DOI: https://doi.org/10.21203/rs.3.rs-2237204/v1
Background: Uterine diverticulum is classified into congenital and acquired types. The acquired type is caused by caesarean scar syndrome, which occurs after caesarean section. There are no detailed reports on diverticulum after enucleation of uterine fibroids. Most cases are treated with hysteroscopy or laparoscopy, but a management consensus is lacking. We managed a patient with a uterine diverticulum, which had formed after uterine myoma enucleation, by combining hysteroscopic and laparoscopic treatments.
Case presentation: The patient was a 37-year-old Japanese woman, G1P0. A previous doctor had performed abdominal uterine myomectomy for a pedunculated subserosal uterine myoma on the right side of the posterior wall of the uterus near the internal cervical os. Menstruation had resumed postoperatively, but a small amount of dark-red bleeding persisted. MRI two months after the myomectomy revealed a diverticulum-like structure 3 cm in diameter, communicating with the uterine lumen, on the right side of the posterior wall of the uterus. Under suspicion of uterine diverticulum after uterine myoma enucleation, the patient sought treatment at our hospital approximately four months after the myomectomy. Through a flexible hysteroscope, a hole was observed, hysterosalpingography showed a fistula opening slightly above the internal cervical os in the posterior wall of the uterus and a contrast-enhanced pocket, measuring approximately 3 cm, in front of it. Uterine diverticulum following enucleation of a uterine myoma was diagnosed, and surgery was thus deemed to be necessary. The portion entering the fistula on the external cervical os side was resected employing a hysteroscope. Intra-abdominal findings included a 4-cm mass lesion on the posterior wall on the right side of the uterus. The mass was opened, and the cyst capsule was removed. A 5-mm fistula was detected and was closed with sutures. Re-suturing was not performed after dissection of the right round ligament, due to tension. The postoperative course has been good, to date, with no recurrence.
Conclusion: Even after myomectomy, the occurrence site may develop a pathological condition similar to caesarean scar syndrome. Such lesions can be treated by incorporating a method similar to the that used for caesarean scar syndrome.
Uterine diverticulum is classified into congenital and acquired types. Congenital uterine diverticulum, caused by Müllerian duct anomalies, is rare, while acquired uterine diverticulum due to surgical trauma, mostly results from caesarean section [1]. Symptoms include abnormal bleeding, dysmenorrhea, and pelvic pain, and this condition can even lead to infertility [2][3]. Treatment selection is based on factors such as the presence of infertility and the desire to preserve the uterus, and the method of treatment is based on the size of the diverticulum, the thickness of the residual muscular layer, and other anatomical factors [2]. While there are several reports on surgical treatment methods such as laparoscopy, hysteroscopy, combinations of the two, and vaginal procedures [4], a gold standard has yet to be established. The number of myomectomy procedures has increased in recent years, though reports of uterine diverticulum after myomectomy are extremely rare. To our knowledge, this is the first case not associated with pregnancy to be reported.
The patient was a 37-year-old Japanese woman, G1P0 (one ectopic pregnancy). The patient had consulted a previous doctor with complaints of lower abdominal pain. A subserosal uterine myoma 9 cm in diameter was found in the posterior wall of the uterus [Fig. 1A, 1B], and was removed after administration of a gonadotropin-releasing hormone antagonist. The surgical findings included a 9-cm pedunculated subserosal uterine myoma that had developed from the right side of the posterior wall of the uterus near the internal cervical ostium. This myoma was also found to have grown into the posterior ligament. The myoma stalk was clamped and cut, and the stump was ligated. The injured muscular layer was sutured in two layers with absorbable thread, and abdominal uterine myomectomy was performed. The histopathological diagnosis was cellular leiomyoma. Menstruation resumed on the 25th day after the procedure, but small amounts of dark-red bleeding (spotting) persisted. Magnetic resonance imaging (MRI) approximately two months after the myomectomy revealed a 3-cm diverticulum-like structure, communicating with a 5-mm fistula and the uterine lumen, on the right side of the posterior wall of the uterus. Under suspicion of uterine diverticulum developing after enucleation of a uterine myoma, the patient was referred to our hospital nearly four months after the myomectomy.
