Groshong catheters: technical aspects and clinical features

After thousands of Groshong catheter applications over more than twenty years, the cause of blood withdrawal drawbacks is not yet completely understood. This phenomenon - which is not typical of closed-tip catheters since it is also common in open-tip catheters - in the Groshong catheter is attributed to the valve (ball-valve effect). The aim of this work is to understand the relationship between causes and effects in order to provide clinicians with practical solutions. Out of the 16 catheters examined, we observed no clear correlation among electron microscope ultrastructural analysis, valve closing pressure, intraluminal clots and clinical failures after different implantation times up to a maximum of 36 months. The ultrastructural analysis revealed an optimal no-time-related aspect for internal and external surfaces, while the closing pressure in each case was compatible with the efficiency of the working valve (range 22-36 cmH 2 O). We conclude that the blood withdrawal drawbacks cannot be attributed to a single cause and certainly not to the silicone biostability or directly to the valve. Different studies are suggesting that clinical failures can be the re-sult of several different causes such as slime or clots in the internal catheter surfaces and fibrin sleeve in the external catheter surfaces. These are common causes in open-tip catheters and we believe that the presence of valves on the tip of the Groshong may encourage inferences. Our suggestion is to place the tip of the Groshong catheter in atrium one centimetre after the junction with the vena cava. After the implant, it is possible to remove the causes of drawbacks by strong flushing using a 5-ml syringe and/or postural manoeuvres.