Anatomy of the lumbar interspinous ligament: findings relevant to epidural insertion using loss of resistance

Background and objectivesThe ‘loss of resistance’ technique is used to determine entry into the epidural space, often by a midline needle in the interspinous ligament before the ligamentum flavum. Anatomical explanations for loss of resistance without entry into the epidural space are lacking. This investigation aimed to improve morphometric characterization of the lumbar interspinous ligament by observation and measurement at dissection and from MRI.MethodsMeasurements were made on 14 embalmed donor lumbar spines (T12 to S1) imaged with MRI and then dissected along a tilted axial plane aligned with the lumbar interspace.ResultsIn 73 interspaces, median (IQR) lumbar interspinous plus supraspinous ligament length was 29.7 mm (25.5–33.4). Posterior width was 9.2 mm (7.7, 11.9), with narrowing in the middle (4.5 mm (3.0, 6.8)) and an anterior width of 7.3 mm (5.7, 9.8).Fat-filled gaps were present within 55 (75%). Of 51 anterior gaps, 49 (67%) were related to the ligamenta flava junction. Median (IQR) gap length and width were 3.5 mm (2.5, 5.1) and 1.1 mm (0.9, 1.7).Detection of gaps with MRI had 100% sensitivity (95% CI 93.5 to 100), 94.4% specificity (72.7, 99.9), 98.2% (90.4, 100) positive predictive value and 100% (80.5, 100) negative predictive value against dissection as the gold standard.ConclusionsThe lumbar interspinous ligament plus supraspinous ligament are biconcave axially. It commonly has fat-filled gaps, particularly anteriorly. These anatomical features may form the anatomical basis for false or equivocal loss of resistance.

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Cervical and High Thoracic Ligamentum Flavum Frequently Fails to Fuse in the Midline

Anesthesiology ◽

10.1097/00000542-200312000-00023 ◽

2003 ◽

Vol 99 (6) ◽

pp. 1387-1390 ◽

Cited By ~ 86

Author(s):

Philipp Lirk ◽

Christian Kolbitsch ◽

Guenther Putz ◽

Joshua Colvin ◽

Hans Peter Colvin ◽

...

Keyword(s):

Ligamentum Flavum ◽

Epidural Needle ◽

Complete Fusion ◽

Thoracic Epidural ◽

Loss Of Resistance ◽

Ligamenta Flava ◽

Mean Width ◽

Human Cadavers ◽

The Mean ◽

High Thoracic Epidural

Background Cervical and high thoracic epidural anesthesia and analgesia have gained increasing importance in the treatment of painful conditions and as components of anesthetics for cardiac and breast surgery. In contrast to the hanging-drop technique, the loss-of-resistance technique is thought to rely on the penetration of the ligamentum flavum. However, the exact morphology of the ligamentum flavum at different vertebral levels remains controversial. Therefore, the aim of this study was to investigate the incidence and morphology of cervical and high thoracic ligamentum flavum mid-line gaps in embalmed cadavers. Methods Vertebral column specimens were obtained from 52 human cadavers. On each dissected level, ligamentum flavum mid-line gaps were recorded and evaluated with respect to shape and size. Results The following variations were encountered: complete fusion in the mid-line, mid-line fusion with a gap in the caudal part, mid-line gap, and mid-line gap with widened caudal end. The incidence of mid-line gaps at the following levels was: C3-C4: 66%, C4-C5: 58%, C5-C6: 74%, C6-C7: 64%, C7-T1: 51%, Th1-Th2: 21%, Th2-Th3: 11%, Th3-Th4: 4%, Th4-Th5: 2%, and Th5-Th6: 2%. The mean width of mid-line gaps was 1.0 +/- 0.3 mm. Conclusions In conclusion, the present study shows that gaps in the ligamenta flava are frequent at cervical and high thoracic levels but become rare at the T3/T4 level and below, such that one cannot always rely on the ligamentum flavum as a perceptible barrier to epidural needle placement at these levels.