During the first visit, transvaginal ultrasound and MRI showed a 3-cm mass lesion on the posterior wall of the uterus [Fig. 1C, 1D, Fig. 2A]. Flexible hysteroscopy revealed a hole in the right posterior wall near the internal cervical ostium, and the surrounding regions were white and demarcated. Hysterosalpingography showed a fistula opening slightly above the internal cervical ostium on the posterior wall of the uterus and an approximately 3-cm contrast-enhanced pocket in front of it [Fig. 2B]. Surgery was deemed to be necessary given the diagnosis of uterine diverticulum following enucleation of a uterine myoma.
The procedure was started employing a hysteroscope. A 5-mm in diameter fistula was observed on the right side of the posterior wall near the internal cervical ostium. A brown blood clot and fluid had accumulated in the pocket [Fig. 3A]. The portion entering the fistula on the external cervical ostium side of the demarcated portion was resected, and a manipulator was then inserted into the uterus. The laparoscope showed a 3-cm mass on the posterior wall of the uterus [Fig. 3B]. When the mass was incised and opened, an accumulation of old blood from bleeding inside the mass was observed, and a capsule-shaped cyst had formed. The cyst wall and the normal muscular layer were detached, and the cyst capsule was removed. A 5-mm in diameter fistula was observed in the posterior portion of the cyst. The tissue around the fistula was trimmed and excised [Fig. 3C]. Using the manipulator as a marker, the fistula was closed with 2-0 absorbable suture, the surrounding muscular layer was brought near the Z suture to cover the fistula closure, and the muscular layer was sutured in three layers [Fig. 3D]. Indigo was injected into the uterine cavity, and no flow out of the sutured portion was detected. Finally, fistula closure was confirmed with the hysteroscope. The round ligament was dissected to release the tension and a Nelaton catheter was inserted to prevent cervical stenosis, and the procedure was completed. Histopathologically, the specimen of the incised capsule showed musculo-vascular tissue and suture granuloma formation with hemosiderin phagocytes [Fig. 3E]. Furthermore, endometrial tissues corresponding to the proliferative phase were observed [Fig. 3F]. The postoperative course was good. The patient was discharged on post-procedural day 6.
Normal menstruation resumed on the 10th day after the procedure, and no abnormal bleeding was observed after the menstrual period. Transvaginal ultrasound performed in the third post-procedure week revealed no indications of mass lesion recurrence. Flexible hysteroscopy showed that the fistula opening near the internal cervical ostium was closed and the mucosa was smooth. MRI obtained approximately three months after the procedure showed the layered structure of the uterine muscular layer to be maintained [Fig. 1E, 1F] and transvaginal ultrasound showed amelioration of the strong anteflexion of the uterus. No evidence of recurrence was seen on either transvaginal ultrasound after 3 months [Fig. 2C], and 6 months [Fig. 2D] or flexible hysteroscopy. The patient was thus assured that attempting pregnancy was feasible.
Most cases with acquired uterine diverticulum have caesarean scar syndrome, which developed after undergoing a caesarean section [1]. Acquired uterine diverticulum after myomectomy has been reported in few cases, all discovered during pregnancy [5]. This is the first report, to our knowledge, to describe diverticulum development after myomectomy in a non-pregnant patient. The prevalence of caesarean scar syndrome after caesarean section ranges from 56% to 80% [6]. A diverticulum reportedly develops in approximately 18% of cases after enucleation of a uterine myoma [5], and the diverticulum frequency after caesarean section is considered to be high. The following are considered to be the causes of uterine diverticulum after caesarean section: 1. incision at a relatively low position near the cervix region; 2. single-layer suture, locking suture, incomplete closure; and 3. factors that induce the formation of adhesions, such as non-closure of the peritoneum and improper hemostasis [2][6][7].
