RESUMO
BACKGROUND: Hypertonic saline (23.4%, HTS) bolus administration is common practice for refractory intracranial hypertension, but its effects on coagulation are unknown. We hypothesize that 23.4% HTS in whole blood results in progressive impairment of coagulation in vitro and in vivo in a murine model of traumatic brain injury (TBI). STUDY DESIGN: For the in vitro study, whole blood was collected from 10 healthy volunteers, and citrated native thrombelastography was performed with normal saline (0.9%, NS) and 23.4% HTS in serial dilutions (2.5%, 5%, and 10%). For the in vivo experiment, we assessed the effects of 23.4% HTS bolus vs NS on serial thrombelastography and tail-bleeding times in a TBI murine model (n = 10 rats with TBI and 10 controls). RESULTS: For the in vitro work, clinically relevant concentrations of HTS (2.5% dilution) shortened time to clot formation and increased clot strength (maximum amplitude) compared with control and NS. With higher HTS dosing (5% and 10% blood dilution), there was progressive prolongation of time to clot formation, decreased angle, and decreased maximum amplitude. In the in vivo study, there was no significant difference in thrombelastography measurements or tail-bleeding times after bolus administration of 23.4% HTS compared with NS at 2.5% blood volume. CONCLUSIONS: At clinically relevant dilutions of HTS, there is a paradoxical shortening of time to clot formation and increase in clot strength in vitro and no significant effects in a murine TBI model. However, with excess dilution, caution should be exercised when using serial HTS boluses in TBI patients at risk for trauma-induced coagulopathy.
Assuntos
Coagulação Sanguínea/efeitos dos fármacos , Hipertensão Intracraniana/sangue , Hipertensão Intracraniana/tratamento farmacológico , Solução Salina Hipertônica/farmacologia , Solução Salina Hipertônica/uso terapêutico , Animais , Lesões Encefálicas Traumáticas/complicações , Modelos Animais de Doenças , Feminino , Humanos , Hipertensão Intracraniana/etiologia , Masculino , Ratos Sprague-Dawley , Autorrelato , Tromboelastografia , Fatores de TempoRESUMO
The search for etiology of stroke in a young patient may present a diagnostic challenge. In rare cases, chronic trauma to the carotid artery may be the cause of cerebral thromboembolic events. The hyoid bone lies in close proximity to the carotid artery bifurcation, and anatomic variants have been implicated in carotid compression, stenosis, dissection, and pseudoaneurysm. We report a case of recurrent strokes in a 32-year-old woman due to an elongated hyoid bone causing thrombus formation in her right internal carotid artery (ICA), resulting in recurrent embolic strokes confirmed on diffusion-weighted magnetic resonance imaging. Computed tomography angiography of the neck and head demonstrated the right hyoid bone was located between the ICA and external carotid artery (ECA), just above the carotid bifurcation, with residual nonocclusive thrombus in the right ICA. Carotid duplex ultrasonography confirmed that with the neck in neutral position, the hyoid was located between the ICA and ECA; however, with neck rotation, the hyoid slipped across the ICA and out of the bifurcation. There was no evidence of carotid stenosis. After an initial course of anticoagulation and antiplatelet therapy, resection of the greater cornu of the hyoid bone with release of the right ICA was performed. One year postoperatively, the patient had complete return of neurologic function and had no further neurologic events. Hyoid bone entrapment of the carotid artery is a rare etiology of thromboembolic stroke caused by repetitive local trauma. The diagnosis can be confirmed by carotid duplex with provocative maneuvers. Partial hyoid resection is a safe and effective treatment to relieve recurrent symptoms. Hyoid bone entrapment may be an important and under-recognized cause of stroke in young adults.
Assuntos
Doenças das Artérias Carótidas/etiologia , Lesões das Artérias Carótidas , Osso Hioide/anormalidades , Embolia Intracraniana/etiologia , Acidente Vascular Cerebral/etiologia , Trombose/etiologia , Adulto , Doenças das Artérias Carótidas/diagnóstico por imagem , Doenças das Artérias Carótidas/fisiopatologia , Lesões das Artérias Carótidas/diagnóstico por imagem , Lesões das Artérias Carótidas/fisiopatologia , Angiografia Cerebral/métodos , Angiografia por Tomografia Computadorizada , Imagem de Difusão por Ressonância Magnética , Feminino , Movimentos da Cabeça , Humanos , Osso Hioide/diagnóstico por imagem , Osso Hioide/cirurgia , Embolia Intracraniana/diagnóstico por imagem , Osteotomia , Posicionamento do Paciente , Recidiva , Acidente Vascular Cerebral/diagnóstico por imagem , Trombose/diagnóstico por imagem , Trombose/fisiopatologia , Resultado do Tratamento , Ultrassonografia Doppler em CoresRESUMO
BACKGROUND: Iliofemoral vein thrombosis can lead to debilitating edema and venous claudication that significantly worsens quality of life, especially in young active individuals. Venous reconstruction becomes increasingly complex and has worsening patency with subsequent revisions so preoperative planning is critical to success. METHODS: We report a case of a 54-year-old man in active military service with profoundly symptomatic leg swelling after failure of 3 previous common femoral vein (CFV) reconstructions. The CFV and distal external iliac vein were thrombosed up to a few centimeters above the inguinal ligament. Direct proximal control would have required a retroperitoneal or transabdominal incision. However, a hybrid approach utilizing through-wire access, remote balloon control of the external iliac vein, cryopreserved vein graft, stent graft, and arteriovenous fistula was able to address the factors (graft size, external compression, adequate flow) contributing to his previous graft failures with a novel, less invasive approach. RESULTS: At 1-year follow-up, he was asymptomatic and the graft remained patent with normal vascular duplex studies. His leg swelling subsided and he was able to return to his previous physical activity level. CONCLUSIONS: A hybrid approach to complex venous reconstruction can provide a minimally invasive and durable alternative to more invasive procedures and alleviate mechanical causes of early graft failure.