Follow-Up After Shunt

Abstract

Adequate postoperative follow-up in shunted patients suffering from normal pressure hydrocephalus (NPH) is an essential part of NPH treatment, considering both technical and clinical factors that are involved in patients’ performance after surgery. Routine follow-up controls are necessary to detect shunt malfunctions and to correct those in time. In patients where the outcome after shunt implantation is not optimal, readjustments of the valve are necessary in order to provide better treatment outcome (“titration of symptoms”). In cases where the clinical improvement after shunting is only partial, it is very challenging to clearly differentiate between non-optimal valve settings and a lack of recovery potential. Non-invasive tap tests through the flushing reservoir can give further information in this situation, can also help to detect shunt malfunctions, and can some extent replace most of the invasive shunt tests. However, it is necessary to be well-informed about the implanted device for adequate execution and interpretation of the non-invasive tests. Although known that non-invasive shunt tests are of great importance with respect to aimed reduction of complication rates, invasive tests remain the gold standard for accurate diagnostics and therefore are a necessary part of shunt complication management. These tests enable direct intracranial pressure monitoring, biochemical analysis of the cerebrospinal fluid, and the detection of shunt malfunction. Indication of shunt revision is dependent on various criteria that are discussed together with both technical and clinical nuances in more detail in this chapter.