β-pyrophosphate: A potential biomaterial for dental applications

Tooth hypersensitivity is a growing problem affecting both the young and ageing population worldwide. Since an effective and permanent solution is not yet available, we propose a new methodology for the restoration of dental enamel using femtosecond lasers and novel calcium phosphate biomaterials. During this procedure the irradiated mineral transforms into a densified layer of acid resistant iron doped β-pyrophosphate, bonded with the surface of eroded enamel. Our aim therefore is to evaluate this densified mineral as a potential replacement material for dental hard tissue. To this end, we have tested the hardness of β-pyrophosphate pellets (sintered at 1000°C) and its mineral precursor (brushite), the wear rate during simulated tooth-brushing trials and the cytocompatibility of these minerals in powder form. It was found that the hardness of the β-pyrophosphate pellets is comparable with that of dental enamel and significantly higher than dentine while, the brushing trials prove that the wear rate of β-pyrophosphate is much slower than that of natural enamel. Finally, cytotoxicity and genotoxicity tests suggest that iron doped β-pyrophosphate is cytocompatible and therefore could be used in dental applications. Taken together and with the previously reported results on laser irradiation of these materials we conclude that iron doped β-pyrophosphate may be a promising material for restoring acid eroded and worn enamel.

Giant saccular superior vena cava aneurysm-a rare and difficult clinical case

A superior vena cava (SVC) aneurysm is an extremely rare case of vascular malformation in the chest cavity. This is a report of a case of a 57-year-old woman with a saccular SVC aneurysm which was 8 cm wide. The chest computed tomography (CT) scan confirmed a giant 75 mm × 79 mm × 81 mm mass containing the contrast medium from SVC, constricting the right lung parenchyma, narrowing the right innominate vein, in contact with the anterolateral chest cavity wall, and adjoining the superior mediastinum. Under general anesthesia and employing the median sternotomy approach, using a cardiopulmonary bypass (CPB), the venous aneurysm was successfully resected. The postoperative period was uneventful. Radical surgical resection using a sternotomy and a CPB is recommended.

Measurement and comparison of individual external doses of high-school students living in Japan, France, Poland and Belarus-the 'D-shuttle' project

Twelve high schools in Japan (of which six are in Fukushima Prefecture), four in France, eight in Poland and two in Belarus cooperated in the measurement and comparison of individual external doses in 2014. In total 216 high-school students and teachers participated in the study. Each participant wore an electronic personal dosimeter 'D-shuttle' for two weeks, and kept a journal of his/her whereabouts and activities. The distributions of annual external doses estimated for each region overlap with each other, demonstrating that the personal external individual doses in locations where residence is currently allowed in Fukushima Prefecture and in Belarus are well within the range of estimated annual doses due to the terrestrial background radiation level of other regions/countries.

[1,4]-sigmatropic rearrangement of chiral nitrones and their utilization in the synthesis of new iminosugars

A new mechanism of nitrone epimerization via [1,4]-sigmatropic rearrangement was proposed and a set of epimeric iminosugars was synthesized.

Perivascular tissue mediated relaxation - a novel player in human vascular tone regulation

Perivascular tissue (PVT) modulates vascular tone, releasing adventitia/adipocyte derived relaxing factor (ADRF). Its physiological role remains unclear. We studied isolated internal thoracic artery (ITA) segments obtained from 132 patients subjected to coronary artery bypass grafting. The vessels were skeletonized in vitro and the ITA rings and PVT were incubated in separate isolated organ baths. Skeletonized ITA segments were first precontracted with 10(-5.5)mol/L 5-hydroxytryptamine hydrochloride. The PVT was next transferred to the ITA tissue bath. This resulted in relaxation of ITA, presumably related to ADRF release from PVT which was floating freely in the tissue bath. The in-vitro relaxation responses were then correlated to patients' characteristics - including demographics, clinical and laboratory data, as well as therapy. Perivascular tissue transfer resulted in 49.7 ± 26.2% relaxation of precontracted ITA segments. In multiple linear regression modelling, the relaxation of ITAto PVT was negatively related to patient age (β = -0.67; 95% CI -1.17 - -0.17; P = 0.009), symptoms of CCS class 4 angina (β = -20.11; 95%CI -32.25 - -7.97; P = 0.001), and positively to body mass (β = 0.37; 95%CI 0.08 - 0.67; P = 0.01) and lack of heart failure symptoms (NYHA class 1) (β = 9.06; 95%CI 0.33 - 17.79; P = 0.04). The relaxation response to PVT was not related to patients' sex, diabetes, hypertension, lipid profile or therapy in both univariate and multivariate analysis. PVT might play an important role in regulating vascular tone in humans as exemplified by its changing physiological function with age and in atherosclerosis.

