Initial experience with intraoperative computed tomography in maxillofacial surgery

Intraoperative Fluoroscopy Reduces Complication and Reoperation Rate in Facial Fractures

Purpose: The purpose of this study is to evaluate surgical outcomes of facial fractures after the introduction of intraoperative radiology. Methods: An historic cohort of patients without intraoperative fluoroscopy (IOF) was compared with a prospective cohort of patients with IOF. Main outcomes were postoperative complications and reoperation rate. Results: There were 51 in the non-IOF group and 49 in the IOF group. In the group with IOF 10 patients required intraoperative revisions (20.46%). Overall postoperative complication rate was higher in the non-IOF group (25.49% vs. 6.12%) due to the significantly higher bone-related complication rate (15.69% vs. 2.04%). Reoperation rate was also higher in the non-IOF group (11.76% vs. 0%). Conclusion: This study demonstrates that IOF reduces bone-related complication and reoperation rate by allowing correction of surgical errors immediately during surgery.

Intraoperative computed tomography and automated registration for image-guided cranial surgery

OBJECTIVES

Two key problems for the use of navigation systems in image-guided surgery are accurate patient-to-image registration and the fact that with ongoing surgery the patient's anatomy is altered while the image data remains unchanged. A system for intraoperative CT imaging and fully automated registration of this image addresses both problems. It had been evaluated successfully in phantom studies. In this clinical study, we assessed the impact of the system on intraoperative workflow and registration accuracy in everyday patient care.

METHODS

In ten patients who underwent image-guided surgery, CT image data were acquired intraoperatively and were automatically registered in the navigation system. Registration accuracy and surgical outcome were assessed clinically. In six of these patients, a maxillary splint with markers had been inserted to cross-check registration accuracy. The target registration error of these markers was measured.

RESULTS

In all cases, registration accuracy was clinically sufficient and the surgical task could be performed successfully. In those cases where a maxillary template with target markers was attached for additional control of the registration accuracy, the target registration error was always better than 2 mm. Automated registration reduced the intraoperative registration time considerably and partially compensated for the time needed to perform the image data acquisition.

CONCLUSIONS

Intraoperative CT imaging and automated registration successfully address the two key problems of image-guided surgery. The method is robust and accurate and proved its usability in everyday patient care.

Image-to-patient registration techniques in head surgery

Frame-based stereotaxy was developed in neurosurgery at the beginning of the last century, evolving from atlas-based stereotaxy to stereotaxy based on the individual patient's image data. This established method is still in use in neurosurgery and radiotherapy. There have since been two main developments based on this concept: frameless stereotaxy and markerless registration. Frameless stereotactic systems ('navigation systems') replaced the cumbersome stereotactic frame by mechanically and later also optically or magnetically tracked instruments. Stereotaxy based on the individual patient's image data introduced the problem of patient-to-image data registration. The development of navigation systems based on frameless stereotaxy has dramatically increased its use in surgical disciplines other than neurosurgery, but image-guided surgery based on fiducial marker registration needs dedicated imaging for registration purposes, in addition to the diagnostic imaging that might have been performed. Markerless registration techniques can overcome the resulting additional cost and effort, and result in more widespread use of image-guided surgery techniques. In this review paper, the developments that led to today's navigation systems are outlined, and the applications and possibilities of these methods in the field of maxillofacial surgery are presented.

Surgical rhinology: recent advances and future directions

The discipline of rhinology is poised on the cusp of explosive growth in its cumulative body of knowledge. Advances in surgical technique, applied technology, and basic science over the past 2 decades have yielded significant benefits to both practitioner and patient. The future holds great promise for continued technical innovation, acquisition of new knowledge,and advances in the science of rhinology.