Appropriate concentration of acetic acid for the preservation of fresh cadaveric brains to be used in surgical training: a preliminary study / Concentración adecuada de ácido acético para la preservación de cerebros de cadáveres frescos para uso en entrenamiento quirúrgico: un estudio preliminar

A small amount of acetic acid (AA), a common preservative, has been shown to increase contamination in cadaveric tissue, while larger concentrations can lead to the tissue becoming hard, especially in fresh brains. This study attempted to optimize the concentration of AA to be used in the cranial cavity in order to produce the most realistic consistency and color. Six adult cadaveric heads were preserved with descending glacial AA at concentrations of 98.5 %, 80 %, 60 %, 40 %, 20 %, and 10 %. The samples were kept at 5 °C for 14 days. The brain cortex was then dissected with a suction tube and forceps to reveal the underlying brain tissue for inspection. Color change, cortical firmness, pia mater stickiness, and participant satisfaction were evaluated. The color of the brains in all concentrations was slightly yellow. However, the temporal area of the brain preserved using 20 % AA was significantly more pink. The pia mater of the brain cortex of all samples was firm and difficult to pry apart, with the firmest consistency being in the brain tissue preserved using 98.5 % AA. The brain tissue in all samples had a liquid-like consistency. The brains preserved in AA at a concentration greater than 60 % yielded higher satisfaction scores. We conclude that acetic acid has a role in brain preservation for skull base surgery training and recommend AA concentrations higher than 60 % for maximal participants satisfaction.

Se ha demostrado que una pequeña cantidad de ácido acético (AA), un preservante común, aumenta la contaminación en el tejido del cadáver, mientras que mayores concentraciones pueden endurecer el tejido, particularmente en cerebros frescos. Este estudio intentó optimizar la concentración de AA en la cavidad craneal para producir una consistencia y coloración cerebral más cercanos a la realidad. Seis cabezas cadavéricas adultas se conservaron con AA glacial descendente en concentraciones de 98,5 %, 80 %, 60 %, 40 %, 20 % y 10 %. Las muestras se mantuvieron a 5 °C durante 14 días. Luego se diseccó la corteza cerebral con un tubo de succión y pinzas para observar e inspeccionar el tejido cerebral subyacente. Se evaluaron el color, la firmeza cortical, la viscosidad y adherencia de la piamadre y la reacción de los participantes ante esta conservación. El color de los cerebros en todas las concentraciones fue ligeramente amarillo. Sin embargo, el área temporal del cerebro, conservada con un 20 % de AA, fue significativamente más rosada. La piamadre de la corteza de todas las muestras fue de consistencia firme y difícil de separar; una mayor resistencia se observó en el tejido cerebral preservado con 98,5 % de AA. La consistencia del tejido cerebral en todas las muestras era líquida. Los cerebros conservados en AA a una concentración superior al 60 % recibieron puntuaciones de satisfacción más elevadas. Concluimos que el ácido acético desempeña un papel en la preservación del cerebro, permitiendo el entrenamiento en cirugía de base de cráneo, por lo que recomendamos concentraciones de AA superiores al 60 % para una satisfacción máxima por parte de los participantes.

A comparative study comparing area of extension of posterior knee capsule via posteromedial injection: a cadaveric study.

BACKGROUND: Periarticular multimodal drug injection (PMDI) has gained popularity as common postoperative pain protocols in knee arthroplasty. PMDI sites can vary, but posterior capsule (PC) is a common injection site because of its abundance of pain nociceptors. PURPOSE: To prove the hypothesis whether posteromedial drug injection alone is sufficient to provide enough effect covering the PC in order to reduce risks of neurovascular injury. Secondary outcomes are to find proper volume of injection and safe zone for PMDI injection. METHODS: Ten fresh cadaveric knees were allocated into two equal groups, which differed in volume of dye injection: 25 ml and 50 ml. Dyes were injected into posteromedial capsule compartment, and the limbs were stored in a freezer for 2 weeks. Then the posterior compartment was carefully dissected to examine spreading of the dye solution. RESULTS: No dye staining was seen superficially beneath subcutaneous tissue of the knees. In deeper layer, the dye mostly occupied medially along the fascia covering semimembranosus muscles. However, dispersion was limited distally by intermuscular septa and popliteal vessels. The 50-ml injection group provided wider extension in the superficial layer, but not in the deep layer. CONCLUSION: The intermuscular septa and the fascia of popliteal vessels were shown to be the boundary between posteromedial and posterolateral compartments of the knee. Separate PMDI for both compartments is necessary to occupy the entire PC. We suggest that 1.5 cm lateral to lateral border of PCL insertion, just above popliteus tendon, is the safe zone for injecting PMDI into the posterolateral capsule.