(13) C Breath Tests Are Feasible in Patients With Extracorporeal Membrane Oxygenation Devices

Temporary extracorporeal membrane oxygenation (ECMO) has been established as an essential part of therapy in patients with pulmonary or cardiac failure. As physiological gaseous exchange is artificially altered in this patient group, it is debatable whether a (13) C-breath test can be carried out. In this proof of technical feasibility report, we assess the viability of the (13) C-breath test LiMAx (maximum liver function capacity) in patients on ECMO therapy. All breath probes for the test device were obtained directly via the membrane oxygenator. Data of four patients receiving liver function assessment with the (13) C-breath test LiMAx while having ECMO therapy were analyzed. All results were compared with validated scenarios of the testing procedures. The LiMAx test could successfully be carried out in every case without changing ECMO settings. Clinical course of the patients ranging from multiorgan failure to no sign of liver insufficiency was in accordance with the results of the LiMAx liver function test. The (13) C-breath test is technically feasible in the context of ECMO. Further evaluation of (13) C-breath test in general would be worthwhile. The LiMAx test as a (13) C-breath test accessing liver function might be of particular predictive interest if patients with ECMO therapy develop multiorgan failure.

Reductions in post-hepatectomy liver failure and related mortality after implementation of the LiMAx algorithm in preoperative work-up: a single-centre analysis of 1170 hepatectomies of one or more segments

OBJECTIVES

Post-hepatectomy liver failure has a major impact on patient outcome. This study aims to explore the impact of the integration of a novel patient-centred evaluation, the LiMAx algorithm, on perioperative patient outcome after hepatectomy.

METHODS

Trends in perioperative variables and morbidity and mortality rates in 1170 consecutive patients undergoing elective hepatectomy between January 2006 and December 2011 were analysed retrospectively. Propensity score matching was used to compare the effects on morbidity and mortality of the integration of the LiMAx algorithm into clinical practice.

RESULTS

Over the study period, the proportion of complex hepatectomies increased from 29.1% in 2006 to 37.7% in 2011 (P = 0.034). Similarly, the proportion of patients with liver cirrhosis selected for hepatic surgery rose from 6.9% in 2006 to 11.3% in 2011 (P = 0.039). Despite these increases, rates of post-hepatectomy liver failure fell from 24.7% in 2006 to 9.0% in 2011 (P < 0.001) and liver failure-related postoperative mortality decreased from 4.0% in 2006 to 0.9% in 2011 (P = 0.014). Propensity score matching was associated with reduced rates of post-hepatectomy liver failure [24.7% (n = 77) versus 11.2% (n = 35); P < 0.001] and related mortality [3.8% (n = 12) versus 1.0% (n = 3); P = 0.035].

CONCLUSIONS

Postoperative liver failure and postoperative liver failure-related mortality decreased in patients undergoing hepatectomy following the implementation of the LiMAx algorithm.

Noninvasive diagnosis of chemotherapy induced liver injury by LiMAx test--two case reports and a review of the literature

Background

Chemotherapy-induced liver injury is a well-known phenomenon after neoadjuvant therapy of liver metastasis and contributes to postoperative morbidity and mortality. Still there is no suitable test available to reliably determine functional impairment and hepatic regeneration after chemotherapy.

Case presentation

We report two cases of caucasian patients who underwent repeated liver function assessments using LiMAx (maximum liver function capacity), Indocyanine plasma disappearance rate and biochemical liver function parameters in the course of adjuvant oxaliplatin-based chemotherapy.

Both patients yielded a decrease from their initial liver function determined by LiMAx. Liver regeneration assessed functional recovery within 4 weeks in case of mild functional impairment after cessation of chemotherapy or within 8 weeks in case of major functional deterioration. Indocyanine plasma disappearance rate and biochemical parameters remained stable or without a clear trend in case of minor functional impairment. This is the first report using a dynamic liver function test to evaluate the impact and recovery from chemotherapy associated liver injury.

Conclusions

The LiMAx test might be a sensitive tool to diagnose mild functional impairment after chemotherapy when standard liver function tests have remained within normal ranges and might be capable to assess the course of regeneration after chemotherapy. This could be useful to optimize individual chemotherapy-free interval before liver surgery can be carried out safely.

Bovine pericardium for portal vein reconstruction in abdominal surgery: a surgical guide and first experiences in a single center

BACKGROUND

Resection and reconstruction of infiltrated vessels achieve resectability of extended pancreatic tumors. The aim of the present study was to assess the feasibility of bovine pericardium as graft material for the individualised portal vein reconstruction and demonstrate a surgical technique for abdominal vein repair.

