An Optimized Preparation Technique for Saphenous Vein Graft
An Optimized Preparation Technique for Saphenous Vein Graft
复制标题
隐静脉移植物的优化制备技术
DOI：
10.1177/000313481508100703
复制
发表时间：
2015
期刊：
影响因子：
--
通讯作者：
C. Brophy
中科院分区：
文献类型：
--
作者：
E. Wise;K. Hocking;Daniel Feldman;P. Komalavilas;Joyce Cheung;C. Brophy
人隐静脉（HSV）仍然是外周和冠状动脉旁路手术中最广泛使用的导管。然而，来自Project of exvivo vein graft Engineering via转染-III （PREVENT III）试验的数据显示，HSV术后1年的静脉移植失败率高达40%。(1)早期静脉移植物衰竭（<1个月）通常是由于技术原因，而晚期静脉移植物衰竭（术后2个月至2年）最常见的原因是新生内膜增生，这是一种病理性变窄，会导致患者严重的发病率和成本。(1) HSV植入动脉循环是一种自体移植。与实体器官异体移植一样，移植物通过手术切除，在“手术台上”进行准备，然后放入受体体内。然而，HSV移植物制备的方法还没有像其他移植器官那样得到优化，可能会对导管造成重大伤害，同时加速新生内膜的生长。(2)
Human saphenous vein (HSV) remains the most widely used conduit for peripheral and coronary bypass procedures. However, data from the Project of Ex-Vivo vein graft Engineering via Transfection-III (PREVENT III) trial revealed vein graft failure rates of HSV as high as 40% at one year postoperatively.(1) While early vein graft failure (<1 month) is often due to technical reasons, late vein graft failure, from between 2 months and 2 years postoperatively, is most commonly due to neointimal hyperplasia, a pathologic narrowing that leads to significant patient morbidity as well as cost.(1) Implantation of HSV into the arterial circulation represents an autologous transplantation. As with solid organ allotransplantation, the graft is surgically removed, prepared on the “back-table” and then placed inside the recipient. However, methods of HSV graft preparation have not been optimized to a similar extent as other transplanted organs, and may cause significant harm to the conduit with concomitant acceleration of neointimal growth.(2)
Collectively, the standard preparation technique for HSV could be improved. A technique that optimizes the current standard preparation method must still allow for identification of leaks and maintenance of graft orientation, yet also preserve physiologic viability of smooth muscle and endothelial cells. We report a rationally engineered optimized preparation technique, addressing alternatives for each deleterious step of HSV graft preparation.
There are several techniques used to prepare HSV prior to implantation. First, the conduit is distended using a hand-held syringe. Even if performed “gently,” manual distension leads to intraluminal pressures in excess of 600 mmHg.(3) Currently, a pressure controlling syringe has been reported for graft distension (Maquet, Germany), though this technology is not widely used in the United States. For hand-held graft distension, an in-line pressure release valve with adaptor tubing was designed, with a maximum pressure of 140 mm Hg allowed before pressure release. Use of this valve prevents supraphysiologic intraluminal pressures in the conduit, preserving endothelium and ameliorating a host of well characterized biochemical and physiologic distension injuries to vascular smooth muscle. In 2014, Li et al. demonstrated, in a series of organ bath experiments, a decreased physiologic response to contractile agonists such as phenylephrine, as well as decreased endothelial-dependent relaxation in tissue distended with a hand-held syringe compared to tissue distended with the in-line pressure release valve, and non-distended control tissue. Furthermore, unregulated distension in porcine saphenous vein led to increased intimal thickness over fourteen days, in an organ culture model, compared with pressure release valve-distension.(3) Additionally, an adjustable bulldog clamp is used for atraumatic occlusion of the lumen opposite to the cannulation site.
