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Robert J Porte

Publications and source records attributed to Robert J Porte.

34 records · Page 2Linked to original sources
PubMed2005

Cyst fluid analysis in the differential diagnosis of pancreatic cystic lesions: a pooled analysis.

BACKGROUND: Pancreatic cystic tumors commonly include serous cystadenoma (SCA), mucinous cystadenoma (MCA), and mucinous cystadenocarcinoma (MCAC). A differential diagnosis with pseudocysts (PC) can be difficult. Radiologic criteria are not reliable. The objective of the study is to investigate the value of cyst fluid analysis in the differential diagnosis of benign (SCA, PC) vs. premalignant or malignant (MCA, MCAC) lesions. METHODS: A search in PubMed was performed with the search terms cyst, pancrea, and fluid. Articles about cyst fluid analysis of pancreatic lesions that contained the individual data of at least 7 patients were included in the study. Data of all individual patients were combined and were plotted in scatter grams. Cutoff levels were determined. RESULTS: Twelve studies were included, which comprised data of 450 patients. Cysts with an amylase concentration <250 U/L were SCA, MCA, or MCAC (sensitivity 44%, specificity 98%) and, thus, virtually excluded PC. A carcinoembryonic antigen (CEA) <5 ng/mL suggested a SCA or PC (sensitivity 50%, specificity 95%). A CEA >800 ng/mL strongly suggested MCA or MCAC (sensitivity 48%, specificity 98%). A carbohydrate-associated antigen (CA) 19-9 <37 U/mL strongly suggested PC or SCA (sensitivity 19%, specificity 98%). Cytologic examination revealed malignant cells in 48% of MCAC (n = 111). DISCUSSION: Most pancreatic cystic tumors should be resected without the need for cyst fluid analysis. However, in asymptomatic patients, in patients with an increased surgical risk, and, in patients in whom there is a diagnostic uncertainty about the presence of a PC, cyst fluid analysis helps to determine the optimal therapeutic strategy.

Adult↗
PubMed2005

Expression of heme oxygenase-1 in human livers before transplantation correlates with graft injury and function after transplantation.

Upregulation of heme oxygenase-1 (HO-1) has been proposed as an adaptive mechanism protecting against ischemia/reperfusion (I/R) injury. We investigated HO-1 expression in 38 human liver transplants and correlated this with I/R injury and graft function. Before transplantation, median HO-1 mRNA levels were 3.4-fold higher (range: 0.7-9.3) in donors than in normal controls. Based on the median value, livers were divided into two groups: low and high HO-1 expression. These groups had similar donor characteristics, donor serum transaminases, cold ischemia time, HSP-70 expression and the distribution of HO-1 promoter polymorphism. After reperfusion, HO-1 expression increased significantly further in the initial low HO-1 expression group, but not in the high HO-1 group. Postoperatively, serum transaminases were significantly lower and the bile salt secretion was higher in the initial low HO-1 group, compared to the high expression group. Immunofluorescence staining identified Kupffer cells as the main localization of HO-1. In conclusion, human livers with initial low HO-1 expression (<3.4 times controls) are able to induce HO-1 further during reperfusion and are associated with less injury and better function than initial high HO-1 expression (>3.4 times controls). These data suggest that an increase in HO-1 during transplantation is more protective than high HO-1 expression before transplantation.

Adult↗
PubMed2005

Minimizing blood loss in liver transplantation: progress through research and evolution of techniques.

Blood loss during liver transplantation has long been recognized as an important cause of morbidity and, especially in the early days, also mortality. It is well known that blood transfusions are associated with an increased risk of postoperative complications, such as infections, pulmonary complications, protracted recovery, and a higher rate of reoperations. Many studies have been performed during the past decades to elucidate the mechanisms of increased blood loss in liver transplantation. In the late 1980s, primary hyperfibrinolysis was identified as an important mechanism of bleeding during liver transplantation. This has provided the scientific basis for the use of antifibrinolytic drugs in liver transplant recipients. Several randomized, controlled studies have shown the efficacy of these compounds in reducing blood loss and transfusion requirements during liver transplantation. In addition, increasing experience and improvements in surgical technique, anesthesiological care and better graft preservation methods have contributed to a steady decrease in blood transfusion requirements in most liver transplant programs. Several centers are now reporting liver transplantation without any need for blood transfusion in up to 30% of their patients. Despite these improvements, most patients undergoing liver transplantation still require blood transfusions that have a negative impact on outcome, emphasizing the need for further attempts to control blood loss by surgeons and anesthesiologists. This paper provides an overview of the clinical and research developments, which have contributed to a reduction in blood loss and transfusion requirements, resulting in an important reduction in morbidity and mortality after liver transplantation during the last two decades.