Types and morphometric study of calcaneal articular facets on human tali of Thai population / Tipos y estudio morfométrico de las facetas articulares calcáneas en talus humano de la población tailandesa

Patterns and variant morphometries of calcaneal articular facets on talus are concerned before performing of joint ankle surgery, including used as a sex determination. Types of talar facets have been documented in many populations except in Thai race. Therefore, this study attempted to classify the types of talus facets and to measure the facet lengths on dried tali of Thais. The 372 dried tali (204 males, 168 females) from Khon Kaen University Bone Collection were observed for variant types and measured for their facet lengths. The facets were classified into 6 types: type I, tree facet are separated (1.88 %); type II (A), the anterior and middle facets are partially connected with predominant ridge (34.68 %); type II (B), the anterior and middle facets are partially connected with slight ridge (32.53 %); type III, the anterior and middle facets are fully fused to form a single facet (2.96 %); type IV, the anterior and middle facets are partially separated by a ridge and partly by a groove (27.42 %); type V, all facets are continuous fused to form a single facet (0.54 %). In addition, the morphometric lengths of AP (anterior to posterior process) and ML1&2 (medial to lateral process) in male are significantly greater than those of female. The AP, ML, and ML2 of male are 56.71±0.16, 41.63±0.18, and 37.85±0.36 mm, while of female are 51.21±0.12, 37.74±0.16, and 33.85±0.28 mm, respectively. This incidence can be used as ankle surgery consideration and an anthropological marker for sex determination of unidentified talus.

Los patrones y las variantes morfométricas de las facetas articulares calcáneas en el talus deben considerarse antes de la realización de la cirugía del tobillo a nivel articular, incluido su uso para la determinación del sexo. Se han documentado los tipos de facetas en el talus en muchas poblaciones, excepto en la raza tailandesa. Por lo tanto, este estudio clasificó los tipos de facetas del talus y se midieron las longitudes de las facetas del talus, en muestras secas de indiviuos tailandeses. Se analizaron 372 talus secos (204 de hombres, 168 de mujeres) de la colección de huesos de la Universidad Khon Kaen, se observaron distintos tipos de variantes y se midieron las longitudes de las facetas. Las facetas se clasificaron en 6 tipos: tipo I, faceta de árbol separadas (1,88 %); tipo II (A), facetas anterior y media parcialmente conectadas con la cresta predominante (34,68 %); tipo II (B), facetas anterior y media están parcialmente conectadas con una ligera cresta (32,53 %); tipo III, facetas anterior y media están completamente fusionadas para formar una sola faceta (2,96 %); tipo IV, facetas anterior y media están parcialmente separadas por una cresta y en parte por una ranura (27,42 %); tipo V, todas las facetas se fusionan continuamente para formar una sola faceta (0,54 %). Además, las longitudes morfométricas del proceso anterior o posterior (AP) y del proceso medial a lateral (ML1 y ML2) en el varón son significativamente mayores que las de la mujer. El AP, ML1 y ML2 de los hombres son 56,71 ± 0,16, 41,63 ± 0,18 y 37,85 ± 0,36 mm, mientras que las mujeres son 51,21 ± 0,12, 37,74 ± 0,16 y 33,85 ± 0,28 mm, respectivamente. Esta incidencia se puede utilizar como una consideración en la cirugía de tobillo y un marcador antropológico para determinar el sexo del talus no identificado.

Cadaveric study of the anatomical reference points for proximal humeral plate positioning.

