2D versus 3D Endoscopy: Head-to-Head Comparison in a Simulated Model of Endoscopic Endonasal Dural Suturing

Objective Endonasal dural suturing (EDS) has been reported to decrease the incidence of cerebrospinal fluid fistula. This technique requires handling of single-shaft instrumentation in the narrow endonasal corridor. It has been proposed that three-dimensional (3D) endoscopes were associated with improved depth perception. In this study, we sought to perform a comparison of two-dimensional (2D) versus 3D endoscopy by assessing surgical proficiency in a simulated model of EDS. Materials and Methods Twenty-six participants subdivided into groups based on previous endoscopic experience were asked to pass barbed sutures through preset targets with either 2D (Storz Hopkins II) or 3D (Storz TIPCAM) endoscopes on 3D-printed simulation model. Surgical precision and procedural time were measured. All participants completed a Likert scale questionnaire. Results Novice, intermediate, and expert groups took 11.0, 8.7, and 5.7 minutes with 2D endoscopy and 10.9, 9.0, and 7.6 minutes with 3D endoscopy, respectively. The average deviation for novice, intermediate, and expert groups (mm) was 5.5, 4.4, and 4.3 with 2D and 6.6, 4.6, and 3.0 with 3D, respectively. No significant difference in procedural time or accuracy was found in 2D versus 3D endoscopy. 2D endoscopic visualization was preferred by the majority of expert/intermediate participants, while 3D endoscopic visualization by the novice group. Conclusion In this pilot study, there was no statistical difference in procedural time or accuracy when utilizing 2D versus 3D endoscopes. While it is possible that widespread familiarity with 2D endoscopic equipment has biased this study, preliminary analysis suggests that 3D endoscopy offers no definitive advantage over 2D endoscopy in this simulated model of EDS.

Diagnosis and Safe Excision of Lumbar Synovial Cysts and Accompanying Pathology: A Perspective

Background: Lumbar synovial cysts are often not sufficiently diagnosed prior to spine surgery. Utilizing both MR and CT studies is critical for recognizing the full extent/severity of these lesions. Methods: In patients with chronic, acute, or subacute lumbar disease, obtaining both MR and CT studies is critical to correctly diagnose; disc disease, hypertrophy/ossification of the yellow ligament (OYL), stenosis, with/without degenerative spondylolisthesis, and/or synovial cysts (SC). Results: MR T2 weighted images directly demonstrate hyperintensity within a SC. They initially cause lateral recess/caudad nerve root and/foraminal compromise, with larger extrusions causing significant lateral thecal sac, and far lateral/superior cephalad root compromise. CT 2 mm cuts often better demonstrate mid-vertebral level compression of cephalad nerve roots with/without SC calcification, along with the extent of mid-vertebral stenosis, hypertrophy/OYL, and DS. When CT studies directly document SC calcification, it alerts the surgeon to the increased potential risk of creating a cerebrospinal fluid fistula with full SC excision, and should prompt the adoption of alternative measures such as decompression/partial removal. Most critically, surgery for synovial cysts often warrants a 2-level laminectomy for fuller visualization of the cephalad and caudad nerve roots, and clearer differentiation of neural tissues from the large fibrotic SC capsule, to effect safer removal. Conclusions: Preoperatively, establishing the full cephalad and cauda extent of lumbar synovial cysts with both MR and CT studies is critical. Anticipation and better visualization of the foraminal/far lateral and superior extent of these lesions often warrants more extensive multilevel laminectomies for thecal sac and both cephalad and caudad root decompression.

The advantages of using a fragment of the fascia lata and autobone in the reconstruction of defects in the base of the skull in patients with CSF leak

Relevance: Diagnosis and treatment of patients with CSF leak, today, is not a fully resolved problem. With small defects in the base of the skull, the overlay technique has worked relatively well. However, when the size of the bone defect is more than 0.6 cm, the surgeon has to resort to the underlay technique of transplant placement. Thus, the search for the optimal technique for reconstruction surgery of the cerebrospinal fluid fistula, especially with large defects of the skull base, is a complex and urgent problem. Purpose of the study: To conduct a comparative assessment of the techniques for reconstruction of the skull base defect lager than 0,6 cm in the anterior cranial fossa in patients with CSF leak using endoscopic endonasal approach. Materials and methods: We observed 44 patients with CSF leak. Depending on the technique of cerebrospinal fluid fistula repair, all patients were divided into 2 groups. The first group of 21 patients was patients who underwent reconstruction surgery of the skull base defect using a generally accepted technique using a fragment of the fascia lata and nasoseptal flap. The second group – 23 patients, consisted of patients who underwent reconstruction surgery with a fragment o fascia lata with fixation of it by a fragment of an autobone according to our technique, followed by the use of a nasoseptal flap. The criterion for evaluating the effectiveness of the surgical treatment was lack of relapse of CSF leak and data from objective research methods (endoscopic examination of the nasal cavity). Results: 1 month after surgical treatment, 3 (14,28%)patients of the 1st group experienced a recurrence of CSF leak, and 1(4,34%) patient of the 2nd group had a recurrence of CSF leak. In 2 patients of the 1st group there was a relapse of CSF leak in the 3rd month of observation, there was no recurrence of CSF leak in patients of the 2nd group, after 6 months in 1 patient of the 1st group there was a relapse of liquorrhea. Conclusions: In patients with CSF leak with a bone defect greater than 0.6 cm, it is appropriate to use the sandwich technique. The technique of reconstruction CSF fistula using a fascia lata with its fixation by autologous bone can significantly reduce the risk of CSF recurrence in comparison with the use of generally accepted techniques for CSF leak. The use of autobone in reconstruction of the cerebrospinal fluid fistula does not affect the change in the architectonics of the nose compared to the generally accepted technique.