Treatment of Single Level Lumbar Spondylolisthesis with Lumbar Interbody Fusion via Oblique Lateral Approach (OLIF)

Objectives: To investigate the effect of lumbar interbody fusion via the oblique lateral approach (OLIF) in the treatment of single level lumbar spondylolisthesis. Methods: Retrospective analysis was made on 32 cases of single level lumbar spondylolisthesis treated by lumbar interbody fusion via the oblique lateral approach from July 2020 to July 2021. 14 males and 18 females;the age was (66.5 ± 11.5) years (55 - 82 years). 1) The operation time, intraoperative blood loss and complications were recorded;2) the scores of visual analog scale. VAS and Oswestry disability index (ODI) of low back pain and lower limb pain were collected before operation and at the last follow-up;by observing the imaging data, the height of the intervertebral space, the anterior convex angle of the intervertebral space, the anterior convex angle of the lumbar spine, the sagittal diameter of the dural sac and the spondylolisthesis were measured. Results: All patients successfully completed the operation, the average operation time was (103.9 ± 21.1) min, the average intraoperative bleeding volume was (72.3 ± 16.4) ml. There was no vascular injury during the operation, no infection occurred in all surgical incisions, and Class I/A healing was achieved. The VAS scores of low back pain and leg pain before operation and at the last follow-up were lower than those before operation, and the difference was statistically significant (P < 0.05);the ODI at the last follow-up was lower than that before operation, and the difference was statistically significant (P < 0.05). At the last follow-up, the height of intervertebral space, the height of intervertebral foramen and the sagittal diameter of dural sac were greater than those before operation, with statistically significant differences (P < 0.05);the spondylolisthesis rate at the last follow-up was lower than that before operation, with a statistically significant difference (P < 0.05). Left thigh surface numbness occurred in 2 cases (6.3%) and disappeared after 1 week;Hip flexion weakness occurred in 1 case (0.03%), which recovered after 12 days;there were no complications such as retroperitoneal hematoma, ureteral injury, retrograde ejaculation, intestinal and lumbar plexus injury. Conclusion: The early clinical effect of OLIF in the treatment of single level lumbar spondylolisthesis is significant. This surgical method is minimally invasive, safe and effective, which can significantly reduce the amount of intraoperative bleeding and reduce the risk of postoperative complications. Its main working principle is to make the annulus fibrosus, posterior longitudinal ligament and ligamentum flavum shrink and recover the height of the intervertebral space through decompression, loosening and stretching of the intervertebral space, so as to achieve the reduction of the slipped vertebral body, increase the height of the intervertebral foramen Enlarge the spinal canal volume and eliminate dynamic compression to play an indirect decompression role, improve the symptoms of low back and leg pain, and reconstruct the stability of the spine through interbody fusion.

Surgical treatment of the thoracic and thoracolumbar disc herniations through the posterior far lateral approach

Objective To evaluate the feasibility,safety and efficacy of surgical treatment of the thoracic and thoracolumbar disc herniations through the posterior far lateral approach.Methods From April 2005 to June 2010,24 consecutive patients

Anatomical study of endoscope-assisted far lateral keyhole approach to the ventral craniocervical region with neuronavigational guidance

Background Image-guided neurosurgery, endoscopic-assisted neurosurgery and the keyhole approach are three important parts of minimally invasive neurosurgery and have played a significant role in treating skull base lesions. This study aimed to investigate the potential usefulness of coupling of the endoscope with the far lateral keyhole approach and image guidance at the ventral craniocervical junction in a cadaver model. Methods We simulated far lateral keyhole approach bilaterally in five cadaveric head specimens （10 cranial hemispheres）. Computed tomography-based image guidance was used for intraoperative navigation and for quantitative measurements. Skull base structures were observed using both an operating microscope and a rigid endoscope. The jugular tubercle and one-third of the occipital condyle were then drilled, and all specimens were observed under the microscope again. We measured and compared the exposure of the petroclivus area provided by the endoscope and by the operating microscope. Statistical analysis was performed by analysis of variance followed by the Student-Newman-Keuls test. Results With endoscope assistance and image guidance, it was possible to observe the deep ventral craniocervical junction structures through three nerve gaps （among facial-acoustical nerves and the lower cranial nerves） and structures normally obstructed by the jugular tubercle and occipital condyle in the far lateral keyhole approach. The surgical area exposed in the petroclival region was significantly improved using the 0° endoscope （1147.80 mm2） compared with the operating microscope （（756.28±50.73） mm2）. The far lateral retrocondylar keyhole approach, using both 0° and 30° endoscopes, provided an exposure area （（1147.80±159.57） mm2 and （1409.94±155.18） mm2, respectively） greater than that of the far lateral transcondylar transtubercular keyhole approach （（1066.26±165.06） mm2） （P 〈0.05）. Conclusions With the aid of the endoscope and image guidance, it is possible to approach the ventral craniocervical junction with the far lateral keyhole approach. The use of an angled-lens endoscope can significantly improve the exposure of the petroclival region without drilling the jugular tubercle and occipital condyle.