Antifibrinolytic Agents↗
PubMed2004

Orthotopic liver transplantation for portosystemic encephalopathy in an adult with congenital absence of the portal vein.

Congenital absence of the portal vein (CAPV) is a very rare venous malformation in which mesenteric venous blood drains directly into the systemic circulation. There is no portal perfusion of the liver and no portal hypertension. This abnormality is usually coincidentally discovered in children, the majority of whom have no signs of encephalopathy and only slightly abnormal liver function tests. Additional anomalies common in CAPV are cardiovascular abnormalities and hepatic tumors. To date, only 5 adult patients (>18 years) with CAPV have been described, none of whom underwent liver transplantation. We describe a 45-year-old man with CAPV and end-stage renal insufficiency due to focal segmental glomerulopathy, who developed therapy-resistant encephalopathy with intermittently high ammonia levels. The patient underwent a combined liver and kidney transplantation and is doing well at 2.5 years of follow-up. Histopathological examination of the native liver showed no portal vein branches in the portal tracts. In conclusion, our experience suggests that, although children with CAPV usually have no symptoms of encephalopathy, this may still develop at a later stage in adult life. When encephalopathy becomes refractory to medical therapy, orthotopic liver transplantation (OLT) can be successfully performed with restoration of normal cerebral function.

Comorbidity↗
PubMed2004

Rapid increase of bile salt secretion is associated with bile duct injury after human liver transplantation.

BACKGROUND/AIMS: Biliary strictures are a serious cause of morbidity after liver transplantation. We have studied the role of altered bile composition as a mechanism of bile duct injury after human liver transplantation. METHODS: In 28 liver transplant recipients, bile samples were collected daily posttransplantation for determination of bile composition. Hepatic expression of bile transporters was studied before and after transplantation. Histopathological criteria as well as biliary concentrations of alkaline phosphatase (ALP) and gamma-glutamyltransferase (gamma-GT) were used to quantify bile duct injury. RESULTS: Early after transplantation, bile salt secretion increased more rapidly than phospholipid secretion, resulting in high biliary bile salt/phospholipid ratio (BA/PL). In parallel with this, mRNA levels of the bile salt transporters NTCP and BSEP increased significantly after transplantation, whereas phospholipid translocator MDR3 mRNA levels remained unchanged. Bile duct injury correlated significantly with bile salt secretion and was associated with a high biliary BA/PL ratio. CONCLUSIONS: Bile salt secretion after human liver transplantation recovers more rapidly than phospholipid secretion. This results in cytotoxic bile formation and correlates with bile duct injury. These findings suggest that endogenous bile salts have a role in the pathogenesis of bile duct injury after liver transplantation.

ATP Binding Cassette Transporter, Subfamily B↗
PubMed2004

Liver transplantation with preservation of the inferior vena cava. A comparison of conventional and piggyback techniques in adults.

