Initial and Long-Term Outcomes of Complex Bifurcation Aneurysms Treated by Y-Stent-Assisted Coiling with Low-Profile Braided Stents.

BACKGROUND AND PURPOSE: Coiling complex intracranial bifurcation aneurysms often necessitates the implantation of double stents in various configurations, such as Y-stent placement. Low-profile braided stents have been introduced recently to facilitate the endovascular treatment of wide-neck aneurysms. We aimed to investigate the feasibility, safety, efficacy, and durability of Y-stent-assisted coiling with double low-profile braided stents for the treatment of complex bifurcation aneurysms. MATERIALS AND METHODS: A retrospective review was performed to identify patients who were treated using Y-stent-assisted coiling with low-profile braided stents. Technical success was assessed, as were initial and follow-up clinical and angiographic outcomes. Periprocedural and delayed complications were reviewed. Preprocedural and follow-up clinical statuses were assessed using the modified Rankin Scale. RESULTS: Forty patients with 40 intracranial aneurysms were included in the study. Y-stent placement was successfully performed in all cases. Immediate postprocedural digital subtraction angiography images revealed total aneurysm occlusion in 72.5% of cases. The mean angiographic follow-up time was 24.8 months. The last follow-up angiograms showed complete occlusion in 85% of patients. During follow-up, only 1 patient showed an increase in the filling status of the aneurysm and that patient did not require retreatment. There was no mortality in this study. The overall procedure-related complication rate, including asymptomatic complications, was 17.5%. A permanent morbidity developed in 1 patient (2.5%). CONCLUSIONS: The long-term angiographic and clinical outcomes of this retrospective study demonstrate that Y-stent-assisted coiling using low-profile braided stents is an effective, relatively safe, and durable endovascular treatment for wide-neck and complex bifurcation aneurysms.

Flow Diversion with Low-Profile Braided Stents for the Treatment of Very Small or Uncoilable Intracranial Aneurysms at or Distal to the Circle of Willis.

BACKGROUND AND PURPOSE: The endovascular treatment of aneurysms located at or distal to the circle of Willis and not amenable to coiling remains a challenge. We report our experience with flow-diversion treatment using low-profile braided stents as a stent monotherapy procedure for treating distally located very small or uncoilable aneurysms. MATERIALS AND METHODS: We retrospectively reviewed our data bases to identify patients with aneurysms located at or distal to the circle of Willis who were treated with stent monotherapy using low-profile braided stents. The immediate and follow-up angiographic findings and clinical status of the patients were assessed. RESULTS: Twenty aneurysms in 19 patients were included in the study. The mean size of the aneurysms was 4.7 ± 2.4 mm. Patients were treated via telescopic implantation of 2 stents for 11 aneurysms; single-stent placement was used for the remaining aneurysms. The technical success rate was 95%. We observed a technical complication in 1 case (5.3%) and a late ischemic event in another (5.3%). The final angiographies during a mean follow-up of 14.7 months showed complete aneurysm occlusion in 73.7%. The complete occlusion rate of the aneurysms treated with telescopic stent placement was 81.8%. The modified Rankin scale scores of all patients at the last follow-up were between 0 and 2. CONCLUSIONS: Flow diversion with low-profile braided stents as a stent monotherapy procedure for very small or uncoilable intracranial aneurysms located at or beyond the circle of Willis is a promising, relatively safe, and durable endovascular procedure.

Vascular loops at the cerebellopontine angle: is there a correlation with tinnitus?

