Fiber arrangements of the vertical lingual muscle in human adult subjects

This study identified the anatomy of the vertical lingual muscle and functional relationships between the vertical lingual and the other lingual muscles in the human tongue. Three whole tongues were obtained from adult human cadavers and were used for histological study by the serial section method. At the tip of the tongue, the fibers of the vertical lingual muscle cross with the transverse lingual muscle, and extend inferiorly to the fibers of the inferior longitudinal lingual muscle. At the body of the tongue, the fibers of the vertical lingual muscle are located between the fibers of the superior longitudinal lingual and inferior longitudinal lingual muscle, crossing the fibers of the transverse lingual muscle, instead of crossing the fibers of the extrinsic lingual muscles. At the base of the tongue, the fibers of the vertical lingual muscle start by the fibers of the superior longitudinal lingual muscle, and connect with the fibers of the posterior muscle bundle of the styloglossus muscle. The average diameters of the vertical lingual muscle fibers increased gradually as they approached the base of the tongue. These findings suggest that posterosuperior movement of the tongue body may be accomplished with downward movement of the tip of the tongue by contractions of both the vertical lingual and the styloglossus muscle. The inferior longitudinal lingual muscle may also play a supporting role for the vertical lingual muscle at the tip of the tongue (AU)

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Mesenteric lymph flow in endotoxemic guinea pigs.

BACKGROUND: Lipopolysaccharide (LPS) is a structural component of the outer membrane of gram-negative bacteria. LPS activates the host cells, leading to the production and release of proinflammatory cytokines. Given the induction duration for the release of cytokines, the initial mechanisms that produce LPS action on a timescale of minutes are not fully understood. We studied the effect of initial LPS-induced action on the lymphatic system by measuring the time-dependent changes in mesenteric lymph flow in guinea pigs in vivo. In addition, we determined the leakage of plasma protein into the lymphatic system using Evans blue dye. METHODS AND RESULTS: The mesenteric lymphatic vessel was cannulated with a polyethylene catheter. We administered drugs via a catheter in jugular vein. The control animals received vehicle intravenously (i.v.). The experimental group received 1 mg/kg or 10 mg/kg LPS i.v. Twenty minutes before injection of the vehicle or LPS, Evans blue dye (5 mg/kg i.v.) was administered. Lymph output was measured every 20 min. The amount of Evans blue in the lymph was determined by spectrophotometry. The mesenteric lymph showed a steady flow rate of approximately 290 µL/kg/20 min. The lymph flow immediately increased after the administration of LPS and reached 3.4-fold and 7.4-fold after 1 h of 1 mg/kg and 10 mg/kg LPS injection, respectively. The albumin content in lymph significantly increased in proportion to the increased lymph volume. CONCLUSIONS: These results suggest that the early increase in mesenteric lymph flow rate in guinea pigs produced by LPS is mediated by vascular hyperpermeability and plasma albumin leakage.

Anatomical study of pectoral intercostal perforators and clinical study of the pectoral intercostal perforator flap for hand reconstruction.

BACKGROUND: The authors have used pectoral intercostal perforator flaps to reconstruct burned or injured hands by staged transfer. This flap is designed with a narrow skin pedicle that includes intercostal perforators from the fifth to eighth intercostal spaces, with a wide flap area that lies on the upper abdomen. The distal area is thinned down to the subdermal vascular network level; thus, such flaps are called "superthin flaps" or subdermal vascular network flaps. In this article, the authors discuss the arterial networks associated with this flap and present clinical cases. METHODS: The authors performed an anatomical study using 13 cadavers to obtain angiograms and dissect the anterior chest and abdominal region. Clinically, the authors retrospectively analyzed 21 cases over 13 years. RESULTS: Anatomically, the anterior intercostal regions could be divided into three segments with regard to vascular supply to the skin and subcutaneous layer. In particular, in the fifth to eighth intercostal spaces, perforators communicated with one another to form a "latticework" pattern. In addition, the vascular territories participating in the pectoral intercostal perforator flap, that is, the intercostal perforators, the superior epigastric artery system, and the deep inferior epigastric artery system, linked with each other through choke vessels. In the authors' clinical cases, functional and aesthetic results were satisfactory. CONCLUSIONS: The pectoral intercostal perforator flap was supported by the arterial networks among perforators in the intercostal spaces and in the upper abdomen. This flap is one useful method for reconstruction of the hand region, providing good quality in terms of thinness and texture.

