Novel benchmark values for redo liver transplantation – does the outcome justify the effort?

Objective

In the era of organ shortage, redo liver transplantation (reLT) is frequently discussed in terms of expected poor outcome, high cost and therefore wasteful resources. However, there is a lack of benchmark data to reliably assess outcomes after reLT. The aim of this study was to define the ideal reLT case, and to establish clinically relevant benchmark values for best achievable outcome in reLT.

Methods

We collected data on reLT between January 2010 and December 2018 from 22 high volume transplant centers on three continents. Benchmark cases were defined as recipients with model of end-stage liver disease score <=25, absence of portal vein thrombosis, no mechanical ventilation before surgery, receiving a graft from a donor after brain death. In addition, early reLT including those for primary non-function (PNF) were excluded. Clinically relevant endpoints covering intra- and postoperative course were selected and complications were graded by severity using the Clavien-Dindo classification and the comprehensive complication index (CCI). The benchmark cutoff for each outcome was derived from the 75th percentile of the median values of all benchmark centers, indicating the “best achievable” result. To assess the utility of the newly established benchmark values, we analyzed patients who received reLT for PNF (non-benchmark patients).

Results

Out of 1110 reLT 413 (37.2%) qualified as benchmark cases. Benchmark values included: Length of intensive care unit and hospital stay: <=6 and <=24 days, respectively; Clavien-Dindo grade >=3a complications and the CCI at 1 year: <=76% and <=72.2, respectively; in-hospital and 1-year mortality rates: <=14.0% and <=14.3%, respectively. The cutoffs for transplant-specific complications such as biliary complications at 1 year, outflow problems at 1 year and hepatic artery thrombosis at discharge were <=27.3%, <=2.5% and <=4.8%, respectively. Patients receiving a reLT for PNF showed mean outcome values all outside the reLT benchmark values. In-hospital mortality rate was 34.4% and the mean CCI at discharge 68.8.

Conclusion

ReLT remains associated with high morbidity and mortality. The availability of benchmark values for outcome parameters of reLT may serve for comparison in any future analyses of individuals, patient groups, or centers, but also in the evaluation of new therapeutic strategies and principles.

Hypothermic machine perfusion in liver transplantation

Dynamic preservation strategies are a promising option to improve graft quality before transplantation, and to extend preservation time for either logistic or treatment reasons. In contrast to normothermic oxygenated perfusion, which intends to mimic physiological conditions in the human body, with subsequent clinical application for up to 24 hrs, hypothermic perfusion is mainly used for a relatively short period with protection of mitochondria and subsequent reduction of oxidative injury upon implantation. The results from two randomized controlled trials, where recruitment has finished are expected this year. Both ex situ perfusion techniques are increasingly applied in clinical transplantation including recent reports on viability assessment, which could open the door for an increased liver utilization in the future.

Risk Assessment in High- and Low-MELD Liver Transplantation

Allocation of liver grafts triggers emotional debates, as those patients, not receiving an organ, are prone to death. We analyzed a high-Model of End-stage Liver Disease (MELD) cohort (laboratory MELD score ≥30, n = 100, median laboratory MELD score of 35; interquartile range 31-37) of liver transplant recipients at our center during the past 10 years and compared results with a low-MELD group, matched by propensity scoring for donor age, recipient age, and cold ischemia time. End points of our study were cumulative posttransplantation morbidity, cost, and survival. Six different prediction models, including donor age x recipient MELD (D-MELD), Difference between listing MELD and MELD at transplant (Delta MELD), donor-risk index (DRI), Survival Outcomes Following Liver Transplant (SOFT), balance-of-risk (BAR), and University of California Los Angeles-Futility Risk Score (UCLA-FRS), were applied in both cohorts to identify risk for poor outcome and high cost. All score models were compared with a clinical-oriented decision, based on the combination of hemofiltration plus ventilation. Median intensive care unit and hospital stays were 8 and 26 days, respectively, after liver transplantation of high-MELD patients, with a significantly increased morbidity compared with low-MELD patients (median comprehensive complication index 56 vs. 36 points [maximum points 100] and double cost [median US$179 631 vs. US$80 229]). Five-year survival, however, was only 8% less than that of low-MELD patients (70% vs. 78%). Most prediction scores showed disappointing low positive predictive values for posttransplantation mortality, such as mortality above thresholds, despite good specificity. The clinical observation of hemofiltration plus ventilation in high-MELD patients was even superior in this respect compared with D-MELD, DRI, Delta MELD, and UCLA-FRS but inferior to SOFT and BAR models. Of all models tested, only the BAR score was linearly associated with complications. In conclusion, the BAR score was most useful for risk classification in liver transplantation, based on expected posttransplantation mortality and morbidity. Difficult decisions to accept liver grafts in high-risk recipients may thus be guided by additional BAR score calculation, to increase the safe use of scarce organs.

Liver transplantation for "very early" intrahepatic cholangiocarcinoma: International retrospective study supporting a prospective assessment

The presence of an intrahepatic cholangiocarcinoma (iCCA) in a cirrhotic liver is a contraindication for liver transplantation in most centers worldwide. Recent investigations have shown that "very early" iCCA (single tumors ≤2 cm) may have acceptable results after liver transplantation. This study further evaluates this finding in a larger international multicenter cohort. The study group was composed of those patients who were transplanted for hepatocellular carcinoma or decompensated cirrhosis and found to have an iCCA at explant pathology. Patients were divided into those with "very early" iCCA and those with "advanced" disease (single tumor >2 cm or multifocal disease). Between January 2000 and December 2013, 81 patients were found to have an iCCA at explant; 33 had separate nodules of iCCA and hepatocellular carcinoma, and 48 had only iCCA (study group). Within the study group, 15/48 (31%) constituted the "very early" iCCA group and 33/48 (69%) the "advanced" group. There were no significant differences between groups in preoperative characteristics. At explant, the median size of the largest tumor was larger in the "advanced" group (3.1 [2.5-4.4] versus 1.6 [1.5-1.8]). After a median follow-up of 35 (13.5-76.4) months, the 1-year, 3-year, and 5-year cumulative risks of recurrence were, respectively, 7%, 18%, and 18% in the very early iCCA group versus 30%, 47%, and 61% in the advanced iCCA group, P = 0.01. The 1-year, 3-year, and 5-year actuarial survival rates were, respectively, 93%, 84%, and 65% in the very early iCCA group versus 79%, 50%, and 45% in the advanced iCCA group, P = 0.02.

CONCLUSION

Patients with cirrhosis and very early iCCA may become candidates for liver transplantation; a prospective multicenter clinical trial is needed to further confirm these results. (Hepatology 2016;64:1178-1188).

Machine Perfusion of Donor Livers for Transplantation: A Proposal for Standardized Nomenclature and Reporting Guidelines

With increasing demand for donor organs for transplantation, machine perfusion (MP) promises to be a beneficial alternative preservation method for donor livers, particularly those considered to be of suboptimal quality, also known as extended criteria donor livers. Over the last decade, numerous studies researching MP of donor livers have been published and incredible advances have been made in both experimental and clinical research in this area. With numerous research groups working on MP, various techniques are being explored, often applying different nomenclature. The objective of this review is to catalog the differences observed in the nomenclature used in the current literature to denote various MP techniques and the manner in which methodology is reported. From this analysis, we propose a standardization of nomenclature on liver MP to maximize consistency and to enable reliable comparison and meta-analyses of studies. In addition, we propose a standardized set of guidelines for reporting the methodology of future studies on liver MP that will facilitate comparison as well as clinical implementation of liver MP procedures.

Hypothermic Oxygenated Liver Perfusion: Basic Mechanisms and Clinical Application

Dynamic preservation strategies such as hypothermic machine perfusion are increasingly discussed to improve liver graft quality before transplantation. This review summarizes current knowledge of this perfusion technique for liver preservation. We discuss optimization of perfusion conditions and current strategies to assess graft quality during cold perfusion. Next, we provide an overview of possible pathways of protection from ischemia-reperfusion injury. Finally, we report on recent clinical applications of human hypothermic machine liver perfusion.

