近澤 研郎

INTRODUCTION: Dienogest (DNG) is widely used to manage endometriosis-associated pain; however, long-term data comparing low and standard doses are limited. Therefore, this study aimed to evaluate the efficacy and safety of 48-week DNG treatment (1 mg/day vs. 2 mg/day) in patients with endometriosis-related dysmenorrhea (composite score). METHODS: In this randomized, open-label, parallel-group, trial, 88 patients with endometriosis were enrolled, all of whom had at least one ovarian endometriotic cyst confirmed by imaging. Other phenotypes of endometriosis, such as deep infiltrating or peritoneal lesions, were not systematically assessed and may have been present. Patients were randomized to receive either 1-mg/day or 2-mg/day DNG. The primary endpoint was the change in menstrual pain measured using a visual analog scale (VAS). Secondary endpoints included changes in the dysmenorrhea score, ovarian endometrioma volume, serum estradiol levels, bone mineral density (BMD), and menopausal symptoms. RESULTS: Both groups demonstrated a significant reduction in menstrual pain (VAS). The mean VAS scores decreased by 44.63 and 54.19 mm in the 1-mg and 2-mg groups, respectively. However, the between-group difference (- 9.57 mm; 95% confidence interval: - 22.7 to 3.56) was not above the predefined non-inferiority margin of - 15 mm; thus, non-inferiority of the 1-mg dose could not be confirmed. Improvements in dysmenorrhea scores and endometrioma volume were also observed in both groups, although greater effects were noted in the 2-mg group than in the 1-mg group. Serum estradiol suppression was comparable between the groups, whereas BMD loss was less pronounced in the 1-mg group than in the 2-mg group. CONCLUSIONS: This study did not demonstrate statistical non-inferiority of 1-mg/day DNG treatment over 2-mg/day DNG treatment for pain relief. These results suggest that the 2-mg/day dose may offer more robust analgesic effects, particularly during the early treatment phase. However, 1-mg/day DNG still showed meaningful symptom improvement with fewer adverse events than 2-mg/day DNG, supporting its potential use in selected patients requiring long-term therapy. Trial Registration Japan Registry of Clinical Trials, trial registration number: jRCTs041210016.

OBJECTIVE: Surgical education programs enhance skills but often lack focus on continuing development for post-certification obstetricians and gynecologists. This study evaluates a post-certification educational program for gynecologic surgeons, focusing on laparoscopic skills, academiclapa, and educational activities. METHODS: This cross-sectional study utilized a web-based survey administered to past participants of the Training Seminar to Reinforce Laparoscopic Surgeries of Young Generations (TRY) and the Gain the Expert's Technique Seminar (GETS), conducted between 2011 and 2023. The participants were post-certification gynecologic surgeons under 40 years old, selected from across Japan, who were seeking laparoscopy certification and aspired to become leading gynecologic surgeons both in Japan and internationally. RESULTS: The survey was distributed to 105 graduates of the TRY and GETS programs, with a response rate of 96.1 %. A total of 82.9 % of the participants obtained a laparoscopy-qualified gynecologist certification after the program. The proportion of graduates presenting to the Japan Society of Gynecologic and Obstetric Endoscopy and Minimally Invasive Therapy Congress has significantly increased over time, with several graduates receiving top congress awards. The percentage of graduates serving as laparoscopic surgery educators increased significantly from 21.8 % to 63.3 % (p < 0.001) and the proportion of mentoring colleagues for certification increased from 1.0 % to 25.7 % (p < 0.001). CONCLUSIONS: This study demonstrated that the educational program may effectively enhance the continuous development of laparoscopic skills and professionalism among post-certification obstetricians and gynecologists, resulting in increased academic activities and contributions to surgical education.

