Adaptive tool for maintaining tissue tension during metroplasty

Abstract

This utility model relates to medical equipment, specifically to an adaptive instrument for maintaining tissue tension during metroplasty. The adaptive instrument for maintaining tissue tension during metroplasty comprises a 40-cm-long support holder. The support holder is conical for 5 cm from its distal end to allow passage into the uterine cavity through the internal cervical os. A movable stop with rounded edges for a tight fit to the cervix, a movable stop retainer with a fastening nut, and a movable retainer for bullet forceps with a fastening nut for securing the instrument during surgery are threaded onto the support holder. Use of this utility model helps prevent uterine perforation. 1 Fig.

Description

[0001] Description of the adaptive instrument for maintaining tissue tension during metroplasty (Fig. 1)

[0002] The proposed device comprises a support holder 40 cm long, having a conical shape over a distance of 5 cm from the distal end for passing into the uterine cavity through the internal os of the cervix, while a movable limiter rounded at the edges for a tight fit to the cervix, a movable limiter retainer with a fastening nut and a movable retainer for bullet forceps with a fastening nut for fixing the instrument during the operation are strung on the support holder.

[0003] The prevalence of cesarean section scar defects, also known as uterine scar niches, ranges from 19% to 61% after one cesarean section and can reach 100% in women after three cesarean sections [1]. In Russia, the incidence of uterine scar niches increased from 2020 to 2022, reaching 20-30% [2] due to the increasing frequency of cesarean sections. These figures may be underestimated due to insufficient testing or asymptomatic progression in some women.

[0004] In patients with a uterine scar defect after cesarean section, the main complaints are menstrual cycle disorders: bleeding from the genital tract after menstruation - 70.8%, intermenstrual bleeding - 12.4%, heavy menstruation - 3.5%, painful menstruation - 8%; secondary infertility - 31% [3].

[0005] The need for metroplasty is obvious, but its effectiveness varies depending on the methods used. The literature describes the technical advantages of using shaping and guiding instruments during laparoscopic metroplasty: Hegar dilators or Foley catheters [4,5]. During suturing, a Hegar dilator is inserted into the uterine cavity to create a certain tension, which ensures precise adaptation of the wound edges and prevents the posterior or anterior wall from entering the suture. This helps maintain the physiological shape of the uterine cavity and avoid its deformation after suturing. The dilator also serves as a guiding landmark, preventing narrowing or stenosis of the cavity in the suture area.

[0006] The required instrument length is determined by the length of the vaginal and cervical canals and the length of the uterine cavity, and can therefore often vary. Additional length is also necessary to ensure a secure grip on the instrument. However, Hegar uterine dilators, traditionally used in laparoscopic metroplasty, are inconveniently short, preventing the assistant from holding the instrument firmly, increasing the risk of uterine perforation and the Hegar dilator being dislodged from the uterine cavity into the pelvic cavity.

[0007] A uterine dilator designed by V.A. Melnikov is known for its extended length due to the inclusion of a handle [6]. However, the dilator was developed to eliminate uterine barotrauma and is perforated. However, barotrauma does not occur during metroplasty, as the uterine cavity is opened to excise the scar. Perforation in the instrument during uterine scar opening will lead to loss of pneumoperitoneum during laparoscopy.

[0008] A device is known that contains a handle and a working part in the form of telescopic hollow rods [7]. A disadvantage of this device is the possibility of tissue injury.

[0009] Also known is the CLERMONT-FERRAND model uterine manipulator, presented and described in the electronic industrial catalog of KARL STORZ SE & Co. KG (Tuttlingen, Germany) [8]. The device is used for total hysterectomy and has a rigid tip that screws into the cervix, which can create the tension on the lower uterine segment necessary for metroplasty. However, such trauma to the cervix is ​​unacceptable during organ-preserving surgeries in patients with reproductive plans.

[0010] One of the closest models to the claimed utility model is the intrauterine manipulator, designed by Z.N. Makian, which features a groove and notches corresponding to the length of the uterine cavity [9]. However, the device itself is not long enough to be securely fixed, which increases the risk of uterine perforation and does not create reliable tissue tension for proper alignment.

[0011] The lack of fixation elements that would prevent the device from shifting relative to the excised scar and maintain its function throughout the surgery is a common drawback of all the models discussed, including the Foley catheter. Furthermore, when using instruments made of soft materials, including the Foley catheter, there is a high risk of suturing the myometrium along with the catheter.

[0012] The well-known Cohen cervical hysterograph, or uterine cannula for chromosalpingoscopy, has similar fastening elements. This instrument also has the ability to adjust the length of the working section. However, its drawback is its thin diameter, which prevents it from serving as a proper guide or maintaining the uterine volume when suturing the excised scar.

[0013] Technical problem of the utility model

[0014] Creation of a surgical instrument that can improve the efficiency, safety and reliability of metroplasty, as well as reduce the economic costs of medical institutions for the operation.

[0015] Technical result

[0016] The technical result is to ensure the prevention of uterine perforation.

[0017] The essence of the utility model

[0018] For convenient and secure insertion into the uterus, the claimed utility model features a long base, a support holder, a stop, and a mount for forceps. All elements are adjustable and secured to the support holder, taking into account the patient's anatomical features.

[0019] The utility model is explained by a description and a drawing, which shows a general view of the assembly and its individual parts in section, where in Fig. 1 the following positions are designated: 1 - support holder; 2 - limiter; 3 - fastening nut No. 1; 4 - movable limiter lock; 5 - movable lock for bullet pliers; 6 - fastening nut No. 2.

