Radiculopathy LumbarSINRBSNCT07531485
The Selective Intraperineural Nerve Root Block Study
A study testing Selective Intraperineural Nerve Root Block(SINRB) and single-level lumbar decompression surgery in people with Radiculopathy Lumbar and Radiculopathy Sacral, run by Xi'an Honghui Hospital at 1 site in China.
Trial summary
Before lumbosacral decompression surgery for radicular pain, selective nerve root block(SNRB) is a common procedure to identify the responsible compressed nerve root(RCNR) and predict surgical outcomes. However, the diagnostic accuracy of conventional SNRB is unsatisfactory, especially in terms of specificity. Read more about this study
- Who is it for?
- Ages 18 to 90 years
- Conditions the study is for
- Radiculopathy Lumbar, Radiculopathy Sacral, Radiculopathy Multiple Sites
- What is being tested?
- Selective Intraperineural Nerve Root Block(SINRB) and single-level lumbar decompression surgery
- Type of treatment
- Injection or infusion, Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 80 participants
- Where
- 1 siteChina
- Study dates
- 13 Apr 2026to 1 Jan 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 90 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Unilateral sciatica >1 month with activity/daily life impairment.
- Suspected L5/S1 root compression at L4-5/L5-S1 with unconfirmed pain correlation, including disc herniation (MSU 1-B/1-A/2-A), lateral recess/foraminal stenosis (Lee grade 2/3), atypical sciatica, or imaging-exam inconsistency.
- Candidates for single-segment, single-root lumbar decompression, electing surgery after informed consent.
Who cannot join
- No significant pre-SINRB/surgery pain, or weakness/numbness as primary symptom.
- Unidentifiable responsible compressed nerve root (RCNR) per surgery.
- Suspected compression of the same nerve root at more than one segment.
- Pregnancy, active malignancy, or surgical contraindications.
- Inability to cooperate with assessment due to comorbidities or dysfunction.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
China1 site
Xi'an Honghui Hospital (North Campus)
Xi'an, Shaanxi, 710026
Ziqiang Yan, +86 29-86520907, honghuixiaozhao@163.com
About this study
Official title: Feasibility, Safety and Diagnostic Accuracy of Selective Intraperineural Nerve Root Block for Identifying Compressed Nerve Root in Lumbosacral Radicular Pain. A Prospective Cohort Study
Before lumbosacral decompression surgery for radicular pain, selective nerve root block(SNRB) is a common procedure to identify the responsible compressed nerve root(RCNR) and predict surgical outcomes. However, the diagnostic accuracy of conventional SNRB is unsatisfactory, especially in terms of specificity. The main limitation is the uncontrolled distribution of anesthetics during injection: when anesthetics spread to surrounding soft tissues instead of acting directly on the RCNR, false-negative results may occur with persistent radicular pain; when anesthetics diffuse to two or more nerve roots including the RCNR, false-positive results may occur even if a normal nerve root is punctured, leading to misdiagnosis.
This study aims to evaluate the diagnostic accuracy of a novel three-dimensional computed tomography multiplanar volume reconstruction (3D-CT MPVR) guided selective intraperineural nerve root block(SINRB) for identifying the RCNR in patients with lumbosacral radicular pain. The investigators hypothesize that this technique will achieve higher diagnostic specificity and overall accuracy than conventional SNRB, by ensuring anesthetics are delivered directly to the target nerve root. This improvement will help clinicians make more accurate surgical plans, achieve better targeted decompression, and ultimately improve postoperative pain relief and functional recovery for patients.
Read more
The main research questions to be addressed in this study are:
- What is the procedural success rate of SINRB?
- Whether SINRB may cause clinically detectable nerve injury?
- Whether sciatica is relieved after SINRB when only the responsible compressed nerve root is blocked?
- Whether sciatica is relieved after SINRB when only a normal unaffected nerve root is blocked?
