Two-layer challenge test as an assessment to predict islet graft function.

BACKGROUND/AIMS: To investigate graft viability assessment before transplantation using 31P-Nuclear Magnetic Resonance (NMR) spectroscopy combining a two-layer old storage method (TLM). METHODOLOGY: Rat pancreases were divided into three groups and respectively subjected to 0 (group 1), and 30 minutes (group 2) of warm ischemia (WI) before procurement. Pancreases were digested and pancreatic digest tissues were preserved for 3 h using TLM. 31P-NMR spectroscopy was used to measure ATP levels of digest tissue. After TLM, the ratio of beta-adenosine triphosphate to phosphate monoester (betaATP/PME) obtained by 31P-NMR spectroscopy was evaluated. Isolated islets were assessed for yield and in vivo function separately using nude mice. RESULTS: The betaATP/PME ratios were 0.11 +/- 0.04, and 0.03 +/- 0.01 in groups 1 and 2, respectively (P < 0.05). Islet yields (IEQ/pancreas) were significantly less in group 3 (P < 0.05) and the cure rate after transplantation of 200 islets to athymic nude mice were 100% (7/7), and 0% (0/7) in groups 1 and 2, respectively. We regard groups 1 as viable group and group 2 as non-viable group. The viable groups and the non-viable group were clearly distinguished by betaATP/PME ratios. CONCLUSION: 31P-NMR spectroscopy combining TLM provided an objective and rapid means to assess severity of islet graft damage prior to transplantation in the rat model.

Prevention of intimal hyperplasia employing the cavitary two-layer method in allogeneic rat heart transplantation.

BACKGROUND: The development of graft arteriosclerosis is a significant contributor to chronic rejection in organ transplant recipients. The purpose of the present study was to establish whether or not the cavitary two-layer method can prevent graft arteriosclerosis after rat heart transplantation. METHODS: F-344 rats served as donors to Lewis recipients. Grafts in the control group (group C) were immediately allotransplanted without preservation. Grafts were also transplanted after cold preservation for 3 h in University of Wisconsin solution (group UW), or employing the cavitary two-layer (CTL) method (group TL). In another group (group W), grafts were subjected to 15-min warm ischemia and then transplanted. Grafts damaged by ischemia were also transplanted after preservation for 3 h using CTL (group WTL). We measured intimal thickening (IT) before transplantation and at 30 and 60 d post-transplant and also assessed the expression of heat shock proteins (HSPs). RESULTS: At 60 d post-transplant, IT in group WTL was significantly lower than in group W (0.30 ± 0.03 versus 0.45 ± 0.04, respectively). In contrast, no significant changes were observed in the cold storage groups. Expression of HSPs 60 and 70 at 60 d in group WTL (25.40% ± 1.64% and 35.96% ± 2.65%, respectively) was reduced compared with group W (46.07% ± 5.84% and 55.11% ± 1.54%, respectively). CONCLUSIONS: CTL reduces IT induced by warm ischemia in rat heart transplantation, and allows the maintenance of low HSP 60 and 70 expression.

Oxygenation of the portal vein by intraperitoneal administration of oxygenated perfluorochemical improves the engraftment and function of intraportally transplanted islets.

OBJECTIVES: One of the major obstacles for successful intraportal islet transplantation (IPIT) is early graft loss due to hypoxia. We therefore examined the effect of intraperitoneal oxygenated perfluorochemical (PFC) on oxygenation of the portal vein with respect to islet engraftment and function after IPIT in a rat model. METHODS: First, we measured the oxygen tension and saturation in the portal vein of Lewis rats before and after intraperitoneal injection of oxygenated PFC. Second, blood glucose levels, glucose tolerance, and the number of surviving islets were measured after IPIT with oxygenated PFC (group 1), with PFC saturated by nitrogen (group 2), and without any PFC (control). RESULTS: Both oxygen tension and saturation in the portal vein significantly increased after injection of oxygenated PFC. In IPIT, the functional success rate in group 1 was 83.3%, compared with 16.7% in group 2 and 16.7% in the control. On the 28th posttransplantation day, the number of engrafted islets in the liver in group 1 (12.8 [SD, 3.3]) was significantly higher than that in group 2 (4.7 [SD, 3.0]) and in the control group (6.5 [SD, 3.3]). CONCLUSIONS: We clearly demonstrated the effect of intraperitoneal oxygenated PFC on oxygenation of the portal vein, resulting in better IPIT outcomes.