BACKGROUND AND PURPOSE: Tinnitus is a common disorder, and the etiology remains mostly unclear. The purpose of this study was to investigate the causative effect of the vascular loop and compression of the vestibulocochlear nerve at the cerebellopontine angle in patients with unexplained tinnitus. MATERIALS AND METHODS: This study was approved by our institutional review board. Written informed consent was obtained from all participants. Fifty-eight patients with unexplained tinnitus and 44 age- and sex-matched asymptomatic controls were examined with temporal MR imaging. Besides the tinnitus and control groups, a third group was formed by asymptomatic sides of patients with unilateral tinnitus. A 3D fast imaging employing steady-state acquisition (3D-FIESTA) sequence was performed in addition to the regular pre- and postcontrast axial and coronal sequences. The anatomic type of vascular loop, the vascular contact, and the angulation of the vestibulocochlear nerve at the cerebellopontine angle (CPA) were evaluated by 2 experienced neuroradiologists. The chi(2) test was used for statistical analysis. RESULTS: No statistically significant differences were found between the patient and control groups for the anatomic type of vascular loop, the vascular contact, and the angulation of the vestibulocochlear nerve at the CPA (P > .05). CONCLUSION: Although 3D-FIESTA MR imaging correctly shows the anatomic relationships of the vestibulocochlear nerve, its vascular compression cannot be attributed as an etiological factor for tinnitus.

Rosai-Dorfman disease with epidural and spinal bone marrow involvement: magnetic resonance imaging and diffusion-weighted imaging features.

Sinus histiocytosis with massive lymphadenopathy (SHML), or Rosai-Dorfman disease, is a rare histiocytic disorder that typically presents with chronic, self-limiting cervical lymphadenopathy. Although this disease mainly affects histiocytes, there are a few reports of bone marrow infiltration. Diffusion-weighted imaging (DWI) is a promising technology in differentiating between various bone marrow pathologies. We here present conventional magnetic resonance imaging and DWI features of a patient with SHML and bone marrow involvement.

Thin-section diffusion-weighted magnetic resonance imaging of the brain with parallel imaging.

BACKGROUND: Thin-section diffusion-weighted imaging (DWI) is known to improve lesion detectability, with long imaging time as a drawback. Parallel imaging (PI) is a technique that takes advantage of spatial sensitivity information inherent in an array of multiple-receiver surface coils to partially replace time-consuming spatial encoding and reduce imaging time. PURPOSE: To prospectively evaluate a 3-mm-thin-section DWI technique combined with PI by means of qualitative and quantitative measurements. MATERIAL AND METHODS: 30 patients underwent conventional echo-planar (EPI) DWI (5-mm section thickness, 1-mm intersection gap) without parallel imaging, and thin-section EPI-DWI with PI (3-mm section thickness, 0-mm intersection gap) for a b value of 1000 s/mm(2), with an imaging time of 40 and 80 s, respectively. Signal-to-noise ratio (SNR), relative signal intensity (rSI), and apparent diffusion coefficient (ADC) values were measured over a lesion-free cerebral region on both series by two radiologists. A quality score was assigned for each set of images to assess the image quality. When a brain lesion was present, contrast-to-noise ratio (CNR) and corresponding ADC were also measured. Student t-tests were used for statistical analysis. RESULTS: Mean SNR values of the normal brain were 33.61+/-4.35 and 32.98+/-7.19 for conventional and thin-slice DWI (P>0.05), respectively. Relative signal intensities were significantly higher on thin-section DWI (P<0.05). Mean ADCs of the brain obtained by both techniques were comparable (P>0.05). Quality scores and overall lesion CNR were found to be higher in thin-section DWI with parallel imaging. CONCLUSION: A thin-section technique combined with PI improves rSI, CNR, and image quality without compromising SNR and ADC measurements in an acceptable imaging time.

Corpus callosum hematoma secondary to isolated inferior sagittal sinus thrombosis.

A 45-year-old female was admitted with headache and vomiting. Cranial computed tomography (CT) demonstrated a callosal hematoma. Magnetic resonance imaging (MRI) showed no venous flow and thrombus replacing the inferior sagittal sinus (ISS) lumen. Under appropriate medical treatment and close follow-up she recovered quickly and, after 2 years, was doing well with corpus callosum infarcts. Isolated inferior sagittal sinus thrombosis is an extremely rare condition with only one previously reported case in the literature. Although it is very rare, isolated inferior sagittal sinus thrombosis should be considered in the differential diagnosis of non-traumatic corpus callosum hematoma.

