Biomedical subjects

Atsushi Takenaka

Publications and source records attributed to Atsushi Takenaka.

At least 19 recordsLinked to original sources

PubMed2007

A comparison of clinical features between chlamydial and non-chlamydial urethritis in men negative for gonococcal infection who attended a urological outpatient clinic in Japan.

OBJECTIVES: The objective of this study was to investigate the clinical features of non-gonococcal urethritis in men who attended a urological outpatient clinic in Japan. MATERIALS AND METHODS: This study included a total of 194 patients diagnosed as having non-gonococcal urethritis and subsequently judged as cured following antibiotic therapy between January 2001 and June 2005. Clinical data were analyzed after dividing these patients into two groups as follows: 96 patients with chlamydial urethritis (CU) and 98 with non-chlamydial urethritis (NCU). RESULTS: The incubation period in the CU group was significantly longer than that in the NCU group (P = 0.0020). The incidence of severity of symptoms in the NCU group was significantly greater than that in the CU group (P = 0.022), and the interval between the appearance of the initial symptom and consulting the clinic was significantly shorter in the NCU group than in the CU group (P = 0.0015). The proportion of commercial sex workers (CSWs) as the causative partner in the NCU group was significantly greater that in the CU group (P < 0.001), and the incidence of oral sex as the causative mode of sexual interaction was significantly more frequent in the NCU group than that in the CU group (P = 0.021). The duration of antibiotic therapy until cured was significantly longer in the CU group than in the NCU group (P = 0.0051). Furthermore, multivariate analysis showed that whether the infection involved CU or NCU was independently associated with the treatment interval irrespective of other factors examined (P = 0.041). CONCLUSIONS: These findings suggest that the clinical characteristics of CU and NCU clearly differ and that CU tends to require a longer time to cure than NCU; therefore, among patients with non-gonococcal urethritis, it would be particularly important to effectively control the spread of CU.

Adult↗

PubMed2007

A clinicoanatomical study of the novel nerve fibers linked to stress urinary incontinence: the first morphological description of a nerve descending properly along the anterior vaginal wall.

When performing anterior colporrhaphy for cystocele, most pelvic surgeons have not considered the neuroanatomy that contributes to urethral function. The aim of the study was to anatomically identify nerve fibers located in the anterior vagina associated with the pathogenesis of incontinence and pelvic organ prolapse. Anterior vaginal specimens were obtained from 17 female cadavers and 33 cases of clinical cystocele by anterior vaginal resection. The specimens were step-sectioned and stained with hematoxylin-eosin, S100 antibody, and tyrosine hydroxylase antibody. As a result, descending nerves 50-200 microm in thickness were identified between the urethra and vagina. They were located more than 10 mm medially from a cluster of nerves found almost along the lateral edge of the vagina and stained with S100 and tyrosine hydroxylase antibody, originated from the cranial part of the pelvic plexus, and appeared to terminate at the urethral smooth muscles. The authors classified the density of S100 positive nerve fibers in the anterior vaginal wall obtained from clinically operated cases of cystocele into three grades (Grade 1, nothing or a few thin nerves less than 20 microm in diameter; Grade 2, thick nerves more than 50 microm in diameter and thin nerves; Grade 3, more than 3 thick nerves in one field at an objective magnification of 40x). Mean urethral mobility (Q-tip) values (28.1 degrees +/-+/- 19.6 degrees ) observed in the Grade 3 cases was significantly lower than those (50.0 degrees +/-+/- 27.4 degrees and 59.4 degrees +/-+/- 19.9 degrees ) in Grade 2 and Grade 1, respectively. In addition, the presence of preoperative or postoperative stress urinary incontinence in the cases of Grade 1 was significantly higher than those of the cases with S100 positive stained nerves. In conclusion, the novel nerve fibers immunohistochemically identified in the anterior vaginal wall are different from those of the common nervous system or the pelvic floor and are associated with the pathogenesis of urethral hypermobility.

Aged↗

PubMed2007

Pelvic autonomic nerve mapping around the prostate by intraoperative electrical stimulation with simultaneous measurement of intracavernous and intraurethral pressure.