Clinical and vascular anatomical study of distally based sural flap.

METHODS: The distally based sural flap has been useful for reconstruction of the distal third portion of the lower leg. We retrospectively review in this report the clinical outcomes. Moreover, we studied the vascular anatomy surrounding the sural nerve using preserved cadavers. Twenty-eight consecutive cases of distally based sural flap transfer were reviewed retrospectively. All flaps were harvested with the deep fascia and lesser saphenous vein, but the sural nerve was excluded in all cases to prevent paresthesia. The sural nerve can be easily detached from the flap by meticulous dissection from the deep fascia without causing significant bleeding. In the vascular anatomic study, barium was injected through the femoral artery after elevating the flap in 20 legs of preserved cadavers. Subsequently, tissue specimens were harvested from the upper, middle, and lower sites of the flap for histologic analyses. RESULTS: Clinically, 22 of 28 flaps survived completely. Distal partial necrosis was observed in 5 flaps, and total necrosis was observed in 1 flap. Causes of total or partial necrosis have been suggested to be dependent on flap shape, pedicle length, and complicating diseases. Anatomic angiography revealed that small extrinsic vessels around the sural nerve and the lesser saphenous vein are important, especially in distally-based sural flap transfer; those around the sural nerve seem to have the most important impact on flap survival. The sural nerve has fewer intrinsic vessels than the extrinsic vessels of the sural nerve and lesser saphenous vein. CONCLUSION: The distally based sural flap was useful for reconstruction of the distal third portion of the lower leg. Moreover, these clinical and anatomic findings suggest that the sural nerve can be preserved to prevent surgically induced paresthesia.

Variations of the bilateral testicular veins: embryological and clinical considerations.

Variations of the bilateral testicular veins were observed during routine dissection of the posterior abdominal wall in a 77-year-old male Japanese cadaver. The right testicular vein consisted of the lateral and medial testicular veins. The right lateral testicular vein drained into the right renal vein. The right medial testicular vein accompanied the right testicular artery to ascend obliquely and drained into the left aspect of the inferior vena cava. The left testicular vein was composed of the lateral, middle and medial testicular veins. Three left testicular veins accompanied the left testicular artery to course cranially and then finally drained into the left renal vein.

Duplication of the inferior vena cava associated with other variations.

Multiple vascular variations, including duplication of the inferior vena cava, double renal arteries and anomalies of the testicular blood vessels, were observed during dissection of the retroperitoneal region of a cadaver of an 87-year-old Japanese man. The right inferior vena cava arose from the union of right common iliac veins and a thinner interiliac vein. This interiliac vein ascended obliquely from right to left and joined the left common iliac veins to form the left inferior vena cava. The right and left inferior venae cavae were of approximately equal width. The right testicular vein consisted of medial and lateral venous trunks. The two venous trunks coalesced to form a single vein, which drained into the confluence of the right inferior vena cava and right renal vein. The left testicular vein was composed of the medial and lateral testicular veins, which drained into the left renal vein. Double renal arteries were seen bilaterally, which originated from the lateral aspects of the abdominal aorta. The right testicular artery arose from the right inferior renal artery and accompanied the lateral trunk of the right testicular vein running downwards. The left testicular artery arose from the ipsilateral inferior renal artery and ran downwards accompanied by the left lateral testicular vein. In addition, the bilateral kidneys showed multicystic changes.