Participants will:
- Undergo one or two SINRB procedures and a single-level lumbar decompression surgery
- Get assessment of pain, mobility disorder and neurological function
Read the detailed description
[Background] It has been reported that approximately 85% of sciatica cases result from nerve root compression secondary to lumbar disc herniation or lumbar spinal stenosis, a clinical entity defined as radicular pain that manifests as radiating pain involving the buttocks and lower extremities. For patients with an inadequate response to conservative management, surgical decompression of the compressed nerve root serves as a conventional and highly effective therapeutic option. Furthermore, if the pain generator can be confirmed to arise from a single nerve root, targeted single-level decompression of that individual nerve root is generally sufficient for pain relief. However, limitations of conventional imaging examinations coupled with overlapping innervation territories of multiple lumbosacral nerve roots often make accurate identification of the symptomatic compressed nerve root challenging in certain patient populations. Misidentification of the pathological nerve root may consequently lead to surgical failure. To address this clinical dilemma, diagnostic selective nerve root block (SNRB) is regarded as the most valuable adjunct modality. In routine clinical practice, complete pain remission following SNRB indicates that the nerve root infiltrated by local anesthetics is the primary pain source.
Regrettably, prior relevant studies have demonstrated that conventional SNRB exhibits relatively low overall diagnostic accuracy, failing to achieve satisfactory sensitivity and specificity simultaneously. Uncontrolled diffusion of injectable agents is recognized as the predominant contributor to such poor diagnostic performance. Specifically, unintended anesthetic contamination of adjacent unaffected nerve roots may trigger false-positive outcomes, while insufficient delivery of local anesthetics to the targeted nerve root can result in false-negative findings. At present, no techniques or strategies for precisely regulating drug distribution during SNRB procedures have been reported in the existing literature.
Interestingly, during the nerve root fluorography in some patients in our team, when linear striation opacities are visualized within the nerve root, which indicates occurrence of intraperineural, the contrast medium typically diffuses only inside and around the targeted nerve root. This phenomenon can also be observed in the illustrative images from a previous study on therapeutic SNRB, yet it seems to have attracted little attention from researchers. Additionally, the findings of this study demonstrated that intraperineural injection occurred in approximately 30% of patients undergoing therapeutic SNRB with accidental intraperineural injection, and no cases of neurological injury were documented during follow-up. Therefore, it is reasonable to hypothesize that intraperineural injection is a safe, feasible approach that enables precise distribution of agents to the targeted nerve root.
Using the postoperative efficacy of single-segment single-nerve-root decompression as the gold standard for identifying the compressed nerve root, the present study aimed to investigate the diagnostic accuracy, safety, and technical feasibility of selective intraperineural nerve root block (SINRB) in patients with radicular pain. A double-blind approach was implemented, with participants and assessors masked to the nerve root status (responsible vs. non-responsible) during evaluations. Meanwhile, to improve the success rate of intraperineural injection, to the best of our knowledge, the present study is the first to adopt three-dimensional computed tomography multiplanar volume reconstruction (3D-CT MPVR) imaging to visualize the anatomical course of the nerve root within the intervertebral foramen.
[Sample Size Estimation] To ensure adequate statistical power for accurately evaluating the diagnostic accuracy of selective intraperineural nerve root block (SINRB) in identifying the responsible compressed nerve root (RCNR) in patients with radicular pain, sample size calculation was performed based on diagnostic test design principles, incorporating the following key parameters: (from preliminary pilot data) an expected sensitivity of 95%, specificity of 96%, 95% confidence level, ±5% margin of error, and a 10% allowance for potential missing data or patient dropout. Using the single-proportion estimation method, the required numbers of positive and negative events were calculated separately for sensitivity and specificity. The sample size required for sensitivity was 80 cases, and for specificity was 66 cases. Accordingly, we plan to enroll 66 patients with single-level lesions (anticipated to yield one positive and one negative result each) and 14 patients with multi-level lesions (anticipated to yield one positive result each). This sample size sufficiently meets the statistical power requirements for the primary study objective-evaluating the sensitivity and specificity of SINRB for RCNR identification-ensuring the scientific rigor, stability, and generalizability of the study findings.
- Conditions
- Radiculopathy Lumbar, Radiculopathy Sacral, Radiculopathy Multiple Sites, Herniated Disc, Foraminal Stenosis
- Being tested
- Selective Intraperineural Nerve Root Block(SINRB), single-level lumbar decompression surgery
- Keywords
- intraperineural, 3D-CT MPVR, diagnostic selective nerve root block, lumbosacral radiculopathy
- Medical subject headings
- Intervertebral Disc Displacement
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Selective Intraperineural Nerve Root Block(SINRB)Diagnostic test
The patient was placed in a standard prone position. The cutaneous puncture point was confirmed via large C-arm oblique fluoroscopy with the projection angle strictly consistent with the preoperative protocol.All puncture manipulations were completed by an experienced spinal surgeon. Under intermittent fluoroscopic guidance, the puncture trajectory was adjusted to keep the needle parallel to the fluoroscopic beam, followed by slow needle advancement until radiating pain was evoked in the patient. The needle was further advanced approximately 1 mm, and 0.2 mL contrast medium was injected subsequently. The visualization of a linear streak shadow within the nerve root confirmed intraneural positioning. The needle was fixed in situ, and 0.5 mL lidocaine was injected.
