Coil embolization in precommunicating (A1) segment aneurysms of anterior cerebral artery

Introduction

Precommunicating (A1) segment aneurysms of the anterior cerebral artery are rare and often pose technical challenges for coil embolization due to their distinctive configurations. Clinical and radiologic outcomes of treating such aneurysms through endovascular coil embolization are presented herein.

Methods

Data accruing prospectively from May 2002 to August 2013 yielded 48 patients harboring 50 A1 segment aneurysms, each classified as proximal, middle, or distal by location. Clinical outcome of the patients and morphological outcome of the aneurysms were assessed, with emphasis on technical aspects of treatment.

Results

The aneurysms studied occupied either proximal (n?=?39), middle (n?=?6), or distal (n?=?5). Proximal aneurysms were largely directed posteriorly (80 %), and most (97 %) were devoid of branches. Middle and distal aneurysms were associated with the medial lenticulostriate artery, cortical branches, or fenestrations. The preshaped “S” and steam-shaped “S” microcatheters facilitated aneurysm selection in 60 % of lesions. Single-microcatheter technique was most commonly applied for coil embolization (62 %), followed by balloon protection (16 %). Successful aneurysmal occlusion could be achieved in 76 % of the patients, with no procedure-related morbidity and mortality. At final follow-up (mean interval, 29.9 months), stable aneurysmal occlusion was sustained in 93 % of the patients (40/43).

Conclusion

A1 segment aneurysms are amenable to safe and efficacious endovascular coil embolization by adjusting procedural strategy to accommodate distinctive anatomic configurations.     

Are iatrogenic renal artery pseudoaneurysms more challenging to embolize when associated with an arteriovenous fistula?

Background

Iatrogenic injuries of the renal artery include pseudoaneurysms (PSA) and pseudoaneurysms with arteriovenous fistula (PSA?+?AVF). They can cause hematuria, anemization and flank pain. Endovascular treatment is recommended due to its effectiveness.

Objective

To assess the potential difference between the embolization of iatrogenic renal PSA and iatrogenic renal PSA?+?AVF, in terms of technical and clinical success rate, procedure complexity and impact on the renal function.

Methods

We retrospectively reviewed 30 embolization procedures of iatrogenic renal PSA and renal PSA?+?AVF in 27 patients in two centers between December 2006 and February 2017, comparing technical and clinical success rate, total procedural time, creatinine before and after the procedure and parenchymal ischemic area after the procedure. All patients underwent CT before embolization procedure and different embolization materials were used.

Results

We identified 15 iatrogenic renal PSA and 15 iatrogenic renal PSA?+?AVF (causes: 23 nephron-sparing surgery, 2 nephrostomies, 1 lithotripsy, 1 ureteroscopic pyelolithotomy, 1 renal biopsy). Microcoils were used in 21 cases, microcoils and Spongostan in 3 cases, microcoils and controlled-release microcoils in 4 cases and controlled-release microcoils in 1 case. No significant statistical differences were found in the comparison of technical and clinical success rate, total procedural time, creatinine and parenchymal ischemic area after the procedure.

Conclusions

Transarterial embolization can be considered as the first-line treatment for renal artery iatrogenic lesions, considering its effectiveness. No statistical significant differences were found in the comparison of the embolization procedures of iatrogenic renal PSA and PSA?+?AVF.

     

Endovascular management of iatrogenic renal arterial lesions and clinical outcomes

PURPOSE

We aimed to evaluate iatrogenic renal arterial lesions, including pseudoaneurysm, arteriovenous fistula, and arteriocaliceal fistula, their management by endovascular embolization, and the clinical results.

METHODS

Fifty-five patients (forty males, fifteen females) with a median age of 40 years (range, 8–85 years), who underwent endovascular embolization of iatrogenic renal arterial lesions between March 2003 and December 2013 were included in this retrospective study. Types of iatrogenic lesions and details of embolization procedures were reported. Estimated glomerular filtration rate (eGFR), renal function tests, hemoglobin, and hematocrit levels before and after embolization were recorded and compared.

