Early host tissue response to different types of vascular prostheses coated with silver acetate or vaporized metallic silver.

OBJECTIVES: In vascular surgery, the infection of prosthetic vascular grafts represents a serious life-threatening complication. Due to the increasing resistance of hospital micro-organisms to standard antibiotic therapies, maximum effort should be put in the primary prevention of such infections. For this purpose, grafts may be coated with different antibacterial silver formulations. In the present study the different effects of silver acetate-coating and vaporized metallic silver-coating on the vascularization and perigraft inflammation during the initial phase after implantation of Intergard Silver (IS) and Silver Graft (SG) were compared. METHODS: Silver acetate-coated IS and vaporized metallic silver-coated SG were implanted into the dorsal skinfold chamber of C57BL/6 mice (n = 8 per group) to study angiogenesis and leukocyte inflammation at the implantation site by means of repetitive intravital fluorescence microscopy over a 14-day period. At the end of the in vivo experiments, apoptosis and cell proliferation in the newly developed granulation tissue surrounding the implants was analyzed by immunohistochemistry. RESULTS: IS exhibited an improved vascularization, resulting in a significantly higher functional capillary density when compared to SG. Moreover, the leukocyte inflammatory response to IS was less pronounced, as indicated by a reduced number of adherent leukocytes in perigraft venules. This was associated with a higher proliferative activity of the granulation tissue incorporating the IS when compared to SG. The numbers of apoptotic cells in the perigraft tissue were low and did not differ between the two groups. CONCLUSION: Silver acetate-coated IS exhibits an improved vascularization and reduced perigraft inflammation during the first 14 days after implantation when compared to vaporized metallic silver-coated SG. This may contribute to reducing the risk of early perigraft seroma formation and subsequent infection.

Graft-versus-host disease or toxic epidermal necrolysis: diagnostic dilemma after liver transplantation.

Graft-versus-host disease (GvHD) and toxic epidermal necrolysis (TEN) are rare and severe complications after liver transplantation. While mild acute GvHD is quite different from TEN and easy to distinguish, severe acute GvHD and TEN can be hard to differentiate because of similar clinical symptoms. We herein report a case with rapid progression of critical illness, after liver transplantation, caused by GvHD or TEN, although between those, diagnosis was not possible during the clinical course. Although, based on the timing/progression of the symptoms and the chimerism of >40%, the case seemed much more clinically consistent with GVHD, the combination of clinical symptoms together with skin rashes and the histologic appearance of skin lesions indicated diagnosis of a Stevens-Johnson syndrome/TEN overlap. The true diagnostic dilemma in such cases is discussed in detail, as these cases emphasize the need for more advanced diagnostic techniques.

Octreotide prophylaxis is not beneficial for biochemical activity and clinical severity of postoperative pancreatic fistula after pancreatic surgery.

BACKGROUND: Prospective randomized trials indicate that prophylactic octreotide treatment does not decrease the incidence of postoperative pancreatic fistula (POPF). The aim of this study was to analyze if octreotide prophylaxis could decrease the severity grade of POPFs after pancreatic surgery. METHOD: Seventy-eight of 684 patients undergoing pancreatic resection with POPF were included in the study. Prophylactic octreotide treatment was started immediately after surgery and was performed in 22 patients, whereas 56 patients had no octreotide treatment and served as controls. Lipase activity was measured in the abdominal drainage on postoperative days (POD) 3, 5 and 7. Primary endpoints of the study were clinical severity of the POPF and lipase activity in the drainage. RESULTS: There was no significant difference concerning length of postoperative hospital stay. Lipase activity in the abdominal drainage was not influenced by octreotide prophylaxis at POD 5 or 7 compared to POD 3. Multivariate analysis showed that the risk to develop a type B or C fistula in the octreotide group was independent of the kind of operation and the consistency of the pancreas (RR = 3.4; CI = 1.0-11.7; p = 0.050 and RR = 6.3; CI = 1.4-29.6; p = 0.019). CONCLUSION: Octreotide prophylaxis after pancreatic surgery has no beneficial effect on clinical severity of POPF.