Prospective randomised trial comparing gonadotrophin-releasing hormone analogues with triple tourniquets at open myomectomy

Authors


Sir,

We read with interest the article by Dr Al-Shabibi et al.1 in which they reported on the superiority of triple tourniquets over GnRH analogues (GnRHa) in reducing blood loss at open myomectomy. We wish to make a number of comments.

We are intrigued by the use of a 5-day course of ‘prophylactic’ antibiotics at a time when we are frequently exhorted to avoid the injudicious use of antibiotics.

The Cochrane review2 reported that intra-operative techniques to limit blood loss at myomectomy are more effective than pretreatment with GnRHa. That 87% of UK consultant gynaecologists still use GnRHa for this purpose reflects the common observation that once formed clinical habits die hard. We advocate the banishment of GnRHa from routine myoma surgery for the following reasons3:

  • • They destroy tissue planes and render fibroid enucleation more difficult. This probably explains their failure to reduce blood loss relative to other techniques.
  • • They are expensive and not cost-effective2.
  • • They have considerable, well-described adverse effects.
  • • They mask smaller fibroids which are missed at surgery, only to re-grow rapidly when their effects wear out. This likely explains the high rates of fibroid ‘recurrence’ following myomectomy.
  • • In our experience, reduction in size of fibroids of ≥20 weeks is often minimal. This lack of efficacy might explain why the authors found they had to use a vertical incision in 26/40 patients (excluding those with prior myomectomy) for uteruses of 16- to 18-week size. We frequently perform myomectomy on ≥20-week size uteruses, and for first time procedures we rarely find the need to use vertical incisions. It really is not too dissimilar to delivering a large baby through a Pfannenstiel incision, with the myomectomy screw often coming in handy to pull down the larger fibroids, and occasionally needing to enucleate the low-lying ones to facilitate access. Previous myoma surgery renders it judicious to use a vertical incision because of the risk of major adhesions.
  • • Although GnRHa pre-treatment to facilitate correction of anaemia is commonly used, this is unnecessarily expensive treatment. Progestogens will achieve the same at much reduced cost and with fewer adverse effects, and when used with intravenous iron sucrose the combination is more effective, rapid and still cheaper than GnRHa.

Our only concession to the use of GnRHa in myoma surgery is in their use to shrink large submucous fibroids to facilitate access for transcervical resection.

Vasopressin is a useful drug in myoma surgery which has received unfavourable press because of injudicious use. Life-threatening complications have been reported, but this has been when high concentrations (≥0.5 units/ml) of the drug have been used. Our experience is that, used at 0.2 units/ml (20 units in 100 ml dilution) and carefully injecting into the myometrium, it is safe and highly effective, allowing us to carry out myomectomy in uteruses enlarged to beyond 20 weeks with very low blood transfusion rates. A literature review supports the contention that 0.05–0.3 units/ml have less adverse effects compared with the doses of ≥0.5 units/ml.4

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