Biomedical subjects

Gen Murakami

Publications and source records attributed to Gen Murakami.

At least 73 records · Page 4Linked to original sources

PubMed2003

Fascial structures and autonomic nerves in the female pelvis: a study using macroscopic slices and their corresponding histology.

We investigated the topographical anatomy of the pelvic fasciae and autonomic nerves using macroscopic slices of five decalcified female pelves. The lateral aspect of the supravaginal cervix uteri and superior-most vagina issued abundant thick fiber bundles. These visceral fibrous tissues extended dorsolaterally, joined another fibrous tissue from the rectum (the actual lateral ligament of the rectum) and attached to the parietal fibrous tissues at and around the sciatic foramina (i.e. the sacrospinous ligament, thick fasciae of the coccygeus and piriformis and dorsal end of the covering fascia of the levator ani). The inferior or ventral vagina also issued thick fiber bundles communicating with the levator ani fascia. This connection between the vagina and levator fascia, when stretched, seemed to provide a macroscopic morphology called the arcus tendineus fasciae pelvis. The overall morphology of the visceroparietal fascial bridge exhibited a bilateral wing-like shape. The fascial bridge complex was adjacent but dorso-inferior to the internal iliac vascular sheath and located slightly ventral to the pelvic splanchnic nerve. However, the pelvic plexus and its peripheral branches were embedded in the fascial complex. The hypogastric nerve ran along and beneath the uterosacral peritoneal fold, which did not contain thick fibrous tissue. During surgery, in combination with the superficially located vascular sheath, the morphology of the visceroparietal fascial bridge and associated nerves seemed to be artificially changed and developed into the so-called cardinal, uterosacral, uterovesical and/or rectal lateral ligaments. The classical and original concepts of these pelvic fascial structures may need to be altered to adjust to these surgical observations.

Aged↗

PubMed2003

Topographic anatomy of the male perineal structures with special reference to perineal approaches for radical prostatectomy.

AIM: Although perineal approaches for radical prostatectomy have recently gained renewed attention as excellent methods for minimally invasive surgery, the most commonly used techniques, Belt's and Young's approaches, have inadequacies regarding the topographical relationship between the rectourethral and levator ani muscles. METHODS: Using macroscopic observations of sagittal slices of 27 male pelvises and smooth muscle immunohistochemical staining of semiserial sections of another eight pelvises, we investigated the topographical anatomy of the perineal structures and their interindividual variations in elderly Japanese men. RESULTS: The inferomedial edge of the levator ani was located 5-15 mm lateral to the midsagittal plane in an area between the urethra and the rectum. The rectourethral smooth muscle had a superoinferior thickness of 5-10 mm and occupied a space between the right and left levator slings. The levator was adjacent to, or continuous with, the striated anal sphincters. A thick connective tissue septum, composed of smooth muscle, was evident between the rectal smooth muscle and the anal sphincter-levator ani complex. CONCLUSION: Because the connective tissue septum guides the surgeon's finger upwards towards the rectoprostatic space, Belt's approach appears relatively easy; however, rectal injury can sometimes occur if the surgeon loses this guidance. In contrast, if the levator edge is identified as the first step in Young's approach, the rectourethral muscle can be precisely divided, leaving a 3-5-mm margin from the rectum and sphincter-levator complex. Clinical investigations are now required to modify Young's approach based on the present results.

Aged↗

PubMed2003

A new perspective on nerve-sparing radical hysterectomy: nerve topography and over-preservation of the cardinal ligament.

BACKGROUND: Nerve-sparing radical hysterectomy was established by Japanese gynecologists. They identified two parts of the cardinal ligament, namely the vascular part and the neural part, and postulated that the neural part contained the pelvic splanchnic nerves. However, our fresh cadaver studies demonstrated that these nerves ran dorsomedially in contrast to the classical concept. The aim of this study is to further validate this finding in clinical cases. METHODS: We examined the intraoperative biopsy specimens collected from the neural part of the cardinal ligament in four patients with cervical carcinoma who underwent nerve-sparing radical hysterectomy with dissection of the neural part. RESULTS: Careful dissections demonstrated that the pelvic splanchnic nerves arise from the dorsomedial side of the neural part at the bottom of the pararectal space. The neural part was composed of a connective tissue with focal positive staining by S-100 protein. CONCLUSIONS: We propose that complete dissection of the cardinal ligament should be performed during nerve-sparing hysterectomy to increase its radicality.