RESULTS

Median follow-up was 24 months. We identified 53 pseudoaneurysms, 30 arteriovenous fistulas, and 11 arteriocaliceal fistulas in 55 patients, after percutaneous nephrolithotomy (n=26), renal biopsy (n=21), nephrostomy (n=3), renal surgery (n=3), and extracorporeal shock wave lithotripsy (n=2). Median number of pseudoaneurysms was 1 (range, 1–4) with a median size of 7 mm (range, 1.5–35 mm). Fifty-one patients underwent coil embolization. Median number of coils was 5 (range, 2–21) and median renal parenchymal loss was 5% (range, 1%–50%). There were no significant differences between pre- and postoperative eGFR and serum parameters.

CONCLUSION

Iatrogenic renal arterial lesion can be a life threatening condition. Superselective coil embolization is a safe, minimally invasive treatment option with minimal renal parenchymal loss and without significant change in renal function.Iatrogenic renal arterial lesions including pseudoaneurysm (PA), arteriovenous fistula (AVF), and arteriocaliceal fistula (ACF) are rare, but life-threatening conditions (1). The chief symptom usually includes macroscopic hematuria (2, 3). Catheter angiography is the gold standard for both diagnosis and treatment (1).Previous studies have evaluated the iatrogenic renal arterial lesions following partial nephrectomy (1, 3–7), but there were only a few studies on iatrogenic renal arterial lesions following any iatrogenic renal interventions (2). In the present study, to the best of our knowledge, we report the largest series of iatrogenic renal arterial lesions following various renal interventions such as biopsy, percutaneous nephrolithotomy (PCNL), percutaneous nephrostomy, and partial nephrectomy. We focused on clinical presentations, imaging findings, management, and outcomes.     

Coil embolization of anterior circulation aneurysms supported by the Solitaire™ AB Neurovascular Remodeling Device

Introduction

The purpose of the study is to evaluate patients with wide-necked or complex aneurysms of the anterior circulation who underwent Solitaire? AB Neurovascular Remodeling Device-assisted coil embolization.

Methods

From February 2008 to March 2009, consecutive data were collected from 45 patients with anterior circulation aneurysms. Eighteen of the patients presented with acute subarachnoid hemorrhage. Forty-six aneurysms were treated with the aid of different applications (n?=?49) of the Solitaire? AB Remodeling Device followed by standard coiling procedure (n?=?43) using bioactive coils or/and bare coils.

Results

Successful positioning of the remodeling device was obtained in 95.9% of the cases. There were two thromboembolic complications (4.1%) and one severe vasospasm requiring retrieval of the device. Permanent procedural morbidity was observed in one patient (2%). The proportion of patients in whom Raymond class 1 occlusion was obtained was 53.5% (n?=?23). Raymond class 2 occlusion was achieved in 42% (n?=?18) and Raymond class 3 occlusion in 4.7% (n?=?2). Thirty-nine patients left the hospital with a good clinical status.

Conclusion

The initial technical and clinical results of Solitaire? AB device-assisted coiling of aneurysms in the anterior circulation are highly encouraging. This technique may enhance the possibilities of the endovascular treatment of these aneurysms in clinical routine.     

Coil embolization of intracranial saccular aneurysms using the Low-profile Visualized Intraluminal Support (LVIS™) device

Introduction

The novel Low-profile Visualized Intraluminal Support (LVIS?, LVIS and LVIS Jr.) device was recently introduced for stent-supported coil embolization of intracranial aneurysms. Periprocedural and midterm follow-up results for its use in stent-supported coil embolization of unruptured aneurysms are presented herein.

Methods

In this prospective multicenter study, clinical and radiologic outcomes were analyzed for 55 patients with saccular aneurysms undergoing LVIS-assisted coil embolization between October 2012 and February 2013. Magnetic resonance angiography or digital subtraction angiography was performed to evaluate midterm follow-up results.

