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

继发于血管供应受损的下肢大截肢手术表明 极高的感染率、伤口并发症、死亡率和再次手术率， 活动性，心血管失调和肌肉无力，降低了未来的可能性 假肢装配这反过来又导致生活质量和医疗保健的妥协 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，但肢体灌注是已知的关键因素。 残端愈合的组成部分。踝臂指数（ABI）和经皮氧分压 （TCPO 2）测量可用于量化肢体灌注，并可帮助确定是否需要 对于截肢，文献中关于这些值在预测截肢中的效用是矛盾的 治不好的，没有明确的联系。如果没有可靠的客观预测手段， 愈合的可能性，截肢的水平是由手术外科医生根据临床确定的， 皮肤和组织完整性、质量和灌注的主观（即视觉）评估。 这项研究介绍了一种可注射皮下生物传感技术与光学分析 数据采集系统，将立即检测临床相关的组织氧合张力， 特定解剖平面。这项研究的首要假设是，准确的实时 通过使用新型可植入生物传感器获得的组织氧张力的测量， 在确定截肢的适当水平的重要组成部分，促进快速 残肢的初步愈合，从而为退伍军人提供了一条早期康复的道路。 活动性，增加假肢安装的可能性，并改善功能。 本研究的目的是：1）将生物传感器测量的组织氧分压与组织氧分压之间的相关性， 临床确定的截肢水平，确定的临床终点为 手术切口/伤口，需要局部伤口护理的手术切口/伤口的二次愈合 无再次手术、伤口翻修再次手术和截肢翻修再次手术， 更接近的水平; 2）建立生物传感器在获得 当皮下植入下肢时，组织氧分压的准确读数 和3）建立初步的指导方针，使用组织氧分压， 结合再截肢的协变量风险评分，以指导术前确定 预测下肢一期愈合的最佳截肢节段 截肢残端，加快假肢安装和移动，最大限度地减少并发症发生率， 降低相关成本。 根据当前的护理标准，截肢水平将由手术外科医生根据以下因素确定： 对周围组织外观（皮肤完整性，水肿量， 近端感染或慢性溃疡的程度（如果存在）和肢体的颜色）。水平 参与本研究不会改变截肢情况。两个生物传感器将被插入 通过无菌19号针在计划的尾部1 cm处皮下组织每个解剖血管小体 切口组织氧分压将在开始前即刻从每个传感器记录。 手术过程中，并在止血带充气后立即再次。截肢手术 手术将按常规进行，手术计划与标准护理无任何改变。研究 术后随访将持续3个月; 3个月时的临床终点将与 组织氧分压在手术中测量正好低于截肢水平。

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.