Broad Ligament↗

PubMed2003

Radical perineal prostatectomy: a novel approach for lymphadenectomy from perineal incision.

PURPOSE: A major disadvantage of radical perineal prostatectomy is that lymphadenectomy cannot be performed through the same incision. We developed a novel approach to access the obturator and internal iliac lymph nodes, partially the external iliac lymph nodes, via the perineal incision. We describe the method of lymphadenectomy. MATERIALS AND METHODS: After moving the rectum off of the prostate we separate the levator ani muscle and endopelvic fascia from the lateral prostate with finger dissection. A trocar mounted balloon distention device is inserted toward this space and distended with 200 cc air to create an intrapelvic space. Using several retractors or laparoscopy for viewing we first identify the obturator nerve and then the external iliac vessels next in order of depth. By retracting the obturator nerve with vessel tape we perform lymph node dissection between the obturator nerve and external iliac vessels under direct vision or laparoscopic guidance. RESULTS: We have performed this technique in 20 consecutive patients because of prostate specific antigen greater than 10 ng/ml, Gleason score greater than 7 or bilateral disease. Bilateral lymph node dissection required 15 to 20 minutes. No major bleeding or complications occurred. The number of nodes was similar to that in our retropubic prostatectomy series because of the limited lymphadenectomy that we usually performed. Fecal incontinence and potency results were almost the same as in patients without lymphadenectomy. Although urinary continence was not good at catheter removal on day 7, patients became dry in 1 to 6 months. CONCLUSIONS: This method resolves the major disadvantage of perineal prostatectomy. Radical perineal prostatectomy with lymphadenectomy via the same incision is feasible and reproducible.

Aged↗

PubMed2003

Crystal structure of zwitterionic trimethylammoniopropane sulfonate.

Crystal structure of zwitterionic trimethylammoniopropane sulfonate (Z1-Methyl) was determined by single-crystal X-ray diffractometry. Z1-Methyl crystallized in the monoclinic system, space group P2(1), with a = 6.3639(2), b = 10.9237(4), c = 8.1505(4) A, beta = 111.078(2) degrees, V = 528.69(4) A3, Z = 2. An inter-molecular ionic association was observed in the crystal. The shortest distance between the methyl protons of the trimethylammonium group and the oxygens of the sulfonate group was 2.51(2) A.

Journal Article↗

PubMed2003

Which portion in a facet is specifically affected by articular cartilage degeneration with aging in the human lumbar zygapophysial joint?

Using 10 osteoligamentous vertebral columns obtained from elderly donated cadavers, we describe in detail degenerative changes of the articular cartilage in lumbar zygapophysial joints to show which portion in a facet is specifically affected. Degenerative changes, including extended cartilage defects, occurred in multiple facets of every specimen. The results demonstrated 5 basic morphologies of degeneration, i.e., 1) marginal dominace in the articular surface, 2) lower segment dominance except for the lowest (L5/S) facet, 3) advancement in the inferior articular process, 4) cranial and caudal dominance rather than the dorsal dominance in the articular surface and 5) progress in a mirror-image manner. These rules seemed to be consistent with differences in size, shape and kinesiological aspects of the facet between segments and between portions in a facet.

Aged↗

PubMed2003

Hypoplasia of the left portal vein territory of the human liver: a case study.

