Ultrasound for Lumbar Spinal Procedures

The utility of intraoperative ultrasonography for spinal cord surgery

OBJECTIVES

Intraoperative ultrasonography (IOUS) offers the advantage of providing real-time imaging features, yet it is not generally used. This study aims to discuss the benefits of utilizing IOUS in spinal cord surgery and review related literature.

MATERIALS AND METHODS

Patients who underwent spinal cord surgery utilizing IOUS at a single institution were retrospectively collected and analyzed to evaluate the benefits derived from the use of IOUS.

RESULTS

A total of 43 consecutive patients were analyzed. Schwannoma was the most common tumor (35%), followed by cavernous angioma (23%) and ependymoma (16%). IOUS confirmed tumor extent and location before dura opening in 42 patients (97.7%). It was particularly helpful for myelotomy in deep-seated intramedullary lesions to minimize neural injury in 13 patients (31.0% of 42 patients). IOUS also detected residual or hidden lesions in 3 patients (7.0%) and verified the absence of hematoma post-tumor removal in 23 patients (53.5%). In 3 patients (7.0%), confirming no intradural lesions after removing extradural tumors avoided additional dural incisions. IOUS identified surrounding blood vessels and detected dural defects in one patient (2.3%) respectively.

CONCLUSIONS

The IOUS can be a valuable tool for spinal cord surgery in identifying the exact location of the pathologic lesions, confirming the completeness of surgery, and minimizing the risk of neural and vascular injury in a real-time fashion.

Correlation between epidural space depth measured with ultrasound and MRI compared to clinical loss of resistance when performing lumbar epidural steroid injection

BACKGROUND

This prospective study assessed the accuracy of MRI and ultrasound (US) measurements as a preprocedural assessment tool for predicting clinical loss of resistance depth (CLORD) during fluoroscopy-guided lumbar epidural steroid injections (ESIs).

MATERIALS AND METHODS

Sixty patients enrolled received lumbar ESIs at an academic chronic pain clinic. The MRI measurement calculated the distance between the skin and the posterior epidural space, while US measurements included transverse and parasagittal oblique views of the interlaminar space. The epidural space measurements were compared with the CLORD during the performance of the prone epidural injections. The differences in measurements were analyzed using two one-sided tests for equivalency with a 0.5 equivalency margin. The intraclass correlation coefficients between CLORD and the imaging modalities were estimated using mixed effects models.

RESULTS

MRI was equivalent to CLORD with a mean difference of -0.2 cm (95% CI -0.39 to -0.11). US transverse and US parasagittal oblique measurements were not equivalent to and underestimated CLORD with mean differences of -0.98 cm (90% CI -1.8 to -0.77) and -0.79 cm (90% CI -1.0 to -5.9), respectively. The intraclass correlation coefficients between MRI and CLORD were the highest at 0.85, compared with 0.65 and 0.73 for transverse and parasagittal oblique US views, respectively.

CONCLUSIONS

MRI measurements are preferable over US for preprocedural assessment of patients receiving lumbar ESIs for predicting CLORD.

Proposal of a Route Map for Cervical Spinal Ultrasonography: A Simple and Clear Learning Tool for Beginners

Spinal ultrasonography has increasingly been used to image axial structures from the cervical to sacral region in recent years. In this work, we propose a comprehensive, systematic cervical scanning protocol that we refined as a route map, especially for beginners, to facilitate teaching, learning, diagnosis, and treatment in clinical pain practice. As a simple and clear tool to demonstrate the scanning protocol, the route map is delineated with rectangles, lines, and arrows. The rectangles represent the positions of the transducer, the arrows indicate route directions, and the lines show the routes of transducer movement. In this article, we describe cervical spinal ultrasonography to illustrate the route map interpretation, scanning protocol and target anatomical structures in detail. We believe that this comprehensive, clear, systematic, and portable route map will be beneficial for inexperienced pain clinicians and ultrasound beginners.

Ultrasound-guided transforaminal epidural injection with fluoroscopy confirmation for the treatment of unilateral lumbar radiculopathy: A randomized controlled non-inferiority study

BACKGROUND

Ultrasound (US)-guided injections for chronic pain has multiple advantages over traditional radiologic method. The study was performed to exam the clinical outcomes of lumbar transforaminal epidural injection (LTFEI) between US and fluoroscopy (FL) guidance for lumbar radiculopathy (LRP).

METHODS

A total of 164 patients with LRP were randomly assigned into US and FL group to receive LTFEI in a 1:1 ratio. Pain relief and functional disability were assessed by numeric rating scale (NRS) and Modified Oswestry Disability Questionnaire (MODQ) scores before treatment, 1 month and 3 months post-intervention. Contrast spread pattern, fluoroscopic image number and complications were also recorded. The primary outcome was accurate rate of contrast dispersing into lumbar epidural space, and non-inferiority margin was predefined at -15 %.

