Abstract
Although cadaver dissections are important for skull base surgeons to acquire anatomical knowledge and techniques, their opportunities are limited in Japan. The Autopsy Imaging Center of the University of Fukui Hospital has both a CT scanner and an MR unit solely for deceased patients. The authors applied the postmortem imaging to cadaver dissections and evaluated its usefulness in surgical education. Ten sides of five formalin-fixed cadaver heads were dissected by ten neurosurgeons. Five neurosurgeons were young, three were moderately experienced, and two were experts in skull base surgery. They performed orbitozygomatic, anterior transpetrosal, posterior transpetrosal, and transcondylar approaches. CT bone images were taken before and after dissections, and MR images were taken before dissection to merge with the CT bone images. The usefulness of the images for each neurosurgeon and for each skull base approach was evaluated. The postmortem imaging system was useful for all neurosurgeons, especially in anterior transpetrosal, posterior transpetrosal, and transcondylar approaches. They could find the insufficiency or excessiveness of their drilling of specific bony structures with the images. Even the experts in skull base surgery could identify regions in which they could add drilling safely to widen the surgical field more. The postmortem imaging system was useful for skull base cadaver dissections. This system is expected to be utilized for education and research on surgical anatomy.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Japanese Ministry of Health, Labour and Welfare (2011) Research of medical institutions: Japanese Ministry of Health, Labour and Welfare
Organization for Economic Co-operation and Development (2013) OECD health data: Organization for Economic Co-operation and Development
Kawase T, Shiobara R, Toya S (1991) Anterior transpetrosal-transtentorial approach for sphenopetroclival meningiomas: surgical method and results in 10 patients. Neurosurgery 28:869–876
Wanibuchi M, Friedman AH, Fukushima T (2009) Middle fossa rhomboid approach (anterior petrosectomy). In: Wanibuchi M, Friedman AH, Fukushima T (eds) Photo atlas of skull base dissection. Thieme, New York, pp 207–237
Matsushima T, Fukui M, Rhoton AL Jr (1997) Surgical anatomy of the temporal bone. In: Torrens M, Al-Mefty O, Kobayashi S (eds) Operative skull base surgery. Churchill Livingstone, New York, pp 45–55
Ohata K, Baba M (1996) Presigmoidal transpetrosal approach. In: Hakuba A (ed) Surgical anatomy of the skull base. Miwa Shoten, Tokyo, pp 109–139
Bertalanffy H, Seeger W (1991) The dorsolateral, suboccipital, transcondylar approach to the lower clivus and anterior portion of the craniocervical junction. Neurosurgery 29:815–821
Wanibuchi M, Friedman AH, Fukushima T (2009) Transcondylar transtubercular approach. In: Wanibuchi M, Friedman AH, Fukushima T (eds) Photo atlas of skull base dissection. Thieme, New York, pp 385–401
Acknowledgments
The authors are grateful to Mr. Akihiko Nishijima for the technical assistance with imaging and to Mr. Hiroyuki Nakade for the support in cadaver dissections.
Author information
Authors and Affiliations
Corresponding author
Additional information
Comments
Mario Ammirati, Columbus, USA
This is a well-written paper in which four skull base approaches (orbitozygomatic, anterior transpetrosal, posterior transpetrosal, and transcondylar) were performed on cadavers by ten neurosurgeons with different skill sets (young, moderately experienced, and skull base surgery experts). Each neurosurgeon used pre-dissection CT and MRI, and the extent of the approach was evaluated with postprosection CT scans. Interestingly, even experienced skull base surgeons did not remove all the bone they could have safely removed. The take-home point of this paper is that aggressive use of intraoperative neuronavigation is worthwhile, even in expert hands, to maximize safe bone removal in complex skull base approaches.
Marian Christoph Neidert, Oliver Bozinov, Zurich, Switzerland
Kodera and colleagues present an article on postmortem imaging (combined CT and MR imaging) as an adjunct to skull base cadaver courses. Pre- and postoperative imaging were compared in order to assess the appropriateness of the approach and to evaluate whether additional bone removal could have been performed. A group of ten neurosurgeons was divided into three subgroups based on their surgical experience, and the usefulness of postmortem imaging was evaluated for different skull base approaches and for the subgroups with different experience levels separately. The authors conclude that postmortem imaging was especially useful in anterior transpetrosal, posterior transpetrosal, and transcondylar approaches and that even experienced experts benefit from postmortem imaging.
This article expands our knowledge, since not many information on this topic is available. It is our strong opinion that the ideal neurosurgical education setting involves both the operating room with an experienced mentor as well as cadaver courses. This article nicely describes a new source for surgical education in those areas where the options to dissect cadavers are limited for various reasons. It adds an adjunct to current cadaver courses, because the described imaging technique offers an additional method to evaluate the dissections, especially for surgical approaches.
Yavor Enchev, Varna, Bulgaria
Skull base pathology is relatively rare in the clinical practice. Its surgical treatment requires profound anatomical knowledge and perfect surgical technique. Gaining an expertise in this field is a complicated and long-term process. Cadaver dissections represent the most valuable educational option in order to acquire anatomical knowledge and reliable surgical experience.
According to cultural reasons, the autopsy rate in Japan is permanently declining. Exploiting the Japanese unprecedented supply of CT scanners and MRI units per capita, in attempt to find an alternative to cadaver dissections, the Japanese health system more widely applies CT and MR imaging, the so-called “autopsy imaging”, for deceased people to investigate causes of dead. This, almost unique practice and experience, gives excellent options for the neurosurgeons desiring to perfect their skills in skull base neurosurgery.
The authors perfectly describe their experience in applying a postmortem imaging in favor of both neurosurgical trainees and experts. They fused CT and MR images obtained before the dissections and introduced them in a neuronavigation system. In this way, they performed four types of CT-MRI-based neuronavigated skull base approaches. The extent of skull base drilling was assessed by postprocedure CT scans, and the usefulness of the images both per neurosurgeon and per approach was evaluated.
The advantages, outlined by the authors, included anatomical education, surgical technique refining, and potential for development of new surgical approaches.
Rights and permissions
About this article
Cite this article
Kodera, T., Arishima, H., Kitai, R. et al. Utility of postmortem imaging system for anatomical education in skull base surgery. Neurosurg Rev 38, 165–170 (2015). https://doi.org/10.1007/s10143-014-0574-2
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10143-014-0574-2