Knowing and acting in the clinical workplace: trainees' perspectives on modelling and feedback.

In this article we discuss clinical workplace learning using a dual approach: a theoretical one and an empirical one. Drawing on the philosophical work of Aristotle, Polanyi and Schön we posit that the 'knowing and acting' underpinning day-to-day medical practice is personal and embraces by nature a tacit dimension. Consequently, imparting and acquiring this knowledge type necessitates personal interaction between trainer and trainee. The tacit dimension particularly influences modelling and feedback. In our empirical exploration we explore these educational routes in two disparate disciplines: surgery and paediatrics. We use a longitudinal design with in-depth interviewing. Our conclusion on modelling is: modelling is a dynamic and fragmented process reflecting discipline bound characteristics and working styles. On feedback it is: 'feedback' serves as vehicle for three distinctive forms of commenting on performance, each holding a specific power of expression for learning. We propose to view clinical workplace learning as: an interactive master-apprenticeship model encompassing modelling and feedback as natural educational routes. We conceptualise modelling and feedback as 'function' of interaction (developing grounded theory). Modelling function and feedback function may serve to study these routes as didactical components of ongoing interaction between trainer and trainee rather than an educator-driven series of unrelated events.

Reduced porcine islet isolation yield in the presence of hyperemic islets.

When studying histological characteristics of porcine pancreata in relation to islet isolation, a remarkably high number of hyperemic islets (HIs) was encountered. The abnormalities observed in these HIs ranged from a single dilated vessel to hemorrhages extending into the surrounding exocrine tissue. The aim of the present study was to compare pancreata with and without HI on islet isolation outcomes. This study involved a histological examination of 143 purebred (74 juvenile and 69 adult) and 47 crossbred (only juvenile) porcine pancreata. Islet isolation was performed in 48 purebred adult pigs and in 25 crossbred pigs. Tissue samples were stained with Aldehyde Fuchsine. The presence of HIs was scored semi-quantitatively (HI-, HI+). We observed HIs in 48% of the purebred and in 68% of the crossbred pigs. However, only 3.3±3.1% and 3.1±4.7% of all assessed islets was hyperemic in HI+ pancreata in purebred and crossbred pigs, respectively. In both groups, significantly higher endocrine cell mass was found in the HI+ pancreata (p<0.01). When the higher endocrine cell mass was taken into account, we found significantly lower yields in the HI+ pancreata in both purebred and crossbred pigs (p=0.03 in both groups). The presence of HIs occurs frequently in porcine donor-pancreata and is associated with reduced isolation outcomes.

Presence of hyperemic islets in human donor-pancreata results in reduced islet isolation yield.

When studying histological characteristics of human donor-pancreata, a remarkably high number of hyperemic islets (HIs) were encountered. The abnormalities in these HIs ranged from single/multiple dilated vessels to hemorrhages extending into the exocrine tissue. We aimed to determine the relevance of the presence of HIs in human donor-pancreata for isolation outcome and to identify donor and procurement factors associated with the occurrence of HIs. The presence of HIs was scored semi-quantitatively (HI-, HI+) in 102 human donor-pancreata. Islet isolation was performed in 40 cases. Donor and procurement factors were retrospectively analyzed in 94 donors. HIs were found in 54.6% of all donor-pancreata. However, only 4.5% of all islets in the affected pancreata was hyperemic. The affected pancreata contained slightly more endocrine tissue, but produced significantly lower yields. When corrected for other factors known to influence isolation outcome, the presence of HIs and endocrine content were the only factors significantly influencing isolation outcome. Prolonged ICU stay and pre-procurement hypertension were associated with the presence of HIs. This study is a first indication that the presence of HIs in human donor-pancreata are associated with reduced isolation outcomes and suggest an impact of the procurement procedure and pre-procurement hemodynamic status of the donor on the islet quality. It is tempting to speculate that this contributes to the generally experienced difficulties in obtaining sufficient amounts of human islets.

More than 25 years of surgical treatment of hydatid cysts in a nonendemic area using the "frozen seal" method.

