A superficial dissection approach to the sphenopalatine (pterygopalatine) ganglion to emphasize osteopathic clinical relevance.

The sphenopalatine (pterygopalatine) ganglion (SPG) is the most superficial ganglia to manipulate from the oral cavity. It has parasympathetic and sensory fibers directly affecting the paranasal sinuses as well as the palatine, nasal, pharyngeal, and lacrimal glands. The SPG can be manipulated intraorally by students and physicians utilizing osteopathic manipulative treatment (OMT) to relieve congestion associated with sinusitis, allergies, headaches, and upper respiratory infections. Within osteopathic medical education programs, students have anecdotally had difficulty identifying this ganglion due to its deep anatomic location and lack of direct visualization. In this article, we discuss that cadaveric dissection with a superficial to deep approach to the SPG has the ability to allow medical students and physicians to better understand the three-dimensional location and osteopathic clinical relevance of this ganglion.

Decompression of the geniculate ganglion and labyrinthine segments of the facial nerve through a middle cranial fossa approach using an ultrasonic surgical system: an anatomic study.

PURPOSE: The aim of this study is to evaluate the feasibility and the safety of a novel, alternative method for bone tissue management in facial nerve decompression by a middle cranial fossa approach. Several applications of Piezosurgery technology have been described, and the technique has recently been extended to otologic surgery. The piezoelectric device is a bone dissector which, using micro-vibration, preserves the anatomic integrity of soft tissue thanks to a selective action on mineralized tissue. METHODS: An anatomic dissection study was conducted on fresh-frozen adult cadaveric heads. Facial nerve decompression was performed by a middle cranial fossa approach in all specimens using the piezoelectric device under a surgical 3D exoscope visualization. After the procedures, the temporal bones were examined for evidence of any injury to the facial nerve or the cochleovestibular organs. RESULTS: In all cases, it was possible to perform a safe dissection of the greater petrosal superficial nerve, the geniculate ganglion, and the labyrinthine tract of the facial nerve. No cases of semicircular canal, cochlea, or nerve damage were observed. All of the dissections were carried out with the ultrasonic device without the necessity to replace it with an otological drill. CONCLUSION: From this preliminary study, surgical decompression of the facial nerve via the middle cranial fossa approach using Piezosurgery seems to be a safe and feasible procedure. Further cadaveric training is recommended before intraoperative use, and a wider case series is required to make a comparison with conventional devices.

Feasibility of a fetal anatomy 3D atlas by computer-assisted anatomic dissection.

OBJECTIVE: To assess the feasibility of 3D modelisation of fetal anatomy by using the Computer-assisted anatomic dissection (CAAD) based on immunolabeled histologic slices and MRI slices with a specific 3D software. STUDY DESIGN: For pelvis and lower limbs, subjects came from legal abortion, medical pregnancy termination, or late miscarriage. Specimens were fixed in 10 % formalin, then embedded in paraffin wax and serially sectioned. The histological slices were stained using HES and Masson Trichrome. Protein S-100 and D2-40 markers were used for immuno-labelling. Serial transverse sections were digitalized and manually aligned. Fetal brain slices were obtained from in utero or post-mortem MRI. RESULTS: CAAD was performed on 10 fetuses: pelvis was modelised with 3 fetuses of 13, 15 and 24 W G, lower limbs with 2 fetuses of 14 and 15 W G and brain with 5 fetuses aged between 19 and 37 W G. Fetal pelvis innervation was analysed after immunolabelling and nerves appeared proportionally bigger than in adults with the same topography. Lower limbs analysis revealed that nerve development was guided by vascular development: the sciatic nerve along the big axial vein, the saphen nerve along the big saphen vein and the sural nerve along the small saphen vein. Fetal brain study allowed to describe the gyration process and the lateral ventricle development. CONCLUSION: CAAD technique provides an accurate 3D reconstruction of fetal anatomy for lower limbs and pelvis but has to be improved for brain model since midline structures were not amendable for analysis. These results need to be confirmed with larger series of specimens at different stages of development.

Robotic Surgical Approach to the Mesial Temporal Region: A Preliminary Three-Dimensional Cadaveric Study of Technical Feasibility.