Although reports of hypoplasia or absence of the liver of left lobe are not few, descriptions of the intrahepatic vessels are rare but valuable for discussion of the pathogenesis. The present report demonstrates a case of the left surgical lobe hypoplasia that is characterized by 1) the scar-like lobe with few parenchymal tissue and dilated bile ducts, 2) no Spiegel's lobe with the portal vein stuck to the inferior vena cava, 3) unusual configurations of the right hepatic vein and the 8th segmental portal vein branch, 4) the hepatic groove on S8, and 5) the trifurcation pattern of the portal vein primary division. According to the macroscopic and histological observations, we hypothesized that the secondary abnormal peritoneal fusion occurred in utero and/or during the postnatal growth, and that it involved the left portal vein and other adjacent structures, resulting in severe atrophy of the left surgical lobe.

Cadaver↗

PubMed2002

Individual variations in aging of the male urethral rhabdosphincter in Japanese.

Although the degenerative changes with aging of the male urethral rhabdosphincter (URS) have been investigated, its individual morphological variations are still unclear. To provide an anatomical basis for clinical evaluation of the individual URS function in the aged, we investigated the structural differences in the URS of 25 elderly Japanese men using semiserial sections stained immunohistochemically and by hematoxylin-eosin. Before removal of the histological specimens, we dissected the ischioanal fossa and labeled several structures by carbon particles to allow proper orientation during the histological observations. In addition, macroscopic slices (10 mm thickness) made from five other male pelves were examined and, when necessary, followed by routine histological procedure to confirm the gross observations. An extended circular URS (over (1/2) circumferential configuration) was found in 15/25 cadavers, but showed very limited height (proximal-distal length) and thickness. A more restricted URS, including even a thin, arc-like pattern, was observed in the remaining cadavers. The attachment of the URS to the smooth muscle layer was loose and usually clearly separated. Continuation between the URS and deep transverse perineal muscle was sometimes observed. The thick fascia of the levetor ani, with high content of smooth muscles, usually provided the lateral or dorsal insertions of the URS. Our results in elderly Japanese subjects suggest that the sphincteric action is weak or incomplete. We suggest that the elderly URS maintains continence by retracting the urethra backward and upward with the aid of the levator sling, rather than the real sphincteric action expected in younger men.

Aged↗

PubMed2002

Location of the ventral margin of the paracaval portion of the caudate lobe of the human liver with special reference to the configuration of hepatic portal vein branches.

The topographic anatomy of the ventral margin of the paracaval portion of the caudate lobe of the human liver has not been clearly described to date. To this end we hypothesize the existence of a precaudate plane, a flat or slightly curved plane defined by the ventral margins of the ligamentum venosum and the hilar plate. Using 76 cadaveric livers, we investigated whether the paracaval portion of the caudate lobe extended ventral to this plane and whether the paracaval caudate branch of the portal vein (PC) ran through this plane to its ventral side. In 28 of the specimens (36.8%), the PC extended over the plane to a variable depth: less than 10 mm in 10 specimens, 10-20 mm in 10, and more than 20 mm in eight specimens. This ventral extension of the PC consistently included its penetration into the dome-like area under the terminals of the three major hepatic veins; therefore, the ventrally extended PC often interdigitated with these veins and their tributaries (in practice, the ventral margin of the paracaval portion of the caudate lobe could generally be considered to run alongside the middle hepatic vein). Moreover, the ventral extension of the PC often reached the upper, diaphragmatic surface or the dorsal surface of the liver immediately to the right of the inferior vena cava. Several branches (termed border branches) in the ventral extension were difficult to identify as belonging to the PC. We discuss both the marginal configuration of the paracaval portion of the caudate lobe and how to identify and operate on the ventrally extended PC and related border branches during liver surgery.

Aged↗

PubMed2002

Last-intercalated node and direct lymphatic drainage into the thoracic duct from the thoracoabdominal viscera.