BACKGROUND: Hydatid disease of the liver remains endemic in the world and is an imported disease in The Netherlands. The aim of this study was to evaluate the treatment and outcome of surgically treated patients for hydatid disease in a single center in The Netherlands. METHODS: This retrospective study included 112 consecutive patients surgically treated for hydatid disease between 1981 and 2007. The primary outcome was relapse of the disease. Secondary outcomes were infections, complications, reoperations, length of hospital stay, and mortality. RESULTS: In all cases, echinococcosis was diagnosed by computed tomography or ultrasonography (US). Serology (enzyme-linked immunosorbent assay, immunofluorescence) confirmed the diagnosis in 92.9%. Most of the cysts were seen only in the liver (73.5%). All cysts were operated on with the frozen seal technique. Relapse of disease was seen in 9 (8.0%) cases. Five (4.5%) required surgical treatment at a later stage. Twenty (17.9%) complications were recorded. Four (3.6%) needed radiological drainage and three (2.7%) a reoperation. Follow-up was performed with US and/or serology at a mean of 24 months (range 0.5-300 months). All but one complication were seen in the liver-operated group, this proved not to be of statistical significance (P = 0.477). Patients with complications stayed significantly longer in hospital than did the patients without complications (P < 0.001). No mortality was observed in this study. CONCLUSIONS: The present study suggests that the frozen seal method of surgery for hydatid disease is safe and effective. Future studies are needed to prove its position in the treatment of hydatid disease as new developments show promising results.

Hyperemic islets: a possible explanation for poor yields in human and porcine islet isolation.

When studying histological characteristics of human and porcine pancreata in relation to islet isolation, we encountered a remarkably high number of hyperemic islets. The abnormalities observed in these islets ranged from a single dilated vessel through multiple widely dilated vessels to hemorrhages extending into the surrounding exocrine tissue. We determined their possible relevance for outcomes of islet isolation. This study involved a histological examination of 143 porcine pancreata (72 juvenile and 71 adult) and islet isolation from 48 adult pancreata. Human pancreata obtained from 71 multiple organ donors yielded islet isolation in 24 cases. To determine their endocrine content, tissue samples were stained with Aldehyde Fuchsin. The presence of hyperemic islets was scored semiquantitatively with pancreata allotted to categories based on the severity. In humans and pigs we observed hyperemic islets in 48% of pancreata, but only 4.0 +/- 2.4% of the islets were hyperemic. In both humans and pigs, significantly higher endocrine content was found in the most severely affected pancreata. When the higher endocrine content was taken into account and isolation results were expressed as ratios of yield and content, we observed significantly lower yields in the most affected pancreata in pigs with a trend toward lower yields in humans. A substantial proportion of human and porcine pancreata contain hyperemic islets. Although the results in humans are preliminary, our data suggest that this phenomenon may contribute to the unpredictable, highly variable islet yields in pigs and humans.

Amount and distribution of collagen in the pancreas have no effect on porcine islet isolation outcome.

Xenotransplantation of porcine islets of Langerhans is considered to be a possible alternative for clinical islet transplantation. However, porcine islet isolation procedures have been shown to produce highly variable yields between pigs with similar backgrounds. One of the variables that could account for this is the collagen substrate within the pancreas. We determined the amount and distribution of collagen within porcine pancreata as they determined islet isolation outcomes. This study involved the histological examination of 140 porcine pancreata (64 juvenile and 76 adult) and islet isolation from 58 adult organs. To quantify the amount of collagen, tissue samples were stained with Sirius Red. Collagen distribution was determined by assessing the presence of collagen in the endocrine-exocrine interface (the "islet capsule"), in tissue samples double-stained with Sirius Red and anti-insulin. Strong variation in total collagen was observed in both adult and juvenile pigs. The mean collagen content in the juvenile group was significantly lower than that in the adult group. Apparently, the pancreas undergoes a process of fibrosis as pigs age. The vast majority of islets from both adult and juvenile pancreata had no or only a limited collagen capsule. However, islet encapsulation was highly variable between pancreata. We observed no significant correlation between total collagen content or the percentage islet encapsulation and islet yield. Although total collagen content and islet encapsulation show great variability between pancreata, neither the amount nor the distribution of collagen affected porcine islet isolation outcome.

Heterogeneity of human pancreata in perspective of the isolation of the islets of langerhans.