The aim of this study is to analyse a single centre's experience with two techniques of liver transplantation (OLT), conventional (CON-OLT) and piggyback (PB-ES), and to compare outcome in terms of survival, morbidity, mortality and post-operative liver function as well as operative characteristics. A consecutive series (1994-2000) of 167 adult primary OLT were analysed. Ninety-six patients had CON-OLT and 71 patients had PB-ES. In PB-ES group two revascularization protocols were used. In the first protocol reperfusion of the graft was performed first via the portal vein followed by the arterial anastomosis (PB-seq). In the second protocol the graft was reperfused simultaneously via portal vein and hepatic artery (PB-sim). One-, 3- and 5-yr patient survival in the CON-OLT and PB-ES groups were 90, 83 and 80%, and 83, 78 and 78%, respectively (p = ns). Graft survival at the same time points was 81, 73 and 69%, and 78, 69 and 65%, respectively (p = ns). Apart from the higher number of patients with cholangitis and sepsis in CON-OLT group, morbidity, retransplantation rate and post-operative liver and kidney function were not different between the two groups. The total operation time was not different between both groups (9.4 h in PB-ES vs. 10.0 h in CON-OLT), but in PB-ES group cold and warm ischaemia time (CIT and WIT), revascularization time (REVT), functional and anatomic anhepatic phases (FAHP and AAHP) were significantly shorter (8.9 h vs. 10.7 h, 54 min vs. 63 min, 82 min vs. 114 min, 118 min vs. 160 min and 87 min vs. 114 min, respectively, p < 0.05). RBC use in the PB-ES group was lower compared to the CON-OLT group (4.0 min vs. 10.0 units, p < 0.05). Except for WIT and REVT there were no differences in operative characteristics between PB-Sim and PB-Seq groups. The WIT was significantly longer in PB-Sim group compared with PB-Seq group (64 min vs. 50 min, p < 0.05); however REVT was significantly shorter in PB-Sim group (64 min vs. 97 min, p < 0.05). Results of this study show that both techniques are comparable in survival and morbidity; however PB-ES results in shorter AAHP, FAHP, REVT and WIT as well as less RBC use. In the PB-ES group there seems to be no advantage for any of the revascularization protocols.

Adult↗
PubMed2004

Plasma MMP-2 and MMP-9 and their inhibitors TIMP-1 and TIMP-2 during human orthotopic liver transplantation. The effect of aprotinin and the relation to ischemia/reperfusion injury.

Uncontrolled activation of matrix metalloproteinases (MMPs) can result in tissue injury and inflammation, yet little is known about the activation of MMPs during orthotopic liver transplantation (OLT). OLT is associated with increased fibrinolytic activity due to elevated plasmin generation. The serine-protease plasmin not only causes degradation of fibrin clots but is also thought, amongst others, to play a role in the activation of some matrix metalloproteinases. We therefore studied the evolution of MMP-2 and -9 plasma concentrations during OLT and the effect of serine-protease inhibition by aprotinin on the level and activation of these MMPs. In a group of 24 patients who participated in a randomized, double-blind, placebo-controlled study we determined serial MMP-2 and MMP-9 plasma levels during transplantation using ELISA (total MMP), activity assays (activatable MMP) and zymography. In addition, the MMP-inhibitors TIMP-1 and TIMP-2 were assessed by ELISA. The putative regulating factors tumor necrosis factor alpha (TNF-alpha) and tissue-type plasminogen activator (t-PA) were assessed as well. Patients were administered high-dose aprotinin, regular-dose aprotinin or placebo during surgery. Plasma TIMP-1, TIMP-2 and MMP-2 level gradually decreased during transplantation. Approximately two-thirds of total MMP-2 appeared to be in its activatable proMMP form. No release of MMP-2 from the graft could be detected. In contrast, plasma levels of MMP-9 increased sharply during the anhepatic and postreperfusion periods. Peak MMP-9 levels of about eight times above baseline were found at 30 minutes after reperfusion. Most MMP-9 appeared to be in its active/inhibitor-complexed form. No significant differences were observed between the three treatment groups. However, in patients with more severe ischemia/reperfusion (I/R) injury the MMP-9 concentration, particularly of the active/inhibitor-complexed form, remained high at 120 minutes postreperfusion compared to patients with no or mild I/R injury. The decrease in plasma levels of MMP-2, TIMP-1 and TIMP-2 during OLT occurred irrespective of the severity of the I/R injury. There was a significant correlation between MMP-9 and t-PA levels, but not with TNF-alpha. In conclusion, OLT is associated with a sharp increase of MMP-9 during the anhepatic and postreperfusion periods, which coincided with the changes in t-PA. MMP-2, TIMP-1 and TIMP-2 gradually decreased during OLT. The composition of these MMPs was not altered by the use of aprotinin, suggesting that serine-protease/plasmin-independent pathways are responsible for MMP regulation during OLT. In addition, only MMP-9 seems to be involved in I/R injury during human liver transplantation.

Adolescent↗
PubMed2003

Recombinant factor VIIa in orthotopic liver transplantation: influence on parameters of coagulation and fibrinolysis.

