The Influence of Endoscopic Techniques on the Exposure Range of the Petroclival Region and the Protection of the Abducens Nerve in the Retrosigmoid Approach: An Anatomical Comparative Study.

OBJECTIVE

To investigate the impact of endoscopic techniques on the exposure of the petroclival region and the protection of the abducens nerve in the retrosigmoid approach by comparing the exposure range of the petroclival region and the length of the abducens nerve exposed in the retrosigmoid approach using endoscopic and microscopic techniques.

METHODS

Twelve skull specimens, which had been perfused with colored latex, were used for microanatomical dissection of the retrosigmoid approach to the petroclival region in the endoscopic anatomy laboratory with the aid of a 0-degree endoscope and a ZEISS microscope. The anatomic structures exposed in the petroclival region under endoscopy and microscope were observed and compared. The area of the petroclival region exposed and the length of the abducens nerve exposed were measured and analyzed.

RESULTS

The area of the petroclival region exposed by the endoscope (1244.98±83.80 mm²) was larger than that exposed by the microscope (631.02±58.32 mm², P<0.001). The subarachnoid segment of the abducens nerve was completely visualized under the endoscope with an average length of 16.62±0.95 mm, while only partially exposed under the microscope with an average length of 10.23±0.50 mm (P<0.001).

CONCLUSION

In the retrosigmoid approach for exposing the petroclival region, the endoscopic technique can expose a larger area of the petroclival region, which is beneficial for the exposure of the petroclival region. The endoscopic technique can expose a longer segment of the abducens nerve, which is more conducive to the protection of the abducens nerve.