[Stent angioplasty for internal carotid artery stenosis]. / Stentangioplastie bei Stenose der A. carotis interna.

BACKGROUND: Stent angioplasty of carotid stenosis has become established as a safe and efficient treatment method alongside carotid endarterectomy due to developments in stent design and refinement of interventional techniques. Today, the protocol for stent angioplasty is largely standardized. OBJECTIVE: The aim of this article is to provide sound insight into the development and current practice of stent angioplasty. Particular attention is paid to technical implementation and periprocedural management.

Acute bilateral vision loss after endovascular treatment of an intracranial aneurysm.

Acute bilateral vision loss (ABVL) is a rare and challenging diagnostic issue that is most often caused by a neurological disorder. Since it can be the presenting symptom of potentially life-threatening diseases, priority should be given to excluding such diagnoses. Special caution is required if ABVL symptoms result after an intracranial intervention. This article reports on a diagnostic approach for a patient suffering from ABVL due to vitreous hemorrhage related to a subarachnoid hemorrhage (SAH) after endovascular intracranial aneurysm treatment. This case study highlights the importance of imaging interpretation and its consequences.

Recurrent reversible in-stent-stenosis after flow diverter treatment.

Flow diverter stents (FDS) are well established in the treatment of intracranial aneurysms which are difficult to treat with conventional endovascular techniques. However, they carry a relatively high risk of specific complications compared to conventional stents. A minor but frequent finding is the occurrence of reversible in-stent-stenosis (ISS) that tend to resolve spontaneously over time. Here, we report the case of a patient in their 30s who was treated with FDS for bilateral paraophthalmic internal carotid artery (ICA) aneurysms. ISS were found at the respective early follow-up examinations on both sides and had resolved at the 1-year follow-up examinations. Surprisingly ISS reoccurred at both sides in later follow-up examinations and again resolved spontaneously. The recurrence of ISS after resolution is a finding that has not been described previously. Its incidence and further development should be investigated systematically. This might contribute to our understanding of the mechanisms underlying the effect of FDS.

Endovascular Treatment Strategies for Aneurysms of the Origin of the Posterior Inferior Cerebellar Artery.

BACKGROUND: Treatment of aneurysms at the origin of the posterior inferior cerebellar artery (PICA) is challenging. Surgery is difficult due to the deep location and proximity to cranial nerves and endovascular treatment is complicated due to the often tortuous anatomy of the PICA and its small diameter. The purpose of this study is to report our experience with the endovascular treatment of aneurysms at the origin of the PICA. METHODS: Consecutive patients with aneurysms at the origin of the PICA who were endovascularly treated at our department were identified from our registry of neuro-angiographies. Clinical, angiographic, and treatment data were analyzed. Endpoints included successful occlusion and recurrence. RESULTS: Twenty-nine patients were included. 79.3% of the aneurysms were wide-neck with a dome-to-neck ratio <2.65.5% of all endovascular procedures were performed by coiling alone. The procedural rupture rate was 18.75% for endovascularly treated aneurysms presenting with subarachnoid hemorrhage (SAH). Successful embolization was achieved non-significantly more often in the coiling-only group (94.7% vs. 70%, P = 0.066). Aneurysm recurrence after successful occlusion was observed in one case. CONCLUSIONS: Though aneurysm and parent vessel characteristics were challenging successful occlusion was achieved in a high rate of treatments, often with standalone coiling. Adjunctive techniques like retrograde stenting seem promising to further enhance endovascular results. Interestingly aneurysms arising solely from the origin of the PICA without the V4-segment involved presented with SAH significantly more often and wide-neck aneurysms presenting with SAH had a significantly higher periinterventional rupture rate.

Treatment of experimental aneurysms with a GPX embolic agent prototype: preliminary angiographic and histological results.

BACKGROUND: Recently, liquid embolic agents have emerged for the endovascular treatment of cerebral aneurysms. Here we describe the in vivo performance of a novel liquid embolization agent (GPX Embolic Device). METHODS: Elastase-induced aneurysms were embolized with a GPX prototype under balloon assistance. Digital subtraction angiography was performed pre-deployment and immediately after, and at 5, 10, and 30 min post-deployment in 10 rabbits and at 1 month in 8 rabbits. The early post-deployment intra-aneurysmal flow was graded as unchanged, moderately diminished, or completely absent. At 1 month the status of aneurysm occlusion was evaluated. Adhesion to catheter material and migration of GPX was assessed. RESULTS: The mean aneurysm neck diameter, width, and height were 3.6±1.0 mm, 3.0±0.8 mm, and 7.4±1.4 mm, respectively. The mean dome-to-neck ratio was 0.9±0.2. Complete stagnation of intra-aneurysmal flow was observed in 9 of 10 aneurysms (90%) within 30 min of device deployment. One aneurysm showed moderately diminished intra-aneurysmal flow at 30 min. At 1 month, 8 aneurysms were completely occluded. There was no evidence of GPX adhesion to the catheter material. Histologically, a leukocyte and foreign body reaction to GPX was detectable 28 days after embolization. CONCLUSIONS: This is the first preclinical study reporting the performance of a protype version of the GPX Embolic Device in a wide-neck aneurysm model. GPX showed promising results by achieving and maintaining high rates of complete angiographic occlusion, but may induce an inflammatory reaction.

