Diagnosing deficits in quality of life and providing tailored therapeutic options: Results of a randomised trial in 220 patients with colorectal cancer.

BACKGROUND: The implementation of quality of life (QoL) concepts in routine care, is still an open matter. We followed the Medical Research Council framework for complex interventions to implement a model of QoL diagnosis and therapeutic options, and investigated its effectiveness in patients with colorectal cancer. METHODS: This randomised, single-blind, multicentre, clinical trial enrolled patients diagnosed with primary colorectal cancer aged 18 years or older who were surgically treated in one of four recruiting hospitals in Germany. All patients received aftercare from one of 178 coordinating practitioners (CPs) who had access to 75 healthcare professionals providing tailored therapies. QoL was measured (EORTC QLQ-C30, QLQ-CR29) in all patients after surgery (baseline) and during aftercare (3, 6, 12, 18 months). Patients were randomised (1:1) into two groups: a care pathway, including QoL-profiles consisting of 13 QoL scales plus specific therapeutic recommendations forwarded to the patient's CP or standard postoperative care adhering to the German national guideline for colorectal cancer (control). The primary endpoint was the proportion of patients in each group with a need for QoL therapy 12 months after surgery. Analyses were done in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, number NCT02321813 and closed to accrual. FINDINGS: Between Jan 13, 2014, and Oct 28, 2015, 220 patients were enrolled and randomly assigned (n = 110 per group). At baseline (in hospital after surgery), a need for QoL therapy was diagnosed in 92/103 (89%) of intervention and 86/104 (83%) of control group patients. At 12 months (primary endpoint) the proportion of patients with a need for QoL therapy was 35/83 (42%; 95% CI 31-54%) in the intervention group versus 50/87 (57%; 95% CI: 46-68%) in the control group (p = 0·046, number needed to treat = 7; 95% CI 3-225). INTERPRETATION: Patients profited from the diagnosis of QoL deficits and tailored therapeutic options in their treatment of colorectal cancer. This trial confirmed the results of a previous RCT in breast cancer patients. The implementation of QoL concepts should become standard in treatment guidelines on cancer care. FUNDING: Federal Ministry of Education and Research (BMBF; grant no. 01GY1339). CLINICAL TRIAL INFORMATION: NCT02321813.

[Do General Surgeons Feel Adequately Prepared for the Complex Questions Associated with the Handling of Multi-Resistant Pathogens? - Results of the MR2 Survey]. / Fühlen sich Chirurgen gerüstet für die komplexen Fragestellungen im Umgang mit multiresistenten Erregern? ­ Ergebnisse der Fragebogenstudie MR2.

Background At the present time, there is no evidence available as to the knowledge of general surgeons regarding multi-resistant pathogens (MRP) and the rational use of antibiotic medication (antibiotic stewardship/ABS) compared with physicians from other disciplines. Methods As part of the MR2 survey (Multiinstitutional Reconnaissance of practice with MultiResistant bacteria - a survey focussing on German hospitals), a questionnaire comprising 4 + 35 items was distributed to urologists, internists, gynaecologists and general surgeons in 18 hospitals. Multivariate regression models were applied to assess the impact of each discipline affiliation on predefined endpoints. Results 456 evaluable surveys were analysed. The response rate of surgeons (156/330; 47%) and physicians from other disciplines (300/731; 41%) did not differ significantly. Based on their self-assessment, surgeons indicated a significantly lower certainty regarding the correct choice of dose, frequency and duration of antibiotic treatment (p = 0.005), the decision between intravenous or oral application (p = 0.005), as well as the accurate interpretation of microbiological reports (p = 0.023). Both surgeons and doctors from other disciplines rated their knowledge of ABS as limited. An insignificant difference was found between surgeons and non-surgeons regarding the knowledge of E. coli resistance against Ciprofloxacin in their own hospital (27.6 vs. 35.3% estimated the correct category; p = 0.114), with 64% of surgeons underestimating the local resistance rates. Both physician groups assumed that the frequent use of broad-spectrum antibiotics is substantially responsible for the increase in MRP. However, in the given case study of a highly symptomatic female patient with uncomplicated urinary tract infection, both physician groups were almost equally likely to propose treatment with a broad-spectrum antibiotic (34.0 vs. 29.3%; p = 0.331). Based on the results of the multivariate models, there were no significant differences between surgeons and non-surgeons with regard to both the attendance of training courses related to MRP/ABS over the past 12 months and the quality of discharge summaries in their hospitals regarding the correct listing of MRP. Conclusion In due consideration of the results of the MR2 survey, mandatory ABS programs should be implemented in hospitals, including regular training of physicians regardless of their discipline.

