Conflict of interest

decanulation of the patient [27]. Since 1973, different types of hemofilters have been developed in order to remove priming volume (water) following the principle of pressure gradient, particularly those made of polycarbonate. These filters have been replaced by the ones made out of poliariletersulfonate in 1986, and later by the current generation of polyamide hemofilters. These are the most practical ones because of its greater biocompatibility, reduced surface, and more ultrafiltration

The effectiveness of ultrafiltration for removing pro-inflammatory agents depends also on the type of hemofilter and on the modality of ultrafiltration procedure used. Berdat et al. studied the effectiveness of poliariletersulfonate filters versus polyamide ones in the two ultrafiltration modalities for the removal of pro-inflammatory agents such as IL-6, IL-10, and TNFα [10]. They prove that IL-6 was better removed by conventional ultrafiltration (CUF) with poliariletersulfonate filter, while TNFα was better removed by modified ultrafiltration (MUF) and poliariletersulfonate filter. The rest of the pro-inflammatory agents were not modified neither for the ultrafiltration modality nor for the hemofilter type. Therefore, it seems that MUF with poliariletersulfonate hemofilter is the better strategy for removing pro-inflammatory agents in pediatric patients with congenital heart surgery. Our results are based on the ultrafiltration modality

rather than the type of filter, since the material of hemofilters that we used was variable.

other inflammatory agents, or to the isolated reduction of tissue edema [29–33].

It has been reported that MUF is not only useful for removing extracellular fluid excess but also cytokines and other inflammatory agents triggered by CPB and surgical trauma. There is some controversy in the study regarding the efficacy of filters in the removal of cytokines, as well as in the differences between the two ultrafiltration modalities [28]. In addition, the comparative results between both ultrafiltration modalities are difficult to interpret due to variations in the ultrafiltration technique, equipment, definitions and objectives, and measurements of cytokines. Finally, it is still not known if the clinical benefits of MUF are due to the removal of cytokines and

Based on the results of this study [34], we can say that although the baseline concentrations of IL-6 in the patients of the problem group were higher in relation to those of the control group, the removal of this pro-inflammatory agent by MUF was statistically significant. This indicates that MUF is a procedure that can benefit pediatric patients with congenital heart disease undergoing CPB because it is able to decrease the concentration of IL-6. Therefore, we consider that the use of MUF in pediatric patients should be routinely recommended as long as hemo-

We thank the Cardio Slim Foundation for the financial support provided to carry out this

effectiveness due to a less than physiological pressure.

178 Advances in Extra-corporeal Perfusion Therapies

5. Conclusion

dynamic conditions allow it.

Acknowledgements

study.

The authors declare no potential conflicts of interest with respect to the research, authorship, or publication of this manuscript.
