Concentration changes of malondialdehyde across the cerebral vascular bed and shedding of L-selectin during carotid endarterectomy.

Departments of Anesthesiology and Vascular Surgery (H-H.E.), University of Heidelberg, Heidelberg, Germany.
Stroke (Impact Factor: 6.16). 03/1999; 30(2):306-11.
Source: PubMed

ABSTRACT Oxidative stress has been postulated to account for delayed neuronal death due to ischemia/reperfusion. We investigated cerebral formation of malondialdehyde as an index of lipid peroxidation in relation to different sources of reactive oxygen species in patients undergoing carotid endarterectomy.
In 25 patients undergoing carotid endarterectomy, jugular venous-arterial concentration differences of brain metabolites, malondialdehyde, plasma total antioxidant status, and soluble P-selectin and L-selectin were measured. A carotid artery shunt (n=5) was placed only after complete loss of somatosensory evoked potentials, indicating a focal cerebral blood flow <15 mL/min per 100 g.
As an indication of cerebral lipid peroxidation, jugular venous-arterial malondialdehyde concentration differences were significantly enhanced before reperfusion, and an additional rise was observed 15 minutes after reperfusion. Plasma total antioxidant status significantly decreased during carotid artery occlusion only in patients with carotid artery shunt. This decrease was matched by cerebral formation of adenosine, hypoxanthine, and nitrite/nitrate. While jugular venous-arterial concentration differences of soluble P-selectin showed changes similar to those of malondialdehyde, the concentration difference for soluble L-selectin was enhanced exclusively at 15 minutes after reperfusion.
Short-term incomplete cerebral ischemia/reperfusion significantly enhanced cerebral lipid peroxidation, as indicated by malondialdehyde formation. The generation of reactive oxygen species by xanthine oxidase or nitric oxide metabolism might be involved in the induction of lipid peroxidation. The additional rise in cerebral release of malondialdehyde was found to coincide with a significant activation of polymorphonuclear leukocytes across the cerebral circulation.

0 0
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: Lipid peroxidation processes (LPO) are evident in many organ failures. Due to their toxic properties, they are causative for cellular dysfunction at the site of their origin and far beyond. This study was conducted to investigate differences in LPO pattern of patients with established acute respiratory distress syndrome (ARDS) and patients with end-stage liver failure undergoing liver transplantation (LTX) as two mayor prototypes of organ failure. In this prospective, nonrandomized, controlled trial, we examined LPO by measuring malondialdehyde (MDA), and the volatile aldehydes hexanal and propanal as LPO-markers. Eighteen patients with ARDS, 16 subjects undergoing liver transplantation due to liver failure, and 8 healthy controls were included to the study. ARDS patients showed significantly higher levels in MDA concentrations than LTX and controls, respectively. However, MDA levels of patients with end-stage liver failure were equal to those of controls. Blood concentrations of hexanal and propanal, specific by-products of lipid peroxidation, were elevated in both patient groups, but significantly higher only in LTX. Unexpectedly, hexanal and propanal concentrations were significantly higher in LTX than in ARDS patients. In both patient groups, MDA showed no differences between arterial and mixed venous blood, whereas volatile aldehydes were higher in arterial than in mixed venous compartment. Both ARDS and LTX-patients showed significant evidence of enhanced LPO. However, proportions of MDA and volatile aldehydes differed substantially between the groups. Thus, for the interpretation of LPO markers, disease-specific factors have to be taken into account. Distinctions might be attributable to differences in the effected lipid components or variations in metabolism.
    Journal of Surgical Research 06/2011; 168(2):243-52. · 2.02 Impact Factor
  • [show abstract] [hide abstract]
    ABSTRACT: Routine shunting to minimize ischemia during carotid endarterectomy (CEA) is controversial. The aim of this study was to stratify the ischemic parameters associated with CEA and evaluate the effect of routine shunting in attempting to mitigate those ischemia. Data from 248 CEAs with routine shunting were retrospectively evaluated. Our assessment included somatosensory evoked potential (SSEP) amplitude reduction more than 50 % and longer than 5 min (SSEP<50%, >5 min), new postoperative diffusion-weighted imaging lesions (new DWI lesions), and severe stenosis as indicated by reduced ipsilateral middle cerebral artery (MCA) signal on preoperative magnetic resonance angiography (MRA asymmetry), as surrogates of hypoperfusion, microembli, and hemodynamic impairment, respectively. SSEP<50%, >5 min occurred in 15 % of CEAs during cross-clamping, and shunting reversed the SSEP changes. New DWI lesions were observed in 4.1 %. Pre-clamping the common and external carotid artery during dissection (pre-clamp method) decreased the rate of new DWI lesions compared to without pre-clamping (3.5 % vs. 7.5 %, P = 0.22). Occlusion time was significantly longer in the pre-clamp method than without pre-clamping (P < 0.0001). However, the incidence of SSEP<50%, >5 min was not increased with the pre-clamp method (p = 1.0) when using information regarding SSEP and collaterals to modify the speed of shunt manipulation. MRA asymmetry was identified in 39 CEAs (15.8 %) with correction of asymmetry postoperatively. MRA asymmetry correlated with symptomatic hyperperfusion (P = 0.0034). Only three CEAs had symptomatic hyperperfusion (1.2 %) with minimal symptoms. Ten CEAs sustained transient ischemia, symptomatic hyperperfusion, or 30-day-stroke (composite postoperative ischemic symptoms). Logistic regression analysis confirmed that SSEP<50%, >5 min (p = 0.009), new DWI lesions (p = 0.004) and MRA asymmetry (p = 0.042) were independent predictors of composite postoperative ischemic symptoms. SSEP<50%, >5 min, new DWI lesions, and MRA asymmetry were able to stratify the ischemic impacts in CEA. Meticulous routine shunting could mitigate those appropriately.
    Acta Neurochirurgica 08/2013; · 1.55 Impact Factor
  • Source

Full-text (2 Sources)

Available from
Feb 22, 2014