Tae Hong Lee

Long-term follow-up after endovascular stent placement for treatment of nutcracker syndrome.

posed in which the intrahepatic PV is accessed directly via the intrahepatic inferior vena cava under intravascular US guidance and a shunt is subsequently created with use of a covered stent (2,3). Another nonsurgical approach to creation of a portosystemic shunt is the intravascular US– guided creation of a transvenous extrahepatic portacaval shunt (4). If the target PVs are located cranially to the hepatic veins or lie at the same caudocranial level but are separated anteroposteriorly from the hepatic veins, accessing the PV from the transjugular route can be difficult or impossible, as in our case (5). One technique to successfully deal with this anatomy is the creation of TIPS via the femoral route (6). Our approach also created a hemodynamically significant shunt by dilating and stent-implanting a small preexisting intrahepatic portovenous fistula. Portovenous shunts occur primarily in patients with chronic liver disease, especially liver cirrhosis. Doppler US with a pulsatile trior biphasic spectral pattern suggests the presence of a portosystemic shunt. Numerous alternative approaches to nonsurgical creation of a portosystemic shunt are available when standard approaches fail. In the rare instances in which a PV–hepatic vein fistula is present, TIPS can be created by placing a stent in this fistula.

Biliary abnormalities associated with portal biliopathy: evaluation on MR cholangiography.

OBJECTIVE The purpose of our study was to evaluate the MRI features of portal biliopathy. CONCLUSION MR cholangiography coupled with dynamic 3D gradient-echo imaging could not only detect portal vein occlusion, cavernous transformation, and gallbladder varices but is also suitable for delineating associated bile duct abnormalities.

Embolization of intracranial aneurysms with HydroSoft coils: results of the Korean multicenter study.

BACKGROUND AND PURPOSE: Various modifications of detachable coils have been attempted to reduce recurrence rates in aneurysmal coil embolization and HydroSoft coil is one of them. The authors report their experience using HydroSoft coils in the treatment of cerebral aneurysms. MATERIALS AND METHODS: The present study is a prospective multicenter observational series of 127 aneurysms in 120 patients treated with HydroSoft coils. RESULTS: Ten centers participated in this study, and there were 92 (72%) unruptured and 35 ruptured aneurysms. Aneurysm volumes were ≥100 mm3 in 21 (17%) and <100 mm3 in 106 (83%) (mean, 56 mm3; range, 5–249 mm3). The average percentage length of HydroSoft coils detached in treated aneurysms was 67% (range, 42%–100%). Immediate postprocedural angiography demonstrated complete aneurysm occlusion in 69% (87/127 aneurysms), residual neck in 20% (25/127), and residual sac in 12% (15/127). Procedure-related adverse events occurred in 4.7% (6/127 aneurysms), including procedural bleeding (5/127) and thromboembolism (2/127), and immediate procedure-related morbidity and mortality rates were 0.8% and 0%. Conventional angiography or MRA follow-up was performed in 83% (105/127) at ≥6 months after treatment (mean interval, 11 months; range, 6–24 months). The overall recanalization rate was 3% (3/105 aneurysms; 2 major and 1 minor recanalizations). Progression to complete aneurysmal occlusion was noted in 20 of 27 aneurysms (74%) during the follow-up. CONCLUSIONS: The safety profile of HydroSoft coils appears acceptable. In terms of initial occlusion rates and durability, embolization by using HydroSoft coils seems to be favorable compared with most large series of pure platinum or coated coils.

A pragmatic protocol for reduction in the metal artifact and radiation dose in multislice computed tomography of the spine : Cadaveric evaluation after cervical pedicle screw placement

Objective: To assess the correlation between the metal artifact degree and the tube voltage (in peak kilovolts; kVp) and tube current (in milliamperes; mA) in multidetector row computed tomography (MDCT) and evaluate the proper protocols for reduction in the metal artifact and the radiation dose. Methods: We performed MDCT examinations for 13 cadavers operated for transpedicular screw insertion from C3 to C7, bilaterally. We used 80, 100, and 120 kVp in all cadavers. For the mA, we arbitrarily applied 100, 150, and 200 in 6 cadavers (experiment 1); 140, 180, and 220 in 4 (experiment 2), and randomly used mAs between 60 and 220 in 3 (experiment 3). The lengths of the artifacts emanating from the anterior and posterior tips of the screw were used for the degree of artifact. Results: In experiment 1, the mA did not significantly affect the metal artifacts (P > 0.05); but the kVp did (P < 0.05). In experiment 2, the mA and kVp did not significantly affect the metal artifact degree (P > 0.05). In experiment 3, the mA did not affect the metal artifacts, but the kVp caused changes in metal artifact degrees (simple quantitative analysis). Conclusions: The proper parameters for the simultaneous reduction in the artifact and radiation dose are suggested to be tube voltages from 100 to 120 kVp and tube currents lower than the generally used values of 200 to 220 mA.

