Sacral nerve stimulation lead implantation using the O-arm

Abstract

Background: Sacral neuromodulation operations have usually been performed based on 2D fluoro images. However, sacral nerve stimulation lead implantation may be challenging when the normal anatomy is confused by obesity or congenital anomalies. Thus the surgical navigation and intraoperative imaging methods could be helpful as those same methods have proven to be feasible methods for guiding other surgical operations. Our recent knowledge about the O-arm in trauma pelvic operations encouraged us to evaluate the usefulness of O-arm guided navigation in sacral neuromodulation. Similar navigation would be useful for complex sacral nerve stimulation lead implantations.

Methods: In this preliminary article we report our experience of utilizing the orthopedically optimized O-arm to implant the S3 stimulation electrode in a patient. The 3D O-arm imaging was performed intraoperatively under surgical navigation control. General anesthesia was used. The obtained 3D image dataset was registered automatically into the patient's anatomy. The stimulation needle was guided and the tined lead electrode was implanted using navigation.

Results: The bony sacral structures were clearly visualized. Due to automatic registration, the navigation was practicable instantly after the O-arm scanning and operation could be performed successfully under navigation control.

Conclusions: To our knowledge, this is the first published tined lead implantation which was guided based on the surgical navigation and intraoperative O-arm images. In this case, the applied method was useful and helped the surgeon to demarcate the region of surgical interest. The method is slightly more invasive than the formal technique but could be an option in anatomically challenging cases and reoperations. However, further evaluation with larger patient series is required before definitive recommendations can be made.

Figure 1

Intraoperative figures of sacral nerve stimulator lead implantation. The O-arm is a transportable CT-like scanner. With automated positioning, it can be easily placed around the patient on the radiolucent table to obtain 2D fluoroscopic images and 3D scanning in desired directions, and repeated when necessary (A). The patient’s position can be adjusted optimally to achieve a surgically and anesthetically comfortable situation (B). Patient tracker fixed to the bone (C). The multipurpose SureTrack instrument tracker was fixed to the needle and used for navigation (D). Needle inside S3, 3D image (E). The sacral structures are clearly visible in the O-arm images; it was possible to guide the instruments used in the correct direction and to the right depths. Inserts with 2D and a 3D images (F). Lead implantation; the O-arm has been moved in the cranial direction allowing free access to the operation area (G).