Second, HSV explants are marked via “off-label” use of a surgical skin marker composed of gentian violet dye and isopropanol alcohol solvent, a procedure that has been shown to render the conduit physiologically non-viable.(2) FDC herein after, FCF) has recently been identified as a non-toxic alternative blue dye which preserves HSV graft cellular physiologic function and viability, while abrogating intimal growth in organ culture.(2) In 2014, Voskresensky et al. demonstrated that HSV segments treated with FCF fully maintained smooth muscle and endothelial physiologic function, relative to unmarked control. Moreover, FCF restored smooth muscle contractility to high-KCl stimuli in HSV that had initial significant functional impairment.(2) Finally, treatment with FCF reduced intimal hyperplasia compared to control untreated HSV in an organ culture model.(2) Mechanistically, it has been proposed that FCF antagonizes vascular P2X7 receptors. P2X7 receptor stimulation leads to activation of downstream cellular processes including migration, proliferation and apoptosis, which have been associated with intimal hyperplasia.(2) Therefore, to mark the graft, a marking pen was employed using water soluble FCF (Vasoprep Surgical Inc, Morristown, NJ).
The final component of standard HSV graft preparation is storage of the tissue in a solution until implantation. Historically, whole blood was the preservation solution of choice for HSV graft, and remains in clinical use in many operating rooms. For solid organs, specially designed preservation solutions containing vital nutrients, antioxidants and a balanced electrolyte composition have been developed; most notably, the University of Wisconsin solution. However, despite advances in preservation media, it was not until 2014 that Harskamp et al. provided the best clinical evidence to date that preservation solution plays a role in vein graft failure.(4) Data from the PREVENT-IV trial (>3,000 patients who underwent coronary artery bypass grafting) was stratified by type of preservation solution, including normal saline, buffered salt solutions or autologous whole blood. Controlling for baseline demographics and operative characteristics, those patients for whom a buffered salt solution (e.g. Plasma-Lyte A, University of Wisconsin solution) was used for graft preservation had a significant improvement in vein graft failure at one year, and trended toward a significant benefit at five years. Balanced salt solutions, designed considering physiologic pH and electrolyte composition, better preserved the HSV graft and reduced vein graft failure.(4) HSV graft is still frequently preserved in normal saline solution prior to implantation. Normal saline, while inexpensive and readily available, is acidic, with a pH < 6.0, mildly hyperosmolar and lacks cellular nutrients or antioxidants that may benefit the conduit. Therefore, the final component of the optimized preparation technique is the use of a balanced, pH-buffered salt solution such as Plasma-Lyte A as the preservation medium, to optimally preserve the graft, particularly the sensitive endothelial monolayer critical to maintenance of graft patency.
Components of the OP bundled as a kit are illustrated in Figure 1. A brief demonstration of the OP is available as an mpeg-4 download at https://redcap.vanderbilt.edu/surveys/?s=HWC8NLAXLK, or for streaming at https://www.youtube.com/watch?v=OKogkvaiQ7I.
Figure 1
Components of the Optimized Preparation Kit
Vein graft preparation represents a unique window of opportunity in which conduit function can be augmented, potentially leading to enhanced vein graft patency. Recognizing an unmet clinical need, an optimized technique has been engineered to prepare HSV graft prior to implantation into the aortocoronary or peripheral circulation. The technique is effective at identifying leaks, maintaining graft orientation and dilating the conduit while requiring only simple modifications from current practice. In vivo studies are currently underway to determine whether there is concomitant improvement in intimal hyperplasia, using a porcine carotid interposition model.
影响因子：
16.9
作者：
Harskamp, Ralf E.;Alexander, John H.;Schulte, Phillip J.;Brophy, Colleen M.;Mack, Michael J.;Peterson, Eric D.;Williams, Judson B.;Gibson, C. Michael;Califf, Robert M.;Kouchoukos, Nicholas T.;Harrington, Robert A.;Ferguson, T. Bruce, Jr.;Lopes, Renato D.
通讯作者：
Lopes, Renato D.
影响因子：
16.9
作者：
Li, Fan Dong;Eagle, Susan;Brophy, Colleen;Hocking, Kyle M.;Osgood, Michael;Komalavilas, Padmini;Cheung-Flynn, Joyce
通讯作者：
Cheung-Flynn, Joyce