Vascular Response on a Novel Fibrin-Based Coated Flow Diverter.

PURPOSE: Due to thromboembolic complications and in-stent-stenosis after flow diverter (FD) treatment, the long-term use of dual antiplatelet treatment (DAPT) is mandatory. The tested nano-coating has been shown to reduce material thrombogenicity and promote endothelial cell proliferation in vitro. We compared the biocompatibility of coated (Derivo Heal) and non-coated (Derivo bare) FDs with DAPT in an animal model. METHODS: Derivo® bare (n = 10) and Derivo® Heal (n = 10) FD were implanted in the common carotid arteries (CCAs) of New Zealand white rabbits. One additional FD, alternately a Derivo bare (n = 5) or Derivo Heal (n = 5), was implanted in the abdominal aorta (AA) for assessment of the patency of branch arteries. Histopathological examinations were performed after 28 days. Angiography was performed before and after FD implantation and at follow-up. RESULTS: Statistical analysis of the included specimens showed complete endothelialization of all FDs with no significant differences in neointima thickness between Derivo® bare and Derivo® Heal (CCA: p = 0.91; AA: p = 0.59). A significantly reduced number of macrophages in the vessel wall of the Derivo Heal was observed for the CCA (p = 0.02), and significantly reduced fibrin and platelet deposition on the surface of the Derivo Heal was observed for the AA. All branch arteries of the stented aorta remained patent. CONCLUSION: In this animal model, the novel fibrin-based coated FD showed a similar blood and tissue compatibility as the non-coated FD.

[Cervical CUP syndrome]. / CUP-Syndrom im Halsbereich.

The term CUP syndrome (cancer of unknown primary) refers to a multifaceted clinical picture in which the affected patients have lymph node and/or distant metastases without the location of the primary tumor being known. The criteria of CUP syndrome are fulfilled if a histologically or cytologically confirmed malignancy is present without a detectable primary tumor after completion of the primary diagnosis. Due to the usually poor prognosis and the manifold appearance, which often does not allow a standardized therapy, cervical CUP syndrome makes specific demands on clinical and imaging diagnostics. Using modern techniques such as positron emission tomography-computed tomography (PET-CT), imaging plays a key role in the detection of a possible occult primary tumor as well as in staging and prognosis assessment.

Accuracy of optical coherence tomography imaging in assessing aneurysmal remnants after flow diversion.

BACKGROUND: Optical coherence tomography (OCT) is an ultra-high resolution real-time intravascular imaging method that is gaining interest in cerebrovascular applications. OBJECTIVE: To compare, in a rabbit elastase aneurysm model, digital subtraction angiography (DSA) and OCT as diagnostic tools for the assessment of aneurysmal remnants and baseline characteristics of aneurysms after flow diverter (FD) implantation. METHODS: With Institutional Animal Care and Use Committee approval, saccular aneurysms were created in 28 rabbits and treated with Derivo FDs. DSA was performed before, and immediately after, stent implantation. As a follow-up, DSA and OCT were performed 28 days after device implantation. RESULTS: DSA and OCT were successfully performed in 23 cases. OCT could not be achieved in 5 cases owing to navigational difficulties in the stent lumen with the OCT catheter. Residual aneurysms were significantly more often visible with OCT (18/23 (78%) than with DSA 12/23 (52%), p = 0.031). CONCLUSION: OCT was more sensitive than conventional angiography for the assessment of residual aneurysms at 28 days after FD implantation in an animal model.

[New approaches to embolization of aneurysms (liquid embolic agents)]. / Neue Wege zur Embolisation von Aneurysmen (Flüssigembolisat).

Various materials are currently available for the endovascular treatment of aneurysms. The choice of material depends on the location and configuration of the aneurysm. To ensure optimal aneurysm treatment, the filling material must incorporate the aneurysm and isolate it from the parent vessel by forming an endothelial layer and neointima proliferation along the aneurysm neck. As a result, the aneurysm can be permanently isolated from the blood flow and the weakened vessel wall can be stabilized in the long term in order to prevent subsequent rupture. Bare metal coils are currently most commonly used. In recent years, liquid embolic agents have increasingly been developed for the endovascular treatment of aneurysms. One of the reasons is that the injected fluid completely fills the aneurysm lumen, so there is no gap between the filling material and the aneurysm wall, regardless of the shape of the aneurysm. Most of the preclinical and clinical studies are available for Onyx. In particular for the treatment of mycotic aneurysms and distal aneurysms of the posterior circulation, liquid embolization with Onyx has already proven to be a possible, effective treatment method.