Multicenter double-blinded randomized controlled trial of standard abdominal wound edge protection with surgical dressings versus coverage with a sterile circular polyethylene drape for prevention of surgical site infections: a CHIR-Net trial (BaFO; NCT01181206).

OBJECTIVE: To determine whether circular plastic wound edge protectors (CWEPs) significantly reduce the rate of surgical site infections (SSIs) in comparison to standard surgical towels in patients undergoing laparotomy. BACKGROUND: SSIs cause substantial morbidity, prolonged hospitalization, and costs and remain one of the most frequent surgical complications. CWEPs have been proposed as a measure to reduce the incidence of SSIs. METHODS: In this randomized controlled, multicenter, 2-arm, parallel-group design, patient- and observer-blinded trial patients undergoing open elective abdominal surgery were assigned to either intraoperative wound coverage with a CWEP or standard coverage with surgical towels. Primary endpoint was superiority of intervention over control in terms of the incidence of SSIs within a 30-day postoperative period. RESULTS: Between September 2010 and November 2012, 608 patients undergoing laparotomy were randomized at 16 centers across Germany. Three patients in the device group and 11 patients in the control group did not undergo laparotomy. Patients' and procedural characteristics were well balanced between the 2 groups. Forty-eight patients discontinued the study prematurely, mainly because of relaparotomy (control, n=9; intervention, n=9) and death (control, n=4; intervention, n=7). A total of 79 patients experienced SSIs within 30 days of surgery, 27 of 274 (9.9%) in the device group and 52 of 272 (19.1%) in the control group (odds ratio=0.462, 95% confidence interval: 0.281-0.762; P=0.002). Subgroup analyses indicate that the effect could be more pronounced in colorectal surgery, and in clean-contaminated/contaminated surgeries. CONCLUSIONS: Our trial shows that CWEPs are effective at reducing the incidence of SSIs in elective and clean or clean-contaminated open abdominal surgery.

Colloid vs. crystalloid infusions in gastrointestinal surgery and their different impact on the healing of intestinal anastomoses.

BACKGROUND: The aim of this study was to investigate if colloid infusions have different effects on intestinal anastomotic healing when compared to crystalloid infusions depending on the amount of the administered volume. MATERIALS AND METHODS: Twenty-eight Wistar rats were randomly assigned to four groups receiving different amounts of either a crystalloid (Cry) or a colloid (Col) infusion solution. Animals with volume restriction (Cry (-) or Col (-)) were treated with a low and animals with volume overcharge (Cry (+) or Col (+)) with a high flow rate. All animals received an infusion for a 60-min period, while an end-to-end small bowel anastomosis was performed. At reoperation, the anastomotic bursting pressure (millimeters of mercury) was measured, as well as anastomotic hydroxyproline concentration. The presence of bowel wall edema was assessed histologically. RESULTS: Median bursting pressures were comparable in the Col (-) [118 mm Hg (range 113-170)], the Cry (-) [118 mm Hg (78-139)], and the Col (+) [97 mm Hg (65-152)] group. A significantly lower median bursting pressure was found in animals with crystalloid volume overload Cry (+) [73 mm Hg (60-101)]. Corresponding results were found for hydroxyproline concentration. Histology revealed submucosal edema in Cry (+) animals. CONCLUSIONS: In case of a fixed, high-volume load, colloids seem to have benefits on intestinal anastomotic healing when compared to crystalloid infusions.

Ischemic preconditioning improves stability of intestinal anastomoses in rats.