OBJECTIVE: We clarified the configuration of the mediastinal lymphatics, focusing on the last intercalated lymph node and the direct drainage vessel to the thoracic duct, based on recent anatomical findings. METHODS: We macroscopically observed the lymphatics during dissections of 205 cadavers in combination with routine histology. We also review the results of injection by other researchers. RESULTS: Efferent vessels draining directly into the thoracic duct or venous angle were frequently found in the following node groups: the right paratracheal node group corresponding to the last intercalated node in 98% of cadavers (201); the brachiocephalic angle node group in 85% of cadavers (174); the right recurrent nerve group in 46% (94); the left superior phrenic node group in 73% (150); the node group at the origin of the left common carotid artery (the preaortico-carotid node) in 37% (76); the pretracheal node group in 25% (51) and the left tracheobronchial node group in 36% (74). Last intercalated nodes appeared common for multiple drainage routes or regional lymphatics. These results were mostly consistent with injection studies by Riquet et al. Direct lymphatic drainage from the esophagus to the thoracic duct was observed in 19% of cadavers (39). Direct lymphatic drainage of lung segments to distant mediastinal nodes is also reviewed. The sentinel node concept is discussed in relation to the above observations. CONCLUSIONS: We hypothesize that the most critical sentinel node, if such usage is allowed, is situated as a guard for a limited specific route and for a common drainage route. We term it the "common terminal node".

Humans↗

PubMed2002

An anatomical study of short hepatic veins, with special reference to delineation of the caudate lobe for hanging maneuver of the liver without the usual mobilization.

BACKGROUND/PURPOSE: The present study was designed to anatomically assess a very recently reported hanging maneuver of the liver without mobilization, in which forceps are inserted blindly between the inferior vena cava (IVC) and liver parenchyma. METHODS: We dissected 56 formalin-fixed livers (1) to determine whether preservation of the caudate vein (the largest vein draining Spiegel's lobe) and inferior right hepatic vein (IRHV) was possible and (2) to identify the territories drained by other, non-preserved short hepatic veins. RESULTS: A potential space for insertion of the forceps was found between the openings of the caudate vein and IRHV; however, if preservation of both veins is absolutely necessary, we recommended protecting the IRHV, such as by taping and retracting it. We classified the other short hepatic veins into two categories, i.e., those draining the left portal vein territory and those draining the right territory. The distributions of the openings of the veins in these territories overlapped. CONCLUSIONS: Clear delineation of the left caudate lobe according to the drainage veins appeared to be difficult when the liver was divided along a straight line in front of the IVC.

Cadaver↗

PubMed2002

The function of the psoas major muscle: passive kinetics and morphological studies using donated cadavers.

This study was carried out to analyze the phasic heterogeneity in the function of the psoas major muscle (PMM) depending on the flexion angle at the hip joint. The study design was a passive kinetic experiment using 25 osteoligamentous specimens with the PMM tendon. We measured the flexion angle of the hip joint where the PMM tendon loses contact with the femoral head and pelvic surface. Ten osteoligamentous specimens were used for additional measurements of the tensile force and pressure exerted on the PMM and/or at the bone-tendon interface when the PMM tendon was gently pulled in line with the PMM origin in the supine position. The tension loading the PMM tendon was measured at seven different angled positions of hip joint flexion (0 degrees, 15 degrees, 30 degrees, 45 degrees, 60 degrees, 75 degrees, and 90 degrees ), using a load cell attached to a traction appliance. The pressure was measured at each of eight sites along the long axis of the PMM, using a pressure sensor. The PMM tendon lost contact with the femoral head at angled positions of 14 degrees (average) hip flexion, and lost contact with the iliopectineal eminence at positions of 54 degrees (average). The tension was stronger at angled positions of 0 degrees -30 degrees at the hip joint. The pressure on the femoral head and pelvic surface were stronger at positions of 0 degrees -30 degrees at the hip joint. The pressure on the femoral head was strongest at a hip flexion of 0 degrees. The tensile force markedly decreased at 45 degrees -60 degrees flexion at the hip joint, while the pressure on the femoral head gradually reduced to zero in the same phases. We concluded that the PMM works phasically: (1) as an erector of the lumbar vertebral column, as well as a stabilizer of the femoral head in the acetabulum at 0 degrees -15 degrees flexion at the hip joint; (2) less as a stabilizer, in contrast to maintaining its erector action, at 15 degrees -45 degrees; and (3) as an effective flexor of the lower extremity, at 45 degrees -60 degrees.

