Surgical alternatives to hysterectomy for menorrhagia have been evolving since the end of the 1960s. The second-generation techniques of endometrial ablation are increasing in popularity due to their short learning curve ; however, as it is a non-visual technique, serious injuries can occur ; these have ranged from cervical tears to laparotomy for visceral injury.
A study examining the complication rates of microwave endometrial ablation showed that it has a perforation rate of 0.26% and a laparotomy rate of 0.07%. Studies examining Thermachoice ablation show a perforation rate of 0.17% and laparotomy rate of 0.02%. Despite this complication rate, no case reports of uterine perforation with a balloon ablative technique has been reported, and this is probably due to under-reporting.
To overcome this potential problem we perform a hysteroscopy prior to insertion of the Thermachoice balloon to ensure that the device is inserted into the uterine cavity; however, this did not help in this case. Inadvertent uterine perforation may have occurred either at the time of the initial hysteroscopy and been missed, or occurred while inserting the Thermachoice balloon catheter.
Uterine perforation has also been reported to occur at a rate of 1.7% in operative hysteroscopies , 0.05% of first-trimester and 0.32% second-trimester termination of pregnancies .
If the Thermachoice had not had a pressure indicator to indicate a problem, then the ablation would have proceeded which may have resulted in trauma to abdominal viscera. We do not know when the perforation occurred, i.e. at instrumentation, during the hysteroscopy or when the Thermachoice balloon was inflated. What is reassuring is that the safety devices in place alerted us to the problem and therefore we avoided any further complications.
This case emphasises the importance of safety devices on these second-generation techniques to try and reduce complications.