UPAL Gel Implantation for Lumbar Discectomy

Both pre-operative and surgical inclusion/exclusion criteria have been established for this trial. Specifically, the study will recruit participants with symptomatic herniated NP unresponsive to nonoperative care and considered candidates for nerve decompression and surgical excision of the herniated lumbar IVD fragments [1 (link)]. Clinical signs and symptoms, as well as magnetic resonance imaging (MRI) findings must corroborate the diagnosis of lumbar IVD herniation. Patients with previous lumbar surgery will not be considered for this trial. Furthermore, only patients who receive single-level discectomy will be considered eligible to receive UPAL gel implantation.
Upon completion of standard discectomy, the treating surgeon will assess the feasibility of AF re-approximation and make the final decision whether the patient will receive UPAL gel implantation and be officially enrolled in the study [1 (link)]. The complete inclusion/exclusion criteria are as follows [1 (link)].
Inclusion criteria.i.

Candidate for lumbar discectomy.

ii.

Radiographic findings corroborating symptoms of IVD herniation.

iii.

Condition unresponsive to 6 consecutive weeks of therapy or experiencing acute/uncontrolled leg pain, defined as a score >80 on the 100-mm visual analog scale (VAS), in which higher scores representing worse pain correspond to worse pain.

iv.

Single-level lumbar IVD herniation.

v.

Persistent and predominant leg pain (score >40 on the 100-mm VAS)

vi.

Age between 20 and 49 years (inclusively).

vii.

Willingness to provide written informed consent, fill in all necessary questionnaires, and return for follow-up.

Exclusion criteria.i.

Previous surgery involving a lumbar level.

ii.

Prior or planned spinal fusion involving a lumbar level.

iii.

Local kyphosis involving the affected disc level, evident on plain radiography of the lumbar spine in the flexion, neutral or extension position.

iv.

Spondylolisthesis or retrolisthesis above grade 1 at the affected level.

v.

Cauda equina syndrome.

vi.

Acute local or systemic infection.

vii.

Active malignancy or other similar comorbidities.

viii.

Current drug or alcohol dependency.

ix.

Current significant emotional disturbance.

x.

Current fracture, tumour, and/or deformity of the lumbar spine.

xi.

Current or planned pregnancy.

xii.

Currently enrolled in other research that could confound the results of the present trial.

xiii.

Presence of a metal implant or any other contraindication to MRI.

xiv.

Allergy to sodium alginate revealed upon skin prick testing.

xv.

Any other reason judged by an investigator or clinical trial doctor to render the candidate unsuitable for this clinical trial.

Eligible candidates will be treated at the Hokkaido University Hospital in Sapporo, Japan, or at Eniwa Hospital in Eniwa, Japan, depending on where the referring orthopaedic surgeons have formal accreditation. The treatment will include discectomy followed by UPAL gel implantation. The discectomy procedure is part of the accepted standard treatment of each participant but is not part of the present study. The discectomies will be performed by the referring surgeons and will not be performed by a single surgeon.