single-level lumbar decompression surgeryProcedure or surgery
All patients underwent single-level lumbar surgery with either endoscopic or conventional open single nerve root decompression, and postoperative anteroposterior and lateral lumbar radiographs were routinely obtained for imaging evaluation.
| Study group | Role | What they receive |
|---|---|---|
| Preoperative Diagnostic SINRB for Responsible Compressed Nerve Root(RCNR) Localization | Experimental | All enrolled subjects will undergo the same standardized surgical procedure.
* For patients with a single suspected lesion and RCNR (typically with ambiguous imaging findings), 2 separate SINRBs are performed (firstly at a non-responsible control root, then at the suspected RCNR) to rule out placebo effect and non-lumbar pain sources. If ≥50% pain relief occurs after the first block, the second SINRB is given the next day after local anesthetic clearance, and patients compare pain relief differences between the two sessions. If relief is less than 50%, the second SINRB is delivered after a 20-minute interval.
* For patients with multiple nerve roots compressed, 1 SINRB is performed at the target nerve root to confirm that single-level surgical decompression can achieve complete pain relief. If complete pain relief or resolution of motor dysfunction is not achieved after the first injection, a second SINRB will be administered to an alternative suspected root to identify the true RCNR. Receives: Diagnostic Test: Selective Intraperineural Nerve Root Block(SINRB); Procedure: single-level lumbar decompression surgery |
What is being measured
The primary outcome is the main question the study is designed to answer.
The change from baseline in standing impairment
Standing impairment was documented via separate video recordings before and after each SINRB procedure, as well as on the second day of postoperative ambulation. Upon completion of data collection, Video recordings of all participants were randomly shuffled, and independent assessors evaluated the presence or absence of standing impairment for each video. Assessors were blinded to the type of nerve root injected (responsible vs. non-responsible), final surgical outcomes, clinical information, imaging results, and the number of SINRB sessions.
Video content: The patient was instructed to stand upright with chest out, head raised, and lumbar spine maintained in an extended position for 20 seconds.
Assessment Criteria: Standing impairment was defined as present if the patient voluntarily bent forward/backward or left/right during the test due to intolerable radicular pain and failed to maintain the initial upright posture. Otherwise, standing impairment was considered absent.
Measured: Baseline, 5mins after SINRB, the second day after ambulation, and 1 month postoperatively
Change from baseline in walking impairment
Walking impairment was evaluated using the same recording and blinding protocols as those for standing impairment.
Video content: Patients maintained an upright position and kept uninterrupted walking for 500 meters.
Judgment criteria: "walking disorder" was defined as present if voluntary termination of walking occurred before completing 500 meters due to intolerable radicular pain. Otherwise, walking impairment was considered absent.
Measured: Baseline, 5mins after SINRB, the second day after ambulation, and 1 month postoperatively
Change from baseline in straight leg raising impairment
The straight leg raising (SLR) impairment was evaluated using the same recording and blinding protocols as those for standing impairment.
Video content: The straight leg raising (SLR) test was performed sequentially on the unaffected side and the affected side.
Assessment criteria: The projection of the heel of the elevated leg onto the contralateral (non-elevated) leg was used as the observation index.
"Presence of SLR impairment on the affected side" was defined as: the heel projection on the affected side failing to reach the patella due to intolerable radicular pain, whereas the heel projection on the unaffected side reached the patella or cephalad to it.
"Absence of SLR impairment on the affected side" was defined as: the heel projection reaching the patella at maximum SLR on the affected side, with or without tolerable radicular pain.
Measured: Baseline, 5mins after SINRB, the second day after ambulation, and 1 month postoperatively
Subjective pain relief
After each SINRB/operation, movements previously inducing severe pain (e.g., standing, walking, lying flat, stair climbing/descending) were repeated.
Video questions: "Where was your worst pain during movement pre-procedure?"; "Where do you feel pain now? Point to it."; "Does residual pain affect walking speed/distance?"; "How much has pain decreased post-SINRB/surgery?" (options: no significant relief; relief with activity-limiting residual pain; essential relief [residual pain not affecting activities]; pain disappeared).
