Morphometric study of the human malleus during prenatal development.

OBJECTIVES: Establish normal reference values for the human malleus during the second and third trimesters of pregnancy, and describe its growth dynamics and ossification process. METHODS: Thirty spontaneously aborted human fetuses, 12-36 weeks of age, were examined. Temporal bones were obtained en bloc and processed using the skeletal clearing and staining technique. Each malleus was obtained by microdissection. Measurements of anatomical points of the malleus were performed. Ossification was recorded. Statistics were applied. RESULTS: Sixty mallei were obtained. At the end of development, the following measurements were obtained in millimeters: head length, 2.87 (2.30-3.44); neck length, 1.15 (0.92-1.38); manubrium length, 4.45 (3.75-5.16); total length, 8.51 (8.02-8.99); neck width, 1.33 (0.70-1.97); manubrium width, 0.84 (0.82-0.86); and Meckel cartilage width, 0.43 (0.06-0.95). The angle of the longitudinal axis of the malleus was 160° (156-164°). The ossification process of the malleus followed a stereotyped pattern that began at week 16, at the level of the neck, with a single center that expanded to the head and then to the manubrium. Toward the end of development, only the umbo remained cartilaginous. There were no sex-based differences in human malleus size during prenatal development. From the beginning of the second trimester of pregnancy, the longitudinal axis of the malleus acquires dimensions comparable to adults. CONCLUSION: The study of the malleus development provides clues that would explain some anomalies in its development, and can influence decision-making during the placement and design of prostheses in the malleus.

Prenatal development of the human tympanic ring: a morphometric study with clinical correlations.

PURPOSE: To establish normal reference values for the human Tympanic Ring (TR) during prenatal development, and to describe and interpret its growth dynamics. METHODS: Fifty spontaneously aborted human fetuses aged 12-37 weeks with normal external characteristics were evaluated. The parameters measured in the TR were the cephalocaudal and dorsoventral axes, total area, thickness, height, and length and angle of the notch of Rivinus (NR). Data were subjected to statistical analysis. RESULTS: The following values were obtained at the end of fetal development: cephalocaudal and dorsoventral axes, 10.03 and 8.3 mm, respectively; ratio between the two axes, 120%; total area, 65.63 mm2; height and thickness, 0.88 mm and 1.10 mm, respectively; and length and angle of the NR, 4.66 mm and 26.2 degrees, respectively. There were variations in the length of the dorsoventral axis throughout fetal development that affected all other parameters, except for the cephalocaudal axis. There were no sex-based differences in TR size. CONCLUSION: The prenatal development of the TR is dynamic as evidenced by the size variations noted throughout fetal development. Notwithstanding, this structure is a reliable and sensitive marker of developmental abnormalities of the external and middle ear.

A Cellularized Biphasic Implant Based on a Bioactive Silk Fibroin Promotes Integration and Tissue Organization during Osteochondral Defect Repair in a Porcine Model.

In cartilage tissue engineering, biphasic scaffolds (BSs) have been designed not only to influence the recapitulation of the osteochondral architecture but also to take advantage of the healing ability of bone, promoting the implant's integration with the surrounding tissue and then bone restoration and cartilage regeneration. This study reports the development and characterization of a BS based on the assembly of a cartilage phase constituted by fibroin biofunctionalyzed with a bovine cartilage matrix, cellularized with differentiated autologous pre-chondrocytes and well attached to a bone phase (decellularized bovine bone) to promote cartilage regeneration in a model of joint damage in pigs. BSs were assembled by fibroin crystallization with methanol, and the mechanical features and histological architectures were evaluated. The scaffolds were cellularized and matured for 12 days, then implanted into an osteochondral defect in a porcine model (n = 4). Three treatments were applied per knee: Group I, monophasic cellular scaffold (single chondral phase); group II (BS), cellularized only in the chondral phase; and in order to study the influence of the cellularization of the bone phase, Group III was cellularized in chondral phases and a bone phase, with autologous osteoblasts being included. After 8 weeks of surgery, the integration and regeneration tissues were analyzed via a histology and immunohistochemistry evaluation. The mechanical assessment showed that the acellular BSs reached a Young's modulus of 805.01 kPa, similar to native cartilage. In vitro biological studies revealed the chondroinductive ability of the BSs, evidenced by an increase in sulfated glycosaminoglycans and type II collagen, both secreted by the chondrocytes cultured on the scaffold during 28 days. No evidence of adverse or inflammatory reactions was observed in the in vivo trial; however, in Group I, the defects were not reconstructed. In Groups II and III, a good integration of the implant with the surrounding tissue was observed. Defects in group II were fulfilled via hyaline cartilage and normal bone. Group III defects showed fibrous repair tissue. In conclusion, our findings demonstrated the efficacy of a biphasic and bioactive scaffold based on silk fibroin and cellularized only in the chondral phase, which entwined chondroinductive features and a biomechanical capability with an appropriate integration with the surrounding tissue, representing a promising alternative for osteochondral tissue-engineering applications.