[0020] The distinguishing feature of the utility model is:

[0021] 1. The support holder is long enough (40 cm) to allow the instrument to be held with the entire hand outside the patient's body without shifting, ensuring a stable position of the instrument relative to the tissues throughout the entire operation.

[0022] 2. The flexible design of the limiter and clamps allows the instrument to be adapted to the length of the vaginal and cervical canals, as well as the uterine cavity, depending on the patient's anatomical parameters, and maintain constant tissue tension during excision and suturing of an incompetent scar, thereby reducing the risk of suturing the posterior uterine wall.

[0023] 3. The stopper is rounded at the edges, ensuring a tight fit against the cervix, thereby preventing excessive advancement of the instrument into the uterine cavity and maintaining pneumoperitoneum.

[0024] 4. A fixator for bullet forceps, which ensures a fixed position of the instrument relative to the tissue throughout the operation without the involvement of an additional assistant, which eliminates accidental displacement of the instrument.

[0025] The combination of the listed features in their interaction ensures the technical result of the claimed utility model - the prevention of uterine perforation.

[0026] The claimed utility model (Fig. 1) is implemented in an experimental prototype made of medical-grade steel. Practical testing was conducted in a medical setting using three clinical examples.

[0027] Clinical example No. 1. Patient F-a, 38 years old.

[0028] The patient complained of prolonged brown spotting after menstruation. A pelvic ultrasound revealed a "niche" in the uterine scar from a cesarean section. A laparoscopy and hysteroscopy were performed, and a scar area with thinning of the uterine wall (a defect measuring 3.0 x 1.5 cm) was visualized in the area of ​​the uterine isthmus. After preliminary dilation of the cervical canal to 10 mm with Hegar dilators, an adaptive instrument was inserted into the cervical canal. The scar area was excised and sutured with figure-of-eight sutures, with a second row of Stratofix sutures.

[0029] Clinical example No. 2. Patient E-a, 32 years old.

[0030] Following an examination for intermenstrual bleeding, an ultrasound revealed a myometrial defect in the area of ​​the uterine scar. A laparoscopy and hysteroscopy were performed, and a "niche" measuring 4.0 x 2.0 cm was visualized in the area of ​​the postoperative scar. After preliminary dilation of the cervical canal to 10 mm with Hegar dilators, an adaptive instrument was inserted into the cervical canal. The scar area was excised and sutured with figure-of-eight sutures, with a second row of Stratofix sutures.

[0031] Clinical example No. 3. Patient S-a, 35 years old.

[0032] An MRI scan performed during preconception preparation revealed an area of ​​myometrial thinning in the area of ​​the postoperative scar. A laparoscopy and hysteroscopy were performed, and an area of ​​myometrial thinning measuring 1 x 1.5 cm was visualized in the area of ​​the postoperative scar. After preliminary dilation of the cervical canal to 10 mm with Hegar dilators, an adaptive instrument was inserted into the cervical canal. The scar area was excised and sutured with figure-of-eight sutures, with a second row of Stratofix sutures.

[0033] Conclusion

[0034] The utility model (Fig. 1) relates to medical equipment and can be used as a device in gynecology for optimizing surgical correction of uterine scar failure.

[0035] References

[0036] 1. Nezhat C, Zaghi B, Baek K, Nezhat A, Nezhat F, Lindheim S, Nezhat C. Outcomes of Laparoscopic Cesarean Scar Defect Repair: Retrospective and Observational Study. Journal of Clinical Medicine. 2023;12(11):3720. https: / / doi.org / 10.3390 / jcm12113720

[0037] 2. Grigoryants A.A., Aksenenko D.V., Dubovoy A.A., Efimova Ya.E., Kolesnikova V.V. Informativeness of diagnostic measures for uterine scar failure after cesarean section. Obstetrics and Gynecology: news, opinions, training. 2025; Vol. 13, No. 1: 44-49. https: / / doi.org / 10.33029 / 2303-9698-2025-13-1-44-49

[0038] 3. van der Voet, L.F.; Bij de Vaate, A.M.; Veersema, S.; Brolmann, H. A.; Huirne, J. A. Long-term complications of caesarean section. The niche in the scar: A prospective cohort study on niche prevalence and its relation to abnormal uterine bleeding. BJOG Int. J. Obstet. Gynaecol. 2014;121:236-244.

[0039] 4. Martynov S.A., Sukhareva T.A., Adamyan L.V. Comparative evaluation of the effectiveness of various methods of laparoscopic metroplasty in patients with significant uterine scar defects after cesarean section. Obstetrics and Gynecology. 2023; 10: 126-136. https: / / dx.doi.org / 10.18565 / aig.2023.163

[0040] 5. Wang Y, Zhang X, Xu B, Ma X. Laparoscopic metroplasty for bicorporeal uterus. Chinese Medical Journal. 2021;134(9):1095-1096. https: / / doi.org / 10.1097 / CM9.0000000000001457

[0041] 6. Melnikov V.A. Uterine dilator. Patent RU2071285C1. IPC A61B 17 / 42, A61M 29 / 00, 1997.

[0042] 7. Golubev A.P., Mazurik S.M., Krivonos S.M., Pilipchenko A.B. Uterine dilator. Patent SU1139443A1, IPC A61M29 / 00, 1985.

[0043] 8. Uterine manipulator, model CLERMONT-FERRAND, KARL STORZ https: / / www.karlstorz.com / ru / ru / product-detail-page.htm?productID=1000144461&cat=1000194523

[0044] 9. Makian Z.G. Intrauterine manipulator with a groove for treating uterine scar leakage after cesarean section. Patent RU195972U1, IPC A61B 17 / 42, 2020.

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