BACKGROUND: The aim of our study was to establish whether ischemic preconditioning (IPC) directly before performing a small bowel anastomosis has an effect on anastomotic stability and healing. MATERIAL AND METHODS: Forty male Wistar rats were randomized to five groups: control (CO, n = 8) with preparation of the superior mesenteric artery (SMA) but without IPC. IPC groups had different intervals of ischemia (occlusion of the SMA) and reperfusion: 10 min ischemia and 20 min reperfusion (IPC10/20, n = 7), 10 min ischemia and 30 min reperfusion (IPC10/30, n = 8), 15 min ischemia and 20 min reperfusion (IPC15/20, n = 8), and 15 min ischemia and 30 min reperfusion (IPC15/30, n = 9). On the fourth postoperative day, the animals were relaparotomized: bursting pressure, hydroxyproline concentration, and histological ischemia mucosal injury scale of the anastomosis were assessed. RESULTS: Four days after operation, the mean bursting pressure was 73 +/- 6 mmHg in the control group, whereas it was significantly higher in IPC10/20 (113 +/- 11 mmHg; p = 0.018), IPC10/30 (110 +/- 13 mmHg; p = 0.001), and IPC15/30 (124 +/- 9 mmHg; p = 0.003). IPC15/20 did not show a significant difference (63 +/- 2 mmHg; p = 0.4). We did not find a significant effect regarding hydroxyproline concentration, but IPC diminished mucosal injury. CONCLUSIONS: IPC directly before performing a small bowel anastomosis has a time-dependent beneficial effect on anastomotic stability, thus indicating a new clinical approach to improve the healing process of intestinal anastomosis.

Impact of different crystalloid volume regimes on intestinal anastomotic stability.

BACKGROUND: Anastomotic insufficiency still remains an unsolved problem in digestive surgery. Little clinical data, regarding the impact of perioperative volume management exist, which suggest lower complication rates in intestinal surgery under restrictive volume regimens. The aim of our study was to investigate the effect of the extent of intraoperative fluid administration with crystalloids on the stability of intestinal anastomoses. MATERIAL AND METHODS: Twenty-one rats were randomly assigned to 3 experimental groups (n = 7 rats/group): control group CO (9 mL kg h crystalloid infusion), volume restriction group V (-) (3 mL kg h), and animals with volume overload V (+) (36 mL kg h). After midline incision, all animals received the corresponding infusion for a 30-minute period. Infusion was continued for further 30 minutes whereas an end-to-end small bowel anastomosis was performed 15 cm proximal to the Bauhin valve with 8 nonabsorbable interrupted inverting sutures. At reoperation on the 4th postoperative day, the anastomotic segment was dissected and the bursting pressure [mmHg] was measured. As a second parameter for the quality of anastomotic healing, hydroxyproline concentration was examined with a spectrophotometric method [microg/g dry tissue]. Histologically, structural changes of the anastomotic segments were assessed by 2 pathologists. Data are given as mean +/- SEM. RESULTS: Anastomotic insufficiency was not seen in all animals. Bursting pressure of CO animals was 102 +/- 8 mmHg. Bursting pressure was lowest in V (+) with high volume exposure at 77 +/- 6 mmHg and significantly lower than V (-) (112 +/- 9 mmHg; P = 0.01) whereas the difference compared with the CO group did not reach significant values. Hydroxyproline concentration in V (+) (64.4 microg/g dry tissue +/- 7.7) was significantly lower compared with V (-) (91.7 microg/g dry tissue +/- 9.1) animals (P < 0.05). In all animals with volume overload a marked submucosal edema was found. CONCLUSION: We could demonstrate for the first time in a systematic investigation, that the quantity of crystalloid infusion, applied intraoperatively, has a significant impact on functional (bursting pressure) and structural (hydroxyproline) stability of intestinal anastomoses in the early postoperative period. Because the stability and quality of an intestinal anastomosis have an impact on insufficiency rates, it should be noted that volume overload may have deleterious effects on anastomotic healing and postoperative complications in digestive surgery, possibly because of a marked bowel wall edema.

The new adhesion prophylaxis membrane A-part--from in vitro testing to first in vivo results.

INTRODUCTION: Formation of postoperative intra-abdominal adhesions is a severe problem in surgery. Apart from standard surgical procedures, a variety of different substances is available to prevent adhesions, but no universal method has been developed so far. A membrane consisting of polyvinyl alcohol (PVA) and carboxymethylcellulose (CMC) has been demonstrated to be antiadhesive. Here, the in vitro testing and first in vivo results in a rabbit sidewall model are reported. MATERIALS AND METHODS: A-part membrane contains a PVA/CMC mixture in a thickness of 40 microm. The composition, dissolution, tensile strength, and elasticity were examined to characterize the membrane in vitro. Experiments in vivo were carried out using a 'rabbit sidewall model' in which a standardized peritoneal trauma was covered with a 5 x 6 cm A-part membrane. Adhesion formation in A-part-treated animals was compared with that in Adept (15 mL/kg body weight) and untreated controls. RESULTS: An 80/20 PVA/CMC mixture forms a stable, elastic, transparent membrane, which can easily be placed intraoperatively. The dissolution shows a half-life of about 2 weeks [day 15: (45.1 +/- 4.9)% SD], which affords good adhesion protection during the initial critical phase of adhesion formation. In wet conditions, the membrane follows abdominal movements without tearing (tensile strength 5.0 +/- 4.2 N/cm SD; elasticity 29.5%). In a rabbit sidewall model, A-part membrane significantly reduced adhesion development by (83.1 +/- 31.5)% SD compared with the control and the Adept group (p < 0.001). CONCLUSION: The properties of the A-part membrane suggest that it may be useful as an antiadhesive in surgery. A-part is effective in in vivo testing as determined in a rabbit sidewall model.

