Transforaminal lumbar puncture for intrathecal nusinersen administration

Transverse interlaminar ultrasound-guided C1-C2 puncture for the intrathecal administration of nusinersen in patients with spinal muscular atrophy

INTRODUCTION/AIMS

Severe spinal deformities and previous spinal orthopedic instrumentation may result in substantial technical challenges for nusinersen delivery through lumbar puncture in patients with spinal muscular atrophy (SMA). The aim of this paper was to review our experience with ultrasound-guided cervical puncture as an alternative approach for the intrathecal administration of nusinersen.

METHODS

This was a retrospective medical record review of transverse interlaminar ultrasound-guided C1-C2 puncture for nusinersen delivery in SMA patients. The details of puncture, complications, and success rate of the procedure were summarized.

RESULTS

There were four patients who received a total of 13 cervical punctures for nusinersen delivery. All procedures were technically successful with no major complications. Full doses of nusinersen were delivered intrathecally.

DISCUSSION

Transverse interlaminar ultrasound-guided C1-C2 puncture is an alternative approach for administering nusinersen if lumbar puncture fails. The success of the technique requires a thorough preprocedural evaluation of cervical spine imaging, sound knowledge of the cervical sonoanatomy and careful manipulation of the needle.

Clinical perspectives: Treating spinal muscular atrophy

Spinal muscular atrophy is a rare and progressive neuromuscular disease that, without treatment, leads to progressive weakness and often death. A plethora of studies have led to the approval of three high-cost and effective treatments since 2016. These treatments, nusinersen, onasemnogene abeparvovec, and risdiplam, have not been directly compared and have varying challenges in administration. In this review, we discuss the evidence supporting the use of these medications, the process of treatment selection, monitoring after treatment, the limited data comparing treatments, as well as future directions for investigation and therapy.

Feasibility of intrathecal therapeutic injections in spinal muscular atrophy patients via a percutaneous transsacral hiatus route: An initial neuroimaging morphometric study

INTRODUCTION/AIMS

Standard fluoroscopic lumbar puncture (LP) can be impossible in patients with severe spinal deformities from spinal muscular atrophy (SMA) who require intrathecal nusinersen therapy. There usually exists a straight trajectory in the lower sacral canal (SC) that could allow image-guided percutaneous transsacral hiatus puncture of the lumbosacral dural sac. In this study we determine whether sacra are comparatively straighter in SMA patients (SMAps) vs healthy controls (HCs), which may facilitate unhindered transsacral hiatus spinal needle insertion for intrathecal nusinersen therapy.

METHODS

We retrospectively analyzed lumbosacral spine computed tomograms (CTs) or CT-myelogram images of 38 SMAps and age- and sex-matched HCs. We digitally measured ventrodorsal sacral curvatures, SC surface areas, dural sac termination levels, and distances from sacral hiatus to the most caudad aspects of dural sacs ("needle distance").

RESULTS

Mean ages of HCs and SMAps were 32.7 and 31.7 years, respectively, with dural sacs terminating at similar levels. Mean values for morphometrics were: (a) midsagittal SC surface area for HCs = 701.2 mm² , and for SMAps = 601.5 mm² (not statistically significant [ns]); (b) using a "line method," sacral curvature for HCs = 61.9°, and SMAp = 35.7° (P = .0009), and was similar when using an "angle summation method"; (c) width of sacral hiatus for HCs = 14.9 mm, and SMAps = 15.0 mm (ns); and (d) "needle distance" for HCs = 54.7 mm, and SMAps = 49.9 mm (ns).

DISCUSSION

SMAps have significantly straighter sacra compared with HCs, which theoretically renders them more amenable to percutaneous transsacral hiatus puncture of the dural sac.

Scoliosis Orthopedic Surgery Combined With Nusinersen Intrathecal Injection Significantly Improved the Outcome of Spinal Muscular Atrophy Patient: A Case Report

Background

Spinal muscular atrophy (SMA) is an autosomal recessive disorder caused by pathogenic variation of the survival motor neuron (SMN) 1 gene. Symptoms of SMA include progressive limb muscle weakness, atrophy, and severe scoliosis. Nusinersen is an antisense oligonucleotide that can enhance the production of the SMN protein. Here, we report a case with scoliosis who received orthopedic surgery combined with Nusinersen intrathecal injections.