The effect of recombinant factor VIIa (rFVIIa) on blood loss was evaluated in cirrhotic patients undergoing orthotopic liver transplantation. In the present study, we explored the effect of rFVIIa on coagulation and fibrinolysis during orthotopic liver transplantation. Coagulation factors, parameters of thrombin generation and parameters of fibrinolysis were measured in six patients who had received a single dose of 80 micro g/kg rFVIIa and in ten controls, during and after orthotopic liver transplantation. Baseline concentrations and course of coagulation factors were similar in patients and controls. Thrombin generation did not rise after the administration of rFVIIa, but showed a sharp increase after reperfusion in patients, as compared with controls. No difference in fibrinolysis was apparent between patients and controls. No evidence of diffuse intravascular coagulation was seen. We conclude that the use of rFVIIa in orthotopic liver transplantation seems to enhance thrombin generation in a localized and time-limited matter, without causing systemic coagulation.

Adult↗
PubMed2002

Graft loss after pediatric liver transplantation.

OBJECTIVE: To describe the epidemiology and causes of graft loss after pediatric liver transplantation and to identify risk factors. SUMMARY BACKGROUND DATA: Graft failure after transplantation remains an important problem. It results in patient death or retransplantation, resulting in lower survival rates. METHODS: A series of 157 transplantations in 120 children was analyzed. Graft loss was categorized as early (within 1 month) and late (after 1 month). Risk factors were identified by analyzing recipient, donor, and transplantation variables. RESULTS: Kaplan-Meier 1-month and 1-, 3-, and 5-year patient survival rates were 85%, 82%, 77%, and 71%, respectively. Graft survival rates were 71%, 64%, 59%, and 53%, respectively. Seventy-one of 157 grafts (45%) were lost: 18 (25%) by death of patients with functioning grafts and 53 (75%) by graft-related complications. Forty-five grafts (63%) were lost early after transplantation. Main causes of early loss were vascular complications, primary nonfunction, and patient death. Main cause of late graft loss was fibrosis/cirrhosis, mainly as a result of biliary complications or unknown causes. Child-Pugh score, anhepatic phase, and urgent transplantation were risk factors for early loss. Donor age, donor/recipient weight ratio, blood loss, and technical-variant liver grafts were risk factors for late loss. CONCLUSIONS: To prevent graft loss after pediatric liver transplantation, potential recipients should be referred early so they can be transplanted in an earlier phase of their disease. Technical-variant liver grafts are risk factors for graft survival. The logistics of the operation need to be optimized to minimize the length of the anhepatic phase.

Adolescent↗
PubMed2002

Pharmacological strategies to decrease transfusion requirements in patients undergoing surgery.

Surgical procedures are inevitably associated with bleeding. The amount of blood loss may vary widely between different surgical procedures and depends on surgical as well as non-surgical factors. Whereas adequate surgical haemostasis may suffice in most patients, pro-haemostatic pharmacological agents may be of additional benefit in patients with (diffuse) surgical bleeding or in patients with a specific underlying haemostatic defect. In general, surgical haemostasis and pharmacological therapies can be complementary in controlling blood loss. The use of pharmacological therapies to reduce blood loss and blood transfusions in surgery has historically been restricted to a few drugs. Antifibrinolytic agents (aprotinin, tranexamic acid and aminocaproic acid) have the best evidence supporting their use, especially in cardiac surgery, liver transplantation and some orthopaedic surgical procedures. Meta-analyses of randomised, controlled trials in cardiac patients have suggested a slight benefit of aprotinin, compared with the other antifibrinolytics. Desmopressin is the treatment of choice in patients with mild haemophilia A and von Willebrand disease. It has also been shown to be effective in patients undergoing cardiac surgery who received aspirin up to the time of operation. However, overall evidence does not support a beneficial effect of desmopressin in patients without pre-existing coagulopathy undergoing elective surgical procedures. Topical agents, such as fibrin sealants have been successfully used in a variety of surgical procedures. However, only very few controlled clinical trials have been performed and scientific evidence supporting their use is still limited. Novel drugs, like recombinant factor VIIa (eptacog alfa), are currently under clinical investigation. Recombinant factor VIIa has been introduced for the treatment of haemophilia patients with inhibitors, either in surgical or non-surgical situations. Preliminary data indicate that it may also be effective in surgical patients without pre-existing coagulation abnormalities. More clinical trials are warranted before definitive conclusions can be drawn about the safety and the exact role of this new drug in surgical patients. Only adequately powered and properly designed randomised, clinical trials will allow us to define the most effective and the safest pharmacological therapies for reducing blood loss and transfusion requirements in surgical patients. Future trials should also consider cost-effectiveness because of considerable differences in the costs of the available pro-haemostatic pharmacological agents.