OBJECTIVE: This study aimed to evaluate the oncological safety of laparoscopic surgery for patients with benign tumors who underwent laparoscopic surgery at our facility and were subsequently diagnosed with borderline ovarian tumors or ovarian cancer. METHODS: We conducted a retrospective review of 45 patients initially diagnosed with benign ovarian tumors who underwent laparoscopic surgery at our institution from January 2009 to April 2024. RESULTS: Postoperative pathological examination identified 32 cases of borderline ovarian tumors and 13 cases of ovarian cancer. Laparoscopic cystectomy was performed in 14 (43.8%) borderline cases and 4 (30.8%) ovarian cancer cases. Out of 14 patients with borderline ovarian tumors who underwent cystectomy, 8 subsequently underwent staging laparotomy, whereas 6 underwent only ovarian tumor cystectomy. In contrast, none of the patients with ovarian cancer completed treatment with only ovarian tumor cystectomy. Recurrent disease was observed in 9.4% of borderline tumor cases, all of which were successfully managed with further surgery. In the ovarian cancer group, recurrence occurred in 31% of patients, with 3 resulting in tumor-related mortality. CONCLUSION: Laparoscopic surgery for borderline ovarian tumors is suggested to be oncologically safe, with low recurrence rate and no adverse impact on survival. However, for ovarian cancer, particularly in cases with peritoneal dissemination, rapid disease progression remains a concern. While this study suggests that laparoscopic surgery may be a viable option for borderline ovarian tumors, further research is needed to validate these findings, particularly for ovarian cancer.

OBJECTIVE: This study aimed to evaluate and compare recurrence-free survival (RFS) between radical hysterectomy followed by adjuvant chemotherapy and initial chemoradiotherapy for cervical cancer at our institution. METHODS: In this retrospective study, we enrolled patients diagnosed with stage IB2-IIB cervical cancer according to the International Federation of Gynecology and Obstetrics 2018 staging system, who underwent either radical hysterectomy with pelvic lymphadenectomy followed by adjuvant chemotherapy or initial concurrent chemoradiation at our institution between 2009 and 2022. RESULTS: Among these patients, 74 and 110 underwent radical hysterectomy and chemoradiation, respectively. The radical hysterectomy group exhibited significantly improved RFS compared with the chemoradiation group; however, no significant difference was observed in overall survival between the groups. Cox hazard analysis for RFS showed that, among the clinical risk factors identified before the initial treatment, only parametrial invasion was statistically significant. No significant difference in RFS was observed between the radical hysterectomy group and chemoradiation group. Regarding recurrence patterns, para-aortic lymph node recurrence occurred significantly more frequently in the chemoradiation group than in the radical hysterectomy group. Postoperative ureteral injury was reported in once case and postoperative ureteral stenosis in 2 cases in the radical hysterectomy group. In contrast, vesicovaginal fistula and rectovaginal fistula were reported in one case each in the chemoradiation group. CONCLUSION: Radical hysterectomy followed by adjuvant chemotherapy provided RFS outcomes comparable to those achieved with initial chemoradiotherapy for stage IB2-IIB and IIIC1-2 cervical cancer. These findings suggest that both approaches are viable, although further prospective studies are needed.

Ovarian mesonephric-like adenocarcinoma is rare and poorly understood, and preoperative diagnosis of this tumor with any diagnostic modality is challenging. Histological features can only be speculated through imaging. Herein, we present the case of a 64-year-old woman with primary ovarian mesonephric-like adenocarcinoma, characterized by a 13 cm pelvic mass detected via ultrasound. Further evaluation with magnetic resonance imaging showed low signal intensity in the solid component on T2-weighted images and high signal intensity on diffusion-weighted images, along with a smooth margin; these findings are consistent with those of previous reports. The patient underwent a total abdominal hysterectomy, bilateral salpingo-oophorectomy, and partial omentectomy. Postoperative pathology confirmed mesonephric-like adenocarcinoma with positive peritoneal cytology. Immunohistochemical analysis showed a positive result for GATA-3 and a negative result for thyroid transcription factor-1. The patient was diagnosed with stage IC3 mesonephric-like adenocarcinoma, and adjuvant chemotherapy with paclitaxel and carboplatin was initiated. Mesonephric-like adenocarcinoma can present with distinct imaging features, including low signal intensity on T2-weighted imaging and high signal intensity on diffusion-weighted imaging, with a smooth solid margin; these imaging features may aid in the preoperative differentiation from other ovarian malignancies, such as serous or clear cell carcinomas.

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.

At our institution, scrub nurses leave the surgical field during the console time for robotic surgeries to attend to other duties. The first assistant then assumes their responsibilities, allowing for efficient use of staff time and resources. This practice improves teamwork and can be presented as a cost-saving measure for hospital administrations.

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.

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.

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.

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.

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.

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.

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.

