A new method for surgical treatment of uterine scar insuffisiency after a previous cesarean section using an intrauterine manipulator with a groove

According to the estimates of the World Health Organization (WHO), cesarean section rates continue to increase worldwide and currently account for more than 23% of all deliveries. [1-3]. In Russia in 2018, this figure constituted 29.4%, and in some obstetric hospitals, it was more than 30–40%, of which about 60% of cases were first births [1–8].

About 12–20% of patients undergoing caesarean delivery develop postoperative complications; in some cases, with the formation of myometrial thinning or dehiscence of the uterine scar [3-14]. According to the International Classification of Diseases (ICD-10), code O34. 2 is assigned to the diagnosis “Maternal care due to uterine scar after previous surgery” [15].

Maternal care due to uterine scar dehiscence (myometrial thinning) after previous surgery includes surgery, that is, repair of uterine scar dehiscence (metroplasty).

According to the definition of the WHO (2015), possible symptoms of uterine scar dehiscence include [1, 3]:

• myometrial thinning of less than 2-3 mm or even its complete absence in the scar area;
• the presence of a “niche” from inside the uterine cavity or cervical canal;
• irregularly-shaped scar and the presence of cysts or inclusions;
• the presence of thickenings or impressions in the scar;
• the significant predominance of connective tissue, but underdeveloped muscle tissue, and a poor capillary network.

Repair of postoperative uterine scar dehiscence includes uterine scar excision, followed by the closure of the uterine defect and re-constitution of the uterine wall in the lower uterine segment [2–8, 11–14].

The uterine scar may be excised by laparoscopic, laparotomic, or vaginal operative approaches using various surgical energy devices including the application of a monopolar electric current (monopolar needle or hook), ultrasonic scalpel (Harmonic), and mechanical scissors [3-5, 8-14].

The combined laparoscopic and hysteroscopic technique (hysteroresectoscopy) of uterine scar dehiscence repair is the most common and considered effective by many authors. The effectiveness of laparoscopic metroplasty is about 93%; vaginal access metroplasty was effective in 90.5% [4–7, 16–19].

The uterine scar dehiscence after the metroplasty was observed in about 7-9.5% of patients; 23–35% of patients were found to have a niche from inside the cervical canal, and the thickness of the scar approaches the minimum acceptable size (about 4-6 mm) [2, 4–12, 16–19 ].

The study was aimed to optimize surgical management of uterine scar dehiscence (thinning) after a previous caesarean section.

Materials and methods

Between 2018 and 2019, 15 patients with uterine scar dehiscence (thinning) were managed at the Department of Operative Gynecology, V.I. Kulakov NMRC for OG&P of Minzdrav of Russia.

The patients underwent a complete clinical and laboratory examination, including ultrasound of the pelvic organs and urinary system; 7 patients received magnetic resonance imaging (MRI) to evaluate the scar topography.

Surgical treatment was performed in accordance with the WHO clinical guidelines [1, 3]. Metroplasty using video-assisted endoscopic technologies was approved by order of the Ministry of Health of the Russian Federation dated April 16, 2019, No. 217n (nomenclature A16.20.039.001).

Results

Fifteen patients aged 25 to 39 with a history of 1- 3 caesarean deliveries were submitted to surgical treatment.

One patient aged 38 who had 3 previous caesarean deliveries and underwent metroplasty for uterine scar dehiscence (see clinical example) postoperatively was found to have a deep niche in the scar region, and the myometrium thickness above the niche was less than 2 mm.

Metroplasty was performed laparoscopically using an intrauterine device with a groove.

We designed a new intrauterine device with a groove1 for surgical treatment of uterine scar dehiscence (metroplasty), which (Fig. 1, 2) is a metal cylinder made of stainless steel: 190 mm long, 13 mm in diameter (there are also options with a smaller diameter - 12.0 mm and 12.5 mm), with an ogive-shaped rounded tip and a semi-cylindrical handle. At a distance of 40 mm to 58 mm (there is an option with a large distance from 50 mm to 68 mm) from the working part of the tip, there is a grooved recess 6 mm deep. The diameter of the groove is 18 mm and corresponds to the curvature of the needle used for sewing the scar (Fig. 3).

An intrauterine device is inserted into the uterine cavity through the cervical canal preliminary dilated with Geghar’s dilators.