Solutions to shortage of liver grafts for transplantation

Increasing the donor supply

Alexis Carrel: genius, innovator and ideologist

Alexis Carrel was a Frenchman from Lyon, who gained fame at the Rockefeller Institute in New York at the beginning of the 20th century. He was the first to demonstrate that arteriovenous anastomoses were possible. Alexis Carrel was awarded the Nobel Prize for his contributions to vascular surgery and transplantation in 1912. He was a versatile scientist, who made numerous discoveries from the design of an antiseptic solution to treat injuries during the First World War to tissue culture and engineering, and organ preservation, making him the father of solid organ transplantation. Together, with the famous aviator and engineer Charles Lindbergh, they were the first scientists capable of keeping an entire organ alive outside of the body, using a perfusion machine. Due to his many dubious ideas and his association with fascism in the 1930s and during the Second World War, many of his scientific achievements have been forgotten today and taken for granted.

Machine perfusion for 'marginal' liver grafts

Due to the critical shortage of deceased donor grafts, clinicians are continually expanding the criteria for an acceptable liver donor to meet the waiting list demands. However, the reduced ischemic tolerance of those extended criteria grafts jeopardizes organ viability during cold storage. Machine perfusion has been developed to limit ischemic liver damage but despite its proven biochemical benefit, machine liver perfusion is not yet considered clinically due to its low practicability. In this review, we summarize our understanding of the role of machine perfusion in marginal liver preservation. The goal is to highlight advantages or disadvantages of current perfusion techniques and to explain the underlying mechanisms. We provide evidence for the need of a liver perfusion performance shortly before implantation, and point out promising designs.

Different protection mechanisms after pretreatment with glycine or alpha-lipoic acid in a rat model of warm hepatic ischemia

BACKGROUND/AIM

Alpha-lipoic (LA) acid pretreatment has previously been described to reduce ischemia/reperfusion injury (IRI) after warm liver ischemia, whereas glycine pretreatment has been shown to be protective mostly in models of cold hepatic ischemia. The aim of this study was to determine whether glycine decreases IRI after warm hepatic ischemia. Furthermore we investigated whether doses of LA other than those used previously are also protective against IRI after warm hepatic ischemia.

METHODS

Selective liver ischemia was maintained over a period of 90 min. In long-term as well as short-term experiments we studied IRI in several groups comparing animal survival as the pivotal endpoint.

RESULTS

Animal survival was improved by glycine and 5,000 micromol LA, whereas all animals died within 3 days after pretreatment with 50 micromol LA. In the glycine group we observed a tendency towards decreased apoptosis-related cell death measured by the activity of caspase-3 in liver tissue and the percentage of TUNEL-positive hepatocytes in comparison to the untreated group. Serum alpha-glutathione S-transferase, lipid peroxidation, and caspase-3 activity as well as the percentage of TUNEL-positive hepatocytes and the percentage of liver necrosis were only significantly decreased by 5,000 micromol LA pretreatment. Liver tissue levels of tumor necrosis factor (TNF)alpha were reduced only in the glycine group whereas TNFalpha was increased in the untreated as well as the LA group. Levels of TNFalpha mRNA were upregulated in both the glycine- and LA-pretreated groups.

CONCLUSION

Our data show that increased animal survival by glycine was accompanied by a reduced TNFalpha content in liver tissue. Protection by glycine is likely to result from a reduction in adverse TNFalpha effects. Administration of high-dose LA on the other hand led to a significant reduction in necrosis- and apoptosis-related cell death in IRI of the liver without a reduction in liver TNFalpha.

Rescue of the cold preserved rat liver by hypothermic oxygenated machine perfusion

The aim of the study was to investigate whether hypothermic oxygenated liver perfusion after cold liver preservation resuscitated metabolic parameters and whether this treatment had a benefit for liver viability upon reperfusion. We preserved rat livers either by cold storage (UW) for 10 h, or by perfusion for 3 h (oxygenated modified UW) after 10 h cold storage. We assessed viability of livers after preservation and after ischemic rewarming+normothermic reperfusion ex vivo. Ten hour cold storage reduced mitochondrial cytochrome oxidase and metabolically depleted the livers. Oxygenated perfusion after cold storage resulted in uploaded cellular energy charge and oxidized mitochondrial cytochrome oxidase. Reperfusion after 10 h cold storage increased formation of superoxid anions, release of cytosolic LDH, lipid peroxidation, caspase activities and led to disruption of sinusoidal endothelial cells. In contrast, reperfusion after 10 h cold storage+3 h hypothermic oxygenated perfusion resulted in no changes of lipid peroxidation, bile flow, energy charge, total glutathione, LDH release and of caspase activation, as compared to fresh resected livers. This study demonstrates, that a metabolically depleted liver due to cold storage can be energy recharged by short-termed cold machine perfusion. The machine perfused graft exhibited improved viability and functional integrity.

Detection of mitochondrial electron chain carrier redox status by transhepatic light intensity during rat liver reperfusion

The aim of the study was to investigate mitochondrial electron transfer during rat liver reperfusion after cold storage and hypothermic machine perfusion. Livers from male Brown Norway rats were preserved (UW) for 10h either by cold storage (CS) or by hypothermic oxygenated perfusion extracorporal (HOPE). Transhepatic photometric analysis allowed determination of the redox status of mitochondrial cytochromes during preservation, rewarming and reperfusion. Mitochondrial electron chain carriers were inhibited at different sites with rotenone and cyanide in some experiments. reversed transcriptional polymerase chain reaction (RT-PCR) was performed after reperfusion concerning transcription of TNFalpha, caspase 9, and c-jun kinase (JNK). Increased superoxide anion formation as well as transcription of TNFalpha, caspase 9, and JNK during reperfusion after cold storage (CS) were related with completely reduced cytochromes before and during reperfusion. In contrast, hypothermic oxygenated livers (HOPE) showed oxygenated cytochromes as well as decreased superoxide anion formation and no detectable transcription of TNFalpha, caspase 9, and JNK. A similar low level of superoxide anion formation was found when electron chain transfer of cold stored livers was inhibited during reperfusion with rotenone but not with cyanide. After hypothermic oxygenation (HOPE) inhibition of mitochondrial electron chain with rotenone showed no change in formation of superoxide anion formation whereas inhibition with cyanide showed increased superoxide anion formation. Thus mitochondrial cytochrome redox status is suggested to be related: (i) with the release of reactive oxygen substances as well as (ii) with the expressions of TNFalpha, caspase 9, and JNK during reperfusion and may thus be usable as predictive marker of liver grafts.

[Adenocarcinoma of the esophagus: prognostic comparison between transthoracic esophageal resection with expanded 2-field lymph node dissection and trans-hiatal esophageal dissection with abdominal lymph node excision]

A retrospective analysis should compare the two operative approaches, transhiatal or transthoracic resection in patients suffering from adenocarcinoma of the esophagus. Between 1985 and 2002 123 cases were presented with adenocarcinoma of the esophagus, treated in 65% by transhiatal resection including abdominal lymph node dissection and in 35% by the transthoracic approach with standardized extended mediastinal and abdominal lymph node dissection. Hospital mortality was 14% (6/43) after transthoracic resection and 3.8% (3/80) after transhiatal resection (ns). Die number of removed and examined abdominal lymph nodes following transhiatal resection was 14.1 (mean) versus 12.3 (mean) after transthoracic resection (ns). Die number of removed and examined mediastinal lymph nodes by transhiatal resection was 6.3 (mean) versus 19.7(mean) after transthoracic resection (p < 0.001). The median survival after transthoracic approach was 19 months versus 20 months after transhiatal approach (ns). Median survival of curatively resected patients (R0) were in both operative procedures similar (21 months). A more differentiated analysis referred to the UICC stages also demonstrated no differences in the survival between transthoracic and transhiatal resection. With respect to less mortality and less morbidity after transhiatal resection and because of the not detectable prognostic advantage of the transthoracic resection we suggest the transhiatal approach as the treatment of choice in patients with adenocarcinoma of the esophagus.

