Department of Oral and Maxillofacial Surgery, University Medical Center Hamburg Eppendorf, University of Hamburg, Martinistr. 52, 20246, Hamburg, Germany.
Interdisciplinary Pain Center, University Hospital Freiburg, University of Freiburg, Breisacherstraße 64, 79106, Freiburg, Germany.
Int J Comput Assist Radiol Surg. 2017 Dec;12(12):2119-2128. doi: 10.1007/s11548-016-1512-2. Epub 2017 Jan 12.
The ATI SPG microstimulator is designed to be fixed on the posterior maxilla, with the integrated lead extending into the pterygopalatine fossa to electrically stimulate the sphenopalatine ganglion (SPG) as a treatment for cluster headache. Preoperative surgical planning to ensure the placement of the microstimulator in close proximity (within 5 mm) to the SPG is critical for treatment efficacy. The aim of this study was to improve the surgical procedure by navigating the initial dissection prior to implantation using a passive optical navigation system and to match the post-operative CBCT images with the preoperative treatment plan to verify the accuracy of the intraoperative placement of the microstimulator.
Custom methods and software were used that result in a 3D rotatable digitally reconstructed fluoroscopic image illustrating the patient-specific placement with the ATI SPG microstimulator. Those software tools were preoperatively integrated with the planning software of the navigation system to be used intraoperatively for navigated placement. Intraoperatively, the SPG microstimulator was implanted by completing the initial dissection with CT navigation, while the final position of the stimulator was verified by 3D CBCT. Those reconstructed images were then immediately matched with the preoperative CT scans with the digitally inserted SPG microstimulator. This method allowed for visual comparison of both CT scans and verified correct positioning of the SPG microstimulator.
Twenty-four surgeries were performed using this new method of CT navigated assistance during SPG microstimulator implantation. Those results were compared to results of 21 patients previously implanted without the assistance of CT navigation. Using CT navigation during the initial dissection, an average distance reduction of 1.2 mm between the target point and electrode tip of the SPG microstimulator was achieved. Using the navigation software for navigated implantation and matching the preoperative planned scans with those performed post-operatively, the average distance was 2.17 mm with navigation, compared to 3.37 mm in the 28 surgeries without navigation.
Results from this new procedure showed a significant reduction (p = 0.009) in the average distance from the SPG microstimulator to the desired target point. Therefore, a distinct improvement could be achieved in positioning of the SPG microstimulator through the use of intraoperative navigation during the initial dissection and by post-operative matching of pre- and post-operatively performed CBCT scans.
ATI SPG 微刺激器旨在固定在上颌后区，集成的引线延伸到翼腭窝，以电刺激蝶腭神经节（SPG），作为治疗丛集性头痛的一种方法。为了确保刺激器的位置非常接近（在 5 毫米以内）SPG，术前手术规划对于治疗效果至关重要。本研究的目的是通过使用被动光学导航系统在植入前引导初始解剖，并将术后 CBCT 图像与术前治疗计划相匹配，以验证微刺激器的术中放置准确性，从而改进手术程序。
使用定制的方法和软件，生成 3D 可旋转数字重建荧光透视图像，说明 ATI SPG 微刺激器的患者特异性放置。这些软件工具在术前与导航系统的规划软件集成，以便在术中用于导航放置。术中，使用 CT 导航完成初始解剖，然后使用 3D CBCT 验证刺激器的最终位置。然后，这些重建图像立即与术前 CT 扫描匹配，插入数字 SPG 微刺激器。这种方法允许对 CT 扫描进行直观比较，并验证 SPG 微刺激器的正确定位。
使用新的 CT 导航辅助方法进行了 24 例 SPG 微刺激器植入手术。将这些结果与 21 例先前未使用 CT 导航辅助植入的患者的结果进行比较。在初始解剖过程中使用 CT 导航，可以将 SPG 微刺激器的目标点和电极尖端之间的平均距离缩短 1.2 毫米。使用导航软件进行导航植入，并将术前计划扫描与术后扫描相匹配，平均距离为 2.17 毫米，而在 28 例未进行导航的手术中为 3.37 毫米。
该新程序的结果显示，SPG 微刺激器到目标点的平均距离显著缩短（p=0.009）。因此，通过在初始解剖过程中使用术中导航，并在术后将术前和术后进行的 CBCT 扫描相匹配，可以显著提高 SPG 微刺激器的定位准确性。
