1
|
Muro S, Shoji S, Suriyut J, Akita K. Anatomy of muscle connections in the male urethra and anorectal canal. BJU Int 2024; 133:752-759. [PMID: 38456568 DOI: 10.1111/bju.16307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2024]
Abstract
OBJECTIVES To elucidate the male urethral muscular structure and its relationship with the anorectal canal muscles, as establishing an anatomical foundation for urethral function will contribute to the prevention, diagnosis, and treatment of urinary incontinence. METHODS Eight male cadavers were used. Using a multifaceted approach, we performed macroscopic anatomical examination, histological analysis of wide-range serial sectioning and immunostaining, and three-dimensional (3D) reconstruction from histological sections. In the macroscopic anatomical examination, pelvic halves were meticulously dissected in layers from the medial aspect. In the histological analysis, the tissue, including the urethra and anorectal canal, was serially sectioned in the horizontal plane. The muscular structures were reconstructed and visualised in 3D. RESULTS The membranous portion of the urethra had three muscle layers: the longitudinal and circular muscles (smooth muscle) and the external urethral sphincter (skeletal muscle). The circular muscle was connected posteriorly to the longitudinal rectal muscle. The external urethral sphincter had a horseshoe shape, with its posterior ends continuing to the external anal sphincter, forming a 3D ring-like sphincter. CONCLUSION This study revealed skeletal and smooth muscle connections between the male urethra and anorectal canal, enabling urethral compression and closure. These anatomical muscle connections suggest a functional linkage between them.
Collapse
Affiliation(s)
- Satoru Muro
- Department of Clinical Anatomy, Tokyo Medical and Dental University (TMDU), Bunkyo-ku, Tokyo, Japan
| | - Sunao Shoji
- Department of Urology, Tokai University School of Medicine, Isehara, Kanagawa, Japan
| | - Janyaruk Suriyut
- Department of Anatomy, Faculty of Medicine, Srinakharinwirot University, Bangkok, Thailand
| | - Keiichi Akita
- Department of Clinical Anatomy, Tokyo Medical and Dental University (TMDU), Bunkyo-ku, Tokyo, Japan
| |
Collapse
|
2
|
Tharnmanularp S, Muro S, Nimura A, Ibara T, Akita K. Significant relationship between musculoaponeurotic attachment of the abdominal and thigh adductor muscles to the pubis: implications for the diagnosis of groin pain. Anat Sci Int 2024; 99:190-201. [PMID: 37985575 PMCID: PMC10902015 DOI: 10.1007/s12565-023-00750-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Accepted: 10/28/2023] [Indexed: 11/22/2023]
Abstract
Groin pain is prevalent in orthopedic and sports medicine, causing reduced mobility and limiting sports activity. To effectively manage groin pain, understanding the detailed anatomy of supporting muscles is crucial. This study aimed to investigate the musculoaponeurotic attachments on the pubis and the relationship among intramuscular aponeuroses of abdominal and thigh adductor musculatures. Macroscopic analyses were performed in 10 pelvic halves. The bone morphology of the pubis was assessed in two pelvic halves using microcomputed tomography. Histological investigations were conducted in two pelvic halves. The external oblique aponeurosis extended to the adductor longus aponeurosis, forming conjoined aponeurosis, which attached to a small impression distal to the pubic crest. The gracilis aponeurosis merges with the adductor brevis aponeurosis and is attached to the proximal part of the inferior pubic ramus. The rectus abdominis and pyramidalis aponeuroses were attached to the pubic crest and intermingled with the gracilis-adductor brevis aponeurosis, forming bilateral conjoined aponeurosis, which attached to a broad area covering the anteroinferior surface of the pubis. Histologically, these two areas of conjoined aponeuroses were attached to the pubis via the fibrocartilage enthesis. Microcomputed tomography revealed two distinctive bone morphologies, a small impression and an elongated osseous prominence on pubis, corresponded to the two areas of conjoined aponeuroses. This study demonstrated close relationships between the aponeurotic attachment of the external oblique and adductor longus, and between the rectus abdominis, pyramidalis, gracilis, and adductor brevis. The findings of aponeurotic complexes would aid in diagnostic and surgical approaches for athletic groin pain.