Persistent notochordal canal mimicking compression fracture: a case report.

A persistent notochordal canal is a rare anomaly that is generally discovered by chance. The radiographic appearance of this entity is characteristic and usually does not require further investigation. However, in some cases plain films may fail to depict this appearance, and computed tomography or magnetic resonance imaging (MRI) is required for final diagnosis. We report the MRI findings of a young woman with persistent notochordal canal who, based on plain radiographs, had first been misdiagnosed as having a compression fracture.

Central nervous system aspergillosis: magnetic resonance imaging, diffusion-weighted imaging, and magnetic resonance spectroscopy features.

Aspergillus infection is invasive in nature in the immunosuppressed population and disseminates throughout the body, with the brain being a common site. Conventional magnetic resonance imaging (MRI) combined with diffusion-weighted imaging (DWI) and magnetic resonance spectroscopy (MRS) play a life-saving role in the early diagnosis and treatment monitoring of this potentially fatal infection. We present MRI, DWI, and MRS findings of a case of central nervous system aspergillosis with treatment follow-up.

Endovascular treatment of obstructive iliac artery dissections.

PURPOSE: To report our results from a study of the endovascular treatment of flow restricting chronic atherosclerotic or catheter-induced segmental iliac artery dissections with bare stents. MATERIAL AND METHODS: Thirty symptomatic patients with 32 lesions, including chronic atherosclerotic (n = 21) and catheter-induced (n = 11) segmental arterial dissections, were treated with primary stenting. The common iliac artery was involved in 19 lesions and the external iliac artery in the remaining 13. Two patients had two lesions in the same vessel. Technical success was defined as restoration of the smooth contoured luminal patency with no more than 20% residual stenosis in diameter in atherosclerotic dissections associated with plaque formation or total obliteration of the false lumen in catheter-induced dissections. Complete relief of, or marked improvements in, presenting symptoms, or at least single category improvement, was assessed for clinical success. RESULTS: Technical success rate was 100%. No procedure-related complications such as distal emboli or early occlusions were observed. Complete symptom relief was achieved in all patients with catheter-induced dissection and in all but three cases with chronic spontaneous atherosclerotic dissection. In two cases, occlusion of the stents occurred during the follow-up period. Clinical and radiological mean follow-up for 24 months (range 3-55) revealed patency of all other stented segments. Cumulative primary patency rate was 97% over 12 months and 90% over 24 months. CONCLUSION: Endovascular treatment of chronic atherosclerotic and catheter-induced short obstructive iliac arterial dissections with bare stents is safe and effective. Patency of the diseased arterial segment with a smooth lumen can be sustained for an extensive period.

Intra-arterial simultaneous administration of anandamide attenuates endothelin-1 induced vasospasm in rabbit basilar arteries.

BACKGROUND: Anandamide induces not only endothelium-dependent vasodilatation through cannabinoid receptors but also some endothelium- independent vasodilator effect by calcitonin gene-related peptide release through vanilloid receptors. Endothelin-1, a powerful vasoconstrictive peptide derived from endothelial cells, has been shown to be converted to its active form after cleaving by a vascular matrix metalloproteinase which is also involved in inactivation of calcitonin gene-related peptide. The purpose of this study was to investigate whether anandamide inhibits the acute vascular and morphological effects of Endothelin-1 applied intra-arterially on rabbit basilar arteries. METHOD: Fifteen albino rabbits were anaesthetised and underwent placement of a vertebral artery catheter for angiography of the basilar artery. Animals were divided, arbitrarily, into animals in which there was either intra-arterial injection of saline (Group I, n=5), Endothelin-1 (Group II, n=5) and Endothelin-1 and anandamide (Group III, n=5). The diameter of the basilar artery between the pre and post injection angiograms was measured in each of the three groups and transmission electron microscopic investigations on basilar arteries were performed. FINDINGS: Angiographic studies showed that simultaneous administration of anandamide significantly attenuated Endothelin-1 induced vasoconstriction. Furthermore, it was demonstrated that anandamide reversed the morphological changes induced by Endothelin-1 on the vessel wall. INTERPRETATION: These results indicated that anandamide overcomes the angiographic and morphological effects of intrarterially administered ET-1 induced vasospasm in rabbit basilar arteries probably by induction of CGRP related vasodilatation through vanilloid receptors and prevents the acute ET-1 induced ultrastructural vessel wall damage.