Comprehensive analysis of the alpha-fetoprotein-specific CD8+ T cell responses in patients with hepatocellular carcinoma.

UNLABELLED: Hepatocellular carcinoma (HCC) is the fifth most common malignancy worldwide, with a poor prognosis and limited therapeutic options. Therefore, the development of novel therapeutic strategies is of high priority. alpha-Fetoprotein (AFP) is overexpressed in the majority of HCCs. Priming of immune responses against AFP results in significant protective antitumoral T cell responses in the mouse model. Little information is available about the hierarchy, breadth, frequency, and peripheral versus intrahepatic distribution of AFP-specific CD8(+) T cell responses in patients with HCC. To address these important issues we comprehensively analyzed CD8(+) T cell responses against full-length AFP in peripheral blood, tumor liver tissue, and nontumor liver tissue from patients with HCC using overlapping AFP peptides. The AFP-specific CD8(+) T cell response was also tested in peripheral blood and liver from patients chronically infected with hepatitis C virus (HCV) and compared to the HCV-specific CD8(+) T cell response. The majority of patients with HCC showed AFP-specific responses, with many responses directed against previously unreported epitopes. These responses were primarily detectable in the HCC tissue and mainly targeted the C-terminus of AFP. Interestingly, AFP-specific T cells were not only found in patients with HCC but also in patients with chronic HCV infection, other liver diseases, and less frequently in healthy subjects. CONCLUSION: In patients with HCC, a high frequency of AFP-specific CD8(+) T cells directed against different epitopes suggest that AFP has a strong and broad immunogenicity. Further, CD8(+) T cells specific for the self-antigen AFP are present in the normal T cell repertoire and are not centrally or peripherally deleted. Our results provide support for strategies to boost AFP-specific CD8(+) T cell responses in patients with HCC but also demonstrate a diversity of immune responses that may be needed for protection.

Pancreatic ischemia/reperfusion injury: impact of different preservation temperatures.

OBJECTIVES: Pancreatic ischemia/reperfusion injury (IRI) can influence the results after transplantation. Temperature during ischemia can affect IRI. A temperature of 4 degrees C is assumed as optimal for graft preservation. There are no data about the impact of different ischemia temperatures in pancreatic IRI. METHODS: Ischemia/reperfusion injury was induced in pancreatic tail segments (2-hour ischemia, 2-hour reperfusion), with rats (7/group) without ischemia served as control. Animals were randomized to the different experimental groups. To achieve the desired temperature (4, 18, or 37 degrees C and 37 degrees C control), pancreatic tail segments were superfused with temperated saline. After reperfusion, microcirculation was observed by intravital fluorescence microscopy. Functional capillary density (FCD), leukocyte adherence in post-capillary venules, and histological damage were analyzed. RESULTS: In IRI groups, decrease of FCD 1 and 2 hours after reperfusion compared with baseline measurements was significant. Functional capillary density in 4 degrees C was better as compared with 18 and 37 degrees C after reperfusion. Lower adherent leukocytes were seen in 4 and 18 degrees C, compared with 37 degrees C and also to CO. In 4 degrees C, histological damage was lower as compared with 18 and 37 degrees C. CONCLUSIONS: We could demonstrate that also in pancreatic IRI, tissue injury is temperature dependent. Compared with 37 degrees C, although a protective effect is established already at 18 degrees C, more protection is achieved with storage at 4 degrees C. Our data suggest that 4 degrees C has the best protective effect on pancreatic IRI.

Remote preconditioning reduces microcirculatory disorders in pancreatic ischemia/reperfusion injury.

