The Exoscope in Neurosurgery: An Overview of the Current Literature of Intraoperative Use in Brain and Spine Surgery

Background: Exoscopes are a safe and effective alternative or adjunct to the existing binocular surgical microscope for brain tumor, skull base surgery, aneurysm clipping and both cervical and lumbar complex spine surgery that probably will open a new era in the field of new tools and techniques in neurosurgery. Methods: A Pubmed and Ovid EMBASE search was performed to identify papers that include surgical experiences with the exoscope in neurosurgery. PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-analyses) were followed. Results: A total of 86 articles and 1711 cases were included and analyzed in this review. Among 86 papers included in this review 74 (86%) were published in the last 5 years. Out of 1711 surgical procedures, 1534 (89.6%) were performed in the operative room, whereas 177 (10.9%) were performed in the laboratory on cadavers. In more detail, 1251 (72.7%) were reported as brain surgeries, whereas 274 (16%) and 9 (0.5%) were reported as spine and peripheral nerve surgeries, respectively. Considering only the clinical series (40 studies and 1328 patients), the overall surgical complication rate was 2.6% during the use of the exoscope. These patients experienced complication profiles similar to those that underwent the same treatments with the OM. The overall switch incidence rate from exoscope to OM during surgery was 5.8%. Conclusions: The exoscope seems to be a safe alternative compared to an operative microscope for the most common brain and spinal procedures, with several advantages that have been reached, such as an easier simplicity of use and a better 3D vision and magnification of the surgical field. Moreover, it offers the opportunity of better interaction with other members of the surgical staff. All these points set the first step for subsequent and short-term changes in the field of neurosurgery and offer new educational possibilities for young neurosurgery and medical students.

Three-Dimensional Exoscopic Temporal Bone Resections for Advanced Head and Neck Cancer

Objectives The three-dimensional (3D) exoscope has several advantages over the operative microscope (OM) but has not been extensively reported for its use in malignant temporal bone resections (TBR). We sought to demonstrate the feasibility of performing TBR, both lateral (LTBR) and subtotal (STBR), using the 3D exoscope for head and neck cancers. Design present study is a retrospective chart review from August 2016 until August 2019. Setting The study was conducted at a tertiary care center. Participants Patients were undergoing TBR with the Karl Storz VITOM 3D exoscope. Main Outcome Measures Demographics, tumor and surgical characteristics, patient outcomes were the primary measurements of this study. Results Fifty-five patients underwent 3D exoscopic TBR from 2016 through 2019 of which 18% (n = 10) underwent STBR. The 3D exoscope was used uninterruptedly in all procedures with no intraoperative complications. Most tumors were primarily T3 (42%, n = 23) or T4 (55%, n = 30) and of cutaneous (62%, n = 34) and parotid (27%, n = 15) origin. These TBR were often accompanied by infratemporal fossa resections (87%, n = 48), auriculectomies (47%, n = 26), mandibulectomies (53%, n = 29), and parotidectomies (96%, n = 53). On final pathology, 24% (n = 13) had microscopically positive margins. Over the study period, 20% (n = 11) of patients had recurrences with a median recurrence time of 5 months (range: 2–30 months). Conclusion In the largest case series of LTBR and STBR under exclusive 3D exoscopic visualization to date, we demonstrate the 3D exoscope is a feasible alternative to the operative microscope for LTBR and STBR. While oncologic outcomes remain to be clarified, it carries significant potential for use in complex oncologic procedures.

The advantages of the dental operative microscope in restorative dentistry

Magnification devices improve direct and indirect vision and precision being significantly higher in microscope use compared to the loupes. Dental loupes are the most commonly used devices for magnification, due to the more affordable prices and the ease of use without major changes in the working protocol and ergonomics. Loupes primary benefits reported refers to ergonomics and posture, restoration evaluation/detection and overall treatment quality. There are some disadvantages that limit the use of loupes among dentists: lack of fixed position (fine movements of the dentist's head disturb the image of the magnified operating field); the need to change the loupes to achieve different magnification. On the contrary, the use of a dental microscope require minimum adjustment and effort so as to reduce postural deviation while working. It has been more than 30 years since dental practitioners raised the issue of using dental operating microscopes (DOM) in restorative dentistry, identifying the benefits of magnification in diagnosis and treatment steps. The growth is evident in recent years, maybe because of the familiarity of dentists with dental microscopes which have already become implicit endowment for endodontic specialists. Fiber optic lighting is the key factor that complements the magnification offered by the microscope so that treatments can now be performed under increased safety conditions and in conditions of significantly higher quality than in the past. Since the beginning of the 2000s the principles of minimally invasive dentistry have been widely promoted in dentistry. These principles are major impetus for the use of microscope by dentists. Working with magnification leads dentists to be more conservative with dental tissues.

