This raised the possibilities of spontaneous expulsion or uterine perforation. A supine abdominal plain radiograph to evaluate the presence or absence of an IUCD in the pelvis showed a "T"-shaped metallic structure midline in the pelvis, which is characteristic of an IUCD (Figure 2). The IUCD was cephalad to the expected position and was oriented with the vertical axis pointing superiorly.
A more extensive ultrasound evaluation of the uterus and adjacent structures documented a densely echogenic, linear foreign body lying along the anterior-superior serosal surface of the uterine body (Figure 3). The foreign body did not move with changes in patient position. These findings were discussed with the obstetrician. A preliminary diagnosis of complete perforation of the uterus with the IUCD lying adjacent to the serosal surface of the uterus was made. An incomplete perforation of the uterus with subserosal placement of the IUCD could not be excluded.
The patient was then taken to the operating room, where a laparoscopic removal of the IUCD was performed. Intraoperative laparoscopic images showed a round perforation of the uterus with the IUCD lying freely in the pelvis along the serosal surface of the uterus (Figure 4).
Ultrasound is commonly used to document the presence and position of an IUCD within the uterus. A highly echogenic linear structure, with a much greater echogenicity than the normal endometrium, is characteristic of an IUCD. The sonographic appearance of an IUCD is determined by its shape and composition. Most IUCDs are now shaped like a "7" or a "T." Intrauterine contraceptive devices are made of a combination of plastic and metal (copper). The metal causes a "reverberation artifact," a series of parallel lines that become progressively weaker posteriorly, when the IUCD is parallel to the ultrasound beam. Plastic tubing is displayed as 2 parallel lines representing an entrance and an exit shadow. A normally positioned IUCD lies in the midline of the endometrial canal, equidistant from the uterine margins.
Intrauterine contraceptive device strings are used to monitor and remove the IUCD. The primary diagnoses of a "lost string" include: 1) IUCD in situ, 2) unrecognized expulsion, and 3) perforation of the uterus. Rare possibilities include: 1) fragmentation of the IUCD with expulsion of the fragment bearing the string, and 2) migration of a linear IUCD into the uterotubal junction.2
Patients with misplaced IUCDs may present with pregnancy, "lost string," vaginal bleeding, or pelvic pain, or may remain asymptomatic for years. Approximately 80% of misplaced IUCDs are found within the uterine cavity, 15% are found in the cervical canal, and 5% perforate the uterus.3
A missing string is the first sign of perforation in approximately 80% of cases.4 The incidence of uterine perforation, the most dangerous complication of IUCD placement, is as high as 2.2 per 1000 insertions.5
A multimodality approach is essential in the diagnosis of a lost IUCD string. There is significant danger in making the diagnosis of missed
expulsion of the IUCD based solely upon ultrasound findings of an empty endometrial cavity. The literature reports a case assumed to be IUCD expulsion based only on ultrasound findings. Afterward, that patient had persistent symptoms, became unintentionally pregnant, and then an intra-abdominal IUCD was documented by radiography.6 This underscores the importance of utilizing a combination of clinical history, ultrasound, and radiographic imaging, leading to the diagnosis of uterine perforation by a misplaced IUCD.
Complete uterine perforation by an intrauterine contraceptive device. Appl Radiol.