Sergio García-García1,2,3, José Juan González-Sánchez1, Sofia Kakaizada2, Michael T Lawton4, Arnau Benet4. 1. Department of Neurosurgery, Hospital Clinic, Barcelona, Spain. 2. Department of Neurosurgery, University of California, San Francisco, California. 3. Department of Neurosurgery, Hospital Sant Joan de Deu, Barcelona Spain. 4. Department of Neurosurgery, Barrow Neurological Institute, Phoenix, Arizona.
Abstract
BACKGROUND: The supraorbital keyhole approach (SOKA) provides a safe and advantageous access to the anterior cranial fossa. The implemented skin incision varies depending on surgeon's preferences and requirements. Facial nerve (FN) injury might appear in up to 5.6% of patients. There is a lack of validated tenets for avoiding FN injury. OBJECTIVE: To define a safety area for FN preservation during a SOKA. METHODS: Ten dried skulls and 5 injected cadaveric heads (10 sides) were used. A Cartesian frame was created with its horizontal axis at the level of the supraorbital notch and the vertical axis just lateral to the frontozygomatic junction (FZj). FNs were dissected and points along their course were registered and transferred to the Cartesian frame. RESULTS: Ten microscopic dissections of the FN were performed preserving all branches. A safety area could be defined 8 mm superior and 10 mm inferior to the FZj extending medially to the supraorbital notch and beyond. A 20 mm2 area superior and lateral to the FZj provided low probability (≤10%) of injuring the FN. Similarly, starting 4 mm inferior to the FZj, a lateral safety area was also found. A probabilistic colored heat map was built to represent the results. CONCLUSION: We provide a "safety zone" for a SOKA incision in which the probability to encounter the FN is low. Clinical studies following our method may validate our findings and add evidence to the tenets for minimizing morbidity related to the SOKA incision.
BACKGROUND: The supraorbital keyhole approach (SOKA) provides a safe and advantageous access to the anterior cranial fossa. The implemented skin incision varies depending on surgeon's preferences and requirements. Facial nerve (FN) injury might appear in up to 5.6% of patients. There is a lack of validated tenets for avoiding FN injury. OBJECTIVE: To define a safety area for FN preservation during a SOKA. METHODS: Ten dried skulls and 5 injected cadaveric heads (10 sides) were used. A Cartesian frame was created with its horizontal axis at the level of the supraorbital notch and the vertical axis just lateral to the frontozygomatic junction (FZj). FNs were dissected and points along their course were registered and transferred to the Cartesian frame. RESULTS: Ten microscopic dissections of the FN were performed preserving all branches. A safety area could be defined 8 mm superior and 10 mm inferior to the FZj extending medially to the supraorbital notch and beyond. A 20 mm2 area superior and lateral to the FZj provided low probability (≤10%) of injuring the FN. Similarly, starting 4 mm inferior to the FZj, a lateral safety area was also found. A probabilistic colored heat map was built to represent the results. CONCLUSION: We provide a "safety zone" for a SOKA incision in which the probability to encounter the FN is low. Clinical studies following our method may validate our findings and add evidence to the tenets for minimizing morbidity related to the SOKA incision.
Authors: Patrick Flanigan; Varun R Kshettry; Jeffrey P Mullin; Arman Jahangiri; Pablo F Recinos Journal: World Neurosurg Date: 2016-03-12 Impact factor: 2.104
Authors: Felix Goehre; Behnam Rezai Jahromi; Ahmed Elsharkawy; Hanna Lehto; Oleg Shekhtman; Hugo Andrade-Barazarte; Francisco Munoz; Ferzat Hijazy; Makhkam Makhkamov; Juha Hernesniemi Journal: Surg Neurol Int Date: 2015-05-28