Managing the Anomalous Vertebral Artery in C1–C2 Stabilization for Congenital Atlantoaxial Instability

Objectives This study aimed to demonstrate the technique of handling the anomalous vertebral artery in congenital atlantoaxial instability. The vertebral artery course can be variable in congenital atlantoaxial instability, especially if there is assimilation of atlas. The surgical technique to stabilize the atlantoaxial joint should ensure the patency and safety of the vertebral artery and prevents devastating stroke. Computed tomography (CT) angiography of the vertebral artery is mandatory in planning the surgical strategies. The vertebral artery can be injured during dissection of soft tissues between atlas and axis and can be compromised during distraction and instrumentation. The vertebral artery needs to be mobilized based on the tortuosity in the course during instrumentation and prevents compression of the artery against bony structures or screw heads. The vertebral artery has to be identified earlier in the course of dissection and should protect it. It is also imperative to choose the surgical approach that can be performed under vision using operative microscope rather than adapting blind procedures like transarticular screw. Here, in our present case, we demonstrate the technique of mobilizing the vertebral artery which was coursing medially preventing the access for the instrumentation and perform stabilization of atlantoaxial joint using Goel–Harms technique, and prevent its compression after placement of screw by deroofing the bony ridges of axis (Figs. 1 and 2). We also emphasize the various technical nuances during the stabilization with distraction of joint space of atlas and axis.The link to the video can be found at: https://youtu.be/pgURpF_jACc.

Georg von Békésy and Bruce Mer: Early Pioneers of Endoscopic Ear Surgery

The binocular operative microscope has been the workhorse of otologic and neurotologic surgeons since the 1950s. Since its advent, however, surgeons recognized that the operative microscope could not “look around corners” and its line-of-sight technology required soft tissue and bony dissection to enable light to reach the surgical plane. Endoscopic technology has evolved to address many of the limitations of operative microscopy. While the endoscope is often viewed as a recent development in otologic surgery, in the following historical article, we highlight the contributions of two mid–20th century pioneers of endoscopic ear surgery: Georg von Békésy and Bruce Mer. In the 1940s, Dr von Békésy envisioned an endoscope for determining stapes mobility. Dr Mer, with a team of engineers, created an otoendoscope to perform some of the first endoscopic ear procedures in the 1960s. Lessons gleaned from von Békésy and Mer’s research include the need for counterculture thinking and the challenges of pioneering ideas beyond technical capacity.

The history of neurosurgery at the House Clinic in Los Angeles

Although most widely known as the birthplace of neuro-otology, the House Clinic in Los Angeles has been the site of several major contributions to the field of neurosurgery. From the beginning of the formation of the Otologic Medical Group in 1958 (later renamed the House Ear Clinic), these contributions have been largely due to the innovative and collaborative work of neurosurgeon William E. Hitselberger, MD, and neuro-otologist William F. House, MD, DDS. Together they were responsible for the development and widespread adoption of the team approach to skull-base surgery. Specific neurosurgical advances accomplished at the House Clinic have included the first application of the operative microscope to neurosurgery, the application of middle fossa and translabyrinthine approaches for vestibular schwannoma, and the development of combined petrosal, retrolabyrinthine, and other alternative petrosal approaches and of hearing preservation surgery for vestibular schwannoma. The auditory brainstem implant, invented at the House Clinic in 1979, was the first ever successful application of central nervous system neuromodulation for restoration of function. Technological innovations at the House Clinic have also advanced neurosurgery. These include the first video transmission of microsurgery, the first suction irrigator, the first debulking instrument for tumors, and the House-Urban retractor for middle fossa surgery.