Pain relief assessment followed the same recording and blinding protocols as for standing impairment.
Measured: 5mins after SINRB, the second day after ambulation, and 1 month postoperatively
Secondary outcomes (5)
Result of SINRB
This outcome measure is a derived variable automatically generated from the primary outcome measure according to a predefined scoring rule. After the independent assessors completed evaluating activity impairment and subjective pain relief in each video, all results were matched with corresponding patients and tabulated.
SINRB test results were judged by the following criteria: For patients with activity impairment, results were positive if all activity impairments resolved (with or without residual pain), otherwise negative. For patients without activity impairment, results were positive if subjective pain relief was rated as "pain disappeared", otherwise negative.
Measured: 5mins after SINRB
Overall clinical assessment after lumbar spine surgery
This outcome measure is a derived variable automatically generated from the primary outcome measure according to a predefined scoring rule. Compared with preoperative status, if all movement impairments resolve postoperatively, or the original pain is rated as "essential relief" or "pain disappeared", the decompressed nerve root is defined as the true responsible compressed nerve root(RCNR) and the sole source of pain.
If pain relief does not meet the above criteria during the initial postoperative assessment, a telephone follow-up will be conducted at 1 month after surgery for re-evaluation. If the patient reports "essential relief" or "pain disappeared" at follow-up, the decompressed nerve root is still regarded as the RCNR and the sole source of pain; otherwise, it is not considered the sole source of pain.
Measured: the second day after ambulation, and 1 month postoperatively
The occurrence of complications
The occurrence of complications during the puncture procedure, including hematoma at the puncture site, infection, allergic reactions, and other related complications, will be recorded in detail.
Measured: 24hs after SINRB
Changes in neurological function before and after SINRB
Changes in neurological function before and after SINRB. Baseline neurological assessment is performed before the first SINRB, including superficial sensory examination of the affected side (medial malleolus , dorsum of the foot, first and second toe web spaces , lateral aspect of the heel) and muscle strength testing of the affected side (ankle dorsiflexion, ankle plantarflexion, great toe dorsiflexion, great toe plantarflexion). At 24 hours after complete resolution of anesthetic effects following the final SINRB, patients are interviewed for new-onset numbness or discomfort, and the above neurological examinations are repeated. To supervise this key data, video recording will be conducted during inquiry and physical examination, with subsequent quality supervision by third-party senior physicians.
Measured: 24hs after SINRB
Success rate of SINRB procedure
The SINRB procedure is clinically successful when intraperineural injection is achieved without contrast/drug contamination per fluoroscopic criteria:
- Drug contamination: Post-lidocaine final radiculography showing contrast extending beyond the target nerve root and spreading along the dura to adjacent nerve roots; otherwise negative.
- Definition of successful intraperineural injection
The injection is judged as successful when all three fluoroscopic imaging features are satisfied simultaneously:
- Tubular outline of the nerve root and the linear striated opacification within the nerve root is noted after the contrast material injection;
- After lidocaine delivery, the striated opacification around the needle tip is diluted or disappeared;
- Re-enhancement of the striated nerve root opacification is observed after supplementary contrast medium reinjection.
Measured: immediately post-SINRB
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted15 Apr 2026
- Study start13 Apr 2026 (estimated)
- Primary completion1 Dec 2026 (estimated)
- Study completion1 Jan 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for Radiculopathy LumbarStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- This is a single-arm, prospective interventional study. All enrolled subjects will undergo the same standardized surgical procedure. The number of diagnostic SINRB administrations (1 or 2) will be tailored to individual clinical indications in accordance with a pre-defined protocol: * For patients with a single suspected symptomatic lesion and responsible compressed nerve root(RCNR)(typically with ambiguous imaging findings), 2 separate SINRB procedures will be performed (firstly at a non-responsible control root, then at the suspected RCNR) to exclude placebo effect and confirm that the identified RCNR is the sole source of pain, ruling out non-lumbar etiologies. * For patients with multiple suspected symptomatic lesions or RCNR, 1 SINRB procedure will be performed on the target nerve root to verify that decompression of this single lesion will achieve complete pain relief. All subjects will be enrolled in a single treatment cohort with no parallel control group.
