Long-term outcome of absorbable synthetic mesh in clean ventral hernia repairs.

BACKGROUND: There are many materials available for the reinforcement of complex abdominal wall reconstruction, including permanent synthetic, biologic, and absorbable synthetic meshes. The recurrence rate of complex hernia repairs beyond 5 years has not been reported. We hypothesized that the use of absorbable synthetic mesh in clean wounds would yield favorable long-term outcomes. STUDY DESIGN: Patients who underwent open complex ventral hernia repair with clean wounds (CDC class 1) using absorbable synthetic mesh (Bio-A, Gore, Flagstaff, AZ) in the retrorectus position were retrospectively reviewed. Chart review and a validated telephone questionnaire to screen for recurrence were utilized to evaluate and document hernia recurrence. RESULTS: A total of 49 patients were included in this study. Patients were followed for recurrences for up to 105 months, with a mean follow-up time of 62.4 months (5.2 years). The total number of midline hernia recurrence was 7 out of the original 49 patients (14%). The mean and median recurrence time are 37.4 and 38.8 months, respectively. Kaplan-Meier survival analysis estimated hernia recurrence rate as 2%, 4.6%, 7.1%, 12%, 15%, and 18% at 12, 24, 36, 48, 60, and 72 months, respectively. CONCLUSION: The use of absorbable synthetic mesh in clean wound ventral hernia repair resulted in favorable long-term recurrence rates. The recurrence rate of absorbable synthetic mesh is similar to that of permanent synthetic mesh, which gives a viable option for patients in whom permanent synthetic mesh is not an option.

Virtual 2D angiography from four-dimensional digital subtraction angiography (4D-DSA): A feasibility study.

BACKGROUND: Digital subtraction angiography (DSA) remains the gold standard for angiographic evaluation of cerebrovascular pathology, however, multiple acquisitions requiring additional time and radiation are often needed. In contrast, 3D-DSA provides volumetric information from a single injection but neglects temporal information. Four-dimensional-DSA (4D-DSA) combines temporal information of 2D-DSA with volumetric information of 3D-DSA to provide time-resolved tomographic 3D reconstructions, potentially reducing procedure time and radiation. This work evaluates the diagnostic quality of virtual single-frame 4D-DSA relative to 2D-DSA images by assessing clinicians' ability to evaluate cerebrovascular pathology. METHODS: Single-frame images of four projections from 4D-DSA and their corresponding 2D-DSA images (n = 15) were rated by two neurointerventional radiologists. Images were graded based on diagnostic quality (0 = non-diagnostic, 1 = poor, 2 = acceptable, 3 = good). Dose area product (DAP) for each case was recorded for all 2D-DSA, 4D-DSA acquisitions, and the overall procedure. RESULTS: The mean diagnostic quality of all four 4D-DSA projections from both raters was 1.75 while the mean of 2D-DSA projections was 2.8. Student's t-test revealed significant difference in diagnostic quality between 4D-DSA and 2D-DSA at all four projections (p < 0.001). On average 4D-DSA acquisitions accounted for 30% dose compared to the overall average aggregated dose per procedure. CONCLUSIONS: The difference in image quality between virtual single-frame 4D-DSA and their respective 2D-DSA images is statistically significant. Furthermore, 4D-DSA acquisitions require less radiation dose than conventional procedures with 2D-DSA acquisitions.

Predictors of intracranial hemorrhage volume and distribution in brain arteriovenous malformation.

Background and purpose Despite evidence regarding risk factors for brain arteriovenous malformation (bAVM)-associated spontaneous intracranial hemorrhage (ICH), few data exist describing the spectrum of clinical outcomes that bAVM-associated ICH may manifest. This study aimed to identify the demographical, clinical, and bAVM anatomical variables associated with ICH volume and the presence of intraventricular hemorrhage (IVH) of ruptured bAVMs, two indicators of worse clinical outcome, to help better predict outcome for unruptured bAVMs. Methods Computed tomography images ( n = 169) of patients with ruptured bAVM in a prospectively maintained institutional database were retrospectively reviewed to calculate ICH volume and the presence or absence of IVH. Demographic, clinical, and bAVM characteristics information was summarized and analyzed with univariable and multivariable regression models to identify the associations of these features with ICH volume and the presence of IVH. Results Patient sex, exclusively deep venous drainage, and lobar location were associated with ICH volume in univariable analysis; exclusively deep venous drainage remained significant in multivariable analysis (PI = 0.33, 95% CI: 0.21-0.52, p < 0.001). Exclusively deep venous drainage, multiple feeding arteries, and venous stenosis were associated with IVH in univariable analysis; exclusively deep venous drainage (OR = 7.27, 95% CI: 1.94-27.29, p = 0.003) remained significant in multivariable analysis. Conclusions Variables associated with ICH volume and the presence of IVH in ruptured bAVMs were evaluated and identified. They impart information that may help predict the clinical outcome of unruptured bAVM, in turn aiding clinicians in treatment planning.