Ischemically damaged heart after preservation by the cavitary two-layer method as a possible donor in rat heart transplantation.

BACKGROUND: The purpose of this study was to examine the possibility of using an ischemically damaged heart, after preservation by the cavitary two-layer (CTL) method, as a donor in heart transplantation. METHODS: Each donor heart was heterotopically transplanted to the recipient aorta. The grafts in Group 1 were immediately transplanted. In Group 2, the grafts with (a) 15- or (b) 30-minute warm ischemia were transplanted. The ischemically damaged grafts were transplanted after preservation for 3 hours in University of Wisconsin (UW) solution (Group 3) or CTL (Group 4). Five-day animal survival, tissue adenine triphosphate (ATP) concentration, biochemical assay and histopathologic data were obtained. RESULTS: Five-day survival in Group 4a was 7 of 8, with significant recovery of the ATP tissue level (9.31 +/- 0.80 micromol/dry weight). Biochemical and pathologic examinations demonstrated that ischemia-reperfusion injury was prevented in Group 4a compared with Group 2a. CONCLUSIONS: An ischemically damaged rat heart preserved for 3 hours by CTL was found to be a potential donor in rat heart transplantation.

Improved quantity and in vivo function of islets isolated by reduced pressure-controlled injection of collagenase in a rat model.

In islet transplantation, insufficient yield is a major obstacle to one-donor/one-recipient transplant. Collagenase, which is injected via a pancreatic duct to separate islets from acini, can so easily distribute into the islet core that it may result in disruption of islets. The purpose of this study was to evaluate the superiority of reduced pressure-controlled collagenase injection (RPCI) at 80 mmHg on islet isolation to injection at 180 mmHg by examining in vivo transplant experiments besides the yield and the glucose stimulation test in a rat model. Lewis rat pancreases were distended with collagenase solution at 80 mmHg pressure as the RPCI group (group 1) and at 180 mmHg (group 2), followed by isolation. The yield in group 1 (1100 +/- 160 islets with 2750 +/- 530 IEQ) was significantly higher than that in group 2 (900 +/- 130 islets with 1570 +/- 350 IEQ, p < 0.01) due to the significant difference of the number of islets sized >150 microm in diameter, although the purity was not significantly different between the two groups. Stimulation indices in the glucose stimulation tests were 2.88 +/- 1.12 in group 1 and 1.93 +/- 0.62 in group 2 (p < 0.05). The cure rate by transplantation of 100 islets to diabetic nude mice in group 1 (8/10) was significantly higher than that in group 2 (3/10, p < 0.05). In a syngenic transplant model of 90% of islets isolated from one donor, the cure rates were 100% and 67% in groups I and 2, respectively (NS). The area under the curve on the graph of IPGTT on postoperative day 28 in group I was significantly smaller than that in group 2 (p < 0.05). In conclusion, our data show that RPCI at 80 mmHg could contribute to consistently high islet yield and in vivo function in a rat model. It was suggested that the current human protocol should be reviewed from this viewpoint.

Application of the two-layer method on pancreas digestion results in improved islet yield and maintained viability of isolated islets.

BACKGROUND: Oxygenation of the pancreas during preservation by the two-layer method (TLM) has shown beneficial effects in islet transplantation. Here, we apply this concept (oxygenation) to the isolation process. METHODS: Rat pancreases were digested using four different methods. Pancreases were digested with preoxygenated perfluorocarbon (PFC) in group 2 and without it in group 1. Additionally, adenosine was included in the collagenase solution in subgroups B but not in subgroups A. Islet yields and viability were compared between groups. RESULTS: Tissue oxygen tension in group 1 was essentially zero during digestion, but rapidly reached around 300 mm Hg and was maintained in group 2. The tissue adenosine triphosphate (ATP) level in rat pancreas just after laparotomy (control) was 4.2+/-0.7 micromol/g dry weight; after digestion, it was 0.12+/-0.03 micromol/g, 0.70+/-0.10 micromol/g, 0.30+/-0.18 micromol/g, and 2.90+/-0.80 micromol/g in groups 1A, 1B, 2A, and 2B, respectively. No significant differences were observed between group 2B and control (P=0.19). Islet yields (IEQ/pancreas) were 1600+/-400, 1400+/-400, 1300+/-400, and 2400+/-100 in groups 1A, 1B, 2A, and 2B, respectively. The islet yield of group 2B was significantly higher than other groups (P<0.05). The cure rate after transplanting 200 islets into athymic nude mice did not differ (80% in all groups). The stimulation indices in the four groups were also the same. CONCLUSIONS: Tissue ATP levels after digestion were well maintained using TLM with adenosine digestion method. Consequently, greater numbers of islets could be retrieved. The new method was at least equivalent to islet function isolated by conventional method. Clinical study is therefore warranted.