- Masking
- None (open label)
- Enrolment
- 80 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Xi'an Honghui Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Lingjiang Li, Xi'an Honghui Hospital
- Investigators
- Lingjiang Li, Attending physician, Principal investigator, Xi'an Honghui Hospital, Xi'an, Shaanxi Province, China
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07531485
- Sponsor's protocol ID
- 2025--KY-085-01
- Acronym
- SINRBS
- Status last verified
- Apr 2026
- First submitted
- 5 Apr 2026
- Last updated
- 15 Apr 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Due to ethical restrictions and patient privacy confidentiality requirements, individual participant data will not be shared
Publications
Sala-Blanch X, Lopez AM, Pomes J, Valls-Sole J, Garcia AI, Hadzic A. No clinical or electrophysiologic evidence of nerve injury after intraneural injection during sciatic popliteal block. Anesthesiology. 2011 Sep;115(3):589-95. doi: 10.1097/ALN.0b013e3182276d10.
PubMed 21862889Beynon R, Elwenspoek MMC, Sheppard A, Higgins JN, Kolias AG, Laing RJ, Whiting P, Hollingworth W. The utility of diagnostic selective nerve root blocks in the management of patients with lumbar radiculopathy: a systematic review. BMJ Open. 2019 Apr 20;9(4):e025790. doi: 10.1136/bmjopen-2018-025790.
PubMed 31005925Pfirrmann CW, Oberholzer PA, Zanetti M, Boos N, Trudell DJ, Resnick D, Hodler J. Selective nerve root blocks for the treatment of sciatica: evaluation of injection site and effectiveness--a study with patients and cadavers. Radiology. 2001 Dec;221(3):704-11. doi: 10.1148/radiol.2213001635.
PubMed 11719666
Study at a glance
From the registry record, last updated by the sponsor on 15 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Feasibility, Safety and Diagnostic Accuracy of Selective Intraperineural Nerve Root Block for Identifying Compressed Nerve Root in Lumbosacral Radicular Pain. A Prospective Cohort Study
- ClinicalTrials.gov ID
- NCT07531485
- Acronym / sponsor ID
- SINRBS / 2025--KY-085-01
- Conditions
- Radiculopathy Lumbar, Radiculopathy Sacral, Radiculopathy Multiple Sites, Herniated Disc, Foraminal Stenosis
- Keywords
- intraperineural, 3D-CT MPVR, diagnostic selective nerve root block, lumbosacral radiculopathy
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 80 participants (estimated)
- Lead sponsor
- Xi'an Honghui HospitalUniversity, hospital or other
- Study start
- 13 Apr 2026 (estimated)
- Primary completion
- 1 Dec 2026 (estimated)
- Study completion
- 1 Jan 2027 (estimated)
- First posted
- 15 Apr 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Before lumbosacral decompression surgery for radicular pain, selective nerve root block(SNRB) is a common procedure to identify the responsible compressed nerve root(RCNR) and predict surgical outcomes. However, the diagnostic accuracy of conventional SNRB is unsatisfactory, especially in terms of specificity. The main limitation is the uncontrolled distribution of anesthetics during injection: when anesthetics spread to surrounding soft tissues instead of acting directly on the RCNR, false-negative results may occur with persistent radicular pain; when anesthetics diffuse to two or more nerve roots including the RCNR, false-positive results may occur even if a normal nerve root is punctured, leading to misdiagnosis.
This study aims to evaluate the diagnostic accuracy of a novel three-dimensional computed tomography multiplanar volume reconstruction (3D-CT MPVR) guided selective intraperineural nerve root block(SINRB) for identifying the RCNR in patients with lumbosacral radicular pain. The investigators hypothesize that this technique will achieve higher diagnostic specificity and overall accuracy than conventional SNRB, by ensuring anesthetics are delivered directly to the target nerve root. This improvement will help clinicians make more accurate surgical plans, achieve better targeted decompression, and ultimately improve postoperative pain relief and functional recovery for patients.
The main research questions to be addressed in this study are:
- What is the procedural success rate of SINRB?
- Whether SINRB may cause clinically detectable nerve injury?
- Whether sciatica is relieved after SINRB when only the responsible compressed nerve root is blocked?
- Whether sciatica is relieved after SINRB when only a normal unaffected nerve root is blocked?
