Clinical and radiological outcomes of one-level cervical corpectomy with an expandable cage for three-column uncomplicated subaxial type «B¼ injures: a multicenter retrospective study.

PURPOSE: To evaluate the clinical and radiological results of the operative management of three-column uncomplicated type «B¼ subaxial injures treated with a one-level cervical corpectomy with an expandable cage. METHODS: This study included 72 patients with a three-column uncomplicated type «B¼ subaxial injures who met the inclusion criteria, underwent a one-level cervical corpectomy with an expandable cage at one of three neurosurgical departments between 2005 and 2020, and were followed up for clinical and radiological outcomes at a minimum 3-yr follow-up. RESULTS: There was a decrease in the VAS pain score from an average of 80 mm to 7 mm (p = 0.03); a decrease in the average NDI score from 62 to 14% (p = 0.01); excellent and good outcomes according to Macnab's scale were 93% (n = 67/72). There was an average change in the cervical lordosis (Cobb method) from -9.10 to -15.40 (p = 0.007), without significant loss of lordosis (p = 0.27). There was no significant degeneration of the adjacent levels by 3 years post-op. The fusion rate, using the Cervical Spine Research Society criteria, was poor: it was 62.5% (n = 45/72), and using the CT criteria, it was 65.3% (n = 47/72). 15.4% patients (n = 11/72) suffered complications. Statistical difference between the fusion and pseudoarthrosis (according to X-ray criteria) subgroups showed that there were no statistically significant differences in the smoking status, diabetes, chronic steroid use, cervical injury level, subtypes of AO type B subaxial injuries and types of expandable cage systems. CONCLUSIONS: One-level cervical corpectomy with an expandable cage, despite a poor fusion rate, can be considered a feasible and relatively safe method for treating three-column uncomplicated subaxial type «B¼ injures, with the benefit of immediate stability, anatomical reduction, and direct decompression of the spinal cord. While no one in our series had any catastrophic complications, we did note a high complication rate.

Interdural course of the ophthalmic artery in the optic canal.

OBJECTIVE: In the current neurosurgical and anatomical literature, the intracanalicular segment of the ophthalmic artery (OphA) is usually described to be within the optic nerve dural sheath (ONDS), implying direct contact between the nerve and the artery inside the optic canal. In the present study, the authors sought to clarify the exact relationship between the OphA and ONDS. METHODS: Ten cadaveric heads were subjected to endoscopic endonasal and transcranial exposures of the OphA in the optic canal (5 for each approach). The relationship between the OphA and ONDS was assessed. Histological examination of one specimen of the optic nerve and the accompanying OphA was also performed to confirm the relationship with the ONDS. RESULTS: In all specimens, the OphA coursed between the two layers of the dura (endosteal and meningeal) and was not in direct contact with the optic nerve, except for the first few millimeters of the proximal optic canal before it pierced the ONDS. Upon reaching the orbit, the two layers of the dura separated and allowed the OphA to literally float within the orbital fat. The meningeal dura continued as the ONDS, whereas the endosteal dura became the periorbita. CONCLUSIONS: This study clarifies the interdural course of the OphA within the optic canal. This anatomical nuance has important neurosurgical implications regarding safe exposure and manipulation of the OphA.

Laboratory Evaluation of a Robotic Operative Microscope - Visualization Platform for Neurosurgery.