Postoperative reduction of fibrinolysis as a prognostic factor of fatal outcome

For the resection of an esophagus carcinoma a mortality rate of 2 to 30% was described. It is still unclear whether an abdominothoracic or transhiatal intervention is superior regarding the outcome. To investigate the prognostic value of fibrinolytic markers, plasmin-alpha2-antiplasmin (PAP) and D-dimer (DD) values were determined daily in the early postoperative period for 11 days. In addition, the course of PAP and DD concentrations was compared with the method of esophagectomy. Of the 28 patients enclosed in the study, 5 died between day 10 and day 34 owing to adult respiratory distress syndrome and septicemia. The PAP and DD concentrations increased in survivors after surgery until day 5 and day 7, respectively. The concentrations were twofold and 10-fold higher than the upper reference level. In contrast, four of five nonsurvivors showed an inadequate increase in PAP concentrations within the reference range, whereas the course of DD was inconspicuous. The sensitivity and specificity of PAP and DD in respect to a fatal outcome was calculated by receiver operating characteristic analysis based on all results: sensitivity 76% (PAP-cut off value 760 microg/L) and 49% (DD 6 mg/L), specificity 77% and 72%, respectively. The biochemical markers showed no significant differences between the abdominothoracic and transhiatal esophagectomy. In the abdominothoracic intervention, lower PAP and higher DD concentrations were observed. The results showed that the PAP concentrations could detect a fatal outcome within the first 5 days after surgery.

Prognostic significance of tumor ploidy and histomorphological parameters in adenocarcinoma of Barrett's esophagus

BACKGROUND

Despite recent advances in surgical and multidisciplinary treatment, the prognosis for patients with adenocarcinoma of Barrett's esophagus remains poor. The low prognostic accuracy of even surgical pathologic TNM staging suggests that additional parameters are necessary in determining the prognosis.

METHOD

In a retrospective analysis of 50 patients who underwent transhiatal or transthoracic esophageal resection due to adenocarcinoma of Barrett's esophagus, a quantitative DNA analysis using image cytometry was performed in addition to the TNM classification and usual morphological criteria. At the time of DNA analysis the histomorphological parameters and survival time were not known.

RESULTS

The main prognostic parameter was the curativity (R classification) of the operation. Considering only patients after R0 resection, a multivariate analysis identified the DNA ploidy, the depth of tumor infiltration and distant metastases of prognostically independent factors. Furthermore, within pT2 and pT3 tumors, which account for 80% of all the tumors, DNA ploidy allows an additional prognostic differentiation which is not possible with pT stage alone.

CONCLUSION

Patients with a diploid or tetraploid tumor without distant metastasis and a tumor stage pT1-pT3 should have curative (R0) resection. In case of an aneuploid DNA content or a pT4 tumor resection alone shows no advantage as compared to palliative nonoperative procedures.

Comparison of iceball diameter and temperature distribution achieved with 3-mm accuprobe cryoprobes in porcine and human liver tissue and human colorectal liver metastases in vitro

We aimed to assess the thermal profile and size of iceballs produced by Accuprobe cryoprobes in fresh porcine and human liver and human colorectal cancer liver metastases in vitro to allow better planning of cryosurgical treatment of liver metastases. Iceballs were produced by a 20-min single freeze cycle using 8-mm cryoprobes in pig liver in a waterbath at 37 degrees C (n = 8) and 3-mm cryoprobes in pig liver (n = 8), human liver (n = 3), and human colorectal cancer liver metastases (n = 8). The iceball diameters and the temperatures at different distances from the cryoprobe were measured. Mean iceball diameters produced by 8-mm cryoprobes in pig liver were 56.3 mm and varied from 38.7 to 39.6 mm for 3-mm cryoprobes in the different tissues used. There was no significant difference in iceball size in the different tissues. The diameter of the zone of -40 degrees C or less was approximately 44 mm using 8-mm cryoprobes in porcine liver and between 27 and 31 mm using 3-mm cryoprobes in the different tissues examined. The results may allow better preoperative planning of the cryosurgical treatment of liver metastases with Accuprobe cryoprobes.

Calcium prevents loss of glutathione and reduces oxidative stress upon reperfusion in the perfused liver

BACKGROUND

Addition of 1.5 mM Ca2+ to the preservation solution (UW) during static cold rat liver preservation have been shown to improve liver function upon reperfusion. Effects of adding calcium to the perfusate during liver machine perfusion are yet not described.

METHODS

A recently developed model for rat liver machine perfusion (hypothermic oscillating oxygenated liver perfusion) was used to perfuse rat livers with calcium free modified UW solution (Group 1) or with modified UW + 2 mM CaCl2 (Group 2) for a period of 10 h (4 degrees C). In both experimental groups an acellular reperfusion at 37 degrees C with Ringer solution and 50 microM ferricytochrome c over a period of 90 min was performed. Liver and perfusate samples were taken before and after reperfusion to assess the cellular energy charge, metabolites, parameters of oxidative stress, cellular calcium, bile flow, enzyme release and TNF alpha.

RESULTS

Hypothermic perfusion with oxygenated calcium free modified UW solution resulted in depletion of cellular calcium and glutathione. Upon reperfusion bile function was inhibited in spite of a sufficiently reloaded energy charge and low LDH release. In contrast machine perfusion with modified UW solution +2 mM Ca2+ prevented the loss of both, cellular calcium and glutathione during the preservation period and led to sufficient bile flow and less release of superoxide anions upon reperfusion.

CONCLUSIONS

The loss of cellular calcium and glutathione during oxygenated machine liver perfusion appeared to be reducible by adding 2 mM Ca2+. Furthermore, upon reperfusion, livers with preserved cellular calcium demonstrated significantly lower oxidative stress and an improved liver function.

Carcinoma of the hypopharynx and the cervical oesophagus: a surgical challenge

OBJECTIVE

To report our results after reconstruction of the upper digestive tract for locally advanced carcinoma of the hypopharynx and cervical oesophagus.

DESIGN

Open study.

SETTING

Teaching University hospital, Germany.

SUBJECTS

Of the 517 patients who presented with carcinoma of the oesophagus between September 1985 and March 1997, 16 had a locally advanced tumour of the hypopharynx and 25 of the cervical oesophagus.

INTERVENTIONS

Free jejunal grafts were used after circular resection in all patients with carcinoma of the hypopharynx, and for the 3 with oesophageal carcinoma in whom we obtained adequate resection margins. In the remainder stomach was used in 21 and colon in 1.

MAIN OUTCOME MEASURES

Morbidity and mortality.

RESULTS

After jejunal grafting 1 patient died within 30 days and 2 died in hospital. After gastric or colonic reconstruction 2 patients died within 30 days and 4 in hospital. There was 1 anastomotic leak, 1 transplant became necrotic and had to be replaced, in 2 patients the recurrent nerve was damaged, 1 patient developed a wound infection and 1 a cardiac infarction. After gastric or colonic replacement 7 patients had paralysed recurrent laryngeal nerves, there was 6 anastomotic leaks, 1 chylous leak, 1 haemorrhage, and in 1 the transplant necrosed.

CONCLUSION

Despite the fact that we compared tumours in different sites, these results suggest that the jejunal graft is safer for upper oesophageal and hypopharyngeal reconstruction.