The success of human islet isolation is hampered by the varied and unpredictable outcomes of the islet isolation procedure. Pancreata which meet well-defined criteria are no guarantee for success. Interindividual variations may contribute to the differences in isolation outcomes. The present study examined several structural elements in the anatomy of the human pancreas for possible relevance for islet isolation. Sixty pancreata were used for histochemical and immunochemical analyses. We assessed the total percentage of endocrine tissue and the size distribution of the islets. Sirius Red staining quantified total collagen content; the degree of islet encapsulation with collagen was correlated with total collagen. We analyzed the percentage of pancreatic edema and amount of intraparenchymal fat. The percentage of endocrine tissue varied 5-fold with wide variations in islet size distribution. A strong variation was observed for total collagen; its content increased slightly with age. The number of islets totally encapsulated with collagen varied strongly with no relation to age or to total collagen. Pancreatic edema and intraparenchymal fat also showed great differences. These differences justifies continued study to evaluate the correlation of these variables with isolation outcomes.

Isolation of the islets of Langerhans from the human pancreas with magnetic retraction.

Low yield and insufficient purity limit the transplantation of human islets of Langerhans. In the rat, a new technique to isolate the islets of Langerhans was developed by intraarterial infusion of iron particles into the islet capillaries. After digestion the iron-loaded islets were purified with magnetic retraction (MR). In the present study, 10 human pancreata not suitable for clinical use were arterially injected with an iron-oxide suspension. After injection a small piece was used for histological analysis, and the tail was intraductally perfused with collagenase and manually digested. The yield was compared with 11 pancreata processed in the standard way. Nine of 10 pancreata were successfully injected with iron-oxide and digested. After MR, enrichment was achieved but the purity was not more than 50%. Similar results between the 2 groups were obtained regarding digestion times (23 +/- 1.1 vs 22.7 +/- 1.5 minutes) and purification yields (1749 +/- 502.1 vs 2111 +/- 501.8 IE/g, P = .6) for the MR vs control groups, respectively. Histological analysis revealed that 60% to 88% of the islets contained iron aggregations with substantially higher concentrations compared with the exocrine tissue. In conclusion, iron-oxide did not influence the isolation outcome before purification. Islet purification with MR gave enrichment but no pure fractions.

Differential inhibition of autoreactive memory- and alloreactive naive T cell responses by soluble cytotoxic T lymphocyte antigen 4 (sCTLA4), CTLA4Ig and LEA29Y.

Cytotoxic T lymphocyte antigen 4 (CTLA4) is a potent inhibitory co-stimulatory molecule believed to be involved in type 1 diabetes and other autoimmune diseases. An association has been reported of both mRNA expression and serum levels of the soluble splice variant of CTLA4 (sCTLA4) with type 1 diabetes. Furthermore, recombinant fusion proteins CTLA4Ig and LEA29Y have been proposed as therapies for type 1 diabetes. We studied the role of (s)CTLA4 in islet autoimmunity. Binding capacity of the proteins to antigen-presenting cells was determined by flow cytometry in competition and binding assays. Functionality of sCTLA4 as well as the therapeutic inhibitory fusion proteins CTLA4Ig and LEA29Y was measured in a dose-response lymphocyte stimulation test, using a panel of diabetes-associated T cell clones reactive to islet autoantigens. As controls, mixed lymphocyte reactions (MLR) were performed to assess functionality of these proteins in a primary alloreactive setting. All three CTLA4 molecules were able to bind to antigen-presenting cells and inhibit the expression of CD80/CD86. sCTLA4 was able to suppress proliferation of different committed autoreactive T cell clones in a dose-dependent manner, whereas CTLA4Ig and LEA29Y were not. Conversely, CTLA4Ig and LEA29Y, rather than sCTLA4, were able to suppress naive alloreactive proliferation in a MLR. Our results indicate a differential role for sCTLA4, CTLA4Ig and LEA29Y proteins in memory versus primary immune responses with implications for efficacy in intervention therapy.

Life-saving therapy for haemorrhaging liver adenomas using selective arterial embolization.

BACKGROUND: Emergency treatment for patients with a ruptured hepatocellular adenoma is controversial. The aim of this study was to evaluate management with selective arterial embolization. METHODS: The study included 11 consecutive patients treated for ruptured hepatocellular adenomas between 2001 and 2006. After initial haemodynamic support, all patients received selective embolization of branches of the hepatic artery. The primary outcome was effectiveness in stopping the bleeding. Secondary outcomes were complications and changes in tumour size after embolization. RESULTS: A single embolization brought haemorrhaging under control in ten patients; one patient needed three embolizations. None of the patients required emergency surgery. In the follow-up of 19 (range 7-49) months, no general or hepatobiliary complications were observed. All 25 adenomas, including those without signs of haemorrhaging in the same liver lobe, were either smaller or not detectable on computed tomography or magnetic resonance imaging after embolization, with the median diameter decreasing from 7.0 to 2.5 cm (P < 0.001). CONCLUSION: Selective embolization of the hepatic artery is a safe and adequate first approach in the management of patients with haemorrhaging hepatocellular adenomas. Furthermore, arterial embolization reduces the size of adenomas in the liver.