The described above new method for surgical treatment of postoperative uterine scar dehiscence differs from existing metroplasty options in the following ways:

• an intrauterine manipulator with a groove is inserted directly under the postoperative uterine scar, which allows it to be optimally dissected and sutured through all layers;
• the postoperative scar excision is performed using mechanical scissors, immersing the scissors branch in the groove;
• the manipulator allows optimal approximation of wound edges for subsequent suturing;
• the uterine incision is closed by suturing techniques for all layers above the manipulator groove, which matches the curved sewing needle (atraumatic needle V-34 (36 mm);
• the manipulator has transverse notches indicating the length from the tip - 70, 80, 90 mm to limit the length of the manipulator insertion (corresponding to the length of the uterine cavity);
• to optimize the excision and its closure, the manipulator can be rotated around its axis to place the groove directly under the manipulation zone (if necessary, it can be located at the 10 - 12 or 2 o’clock position).

Case 1. A 38-year-old patient with a history of 3 caesarean deliveries presented with signs of uterine scar dehiscence. In 2017, she underwent laparoscopic repair of uterine scar dehiscence using a standard technique and an ultrasonic scalpel.

Ultrasonography (Fig. 4, A) showed a myometrial defect in the area of ​​the postoperative scar with a niche sized 9mm × 3mm × 14mm and filled with menstrual detritus. The myometrial thickness over the niche was about 2 mm.

Conclusion: a myometrial defect in the area of the postoperative uterine scar, a history of uterine scar metroplasty.

Laparoscopy was performed using standard aseptic techniques and with pneumoperitoneum. A Karl Storz laparoscope and two lateral trocars were introduced into the abdominal cavity in the right iliac (Ø5mm) and left iliac (Ø12 mm) areas.

The uterus was enlarged to 5 - 6 weeks gestational size, spherical, pale pink in color, and was displaced posteriorly. On the anterior uterine wall, in the area of the vesicouterine fold, there was a post-caesarean section uterine scar. The scar was inverted and crater-shaped, up to 0.5 cm deep, up to 2 cm long, and up to 1.0 cm wide, and prolapsing at instrumental palpation. The right ovary measured 2.5×2.0×1.5 cm and had expressed follicles. The left ovary measuring 3×2.5×2.0 cm was fixed to the pelvic wall and had expressed follicles. The fallopian tubes on both sides were free throughout; fimbriae were expressed. Chromopertubation showed that both fallopian tubes were patent.

Hysteroscopy revealed a niche along the front and side walls of the upper third of the cervical canal. The niche had an irregular shape and was about 8 mm deep, about 10 mm wide, and about 20 mm long (from 10 to 2 o’clock position). The inner walls of the niche were irregular and had atrophic mucosa, pronounced vascular pattern, and cystic inclusions. Description of the procedure (Fig. 5, A – E).

The cervical canal was dilated to Geghar’s No.12. An intrauterine grooved manipulator with a diameter of 12 mm was inserted. The peritoneum was opened in the region of the vesicouterine fold (plica vesicouterina). The urinary bladder, which was intimately fixed to the scar, was separated by blunt and sharp dissection. The lower uterine segment around the postoperative scar was exposed. Provisional myometrial incisions about 2 mm in depth were made along the proximal and distal edges of the scar using a monopolar needle. The scar was grasped by a serrated forceps and excised down to healthy tissue along the provisional incisions. The groove of the intrauterine device was exposed.

The edges of the wound were approximated above the groove and closed with three “duplicate” vicryl sutures. The second row of sutures consisted of submersible serous-muscular vicryl sutures. Peritonization was performed by a continuous suture using the peritoneum of the vesicouterine fold. Hemostasis was achieved by a bipolar coagulator. After a final check for hemostasis, the skin was closed with skin sutures and a sterile adhesive bandage.

The follow-up ultrasound (Fig. 4, B) 3 months after surgery showed that the myometrial thickness of the lower uterine segment in the scar area was 17 mm and had a homogeneous structure.

The complexity of repair of uterine scar dehiscence is mostly attributable to anatomical and topographic features including location of the lower uterine segment with the scar under the vesicouterine fold of the parietal peritoneum or urinary bladder; immediate proximity in the ascending uterine vessels; and the need to verify the area of uterine scar and determine the boundaries of scar excision within healthy tissue.

In some cases, the outcome of uterine scar defect repair depends on the probability of cervical epithelium invagination into the niche with the formation of pseudocysts or ectopic endometrial lesions (endometriosis) [19–22].

Conclusion

The newly proposed method for surgical treatment of uterine scar dehiscence after a previous caesarean section using the grooved intrauterine device allows for effective restoration of the lower uterine segment due to the optimization of metroplasty at all stages.

The results of metroplasty depend on adequate excision of the dehiscent scar down to healthy myometrium, an optimal approximation of wound edges, and myometrial suturing. The scar excision through the groove of the manipulator using mechanical scissors and closing wound edges over the groove provides the best conditions for the uterine defect repair.

The method of repair of uterine scar dehiscence using a new intrauterine manipulator with a groove can be recommended for routine clinical application and may be further optimized in the process.