What can be found inside shunt catheters

Obstruction of shunt catheters is one of the main causes of shunt malfunction. The fragments of shunts removed from five patients were examined using scanning electron microscopy with a (SEM) JEOL JSM-6390 LV microscope. Fifteen catheters from the brain ventricle, lumbar space, and peritoneal space were studied. SEM studies showed that the catheters' surfaces were not sufficiently smooth. The inner surface was often covered by a web of collagen fibrils. Aggregates of red and white blood cells, platelets, lymphocytes, mast cells, and macrophages were trapped in the collagen web. Such cellular aggregates formed a coherent, delicate web mainly consisting of ultrastructurally unchanged cellular elements and were well preserved. Other types of aggregates contained completely destroyed cells that appeared to be submerged in thick collagen web fibrils.We also found a few ultrastructural abnormalities among morphologically unchanged cellular elements. The presence of abnormal red cells showing unusual variability in their shape and size including spherocytosis (thickened, spheroid, and crenate red cells), elliptocytosis (elongated, rod-shaped, or tear-drop red cells), the thalassaemic phenotype of red cells (with inclusion of precipitated unstable hemoglobin in the form of Heinz bodies distorting the red cells, leading to their lysis) was a striking finding. Under scanning electron microscopy, we also recognized swollen or crumpled red cells that looked like potato crisps. Aggregation of thickened blood platelets and white cells was observed frequently. Our study confirmed the importance of the smoothness of the inner surface of the catheter. Smoothness can prevent the formation of cell and protein deposits.