Study compares two lumbar ESP block approaches in cats
Bottom line
A new cadaver study in Veterinary Sciences compared longitudinal and transverse ultrasound-guided approaches for lumbar erector spinae plane, or ESP, blocks in cats, adding to a still-small evidence base for feline locoregional anesthesia. The study builds on earlier feline work showing that a lumbar ESP block can be performed at the L2 level with a longitudinal approach and can stain dorsal branches of the spinal nerves across multiple segments, while related canine cadaver studies have suggested that approach selection may influence injectate spread and target coverage. (mdpi.com)
Why it matters: For veterinary professionals, the question isn't simply whether lumbar ESP blocks are feasible in cats, but which sonographic approach may offer more consistent needle visualization, safer execution, and more reliable spread when used as part of multimodal analgesia. Because the current evidence is cadaveric, these findings should be interpreted as an anatomical and technical guide rather than proof of clinical analgesic efficacy, but they can still help clinicians refine block selection for feline spine, flank, and dorsal body wall pain protocols. (mdpi.com)
What to watch: The next step is live-cat clinical work that tests whether one lumbar ESP approach delivers measurably better analgesia, opioid-sparing, or procedural ease in practice. (mdpi.com)
Key facts
- Study type
- Feline cadaver study
- Journal
- Veterinary Sciences
- Topic
- Longitudinal versus transverse ultrasound-guided lumbar erector spinae plane, or ESP, blocks
- Species
- Cats
- Focus
- Injectate distribution and staining of dorsal branches of the spinal nerves
- Evidence base
- Still small for feline locoregional anesthesia
- Prior feline finding
- Lumbar ESP block at L2 with a longitudinal approach
- Prior feline finding
- Average staining of five spinal segments
A new feline cadaver study in Veterinary Sciences takes a closer look at a practical question for regional anesthesia: whether longitudinal or transverse ultrasound-guided approaches perform differently for lumbar erector spinae plane blocks in cats. The paper focuses on injectate distribution and staining of the dorsal branches of the spinal nerves, an important anatomical proxy for whether the block is likely to cover the intended structures. (mdpi.com)
That question comes after a steady expansion of ESP block research in veterinary medicine. The technique was first described in human medicine in 2016, then adapted across species, with dogs receiving the most study to date. In cats, published work has been more limited, especially in the lumbar region. Earlier feline cadaver research described a lumbar ESP technique at L2 using a longitudinal approach and found spread across multiple spinal segments, while a recent case report described lumbar ESP block as part of multimodal analgesia in a polytraumatized cat. (mdpi.com)
The broader comparative backdrop comes mainly from canine work. A 2020 canine cadaver study evaluated two ultrasound-guided lumbar ESP approaches, and a later thoracic canine cadaver study directly compared transverse and longitudinal approaches, reflecting growing interest in how probe orientation and needle path may affect spread, visualization, and reproducibility. Those studies don't answer the feline question directly, but they help explain why a head-to-head comparison in cats is relevant now. (pubmed.ncbi.nlm.nih.gov)
What makes this study useful is that it addresses technique selection, not just feasibility. In fascial plane blocks, small differences in needle trajectory or transducer orientation can change whether injectate follows the intended plane, reaches adjacent segments, or remains too localized. Prior feline lumbar work suggested that the longitudinal approach can produce broad craniocaudal spread and stain an average of five spinal segments, which sets a benchmark for interpreting any new transverse-versus-longitudinal comparison. (mdpi.com)
Expert reaction specific to this new paper was limited in publicly indexed sources, but the surrounding literature points to cautious optimism rather than overreach. Reviews and cadaver studies consistently describe ESP block as a promising component of multimodal analgesia, while also noting that mechanism of action and clinical effect can vary by species, level, volume, and technique. In dogs undergoing hemilaminectomy, retrospective clinical data have suggested ESP block may support analgesia as part of a broader pain plan, but cadaveric spread still shouldn't be treated as a direct stand-in for patient outcome. (link.springer.com)
Why it matters: For veterinary teams, this is the kind of incremental methods paper that can still change practice at the margins. Feline regional anesthesia often advances through cadaver validation before clinical adoption, and approach comparisons can help anesthetists choose the technique that best balances image quality, ergonomics, consistency of spread, and safety. That's especially relevant in cats, where working space is limited and technical precision matters. If one approach proves more reliable anatomically, it could become the preferred teaching and practice method for clinicians building feline locoregional protocols. (mdpi.com)
There are still important limits. Cadaver models can't capture perfusion, tissue compliance, drug absorption, or real analgesic response in live patients. They also don't resolve the bigger clinical questions, including ideal local anesthetic choice, dose, duration, or which surgeries benefit most. So the study is best read as a technical and anatomical comparison, not a definitive clinical recommendation. (mdpi.com)
What to watch: Watch for follow-up studies in live cats, especially prospective trials that compare pain scores, rescue analgesia, opioid use, and block performance time between approaches, as well as any effort to standardize feline ESP training and dosing. (mdpi.com)