Results

The standard LVIS device, deployed in 27 patients, was more often used in internal carotid artery (ICA) aneurysms (n?=?19), whereas the LVIS Jr. (a lower profile stent, n?=?28) was generally reserved for anterior communicating artery (n?=?14) and middle cerebral artery (n?=?8) aneurysms. With LVIS-assisted coil embolization, successful occlusion was achieved in 45 aneurysms (81.8 %). Although no instances of navigation failure or stent malposition occurred, segmentally incomplete stent expansion was seen in five patients where the higher profile LVIS was applied to ICA including carotid siphon. Procedural morbidity was low (2/55, 3.6 %), limited to symptomatic thromboembolism. In the imaging of lesions (54/55, 98.2 %) at 6-month follow-up, only a single instances of major recanalization (1.9 %) occurred. Follow-up angiography of 30 aneurysms (54.5 %) demonstrated in-stent stenosis in 26 (86.7 %), with no instances of stent migration. Only one patient suffered late delayed infarction (modified Rankin Scale 1).

Conclusion

The LVIS device performed acceptably in stent-assisted coil embolization of non-ruptured aneurysms due to easy navigation and precise placement, although segmentally incomplete stent expansion and delayed in-stent stenosis were issues.     

Extrahepatic Pseudoaneurysms and Ruptures of the Hepatic Artery in Liver Transplant Recipients: Endovascular Management and a New Iatrogenic Etiology

Purpose

To characterize extrahepatic pseudoaneurysm regarding incidence and etiology and determine the effectiveness of endovascular management.

Methods

A retrospective audit of 1,857 liver transplants in two institutions was performed (1996–2009). Recipients’ demographics, clinical presentation, transplant type, biliary anastomosis, and presence of biliary endoprostheses were noted. Pseudoaneurysms were classified into iatrogenic (associated with biliary endoprosthesis or angioplasty) or spontaneous extrahepatic pseudoaneurysms. Spontaneous and iatrogenic pseudoaneurysms were compared for time from transplant, presenting symptoms, location in the arterial anatomy, and 3-month graft survival. Arterial patency and 6-month graft survival were calculated.

Results

Twenty pseudoaneurysms were found (1.1 %, 20/1,857): 9 (0.5 % of transplants, 9/1,857) were spontaneous and 11 (0.6 % of transplants, 11/1,857) were “iatrogenic” (due to minimally invasive procedures: 4 angioplasty and 7 biliary endoprostheses). Sixty percent (12/20) underwent endovascular management (4 coil embolization and 8 stent-grafts). Technical success was 83 % (10/12) with a mean arterial patency of 70 % (follow-up mean, 4.9; range, 0–18 months). The 1-, 3-, and 6-month graft survival was 70, 40, and 35 %, respectively.

Conclusions

Due to minimally invasive procedures, posttransplant extrahepatic pseudoaneurysms are no longer an exclusive complication of the transplant surgery itself. Endovascular management is effective to stabilize patients but has not improved historic postsurgical graft survival.     

N-butyl Cyanoacrylate Glue Embolization of Arterial Networks to Facilitate Hepatic Arterial Skeletonization before Radioembolization

Purpose

Avoidance of nontarget microsphere deposition via hepatoenteric anastomoses is essential to the safety of yttrium-90 radioembolization (RE). The hepatic hilar arterial network may remain partially patent after coil embolization of major arteries, resulting in persistent risk. We retrospectively reviewed cases where n-butyl cyanoacrylate (n-BCA) glue embolization was used to facilitate endovascular hepatic arterial skeletonization before RE.

Methods

A total of 543 RE procedures performed between June 2004 and March 2012 were reviewed, and 10 were identified where n-BCA was used to embolize hepatoenteric anastomoses. Arterial anatomy, prior coil embolization, and technical details were recorded. Outcomes were reviewed to identify subsequent complications of n-BCA embolization or nontarget RE.

Results

The rate of complete technical success was 80 % and partial success 20 %, with one nontarget embolization complication resulting in a minor change in treatment plan. No evidence of gastrointestinal or biliary ischemia or infarction was identified, and no microsphere-related gastroduodenal ulcerations or other evidence of nontarget RE were seen. Median volume of n-BCA used was <0.1 ml.

Conclusion

n-BCA glue embolization is useful to eliminate hepatoenteric networks that may result in nontarget RE, especially in those that persist after coil embolization of major vessels such as the gastroduodenal and right gastric arteries.     