High-flow arterioportal fistula: treatment with detachable balloon occlusion.

Transarterial embolization is one of the treatment choices for symptomatic hepatic arterioportal fistula that has low mortality and morbidity. Proper selection of the technique and embolic material is very important for the success of the procedure. We present a case with high-flow arterioportal fistula treated with transarterial embolization using detachable balloons.

Renal infarct: contrast-enhanced power Doppler sonographic findings.

Power Doppler sonography (PDUS) is a promising technique for the diagnosis of renal infarcts. PDUS's efficacy may be enhanced by using sonographic contrast agents. We evaluated 3 cases of renal infarction using PDUS and the sonographic contrast agent Levovist. The findings were compared with those of other imaging modalities, such as scintigraphy, CT, and angiography. In case 1, PDUS showed a patent interlobar artery only in the lower part of the right kidney and no other perfusion of the right renal parenchyma. Contrast-enhanced PDUS showed patchy areas of preserved perfusion in the lower and middle-upper anterior portions of the kidney. In case 2, PDUS showed diffuse and patchy perfusion defects in the anterolateral portion of the right kidney. On contrast-enhanced PDUS, no signal enhancement was seen in these areas, but the perfusion defects were better delineated. In case 3, PDUS showed no perfusion in the upper pole of the kidney; the nonperfused area extended to the posterior upper portion of the kidney but could not be distinguished from normal tissue. After injection of the contrast agent, there was no enhancement of the posterior extension of the upper pole infarct, but Doppler signals from the surrounding normal parenchyma were enhanced, so the area was more clearly demarcated. The administration of the contrast agent facilitated the visualization of the infarcts in all 3 cases.

Evaluation of osteoporosis in thalassemia by quantitative computed tomography: is it reliable?

This study was conducted to quantify the degree of osteoporosis in thalassemic patients by single energy quantitative computed tomography (SEQCT) and to test the reliability of this method. On 38 thalassemic patients with osteoporosis and 38 normal control subjects, bone mineral density (BMD) measurements were done by SEQCT. BMD and standard deviation (SD) of the x-ray attenuation numbers of pixels within region of interest (ROI) of the measurement areas were compared between two groups. Mean BMD values for thalassemic patients and control group were 173.4 and 158.2 mg/cm3, respectively. Mean BMD value for thalassemic patient group was significantly higher. Mean SD values of ROI for control group and thalassemic patients were 41.4 and 71.1, respectively. The difference between the SD values was also statistically significant. Positive correlation was noted between SD values and patients' ages in the thalassemic group. Results of SEQCT method may not reflect the clinical and conventional radiographic findings of osteoporosis seen in thalassemic patient group and should be used cautiously. Other methods of BMD measurement, such as photon absorbsiometry and x-ray absorbsiometry, should also be investigated for their accuracy in this patient group.

Primary stenting for complex atherosclerotic plaques in aortic and iliac stenoses.

