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Michiel B. Lequin,Martin Barth,Claudius Thomė,Gerrit J. Bouma 대한척추신경외과학회 2012 Neurospine Vol.9 No.4
Objective: Discectomy as a treatment for herniated lumbar discs results in outcomes after surgery that are not uniformly positive. Surgeons face the dilemma between limited nucleus removal which is associated with a higher risk of recurrence, or more aggressive nucleus removal which may lead to disc height loss and persistent back-pain. annulus closure devices may allow for the benefits of limited nucleus removal without the increased risk of recurrence. This is an interim report of an ongoing 24-month post-marketing study of the Barricaid® annulus closure device, consisting of a flexible polymer mesh that blocks the defect, held in place by a titanium bone anchor. Methods: We prospectively enrolled 45 patients at four hospitals, and implanted the Barricaid® after a limited discectomy. annulus defect size and volume of removed nucleus were recorded. Reherniations were reported, pain and function were monitored and imaging was performed at regular intervals during 24 months of follow-up. Results: At 12 months postsurgery, pain and function were significantly improved, comparing favorably to reported results from limited discectomy. Disc height has been well maintained. One reherniation has occurred (2.4%), which was associated with a misplaced device. No device fracture, subsidence or migration has been observed. Conclusion: The use of an annulus closure device may provide a reduction in reherniation rate for lumbar discectomy patients with large annulus defects who are at the greatest risk of recurrence. Using such a device should provide the surgeon increa- sed confidence in minimizing nucleus removal, which, in turn, may preserve disc height and biomechanics, reducing dege- neration and associated poor clinical outcomes in the long-term. A randomized multicenter study evaluating limited discectomy with and without the Barricaid® is currently underway, and will provide a higher level of evidence. Objective: Discectomy as a treatment for herniated lumbar discs results in outcomes after surgery that are not uniformly positive. Surgeons face the dilemma between limited nucleus removal which is associated with a higher risk of recurrence, or more aggressive nucleus removal which may lead to disc height loss and persistent back-pain. annulus closure devices may allow for the benefits of limited nucleus removal without the increased risk of recurrence. This is an interim report of an ongoing 24-month post-marketing study of the Barricaid® annulus closure device, consisting of a flexible polymer mesh that blocks the defect, held in place by a titanium bone anchor. Methods: We prospectively enrolled 45 patients at four hospitals, and implanted the Barricaid® after a limited discectomy. annulus defect size and volume of removed nucleus were recorded. Reherniations were reported, pain and function were monitored and imaging was performed at regular intervals during 24 months of follow-up. Results: At 12 months postsurgery, pain and function were significantly improved, comparing favorably to reported results from limited discectomy. Disc height has been well maintained. One reherniation has occurred (2.4%), which was associated with a misplaced device. No device fracture, subsidence or migration has been observed. Conclusion: The use of an annulus closure device may provide a reduction in reherniation rate for lumbar discectomy patients with large annulus defects who are at the greatest risk of recurrence. Using such a device should provide the surgeon increa- sed confidence in minimizing nucleus removal, which, in turn, may preserve disc height and biomechanics, reducing dege- neration and associated poor clinical outcomes in the long-term. A randomized multicenter study evaluating limited discectomy with and without the Barricaid® is currently underway, and will provide a higher level of evidence.
Zhang, Ellen Ziyi,Oh, Wang-Yuhl,Villiger, Martin L,Chen, Liang,Bouma, Brett E,Vakoc, Benjamin J Optical Society of America 2013 Optics express Vol.21 No.1
<P>Polarization mode dispersion (PMD), which can be induced by circulators or even moderate lengths of optical fiber, is known to be a dominant source of instrumentation noise in fiber-based PS-OCT systems. In this paper we propose a novel PMD compensation method that measures system PMD using three fixed calibration signals, numerically corrects for these instrument effects and reconstructs an improved sample image. Using a frequency multiplexed PS-OFDI setup, we validate the proposed method by comparing birefringence noise in images of intralipid, muscle, and tendon with and without PMD compensation.</P>
Oh, Wang-Yuhl,Vakoc, Benjamin J.,Shishkov, Milen,Tearney, Guillermo J.,Bouma, Brett E. The Optical Society 2010 Optics letters Vol.35 No.17
<P>We demonstrate a high-speed wavelength-swept laser with a tuning range of 104nm (1228-1332nm) and a repetition rate of 403kHz. The design of the laser utilizes a high-finesse polygon-based wavelength-scanning filter and a short-length unidirectional ring resonator. Optical frequency domain imaging of the human skin in vivo is presented using this laser, and the system shows sensitivity of higher than 98dB with single-side ranging depth of 1.7mm over 4dB sensitivity roll-off.</P>
Progress in Intracoronary Optical Coherence Tomography
Suter, M J,Tearney, G J,Wang-Yuhl Oh,Bouma, B E IEEE 2010 IEEE journal of selected topics in quantum electro Vol.16 No.4
<P>Understanding the etiology and evolution of the vulnerable coronary plaque is important for the early detection, treatment, and prevention of coronary artery disease. Intravascular optical coherence tomography (OCT) enables imaging of the coronary arteries <I>in vivo</I> with sufficient resolution to accurately differentiate arterial pathology, however, the clinical utility of this technology has been limited due to slow image acquisition rates. The development of high-speed Fourier-domain OCT techniques, including optical frequency-domain imaging, enables comprehensive microstructural imaging of long coronary artery segments. Other OCT advancements, including polarization sensitive OCT provide complementary birefringence information that is related to tissue composition. Together with new image processing, acquisition, and display techniques, these advances have enhanced the usability and utility of intracoronary OCT, bringing it closer to becoming a mainstream imaging modality in interventional cardiology.</P>
Compensation of motion artifacts in catheter-based optical frequency domain imaging
Ha, J. Y.,Shishkov, M.,Colice, M.,Oh, W. Y.,Yoo, H.,Liu, L.,Tearney, G. J.,Bouma, B. E. Optical Society of America 2010 Optics express Vol.18 No.11
<P>A novel heterodyne Doppler interferometer method for compensating motion artifacts caused by cardiac motion in intracoronary optical frequency domain imaging (OFDI) is demonstrated. To track the relative motion of a catheter with regard to the vessel, a motion tracking system is incorporated with a standard OFDI system by using wavelength division multiplexing (WDM) techniques. Without affecting the imaging beam, dual WDM monochromatic beams are utilized for tracking the relative radial and longitudinal velocities of a catheter-based fiber probe. Our results demonstrate that tracking instantaneous velocity can be used to compensate for distortion in the images due to motion artifacts, thus leading to accurate reconstruction and volumetric measurements with catheter-based imaging.</P>