PURPOSE: In previous studies we noted that the neurovascular bundle was not identical to the bundle of the cavernous nerve fibers. In this study we sought to prove these anatomical findings electrophysiologically and map the autonomic nerve fibers by intraoperative simultaneous measurement of intracavernous pressure and intraurethral pressure. MATERIALS AND METHODS: Between January 2004 and May 2005 electrical stimulation was performed in 27 open pelvic surgeries, including 26 radical retropubic prostatectomies and 1 radical cystectomy, using an original bipolar electrode before prostate removal. Nerve stimulation was performed at the base of the so-called neurovascular bundle (point A) and the rectal wall about 1 cm posterolateral, apart from the neurovascular bundle (point B). Intracavernous pressure and intraurethral pressure were measured simultaneously. RESULTS: The mean +/- SD increase in intracavernous pressure was 9.8 +/- 6.3 cm H2O at point A and 13.5 +/- 7.3 cm H2O at point B. Intracavernous pressure at point B was significantly higher than at point A (p = 0.0240). The mean increase in intraurethral pressure was 17.0 +/- 9.4 cm H2O at point A and 11.2 +/- 8.1 cm H2O at point B. Intraurethral pressure at point A was significantly higher than at point B (p = 0.0353). CONCLUSIONS: The course of the cavernous nerves did not always agree with the surgically identified neurovascular bundle. The distribution of cavernous nerves was wider than our image of the neurovascular bundle and it existed on the rectal wall posterolateral, apart from the neurovascular bundle rather than the neurovascular bundle itself. The surgically identified neurovascular bundle contained the nerve fibers contributing to urinary continence.

Aged↗

PubMed2006

Significance of micrometastases in pelvic lymph nodes detected by real-time reverse transcriptase polymerase chain reaction in patients with clinically localized prostate cancer undergoing radical prostatectomy after neoadjuvant hormonal therapy.

OBJECTIVE: To clarify the significance of micrometastases in pelvic lymph nodes in patients treated by radical prostatectomy (RP) for prostate cancer after neoadjuvant hormonal therapy (NHT). PATIENTS AND METHODS: The study included 52 patients with clinically localized prostate cancer who received NHT followed by RP. The expression of prostate-specific antigen (PSA) and prostate-specific membrane antigen (PSMA) in 989 lymph nodes isolated from the 52 patients were assessed by a fully quantitative real-time reverse-transcriptase polymerase chain reaction (RT-PCR). We regarded specimens in which either PSA or PSMA mRNA were positive as showing the 'presence of micrometastasis'. Lymph node specimens were also stained immunohistochemically with an antibody against PSA. RESULTS: Pathological examinations detected tumour cells in 11 lymph nodes from four patients, and real-time RT-PCR further identified micrometastasis in 40 lymph nodes from 19 patients with no pathological evidence of nodal involvement. The presence of micrometastatic cancer cells was confirmed by immunohistochemical staining in 19 lymph nodes from 11 patients with pathologically negative nodes. The presence of micrometastases was significantly associated with other conventional prognostic variables, including the pretreatment serum PSA level, biopsy Gleason score and surgical margin status. The biochemical recurrence-free survival rate in patients with no micrometastasis was significantly higher than that in those with micrometastasis. Furthermore, multivariate analysis identified the presence of micrometastasis as an independent factor predicting biochemical recurrence. CONCLUSIONS: Although residual foci of atrophic prostate cancer cells in resected lymph nodes after NHT can be difficult to diagnose by routine pathological examination, the present results show the usefulness of quantitative real-time RT-PCR targeting PSA and PSMA genes for detecting micrometastatic tumour foci in pelvic lymph nodes from patients with localized prostate cancer treated by NHT followed by RP. Furthermore, the present findings suggest that micrometastases in pelvic lymph nodes might be, at least partly, important in the development of biochemical recurrence in some patients undergoing RP after NHT.

Androgen Antagonists↗

PubMed2006

Ghrelin expression in human testis and serum testosterone level.

