Contrast-free dynamic susceptibility contrast using sinusoidal and bolus oxygenation challenges.

Deoxygenation-based dynamic susceptibility contrast (dDSC) MRI uses respiratory challenges as a source of endogenous contrast as an alternative to gadolinium injection. These gas challenges induce T2*-weighted MRI signal losses, after which tracer kinetics modeling was applied to calculate cerebral perfusion. This work compares three gas challenges, desaturation (transient hypoxia), resaturation (transient normoxia), and SineO2 (sinusoidal modulation of end-tidal oxygen pressures) in a cohort of 10 healthy volunteers (age 37 ± 11 years; 60% female). Perfusion estimates consisted of cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT). Calculations were computed using a traditional tracer kinetics model in the time domain for desaturation and resaturation and in the frequency domain for SineO2. High correlations and limits of agreement were observed among the three deoxygenation-based paradigms for CBV, although MTT and CBF estimates varied with the hypoxic stimulus. Cross-modality correlation with gadolinium DSC was lower, particularly for MTT, but on a par with agreement between the other perfusion references. Overall, this work demonstrated the feasibility and reliability of oxygen respiratory challenges to measure brain perfusion. Additional work is needed to assess the utility of dDSC in the diagnostic evaluation of various pathologies such as ischemic strokes, brain tumors, and neurodegenerative diseases.

Safety, Efficacy, and Durability of Outcomes: Results from SECURE: A Single Arm, Multicenter, Prospective, Clinical Study on a Minimally Invasive Posterior Sacroiliac Fusion Allograft Implant.

Introduction: Research suggests that sacroiliac joint (SIJ) dysfunction is responsible for 15% to 30% of reported low back pain cases. Recently, there has been an increasing interest in SIJ fusion using minimally invasive surgery (MIS) due to safety. Initially, devices designed for MIS were intended for lateral approaches. A minimally invasive sacroiliac fusion implant for use with a posterior approach has been developed and is regulated for clinical use under the regulatory framework required for human cells, tissues, or cellular or tissue-based products (HCT/Ps). Methods: A multi-center, prospective, single-arm study was launched after initial studies provided preliminary data to support safety, efficacy, and durability of this minimally invasive sacroiliac posterior fusion LinQ allograft implant (NCT04423120). Preliminary results were reported previously. Final results for the full participant cohort are presented here. Results: One-hundred and fifty-nine (159) participants were enrolled across 16 investigational sites in the US between January 2020 and March 2022. One-hundred and twenty-two (122) participants were implanted. At the 1-month follow-up, 82 participants satisfied all criteria for the composite responder endpoint, representing 73.2% of the study cohort. These results stayed consistent across the remaining study timepoints with 66.0%, 74.4%, and 73.5% of participants classified as responders at the 3-, 6- and 12-month follow-up visits, respectively. VAS scores were significantly reduced (p < 0.0001) and ODI scores were significantly improved (p < 0.0001). All domains of the PROMIS-29 were also significantly improved (all p's <0.0001). Only one procedure-related serious AE was reported in the study. Conclusion: These results suggest that the posterior approach LinQ Implant System is a safe and effective treatment for sacroiliac joint dysfunction at 12 months, with results that are favorable compared to outcomes reported for an FDA-cleared lateral approach.

Pacific Spine and Pain Society (PSPS) Evidence Review of Surgical Treatments for Lumbar Degenerative Spinal Disease: A Narrative Review.

INTRODUCTION: Interventional treatment options for the lumbar degenerative spine have undergone a significant amount of innovation over the last decade. As new technologies emerge, along with the surgical specialty expansion, there is no manuscript that utilizes a review of surgical treatments with evidence rankings from multiple specialties, namely, the interventional pain and spine communities. Through the Pacific Spine and Pain Society (PSPS), the purpose of this manuscript is to provide a balanced evidence review of available surgical treatments. METHODS: The PSPS Research Committee created a working group that performed a comprehensive literature search on available surgical technologies for the treatment of the degenerative spine, utilizing the ranking assessment based on USPSTF (United States Preventative Services Taskforce) and NASS (North American Spine Society) criteria. RESULTS: The surgical treatments were separated based on disease process, including treatments for degenerative disc disease, spondylolisthesis, and spinal stenosis. CONCLUSIONS: There is emerging and significant evidence to support multiple approaches to treat the symptomatic lumbar degenerative spine. As new technologies become available, training, education, credentialing, and peer review are essential for optimizing patient safety and successful outcomes.

Identifying SCS Trial Responders Immediately After Postoperative Programming with ECAP Dose-Controlled Closed-Loop Therapy.

INTRODUCTION: Drawbacks of fixed-output spinal cord stimulation (SCS) screening trials may lead to compromised trial outcomes and poor predictability of long-term success. Evoked compound action potential (ECAP) dose-controlled closed-loop (CL) SCS allows objective confirmation of therapeutic neural activation and pulse-to-pulse stimulation adjustment. We report on the immediate patient-reported and neurophysiologic treatment response post-physiologic CL-SCS and feasibility of early SCS trial responder prediction. METHODS: Patient-reported pain relief, functional improvement, and willingness to proceed to permanent implant were compared between the day of the trial procedure (Day 0) and end of trial (EOT) for 132 participants in the ECAP Study undergoing a trial stimulation period. ECAP-based neurophysiologic measurements from Day 0 and EOT were compared between responder groups. RESULTS: A high positive predictive value (PPV) was achieved with 98.4% (60/61) of patients successful on the Day 0 evaluation also responding at EOT. The false-positive rate (FPR) was 5.6% (1/18). ECAP-based neurophysiologic measures were not different between patients who passed all Day 0 success criteria ("Day 0 successes") and those who did not ("needed longer to evaluate the therapy"). However, at EOT, responders had higher therapeutic usage and dose levels compared to non-responders. CONCLUSIONS: The high PPV and low FPR of the Day 0 evaluation provide confidence in predicting trial outcomes as early as the day of the procedure. Day 0 trials may be beneficial for reducing patient burden and complication rates associated with extended trials. ECAP dose-controlled CL-SCS therapy may provide objective data and rapid-onset pain relief to improve prognostic ability of SCS trials in predicting outcomes. TRIAL REGISTRATION: The ECAP Study is registered with ClinicalTrials.gov (NCT04319887).