Leave Nothing Behind: Treatment of Intracranial Atherosclerotic Disease with Drug-Coated Balloon Angioplasty.

PURPOSE: Intracranial atherosclerosis disease (ICAD) is an essential cause of stroke. The characteristics of effective treatment include low periprocedural risk and a sustained treatment effect. Angioplasty with a conventional balloon for ICAD is safe but has a dauntingly high restenosis rate. Drug-coated balloon (DCB) angioplasty might reduce the risk of restenosis while maintaining the overall safety of the procedure. METHODS: This study included symptomatic ICAD patients with more than 70% stenosis. Intermediate catheters were placed distally, and the lesions were predilated with a conventional balloon, followed by a DCB (SeQuent Please, B Braun, Melsungen, Germany). The primary endpoint was any stroke or death within 30 days or ipsilateral ischemic stroke thereafter. The secondary endpoint was arterial restenosis of more than 50% during follow-up. RESULTS: A total of 39 sessions of DCB angioplasty were performed for 39 lesions in 35 patients between October 2015 and April 2018 in a single center. All of the DCBs could be navigated to the lesions. Major periprocedural complications were noted in two patients (5.7%, 2/35), and minor periprocedural complications were also noted in two patients (5.7%, 2/35). The average percentages of stenosis of the lesions were 76.6% ± 7% before treatment, 32.4% ± 11.2% after DCB angioplasty, and 25% ± 16% at follow-up. Stenosis over 50% was present in 3 lesions during the follow-up period (8.3%, 3/36). CONCLUSION: In this study, the application of DCBs to treat ICAD patients was feasible and safe. A larger scale clinical trial is warranted to further evaluate the safety and efficacy of this treatment.

Long-Term Complications of Cranioplasty Using Stored Autologous Bone Graft, Three-Dimensional Polymethyl Methacrylate, or Titanium Mesh After Decompressive Craniectomy: A Single-Center Experience After 596 Procedures.

OBJECTIVE: Cranioplasty is a technically simple procedure intended to repair defects of the skull to provide protection after craniectomy, improve functional outcomes, and restore cosmesis. Several materials have been used for the restoration of skull defects, including autologous bone grafts (AGs), polymethyl methacrylate (PMMA) flaps, and titanium mesh (T-mesh). However, the long-term results of cranioplasty after use of these materials are controversial. METHODS: Medical records of 596 patients who underwent cranioplasty at our medical center between 2009 and 2015 with at least 2.5 years of follow-up were retrospectively reviewed. Patients were classified into 3 groups according to the materials used: AG, three-dimensional PMMA, and T-mesh. Demographic and clinical characteristics and postoperative complications were analyzed. RESULTS: Cranioplasty with AG had the highest bone flap depression rate (4.9%; P = 0.02) and was associated with a 26% long-term bone flap resorption. Younger age was a risk factor for bone flap resorption. T-mesh had a higher risk of postoperative skin erosion and bone exposure (17%; P = 0.004). Patients with diabetes, previous craniotomy, or hydrocephalus showed a higher risk of postoperative skin erosion. PMMA was associated with the highest rate of postoperative infection (14.4% <3 months, 28.1% >3 months; P < 0.05), and previous craniotomy may increase the infection risk after cranioplasty with PMMA. CONCLUSIONS: Complications after cranioplasty are high, and the various types of cranioplasty materials used are associated with different complications. Surgeons need to be aware of these potential complications and should choose the appropriate material for each individual patient.

Hydrodynamic characteristics of immobilized cell beads in a liquid-solid fluidized-bed bioreactor.

This study examined the hydrodynamic characteristics of a liquid-solid fluidized-bed bioreactor using elastic particles (PVA gel beads) of various diameters as carriers. The drag coefficient-Reynolds number, velocity-voidage, and expansion index-Reynolds number relationships observed during fluidization of PVA gel beads in a fluidized bed in our experiments were compared with the published results. Predictions made from previous correlations were examined with our new experimental findings, revealing the inadequacy of most of these correlations. Thus, new correlations describing the above-mentioned relationships are suggested. The drag coefficient of immobilized cell beads is larger than that of free cell ones at the same Reynolds number because the surface of the immobilized cell beads is rougher. For multiparticle systems, the correction factor, f(epsilon), is a function of the falling gel bead properties (Reynolds number) as well as the fluidized gel bead properties (Archimedes number), and depend strongly on the bed voidage (epsilon). A new simple relation was developed to predict easily the epsilon value from 0.5-0.9 at 4,986 < A(r) < 40,745 or 34 < Re(t) < 186. For all the immobilized cell beads used in this study, the prediction error of the bed voidage was less than 5% at epsilon > 0.5. The prediction equations in this study can be further applied to analyzing the hydrodynamic characteristics of a fluidized-bed reactor using similar entrapped elastic particles as carriers.