Ghrelin, which is the endogenous ligand for the growth hormone (GH) secretagogue receptor (GHS-R), has been primarily linked to the central neuroendocrine regulation of GH secretion and food intake, although additional peripheral actions of ghrelin have also been reported. Recent research has suggested that ghrelin also affects testosterone (T) secretion in vitro. To investigate the role of ghrelin in human testicular function, we examined the expression of ghrelin in testicular tissues by immunohistochemistry. Testicular tissue samples were collected from the testes of 5 fertile volunteers, 8 patients with obstructive azoospermia, and 36 oligospermic patients with varicocele testis. In the testicular tissues, ghrelin was stained using the antighrelin polyclonal antibody, and the Johnsen score was calculated. The concentrations of serum follicle-stimulating hormone (FSH), lutenizing hormone (LH), and T were determined by chemiluminescence assays. Immunostaining of ghrelin was detected in the interstitium and in Leydig cells. Ghrelin expression by Leydig cells was inversely correlated with the serum T concentration (r=-.50; P<.001), but was not directly related to spermatogenesis. We conclude that steroidogenic dysfunction is associated with increased ghrelin expression in human testes.

Adult↗

PubMed2006

Preservation of the puboprostatic collar and puboperineoplasty for early recovery of urinary continence after robotic prostatectomy: anatomic basis and preliminary outcomes.

OBJECTIVES: The aims of the present study are to prove the hypothesis that the preservation of the puboprostatic collar and puboperineoplasty contribute to the early recovery of urinary continence after robotic radical prostatectomy. We reconfirm the anatomy of the periurethral supporting tissue and show the preliminary result on the early continence of patients undergoing this modification. METHODS: Using 10, male, fresh cadavers, we traced the endopelvic fascia, the fascia of levator ani, puboprostatic ligaments, rhabdosphincter, and puboperinealis muscle to devise strategies in preserving this complex. The modifications were then attempted by a single surgeon (A.K.T.) in 19 patients undergoing robotic prostatectomy during September 2005. RESULTS: After incision of the endopelvic fascia within the fascial tendinous arch of the pelvis, the puboprostatic collar and the levator ani could be separated laterally. The puboperinealis muscle attached to part of the pubic symphysis behind the puboprostatic ligament and terminated at the perineal body. We were able to preserve the puboprostatic collar in all attempted cases. Furthermore, puboperineoplasty took 5min to complete. The total continence rate was 63.2% at median follow-up of 38.1 d. Immediate continence rate just after catheter removal was 42.1%. The rate at 1 and 4 wk was 52.6% and 71.4%, respectively. The margins of the examined specimens were all negative for malignancy. CONCLUSIONS: This modification should preserve or allow for early recovery of urinary continence from an anatomic perspective. Further studies are necessary to elucidate the clinical impact on a patient's early continence.

Adult↗

PubMed2006

Protruding disordered loop of gC1qR is specifically exposed and related to antiapoptotic property in germ cell lineage.

We established a monoclonal antibody (MAb), 5G9, with the use of a fixed seminoma tissue from an archival paraffin-embedded specimen, as an immunogen. Without antigen retrieval, positive 5G9-immunohistochemical staining was confined mostly to primordial germ cells, spermatogonia and various germ cell tumors. 5G9 recognized a mitochondrial 32-kD protein with an isoelectric point of pH 4.2, identified as a multifunctional ubiquitous protein, receptor for globular head of C1q (gC1qR), whose epitope was mapped in a disordered loop connecting the beta3 and the beta4 strands. Reflecting the ubiquitous distribution of gC1qR, with antigen retrieval, 5G9 was found reactive to a wide range of normal and tumor tissues. Since several co-precipitated and phosphorylated bands were observed in various human cell lines but not in germ cell tumor cell lines by in vitro phosphorylation assay, we speculate that the epitope of gC1qR is specifically unmasked in the germ cell lineage. By reducing gC1qR by siRNA, a significant increase was observed in the number of apoptotic cells in ITO-II and TCam-2 cell lines, but to a lesser extent in the Colo201 colon cancer cell line, showing an antiapoptotic property of gC1qR in the germ cells. Since protein-protein interaction is partially preserved by fixation, archival paraffin-embedded specimens can be a valuable source of immunogens for generating monoclonal antibodies (MAbs) that recognize tissue-specific protein conformation.

Antibodies, Monoclonal↗

PubMed2006

Anatomy of autonomic nerve component in the male pelvis: the new concept from a perspective for robotic nerve sparing radical prostatectomy.