Angiographic outcome after endovascular therapy for anterior communicating artery aneurysms: correlation with vascular morphological features

Purpose

The purpose of this study is to analyze the effect of morphological features on angiography after endovascular embolization for anterior communicating artery (AcoA) aneurysms.

Materials and methods

We conducted a retrospective case review of 32 consecutive patients (19 males and 13 females) with AcoA aneurysms treated by endovascular coil embolization between February 2003 and August 2011. Mean age was 61?years (range 36?C90?years). Twenty-eight aneurysms were ruptured and 4 were unruptured. We evaluated morphological features included direction of the dome, dome size, dome to neck ratio, presence of irregularity, and angle between A1 segment of the anterior cerebral artery and C1 segment of the internal carotid artery. Immediate angiographic results (complete or incomplete occlusion) and the occurrence of procedural complications (aneurysmal rupture and thromboembolic events) were correlated with morphological features. Fisher??s exact test was used for statistical analysis.

Results

A single factor significantly associated with incomplete occlusion was superior dome direction (p?=?0.037). Other morphological features did not correlate with angiographical results. There was no correlation between morphological features and procedural complications.

Conclusion

Incomplete occlusion after coil embolization for AcoA aneurysms is more common in cases of superior dome direction.     

Multiple Renal Artery Pseudoaneurysms in Patients Undergoing Renal Artery Embolization Following Partial Nephrectomy: Correlation with RENAL Nephrometry Scores

Purpose

To describe the incidence of multiple renal artery pseudoaneurysms (PSA) in patients referred for renal artery embolization following partial nephrectomy and to study its relationship to RENAL nephrometry scores.

Materials and Methods

The medical records of 25 patients referred for renal artery embolization after partial nephrectomy were retrospectively reviewed for the following parameters: size and number of tumors, RENAL nephrometry scores, angiographic abnormalities, technical and clinical outcomes, and estimated glomerular filtration rates (eGFRs) after embolization.

Results

Twenty-four patients had primary renal tumors, while 1 patient had a pancreatic tumor invading the kidney. Multiple tumors were resected in 4 patients. Most patients (92 %) were symptomatic, presenting with gross hematuria, flank pain, or both. Angiography revealed PSA with (n = 5) or without (n = 20) AV fistulae. Sixteen patients (64 %) had multiple PSA involving multiple renal vessels. Higher RENAL nephrometry scores were associated with an increasing likelihood of multiple PSA. Multiple vessels were embolized in 14 patients (56 %). Clinical success was achieved after one (n = 22) or two (n = 3) embolization sessions in all patients. Post-embolization eGFR values at different time points after embolization were not significantly different from the post-operative eGFR.

Conclusion

A majority of patients requiring renal artery embolization following partial nephrectomy have multiple pseudoaneurysms, often requiring selective embolization of multiple vessels. Higher RENAL nephrometry score is associated with an increasing likelihood of multiple pseudoaneurysms. We found transarterial embolization to be a safe and effective treatment option with no long-term adverse effect on renal function in all but one patient with a solitary kidney.

     

Transcatheter embolisation of iatrogenic renal vascular injuries

Purpose

The aim of our study was to review our experience and long-term follow-up in the treatment of iatrogenic renal vascular injuries using transcatheter embolisation.

Materials and methods

Our retrospective analysis of cases collected in two interventional centres consists of a total of 21 patients who underwent renal arterial embolisation (RAE) for iatrogenic arterial kidney bleeding. Biopsy (n = 4), percutaneous nephrolithotomy (n = 4), nephron-sparing surgery (n = 4), guidewire-induced arterial perforation during coronary angiography or renal stenting (n = 3), percutaneous nephrostomy (n = 3), renal endopyelotomy/pyeloplasty (n = 2) and surgical nephrectomy were the iatrogenic causes. Seven patients presented with haemodynamic instability requiring blood transfusion (33.3 %), the remaining were haemodynamically stable (66.7 %). Diagnostic renal angiography revealed 9 actively bleeding vessels, 6 pseudoaneurysms, 4 arteriovenous fistulas and 1 arterio-calyceal fistula. In one patient selective renal arteriography was negative probably because the bleeding observed at CT angiography was self-limited. Twenty-one embolisation procedures were performed in 20 patients; one patient required a second embolisation 3 h after the first one. Embolisation was performed with microcoils, polyvinyl alcohol particles, embospheres, spongostan emulsion and vascular plug.

