Bandyk D F, Kinney E V, Riefsnyder T I, Kelly H, Towne J B
Department of Surgery, University of South Florida College of Medicine, Tampa.
J Vasc Surg. 1993 Sep;18(3):398-405; discussion 405-6.
Complications of grafts infected with coagulase-negative staphylococci can be eradicated by antibiotic administration, tissue debridement, and in situ graft replacement, but successful treatment may be diminished in a setting of altered immune function.
In a canine model of an established aortic graft infection from Staphylococcus epidermidis, outcomes after in situ replacement were compared between normal dogs and animals made immune-deficient by administration of azathioprine (50 mg/day) and prednisone (10 mg/day). In situ replacement of an infected infrarenal aortic graft with either antibiotic-bonded (silver-ciprofloxacin: Ag-cipro) or conventional polytetrafluoroethylene (PTFE) grafts was performed in 17 control and 18 immune-deficient animals.
Four weeks after implantation of a Dacron graft colonized with a biofilm of S. epidermidis, all study animals demonstrated a bacterial biofilm infection with perigraft inflammation or abscess, and in immune-suppressed dogs the incidence of perianastomotic aortitis was increased (p < 0.05). Six weeks after in situ replacement both the Ag-cipro and conventional PTFE grafts were healed without signs of infection in controls, but anatomic evidence of persistent infection and increased S. epidermidis recovery was observed in immune-suppressed animals that underwent in situ replacement of a standard (five of seven) versus antibiotic-bonded (one of 11) PTFE graft (p < 0.006). Overall in situ replacement with an antibiotic-bonded graft yielded a lower frequency of S. epidermidis recovery (two of 19 Ag-cipro graft biofilm with positive culture results versus nine of 16 conventional graft biofilm with positive culture results; (p < 0.003).
This study supports the efficacy of in situ replacement for low-grade graft infections caused by S. epidermidis in normal hosts and demonstrates superiority of antibiotic-bonded grafts in immune-deficient hosts.
感染凝固酶阴性葡萄球菌的移植物并发症可通过抗生素治疗、组织清创和原位移植物置换来根除，但在免疫功能改变的情况下，成功治疗可能会受到影响。
在犬类表皮葡萄球菌所致主动脉移植物感染模型中，比较正常犬与通过给予硫唑嘌呤（50毫克/天）和泼尼松（10毫克/天）造成免疫缺陷的动物原位置换后的结果。在17只对照动物和18只免疫缺陷动物中，用抗生素结合（银-环丙沙星：Ag-cipro）或传统聚四氟乙烯（PTFE）移植物原位置换感染的肾下腹主动脉移植物。
在植入被表皮葡萄球菌生物膜定植的涤纶移植物4周后，所有研究动物均表现出细菌生物膜感染并伴有移植物周围炎症或脓肿，在免疫抑制犬中，吻合口周围主动脉炎的发生率增加（p<0.05）。原位置换6周后，对照动物中Ag-cipro移植物和传统PTFE移植物均愈合且无感染迹象，但在接受标准（7只中的5只）与抗生素结合（11只中的1只）PTFE移植物原位置换的免疫抑制动物中，观察到持续感染的解剖学证据和表皮葡萄球菌恢复增加（p<0.006）。总体而言，用抗生素结合移植物进行原位置换产生的表皮葡萄球菌恢复频率较低（19个Ag-cipro移植物生物膜中有2个培养结果为阳性，而16个传统移植物生物膜中有9个培养结果为阳性；（p<0.003）。
本研究支持原位置换对正常宿主中由表皮葡萄球菌引起的轻度移植物感染的疗效，并证明抗生素结合移植物在免疫缺陷宿主中的优越性。