A novel technique for auxiliary partial liver transplantation with reno-portal anastomosis and avoidance of the hepatoduodenal ligament.

Auxiliary liver transplantation (ALT) is a treatment for acute liver failure when regeneration of the native liver is possible or for metabolic disorders. In selected cases ALT and orthotopic liver transplantation (OLT) have similar survival when ALT is performed in the orthotopic position (auxiliary partial orthotopic liver transplantation, APOLT). Drawback of ALT with portal vein to portal vein anastomosis is the frequent occurrence of thrombosis, compromising both graft and native liver, and the necessity of a significant resection. To avoid division of portal flow we performed ALT with an end-to-end anastomosis between the graft portal vein and the left renal vein of the recipient (reno-portal ALT, REPALT). The hepatic artery was anastomosed to the aorta using an iliac arterial graft conduit. The bile duct was anastomosed to the stomach. In the two cases presented here excellent immediate graft function occurred with rapid regeneration of the graft and without early vascular complications.

Integrin signaling via RGD peptides and anti-beta1 antibodies confers resistance to apoptosis in islets of Langerhans.

Islet transplantation is associated with a high rate of early graft failure caused by early immune attack and poor functionality of islets. Apoptosis of islet cells appears soon after islet isolation and primarily involves the beta-cell. The purpose of this study was to determine the effect of ligation to extracellular matrix (ECM) proteins on survival of the islets of Langerhans following islet isolation. Islets that had been cultured for 24 h on collagen type I showed an islet survival of 59.7 +/- 8.7%, while islets that had been cultured on collagen type IV and laminin showed an islet survival of 88.6 +/- 10.3 and 94.3 +/- 5.6%, respectively. Islets that had been pretreated with anti-beta1 antibodies and argenin-glycin-aspartic acid (RGD) peptides showed a decrease in the level of apoptosis by a factor of 2.5 and 3.1, respectively, and an increase of phospho-Akt Ser 473 activity by a factor of 3.1 and 2.9, respectively, compared with untreated islets. When detached from their natural ECM surrounding in the pancreas, islet cells undergo apoptosis, unless islets are cultured on collagen IV or laminin or treated with anti-beta1 integrin antibodies or RGD peptides to mimic ECM ligation. These results indicate that inhibition of anoikis may offer opportunities to improve function and viability of islet cells.

Locoregional therapies of liver metastases in a rat CC531 coloncarcinoma model results in increased resistance to tumour rechallenge.

BACKGROUND: Locoregional treatments like photodynamic therapy (PDT), radiofrequency ablation (RFA) or hepatic artery infusion (HAI) of chemotherapeutics may be applied for unresectable colorectal liver metastases. We evaluated the effect of these treatments on the immune response in a rat colon tumour liver metastases model. METHOD: Wag/Rij rats were inoculated at day 0 with CC531 tumour cells at two sites in the liver. At day 15, one of two tumours was treated with RFA or PDT, or the liver was treated by HAI. Twelve days later (day 27), rats were rechallenged locally with CC531 cells in the liver or systemically with CC531 cells in the femoral vein. At day 42, tumour growth in liver and lungs was determined. RESULTS: RFA, PDT and HAI were very effective in liver tumour eradication, but following RFA or PDT there was no inhibitory effect on untreated nearby liver tumours. Outgrowth after local rechallenge was, however, significantly inhibited in RFA-, PDT- and HAI-treated rats, whereas all control rats showed outgrowth of a third liver tumour. After systemic rechallenge, control rats developed lung metastases whereas treated rats did not, but this difference was not statistically significant. CONCLUSION: These results show that following PDT, RFA and HAI resistance to local and possibly systemic tumour rechallenge is increased. This may be partly due to the induction or enhancement of a cellular immune response.

[Transplantation of the islets of Langerhans in patients with diabetes mellitus type 1]. / Transplantatie van eilandjes van Langerhans bij patiënten met diabetes mellitus type 1.

