BJOG: An International Journal of Obstetrics & Gynaecology | 2019
Gynaecological surgery
Abstract
In comes 2019 and a very happy New Year to all of you. BJOG has historically published more manuscripts relating to obstetrics than to gynaecology. This is no longer the case as increasingly more gynaecological studies are being reported in the journal. For example, in the October 2018 issue, there were an equal number of original articles (i.e. excluding systematic and narrative reviews, and commentaries) relating to obstetrics and to gynaecology. Given the equal importance of both sections of the speciality, I believe this a healthy development and will help to maintain our readership’s continuing interest. In this month’s Editorial, I would like to highlight two articles relating to gynaecological surgery. The first article, which is by Baekelandt and colleagues (pages 105–13), reports the results of a randomised controlled trial comparing transvaginal natural orifice transluminal endoscopy surgery (vNOTES) for hysterectomy with total laparoscopic hysterectomy (TLH) for benign indications. The investigators evaluated the laparotomy conversion rate and the duration of postoperative stay in hospital associated with these types of hysterectomies. Surgical trials are notoriously difficult to perform without the risk of bias in the results. In Baekelandt and colleagues’ trial, all the surgical procedures in both groups were performed by a single surgeon, which limits the generalisability of the results observed. However, recruitment of several different surgeons to improve the external validity of the study would be difficult given the need to find individuals who are equally skilled and familiar with vNOTES and TLH. Blinding is another issue affecting surgical trials. It is obviously impossible to mask the surgeon doing the procedure. To mask the patient and the assessors, Baekelandt et al. used sham abdominal incisions for patients allocated into the vNOTES group. Nevertheless, there remains uncertainty about the effectiveness of this method of blinding and this was not formally evaluated in this study. This trial was designed as a non-inferiority study using hysterectomy by the allocated technique as the primary outcome measure. The planned sample size (32 women in each study group) was calculated with an assumption of a 5% laparotomy conversion rate in the TLH group and 15% in the vNOTES arm. The assumed conversion rate in the vNOTES arm was derived by asking ten women treated by total vaginal natural orifice transluminal endoscopic surgery to choose what conversion rate they would accept from five cut-off values: 5%, 10%, 15%, 20% or 25%. Most of these women chose 15% and this cut-off was used, although it could be argued to be too large a difference for a non-inferiority study. Not surprisingly, there was not a single laparotomy conversion in any of the women allocated to either study group. It is, therefore, possible that a difference in this outcome may be observed if a more conservative margin was employed for non-inferiority, which would require a larger sample size. The second article is by Phillips and colleagues (pages 96–104) and relates to the predictive ability of different classifications of the extent of surgery for the management of advanced ovarian cancer (AOC). There are two broad types of classification systems being used: one is based on the types of surgical procedures and the other on the number of surgical procedures. As an example, the National Institute for Health and Care Excellence (NICE) guidance recommends the use of a classification employing the former system and considers ‘standard’ surgery to encompass total abdominal hysterectomy, bilateral salpingo-oophorectomy, omentectomy, and pelvic and/or paraaortic lymphadenectomy. Bowel surgery is also included in the ‘standard’ category as long as it is only restricted to localised, non-multiple bowel resection. The alternative category under this classification is ‘ultra-radical’ which includes diaphragmatic stripping, extensive peritoneal stripping, multiple bowel resections, liver resection, partial gastrectomy, cholecystectomy and splenectomy. Phillips et al. retrospectively applied the NICE classification and five others to over 600 patients who had undergone surgery for AOC, with the aim of comparing the ability of each to predict postoperative morbidity. They found that classifications based on the type of procedures were less likely to be predictive of major morbidity than were those based on the number of procedures. The authors concluded that what is termed radical surgery for AOC should not be based on what abdominal or pelvic structures are removed, but instead on the number of peritoneal organs resected.