[Pulmonary complications following esophageal surgery. Significance of aspiration]

Objective of this study was to show the different causes and the importance of pulmonary complications after esophageal surgery and their management by general and intensive care measures. In the University Hospital for General and Abdominal Surgery of Mainz 222 patients were treated for esophageal cancer from 9/1985 to 5/1997. Data of 214 patients were available for this investigation. In 65 cases a transhiatal dissection (blunt dissection) and in 149 patients a abdomino-thoracic dissection were performed. 54 (25.2%) patients had to be reintubated. 30-day lethality was 7.9% (n = 17) and hospital lethality was 13.1% (n = 28). 82 (38.3%) patients developed pulmonal dysfunction (pneumonia) which was aggravated by a following ARDS in 16 patients (19.5%). 21 (25.6%) of these patients died. In only 24 (29.3%) patients an isolated pneumonia occurred without evidence of general or surgical complications. In 65 of 82 patients further microbiologically examinations were documented. In 39 (60%) cases gastrointestinal bacteria were found. Therefore aspiration or microaspiration respectively are considered to co-cause pulmonary complications. Postoperative psychosyndrome, recurrent nerve palsy and ASA-risk stratification were accompanied by elevated rates of pneumonia. Careful selection of patients for esophageal resection, atraumatic surgical technique and reduction of general and surgical complications and intensive care measures can help to avoid postoperative pulmonary complications. Reduction of mediators activated by surgical trauma is not feasible so in the moment prevention of aspiration seems to be the most effective therapy in the postoperative course.

Reduced oxidative stress during acellular reperfusion of the rat liver after hypothermic oscillating perfusion

BACKGROUND

ATP resynthesis during reperfusion after liver preservation has been shown to be well correlated with the function of transplanted grafts. Nevertheless, the advantages of a cellular energy charge loading during the preservation period are yet not fully understood. This study evaluates the effects of different nucleotide levels at the end of preservation on metabolic changes and oxidative stress during reperfusion.

METHODS

Two experimental groups were chosen reflecting different energy charge states after preservation: static cold storage for 10 hr and hypothermic oxygenated oscillating perfusion for 10 hr. In both experimental groups, normothermic ex vivo acellular reperfusion over 40 min was performed. A third group consisted of nonpreserved livers similarly reperfused for 40 min. Superoxide formation was detected by the superoxide dismutase inhibitable reduction of ferricytochrome c added to the normothermic perfusate.

RESULTS

Superoxide formation and lipid peroxidation malondialdehyde were significantly lower during reperfusion after the energy charge loading before reperfusion by the hypothermic oscillating perfusion technique. However, oxygen radical formation, liver cell injury (lactate dehydrogenase [LDH] release), and TNFalpha release were significantly higher in energy charge-depleted groups (nonpreserved and cold stored livers).

CONCLUSIONS

Hypothermic oscillating oxygenated perfusion led to the elevated energy charge during preservation and led to reduced oxygen radical formation as well as less lipid peroxidation during reperfusion, in contrast to cold stored livers and nonpreserved livers. This suggests a correlation between the energy charge before reperfusion and oxygen radical formation as well as liver injury at reperfusion.

[99mTc-MIBI-scintigraphy before parathyroid surgery?]

AIM

In a non prospective study the value of preoperative parathyroid imaging with 99mTc-MIBI-scintigraphy was evaluated.

PATIENTS AND METHODS

From August 1, 1987 to December 15, 1997 453 patients were operated on for hyperparathyroidism. Preoperatively 116 patients underwent 99mTc-MIBI-scanning, which had been carried out by several institutes.

RESULTS

Primary hyperparathyroidism. Sensitivity of MIBI-scintigraphy in solitary parathyroid adenoma (n = 48) and first-time cervical exploration was 54% (25 true positive scans) and overall sensitivity was 50% (25 true positive scans in 53 patients). In 6 patients with persistence or recurrence of primary hyperparathyroidism MIBI-scintigraphy was true positive (sensitivity 100%). Neither the volume nor the weight of the adenomas influenced the result of MIBI-scanning. There was no correlation between preoperative serum concentrations of calcium and intact parathormone and sensitivity of MIBI-scintigraphy. Renal hyperparathyroidism. Before first-time cervical exploration sensitivity of MIBI-scintigraphy (n = 40) for detecting all abnormal parathyroid glands in the presence of diffuse hyperplasia yielded only 10%. In 5 of 7 patients, who underwent reexplorations of the neck or mediastinum for persistence or recurrence of renal hyperparathyroidism MIBI-scintigraphy was true positive (sensitivity 71%). The sensitivity for detection of hyperplastic parathyroid glands correlated with the weight as well as with the volume of the glands (p < 0.001). The weight of imaged glands ranged from 0.21 to 9.76 g, median 1.27 g and their median volume was 1.12 ml (range: 0.04-15.63 ml). For non imaged glands a median weight of 0.49 g and a median volume of 0.3 ml (ranges: 0.03-10.34 g, 0.009-9.8 ml, respectively) could be estimated.

CONCLUSIONS

First-time cervical exploration for hyperparathyroidism can be carried out with a high success rate and without any preoperative localization study. Before recurrent parathyroid surgery we recommend 99mTc-MIBI-scintigraphy because of its > 90% sensitivity.

Beta 1 integrin expression in adenocarcinoma of Barrett's esophagus

BACKGROUND/AIMS

In vitro and in vivo studies did not show that beta 1 integrin expression is associated with malignant transformation or that it is of prognostic value in some malignant tumors. There are no data on the expression or prognostic value of beta 1 integrins in adenocarcinoma of Barrett's esophagus.

METHODOLOGY

We assessed the expression pattern and the prognostic impact of beta 1 integrins in paraffin-embedded specimens of 41 patients with adenocarcinoma of Barrett's esophagus by immunochemistry. At the time of investigation, neither histomorphological parameters nor the survival time were known.

RESULTS

There was no correlation between histomorphological parameters and the expression of beta 1 integrins. The expression of beta 1 integrins had no influence on long- term survival. There was a relationship between the prognosis and the following histopathological parameters: pT, pN and pM category, the UICC stage, the presence of lymphangiosis, and the DNA content of the tumor cells.

CONCLUSIONS

The preliminary results obtained in this study did not show that the expression of beta 1 integrins was of prognostic value in patients with adenocarcinoma of Barrett's esophagus. Further studies in a larger number of patients are required to confirm the results obtained in this investigation.

Prognostic significance of cyclin D1 in esophageal squamous cell carcinoma patients treated with surgery alone or combined therapy modalities

In the present study, the expression of cyclin D1, as detected by immunohistochemistry, was compared with other prognostic variables and its prognostic impact was evaluated in a group of 172 patients with squamous cell carcinoma (SCC) of the esophagus who underwent potentially curative resection therapy and in a second group of 38 patients with SCC of the esophagus who were treated by combined modality therapy (radiochemotherapy +/- surgery). Expression of cyclin D1 in surgically treated carcinomas correlated negatively with tumor differentiation (p = 0.026) but positively with mitotic activity (p = 0.0199) and nodal status (p = 0.040). There were no significant correlations with pT category. Patients with cyclin D1-positive carcinomas showed significantly worse overall survival than patients with cyclin D1-negative carcinomas, both in univariate (p = 0.0016) and in multivariate survival analyses (p = 0.0038). Expression of cyclin D1 in carcinomas with multimodal treatment was correlated with poor response to chemotherapy (p = 0.026) but not with overall survival. We thus consider expression of cyclin D1 to be an important parameter, predicting an unfavorable overall survival of surgically treated esophageal cancer patients.