Participants will:
- Undergo one or two SINRB procedures and a single-level lumbar decompression surgery
- Get assessment of pain, mobility disorder and neurological function
Detailed description
[Background] It has been reported that approximately 85% of sciatica cases result from nerve root compression secondary to lumbar disc herniation or lumbar spinal stenosis, a clinical entity defined as radicular pain that manifests as radiating pain involving the buttocks and lower extremities. For patients with an inadequate response to conservative management, surgical decompression of the compressed nerve root serves as a conventional and highly effective therapeutic option. Furthermore, if the pain generator can be confirmed to arise from a single nerve root, targeted single-level decompression of that individual nerve root is generally sufficient for pain relief. However, limitations of conventional imaging examinations coupled with overlapping innervation territories of multiple lumbosacral nerve roots often make accurate identification of the symptomatic compressed nerve root challenging in certain patient populations. Misidentification of the pathological nerve root may consequently lead to surgical failure. To address this clinical dilemma, diagnostic selective nerve root block (SNRB) is regarded as the most valuable adjunct modality. In routine clinical practice, complete pain remission following SNRB indicates that the nerve root infiltrated by local anesthetics is the primary pain source.
Regrettably, prior relevant studies have demonstrated that conventional SNRB exhibits relatively low overall diagnostic accuracy, failing to achieve satisfactory sensitivity and specificity simultaneously. Uncontrolled diffusion of injectable agents is recognized as the predominant contributor to such poor diagnostic performance. Specifically, unintended anesthetic contamination of adjacent unaffected nerve roots may trigger false-positive outcomes, while insufficient delivery of local anesthetics to the targeted nerve root can result in false-negative findings. At present, no techniques or strategies for precisely regulating drug distribution during SNRB procedures have been reported in the existing literature.
Interestingly, during the nerve root fluorography in some patients in our team, when linear striation opacities are visualized within the nerve root, which indicates occurrence of intraperineural, the contrast medium typically diffuses only inside and around the targeted nerve root. This phenomenon can also be observed in the illustrative images from a previous study on therapeutic SNRB, yet it seems to have attracted little attention from researchers. Additionally, the findings of this study demonstrated that intraperineural injection occurred in approximately 30% of patients undergoing therapeutic SNRB with accidental intraperineural injection, and no cases of neurological injury were documented during follow-up. Therefore, it is reasonable to hypothesize that intraperineural injection is a safe, feasible approach that enables precise distribution of agents to the targeted nerve root.
Using the postoperative efficacy of single-segment single-nerve-root decompression as the gold standard for identifying the compressed nerve root, the present study aimed to investigate the diagnostic accuracy, safety, and technical feasibility of selective intraperineural nerve root block (SINRB) in patients with radicular pain. A double-blind approach was implemented, with participants and assessors masked to the nerve root status (responsible vs. non-responsible) during evaluations. Meanwhile, to improve the success rate of intraperineural injection, to the best of our knowledge, the present study is the first to adopt three-dimensional computed tomography multiplanar volume reconstruction (3D-CT MPVR) imaging to visualize the anatomical course of the nerve root within the intervertebral foramen.
[Sample Size Estimation] To ensure adequate statistical power for accurately evaluating the diagnostic accuracy of selective intraperineural nerve root block (SINRB) in identifying the responsible compressed nerve root (RCNR) in patients with radicular pain, sample size calculation was performed based on diagnostic test design principles, incorporating the following key parameters: (from preliminary pilot data) an expected sensitivity of 95%, specificity of 96%, 95% confidence level, ±5% margin of error, and a 10% allowance for potential missing data or patient dropout. Using the single-proportion estimation method, the required numbers of positive and negative events were calculated separately for sensitivity and specificity. The sample size required for sensitivity was 80 cases, and for specificity was 66 cases. Accordingly, we plan to enroll 66 patients with single-level lesions (anticipated to yield one positive and one negative result each) and 14 patients with multi-level lesions (anticipated to yield one positive result each). This sample size sufficiently meets the statistical power requirements for the primary study objective-evaluating the sensitivity and specificity of SINRB for RCNR identification-ensuring the scientific rigor, stability, and generalizability of the study findings.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- This is a single-arm, prospective interventional study. All enrolled subjects will undergo the same standardized surgical procedure. The number of diagnostic SINRB administrations (1 or 2) will be tailored to individual clinical indications in accordance with a pre-defined protocol: * For patients with a single suspected symptomatic lesion and responsible compressed nerve root(RCNR)(typically with ambiguous imaging findings), 2 separate SINRB procedures will be performed (firstly at a non-responsible control root, then at the suspected RCNR) to exclude placebo effect and confirm that the identified RCNR is the sole source of pain, ruling out non-lumbar etiologies. * For patients with multiple suspected symptomatic lesions or RCNR, 1 SINRB procedure will be performed on the target nerve root to verify that decompression of this single lesion will achieve complete pain relief. All subjects will be enrolled in a single treatment cohort with no parallel control group.
