurcation in all cases. Onyx(®) was used as the embolic agent of choice (88.9 % cases), with concurrent balloon remodelling. The overall primary technical success rate was 100 %. Repeat intervention was carried out in 1 case, secondary to reperfusion >8 years post-initial treatment. Long-term clinical follow-up was available in 55.6 % of cases (mean 29.8 months; range 3.3-90.1 months). Early post-procedural renal function, as measured by serum creatinine, remained within the normal reference range. Renal parenchymal loss post-embolisation was ≤20 % in 77.8 % of cases, as estimated on imaging. Minor complications included non-target embolization of Onyx(®) with no clinical sequelae (n = 1), transient pain requiring only oral analgesia with no prolongation of hospital stay (n = 2). No major complications occurred as a consequence of embolisation.

CONCLUSION

Endovascular therapy is an effective and safe primary therapy for TRAA with high success rate and low morbidity, supplanting surgery as primary therapy. Current experience in the use of Onyx(®) in TRAA is primarily limited to individual case reports, and this represents the largest case series of Onyx(®)-treated TRAAs to date.

Kinetics of endothelialization of the multilayer flow modulator and single-layer arterial stents

The multilayer flow modulator (MFM; Cardiatis, Isnes, Belgium) is a self-expandable mesh of braided cobalt alloy wires, used for treatment of aortic and peripheral aneurysms. To further improve our understanding of this novel technology, the endothelialization kinetics of the MFM was investigated and compared with those of two marketed single-layer stents. Five porcine animal models were used in which a total of 19 stents were implanted in the iliac and carotid arteries between one and five weeks before sacrifice. All 19 stents were successfully delivered. For all devices, nonsignificant signs of inflammation or thrombosis were noted, and there was no evidence of local intolerance. The MFM developed a thin layer of endothelial cells earlier and was associated with less neointimal development than the two single-layer stents. A differing phenomenon of integration was also revealed and hypothesized as endothelialization from adhesion of circulating endothelial progenitor cells, as well as adhesion from the arterial wall, and also by the differences in trauma exposed to the arterial wall.

Endovascular repair of a juxtarenal saccular aneurysm using the Multilayer Flow Modulator: report of the first case performed in a Public Hospital in Brazil

Endovascular treatment of abdominal aortic aneurysms (AAA), involving the exits of the renal and visceral arteries still constitutes a considerable challenge. Many different techniques have been developed over the years in attempts to surmount the difficulties presented by these cases. Techniques that have gained prominence include fenestrated or branched stents, methods involving parallel prostheses, such as the chimney, periscope and sandwich techniques, and, more recently, flow modulation with Multilayer stents. We describe a case of a complex juxtarenal saccular AAA with a high surgical risk, both according to cardiological assessment and because the patient had a difficult airway caused by a total laryngectomy for early stage laryngeal neoplasm. In view of the technical simplicity of using Multilayer stents, the presence of chronic obstructive aortoiliac disease, ostial stenosis of the renal artery and a small diameter suprarenal aorta, options involving fenestrated/branched stents and techniques involving parallel prostheses were ruled out, because of the need for multiple accesses. In view of the dilemma it presented, we describe this case as a therapeutic challenge and present the treatment option employed, which has been successful over the short term.

Endovascular Aneurysm Repair for Multiple Aneurysms as a Sequel of Hypereosinophilic Syndrome

This case represents the first report of multiple arterial aneurysms including aortic, iliac, visceral, and coronary aneurysms associated with hypereosinophilic syndrome. It presents an interesting case of epinephrine abuse and the unfortunate sequelae. This case illustrates novel approaches in emergency repair of internal iliac artery aneurysm rupture and the management of visceral artery aneurysms and exemplifies how multiple endovascular technologies can be utilized even in the high-risk polymorbid patient.

An Unusual Case of Fibromuscular Dysplasia with Bilateral Renal Macroaneurysms: Three-year Outcome After Endovascular Treatment

Fibromuscular dysplasia (FMD) is an idiopathic, segmental, non-inflammatory and non-atherosclerotic disease that affects arterial walls, leading to stenosis of small and medium-sized arteries. FMD mostly involves renal and intracranial arteries and only in few patients is associated with macroaneurysms (RAAs). We present the case of a 45-years old woman with recent history of grade 2 hypertension that suffered of subarachnoid haemorrhage due to rupture of a basilar artery aneurysm. The cerebral aneurysm was immediately treated by coil embolization and an abdominal angio-CT scan was performed to investigate the presence of renovascular hypertension. The exam showed the presence of FMD of the renal arteries associated with presence of bilateral RAAs. Due to the high risk of rupture, the bigger aneurysm (2,5 cm diameter) present on the left artery was immediately treated by coil embolization. The fusiform aneurysm, present on the right renal artery, was instead treated one year later by using two flow diverter stents. After three years, an angiographic study showed that both cerebral and renal aneurysms were excluded from the blood flow without evidence of arterial restenosis.