OBJECTIVES: The objective of the study was to investigate the long-term outcomes, in particular, recurrence risk, especially tumor volume, for Stage IA endometrial cancer and to identify the risk factors for recurrence. MATERIALS AND METHODS: This single-center retrospective study analyzed women who underwent primary surgical treatment for the International Federation of Gynecology and Obstetrics Stage IA (Grade 1 or 2) endometrioid carcinoma at our institute between January 2010 and July 2018. Patients' demographic characteristics, including age, operative time, number of lymph nodes, final stage, volume index as tumor volume, and final histological type, were reviewed. A total of 168 patients were enrolled, with 95 and 73 patients in the laparotomy and laparoscopy groups, respectively. The Cox proportional hazards model was used to adjust for prognostic factors in the analysis including upstaged patients, tumor histology, lymphovascular invasion, and volume index. RESULTS: There was no difference in the recurrence rate between laparoscopic and open surgeries for Stage IA endometrial cancer. The operative time was longer, and the amount of blood loss was lesser in the laparoscopy group than in the laparotomy group. For all patients undergoing either laparoscopy or open surgery, upstaged ≥IB, nonendometrioid Grade 1 or 2, lymphovascular invasion, and volume index ≥36 were significant independent recurrence risk factors. CONCLUSION: Laparoscopic surgery for Stage IA endometrial cancer is technically and oncologically safe. Patients with a high-volume index have a higher recurrence risk. Furthermore, the volume index can be a recurrence predictor in low-risk endometrial cancer patients.

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.

AIM: We aimed to evaluate regional disparities in the proportion of the three main laparoscopic surgeries for benign gynecological diseases among 47 prefectures in Japan and their correlation with the number of laparoscopy-qualified gynecologists per population. METHODS: In this retrospective ecological study, we collected the data of patients from 47 prefectures in 2017 using "The National Database of Health Insurance Claims and Specific Health Checkups of Japan" Open Data from the Ministry of Health, Labor and Welfare in Japan. The primary outcome of the study was the proportion of laparoscopic surgeries conducted for benign gynecologic diseases (hysterectomy, myomectomy and surgery for the benign ovarian diseases). The main exposure was the number of laparoscopy-qualified gynecologists per 100 000 females. RESULTS: The average proportion of laparoscopic hysterectomies, myomectomies and surgeries for the benign ovarian disease were 38% (standard deviation (SD) 16, range 12-74), 48% (SD 18, range 9-81) and 60% (SD 11, range 36-79), respectively. Multiple regression analysis showed a significant correlation between the number of laparoscopy-qualified gynecologists per 100 000 females and the proportion of the three main laparoscopic surgeries. CONCLUSION: There are obvious regional disparities in the proportion of the three main laparoscopic procedures for benign gynecological diseases among 47 prefectures. The number of laparoscopy-qualified gynecologists correlated significantly with these regional disparities. The academic society should monitor these regional disparities and make an effort to reduce these regional disparities by increasing laparoscopy-qualified gynecologists in areas where the widespread use of laparoscopic techniques is lagging.

Investigate the efficacy of a hospitalized weight reduction program before laparoscopic surgery among high body mass index (BMI) patients with endometrial cancer. The patients were housed in a shared room, received exercise guidance, and restricted to a total caloric intake of 1200 kcal. A physiotherapist and a dietitian provided pedometer and nutritional guidance, respectively. The primary outcome was weight reduction. Among the 16 patients included, 12 (75%) had Stage I endometrial cancer and 10 (62.5%) underwent laparoscopic surgery. Weight and BMI at first consultation were 88.4±10.4 kg and 34.8±3.9 kg/m2, respectively. The rate of weight reduction was 6.5%±2.5%; on average, BMI decreased by 2.1±1.0 kg/m2. The duration from initial consultation to surgery was 39.1±11.4 days. Hospitalization duration until weight reduction was 20.8±8.0 days; there were no surgical complications. Our hospitalized weight reduction program may be effective for obese endometrial cancer patients.