Results

The technical success rate was 100 %. The overall clinical success rate was 95 %. Apart from a patient who died due to disseminated intravascular coagulation, no major complications requiring intensive care treatment were encountered during or after the procedures. No patient required emergency surgery or subsequent surgical treatment. No statistically significant differences in eGFR or renal function stage appeared after RAE.

Conclusions

Percutaneous treatment can be proposed as a first-line treatment in iatrogenic renal arterial injuries, resulting in a safe and effective procedure.     

Endovascular treatment of head and neck arteriovenous malformations

Introduction

Head and neck arteriovenous malformations (H&N AVM) are associated with considerable clinical and psychosocial burden and present a significant treatment challenge. We evaluated the presentation, response to treatment, and outcome of patients with H&N AVMs treated by endovascular means at our institution.

Methods

Patients with H&N AVMs treated by endovascular means from 1984 to 2012 were evaluated retrospectively. These included AVMs involving the scalp, orbit, maxillofacial, and upper neck localizations. Patient’s clinical files, radiological images, catheter angiograms, and surgical reports were reviewed.

Results

Eighty-nine patients with H&N AVMs (46 females, 43 males; 48 small, 41 large) received endovascular therapy. The goals of treatment were curative (n?=?30), palliative (n?=?34), or presurgical (n?=?25). The total number of endovascular treatment sessions was 244 (average of 1.5 per patient). The goal of treatment was met in 92.1 % of cases. Eventual cure was achieved in 42 patients accounting for 58.4 % (52/89) of all patients who underwent treatment for any goal. Twenty-eight of these patients were cured by embolization alone (28/89, 31.4 %) of which 18 were single-hole AVFs. Twenty-four were cured by planned surgical excision after presurgical embolization (24/89, 27 %). Seven patients (7/89, 7.2 %) suffered transient and two (2/89, 2.2 %) permanent endovascular treatment complications.

Conclusion

Endovascular treatment is effective for H&N AVMs and relatively safe. It is particularly effective for symptom palliation and presurgical aid. Embolization is curative mostly in small lesions and single-hole fistulas. In patients with large non-curable H&N AVMs, endovascular therapy is often the only palliative option.     

Transsinusoidal Portal Vein Embolization with Ethylene Vinyl Alcohol Copolymer (Onyx): A Feasibility Study in Pigs

Purpose

Portal vein embolization is performed to increase the future liver remnant before liver surgery in patients with liver malignancies. This study assesses the feasibility of a transsinusoidal approach for portal vein embolization (PVE) with the ethylene vinyl alcohol copolymer, Onyx.

Methods

Indirect portography through contrast injection in the cranial mesenteric artery was performed in eight healthy pigs. Onyx was slowly injected through a microcatheter from a wedged position in the hepatic vein and advanced through the liver lobules into the portal system. The progression of Onyx was followed under fluoroscopy, and the extent of embolization was monitored by indirect portography. The pigs were euthanized immediately (n?=?2), at 7?days (n?=?4), or at 21?days postprocedure (n?=?2). All pigs underwent necropsy and the ex vivo livers were grossly and histopathologically analyzed.

Results

Transsinusoidal PVE was successfully performed in five of eight pigs (63%). In 14 of 21 injections (67%), a segmental portal vein could be filled completely. A mean of 1.6 liver lobes per pig was embolized (range 1–2 lobes). There were no periprocedural adverse events. Focal capsular scarring was visible on the surface of two resected livers, yet the capsules remained intact. Histopathological examination showed no signs of recanalization or abscess formation. Mild inflammatory reaction to Onyx was observed in the perivascular parenchyma.

Conclusions

The porcine portal vein can be embolized through injection of Onyx from a wedged position in the hepatic vein. Possible complications of transsinusoidal PVE and the effect on contralateral hypertrophy need further study.     

Endovascular management of spinal dural arteriovenous fistulas in 78 patients

Introduction

The purpose of this study was the evaluation of the safety and efficiency of the endovascular treatment of spinal dural arteriovenous fistulas (SDAVFs).