Clinical and anatomical study of cervicopectoral superthin flaps.

BACKGROUND: The authors have used cervicopectoral superthin flaps to reconstruct face, chin, and neck scar contractures. In the authors' clinical experience, three types of flaps could be harvested: (1) cutaneous pedicled flaps, (2) musculocutaneous pedicled flaps, and (3) muscle pedicled flaps. In the present study, the authors discuss the clinical usefulness of these flaps. Moreover, through their anatomical study using cadavers, the authors attempted to clarify the mechanism of blood flow into these flaps. METHODS: The authors retrospectively analyzed seven clinical cases. In their anatomical study, the authors performed selective angiograms of the vessels related to 30 cervicopectoral flaps from 15 preserved cadavers. RESULTS: Clinically, six of seven flaps survived completely, and contractures were released. Three types of perforators were identified, and their networks were observed in the anatomical study. CONCLUSIONS: Various types of cervicopectoral superthin flaps can be harvested for the reconstruction of contoured sensitive areas. If a much larger than average flap is designed, the pectoral intercostal artery can be attached to the flap for microvascular augmentation.

Nerve fiber analysis for the lingual nerve of the human adult subjects.

The neuro-motor control of the human tongue musculature had not been investigated in detail. This study identified first that the lingual nerve should play the neuro-motor control of some lingual muscles. Six en bloc samples (12 sides), including the tissues from the skull base to the hyoid bone, and three whole tongues were obtained from adult human cadavers. The former samples were used for the study of nerve fiber analysis of the lingual nerve with the aid of binocular stereomicroscope, and the latter samples were used for histological study by serial section method. On nerve fiber analysis of the lingual nerve from the trigeminal ganglion to the tongue musculature, we found that the motor- root of the trigeminal nerve gave off its supply to the lingual nerve and traveled into the lingual nerve, and branched to the superior and the inferior longitudinal muscles. On histological study, it was revealed that in the anterior part of the tongue the superior and the inferior longitudinal muscles surrounded the other lingual musculature and combined with the sub-mucosal connective tissues closely like the cutaneous muscle, for example, the facial muscles. The lingual nerve entered the inner side of the space between the genioglossus and the inferior longitudinal muscles with the lingual artery. These findings suggested that the superior and the inferior longitudinal muscles should be innervated by the motor fibers traveled into the lingual nerve from the motor root of the trigeminal nerve, and do not originate from the myotome originating in occipital somites but branchial muscles.

Physiological studies of retrusive movements of the human tongue.

SUMMARY: This study identified that physiologically the superior pharyngeal constrictor muscle at the level of the base of the tongue contributes to retrusive movement of the tongue with constriction of the mid-pharyngeal cavity and possesses unique properties in terms of motor speech control along with the genioglossus muscle. From a kinematic study involving trans-nasal fiberscopy and lateral X-ray fluorography, retrusive movement of the tongue was highly correlated with constrictive movement of the mid-pharyngeal cavity. An electromyographic study revealed that the superior pharyngeal constrictor muscle at the level of the base of the tongue contributes to retrusive movement of the tongue and that the genioglossus muscle contributes to protrusive movement. We also noted that this relationship between the activities of these two muscles were in response to postural changes during vowel productions without changes in the acoustic features. These findings suggest that these two muscles act not only antagonistically to produce retrusive and protrusive movement of the tongue, but also they complement each other to conserve the shape of the vocal tract for speech production. The functional relationship between these two muscles could contribute the consecutive movement of human speech production under various conditions and might be useful when applying rehabilitation approaches for the patients with neurological speech and swallowing disorders.

Clinical reappraisal of the segmental pectoralis major turn-over flap for coverage of the local mediastinal wound.

The viability of a long and narrow pectoralis major turn-over flap based on one intercostal muscle perforator was supported by the result of our cadaveric injection study. This flap preserves the muscular strength and aesthetic contour of the anterior axillary line, and is attractive for reconstruction of the mid-sternum.