AIM: This study aimed to investigate the trends in overall hysterectomy and other alternative therapies for benign uterine diseases per population aged 40-54 years in Japan. METHODS: We conducted a national representative cohort study in Japan. We obtained data from 'The National Database of Health Insurance Claims and Specific Health Checkups of Japan' Open Data. The primary outcome was the number of overall hysterectomies for benign gynecologic diseases per population aged 40-54 years, from 2014 to 2017 in Japan. The secondary outcome was the number of alternative surgical and drug therapies to hysterectomy per population. We also analyzed the correlation between the number of laparoscopy-qualified gynecologists and the number of overall hysterectomies per population among 47 prefectures in 2017. RESULTS: The number of overall hysterectomies for benign gynecological diseases per 100 000 females aged 40-54 years gradually increased from 320 in 2014 to 344 in 2017 (7.5% increase overall). Moreover, there was a significant increase in the use of levonorgestrel intrauterine systems. We could not explain the reason for this increase in the rate of overall hysterectomies by summarizing the increase or decrease of alternative therapies to hysterectomy. Multiple regression analysis showed a significant correlation between the number of laparoscopy-qualified gynecologists and the number of overall hysterectomies among 47 prefectures. CONCLUSION: Despite the spread of alternative therapies to hysterectomy, there was an increasing trend for overall hysterectomies in Japan. The reason was not clear but may be related to the spread of laparoscopic hysterectomy.

OBJECTIVE: To evaluate the benefits of nedaplatin treatment in patients with a history of hypersensitivity reactions to carboplatin. MATERIALS AND METHODS: We retrospectively reviewed the medical records of patients with ovarian, fallopian, and peritoneal cancers and with a history of hypersensitivity to carboplatin between January 2010 and December 2016 at the Department of Gynecology in the Saitama Medical Center associated with Jichi Medical University. We studied the response rate to treatment with a nedaplatin-based regimen compared to that of a carboplatin regimen. Fisher's exact test was used to determine statistical significance. RESULTS: Thirty-one patients with a past hypersensitivity to carboplatin were treated with nedaplatin-based regimen, while ten patients were treated with other drugs. The response rates in the nedaplatin- and non-nedaplatin-treated patient groups were 71.4% and 30.0%, respectively (P = 0.021). Among all the patients, only one experienced hypersensitivity reaction to nedaplatin. CONCLUSION: The nedaplatin regimen following hypersensitivity to carboplatin was safe, feasible, and effective in achieving complete or partial response.

The majority of patients with benign ovarian cysts undergo laparoscopic surgery using both cystectomy and stripping techniques. However, these techniques have difficulty correctly identifying cleavage planes and are prone to cyst rupture. We present a surgical cystectomy technique that correctly identifies the cleavage plane with a low risk of ovarian cyst rupture, even in patients with multicystic ovarian cysts. Cystectomy was performed using Maryland forceps with gentle open and close dissecting motions only. Both the surgeon and assistant handled the ovarian cortex and cyst wall, and soft traction between the cortex and cyst wall as far as the nearby dissection plane without grasping the cyst wall was essential. In patients with multicystic ovarian cysts, making a plane at the notch between cysts decreases the risk of cyst rupture. This technique allows the correct identification of the cleavage plane for dissection and avoids the risk of cyst rupture.Impact StatementWhat is already known on this subject? The majority of patients with benign ovarian cysts undergo laparoscopic surgery using both cystectomy and stripping techniques. These techniques have difficulty correctly identifying cleavage planes and are prone to cyst rupture.What do the results of this study add? This technique allows the correct identification of the cleavage plane for dissection and avoids the risk of cyst rupture.What are the implications of these findings for clinical practice and/or further research? Our technique might be useful for the preservation of the ovarian reserve because patients in this study had a low proportion of ovarian follicles in the surgical specimen.

Most fetal ovarian cysts increase in size during the late stages of pregnancy. Early treatment of a huge neonatal cyst may reduce the risk of gastrointestinal obstruction.

Trainees require extensive experience to perform radical hysterectomy. Before starting training during an actual operation, trainees should be familiar with the pelvic anatomy and should simulate surgical procedures. Many simulators are available for virtual reality training of laparoscopic operations, but they are very expensive. The materials required to construct our model included sponges and colored wires sold in home improvement stores that allowed for superior cost effectiveness. The model represented almost all peripheral vessels and nerves around the uterus, including the minor vessels. Attaching and detaching the vessels was easy, facilitating reconstruction of the dissected vessels. The wires were easy to bend, ensuring high operability. This model allows for the simulation of laparoscopic radical hysterectomy in a dry box. Our model was superior to a 2-dimensional picture for the memorization of branching and positional relationships of the blood vessels. Comparison of our model with actual operative videos showed that the dry box provided an identical surgical view of an actual laparoscopic radical hysterectomy. We developed a peripheral bloodstream model of the uterus for repeated simulation of laparoscopic radical hysterectomy with an actual surgical view using a dry box.