Case Presentation

Scoliosis orthopedic surgery followed by Nusinersen intrathecal injections was given to a 16-year-old girl who had thoracic and lumbar scoliosis and type 3 SMA. Surgery was performed for T3-S2 posterolateral fusion (PLF), with a channel left on the vertebral laminae of L3-L4. The balance of the spine and pelvis was significantly improved and the height increased by 9 cm. Lumbar puncture was conducted with local anesthesia under ultrasound and CT guidance through the laminae channel and Nusinersen was successfully injected. Comparing the two approaches, real-time ultrasound guidance for intrathecal Nusinersen injections after spinal surgery is preferred, however, CT guidance is an alternative if the initial puncture procedure is difficult. After the aforementioned multidisciplinary treatment, a good outcome was achieved, as demonstrated by a 2-point increase in RULM and MFM32 scores 2 months later.

Conclusion

Scoliosis orthopedic surgery combined with Nusinersen intrathecal injection is an effective treatment for SMA patients with scoliosis.

Ultrasound-guided nusinersen administration for spinal muscular atrophy patients with severe scoliosis: an observational study

BACKGROUND

This observational study describes our experience delivering nusinersen through lumbar puncture with real-time ultrasound guidance in spinal muscular atrophy (SMA) patients with severe scoliosis.

RESULTS

Intrathecal nusinersen via real-time ultrasound-guided lumbar puncture was given to three patients who had severe thoracic and lumbar scoliosis: a 34-year-old female with type 3a SMA, a 28-year-old male with type 2a SMA, and a 14-year-old girl with type 3a SMA. Lumbar puncture was performed without sedation under ultrasound guidance using a 22G echogenic needle in the interlaminar aspect of the L4-L5 or L5-S1 interspace and a full dose of nusinersen (12 mg/5 mL) was injected after visualizing free cerebrospinal fluid flow. Patients completed their four loading doses and one maintenance dose of nusinersen. All 15 procedures were successful and well tolerated.

CONCLUSIONS

Real-time ultrasound-guided lumbar puncture is an effective and radiation-free technique to administer intrathecal nusinersen in SMA patients with severe scoliosis when done by practitioners with expertise in this procedure.

A Systematic Review of Procedural Complications from Transforaminal Lumbar Puncture for Intrathecal Nusinersen Administration in Patients with Spinal Muscular Atrophy

BACKGROUND

Spinal muscular atrophy is a progressive neurodegenerative disorder that can be treated with intrathecal antisense oligonucleotide therapy (nusinersen). However, administration is often complicated by posterior spinal fusion and neuromuscular scoliosis, necessitating a transforaminal approach.

PURPOSE

To assess the safety profile of the transforaminal approach for intrathecal access.

DATA SOURCES

Searches of the PubMed, Web of Science, and SCOPUS databases.

STUDY SELECTION

Thirteen articles were selected based on inclusion of transforaminal access and appropriate clinical information about the procedure.

DATA ANALYSIS

Complications were taken from the included articles and aggregated based on Cardiovascular and Interventional Radiological Society of Europe scale adverse event grading.

DATA SYNTHESIS

Total number of complications and grade of complications were analyzed, by year and in total.

LIMITATIONS

Selection bias in publication, small patient population size, and variability of the procedure limits the available data.

CONCLUSIONS

Transforaminal approach is a safe alternative for intrathecal access in patients with spinal muscular atrophy and may be applicable to a larger patient population.

Posterior Spinal Correction and Fusion Surgery in Patients with Spinal Muscular Atrophy-Associated Scoliosis for Whom Treatment with Nusinersen Was Planned

INTRODUCTION

Spinal muscular atrophy (SMA) is defined as a neuromuscular disorder induced by progressive weakness of the skeletal muscle and is usually accompanied by progressive spinal deformity including scoliosis. The newly developed Nusinersen, which is the first approved drug worldwide for SMA, requires accurate intrathecal injection, which is sometimes difficult in patients with severe spinal deformity.

TECHNICAL NOTE

For an accurate intrathecal approach in patients who have spinal fusion surgery to treat neuromuscular scoliosis, we have combined an L3 laminectomy with spinal correction and fusion surgery. Here, we review four cases of SMA in patients who underwent the additional L3 laminectomy during surgery to treat spinal scoliosis. A successful intrathecal approach was made using fluoroscopic guidance in all four patients, who were then administered with Nusinersen.