Prognostic significance of cyclin D1 in esophageal squamous cell carcinoma patients treated with surgery alone or combined therapy modalities

In the present study, the expression of cyclin D1, as detected by immunohistochemistry, was compared with other prognostic variables and its prognostic impact was evaluated in a group of 172 patients with squamous cell carcinoma (SCC) of the esophagus who underwent potentially curative resection therapy and in a second group of 38 patients with SCC of the esophagus who were treated by combined modality therapy (radiochemotherapy +/- surgery). Expression of cyclin D1 in surgically treated carcinomas correlated negatively with tumor differentiation (p = 0.026) but positively with mitotic activity (p = 0.0199) and nodal status (p = 0.040). There were no significant correlations with pT category. Patients with cyclin D1-positive carcinomas showed significantly worse overall survival than patients with cyclin D1-negative carcinomas, both in univariate (p = 0.0016) and in multivariate survival analyses (p = 0.0038). Expression of cyclin D1 in carcinomas with multimodal treatment was correlated with poor response to chemotherapy (p = 0.026) but not with overall survival. We thus consider expression of cyclin D1 to be an important parameter, predicting an unfavorable overall survival of surgically treated esophageal cancer patients.

[Systematic internal quality control in surgery 1993 to 1997]

From April 1, 1993 to Dec. 31, 1997, the perioperative course of 5690 patients was recorded prospectively and postoperative morbidity and lethality was determined in the framework of a program for a systematic internal quality control. Goal of the program is the demonstration of treatment quality which possibly out quality improvement. The share of old and sicker patients was significantly increasing during the observation period. Morbidity and hospital lethality remained constant despite a rising necessity of postoperative intensive care. High risk surgery was performed on more patients in the university hospital than in non-university hospitals. The rate of postsurgical complications was lower, length of stay was equal (surgery for inguinal hernia) or lower (cholecystectomy). The rate of not indicated appendectomy could be lowered and morbidity and lethality in the treatment of esophagus carcinoma was lowered by the application of this concept. For the partial duodenopanceatectomy, the examination of the individual surgeon as a risk factor revealed a significant dependence on the experience of the surgeon. There was only a tendency of this effect demonstrable in medium or small surgery like colon resection of gastrectomy. The rate of continence preservation in rectal carcinoma was increased to 75% combined with a drop of perioperative morbidity and length of stay. The systematic internal quality control allows for the assessment of treatment quality and the fast recognition of weak spots. It is a suitable complementary tool for quality improvement in the framework of quality management in surgical patients. The extension of the concept by recording postoperative quality of life and long time results is planned.

Hypothermic oscillating liver perfusion stimulates ATP synthesis prior to transplantation

BACKGROUND

ATP and glycogen depletion often have been demonstrated during cold storage of the liver prior to transplantation. Suppression of events that lead to metabolic depression and to lipid peroxidation could contribute to improvement of liver preservation. A new method of liver preservation for transplantation is therefore suggested, an oscillating oxygenated hypothermic liver perfusion.

METHODS

Biochemical analysis of liver tissue samples and perfusate after 10 h of perfusion by the presented oscillating perfusion model were compared with results after continuous liver perfusion for 10 h as well as with data derived from cold-stored livers over a period of 10 h. Particular reference was made to nucleotide metabolites, glycogen content, lipid peroxidation, glutathione content, glycolytic metabolites, and enzyme release before and after preservation.

RESULTS

Glycogen depletion occurred to the same degree in hypothermic storage and machine perfusion (oscillating as well as continuous perfusion), but the energy charge was significantly increased after oxygenated perfusion, whereas cold storage resulted in a significant energy charge depletion. In addition, perfusion by an oscillating technique yielded superior energy charge loading compared to the continuous perfusion technique and diminished the other hand lipid peroxidation.

CONCLUSIONS

Hypothermic oscillating oxygenated perfusion could be important for the improvement of the quality of energy-depleted organs prior to transplantation.

Expression of p21WAF1 predicts outcome of esophageal cancer patients treated by surgery alone or by combined therapy modalities

The p21WAF1 protein is an important regulator of the cell cycle. Its expression and prognostic significance were investigated immunohistochemically in samples of normal esophageal squamous epithelium (n = 10), severe squamous cell dysplasia (n = 20), carcinoma in situ (n = 14), permanent esophageal squamous cell carcinoma cell lines (n = 3), and invasive squamous cell carcinomas treated either by potentially curative resection (n = 172) or by combined modality therapy (radiochemotherapy +/- surgery; n = 38). Whereas p21WAF1 expression in the normal epithelium was restricted to a few cells adjacent to the basal cell layer, p21WAF1 overexpression was frequently found in preneoplasias and invasive carcinomas. Expression of p21WAF1 in invasive carcinomas was not correlated with tumor differentiation, pT category, or pN category. Among carcinomas treated by potential curative resection, univariate (P = 0.0025) and multivariate (P = 0.0081) survival analysis showed significant correlation of strong p21WAF1 expression (> or =50% p21WAF1-positive tumor cells) with poor overall survival. Univariate survival analysis (P = 0.0006) revealed the same prognostic influence in the group of patients treated by combined modality therapy. We conclude that overexpression of p21WAF1 protein is a frequent event in preneoplasias and neoplasias of the esophagus. Immunohistochemical examination of p21WAF1 expression may provide important prognostic information for decision-making in the treatment of patients with esophageal cancer.

Expression of CD44 variant proteins in adenocarcinoma of Barrett's esophagus and its relation to prognosis

BACKGROUND

None of the commonly used staging criteria accurately determine the prognosis of a patient with adenocarcinoma of Barrett's esophagus. The authors therefore assessed the expression pattern and prognostic impact of CD44 standard and CD44 isoforms CD44v4, v5,v6,v7, and v10 in adenocarcinoma of Barrett's esophagus.

METHODS

Specimens from 41 patients with adenocarcinoma of Barrett's esophagus who underwent esophageal resection were embedded in paraffin and studied immunohistochemically to determine the expression of CD44 splice variants. Histomorphologic parameters and survival time were not known at the time of the investigation.

RESULTS

Correlations between favorable clinical or histomorphologic parameters and CD44s or any of the split variants could not be established. Down-regulation of CD44s and the split variant v10 was significantly correlated with pT classification. Furthermore, down-regulation of CD44v10 and up-regulation of CD44v7 were significantly correlated with ploidy. There was a significant correlation between CD44s and split variants in tumorous and nontumorous tissue from the same patient. Down-regulation of CD44s and CD44v4 had a significant influence on prognosis in that it was associated with shortened life expectancy. Multivariate analysis revealed that the expression of CD44v4 was an independent factor in prognosis.

CONCLUSIONS

The results obtained for this small patient sample suggest that CD44v4 is a new independent prognostic parameter for adenocarcinoma of Barrett's esophagus that can be determined preoperatively by biopsy. It may therefore be helpful in planning therapy by allowing the identification of patients who may benefit from esophageal resection as well as those who are at high risk for morbidity and mortality even when the tumor is otherwise resectable. Further studies of larger patient samples are required to validate the results of the current study.

Prognostic relevance of histomorphological parameters and DNA content and their therapeutic consequences in esophageal carcinoma: a multivariate approach

BACKGROUND/AIMS

Despite recent advances in surgical and multidisciplinary treatment, the prognosis for patients with esophageal carcinoma remains poor. The low prognostic accuracy of even surgical pathological TNM staging suggests that additional parameters would be useful in determining the prognosis.

METHODOLOGY

We undertook a retrospective analysis of 115 patients who had undergone transhiatal and transthoracic esophageal resection due to squamous cell carcinoma of the esophagus. In addition to TNM classification and the usual morphological criteria, a quantitative DNS analysis using Image DNA cytometry was performed. At the time of DNA analysis, histomorphological parameters and survival time was not known.

RESULTS

The main prognostic parameter was the curativity (R classification) of the operation. Using only patients who had had R0 resection, a multivariate analysis was performed. Parameters included: patient age; preoperative ASA classification; tumor localization; pN category; number of intra-thoracal lymph nodes removed; pT category; pM category; grading; lymphangiosis; ploidy; operative procedure, and the development of postoperative complications identifying the ploidy, and the depth of tumor infiltration of prognostically independent factors.