METHODS

We performed a MEDLINE search to review the methods for complex abdominal vein reconstruction in the course of extended pancreatectomy. Moreover, clinical data of patients receiving portal vein reconstruction using a bovine pericardial patch at our institution were retrospectively analyzed.

RESULTS

Based on the results of a review of the literature, autologous venous grafts using the internal jugular vein represent the most popular option for segmental portal vein reconstruction in case of impossible direct suture. At our center, segmental portal vein reconstruction with bovine pericardial patch in course of pancreatic surgery was performed in 4 patients. No case of vascular complications such as occlusion, segmental stenosis or thrombosis occurred.

CONCLUSIONS

Our experience suggests a surgical procedure for an individual size-matched portal vein reconstruction using bovine pericardium. Although first results appear promising, prospective studies are required to objectively assess the patency of bovine pericardium compared with autologous and synthetic interposition grafts for portal vein reconstruction.

Portal vein embolization with plug/coils improves hepatectomy outcome

BACKGROUND

Portal vein embolization (PVE) has become the standard of care before extended hepatectomy. Various PVE methods using different embolization materials have been described. In this study, we compared PVE with polyvinyl alcohol particles alone (PVA only) versus PVA with plug or coils (PVA + plug/coils).

MATERIALS AND METHODS

Patients undergoing PVE before hepatectomy were included. PVA alone was used until December 2013, thereafter plug or coils were placed in addition. The volume of left lateral liver lobe (LLL), clinical parameters, and liver function tests were measured before PVE and resection.

RESULTS

A total of 43 patients were recruited into the PVA only group and 42 were recruited into the PVA + plug/coils group. There were no major differences between groups except significantly higher total bilirubin level before PVE in the PVA only group, which improved before hepatectomy. Mean LLL volume increased by 25.7% after PVE in the PVA only group and by 44% in the PVA + plug/coils group (P < 0.001). Recanalization was significantly less common in the PVA + plug/coils group. In multivariate regression, initial LLL volume and use of plug or coils were the only parameters influencing LLL volume increase. The postoperative liver failure rate was significantly reduced in PVA + plug/coils group (P = <0.001).

CONCLUSIONS

PVE using PVA particles together with plug or coils is a safe and efficient method to increase future liver remnant volume. The additional central embolization with plug or coils led to an increased hypertrophy, due to lower recanalization rates, and subsequently decreased incidence of postoperative liver failure. No additional procedure-specific complications were observed in this series.

Imaging-based evaluation of liver function: comparison of ⁹⁹mTc-mebrofenin hepatobiliary scintigraphy and Gd-EOB-DTPA-enhanced MRI

OBJECTIVES

To compare Gd-EOB-enhanced MRI and (99m)Tc-mebrofenin hepatobiliary scintigraphy (HBS) as imaging-based liver function tests for separate evaluation of right (RLL) and left liver lobe (LLL) function.

METHODS

Fourteen patients underwent Gd-EOB-enhanced MRI and (99m)Tc-mebrofenin HBS after portal vein embolization within 24 h. Relative enhancement (RE) and hepatic uptake index (HUI) were determined from MRI; and T max, T 1/2 and mebrofenin uptake were determined from HBS, all values separately for RLL and LLL.

RESULTS

Mebrofenin uptake correlated significantly with HUI and RE for both liver lobes. There was strong correlation of mebrofenin uptake with HUI for RLL (r (2) = 0.802, p = 0.001) and RE for LLL (r (2) = 0.704, p = 0.005) and moderate correlation with HUI for LLL (r (2) = 0.560, p = 0.037) and RE for RLL (r (2) = 0.620, p = 0.018). Correlating the percentage share of RLL function derived from MRI (with HUI) with the percentage of RLL function derived from mebrofenin uptake revealed a strong correlation (r (2) = 0.775, p = 0.002).

CONCLUSIONS

Both RE and HUI correlate with mebrofenin uptake in HBS. The results suggest that Gd-EOB-enhanced MRI and (99m)Tc-mebrofenin HBS may equally be used to separately determine right and left liver lobe function.

KEY POINTS

• Information about liver function can be acquired with routine Gd-EOB-MRI. • Gd-EOB-MRI and (99m) Tc-mebrofenin HBS show elevated function of non-embolized lobe. • Gd-EOB-MRI and (99m) Tc-mebrofenin HBS can determine lobar liver function.

Enzymatic liver function capacity correlates with disease severity of patients with liver cirrhosis: a study with the LiMAx test

BACKGROUND

Assessment and quantification of actual liver function is crucial in patients with chronic liver disease to monitor disease progression and predict individual prognosis. Mathematical models, such as model for end-stage liver disease, are used for risk stratification of patients with chronic liver disease but do not include parameters that reflect the actual functional state of the liver.

