We read with interest the paper ''A new training method to improve deep microsurgical skills using a mannequin head'' by Dr. Takeuchi et al. 1 In the introduction, the authors state that ''There have been many previous reports of training methods for typical microsurgical techniques, including suturing of surgical gloves, Silastic tubes, living animals, and chicken wing arteries. However, there have been no reports of training methods to improve deep microsurgical skills under the various hand positions specific to neurosurgical operation.''
Although the manneguin head is a very elegant tool to practice microsurgical skills at a deep surgical level, the authors have omitted several articles describing more or less the same model, i.e., performing microsurgery through a narrow field at a deep level. In 2000, we have published a paper on a skull-cast model that was intended to simulate the human anatomy and deep surgical conditions. 2 This model consisted of a human skull-cast model made from plaster cut such a way, that when placed on a operating table, it represented a standard position of a pterional approach and that the point of operation was at the same depth as the hypothetical circle of Willis. A standard pterional opening was made in de-skull-cast and the model was placed over the rat. Subsequently, all surgical procedures starting from tissue preparation to performing an arterial, venous, and/or nerve repair were performed with the cast over the rat using microneurosurgical bayonet instruments and a surgical microscope. The microsurgical procedures such as end-to-end vessel anas-