Contrast media induces hypoperfusion in kidneys with ureteral stone: Doppler US study

Ünal, Birsen; Kara, Simay; Bilgili, Yasemin Karadeniz

doi:10.1016/j.ultrasmedbio.2004.09.013

Cited by 2 publications

(1 citation statement)

References 25 publications

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“…The 2-MHz ultrasound parameters used were a peak free-field rarefactional acoustic pressure amplitude (P R ) of 0.47 MPa, a pulse repetition frequency (PRF) of 10.5 kHz and a duty cycle of 13%. Others have measured an increase in thrombolysis with increasing duty cycle, so the apparatus settings that produce the largest duty cycle of 13% were employed to maximize thrombolytic effects [16, 39-41]. Pressure attenuation of 2-MHz pulsed US through the micropipette wall is 41±5%.…”

Section: Methodsmentioning

confidence: 99%

Combination Treatment with rt-PA is More Effective than rt-PA Alone in an in Vitro Human Clot Model

Meunier

Holland²,

Porter³

et al. 2011

CNR

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Incidence of intra-cranial hemorrhage linked to treatment of ischemic stroke with recombinant tissue plasminogen activator (rt-PA) has led to interest in adjuvant therapies such as ultrasound (US) or plasminogen, to enhance rt-PA efficacy and improve patient safety. High-frequency US (~MHz) such as 2-MHz transcranial Doppler (TCD) has demonstrated increased recanalization in situ. Low-frequency US (~kHz) enhanced thrombolysis (UET) has demonstrated higher lytic capabilities but has been associated with incidence of intracerebral hemorrhage in some clinical trials. In vitro studies using plasminogen have shown enhancement of lysis. This study compared rt-PA-induced lysis using adjuvant therapies, with 120-kHz or 2-MHz pulsed US, or plasminogen, in an in vitro human whole blood clot model. Blood was drawn from 30 subjects after local institutional approval. Clots were exposed to rt-PA at concentrations of 0 to 3.15 μg/ml. Clots were exposed to rt-PA alone (rt-PA) or in combination with plasminogen (Plg), 120-kHz US (120-kHz), or 2-MHz US (2-MHz). Thrombolytic efficacy was determined by assessing the percent fractional clot loss (FCL) at 30 minutes using microscopic imaging. There was no enhancement of lysis for combination therapy with [rt-PA]=0 μg/ml. Adding rt-PA increased lysis for all groups. As [rt-PA] increased, lysis tended to increase for 120-kHz and Plg (FCL: from 50% to 70%, 120-kHz; 65% to 83%, Plg) but not for 2-MHz (58% to 52%). Lytic efficacy in combination therapy depends on rt-PA concentration and the adjuvant therapy type. For non-zero rt-PA concentrations, all combination therapies produced more lysis than rt-PA alone.

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Section: Methodsmentioning

confidence: 99%