AIM

We aimed to evaluate the potential of a (13)C-based liver function test as a stratification tool by comparison with other liver function tests and clinical parameters in a large sample of healthy controls and cirrhotic patients.

METHODS

We applied maximum liver function capacity (LiMAx) to evaluate actual liver function in 347 patients with cirrhosis and in 86 controls.

RESULTS

LiMAx showed strong negative correlation with Child-Pugh Score (r = -0.707; p < 0.001), MELD (r = -0.686; p < 0.001) and liver function tests. LiMAx was lower in patients with liver cirrhosis compared to healthy controls [99 (57-160) µg/kg/h vs. 412 (365-479) µg/kg/h, p < 0.001] and differed among Child-Pugh classes [a: 181 (144-227) µg/kg/h, b: 96 (62-132) µg/kg/h and c: 52 (37-81) µg/kg/h; p < 0.001]. When stratified patients according to disease severity, LiMAx results were not different between cirrhotic patients and cirrhotic patients with transjugular intrahepatic portosystemic shunt.

CONCLUSIONS

LiMAx appears to provide reliable information on remnant enzymatic liver function in chronic liver disease and allows graduation of disease severity.

Prognostic value of enzymatic liver function for the estimation of short-term survival of liver transplant candidates: a prospective study with the LiMAx test

LiMAx has been recently proposed as a new quantitative liver function test. Thus, we aimed to evaluate the diagnostic ability of LiMAx to assess short-term survival in liver transplant candidates and compare its performance to the model for end-stage liver disease (MELD) and indocyanine green plasma disappearance rate (ICG-PDR). Liver function of 167 chronic liver failure patients without hepatocellular carcinoma was prospectively investigated when they were evaluated for liver transplantation. Primary study endpoints were liver-related death within 6 months of follow-up. Within 6 months of follow-up, 18 patients died and 36 underwent liver transplantation. Median LiMAx results on evaluation day were significantly lower in patients who died (99 μg/kg/h vs. 55 μg/kg/h; P = 0.024), while median ICG-PDR results did not differ within both groups (4.4%/min vs. 3.5%/min; P = 0.159). LiMAx showed a higher negative predictive value (NPV: 0.93) as compared with ICG-PDR (NPV: 0.90) and the MELD (NPV: 0.91) in predicting risk of death within 6 months. In conclusion, LiMAx provides good prognostic information of liver transplant candidates. In particular, patients who are not at risk of death can be identified reliably by measuring actual enzymatic liver function capacity.

Predictors of quality of life in patients evaluated for liver transplantation

INTRODUCTION

Health-related quality of life (HRQOL) is severely impaired in advanced liver disease. The purpose of this study was to evaluate the impact of actual liver function and disease-specific factors on HRQOL of patients evaluated for liver transplantation.

PATIENTS AND METHODS

Disease-specific QOL was analyzed in 142 patients evaluated for liver transplantation using the German version of the Chronic Liver Disease Questionnaire (CLDQ-D). We performed quantitative liver function tests and collected clinical and demographical data of patients after their referral to our transplant department. Values were correlated with CLDQ-D scores.

RESULTS

Neither model for end-stage liver disease (MELD) nor dynamic liver function test results were related to quality of life. Serum albumin concentration was a strong but not independent factor correlated with global CLDQ-D (r = 0.269, p < 0.001). Independent predictors of global CLDQ-D were ascites and butyrylcholinesterase serum concentration (B = -0.486, p < 0.001 and B = 0.196, p = 0.002, respectively).

CONCLUSION

Actual liver function is not related to decreased quality of life, whereas ascites and hypoproteinemia represent the major factors influencing physical and social aspects of daily life in potential liver transplant candidates.

Growth hormone/insulin-like growth factor 1 dynamics in adult living donor liver transplantation

End-stage liver disease is accompanied by decreased serum levels of insulin-like growth factor 1 (IGF1) and inversely increased serum levels of growth hormone (GH). Previous reports have demonstrated rapid GH/IGF1 axis recovery after orthotopic liver transplantation. This study investigated the effect in an adult-to-adult living donor liver transplantation (LDLT) model and characterized GH/IGF1 alterations and liver regeneration in both donors and recipients. Sequential blood samples were prospectively collected from 30 donor-recipient pairs during the perioperative course of LDLT. A distinct set of biochemical parameters, including serum GH, serum IGF1, and standard liver blood tests, was analyzed at different time points (preoperatively and during 12 months of follow-up after surgery). Recipients showed significantly higher GH serum levels and lower IGF1 serum levels in comparison with donors before surgery and throughout the first postoperative days (PODs). The GH serum levels of recipients declined, whereas donor levels inversely increased during the early postoperative period to a normal range. Recipients' IGF1 serum levels were restored within the first operative week. In parallel, donor IGF1 levels decreased by 50% after living donation, and preoperative serum levels were restored after 6 months. Donors showed delayed recovery of liver function in comparison with recipients. The dynamics of IGF1 strongly correlated with routine laboratory parameters of liver function. In conclusion, recipients showed a rapid recovery of the GH/IGF1 hormonal axis and liver function after LDLT, whereas donors showed altered GH signaling and regenerative delay in the early PODs after living donation.

