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Author's reply: Perineal reconstruction after abdominoperineal excision using inferior gluteal artery perforator flaps (Br J Surg 2012 99 584–588)

Sir We have read with interest Blazeby’s article on recruitment of patients into randomized clinical trials (RCTs) in surgery. The article reports on two randomized trials in surgery, the ProtecT trial and the ROSSINI trial; it praises the high level of recruitment of patients into these trials, and concludes that the trials will show that ‘RCTs in surgery can be conducted and completed’. We believe strongly that randomized trials should be performed where they are feasible and likely to provide the highest level of evidence. These randomized trials should be designed and conducted to yield optimal recruitment rates, for which Blazeby provides us with very helpful advice. However, the current examples of successful trials are not representative of the many types of surgical intervention for which it is often much more problematic to perform an RCT. The ProtecT trial deals with cancer treatment with a primary outcome at 10year follow-up. Cancer treatment and research profits highly from the good administrative infrastructure and large databases, characteristics that are lacking in most surgical areas. For this trial, we will have to wait for the final followup and crossover rates. The ROSSINI trial deals with an add-on procedure for prevention of wound infections, while the primary surgical intervention remains untouched. Thus this trial is not concerned with the primary surgical intervention. We would like to point out that neither trial has yet been completed. Enrolment in the ProtecT trial is reported to have risen from 30 to 65 per cent. This has to be encouraged, but it remains uncertain what the final recruitment rate will be, and whether 65 per cent is an acceptable response rate at all. For the ROSSINI trial no recruitment rate is actually reported. Although the RCT is generally considered the highest level of evidence, in surgical practice this may not always be true. Compared with pharmaceutical RCTs, the randomization process in surgical trials is cumbersome and creates an artificial situation that may deviate from ‘normal’ clinical practice. This situation carries the risk of performance bias, as the surgical team is often more experienced with one of the techniques. Furthermore, patients may refuse to be subject to experimentation or show preference for the ‘new’ technique either by going to other clinics or crossing over during the study. This is possibly due to the widespread availability of surgical techniques and devices only after publication of the technique or receiving the CE mark. Among other factors, this has resulted in low recruitment rates and a high rate of crossover in recently published high-quality surgical trials, such as the vertebroplasty trials1,2 and the SPORTS trial3. Besides the problem of performance bias and selection bias, adequate blinding is another major difficulty and impossible for many surgical interventions that do not ethically or technically allow sham procedures. Finally, even in the fortunate situation that an RCT is adequately powered, the sample size may be too low to detect differences in complications, as it is calculated to answer only one primary effectiveness question usually within a limited time frame. Therefore, long-term adverse effects in particular remain undetected. Many of the above disadvantages may be circumvented by conducting large prospective registry studies. Such studies allow comparison of usual care or ‘schools’. Each surgeon can perform at their best skills level in the clinical setting where this treatment has been optimized. Performance bias and thus care provider bias is then less of an issue. Another advantage is that the large sample sizes can reveal rare but serious complications and provide an estimate of clinical outcome, especially in the long term in the general treated population. An example of the success of this rationale can be found in the prosthesis survival studies that used the Swedish arthroplasty registries. This and other observational designs should be pursued. To improve comparability, clinical (or surgeon) equipoise4 can be used to confirm suitability of both techniques. Blazeby concludes that the ProtecT and ROSSINI trials show that ‘RCTs in surgery can be conducted and completed’. We believe that this general conclusion cannot be drawn from these specific trials, which have not even been completed. On the contrary, we believe that for many surgical questions it is impossible to gain unbiased answers by conducting an RCT. Other trial designs may be preferable for studying the effect of surgery, considering the right, innovative and creative methodological choices. W. C. H. Jacobs1, M. C. Kruyt2 and F. C. Oner2 1Leiden University Medical Centre, Leiden, and 2University Medical Centre Utrecht, Utrecht, The Netherlands (e-mail: w.c.h.jacobs@lumc.nl) DOI: 10.1002/bjs.8851