 Subjects have the right to withdraw from the study at any time for any reason. The investigator also has the right to withdraw subjects from the study in the event of intercurrent illness, adverse events, treatment failure after a prescribed procedure, protocols violation, cure, administrative reasons or other reasons. It is understood by all concerned that an excessive rate of withdrawal can render the study uninterpretable: therefore, unnecessary, withdrawal of subjects should be avoided. Should subjects decide to withdraw, all efforts will be made to complete and report the observation as thoroughly as possible. A complete final evaluation at the time of the patients withdrawal should be made with an explanation of why the subjects was withdrawn from the study. 