Successful 40-hour preservation of the canine small intestine with the cavitary 2-layer method with glutamine supplementation.

BACKGROUND: We recently reported that the cavitary 2-layer method (cTLM) allowed stable 24-hour preservation of canine intestine. The aim of this study was to examine the possibility of the 40-hour preservation by cTLM that is supplemented with glutamine. METHODS: Canine jejunal segments (40 cm) were allotransplanted heterotopically without storage (group 1), after 40-hour cold storage with University of Wisconsin solution (group 2), cTLM (group 3), UW with 2% glutamine (group 4), or cTLM with 2% glutamine (group 5). Mucosal glutamine, histidine, tryptophan, glutathione, and adenosine triphosphate concentrations were determined immediately after preservation. At day 7 after the transplantation, maltose absorption test and histopathologic analysis were performed. RESULTS: Mucosal glutamine concentrations increased significantly with glutamine supplementation during preservation in groups 4 and 5 (P < .01). Mucosal adenosine triphosphate levels in cTLM groups (groups 3 and 5) were similar to those in group 1; group 4 showed very low levels after preservation, despite glutamine supplementation. Mucosal glutathione did not differ among groups 2, 3, 4, and 5 and were significantly lower than in group 1. In the absorption test, serum glucose curves showed a peak level by 30 minutes in groups 1 and 5; delayed peaks were seen in groups 2, 3, and 4 compared with group 1. The villous heights were 879, 555, 685, 688, and 773 microm in groups 1, 2, 3, 4, and 5, respectively (group 1 vs group 2, 3, and 4: P < .05). CONCLUSION: cTLM that was supplemented with glutamine extended a safe preservation period up to 40 hours in canine segmental small intestinal transplantation, although this study failed to elucidate a precise mechanism of the glutamine beneficial effect on the graft mucosa.

Impact of the two-layer method on the quality of isolated pancreatic islets.

BACKGROUND/AIMS: We have already reported that the two-layer method (UW/PFC) reduces warm and cold ischemic injuries before islet isolation, and results in improvement of islet yield and viability. In this study, we try to evaluate the effect of the two-layer method on isolated islets. METHODOLOGY: We used male Wister rats. Isolated islets were cultured or preserved in various conditions for 24 hours. In group 1, islets were not cultured (control). In group 2, islets were cultured in RPMI at 37 degrees C. In groups 3 and 4, islets were cultured with "modified" two-layer method (RPMI/PFC) at 37 degrees C and 4 degrees C, respectively. In groups 5 and 6, islets were preserved in UW and with the two-layer method (UW/PFC), respectively at 4 degrees C. Islets in each group were evaluated in terms of function and viability in vitro. RESULTS: Stimulation Indices were 1.3, 2.6, 3.7, 1.2, 1.4, and 2.4 in groups 1, 2, 3, 4, 5 and 6, respectively. Islets in groups 2, 3 and 6 showed clear response to glucose stimulation. Among these 3 groups, the total viability of islets assessed by FDA/PI staining was 88%, 92%, and 76% in groups 2, 3, 6, respectively. CONCLUSIONS: Although in vivo studies are mandatory, the present study is supportive that the "modified" two-layer method (RPMI/PFC), which uses oxygenated PFC and RPMI, may be superior to conventional culture method with RPMI. This method may achieve further improvement of islet viability before implantation.

Possibility of islet transplantation from a nonheartbeating donor pancreas resuscitated by the two-layer method.

