title: Tissue reaction induced by implanted venous access ports in adult patients after infection of the implantation site.
abstract: Implantable long-term central venous port systems (CVPS) are widely used as a permanent means of accessing the vascular system for intravenous delivery of drugs, parenteral nutrition, blood transfusion, and blood sampling. These systems allow easy and repetitive puncture without causing much damage to the vessels. However, the body foreign surface of CVPS induces an inflammatory response with varying intensity (depending on the implant materials) that leads to formation of a fibrous tissue capsule around the implant. This study was designed to investigate the influence of bacterial infection on the tissue reaction induced by implanted CVPS in adult patients. 20 patients (9 women, 11 men, 58 ± 14 yrs of age) were included in this study. These patients received explantation of a polysulfone based CVPS (ChemoSite™, Covidien, Mansfield, USA) due to port related infections (patients with bacterial infections at the implantation site: group A, 5 men, 1 women) or to other reasons such as termination of treatment, thrombosis, or CVPS dysfunction (patients without bacterial infections, group B, 6 men, 8 women) 299.9 ± 261.2 days after CVPS implantation. A sample of the encapsulating tissue covering the CVPS together with surrounding tissue (at least 1 × 1 cm2) was placed in a small container with fixing agent, a buffered neutral 4% formalin solution (pH 7). Histological sections of the samples were prepared for light microscopic analysis after paraffin embedding. Sections of 3 μm were cut and stained with haematoxylin and eosin, Weigert's elastic stain, and Heidenhain's azan stain. There was no difference in thickness, collagen and elastin content, or cell and capillary density of the fibrous capsule between both groups. Due to the wound healing reaction involving angiogenesis and fibroblast activation cell density and number of capillaries in the capsule tissue of all patients showed a positive correlation (r = 0.45, p < 0.05). However, the study demonstrated that at the end of the foreign body reaction the artificial tissue layer which covers the CVPS after implantation due to foreign body reaction shows only low reactivity towards infections.
authors.affiliation: Center for Medical Basic Research, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany.
authors.forename: B
authors.initials: B
authors.lastname: Hiebl
authors.affiliation: Faculty of Veterinary Medicine, Institute of Veterinary Anatomy, Freie Universität Berlin, Berlin, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Hopperdietzel
authors.affiliation: Faculty of Veterinary Medicine, Institute of Veterinary Anatomy, Freie Universität Berlin, Berlin, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Hünigen
authors.affiliation: Faculty of Veterinary Medicine, Institute of Veterinary Anatomy, Freie Universität Berlin, Berlin, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Dietze
authors.affiliation: Institute of Biomaterial Science and Berlin-Brandenburg Center for Regenerative Therapies, Helmholtz-Zentrum Geesthacht, Teltow, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Jung
authors.affiliation: Department of Radiology, Charité-University Medicine Berlin, Berlin, Germany.
authors.forename: S M
authors.initials: SM
authors.lastname: Niehues
mesh_terms: D000328:Adult; D000368:Aged; D001424:Bacterial Infections / Q000097:blood / Q000175:diagnosis; D001672:Biocompatible Materials / Q000737:chemistry*; D001794:Blood Pressure; D002196:Capillaries; D002405:Catheterization, Central Venous / Q000009:adverse effects*; D062905:Central Venous Catheters; D003094:Collagen / Q000737:chemistry; D004548:Elasticity; D004549:Elastin / Q000737:chemistry; D005260:Female; D005347:Fibroblasts / Q000378:metabolism; D005549:Foreign-Body Reaction; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D009389:Neovascularization, Pathologic; D011183:Postoperative Complications; D013530:Surgical Wound Infection / Q000473:pathology*; D014945:Wound Healing
chemical_list: D001672:Biocompatible Materials; D003094:Collagen; D004549:Elastin
keywords: Encapsulation; biomaterial; central venous access system; infection