Pipeline Embolization Device for Large/Giant or Fusiform Aneurysms: An Initial Multi-Center Experience in Korea

Purpose The purpose of this study was to assess the safety and early outcomes of the Pipeline device for large/giant or fusiform aneurysms. Materials and Methods The Pipeline was implanted in a total of 45 patients (mean age, 58 years; M:F=10:35) with 47 large/giant or fusiform aneurysms. We retrospectively evaluated the characteristics of the treated aneurysms, the periprocedural events, morbidity and mortality, and the early outcomes after Pipeline implantation. Results The aneurysms were located in the internal carotid artery (ICA) cavernous segment (n=25), ICA intradural segment (n=11), vertebrobasilar trunk (n=8), and middle cerebral artery (n=3). Procedure-related events occurred in 18 cases, consisting of incomplete expansion (n=8), shortening-migration (n=5), transient occlusion of a jailed branch (n=3), and in-stent thrombosis (n=2). Treatment-related morbidity occurred in two patients, but without mortality. Both patients had modified Rankin scale (mRS) scores of 2, but had an improved mRS score of 0 at 1-month follow-up. Of the 19 patients presenting with mass effect, 16 improved but three showed no changes in their presenting symptoms. All patients had excellent outcomes (mRS, 0 or 1) during the follow-up period (median, 6 months; range, 2-30 months). Vascular imaging follow-up (n=31, 65.9%; median, 3 months, range, 1-25 months) showed complete or near occlusion of the aneurysm in 24 patients (77.4%) and decreased sac size in seven patients (22.6%). Conclusion In this initial multicenter study in Korea, the Pipeline seemed to be safe and effective for large/giant or fusiform aneurysms. However, a learning period may be required to alleviate device-related events.

Periorbita: computed tomography and magnetic resonance imaging findings.

Purpose The periorbita has been regarded as the critical structure in decision of exenteration in the patients with paranasal (PNS) malignancies. The purpose of this study is to present the CT and MRI findings of the periorbita with PNS malignancies. Materials and Methods Ten patients with PNS cancers were chosen for this study. PNS CT and MRI scans were performed on all patients. The imaging findings were reviewed retrospectively by consensus of two neuroradiologists. Assessment of the defect of the orbital bone and invasion of the orbital fat was made by CT and MRI. The signal intensity (SI), thickness, enhancement, and correlation with the orbital bone of the periorbita were analyzed on MRI. The intraoperative and pathologic reports were used as the gold standard for orbital invasion. Results In patients with bone defects, it was impossible to differentiate the periorbita from the mass on CT. The periorbita showed hypointensity on T2-weighted images compared with the SI of mass. On Gd-enhanced T1-weighted images, the periorbita showed less enhancement than the mass in nine patients. Six patients showed two hypointense layers (the outer bony wall and the inner periorbita) between the mass and orbital fat on T2-weighted images. The thickness of the periorbita was 0.79–1.4 millimeter. Orbital invasion was more conspicuous on T2-weighted coronal images than on the CT images. Conclusions MRI was more conspicuous for detecting orbital invasion than CT. The mass beyond the thickened periorbita on T2-weighted images was considered to be a positive finding of orbital invasion.

Effect of triolein emulsion on the blood-testis barrier in cats.

Purpose:Although the blood–testis barrier (BTB) is beneficial physiologically, it acts as an obstacle to chemotherapy. We wished to determine whether a triolein emulsion could alter the permeability of the BTB in cats. Materials and Methods:An emulsion of 0.05-mL triolein in 20 mL of saline was infused into the abdominal aorta just proximal to the branching of the renal arteries of each of 15 cats (embolic group). As controls, 12 cats were each similarly infused with 20 mL of normal saline (control group). Pre and postcontrast MR images were obtained 30 minutes and 2 hours after embolization. The images were analyzed for the presence and degree of contrast enhancement (qualitative analysis), and the contrast enhancement ratios (CER) derived from one testis of each animal were compared and statistically analyzed by the mixed linear model (quantitative analysis). Results:Contrast enhancement of the testis was observed in both groups at both time points, but it was more prominent in the embolic group. The CERs in the embolic group (0.63 at 30 minutes, 0.42 at 2 hours) were significantly higher than in the control group (0.36 at 30 minutes, 0.28 at 2 hours; P = 0.0001). In each group, the CERs at 2 hours were significantly lower than those at 30 minutes (P = 0.006). Conclusion:Intra-arterial infusion of triolein emulsion increased the permeability of the BTB. This result may be useful in future studies of BTB disruptions caused by fat emulsions.

