Eberval G. Figueiredo, Manoel J. Teixeira and Leonardo C. Welling
Sergiy V. Kushchayev, Evgenii Belykh, Yakiv Fishchenko, Aliaksei Salei, Oleg M. Teytelboym, Leonid Shabaturov, Mark Cruse and Mark C. Preul
General Mikhail Kutuzov (circa 1745–1813) brilliantly repelled Napoleon’s invasion of Russia. Honored as a national hero and a savior of Russia, Kutuzov has a unique medical story. He was shot in the head twice while fighting the Turks (1774 and 1788) and survived the serious injuries seemingly against all odds. The first bullet “ran through the head from one temple to the other behind both eyes.” The second bullet entered the cheek, destroyed upper teeth, traveled through the head, and exited the occiput. Massot, a French surgeon with the Russian army, wrote after treating Kutuzov’s seemingly two mortal wounds: “It must be believed that fate appoints Kutuzov to something great, because he was still alive after two injuries, a death sentence by all the rules of medical science.” Aided by Massot’s expert surgical technique, Kutuzov lived to become intimately engaged in events that altered world history. His health did, however, suffer significant effects due to the bullet wounds. In 1812, as Napoleon’s Grande Armée approached, Kutuzov realized he could not confront Napoleon and he strategically retreated from Moscow, submitting the French to the harsh winter and Russian cavalry. Napoleon’s devastated army retreated to Paris, and Kutuzov became the personification of Russian spirit and character. Kutuzov’s survival of two nearly mortal head wounds created the legends, additional mystery, and drama surrounding him, not the least astonishing of which was the skilled neurosurgical care that probably saved his life.
Ting Lei, Evgenii Belykh, Alexander B. Dru, Kaan Yagmurlu, Ali M. Elhadi, Peter Nakaji and Mark C. Preul
Chen Jingrun (1933–1996), perhaps the most prodigious mathematician of his time, focused on the field of analytical number theory. His work on Waring's problem, Legendre's conjecture, and Goldbach's conjecture led to progress in analytical number theory in the form of “Chen's Theorem,” which he published in 1966 and 1973. His early life was ravaged by the Second Sino-Japanese War and the Chinese Cultural Revolution. On the verge of solving Goldbach's conjecture in 1984, Chen was struck by a bicyclist while also bicycling and suffered severe brain trauma. During his hospitalization, he was also found to have Parkinson's disease. Chen suffered another serious brain concussion after a fall only a few months after recovering from the bicycle crash. With significant deficits, he remained hospitalized for several years without making progress while receiving modern Western medical therapies. In 1988 traditional Chinese medicine experts were called in to assist with his treatment. After a year of acupuncture and oxygen therapy, Chen could control his basic bowel and bladder functions, he could walk slowly, and his swallowing and speech improved. When Chen was unable to produce complex work or finish his final work on Goldbach's conjecture, his mathematical pursuits were taken up vigorously by his dedicated students. He was able to publish Youth Math, a mathematics book that became an inspiration in Chinese education. Although he died in 1996 at the age of 63 after surviving brutal political repression, being deprived of neurological function at the very peak of his genius, and having to be supported by his wife, Chen ironically became a symbol of dedication, perseverance, and motivation to his students and associates, to Chinese youth, to a nation, and to mathematicians and scientists worldwide.
Ali Tayebi Meybodi, Leandro Borba Moreira, Michael T. Lawton, Jennifer M. Eschbacher, Evgenii G. Belykh, Michelle M. Felicella and Mark C. Preul
In the current neurosurgical and anatomical literature, the intracanalicular segment of the ophthalmic artery (OphA) is usually described to be within the optic nerve dural sheath (ONDS), implying direct contact between the nerve and the artery inside the optic canal. In the present study, the authors sought to clarify the exact relationship between the OphA and ONDS.
Ten cadaveric heads were subjected to endoscopic endonasal and transcranial exposures of the OphA in the optic canal (5 for each approach). The relationship between the OphA and ONDS was assessed. Histological examination of one specimen of the optic nerve and the accompanying OphA was also performed to confirm the relationship with the ONDS.