Methods

Between May 1992 and August 2012, 78 patients (59 men) with an angiographically proven SDAVF with pial venous drainage were treated by endovascular embolization (n?=?61) and/or surgery (n?=?31) at three German hospitals by a single team of physicians and according to a uniform therapeutic concept.

Results

Endovascular treatment resulted in a complete occlusion of the fistula in 47 cases (77 %). After failed embolization with residual shunt, 14 DAVFs were surgically cured (23 % failure rate). We had one permanent and two minor complications after endovascular therapy. Within a postoperative period of 2 weeks, 73.6 % of patients improved in gait disability, 51.1 % in micturition function, and 70.5 % in paresthesia of the lower extremities. Long-term follow-up data showed further improvement of clinical symptoms confirmed by normalization or resolution of spinal changes on MRI.

Conclusions

An interdisciplinary approach to the management of SDAVFs is mandatory. Patients without a common origin of arteries supplying the spinal cord and the dural fistula, and without a stenosis or occlusion of the concerning segmental artery are potential candidates for endovascular treatment (diluted n-butyl-2-cyanoacrylate). Only occlusion of the “nidus” and the proximal segment of the draining vein can lead to clinical improvement.     

Selective transarterial embolization with n-butyl-2-cyanoacrylate for the treatment of arterial hemorrhage after third molar extraction

Introduction

Comprehensive reports concerning selective embolization for arterial bleeding from third molar removal have not been published. We analyzed cases of arterial bleeding from third molar extraction that required transarterial embolization, and we demonstrate representative cases.

Methods

Five consecutive patients (three men and two women, aged 24 to 37 years) who underwent transarterial embolization at our institution were included in this study. Four of them showed postoperative bleeding after lower third molar removal, and one suffered bleeding after upper third molar extraction. The period of time from extraction to embolization varied from 5 h to 5 weeks.

Results

Angiography revealed pseudoaneurysms at the inferior alveolar artery in four cases and at the superior alveolar artery in one case. The pseudoaneurysms were selectively embolized using 25–33 % n-butyl-2-cyanoacrylate (NBCA)–lipiodol. All of the cases showed good results angiographically and clinically. Transit hypoesthesia at the region of the mental nerve was observed in one patient.

Conclusion

Selective transarterial embolization is an effective technique for arterial bleeding from third molar removal when it is difficult to obtain hemostasis by dental procedures. Injection of NBCA can be useful when the alveolar artery is too small to embolize with coils.     

Postpartum haemorrhage from ruptured pseudoaneurysm: efficacy of transcatheter arterial embolisation using N-butyl-2-cyanoacrylate

Objectives

To evaluate the efficacy of transcatheter arterial embolisation (TAE) using N-butyl-2-cyanoacrylate (NBCA) in the treatment of postpartum haemorrhage (PPH) due to ruptured pseudoaneurysm.

Methods

From March 2004 to December 2010, 33 patients underwent TAE using NBCA for massive PPH. Twenty-one patients (63.6 %) were in coagulopathic condition. Angiograms and medical records were retrospectively reviewed to determine technical/clinical success, complications and recurrent haemorrhage after TAE. Telephone interviews were conducted to obtain fertility-related data.

Results

Emergent angiograms revealed ruptured pseudoaneurysms at the uterine (n?=?17), vaginal (n?=?14), internal pudendal (n?=?3) and obturator (n?=?1) arteries, which were successfully embolised with NBCA. Four patients required additional embolisation of the uterine (n?=?3) or ovarian artery (n?=?1) with an absorbable gelatine sponge. Adequate haemostasis was achieved in 31 patients (93.9 %) after TAE. Two patients experienced persistent (n?=?1) or recurrent (n?=?1) haemorrhage, which required hysterectomy. There were no major embolisation-related complications. All 29 patients who were interviewed reported regaining of their regular menstruation. Nine patients had normal pregnancies and delivered healthy babies at full term.

Conclusions

TAE using NBCA is an effective treatment of PPH from ruptured pseudoaneurysms. In particular, NBCA is a potent embolic material in patients with coagulopathy. It does not seem to adversely affect future fertility.

