Study Overview: This study is looking at how well a medicine called DEFENCATH® works to stop infections in people who need a special kind of nutrition called Total Parenteral Nutrition (TPN). TPN is given through a tube called a Central Venous Catheter (CVC) because some people can't eat food the normal way. The study will compare DEFENCATH® to another medicine called heparin.

Key Points:

• Participants need to visit multiple times and be able to follow study rules, like keeping a diary and using medicines correctly.
• Participants must be on TPN for at least 3 days a week, and the study will last over 6 months.
• Participants should not have certain health issues like skin infections at the catheter site or be taking certain medications.

Eligibility: Participants must be 18 years or older, living in the US or Türkiye, and need TPN for more than 6 months. They should not have had antibiotics recently or other medical conditions listed in the exclusion criteria, like unstable heart conditions or recent bone marrow transplants.