OBJECTIVE: Robotic surgical systems are used worldwide in various fields. In this study, we present the advantages and disadvantages of the most common robotic surgical system, the da Vinci Xi system, in the supracerebellar transtentorial approach to the mesial temporal region and discuss options for its integration into neurosurgery. METHODS: Our study was conducted at the Advanced Simulation and Applied Endoscopic Surgery Training and Research Center and Anatomy Laboratory. Four formalin-fixed human cadaveric head specimens with red silicone dye injected into their arterial structures and blue silicone dye injected into their venous structures were used in the study. Dissections were performed in microscopic and robotic stages. All phases were photographed using a three-dimensional photographic technique. RESULTS: The mesial temporal lobe could be accessed via the supracerebellar transtentorial route with the use of the robotic system. We show that the robotic system can be used in difficult approaches and narrow regions with a wider exposure and superior image quality than with the microscopic approach, improving the ergonomics for the surgeon. The shortcomings of robotic systems are examined and innovative solutions are offered. CONCLUSIONS: This study shows the advantages and disadvantages of the robotic surgical approach to the mesial temporal region via the supracerebellar transtentorial route. Robotic surgical systems can play a major role in neurosurgical practices with the tools designed and the innovative solutions determined in this study. Nevertheless, further research and development of these systems and related instruments are necessary to ensure their wider implementation in neurosurgery.

Origin and nature of pelvic ureter innervation.

AIMS: Innervation of the pelvic ureter traditionally comes from the pelvic plexus. This innervation is independent: adrenergic and cholinergic. The purpose of this study was to describe more precisely the origin and nature of its innervation (adrenergic, cholinergic, nitrergic, and somatic). METHODS: Six specimens of normal human fetal pelvis (four male and two female) from 20 to 30 weeks gestation were studied. The sections of these fetuses, carried out every 5 µm without interval, were treated with Hematoxylin Eosin (HE), with Masson's trichrome (TriM), immunolabeling of smooth muscle cells with smooth anti-actin, of nerves with anti-S100 protein, anti-tyrosine hydroxylase, anti-VAChT, anti-nNOS, and with anti- peripheral myelin protein 22 (PMP 22). The slides were scanned and two-dimensional images reconstructed in 3D, and analyzed. RESULTS: The terminal pelvic ureter travels above and inside the inferior hypogastric plexus (IHP). The nerve fibers that innervate the ureterovesical junction come mainly from the superior hypogastric plexus (SHP) which gives off the hypogastric nerves and pelvic branches of the sacral plexus that form the IHP. Most nerve fibers meet below the ureter, behind the bladder to form an ascending bundle, which innervates the pelvic ureter. Immunohistochemical analysis shows that the nerves of the pelvic ureter consist of adrenergic, cholinergic, and nitrergic fibers. CONCLUSION: The innervation of the distal ureter depends mainly on the SHP. This innervation is adrenergic, cholinergic, and nitrergic. It innervates the pelvic ureter in an ascending manner. This anatomical information can change rectal resection and ureteral reimplantation techniques and drug treatments for pelvic ureter stones. Neurourol. Urodynam. 36:271-279, 2017. © 2015 Wiley Periodicals, Inc.

The visceromotor and somatic afferent nerves of the penis.

INTRODUCTION: Innervation of the penis supports erectile and sensory functions. AIM: This article aims to study the efferent autonomic (visceromotor) and afferent somatic (sensory) nervous systems of the penis and to investigate how these systems relate to vascular pathways. METHODS: Penises obtained from five adult cadavers were studied via computer-assisted anatomic dissection (CAAD). MAIN OUTCOME MEASURES: The number of autonomic and somatic nerve fibers was compared using the Kruskal-Wallis test. RESULTS: Proximally, penile innervation was mainly somatic in the extra-albugineal sector and mainly autonomic in the intracavernosal sector. Distally, both sectors were almost exclusively supplied by somatic nerve fibers, except the intrapenile vascular anastomoses that accompanied both somatic and autonomic (nitrergic) fibers. From this point, the neural immunolabeling within perivascular nerve fibers was mixed (somatic labeling and autonomic labeling). Accessory afferent, extra-albugineal pathways supplied the outer layers of the penis. CONCLUSIONS: There is a major change in the functional type of innervation between the proximal and distal parts of the intracavernosal sector of the penis. In addition to the pelvis and the hilum of the penis, the intrapenile neurovascular routes are the third level where the efferent autonomic (visceromotor) and the afferent somatic (sensory) penile nerve fibers are close. Intrapenile neurovascular pathways define a proximal penile segment, which guarantees erectile rigidity, and a sensory distal segment.