Key Points

? Transcatheter arterial embolisation is a safe and effective treatment for postpartum haemorrhage. ? NBCA is potent embolic material to treat bleeding patients with severe coagulopathy. ? NBCA does not seem to adversely affect future fertility.     

Microguidewire protection of wide-necked aneurysms incorporating orifices of tortuous acute-angled vessels: a novel approach

Introduction

Protective/remodeling techniques for treating wide-necked intracranial aneurysms are constantly sought. However, their utility may be limited in lesions that incorporate the orifice of acute-angled efferent branch vessels. Furthermore, passage of a protective microcatheter may be challenging if a small branch is extremely tortuous. This study was conducted to explore a novel method of treating wide-necked aneurysms, utilizing microguidewire protection.

Methods

A microcatheter is first passed into parent artery (proximal to aneurysm) to position a microguidewire proximally in the involved branch. A second microcatheter is then inserted into aneurysmal sac. Advancement of the first microcatheter forces the microguidewire to shift, thus covering aneurysmal neck. A framing coil may then be placed within aneurysmal sac, under microguidewire protection. After completing initial coil insertion, easing of tension on the microcatheter allows separation of protective microguidewire and frame coil, confirming stability of the initial coil.

Results

This technique was applied to 11 intracranial saccular aneurysms of M1 segment (n?=?6), middle cerebral artery bifurcation (n?=?4), and anterior communicating artery (n?=?1) with success, combining stent protection in two patients. Coil embolization was thus facilitated, resulting in excellent outcomes for all patients. No morbidity or mortality was directly related to microguidewire protection.

Conclusion

Our small study suggests that microguidewire protection may be a safe alternative, if traditional remodeling or protective options are infeasible due to intrinsic vascular properties. This technique is particularly suited for treatment of wide-necked aneurysms where passage of protective microcatheters into involved branches is not achievable.     

Aortic Branch Artery Pseudoaneurysms Associated with Intramural Hematoma: When and How to Do Endovascular Embolization

Purpose

To describe when and how to perform endovascular embolization of aortic branch artery pseudoaneurysms associated with type A and type B intramural hematoma (IMH) involving the descending thoracic and abdominal aorta (DeBakey I and III) that increased significantly in size during follow-up.

Materials and Methods

Sixty-one patients (39 men; mean ± standard deviation age 66.1 ± 11.2 years) with acute IMH undergoing at least two multidetector computed tomographic examinations during follow-up for 12 months or longer were enrolled. Overall, 48 patients (31 men, age 65.9 ± 11.5) had type A and type B IMH involving the descending thoracic and abdominal aorta (DeBakey I and III).

Results

Among the 48 patients, 26 (54 %; 17 men, aged 64.3 ± 11.4 years) had 71 aortic branch artery pseudoaneurysms. Overall, during a mean follow-up of 22.1 ± 9.5 months (range 12–42 months), 31 (44 %) pseudoaneurysms disappeared; 22 (31 %) decreased in size; two (3 %) remained stable; and 16 (22 %) increased in size. Among the 16 pseudoaneurysms with increasing size, five of these (three intercostal arteries, one combined intercostobronchial/intercostal arteries, one renal artery), present in five symptomatic patients, had a significant increase in size (thickness >10 mm; width and length >20 mm). These five patients underwent endovascular embolization with coils and/or Amplatzer Vascular Plug. In all patients, complete thrombosis and exclusion of aortic pseudoaneurysm and relief of back pain were achieved.

Conclusion

Aortic branch artery pseudoaneurysms associated with type A and type B IMH involving the descending thoracic and abdominal aorta (DeBakey I and III) may be considered relatively benign lesions. However, a small number may grow in size or extend longitudinally with clinical symptoms during follow-up, and in these cases, endovascular embolization can be an effective and safe procedure.     

Long-term results of preventive embolization of renal angiomyolipomas: evaluation of predictive factors of volume decrease

Objectives

To evaluate the efficacy of selective arterial embolization (SAE) of angiomyolipomas based on the percentage volume reduction after embolization and to identify predictive factors of volume decrease.

