Katsuji Kumaki

Nerve supply to the accessory soleus muscle

An accessory soleus muscle was found in the right leg of a cadaver in the dissecting room. This anomalous muscle was situated medially between the distal part of the tibia and the tendo calcaneus. The muscle arose from the anterior aponeurosis of the soleus muscle and was attached with a separate tendon to the calcaneus anteromedial to the tendo calcaneus. The soleus muscle was supplied by two nerves from the tibial nerve. The ramus posterior entered its posterior surface near the proximal border, and the ramus anterior entered the bipenniform part which was located on the anterior aspect of the soleus. One of branches from the r. anterior descended on the surface of the medial half of the bipenniform part and gave off a few twigs for this muscle part. Finally, its terminal entered the accessory soleus muscle and ramified in this muscle. In a teased preparation of the tibial nerve, both the nerve fibres composing this branch to the anomalous muscle and those constituting the r. anterior proper which supplied the bipenniform part were contained in the same funiculus. This mode of nerve supply to the soleus and the accessory soleus muscle suggested that this anomalous muscle derived from the part of the proper soleus muscle supplied by the r. anterior.

Variations in the course of the maxillary artery in Japanese adults

Many authors have studied variation in the maxillary artery but there have been inconsistencies between reported observations. The present research aimed to examine the courses and branching patterns of the trunk and branches of the maxillary artery in a large sample of Japanese adult cadavers. The course of the maxillary artery should be reclassified into seven groups as a clear relationship was found between the origin of the middle meningeal artery and the course of the maxillary artery. This indicates that conventional theory about the formation of the maxillary artery, which was considered to be a direct derivative of the stapedial artery, might be inaccurate. Many variations in the origin of the inferior alveolar artery were found. Notably, the inferior alveolar artery origin from the external carotid artery and a double origin of the inferior alveolar artery was also observed. Thus, the maxillary artery might be derived from a combination of both the external carotid and stapedial arteries.

Nerve communication between the glossopharyngeal nerve, external carotid plexus and the superficial cervical ansa: Human autopsy case

The authors encountered a very rare human autopsy case in which the supernumerary branch of the glossopharyngeal nerve and a nerve branch arising from the external carotid plexus communicated with the superficial cervical ansa. This anomaly was observed on the left side of a 71-year-old male cadaver during the gross anatomical seminar at Niigata University in 2004. The nerve fascicle and fiber analyses indicated that the supernumerary branch of the glossopharyngeal nerve separated cranial to the branches to the pharyngeal constrictor muscles, carotid sinus and stylopharyngeal muscle and sent the nerve fibers to the muscular branches to the platysma and the cutaneous branches to the cervical region. Additionally, it was shown that the branch arising from the external carotid plexus sent the nerve fibers to the cutaneous branch to the cervical region. Although the external carotid plexus is primarily postganglionic sympathetic fibers originating from the superior cervical ganglion, the vagus and glossopharyngeal nerves gave off branches connecting to the plexus, and therefore it was not possible to determine the origins of this branch of the external carotid plexus. The present nerve fascicle analysis demonstrates that the supernumerary branch of the glossopharyngeal nerve, which innervated the platysma, did not share any nerve components with the branches to the pharyngeal constrictor muscles, carotid sinus and stylopharyngeal muscle, suggesting that this supernumerary branch may be categorized into the different group from these well-known branches.

Nerve fiber analysis of ansa cervicalis-vagus communications

Communications between the ansa cervicalis and the vagus nerve, although described only as variations in many textbooks, can be observed frequently in the dissection room. Following macroscopic observation, some of such cases were subsequently dissected under surgical microscope to determine the nature of such communications. As a result, two broad categories of communications between the ansa cervicalis complex and the vagus nerve could be recognized: (i) false (pseudo) communications, where the two nerves were attached only by the connective tissue with no fiber exchange; and (ii) true communications, with nerve fiber involvement. Fiber analysis showed that the majority of the ansa-vagal communications observed during gross dissection were of the first category. True communications, when present, were only scanty contributions and always directed towards the side of the vagus. In addition, the vagus (region of the inferior ganglion) and hypoglossal nerves were found to be in close contact at the base of the skull and usually could not be separated by gross dissection. But such attachments, too, were shown to be almost entirely of false nature except for the possible presence of a few fine nerve filaments. It seems that the ansa-vagal communications are merely a result of the close physical relationship between the two structures and serve no significant functional purpose, but at the same time may hinder the prospects of using ansa cervicalis in surgical procedures such as re-innervation of laryngeal and facial muscles, following damage to recurrent laryngeal and facial nerves, respectively.

