Optical neuronavigation advances equine pituitary access study
Bottom line
Optical neuronavigation may help surgeons reach the equine pituitary gland through a transcranial approach, according to a new cadaver study in the American Journal of Veterinary Research. In 13 equine cadaver heads, investigators used a fiducial array plus either CT guidance in seven heads or MRI guidance in six heads to plan and execute pituitary access, then compared tissue retrieval using different imaging modalities and instruments. Earlier conference reporting from the same project found pituitary tissue in 6 of 13 samples, with MRI offering better contrast and more accurate targeting than CT. The work builds on several years of equine neuronavigation research and reflects ongoing interest in whether image-guided neurosurgery could eventually support intervention for pituitary disease in horses. (academic.oup.com)
Why it matters: For veterinary professionals, this is still early-stage, preclinical work, but it addresses a long-standing problem: how to safely and reproducibly access the equine pituitary, a difficult anatomic target that matters in pituitary pars intermedia dysfunction, or PPID. Current PPID management remains medical, with pergolide central to treatment recommendations, and major guidelines note that the evidence base in equine PPID is still limited overall. If neuronavigation can improve targeting and tissue acquisition, it could eventually expand options for biopsy, research sampling, or highly selected surgical intervention at referral centers, though the field remains constrained by cost, training, and the fact that most veterinary CASN evidence is still cadaveric or ex vivo. (beva.onlinelibrary.wiley.com)
What to watch: The next step is whether this technique moves from cadaver feasibility into live-horse clinical studies that can better define safety, diagnostic yield, and any realistic role in PPID care. (pubmed.ncbi.nlm.nih.gov)
Key facts
- Study type
- Cadaver study
- Journal
- American Journal of Veterinary Research
- Sample size
- 13 equine cadaver heads
- Imaging used
- CT in 7 heads, MRI in 6 heads
- Procedure
- Optical neuronavigation-guided transcranial pituitary access
- Comparison
- MRI-guided versus CT-guided targeting, and automated tissue resection device versus biopsy needle
- Earlier conference result
- Pituitary tissue was found in 6 of 13 samples
- Reported imaging advantage
- MRI offered better contrast and more accurate targeting than CT
- Clinical context
- Potential relevance to PPID in horses
A new American Journal of Veterinary Research study evaluates whether optical neuronavigation can make transcranial access to the equine pituitary gland more feasible, a technically challenging goal with potential relevance for advanced equine neurosurgery. The investigators used 13 equine cadaver heads and compared MRI-guided versus CT-guided targeting, while also assessing an automated tissue resection device against a standard biopsy needle. The study adds to a small but growing body of work exploring computer-assisted surgical navigation in horses. (pmc.ncbi.nlm.nih.gov)
The clinical backdrop is PPID, one of the most common endocrine disorders in older horses and ponies. Although the disease is routinely managed medically, interest in surgical access to the pituitary has persisted for years because human and canine pituitary disease can, in some settings, be approached surgically. An earlier abstract from this same equine project explicitly framed pituitary tissue extraction as a possible future treatment avenue for PPID and reported that MRI-based targeting outperformed CT for accurate tissue acquisition. (beva.onlinelibrary.wiley.com)
That interest has been shaped by the anatomy and the risks. Prior investigators have described development of surgical approaches to the equine pituitary and argued that image guidance could improve success, while a later case report of a navigated transsphenoidal approach in a mare showed both the promise and the hazards of this line of work. In that case, neuronavigation helped reach and sample a pituitary macroadenoma, but visualization remained limited in the long, narrow working channel, and postmortem assessment identified iatrogenic brain injury after partial tumor removal. (pmc.ncbi.nlm.nih.gov)
The newer AJVR study appears to push the field forward by focusing on transcranial access, image-guided planning, and instrument choice in a controlled cadaver model. Based on the available abstract and prior conference details, the protocol used a fiducial array secured to the frontal bone before imaging, then assigned heads to CT or MRI planning. Histopathology was used to assess tissue acquisition. In the earlier report, pituitary tissue was identified in 46% of submitted samples, and MRI's superior contrast resolution was cited as a key advantage for localizing the gland. That fits with broader neuronavigation literature in horses, which has already suggested that optical guidance is feasible and that image quality and registration strategy can materially affect targeting accuracy. (academic.oup.com)
There doesn't appear to be broad outside commentary on this specific paper yet, but the surrounding literature offers a clear industry perspective: computer-assisted surgical navigation is gaining credibility in veterinary surgery, while still sitting in an early translational phase. A 2026 narrative review led by Bonilla described consistent benefits across veterinary applications, including more accurate access to complex targets and less reliance on fluoroscopy, but also emphasized that most published evidence remains cadaveric or ex vivo and that adoption is limited by cost, workflow complexity, and training demands. (pubmed.ncbi.nlm.nih.gov)
Why it matters: For equine practitioners, this study is less about an immediate change in PPID treatment and more about technical progress in a field that has had few practical routes beyond medical management. BEVA's 2024 primary care guidelines describe PPID diagnosis and treatment as areas where evidence is often conflicting or sparse, and the Equine Endocrinology Group continues to update recommendations centered on diagnosis and medical management. Against that backdrop, better surgical targeting could matter first for research and referral-level diagnostics, and only later, if safety and efficacy are established, for therapeutic intervention in rare cases. (beva.onlinelibrary.wiley.com)
The study also highlights a more general trend in referral practice: advanced imaging is no longer the bottleneck it once was, but converting imaging into precise, minimally invasive intervention is still a work in progress. In horses especially, the logistics of anesthesia, positioning, registration, and instrument reach make translation harder than in small animals or people. Earlier equine neuronavigation work has already pointed out that planning workflows can require extra imaging and anesthesia events, which is a meaningful barrier in this species. (pmc.ncbi.nlm.nih.gov)
What to watch: The key questions now are whether the full AJVR paper reports a meaningful advantage for MRI over CT and for the automated resection device over a standard biopsy needle, and whether follow-on studies can show acceptable safety and diagnostic yield in live horses before any clinical role is seriously considered. (academic.oup.com)