CONCLUSIONS

In the case of a diploid or tetraploid DNA content, tumor resection is recommended even in the case of lymph node metastasis at the truncus coeliacus. Patients with a diploid or tetraploid tumor without distant metastasis and tumor stage pT1-pT3 may, after curative (RO) transthoracic resection with two-field lymph node dissection, have an advantage over patients having a transmediastinal procedure in terms of long-term follow up. In cases of aneuploid DNA content, tumor resection shows no advantage over palliative non-operative procedures. Preoperative radio- or chemotherapy may improve the prognosis of these patients.

[Guidelines in therapy of esophageal carcinoma]

Tumor stage and tumor localization (suprabifurcal and infrabifurcal) are the two decisive criteria referred to in the surgical treatment of esophageal cancer. Complete tumor resection (R0 resection) is a prerequisite for curative efforts. The thoracic squamous cell tumors are adequately treated by an abdominothoracic resection with abdominal and mediastinal lymph node dissection. The transmediastinal approach does not meet the requirements of an oncological resection and is only indicated under special conditions. In contrast the distal adenocarcinomas (Barrett carcinoma) can be curatively resected by both surgical approaches, the transthoracic and the transmediastinal. Presently, an adjuvant therapy after R0 resection of esophageal cancer is not indicated outside of clinical studies. Neoadjuvant methods in case of a local advanced tumor are currently being clinically tested.

[Liver metabolism during cold ischemic incubation in UW solution in the rat model]

Simple cold storage of livers for transplantation activates glycolysis due to lack of oxygen. Energy derived from glycolysis may be critical for cell survival and liver cell death may occur once glycolysis is inhibited in the liver due to accumulation of end products or lack of substrates (glycogen). The relationship between cell death (lactate dehydrogenase, LDH release), anaerobic glycolysis (lactate production), and glycogen content of liver tissue was studied during cold incubation of liver slices in UW solution. Rat livers slices from male Sprague Dawley rats were incubated at 4 degrees C in UW solution, with continuous gentle shaking, under conditions of chemical hypoxia (KCN, 5 mM). The rate of lactate production, LDH release-ATP and glycogen content were measured spectrophotometrically and by HPLC. Lactate increased nearly linearly for the first 48 h of incubation; total lactate which had accumulated after 48 h was 33.9 +/- 0.81 mumol/g and at 96 h nearly the same, 31.3 +/- 1.2 mumol/g. Glycolysis stopped, apparently, because of the depletion of liver slice glycogen which was initially 228.8 +/- 1.7 mumol/g wet wt. It decreased to 34.7 +/- 2.7 mumol/g at 48 h and to 18.7 +/- 1.1 mumol/g at 72 h and remained at this level for the next 24 h. An increased leakage of LDH occurred once glycogen metabolism (and accumulation) ceased. LDH release could be stimulated after only a few hours of cold incubation of liver tissue slices by adding glycolysis inhibitor (iodoacetic acid) to the medium. After 24 h. LDH release was 24.4 +/- 1.8% and increased to 52.8 +/- 5.2% (P < 0.05, Student's t-text) with iodoacetic acid. Adding a glycolytic substrate (fructose, 10 mM) to the medium maintained lactate production for 96 h. The stimulation of glycolysis by fructose also reduced cell death: LDH release was significantly lower at 72- and 96-h incubation (P < 0.001, two-way ANOVA). The ATP content was significantly higher with fructose (P < 0.001). Adding glucose (20 mM) and fructose (10 mM) in combination resulted in prolonged cell survival, significantly delayed glycogen depletion and significantly higher ATP content at 48 and 72 h (two-way ANOVA). Livers from rats who had fasted for 24 h demonstrated the same LDH release at 48 h when incubated with glucose (20 mM) and fructose (10 mM). In conclusion, LDH leakage from hypoxic cold-stored liver slices is related to anaerobic glycolysis. Anaerobic glycolysis appears to continue slowly under hypothermia and provides sufficient energy for maintenance of cell viability. A stimulation of glycolysis in the cold is possible by fructose and results in prolonged cell survival under hypothermic conditions. Glycogen depletion can be slowed down by combining glucose and fructose.

Expression of Bcl-X(L), an antiapoptotic member of the Bcl-2 family, in esophageal squamous cell carcinoma

Bcl-X, a Bcl-2-related protein, is a potent antagonist of apoptosis in its long splice variant (Bcl-X(L)). The present study was performed to determine its expression in preneoplastic and neoplastic lesions of the esophagus, its correlation with other members of the Bcl-2 family, and its impact on the outcome of surgically treated esophageal cancer patients. Samples of normal esophageal squamous epithelium (n = 10), severe squamous cell dysplasias (n = 19), carcinomas in situ (n = 14), invasive squamous cell carcinomas (n = 172), and lymph node metastases (n = 21) were immunohistochemically analyzed for Bcl-X(L) expression using a polyclonal anti-Bcl-X(L) antibody. The immunostaining was evaluated according to a score system (0-12 points) based on the percentage of positive tumor cells and the relative immunostaining intensity. Cytoplasmic staining for Bcl-X(L) protein was invariably found in all cell layers of the normal esophageal squamous epithelium. In contrast, a considerable portion of preneoplastic and neoplastic lesions display a decreased Bcl-X(L) expression as compared with that in the normal esophageal epithelium. On comparison of the amount of Bcl-X(L) expression between the different types of lesions, however, no significant differences were found between severe squamous cell dysplasias (mean immunoreactive score +/- SD, 5.2 +/- 1.8), carcinomas in situ (5.2 +/- 2.2), invasive carcinomas (4.5 +/- 2.8), and lymph node metastases (4.2 +/- 2.6). In invasive carcinomas, Bcl-X(L) expression decreased continuously with decreasing tumor differentiation (P = 0.0001) and was also directly correlated with bcl-2-associated X protein expression (P = 0.0001). On the contrary, an inverse correlation was found between Bcl-X(L) expression and Bcl-2 protein expression (P = 0.0001). No correlation was found between Bcl-X(L) expression and the parameters pT category, pN category, and tumor size. In the univariate survival analysis, patients with low immunoreactive scores (< or = 4) of Bcl-X(L) expression in the tumor tissue showed lower 2-year and 5-year survival rates than patients with high immunoreactive scores (> 4; P = 0.0485). In multivariate survival analysis, however, only the parameters pN category and pT category, but not Bcl-X(L) expression, could be verified as independent prognostic factors. This tendency of decreasing levels of an antiapoptotic protein toward unfavorable outcome is supported by an increasing number of studies on the role of Bcl-2, another antiapoptotic protein, and must be interpreted against the backdrop of apoptosis as a result of the interaction of many cell death-promoting and protecting proteins.

Rat liver preservation by hypothermic oscillating liver perfusion compared to simple cold storage

Rat livers were preserved hypothermically for 10 or 24 h in vitro as if for transplantation. Two methods of preservation were compared using physiological and biochemical parameters: simple storage and oscillating perfusion. By measuring the nucleotides after preservation the calculated energy charge was significantly higher after 10 and 24 h of oscillating perfusion compared to the simple storage group. In addition, a significant energy charge loading was demonstrated by 10 h oscillating perfusion compared to the initial value prior to perfusion. The oscillating, computer-controlled perfusion permits continuous monitoring of perfusate temperature, O2 consumption, pCO2, portal vein pressure, and pH and also automatic sample collection and pH compensation. In addition, the perfusate can be easily exchanged by using two different pumps or be rewarmed by a heat exchanger. For measuring of short-lived metabolites (interleukins, oxygen radicals, prostaglandins) sampling can be performed directly out of the vena cava outflow. pH and temperature stability was maintained by a data acquisition and controlling system. Because of a special designed liver chamber a combination of storage and perfusion with or without substrates was possible. The demonstrated standardized perfusion technique was achieved by a combination of special equipment and computer-aided monitoring and allows further experiments to improve understanding of ischemic and reperfusion injury.