BACKGROUND: The shortage of cadaveric donors is a problem in islet transplantation, and recent improvements in this field have led to renewed interest in the use of nonheartbeating (NHB) donors. NHB donor pancreata that could provide a significant source for islet transplantation are associated with warm ischemic injury. We tested whether the two-layer method (TL) could improve islet yield and function from damaged pancreata after warm ischemia (WI). METHODS: Lewis rats were divided into six groups. In groups 1 to 3, rats were subjected to 0, 30, and 45 minutes of WI, respectively. Islets were isolated immediately (subgroup a) or after 3-hour preservation with TL (subgroup b). Isolated islets were assessed in terms of islet yield and in vivo function. We also assessed the pancreatic tissue ATP concentration before isolation and distended pancreata morphologically after chemical digestion by H&E staining. RESULTS: Islet yield decreased significantly after 30 minutes of WI in group 2a, whereas TL preservation doubled this decreased yield in group 2b. Forty-five minutes of WI resulted in nearly no islet yield in both groups 3a and 3b. The success rates of transplantation in groups 1a, 1b, 2a, and 2b were 100%, 100%, 0%, and 75%, respectively. Increased tissue ATP levels and alleviation of morphological islet damage were observed in group 2b. CONCLUSIONS: These results demonstrated that pancreata damaged from 30-minute WI were restored by 3-hour TL preservation. TL may allow the selective use of NHB donors as an alternative source for islet transplantation.

No mortality among 100 consecutive pancreaticoduodenectomies in a middle-volume center.

Mortality rate following pancreaticoduodenectomy has markedly decreased in high-volume centers. We achieved zero mortality among 100 pancreaticoduodenectomies in a middle-volume center. The purpose of this study was to review our experience and analyze factors contributing to the zero mortality. Patient backgrounds, intraoperative variables, postoperative complications, and surgical, radiologic, and other medical interventions for the complications were retrospectively analyzed for 100 consecutive pancreaticoduodenectomies for malignant or benign disease. The mean age of the patients was 63 years. Altogether, 59 patients had preoperative co-morbidity, and 35 had a past history of abdominal surgery. The median operating time and blood loss were 525 minutes and 1215 ml, respectively. Postoperative complications occurred in 42 patients. The most frequent complication was pancreatic stump leak (n = 12), but no life-threatening pancreatic anastomotic leak occurred. This may result from the duct invagination anastomosis applied to 67 pancreases with a small duct. Serious complications were seen in six patients; two patients required surgical intervention, but four were successfully treated with the help of interventional radiologists or internists. Radiologic intervention was applied to 13 patients: drainage of an intraabdominal abscess/collection and vascular intervention. In addition to advances in surgical techniques to reduce local complications, particularly pancreatic anastomotic leak, intimate collaboration with experienced interventional radiologists and internists allows zero mortality even in middle-volume centers.

Detailed analysis of mucosal restoration of the small intestine after the cavitary two-layer cold storage method.

Small bowel transplantation (SBT) is associated with a high incidence of infectious complications because of ischemia/reperfusion (I/R) mucosal injury concomitant with potent immunosuppression. In this study, we evaluated whether the cavitary two-layer method (cTLM) could reduce I/R injury and allow early mucosal restoration, particularly after prolonged preservation and transplantation. Canine heterotopic segmental SBT was performed immediately without preservation (group 1), after 24-h preservation in UW solution (group 2) or by the cTLM (group 3). The graft samples were taken 1 h after reperfusion and on days 1, 4 and 7. We assessed graft mucosa with detailed microscopic and electromicroscopic analyses. In Group 3, histological injury and cell apoptosis after transplantation were significantly alleviated and rapidly recovered to a similar level of group 1. The mucosal restoration was morphologically completed within 4 days. In contrast, in group 2, more pronounced mucosal injury and delayed recovery were noted. Crypt cell proliferation activity was well maintained in groups 1 and 3 throughout the experimental period. Our ultrastructural analysis suggested that mitochondrial integrity achieved by the cTLM was a basal mechanism under the prompt mucosal restoration. The cTLM could reduce I/R injury, facilitate mucosal regeneration and restore the nearly normal structure early after SBT.

Superiority of the two-layer method before islet isolation confirmed by in vivo viability assessment.

