Skeletal Muscle Complex Between the Vagina and Anal Canal: Implications for Perineal Laceration.

INTRODUCTION AND HYPOTHESIS: The anatomy of the skeletal muscles located between the vagina and anus is important during complex obstetric laceration reconstructions. We aimed to clarify the composition of skeletal muscles located between the vagina and anal canal and their three-dimensional configuration relevant to perineum repair. METHODS: This observational study involved ten female cadavers. An anatomical dissection was performed to observe the muscles around the vagina and anal canal. Immunohistological analysis of the midsagittal section was performed to clarify the composition of the muscles, and dissection was performed to correspond to the cross-section. Wide-range serial sectioning and three-dimensional reconstruction were used to support these findings histologically and visualize the three-dimensional arrangement. RESULTS: The region between the vagina and anal canal included the anterior part of the external anal sphincter, superficial transverse perineal muscle approaching from the lateral side, and levator ani, located cranially. They converge three-dimensionally in the median from each direction, forming a muscle complex between the vagina and anal canal. CONCLUSIONS: The medial region between the vagina and anal canal in those giving birth includes a skeletal muscle complex formed by the confluence of the external anal sphincter, anterior bundle of the levator ani, and superficial transverse perineal muscle. In cases of severe perineal lacerations, these muscles could be injured. The anatomical knowledge that a part of the levator ani forms a muscle sling anterior to the anal canal is particularly important for obstetricians and gynecologists repairing obstetric lacerations and treating pelvic floor disorders.

Denonvilliers' fascia as a potential nerve-course marker for the female urinary bladder.

OBJECTIVES: This study investigated the relationship between Denonvilliers' fascia (DF) and the pelvic plexus branches in women and explored the possibility of using the DF as a positional marker in nerve-sparing radical hysterectomy (RH). METHODS: This study included eight female cadavers. The DF, its lateral border, and the pelvic autonomic nerves running lateral to the DF were dissected and examined. The pelvis was cut into two along the mid-sagittal line. The uterine artery, deep uterine veins, vesical veins, and nerve branches to the pelvic organs were carefully dissected. RESULTS: The nerves ran sagitally, while the DF ran perpendicularly to them. The rectovaginal ligament was continuous with the DF, forming a single structure. The DF attached perpendicularly and seamlessly to the pelvic plexus. The pelvic plexus branches were classified into a ventral part branching to the bladder, uterus, and upper vagina and a dorsal part branching to the lower vagina and rectum as well as into four courses. Nerves were attached to the rectovaginal ligament and ran on its surface to the bladder ventral to the DF. The uterine branches split from the common trunk of these nerves. The most dorsal branch to the bladder primarily had a common trunk with the uterine branch, which is the most important and should be preserved in nerve-sparing Okabayashi RH. CONCLUSION: The DF can be used as a marker for nerve course, particularly in one of the bladder branches running directly superior to the DF, which can be preserved in nerve-sparing Okabayashi RH.

Why don't we follow influencers in obstetrics and gynaecology on Twitter to obtain information on the most recent international congresses?

We proposed following influencers in obstetrics and gynecology on Twitter. We believe that the use of Twitter may help obstetrics and gynecology doctors in low-income countries as well as stimulate fellows and residents by following actual discussions at international conferences.

Improved bladder function in radical hysterectomy without worsening oncologic outcome: resection of the posterior layer of the vesicouterine ligament with the procedure limited to the vesical veins.

