Incidencias de hernias abdominales anteriores en pacientes asistidos en el Hospital Militar Cap.(Av) Dr. Guillermo Hernández Jacobsen: mayo 2005-octubre 2006 / Incidence abdominal hernias in patients assisted at the Hospital Militar Cap.(Av) Dr. Guillermo Hernandez Jacobsen: may 2005-october 2006

Se realizó un estudio retrospectivo y descriptivo con 207 pacientes de todas las edades operados en el Servicio de Cirugía General y Pediátrica en el Hospital Militar de San Cristóbal, a quienes se les practico Herniplastia en la pared abdominal anterior. Durante el periodo de dieciocho meses comprendidos desde mayo 2005 a octubre 2006. Más de la tercera parte de los pacientes tenían entre 16 y 30 años de edad, con predominio del sexo masculino, en una relación 2:1 a excepción de la Crural. El mayor número de cirugía de urgencia se realizó en personas mayores de 76 años. La hernia Umbilical fue el diagnóstico operatorio más frecuente (52.17 por ciento). La Hernia inguinal fue la segunda en frecuencia y constituyo la asociada con mayor relevancia. La Epigástrica predominó ante la Crural. La mortalidad por complicación fue nula. Cerca del 4 por ciento de los pacientes fue intervenido de emergencia. Por lo que concluimos que nuestros resultados en los diferentes tipos de hernias estudiados no escapan de los observados en las estadísticas nacionales e internacionales.

Rectovaginal fascia: An important structure in pelvic visceral surgery? About its development, structure, and function.

BACKGROUND: The existence, development, and function of the rectovaginal fascia has been discussed in literature. In women, a defect in the fascia leads to rectoceles and severe constipation. In pediatric textbooks for anorectal or urogenital surgery, however, it is not mentioned. Does the fascia exist in children? METHODS: The pelvises of 31 female and, as controls, 31 male fetuses (age from 9 weeks of gestation to newborn) were plastinated. Sections (transversal, sagittal, and frontal) were stained with azure II/ methylenblue/ basic fuchsin and viewed at a magnification of 6.5x to 80x. In addition, the authors investigated macroscopically and microscopically the rectovaginal fascia in 1 fetal and 1 adult cadaver. RESULTS: At the beginning of the fetal period the authors recognized the anlage of the rectovaginal fascia caudal from the rectouterine excavation. Later, a fascia of connective tissue develops. It is connected directly to areolar connective tissue at the dorsal wall of the vagina. Neurovascular bundles are situated ventrolaterally of the rectal wall. At the level of the anorectal flexure this fascia separates the rectum and the vagina. CONCLUSIONS: Our investigations indicate that the rectovaginal fascia is completely developed in newborns, through differentiation of mesenchyme, which develops into a fascia. It protects different compartments and serves as an abutment to the rectal wall. Thus, it is important for adequate bowel emptying. For the surgeon it is a leading structure for preventing nerve damage of the autonomic nerve supply of the pelvic organs. It should be known, protected, and, if necessary, reconstructed.

Effects of masticatory muscle function and bite-raising on mandibular morphology in the growing rat.