Collapse
Affiliation(s)
- Suthasinee Tharnmanularp
- Department of Clinical Anatomy, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-Ku, Tokyo, 113-8510, Japan
| | - Satoru Muro
- Department of Clinical Anatomy, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-Ku, Tokyo, 113-8510, Japan.
| | - Akimoto Nimura
- Department of Functional Joint Anatomy, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Takuya Ibara
- Department of Functional Joint Anatomy, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Keiichi Akita
- Department of Clinical Anatomy, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-Ku, Tokyo, 113-8510, Japan
| |
Collapse
|
3
|
Hyuga T, Fujimoto K, Hashimoto D, Tanabe K, Kubo T, Nakamura S, Ueda Y, Fujita-Jimbo E, Muramatsu K, Suzuki K, Osaka H, Asamura S, Moriya K, Nakai H, Yamada G. Wound healing responses of urinary extravasation after urethral injury. Sci Rep 2023; 13:10628. [PMID: 37391520 PMCID: PMC10313654 DOI: 10.1038/s41598-023-37610-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Accepted: 06/24/2023] [Indexed: 07/02/2023] Open
Abstract
The post-surgical fluid leakage from the tubular tissues is a critical symptom after gastrointestinal or urinary tract surgeries. Elucidating the mechanism for such abnormalities is vital in surgical and medical science. The exposure of the fluid such as peritonitis due to urinary or gastrointestinal perforation has been reported to induce severe inflammation to the surrounding tissue. However, there have been no reports for the tissue responses by fluid extravasation and assessment of post-surgical and injury complication processes is therefore vital. The current model mouse study aims to investigate the effect of the urinary extravasation of the urethral injuries. Analyses on the urinary extravasation affecting both urethral mesenchyme and epithelium and the resultant spongio-fibrosis/urethral stricture were performed. The urine was injected from the lumen of urethra exposing the surrounding mesenchyme after the injury. The wound healing responses with urinary extravasation were shown as severe edematous mesenchymal lesions with the narrow urethral lumen. The epithelial cell proliferation was significantly increased in the wide layers. The mesenchymal spongio-fibrosis was induced by urethral injury with subsequent extravasation. The current report thus offers a novel research tool for surgical sciences on the urinary tract.
Collapse
Affiliation(s)
- Taiju Hyuga
- Department of Developmental Genetics Institute of Advanced Medicine, Wakayama Medical University, Kimiidera 811-1, Wakayama City, Wakayama, 641-8509, Japan.
- Department of Pediatric Urology, Jichi Medical University Children's Medical Center Tochigi, Yakushiji 3311-1, Shimotsuke City, Tochigi, 329-0498, Japan.
| | - Kota Fujimoto
- Department of Developmental Genetics Institute of Advanced Medicine, Wakayama Medical University, Kimiidera 811-1, Wakayama City, Wakayama, 641-8509, Japan
- Department of Plastic and Reconstructive Surgery, Wakayama Medical University, Kimiidera 811-1, Wakayama City, Wakayama, 641-8509, Japan
| | - Daiki Hashimoto
- Department of Developmental Genetics Institute of Advanced Medicine, Wakayama Medical University, Kimiidera 811-1, Wakayama City, Wakayama, 641-8509, Japan
| | - Kazuya Tanabe
- Department of Pediatric Urology, Jichi Medical University Children's Medical Center Tochigi, Yakushiji 3311-1, Shimotsuke City, Tochigi, 329-0498, Japan
| | - Taro Kubo
- Department of Pediatric Urology, Jichi Medical University Children's Medical Center Tochigi, Yakushiji 3311-1, Shimotsuke City, Tochigi, 329-0498, Japan
| | - Shigeru Nakamura
- Department of Pediatric Urology, Jichi Medical University Children's Medical Center Tochigi, Yakushiji 3311-1, Shimotsuke City, Tochigi, 329-0498, Japan
