Effect of Fibrin Sealant on Perianastomotic Tumor Growth in an Experimental Model of Colorectal Cancer Surgery J. R. McGregor, M.D., F.R.C.S.,* D. H. Reinbach, F.R.C.S.,* S. W. Dahill, B.Sc., M.B. Ch.B.,~- P. J. O'Dwyer, M.Ch., F.R.C.S.I.* From the University Departments of* Surgery and af Pathology, Western Infirmary, Glasgow, United Kingdom Viable intraluminal tumor cells can penetrate a clinically intact rodent colonic anastomosis and give rise to peri- anastomotic tumor growth. The aim of this study was to determine whether transanastomotic cell migration can be prevented by fibrin-based tissue sealant. Following distal colonic transection and reanastomosis with 5/0 silk sutures, Fischer F344 rats were randomly allocated to three experimental groups. In Group A, a circumferential ring of tissue sealant was placed around the serosal sur- face of the anastomosis; in Group B, sealant was limited to 50 percent of the anastomotic circumference; and, in Group C, no sealant was applied. All rats then had 105 Mtln3 carcinoma cells injected into the proximal colonic lumen via a rectal catheter. The incidence of perianas- tomotic tumor at 21 days was significantly lower in Group A (3 of 14 animals) than in Group B (11 of 16 rats) (P - - 0.012; Fisher's exact test) or Group C (10 of 14 rats; P - 0.011). A further experiment demonstrated that sealant did not protect the anastomosis when tumor cells were instilled directly into the peritoneal cavity. A topical carcinocidal action therefore appears unlikely, but our results suggest that a circumferential anastomotic ring of fibrin sealant forms an effective mechanical barrier pre- venting intraluminal tumor cells from reaching the peri- toneal cavity. [Key words: Intraluminal tumor cells; Per- ianastomotic tumor growth; Fibrin tissue sealant] McGregorJR, Reinbach DH, Dahill SW, O'Dwyer PJ. Effect of fibrin sealant on perianastomotic tumor growth in an experimental model of colorectal cancer surgery. Dis Colon Rectum 1993;36:834-839. L ocoregional tumor growth represents the most common form of relapse following "curative" resection of colorectal cancer. ~-4 Viable exfoliated malignant cells are present within the colonic lu- Supported by a grant from the Research Support Group of the Greater Glasgow Health Board. Provisional results were presented at a meeting of the Surgical Research Society of Great Britain and Ireland, Lancaster, United Kingdom,July 1991, and published in abstract form in the British Journal of Surgery. Address reprint requests to Mr. McGregor: Lecturer in Surgery, University Department of Surgery, Western Infirmary, Glasgow Gll 6NT, United Kingdom. men of patients with large bowel cancer, 5 and their implantation and proliferation may be a cause of disease recurrence. 6 anastomotic recurrence is seen in approximately 5 to 15 percent of patients following restorative surgery, 6 but in such instances tumor growth is predominantly on the serosal sur- face of the bowel and is usually associated with disease elsewhere in the operative field. 1' 2 To give rise to this form of recurrence, intraluminal tumor cells must gain access to the perianastomotic tis- sues. Experimental work has demonstrated that intra- luminal tumor cells can migrate across an intact rodent colonic anastomosis 7-1~ and that any com- promise in anastomotic integrity increases tumor development. 1~ Furthermore, in a prospective ran- domized clinical trial designed to compare gas- trointestinal anastomotic techniques, we have re- cently reported an association between impaired anastomotic integrity and an increased incidence of locoregional tumor recurrence. 12 It is reasonable to assume that exfoliated colo- rectal cancer cells may remain viable within the colonic lumen for several hours following colorec- tal cancer surgery, and our hypothesis is based on a belief that these cells may migrate across the anastomosis in the early postoperative period. Im- plantation of these cells at a favorable site may then be an important mechanism in the generation of locally recurrent tumor. In recent years, biologic fibrin-based tissue seal- ants have been adapted to a number of potential applications in general surgery. This study was designed primarily to determine whether the ap- plication of such an agent around an experimental large bowel anastomosis could act as an effective 834