In all specimens, the OphA coursed between the two layers of the dura (endosteal and meningeal) and was not in direct contact with the optic nerve, except for the first few millimeters of the proximal optic canal before it pierced the ONDS. Upon reaching the orbit, the two layers of the dura separated and allowed the OphA to literally float within the orbital fat. The meningeal dura continued as the ONDS, whereas the endosteal dura became the periorbita.
This study clarifies the interdural course of the OphA within the optic canal. This anatomical nuance has important neurosurgical implications regarding safe exposure and manipulation of the OphA.
Xiaochun Zhao, Robert T. Wicks, Evgenii Belykh, Colin J. Przybylowski, Mohamed A. Labib and Peter Nakaji
Neurocysticercosis is primarily managed with anthelminthic, antiepileptic, and corticosteroid therapies. Surgical removal of the larval cyst is indicated when associated mass effect causes neurological symptoms, as demonstrated in two cases. Cyst resection was achieved via the far lateral approach for a cervicomedullary cyst in one patient and via the subtemporal approach for a mesencephalic cyst in another. The cyst wall should be kept intact, when possible, to avoid dissemination of the inflammation-evoking contents. As the contents are usually semisolid and can be removed via suction, it is not necessary to remove the gliotic capsule or adherent portions of the cyst wall in highly eloquent locations.
The video can be found here: https://youtu.be/GqbaJu5sy1o.
Michael A. Bohl, Nikolay L. Martirosyan, Zachary W. Killeen, Evgenii Belykh, Joseph M. Zabramski, Robert F. Spetzler and Mark C. Preul
Despite an overwhelming history demonstrating the potential of hypothermia to rescue and preserve the brain and spinal cord after injury or disease, clinical trials from the last 50 years have failed to show a convincing benefit. This comprehensive review provides the historical context needed to consider the current status of clinical hypothermia research and a view toward the future direction for this field. For millennia, accounts of hypothermic patients surviving typically fatal circumstances have piqued the interest of physicians and prompted many of the early investigations into hypothermic physiology. In 1650, for example, a 22-year-old woman in Oxford suffered a 30-minute execution by hanging on a notably cold and wet day but was found breathing hours later when her casket was opened in a medical school dissection laboratory. News of her complete recovery inspired pioneers such as John Hunter to perform the first complete and methodical experiments on life in a hypothermic state. Hunter’s work helped spark a scientific revolution in Europe that saw the overthrow of the centuries-old dogma that volitional movement was created by hydraulic nerves filling muscle bladders with cerebrospinal fluid and replaced this theory with animal electricity. Central to this paradigm shift was Giovanni Aldini, whose public attempts to reanimate the hypothermic bodies of executed criminals not only inspired tremendous scientific debate but also inspired a young Mary Shelley to write her novel Frankenstein. Dr. Temple Fay introduced hypothermia to modern medicine with his human trials on systemic and focal cooling. His work was derailed after Nazi physicians in Dachau used his results to justify their infamous experiments on prisoners of war. The latter half of the 20th century saw the introduction of hypothermic cerebrovascular arrest in neurosurgical operating rooms. The ebb and flow of neurosurgical interest in hypothermia that has since persisted reflect our continuing struggle to achieve the neuroprotective benefits of cooling while minimizing the systemic side effects.
Kaan Yagmurlu, Sam Safavi-Abbasi, Evgenii Belykh, M. Yashar S. Kalani, Peter Nakaji, Albert L. Rhoton Jr., Robert F. Spetzler and Mark C. Preul
The aim of this investigation was to modify the mini-pterional and mini-orbitozygomatic (mini-OZ) approaches in order to reduce the amount of tissue traumatization caused and to compare the use of the 2 approaches in the removal of circle of Willis aneurysms based on the authors' clinical experience and quantitative analysis.
Three formalin-fixed adult cadaveric heads injected with colored silicone were examined. Surgical freedom and angle of attack of the mini-pterional and mini-OZ approaches were measured at 9 anatomical points, and the measurements were compared. The authors also retrospectively reviewed the cases of 396 patients with ruptured and unruptured single aneurysms in the circle of Willis treated by microsurgical techniques at their institution between January 2006 and November 2014.