Since 1921 and until recently, insulin by injection has been the only treatment for patients with diabetes mellitus type 1. After pancreas transplantation, which became possible in 1977, the next logical step to cure patients with diabetes mellitus type 1 is the transplantation of the islets of Langerhans. In the last few years, the results of islet transplantation are markedly improved thanks to developments in the isolation technique and better immunosuppressive protocols. Ongoing problems in islet transplantation are allo-immunity, auto-immunity and the growing shortage of donor pancreases. Alternatives to pancreas donation, be it post-mortem or from a living donor, could be: sources for islets are xenotransplantation with the aid of pig islets and beta-cell neogenesis from embryonic stem cells or pancreatic duct cells.

Stable transplantation results of magnetically retracted islets: a novel method.

AIMS/HYPOTHESIS: Large quantities of pure viable donor islets are necessary for clinical transplantation. At present, low yields and low viability of pancreatic islets after transplantation necessitate the use of multiple donors for a single recipient. In this study an improved method for obtaining large quantities of pure viable islets of Langerhans for transplantation was developed in the rat. METHODS: Islets of Langerhans were isolated from Albino Oxford rats. The donor pancreata were perfused in situ with iron oxide, which resulted in entrapment of iron particles in the capillaries of the islets. Subsequently, the islets were isolated by magnetic retraction. Islets obtained with this method were compared with islets obtained by density gradient-isolated islets with respect to yields, purity, and insulin production capacity. Islets isolated with the magnetic retraction method were transplanted under the renal capsule of streptozotocin-induced diabetic recipients. Blood-glucose levels in the recipients were monitored for 2 months after transplantation. RESULTS: This method yielded more pure and viable islets than the conventional protocol. No contamination of exocrine tissue was observed after isolation. Furthermore, the islets isolated by magnetic retraction stained strongly positive for insulin during the entire observation period in vitro, and produced high amounts of insulin upon a challenge with glucose. The islets that were obtained by this new protocol were suitable for safe and effective transplantation. CONCLUSIONS/INTERPRETATION: We have shown that both the quantity and quality of islets obtained with this method were sufficient to induce insulin independence in a diabetic recipient using islets from only one donor.

The intercollegiate Basic Surgical Skills Course.

OBJECTIVE: This study was undertaken to establish residents' progress in minimal access surgery (MAS) after attending the Intercollegiate Basic Surgical Skills Course (BSSC) by means of the Xitact LS500 laparoscopy simulator assessment program. METHODS: Twenty-five surgical residents attended the BSSC in Leiden and Eindhoven, The Netherlands. Before and after the course, participants performed three "runs" on the Xitact LS500, featuring a standardized laparoscopic cholecystectomy clip-and-cut task. A control group of 25 interns not attending the course also performed two sessions of three runs. Parameters of interest were "score" and "time for completion of task". RESULTS: No significant differences were found within the resident group for the parameters "time" and "score" when comparing outcomes pre- and post-BSSC. No significant differences were found comparing time and score between residents and interns on each of the six runs, except for time in run 2. Over six runs, both residents and interns became significantly faster. CONCLUSIONS: The Xitact LS500 cholecystectomy simulator did not detect significant improvement in MAS performance among a group of surgical residents attending the BSSC.

Aprotinin in orthotopic liver transplantation: evidence for a prohemostatic, but not a prothrombotic, effect.

Aprotinin reduces blood transfusion requirements in orthotopic liver transplantation (OLT). Concern has been voiced about the potential risk for thrombotic complications when aprotinin is used. The aim of this study is to evaluate the effects of aprotinin on the two components of the hemostatic system (coagulation and fibrinolysis) in patients undergoing OLT. As part of a larger, randomized, double-blind, placebo-controlled study, we compared coagulation (fibrinogen level, activated partial thromboplastin time [aPTT], prothrombin time, and platelet count) and fibrinolytic variables (tissue-type plasminogen activator [tPA] antigen and activity, plasminogen activator inhibitor activity, and D-dimer), as well as thromboelastography (reaction time [r], clot formation time, and maximum amplitude) in 27 patients administered either high-dose aprotinin (2 x 10(6) kallikrein inhibitor units [KIU] at induction, continuous infusion of 1 x 10(6) KIU/h, and 1 x 10(6) KIU before reperfusion; n = 10), regular-dose aprotinin (2 x 10(6) KIU at induction and continuous infusion of 0.5 x 10(6) KIU/h; n = 8), or placebo (n = 9) during OLT. Blood samples were drawn at seven standardized intraoperative times. Baseline characteristics were similar for the three groups. During the anhepatic and postreperfusion periods, fibrinolytic activity (plasma D-dimer and tPA antigen levels) was significantly lower in aprotinin-treated patients compared with the placebo group. Interestingly, coagulation times (aPTT and r) were significantly more prolonged in aprotinin-treated patients than the placebo group. No difference was seen in the incidence of perioperative thrombotic complications in the entire study population (n = 137). Aprotinin has an anticoagulant rather than a procoagulant effect. Its blood-sparing (prohemostatic) effect appears to be the overall result of a strong antifibrinolytic and a weaker anticoagulant effect. These findings argue against a prothrombotic effect of aprotinin in patients undergoing OLT.

