Purpose: To evaluate the learning curve for exoscope and three-dimensional (3D) 4K hybrid visualization in terms of operating time, advantages, disadvantages, and surgical complications in tubular-access minimally invasive spine surgery (MISS) and to assess surgeon satisfaction with image quality, ergonomics, and ability to perform target site treatment.
Overview of Literature: Working through tubular retractors poses a challenge. The extreme angulations during microsurgical decompression, especially contralateral decompression, require surgeons to work non-ergonomically. An exoscope allows surgeons to work ergonomically and independently of the microscope oculars as visualizations are now provided by large 3D 4K monitors. However, the value and efficacy of solely depending on an exoscope and 3D 4K monitors during microsurgical work are still unknown.
Methods: Seventy-four patients (99 levels) underwent trans-tubular MISS between March 2018 and January 2019. Five patients were excluded: one had pyogenic discitis, two had revisions, and two were trans-tubular transoral. In total, we analyzed 69 for operating time, blood loss, and complications. The learning curve graph was plotted using the surgical time for each procedure. Surgeons were asked to rate their satisfaction with image quality, ability to maintain ergonomic posture, and efficient target site treatment.
Results: For tubular microdiscectomy, the operating time plateaued after six cases, and for tubular decompression and minimally invasive transforaminal lumbar interbody fusion, the operating time plateaued after nine cases. Mean operating time was significantly reduced after the plateau. Complications included four cases of dural tear. All patients improved symptomatically, and there were no postoperative neurological deficits.
Conclusions: Use of the exoscope has a short learning curve. Surgeons benefit from improved ergonomic posture during surgery, and resident teaching appears to be good. The only drawback is the need to rearrange the operating table setup. Complications were comparable to those when using the surgical microscope. An exoscope with hybrid digital visualization provides excellent visualization, depth perception, clarity, and precision target site treatment.
METHODS: Incidence of thigh pain was lower in 2008 compared to 2006 and 2007 (p < 0.0001). The percentage of patients requiring blood transfusions (p = 0.09), duration of IDC ≥ 7 days (p = 0.27), wound dehiscence and re-operation rate were lower in 2008 in contrast to 2006 and 2007 (p = 0.43). Only 209 patients (82.3%) were available for review at 1 year. There were two (1.0%) cases of recurrent vault prolapse.
RESULTS: The subjective and objective cure rates at 1 year after this mesh implant surgery in 2006, 2007 and 2008 were 92.1% and 92.1%; 97.0% and 92.4% and 100% and 97%, respectively. The mesh erosion rate was remarkably lower in 2008 as compared to 2007 and 2006 (p < 0.001).
CONCLUSIONS: This synthetic mesh-augmented implant surgery is effective and safe, and surgical outcome appears related to the learning curve of the surgeon.