| | - Yuko Ueda
- Department of Urology, Wakayama Medical University, Kimiidera 811-1, Wakayama City, Wakayama, 641-8509, Japan
| | - Eriko Fujita-Jimbo
- Department of Pediatrics, Jichi Medical University School of Medicine, Yakushiji 3311-1, Shimotsuke City, Tochigi, 329-0498, Japan
| | - Kazuhiro Muramatsu
- Department of Pediatrics, Jichi Medical University School of Medicine, Yakushiji 3311-1, Shimotsuke City, Tochigi, 329-0498, Japan
| | - Kentaro Suzuki
- Faculty of Life and Environmental Sciences, University of Yamanashi, Takeda 4-4-37, Kofu City, Yamanashi, 400-8510, Japan
| | - Hitoshi Osaka
- Department of Pediatrics, Jichi Medical University School of Medicine, Yakushiji 3311-1, Shimotsuke City, Tochigi, 329-0498, Japan
| | - Shinichi Asamura
- Department of Plastic and Reconstructive Surgery, Wakayama Medical University, Kimiidera 811-1, Wakayama City, Wakayama, 641-8509, Japan
| | - Kimihiko Moriya
- Department of Pediatric Urology, Jichi Medical University Children's Medical Center Tochigi, Yakushiji 3311-1, Shimotsuke City, Tochigi, 329-0498, Japan
| | - Hideo Nakai
- Department of Pediatric Urology, Jichi Medical University Children's Medical Center Tochigi, Yakushiji 3311-1, Shimotsuke City, Tochigi, 329-0498, Japan
| | - Gen Yamada
- Department of Developmental Genetics Institute of Advanced Medicine, Wakayama Medical University, Kimiidera 811-1, Wakayama City, Wakayama, 641-8509, Japan.
- Department of Plastic and Reconstructive Surgery, Wakayama Medical University, Kimiidera 811-1, Wakayama City, Wakayama, 641-8509, Japan.
| |
Collapse
|
4
|
Muro S, Akita K. Pelvic floor and perineal muscles: a dynamic coordination between skeletal and smooth muscles on pelvic floor stabilization. Anat Sci Int 2023:10.1007/s12565-023-00717-7. [PMID: 36961619 DOI: 10.1007/s12565-023-00717-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Accepted: 03/15/2023] [Indexed: 03/25/2023]
Abstract
The purpose of this review is to present our researches on the pelvic outlet muscles, including the pelvic floor and perineal muscles, which are responsible for urinary function, defecation, sexual function, and core stability, and to discuss the insights into the mechanism of pelvic floor stabilization based on the findings. Our studies are conducted using a combination of macroscopic examination, immunohistological analysis, 3D reconstruction, and imaging. Unlike most previous reports, this article describes not only on skeletal muscle but also on smooth muscle structures in the pelvic floor and perineum to encourage new understanding. The skeletal muscles of the pelvic outlet are continuous, which means that they share muscle bundles. They form three muscle slings that pass anterior and posterior to the anal canal, thus serving as the foundation of pelvic floor support. The smooth muscle of the pelvic outlet, in addition to forming the walls of the viscera, also extends in three dimensions. This continuous smooth muscle occupies the central region of the pelvic floor and perineum, thus revising the conventional understanding of the perineal body. At the interface between the levator ani and pelvic viscera, smooth muscle forms characteristic structures that transfer the lifting power of the levator ani to the pelvic viscera. The findings suggest new concepts of pelvic floor stabilization mechanisms, such as dynamic coordination between skeletal and smooth muscles. These two types of muscles possibly coordinate the direction and force of muscle contraction with each other.
Collapse
Affiliation(s)
- Satoru Muro
- Department of Clinical Anatomy, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-Ku, Tokyo, 113-8510, Japan.
