Can Keloids Be Present In Grafts?

Question : I am an RN. My husband is 70 with a history of CAD. In 2001, he had a heart attack caused by a lipid-rich cholesterol blockage in the right coronary artery. It was treated successfully with angioplasty and two stents were placed. In 2007, he survived a witnessed cardiac arrest. (He is the <1% that survives and can function independently.) Also by angioplasty, the same type of blockage was removed from the circumflex, a stent impregnated with heparin was placed, and the stents from the first event were replaced with the newer type stents. . . On Monday, he had an exploratory heart XXXXXXX He has some scarring around the stents in the RCA, but the circumflex has significant scar tissue creating a 90% blockage (with good flow downstream) and a lipid blockage in a branching artery below the circumflex (with good flow downstream). The cardiologist has referred my husband to a surgeon for possible CABG. . . I asked the cardiologist about my husband's history of keloid scarring. Not only does he have keloid scars on his abdomen from other surgeries, he tried to keloid his urethra closed (three times) after a radical prostatectomy in 2003. About eight weeks after the initial surgery, he experienced bladder spasms and an inability to empty his bladder. The urologist took him back to the OR and replaced the Foley for a week. Like I said, this happened three times - about every 8-10 weeks. The urologist even tried to open the urethra by cutting shallow enough as to not create any bleeding and it didn't work. Finally, the urologist told my husband that he could keep taking him back to the OR every eight weeks and charging his insurance $4,000 each time OR my husband could pass a XXXXXXX for six months. The urologist gave him Coude-tip rigid catheters and a schedule to follow that tapered off by the end of six months. It worked. . . When the cardiologist told me about the surgical consult on Monday, I told him that my husband keloids and asked about the possibility of keloids developing in the CABG graft(s). He said that is a valid question and a very real possibility, but he didn't think it is a concern. He stopped short and said it is a question that is better suited for the cardiac surgeon to answer. Every source I have looked at to answer this question only addresses the frequency and types of treatment for keloid formation on the skin, not the graft(s) itself. The cardiologist alluded to the idea that since vascular and cardiac tissue is different, he doesn't think it will be a problem. It would seem to me that if my husband has created enough scar tissue around a stent to cause a 90% blockage in only eight years, then it is likely that he is looking at keloid formation around the graft(s) within only a few months. When my husband experienced this problem with his urethra, he had very definite symptoms that there was a problem, especially the bladder spasms. Being s/p CABG, the only sign that there is a problem will be another heart attack. Am I missing something? Is there any way to prevent keloid formation in a CABG graft?