Ahmet Kagan Karabulut

Brachial plexus variations in human fetuses.

OBJECTIVEWe examined the anatomic variations of the brachial plexus (BP) in human fetuses. METHODSThis study was performed with 200 BPs from spontaneously aborted fetuses without detectable malformations. The plexuses were dissected, and the normal position and/or morphological variations of the BP were determined and photographed. RESULTSThere were no variations in 93 plexuses, and 107 plexuses were observed to have different variations. Morphological variations were observed more frequently among female fetuses and right sides. The BPs were composed mostly of the C5, C6, C7, and C8 nerves and the T1 nerve (71.5%). A prefixed plexus was observed in 25.5% of cases, and a postfixed plexus was observed in 2.5% of cases. In one case (0.5%), the C4 and T2 nerves joined the formation. The inferior trunk was not formed in 9% of cases. The superior trunk was not formed in 1% of cases. In one plexus, the superior trunk was formed by the ventral rami of the C4 and C5 nerves. In one case, the inferior trunk was formed by the ventral rami of the T1 and T2 nerves. Division variations were observed most frequently. There were also variations in the terminal branches, such as the roots of the median nerve joining in the distal part of the arm (8.5%), the axillary nerve being separate from the posterior division of the superior trunk (2.5%), and a connection existing between the median and musculocutaneous nerves (1%). CONCLUSIONKnowledge of BP variations is important for surgeons who perform surgical procedures in the cervical and axillary regions.

The relationship between the lumbosacral enlargement and the conus medullaris during the period of fetal development and adulthood

The spinal cord is situated within the vertebral canal by the third month of intrauterine life. The spinal cord possesses two symmetrical enlargements, which constitute the segments of the plexuses the cervical enlargement for the brachial plexus and the lumbosacral enlargement for the lumbar and sacral plexus. In our study, we aimed to investigate the relationship between the termination level of the lumbosacral enlargement (TLLE) and that of the conus medullaris (TLCM) during the period of fetal development and adulthood. We used a total of 75 cases 25 fetuses (male 16, female 9) whose crown-rump length ranged between 90–190 mm, 25 premature and full-term neonates (male 17, female 8) whose post-menstrual ages ranged between 33–55 weeks, and 25 adults (male 12, female 13) aged between 22–72 years. The dissection technique for fetuses, ultrasonography for premature and full-term newborns, and magnetic resonance imaging (MRI) for adults were used to determine lumbosacral enlargement and TLCM. The differences between the TLCM and the termination level of the largest part of the transverse diameter of the lumbosacral enlargement were investigated. The differences between the TLLE and TLCM were found in different ratios from the period of fetal development to adulthood. Therefore, during medical treatment and surgical procedures this should be taken into account to avoid complications.

The course and variations of the branches of the musculocutaneous nerve in human fetuses

The course and branches of the musculocutaneous nerve (MCN) were dissected in 140 human fetal arms. The MCN entered the superior, middle, and inferior part of coracobrachialis in 43%, 37%, and 17% of arms, respectively, and the remaining 3% did not pierce coracobrachialis. The motor branches to biceps were classified as follows: Type 1 (83.6%): a single branch that bifurcated to supply the two heads of biceps; Type 2 (14.3%): two separate branches each innervating one head of biceps; Type 3 (2.1%): a single branch that bifurcated to supply each head of biceps plus an additional branch that innervated the distal part of biceps. The motor branches to brachialis were classified as follows: Type 1 (93.6%): a single branch to brachialis; Type 2 (6.4%): a single branch that bifurcated into two branches both supplying brachialis. Communications between the MCN and the median nerve (MN) were observed in 10% of specimens, of which three types (A, B, C) could be identified depending on their origin and union. In the most frequently observed type (B, 50% of cases) the communicating branch arose from the proximal part of the MCN and joined the MN in the middle or distal part of arm. The data presented here will be of use to surgeons, especially pediatric surgeons who undertake surgical procedures in the axilla and arm. Clin. Anat. 22:337–345, 2009.

An investigation of the conus medullaris and filum terminale variations in human fetuses.