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Concordance between the loss of resistance technique and ultrasound in measuring the distance from the skin to the epidural space in pediatric patients: Observational study

Colombian Journal of Anesthesiology ◽

10.5554/22562087.e935 ◽

2020 ◽

Vol 48 (4) ◽

Author(s):

Piedad Cecilia Echeverry-Marín ◽

Andrea Carolina Pérez-Pradilla ◽

Bernardo Reyes-Escobar ◽

Rocío del Pilar Pereira-Ospina ◽

Manuela Quiroga-Carrillo

Keyword(s):

Observational Study ◽

Latin American ◽

Dura Mater ◽

Epidural Space ◽

Pediatric Patients ◽

Ligamentum Flavum ◽

Standard Technique ◽

Conventional Technique ◽

Ultrasound Measurement ◽

Loss Of Resistance

Introduction: The use of ultrasound in regional anesthesia has become a standard technique to improve nerve block accuracy and reduce associated complications. The literature reports a good correlation between the distance from the skin to the dura mater or the ligamentum flavum measured on ultrasound and the conventional technique of “loss of resistance”. Latin American populations have not been included in the studies conducted so far but, because of differences in physical build, it is important to determine whether this correlation is maintained in the various populations. This paper offers new information about the role of ultrasound in determining the distance to the ligamentum flavum and recognizing the proximity of the dura mater to avoid accidental puncture of this structure in Latin American populations. Objective: To determine correlation and concordance in estimating the distance from the skin to the epidural space between the loss of resistance technique and ultrasound measurement. Methodology: Observational study conducted in 52 pediatric patients who received general anesthesia plus peridural analgesia for acute perioperative pain management between July 2014 and November 2015 to assess correlation and concordance between loss of resistance and ultrasound measurement of distance to the epidural space. Results: There is a correlation between distances measured using the two techniques, which appears to be higher as patient age increases. As for concordance, the study found that 0.43 cm should be added to the ultrasound measurement to achieve agreement with the distance obtained using the loss of resistance technique; however, the interval between the two measurements is 1.15 cm. Conclusions: A correlation was found between the measurement taken from the skin to the peridural space using ultrasound and the measurement obtained with the traditional needle puncture and loss of resistance technique. Although concordance was not as expected and the distance measured with ultrasound may be smaller than the real measurement with the needle, ultrasound offers good guidance regarding proximity to the peridural space.

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Virtual Reality Based Enhanced Visualization of Epidural Insertion

Volume 2: 32nd Computers and Information in Engineering Conference, Parts A and B ◽

10.1115/detc2012-70951 ◽

2012 ◽

Author(s):

Neil Vaughan ◽

Venketesh N. Dubey ◽

Michael Y. K. Wee ◽

Richard Isaacs

Keyword(s):

Epidural Space ◽

Ligamentum Flavum ◽

Subcutaneous Fat ◽

3D Models ◽

Stereoscopic Vision ◽

Needle Placement ◽

Anatomical Structures ◽

Stereoscopic 3D ◽

Interspinous Ligament ◽

Full Color

This paper outlines an approach to create stereoscopic 3D computer graphics for visualization of epidural insertions. The graphics are built from several 3D vertex models of the anatomical structures including the vertebrae, tissue layers and the skin, subcutaneous fat, supraspinous ligament, interspinous ligament, ligamentum flavum and epidural space. The 3D models are wrapped with full color textures and vertex edges are rounded. The objects are stored in object files and are rendered as 3D by a custom OpenGL application. Graphics drivers calculate the angles and offset for the two separate stereo images and render both in 3D. The stereoscopic images are viewed through a visor containing two OLED micro-displays in stereo using the page-flipped method. The completed stereo simulation allows depth to be perceived so that the operator can judge depth of the needle tip in relation to tissue layers and bones, which aids to the location of the epidural space. Applying stereoscopic vision to epidural simulators will help the operator to visualize the depths required for correct needle placement in the epidural space.

