A port catheter system is a subcutaneously placed access to the usually central venous system, designed for long-term use. Through the port system, the administration of substances with higher osmolarity (cytostatics, nutritional solutions, blood components) can occur over a longer period. Other advantages include the completely subcutaneous position, which reduces the risk of infection compared to percutaneously inserted catheters, and the improved quality of life for patients regarding personal hygiene and physical activities.
The first port systems were described in 1982 [1, 2] and quickly gained increasing importance as permanent and safe central venous accesses, especially in oncological therapy, due to the very good clinical results.
The available access routes for catheter implantation include the V. cephalica, the V. jugularis externa et interna, the V. subclavia in the shoulder-thorax area, and the V. basilica [3]. The implantation method, access route, and implantation site have no impact on early and late complications, as shown by a randomized controlled trial from 2009 [4]. However, studies have shown that left-sided catheter positions and the position of the catheter tip in the upper part of the V. cava superior have a higher risk for thrombotic events [5, 6].
Intraoperative complications occur relatively rarely and are below 2% [7]. Most problems arise in the long-term course. In addition to patient-inherent risk factors, improper handling of port systems plays a significant role in infections. Port infections are among the most common complications and are thus also the most common cause for port explantation [8, 9]. The spectrum of germs is dominated by gram-positive skin pathogens such as S. epidermidis, S. aureus, and various streptococci. An increasing number of Candida-related infections have been reported [10, 11]. The colonization of S. epidermidis is said to be successfully eliminated by the intraluminal application of vancomycin according to a study by Gaillard et al. [12]. A reduction in catheter-related bacteremia in high-risk patients through a catheter block with vancomycin was described in a meta-analysis by Safdar et al. [13]. Bissling et al. demonstrated a significant reduction in catheter infections through catheter blockage with taurolidine [14].
The pharmacological prophylaxis of catheter-associated thrombosis is controversially discussed. The benefit of thrombosis prophylaxis was shown by Monreal et al. [15], while more recent randomized studies and a meta-analysis did not show a significant effect on the reduction of thromboembolic events by central venous catheter systems [16 - 19]. Accordingly, the regular flushing of the port system with heparin solution is controversial [20]. The regular flushing of the port system with heparinized NaCl solution is recommended according to various manufacturers' instructions, but there is no evident data proving a benefit compared to normal NaCl solution. Heparin-associated side effects in case of overdose (bleeding, heparin-induced thrombocytopenia) and the unclear legal situation regarding the intravenous administration of drugs by outpatient nursing services argue against a standardized flushing of the port system with heparinized NaCl solution. Corresponding references can be found in the guidelines of the German Society for Nutritional Medicine [21, 22].