CONCLUSIONS

Our findings show that additional lumbar laminectomy during surgery for spinal scoliosis has effectively allowed for intrathecal injection of Nusinersen.

Computed-tomography-guided transforaminal intrathecal nusinersen injection in adults with spinal muscular atrophy type 2 and severe spinal deformity. Feasibility, safety and radiation exposure considerations

BACKGROUND AND PURPOSE

The purpose was to investigate our centre's experience on computed-tomography-guided (CT-guided), transforaminal, intrathecal administration of nusinersen in adult subjects with spinal muscular atrophy (SMA) type 2 and severe spinal deformity.

METHOD

This is a retrospective, single-centre study investigating the feasibility and safety of CT-guided, transforaminal, lumbar puncture for the intrathecal administration of nusinersen (Spinranza®; Biogen; Cambridge, MA, USA) in a cohort of adult subjects with SMA type 2, severe neuromuscular scoliosis and previous spinal surgery. Between January 2019 and October 2019, five male, adult, SMA type 2 subjects were eligible to be treated in our centre with nusinersen. The mean age of the patients was 31 ± 9 years (range 19-43 years). The study's outcome measures were technical success, adverse events and radiation exposure.

RESULTS

In total, four patients completed the four loading doses, whilst the fifth patient received only one loading dose; two patients also received their first maintenance doses. Overall, 20 consecutive transforaminal, intrathecal treatments were analysed. Technical success was 100% (20/20 intrathecal infusions). No adverse events were documented following the procedures. Mean dose-length product (DLP) value per injection was 665.4 ± 715.5 mGy*cm. Estimated mean effective dose per injection was 12.7 ± 12.9 mSv. Subgroup analysis between the chronologically first 10 versus subsequent 10 procedures demonstrated a clear trend towards less radiation exposure in the latter, although this difference did not reach statistical significance (DLP: 984.7 ± 903.3 vs. 436.7 ± 321.5 mGy*cm, P = 0.165; respectively).

CONCLUSIONS

In this retrospective series, CT-guided transforaminal access for intrathecal injection of nusinersen was proven feasible and safe. A decrease in radiation dose over time was noted. Protocols to minimize radiation exposure are essential.

Transforaminal intrathecal delivery of nusinersen for older children and adults with spinal muscular atrophy and complex spinal anatomy: an analysis of 200 consecutive injections

BACKGROUND

Nusinersen is the only approved treatment for all spinal muscular atrophy (SMA) subtypes and is delivered intrathecally. Distorted spinal anatomy and instrumentation preclude standard approaches for intrathecal access, necessitating alternative techniques for delivery. The purpose of this study is to report technical success and adverse events of transforaminal intrathecal delivery of nusinersen.

METHODS

28 patients, mean age 24.1±9.8 years (range 10.0-51.0 years), with intermediate or late onset SMA, underwent a combined 200 transforaminal nusinersen injections. All patients had osseous fusion or spinal instrumentation precluding standard posterior access routes. Patients who underwent nusinersen injections using a technique other than transforaminal lumbar puncture (n=113) were excluded. Technical success, adverse events (AEs) and radiation exposure were recorded.

RESULTS

200 (100%) procedures were technically successful; 6 (3%) required a second level of attempt for access. 187 (93.5%) interventions were completed using cone beam computed tomography (CBCT) with two-axis fluoroscopic navigational overlay. 13 (6.5%) procedures were performed with fluoroscopic-guidance only at subsequent sessions. There were 8 (4.0%) mild AEs and 2 (0.5%) severe AEs; one patient received antibiotics for possible traversal of the large bowel but did not develop meningitis, and one patient developed aseptic meningitis. Mean air kerma was 74.5±161.3 mGy (range 5.2-1693.0 mGy).

CONCLUSION

Transforaminal intrathecal delivery of nusinersen is feasible and safe for gaining access in patients with distorted spinal anatomy. The use of CBCT delineates anatomy and optimizes needle trajectory during the initial encounter, and may be used selectively for subsequent procedures.

