Off-hours cases have longer gaps between imaging and procedures, and better understanding of these patterns could increase efficiency.
Most mechanical thrombectomies for large vessel occlusion strokes occur during off-hours, according to an analysis of 10 stroke centers located across the United States. Better understanding of the total call burden of mechanical thrombectomy would help centers manage stroke call coverage more efficiently and avoid off-hours delays, the study authors say.
Unlike MIs and smaller strokes, which most often occur in the early morning hours (probably due to factors related to circadian rhythms and hormonal variations), large vessel occlusion strokes have a less predictable pattern of occurrence. This can make timely availability of endovascular care a challenge, said Edgar A. Samaniego, MD (University of Iowa Hospital and Clinics, Iowa City, IA), commenting on the findings for Neurovascular Exchange via email.
For their study published online recently in the Journal of NeuroInterventional Surgery, Kyle M. Fargen, MD (Wake Forest University, Winston-Salem, NC) and colleagues conducted a multicenter retrospective study of all 189 patients who underwent emergent thrombectomy for acute ischemic stroke during a 3-month period from June through August 2016 at one of 10 institutions.
Each hospital conducted an average of 18.9 procedures during the study period, for an average of 0.2 cases per day or 75.6 cases per year. The highest-volume center treated 0.49 cases per day, and the lowest volume center treated 0.09 cases per day.
Procedures took place most commonly on weekdays (n = 148 vs 41) and during non-work hours (n = 119 vs 70, P < 0.001 for both). The most common period for thrombectomy procedures was between 8:00 PM and 9:00 PM.
Delays During Off-Hours
The median time from notification to groin puncture was 84 minutes, with an interquartile range (IQR) of 56-145 minutes. Median time from puncture to closure was 57 minutes (IQR 33-80 minutes). The median time from imaging completion to procedural start was 52 minutes longer during non-work hours than during work hours (P < 0.001). Procedure length did not differ based on day of the week or time of day.
Samaniego noted that a greater proportion of thrombectomies may have been performed off-hours because strokes that occur in the early morning (ie, “wake up” strokes) generally have an unknown time of onset, making them frequently ineligible for endovascular interventions. “This may change in the future with better imaging stratification and once the results of current trials are published,” he noted.
He added that it is difficult to draw solid conclusions from this study, because it remains unclear how the centers were chosen for inclusion. “A more detailed description of each participating center is necessary to interpret these result,” Samaniego explained. “For example, are these centers mostly rural or metropolitan centers? Do these centers have large telestroke programs? How are most of the transfers in these centers (ambulance or helicopter)?”
That said, the findings do have some clinical implications, he asserted. “This study underlines the [importance of] implementation of 24/7 stroke teams.”
That the median time from imaging to procedures was longer during non-work hours should “prompt better awareness of the stroke team about after-hours delays [such as] availability of imaging interpretation, availability of procedural nurses, [and] time of transfer from imaging to the angio suite,” Samaniego urged. “A detailed analysis of the delays would trigger better allocation of resources to improve door-to-needle time.”
According to the authors, theirs is the first study to quantify the frequency of mechanical thrombectomy cases by time of day. “Our findings indicate that the majority of cases occur off-hours, with important operational implications for hospitals implementing stroke call coverage,” they conclude. “Future prospective studies will evaluate the total call burden more completely, including the staff burden incurred by the high rate of cases evaluated that do not undergo treatment.”
Source:
Wilson TA, Leslie-Mazwi T, Hirsch JA, et al. A multicenter study evaluating the frequency and time requirement of mechanical thrombectomy. J NeuroInterv Surg. 2017;Epub ahead of print.
Disclosures:
Fargen and Samaniego report no relevant conflicts of interest.
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