Foundations of the Diagnosis and Management of Idiopathic Intracranial Hypertension and Pulsatile Tinnitus.

Venous sinus stenosis has garnered increasing academic attention as a potential etiology of idiopathic intracranial hypertension (IIH) and pulsatile tinnitus (PT). The complex anatomy of the cerebral venous sinuses and veins plays a crucial role in the pathophysiology of these conditions. Venous sinus stenosis, often found in the superior sagittal or transverse sinus, can lead to elevated intracranial pressure (ICP) and characteristic IIH symptoms. Stenosis, variations in dural venous anatomy, and flow dominance patterns contribute to aberrant flow and subsequent PT. Accurate imaging plays a vital role in diagnosis, and magnetic resonance (MR) venography is particularly useful for detecting stenosis. Management strategies for IIH and PT focus on treating the underlying disease, weight management, medical interventions, and, in severe cases, surgical or endovascular procedures. Recently, venous sinus stenting has gained interest as a minimally invasive treatment option for IIH and PT. Stenting addresses venous sinus stenosis, breaking the feedback loop between elevated ICP and stenosis, thus reducing ICP and promoting cerebrospinal fluid outflow. The correction and resolution of flow aberrances can also mitigate or resolve PT symptoms. While venous sinus stenting remains an emerging field, initial results are promising. Further research is needed to refine patient selection criteria and evaluate the long-term efficacy of stenting as compared to traditional treatments.

Challenges in the use of Venous Sinus Stenting in the Treatment of Idiopathic Intracranial Hypertension and Pulsatile Tinnitus.

Although numerous case series and meta-analyses have shown the efficacy of venous sinus stenting (VSS) in the treatment of idiopathic intracranial hypertension and idiopathic intracranial hypertension-associated pulsatile tinnitus, there remain numerous challenges to be resolved. There is no widespread agreement on candidacy; pressure gradient and failed medical treatment are common indications, but not all clinicians require medical refractoriness as a criterion. Venous manometry, venography, and cerebral angiography are essential tools for patient assessment, but again disagreements exist regarding the best, or most appropriate, diagnostic imaging choice. Challenges with the VSS technique also exist, such as stent choice and deployment. There are considerations regarding postprocedural balloon angioplasty and pharmacologic treatment, but there is insufficient evidence to formalize postoperative decision making. Although complications of VSS are relatively rare, they include in-stent stenosis, hemorrhage, and subdural hematoma, and the learning curve for VSS presents specific challenges in navigating venous anatomy, emphasizing the need for wider availability of high-quality training. Recurrence of symptoms, particularly stent-adjacent stenosis, poses challenges, and although restenting and cerebrospinal fluid-diverting procedures are options, there is a need for clearer criteria for retreatment strategies. Despite these challenges, when comparing VSS with traditional cerebrospinal fluid-diverting procedures, VSS emerges as a favorable option, with strong clinical outcomes, lower complication rates, and cost-effectiveness. Further research is necessary to refine techniques and indications and address specific aspects of VSS to overcome these challenges.

Future Directions and Innovations in Venous Sinus Stenting.

This review explores the future role of venous sinus stenting (VSS) in the management of idiopathic intracranial hypertension and pulsatile tinnitus. Despite its favorable safety profile and clinical outcomes compared with traditional treatments, VSS is not yet the standard of care for these conditions, lacking high-level evidence data and guidelines for patient selection and indications. Current and recently completed clinical trials are expected to provide data to support the adoption of VSS as a primary treatment option. Additionally, VSS shows potential in treating other conditions, such as dural arteriovenous fistula and cerebral venous sinus thrombosis, and it is likely that the procedure will continue to see an expansion of its approved indications. The current lack of dedicated venous stenting technology is being addressed with promising advancements, which may improve procedural ease and patient outcomes. VSS also offers potential for expansion into modulation of brain electrophysiology via endovascular routes, offering exciting possibilities for neurodiagnostics and treatment of neurodegenerative disorders.

Impaired drainage of vein of Labbé following venous sinus stenting for idiopathic intracranial hypertension.

