Objective: We developed a non-invasive scintigraphic procedure to control the function of percutaneous catheter-port systems for continuous insulin therapy. The aim of the study was to evaluate the scintigraphic results and to compare the absorption kinetics of intraperitoneal and umbilical catheter-ports.
Material and methods: Seven patients with intraperitoneal and nine patients with umbilical catheter-port systems implanted into the partially redilated umbilical vein were investigated. All these patients had normal functioning catheter-ports. Additionally, three patients with intraperitoneal and three patients with umbilical catheter-port dysfunction confirmed either by radiography or laparoscopy were studied. After the injection of (99 m)TcO (4)(-) into the port a region-of-interest was drawn around the activity at the tip of the catheter and the half-life of tracer absorption (T(1/2)) calculated.
Results: The normal intraperitoneal catheter-port group showed a T(1/2) value of 6.7 +/- 3.2 min and the normal umbilical catheter-port group a T(1/2) of 6.6 +/- 2.0 min. There was no significant difference in T(1/2) between intraperitoneal and umbilicial systems. The dysfunctional catheter-port group (T(1/2) 19.3 +/- 6.7 min) differed ( p = 0.0005) from the normal catheter-port group (T(1/2) 6.7 +/- 3.2 min). On the basis of the normal group an upper threshold value of T(1/2) was calculated to be 11.8 min.
Conclusions: Imaging with (99 m)TcO (4)(-) is an accurate, non-invasive, and quick method to assess the function of insulin catheter-ports. A T(1/2) value > 11.8 min is indicative of a catheter dysfunction. Umbilical and intraperitoneal catheter-ports show similar absorption rates of (99 m)TcO (4)(-).