BACKGROUND: Complications following locking plate fixation in proximal humeral fractures often related to malposition plates and inadequate screw fixation. However, literature did not define the best anatomical reference point for plate positioning. We conducted a study to assess the occurrence of subacromial impingement and screw perforation with two anatomical reference points for proximal humeral plate positioning. METHOD: Sixty shoulders of 30 cadavers were dissected, and proximal humeral locking plate was placed in two different levels in the coronal plane of the upper tip of plate: (1) the proximal portion of bicipital groove group and (2) the most prominent of lesser tuberosity group. Subacromial impingement during passive forward elevation and screw perforation were assessed in relation to the plate positioning. RESULTS: No subacromial impingement during passive motion contacted to the plate in both groups. The calcar screw perforation rate was significantly lower in the proximal portion of the bicipital groove group (2 of 60 specimens, 3.33%) than the most prominent of lesser tuberosity group (52 of 60 specimens, 86.67%). The most proximal screws of the plate were no humeral head perforation in all specimens. CONCLUSION: Our study would suggest that two anatomical reference points could be used to be the landmark to avoid the subacromial impingement and the most proximal screw perforation. However, the placement of the locking plate using the proximal portion of bicipital groove reference is better for calcar screw insertion.

Monitoring the biochemical alterations in hypertension affected salivary gland tissues using Fourier transform infrared hyperspectral imaging.

Fourier transform infrared spectroscopy (FTIR) imaging has been applied to investigate biochemical differences between salivary glands from control and hypertensive rats. Male Sprague-Dawley rats were divided into two groups including a control group and another hypertension group that were treated orally, with N-nitro-l-arginine methyl ester (l-NAME) via drinking water for 3 weeks to develop hypertension. In the control group, rats were treated with only drinking water for 3 weeks. The formalin-fixed paraffin embedded tissue specimens from submandibular and sublingual glands were analysed with a FTIR focal plane array imaging spectrometer and multi-composite images of all tissue sections were analysed simultaneously using Unsupervised Hierarchical Cluster Analysis (UHCA) and the extracted spectra were further analysed using Partial Least Squares Discriminant Analysis (PLS-DA). In general, hypertension affected salivary gland tissues were characterised by higher concentrations of triglycerides as evidenced by an increase in the 1745 cm-1 band. Higher concentrations of carbohydrates and proteins were also observed in the hypertensive group along with a decrease in bands associated with nucleic acids. PLS-DA scores plots provided good differentiation in sublingual gland tissues between control (n = 3734 spectra) and hypertension (n = 4538) and also in submandibular gland tissues between control (n = 5051) and hypertension (n = 4408). We have shown that FTIR imaging can be used to differentiate the macromolecular information between physiological and pathological conditions in tissue biopsy specimens. In the next phase, we will investigate the infrared predictive markers of hypertension in biofluids including serum and saliva using attenuated total refection spectroscopy.

Sexual dimorphism using the interstyloid distances and clinical implication for elongated styloid process in Northeastern Thailand / Dimorfismo sexual usando la distancia inter-estiloide y la implicación clínica del proceso estiloides elongado en el Noreste de Tailandia

Skeletal remains are crucial in forensic identification of the sex, especially human skulls including the styloid process, a bony projection from the skull. Hence, the objectives of the present study were undertaken to assess the value of the styloid process for the sex identification of unknown skulls and also to investigate the prevalence of elongated styloid process in 102 human dry skulls from the northeast Thai population. As a result, the interstyloid distances at both base and tip of the styloid processes were found to be significantly different between male and female specimens, although no significant difference was found in the length of the styloid process between males and females. In addition, the occurrence of the elongated styloid process was not associated with the gender, although its prevalent laterality on the left was recognized. It is suggested that the styloid process can be applied to the sex identification by measuring the interstyloid distance at the base or the tip of these processes.

Los restos óseos son cruciales para la identificación forense del sexo, especialmente en los cráneos humanos, incluyendo el proceso estiloides, una proyección ósea del cráneo. Por lo tanto, los objetivos del presente estudio consistieron en evaluar el valor del proceso estiloides en la identificación del sexo de cráneos desconocidos y también para investigar la prevalencia del proceso estiloides elongado en 102 cráneos secos humanos de la población del Noreste de Tailandia. Como resultado, se encontró que las distancias inter-estiloides tanto en la base y la punta de los procesos estiloides eran significativamente diferentes entre las muestras de hombres y mujeres, aunque no se encontró diferencia significativa en la presencia del proceso estiloides entre ambos. Además, la aparición del proceso estiloides elongado no se asoció con el sexo, aún cuando se observó su prevalencia en el lado izquierdo. Sugerimos que el proceso estiloides se puede utilizar en la identificación del sexo mediante la medición de la distancia inter-estiloide en la base o en la punta de estos procesos.