Evaluation of gadolinium-EOB-DTPA uptake after portal vein embolization: value of an increased flip angle

BACKGROUND

The optimal sequence for Gd-EOB-DTPA uptake measurement in the liver with the purpose of liver function measurement is still not defined.

PURPOSE

To prospectively evaluate the effect of an increased flip angle (FA) of a T1-weighted fat-saturated 3D sequence for the measurement of hepatocyte uptake of Gd-EOB-DTPA magnetic resonance imaging (MRI) after right portal vein embolization (PVE).

MATERIAL AND METHODS

Ten patients who received a PVE prior to an extended hemihepatectomy were examined 14 days after PVE using Gd-EOB-DTPA enhanced MRI of the liver using the standard FA of 10° and the increased FA of 30°.

RESULTS

Relative enhancement of the right liver lobe (RLL) was 0.52 ± 0.12 for 10° and 1.41 ± 0.39 for 30°. Relative enhancement of the left liver lobe (LLL) was 0.58 ± 0.11 for 10° and 2.05 ± 0.61 for 30°. Relative enhancement of the RLL was significantly higher for 30° than for 10° (P = 0.009) and significantly higher in the 30° than in the 10° sequences (P = 0.005) for the LLL.

CONCLUSION

A flip angle of 30° increases the contrast between liver partitions with and without portal venous embolization. Thereby, the sensitivity for differences in uptake intensity is increased. This could be of value for a more exact determination of differences in regional liver function and, consequently, the estimation of the future remnant liver function.

Improved hypertrophy of future remnant liver after portal vein embolization with plugs, coils and particles

PURPOSE

To retrospectively analyze efficacy as measured by volume gain of future remnant liver (FRL) after right portal vein embolization (PVE) using particles only versus particles and additional central plug and/or coil (CP/C) embolization.

METHODS

All patients who underwent PVE between July 2011 and December 2012 were retrospectively analyzed. Right PVE was performed either with particle-only (PO) embolization or additional CP/C embolization. All enrolled patients underwent computed tomography or magnetic resonance imaging before PVE and surgery. The images were used for volumetry of the FRL.

RESULTS

Of 75 patients, 40 had PO and 35 CP/C embolization. Age, sex, and tumor entities did not differ significantly between the two groups. Tumor entities included cholangiocarcinoma (n = 52), metastasis from colorectal cancer (n = 14), hepatocellular carcinoma (n = 2), and others (n = 7). Time from PVE to preoperative imaging was similar in both groups. FRL volume before PVE was 329 ± 121 ml in the PO group and 333 ± 135 ml in the CP/C group, and 419 ± 135 ml and 492 ± 165 ml before operation. The average percentage volume gain was significantly higher in the CP/C group than in the PO group, with 53.3 ± 34.5 % versus 30.9 ± 28.8 % (p = 0.002).

CONCLUSION

Right PVE with additional CP/C embolization leads to a significantly higher gain in FRL volume than embolization with particles alone.

Early diagnosis of sepsis-related hepatic dysfunction and its prognostic impact on survival: a prospective study with the LiMAx test

INTRODUCTION

Liver dysfunction can derive from severe sepsis and might be associated with poor prognosis. However, diagnosis of septic liver dysfunction is challenging due to a lack of appropriate tests. Measurement of maximal liver function capacity (LiMAx test) has been successfully evaluated as a new diagnostic test in liver resection and transplantation. The aim of this study was to evaluate the LiMAx test during sepsis in comparison to biochemical tests and the indocyanin green test (ICG-PDR).

METHODS

We prospectively investigated 28 patients (8 female and 20 male, age range 35 to 80 years) suffering from sepsis on a surgical ICU. All patients received routine resuscitation from septic shock (surgery, fluids, catecholamines, antibiotic drugs). The first LiMAx test and ICG-PDR were carried out within the first 24 hours after onset of septic symptoms, followed by day 2, 5 and 10. Other biochemical parameters and scores determining the severity of illness were measured daily. Clinical outcome parameters were examined after 90 days or at the end of treatment. The population was divided into 2 groups (group A: non-survivors or ICU length of stay (ICU-LOS) >30 days versus group B: survivors and ICU-LOS <30 days) for analysis.