Expression of Bax, a pro-apoptotic member of the Bcl-2 family, in esophageal squamous cell carcinoma

Samples of normal esophageal squamous epithelium (n = 10), severe squamous cell dysplasia (n = 22), carcinoma in situ (n = 15), invasive squamous cell carcinoma (n = 172), lymph-node metastasis (n = 21) and 2 permanent esophageal squamous cell carcinoma cell lines were analyzed immunohistochemically for Bax expression using a polyclonal anti-Bax antibody. Immunostaining was evaluated according to a score system (0-8 points) based on the percentage of positive tumor cells and the relative immunostaining intensity. Cytoplasmatic staining for Bax protein was found uniformly in all cell layers of the normal esophageal squamous epithelium. In contrast, a gradual loss of immunoreactivity for Bax was found in a fraction of pre-neoplastic and neoplastic lesions. Upon comparison of the amount of Bax expression between the different types of lesion, however, no significant differences were found between severe squamous cell dysplasias, carcinomas in situ, invasive carcinomas and lymph-node metastases. In both esophageal carcinoma cell lines, immunoreactivity for Bax was found and confirmed by means of Northern blot analysis. In invasive carcinomas, Bax immunoreactivity was inversely correlated with Bcl-2 expression (p = 0.0243) and decreased continuously with decreasing tumor differentiation (p = 0.0011). No correlation was found between Bax expression and the following parameters: depth of invasion, nodal status and tumor size. Bax expression had no influence on the post-operative survival of esophageal cancer patients.

Prognostic significance of urokinase-type plasminogen activator expression in squamous cell carcinomas of the esophagus

In the present study, urokinase-type plasminogen activator (uPA) expression in 150 potentially curatively resected SCCs of the esophagus was analyzed immunohistochemically by means of a murine monoclonal antibody (American Diagnostica, Greenwich, CT) and correlated with survival. Altogether, 122 of the 150 tumors (81.3%) expressed different levels of uPA. Among the 122 uPA-positive tumors, 104 (85.2%) showed a weak staining intensity, and 18 (14.8%) showed a strong staining intensity. Among the uPA-positive tumors, 29 (23. 8%) tumors showed a uPA immunoreactivity in 6-25% of all tumor cells, 30 (24.6%) showed a uPA immunoreactivity in 26-50% of all tumor cells, 41 (33.6%) showed a uPA immunoreactivity in 51-75% of all tumor cells, and 22 (18.0%) showed a uPA immunoreactivity in 76-100% of all tumor cells. No significant correlation could be shown between the different patterns of uPA expression and various clinicopathological parameters, such as pT category, pN category, tumor size, histological grade, blood vessel invasion, lymphatic vessel invasion, and inflammatory response. Concerning the overall postoperative survival, no significant differences between uPA-positive and uPA-negative tumors could be verified. This also held true when different cut points in the percentage of uPA-positive tumor cells were used. In contrast, the intensity of uPA staining provided significant prognostic information in that patients with strongly uPA-positive tumors had a poorer outcome than patients with weakly uPA-positive or uPA-negative tumors. Moreover, as shown by stepwise multivariate Cox regression analysis, the intensity of uPA expression was an independent prognostic factor.

Expression of Bax, a pro-apoptotic member of the Bcl-2 family, in esophageal squamous cell carcinoma

Samples of normal esophageal squamous epithelium (n = 10), severe squamous cell dysplasia (n = 22), carcinoma in situ (n = 15), invasive squamous cell carcinoma (n = 172), lymph-node metastasis (n = 21) and 2 permanent esophageal squamous cell carcinoma cell lines were analyzed immunohistochemically for Bax expression using a polyclonal anti-Bax antibody. Immunostaining was evaluated according to a score system (0-8 points) based on the percentage of positive tumor cells and the relative immunostaining intensity. Cytoplasmatic staining for Bax protein was found uniformly in all cell layers of the normal esophageal squamous epithelium. In contrast, a gradual loss of immunoreactivity for Bax was found in a fraction of pre-neoplastic and neoplastic lesions. Upon comparison of the amount of Bax expression between the different types of lesion, however, no significant differences were found between severe squamous cell dysplasias, carcinomas in situ, invasive carcinomas and lymph-node metastases. In both esophageal carcinoma cell lines, immunoreactivity for Bax was found and confirmed by means of Northern blot analysis. In invasive carcinomas, Bax immunoreactivity was inversely correlated with Bcl-2 expression (p = 0.0243) and decreased continuously with decreasing tumor differentiation (p = 0.0011). No correlation was found between Bax expression and the following parameters: depth of invasion, nodal status and tumor size. Bax expression had no influence on the post-operative survival of esophageal cancer patients.

Bile duct warmer in hepatic cryosurgery--a pig liver model

Freezing of the common bile duct resulted in injury, stenosis, or perforation of the bile duct in a dog model. Biliary cutaneous fistulas and bile leaks are reported as complications of hepatic cryosurgery in man. In an ex vivo pig liver model we compared freezing close to the bile duct with and without warming the bile duct with warmed saline solution via an inserted catheter ("bile duct warmer"). The recorded temperatures at the outer wall of the bile duct were -50 degrees C after 10 min of freezing without and 5. 8 degrees C with the use of the warmer (P < 0.001, two-way ANOVA). The bile duct warmer system may be a simple and inexpensive device in reducing perioperative morbidity after hepatic cryosurgery of hepatic liver lesions close to a bile duct.

[Influence of the number of dissected lymph nodes on local recurrence of rectal carcinomas. A staging effect]

In 386 patients with rectal carcinoma of UICC stage I-III operated on between 1 January 1985 and 31 December 1995 we investigated the influence of the number of dissected lymph nodes on tumor stage and local recurrence retrospectively. We found a significant correlation between the number of lymph nodes dissected and the number of detected lymph node metastases. Following this result we found an increase in UICC stage III (P = 0.013) and pTx pN2 tumors (P = 0.000) in correlation with the number of dissected lymph nodes. Significantly lower rates of local recurrence were found only in UICC stage I and UICC stage II. Overall and in a multivariate analysis the number of dissected lymph nodes had no influence on local recurrence. It was shown that lower local recurrence rates in UICC stage I and II did not depend on therapeutic benefit but on stage migration because of more exact tumor staging. The influence of other surgical factors, especially total mesorectal excision, remains to be discussed.

The prognostic significance of epidermal growth factor receptor expression in squamous cell carcinomas of the oesophagus

EGFR expression in 150 potentially curative resected squamous cell carcinomas of the oesophagus was analyzed immunohistochemically and correlated with survival. Altogether, 124 of 150 (82.7%) tumours expressed different levels of EGFR. The percentage of tumour cells expressing EGFR varied greatly between the different tumours (median: 70%). 62 (50.0%) tumours showed weak and intense staining, respectively. Regarding the staining pattern 19 (15.3%) tumours showed exclusively membraneous immunoreactivity, 27 (21.8%) an exclusively cytoplasmic immunoreactivity and 78 (62.9%) a mixed staining pattern. No significant correlation however could be found between EGFR expression and various clinicopathologic parameters such as pT category, pN category, tumour size, histologic grade and blood vessel invasion. In univariate survival analysis, no correlation between EGFR expression and postoperative survival time was observed. In a forward multivariate Cox regression analysis only the parameters lymphatic-vessel invasion (p = 0.001), pT category (p = 0.0034) and pN category (p = 0.0256), but not the EGFR expression, could be verified as independent prognostic variables. In conclusion, the evaluation of the EGFR expression does not provide prognostic information for patients who underwent potentially curative resection for SCC of the oesophagus.

Basaloid squamous cell carcinoma of the esophagus: diagnosis and prognosis

BACKGROUND

Basaloid squamous cell carcinoma (BSCC) is a recently recognized, poorly differentiated variant of squamous cell carcinoma (SCC), which is located predominantly in the upper aerodigestive tract.

