Ultrasound-assisted intrathecal injection of nusinersen in a patient with severe vertebral deformity: a case report

A horizontal and perpendicular interlaminar approach for intrathecal nusinersen injection in patients with spinal muscular atrophy and scoliosis: an observational study

BACKGROUND

Lumbar puncture is challenging for patients with scoliosis. Previous ultrasound-assisted techniques for lumbar puncture used the angle of the probe as the needle trajectory; however, reproducing the angle is difficult and increases the number of needle manipulations. In response, we developed a technique that eliminated both the craniocaudal and lateromedial angulation of the needle trajectory to overall improve this technique. We assessed the feasibility and safety of this method in patients with scoliosis and identify factors related to difficult lumbar puncture.

METHODS

Patients with spinal muscular atrophy and scoliosis who were referred to the anesthesia department for intrathecal nusinersen administrations were included. With a novel approach that utilized patient position and geometry, lumbar puncture was performed under ultrasound guidance. Success rates, performance times and adverse events were recorded. Clinical-demographic and spinal radiographic data pertaining to difficult procedures were analyzed.

RESULTS

Success was achieved in all 260 (100%) lumbar punctures for 44 patients, with first pass and first attempt success rates of 70% (183/260) and 87% (226/260), respectively. Adverse events were infrequent and benign. Higher BMI, greater skin dural sac depth and smaller interlaminar size might be associated with greater difficulty in lumbar puncture.

CONCLUSIONS

The novel ultrasound-assisted horizontal and perpendicular interlaminar needle trajectory approach is an effective and safe method for lumbar puncture in patients with spinal deformities. This method can be reliably performed at the bedside and avoids other more typical and complex imaging such as computed tomography guided procedure.

Ultrasound-guided interlaminar approach for nusinersen administration in patients with spinal muscular atrophy with spinal fusion or severe scoliosis

BACKGROUND

Intrathecal injection of medications can be challenging in spinal muscular atrophy (SMA) patients with severe scoliosis or after spine surgery. Here we report our experience with real-time ultrasound (US)-guided intrathecal administration of nusinersen in patients with SMA.

METHODS

Seven patients (six children and one adult) with either spinal fusion or severe scoliosis were enrolled. We performed intrathecal injections of nusinersen under US guidance. The efficacy and safety of US-guided injection were explored.

RESULTS

Five patients had undergone spinal fusion, while the other two presented severe scoliosis. Success was achieved in 19/20 lumbar punctures (95%), 15 of which were performed through the near-spinous process approach. The intervertebral space with a designated channel was selected for the five postoperative patients, while the interspaces with the smallest rotation angle were chosen for the other two patients with severe scoliosis. In 89.5% (17/19) of the punctures, the number of insertions was no more than two. No major adverse events were observed.

CONCLUSION

Given its safety and efficacy, real-time US guidance is recommended for SMA patients with spine surgery or severe scoliosis, and the near-spinous process view can be used as a interlaminar puncture approach for US guidance.

Clinical Pharmacokinetics of Approved RNA Therapeutics

RNA-mediated drugs are a rapidly growing class of therapeutics. Over the last five years, the list of FDA-approved RNA therapeutics has expanded owing to their unique targets and prolonged pharmacological effects. Their absorption, distribution, metabolism, and excretion (ADME) have important clinical im-plications, but their pharmacokinetic properties have not been fully understood. Most RNA therapeutics have structural modifications to prevent rapid elimination from the plasma and are administered intravenously or subcutaneously, with some exceptions, for effective distribution to target organs. Distribution of drugs into tissues depends on the addition of a moiety that can be transported to the target and RNA therapeutics show a low volume of distribution because of their molecular size and negatively-charged backbone. Nucleases metabolize RNA therapeutics to a shortened chain, but their metabolic ratio is relatively low. Therefore, most RNA therapeutics are excreted in their intact form. This review covers not only ADME features but also clinical pharmacology data of the RNA therapeutics such as drug-drug interaction or population pharmacokinetic analyses. As the market of RNA therapeutics is expected to rapidly expand, comprehensive knowledge will contribute to interpreting and evaluating the pharmacological properties.

Ultrasound assisted lumbar intrathecal administration of nusinersen in adult patients with spinal muscular atrophy: A case series

INTRODUCTION/AIMS

Intrathecal nusinersen administration can be challenging in certain adult spinal muscular atrophy (SMA) patients with difficult spinal anatomy who require imaging techniques (fluoroscopy or computed tomography scans) or invasive approaches (catheter placement, laminotomy) to identify the intrathecal space. We used ultrasound (US) assistance to access the lumbar intrathecal space in patients with SMA who experienced previous difficulties or failures with intrathecal dosing.

METHODS

Eighteen adult patients with difficult spines were enrolled. We used US assistance, and we recorded the successful administrations, number of attempts, procedure times, and "patient satisfaction."

RESULTS

There were 57 consecutive successful nusinersen spinal administrations in all patients enrolled. In 50% of patients, two or fewer attempts were needed to obtain a successful administration, with four or fewer attempts in 83.3%; only three patients reported more than four attempts because of both severe scoliosis and severe spine rotation (two patients) and obesity (one patient). The mean procedure time was 11.8 min (range, 1.7-28.9). Patient satisfaction was 4.97/5 (range, 4-5; median, 5) on Likert scale at 5 min and at 72 h. No major adverse events were reported, and two post dural puncture headaches were managed with medical therapy and with complete resolution within 72 h.

DISCUSSION

US assistance seems to be a valid option among treatment choices for intrathecal nusinersen administration in patients with difficult spine. The absence of radiation exposure and the lack of need for intravenous sedation or general anesthesia are additional potential advantages to US assisted administration.

Ultrasound-guided lumbar puncture for nusinersen administration in spinal muscular atrophy patients

BACKGROUND AND PURPOSE

The purpose was to report the results of ultrasound-guided lumbar puncture for the administration of nusinersen in spinal muscular atrophy (SMA) patients with complex spines.

METHODS

Eighteen SMA patients (five children, five adolescents and eight adults) with either severe scoliosis or spondylodesis were evaluated for ultrasound-guided lumbar puncture. Ultrasound was performed with a 3.5 MHz transducer to guide a 22 gauge × 15 mm needle, which was placed in the posterior lumbar space following a parasagittal interlaminar approach.

RESULTS

Twelve patients had undergone spinal instrumentation (nine growing rods and three spinal fusion) whilst the other six showed severe scoliosis. Success was achieved in 91/94 attempts (96.8%), in 14/18 patients (77.8%), including 100% of children and adolescents and 50% of adult patients. In two of the unsuccessfully treated patients, computed tomography and fluoroscopy-guided transforaminal lumbar punctures were also tried without success. After a median follow-up of 14 months, only few adverse events, mostly mild, were observed.

CONCLUSION

The ultrasound-guided lumbar puncture, following an interlaminar parasagittal approach, is a safe and effective approach for intrathecal treatment with nusinersen in children, adolescents and carefully selected adult SMA patients with complex spines and could be considered the first option in them.