BACKGROUND: Although the outcome of islet transplantation has improved, there remains a major obstacle in isolating viable islets from prolonged preserved pancreas. We previously reported that the two-layer cold storage method (TLM) improved the yield and in vitro function. In this study, we performed in vivo accurate functional analyses of islets from TLM-preserved pancreas and investigated pancreatic duct cell viability, which may critically affect islet isolation. METHODS: Rat islets isolated from fresh pancreas (group 1), after preservation in the University of Wisconsin (UW) solution (group 2) or by the TLM (group 3), were examined by assessing islet yields, stimulation indices, cure rates after transplantation to diabetic nude mice, and trypan blue uptake of pancreatic duct cells. RESULTS: TLM significantly improved the islet yield compared with UW cold storage. The cure rates after transplantation were 100%, 0%, and 80% for groups 1, 2, and 3, respectively. This indicates that islet viability was well maintained even after 24 hr of TLM preservation. The percentages of nonviable duct cells were 4.1%+/-1.9%, 48.3%+/-8.0%, and 26.1%+/-21.4% in groups 1, 2, and 3, respectively, showing that the TLM was superior to UW as seen by this duct cell viability assessment. CONCLUSIONS: The TLM used for pancreas preservation before islet isolation results in excellent islet function in addition to improved islet yield comparable to freshly isolated islets. The underlying mechanism may be duct cell viability maintained during TLM preservation. Therefore the TLM is an excellent preservation technique for isolating sufficient numbers of highly viable islets.

Influence of collagenase loading on long-term preservation of pig pancreas by the two-layer method for subsequent islet isolation.

BACKGROUND: The introduction of the two-layer method (TLM) for long-term human pancreas preservation revealed the enormous potential of TLM to improve graft function of isolated islets. It is still unclear whether pig islets can be successfully isolated from pancreases after prolonged cold ischemia. To clarify this question, pig pancreases were subjected to 7-hour preservation by University of Wisconsin solution (UWS) storage or TLM. Another aim was to verify whether TLM can be synergistically combined with intraductal collagenase injection before cold storage. METHODS: After intraductal flush with UWS, organs were distended with 4.4 PZ-U/g of UWS-dissolved collagenase NB-8 and neutral protease adjusted to respectively 1.1, 0.2, 0.5, or 0.8 DMC-U/g for pancreases freshly procured (n=6) or distended with enzymes before (TLM preloaded, n=7) or after cold storage (UWS storage, n=4; TLM postloaded, n=10). RESULTS: Purified islet yield decreased from 429,200+/-86,700 islet equivalents (IEQ) in unstored pancreases to respectively 37,670+/-19620, 210,400+/-22900 and 238,000+/-26600 IEQ in UWS-stored (P<0.01), TLM-preloaded, or postloaded organs (P<0.05). Purity (>90%), viability (>95%), and insulin content were not different between groups. Islets from UWS-stored pancreases fragmented extensively, preventing further assessment of in vivo function. Compared with other experimental groups, islets from TLM-preloaded organs were characterized by enhanced basal and stimulated insulin release. Sustained normoglycemia was observed in diabetic nude mice transplanted with islets from TLM-postloaded or unstored pancreases in contrast with transient function in TLM-preloaded islets. CONCLUSIONS: This study demonstrates that significant amounts of intact pig islets can be isolated after prolonged pancreas preservation by TLM. Enzyme administration before TLM preservation decreases islet graft function.

Resection of the colon simultaneously with pancreaticoduodenectomy for tumors of the pancreas and periampullary region: short-term and long-term results.

Simultaneous resection of the colon with pancreaticoduodenectomy (PD) is occasionally inevitable to accomplish curative resection in instances when a periampullary tumor involves the mesentery of the colon. However, there is little information regarding short- and long-term outcomes of this aggressive surgery. Among 95 consecutive patients who underwent PD for periampullary malignant tumors, 12 had simultaneous resection of the right colon (group 1) and 83 underwent PD alone (group 2). Intraoperative variables, postoperative morbidity and mortality, and the length of the hospital stay were comparatively analyzed. Survival was also compared between the groups in a subset of 36 pancreatic adenocarcinoma patients. Group 1 included more patients with pancreatic cancer, and portal vein resection was more frequently performed, which seemed to be associated with a significantly longer operating time (640 vs. 510 minutes) and increased total blood loss (1965 vs. 1220 ml). However, morbidity and mortality rates did not differ between the groups (50,0% and 0%, respectively, in group 1; 44.6% and 1.2%, respectively, in group 2). The median hospital stays were 67 and 48 days in groups 1 and 2, respectively. In a subset of 36 pancreatic adenocarcinoma patients, the median progression-free survivals were 6 months in both groups 1 and 2; the median overall survivals were 14 months in group 1 and 12 months in group 2. There was no statistically significant difference in survival between the groups. Simultaneous right hemicolectomy with curative intent at the time of PD could thus be performed safely and may offer a survival benefit even for individuals who have advanced pancreatic cancers with involvement of the transverse mesocolon.