METHODS

In this study, clinical and pathologic parameters of 17 BSCCs and 133 typical SCCs of the esophagus that underwent potentially curative resection (no distant metastases, no residual tumor) were compared. In addition, light microscopic, electron microscopic, and immunohistochemical features of BSCC were investigated, to determine whether this type of carcinoma could be differentiated from other poorly differentiated carcinomas of the esophagus.

RESULTS

Light microscopic study showed that BSCC was composed of relatively small tumor cells, arranged in solid lobules with abundant comedo-type necrosis. BSCC was almost invariably accompanied by areas of concomitant typical SCC, foci of squamous cell differentiation, and/or severe squamous cell dysplasia or carcinoma in situ of the adjacent mucosa. Ultrastructurally, BSCC inconsistently showed features of squamous cell differentiation. Immunohistochemically, BSCC displayed poor reactivity for antibodies against wide-range cytokeratins and cytokeratin subtypes that are typical of squamous cell epithelia (cytokeratin 13 and cytokeratin 14). Infrequently, expression of Leu7, smooth muscle actin, and S-100 protein was found. In comparison with typical SCC, the characteristic features of BSCC were older patient age, higher proliferative activity (MIB-1 labelling index), and higher apoptotic indices. No differences were found with regard to pT classification, pN classification, tumor size, blood vessel invasion, lymphatic vessel invasion, neural invasion, or patient gender. Moreover, no differences in overall survival rates were found.

CONCLUSIONS

BSCC is a distinct histopathologic variant of SCC, characterized by a poor degree of differentiation and high proliferative activity. However, after potentially curative resection, the prognosis of patients with BSCC of the esophagus does not differ from that of patients with typical SCC.

Basaloid squamous cell carcinoma of the esophagus: diagnosis and prognosis

BACKGROUND

Basaloid squamous cell carcinoma (BSCC) is a recently recognized, poorly differentiated variant of squamous cell carcinoma (SCC), which is located predominantly in the upper aerodigestive tract.

METHODS

In this study, clinical and pathologic parameters of 17 BSCCs and 133 typical SCCs of the esophagus that underwent potentially curative resection (no distant metastases, no residual tumor) were compared. In addition, light microscopic, electron microscopic, and immunohistochemical features of BSCC were investigated, to determine whether this type of carcinoma could be differentiated from other poorly differentiated carcinomas of the esophagus.

RESULTS

Light microscopic study showed that BSCC was composed of relatively small tumor cells, arranged in solid lobules with abundant comedo-type necrosis. BSCC was almost invariably accompanied by areas of concomitant typical SCC, foci of squamous cell differentiation, and/or severe squamous cell dysplasia or carcinoma in situ of the adjacent mucosa. Ultrastructurally, BSCC inconsistently showed features of squamous cell differentiation. Immunohistochemically, BSCC displayed poor reactivity for antibodies against wide-range cytokeratins and cytokeratin subtypes that are typical of squamous cell epithelia (cytokeratin 13 and cytokeratin 14). Infrequently, expression of Leu7, smooth muscle actin, and S-100 protein was found. In comparison with typical SCC, the characteristic features of BSCC were older patient age, higher proliferative activity (MIB-1 labelling index), and higher apoptotic indices. No differences were found with regard to pT classification, pN classification, tumor size, blood vessel invasion, lymphatic vessel invasion, neural invasion, or patient gender. Moreover, no differences in overall survival rates were found.

CONCLUSIONS

BSCC is a distinct histopathologic variant of SCC, characterized by a poor degree of differentiation and high proliferative activity. However, after potentially curative resection, the prognosis of patients with BSCC of the esophagus does not differ from that of patients with typical SCC.

[Systematic clinical quality assurance in surgery]

Between April 1993 and December 1995 the perioperative courses of 3183 patients were recorded within the frame work of a quality assurance project at the Department of Surgery, University of Mainz. The age of the operated patients and the rate of morbidity increased significantly during the observation period. Morbidity and mortality were not correlated to increasing need for intensive care. Morbidity was dependent on the surgical approach and also on the surgeon. On the other hand, high numbers of operations did not necessarily correlate with low complications rates. The concept described makes it possible to compare quality assurance among different hospitals, helps surgeons to recognize and improve their weak points, and serves as an additional method for monitoring the quality of treatment in the clinic.

The prognostic significance of tumour cell proliferation in squamous cell carcinomas of the oesophagus

Tumour samples from 150 patients with squamous cell carcinoma of the oesophagus were investigated immunohistochemically with the monoclonal antibody MIB-1, which recognises proliferating cells. Using light microscopy, the number of MIB-1-positive tumour cells was counted in the areas with the highest proliferative activity. The MIB-1 index was determined as the proportion of MIB-1-positive and MIB-1-negative tumour cells. A considerable variation of the MIB-1 indices was found between the different tumours with a minimum of 6% and a maximum of 95% (median, 33%). The MIB-1 index correlated significantly with the mitotic activity in the tumour tissue (r = 0.33; P = 0.0001) and with the proportion of apoptotic tumour cells (r = 0.25; P = 0.0017). No significant correlation was found between the MIB-1 index and various other prognostic parameters including pT classification, pN classification, tumour grade, blood vessel invasion and lymphatic vessel invasion. In the univariate survival analysis no significant difference was found between tumours with low (< or = 33%) and high MIB-1 index (> 33%) 5-year survival rate: low MIB-1 index, 19.2%; high MIB-1 index, 22.2%). In a Cox proportional hazard regression analysis only the parameters lymphatic vessel invasion (P = 0.0001), pT classification (P = 0.0034) and pN classification (P = 0.0256), but not the MIB-1 index, could be verified as independent prognostic variables. In conclusion, evaluation of the MIB-1 index does not provide prognostic information for oesophageal cancer patients.

Selective approach to the treatment of oesophageal cancer

Between September 1985 and December 1994, 322 patients with oesophageal cancer were treated. Of the 190 patients who underwent operation, 173 had an oesophageal resection; in 124 this was performed as an abdominothoracic resection and in 49 by the transhiatal approach. The assessment of radicality after histological examination revealed a curative (R0) resection in 121 patients (70 per cent) and a palliative (R1-R2) resection in 52 (30 per cent). Prognosis was correlated with the extent of mediastinal lymph node dissection. In 77 patients with stage pT1-3 pN0-1 pM0 the 5-year survival rate was 40 per cent after abdominothoracic resection with two-field lymph node dissection and zero after transhiatal resection (P = 0.01). The authors propose a differentiated surgical approach involving abdominothoracic resection with two-field lymph node dissection for patients with limited tumours (pT1-3 pN0-1 M0) if the operative risk is tolerable. Transhiatal resection appears to be effective only in patients with early tumours (Union Internacional Contra la Cancrum stage 0).

bcl-2 expression and prognosis in squamous-cell carcinomas of the esophagus

The bcl-2 proto-oncogene is a known inhibitor of apoptosis and may be an important regulator of tumor growth. In the present study, bcl-2-protein expression was investigated by immunohistochemistry and correlated with prognosis in a series of 150 potentially curatively resected squamous-cell carcinomas of the esophagus. For comparison, bcl-2-protein expression was analyzed in normal esophageal mucosa, severe squamous dysplasias and carcinomas in situ. bcl-2 immunoreactivity was found in 40 out of 150 invasive squamous-cell carcinomas; the remaining carcinomas were completely negative. bcl-2-protein expression was found more frequently among poorly differentiated than among well-differentiated tumors (p < 0.0001). No correlation was found between bcl-2-protein expression and the parameters tumor size, depth of invasion and nodal status. Moreover, bcl-2-protein expression had no significant influence on overall survival. Whereas in normal mucosa bcl-2 immunoreactivity was restricted to the basal-cell layer, in 9 out of 15 severe squamous dysplasias and in 7 out of 14 carcinomas in situ bcl-2 staining was detected in all epithelial layers. Thus, bcl-2-protein is frequently expressed in invasive squamous-cell carcinomas of the esophagus and in precursor lesions of esophageal cancer, but has no significant impact on the outcome of esophageal cancer.