Effective and selective stretching of the medial head of the gastrocnemius

Muscle injury frequently occurs in the medial head of the gastrocnemius (MG), and stretching is used for treatment. However, there are no studies based on anatomical considerations and biomechanics. This study therefore examined the macroscopic anatomical structure of the triceps surae muscle to design an effective and selective MG stretching method, before quantitatively verifying that method by ultrasonography. The macroscopic anatomy was analyzed in 16 Japanese cadavers (25 legs). Based on the anatomical findings and the arrangement of fascicles in the MG, we concluded that ankle inversion might be advantageous for selective stretching of the tendon fiber bundles into which the MG inserts. We devised a method in which the limb was initially positioned with the knee joint in extension and the ankle joint in plantar flexion. Then, the ankle was dorsiflexed and inverted. The proposed method was compared with standard stretching and verified by ultrasonography in eight healthy adult males. This method effectively and selectively stretched the MG, producing a significantly decreased pennation angle and increased muscle fiber length. This method may be beneficial for preventing future injuries and may enhance the effect of therapy on the MG.

Morphological analysis of the branches of the dorsal pancreatic artery and their clinical significance.

The dorsal pancreatic artery (DP), characterized by a course that crosses behind the proximal part of the splenic vein. It is regarded as clinically important, providing essential distribution to the pancreas. However, the origin of the DP is extremely variable and therefore cannot provide a sufficient basis for identifying it. The DPs of 11 cadavers were investigated in terms of origin, course and distribution. A total of 45 branches of the DP are classified into seven types on the basis of course and distribution. One of these seven types was consistently observed among the specimens: it ran to the right, passed behind the superior mesenteric vein and anterior surface of the posterior part of the head of the pancreas, and then distributed to the uncinate process and the posterior part of the head of the pancreas. Variations in the branching pattern of the DP can be explained from the following perspective: the consistent branch (#5) is the stem of the DP, and other branches originate from it. It is advisable for surgeons to pay attention to this consistent branch of the dorsal pancreatic artery when performing a pancreaticoduodenectomy. Clin. Anat. 645–652, 2014.

Middle thymothyroid artery arising from the common carotid artery: case report of a rare variation

A middle thymothyroid artery, arising from the anterior aspect of the right common carotid as an anomalous branch was observed in a 71-year-old Japanese male cadaver. It soon divided into a thyroidea ima artery, a branch supplying the sternoclavicular joints, and a thymic branch. In addition, twigs from these three main branches supplied the sternohyoid and sternothyroid muscles, right inferior parathyroid gland and also some deep cervical lymph nodes. Anatomical features, clinical implications and a brief account of the developmental aspects of this rare variation are included in this report.

Gross anatomical study on the human myocardial bridges with special reference to the spatial relationship among coronary arteries, cardiac veins and autonomic nerves

Coronary arteries are frequently covered by cardiac muscles. This arrangement is termed a myocardial bridge. Previous studies have shown that myocardial bridges can cause myocardial ischemic diseases or cardiac arrhythmia, but the relevant pathogenic mechanisms remain unknown. We examined 60 hearts from Japanese cadavers macroscopically to clarify the spatial relationships among coronary arteries, cardiac veins and autonomic nerves. We found 86 myocardial bridges in 47 hearts from the 60 cadavers examined (78.3%). Next, we dissected out nine hearts with myocardial bridges in detail under the operating microscope. We found no additional branches of coronary arteries on the myocardial bridge surfaces. However, the cardiac veins, which usually accompany the coronary arteries, ran independently on the myocardial bridge surfaces in the same region. Cardiac autonomic nerves comprised two rami: one was associated with the coronary artery under the myocardial bridge and the other ran on the surface of the bridge. Such spatial relationships among the coronary arteries, cardiac veins and cardiac autonomic nerves at the myocardial bridges are quite similar to those in mouse embryo hearts. Clin. Anat. 29:333–341, 2016.

Variations in the course of the superior gluteal artery in relation to the lumbosacral plexus

The course of the superior gluteal artery (SGA) as it passes through the lumbosacral plexus is variable. The variations of the arterial course in relation to the lumbosacral plexus have focused on statistical analysis, and it is limited arterial diversity. In this study, we investigated the positional relation between the SGA and the furcal nerve (FN): guide to segmentation of the lumbosacral plexus, arising from the L4, ie, the contribution to the femoral nerve, obturator nerve, and lumbosacral trunk. We could classify the pathway of the SGA into three types based on its positional relation to the FN. The SGA courses under the ramus from which the FN originates (Type A), under the ramus one segment below the origin of the FN (Type B), or between the obturator nerve and the lumbosacral trunk (Type C). The SGA pathway in Types A and B showed a cranial or caudal shift along with cranial or caudal deviation of the FN. In summary, the variation in the SGA pathway was correlated with cranial or caudal shift of the FN. Our findings indicate that variations of the SGA pathway are associated not only with arterial transformation, but also with diversity of the lumbosacral plexus.