OC138: The pre-operative assessment (including MRI) and surgical approach to uterine abnormalities

The prevalence of congenital uterine anomalies has been estimated at between 0.0001 and 10%. Many uterine abnormalities will not require intervention as they have no impact on the patient. Factors to consider when planning surgery include the patient's age, fertility status and symptoms such as pelvic pain. Mild abnormalities such as uterine septae are amenable to hysteroscopic surgery whilst an obstructed uterine horn will require excision. Where there is a significant uterine abnormality, the minimum pre-operative work-up should include an ultrasound, IVU and hysteroscopy. The incidence of renal tract abnormalities ranges from 31–100%. Hysteroscopy enables determination of whether the uterine horn communicates with the other uterus or vagina. Where the uterine horn is to be removed, it is important to consider whether the remaining uterus is of adequate size to contain a pregnancy otherwise a metroplasty may be more appropriate. Transvaginal ultrasound is valuable in the diagnosis of anomalies in the older woman but is contraindicated in the child or adolescent who is not sexually active. In these cases, magnetic resonance imaging (MRI) is the investigation of choice. MRI correlates well with findings at laparotomy and is important in planning the appropriate surgical approach. Where the uterine horn communicates with the main uterine body but is not adequate for pregnancy then removal of the fallopian tube alone can be considered to prevent pregnancy within the horn. If the horn is non-communicating, surgery would normally entail removal of the horn due to haematometra, pain and endometriosis Laparoscopic removal of an accessory uterine horn was first reported in 1994. The technique results in minimal scarring and quick patient recovery. It is advisable to remove the fallopian tube on the ipsi-lateral side to remove the chance of an ectopic pregnancy on that side. GnRh analogues can be given pre-operatively to reduce vascularity and make surgery easier especially if associated with severe endometriosis. Most patients with uterine abnormalities will be young and require future fertility. The cosmetic results will also be important to this age group.