Endovascular management of pararenal aortic aneurysms with multiple overlapping uncovered stents

OBJECTIVE

This study aims at evaluating the safety and efficacy of a porous stent system consisting of multiple overlapping uncovered stents in the treatment of complex aortic aneurysms with vital branches.

METHODS

Data of all patients with aortic aneurysms treated in our center with multiple overlapping uncovered stents between February 2010 and December 2011 were retrospectively reviewed. Preoperative characteristics, intraoperative details, and follow-up outcomes were documented. Technical success was defined as successful deployment of the stents to target locations without procedure-related complications. Clinical success was characterized by complete shrinkage or stabilization of the aneurysm, preservation of vital branches, and absence of major complications. Patients were grouped, according to rapidity of aneurysm thrombosis, into fast-thrombosis group (complete thrombosis of aneurysmal sac was achieved in ≤6 months) and a delayed-thrombosis group (>6 months required for complete thrombosis). Possible factors affecting the speed of thrombosis were analyzed statistically with the Fisher exact test and the t-test.

RESULTS

This porous stent system was used to treat 34 patients (23 men, 11 women; mean age, 65.7 years). Technical success was achieved in all patients (100%). Regular follow-up over 6 months was achieved in 29 patients (mean length of follow-up, 11.4 months). Complete thrombosis of the aneurysm sac within 12 months was observed in 24 patients (83%). Aneurysm shrinkage was documented in seven patients (24%) and stabilization in 21 (72%). All branch arteries covered by bare stents stayed patent during follow-up. The overall clinical success rate reached 97% in the follow-up group. Risk factors for delayed thrombosis included fewer stents implanted (P = .013), longer sac entrance (P = .043), and use of antiplatelet medication (P = .040).

CONCLUSIONS

An alternative method of management of complicated aortic aneurysm appears to be feasible using overlapping bare stents, which may prevent aneurysm growth while preserving vital branches. The short-term outcome of our study seems encouraging but is not sufficient to draw a robust conclusion. Further hemodynamic and clinical studies are warranted to evaluate long-term efficacy.

Endovascular treatment of an anastomotic iliac pseudoaneurysm after surgical aortic repair using a Cardiatis multilayer stent

The Cardiatis multilayer stent (Cardiatis, Isnes, Belgium) is a cobalt, self-expandable bare stent made of two interconnected layers without any covering that allows a pressure decrease and thrombus formation into an aneurysmal sac, while improving laminar flow in the main artery and surrounding vital branches. We report a case of an anastomotic iliac pseudoaneurysm successfully treated with the deployment of a Cardiatis multilayer stent.

Using the Multilayer Stent as a Supplement to EVAR in Combined Abdominal Aortic Aneurysm and Iliac Artery Aneurysm With Inadequate Distal Landing Zone—A Case Report

Combined abdominal aortic aneurysm (AAA) and iliac artery aneurysm (IAA) is a common condition. The recently approved Cardiatis Multilayer stent (Cardiatis, Isnes, Belgium) is an innovative stent system for peripheral aneurysm management that has been applied in several clinical cases. After deployment, the unique stent design reduces mean velocity and vorticity within the aneurysm sac, causing thrombus formation and thus exclusion of the aneurysm while the vessels branching from the aneurysm remain patent. We describe a case of combined AAA and IAA with successful endovascular aneurysm repair of the AAA and treatment of the internal iliac artery with the Cardiatis Multilayer stent at 12 months of follow-up.

Flow-diverting stents for the treatment of arterial aneurysms

BACKGROUND

Anatomic factors may limit the application of stent grafts for the treatment of arterial aneurysms. Flow- diverting stents (FDSs) are specially designed to reduce flow velocity in the aneurysm sac and promote thrombosis while maintaining flow in the main artery and branch vessels. FDSs include the Pipeline Embolization Device (ev3, Plymouth, Minn), the SILK Arterial Reconstruction Device (Balt Extrusion, Montmorency, France), and the Cardiatis Multilayer Stent (Cardiatis, Isnes, Belgium). The first two have been mainly used for the treatment of intracranial aneurysms. The aim of this study was to review the current role of FDSs in the treatment of extracranial arterial aneurysms.

METHODS

A systematic electronic health database search was conducted using PubMed, Ovid, Medline, and the Cochrane Database on all accessible published articles through March 2012. An additional search for abstracts presented in international congresses for vascular surgery was also performed. Full-text articles and abstracts were analyzed separately due to the heterogeneity of the data.

