Marland Jamie R K, Gray Mark E, Argyle David J, Underwood Ian, Murray Alan F, Potter Mark A
School of Engineering, Institute for Integrated Micro and Nano Systems, University of Edinburgh, Scottish Microelectronics Centre, King's Buildings, Edinburgh EH9 3FF, UK.
The Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Easter Bush, Roslin, Midlothian EH25 9RG, UK.
Micromachines (Basel). 2021 Jul 10;12(7):810. doi: 10.3390/mi12070810.
Anastomotic leakage (AL) is a common and dangerous post-operative complication following intestinal resection, causing substantial morbidity and mortality. Ischaemia in the tissue surrounding the anastomosis is a major risk-factor for AL development. Continuous tissue oxygenation monitoring during the post-operative recovery period would provide early and accurate early identification of AL risk. We describe the construction and testing of a miniature implantable electrochemical oxygen sensor that addresses this need. It consisted of an array of platinum microelectrodes, microfabricated on a silicon substrate, with a poly(2-hydroxyethyl methacrylate) hydrogel membrane to protect the sensor surface. The sensor was encapsulated in a biocompatible package with a wired connection to external instrumentation. It gave a sensitive and highly linear response to variations in oxygen partial pressure in vitro, although over time its sensitivity was partially decreased by protein biofouling. Using a pre-clinical in vivo pig model, acute intestinal ischaemia was robustly and accurately detected by the sensor. Graded changes in tissue oxygenation were also measurable, with relative differences detected more accurately than absolute differences. Finally, we demonstrated its suitability for continuous monitoring of tissue oxygenation at a colorectal anastomosis over a period of at least 45 h. This study provides evidence to support the development and use of implantable electrochemical oxygen sensors for post-operative monitoring of anastomosis oxygenation.
吻合口漏（AL）是肠切除术后常见且危险的并发症，会导致显著的发病率和死亡率。吻合口周围组织的缺血是AL发生的主要危险因素。术后恢复期持续的组织氧合监测将能早期且准确地识别AL风险。我们描述了一种满足这一需求的微型可植入式电化学氧传感器的构建与测试。它由一系列微加工在硅基片上的铂微电极组成，并带有聚（甲基丙烯酸2-羟乙酯）水凝胶膜以保护传感器表面。该传感器封装在生物相容性封装中，并通过有线连接至外部仪器。它在体外对氧分压变化给出灵敏且高度线性的响应，不过随着时间推移其灵敏度会因蛋白质生物污染而部分降低。使用临床前体内猪模型，该传感器能可靠且准确地检测急性肠缺血。组织氧合的分级变化也是可测量的，相对差异比绝对差异检测得更准确。最后，我们证明了它适用于在结直肠吻合口至少45小时内持续监测组织氧合。本研究为支持开发和使用可植入式电化学氧传感器用于吻合口氧合的术后监测提供了证据。