Aged↗

PubMed2002

Laminar configuration of the transverse carpal ligament.

We investigated the laminar configuration of the transverse carpal ligament, using 77 hands from 44 donated cadavers. According to the running directions and attachments of the fiber bundles composing the ligament, we identified four basic bundle patterns: proximal transverse, distal transverse, radial oblique, and ulnar oblique. Although these patterns often coexisted and the bundles were somewhat intermingled, a specific pattern was very evident in several laminae. Laminae with the distal transverse bundle pattern were the thickest and were reinforced by additional fibers which originated from the palmar aponeurosis and were deeply inserted into the lamina. Based on the laminar configurations of the superficial and deep layers and their composite fiber bundles, we classified the ligaments into four types. Type I, in which distal transverse and ulnar oblique laminae predominated in every layer, was the most common (44.2%), while another large group (41.6%) exhibited type II ligaments, comprising distal transverse and ulnar oblique laminae in the superficial layer and proximal transverse and radial oblique laminae in the deep layer. Thus, in almost half of the patients (type II), the strong distal transverse lamina is likely to be excised during the final step of endoscopic carpal tunnel release because of its superficial localization. This could be a major reason for the frequent occurrence of incomplete release. Moreover, the almost universal superficial ulnar oblique bundle pattern (observed in type I, II, and III ligaments), predisposes to scarring, which may cause radial shifting of the ulnar neurovascular bundle and may affect the palmar branch of the median nerve. We conclude that the interindividual variability seen in the results of endoscopic carpal tunnel release, including minor complications, depends partly on configurational variations in the laminar arrangement of the transverse carpal ligament.

Aged↗

PubMed2002

Aortic root remodeling operation: how do we tailor a tube graft?

BACKGROUND: In aortic root remodeling operation, it is difficult to perform graft sizing and tailor a graft appropriately. Thus the aim of this study was to create guidelines for sizing and tailoring that would help to standardize the operation. METHODS: We studied the anatomy of the aortic root and assessed the reliability of three equations reported to assist in graft sizing with aortic root casts obtained from 127 cadavers. RESULTS: Yacoub's equation and ours accurately predicted the diameter at the sinotubular junction. Three cusps of the aortic valve were not equal in size. Sinus height of the aortic root was unpredictable. CONCLUSIONS: Based on these results, we recommend that aortic root remodeling operation should be performed as follows: (1) graft sizing should be performed using Yacoub's way or our way; (2) the tube graft should be cut into three parts in proportion to the size of each cusp; and (3) the position of the commissures in the tube graft should be secured with sutures first, and the depth of the sinuses should be determined later.

Adult↗

PubMed2002

Histology of the bone-tendon interfaces of limb muscles in lizards.

Lizards exhibit continual bone growth at the epiphysis, and their limb muscles are distributed differently from those of mammals because of differences in weight bearing. We therefore characterized the bone-tendon (B-T) interface (also termed the enthesis) in lizards. Using the forelimbs of five monitor lizards and three iguanas, we performed histological investigations on 57 B-T interfaces. Most reptilian tendons were very short and were often composed of wavy fiber bundles. Fibrocartilage (FC)-mediated direct insertion was observed at all epiphyses, whereas periosteum-mediated indirect insertions, including fleshy attachments, were often located on the flat surfaces of the pectoral girdles and at the diaphyses of the limb bones. The reptilian B-T interface was characterized by variability in the morphology of the FC-mediated insertions, especially by morphologies intermediate between those of FC- and periosteum-mediated interfaces; i.e., 1) various degrees of absence of the clear FC zonation seen in mammals, including the tidemark; 2) involvement of the periosteum in the FC; 3) the presence of various types of FC cells in the tendon near the interface, to reinforce the tendon against compression or shear stress; and 4) both FC and hyaline cartilage (lateral articular cartilage) receiving the tendon at the epiphysis. Overall, variations in the connective tissue, especially the FC tissue, were very evident in the reptilian B-T interface. The specific structures of the interfaces probably represent adaptations to the continuous growth and loose joint structures of lizards.