The aim of this series of investigations was to study the effect of masticatory muscle function on the growth pattern and on the internal structure of the mandible during growth. The muscular and dentoskeletal growth adaptation to prolonged bite-raising and the role of the functional state of the masticatory muscles in this adaptation were also to be elucidated. Differences in masticatory muscle function were induced in young rats by altering the consistency of the diet. Bite-raising was produced by the insertion of posterior bite blocks. Morphometric analysis of the internal bone structures of the mandible was performed on microradiographs, and videodensitometric analysis was performed on lateral radiographs and microradiographs. The effect of muscle function and bite-raising on mandibular growth was studied on a series of lateral cephalograms, superimposed on bone markers. Muscle belly, sarcomere and aponeurosis length adaptation to bite-raising was studied in situ with a digital caliper and under a microscope after fluorescent vital staining of the deep masseter muscle. A soft diet altered the pattern of growth of the mandible and reduced bone growth in the angular region. Transversal dimensions and cross-sectional area of the dentoalveolar process were smaller. Bone mass in areas possibly subjected to direct loads or bending forces was smaller. This was due to either less trabecular bone or thinner cortical bone. Only a few sites showed lower bone density. Posterior bite-blocks affected the size of the mandible as well as its growth pattern, and intruded lower molars. The soft diet influenced the effect of bite-blocks and caused less intrusion of upper molars and less inhibition of bone growth at the angular process. The deep masseter muscle adapted to bite-raising by elongation of the aponeurosis, but less in rats on a soft diet. Changes in masticatory muscle function affected the growth of the mandible in both the sagittal and transversal plane. Reduced loads on molars and condyle and smaller bending forces in other regions of the mandible possibly reduced the levels of stimulation of the osteocyte network and osteoblasts, thus inducing less trabecular bone and cortical bone formation in specific areas. In rats fed the soft diet, smaller increase in bone density represented an adaptation process in areas characterised by a lower bone apposition rate. The forces produced by the passive stretching of the masseter muscle affected the skeletal growth pattern and dental eruption. Weaker forces possibly produced by passive stretching of hypofunctional muscles resulted in more eruption of the upper molars and less inhibition of periosteal bone apposition in the angular region. Length adaptation in the masseter muscle through lengthening of the aponeurosis and dentofacial growth adaptation possibly decreased passive forces applied to teeth and skeletal structures, particularly in rats with higher functional demands. This may have caused a gradually decreasing effect of the appliance.

Adaptation of normal and hypofunctional masseter muscle after bite-raising in growing rats.

The aim of this study was to analyze the effects of prolonged muscular elongation induced by bite-raising on the length of the muscle belly, sarcomeres and aponeurosis of the anterior deep masseter in the growing rat. Another aim was to determine the role of different functional conditions of this muscle in the adaptation process. Ninety-six young male rats were split into two groups: one was fed a hard diet and the other a soft diet to develop different functional capacities in the masticatory muscles. After 2 wk, half of the rats in both groups were fitted with an appliance that raised the bite by 2 mm. The measurements on the muscles were performed in situ. The insertion of the appliance stretched the anterior masseter muscle. After 4 wk, the vertical dentoskeletal dimension, the muscle belly, and the sarcomeres showed no difference in length among the groups. However, the aponeurosis was longer in the rats wearing the appliance compared to the controls, and among the bite block groups it was longer in the rats fed a hard diet. Length adaptation occurred in the aponeurosis. Clinically this may imply a need for reactivation of functional appliances to increase their efficiency, at a rate possibly depending on masseter muscles functional condition.

The effect of pulsed expansion of subfascially placed expanders on the extent and duration of mitosis in the capsule and rat integument.

This study investigated the mitotic activity in the subdermally induced capsule and the epithelium surrounding tissue expanders maintained by pulsed expansions. Tissue expanders were placed into the fascial plane beneath the panniculus muscle of the rat and expanded sequentially. The volume in the expander was rapidly increased to a constant level and maintained for 48 hours; this was followed by a total decrease of volume for 48 hours. The procedure was repeated with volumes of 20, 30, and 40 mL. At the conclusion of each cycle of expander inflation, a group of rats was killed, and biopsy specimens of the induced capsule and epithelium were obtained. The developing capsule exhibited a significant increase in the mitotic index in the layers adjacent to the expander. The highest mitotic index was obtained with an inflation of 30 mL. These observations suggest that cellular proliferation, growth, and development of the extracellular matrix in the induced subdermal capsule can be sustained by pulsed volume changes in the expander.

[Development of the rectal fascia]. / Entwicklung der Fascia recti.

