The surgical vascular anatomy of the minimally invasive lateral lumbar interbody approach: a cadaveric and radiographic analysis.

PURPOSE: The minimally invasive (MI) lateral lumbar interbody fusion (LLIF) approach has become increasingly popular for the treatment of degenerative lumbar spine disease. The neural anatomy of the lumbar plexus has been studied; however, the pertinent surgical vascular anatomy has not been examined in detail. The goal of this study is to examine the vascular structures that are relevant in relation to the MI-LLIF approach. METHODS: Anatomic dissection of the lumbar spines and associated vasculature was performed in three embalmed, adult cadavers. Right and left surgeon perspective views during LLIF were for a total of six approaches. During the dissection, all vascular elements were noted and photographed, and anatomical relationships to the vertebral bodies and disc spaces were analyzed. In addition, several axial and sagittal MRI images of the lumbar spine were analyzed to complement the cadaveric analysis. RESULTS: The aorta descends along the left anterior aspect of lumbar vertebra with an average distance of 2.1 cm (range 1.9-2.3 cm) to the center of each intervertebral disc. The vena cava descends along the right anterior aspect of lumbar vertebrates with average distance of 1.4 cm (range 1.3-1.6 cm) to the center of the intervertebral disc. Each vertebral body has two lumbar arteries (direct branches from the aorta); one exits to the left and one to the right side of the vertebral body. The lumbar arteries pass underneath the sympathetic trunk, run in the superior margin of the vertebral body and extend all the way across it, with average length of 3.8 cm (range 2.5-5 cm). The mean distance between the arteries and the inferior plate of the superior disc space is 4.2 mm (range 2-5 mm) and mean distance of 3.1 cm (range 2.8-3.8 cm) between two arteries in adjacent vertebrae. One of the cadavers had an expected normal anatomical variation where the left arteries at L3-L4 anastomosed dorsally of the vertebral bodies at the middle of the intervertebral disc. CONCLUSIONS: Understanding the vascular anatomy of the lateral and anterior lumbar spine is paramount for successfully and safely executing the LLIF procedure. It is imperative to identify anatomical variations in lumbar arteries and veins with careful assessment of the preoperative imaging.

Fusion after intradural spine tumor resection in adults: A review of evidence and practices.

There is ample evidence supporting concomitant fusion after intradural spinal tumor resection in select pediatric patients. Unfortunately, the data are scarcer in adults. The objective of this work is to review the published literature and analyze practice patterns for stabilization and fusion after intradural tumor resection in adults. We performed a literature review via PubMed for information available regarding fusion in adults with intradural spine tumors. Additionally, we manually searched the references of selected articles to add relevant articles. Finally, we retrieved the criteria for fusion (if any) in the selected studies. A total of 639 articles were found and 35 were finally selected for analysis. Of those, three were literature reviews and 32 were retrospective case series. There were a total of 1288 patients on the series with 104 of them requiring fusion (8.1%). The median follow up of all the series was 24 months (range 1.5-180).The criteria for fusion that were common in most cases series were: previous deformity (i.e. kyphosis in the cervical spine), 3 or more levels of laminectomy, laminectomy encompassing a spinal junction, "young adults" (33 ± 4.2 years), facetectomy ≥ 50% (unilateral or bilateral), persistence of deformity after 1 year of the surgery and, C2 laminectomy. There appears to be some consistent practices for fusion after intradural tumor resection in adults, but this is based on retrospective analyses of case series. Prospective or randomized trials will likely provide more evidence based support for this practice.

Posterior atlantoaxial fixation: A cadaveric and fluoroscopic step-by-step technical guide.

BACKGROUND: Atlantoaxial surgical fixation is widely employed treatment strategy for a myriad of pathologies affecting the stability of the atlantoaxial joint. The most common technique used in adults, and in certain cases in children, involves a posterior construct with C1 lateral mass screws, and C2 pars or pedicle screws. This technical note aims to provide a step-by-step guide to this procedure using cadaveric and fluoroscopic images. METHODS: An embalmed, human, cadaveric, specimen was used for this study. The subject did not have obvious occipital-cervical pathology. Dissections and techniques were performed to mimic actual surgical technique. Photographs were taken during each step, and the critical aspects of each step were highlighted. Fluoroscopic images from a real patient undergoing C1/C2 fixation were also utilized to further highlight the anatomic-radiographic relationships. This study was performed without external or industry funding. RESULTS: Photographic and radiographic pictures and drawings are presented to illustrate the pertinent anatomy and technical aspects of this technique. The nuances of each step, including complication avoidance strategies are also highlighted. CONCLUSIONS: Given the widespread utilization of this technique, described step-by-step guide is timely for surgeons and trainees alike.

A new system for neuronavigation and stereotactic biopsy pantograph stereotactic localization and guidance system.

Everyday, neurosurgeons face the problem of orientation within the brain but the advent of stereotactic surgery and neuronavigation have solved this problem. Frame-based stereotactic systems (FBSS) and neuronavigation systems have their own strengths and priority and pitfalls, which were the main driving force for us to design a new system. This hybrid system comprises three main parts: main frame, monitoring system, and pantograph, which are connected to each other and to the operating table by particular attachments. For using this system, after performing CT SCAN or Magnetic Resonance Imaging (MRI) the axial view will be transferred to Liquid Cristal Display (LCD). In the operating room, the head of the patient fixes to the operating table and registration is completed by two arms of pantograph. We made a simulation operation with our system on an occipital cavernous angioma and a frontal oligodendroglioma. The software, which have been used for simulation were as follows; Poser (version-7), Catia (version 5- R18), and 3 Dimension Max (version 2008). The accuracy of this system is approximately two millimeter. The advantages of this system are: easy to use, much less expensive, and compatible with different devices, which may be needed during neurosurgical operation. For countries that do not have the opportunity to have sophisticated technology and neuronavigation system, we believe that our system is a one-stop solution.