ICA injury during endoscopic sinus or skull base surgery is a devastating complication. Intra-operative and peri-operative management requires the surgical team to be well prepared. Given that ICA injury is a rare event, many surgeons have limited experience managing this complication should it occur [3, 4]. This study led to the development of a protocol (Fig. 3) to improve preparedness of surgical teams with variable levels of experience managing ICA injury.

A review of the literature revealed several important considerations that should be taken into account when managing ICA injury intra-operatively. Surgeons must promptly identify the injury and call for help from a surgical colleague as a four hand approach to managing this complication is optimal [6]. In addition, communication with colleagues in anesthesia is essential as major resuscitation may be necessary. Management of bleeding may be accomplished by use of a muscle patch, direct vessel closure, surgical clips, or bipolar electrocauterization, above other techniques [6, 7, 13]. Within the multi-disciplinary working group, the decision was made to organize the protocol in a chronological manner; guiding the team through the important considerations that must be considered. Regarding materials, emphasis was placed on the crushed muscle patch as the ideal option, in combination with various other packing adjuncts. Given the seriousness, ICA injury can induce panic and cause confusion within the operating theatre. A protocol could guide individual team members and promote a more coordinated effort in an otherwise potentially chaotic environment. Structured bleeding management protocols have been associated with improved patient outcomes [14]. The implementation of a bleeding management protocol in a cardiac surgery program was associated with significant reductions in the transfusion of allogeneic blood products, improved outcomes, and reduced cost [14]. Within the skull base literature, roughly 64% of centres have no formal ICA injury management protocol in place before first incidence of injury [3]. Standardized introduction of evidence-informed protocols at sites with high volume endoscopic endonasal surgery may provide teams with an improved capacity to manage this complication.

In high stress clinical scenarios, optimized team dynamics can be an important driver of success [12]. While a structured protocol may not change a clinical outcome, it provides a framework during a high-tension time period [8, 12]. The multi-disciplinary stakeholders included within this study were members who have direct involvement with rhinology and skull base patients. Hearing diverse perspectives from surgical, anesthesia, and nursing teams potentially reduces bias and provides a more holistic outlook. In addition, we discovered that navigating the hospital-to-hospital transfer process in order to obtain interventional neuroradiology services can be challenging in our local jurisdiction. Clarifying this becomes paramount when considering the high annual volume of endoscopic sinus surgery.

Managing challenging and time-sensitive complications in the operating theatre requires more than just a protocol for guidance. While a protocol may provide much needed support, it does not replace adequate training. Repeated exposure and practice in the form of surgical simulation can serve as an important education tool. In a recent survey of skull base surgeons who previously attended a course with vascular injury simulation, 20.6% of respondents reported an ICA injury in past 12 months [15]. While this relatively high rate may not represent the broader skull base community, it is insightful to appreciate that 50.9% of these injuries were associated with pituitary surgery with the parasellar carotid artery being the most commonly injured segment (39%) [15]. The same study found that when learning how to manage ICA injury, surgeons preferred live surgery, cadaver models, and animal models over computer-based simulation. Given that patient-related risk factors are the most common for ICA injury, practiced learning via the use of live models could serve as an important utility in training surgeons to manage these challenging situations [3]. Sheep models [16], three-dimensional printed synthetic models [17], and cadaver models have been described [18], with the latter having been associated with improved performance and reduced blood loss following repeat simulations.

There are several limitations to this study. Firstly, while the multi-disciplinary working group had a diverse range of expertise, we did not quantify the amount of experience each member has in managing this ICA injury intra-operatively. The systematic nature of our study protocol, focusing on literature review, was intended to tackle this potential lack of experience. Nonetheless, a larger expert panel with documented experience in managing ICA injury may have served to address this limitation. Further limitations included the size of our expert panel and that all members were from one institution. Given the relative rarity of ICA injury, establishing a larger working group from multiple centres would have increased the diversity of perspectives and may have ultimately improved the overall quality of the protocol. This point is underscored when reflecting on the expert-reliant nature of the study design. Lastly, it is important to highlight that the protocol developed in this study has not been validated. This study details the steps taken to design the protocol. Moving forward, incorporating this protocol in simulation-based workshops may help establish its external validity.