Recanalization with Wingspan stent for acute middle cerebral artery occlusion in failure or contraindication to intravenous thrombolysis: a feasibility study.

BACKGROUND AND PURPOSE: Recanalization with the Wingspan stent, which can be deployed rapidly and safely, is an option for treating acute ischemic stroke when intravenous thrombolysis has failed or is contraindicated. This study was performed to evaluate feasibility, efficacy, and safety of recanalization for acute middle cerebral artery occlusion using the Wingspan stent. MATERIALS AND METHODS: We collected 10 patients with acute MCA occlusion in whom recanalization was not achieved with a standard intravenous thrombolysis, or who were ineligible for intravenous thrombolysis, or who presented after 3 hours of symptom onset and in whom the stent placement could be completed within 8 hours from symptom onset. We analyzed angiographic and clinical results. RESULTS: Successful recanalization with the Wingspan stent was achieved in all patients. The mean NIHSS score on admission was 12.7 points (range 4–21). The occlusion sites were located in the 1st segment (n = 7; 2 left, 5 right) and 2nd segment (n = 3, all right) of the MCA. The mean time interval from stroke symptom onset to stent placement was 344.8 ± 76.3 minutes. No intracranial hemorrhage, vessel perforations, or dissections occurred in any patient. Nine patients improved on the NIHSS at 7 days. One patient did not have a change in the NIHSS score, even though the occluded artery was completely recanalized. At 7 days, the NIHSS score of all patients was 4.4 ± 4.7 (median 4, range 0–13). At discharge, an mRS of ≤3 was achieved in all patients and an mRS of ≤2 was achieved in 7 patients (70%). CONCLUSIONS: This small case series demonstrates the feasibility of using the Wingspan stent safely and effectively for MCA occlusions when standard treatments are ineffective or not available.

Traumatic Carotid Cavernous Fistula with a Connection between the Supraclinoid Internal Carotid Artery and Cavernous Sinus via a Pseudoaneurysm Presenting with Delayed Life-threatening Epistaxis

Traumatic carotid cavernous fistula (CCF) presents most commonly as a direct connection between the cavernous segment of internal carotid artery (ICA) and cavernous sinus (CS), and often accompanies basal skull fracture (BSF). The most frequently reported signs and symptoms are proptosis, chemosis, and bruit. Epistaxis is uncommon symptom of CCF. A 63-year-old man with a history of BSF due to blunt head trauma eight months previously was referred to our emergency room for massive epistaxis. Cerebral angiography demonstrated a high-flow CCF with a connection between the supraclinoid portion of left ICA and CS via a pseudoaneurysm, suggesting the life-threatening epistaxis had been caused by high-flow shunting, through the gap created by the BSF. After the complete obliteration of the pseudoaneurysm arising from the supraclinoid ICA by stent-assisted coil embolization, the CCF was no longer evident and epistaxis ceased. To the best of our knowledge, this is the first case of a traumatic CCF with a connection between the supraclinoid ICA and CS via a pseudoaneurysm, presenting with delayed life-threatening epistaxis.

Huge Intramural Hematoma in a Thrombosed Middle Cerebral Artery Aneurysm: A Case Report.

We describe a case of a huge intramural hematoma in a thrombosed middle cerebral artery aneurysm. A 47-year-old female patient with liver cirrhosis and thrombocytopenia presented to the neurosurgical unit with a 5-day history of headache and cognitive dysfunction. Magnetic resonance imaging and computed tomography of the brain showed a thrombosed aneurysm located in the right middle cerebral artery with a posteriorly located huge intramural hematoma mimicking an intracerebral hematoma. Imaging studies and cerebrospinal fluid analysis showed no evidence of subarachnoid hemorrhage. Angiography showed a partially thrombosed aneurysm at the origin of the right anterior temporal artery and an incidental aneurysm at the bifurcation of the right middle cerebral artery. Both aneurysms were embolized by coiling. After embolization, the thrombosed aneurysmal sac and intramural hematoma had decreased in size 4 days later and almost completely disappeared 8 months later. This is the first reported case of a nondissecting, nonfusiform aneurysm with a huge intramural hematoma, unlike that of a dissecting aneurysm.