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A Marston

Publications and source records attributed to A Marston.

14 recordsLinked to original sources

An immunohistochemical study of mesothelial cell seeding for knitted Dacron.

Six greyhounds underwent bilateral femoral artery replacement with knitted Dacron, one side seeded with omental digest at graft preclotting, the other acting as an unseeded control. Grafts were removed at 24 hours and two months. Tissue was examined using a monoclonal antibody (MNF116) directed against a broad range of human cytokeratins to differentiate mesothelial cells (MC) from microvascular endothelial cells (MEC), which stained only with a polyclonal antibody directed against von Willebrand Factor (anti-vWF). Cells released from omentum by collagenase stained with MNF116 and reacted poorly with anti-vWF. Identical cells were observed to be within the interstices of seeded but not control knitted Dacron. Few remained in seeded grafts (n = 2) removed at 24 hours and none at two months (n = 4).

Animals

Blood pressure changes in the marginal artery of the colon following occlusion of the inferior mesenteric artery.

The perfusion pressure in the marginal artery of the descending colon was measured continuously at laparotomy in eight patients and the effect of sudden occlusion of the inferior mesenteric artery recorded. Three patients with ulcerative colitis, all in their early 30s, and five elderly patients with colonic or rectal carcinoma were studied. In all patients occlusion caused an initial and marked pressure drop, which remained reduced at a critically low level in two of the elderly patients. Such a reduction in perfusion pressure is probably still insufficient to interfere with the nourishment of the terminal part of the colon provided that the systemic pressure is kept at a normal level. However, since in many patients there is a sharp drop in systemic blood pressure during the recovery phase after surgery, it appears likely that the perfusion pressure in the marginal artery may in those cases be insufficient to maintain an adequate blood flow to the colon despite the inherent tendency of "auto-regulation" in this vascular bed. The results of the present study indicate that, contrary to previous belief, ligation of the inferior mesenteric artery may increase the risk of ischaemia in the terminal part of the descending colon, leading to anastomotic dehiscence after anterior resection, or sloughing after a "pull-through" operation. This complication could probably be prevented by a more generous resection of the sigmoid and descending colon, thus reducing the length of the anastomosis formed by the arc of Riolan and by careful maintenance of an adequate blood pressure during the recovery phase.

Adult