The DaVinci Robot (Intuitive Surgical, Sunnyvale California) with its magnified 3-D vision and multi-jointed wristed instruments enabled us to perform radical prostatectomy with consideration for the pelvic anatomy. In the present paper, we review the pelvic autonomic neuroanatomy with respect to robotic prostatectomy and demonstrate the procedures and critical points of nerve-sparing robotic radical prostatectomy based on novel anatomic concepts. Microscopic and macroscopic data were acquired from 30 fresh and 25 fixed male cadavers. A video study of 205 surgeries was performed for establishing the anatomy relevant to robotic prostatectomy. From a practical standpoint, we could group the relevant neural tissue into three broad zones: (1) proximal neurovascular plate (PNP), (2) predominant neurovascular bundles (PNB), (3) accessory distal neural pathways (ANP). Autonomic ganglion cells existed widely not only in nerve components but also along the viscera. The critical areas of nerve sparing surgery were the distal end of PNP, the entire PNB, and the circumference of the apex. Interindividual differences of cell counts were evident in all sites. Based on these concepts, we established the Athermal Robotic Technique (ART) for nerve sparing prostatectomy. Surgical and oncological outcomes were not mature but feasible. These tri-zonal and ganglion cell concepts may be of benefit to new surgeons undertaking nerve-sparing robotic radical prostatectomy.

Autonomic Pathways↗

PubMed2006

Operating behind Denonvilliers' fascia for reliable preservation of urogenital autonomic nerves in total mesorectal excision: a histologic study using cadaveric specimens, including a surgical experiment using fresh cadaveric models.

PURPOSE: Little is known about which urogenital nerves are liable to be injured along surgical planes in front of or behind Denonvilliers' fascia. METHODS AND RESULTS: Using semiserial histology for five fixed male pelves, we demonstrated that: 1) left/right communicating branches of bilateral pelvic plexuses run immediately in front of Denonvilliers' fascia; and 2) a lateral continuation of Denonvilliers' fascia separates the urogenital neurovascular bundle from the mesorectum. Notably, the mesorectum contains no or few extramural ganglion cells. At the level of the seminal vesicles, incision in front of Denonvilliers' fascia seems likely to injure superior parts of the pelvic plexus and the left/right communication. Moreover, at the prostate level, this incision misleads the surgical plane into the neurovascular bundle. Fresh cadaveric dissections of five unfixed male pelves confirmed that the surgical plane in front of Denonvilliers' fascia continues to a fascial space for the pelvic plexus containing ganglion cell clusters lateral and/or inferior to the seminal vesicles. CONCLUSIONS: To preserve all autonomic nerves for urogenital function, optimal total mesorectal excision for rectal cancer requires dissection behind Denonvilliers' fascia.

Aged↗

PubMed2006

Transperineal extended biopsy improves the clinically significant prostate cancer detection rate: a comparative study of 6 and 12 biopsy cores.

BACKGROUND: We evaluated the improvement in the rate of prostate cancer detection when using a 12-core transperineal biopsy protocol including transitional zone biopsy. METHODS: Between April 2003 and November 2004, 247 consecutive men underwent transperineal systemic 12-core biopsy of the prostate. Six cores were obtained at the peripheral zone, four at the transitional zone and two at the apex. We examined the cancer detection rate in each of the 12 cores, and also determined the improvement of cancer detection resulting from the extensive 12-core versus standard 6-core biopsy. RESULTS: Using the extensive 12-core biopsy, prostate cancer was detected in 98 cases (39.7%). Prostate-specific antigen (PSA), PSA density, the positive rate in digital rectal examination and transrectal ultrasound findings were significantly higher in the prostate cancer group than in the non-prostate cancer group, and prostate volume was larger in non-prostate cancer group. Every site showed almost the same positive rate, between 17.8 and 21.5%. There were 20 cases which were positive in the extended biopsy, but negative in the sextant. The detection improved significantly (20.4%). The improvement of cancer detection in extended biopsy was better in men with PSA levels of 10 ng/mL or less (28.9%), PSA density 0.3 or less (25.8%), negative digital rectal examination (23.3%), and negative transrectal ultrasound (21.6%). Of these twenty patients, no cases with insignificant tumor were detected in the six prostatectomy cases. In particular, three cases of the six were transitional-zone-only cancer. CONCLUSION: Transperineal extended 12-core biopsy including 4 transitional zone cores is a more useful procedure than transperineal 6-core biopsy. Routine transitional zone biopsy, that is different from transrectal biopsy, might be useful for detecting biologically significant cancer.