A significant difference in surgical freedom was found in favor of the mini-pterional approach for access to the ipsilateral internal carotid artery (ICA) and middle cerebral artery (MCA) bifurcations, the most distal point of the ipsilateral posterior cerebral artery (PCA), and the basilar artery (BA) tip. No statistically significant differences were found between the mini-pterional and mini-OZ approaches for access to the posterior clinoid process, the most distal point of the superior cerebellar artery (SCA), the anterior communicating artery (ACoA), the contralateral ICA bifurcation, and the most distal point of the contralateral MCA. A trend toward increasing surgical freedom was found for the mini-OZ approach to the ACoA and the contralateral ICA bifurcation. The lengths exposed through the mini-OZ approach were longer than those exposed by the mini-pterional approach for the ipsilateral PCA segment (11.5 ± 1.9 mm) between the BA and the most distal point of the P2 segment of the PCA, for the ipsilateral SCA (10.5 ± 1.1 mm) between the BA and the most distal point of the SCA, and for the contralateral anterior cerebral artery (ACA) (21 ± 6.1 mm) between the ICA bifurcation and the most distal point of the A2 segment of the ACA. The exposed length of the contralateral MCA (24.2 ± 8.6 mm) between the contralateral ICA bifurcation and the most distal point of the MCA segment was longer through the mini-pterional approach. The vertical angle of attack (anteroposterior direction) was significantly greater with the mini-pterional approach than with the mini-OZ approach, except in the ACoA and contralateral ICA bifurcation. The horizontal angle of attack (mediolateral direction) was similar with both approaches, except in the ACoA, contralateral ICA bifurcation, and contralateral MCA bifurcation, where the angle was significantly increased in the mini-OZ approach.
The mini-pterional and mini-OZ approaches, as currently performed in select patients, provide less tissue traumatization (i.e., less temporal muscle manipulation, less brain parenchyma retraction) from the skin to the aneurysm than standard approaches. Anatomical quantitative analysis showed that the mini-OZ approach provides better exposure to the contralateral side for controlling the contralateral parent arteries and multiple aneurysms. The mini-pterional approach has greater surgical freedom (maneuverability) for ipsilateral circle of Willis aneurysms.
Xiaochun Zhao, Ali Tayebi Meybodi, Mohamed A. Labib, Sirin Gandhi, Evgenii Belykh, Komal Naeem, Mark C. Preul, Peter Nakaji and Michael T. Lawton
Aneurysms that arise on the medial surface of the paraclinoid segment of the internal carotid artery (ICA) are surgically challenging. The contralateral interoptic trajectory, which uses the space between the optic nerves, can partially expose the medial surface of the paraclinoid ICA. In this study, the authors quantitatively measure the area of the medial ICA accessible through the interoptic triangle and propose a potential patient-selection algorithm that is based on preoperative measurements on angiographic imaging.
The contralateral interoptic trajectory was studied on 10 sides of 5 cadaveric heads, through which the medial paraclinoid ICA was identified. The falciform ligament medial to the contralateral optic canal was incised, the contralateral optic nerve was gently elevated, and the medial surface of the paraclinoid ICA was inspected via different viewing angles to obtain maximal exposure. The accessible area on the carotid artery was outlined. The distance from the distal dural ring (DDR) to the proximal and distal borders of this accessible area was measured. The superior and inferior borders were measured using the clockface method relative to a vertical line on the coronal plane. To validate these parameters, preoperative measurements and intraoperative findings were reviewed in 8 clinical cases.
In the sagittal plane, the mean (SD) distances from the DDR to the proximal and distal ends of the accessible area on the paraclinoid ICA were 2.5 (1.52) mm and 8.4 (2.32) mm, respectively. In the coronal plane, the mean (SD) angles of the superior and inferior ends of the accessible area relative to a vertical line were 21.7° (14.84°) and 130.9° (12.75°), respectively. Six (75%) of 8 clinical cases were consistent with the proposed patient-selection algorithm.