Interventional magnetic resonance imaging guided carotid embolectomy using a novel resonant marker catheter: demonstration of preclinical feasibility.

To assess the visualization and efficacy of a wireless resonant circuit (wRC) catheter system for carotid artery occlusion and embolectomy under real-time MRI guidance in vivo, and to compare MR imaging modality with x-ray for analysis of qualitative physiological measures of blood flow at baseline and after embolectomy. The wRC catheter system was constructed using a MR compatible PEEK fiber braided catheter (Penumbra, Inc, Alameda, CA) with a single insulated longitudinal copper loop soldered to a printed circuit board embedded within the catheter wall. In concordance with IACUC protocol (AN103047), in vivo carotid artery navigation and embolectomy were performed in four farm pigs (40-45 kg) under real-time MRI at 1.5T. Industry standard clots were introduced in incremental amounts until adequate arterial occlusion was noted in a total of n=13 arteries. Baseline vasculature and restoration of blood flow were confirmed via MR and x-ray imaging, and graded by the Thrombolysis in Cerebral Infarction (TICI) scale. Wilcoxon signed-rank tests were used to analyze differences in recanalization status between DSA and MRA imaging. Successful recanalizations (TICI 2b/3) were compared to clinical rates reported in literature via binomial tests. The wRC catheter system was visible both on 5° sagittal bSSFP and coronal GRE sequence. Successful recanalization was demonstrated in 11 of 13 occluded arteries by DSA analysis and 8 of 13 by MRA. Recanalization rates based on DSA (0.85) and MRA (0.62) were not significantly different from the clinical rate of mechanical aspiration thrombectomy reported in literature. Lastly, a Wilcoxon signed rank test indicated no significant difference between TICI scores analyzed by DSA and MRA. With demonstrated compatibility and visualization under MRI, the wRC catheter system is effective for in vivo endovascular embolectomy, suggesting progress towards clinical endovascular interventional MRI.

In vitro clearance of doxorubicin with a DNA-based filtration device designed for intravascular use with intra-arterial chemotherapy.

To report a novel method using immobilized DNA within mesh to sequester drugs that have intrinsic DNA binding characteristics directly from flowing blood. DNA binding experiments were carried out in vitro with doxorubicin in saline (PBS solution), porcine serum, and porcine blood. Genomic DNA was used to identify the concentration of DNA that shows optimum binding clearance of doxorubicin from solution. Doxorubicin binding kinetics by DNA enclosed within porous mesh bags was evaluated. Flow model simulating blood flow in the inferior vena cava was used to determine in vitro binding kinetics between doxorubicin and DNA. The kinetics of doxorubicin binding to free DNA is dose-dependent and rapid, with 82-96 % decrease in drug concentration from physiologic solutions within 1 min of reaction time. DNA demonstrates faster binding kinetics by doxorubicin as compared to polystyrene resins that use an ion exchange mechanism. DNA contained within mesh yields an approximately 70 % decrease in doxorubicin concentration from solution within 5 min. In the IVC flow model, there is a 70 % drop in doxorubicin concentration at 60 min. A DNA-containing ChemoFilter device can rapidly clear clinical doses of doxorubicin from a flow model in simple and complex physiological solutions, thereby suggesting a novel approach to reduce the toxicity of DNA-binding drugs.

Block Copolymer Membranes for Efficient Capture of a Chemotherapy Drug.

We introduce the use of block copolymer membranes for an emerging application, "drug capture". The polymer is incorporated in a new class of biomedical devices, referred to as ChemoFilter, which is an image-guided temporarily deployable endovascular device designed to increase the efficacy of chemotherapy-based cancer treatment. We show that block copolymer membranes consisting of functional sulfonated polystyrene end blocks and a structural polyethylene middle block (S-SES) are capable of capturing doxorubicin, a chemotherapy drug. We focus on the relationship between morphology of the membrane in the ChemoFilter device and efficacy of doxorubicin capture measured in vitro. Using small-angle X-ray scattering and cryogenic scanning transmission electron microscopy, we discovered that rapid doxorubicin capture is associated with the presence of water-rich channels in the lamellar-forming S-SES membranes in aqueous environment.