Vestibular Implant Imaging.

Analogous to hearing restoration via cochlear implants, vestibular function could be restored via vestibular implants that electrically stimulate vestibular nerve branches to encode head motion. This study presents the technical feasibility and first imaging results of CT for vestibular implants in 8 participants of the first-in-human Multichannel Vestibular Implant Early Feasibility Study. Imaging characteristics of 8 participants (3 men, 5 women; median age, 59.5 years; range, 51-66 years) implanted with a Multichannel Vestibular Implant System who underwent a postimplantation multislice CT (n = 2) or flat panel CT (n = 6) are reported. The device comprises 9 platinum electrodes inserted into the ampullae of the 3 semicircular canals and 1 reference electrode inserted in the common crus. Electrode insertion site, positions, length and angle of insertion, and number of artifacts were assessed. Individual electrode contacts were barely discernible in the 2 participants imaged using multislice CT. Electrode and osseous structures were detectable but blurred so that only 12 of the 18 stimulating electrode contacts could be individually identified. Flat panel CT could identify all 10 electrode contacts in all 6 participants. The median reference electrode insertion depth angle was 9° (range, -57.5° to 45°), and the median reference electrode insertion length was 42 mm (range, -21-66 mm). Flat panel CT of vestibular implants produces higher-resolution images with fewer artifacts than multidetector row CT, allowing visualization of individual electrode contacts and quantification of their locations relative to vestibular semicircular canals and ampullae. As multichannel vestibular implant imaging improves, so will our understanding of the relationship between electrode placement and vestibular performance.

The Occipital Emissary Vein: A Possible Marker for Pseudotumor Cerebri.

BACKGROUND AND PURPOSE: Transverse sinus stenosis can lead to pseudotumor cerebri syndrome by elevating the cerebral venous pressure. The occipital emissary vein is an inconstant emissary vein that connects the torcular herophili with the suboccipital veins of the external vertebral plexus. This retrospective study compares the prevalence and size of the occipital emissary vein in patients with pseudotumor cerebri syndrome with those in healthy control subjects to determine whether the occipital emissary vein could represent a marker of pseudotumor cerebri syndrome. MATERIALS AND METHODS: The cranial venous system of 46 adult patients with pseudotumor cerebri syndrome (group 1) was studied on CT venography images and compared with a group of 92 consecutive adult patients without pseudotumor cerebri syndrome who underwent venous assessment with gadolinium-enhanced 3D-T1 MPRAGE sequences (group 2). The presence of an occipital emissary vein was assessed, and its proximal (intraosseous) and distal (extracranial) maximum diameters were measured and compared between the 2 groups. Seventeen patients who underwent transverse sinus stent placement had their occipital emissary vein diameters measured before and after stent placement. RESULTS: Thirty of 46 (65%) patients in group 1 versus 29/92 (31.5%) patients in group 2 had an occipital emissary vein (P < .001). The average proximal and distal occipital emissary vein maximum diameters were significantly larger in group 1 (2.3 versus 1.6 mm, P <.005 and 3.3 versus 2.3 mm, P < .001). The average maximum diameters of the occipital emissary vein for patients who underwent transverse sinus stent placement were larger before stent placement than after stent placement: 2.6 versus 1.8 mm proximally (P < .06) and 3.7 versus 2.6 mm distally (P < .005). CONCLUSIONS: Occipital emissary veins are more frequent and larger in patients with pseudotumor cerebri syndrome than in healthy subjects, a finding consistent with their role as collateral venous pathway in transverse sinus stenosis. A prominent occipital emissary vein is an imaging sign that should raise the suspicion of pseudotumor cerebri syndrome.

Outcomes of endoscopic ultrasound-guided biliary drainage: A systematic review and meta-analysis.

Background: Success and event rates of endoscopic ultrasound (EUS)-guided biliary drainage vary with techniques, and results from different studies remain inconsistent. Objective: We conducted a proportion meta-analysis to evaluate the efficacy and safety of EUS-guided biliary drainage and compare the outcomes of current procedures. Methods: We searched MEDLINE, Embase, Cochrane and Web of knowledge to identify studies reporting technical success, clinical success and complication rates of EUS-guided biliary drainage techniques to estimate their clinical and technical efficacy and safety. Results: We identified 17 studies including a total of 686 patients. The overall clinical success and technical success rates were respectively 84% confidence interval (CI) 95% (80-88) and 96% CI 95% (93-98) for hepaticogastrostomy, and respectively 87% CI 95% (82-91) and 95% CI 95 (91-97) for choledochoduodenostomy. Reported adverse event rates were significantly higher (p = 0.01) for hepaticogastrostomy (29% CI 95% (24-34)) compared to choledochoduodenostomy (20% CI 95% (16-25)). Compared with hepaticogastrostomy, the pooled odds ratio for the complication rate of choledochoduodenostomy was 2.01 (1.25; 3.24) (p = 0.0042), suggesting that choledochoduodenostomy might be safer than hepaticogastrostomy. Conclusion: The available literature suggests choledochoduodenostomy may be a safer approach compared to hepaticogastrostomy. Randomized controlled trials with sufficiently large cohorts are needed to compare techniques and confirm these findings.

Very late heart transplant rejection is associated with microvascular injury, complement deposition and progression to cardiac allograft vasculopathy.

In heart transplants, the significance of very late rejection (after 7 years post-transplant, VLR) detected by routine endomyocardial biopsies (EMB) remains uncertain. Here, we assessed the prevalence, histopathological and immunological phenotype, and outcome of VLR in clinically stable patients. Between 1985 and 2009, 10 662 protocol EMB were performed at our institution in 398 consecutive heart transplants recipients. Among the 196 patients with >7-year follow-up, 20 (10.2%) presented subclinical ≥3A/2R-ISHLT rejection. The VLR group was compared to a matched control group of patients without rejection. All biopsies were stained for C4d/C3d/CD68 with sera screened for the presence of donor-specific antibodies (DSAs). In addition to cellular infiltrates with myocyte damage, 60% of VLR patients had evidence of intravascular macrophages. C4d and/or C3d-capillary deposition was found in 55% VLR EMB. All cases of VLR associated with microcirculation injury had DSAs (mean DSA(max) -MFI = 1751 ± 583). This entity was absent from the control group (p < 0.0001). Finally, after a similar follow-up postreference EMB of 6.4 ± 1 years, the mean of CAV grade was 0.76 ± 0.18 in the control group compared to 2.06 ± 0.26 in the VLR group respectively, p = 0.001). There was no difference in patient survival between study and control groups. In conclusion, VLR is frequently associated with complement-cascade activation, microvascular injury and DSA, suggesting an antibody-mediated process. VLR is associated with a dramatic progression to severe CAV in long-term follow-up.