| Arm | Type | Receives |
|---|---|---|
| Preoperative Diagnostic SINRB for Responsible Compressed Nerve Root(RCNR) Localization | Experimental | Diagnostic Test: Selective Intraperineural Nerve Root Block(SINRB), Procedure: single-level lumbar decompression surgeryAll enrolled subjects will undergo the same standardized surgical procedure. * For patients with a single suspected lesion and RCNR (typically with ambiguous imaging findings), 2 separate SINRBs are performed (firstly at a non-responsible control root, then at the suspected RCNR) to rule out placebo effect and non-lumbar pain sources. If ≥50% pain relief occurs after the first block, the second SINRB is given the next day after local anesthetic clearance, and patients compare pain relief differences between the two sessions. If relief is less than 50%, the second SINRB is delivered after a 20-minute interval. * For patients with multiple nerve roots compressed, 1 SINRB is performed at the target nerve root to confirm that single-level surgical decompression can achieve complete pain relief. If complete pain relief or resolution of motor dysfunction is not achieved after the first injection, a second SINRB will be administered to an alternative suspected root to identify the true RCNR. |
Who may qualify
- Ages
- 18 to 90 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Unilateral sciatica >1 month with activity/daily life impairment.
- Suspected L5/S1 root compression at L4-5/L5-S1 with unconfirmed pain correlation, including disc herniation (MSU 1-B/1-A/2-A), lateral recess/foraminal stenosis (Lee grade 2/3), atypical sciatica, or imaging-exam inconsistency.
- Candidates for single-segment, single-root lumbar decompression, electing surgery after informed consent.
Key exclusion criteria (5 listed)
- No significant pre-SINRB/surgery pain, or weakness/numbness as primary symptom.
- Unidentifiable responsible compressed nerve root (RCNR) per surgery.
- Suspected compression of the same nerve root at more than one segment.
- Pregnancy, active malignancy, or surgical contraindications.
- Inability to cooperate with assessment due to comorbidities or dysfunction.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Selective Intraperineural Nerve Root Block(SINRB)The patient was placed in a standard prone position. The cutaneous puncture point was confirmed via large C-arm oblique fluoroscopy with the projection angle strictly consistent with the preoperative protocol.All puncture manipulations were completed by an experienced spinal surgeon. Under intermittent fluoroscopic guidance, the puncture trajectory was adjusted to keep the needle parallel to the fluoroscopic beam, followed by slow needle advancement until radiating pain was evoked in the patient. The needle was further advanced approximately 1 mm, and 0.2 mL contrast medium was injected subsequently. The visualization of a linear streak shadow within the nerve root confirmed intraneural positioning. The needle was fixed in situ, and 0.5 mL lidocaine was injected. | Diagnostic test | Preoperative Diagnostic SINRB for Responsible Compressed Nerve Root(RCNR) Localization |
| single-level lumbar decompression surgeryAll patients underwent single-level lumbar surgery with either endoscopic or conventional open single nerve root decompression, and postoperative anteroposterior and lateral lumbar radiographs were routinely obtained for imaging evaluation. | Procedure or surgery | Preoperative Diagnostic SINRB for Responsible Compressed Nerve Root(RCNR) Localization |
Primary outcome
The change from baseline in standing impairment
Time frame: Baseline, 5mins after SINRB, the second day after ambulation, and 1 month postoperatively
Standing impairment was documented via separate video recordings before and after each SINRB procedure, as well as on the second day of postoperative ambulation. Upon completion of data collection, Video recordings of all participants were randomly shuffled, and independent assessors evaluated the presence or absence of standing impairment for each video. Assessors were blinded to the type of nerve root injected (responsible vs. non-responsible), final surgical outcomes, clinical information, imaging results, and the number of SINRB sessions. Video content: The patient was instructed to stand upright with chest out, head raised, and lumbar spine maintained in an extended position for 20 seconds. Assessment Criteria: Standing impairment was defined as present if the patient voluntarily bent forward/backward or left/right during the test due to intolerable radicular pain and failed to maintain the initial upright posture. Otherwise, standing impairment was considered absent.