OBJECTIVES: Remote preconditioning (RPC) can protect from ischemia/reperfusion injury (IRI). We investigated the influence of RPC in pancreatic IRI. METHODS: Wistar rats were randomized to 2 hours of ischemia and 2 hours of reperfusion of a pancreatic tail segment with or without 15 minutes of infrarenal ischemia 60 minutes before IRI. Microcirculatory measurements before ischemia and 1 and 2 hours after reperfusion included functional capillary density and leukocyte adherence in postcapillary venules, quantified by intravital fluorescence microscopy. Histology and tissue myeloperoxidase activity were further parameters of pancreatic injury. RESULTS: Remote preconditioning caused an improvement of microcirculation (functional capillary density: 1 hour after reperfusion, 460 +/- 13 vs 350 +/- 9 cm/cm2; 2 hours after reperfusion, 437 +/- 13 vs 295 +/- 13 cm/cm2; P < 0.01) and reduced inflammatory tissue response (leukocyte adherence in postcapillary venules: 2 hours after reperfusion, 155 +/- 55 vs 748 +/- 187 cells/mm2; P < 0.01). Histology was significantly better in preconditioned animals (IR, 8.1+/- 1.3 score points; RPC, 6.2 +/- 1.3 score points; P < 0.05). The difference in myeloperoxidase activity was not significant (ischemia/reperfusion [IR], 105 +/- 72; RPC, 245 +/- 209 mU x min(-1) x mg(ti)(-1); P = 0.13). CONCLUSIONS: With our dynamic functional microcirculatory measurements, we could demonstrate that RPC is a feasible method to reduce experimental pancreatic IRI. This was seen in an attenuation of nutritive tissue perfusion and a reduction of inflammatory tissue response and a lower histological damage. Because it is easy to perform before organ harvest, RPC could be a step to improve organ procurement in pancreas transplantation. Clinical studies are the next step to evaluate RPC in pancreas transplantation.

Complete pancreatic encasement of the portal vein--surgical implications of an extremely rare anomaly.

BACKGROUND: Due to the complex embryologic development, pancreatic anatomy can be very variable. DISCUSSION: The authors present the second ever reported case in the literature of a complete pancreatic encasement of the portal vein which forced us to alter the standard operative procedure of pancreatic head resection, thus enabling possible dangerous complications.

Characterization of ischemia/reperfusion-induced gene expression in experimental pancreas transplantation.

BACKGROUND: The aim of this study was to identify genes that are differentially expressed in the early period after pancreatic cold ischemia/reperfusion (I/R) injury. METHODS: Grafts of isogeneic rat pancreaticoduodenal transplantation were subjected to different preservation solutions and cold ischemia times (CITs): University of Wisconsin (UW), 6-hour CIT; UW, 18-hour CIT; and physiologic saline solution, 6-hour CIT. Animals that did not receive transplants served as controls. At 2-hour reperfusion, grafts were removed and pancreatic RNA was isolated, pooled, and hybridized to Affymetrix RG-U34A arrays. Quantitative reverse-transcription polymerase chain reaction was used to confirm the results of microarray technology. RESULTS: A total of 49 genes were consistently upregulated (more than threefold) in all three groups of transplant recipient animals. Prominent genes include transcription factors; cytoskeletal factors; heat-shock proteins (e.g. Hsp27, Hsp90); molecules involved in inflammation (e.g. PAPIII), immunology, signal transduction, and translation; and genes that have not been associated with I/R injury so far (e.g. Best5). Messenger RNA levels of some genes were exclusively downregulated in response to the different conditions applied to the pancreatic grafts: Cybb, Reg3a, Per2, BMAL1, MAP, and Isl2. CONCLUSIONS: These results provide new insight in I/R-induced gene expression after experimental pancreas transplantation. The reported upregulation of heat shock proteins, Best5, and PAPIII may play a pathologic role in pancreatic cold I/R injury and could therefore provide a promising perspective for further investigations.

Effects of organ preservation, ischemia time and caspase inhibition on apoptosis and microcirculation in rat pancreas transplantation.