PURPOSE: The impact of venous sinus stenting (VSS) on vein of Labbé (VOL) drainage is poorly understood. The purpose of the study is to examine the incidence and potential high risk factors of impaired VOL drainage among idiopathic intracranial hypertension (IIH) patients following VSS. MATERIALS AND METHODS: Institutional review board approved prospective evaluation of all IIH patients who underwent VSS over a 5 year period (January 2012 to December 2017) at Weill Cornell Medical Center constituted the study population. Patient demographics, procedural details (laterality of stenting, balloon angioplasty, number of stents, and stent diameters), morphology of the VOL and changes in the flow in the VOL, type of sinus stenosis, and transverse sinus symmetry were evaluated. We used χ2 analysis to evaluate impaired VOL drainage against other variables. Statistical significance was set at 0.05. RESULTS: 70 consecutive patients (67 women, 3 men) with a mean age of 31±9.8 years underwent VSS. Stenosis was extrinsic in 63% (n=44) and intrinsic in 37% (n=26) of patients. Impaired drainage of the VOL was detected in 9/70 (13%) patients. Ipsilateral VOL was recognized as dominant in 20% (n=14), co-dominant in 51% (n=36), and non-dominant in 29% (n=20) of patients. Impaired VOL drainage was significantly associated with ipsilateral VOL dominance (P=0.001) and stent diameter of ≥9 mm (P=0.042). All patients demonstrated widely patent VOL on follow-up contrast enhanced MR venography at 3 months and 24 months. CONCLUSION: Impaired drainage of the ipsilateral VOL is a potential consequence of VSS with 13% incidence, and has significant association with ipsilateral superficial cortical venous drainage via dominant VOL and stent diameter of ≥9 mm. CLINICAL TRIAL REGISTRATION: NCT01407809.

Anatomic measurements of cerebral venous sinuses in idiopathic intracranial hypertension patients.

PURPOSE: Magnetic resonance venography (MRV) has not been validated in pre-operative planning of the dural venous sinus stenting (VSS) among idiopathic intracranial hypertension (IIH) patients. We aim to prospectively evaluate dural venous sinus measurement in IIH patient population on two-dimensional time-of-flight (2D-TOF) MRV and Three-dimensional contrast-enhanced (3D-CE) MRV acquisitions and compare them against real-time endoluminal measurements with intravascular ultrasound (IVUS), served as the reference. MATERIALS AND METHODS: The study has been approved by the Weill Cornell Medicine institutional review board. All patients signed written informed consent approved by IRB. Prospective evaluation of forty-five consecutive IIH patients treated with VSS at our institution were evaluated. Patients with pre-stent magnetic resonance venography (MRV) ≤ 6-months of VSS and intravascular ultrasound (IVUS) during VSS constituted the study population. Maximum diameter (in mm), Area (in cm2) and Perimeter (in cm) were measured at posterior 1/3rd of superior sagittal sinus (SSS), proximal transverse sinus (PTS), proximal sigmoid sinus (PSS) and mid sigmoid sinus (MSS) on 2D-TOF-MRV, 3D-CE-MRV and IVUS. Statistical analysis performed using box and whisker plots, Bland-Altman analysis and paired sample t-test. RESULTS: Twenty (n = 20) patients constituted our study population. The mean age was 30±11 years (7-59 years) and 18 out of 20 were female patients. Mean weight and BMI (range) were 86.3±18.3 kilograms (30.8-107.5 kgs) and 32.9±6.8 kg/M2 (16.4-48.3kg/M2) respectively. The CE-MRV significantly oversized the cerebral venous sinuses compared to TOF-MRV (Dmax: +2.0±1.35 mm, p<0.001; Area: +13.31±10.92 mm2, p<0.001 and Perimeter: +4.79±3.4 mm, p<0.001) and IVUS (Dmax: +1.52±2.16 mm, p<0.001; Area: +10.03±21.5 mm2, p<0.001 and Perimeter: +4.15±3.27 mm, p<0.001). The TOF-MRV sinus measurements were in good agreement with the IVUS measurements with no significant variation (Dmax: +.21±2.23 mm, p = 0.49; Area: +2.51±20.41mm2, p = 0.347 and Perimeter: +.001±1.11 mm, p = 0.991). CONCLUSION: We report baseline cerebral venous sinus measurements (maximum diameter, area and perimeter) in patients with idiopathic intracranial hypertension. In our experience, TOF-MRV is a reliable representation of endoluminal cerebral venous sinus dimensions, and CE-MRV measurements reflected an overestimation of the endoluminal sinus dimensions when compared against the real time IVUS measurements.