RESULTS

Epidemiological baseline characteristics of both groups were similar. Group A patients had significant lower LiMAx and ICG-PDR values than patients in group B. Determination of ICG-PDR by finger probe failed in 14.3% of tests due to insufficient peripheral pulses. Respiratory, renal and hepatic dysfunction (LiMAx and ICG-PDR) were associated with prolonged ICU-LOS. Only LiMAx <100 μg/kg/h and respiratory dysfunction were associated with increased mortality. For LiMAx <100 μg/kg/h receiver operating characteristic-analysis revealed a 100% sensitivity and 77% specificity for death.

CONCLUSIONS

Sepsis-related hepatic dysfunction can be diagnosed early and effectively by the LiMAx test. The extent of LiMAx impairment is predictive for patient morbidity and mortality. The sensitivity and specificity of the LiMAx test was superior to that of ICG-PDR regarding the prediction of mortality.

Predicting the prognosis in acute liver failure: results from a retrospective pilot study using the LiMAx test

BACKGROUND

Acute liver failure (ALF) is a rare but potentially life-threatening condition and liver transplantation (LTX) remains frequently the only effective therapy. Nevertheless, some patients recover without LTX but the individual indication for or against LTX remains difficult.

AIM

To evaluate maximal liver function capacity (LiMAx) for predicting the prognosis of ALF. Material and methods. Clinic data of 12 patients was retrospectively analyzed to compare the different liver function test results with the patients' clinical outcome. Patients were assessed by the LiMAx test, a non-invasive breath test determining cytochrome P450 1A2 capacity using intravenous 13C-methacetin. Statistical analysis compared patients with spontaneous recovery versus non-recovery (LTX or death).

RESULTS

Twelve patients (6 male, 6 female; 49 [11-72] years) with viral hepatitis (n = 2), toxic liver injury (n = 3), or cryptogenic liver failure (n = 7) were analyzed. Seven patients fully recovered from ALF and were discharged without LTX. Three patients died and two underwent LTX. The King's College Criteria (KCC) was fulfilled in only one out of five patients without recovery. The LiMAx was 19 ± 19 (16-62) for non-recovery vs. 94 ± 119 (39-378) μg/kg/h for recovery (P = 0.018). In contrast, all biochemical parameters [bilirubin (P = 0.106), creatinine (P = 0.343), AST (P = 0.53), ALT (P = 0.876) and INR (P = 0.876) were statistically indistinct. Also the Model for End-Stage Liver Disease (MELD) score did not show a difference [35 ± 4.3 (29-40) vs. 30 ± 11.5 (6-40); P = 0.27].

CONCLUSIONS

Maximal liver function capacity determined by LiMAx test is severely impaired in patients with ALF. The LiMAx test might be effective in predicting the individual prognosis and the need for LTX in ALF.

Mechanisms of vasodilatatory effect of perivascular tissue of human internal thoracic artery

It has beed showed that perivascular adipose tissue (PVAT) of human internal thoracic artery (ITA) releases adventitia/adipocyte-derived relaxing factor (ADRF). The precise mechanism of vasodilatatory effect of ADRF is still unknown. It was suggested that various potassium channels may be involved in the action of ADRF. The aim of this study was to assess the involvment of potassium channels in the vasorelaxing properties of ADRF in human internal thoracic artery. Human ITA rings were studied in vitro. First the ability of perivascular tissue of human ITA to release ADRF to the bath was checked. In subsequent experiments two fragments of skeletonised ITA were used to assess the involvement of various potassium channels in vasorelaxing action of PVAT. Segment of ITA, precontracted with serotonin (10(-5.5)M), was relaxed by adding PVAT to tissue bath, first without and then in the presence of appropriate potassium channel blocker. Second segment served as a control (no addition of PVAT). The magnitude of relaxation was measured and compared between preparations. This protocol was used to analyze the influence of iberiotoxin (100 nM), apamin (1 uM), 4-aminopyridine (1 mM, 5 mM), BaCl₂ (100 uM) and glibenclamide (10 uM). The addition of PVAT to precontracted skeletonized ITA caused significant vasorelaxation (54.6±8.03 mN versus 33.7±6.58 mN p=0.03). Similar effect was seen when 5 ml of aliquot from separate incubation of PVAT was added (36.3±5.45 mN versus 20.7±3.02 mN; p<0.001). PVAT dependent relaxation was blocked in the presence of Ca⁺² dependent potassium channel blocker iberiotoxin (47.4±16.67 mN versus 43.3±14.54 mN; p=0.36) and 4-aminopyridine (5 mM) (59.3±3.54 mN versus 51.6±4.77 mN; p=0.12). We conclude that perivascular adipose tissue of human ITA releases relaxing factor that seems to act with the involvement of Ca⁺² dependent potassium channels.

