The Selective Intraperineural Nerve Root Block Study

NCT07531485 | Not Yet Recruiting

• 1 other identifier: 2025--KY-085-01
• Study Type: interventional
• Target: 80
• Locations: 1 country
• Sites: 1

Brief 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. 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

Conditions

Radiculopathy Lumbar; Radiculopathy Sacral; Radiculopathy Multiple Sites; Herniated Disc; Foraminal Stenosis

Keywords

intraperineural; 3D-CT MPVR; diagnostic selective nerve root block; lumbosacral radiculopathy

Outcome Measures

Primary Outcomes (4)

• 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.

  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.

  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.

  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.

  5mins after SINRB, the second day after ambulation, and 1 month postoperatively

Secondary Outcomes (5)

• Result of SINRB

  5mins after SINRB

• Overall clinical assessment after lumbar spine surgery

  the second day after ambulation, and 1 month postoperatively

• The occurrence of complications

  24hs after SINRB

• Changes in neurological function before and after SINRB

  24hs after SINRB

• Success rate of SINRB procedure

  immediately post-SINRB

Study Arms (1)

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.

Diagnostic Test: Selective Intraperineural Nerve Root Block(SINRB); Procedure: single-level lumbar decompression surgery

Interventions

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.

Preoperative Diagnostic SINRB for Responsible Compressed Nerve Root(RCNR) Localization

single-level lumbar decompression surgery PROCEDURE

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.

Preoperative Diagnostic SINRB for Responsible Compressed Nerve Root(RCNR) Localization

Eligibility Criteria

• Age: 18 Years - 90 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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.

You may not qualify if:

• 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.

Sponsors & Collaborators

• Xi'an Honghui Hospital: lead

Study Sites (1)

Xi'an Honghui Hospital (North Campus)

Xi'an, Shaanxi, 710026, China

Location

Related Publications (3)

• 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.

  PMID: 21862889 BACKGROUND

• Beynon 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.

  PMID: 31005925 BACKGROUND

• Pfirrmann 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.

  PMID: 11719666 BACKGROUND

MeSH Terms

Conditions

Intervertebral Disc Displacement

Condition Hierarchy (Ancestors)

Spinal Diseases; Bone Diseases; Musculoskeletal Diseases; Hernia; Pathological Conditions, Anatomical; Pathological Conditions, Signs and Symptoms

Study Officials

• Lingjiang Li, Attending physician

  Xi'an Honghui Hospital, Xi'an, Shaanxi Province, China

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Lingjiang Li, Attending physician

CONTACT

+86 29-83661911; lilingjiang11@126.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Masking Details: Blinding design was adopted for bias control. Both participants and independent outcome assessors remained fully blinded during diagnostic SINRB evaluation. Neither subjects nor assessors knew whether each injection targeted the suspected symptomatic responsible nerve root or a non-responsible nerve root. Participants were only informed of the predefined clinical rule: once complete pain relief was achieved following a single SINRB, subsequent blocking procedures would be discontinued. In addition, an injection may also be administered to non-responsible nerve roots to serve as a negative control, and participants would remain unaware of whether the responsible or non-responsible nerve root was injected first. Independent assessors performed clinical evaluations before and after each SINRB using separately recorded video footage. The order of video files was randomized to ensure that assessors remained unaware of how many SINRB procedures each participant had undergone.
• Purpose: DIAGNOSTIC
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Attending Physician

Model Details: 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.

Study Record Dates

• First Submitted: April 5, 2026
• First Posted: April 15, 2026
• Study Start: April 13, 2026
• Primary Completion (Estimated): December 1, 2026
• Study Completion (Estimated): January 1, 2027
• Last Updated: April 15, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will not share

Locations

CN (1)