Diagnostic endoscopy of the navicular bursa using a needle endoscope by direct or transthecal approach: A comparative cadaver study.

The study investigates the benefits and potential damages between direct and transthecal approaches, two methods of needle endoscopy carried out on cadaver horse forelimbs, for diagnosis in the navicular bursa. The findings highlight the direct approach as superior, providing better visualization of ipsilateral structures in the navicular bursa with negligible damage.

Research Context

• The research revolves around two principal techniques of performing diagnostic needle endoscopy on the navicular bursa of horse forelimbs – the direct approach and the transthecal approach. The aim of the study is to compare these approaches in terms of practicability, visualization of structures, and any iatrogenic (unexpected) damage caused during the process.

Research Methodology

• The study used 30 equine cadaver forelimbs for carrying out the procedures. The researchers used both direct and transthecal approaches for inserting the needle endoscope into the navicular bursa.
• They carried out video recordings of these endoscopic procedures and ascertained all the structures they could visualize within the navicular bursa.
• Parameters like the number of attempts required to access the navicular bursa and the total time taken for insertion and examination were recorded. After dissection, the researchers evaluated and scored the distribution and severity of iatrogenic lesions.

Research Findings

• There wasn’t any significant difference in terms of the number of attempts or the time required for insertion and examination between the two approaches.
• However, the direct approach made a significant difference in casing increased visibility of the ipsilateral abaxial and proximal margins of the navicular bone, along with the ipsilateral collateral sesamoidean ligament.
• Regardless of the approach taken, the iatrogenic lesions were superficial and focal, indicating less harm to the subject. The type of trocar tip used, whether blunt or sharp, did not affect the severity of lesions.

Research Conclusions

• Compared to the transthecal approach, the direct approach stands out as it provides significantly better visualization of the ipsilateral structures within the navicular bursa.
• Therefore, needle endoscopy is validated as a reliable technique to evaluate the navicular bursa, posing as a potential successor or complementary method to existing diagnostic procedures in horses suffering from lameness localized to the navicular region.