OBJECTIVE: The classic Okabayashi nerve-sparing radical hysterectomy involves complete resection of the posterior leaf of the vesicouterine ligament, whereas in the simplified nerve-sparing radical hysterectomy, only the vesical veins and some connective tissue of the posterior layer of the vesicouterine ligament are resected. This study aimed to compare bladder function and cervical carcinoma relapse-free survival between these two techniques. METHODS: We conducted a retrospective, historical control study. All female patients aged >20 years who were diagnosed with cervical cancer stage IB1-IIB and underwent radical hysterectomy with pelvic lymphadenectomy between 2009 and 2022 were enrolled. Patients who had a history of other cancers and those who were treated with non-surgical approaches or non-radical hysterectomy were excluded. The primary outcome was relapse-free survival during the follow-up period. RESULTS: A total of 114 patients who underwent curative-intent radical hysterectomy were included in this study. The median follow-up duration was 60 months. No significant difference was observed in relapse-free survival between the two surgical procedures. The simplified nerve-sparing radical hysterectomy was superior in terms of both motor and sensory bladder function outcomes. CONCLUSION: Resection of the posterior layer of the vesicouterine ligament, with the procedure limited to the vesical veins, is an effective and safe method for radical hysterectomy. It may be more useful for preserving the bladder function, without leading to unfavorable oncologic outcomes.

Strangulated bowel obstruction caused by vaginal perforation due to vaginal cancer in a patient with chronic uterine prolapse.

A woman in her 90s with chronic uterine prolapse presented with abdominal pain and a vaginal mass. The patient had generalised peritonitis and a strangulated bowel obstruction originating from a perforated posterior vagina. We performed partial intestinal resection and a total hysterectomy, including excision of the perforation of the vaginal site and the adnexa. The patient died on postoperative day 8 due to worsening systemic sepsis. The pathological diagnosis revealed an invasive carcinoma in the perforated area of the vagina. Obstetric factors are the most frequent cause of female genital tract perforation, and chronic uterine prolapse is associated with this condition; however, vaginal cancer has never been reported as a cause of perforation. Therefore, close collaboration in gynaecology should be considered to investigate whether vaginal perforation and uterine prolapse are related to cancer.

Efficacy and Safety of the Surgery-First Approach Compared to the Chemotherapy-First Approach for Treating Low-Risk Gestational Trophoblastic Neoplasia: A Systematic Review and Meta-Analysis.

For gestational trophoblastic neoplasia (GTN) affecting women of reproductive age, the chemotherapy-first approach is often preferred over the surgery-first approach. Low-risk GTN is treated with a chemotherapy-first approach, but the number of courses required can affect fertility. A surgery-first approach may decrease the number of chemotherapy courses, but its efficacy and safety compared to a chemotherapy-first approach are unclear. Thus, we investigated the efficacy and safety of the surgery-first approach compared to the chemotherapy-first approach in treating low-risk GTN. We searched the MEDLINE, Embase, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, and World Health Organization International Clinical Trials Registry Platform databases for relevant articles in July 2023. A systematic review and meta-analysis of outcome measures were conducted using a random-effects model. The primary outcomes were remission, the mean number of chemotherapy courses required to cure, and adverse events. The certainty of the evidence was evaluated using the Grading of Recommendations, Assessment, Development, and Evaluation approach. This study protocol was registered in the Open Science Framework (https://osf.io/kysvn/). Studies for low-risk GTN included a qualitative synthesis (with 2,192 participants and ten studies, eight of which were about second uterine curettage and two about hysterectomy) and a meta-analysis (with 138 participants and two randomized controlled trials (RCTs) that compared first-line treatments of second uterine curettage and chemotherapy). Second uterine curettage may result in little to no difference in remission (risk ratio: 1.00, 95% confidence interval: 0.96-1.05; low certainty) and a slight reduction in adverse events (risk ratio: 0.87, 95% confidence interval: 0.47-1.60; low certainty). The evidence is very uncertain on the mean number of chemotherapy courses (mean difference: 2.84 lower, 95% confidence interval: 7.31 lower to 1.63 higher; very low certainty). Based on clinical outcomes, second uterine curettage can be comparable to the chemotherapy-first approach as a first-line treatment option for low-risk GTN; however, the overall certainty of the evidence was low or very low.

Volume Index Measured Using Magnetic Resonance Imaging for Diagnosing Cervical Cancer Tumors <2 cm.

