Second-generation thermal endometrial ablation: beware of metal clips in the lower abdomen

Gynecol Surg (2013) 10:291–294 DOI 10.1007/s10397-013-0787-3 CASE REPORT Second-generation thermal endometrial ablation: beware of metal clips in the lower abdomen J. W. van den Brink & Kirsten Kluivers & Theodoor Nieboer Received: 17 December 2012 / Accepted: 16 January 2013 / Published online: 7 February 2013 # Springer-Verlag Berlin Heidelberg 2013 Introduction In The Netherlands, the incidence of excessive vaginal blood loss in fertile women is 5.2 per 1,000 women (National Guideline of GPs, 2008). Endometrial ablation is a widely used treatment for patients with abnormal or excessive vaginal blood loss because of it is efficacy and safety [1]. Complications during or after endometrial ablation are rare, and hysterectomy can be avoided [2, 3]. The first-generation endometrial ablation techniques were introduced in the mid-1980s and included loop resection, rollerball, or laser ablation [1]. These techniques require visualization of the uterine cavity [4]. Several complications may occur such as fluid overload syndrome, uterine perforation, cervical laceration, or hematometra. New techniques have been developed since 1990; these are known as the second-generation ablation techniques, and hysteroscopy is not necessary in the majority of these techniques [4, 5]. The second-generation ablation techniques include thermal balloon (ThermaChoice), hot fluid circulation (Hydro ThermAblator), cryotherapy (Her Option), microwave energy (MEA), and radiofrequency electrosurgery (NovaSure) [1]. In a Cochrane database metaanalysis, these new techniques were associated with shorter operative time (median difference, 15 min), a greater likelihood for the use of local anesthesia and less complications compared to the first-generation techniques [6]. Therefore, the second-generation endometrial ablation techniques are currently widely used. The NovaSure consists of a single-use three-dimensional bipolar device and a radiofrequency controller with a constant J. W. van den Brink (*) : K. Kluivers : T. Nieboer Radboud University Nijmegen Medical Centre—Obstetrics/ Gynaecology, Nijmegen, The Netherlands e-mail: power generator (maximum power delivery capacity, 180 W). It functions at 500 kHz with a power cut-off limit at a tissue impedance of 50Ω. To prevent heating of the extra-uterine environment, tissue impedance is monitored continuously. In general, the endometrial layer has a tissue impedance <50Ω and the myometrial layer ≥50Ω, and the generator will switch off automatically when the myometrial layer is reached or after a maximum procedure time of 2 min [7]. Due to the controller, the NovaSure is considered as a relatively safe endometrial ablation technique. We report a case in which persistent abdominal pain occurred after endometrial ablation with the NovaSure, most likely due to heat conductance through tubo-isthmic-placed metal hemoclips. Case report A 45-year-old multiparous woman visited the outpatient clinic with hypermenorrhoea which resulted in hypochromic anemia. For 2 years, she suffered hypermenorrhoea responding neither to oral contraceptive pills nor to a levonorgestrel intrauterine device. Her medical history included a laparoscopic right-sided salphingectomy due to an ectopic pregnancy. Transvaginal ultrasound showed a subserosal myoma of 2.7×1.7 cm in a moreover normal-size uterus; no adnexal abnormalities were seen. After counseling for all therapeutic options, a NovaSure procedure was planned under general anesthesia. A preoperative checklist was executed, and no contraindications for the NovaSure were found. Hysteroscopy prior to the NovaSure procedure, which is a local hospital policy in our center, showed a normal uterine cavity. The sounding length was 10 cm with a cavity width of 2.8 cm, and the power was 100 W, the procedure time was 64 s. Hysteroscopy directly after the 292 procedure showed a fully disintegrated endometrium without signs of uterine perforation. Two days after endometrial ablation, the patient complained of lower abdominal pain with a body temperature of 38.1 °C. Laboratory test showed elevated infection parameters: C-reactive protein 251 mg/L (normal range, <10 mg/L) and leucocytes 16.4×109 per liter (normal range, 4–11×109 per liter). Cultures were taken from the cervix, and broad-spectrum antibiotics were administered intravenously. After 3 days, the patient’s clinical condition enhanced, and infection parameters dropped significantly, and she was discharged from hospital. Oral antibiotics were continued for 2 weeks. Culture of the cervix showed a group B streptococcus. During follow-up in the outpatient clinic, she kept complaining of right-sided abdominal pain despite the use of multiple analgesics and antibiotics. Abdominal examination revealed a pressure pain in the lower right abdomen without rebound tenderness. Laboratory tests showed C-reactive protein 5 mg/L and leucocytes 8.8×109 per liter. Transvaginal ultrasound showed no abnormalities. Due to the persistence of pain 5 weeks after surgery, a CT scan was performed. This showed an unexpected finding of multiple metal clips on the right side of the uterus and one clip near the umbilicus. There were no signs of tubo-ovarian abscesses. On further inquiry, it was obvious that these clips were metal hemoclips placed during removal of the right fallopian tube due to an ectopic pregnancy 18 years ago in another medical center. We hypothesized that heat conductance during the endometrial ablation through the metal hemoclips might have led to thermal damage of the uterine cornu and parametrium. A diagnostic hysteroscopy and laparoscopy was performed. At hysteroscopy, there was a normal uterine cavity, and some regeneration of the endometrial layer was seen. During laparoscopy, normal ovaries were seen. Two right-sided tubo-isthmic-placed metal hemoclips were located with erythema of the cornu as a sign of inflammation (Fig. 1). Furthermore, four metal hemoclips were located on the lateral side of the parametrium without signs of inflammation (Fig. 2). No signs of abscesses were seen. The two tubo-isthmic-placed metal hemoclips were removed and the cornu was coagulated, while the other metal hemoclips remained in situ. Within 3 weeks after surgery, the patient’s abdominal pain decreased, and she recovered completely. The removed endometrium showed on pathological examination no signs of hyperplasia or atypia. Gynecol Surg (2013) 10:291–294 Fig. 1 Laparoscopic view of the right ovary, uterine cornu, and round ligament. At least seven hemoclips are visible through tubo-isthmic-placed metal hemoclips. We hypothesize that the abdominal pain was caused by thermal damage because after antibiotic treatment, she kept complaining of abdominal pain despite normal infection parameters. In cases of persistent abdominal pain after endometrial ablation of unknown origin, further diagnostic evaluation is advocated. In our case, a CT scan was performed because no abnormalities were found a (...truncated)