Change from baseline in walking impairment
Time frame: Baseline, 5mins after SINRB, the second day after ambulation, and 1 month postoperatively
Walking impairment was evaluated using the same recording and blinding protocols as those for standing impairment. Video content: Patients maintained an upright position and kept uninterrupted walking for 500 meters. Judgment criteria: "walking disorder" was defined as present if voluntary termination of walking occurred before completing 500 meters due to intolerable radicular pain. Otherwise, walking impairment was considered absent.
Change from baseline in straight leg raising impairment
Time frame: Baseline, 5mins after SINRB, the second day after ambulation, and 1 month postoperatively
The straight leg raising (SLR) impairment was evaluated using the same recording and blinding protocols as those for standing impairment. Video content: The straight leg raising (SLR) test was performed sequentially on the unaffected side and the affected side. Assessment criteria: The projection of the heel of the elevated leg onto the contralateral (non-elevated) leg was used as the observation index. "Presence of SLR impairment on the affected side" was defined as: the heel projection on the affected side failing to reach the patella due to intolerable radicular pain, whereas the heel projection on the unaffected side reached the patella or cephalad to it. "Absence of SLR impairment on the affected side" was defined as: the heel projection reaching the patella at maximum SLR on the affected side, with or without tolerable radicular pain.
Subjective pain relief
Time frame: 5mins after SINRB, the second day after ambulation, and 1 month postoperatively
After each SINRB/operation, movements previously inducing severe pain (e.g., standing, walking, lying flat, stair climbing/descending) were repeated. Video questions: "Where was your worst pain during movement pre-procedure?"; "Where do you feel pain now? Point to it."; "Does residual pain affect walking speed/distance?"; "How much has pain decreased post-SINRB/surgery?" (options: no significant relief; relief with activity-limiting residual pain; essential relief [residual pain not affecting activities]; pain disappeared). Pain relief assessment followed the same recording and blinding protocols as for standing impairment.
5 secondary outcomes
Result of SINRB
Time frame: 5mins after SINRB
Overall clinical assessment after lumbar spine surgery
Time frame: the second day after ambulation, and 1 month postoperatively
The occurrence of complications
Time frame: 24hs after SINRB
Changes in neurological function before and after SINRB
Time frame: 24hs after SINRB
Success rate of SINRB procedure
Time frame: immediately post-SINRB
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 15 Apr 2026.
- Background: PubMed 21862889Sala-Blanch X, Lopez AM, Pomes J, Valls-Sole J, Garcia AI, Hadzic A. No clinical or electrophysiologic evidence of nerve injury after intraneural injection during sciatic popliteal block. Anesthesiology. 2011 Sep;115(3):589-95. doi: 10.1097/ALN.0b013e3182276d10.
- Background: PubMed 31005925Beynon R, Elwenspoek MMC, Sheppard A, Higgins JN, Kolias AG, Laing RJ, Whiting P, Hollingworth W. The utility of diagnostic selective nerve root blocks in the management of patients with lumbar radiculopathy: a systematic review. BMJ Open. 2019 Apr 20;9(4):e025790. doi: 10.1136/bmjopen-2018-025790.
- Background: PubMed 11719666Pfirrmann CW, Oberholzer PA, Zanetti M, Boos N, Trudell DJ, Resnick D, Hodler J. Selective nerve root blocks for the treatment of sciatica: evaluation of injection site and effectiveness--a study with patients and cadavers. Radiology. 2001 Dec;221(3):704-11. doi: 10.1148/radiol.2213001635.
- Individual participant dataSharing planned: No. Due to ethical restrictions and patient privacy confidentiality requirements, individual participant data will not be shared
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Lingjiang Li, Attending physician principal investigator
Xi'an Honghui Hospital, Xi'an, Shaanxi Province, China
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Selective Intraperineural Nerve Root Block(SINRB) and single-level lumbar decompression surgery in people with Radiculopathy Lumbar and Radiculopathy Sacral, run by Xi'an Honghui Hospital at 1 site in China.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 15 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in China. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Lingjiang Li, Attending physician (+86 29-83661911, lilingjiang11@126.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
The change from baseline in standing impairment (time frame: Baseline, 5mins after SINRB, the second day after ambulation, and 1 month postoperatively). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07531485, which also lists 3 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 15 Apr 2026.