Use of a Novel Tissue Oxygen Tension Biosensor to Reliably Predict Healing of Lower Extremity Amputations for Rapid Facilitation of Patient Mobility

继发于血管受损的主要下肢截肢手术显示 极高的感染率、伤口并发症、死亡率和再手术率，导致 移动性、心血管去调理和肌肉无力，降低未来的可能性 假肢配件。这反过来又导致生活质量的妥协和医疗保健的增加 退伍军人健康管理局的支出。 虽然多种因素导致伤口愈合延迟或失败，但肢体灌流是一个已知的关键因素。 残肢愈合中的组件。踝臂指数(ABI)和经皮血氧分压 (TCPO2)测量可以用来量化肢体血流灌注，并有助于确定需要 对于截肢，文献中关于这些值在预测截肢方面的效用是相互矛盾的。 残肢愈合，没有建立明确的联系。没有可靠的客观手段来预测 愈合的可能性，截肢程度由手术外科医生根据临床情况决定 皮肤和组织完整性、质量和灌注度的主观(即视觉)评估。 这项研究介绍了一种可注射的皮下生物传感技术，用于光学分析 数据采集系统，将立即检测临床相关的组织氧合压力 特定的解剖平面。这项研究的首要假设是准确的实时 利用一种新型植入式生物传感器测量组织氧分压. 在确定适当的截肢程度时，一个至关重要的组成部分，促进FAST 残肢的一期愈合，从而为退伍军人提供了一条更早 移动性，假体装配的可能性增加，功能得到改善。 这项研究的目的是1)将生物传感器测量到的组织氧分压与足底1厘米以下的组织氧分压进行关联 临床确定的截肢水平和已确定的临床一期愈合终点 外科手术切口/伤口，需要局部伤口护理的外科伤口/伤口的二次愈合 不再手术，伤口翻修再手术，再次手术翻修截肢。 更接近的水平；2)建立生物传感器在获得 皮下植入肢体时组织氧分压的准确读数 和3)建立组织氧分压的初步使用指南 结合截肢手术的协变量风险评分在术前指导确定 最佳预测肢体一期愈合的最合适截肢水平 截肢残肢，加快假体装配和移动性，最大限度地减少并发症发生率，以及 降低相关成本。 根据目前的护理标准，截肢程度将由手术外科医生根据 对周围组织外观的临床判断(皮肤完整性、水肿量、 近端感染程度或慢性溃疡(如有，以及肢体颜色)。的水平 截肢手术不会因参与研究而改变。两个生物传感器将被插入到 通过无菌的19号针将每个解剖的被子体的皮下组织向计划的尾部1厘米 切开。在手术开始前，每个传感器都会记录组织氧分压。 手术和止血带充气后立即再次使用止血带。外科截肢手术 手术将按常规进行，手术计划不会改变护理标准。学习 术后将继续随访3个月；3个月的临床终点将与 术中测得的组织氧分压略低于截肢水平。

Major lower extremity amputation procedures secondary to compromised vascularity demonstrate extremely high rates of infection, wound complication, mortality, and reoperation, resulting in reduced mobility, cardiovascular deconditioning, and muscle weakness, decreasing the probability of future prosthetic fitting. This in turn results in a compromise in quality of life and increased health care expenditures by the Veterans Health Administration. While multiple factors contribute to delayed or failed wound healing, limb perfusion is a known critical component in stump healing. While ankle-brachial index (ABI) and transcutaneous oxygen pressure (TCPO2) measurements can be used to quantify limb perfusion and can assist in determining the need for an amputation, the literature is conflicted as to the utility of these values in predicting amputation stump healing, with no clear association established. Without reliable objective means of predicting the likelihood of healing, the level of amputation is determined clinically by the operating surgeon based on subjective (i.e. visual) assessment of skin and tissue integrity, quality, and perfusion. This study introduces an injectable subcutaneous bio-sensing technology used with an optical analysis data acquisition system that will immediately detect clinically relevant tissue oxygenation tension in a specific anatomic plane. The overarching hypothesis of this study is that accurate real-time measurement of tissue oxygen tension obtained by use of a novel implantable biosensor is a vital component in determining the appropriate level of amputation, promoting fast primary healing of the residual limb thereby providing a path for the veteran to earlier mobility, increased likelihood of prosthetic fitting, and improved function. This study aims to 1) correlate tissue oxygen tension measured by the biosensor 1 cm below the clinically determined amputation level with established clinical endpoints of primary healing of surgical incision/wound, secondary healing of surgical incision/wound requiring local wound care without reoperation, reoperation for wound revision, and reoperation for revision amputation at a more proximal level; 2) establish the reliability and responsiveness of the biosensor in obtaining accurate readings of the tissue oxygen tension when implanted subcutaneously in the lower extremity of human subjects and 3) establish preliminary guidelines for use of tissue oxygen tension in conjunction with covariate risk score for reamputation to preoperatively guide the determination of the most appropriate level of amputation to best predict primary healing of lower extremity amputation stumps, expediting prosthetic fitting and mobility, minimizing complication rates, and decreasing associated costs. Per current standard of care, the amputation level will be determined by the operating surgeon based on clinical judgement of the appearance of the surrounding tissue (skin integrity, amount of edema, proximal extent of infection or chronic ulceration if present, and color of the limb). The level of amputation will not be altered by participation in the study. Two biosensors will be inserted into the subcutaneous tissue of each anatomic angiosome via a sterile 19 Gauge needle 1 cm caudad to the planned incision. Tissue oxygen tension will be recorded from each sensor immediately prior to the start of the surgical procedure and again immediately after inflation of the tourniquet. The surgical amputation procedure will proceed routinely with no alteration in the surgical plan from standard of care. Study follow-up will continue for 3 months after surgery; clinical endpoints at 3 months will be correlated with tissue oxygen tension measured intra-operatively just below the level of amputation.