Contrast enhanced magnetic resonance venography in the follow-up evaluation of idiopathic intracranial hypertension patients with cerebral venous sinus stenting.

PURPOSE: Role of contrast-enhanced magnetic resonance venography (CE-MRV) in the follow-up of venous sinus stenting (VSS) among the idiopathic intracranial hypertension (IIH) patients. MATERIALS AND METHODS: Prospective evaluation of VSS patients with CE-MRV, DRCV and DSA for follow-up of clinically suspected recurrent stenosis. CE-MRV was evaluated against DRCV and DSA. RESULTS: Ten patients with twelve episodes of recurrent symptoms. Sensitivity, specificity, PPV, NPV and accuracy of the CE-MRV for the detection of recurrent stenosis were: 100%, 33.33%, 81.82%, 100% and 83.3% respectively. CONCLUSION: CE-MRV was a reliable first-line investigation for the detection of recurrent stenosis following VSS.

Selective ophthalmic artery chemosurgery (SOAC) for retinoblastoma: fluoroscopic time and radiation dose parameters. A baseline study.

OBJECTIVE: To evaluate fluoroscopic time and radiation dose parameters, and factors affecting these parameters, during selective ophthalmic artery chemosurgery (SOAC) for retinoblastoma. MATERIALS AND METHODS: Retrospective review from the prospective database of all patients with retinoblastoma treated with SOAC over a 5-year period (September 2009-January 2015) at a single institution after receiving institutional review board approval. Patient demographics, arterial approach, access device, side of treatment, number of SOAC cycles/patient, number of drugs/SOAC, and radiation parameters (outcome variables), including the fluoroscopic time, dose-area product (DAP), and total radiation dose, were obtained from the database. Generalized linear regression was used for univariate and multivariate analysis of the outcome variables. RESULTS: In 218 patients (M:F=94:124), 272 eyes were treated by 833 SOAC infusions during 792 procedures. Mean age, weight, SOAC cycle/patient, and drugs/cycle were 19±19.5 months, 11.4±6.4 kg, 2.72±1.6, and 2.48±0.8, respectively. Mean fluoroscopic time, DAP, and doses were 10.2±8.4 min, 218.7±240.8 cGy.cm2, and 42.3±41.4 mGy, respectively. Radiation parameters (fluoroscopic time, DAP, and dose) were significantly lower (p<0.001) for the ophthalmic artery (OA) approach (7.5±5.4; 147.7±138.4; 28.5±29.4) than with middle meningeal artery (13.4±5.6; 242±138; 51.4±27) and balloon-assisted infusion in the internal carotid artery (ICA; 17.8±11.5; 449.8±361; 81.8±63.3). Radiation parameters for microcatheter access (8.6±7.1; 193.4±181.3; 42.3±37) were significantly lower (p<0.001) than with the ICA (17.8±11.5; 449.8±361; 81.8±63.3). Radiation parameters for bilateral IA chemotherapy (IAC; 16.8±11.6; 320.7±268.7; 60.8±45.6) were significantly higher (p<0.001) than for unilateral IAC (8.9±6.6; 212.7±247; 42±41). CONCLUSIONS: In SOAC for retinoblastoma, the OA approach, microcatheter access, and unilateral treatment were associated with significantly lower radiation parameters. We established benchmark radiation parameters for retinoblastoma SOAC in our patient cohort.

Automating Perforator Flap MRA and CTA Reporting.

