Ryan P. Morton, Brian W. Hanak, Michael R. Levitt, Kathleen R. Fink, Eric C. Peterson, Marcelo D. Vilela, Louis J. Kim and Randall M. Chesnut
The stroke rate, management, and outcome after blunt cerebrovascular occlusion (Biffl Grade IV injury) is not well defined, given the rarity of the disease. Both hemodynamic failure and embolic mechanisms have been implicated in the pathophysiology of subsequent stroke after blunt cerebrovascular occlusion. In this study, the authors evaluated their center's experience with Biffl Grade IV injuries, focusing on elucidating the mechanisms of stroke and their optimal management.
A retrospective review identified all internal carotid artery (ICA) or vertebral artery (VA) Biffl Grade IV injuries over a 7-year period at a single institution.
Fifty-nine Biffl Grade IV injuries were diagnosed affecting 11 ICAs, 44 unilateral VAs, and 2 bilateral VAs. The stroke rates were 64%, 9%, and 50%, respectively. Of the 11 Biffl Grade IV ICA injuries, 5 presented with stroke while 2 developed delayed stroke. An ipsilateral posterior communicating artery greater than 1 mm on CT angiography was protective against stroke due to hemodynamic failure (p = 0.015). All patients with Biffl Grade IV injuries affecting the ICA who had at least 8 emboli per hour on transcranial Doppler (TCD) ultrasonography developed an embolic pattern of stroke (p = 0.006). Treatment with aspirin versus dual antiplatelet therapy had a similar effect on stroke rate in the ICA group (p = 0.5) and all patients who suffered stroke either died (n = 3) or required a decompressive hemicraniectomy with subsequent poor outcome (n = 4). All 10 strokes associated with Biffl Grade IV VA injuries were embolic and clinically asymptomatic. In VA Biffl Grade IV injury, neither the presence of emboli nor treatment with antiplatelet agents affected stroke rates.
At the authors' institution, traumatic ICA occlusion is rare but associated with a high stroke rate. Robust collateral circulation may mitigate its severity. Embolic monitoring with TCD ultrasonography and prophylactic antiplatelet therapy should be used in all ICA Biffl Grade IV injuries. Unilateral VA Biffl Grade IV injury is the most common type of traumatic occlusion and is associated with significantly less morbidity. Embolic monitoring using TCD and prophylactic antiplatelet therapy do not appear to be beneficial in patients with traumatic VA occlusion.
Ryan P. Morton, I. Josh Abecassis, Josiah F. Hanson, Jason Barber, John D. Nerva, Samuel N. Emerson, Chibawanye I. Ene, Michelle M. Chowdhary, Michael R. Levitt, Andrew L. Ko, Timothy H. Dellit and Randall M. Chesnut
The authors' aim was to report the largest study on predictors of infection after cranioplasty and to assess the predictive value of intraoperative bone flap cultures before cryopreservation.
They retrospectively examined all cranioplasties performed between March 2004 and November 2014. Throughout this study period, the standard protocol during initial craniectomy was to obtain a culture swab of the extracted autologous bone flap (ABF)—prior to its placement in cytostorage—to screen for microbial contamination. Two consecutive protocols were employed for the use and interpretation of the intraoperative swab culture results: A) From March 2004 through June 2013, any culture-positive ABF (+ABF) was discarded and a custom synthetic prosthesis was implanted at the time of cranioplasty. B) From July 2013 through November 2014, any ABF with a skin flora organism was not discarded. Instead, cryopreservation was maintained and the +ABF was reimplanted after a 10-minute soak in bacitracin irrigation as well as a 3-minute soak in betadine.
Over the 10.75-year period, 754 cranioplasty procedures were performed. The median time from craniectomy to cranioplasty was 123 days. Median follow-up after cranioplasty was 237 days for protocol A and 225 days for protocol B. The overall infection rate after cranioplasty was 6.6% (50 cases) occurring at a median postoperative Day 31. Staphylococcus spp. were involved as the causative organisms in 60% of cases.
Culture swabs taken at the time of initial craniectomy were available for 640 ABFs as 114 ABFs were not salvageable. One hundred twenty-six (20%) were culture positive. Eighty-nine +ABFs occurred during protocol A and were discarded in favor of a synthetic prosthesis at the time of cranioplasty, whereas 37 +ABFs occurred under protocol B and were reimplanted at the time of cranioplasty.
Cranioplasty material did not affect the postcranioplasty infection rate. There was no significant difference in the infection rate among sterile ABFs (7%), +ABFs (8%), and synthetic prostheses (5.5%; p = 0.425). All 3 +ABF infections under protocol B were caused by organisms that differed from those in the original intraoperative bone culture from the initial craniectomy. A cranioplasty procedure ≤ 14 days after initial craniectomy was the only significant predictor of postcranioplasty infection (p = 0.007, HR 3.62).
Cranioplasty procedures should be performed at least 14 days after initial craniectomy to minimize infection risk. Obtaining intraoperative bone cultures at the time of craniectomy in the absence of clinical infection should be discontinued as the culture results were not a useful predictor of postcranioplasty infection and led to the unnecessary use of synthetic prostheses and increased health care costs.