The contralateral interoptic approach is a feasible route to access aneurysms that arise from the medial paraclinoid ICA. An aneurysm can be safely clipped via the contralateral interoptic trajectory if 1) both proximal and distal borders of the aneurysm neck are 2.5–8.4 mm distal to the DDR, and 2) at least one border of the aneurysm neck on the coronal clockface is 21.7°–130.9° medial to the vertical line.
Evgenii Belykh, Ting Lei, Sam Safavi-Abbasi, Kaan Yagmurlu, Rami O. Almefty, Hai Sun, Kaith K. Almefty, Olga Belykh, Vadim A. Byvaltsev, Robert F. Spetzler, Peter Nakaji and Mark C. Preul
Microvascular anastomosis is a basic neurosurgical technique that should be mastered in the laboratory. Human and bovine placentas have been proposed as convenient surgical practice models; however, the histologic characteristics of these tissues have not been compared with human cerebral vessels, and the models have not been validated as simulation training models. In this study, the authors assessed the construct, face, and content validities of microvascular bypass simulation models that used human and bovine placental vessels.
The characteristics of vessel segments from 30 human and 10 bovine placentas were assessed anatomically and histologically. Microvascular bypasses were performed on the placenta models according to a delineated training module by “trained” participants (10 practicing neurosurgeons and 7 residents with microsurgical experience) and “untrained” participants (10 medical students and 3 residents without experience). Anastomosis performance and impressions of the model were assessed using the Northwestern Objective Microanastomosis Assessment Tool (NOMAT) scale and a posttraining survey.
Human placental arteries were found to approximate the M2–M4 cerebral and superficial temporal arteries, and bovine placental veins were found to approximate the internal carotid and radial arteries. The mean NOMAT performance score was 37.2 ± 7.0 in the untrained group versus 62.7 ± 6.1 in the trained group (p < 0.01; construct validity). A 50% probability of allocation to either group corresponded to 50 NOMAT points. In the posttraining survey, 16 of 17 of the trained participants (94%) scored the model's replication of real bypass surgery as high, and 16 of 17 (94%) scored the difficulty as “the same” (face validity). All participants, 30 of 30 (100%), answered positively to questions regarding the ability of the model to improve microsurgical technique (content validity).
Human placental arteries and bovine placental veins are convenient, anatomically relevant, and beneficial models for microneurosurgical training. Microanastomosis simulation using these models has high face, content, and construct validities. A NOMAT score of more than 50 indicated successful performance of the microanastomosis tasks.
Nikolay L. Martirosyan, Jennifer M. Eschbacher, M. Yashar S. Kalani, Jay D. Turner, Evgenii Belykh, Robert F. Spetzler, Peter Nakaji and Mark C. Preul
This study evaluated the utility, specificity, and sensitivity of intraoperative confocal laser endomicroscopy (CLE) to provide diagnostic information during resection of human brain tumors.
CLE imaging was used in the resection of intracranial neoplasms in 74 consecutive patients (31 male; mean age 47.5 years; sequential 10-month study period). Intraoperative in vivo and ex vivo CLE was performed after intravenous injection of fluorescein sodium (FNa). Tissue samples from CLE imaging–matched areas were acquired for comparison with routine histological analysis (frozen and permanent sections). CLE images were classified as diagnostic or nondiagnostic. The specificities and sensitivities of CLE and frozen sections for gliomas and meningiomas were calculated using permanent histological sections as the standard.
CLE images were obtained for each patient. The mean duration of intraoperative CLE system use was 15.7 minutes (range 3–73 minutes). A total of 20,734 CLE images were correlated with 267 biopsy specimens (mean number of images/biopsy location, in vivo 84, ex vivo 70). CLE images were diagnostic for 45.98% in vivo and 52.97% ex vivo specimens. After initiation of CLE, an average of 14 in vivo images and 7 ex vivo images were acquired before identification of a first diagnostic image. CLE specificity and sensitivity were, respectively, 94% and 91% for gliomas and 93% and 97% for meningiomas.
CLE with FNa provided intraoperative histological information during brain tumor removal. Specificities and sensitivities of CLE for gliomas and meningiomas were comparable to those for frozen sections. These data suggest that CLE could allow the interactive identification of tumor areas, substantially improving intraoperative decisions during the resection of brain tumors.