Administration, Topical↗
PubMedDate not supplied

Extrahepatic bile duct resection in combination with liver resection for hilar cholangiocarcinoma: a report of 42 cases.

From September 1986 until December 2001, 42 patients (20 males and 22 females) underwent a combined extrahepatic bile duct resection (EHBDR) and liver resection (LR) for hilar cholangiocarcinoma (HC). The aim of this study was to analyze patient survival, morbidity, and mortality as well as to seek predictive factors. The 1-, 3-, and 5-year actuarial patient survival was 72%, 37%, and 22%, respectively. Median survival was 19 months. Hospital mortality, all due to septic complications, was 12%. Morbidity was observed in 32 patients (76%). Infections were the most dominant complication. Patients (n=11) with American Joint Committee on Cancer (AJCC) stage I or stage II tumors exhibited a superior survival compared with patients (n=31) with stage III or IV tumors (p=0.023). Patients with tumor-free lymph nodes (n=26) indicated a greater survival compared with patients with tumor-positive lymph nodes (n=16) (p=0.004). Patients undergoing vascular reconstructions indicated a trend toward higher mortality and lower survival (p=0.068). Over 20% of the patients with hilar cholangiocarcinoma can survive more than 5 years after a combined EHBDR and LR at the cost of 12% perioperative mortality and a 76% morbidity. Results might improve with the prevention of infectious complications and improved selection of patients to avoid vascular reconstruction and to predict a negative nodal state.

Adult↗
PubMedDate not supplied

End-to-side caval anastomosis in adult piggyback liver transplantation.

No consensus exists regarding the optimal reconstruction of the cavo-caval anastomosis in piggyback orthotopic liver transplantation (PB-LT). The aim of this study was to analyze our experience with end-to-side (ES) cavo-cavostomy. Outcome parameters were patient and graft survival and surgical complications. During the period 1995-2002 146 full-size PB-LT in 137 adult patients were performed with ES cavo-cavostomy without the routine use of temporary portocaval shunt (TPCS). In 12 patients (8%) this technique was used for implantation of second or third grafts. Veno-venous bypass was not used in any case and TPCS was performed only in eight patients (6%). One-, three- and five-yr patient and graft survival were 84%, 79% and 75%, and 81%, 74% and 69%, respectively. The median number of intraoperative transfusion of packed red blood cells (RBC) was 2.0 (range 0-33) and 30% of the patients (n = 43) did not require any RBC transfusion. Surgical complications of various types were observed after 49 LT (34%) and none of the complications was specifically related to the technique of ES cavo-cavostomy. Our experience indicates that PB-LT with ES cavo-cavostomy is a safe procedure, can safely be performed without the routine use of a TPCS, has a very low risk of venous outflow obstruction and can also be used effectively during retransplantations.

Adolescent↗
PubMedDate not supplied

Outcome and pattern of recurrence after curative resection for hepatocellular carcinoma in patients with a normal liver compared to patients with a diseased liver.

BACKGROUND/AIMS: The purpose of this study was to investigate whether differences existed in demography and outcome after resection for hepatocellular carcinoma (HCC) in patients with a normal liver compared to patients with a diseased liver. METHODOLOGY: Twenty-seven Caucasian patients with HCC in a histologically proven normal liver (NL group) in the Netherlands and 141 Asian patients with HCC in a diseased liver (DL group) in Japan underwent a curative liver resection. Patient and tumor characteristics, post-resectional disease-free, overall survival rates and pattern of recurrence were investigated. RESULTS: HCC's in the NL group were found to be larger, in a more advanced stage and needed more extended resections compared to HCC's in the DL group. Microvascular invasion was similar in both groups, while capsule formation was observed less in the NL group. Overall survival and disease-free survival after curative resection were not statistically different between both groups. Also even after stratification for T-stage, there was no difference in survival. Although the rate of recurrence was similar in both groups, a significantly higher number of extrahepatic metastases was observed in the NL group. CONCLUSIONS: Distinct demographic differences existed between patients with HCC in the NL group compared to patients in the DL group. Extrahepatic recurrences were more frequent after curative resection for HCC in a normal liver. No difference in survival was demonstrated between both groups.

Adult↗