The morphologic structure of the conus medullaris and filum terminale was investigated by dissection in 123 human fetuses, obtained from Selçuk University, Faculty of Medicine and Maternity hospital of Konya between 1992–1995. In 78 fetuses, the conus medullaris and filum terminale had a normal morphologic aspect, whereas there was a slight depression or groove formation in the closure region of the caudal neuropore in 45 fetuses. In 15 fetuses, important malformations of the cranium and vertebral column were observed. The morphologic aspects of the conus medullaris in 30 fetuses were abnormal in shape and position, among them 24 fetuses had an abnormal filum terminale (grooved, depressed, thickened or duplicated) whereas it was normal in 6. Deficiency of closure of the caudal neuropore was considered to have a negative effect on the fetal development of the filum terminale.

The motor branches of median and ulnar nerves that innervate superficial flexor muscles: a study in human fetuses

PurposeWe aimed to describe the distribution of the motor branches of the median and ulnar nerves that innervate the superficial flexor muscles in detail, as well as to determine any communication between these two nerves in a series of 100 human fetuses.MethodsThis study was performed on 200 upper limbs from 100 fetuses. However, the motor branches of the median nerve were determined on 50 upper limbs because of the developmental properties of medial epicondylar muscles.ResultsThe motor branch, which innervates the pronator teres, is classified into two types and four subtypes. The flexor carpi radialis branch arose as a single branch in 30% of the cases. The innervation of the flexor digitorum superficialis was also performed by a single muscular branch in 88% of the cases and by two branches in 12% of the cases. The ulnar nerve was classified into two types according to the number of muscular branches in the forearm. Martin–Gruber anastomosis was observed in 7.5% of the cases.ConclusionsThese results show differences from classical definitions regarding the muscular branching patterns of the median and ulnar nerves. We suggest revisiting the classical descriptions of innervation patterns of pronator teres, palmaris longus and flexor carpi radialis muscles, since the variations observed in their innervation patterns are more diverse than has been described.

Communications between the palmar digital branches of the median and ulnar nerves: A study in human fetuses and a review of the literature†

In this study, median nerves (MNs) and ulnar nerves (UNs) were dissected in 200 palmar sides of hands (left and right) of 100 (50 male, 50 female) spontaneously aborted fetuses with no detectable malformations. The fetuses, whose gestational ages ranged from 13 to 40 weeks, were dissected under an operating microscope. The MN divided first into a lateral ramus and a medial ramus and then formed a common digital nerve. The first common digital nerve trifurcated in all of the studied cases. The branching patterns were classified into two types (Type 1 and Type 2) based on the relationship with the flexor retinaculum (behind/distal of it). A communication branch between the UNs and MNs in the palmar surface of the hand was found in 59 hands (29.5%). The proper palmar digital nerves were numbered from p1 to p10, starting from the radial half of the thumb to the ulnar half of the little finger, and these nerves exhibited six types of variations. The present data obtained from human fetuses will aid in elucidating the developmental anatomy of the nervous system and provide hand surgeons with a more complete anatomical picture to help them to avoid iatrogenic injuries. Clin. Anat. 23:234–241, 2010.

Anatomical Examination of the Foramens of the Middle Cranial Fossa

Tres foramenes pueden ser identificados en el ala mayor del esfenoides: El foramen redondo (FR), foramen oval (FO) y el foramen espinoso (FS). Puede ademas existir otro foramen llamado foramen oval accesorio o foramen de Vesalio (FV), que conecta la fosa craneal media a la fosa pterigoidea. Se describe como una abertura con paredes lisas por anterior y medial al foramen oval, que conduce a un canal oblicuo dirigido hacia la fosa pterigoidea. FV estuvo presente entre FO y FR en 14 (31,8%) de 44 craneos secos y 6 (33,3%), en 18 lados en la base de craneos de cadaveres (total 20 (32,3%) de 62). El diametro de los foramenes en los lados derecho e izquierdo se observo casi simetricos. Las distancias de FR desde la linea mediana en el lado izquierdo fue mayor que en el lado derecho. Ademas, la distancia entre FO y el vertice de la porcion petrosa y la distancia entre el FS y el vertice porcion petrosa fueron mayores en el lado izquierdo. En el lado derecho la distancia entre A y FR, asi como la distancia entre A y FS fueron mayores. Por otra parte, la distancia entre los FR y el vertice del porcion petrosa fue mayor en el lado derecho. Las variaciones anatomicas en el tamano de la apariencia y la distancia de FR, DE, FS y FV son de gran importancia quirurgica. Podemos inferir que la informacion proporcionada en este estudio puede ayudar al neurocirujano y anatomista para aumentar el conocimiento sobre la anatomia de la fosa craneal media.