Low-set ears and associated anomalies in human foetuses.

OBJECTIVES: To determine the prevalence of low-set ears (LSE) in a group of human foetuses, to analyse the associated anomalies, and to review the development mechanisms possibly involved. METHODS: A total of 1759 human foetuses from spontaneous abortion were evaluated. Foetuses were obtained from the Foetuses and Embryos Collection of the Embryology Department of the Faculty of Medicine of the Autonomous University of Nuevo León. The Ethics Committee gave its approval for this study (EH-230-16). The position of the auricles was determined according to the standards recommended by the Elements of Morphology. Two study groups were created: foetuses with LSE and foetuses with normal ears. In both groups, a detailed examination of the external morphology was performed, followed by thoraco-abdominal micro dissection. Statistical analysis was performed. RESULTS: Two hundred two of the foetuses presented LSE (1148 per 10,000). In this group, 68.8% did not present associated anomalies, while 31.2% had an associated anomaly. The most frequently affected organ was the heart (53.6%), followed by the digestive tract (23.9%), urinary system (16.9%), head and neck (4.2%), and limbs (1.4%). In the group of foetuses with normal ears, only 7.4% of the specimens had associated anomalies, which was a significant difference compared with the LSE group. CONCLUSIONS: Based on the obtained results, we consider that LSE can be used as a sensitive indicator of major anomalies. It is recommended to include a systematic assessment of the position of the auricles in the initial clinical evaluation of any newborn.

Randomized double-blind placebo-controlled trial of buccal misoprostol to reduce the need for additional uterotonic drugs during cesarean delivery.

OBJECTIVE: To determine whether buccal misoprostol during cesarean delivery in conjunction with active management of the third stage of labor reduces the need for additional uterotonic drugs. METHOD: A double-blind, randomized, placebo-controlled trial was performed in Monterrey, Mexico, between February 2008 and December 2013. Eligible women had risk factors for uterine atony and were to undergo cesarean delivery under epidural block. Using a computer-generated sequence and blocks of six, patients were randomly assigned to receive 400µg misoprostol or 800µg placebo buccally after cord clamping. Both groups received an intravenous oxytocin infusion. The primary outcome was the need for additional uterotonic drugs. Analyses were performed per protocol. Patients, investigators, and data analysts were masked to group assignment. RESULTS: A total of 120 women were included in analyses (60 in each group). At least one additional uterotonic drug was required in 24 (40%) women in the placebo group versus 6 (10%) women in the misoprostol group (relative risk 0.16; 95% confidence interval 0.06-0.44). No adverse effects due to misoprostol were recorded. CONCLUSION: Buccal misoprostol during cesarean delivery reduced the need for additional uterotonic drugs to treat uterine atony. ClinicalTrials.gov:NCT01733329.

Morphological Analysis of Major Segments of Coronary Artery Occlusion: Importance in Myocardial Revascularization Surgery / Análisis Morfológico de los Principales Segmentos de Oclusión de las Arterias Coronarias: Importancia en la Cirugía de Revascularización Miocárdiaca

Revascularization surgery should ensure morphological similarity between the coronary artery and the graft. This is an important factor for its duration and permeability. The aim of this study was to analyze the morphological characteristics and morphometrics of the coronary artery segments with greater occlusion. This was an observational, cross-sectional descriptive study that consisted of two phases. A macroscopic phase in which 11 cadaveric hearts were extracted and coronary dominance and length of the anterior interventricular artery (AIA), the right coronary artery (RCA) and the circumflex artery (CXA) were determined. In the microscopic phase a total of 77 segments of these arteries were obtained and the luminal diameter, wall thickness, and amount of elastic fibers and the presence and size of the atheroma were determined. Right coronary dominance was the most frequent. Total vessel length was 15.65±1.17 cm for the AIA, 12.67±2.02 cm for the RCA and 8.79±2.5 cm for the CXA. Diameters ranged from 2.3 mm in the proximal segments and between 1.1 mm to 1.8 mm in the distal segments. Wall thickness in the proximal segments was between 354 µm and 396 µm and in the distal segments it ranged from 120 µm to 305 µm. The amount of elastic fibers showed that they were muscular arteries. Atheromas were present in 35% in the CXA, and in 32.5% in the AIA and the RCA. The largest ones were found in the proximal segments. This study examined the morphology and morphometry of the segments of the coronary arteries that are more frequently occluded. It provides information on the most significant parameters to be considered for election of the vascular graft in myocardial revascularization surgery.