Total anatomic vascular dissection for lobectomy by using only energy devices.

BACKGROUND: The introduction of ultrasonic energy into surgical dissecting devices was a technological breakthrough in minimally invasive surgery in the 1990s. METHODS: Nowadays, the energy devices are used very often during video-assisted thoracoscopic surgery (VATS) especially for lymph node dissection and for transection of small pulmonary vessels. However these devices can be used for hilar anatomic dissection in expert hands. RESULTS: In this video we show a right lower lobectomy performed by uniportal VATS in where the anatomic dissection of artery, vein and bronchus was performed by only using an ultrasonic energy device (Harmonic scalpel). The total surgical time for lobectomy was 30 minutes and 20 minutes for lymph node dissection. CONCLUSIONS: The use of energy devices for vascular and bronchial dissection during lobectomy is feasible and safe when performed by expert thoracoscopic surgeons.

Anatomo-functional study of the temporo-parieto-occipital region: dissection, tractographic and brain mapping evidence from a neurosurgical perspective.

The temporo-parieto-occipital (TPO) junction is a complex brain territory heavily involved in several high-level neurological functions, such as language, visuo-spatial recognition, writing, reading, symbol processing, calculation, self-processing, working memory, musical memory, and face and object recognition. Recent studies indicate that this area is covered by a thick network of white matter (WM) connections, which provide efficient and multimodal integration of information between both local and distant cortical nodes. It is important for neurosurgeons to have good knowledge of the three-dimensional subcortical organisation of this highly connected region to minimise post-operative permanent deficits. The aim of this dissection study was to highlight the subcortical functional anatomy from a topographical surgical perspective. Eight human hemispheres (four left, four right) obtained from four human cadavers were dissected according to Klingler's technique. Proceeding latero-medially, the authors describe the anatomical courses of and the relationships between the main pathways crossing the TPO. The results obtained from dissection were first integrated with diffusion tensor imaging reconstructions and subsequently with functional data obtained from three surgical cases, all resection of infiltrating glial tumours using direct electrical mapping in awake patients. The subcortical limits for performing safe lesionectomies within the TPO region are as follows: within the parietal region, the anterior horizontal part of the superior longitudinal fasciculus and, more deeply, the arcuate fasciculus; dorsally, the vertical projective thalamo-cortical fibres. For lesions located within the temporal and occipital lobes, the resection should be tailored according to the orientation of the horizontal associative pathways (the inferior fronto-occipital fascicle, inferior longitudinal fascicle and optic radiation). The relationships between the WM tracts and the ventricle system were also examined. These results indicate that a detailed anatomo-functional awareness of the WM architecture within the TPO area is mandatory when approaching intrinsic brain lesions to optimise surgical results and to minimise post-operative morbidity.

Evaluation of a haptics-based virtual reality temporal bone simulator for anatomy and surgery training.

INTRODUCTION: Virtual reality simulation training may improve knowledge of anatomy and surgical skills. We evaluated a 3-dimensional, haptic, virtual reality temporal bone simulator for dissection training. METHODS: The subjects were 7 otolaryngology residents (3 training sessions each) and 7 medical students (1 training session each). The virtual reality temporal bone simulation station included a computer with software that was linked to a force-feedback hand stylus, and the system recorded performance and collisions with vital anatomic structures. Subjects performed virtual reality dissections and completed questionnaires after the training sessions. RESULTS: Residents and students had favorable responses to most questions of the technology acceptance model (TAM) questionnaire. The average TAM scores were above neutral for residents and medical students in all domains, and the average TAM score for residents was significantly higher for the usefulness domain and lower for the playful domain than students. The average satisfaction questionnaire for residents showed that residents had greater overall satisfaction with cadaver temporal bone dissection training than training with the virtual reality simulator or plastic temporal bone. For medical students, the average comprehension score was significantly increased from before to after training for all anatomic structures. Medical students had significantly more collisions with the dura than residents. The residents had similar mean performance scores after the first and third training sessions for all dissection procedures. DISCUSSION: The virtual reality temporal bone simulator provided satisfactory training for otolaryngology residents and medical students.