Animals↗

PubMed2002

Configurations of the segmental and subsegmental bronchi and arteries in the right upper lobe of the human lung with special reference to their concomitant relations and double subsegmental arterial supply.

The basic, concomitant topographical relation between the segmental bronchus and artery shows derived figures in the dorsolateral part of the cranial portion of the mammalian lung, especially in humans. However, the pulmonary arterial supply has not been investigated well in the subsegmental level, even in humans. One or two subsegments of S2 received a double arterial supply from both the superior and inferior pulmonary trunks in 39.8% of the right upper lobes of 194 human lung dissections, whereas 20.6% did so in S3, although the latter cases were limited to one of the two subsegments. Moreover, we found several arterial patterns that were significantly frequently observed in a specific group of the bronchial tree in S2 and/or S3. Invasion of an additional artery of inferior trunk origin seemed to happen at the same time in both segments even without complementary territorial relations with the essential segmental artery of the superior trunk origin. S2 and S3 in the human right lung seemed to be the best fields for reconsideration of the basic rules in the lung segment system in mammals as a result of their having the largest sets of variations. We speculate that the discrepancy between the bronchial and arterial ramification patterns, which was frequently found in S2 and S3, is a result of a hypothetical secondary increase of the comparative volume of this area in evolution and/or development of the lung.

Aged↗

PubMed2002

Does the cardinal ligament of the uterus contain a nerve that should be preserved in radical hysterectomy?

The cardinal ligament (CL) of the uterus is present as a specific part of the parametrium when the pararectal and paravesical spaces are developed surgically. According to usual nerve-sparing radical hysterectomy (the Tokyo method), the CL is divided into two parts, the vascular part for dissection and the nerve part that contains the pelvic splanchnic nerve (PSN) as a major target for nerve sparing. In contrast, we hypothesized that the CL and another structure outside of the usual area for surgical dissection, that is, the lateral rectal ligament, are mutually continuous and that the PSN runs through the lateral ligament rather than the CL. In the present study, a combination of routine dissection, fresh cadaver dissection and in situ sectional anatomy revealed that: (i) the CL did not contain the PSN; (ii) a well-defined fascial structure existed in the bottom or dorsal margin of the CL area; and (iii) the pelvic plexus was separated from vascular components of the CL. The present results provide a new perspective for nerve-sparing radical hysterectomy with extensive lateral parametrial dissection of the CL.

Aged↗

PubMed2002

Human liver caudate lobe and liver segment.

Recently, the caudate lobe has seemed to be the final target for aggressive cancer surgery of the liver. This lobe has five surfaces: the dorsal, left and hilar-free surfaces and the right and ventral-border planes. Surgeons have divided the caudate lobe into three parts: Spiegel's lobe, which is called the 'caudate lobe and papillary process' by anatomists, the caudate process, viewed as almost the same entity by anatomists, and the paracaval portion corresponding to the dorsally located parenchyma in front of the inferior vena cava. All three parts are supplied by primary branches originating from the left and right portal veins, including the hilar bifurcation area. The hilar bifurcation branch often (50%) supplies the paracaval portion and it sometimes (29%) extends its territory to Spiegel's lobe. It was postulated by Couinaud that the paracaval portion or the S9 is not defined by its supplying portal vein branch but by its 'dorsal location' in the liver. Couinaud's caudate lobe or dorsal-liver concept cause, and still now causes, great logical confusion for surgeons. We attempt here to describe the margins of the lobe, border branches of the portal vein, the left/right territorial border of the portal vein or Cantile's line and other topics closely relating to the surgery within these contexts. Finally, the caudate lobe as a liver segment will be discussed.

Bile Duct Neoplasms↗