Duplicate testicular veins accompanied by anomalies of the testicular arteries.

Duplicate testicular veins associated with other anomalies of the testicular arteries were observed during dissection of the posterior abdominal wall in a 90-year-old Japanese male cadaver. The right testicular vein was composed of the medial and lateral testicular veins. The medial testicular vein drained into the inferior vena cava, whereas the lateral testicular vein drained into the confluence of the inferior vena cava and right renal vein. Several anastomosing branches were seen between the medial and lateral testicular veins. The left testicular vein was formed after the medial and lateral venous trunks joined and drained into the ipsilateral renal vein. The right testicular artery originated from the anterior surface of the abdominal aorta at the level of the left renal artery, passed posterior to the inferior vena cava, and accompanied the right lateral testicular vein running downwards. The left testicular artery arose from the abdominal aorta at a level of 5 cm below the origin of the right testicular artery, and then ran downwards accompanied by the medial trunk of the left testicular vein.

Morphological studies for retrusive movement of the human adult tongue.

This study identified the anatomical and close functional relationship between the transverse lingual and superior pharyngeal constrictor muscle. Two en bloc samples (including the tongue and mid-pharyngeal wall) and four whole tongues were obtained from adult human cadavers. We found that fibers of the superior pharyngeal constrictor muscle connected with fibers of the transverse lingual muscle, forming a ring of muscle at the base of the tongue. The average diameters of the transverse muscle fibers increased in size gradually as they approached the base of the tongue. Distribution of the muscle spindles in the transverse lingual muscle and the genioglossus muscle also increased as they reached posteriorly near the base of the tongue. These findings suggest that a ring of muscle formed by the postero-inferior portion of the transverse lingual muscle and the superior pharyngeal constrictor may be largely responsible for the retrusive movement of the tongue and the constrictive movement of the pharyngeal cavity as an antagonist of the genioglossus muscle.

Pathways of anesthetic from the thoracic paravertebral region to the celiac ganglion.

Communication between the lower thoracic paravertebral region and the celiac ganglion through the retrocrural space was investigated. After dye was injected into the endothoracic fascia in the lower thoracic paravertebral region at the T11 level, its spread to the celiac ganglion was examined in fifteen cadavers. The dye reached the celiac ganglion in nine cadavers (60%) by passing through the retrocrural space, along the greater and lesser splanchnic nerves and through the split in the crus of the diaphragm through which the splanchnic nerves traveled. In the remaining six cadavers, dye spread toward the ganglion along the crus of the diaphragm. In three living subjects the spread of a radio-opaque dye injected in the same manner was studied using 3D-computed tomography. This study confirmed that the radio-opaque dye traveled toward the celiac ganglion along the crus of the diaphragm. From our results we suggest that a fluid communication may exist between the lower thoracic paravertebral region and the celiac ganglion in cadavers and in living humans and that clinicians should be aware of this possible route of spread when administering lower thoracic paravertebral anesthesia.

Appendectomy in rabbits with extended unilateral anesthesia.

Thoracic paravertebral anesthesia was not believed to accompany numbness in the lumbar nerve region. However, we recently discovered that thoracic paravertebral anesthesia could produce analgesia in the lumbar region. We called this block extended unilateral anesthesia. In this study, appendectomy was attempted in rabbits with extended unilateral anesthesia. After a catheter was inserted into the endothoracic fascia in the paravertebral region on the right side at the level of the 11th thoracic vertebra, a 3-ml dose of 2% mepivacaine was injected repeatedly through the catheter. After an injection of the local anesthetic we could observe motor and sensory paralysis unilaterally from the chest down to the lower limb in all the rabbits, the extended unilateral anesthesia. With this anesthesia, we could accomplish appendectomy. This is the initial report of extended unilateral anesthesia applied to appendectomy in rabbits. We think that this anesthesia could be beneficial in future medical and veterinary use.