Virtual reality surgical planning for endoscopic endonasal approaches to the craniovertebral junction.

PURPOSE: To demonstrate the utility of virtual reality (VR) for preoperative surgical planning of endoscopic endonasal craniovertebral junction (CVJ) surgery. MATERIALS AND METHODS: Five patients who had undergone endoscopic endonasal surgery of the craniovertebral junction with preoperative virtual reality surgical planning were identified and described. RESULTS: The anterior approach to the CVJ has been traditionally accomplished transorally. However, recently the transnasal endoscopic approach to this location has been described. Multiple anatomical studies have been conducted using the nasopalatine, nasoaxial, and rhinopalatine lines (NPL, NAxL, RPL) in an attempt to preoperatively delineate the inferior limits of endoscopic dissection. The use of advanced surgical simulation using immersive virtual reality is an innovative approach for analyzing CVJ anatomy and developing a surgical plan. VR simulation through the use of interactive and highly accurate patient specific models allows for the creation of three-dimensional (3D) digital reconstructions via the fusion of CT and MRI studies. Incorporation of simulation technology has been shown to increase surgeon proficiency while simultaneously decreasing complication rates. The described case series demonstrates the novel utility of VR planning for designing the endoscopic surgical approach to the CVJ. CONCLUSIONS: VR technology allows for the creation of anatomically accurate 3D models that can be used for preoperative planning of endoscopic endonasal surgery. Such models help in the development of safe surgical plans by predicting inferior and lateral planes of dissection and assisting in the identification of critical structures.

The utility of augmented reality in lateral skull base surgery: A preliminary report.

OBJECTIVE: To discuss the utility of augmented reality in lateral skull base surgery. PATIENTS: Those undergoing lateral skull base surgery at our institution. INTERVENTION(S): Cerebellopontine angle tumor resection using an augmented reality interface. MAIN OUTCOME MEASURE(S): Ease of use, utility of, and future directions of augmented reality in lateral skull base surgery. RESULTS: Anecdotally we have found an augmented reality interface helpful in simulating cerebellopontine angle tumor resection as well as assisting in planning the incision and craniotomy. CONCLUSIONS: Augmented reality has the potential to be a useful adjunct in lateral skull base surgery, but more study is needed with large series.

Perforation of a nasoseptal flap does not increase the rate of postoperative cerebrospinal fluid leak.

BACKGROUND: The nasoseptal flap (NSF) has been shown to be a valuable addition to the reconstructive armamentarium of the endoscopic skull-base surgeon. We aimed to evaluate the rate of postoperative cerebrospinal fluid (CSF) leak after use of a NSF that had a small tear during harvest. METHODS: After Institutional Review Board (IRB) approval, we analyzed our database of patients undergoing skull-base resection. We included all patients who had a NSF reconstruction, septoplasty, and/or spur on preoperative computed tomography (CT) imaging. We then evaluated video of each procedure to determine if a tear occurred in the NSF during harvest. Patient records were reviewed to determine if a postoperative CSF leak occurred. RESULTS: We evaluated video of 21 patients who underwent a skull-base resection, were reconstructed with a NSF, and had either a septoplasty or evidence of a septal spur on CT imaging. Of these 21 cases, 11 small tears occurred during harvest of the NSF flap and none of the patients with a torn NSF had a postoperative CSF leak. CONCLUSION: Our series shows a 0% postoperative CSF leak rate in patients undergoing skull-base reconstruction with a NSF that was torn during harvest. Small tears in the NSF do not seem to affect postoperative CSF leak rates.

Surgical pathway seeding of clivo-cervical chordomas.

UNLABELLED: Objective Clival chordomas are slow-growing aggressive tumors that originate from the extra-axial remnants of the notochord. Current management of these tumors use surgical resection combined with radiation therapy. Given the location and invasive nature of these tumors, complete resection is difficult. A variety of both open and endoscopic therapeutic approaches have evolved and combined with the improvements in proton therapy, long-term control of these tumors appears to be improving. However, in recent literature the relatively rare complication of surgical seeding or surgical pathway recurrence has been reported. We report a case of surgical seeding following primary resection and review the world literature regarding surgical pathway recurrence. Study Design Retrospective chart review and review of current literature. Methods We report a case of a patient with a large chordoma that required treatment with a staged endoscopic endonasal and external transcervical approach. The patient subsequently developed recurrent disease along the cervical skin incision due to surgical seeding. Literature review and case reports were identified by a comprehensive search of Medline for the years 1950 to 2012. Results The overall surgical pathway recurrence rate for clival chordoma resection based on analysis of the open nonendoscopic published case studies was 14 of 497 (2.8%). Conclusion Tumor seeding can occur anywhere along the operative route and is often outside the field of radiotherapy. Increased awareness of this rare occurrence is necessary. The use of novel techniques to minimize exposure to tumor including primary endoscopic resection and so-called clean oncologic technique may help limit tumor seeding. LEVEL OF EVIDENCE: 4.