Aged↗

PubMed2006

High-dose chemotherapy for male germ cell tumor.

Today, 20-30% of male patients with advanced germ cell tumor (GCT) do not have durable, complete remission in spite of cis-platinum (CDDP)-based chemotherapy. High-dose chemotherapy (HDCT) has been tried in CDDP refractory GCT patients. Initially HDCT was performed with autologous bone marrow transplantation in heavily treated patients. However, the clinical outcome was not good and the treatment-related death rate was not ignorable. Therefore, earlier introduction of HDCT with peripheral blood stem cell transplantation was preferable as it renders HDCT more effective and less toxic, and multicycle HDCT is feasible. The durable free rate of recent HDCT for refractory GCT patients is 32-65%. HDCT is also performed as first line chemotherapy for poor prognosis GCT patients. Induction chemotherapy followed by multicycles of HDCT was tried. The durable free rate of recent HDCT as first line chemotherapy is 43-73%. Although previous reports suggest the superiority of HDCT, one recent randomized controlled trial (RCT) failed to show an improvement with one cycle of HDCT followed by three cycles of standard-dose chemotherapy (SDCT) compared with four cycles of SDCT. Ongoing RCT comparing multicycles of HDCT with SDCT for poor prognostic GCT patients will clarify the role of HDCT. Recently, new regimens of HDCT containing paclitaxel have been devised. In this review, the history, current status and future of HDCT for advanced or refractory GCT will be discussed.

Antineoplastic Agents↗

PubMed2006

Hydronephrosis caused by intra-abdominal abscess from cecal perforation by an ingested fish bone.

A patient was treated for hydronephrosis caused by an intra-abdominal abscess arising from cecal perforation by an ingested fish bone. To the authors' knowledge there is no previous report of such ureteral obstruction. Ureteral stenting, drainage of the abscess, and ileocecal resection were performed. Six months of stenting were required to attain ongoing ureteral patency following removal.

Abdominal Abscess↗

PubMed2006

The proximal neurovascular plate and the tri-zonal neural architecture around the prostate gland: importance in the athermal robotic technique of nerve-sparing prostatectomy.

OBJECTIVE: To review the neural architecture around the prostate gland, as it is relevant for nerve-sparing robotic prostatectomy, including in particular the anatomy of the proximal neurovascular tissue, the neurovascular bundle (NVB), and accessory neural pathways (ANPs). MATERIALS AND METHODS: The aims of this study were achieved in collaboration between the Cornell Institute of Robotic Surgery, New York, NY, USA and the Institute of Urology at the University of Innsbruck, Austria. The broad steps were: (i) anatomical studies of 10 fresh and two fixed male cadavers; and (ii) collection of videotape and still image data from 200 men undergoing radical prostatectomy by the athermal robotic technique at the Cornell Institute. RESULTS: From a surgical standpoint there was a tri-zonal neural architecture including the proximal neurovascular plate (PNP), the predominant NVB (PNB) and ANPs. The PNP was a mean (range) of 5 (3-10) mm lateral to the seminal vesicles, was 3 (2-7) mm thick, 7 (5-25) mm wide and 9 (4-30) mm long. It was within 6 (4-15) mm of the bladder neck, 5 (2-7) mm of the endopelvic fascia and overlapped 5 (0-7) mm of the proximal prostate. The PNB varied in shape and size from the proximal to distal end, was thickest at the base and most variable near the apex. In eight of 12 cases, there was a medial extension behind the prostate, which converged medially at the apex in four cases. ANPs were noted within the layers of levator fascia and/or lateral pelvic fascia on the anterolateral aspect in five cases and in three on the posterior aspect of the prostate. In nine cadavers, the proximal third of the prostate was covered by the PNP where these ANPs were most prominent. The ANPs formed a plexus on the posterolateral aspect of the apex in four cases. CONCLUSION: We have created an anatomical map of neurovascular tissue relevant to robotic prostatectomy. A tri-zonal neural architecture is described which has helped in standardizing the steps of robotic prostatectomy.

Adult↗

PubMed2005

Phase I study of a combination of s-1 and weekly paclitaxel in patients with advanced or recurrent gastric cancer.

