Prospective Within Subject Comparison of Fluoroscopically Guided Lumbosacral Facet Joint Radiofrequency Ablation Using a Multi-Tined (Trident) Versus Conventional Monopolar Cannula.

BACKGROUND: Radiofrequency ablation (RFA) for the lumbar facet joints has demonstrated efficacy in the management of chronic low back pain. The traditional technique uses a conventional monopolar (CM) cannula placed parallel to the putative nerve to produce a thermal lesion resulting in pain relief of the facet joints. A new multi-tined (MT) cannula has come onto the market that allows targeting the putative nerve using a perpendicular to the nerve approach. OBJECTIVES: This study describes the technique using the MT cannula and compares its efficacy and procedural characteristics to the CM cannula. STUDY DESIGN: This is a pre-post crossover observational study. METHODS: Fifty-one patients were recruited between June 2015 and March 2020. Each patient underwent 2 fluoroscopic guided lumbosacral RFA procedures on 2 separate occasions at the same facet joints, using the CM and MT cannula consecutively. The primary outcome measure was change in pain on the 11-point numeric rating scale (NRS). Secondary outcome measures included change in Pain Disability Quality of Life Questionnaire (PDQQ) score, duration and magnitude of pain relief, local anesthetic use, adverse events, procedural and fluoroscopy exposure time, and radiation dose. RESULTS: There were no statistically significant difference between CM versus MT canula in terms of absolute (4.0 versus 4.3) and relative (52% versus 57%) change in NRS (P = 0.99) and PDQQ (22 versus 22, P = 0.61) at 3 months, or overall pain magnitude (71% versus 72%, P = 0.96) and duration of relief (8.7 months versus 8.4 months, P = 0.68). The procedures using the MT cannula were completed faster (37.6 minutes versus 31.1 minutes, P < 0.001) and required less local anesthetic (15.8 mL versus 11.0 mL, P < 0.001) and radiation dose (41.5 mGy versus 30.2 mGy, P = 0.05). No adverse events were observed with either cannula. LIMITATIONS: This was an observational study at a single center with the proceduralist not blinded to the intervention. CONCLUSION: This study demonstrated that the outcomes in terms of pain, disability, quality of life, adverse events, and fluoroscopy exposure time were equivalent between the 2 cannulae. However, RFA using the MT cannula was faster to perform and involved less local anesthetic and radiation.

Alternative splicing of the first intron of the steroid receptor RNA activator (SRA) participates in the generation of coding and noncoding RNA isoforms in breast cancer cell lines.

The Steroid Receptor RNA Activator 1 (SRA1) has originally been described as a noncoding RNA specifically activating steroid receptor transcriptional activity. We have, however, identified, in human breast tissue, exon- 1 extended SRA1 isoforms containing two initiating AUG codons and encoding a protein we called SRAP. We recently reported a decreased estrogen receptor activity in breast cancer cells overexpressing SRAP, suggesting antagonist roles played by SRA1 RNA and SRAP. SRA1 appears to be the first example of a molecule active both at the RNA and at the protein level. No data are currently available regarding the mechanisms possibly involved in the generation of coding and noncoding functional SRA1 RNAs. Using 5'-Rapid Amplification of cDNA Extremities (5'-RACE), we have herein identified several putative transcription initiation sites surrounding the second methionine codon and used to generate coding SRA1 transcripts. In the process, we also identified an alternatively spliced noncoding SRA1 transcript still containing an intron-1 sequence. Using targeted RT-PCR approaches, we confirmed the presence in breast cancer cell lines of SRA1 RNAs containing a full as well as a partial intron-1 sequence and established that the relative proportion of these RNAs varied within breast cancer cell lines. Using a "minigene" strategy, we also showed that artificial RNAs containing the SRA1 intron-1 sequence are alternatively spliced in breast cancer cell lines. Interestingly, the splicing pattern of the minigene products parallels the one of the endogenous SRA1 transcripts. Altogether, our data suggest that the primary genomic sequence in and around intron-1 is sufficient to lead to a differential splicing of this intron. We propose that alternative splicing of intron-1 is one mechanism used by breast cancer cells to regulate the balance between coding and functional noncoding SRA1 RNAs.