Transversus menti muscle in a thai cadaver / Músculo transversus menti en un cadaver tailandés

In submental and around the mouth areas, the superfacial muscles are considered in surgery of some deformities of mouth angle. Herein, we report a rare case of the Transversus menti muscle (TM) in a Thai 74 year-old male cadaver. This TM originated from both sides of the oblique line of depressor anguli oris and formed as transverse fibers in submental area. Their fiber ran under the chin and was superficial to platysma muscle. The TM was innervated and supplied by mandibular branches of facial nerve and small branches of the submental artery. This report attempted to discuss the possible function and clinical significance of the TM.

Alrededor de la boca y en áreas submentonianas, los músculos superficiales son considerados en la cirugía de algunas deformidades del ángulo de la boca. Este estudio presenta un caso raro de músculo transversus menti (TM), en un cadáver tailandés de sexo masculino de 74 años de edad. El músculo TM se originó a partir de los dos lados de la línea oblicua del músculo depresor del ángulo oral y se formó como fibras transversales en el área submentoniana. Sus fibras se desplazaron debajo del mentón y superficialmente al platisma. El músculo TM estaba inervado e irrigado por ramos mandibulares de nervio facial y pequeñas ramas de la arteria submentoniana. Se discute su posible función y el significado clínico del músculo TM.

Commentary: Is the Evidence for Localization of Nephrin on the Slit Diaphragm Rigid? / Comentario: ¿Está la Evidencia para la Localización de Nefrina en el Diafragma de Ranura Rígido?

After careful observation of immuno-electron microscopic findings of the renal glomerular podocyte slit so far published by various authors, it should be noted that no convincing evidence is present for localization of nephrin-immunoreactivity in the slit itself, but that nephrin-immunoreactivity is dominantly localized along the membranes of podocyte pedicles from their tip over a substantial extension. In addition, the notion that the slit diaphragm is composed of strands is compatible with the widely distributed view that the slit strands represent rod-shaped nephrin molecules. However, 3-D findings that the diaphragm is composed of not only strands but also membranous elements have recently demonstrated separately by embedment-free section electron microscopy as well as by frozen/deep-etched replica electron microscopy. It is therefore suggested that the molecular composition of the slit diaphragm remain to be further elucidated, and that it is also necessary to re-consider how nephrin is involved in the renal glomerular filtration based on the exact localization along the podocyte membrane, but not in the slit itself. The present author would welcome any criticism and opinion on his consideration.

Después de una cuidadosa observación de los hallazgos inmunoquímicos, vía microscopio electrónico, de la hendidura del podocito glomerular renal ampliamente publicados por varios autores, se debe hacer notar que no existe evidencia convincente de la presencia de inmunorreactividad de nefrina en la hendidura propiamente tal, ya que la inmunorrectividad de nefrina está predominantemente localizada a lo largo de la membrana de los podocitos desde su extremo sobre una sustancial extensión. Agregado a ello, la idea de que el diafragma de la hendidura está compuesto de filamentos es compatible con la visión que los filamentos diafragmáticos representan moléculas de nefrina en forma de varilla. Sin embargo, hallazgos en 3D muestran que el diafragma está compuesto no solamente de filamentos sino que también por elementos membranosos que han sido demostrados recientemente por sección libre de microscopía electrónica (embedment-free), así como también por microscopía electrónica de réplica por congelación y grabado profundo (frozen/deep-etched). Por lo tanto, se ha sugerido que la composición molecular del diafragma de filtración permanece para ser estudiada en el futuro y que es también necesario reconsiderar como la nefrina está involucrada en la filtración glomerular renal basados en la localización exacta a lo largo de la membrana del podocito pero no en la hendidura misma. A los autores les gustaría recibir alguna crítica u opinión sobre su consideración.

Frontal sinus drainage in Thai adult skulls.