En la cirugía de revascularización miocárdica se debe asegurar la similitud morfológica entre la arteria coronaria y el injerto. Esto es un factor importante en su duración y permeabilidad. El objetivo fue analizar las características morfológicas y morfométricas de los segmentos de mayor oclusión de las arterias coronarias. Estudio observacional, transversal y descriptivo que constó de dos fases. Una macroscópica en la que se extrajeron 11 corazones de cadáveres y se determinó la dominancia coronaria y longitud de la arteria interventricular anterior (AIA), la arteria coronaria derecha (ACD) y la arteria circunfleja (ACX). En la fase microscópica se obtuvo un total de 77 segmentos de estas arterias y se determinó el diámetro luminal, grosor de pared, cantidad de fibras elásticas y presencia y tamaño de ateroma. La dominancia coronaria derecha fue la más frecuente. La longitud total de los vasos fue de 15,65±1,17 cm para la AIA, de 12,67±2,02 cm para la ACD y 8,79±2,5 cm para la ACX. Los diámetros oscilaron entre los 2,3 mm en los segmentos proximales y entre 1,1 mm a 1,8 mm en los segmentos distales. Los grosores de pared en los segmentos proximales se presentaron entre 354 µm y 396 µm y en los segmentos distales oscilaron entre 120 µm a 305 µm. La cantidad de fibras elásticas demostró que son arterias musculares. El 35% de los ateromas se presentó en la ACX y el 32,5% en la AIA al igual que en la ACD. Los de mayor tamaño se encontraron en los segmentos proximales. Este estudio analizó la morfología y la morfometría de los segmentos de las arterias coronarias que se ocluyen con mayor frecuencia. Los resultados encontrados aporta información sobre los parámetros más significativos que se deben considerar para la elección del injerto vascular en la cirugía de revascularización miocárdica.

Prenatal development of the maxillary sinus: a perspective for paranasal sinus surgery.

OBJECTIVE: To review the prenatal development of the maxillary sinus under the perspective of the sinus surgery. STUDY DESIGN: Cross-sectional study. SETTING: Basic embryology laboratory. SUBJECTS AND METHODS: Morphometry and morphology of the maxillary sinus and its ostium were studied under stereomicroscopy in 100 human fetuses from the 9th to the 37th week. Fetuses were obtained from the Fetal Collection of the School of Medicine of the Universidad Autónoma de Nuevo León. Approval was granted by the Ethics Committee. Statistics were applied. RESULTS: The maxillary sinus begins its development at the 10th week. On the 37th week, the anterior-posterior diameter has a mean of 4.36 mm; ossification of the medial wall was absent, and the floor was located below the attachment of the inferior turbinate. Septa and recesses were temporarily observed. Some variations in shape were observed; however, only the oval shape persisted. Maxillary sinus hypoplasia was not found, although asymmetry was present in 30% of cases. The ostium was located at the anterior third of the ethmoid infundibulum; its final dimensions were 1.96 mm in length and 0.44 mm in width. The mean length between the ostium to the lamina papyracea and nasolacrimal duct was 1 mm. One case of double maxillary sinus was observed. Significant difference between the variables, in accordance with the age, was found (P = .02). CONCLUSION: Knowledge of prenatal development of the maxillary sinus improves the perspective of the sinus surgeon and helps the understanding of postnatal anatomy, especially in children.

Estudio Anatómico de los Arcos Palmares: Diámetro y Presentación / Anatomic Study of the Palmar Archs: Diameter and Presentation

Las arterias más importantes de la mano son la radial y ulnar, las que forman los arcos palmares superficial y profundo. La descripción detallada de las características anatómicas de los arcos palmares ha contribuido al desarrollo de nuevas técnicas microquirurgicas en la mano. Los objetivos de este estudio fueron establecer el patrón arterial de la mano, así como determinar el diámetro luminal de las arterias que contribuyen a la formación de los arcos. Se realizó un estudio descriptivo, utilizándose 25 manos de cadáveres embalsamados. Se seccionaron las arterias en diferentes puntos para su tinción y observación al microscopio de luz. El arco palmar superficial completo fue observado en 14 (56%) muestras y en 11 (44%) se presentó de manera incompleta. El arco palmar profundo completo se encontró en 20 muestras (80%) y sólo en 5 (20%) fue incompleto. La presentación de los arcos arteriales palmares es muy compleja y variada, encontrándose siempre, al menos uno de los arcos completo.

The radial artery and unlar artery are the most important arteries of the hand, they form a superficial and deep palmar arches. The detailed description of the anatomic characteristics of the palmar arches have contributed to develop new microsurgical techniques for the hand. The aim of this study was to establish the arterial pattern in the hand, and also to determine the luminal diameter of the arteries that contributes to palmar arches. It was a descriptive study. We used 25 hands of embalmed cadavers. We cut the arteries in differents points and after that they were stained and observed in optical microscope. The complete superficial palmar arch was found in 14 (56%) samples and 11 (44%) samples it was incomplete. The complete deep palmar arch was found in 20 (80%) samples and 5 (20%) it was incomplete. The presentation of the palmar arches is complex and variable, but always exist one complete arch (deep or superficial).