OBJECTIVE: A phase I study of weekly intravenous paclitaxel combined with a fixed dose of S-1, a dihydropyrimidine-dehydrogenase-inhibitory oral fluoropyrimidine, was conducted for patients with advanced or recurrent gastric cancer (ARGC). Endpoints of this study were to examine the toxicity profile OF this regimen and to determine the recommended dose (rd) of paclitaxel. METHODS: S-1 was fixed at a dose of 80 mg/m(2) per day and was administered for 2 weeks (days 1--14) followed by a 2-week rest. Two dose levels of paclitaxel (level 1: 60 mg/m(2), level 0: 50 mg/m(2)) were studied. Paclitaxel was infused over 1 h on days 1, 8, and 15. Plasma sampling was performed to characterize the pharmacokinetics and pharmacodynamics of paclitaxel in some patients. Fifteen patients were enrolled (6 patients in level 1, and 9 patients in level 0). Dose-limiting toxicities were defined as grade 4 hematological (including grade 3 febrile neutropenia) and grade 3 non-hematological (except anorexia, nausea, vomiting and depilation) toxicities. RESULTS: Three of 6 patients in level 1 developed grade 4 neutropenia or grade 3 febrile neutropenia, and 1 of them also showed grade 3 diarrhea, which settled the maximum-tolerated dose at this level. At level 0, 2 of 9 patients developed grade 4 neutropenia or grade 3 febrile neutropenia, and the RD of paclitaxel for this protocol was set at this level. Pharmacologic studies demonstrated the persistence of significant serum paclitaxel levels over 24 h after drug administration at both levels. Objective responses according to Response Evaluation Criteria in Solid Tumors were observed in 3 of 6 patients who had measurable disease. CONCLUSION: A combination of S-1 and weekly paclitaxel was feasible and well tolerated, and is suggested to produce a worthwhile response in ARGC. These results warrant further investigation, and a phase II study has already been started.

Adult↗

PubMed2005

Interindividual variation in distribution of extramural ganglion cells in the male pelvis: a semi-quantitative and immunohistochemical study concerning nerve-sparing pelvic surgery.

OBJECTIVE: We examined distribution and numbers of extramural ganglion cells in the male pelvis, classifying them as sympathetic or parasympathetic. METHODS: Specimens were obtained from 14 formalin-fixed donated male cadavers. Semiserial sections were processed for histologic examination, and for immunohistochemistry using anti-tyrosine hydroxylase (TH) or anti-peptide histidine isoleucine (PHI). RESULTS: Like those along the sacral sympathetic trunk, most other pelvic ganglion cells were located in and along nerve components. Yet the ganglion cell clusters attached to pelvic viscera accounted for 22% to 38% of ganglion cells. These were seen at the dorsal aspect of the bladder, the bladder/prostate junction, the dorsal aspect of the seminal vesicle, and along the prostate, but not along the extrapelvic pudendal nerve, cavernous tissues including the penile hilum, the rhabdosphincter, retropubic fat or recto-urethral muscle. Two fold interindividual variation was seen for total ganglion cell number (3044 to 6522) in the pelvis. TH-positive and PHI-positive cells intermingled at various ratio in every ganglion cell cluster. Sympathetic TH-positive proportions tended to be site-specific. CONCLUSIONS: Pelvic autonomic cells exist not only in nerve components but also along viscera. Even nerve-sparing radical prostatectomy can compromise visceral ganglia. Simple classification of pelvic nerve components as sympathetic or parasympathetic would seem misleading given coexistence of both cell types in a ganglion.

Aged↗

PubMed2005

Variation in course of cavernous nerve with special reference to details of topographic relationships near prostatic apex: histologic study using male cadavers.