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A Pressure Comparison Between Midline and Paramedian Approaches to the Cervical Epidural Space

January 2018 - Pain Physician ◽

10.36076/ppj.2014/17/155 ◽

2014 ◽

Vol 2;17 (2;3) ◽

pp. 155-162

Author(s):

Jee Youn Moon

Keyword(s):

Epidural Space ◽

Ligamentum Flavum ◽

Peak Pressure ◽

Positive Pressure ◽

Negative Peak ◽

Pressure Decrease ◽

Loss Of Resistance ◽

The Moment ◽

Midline Approach ◽

Pressure Changes

Background: In the cervical spine, the ligamentum flavum (LF) is often incompletely fused at the midline. Therefore, accessing the epidural space (ES) using the loss of resistance (LOR) technique via the midline approach could be less reliable than the paramedian approach. Since the tactile sensation of LOR is due to abrupt loss of pressure upon entering the ES, we have compared pressure changes between the 2 different cervical epidural techniques. Objectives: The aim of this study was to compare pressure changes during the pathway to the cervical ES between the 2 approaches. Study Design: A prospective, open-labeled, randomized, comparative study. Setting: An interventional pain management practice in a hospital, Republic of Korea. Methods: The 74 patients were randomly assigned to either a midline or paramedian group. The pressure changes were monitored and classified into 4 grades according to the following criteria: Grade I. The pressure waveform sequence consisted of 3 components in chronological order: 1) a high positive pressure just prior to entering the ES; 2) an abrupt pressure decrease at the moment of entering the ES; and 3) a negative peak pressure before cervical epidural pressure equilibration. Grade II. A high positive pressure followed by a precipitous pressure drop, without negative peak pressure upon entering the ES. Grade III. High positive pressure before entering the ES, followed by continuous pressure decrease without negative pressure. Grade IV. No pressure changes before or after entering the cervical ES. Results: An abrupt pressure decrease at the moment of exiting the LF or entering the ES was more frequently observed when using the paramedian approach (P < 0.05) with the odds ratio of 4.96 (95% CI, 1.63 – 15.12) as compared with the midline approach. Limitations: A correlation between the abrupt pressure decrease and LOR tactile sensation has been assumed. Conclusion: Under the assumption that the LOR sensation is due to an abrupt decrease in pressure the moment the needle enters the ES or exits the LF, this study claims that the accuracy of accessing the cervical ES can be improved significantly using the paramedian approach. Clinical trial: NCT01009385. Institutional Review Board (IRB): H-1208-107-422 Key words: Cervical epidural injection, loss of resistance technique, ligamentum flavum, midline approach, paramedian approach, epidural space

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Epidural Needle Extension through the Ligamentum Flavum Using the Standard versus the CompuFlo®-Assisted Loss of Resistance to Saline Technique: A Simulation Study

Anesthesiology Research and Practice ◽

10.1155/2020/9651627 ◽

2020 ◽

Vol 2020 ◽

pp. 1-4

Author(s):

E. Capogna ◽

A. Coccoluto ◽

M. Velardo

Keyword(s):

Epidural Space ◽

Simulation Study ◽

Ligamentum Flavum ◽

Standard Technique ◽

High Sensitivity ◽

Tuohy Needle ◽

Epidural Needle ◽

Loss Of Resistance ◽

The Mean ◽

Extension Length

Background. The CompuFlo® epidural system has been recently introduced and validated as an objective and sensible tool to detect the epidural space. We aimed to verify whether the high sensitivity of the instrument may help the anesthesiologist to identify the epidural space very early, limiting the extension of the Tuohy needle into the epidural space. Methods. In this prospective, simulation study, we evaluated the Tuohy needle extension through a simulated ligamentum flavum during the epidural procedure performed by 52 expert anesthesiologists by using the CompuFlo® epidural instrument or their standard loss of resistance to saline technique (LORT). Results. The mean (SD) needle extension length was 3.90 (3.71) mm in the standard technique group and 0.68 (0.46) mm in the CompuFlo® group (P<000001). The extremely reduced variability of the data in the CompuFlo® group (F test 0.01) made the results obtained with this instrument highly predictable. Conclusions. Puncturing high-resistance material that simulated the ligamentum flavum, the use of CompuFlo® has determined the arrest of the needle more precociously when compared with the traditional LORT.

