Alternative forms of instrument actuation, camera control and master console ergonomics should be explored to improve instrument precision, sphere of action, size and minimize assistance required.

A series of in vitro studies were designed to determine whether di-(2-ethyl-hexyl)-phthalate (DEHP)-plasticized polyvinyl chloride (PVC) and DEHP itself initiated an inflammatory response in both human and rat blood. Additionally, the effect of methanol washing of the PVC on the inflammatory response was studied in both blood types. Blood from both species was exposed to first, no material; second, ground DEHP-plasticized PVC; third, methanol-washed ground DEHP-plasticized PVC; and fourth, known concentrations of DEHP. The expression of the integrin CD11b was employed as a marker of the inflammatory response. After 20 minutes' exposure to PVC, CD11b expression increased to 210 +/- 32% of baseline in human blood and to 238 +/- 21.7% in rodent blood. Both blood types showed an increase in CD11b expression with increasing concentrations of DEHP (214 +/- 40.8% of baseline levels in human blood and 237 +/- 14.5% in rodent blood at the highest concentration). Methanol washing resulted in a significant moderation in CD11b upregulation in both blood types; 117 +/- 27% of baseline in human and 150 +/- 14.7% in rodent. These results support the hypothesis that DEHP-plasticized PVC and DEHP itself are proinflammatory in blood from both species, and suggest that the rodent is an appropriate model for studies of this nature.

Cardiopulmonary bypass (CPB) has improved a great deal since its first applications in the early 1950s. If improvements are to be continued, a preclinical model of CPB for small animals is desirable, mainly because of convenience of equipment and low costs. We review the different models of CPB for rats that have been designed, discuss their characteristics and points where improvements may be made. We give suggestions and requirements for a new up-to-date model that could be a useful tool in continued research on the pathophysiology and therapeutic strategies of CPB.

The Pall LG6 arterial line filter has been designed to remove free circulating leukocytes from the arterial line of the extracorporeal circuit employed in openheart surgery. The filter was evaluated and compared to a control filter (Pall Stat-Prime) in terms of its general blood handling characteristics, particularly with regard to the associated level of leukocyte removal. The gross air handling characteristics of the filters were also assessed together with pressure drop. It was found that the filters differed little in terms of all factors studied other than the level of leukocyte depletion. The LG6 filter was associated with substantial levels of leukocyte depletion, particularly the depletion of neutrophils. Over the 90 minute perfusion period the LG6 filter was found to be associated with a neutrophil depletion rate of around 70% while preferentially sparing lymphocytes. This compared to a 10-20% depletion rate in the control filter. This was achieved without apparently compromising the performance of the filter in terms of the other factors studied.

Cardiopulmonary bypass (CPB) is associated with the production of inflammatory responses, which can have significant influence on prognosis. We studied the effects of leucocyte-depletion filters on inflammatory parameters and early postoperative prognosis during coronary revascularization. Twenty patients undergoing elective coronary revascularization were randomly divided into two groups. Ten patients had leucocyte-depletion filters added to the CPB circuit (treatment group) and 10 were used as control cases (control group). Expression of CD11b on neutrophils, and production of myeloperoxidase and lactoferrin, were measured in arterial samples between induction and 3 h postbypass. In addition, clinical parameters were measured during inpatient recovery. CD11b neutrophil expression, and myeloperoxidase and lactoferrin production, were found to be upregulated during CPB and then to decline to preoperative levels by the third postoperative hour. Blood transfusion requirements were reduced in the treatment group, equalling 1.5 +/- 1.2 units, compared to 2.7 +/- 1.1 units for the control group (p value = 0.034) and so were the volumes of crystalloid infused during the first 24 h postoperatively, equalling 3.9 +/- 1.21 in the treatment group and 3.3 +/- 0.71 in the control group (p value = 0.021). Overall, the application of leucocyte depletion produced an early clinical advantage, underlining the need for an improved understanding and manipulation of the inflammatory response to CPB.

The authors' experiments have demonstrated a significant risk of systemic fat mobilization and fat embolism after liposuction in the animal model. Further clinical investigation is required to evaluate the real clinical risk of this procedure from this perspective.

Cerebral injury is a well-known complication of cardiac surgery. Investigations of both injury mechanisms and neuroprotective strategies have partially been limited by the lack of an adequate preclinical model of small animal cardiopulmonary bypass (CPB). We sought to determine if neurological injury could be demonstrated in a recovery model of complete CPB in the rat. Rats (n = 5) underwent 45 min of normothermic CPB followed by 24 h of recovery. Compared to sham-operated rats (n = 5), the CPB group showed a worse neurological outcome score (median, 25-75th percentile) compared to controls (5, 4-7 vs 9, 8-9, p = 0.016). This rat model of CPB may allow for the study of CPB-associated neurological injury.

The aim of the study was to assess the effect of exposed surface area of diethylhexylphthalate plasticized polyvinylchloride (PVC) on the expression of the adhesion molecule CD11b(mac-1) on neutrophils and to determine whether there is any apparent advantage in the current trend in reducing circuit surface area in terms of neutrophil activation. The study was carried out using a parallel plate rodent recirculation biomaterial testing model on 4 groups of 10 adult male Sprague Dawley rats weighing between 350 and 450 g. One group comprised the control group in which there was no biomaterial exposure. In the remaining 3 groups, the animals were subjected to either high (48 cm2), intermediate (24 cm2), or low (12 cm2) biomaterial surface area exposure. The parallel plate test cell was connected to the right femoral circulation and recirculation initiated at a flow rate of 1.5 ml/min for a period of 60 min. Blood samples were taken at 0, 30, and 60 min for the assessment of CD11b expression. Cd11b was assessed using flow cytometric analysis on neutrophils. The results demonstrated that there was a surface area related effect in the upregulation of CD11b. The difference at the terminal sample point between the highest surface area group (293.95 +/- 18.57%) and the low surface area group (133.80 +/- 49.31%) was highly statistically significant (p < 0.001). These results demonstrate that there may be some gain in terms of reduced inflammatory response from reducing the exposed surface area of PVC in extracorporeal perfusion circuits.