Transforaminal lumbar puncture for intrathecal access: Case series with literature review and comparison to other techniques

Fluoroscopic-guided lumbar puncture (LP) is a procedure commonly performed by radiologists, which in some circumstances may be difficult or impossible using a traditional posterior interspinous or interlaminar approach. Alternatives to LP include cervical and cisternal punctures, placement of an Ommaya reservoir, and lumbar laminectomy. More recently, however, there has been a move toward access of the thecal sac through a transforaminal approach in patients with challenging anatomy. This report outlines our approach and experience using transforaminal LP (TFLP) in patients with spinal muscular atrophy (SMA) with a 100% success rate. We discuss its utility in other patients with difficult access and compare TFLP with other techniques to access the intrathecal space.

Intrathecal nusinersen administration in adult spinal muscular atrophy patients with complex spinal anatomy

Background:

Intrathecal administration of nusinersen in adult spinal muscular atrophy (SMA) patients presents challenges owing to severe scoliosis and previous spinal surgery with metal implantation. In patients with a complex spinal situation, the potential risks of the intrathecal administration may lead to delayed treatment initiation.

Methods:

In this study, we analyzed 53 CT-guided lumbar punctures of 11 adult nonambulatory SMA type 2 and 3 patients. All patients had scoliosis and six patients had previously undergone metal implantation.

Results:

Drug administration was successful in 100% of the patients and none of the patients opted for treatment discontinuation. Complete osseous fusion precluded conventional posterior interlaminar access in eight lumbar punctures in four patients, which required alternative routes including transforaminal punctures and translaminar drilling. Median duration of all lumbar punctures was 9 min and median radiation exposure was 100 mGy* cm. The most common adverse event was post-lumbar puncture syndrome that occurred in five lumbar punctures (9.4%).

Conclusions:

Our data demonstrate that nusinersen can be successfully, safely, and rapidly administered in adult SMA patients with complex spinal conditions and suggest the translaminar drilling technique as an alternative delivery route. Therefore, intrathecal nusinersen treatment should not be withheld from patients because of severe spine deformities, however, drug efficacy in adult SMA patients needs to be investigated in further studies.

Simple Fluoroscopy-Guided Transforaminal Lumbar Puncture: Safety and Effectiveness of a Coaxial Curved-Needle Technique in Patients with Spinal Muscular Atrophy and Complex Spines

Patients with spinal muscular atrophy often have complete interlaminar osseous fusion, precluding lumbar puncture via the standard interlaminar approach. Recently, we have developed a new coaxial curved-needle variation of fluoroscopy-guided transforaminal lumbar puncture for intrathecal injections in this patient population. Between October 2017 and November 2018, fifty-nine consecutive transforaminal lumbar punctures using this technique were performed in 12 patients with spinal muscular atrophy for intrathecal nusinersen injection, with a 100% technical success rate and no C1-2 punctures required. One major complication occurred, consisting of a post-dural puncture headache, which required a therapeutic transforaminal epidural blood patch. Two minor complications occurred, both of which involved inadvertent puncture of a dorsal muscular arterial branch, without clinical sequelae. A fluoroscopy-guided curved-needle transforaminal approach is an effective technique for lumbar puncture in difficult cases, such as in this cohort of patients with spinal muscular atrophy and complete interlaminar osseous fusion undergoing intrathecal nusinersen injections.

Intrathecal administration of nusinersen in adult and adolescent patients with spinal muscular atrophy and scoliosis: Transforaminal versus conventional approach

Spinal deformities and surgical correction of scoliosis can make intrathecal delivery of nusinersen very challenging. We aim to evaluate the feasibility and safety of intrathecal administration of nusinersen either via interlaminar or transforaminal approach in a cohort of adult and adolescent patients with spinal muscular atrophy (SMA). Twelve patients were treated with nusinersen in our center under CT-guidance; after a CT scan of the lumbar column, we identified a safe virtual trajectory for the needle and defined patients to address to the transforaminal approach (seven patients) or the interlaminar approach (five patients). Out of 47 procedures, all injections but one were successful. There was one adverse event (post-lumbar puncture syndrome) in the interlaminar approach group (out of 20 procedures) and four adverse events in TFA group (out of 27 procedures) including one serious adverse event, a subarachnoid hemorrhage that required hospitalization. Transforaminal approach can be considered an effective option for nusinersen administration but potentially associated with serious complications, therefore it should be recommended in very selected patients.

