R. Shane Tubbs, Eyas M. Hattab, Marios Loukas, Joshua J. Chern, Melissa Wellons, John C. Wellons III, Bermans J. Iskandar and Aaron A. Cohen-Gadol
Endocrine dysfunction following endoscopic third ventriculostomy (ETV) is rare, but it has been reported. In the present study the authors sought to determine the histological nature of the floor of the third ventricle in hydrocephalic brains to better elucidate this potential association.
Five adult cadaveric brains with hydrocephalus were examined. Specifically, the floors of the third ventricle of these specimens were studied histologically. Age-matched controls without hydrocephalus were used for comparison.
Although it was thinned in the hydrocephalic brains, the floor of the third ventricle had no significant difference between the numbers of neuronal cell bodies versus nonhydrocephalic brains.
Although uncommon following ETV, endocrine dysfunction has been reported. Based on the present study, this is most likely to be due to the injury of normal neuronal cell bodies found in this location, even in very thinned-out tissue.
R. Shane Tubbs, Marios Loukas, Mohammadali M. Shoja, John C. Wellons and Aaron A. Cohen-Gadol
Cadavers are often used in the teaching of various neurosurgical procedures. One aspect of this resource that has not been previously explored is the postmortem dilation of the ventricular system, which is often collapsed, for the purpose of training neurosurgeons in the use of intraventricular endoscopy.
Nine adult cadavers without a history of hydrocephalus or other known intracranial pathology were used for this study. Four specimens were obtained post embalming, and 5 specimens were fresh (time from death until the procedure < 5 hours). In all cadavers catheters were placed into the lateral ventricles; saline and then air were injected into the ventricles through the catheters. Ventriculostomy sites were filled with rubber stoppers, and in fresh specimens, formal embalming was performed with cadavers in the Trendelenburg position. Lastly, serial horizontal sectioning of the cranium was performed in all cadavers to verify ventricular dilation.
None of the 4 embalmed specimens were found to have ventriculomegaly following injection. However, this condition was found in 4 of the 5 fresh specimens. In the single fresh cadaver without ventriculomegaly, the cause of death had been massive intracranial subarachnoid hemorrhage, which distorted the ventricular system. This may have prevented cannulation of the ventricle and ventricular expansion in this specimen.
The ventricular system of fresh human cadavers can be dilated postmortem. The method described herein may be useful to neurosurgical trainees or those trained neurosurgeons wishing to practice intraventricular endoscopy.
R. Shane Tubbs, Marios Loukas, Mohammadali M. Shoja, Ghaffar Shokouhi, John C. Wellons III, W. Jerry Oakes and Aaron A. Cohen-Gadol
Various donor nerves, including the ipsilateral long thoracic nerve (LTN), have been used for brachial plexus neurotization procedures. Neurotization to proximal branches of the brachial plexus using the contralateral long thoracic nerve (LTN) has, to the authors' knowledge, not been previously explored.
In an attempt to identify an additional nerve donor candidate for proximal brachial plexus neurotization, the authors dissected the LTN in 8 adult human cadavers. The nerve was transected at its distal termination and then passed deep to the clavicle and axillary neurovascular bundle. This passed segment of nerve was then tunneled subcutaneously and contralaterally across the neck to a supra- and infraclavicular exposure of the suprascapular and musculocutaneous nerves. Measurements were made of the length and diameter of the LTN.
All specimens were found to have a LTN that could be brought to the aforementioned contralateral nerves. Neural connections remained tension free with left and right neck rotation of ~ 45°. The mean length of the LTN was 22 cm with a range of 18–27 cm. The overall mean diameter of this nerve was 3.0 mm. No gross evidence of injury to surrounding neurovascular structures was identified in any specimen.
Based on the results of this cadaveric study, the use of the contralateral LTN may be considered for neurotization of the proximal musculocutaneous and suprascapular nerves.