Investigation of Developmental Toxicity and Teratogenicity of Antiemetics on Rat Embryos Cultured In Vitro

In this study, we aimed to investigate and compare the direct toxic and teratogenic effects of dimenhydrinate, metoclopramide and trimethobenzamide HCl, antiemetic drugs on embryonic growth and development in cultured rat embryos. Embryos were explanted on day 9.5 of gestation and cultured. Whole rat serum was used as a culture medium for the control group while different concentrations of dimenhydrinate (2.5–20 μg/ml), metoclopramide (10–50 μg/ml) and trimethobenzamide HCl (25–100 μg/ml) were added to serum for the experimental groups. Effects of antiemetics on embryonic developmental parameters were compared, and embryos were evaluated for the presence of any malformations. Also, the total DNA was extracted from the cells to determine the fragmentation of nuclear DNA of embryonic cells. Compared with the control embryos, the antiemetics significantly decreased all growth and developmental parameters dose dependently. There was no difference regarding the fragmentation of nuclear DNA of the all used agents and controls. Amongst the agents, trimethobenzamide HCl was found to have more toxic and teratogenic potential, and metoclopramide appears to be the least toxic antiemetic and therefore could be more safely used and might be preferred for the treatment of nausea and vomiting in pregnancy.

Developmental Anomalies of Bronchial Tree: A Multidetector Computerized Tomography Study

Las anomalias del arbol bronquial pueden causar una infeccion pulmonar aguda recurrente y sintomas de obstruccion persistente. Las anomalias del desarrollo del arbol bronquial se presentan principalmente como informes de casos con una anomalia de acompanante. Sin embargo, en este estudio se detectaron estas anomalias en las imagenes de tomografia computarizada multidetector (TCMD), donde no se habian informado esta patologia. Se evaluaron las imagenes de TCMD toracica de 400 pacientes (0-74 anos, 224 hombres y 176 mujeres). Se detectaron cuatro bronquios traqueales (1%). Tres de ellos fueron de tipo desplazado, uno fue tipo bronquio de cerdo, y dos bronquio cardiaco accesorio (0,5%), originados de la pared medial del bronquio intermedio. De acuerdo con nuestros resultados, la incidencia de bronquio traqueal y bronquios cardiacos accesorios parecen ser mayor en la poblacion turca.

An investigation of non-depolarizing muscle relaxants on embryonic development in cultured rat embryos

Background and objective: We have investigated the toxic and teratogenic effects of certain non-depolarizing muscle relaxants on embryonic development in cultured rat embryos. Methods: Rat embryos of 9.5 days were explanted and cultured in vitro for 48 h in rat serum. Whole rat serum was used as a culture medium for the control group while different concentrations of atracurium, cis-atracurium, rocuronium and mivacurium were added to rat serum for the experimental groups. Dose-dependent effects of these agents on embryonic developmental parameters were compared using morphological and biochemical methods. Each embryo was evaluated for the presence of any malformations. Results: When compared to the control embryos, the muscle relaxants significantly decreased all growth and developmental parameters dose dependently with an increase in overall dismorphology. Among these malformations, maxillary deformity was most frequently observed. These effects were observed in much lower doses with atracurium and cis-atracurium compared to those with rocuronium and mivacurium. Conclusions: Our results suggest that non-depolarizing muscle relaxants cause dose-dependent toxicity on rat embryos at concentrations much greater than those in clinical practice. Although, these agents seems to have a low potential for causing developmental toxicity during organogenesis, because of the lower toxic effects observed with rocuronium and mivacurium, these agents may be preferred when recurrent administrations are necessary for parturients.