RESULTS

Results of the use of FDSs in arterial aneurysms were reported in 12 full-text articles including 35 patients (26 men, age 65.4) with 38 aneurysms. The aneurysms were located in the hepatic (n = 12), splenic (n = 6), renal (n = 5), celiac (n = 4), superior mesenteric (n = 3), subclavian (n = 2), gastroduodenal (n = 1), and popliteal arteries (n = 1) and in the descending thoracic (n = 1), suprarenal (n = 1) and infrarenal aorta (n = 2). The 30-day mortality was 5.7% (2 of 35 patients). Three stent thromboses occurred (8.3%), none of them with clinical consequences. Thirty patients with 33 aneurysms and patent FDSs were monitored for an average of 9.2 months. Thrombosis occurred in 90.6%, and volume reduction was observed in 81% of the aneurysms. No branch vessel occlusion occurred. Twelve abstracts were identified, including 133 patients (mean age, 64.7 years). They included 62 peripheral, 28 visceral, and 43 abdominal and thoracoabdominal aneurysms. The Cardiatis Multilayer Stent was used in all cases. Thrombosis was achieved in all but two peripheral and visceral aneurysms. Volume reduction was observed in 82.7%, and no branch vessel occlusion occurred. In aortic aneurysms, better results regarding aneurysm thrombosis, reduction of the volume, and patency of collateral branches were reported at 12 months rather than at 6 months postoperatively. No aneurysm rupture has yet been described.

CONCLUSIONS

Initial clinical experience with the use of FDSs in the treatment of visceral and peripheral aneurysms yielded satisfactory results in technical success, aneurysm thrombosis and shrinkage, and in patency of branch vessels. The results in aortic aneurysms are still under investigation. No aneurysm rupture has yet been described. There is a significant incidence of FDS thrombosis. Volume reduction of the aneurysm is a clearer evidence of the clinical success after treatment with FDSs than aneurysm thrombosis.

Endovascular treatment of eight renal artery aneurysms

BACKGROUND

Renal artery aneurysms (RAA) are a relatively rare vascular entity. Treatment could be either surgical or via an endovascular route. The main aim of therapy is to prevent lethal rupture.

PURPOSE

To evaluate the angiographic and clinical results after endovascular treatment (EVT) of eight renal artery aneurysms.

MATERIAL AND METHODS

From January 2000 to June 2011, 18 patients presented with 18 renal artery aneurysms. One was classified as Rundback type I, 15 were type II, and two aneurysms were type III. Endovascular treatment was considered unsafe in 10 cases (all were Rundback type II), and were referred to surgery. The remaining eight aneurysms were treated endovascularly during altogether nine sessions. Among these, four patients were asymptomatic, three were hypertensive, and one presented with ipsilateral flank pains. Aneurysmal sac diameter varied between 12 and 50 mm. EVT included selective coil embolization in five cases, covered stents in two cases, and parent artery occlusion in one.

RESULTS

Follow-up with CT angiography was obtained in all endovascularly treated aneurysms (range 6-54 months, mean 15 months). Complete durable occlusion was achieved in all aneurysms except one, which showed re-expansion after 20 months and was retreated with covered stent implantation. Clinically silent, branch occlusion occurred after four procedures with subsequent limited (less than 25%) ischemic parenchymal loss. All patients were discharged with preserved renal function. Clinical improvement was noted in all symptomatic patients.

CONCLUSION

Endovascular treatment of renal artery aneurysms is an adequate treatment and can be proposed, if feasible, as first step.

Placement of endovascular stent across the branching arteries: long-term serial evaluation of stent-tissue responses overlying the arterial orifices in an experimental study

PURPOSE

This study was designed to investigate the effects of stenting across the branching arteries on the patency and stent-tissue responses over the branching arterial orifices.

METHODS

Thirteen dogs were observed after placing aortic stents across the celiac arteries (CA), superior mesenteric arteries (SMA), and renal arteries (RA). The animals were grouped according to stent types: large-cell group (n = 6) and small-cell group (n = 7). Angiography was performed to evaluate the branching artery patency at 2, 6, and 12 months after stent insertion, and the stent-tissue responses covering the orifices were evaluated on histopathologic examination.

RESULTS

All branching arteries were patent on follow-up angiography; however, three patterns of stent-tissue responses over the orifices were observed: neointimal layering, bridging septa, and papillary hyperplasia. Although neointimal layering and bridging septa were evenly observed, severe papillary hyperplasia was more frequent at SMA and CA than RA. Four RA showed less than 50% ostial patency, and localized infarct was observed in six kidneys (24%). The ostial patency tended to decrease with small-cell stent during the follow-up period.

CONCLUSIONS

Various stent-tissue responses over the branching artery orifices are induced by the aortic stent covering the branching arteries and may not be easily detected by conventional angiography. Subclinical renal infarct also may occur despite patent renal angiography.

The role of interventional radiology in the management of abdominal visceral artery aneurysms

Abdominal visceral artery aneurysms (VAA) include true and false aneurysms. The majority are asymptomatic and are discovered on cross-sectional imaging performed for unrelated clinical indications. With the maturation of techniques and devices used for embolization procedures and the treatment of aneurysms in other locations, most VAAs are now suitable for treatment by minimally invasive transcatheter techniques. The choice of technique used greatly depends on the local anatomy of the VAA and the experience of the interventional radiologist in complex vascular interventional techniques.