Use of a compact high-definition two-dimensional exoscope in surgical treatment of large vestibular schwannoma

Abstract

Background: Extra-corporeal video telescope operating monitor system provides a necessary instrument to perform high-precision neurosurgical procedures that could substitute or supplement the traditional surgical microscope. The present study was designed to evaluate a compact high-definition two-dimensional exoscope system for assisting in surgical removal of large vestibular schwannoma (VS), as an alternative to a binocular surgical microscope. Methods: Patients with Koos grade 3 and grade 4 VS undergoing surgery were enrolled in this prospective cohort study between January 2013 and June 2018. The demographics and tumor characteristics (size, Koos grade, composition [cystic or solid mass]) were matched between the two groups of patients. The following outcome measurements were compared between the two groups: duration of surgery, volume of blood loss, extent of tumor resection, number of operating field adjustments, pre-and post-operative facial and cochlear nerve function evaluated at 3 months post-surgery, complications and surgeons' comfortability. Results: A total of 81 patients received tumor resection through the retrosigmoid approach under either an exoscope (cases, n = 39) or a surgical microscope (control, n = 42). Patients in the two groups had comparable tumor location (P = 0.439), Koos grading (P = 0.867), and composition (P = 0.891). While no significant differences in the duration of surgery (P = 0.172), extent of tumor resection (P = 0.858), facial function (P = 0.838), and hearing ability (P = 1.000), patients operated on under an exoscope had less blood loss (P = 0.036) and a fewer field adjustments (P < 0.001). Both primary and assistant surgeons reported a high level of comfort operating under the exoscope (P = 0.001 and P < 0.001, respectively). Conclusions: The compact high-definition two-dimensional exoscope system provides a safe and efficient means to assist in removing large VSs, as compared to a surgical microscope. After the acquaintance with a visual perception through a dynamic hint and stereoscopically viewing corresponding to the motion parallax, the exoscope system provided a comfortable, high-resolution visualization without compromising operational efficiency and patient safety.

Three-Dimensional Exoscopic Versus Microscopic Resection of Vestibular Schwannomas: A Comparative Series

“…Chen et al 17 published a similar series comparing a two-dimensional exoscope system with the operative microscope for resection of VS. They documented a reduction of blood loss in exoscope surgeries and similar clinical and radiological results compared with microscope use.…”

Exoscope as a Teaching Tool: A Narrative Review of the Literature

“…Various studies point out, in particular, an increase in the average duration of neurosurgical intervention with respect to the same intervention conducted with an OM, although the difference in average duration often proves to be not statistically significant ( 34 ). Some authors hypothesize that this difference in operative durations can be explained due to a shallower depth of field and constant need for repositioning and refocusing, at least in experimental settings, which might be variable across different brands of exoscopes ( 8 ), while others complain the lack of a mouthpiece ( 30 ).…”

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

“…One of the characteristics ascribed to exoscopes is that they are superior to a conventional OM in terms of ergonomic features both in brain and spine surgery [ 37 , 39 , 49 , 52 , 67 , 69 , 90 , 91 , 92 , 94 , 95 , 96 , 97 , 111 , 112 , 113 , 114 , 115 ], as the ergonomic handling and the ease of intraoperative positioning of the device were found to be beneficial. Second, 3D monitors lead to an improved involvement of the co-surgeon and the scrub nurse during the procedure, and although some authors were satisfied with the high-resolution 3D digital images during surgery [ 52 , 60 , 68 , 73 ], others were not satisfied with the visual quality. In spine surgery, when two neurosurgeons are operating facing each other, the use of 2 monitors each positioned in front of each surgeon allows extreme freedom of movement and modification of the surgical corridor [ 89 ].…”

“…Rotermund et al [ 95 ] reported the largest series of patients underwent transsphenoidal surgery for pituitary adenoma (239 patients), reporting that no serious episodes or minor complications occurred based on the usage of the exoscope, as well as no significant differences regarding the duration of surgery, complications or extent of resection compared to conventional microscopy. Chen et al [ 73 ] reported a total of 81 patients received tumor resection through the retrosigmoid approach with either an exoscope (39 patients) or an OM (42 patients). Patients in the two groups had comparable tumor location ( p = 0.439) and Koos grading ( p = 0.867).…”