Increase in left liver lobe function after preoperative right portal vein embolisation assessed with gadolinium-EOB-DTPA MRI

OBJECTIVES

To prospectively evaluate the early development of regional liver function after right portal vein embolisation (PVE) with Gd-EOB-DTPA-enhanced MRI in patients scheduled for extended right hemihepatectomy.

METHODS

Ten patients who received a PVE before an extended hemihepatectomy were examined before and 14 days after PVE using Gd-EOB-DTPA-enhanced MRI of the liver. In these sequences representative region of interest measurements were performed in the embolised right (RLL) and the non-embolised left liver lobe (LLL). The volume as well as hepatic uptake index (HUI) was calculated independently for each lobe.

RESULTS

Relative enhancement 14 days after PVE decreased in the RLL and increased significantly in the LLL (P < 0.05). Average hepatic uptake index (HUI) for RLL was significantly lower 14 days after PVE than before PVE (P < 0.05) and significantly higher for LLL (P < 0.05).

CONCLUSIONS

A significant shift of contrast uptake from the right to the left liver lobe can be depicted as early as 14 days after right PVE by using Gd-EOB-DTPA-enhanced MRI, which could reflect the redirected portal venous blood flow and the rapid utilisation of a hepatic functional reserve.

KEY POINTS

• Preoperative portal vein embolisation (PVE) is widely performed before right-sided hepatic resection. • PVE increases intravenous contrast medium uptake in the left lobe of liver. • The hepatic uptake index for the left liver lobe increases rapidly after PVE. • Left liver lobe function increase may be visualised by Gd-EOB-DTPA-enhanced MRI.

Interpretation of non-invasive breath tests using (13)C-labeled substrates--a preliminary report with (13)C-methacetin

Non-invasive breath tests can serve as valuable diagnostic tools in medicine as they can determine particular enzymatic and metabolic functions in vivo. However, methodological pitfalls have limited the actual clinical application of those tests till today. A major challenge of non-invasive breath tests has remained the provision of individually reliable test results. To overcome these limitations, a better understanding of breath kinetics during non-invasive breaths tests is essential. This analysis compares the breath recovery of a ¹³C-methacetin breath test with the actual serum kinetics of the substrate. It is shown, that breath and serum kinetics of the same test are significantly different over a period of 60 minutes. The recovery of the tracer ¹³CO₂ in breath seems to be significantly delayed due to intermediate storage in the bicarbonate pool. This has to be taken into account for the application of non-invasive breath test protocols. Otherwise, breath tests might display bicarbonate kinetics despite the metabolic capacity of the particular target enzyme.

[Implantation of plastic and metal stents to biliary tract in obstructive jaundice in material of Surgery Department of 4th Military Clinical Hospital in Wroclaw]

INTRODUCTION

A method of treatment for malignant bile duct strictures depends on early diagnosis, location and extent of tumor infiltration. Patients eligible for radical surgery should be operated.

AIM OF THE STUDY

The authors used plastic and metal prostheses in the treatment of biliary tract cancer cholestasis.

MATERIAL AND METHODS

Retrospective analysis was done in 2730 endoscopies performed in the Laboratory of the Department of Endoscopic Surgery, 4th Military Hospital in Wroclaw in 2008-2011. The authors analyzed 441 cases of prosthetic biliary cancer.

RESULTS

223 patients (51%) were treated for pancreatic head tumor, 98 pts (22%)--for papilla of Vater tumor, 85 pts (19%)--due to Klatskin tumor and 35 pts (8%)--due to tumor of the gallbladder. Plastic prostheses were inserted in 228 (65.4%) patients, self-expanding metal prostheses--in 21 patients (4.9%). Dilatation of the bile duct or the inserted prosthesis was performed in 48 (11.1%) pts. 27 patients (6.1%) had endoscopic treatment failure. 32 patients (7.3%) had following complications of biliary prosthesis: bleeding into the bile duct, into the digestive tract--4 cases (1%), the migration of the prosthesis--7 (1.6%), cholangitis--21 cases (4.7%).

CONCLUSIONS

Palliative biliary stenting is a safe method that provides efficient drainage of bile. It shows a definitive advantage over percutaneous, biliary transhepatic drainage.

Function and volume recovery after partial hepatectomy: influence of preoperative liver function, residual liver volume, and obesity

BACKGROUND

The regenerative capacity of the liver is an essential pre-condition for the successful application of partial hepatectomy. However, the actual kinetics of functional recovery remains unspecified and no adequate tool for its clinical monitoring has yet been available.

