Oxygenated University of Wisconsin solution for 24-hour pancreas preservation: Equivalent to two-layer method?

ASSOCIATION FOR ACADEMIC SURGERY AND SOCIETY OF UNIVERSITY SURGEONS—ABSTRACTS MODEL IN RATS. Gordon CR, Strande L, Matthews MS, Marra S, DelRossi AJ, Alexander JB, Hewitt CW; RWJMSCooper University Hospital Introduction: Abbott developed the first experimental heterotopic heart transplant model by use of an aortic anastomosis in 1964. Since then, this model has undergone numerous modifications such as sutureless cervical vessel and femoral vessel anastomoses. Previously, we reported a new modified technique for heterotopic femoral heart transplantation which includes the use of hemostatic vessel clips and trans-femoral echocardiography 1. Our purpose was to study the histopathology of acute allograft rejection in this modified model, and to further validate our previous findings. Method: ACI and Lewis rats weighing 150 to 250g were used as donors and recipients, correspondingly. The left common carotid and left pulmonary arteries were anastomosed to the femoral artery and vein in an end-to-end fashion, respectively. Our improved modifications allowed total operative time to average around two hours. These improvements included heparinization of both donor and recipient, the use of hemostatic vessel clips, and a ventricular prolene stay suture for both easy graft mobilization and secure femoral placement. Results: Heterotopic transplant hearts, along with various other organs, were harvested from the femoral position in both syngeneic (n⫽5) and allogeneic (n⫽5) rats. Acute graft rejection was defined as absent ventricular contraction on trans-femoral echocardiography in the presence of anastomotic patency. Tissue specimens were fixed and stained with H&E. All slides were reviewed blindly by an experimental histopathologist. Gross examination of the allogeneic (ACI to Lewis) hearts revealed a necrotic, edematous, friable heart entrapped within a diffuse inflammatory capsule. Microscopic examination of the allograft exposed multiple hallmarks of acute graft rejection, including severe lymphoplasmocytic infiltration, diffuse vasculitis, intra-cardiac hemorrhage, myocytic degeneration with necrosis, significant phagocytosis of cardiac myocytes, presence of hemosiderin-laden macrophages, interstitial edema, and thrombus formation. Conclusion: In an effort to study allogeneic cardiac transplantation in rats, we developed a modified model that is both less time-consuming and labor-intensive. Our histopathologic findings confirm the presence of acute graft rejection, which includes demonstration of lymphoplasmocytic infiltration, vasculitis, intracardiac hemorrhage, myocytic degeneration with necrosis, phagocytosis of myocytes, presence of hemosiderin-laden macrophages, interstitial edema, and thrombus formation. This further validates the utility of this transplant model. 1Gordon CR, Strande L, Matthews MS et al. “A New Modified Technique for Heterotopic Femoral Heart Transplantation in Rats.” The American Society of Reconstructive Microsurgery, Annual Meeting, January 2006. (submitted) 439. OXYGENATED UNIVERSITY OF WISCONSIN SOLUTION FOR 24-HOUR PANCREAS PRESERVATION: EQUIVALENT TO TWO-LAYER METHOD? Zhao PX, Shen J, Skarbek R, Conners M, Millis J; The Un of Chicago Combining perfluorocarbons (PFCs) and University of Wisconsin (UW) solution, “two-layer method” (TLM), has gained favor for pancreas preservation. We investigated dynamic oxygen profiles of UW and PFC used to preserve Wistar rat pancreas to determine if oxygenated UW solution alone and oxygenated TLM solutions provide similar protective effects to a preserved pancreas and isolated islets. After pre-oxygenation, pO 2 of UW and PFC was assessed for 24 hours. Degree of pancreas preservation was assessed by islet yield, viability, and in vitro islet function. In addition, preserved and freshly procured pancreata were stained and observed by light microscopy. We observed no significant differences between the pO 2 of UW in TLM vs. oxygenated UW alone during preservation. Islet yields from oxygenated preservation conditions and freshly isolated were not statistically different from each other, but all were signif-

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icantly higher than those from the un-oxygenated UW group. Morphologically, less shrunken cytoplasm and condensed nuclear chromatin were observed in oxygenated UW and TLM groups. These studies confirm that oxygen content in the preservation solutions is important for Wistar rat pancreas preservation, and that oxygenated UW solution alone has protective effects equivalent to those of the more complicated TLM. 440. IS VEGF RELATED TO PSYCHOSOCIAL FACTORS IN PATIENTS WITH COLORECTAL CANCER. A. Sharma, L. Madden, J. R. Monson, L. G. Walker, J. Greenman; University of Hull, Hull, UNITED KINGDOM. Introduction: Recently the association of a proangiogenic cytokine (VEGF) with psychosocial factors has been demonstrated in patients with ovarian cancer. In addition, both the level of VEGF and psychosocial factors have been independently shown to be of prognostic value in colorectal cancer. The aim of this study was to investigate if there is an association between psychosocial factors and the level of VEGF in colorectal cancer patients. Methods: A consecutive series of eligible patients undergoing elective resection for colorectal cancer were invited to participate in the study. Standardised, reliable and validated psychological questionnaires (HADS, PANAS, MRS, FACT-C, CECS, EQ-5D, EPQ-R) were administered 7 days prior to surgery and then 6 weeks after the operation, and a blood sample was obtained at the same time points for determination of VEGF levels. Solid phase sandwich ELISA was used for VEGF analysis using serum samples and following manufacturer’s instructions (Biosource UK). Nonparametric correlations were obtained between psychological scores and pre and postoperative VEGF levels. Factors found to be significantly correlated on this analysis were used in a linear regression model to predict VEGF levels. Results: One hundred and four patients with colorectal cancer were recruited and followed up. There were 70 males (67.3%) and the mean age of the group was 67.6 years. Sixty-two (59.6%) patients had early stage disease (TNM stage I and II) while 42 had advanced disease (TNM stage III and IV). There was a significant association between TNM stage and preoperative VEGF level (p⫽0.026). Preoperative VEGF was negatively correlated with EQ-5D scores, FACT -C additional concern total score, FACT-C functional score, the positive affectivity (PA) scale of the PANAS. VEGF was positively correlated with HADS depression score. Postoperative VEGF had significant negative correlation with EQ 5D score, preoperative physical wellbeing, additional concern score, postoperative functional score, additional concern score and was positively correlated with both the post operative HADS scales. However, linear regression analysis showed that none of these psychosocial factors could independently predict pre or postoperative VEGF levels in these patients with colorectal cancer. Discussion: Mechanisms other than modulation of proangiogenic factors may explain the association of psychosocial factors with prognosis in colorectal cancer patients. 441. THE INTESTINAL INJURY AFTER HEMORRHAGIC SHOCK AND RESUSCITATION EXHIBITS INFLAMMATORY ELEMENTS OF REPERFUSION INJURY. B. Williams, J. Afnan, S. Oakes, F. Moore, Jr.; Brigham and Women’s Hospital, Boston, MA. Introduction: Intestinal injury after hemorrhagic shock is well recognized and thought to be a source of significant additional morbidity. A role for inflammatory mediators, particularly the complement system, in the genesis of either the local injury or its systemic consequences has been suspected. We hypothesize that reperfusion damage after hypotension and resuscitation is the cause of the intestinal injury, and that, as a result, the intestine would demonstrate the characteristic immunohistochemistry of reperfusion injury with deposition of IgM and complement. Methods: Male SpragueDawley rats were anesthetized and acutely bled to 50% of total blood