Surgical breast reconstruction after mastectomy requires precise perforator coordinates/dimensions, perforator course, and fat volume in a radiology report. Automatic perforator reporting software was implemented as an OsiriX Digital Imaging and Communications in Medicine (DICOM) viewer plugin. For perforator analysis, the user identifies a reference point (e.g., umbilicus) and marks each perforating artery/vein bundle with multiple region of interest (ROI) points along its course beginning at the muscle-fat interface. Computations using these points and analysis of image data produce content for the report. Post-processing times were compared against conventional/manual methods using de-identified images of 26 patients with surgically confirmed accuracy of perforator locations and caliber. The time from loading source images to completion of report was measured. Significance of differences in mean processing times for this automated approach versus the conventional/manual approach was assessed using a paired t test. The mean conventional reporting time for our radiologists was 76 ± 27 min (median 65 min) compared with 25 ± 6 min (median 25 min) using our OsiriX plugin (p < 0.01). The conventional approach had three reports with transcription errors compared to none with the OsiriX plugin. Otherwise, the reports were similar. In conclusion, automated reporting of perforator magnetic resonance angiography (MRA) studies is faster compared with the standard, manual approach, and transcription errors which are eliminated.

Breast Tissue Expanders with Magnetic Ports: Clinical Experience at 1.5 T.

BACKGROUND: The purpose of this study was to evaluate breast tissue expanders with magnetic ports for safety in patients undergoing abdominal/pelvic magnetic resonance angiography before autologous breast reconstruction. METHODS: Magnetic resonance angiography of the abdomen and pelvis at 1.5 T was performed in 71 patients in prone position with tissue expanders with magnetic ports labeled "MR Unsafe" from July of 2012 to May of 2014. Patients were monitored during magnetic resonance angiography for tissue expander-related symptoms, and the chest wall tissue adjacent to the tissue expander was examined for injury at the time of tissue expander removal for breast reconstruction. Retrospective review of these patients' clinical records was performed. T2-weighted fast spin echo, steady-state free precession and gadolinium-enhanced spoiled gradient echo sequences were assessed for image artifacts. RESULTS: No patient had tissue expander or magnetic port migration during the magnetic resonance examination and none reported pain during scanning. On tissue expander removal (71 patients, 112 implants), the surgeons reported no evidence of tissue damage, and there were no operative complications at those sites of breast reconstruction. CONCLUSION: Magnetic resonance angiography of the abdomen and pelvis in patients with certain breast tissue expanders containing magnetic ports can be performed safely at 1.5 T for pre-autologous flap breast reconstruction perforator vessel mapping. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Contrast-enhanced time-resolved MRA for pre-angiographic evaluation of suspected spinal dural arterial venous fistulas.

BACKGROUND: Spinal digital subtraction angiography (DSA) is the gold standard for diagnosis of spinal dural arterial venous fistulas (SDAVFs), but can require extensive time, radiation exposure and contrast dose. We hypothesize that contrast-enhanced time-resolved MR angiography (CE-TR MRA) will have utility for the non-invasive diagnosis and pre-angiographic localization of SDAVFs. METHODS: Eighteen patients underwent both CE-TR MRA and DSA for suspected SDAVFs, with DSA performed a median of 11 days (range 0-41) after MRA. CE-TR MRA was performed on a 1.5 T GE unit using Time Resolved Imaging of Contrast Kinetics (TRICKS). CE-TR MRA and DSA images were evaluated for the presence of SDAVFs and location of the feeding arterial supply, with DSA as the reference standard. DSA was also evaluated for the number of vessels catheterized, contrast volume and fluoroscopic and procedure times. RESULTS: Eight of the 18 patients were positive for SDAVF on DSA. Sensitivity, specificity, positive predictive value and negative predictive value for the 18 CE-TR MRAs were 88%, 90%, 88% and 90%, respectively. Localization of the SDAVF arterial supply on CE-TR MRA was within one vertebral level from DSA for 6/7 SDAVFs. Compared with patients with a SDAVF and feeding artery identified on CE-TR MRA, patients with negative or suboptimal CE-TR MRA had a significantly increased number of vessels catheterized (p=0.027) and larger contrast volumes (p=0.022). CONCLUSIONS: CE-TR MRA is a useful initial examination for the diagnosis and localization of SDAVFs, with a high concordance rate with DSA. When CE-TR MRA demonstrates a SDAVF, the number of catheterized vessels and contrast dose can be decreased during DSA.