Background We assessed a new robotic visualization platform with novel user-control features and compared its performance to the previous model of operative microscope. Methods In a neurosurgery research laboratory, we performed anatomical dissections and assessed robotic, exoscopic, endoscopic, fluorescence functionality. Usability and functionality were tested in the operating room over 1 year. Results The robotic microscope showed higher sensitivity for fluorescein sodium, higher detail in non-fluorescent background, and recorded/presented pictures with color quality similar to observation through the oculars. PpIX visualization was comparable to the previous microscope. Near-infrared indocyanine green imaging 3-step replay allowed for more convenient accurate assessment of blood flow. Point lock and pivot point functions were used in dissections to create 3D virtual reality microsurgical anatomy demonstrations. Pivot point control was particularly useful in deep surgical corridors with dynamic retraction. 3D exoscopic function was successfully used in brain tumor and spine cases. Endoscopic assistance was used for around-the-corner views in minimally invasive approaches. We present illustrative cases highlighting utility and new ways to control the operative microscope. Conclusion Improvements of the robotic visualization platform include intraoperative fluorescence visualization using FNa, integrated micro-inspection tool, improved ocular imaging clarity, and exoscopic mode. New robotic movements positively assist the surgeon and provide improved ergonomics and a greater level of intraoperative comfort, with the potential to increase the viewing quality. New operational modes also allow significant impact for anatomy instruction. With the increasing number and complexity of functions, surgeons should receive additional training in order to avail themselves of the advantages of the numerous novel features.

The End-to-Side Anastomosis: A Comparative Analysis of Arterial Models in the Rat.

BACKGROUND: The end-to-side anastomosis is 1 of the most common anastomosis configurations used in cerebrovascular surgery. Although several living practice models have been proposed for this technique, few involve purely arterial vessels. The purpose of the present study was to compare 2 arterial models using common carotid arteries (CCAs) and common iliac arteries (CIAs) in rats. METHODS: The CIAs and CCAs were exposed in 10 anesthetized rats, and their lengths and diameters were measured. Also, the mobilization extent of each vessel along its contralateral counterpart was measured after each artery had been transected at its proximal exposure point. We also studied the technical advantages and disadvantages of each model for practicing end-to-side anastomosis. RESULTS: The average diameters of the CCA and CIA were 1.1 and 1.3 mm, respectively. The average extent of mobilization along the contralateral vessel was 13.9 mm and 10.3 mm for CCA and CIA, respectively. The CCA model had the advantages of greater arterial redundancy (allowing completion of both suture lines extraluminally) and a minimal risk of venous injury. The main disadvantage of the CCA model was the risk of cerebral ischemia. The CIA model was not limited by the ischemic time and provided the technical challenge of microsurgical dissection of the common iliac vein from the CIA, although it had limited CIA redundancy. CONCLUSIONS: Both CCA and CIA models could be efficiently used for practicing the end-to-side anastomosis technique. Each model provides the trainee with a specific set of advantages and disadvantages that could help with the optimal selection of the practice model according to trainee's skill level.

Carotid Endarterectomy Surgical Simulation Model Using a Bovine Placenta Vessel.

BACKGROUND: Carotid endarterectomy (CEA) is a common, well-developed surgical procedure. Although surgical simulation is gaining in importance for residency training, CEA practice opportunities for surgical residents are limited. OBJECTIVE: To describe a new haptic CEA model. METHODS: Six bovine placentas were used to create the model. Each placenta provided about 6 large arterial and venous bifurcations. In total, 36 large-vessel bifurcations were dissected and prepared for the CEA simulation. Bovine placenta vessels were arranged to simulate the common carotid artery (CCA), internal carotid artery (ICA), and external carotid artery (ECA). The diameters and wall thicknesses were measured and compared with human CCA, ICA, and ECA parameters. RESULTS: All bovine placentas provided vessels suitable for modeling carotid artery bifurcations and CEA training. Mean ± SD diameters of simulated CCAs, ECAs, and ICAs were 11.2 ± 1.8, 4.3 ± 0.5, and 9.8 ± 3.0 mm, respectively, from nondilated veins and 8.7 ± 1.4, 4.4 ± 1.3, and 7.2 ± 1.7 mm, respectively, from nondilated arteries. Mean vessel wall thicknesses were 2.0 ± 0.6 mm for arteries and 1.4 ± 0.5 mm for veins. Placental vessel tissue had dimensions and handling characteristics similar to those of human carotid arteries. The CEA procedure and its subtasks, including vessel-tissue preparation and surgical skills performance, could be reproduced with high fidelity. CONCLUSION: A bovine placenta training model for CEA is inexpensive and readily available and closely resembles human carotid arteries. The model can provide a convenient and valuable simulation and practice addition for vascular surgery training.