Response to: “Is There a Link Between Longer Operating Times and Increased Risk?” and “Papers Regarding Operative Times and Complications Can Be Misleading”

Sirs: Thank you very much for your letters to the editor.1,2 We hope we can help clarify and address some of the concerns raised. Our study actually did address many of these concerns using multivariate logistic regression and risk adjustment. This method simultaneously analyzes the effect of multiple independent variables on a dependent variable in relation to one another. Logistic regression aims to find which of the independent variables (ie, operative time, age, BMI, sex, smoking status) has a true relationship to the observed outcome (postoperative complication) and to adjust the reported effect of the variable of interest by weighing the influence of the other variables. Essentially, by using this model, we were able to adjust for confounders of operative time. Thus, we did in fact control for the confounders and addressed the patient characteristics and various procedures statistically. There are some flaws in our data, including some aberrant operative times, which were subject to errors based on what was reported by nurses, time outs, and surgical reports. Being a retrospective study, it is difficult to determine the source of error, and ideally we would have excluded these cases from our study. However, it is unlikely that these few outliers would have significantly affected our results, as we looked at over 1,750 cases, and the effect should wash out reasonably with the sample size. Moreover, we acknowledge that stratification of groups was incomplete, which is an inherent problem for any study using CPT codes to define cohorts. There clearly is selection bias. Indeed, our “lipectomy” group included both liposuction cases and abdominoplasties, and it is possible that the extent of dissection and complexity of surgery played a role in complication rates for this cohort. However, it is not true that our SMAS flap or free flap cases involved only one type of surgery, and so it is unlikely that this was the reason we found operative time to have no significant effect on morbidity in these groups. In fact, the facelift patients almost always had other concurrent procedures, including blepharoplasty, fat injection, and neck and brow lifts. The free flaps—most of which were trauma cases—covered a wide range of procedures involving a variety of donor sites and significant variability in size and nature of the defects. Nevertheless, it stands to reason that the longer the procedure, the more complex it will be and thus the patient would likely be more prone to developing a complication. We also recognize that time is not the only factor to consider and a 4 hour facelift is clearly different than a 4 hour liposuction and abdominoplasty physiologically for a patient. Perhaps it is the complexity of the case that drives surgical outcomes, and this should be emphasized over effect of operative time. Surgical practice dictates that the surgeon and patient must weigh the risks and benefits of any procedure to determine whether it should be performed. No surgery is without risk. This is the essence of the informed consent process where this is reviewed with the patient. Surgeons and patients alike must decide what their “tolerance” is for risk. The main point of our study is to provide surgeons with a guideline to safely perform complex operations, regardless of whether duration of surgery is the true underlying cause and to help them understand and share the inherent risk of those procedures studied in this cohort. Simply embracing a “6-hour time limit” as published in the 2009 advisory3 was not enough for our team given the complex nature of these procedures. At what time point does complexity manifest itself as an increase in morbidity? We have to embrace “evidence” to help us better understand outcomes and risk rather than relying on “loose markers”. We routinely perform procedures well over three hours in our practice, most of which are elective. As physicians should we accept “6 hour” recommendations propagated without any supportive evidence to suggest that it is a realistic time point? It is important to clarify that we do not suggest that surgeons keep all operations to less than 3 hours in duration, but simply that risk increases after this time point. Risk is multifactorial and based on a number of factors having to do with the patient and operative plan. Whether the perceived benefit of a more prolonged operative time must be balanced by the risk is ultimately up to the surgeon and their patient. It is our hope that by elucidating the risk of morbidity at each length of surgery in this select, retrospective cohort, that plastic surgeons can better plan and discuss the risk of morbidity with their patients. We would submit to you that data such as this helps to better protect the physician by allowing us to educate the patients about the inherent risks involved with performing more complicated procedures. Dr Kenkel is an investigator for Allergan (Irvine, California), Erchonia (McKinney, Texas), and Ultrashape (San Ramon, California) and serves on the Advisory Board for Kythera (Calabasas, California) and Ulthera (Mesa, Arizona). The other authors have nothing to disclose. The authors received no financial support for the research, authorship, and/or publication of this article.