We would like to thank Camporesi et al. for their interest in the locked procedure pack (WireSafe) and our article. They are, of course, absolutely correct that the WireSafe is not intended to prevent guidewire breakage or malfunction; however, in our simulation it was shown to be highly efficacious in preventing clinicians simply forgetting to remove the whole guidewire.1 We see these as two separate problems requiring two separate solutions. Guidewire fracture or impingement due to kinking or unraveling needs to be addressed with improvements in manufacturing, materials, and operative technique. However, whole guidewire retention due to forgetfulness requires an understanding of human factors science and the inevitable fallibility of human operators, made worse by suboptimal working conditions. The well-recognized success of the energy, transportation, and other high-reliability industries use system changes and fail-safe forcing functions engineered into equipment design to prevent rare, but serious, errors and these are tested in a simulation setting. The incidence we quoted was from the article by Vannucci et al., referring to whole guidewire retention due to forgetfulness, and was 1:3,291.2 Interestingly, the incidence for “operator distraction” from the article by Omar et al. was almost identical at 1:3,221.3 These concordant figures would equate to approximately four forgotten guidewires everyday in the United States (an estimated 5,000,000 central venous catheters are placed annually2 ). A recent article evaluating 391 cases from the U.S. Veterans Health Administration also supported the incidence of forgotten guide wires in the United States, and in addition, showed that 91% were whole—rather than fractured—guidewires.4 Regarding statistical significance for rare events in routine clinical practice, as discussed in our article, studies can seldom be powered to achieve significance.
Awareness and educational programs alone may have a higher cost and a more limited impact in the long term than design improvement. In the United Kingdom, the National Health Service England database contains 237 cases of forgotten whole guidewires (2004 to 2015).5 Despite being made a never event and increasing educational efforts in the National Health Service, the reported incidence has been increasing.5 Although immediate documentation of removal is commendable, we note that in one of the cases reported by Vannucci et al., guidewire removal was documented when it had, in fact, not been removed,2 and we have observed this occurring in the National Health Service.
We strongly disagree that comparable reductions would be seen by educational programs and improving documentation alone. Short-term improvements are often seen, but the negative effects of associated cost, increased cognitive load, creeping complacency, and warning fatigue blight these programs. An engineered (forcing function) safety solution delivers a sustained effect over time and if detected immediately, forgotten guidewires are normally amenable to bedside removal.
We also thank Drs. Kapoor and Mayall for their particularly perceptive letter addressing a loophole, about which we have agonized, relating to guidewires being flushed into the circulation. As described above, this would affect a small minority of these never events as the guidewire remains within the catheter at the time of the postoperative x-ray in the majority,5 and may migrate thereafter. Therefore, this should not discourage hospitals from using this solution. Our plan to use prefilled syringes was thwarted by the requirement of ethylene oxide, rather than gamma sterilization, by current packing companies; the former changes the pH and composition of saline in plastic sealed syringes. To prevent this, the WireSafe is sized to include a glass ampoule, an ampoule breaker, and a syringe with a filter needle, and we continue to try to influence packing companies to provide, and end users to request, these features. Additionally, we are aware of one company that is in the final stages of producing an ethylene oxide–compatible saline syringe, which we would endorse the use of within the WireSafe.
Dr. Young has patented and is the inventor of the Venner WireSafe based on the locked pack described in this letter. Dr. Mariyaselvam has been selected as a National Health Service Innovation Accelerator Fellow and National Health Service Clinical Entrepreneur Fellow to support the implementation of the Venner WireSafe. Both have ownership rights to the intellectual property and hope to be involved with supporting and advising on the commercialization of the Venner WireSafe, and may benefit financially alongside its clinical success, subject to future negotiation and agreement.