Intraoperative continuous external bile drainage during pancreaticoduodenectomy.

PURPOSE: The common hepatic duct is usually divided during the early stage of pancreaticoduodenectomy. However, abrupt, complete, and prolonged closure of the proximal common duct stump can cause liver damage in the course of this long operation, resulting in postoperative liver dysfunction and associated complications. Here, we investigate this phenomenon further. METHODS: We performed intraoperative continuous external bile drainage (IBD) in 43 consecutive patients (drainage group) and compared postoperative liver enzyme levels, morbidity including liver dysfunction, and outcomes with those of a control group (n = 41). RESULTS: There were no complications associated with IBD catheter insertion in this series. The drainage group had significantly lower transaminase levels within the first 7 postoperative days (PODs) than the control group. Postoperative liver dysfunction was confirmed in six patients from the control group and in one patient from the drainage group (P = 0.04). However, there were no significant differences between these two groups in terms of postoperative morbidity (other than liver dysfunction), relaparotomy, and in-hospital mortality rates. CONCLUSION: Intraoperative continuous external bile drainage failed to improve the overall morbidity and mortality rates in this series. However, our findings showed that prolonged intraoperative complete closure of the common hepatic duct contributed to postoperative liver dysfunction in most patients and that IBD, which is easy and safe to perform, could reduce intra-operative liver damage and prevent postoperative liver dysfunction.

Objective and rapid assessment of pancreas graft viability using 31P-nuclear magnetic resonance spectroscopy combined with two- layer cold storage method.

BACKGROUND: With the current shortage of donors, there is a critical need to optimally use "less-than-ideal" donors for pancreas transplantation. Objective and rapid means for assessing graft viability and suitability for transplantation are mandatory. This study examined the possibility of graft viability assessment and posttransplant outcome prediction using (31)P-nuclear magnetic resonance (NMR) spectroscopy combined with the two-layer cold-storage method (TLM). METHODS: Canine pancreas grafts were preserved with TLM for 24 hours after 0, 60, or 120 minutes of warm ischemia (groups 1, 2, or 3, respectively). After preservation, we determined intragraft phosphate metabolites noninvasively using (31)P-NMR spectroscopy. Time required for this assessment was 5 minutes. Because our previous studies demonstrated that all grafts in groups 1 and 2 were successfully transplanted (the viable group), whereas all in group 3 failed to survive (the nonviable group), the possibility of posttransplant outcome prediction was examined on the basis of the comparison between these two groups. RESULTS: The ratios of inorganic phosphate/gamma-adenosine triphosphate (Pi/gamma-ATP) and Pi/beta-ATP reflected the extent of graft damage, and the differences were statistically significant among groups 1, 2, and 3. On the basis of analyses of receiver operator characteristic curves, the optimum cutoff levels between the viable and nonviable groups were 1.6 and 2.2 for Pi/gammaATP and Pi/betaATP, respectively. The accuracy rates of these ratios were both 83%. CONCLUSION: (31)P-NMR spectroscopy combined with TLM preservation could provide an objective, rapid, and possibly noninvasive means to assess pancreas graft viability and to determine suitability of damaged pancreata for organ transplantation.

Safety of portal vein resection using centrifugal pump-assisted venous bypass between the superior mesenteric vein and the umbilical vein.