Methods

Patients receiving prophylactic SAE of renal angiomyolipomas were included retrospectively over 3 years. The volume change after SAE and haemorrhagic or surgical events were recorded. Initial tumour volume, percentage tumour fat content, mean tumour density, embolic agent used, number of angiomyolipomas and tuberous sclerosis disease were evaluated as predictive factors of volume decrease.

Results

A total of 19 patients with 39 angiomyolipomas were included with median follow-up of 28 months (interquartile range 21–37 months). All treatments were technically successful (92 % primary and 8 % secondary). No distal bleeding or any increase in size or surgical nephrectomy after SAE was recorded. Mean volume reduction was 72 % (±24 %). Volumes before SAE (R ²?=?0.276; p?=?0.001), percentage fat content (R ²?=?0.612; p?<?0.0001) and mean angiomyolipoma density (R ²?=?0.536; p?<?0.0001) were identified as predictive factors of volume decrease. In multivariate regression, only percentage fat content influenced volume decreases.

Conclusions

SAE is an efficient treatment for angiomyolipoma devascularisation and volume reduction. A significant reduction of volume is modulated by the initial volume and tissue composition of the tumour.

Key Points

? Selective arterial embolization is effective for angiomyolipoma devascularisation and volume reduction ? Volume reduction depends of initial volume and tissue composition of the tumour ? Selective arterial embolization is a low radiation treatment     

Endovascular Broad-Neck Aneurysm Creation in a Porcine Model Using a Vascular Plug

Purpose

Ruptured cerebral arterial aneurysms require prompt treatment by either surgical clipping or endovascular coiling. Training for these sophisticated endovascular procedures is essential and ideally performed in animals before their use in humans. Simulators and established animal models have shown drawbacks with respect to degree of reality, size of the animal model and aneurysm, or time and effort needed for aneurysm creation. We therefore aimed to establish a realistic and readily available aneurysm model.

Materials and Methods

Five anticoagulated domestic pigs underwent endovascular intervention through right femoral access. A total of 12 broad-neck aneurysms were created in the carotid, subclavian, and renal arteries using the Amplatzer vascular plug.

Results

With dedicated vessel selection, cubic, tubular, and side-branch aneurysms could be created. Three of the 12 implanted occluders, two of them implanted over a side branch of the main vessel, did not induce complete vessel occlusion. However, all aneurysms remained free of intraluminal thrombus formation and were available for embolization training during a surveillance period of 6 h. Two aneurysms underwent successful exemplary treatment: one was stent-assisted, and one was performed with conventional endovascular coil embolization.

Conclusion

The new porcine aneurysm model proved to be a straightforward approach that offers a wide range of training and scientific applications that might help further improve endovascular coil embolization therapy in patients with cerebral aneurysms.     

Endovascular treatment of proximal superior middle cerebral artery aneurysms

Introduction

Aneurysms superiorly located on the proximal segment of the middle cerebral artery (PMCAA) are rare and challenging to treat. No information is available regarding their management by endovascular approach. The aim of this study was to report our experience with endovascular treatment (EVT) of PMCAA.

Methods

A retrospective review of our prospectively maintained database identified all PMCAA treated in our institution. The clinical charts, procedural data, and angiographic results were reviewed.

Results

From April 2004 to December 2011, 17 patients were identified including six who presented with subarachnoid hemorrhage (SAH) and 11 with an unruptured PMCAA. All aneurysms were small (<6?mm) and had a branch arising from the neck or the sac, and 15/17 were wide-necked. All patients were successfully treated by balloon-assisted coiling (n?=?10), stent-assisted coiling (n?=?5), and coiling (n?=?2). No technical or clinical complication occurred. Fifteen patients showed an excellent clinical outcome, and two kept a slight or a significant deficit that were both SAH-related. Immediate anatomical outcome includes nine complete occlusions and eight neck remnants. Imaging follow-up in 11 patients (mean?=?21, range, 6 to 60?months) showed stable or improved results in all cases.

Conclusion

Our study is the first reported series of patients with PMCAA treated by selective embolization. It suggests that EVT is a safe and effective alternative to surgery for the management of PMCAA. Balloon- or stent-assisted coiling are needed in most cases because of PMCAA morphological characteristics.