This study was undertaken to examine the impact of ischemia-reperfusion (I/R) injury on microcirculation and apoptosis in experimental pancreas transplantation. Pancreatic grafts were subjected to different preservation solutions and cold ischemia times (CITs): University of Wisconsin (UW), 6-h CITs (group U6); UW, 18-h CITs (group U18); normal saline, 6-h CITs (group S6); and normal saline, 6-h CITs with Z-Asp-2,6-dichlorobenzoyloxymethylketone (pan-caspase inhibitor; group S6 & CI). Nontransplanted animals served as controls. At 1- and 2-h reperfusion microcirculation was assessed by means of intravital microscopy. Apoptosis was detected by in situ nick end-labeling method (TUNEL) at 2-h reperfusion. Deterioration of microcirculation was lowest in group U6 and highest in groups S6 and S6 & CI compared with controls. The apoptotic index (cells per high power fields) of groups U6, U18 and S6 correlated well with functional capillary density (r=- 0,70, p < 0.0001) and leucocyte sticking (r= 0,69, p < 0.0001) at 1-h reperfusion. Caspase inhibition had no impact on microcirculation but significantly reduced AI compared with group S6 (p < 0.001). These data suggest that pancreatic I/R injury-induced apoptotic cell death well predicts the extent of [corrected] microcirculatory impairment. Caspase inhibition might be a promising strategy in reducing I/R injury in pancreas transplantation.

Ischemic preconditioning fails to improve microcirculation but increases apoptotic cell death in experimental pancreas transplantation.

Brief periods of warm ischemia and subsequent short reperfusion before either long-term cold or warm ischemic insult (ischemic preconditioning, IPC) have proven to ameliorate ischemia/reperfusion (I/R) injury in various organs, such as the liver and lung. The aim of this study was to examine the effect of IPC on pancreatic cell apoptosis and microcirculatory impairments in experimental pancreas transplantation. Male Lewis rats served as donors and recipients of heterotopic syngeneic pancreaticoduodenal transplantation. Recipient animals were divided into two experimental groups: group Tx (n=7) received grafts without IPC, group Tx&IPC received grafts with IPC. Animals that had not undergone transplantation but whose pancreata had been exteriorized served as controls (n=5). All pancreatic grafts were preserved in University of Wisconsin solution for 6 h at 4 degrees C. IPC was induced by interruption of the arterial blood flow for 10 min followed by 10 min of reperfusion. One and two hours after reperfusion, graft microcirculation was assessed by means of intravital microscopy (IVM). Rats were immediately killed after the second measurement and DNA breaks of acinar cells were detected by in situ terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate digoxigenin nick end-labelling (TUNEL) assay and gel electrophoresis (laddering). The apoptotic index (AI) was defined as the number of apoptotic cells per high-power field. Analysis of both groups of transplanted grafts showed a significant decrease in functional capillary density (FCD) and a significant increase in leukocyte sticking to postcapillary venules (LAV) at 1 h and 2 h of reperfusion, compared with animals that had not undergone transplantation ( P<0.01). In parallel, AI was significantly increased in transplanted grafts compared to the controls ( P<0.01). Grafts subjected to IPC showed no significant differences, neither for FCD nor LAV, at both time points if compared with grafts of group Tx. However, IPC resulted in a significant increase in AI ( P<0.05). We can conclude that IPC has no effect on pancreatic microcirculation but enhances acinar cell apoptosis in experimental pancreas transplantation. These results indicate that IPC might increase I/R injury after pancreatic cold ischemia.

Brain death impairs pancreatic microcirculation.

Brain death (BD) influences the quality of donor grafts in transplantation. To evaluate the impact of BD on pancreas grafts, we investigated the influence of BD on the microcirculation and histology of the pancreas in a rat model of explosive BD. A group of Wistar rats (n=7), rendered brain dead by inflating an intracranially inserted Fogarty catheter was compared with controls (CO) using intravital epifluorescence-microscopy over 4 h after BD induction; functional capillary density (FCD), leukocyte adherence (AL) in post-capillary venules, histology and pancreatic enzymes were investigated. Four hours after BD, FCD decreased (333 +/- 11 vs. baseline 444 cm/cm2 +/- 5 SEM; p<0.01) and showed lower values than CO (388 +/- 9 p<0.01). In BD, AL was increased (628 cells/mm2 +/- 110 SEM vs. baseline 123 +/- 32, and vs. CO 180 +/- 33; p<0.001). BD caused increased histological damage (CO 1.6 score-points +/- 0.7 SD vs. BD 8.3 +/- 7.1; p<0.05). Amylase was higher in BD (p<0.05) but did not reach pathological values. We show for the first time that BD causes relevant changes in pancreatic microcirculation, histology and leukocyte endothelial interaction which might have a serious impact on the function of grafts. New strategies for preventing this damage are therefore highly desirable in order to improve the outcome of pancreas transplantation.