In patients who have undergone caesarean section, one of the causative factors might be that the incision site is in the lower uterine segment. The lower uterine segment is potentially weak at the Müllerian duct junction [8]. New blood vessels appear in the surgical scar, and pathologically, bleeding from these new blood vessels and inadequate drainage due to a smaller than normal muscular layer appear to lead to accumulation of fluid in the scar region. In addition, there might be an endometrial gland in the muscular layer around the scar region which results in a pathological condition like adenomyosis.
In our present patient, the pedunculated subserosal myoma was located near the cervix, such that the incision near the cervix had to be sutured. The menstrual blood trapped in the scar is also considered to result in hemorrhage. However, Tanimura et al. reported that such hemorrhage could be caused by the scar itself since they detected an endometrial gland and stromal tissue deep in the scar [2][9]. We also detected endometrial tissue in the incision site, which suggested that the patient’s abnormal bleeding could have been due to bleeding from the capsule tissue itself. It is also possible that the endometrium was pulled towards the serosa and sewn in when the pedunculated fibroid was pulled.
Laparoscopic repair of uterine diverticulum was first reported in 2008 [2], and has since been combined with hysteroscopy. With the latter approach, the scar tissue is excised under a hysteroscope and the wound is trimmed and sutured employing a laparoscope [3][4]. More recently, there have been reports on the levonorgestrel intrauterine system [6] and low dose estrogen plus progestin [10] as hormone therapy. Hormone therapy was not adopted in our present case due to the patient’s desire to have children.
In caesarean scar syndrome, especially in cases with a retroverted uterus, tension is exerted on the wound, and this has been speculated to lead to uterine diverticulum development. The failure rate of repair procedures is high in retroverted uterus cases [6], at approximately 86% [2]. Therefore, in a case with a retroverted uterus, in which lesion excision/suture is not possible, the round ligament can be sewn to reduce the tension exerted on the wound. In our present patient, the wound was on the posterior wall, which was opposite the wound observed in caesarean scar syndrome cases. Since the uterus was markedly anteflexed, leaving it as it was would have exerted strong tension on the wound in the posterior wall, which might have delayed the wound healing as well as causing recurrence. Therefore, the round ligament that was detached when searching for the ureter was not sutured. The uterine anteflexion angle was found to be loose upon comparing the uterine sagittal planes in transvaginal ultrasound images obtained the 7th day, 30th day, 3rd, and 6th month after the procedure. The release of tension on the wound is suggested to be an important procedure, in addition to sufficient trimming of the demarcated portion and careful suturing.
In parallel with the current increase in the rate of caesarean section worldwide, it is expected that late marriage and childbearing will increase the need for uterine preservation and uterine myomectomy. In the presence of the aforementioned conditions, the course may be similar to that of caesarean scar syndrome after myomectomy. The treatment methods will be similar to that applied to caesarean scar syndrome. Reducing the tension exerted on the wound is potentially useful, in addition to removing the demarcated tissue and re-suturing by employing a combination of laparoscopy and hysteroscopy. It was also suggested that uterine flexion repair with a round ligament and wound reduction by preventing. In addition, releasing cervical canal stenosis using a hysteroscope and a Neraton catheter may be beneficial.
Author Contribution
Rina Kawatake, Aki Maebayashi, and Masaji Nagaishi treated the case. Aki Maebayashi and Rina Kawatake wrote the manuscript. Aki Maebayashi, Haruna Nishimaki, and Kei Kawana contributed to the diagnosis, obtained informed consent, and determined the clinical management of this case. All authors read and approved the final manuscript.
Funding
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Availability of data and materials
The data presented in this case report are available from the corresponding author on reasonable request.
Ethics approval and consent to participate
All procedures performed were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. Institutional Review Board (IRB) approval is not needed for this type of study. Written informed consent was also obtained from the patient for publication of this case report and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of the journal.
Consent for publication
Written informed consent was obtained from the patient for all diagnostic tests and treatments, as well as for publication of this case report and any accompanying images. A copy of the written consent form is available for review by the Editor-in-Chief of the journal.
Competing interests
The authors have no competing interests to disclose.
Acknowledgements
The authors thank Bierta Barfod for her contribution to the language editing of this manuscript.