Research Group Minimally-Invasive Interdisciplinary Therapeutical Intervention (MITI), Klinikum Rechts Der Isar, Technical University of Munich, Trogerstraße 26, 81675, Munich, Germany.
Department of Mechanical Engineering and Munich Institute of Biomedical Engineering, Chair of Medical Materials and Implants, TUM School of Engineering and Design, Technical University of Munich, Garching, Germany.
Int J Comput Assist Radiol Surg. 2022 Dec;17(12):2269-2280. doi: 10.1007/s11548-022-02722-z. Epub 2022 Sep 10.
Colorectal anastomoses are among the most commonly performed interventions in abdominal surgery, while associated patient trauma is still high. Most recent trends of endoscopic anastomosis devices integrate magnetic components to overcome the challenges of minimally invasive surgery. However, the mutual attraction between magnetic implant halves may increase the risk of inadvertently pinching healthy structures. Thus, we present a novel anastomosis device to improve system controllability and flexibility.
A magnetic implant and an applicator with electromagnetic control units were developed. The interaction of magnetic implants with the electromagnets bears particular challenges with respect to the force-related dimensioning. Here, attraction forces must be overcome by the electromagnet actuation to detach the implant, while the attraction force between the implant halves must be sufficient to ensure a stable connection. Thus, respective forces were measured and the detachment process was reproducibly investigated. Patient hazards, associated with resistance-related heating of the coils were investigated.
Anastomosis formation was reproducibly successful for an implant, with an attraction force of 1.53 [Formula: see text], resulting in a compression pressure of [Formula: see text]. The implant was reproducibly detachable from the applicator at the anastomosis site. Coils heated up to a maximum temperature of [Formula: see text]. Furthermore, we were able to establish a neat reconnection of intestinal bowel endings using our implant.
As we achieved nearly equal compression forces with our implant as other magnetic anastomosis systems did (Magnamosis™: 1.48 N), we concluded that our approach provides sufficient holding strength to counteract the forces acting immediately postoperatively, which would eventually lead to an undesired slipping of the implant halves during the healing phase. Based on heat transfer investigations, preventive design specifications were derived, revealing that the wall thickness of a polymeric isolation is determined rather by stability considerations, than by heat shielding requirements.
结直肠吻合术是腹部外科最常见的手术之一，而相关的患者创伤仍然很高。最近内镜吻合器的发展趋势是集成磁性组件，以克服微创手术的挑战。然而，磁性植入物两半之间的相互吸引力可能会增加无意中夹住健康结构的风险。因此，我们提出了一种新型吻合器来提高系统的可控性和灵活性。
开发了一种磁性植入物和一种带有电磁控制单元的施夹器。磁性植入物与电磁铁的相互作用在力相关的尺寸设计方面具有特殊的挑战。在这里，必须通过电磁铁致动来克服吸引力以分离植入物，而植入物两半之间的吸引力必须足以确保稳定的连接。因此，测量了相应的力，并可重复地研究了分离过程。还研究了与线圈相关的阻力加热相关的患者危害。
对于具有 1.53 [公式：见正文]吸引力的植入物，吻合形成可重复成功，从而产生[公式：见正文]的压缩压力。植入物可从吻合部位的施夹器上可重复地分离。线圈加热到最高温度[公式：见正文]。此外，我们能够使用我们的植入物成功地重建肠末端的吻合。
由于我们的植入物几乎能达到与其他磁性吻合系统相同的压缩力（Magnamosis™：1.48 N），我们得出结论，我们的方法提供了足够的保持强度以抵消术后立即作用的力，这最终会导致植入物两半在愈合阶段发生不希望的滑动。基于传热研究，得出了预防性设计规范，表明聚合物隔离层的壁厚主要取决于稳定性考虑，而不是热屏蔽要求。
