Wide Variability in Prethrombectomy Workflow Practices in the United States: A Multicenter Survey

Discussion

With the goal of maximizing the clinical outcome benefit of mechanical thrombectomy, several groups have described efficient workflows or suggested improvements to facilitate timely thrombectomy in patients with LVO.^{7,16,18⇓⇓⇓⇓⇓–24} These case studies can serve as important prototypes for other hospitals attempting to redesign their own prethrombectomy workflows. However, these prototypes are likely to be heavily influenced by institution-specific factors. As such, hospitals looking to these examples for guidance may not become aware of workflow variations in effect at other experienced centers. By reviewing in aggregate the workflows at many centers rather than just a single facility, our findings offer a more institution-agnostic view of real-world prethrombectomy workflows. Moreover, the considerable heterogeneity we identified in these workflows suggest areas where consensus on universal best practices is not established or does not exist, while also suggesting opportunities for workflow customization tailored to conditions at individual hospitals.

Mirroring the practices in recent positive thrombectomy trials,^{1⇓⇓⇓–5} we found nearly universal use of noninvasive angiography to identify LVO before attempted thrombectomy. However, we also found that nearly two-thirds of institutions routinely used perfusion imaging for patient selection despite the fact that perfusion imaging was not consistently used in the initial trials demonstrating the effectiveness of thrombectomy.^2⇓⇓–5 Overall, only a small minority of institutions made routine use of MR imaging for patient selection, presumably reflecting resource constraints and the greater time typically required for MR imaging.

One common workflow solution was to have an acute response team of nonphysicians able to respond immediately to cases of suspected LVO alongside neurology and emergency department physicians. These teams are fluent in prethrombectomy workflows and can facilitate timely management in the acute care setting. Several respondents expressed frustration at a perceived lack of awareness among nonspecialists of the need for rapid evaluation in patients with LVO and noted that acute response teams can bridge this awareness gap until emergency department teams gain familiarity with modern reperfusion strategies in LVO.

At most institutions, initial contact occurs with a single NI physician who is responsible in turn for notifying the remainder of the NI team. Some hospitals facilitate this notification process by designating specific personnel to identify and contact the full NI team, freeing the physician to focus on medical decision-making. A large majority of facilities initiate NI consultation on clinical grounds even before the acquisition of neuroimaging necessary for patient selection. This approach²⁵ may confer some time benefit, but comes at the cost of more frequent consultation for patients who later prove to have imaging contraindications to thrombectomy (eg, intracranial hemorrhage, absence of LVO, or a large burden of completed infarction). However, we note that though initial NI consultation precedes neuroimaging at most institutions, it is far less common to activate the full NI team before completing the clinical and imaging evaluation necessary to fully assess the appropriateness of thrombectomy. Once the NI team is activated, most hospitals set a mandatory response time for NI team members.

Transport of patients to the neuroangiography suite is most commonly handled by members of the emergency department team. Furthermore, at many facilities, patients can be transported to the neuroangiography suite by the emergency department team before the arrival of the NI team. Even if the NI team is in house, active ownership of the patient transport process by the emergency department team may allow the NI team to work in parallel to set up the neuroangiography suite. Thus, regardless of NI team location, an emergency department–led transport process may help to minimize the actual time penalty associated with team travel and room setup.

Most commonly, a procedural tray is set up by the NI team upon arrival, as opposed to a “dry tray” set up in advance by the NI team or a conventional tray set up by an in-house designee while the NI team travels to the hospital. Each of these approaches has its virtues; setting up the tray in advance of team arrival likely confers a small time benefit, but sacrifices a clear chain of custody for sterile supplies. Regardless of the approach, most NI teams save time by initially opening a basic diagnostic angiography tray, thereby allowing the NI physician to establish arterial access and perform initial angiographic runs while other NI team members work in parallel to retrieve additional thrombectomy supplies. Curiously, many centers have not centralized the location of these supplies within the neuroangiography suite—for example, on a supply cart or cabinet dedicated to stroke interventions—which is a simple and straightforward means to facilitate the retrieval of thrombectomy devices and reduce the cognitive burden on NI team members.

The preferred type of anesthesia during thrombectomy procedures is most commonly conscious sedation, possibly reflecting a desire to avoid the time delay of intubation or concern about early data suggesting worsened postthrombectomy outcomes with general anesthesia.^26⇓–28 Regardless of the type of anesthesia used, members of the anesthesiology service routinely assist thrombectomy at two-thirds of the surveyed institutions. Although our and other investigators' experience is that door-to-puncture times are shortest when the number of teams engaged in the prethrombectomy workflow is minimized,^16,22 these data suggest that many NI physicians value having more experienced personnel provide sedation and/or anesthesia, thereby allowing NI physicians to concentrate on the technical aspects of the procedure.

There are 3 principal limitations of this work. First, although we have captured details about the degree of workflow variation between hospitals, we cannot evaluate the validity of these workflow variations without knowledge of door-to-puncture times and clinical outcomes, which many hospitals are unwilling or unable to disclose. Thus, although our data may suggest general agreement on highly consistent workflow steps, we cannot define best practices on the basis of patient impact. Second, although the sample size of 30 institutions is sufficient to extract qualitative insights into practice patterns and the general scale of workflow variation, it is not sufficiently large to permit accurate quantitative assessment. Third, all surveyed institutions are experienced stroke centers, which likely skews demographics toward large, academic institutions that may have different infrastructure and resources than smaller, nonacademic centers.

Our results suggest an opportunity for future work to detail the impact of specific workflow variations on clinical outcomes across multiple institutions. However, it is important to note that not all workflow variations will meaningfully impact time to treatment, though all are likely to impact workflow complexity. The benefits of reduced workflow complexity can be difficult to capture in patient-centered clinical outcome data, but may include increased speed, greater capacity to multitask, fewer errors, and decreased cognitive stress, all of which are likely to be important during critical and time-sensitive procedures.