RESULTS

The accuracy of LTFEI was 90.2 % and 91.5 % in US and FL group, and the lower limit of the 95 %CI of mean difference between two modalities (-4.9 % (95 %CI: -12.8 %, 3.1 %)) was above the non-inferiority margin. Procedure time in US group (531.90 ± 67.12 s) was shorter than FL group (904.20 ± 120.20 s) (p < 0.05), while radiation dosage in the US group was lower than in the FL group (3047.20 ± 569.53 vs. 8807.50 ± 1039.10 μGy m², p < 0.001). Both groups didn't differ in pain reduction (F = 1.050, p = 0.306) and functional improvement (F = 0.103, p = 0.749) during follow-up period. No severe complications occurred in both groups.

CONCLUSIONS

US-guided LTFEI confirmed by FL was not inferior to conventional FL method in terms of accurate rate of lumbar epidural contrast dispersion. Effective pain relief and functional ability improvement were comparable between two modalities, and US technique had advantages of less radiation exposure and possible facilitation of avoiding critical vessels around intervertebral foramen.

Ultrasound-Guided In-Plane Interlaminar Lumbar Endoscopic Approach with Smartphone and Portable Light Source: Description of a New Surgical Technique

Introduction Endoscopic spine surgery enables the minimally invasive treatment of pathologies affecting the spinal cord and roots. Herein we describe an unprecedented technique Ultrasound-Guided in-plane interlaminar lumbar endoscopic approach with a smartphone and portable light source.

Methods The interlaminar approach was performed in a cadaveric specimen at L4 to 5 and L5 to S1 bilaterally. A curvilinear 2 to 5 MHz ultrasound probe was employed, the puncture was performed with the needle, a guide wire was inserted until the flavum ligament, followed by the dilator and working cannula. A 30° spinal endoscope, with an optical adapter of the endoscope camera for smartphone and portable endoscope lighting was inserted, the flavum ligament was visualized, and an opening in this site was performed with the scissors. Open dissection of the specimen was subsequently performed by identifying the puncture site in the interlaminar window.

Results The four interlaminar punctures were successfully guided by ultrasound; the opening of the ligamentum flavum was performed in the most lateral part of the interlaminar space, near the junction of the superior and inferior articular processes of the corresponding vertebrae in all the punctures.

Discussion The ultrasound makes possible to identify facets, foramina, transverse processes, and the interlaminar space. It is possible to minimize the use of radioscopy and its associated risks, both for patients and health professionals.

Conclusions The ultrasound-guided, in-plane, interlaminar, lumbar endoscopic approach with smartphone-adapted endoscope and portable light source is feasible and practical, minimizing radiation risks and making it possible to perform endoscopic spinal surgery.

Ultrasound-Guided Lumbar Spine Injection for Axial and Radicular Pain: A Single Institution Early Experience

STUDY DESIGN

Clinical audit via retrospective review of a database.

PURPOSE

To report an early experience using ultrasound-guided lumbar spinal injection for axial and radicular pain in an Asian multiethnic cohort.

OVERVIEW OF LITERATURE

Ultrasound-guided spine injection therapy is a comparatively new technique in the management of axial and radicular pain from degenerative lumbar spinal conditions, which may be a reasonable alternative to conventional fluoroscopic or computed tomography-guided injection.

METHODS

A retrospective review was conducted, involving all patients who underwent ultrasound-guided lumbar spine injection therapy at a single institution over 1 year. Patients were evaluated by two interventionists, who then performed standardized ultrasound-guided lumbar facet joint and pararadicular spinal injections.

RESULTS

There were 42 patients treated at our Sports Medicine Centre; with 27 patients (64.3%) receiving facet joint injections and 18 patients (42.9%) receiving nerve root injections. The majority (90.5%) of patients experienced an improvement of >30% in pain intensity at 3 months post-injection, using the Numerical Rating Scale pain score (p<0.001); with 40 patients (95.2%) reporting a reduction in Oswestry Disability Index score (p<0.001). No complications were reported.

CONCLUSIONS

Our initial experience confirms the safety, feasibility, and effectiveness of ultrasound-guided lumbar spinal injection for the treatment of axial and radicular pain in an Asian multiethnic cohort.

Diagnostic nerve blocks in the management of low back pain secondary to facet joint syndrome

Low back pain is currently one of the main public health problems. Among the multiple causes, pain in the zygapophysial joints, also called facets or posterior vertebral joints, are an important cause, usually secondary to osteoarthritis. The source of low back pain is often difficult to find, making the therapeutic approach to the patient sub-optimal. Diagnostic blocks are a very important tool in establishing an adequate treatment for patients with low back pain, as long as they are performed accurately, with an adequate local anaesthetic volume, with a suitable image and fluoroscopic projection and its result are precisely interpreted. In this article a review is presented on the importance of diagnostic blocks, as well as how they should be performed in order to obtain the maximum information and the greatest therapeutic benefit.