| | - Keiichi Akita
- Department of Clinical Anatomy, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-Ku, Tokyo, 113-8510, Japan
| |
Collapse
|
5
|
Muro S, Akita K. Novel combination method of wide-range serial sectioning and 3D reconstruction visualizing both macro-level dynamics and micro-level interactions in an attempt to analyze the female pelvic floor. Anat Sci Int 2023:10.1007/s12565-023-00710-0. [PMID: 36882587 DOI: 10.1007/s12565-023-00710-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 02/23/2023] [Indexed: 03/09/2023]
Abstract
The present report presents details of the method for combining wide-range serial sectioning and 3D reconstruction using an adult cadaver. For several decades, anatomists have utilized a variety of non-destructive three-dimensional (3D) visualization methods to complement gross anatomical analysis methods. These include vascular casting for the visualization of vascular morphology and micro-CT for the visualization of bone morphology. However, these conventional methods are restricted by the properties and sizes of the target structures. Here, we introduce a method to conduct 3D reconstruction based on wide-range serial histological sections from adult cadavers, which overcomes previous restrictions. An attempt at 3D visualization of the female pelvic floor muscles provides a detailed description of the procedure. Supplemental video and 3D PDF files allow multifaceted observation of 3D images. Wide-range serial sectioning visualizes morphology beyond the scope of conventional methods, while 3D reconstruction enables non-destructive 3D visualization of any structure that can be observed on a histological section, including skeletal muscle, smooth muscle, ligaments, cartilage, connective tissue, blood vessels, nerves, lymph nodes, and glands. The novel combination of both methods is instrumental in meso-anatomy, a discipline intermediate between macro-anatomy and micro-anatomy.
Collapse
Affiliation(s)
- Satoru Muro
- Department of Clinical Anatomy, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan.
| | - Keiichi Akita
- Department of Clinical Anatomy, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan
| |
Collapse
|
6
|
Muacevic A, Adler JR. Cowper's Syringocele: A Literature Review. Cureus 2022; 14:e32583. [PMID: 36540322 PMCID: PMC9757912 DOI: 10.7759/cureus.32583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/15/2022] [Indexed: 12/23/2022] Open
Abstract
Cowper's syringocele is a rare but underdiagnosed cystic dilatation of the main ducts of Cowper's gland. It is becoming more widely known in the adult population. Recent research proposes that syringoceles should be categorized according to the intraductal pressures causing ductal dilatation from mild to gross ultimately involving the gland itself. Although there may be some overlap in the clinical manifestations of different syringoceles, mildly dilated ducts are frequently asymptomatic. Moreover, moderate to gross duct dilatations can manifest as lower urinary tract symptoms (LUTS) or obstructive symptoms. A valid differential diagnosis is essential because these symptoms can be found in a wide range of severe illnesses. Syringocele can be diagnosed by ultrasonography in combination with voiding retrograde/antegrade cystourethrogram (VCUG), nevertheless, other procedures like cystourethroscopy, CT scan, and MRI scans can be helpful. Initially, conservative surveillance is advised, but if necessary, endoscopic marsupialization or surgical excision is the preferred treatment modality to address persistent problems.
Collapse
|
7
|
Muro S, Kim J, Tsukada S, Akita K. Significance of the broad non-bony attachments of the anterior cruciate ligament on the tibial side. Sci Rep 2022; 12:6844. [PMID: 35477722 PMCID: PMC9046205 DOI: 10.1038/s41598-022-10806-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 04/12/2022] [Indexed: 11/09/2022] Open
Abstract
Knowledge of the anatomy of the anterior cruciate ligament (ACL) is important to understand the function and pathology of the knee joint. However, on the tibial side of ACL, its structural relationships with the articular cartilage and lateral meniscus remain unclear. Furthermore, conventional research methods are limited to analyzing the bone attachments. We provide a comprehensive, three-dimensional anatomical description of the tibial side of the ACL that questions the principle that “a ligament is necessarily a structure connecting a bone to another bone.” In our study, 11 knees from 6 cadavers were used for macroscopic anatomical examinations, serial-section histological analyses, and three-dimensional reconstructions. The attachments of the tibial side of ACL consisted of attachments to the bone (102.6 ± 27.5 mm2), articular cartilage (40.9 ± 13.6 mm2), and lateral meniscus (6.5 ± 4.6 mm2), suggesting that the ACL has close structural relationships with the articular cartilage and lateral meniscus. Our study demonstrates that the tibial side of the ACL is not attached to the bone surface only and provides new perspectives on ligamentous attachments. Considering its attachment to the articular cartilage would enable more accurate functional evaluations of the mechanical tensioning of the ACL.
Collapse
Affiliation(s)
- Satoru Muro
- Department of Clinical Anatomy, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan.
| | - Jiyoon Kim
- Department of Clinical Anatomy, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan
| | - Sachiyuki Tsukada
- Department of Clinical Anatomy, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan
| | - Keiichi Akita
- Department of Clinical Anatomy, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan
| |
Collapse
|