Hysteroscopic removal, with or without laparoscopic assistance, of first-trimester cesarean scar pregnancy

Abstract

Objective: To demonstrate the implementation and potential benefits of hysteroscopic removal, with or without concomitant laparoscopic assistance, of first-trimester cesarean scar pregnancies (CSPs).

Design: Patients with prior cesarean deliveries may have scar formation at the muscular wall of the uterine isthmus, resulting in a cesarean scar defect (CSD), also known as an isthmocele or diverticulum. When implantation of a trophoblast occurs at the CSD, a CSP develops, and with progression onto higher gestational age, it carries risks for serious complications, such as placenta previa spectrum, life-threatening bleeding, uterine rupture, and cesarean hysterectomy. Therefore, early termination is often recommended. Given that the chorionic frondosum only penetrates the decidual basalis layer during the first trimester and does not invade the distal myometrial segment until early second trimester, operative hysteroscopy can be a reliable and efficient treatment modality for early intervention. This narrated video features the systematic approach and surgical management for patients with first-trimester CSPs.

Setting: Academic tertiary hospital.

Patient(s): Three multiparous women between 34 and 38 years of age diagnosed with CSPs within the first trimester.

Intervention(s): Initial assessment with transvaginal ultrasonography and color Doppler flow identifies the site of implantation and measures the residual myometrial thickness (RMT), which are important parameters for classifying the CSPs into type I or type II. Type I CSPs often present at an earlier gestational age, have a thicker RMT, and grow toward the uterine cavity, while type II CSPs are frequently noted at a higher gestational age, have a thinner RMT, demonstrate obvious scar dehiscence, and often invade toward the bladder. The patients received either operative hysteroscopy alone or with concomitant laparoscopic assistance and repair of CSD dehiscence. For all hysteroscopic operations, misoprostol (200 μg) was given 4 hours before the procedure while oxytocin (20 U in 1000 mL isotonic solution, intravenous infusion) was infused immediately after removal of the placental tissue. For laparoscopic excision and repair of the dehiscent scar, local injection of 5 mL terlipressin acetate (1 mg) was added before the initiation of laparoscopic CSD excision.

Main outcome measure(s): Appraisal of the parameters used for preoperative assessment, the efficacy of the surgical procedures, and the intention to minimize the associated risks and morbid sequalae were evaluated.

Result(s): Most of the type I CSPs or type II CSPs with gestational age <8 weeks and RMT >3 mm can be successfully treated with operative hysteroscopy alone. In contrast to blind dilatation and curettage, operative hysteroscopy offers direct visualization to ensure complete removal of the chorionic villi, which can occasionally be buried deep within the concavity of the CSD. It is worth noting that gently sweeping the decidua basalis from the myometrium with the loop resectoscope is more than enough to separate the chorionic villi within and completely displace the placental tissues without causing massive hemorrhage. For type II CSPs in late first-trimesters showing distended CSDs and diminished RMT, laparoscopy can be established before the hysteroscopic procedure for better surveillance and to prevent inadvertent myometrial perforation. Then, hysteroscopic removal of CSP can further induce uterine contractions to help reduce blood loss during subsequent laparoscopic repair of CSD.

Conclusion(s): Accurate diagnosis and timely management of CSPs during the first trimester are crucial for preventing significant morbidities associated with advanced gestational age. Operative hysteroscopy offers the benefit of direct visualization for competent detachment of the decidua basalis of the CSP from the steep concavity of the CSD. Furthermore, the employment of laparoscopy for type II CSPs helps avoid inadvertent complications related to the thin RMT and allows concomitant repair of the extensive dehiscence.

Keywords: Nontubal ectopic pregnancy; cesarean scar defect; cesarean scar pregnancy; hysteroscopy; obstetric complication.