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Alternative Approach To Needle Placement In Spinal Cord Stimulator Trial/Implantation

January 2018 - Pain Physician ◽

10.36076/ppj.2011/14/45 ◽

2011 ◽

Vol 1;14 (1;1) ◽

pp. 45-53

Author(s):

Jie Zhu

Keyword(s):

Spinal Cord ◽

Epidural Space ◽

Ligamentum Flavum ◽

Lumbar Spine Surgery ◽

Low Back ◽

Spinal Cord Stimulator ◽

Needle Placement ◽

Lead Placement ◽

Loss Of Resistance ◽

Alternative Approach

Neuromodulation with spinal cord stimulation is a proven, cost effective treatment for the management of chronic radicular low back pain from failed low back surgery syndrome and other neuropathic pain conditions. The traditionally instructed method for percutaneous spinal cord stimulator lead placement promotes the use of a “loss of resistance” technique under anteroposterior fluoroscopic guidance to assure midline lead placement and proper entry into the epidural space. Loss of resistance is a reliable method to locate the epidural space in most clinical situations. However, in certain circumstances such as a congenital underdeveloped ligamentum flavum or defects of the ligamentum flavum, sometimes occurring after lumbar spine surgery, it might become difficult to use a loss of resistance technique to locate the epidural space. In this case, the level of resistance might not be clear. Further, a false loss of resistance might occur between changes in fascial planes that might lead to the uncertainty of needle depth. This paper introduces an alternative method for needle placement for spinal cord stimulator (SCS) trials and implantation without using the traditional loss of resistance technique. The technique allows for precise visual monitoring of the Tuohy needle tip under fluoroscopy to gauge needle depth as it enters into the tissue and the epidural space based on anatomic structural landmarks. This method allows for multiple lead placement or single lead insertion multiple times in the same interlaminar space. This is an alternative approach to the loss of resistance technique based on the fluoroscopic landmarks. Theoretically, this should be a safer approach for accessing the epidural space; however, further studies are needed to evaluate its safety. Key words: spinal cord stimulator, loss of resistance, epidural access, lumbar radicular symptoms of lower limbs, neuromodulation, posterior column stimulator

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Faculty Opinions recommendation of A retrospective effectiveness study of loss of resistance to air or saline for identification of the epidural space.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1781957.1311055 ◽

2010 ◽

Author(s):

Barbara M Scavone ◽

Christopher Cambic

Keyword(s):

Epidural Space ◽

Effectiveness Study ◽

Loss Of Resistance

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Added value of diffusion-weighted MRI in assessment of pleural lesions

Egyptian Journal of Radiology and Nuclear Medicine ◽

10.1186/s43055-021-00557-3 ◽

2021 ◽

Vol 52 (1) ◽

Author(s):

Youssriah Yahia Sabri ◽

Ikram Hamed Mahmoud ◽

Lamis Tarek El-Gendy ◽

Mohamed Raafat Abd El-Mageed ◽

Sally Fouad Tadros

Keyword(s):

Positive Predictive Value ◽

Negative Predictive Value ◽

Predictive Value ◽

Diagnostic Value ◽

Added Value ◽

Adc Value ◽

Pleural Diseases ◽

Conventional Mri ◽

Malignant Lesions

Abstract Background There are many causes of pleural disease including variable benign and malignant etiologies. DWI is a non-enhanced functional MRI technique that allows qualitative and quantitative characterization of tissues based on their water molecules diffusivity. The aim of this study was to evaluate the diagnostic value of DWI-MRI in detection and characterization of pleural diseases and its capability in differentiating benign from malignant pleural lesions. Results Conventional MRI was able to discriminate benign from malignant lesions by using morphological features (contour and thickness) with sensitivity 89.29%, specificity 76%, positive predictive value 89%, negative predictive value 76.92%, and accuracy 85.37%. ADC value as a quantitative parameter of DWI found that ADC values of malignant pleural diseases were significantly lower than that of benign lesions (P < 0.001). Hence, we discovered that using ADC mean value of 1.68 × 10-3 mm2/s as a cutoff value can differentiate malignant from benign pleural diseases with sensitivity 89.3%, specificity 100%, positive predictive value 100%, negative predictive value 81.2%, and accuracy 92.68% (P < 0.001). Conclusion Although DWI-MRI is unable to differentiate between malignant and benign pleural effusion, its combined morphological and functional information provide valid non-invasive method to accurately characterize pleural soft tissue diseases differentiating benign from malignant lesions with higher specificity and accuracy than conventional MRI.

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