Routine testing of liver function after biliary-enteric anastomosis has no clinical relevance.

BACKGROUND/AIMS: Patients who had a biliary-enteric anastomosis often have elevated liver function tests. The aim of this study was to investigate whether elevated liver function tests are associated with recurrent episodes of cholangitis. METHODOLOGY: Thirty-two patients, who received a biliary-enteric anatomosis for benign biliary disease were evaluated. Follow-up consisted of the patient's history, physical examination, determination of liver function tests, ultrasonography and hepatobiliary scintigraphy using 99mTc-HIDA. RESULTS: Median duration of follow-up was 45 months (range: 1-192) and liver function tests were elevated in 22 patients (69%) at some time during follow-up. Dilated intrahepatic ducts were found in 3 of 30 patients (10%), all of whom had elevated liver function tests at follow-up. Delayed passage from the liver was observed using scintigraphy in 10 (31%) of the patients. Seven patients (22%) experienced one episode of cholangitis and none experienced more than one episode. Multivariate analysis showed that male sex was an independent risk factor for elevated liver function tests (odds ratio: 10.9; P < 0.05). For cholangitis, no risk factors could be identified. CONCLUSIONS: It is concluded that elevated liver function tests are relatively common after a biliary-enteric anastomosis for benign biliary tract disease and are not predictive of the occurrence of cholangitis. We, therefore, recommend omitting routine laboratory screening for elevated liver function tests in the follow-up of a biliary-enteric anastomosis.

Reduced need for vasopressors in patients receiving aprotinin during orthotopic liver transplantation.

BACKGROUND: Graft reperfusion in orthotopic liver transplantation is often associated with significant hemodynamic changes, including decreased systemic vascular resistance and arterial blood pressure. Vasopressive drugs are often required to maintain adequate perfusion pressure during the early postreperfusion period. The exact mechanism of this postreperfusion syndrome is unknown, but release of bradykinin, a potent vasodilatator, via the kallikrein system may play a role. Aprotinin is a broad-spectrum inhibitor of serine proteases such as kallikrein and therefore may ameliorate the postreperfusion syndrome and reduce the need for vasopressors. METHODS: In a randomized, double-blind study, the authors compared hemodynamic variables (systemic vascular resistance, cardiac index, arterial blood pressure, mean pulmonary artery pressure, central venous pressure) and the requirement of epinephrine during transplantation in 67 patients who received either high-dose aprotinin (2 x 10(6) kallikrein inhibitor units [KIU] at induction, continuous infusion of 1 x 10(6) KIU/h, 1 x 10(6) KIU before reperfusion; n = 24), regular-dose aprotinin (2 x 10(6) KIU at induction, continuous infusion of 0.5 x 10(6) KIU/h; n = 21), or placebo (n = 22). RESULTS: Baseline characteristics were similar for all three groups. Erythrocyte transfusion requirement was significantly higher in the placebo group compared with both aprotinin-treated groups. No major differences in hemodynamic variables were found between the three groups. The total amount of epinephrine (median, range) used during transplantation, however, was significantly lower in patients who received aprotinin (high dose, 20, 0-170 microg; regular dose, 30, 0-140 microg), compared with patients who received placebo (70, 0-2,970 microg; P = 0.0017). This difference was largely attributable to differences in the early postreperfusion period. CONCLUSIONS: Prophylactic use of aprotinin ameliorates the postreperfusion syndrome in orthotopic liver transplantation, as reflected by a significant reduction in vasopressor requirements.