BACKGROUND/AIM: Diagnosis of cervical cancer with tumor diameter <2 cm using magnetic resonance imaging alone has not been investigated. Moreover, whether tumor volume can be used for diagnosing the true tumor diameter remains unknown. Here, we investigated the utility of early cervical cancer volume index in diagnosing cervical cancer with a tumor diameter of <2 cm, which can be treated using more conservative surgery. PATIENTS AND METHODS: This single-center retrospective study analyzed women who underwent radical hysterectomy for cervical cancer with a tumor diameter of <2 cm and clinical stages IA2, IB1, IB2, IB3, and IIA1 at our institute between January 2009 and April 2022. The volume index, defined as the product of the maximum longitudinal diameter along the uterine axis, maximum anteroposterior diameter (thickness) on a sagittal section image, and maximum horizontal diameter on a horizontal section image, was evaluated using either T2-weighted magnetic resonance imaging or gadolinium-enhanced T1-weighted imaging. The receiver operating characteristic curve for the volume index was also calculated. RESULTS: The sensitivity and specificity of magnetic resonance imaging for measuring the tumor diameter were 0.92 and 0.84, respectively. The calculated cut-off value was 2.60, whereas the volume index area under the curve was 0.955, with a sensitivity of 0.92 and specificity of 0.93. CONCLUSION: Considering the specificity and low incidence of false-negative results, the volume index can be used for preoperative diagnosis of pT1B1 cervical cancer, which can be treated with more conservative surgery.

Anatomical basis for contribution of hip joint motion by the obturator internus to defaecation/urinary functions by the levator ani via the obturator fascia.

The functional association between hip joint motion and defaecation/urinary function has attracted considerable research and clinical attention owing to the potential novel approaches for pelvic floor rehabilitation; however, the anatomical basis remains unclear. This study, therefore, aimed to analyse the anatomical basis of force transmission between the obturator internus, a muscle of the hip joint, and the levator ani, a muscle of the pelvic floor. Twenty-three cadavers were used for macroscopic and histological analyses. The three-dimensional structures of the muscles and fascia were recorded using a high-definition camera and a 3D scanner. The arrangement and attachment of the muscle fibres, tendons and fascia were visualised using histological sections stained with Masson's trichrome. The obturator internus and levator ani were in broad contact through the obturator fascia. The height of their contact area was 24.6 ± 9.1 mm. Histologically, the obturator internus and levator ani shared a large area of the obturator fascia, and the obturator fascia provided the attachment of several muscle layers of the levator ani. The contribution of hip joint motion to defaecation/urinary function can be explained by the broad 'planar' contact between the obturator internus and levator ani. This anatomical feature suggests that movement of the obturator internus creates the foundation for the function of the levator ani and contributes to pelvic floor support through the obturator fascia. This study provides an anatomical basis for the effectiveness of the hip muscles in improving defaecation/urinary function by enabling balanced and proper movements.

Risk Factors Associated with Perineal and Vaginal Lacerations and Vaginal Removal in Total Laparoscopic Hysterectomy.

Objectives: This study aimed to identify risk factors associated with perineal and vaginal lacerations related to vaginal removal during total laparoscopic hysterectomy (TLH). Materials and Methods: We retrospectively assessed 134 patients who underwent TLH, of whom 44 (32.8%) had vaginal lacerations. Results: Univariate analysis revealed that for patients with myomas and adenomyosis, gonadotropin-releasing hormone agonist use and myomas with a transverse diameter of ≥5 cm were significant risk factors, while multiparity (vaginal delivery) was a protective factor for perineal and vaginal lacerations. Moreover, multivariate analysis indicated that multiparity was the only statistically significant protective factor. For cervical intraepithelial neoplasia, endometrial cancer, and endometrial hyperplasia, only a uterine transverse diameter of ≥5 cm was a significant risk factor for perineal or vaginal lacerations. Conclusion: For patients with large myomas, multiple vaginal delivery was a protective factor, and in patients with normal-sized uteri, a uterine transverse diameter of ≥5 cm was a risk factor for perineal or vaginal lacerations.