The development of the fascia recti was investigated by 300-600 microns thick sections through the pelves of 8-35-week-old human fetuses, of newborn children and adults. The pelves were impregnated with an epoxy resin and cut with a diamond wire-saw. We here report that the fascia recti develops as part of the adventitia recti. In 9-week-old fetuses the latter consists of condensed mesenchyme which in 18-20-week-old fetuses develops to a fibrous connective tissue surrounding the rectum. In newborn children adipose tissue starts spreading between the connective tissue lamellae of the adventitia recti and thereby separates them. The most external of these connective tissue lamellae is rather dense and can be regarded as fascia recti. In the adult we found it not always as strongly marked as in newborn children. The close developmental relations between the fascia recti and the tissue of the adventitia recti might be seen as cause for the temporary stop of tumor spread at the fascia recti.

Connective tissues of the hand and foot.

In this paper we are submitting studies on the onto- and phylogenetic development of the superficial muscular and fascial layers of the hand and forearm of mammals. The object of this study was to investigate the following items: the ontogenetic development of the m. flexor digitorum superficialis, of the m. flexor digitorum profundus, of the m. palmaris longus, of the palmaris brevis of the human hand, the nerve supply of these muscles, the development of palmar and plantar aponeurosis and of other fasciae related to the palmar and plantar aponeuroses. We compared conclusions drawn from the studies on the ontogenetic development with observations gained from the phylogenetic development of the structures of the human hand and forearm and applied our findings to various species of mammals. The results of these comparisons are expressed in this study presenting interpretations of the phylogenetic development of superficial muscular and fascial layers of the mammalian hand and foot. Furthermore we ascertained the homology of the superficial muscular and fascial layer of the mammalian autopodion, we reviewed one of the theories on the origin of Dupuytren's contracture and commented on opinions of the developmental origin of certain muscular varieties present in the human hand and forearm. Apart from this we established certain basic data on the development of the fasciae of the human hand and foot. Our findings on the variability of the palmar aponeurotic attachments of the human hand were confronted with the incidence and frequency of one particular finger when affected by a Dupuytren's contracture and we commented on the predisposition of certain fingers or toes for the affliction of this impairment. We conducted 152 series of histological sections through the hand and feet of embryos and foetuses sized 12-100 mm in c.-r. length, as well as 84 series of histological transverse sections through human embryonal hands in order to study the ontogenetic development of superficial muscular and fascial layers of the human hand, forearm and foot. The embryonal extremities were cut transversally, parallel to the palm and several sagittal sections were carried out for control purposes. The phylogenetic development of the superficial muscular and fascial layers of the hand was investigated by specimens processed under a micro-dissecting microscope. 55 specimens of various extremities were thus prepared, obtained from 22 species of mammals. Many animals were selected in order to cover species of mammals significant for their evolution.(ABSTRACT TRUNCATED AT 400 WORDS)

[Development, configuration and structure of the temporal fascia in humans]. / Sviluppo, configurazione e rapporti della fascia temporale nell'Uomo.

The genesis, configuration and structure of the temporal fascia in humans, during the various stages of fetal development and in the adult were studied in order to contribute to the knowledge of its morphological and topographical characteristics. The most remarkable results are: (1) In the adult, there is a thin connective laminar layer interposed between the "galea capitis" and the temporal fascia, derived from the deep subcutaneous layer; (2) the temporal fascia develops about the third month of intra-uterine life and is well outlined at the fourth month. In this period it seems to be subdivided, in its lower third, into two layers (superficial and deep) reaching the zygomatic arch and circumscribing a triangular space in the frontal sections, originally occupied by loose connective tissue and then, beginning from the fifth month, by fatty tissue; (3) the two uncoupling or unlaminar layers of the temporal fascia in the adult join the lateral surface of the zygomatic arch; (4) from the end of the fifth fetal month, an accumulation of primary fat is interposed between the temporal m. and its fascia: this is to be interpreted as a temporal extension of the Bichat's fat-ball in the cheek.