PURPOSE: To evaluate the efficacy of primary stenting for complex atherosclerotic plaques in aortic and iliac stenoses that are not amenable to balloon angioplasty alone. METHODS: Nineteen patients with complex atherosclerotic plaques were treated with a Palmaz stent (n = 19), Wallstent (n = 1), Strecker stent (n = 1), or Memotherm stent (n = 1). A total of 22 stenoses presenting with complex plaque morphology including ulcerated plaques, ulcerated plaques with focal aneurysms, plaques with heavy calcification, severely eccentric plaques, plaques with overhanging edge, and plaques with spontaneous dissection were stented. The lesions were in the aorta (n = 1), common iliac artery (n = 19), or external iliac artery (n = 2). RESULTS: Immediate angiography after stent placement revealed restoration of patency of the stented segment. Focal aneurysms and ulcerated areas were occluded in the follow-up angiographies obtained 4-12 weeks after the procedure. In one case with poor distal runoff and multiple complex lesions of the iliac artery, subacute occlusion occurred. Clinical and angiographic follow-up (3-46 months) revealed patency of all other stented segments. CONCLUSION: Primary stenting is an effective and reliable approach for complex plaques in stenoses. Patency of the arterial segment with a smooth lumen can be created without the risk of acute complications such as distal embolization, dissection, or occlusion.

MR imaging and MR angiography in popliteal artery entrapment syndrome.

Popliteal artery entrapment (PAE) syndrome is an uncommon congenital anomaly seen in young adults causing ischemic symptoms in the lower extremities. It is the result of various types of anomalous relationships between the popliteal artery and the neighboring muscular structures. The purpose of this study was to define the role of MR imaging combined with MR angiography in the diagnosis of PAE cases. Four cases with segmental occlusion and medial displacement of popliteal artery in digital subtraction angiography (DSA) examinations were diagnosed as PAE syndrome by MR imaging and MR angiography. The DSA and MRA images are compared. All of the cases showed various degrees of abnormal intercondylar insertion of the medial head of the gastrocnemius muscle. The MR images showed detailed anatomy of the region revealing the cause of the arterial entrapment. Subclassification of the cases were done and fat tissue filling the normal localization of the muscle was evaluated. The DSA and MRA images demonstrated the length and localization of the occluded segment and collateral vascular developments equally. It is concluded that angiographic evaluation alone in PAE syndrome might result in overlooking the underlying cause of the arterial occlusion, which in turn leads to unsuccessful therapy procedures such as balloon angioplasty. Magnetic resonance imaging combined with MR angiography demonstrates both the vascular anatomy and the variations in the muscular structures in the popliteal fossa successfully, and this combination seems to be the most effective way of evaluating young adults with ischemic symptoms suggesting PAE syndrome.

Treatment of recurrent nasolacrimal duct obstructions with balloon-expandable metallic stents: results of early experience.

PURPOSE: To evaluate the efficacy of Palmaz balloon-expandable metallic stents for the maintenance of luminal patency in the treatment of recurrent nasolacrimal duct, obstructions after failed transluminal balloon dilatation. METHODS: Metallic stents were implanted in the nasolacrimal duct of four patients with recurrent epiphora. All the patients had already undergone transluminal balloon dilatation of the nasolacrimal duct with no or only temporary improvement. In two eyes, 9.5-mm-long Palmaz stents were used; in the other two eyes, 20-mm-long articulated-design Palmaz stents were placed under digital fluoroscopic monitoring. In each case, the upper tip protruded slightly into the lacrimal sac and the lower end was positioned inside the nasolacrimal duct. RESULTS: The stents were placed accurately in all cases, and no complications were observed. After stent placement, all patients had complete resolution of epiphora. During the follow-up period of 10 months, although complete obstruction did not occur in any case, complete resolution of epiphora was maintained only in one of four eyes. In two eyes, improvement was remarkable. In one eye with partial improvement, intrastent balloon dilatation was performed. CONCLUSION: Treatment of recurrent nasolacrimal duct obstructions with balloon-expandable metallic stents is a noninvasive, efficient, and safe outpatient procedure that may be an alternative to surgery as a means for managing epiphora.