In all, neither of the two models outperformed the other and both were insufficient to properly characterize the relationship between drainage and opening pressures of valves in series. These results indicate low flowrate variability of isolated valves but high variability of valves placed in series. Without a consistent model from which opening pressure setting of valves in series can be determined, physicians must rely on a trial-and-error method in optimal opening pressure determination which directly impacts patient outcomes. These findings underscore the difficulties faced by physicians in determination of optimal valve settings for shunted patients.
Williams et al. (Thu,) studied this question.