Pushing the envelope in microsurgery: Insights from ultra‐safe healthcare and systems

Abstract

In the modern era, microsurgical breast reconstruction is now routinely successful, with flap loss rates widely reported on the order of 1–2%. While this represents a far improvement from the advent of microsurgery, another context in which to consider this is in comparison to other spheres of human activity. Ultra-safe healthcare is defined as that for which the risk of a significant adverse event occurs on the order of 10–10, which include anesthesia in an ASA Class 1 patient and blood transfusions (Lagasse, 2002; Vamvakas & Blajchman, 2009). These areas are subsets of ultra-safe systems (USS), such as commercial aviation and the nuclear industry (Amalberti et al., 2005). In comparison to these areas, free flap surgery is 1000 to 10,000 times less successful. One common attribute of USS is the use of comprehensive adverse event reporting and analysis processes, which are largely credited for the extremely high levels of efficacy that can be achieved (Barach & Small, 2000). Examples of these reporting and analysis mechanisms include the Aviation Safety Reporting System (ASRS) used by the commercial airline industry, and the Human Factors Analysis and Classification System (HFACS) developed by the U.S. Navy (ASRS, 2020; HFACS, 2020). In surgery, the traditional means for adverse event reporting and analysis has been Morbidity and Mortality (M&M). However, it is unclear how its processes compare to the ASRS and other reporting systems used in USS. The objective of this study was to examine this issue in the context of abdominally based microsurgical breast reconstruction. At our institution, the occurrence of a free flap loss triggers a formal investigation through our departmental M&M processes that results in a report based on medical record analysis, faculty discussion, and literature review, thus providing consistently available information. This, combined with the fact that abdominally based microsurgical breast reconstruction is complex but that cases generally have similar procedural steps, made this an appropriate clinical context for this study. First, a framework for evaluating the processes of M&M was developed by applying the data points and concepts in the ASRS and HFACS to the practice of free flap surgery (Table 1). Second, using this framework, M&M data was reviewed in order to characterize the nature of the analyses and causes ascribed to cases of free flap loss. Specifically, a 9-year retrospective review of M&M cases (2011–2019) involving free flap loss after abdominally based microsurgical breast reconstruction was performed. A total of 31 cases of free flap loss after abdominally based microsurgical breast reconstruction were reviewed. In case analyses, the operative plan (100%) and phase of care (100%) where the error occurred were most commonly reported, but nearly all other factors were rarely considered, including work hours (0%), surgical team experience (0%), equipment (0%), and trainee instruction (0%). While internal conditions (e.g., medical comorbidities, hemodynamic stability, surgical history) were considered in 90.3% of cases, external conditions (e.g., concurrent clinic, concurrent meetings, concurrent surgery, on-call) were considered 0% of the time. The final causal attribution to morbidity was patient disease (12.9%), perioperative management (6.4%), surgical judgment (48.4%), and technical error (32.3%). The results of this study indicate that while the analyses of M&M identify causes of morbidity, these infrequently represent root causes. For example, ascribing a technical error as the cause of morbidity fails to consider the deeper contributory factors, such as fatigue or trainee instruction. Another potential factor is insufficient supervision, like that which can occur with a simultaneous operating room. Yet operative time, work hours, concurrent patient care or administrative responsibilities, and instruction were rarely considered. The same issue exists for cases in which surgical judgment was ascribed as the cause, which fails to address why exactly the judgment was erroneous (e.g., inexperience, incomplete information). The lack of a deeper inquiry into root causes hinders our ability to take meaningful steps toward avoiding a similar error in the future. Another lesson that we can learn from other USS is that it may not be sufficient to consider only the cases in which free flap losses actually occur, without also considering those in which they nearly occur. In the setting of free flap surgery, this might include anastomotic revision or perforator injury. Investigating instances of “near misses” may provide us with additional insight into the root causes of morbidity. Near misses occur 3–300 times more often than adverse events, enabling a more robust quantitative analysis (Battles et al., 1998). In addition, consideration of near misses minimizes the impact of hindsight bias (Billings, 1998). Lastly, the liability and blame that can potentially occur when an adverse outcome actually occurs are less of a concern for near miss events. This study is limited by its small sample size. However, the purpose of this study is primarily to present preliminary data regarding an idea on a topic that has previously received little attention in the surgical disciplines. Further investigation would be beneficial, possibly in a multicenter fashion to increase statistical power given the low incidence of free flap loss, and including additional variables (e.g., sleep quality). Another limitation is that while microsurgery and other USS such as aviation are in many ways similar, they differ in important ways. However, at the core of this study is the general manner of Received: 3 October 2020 Revised: 15 November 2020 Accepted: 28 January 2021