| Research Abstract |
1. We investigated the effect of a distal splenic arterio-venous fistula (A-V fistula) on splenic arterial blood flow (SABF) and tissue blood flow (TBF) in a segmental pancreatic autograft both in dogs and in clinical cases, and following conclusions were obtained, (1) After splenectomy, not only SABF but also TBF extremely decreased, which phenomena should result in causing thrombosis of the graft. (2) Both SABF and TBF were significantly increased by performing A-V fistula. (3) We applied A-V fistula in 8 clinical cases, which was very effective to prevent thrombosis and to maintain normal pancreatic function of the autograft in all cases.
2. A pancreatic graft is generally transplanted heterotopiccally, in other words completely denervated. Then, the blood flow must be mainly regulated byhumoral substances. we investigated. correlation between prostaglafidins (PGI_2, TxA_2) and blood flow, and following conclusions were obtained. (1) Both PGI_2 and TxA_2 were secreted from the graft into the simple cold storage solution, and these secretion continued actively till the first 7 hours in preservation. (2) We divided experimental animals into two groups, the one with autograft preserved for 3 hours (3) hrs group and another with autograft preserved for 24 hours (24 hrs group). In 3 hrs groupSIGMA PGI_2 secretion during preservation was dominant, on the other hand in 24 hrs group SIGMA TxA_2 secretion was dominant. (3) After transplantation, both SABF and TBF were significantly higher in 3 hrs group than in situ denervated control group (so called reactive hyperemia), on the other hand they were remarkably lower in 24 hrs group than in control group. PGI_2/TxA_2 ratio was positively correlative to SABF and TBF. (4) Graft survival rate was 80% in 3 hrs group, and 20% in 24 hrs group. (5) TxA_2 synthetic inhibitor (OKY-046) was effective to elevate PGI_2/TxA_2 ratio, resulting in improvement of SABF and TBF.
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