BACKGROUND/AIMS: To achieve complete resection of pancreatic cancer, portal vein resection has been performed with increasing frequency at the time of pancreaticoduodenal resection (pancreaticoduodenectomy or total pancreatectomy). In the meantime, visceral congestion and liver ischemia are of great concern during the procedure. We investigated safety of portal vein resection using a centrifugal pump-assisted bypass between the superior mesenteric vein and the umbilical vein. METHODOLOGY: A retrospective comparison was performed in 49 consecutive patients who underwent pancreatoduodenal resection with or without portal vein resection using the bypass for pancreatic cancer. Twenty-two patients underwent portal vein resection using the bypass (group 1). The other 27 patients undergoing pancreatoduodenal resection without portal vein resection comprise the control group (group 2). RESULTS: Total operative time was 756 +/- 159 min and 526 +/- 109 min (p<0.001) and median blood loss was 2090 mL and 1200 mL in groups 1 and 2, respectively. However, the centrifugal pump-assisted bypass allowed stable bypass flow, and neither intestinal edema nor ischemic change of the liver was observed during portal vein resection and the subsequent reconstruction. Postoperatively, the peak postoperative AST, ALT and total bilirubin levels showed no significant difference and postoperative day of starting a liquid diet was similar between the groups (9.0 +/- 5.4 vs. 9.8 +/- 3.8 days, p=0.48). In addition, the rates of morbidity (55% vs. 48%) including biliary and pancreatic leak as well as mortality (9% vs. 4%) did not significantly differ between the 2 groups. CONCLUSIONS: The centrifugal pump-assisted bypass may be useful to prevent hepatic ischemia and visceral congestion during portal vein resection procedures, resulting in similar postoperative outcomes to the control after pancreaticoduodenal resection for pancreatic cancer.

Protection against ischemia/reperfusion injury by the cavitary two-layer method in canine small intestinal transplantation with reduction of reactive oxygen species.

BACKGROUND: Ischemia and reperfusion (I/R) injury is a major determinant of early graft dysfunction and long-term graft survival in small intestinal transplantation. The cavitary two-layer method (TLM) has been reported to be superior to the University of Wisconsin cold storage method (UWM) in long-term preservation of canine small intestine. This study was designed to evaluate the protective effect of the cavitary TLM against I/R injury in canine small intestinal transplantation. METHODS: Intestinal grafts harvested from beagles were allotransplanted after 24-hour preservation by UWM (group 1) or the cavitary TLM (group 2). The graft in the controls (group 3) was immediately allotransplanted without preservation. I/R injury was assessed by functional success rates, biochemical assay, graft adenosine triphosphate (ATP) and lipid peroxidation (LPO) concentrations, and histopathologic examination including TUNEL staining for apoptosis. RESULTS: In group 1, ATP recovery was delayed after reperfusion, and most recipients died with hemorrhage of the grafts and lungs. In group 2, graft ATP concentrations recovered rapidly, and I/R injury was prevented with reduced LPO production, resulting in good outcome. CONCLUSIONS: The cavitary TLM protected intestinal grafts against I/R injury evidenced by maintenance of graft ATP levels and reduction of LPO production compared with UWM in canine small intestinal transplantation.

Pancreas preservation by the 2-layer cold storage method before islet isolation protects isolated islets against apoptosis through the mitochondrial pathway.

BACKGROUND: Apoptosis in isolated islets has been implicated in primary nonfunction or early graft failure after islet transplantation. Recently, pancreas preservation by the 2-layer method (TLM) before islet isolation has been proved to improve the islet yield, quality, and transplant results not only in experimental models, but also in clinical settings. We examined the influence of TLM on apoptosis of isolated islets. METHOD: Rat islets freshly isolated and after pancreas preservation by TLM or conventional cold storage in University of Wisconsin solution (UW) were examined and compared. Islet apoptosis was assessed by TUNEL and annexin V assays. The apoptosis pathways involved were investigated by measurement of caspase 3, 8, and 9 activities and by immunoblotting for total and phosphorylated c-Jun NH2-terminal kinase (JNK) and p38. RESULTS: Islet apoptosis in the UW group was significantly increased compared with the fresh and TLM groups. Both caspase 3 and 9 activities in the UW group were higher than in the fresh and TLM groups with an approximate increase of 2- to 3-fold. On the other hand, there was no significant difference in caspase 8 activity among these 3 groups. JNKs were strongly activated both in the TLM and UW groups; although they were not activated in the fresh group, p38 was activated to almost the same levels in these 3 groups. CONCLUSIONS: Pancreas preservation by TLM before islet isolation protects isolated islets against apoptosis mainly through the mitochondrial pathway. Pancreas storage before islet isolation even with TLM triggers activation of JNKs in isolated islets.