OBJECTIVE: To study the pattern of the nasofrontal drainage in relation to the neighboring anatomical structures in adult Thai cadavers. MATERIAL AND METHOD: The anterior aspect of the frontal bone of the embalmed half-head was drilled to identify the presence of the frontal sinus i.e. 40 from only one side of each cadaver were chosen. A silicone base and catalyst were combined then injected into the frontal sinus, which flowed into the nasal cavity through its natural ostium, thereby creating a cast of the nasofrontal connection(s). After allowing five minutes for the silicone to set, the total vertical lamella of the middle turbinate was removed, so the cast could be measured, the connections meticulously dissected and the surrounding structures observed RESULTS: The investigation revealed five patterns of nasofrontal drainage. The most (60%) common pathway was directly through the frontal recess, while the other pathways 12.5, 10, 10 and 7.5 percent were drained directly into the ethmoid infundibulum, through the agger nasi cell and then into the ethmoid infundibulum, into both the agger nasi cell, the ethmoid infundibulum and the suprabullar recess, respectively. The average sizes of the anteroposterior and mediolateral diameters of the frontal sinus ostium were 6.5 and 5.5 mm, respectively. The agger nasi cell was present in every cadaver with a frontal sinus and was always superior to the ventral attachment of the middle turbinate. CONCLUSION: The agger nasi cell is the key structure vis-a-vis planning and performing frontal sinus surgery. In preparation for endoscopic intranasal frontal sinus surgery, it is practical to extend the infundibulotomy superiorly into the agger nasi cell, then remove its medial, posterior and superior wall.

Landmark of ethmoid arteries in adult Thai cadavers: application for sinus surgery.

BACKGROUND: Ethmoid arteries, branches of the ophthalmic artery, are crucial structures supplying ethmoid mucosa. Its locations are important during ethmoid sinus surgery. There has been no study in Thais before. OBJECTIVE: To determine the number and locations of ethmoid arteries in relation to important surrounding structures. MATERIAL AND METHOD: A prospective, descriptive study in 42 Thai cadaveric adult half-heads was conducted at departments of Otorhinolaryngology and Anatomy, Faculty of Medicine, Khon Kaen University, Thailand. Meticulous dissections were performed to identify number of ethmoid arteries branching from ophthalmic artery and site of entrance of the arteries into ethmoid sinus. Relationships of these arteries with anterior ethmoid crest, optic foramen, bulla lamella and middle third of basal lamella of middle turbinate were studied. OUTCOMES: Types of ethmoid arteries, distances between ethmoid arteries and their relations to important surrounding structures: anterior lacrimal crest, optic foramen, superior aspects of bulla lamella, middle third of basal lamella of middle turbinate and the superior aspect of anterior wall of sphenoid sinus. RESULTS: All specimens had anterior and posterior ethmoid arteries. The prevalence of tertiary ethmoid artery was 36% (95% CI22-52%). The mean distance between the anterior ethmoid artery and anterior lacrimal crest, anterior ethmoid artery and posterior ethmoid artery and the distance between posterior ethmoid artery and optic foramen were 24.3, 13.5 and 6.4 millimeters respectively. Most of the entry of anterior ethmoid artery into the ethmoid sinus was in the posterior half of the distance between the bulla lamella and middle third of basal lamella of middle turbinate, 85.7%. CONCLUSION: This is the first study of location of ethmoid arteries in Thai adult cadavers. The information of the present study may be useful for sinus surgeon.

The prevalence of an Onodi cell in adult Thai cadavers.

Endoscopic sinus surgery in patients who have an Onodi cell (sphenoethmoid cell) carries a high risk for optic nerve injury. We meticulously dissected 65 embalmed cadaver adult half-heads and attempted to identify an optic canal bulge in each with a nasal endoscope. Our aims were to determine the prevalence of an Onodi cell in adult Thai cadavers, to ascertain the prevalence of an overriding ethmoid cell, and to measure the length of an overriding ethmoid cell's superior and posterior extensions in relation to the anterior sphenoid wall. Moreover, we attempted to determine the minimum amount of bone thickness between an Onodi cell and the optic nerve. We found that an Onodi cell was present in 39 of the 65 specimens (60.0%). We also found that an overriding ethmoid cell was present in 14 specimens, which accounted for 21.5% of the total number of specimens and 36.8% of 38 Onodi cell-positive specimens (the presence or absence of an overriding ethmoid cell was not recorded in one of the 39 Onodi cell-positive specimens). The distance of the overriding ethmoid cell's superior and posterior extensions from the anterior sphenoid wall ranged from 3 to 13 mm (median: 7) and from 4 to 16 mm (median: 9.5), respectively. Measurements of the minimum amount of bone thicknesses between each Onodi cell and optic nerve ranged from 0.03 to 0.54 mm (median: 0.08). Our study demonstrated that the prevalence of an Onodi cell in adult Thai cadavers was as great as the prevalence reported in the only other gross anatomic dissection study performed in Asia and much higher than rates generally reported in Western countries.