A young and booming approach:the extreme lateral supracerebellar infratentorial approach

Surgical accesses to lesions of the posterolateral pontomesencephalic junction（PMJ）region and the posterolateral tentorial gap remain a challenge in the field of neurosurgery.Since the first report of application of the extreme lateral supracerebellar infratentorial（ELSI）approach in resecting the PMJ lesions in 2000,a few articles concerning the ELSI approach have been published.The present review mainly provided an intimate introduction of the ELSI approach,and evalu- ated it in facets of patient position,skin incision,craniectomy,draining veins,retraction against the cerebellum,exposure limits,patient healing,as well as advantages and limitations compared with other approaches.The ELSI approach is proposed to be a very young and promising approach to access the lesions of posterolateral PMJ region and the posterolateral tentorial gap.Besides,it has several advantages such as having a shorter surgical pathway,causing less surgical complications,laborsaving,etc.Still,more studies are needed to improve this approach.

Surgical approaches to the petrous apex

The petrous apex is a difficult to reach surgical area due to its deep position in the skull base and many vital surrounding structures.Petrous apex pathology ranges from extradural cholesterol granulomas,cholesteatomas,asymmetric pneumatization,and osteomyelitis to intradural meningiomas and schwannomas.Certain lesions,such as cholesterol granulomas,can be managed with drainage while neoplastic lesions must be completely resected.Surgical options use open,endoscopic,and combined techniques and are categorized into anterior,lateral,and posterior approaches.The choice of approach is determined by the nature of the pathology and location relative to vital structures and extension into surrounding structures and requires thorough preoperative evaluation and discussion of surgical goals with the patient.The purpose of this state-of-the-art review is to discuss the most commonly used surgical approaches to the petrous apex,and the anatomy on which these approaches are based.

Classification and microsurgical treatment of foramen magnum meningioma

Background To investigate the classification and microsurgical treatment of foramen magnum meningioma(FMM).Methods We retrospectively analyzed 76 patients with FMM and classified them into two classifications,classification ABS according to the relationship between the FMM and the brainstem and classification SIM according to the relationship between the FMM and the vertebral artery(VA).All patients underwent either the far lateral approach(54 cases)or the suboccipital midline approach(22 cases).Results Of the 76 cases,47 cases were located ahead of the brainstem(A),16 cases at the back of the brainstem(B),and 13 cases were located laterally to the brainstem(S).There were 15 cases located superior to the VA(S),49 cases were inferior(I),and 12 cases were mixed type(M).Among 76 cases,71 cases were resected with Simpson grade 2(93.42%),3 with Simpson grade 3(3.95%),and 2 with Simpson grade 4(2.63%).We summarized four anatomical triangles:triangles SOT,VOT,JVV,and TVV.The mean postoperative Karnofsky performance score was improved in all patients(p<0.05).However,several complications occurred,including hoarseness and CSF leak.Conclusion ABS and SIM classifications are objective indices for choosing the surgical approach and predicting the difficulty of FMMs,and it is of great importance to master the content,position relationship with the tumor,and variable anatomical structures in the four"triangles"for the success of the operation.

An improved single-π equivalent circuit model for on-chip inductors in GaAs process

An improved single-π equivalent circuit model for on-chip inductors in the GaAs process is presented in this paper. Considering high order parasites, the model is established by comprising an improved skin effect branch and a substrate lateral coupling branch. The parameter extraction is based on an improved characteristic function approach and vector fitting method. The model has better simulation than the previous work over the measured data of 2.5r and 4.5r on-chip inductors in the GaAs process.