Endotoxin preconditioning in pancreatic ischemia/reperfusion injury.

OBJECTIVES: Prospective organ donors are exposed to various stress types. The effect of endotoxin pretreatment (ETX) on pancreatic ischemia/reperfusion injury (IRI) is unclear. We investigated, using a rat model of pancreatic IRI of an in situ isolated pancreatic tail segment, the effect of ETX on postischemic microcirculation and organ damage. METHODS: Twenty-four hours before pancreatic dissection, either intraperitoneal application of ETX (1 mg/kg in 0.9% NaCl) or saline only (control) was performed. Two-hour normothermic ischemia of the pancreatic tail was induced by clamping the splenic vessels and was followed by a reperfusion period of 2 hours. Microcirculatory parameters were measured by intravital epifluorescence microscopy [functional capillary density (FCD), adherent leukocytes (ALs), and histology]. The presented data represent the mean +/- SEM/SD as appropriate. RESULTS: ETX pretreatment caused a significantly greater decrease in FCD (497 +/- 6 cm/cm2 baseline versus 326 +/- 15 cm/cm2 2 hours of reperfusion) compared with controls (498 +/- 8 versus 258 +/- 15 cm/cm2) 2 hours after reperfusion (P < 0.01). Two hours after reperfusion, ALs were significantly decreased in ETX animals compared with controls (ETX: 141 +/- 37 versus 273 +/- 36 cells/mm2, P < 0.05). Histologic damage was less in ETX (6.4 score points +/- 0.32 versus 8.8 +/- 0.33 control, P < 0.05). CONCLUSION: ETX preconditioning decreases microcirculatory deterioration caused by IRI by means of less loss of nutritive tissue perfusion, decrease in ALs, and less histologic damage. This indicates a protective effect of ETX preconditioning in pancreatic IRI.

Intra-arterial instillation of microencapsulated, Ifosfamide-activating cells in the pig pancreas for chemotherapeutic targeting.

BACKGROUND: The therapeutic efficacy of intratumoral instillation of genetically engineered, CYP2B1-expressing, microencapsulated cells in combination with ifosfamide had been previously demonstrated in xenografted human pancreatic ductal carcinomas [Gene Ther 1998;5:1070-1078]. Prior to a clinical study, the feasibility of an intra-arterial application of microencapsulated cells to the pancreas and its consequences to the organ had to be evaluated. MATERIAL AND METHODS: Microencapsulated, CYP2B1-producing cells were instilled both in vivo (transfemoral angiographical access) and in vitro (perfusion model) in the splenic lobe of the pig pancreas. In vivo, animals were monitored clinically for 7 days, then treated with ifosfamide and sacrificed. In vitro, ifosfamide was administered intra-arterially. RESULTS: In all animals, 100 microcapsules could be instilled safely via the femoral route without clinical, biochemical or histological signs of pancreatitis. Histological examination revealed partial obstruction of small arteries by the capsules, without causing any parenchymal damage. In vitro, instillation reduced blood flow by half. Ifosfamide, also in combination with the capsules, did not add any damage to the pancreas. CONCLUSION: Intra-arterial instillation of microencapsulated cells to the pig pancreas is feasible and safe. Neither pancreatitis, foreign body reactions nor circulatory disturbances were observed. Clinical application of this genetically enhanced chemotherapeutic method seems possible.

Microcirculatory events in ischemia/reperfusion of the pancreas defined by continuous tissue oximetry.

In ischemia/reperfusion of the pancreas impairment of microcirculation after reperfusion is believed to be of critical importance. The 'no-reflow' phenomenon is thought to cause persisting tissue ischemia, while the 'reflow-paradox' is defined as secondary impairment of nutritive perfusion. These phenomena have been shown by intravital microscopy but their effect on tissue oxygenation as assessed by continuous tissue oximetry has not been identified. In landrace pigs tissue oxygenation was investigated in warm ischemia/reperfusion of the pancreas by the use of continuous tissue oximetry. After reperfusion rapid reoxygenation occurred which was followed by a period of secondary hypoxia. Thereafter, secondary reoxygenation was found, and finally tertiary hypoxia with a gradual decline of tissue pO(2) was noted. The data show a relevant impairment of tissue oxygenation after reperfusion. However, 'no-reflow' seems not to be a primary failure of capillary reperfusion but the consequence of a short reperfusion period followed by secondary ischemia. The 'reflow-paradox' most likely corresponds to tertiary ischemia.