OBJECTIVES: To study interindividual variation in the cavernous nerve course near the rhabdosphincter and the apex of the prostate as a basis for refining nerve-sparing radical prostatectomy. The varying anatomy of the cavernous nerve might account for the disparate potency rates after nerve-sparing radical prostatectomy. METHODS: We examined serial histologic sections from 20 male pelves (7 frontal, 8 sagittal, and 5 axial sections) and performed 5 fresh cadaver dissections. RESULTS: In the fresh dissections, the macroscopically identified neurovascular bundle consistently showed an almost straight proximal-to-distal course along the urethra. However, on histologic analysis, the types of the nerve course were classified as frontal (2 of 7 specimens), sagittal (3 of 8), and axial (2 of 5). In the frontal and sagittal courses, the nerves passed through the connective tissue of a narrow potential space between the rhabdosphincter and the levator ani. In the specimens showing an axial course, the nerves were spatially distinct from the prostate, coursing ventromedially in the pararectal space. Thus, the nerves could display a long, tortuous course, passing through the rectourethral muscle at its thickest portion. In addition, a nerve component supplying the area of the rhabdosphincter seemed to accompany the cavernous nerve. CONCLUSIONS: The neurovascular bundle, previously defined in terms of surgery, is likely to differ from the actual course of the cavernous nerve when this is axial, passing through the pararectal space and rectourethral muscle. To avoid cavernous nerve injury, the rectourethral muscle must be managed carefully in both the retropubic and the perineal approaches.

Aged↗

PubMed2005

A novel technique for approaching the endopelvic fascia in retropubic radical prostatectomy, based on an anatomical study of fixed and fresh cadavers.

OBJECTIVE: To present the anatomical basis and details of a technique for an approach to the endopelvic fascia devised to preserve urinary continence. PATIENTS, MATERIALS AND METHODS: For cross-sectional macroscopic observation, seven formalin-fixed specimens of the male pelvic contents including the pelvic wall were serially sectioned at a 5-mm thickness. Semi-serial sections from eight other specimens were examined histologically. Eight fresh cadavers were dissected to mimic the various steps in a retropubic radical prostatectomy. After approaching the endopelvic fascia in an anatomically determined manner to reach the paraprostatic space, the pubic bone was removed and nerves near the rhabdosphincter dissected. To assess the clinical implication of this approach, we examined the time to achieve continence in 23 consecutive patients who had a radical retropubic prostatectomy using the new technique. RESULTS: Sectional macroscopic observation depicted the fascia of the levator ani as a definite structure adherent to but not fused with the lateral pelvic fascia. The thin fascia overlying the levator ani fascia and lateral pelvic fascia represented the true endopelvic fascia. Microscopically, the lower part of the fascia of the levator ani was rich in smooth muscle, which interdigitated with the framework of the rhabdosphincter. In fresh cadavers, the levator ani muscle was removed laterally still covered by its fascia, without visualizing the muscle fibres. Small branches from the pudendal nerve entered the rhabdosphincter. The mean (sd, range) distance from the lowest point of the endopelvic fascia to the point where the sphincteric branch entered the rhabdosphincter was 5.5 (1.8, 3-8) mm. The continence rate at 1, 3, 6 and 9 months after surgery using the new technique was 44%, 83%, 96% and 100%, respectively. CONCLUSIONS: Preserving the fascia of the levator ani helps to protect the levator ani muscle, rhabdosphincter and pudendal nerve branches to the rhabdosphincter. In retropubic radical prostatectomy, this anatomical approach to the endopelvic fascia should preserve or allow the earlier recovery of urinary continence.

Aged↗

PubMed2005

Assessment of microheterogeneity of blood flow in the rat urinary bladder by high-resolution digital radiography.

OBJECTIVES: To assess high-resolution digital radiography for measuring blood flow and thus examine the microheterogeneity of bladder microcirculation in a rat model. MATERIALS AND METHODS: Microheterogeneity of blood flow in both mucosa and detrusor muscle of eight anaesthetized rats was investigated using an imaging technique with very high spatial resolution (0.1 x 0.1 mm(2)) using digital radiography combined with the deposition of (3)H-labelled desmethylimipramine. The spatial pattern of blood flow was quantified by the coefficient of variation of the regional flow (CV = sd/mean). RESULTS Muscle blood flow was less than mucous blood flow (muscle : mucosa, 2.9 : 5) in the empty bladder. In the muscle layer the blood flow distribution was more heterogeneous than that in the mucosa, with a mean (sd) CV in muscle and mucosa of 0.33 (0.033) and 0.16 (0.019), respectively (P < 0.001) at the capillary level. CONCLUSION: There was a heterogeneous distribution of blood flow in the microcirculation to capillary vessels in the muscular layer, possibly reflecting a difference in dynamic blood flow of regional perfusion of the emptied bladder.

Animals↗