Transoral anatomy of the tonsillar fossa and lateral pharyngeal wall: anatomic dissection with radiographic and clinical correlation.

OBJECTIVES/HYPOTHESIS: To evaluate the transoral anatomy of the tonsillar fossa and lateral pharyngeal wall and to correlate these findings with radiographic measurements and transoral robotic surgery (TORS) of patients with early tonsillar tumor. STUDY DESIGN: Preclinical cadaveric study and patient cohort. METHODS: Six complete cadaveric dissections were performed to identify key anatomic landmarks, and these landmarks were validated in two consecutive patients with T1 human papillomavirus-positive squamous cell carcinoma of the tonsil treated by TORS. For radiographic landmark analysis, 25 patients who underwent contrast-enhanced computed tomography (CT) of the neck for a variety of endoscopic skull base procedures were selected. Measurements were taken from the lateral pharyngeal wall at C2-C3 interspace and greater horn of hyoid (C6) to the external carotid artery (ECA). RESULTS: The glossopharyngeal (IX) nerve was consistently identified deep to the superior constrictor musculature and at the intersection of the posterior tonsillar pillar with the base of tongue. The styloglossus muscle forms the deep plane medial to the ECA. The mean measurements for left C2-C3 interspace to the ECA and right C2-C3 interspace to ECA were 17.6 ± 0.8 mm and 18.4 ± 0.8 mm, respectively. Similarly, the mean measurements for left hyoid to ECA and right hyoid to ECA were 3.4 ± 0.8 mm and 4.3 ± 0.6 mm, respectively. CONCLUSIONS: A systematic approach to dissect the tonsillar fossa and lateral pharyngeal wall can be performed using key anatomic landmarks. CT measurements taken at the C2-C3 interspace and greater horn of hyoid bone (C6 level) to the ECA are consistently and reliably achieved.

Venous communication between the right and left kidneys: a rare anatomic variation / Comunicación venosa entre los riñones derecho e izquierdo: una rara variación anatómica

Renal vascular anatomic variations, especially of the renal arteries, have been observed in about 20-30 percent of cases, which are very often verified in the left antimere. These variations showed two or three renal arteries stemming directly from the aorta. These anatomic variations have been considered extremely important risk factors in surgical proceedings by different authors. The dissection of a cadaver showed an uncommon venous feature in addition to renal artery variation, specially, in the left antimere. A direct venous communication between left and right kidneys was verified without there being any relation to the inferior cava vein or common iliac veins. Thus, the knowledge of blood vessel anatomic variation is an important element to improve surgical techniques as well as to provide precise analyses of urological and radiological proceedings in different renal diseases. Specially, taking into consideration that hard traction of the renal pedicle could rupture the vessels, leading to lethal hemorrhaging.

Se han observado variaciones anatómicas vasculares renales, especialmente de las arterias renales, en una frecuencia alrededor del 20 a 30 por ciento de los casos, cuya incidencia se verifica a menudo en el antímero izquierdo. En estas variaciones, de acuerdo con lo que se notó, dos o tres arterias renales provenían directamente de la aorta. Distintos autores han considerado que estas variaciones anatómicas son factores de riesgo extremadamente importantes en los procedimientos quirúrgicos. En esta investigación, por medio de la disección de un cadáver, se observó una característica venosa rara, además de la variación de la arteria renal, especialmente en el antímero izquierdo. Se verificó una comunicación venosa directa entre los ríñones izquierdo y derecho, pese al hecho que no sea común cualquier relación con la vena cava inferior o las venas ilíacas comunes. Así, el conocimiento de la variación anatómica del vaso sanguíneo es un elemento importante para implementar técnicas quirúrgicas, así como proporcionar análisis exactos de procedimientos urológicos y radiológicos en diversas enfermedades renales, pues se debe considerar además que la tracción dura del pedículo renal podría romper los vasos y ocasionar una hemorragia mortal.