Nusinersen treatment of spinal muscular atrophy: current knowledge and existing gaps

Spinal muscular atrophy (SMA) is a recessive disorder caused by a mutation in the survival motor neuron 1 gene (SMN1); it affects 1 in 11 000 newborn infants. The most severe and most common form, type 1 SMA, is associated with early mortality in most cases and severe disability in survivors. Nusinersen, an antisense oligonucleotide, promotes production of full-length protein from the pseudogene SMN2. Nusinersen treatment prolongs survival of patients with type 1 SMA and allows motor milestone acquisition. Patients with type 2 SMA also show progress on different motor scales after nusinersen treatment. Nusinersen was recently approved by the European Medicines Agency and the US Food and Drug Administration; it is now reimbursed in several European countries and in the USA. In Australia, the transition from expanded access programme to commercial availability is coming soon. In New Zealand, an expanded access programme is opened, and in Canada price negotiation for the treatment is in progress. In this review we exemplify the clinical benefit of nusinersen in subgroups of patients with SMA. Nusinersen represents the first efficacious marked approved drug in type 1 and type 2 SMA. Different knowledge gaps, such as results in older patients, in patients with permanent ventilation, in patients with neonatal forms, or in patients after spinal fusion, still need to be addressed. WHAT THIS PAPER ADDS: Identifies gaps in knowledge about the efficacy of nusinersen in broader populations of patients with spinal muscular atrophy. Identifies open questions in populations of patients where proof of efficacy is available.

Intrathecal administration of nusinersen in adolescent and adult SMA type 2 and 3 patients

Spinal muscular atrophy is a genetic motor neuron disease that leads to progressive muscular atrophy and muscle weakness. In December 2016, the Food and Drug Administration, and in June 2017, the European Medicines Agency approved the antisense oligonucleotide nusinersen for treatment of spinal muscular atrophy. Nusinersen has to be repeatedly administered intrathecally. Due to the clinical features of SMA, the application of the ASO by lumbar puncture can be challenging in symptomatic patients considering the frequently observed scoliosis, previous spine fusion surgeries, joint contractures, and respiratory insufficiency. To evaluate safety and feasibility of the intrathecal treatment in adolescent and adult SMA type 2 and 3 patients, we analyzed 93 lumbar punctures, monitored number of lumbar puncture attempts, duration of the procedure, injection site, and needle length. Oxygen saturation during the intervention, medication for sedation and local anesthesia, adverse events related to lumbar punctures, and macroscopic analysis of CSF were recorded. Moreover, we analyzed the use of CT-scans for performing lumbar punctures and its associated radiation exposure. Performing lumbar puncture for the intrathecal administration of nusinersen in adolescent and adult patients with later-onset SMA is feasible and safe, even in patients with complex spinal anatomies and respiratory insufficiency. To guarantee the quality of the procedure, we recommend establishing an experienced interdisciplinary team consisting of neurologists and/or neuropediatricians, anesthesiologists, orthopedic surgeons, and/or neuroradiologists.

C1 Posterior Arch Flare Point: A Useful Landmark for Fluoroscopically Guided C1-2 Puncture

BACKGROUND AND PURPOSE

The C1-2 intrathecal puncture is routinely performed when lumbar puncture is not feasible. Usage has steadily decreased in part because of the perceived high risk of injury to the cervical cord. Up to this point, vague fluoroscopic guidelines have been used, creating uncertainty about the actual needle location relative to the spinal cord. We present a novel osseous landmark to aid in C1-2 intrathecal puncture, corresponding to the posterior spinal cord margin on lateral fluoroscopic views. This landmark, which we have termed the "flare point," represents the triangular "flaring" of the posterior C1 arch at its junction with the anterior arch.

MATERIALS AND METHODS

Cervical spine CT myelograms were reviewed. High-resolution axial images were reformatted into the sagittal plane, and maximum-intensity-projection images were created to simulate a lateral fluoroscopic view. Tangential lines were drawn along the superior cortices of the anterior and posterior C1 arches, with the point of intersection used to approximate the flare point. Chart review was performed for all C1-2 punctures using the flare point technique in the past 3 years.

RESULTS

Forty-two cervical myelograms were reviewed. The average flare point was 0.2 ± 0.5 mm posterior to the dorsal spinal cord margin. In 37/42 subjects, the flare point was localized posterior to the spinal cord. Targeting by means of the flare point was used in 16 C1-2 punctures without complications.

CONCLUSIONS

The C1 posterior arch flare point accurately approximates the dorsal spinal cord margin on myelography. Targeting between the flare point and the spinolaminar line, at the mid-C1-2 interspace, allows safe and optimal needle positioning.