METHODS

Eighty-five patients receiving major hepatectomy were investigated from the preoperative evaluation until 12 weeks after surgery. Liver function was determined by the LiMAx test for the enzymatic capacity of cytochrome P450 1A2. Liver volume was determined by volumetric analysis of repeated computer tomography scans. Functional and volume recovery were compared during follow-up.

RESULTS

Major hepatectomy decreased liver function capacity to 35.7 ± 13.8% of preoperative function. It was shown that functional recovery already reaches 77.2 ± 33.5% of preoperative values within 10 days. The actual kinetics were dependent from the type and extent of hepatectomy. Complete functional restoration was achieved within 12 weeks, while liver volume still remained at 73.2 ± 14.8% of preoperative. A constant but interindividually variable correlation between function and volume was observed at all points in time.

CONCLUSION

Partial hepatectomy leads to fast and complete functional recovery, while volume recovery is delayed and remains often incomplete. The functional recovery is mainly influenced by the preoperative liver function, the residual liver volume, and by obesity.

Pressure-induced phase transition in LiLuF4:Pr3+ investigated by an optical technique

The luminescence and luminescence kinetics of LiLuF(4) doped with 1.5 at.% of Pr(3+) obtained at high hydrostatic pressure changing from ambient to 220 kbar applied in a diamond anvil cell are presented. It has been shown that pressure causes shift of the emission lines toward the red with rates of the order of single cm(-1) kbar(-1). The pressure-induced phase transition from tetragonal to fergusonite structure for pressure above 100 kbar was observed. The crystal field calculations performed showed that this phase transition reduces the point symmetry of the Pr(3+) site from the S(4) to the C(2) point group.

[Use of Gianturco-Wallace and tornado coils in perforators embolisation in chronic venous ulcers treatment]

AIM OF THE STUDY

Embolisation is a endovascular technique of vessels closure using embolisation material, which is applied into vessels throw catheter. As an embolisation material coils Gianturco-Wallace i Tornado (Cook) were used. Length and size of coils was determined individually during precedure.

MATERIALS AND METHODS

38 patients of Vascular Surgery Department and Radiology Department of Medical University in Wroclaw were treated by endovascular embolisation of insufficient perforators. Procedures were made on 40 limbs with post-thrombotic complex and venous ulcers (6th degree of CEAP classification). 68 endovascular procedures were made, 143 metal coils were used.

RESULTS

Using endovascular method 85% of ulcers were comletely cured.

CONCLUSIONS

Endovascular embolisation is safe and effective method of veonous ulcers curing. Itmay be used at outpatients clinic.

Liver volume measurement: reason of the difference between in vivo CT-volumetry and intraoperative ex vivo determination and how to cope it

Purpose

Volumetric assessment of the liver regularly yields discrepant results between pre- and intraoperatively determined volumes. Nevertheless, the main factor responsible for this discrepancy remains still unclear. The aim of this study was to systematically determine the difference between in vivo CT-volumetry and ex vivo volumetry in a pig animal model.

Material and Methods

Eleven pigs were studied. Liver density assessment, CT-volumetry and water displacement volumetry was performed after surgical removal of the complete liver. Known possible errors of volume determination like resection or segmentation borders were eliminated in this model. Regression analysis was performed and differences between CT-volumetry and water displacement determined.

Results

Median liver density was 1.07 g/ml. Regression analysis showed a high correlation of r² = 0.985 between CT-volumetry and water displacement. CTvolumetry was found to be 13% higher than water displacement volumetry (p < 0.0001).

Conclusion

In this study the only relevant factor leading to the difference between in vivo CT-volumetry and ex vivo water displacement volumetry seems to be blood perfusion of the liver. The systematic difference of 13 percent has to be taken in account when dealing with those measures.

Effect of tacrolimus dosing on glucose metabolism in an experimental rat model

BACKGROUND

Post-transplant diabetes mellitus (PTDM) is a serious complication after transplantation. The complex clinical situation makes it difficult to distinct influence of the single factors. To define impact of calcineurin inhibitor therapy on the PTDM after transplantation an experimental study analyzing the impact of different tacrolimus - dosages on the pancreatic beta-cell function was designed.

MATERIAL/METHODS

Male Wistar rats received different doses of tacrolimus (0.1, 0.5, 1 and 10 mg/kg day) or tap water for 14 days. Serum glucose, insulin and creatinine levels were measured. Pancreas tissue was fixed in formaldehyde and stained with anti-insulin antibody. Staining intensity was assessed in a semiquantitive, blinded manner.

RESULTS

There was no difference in the serum glucose and insulin levels between the tacrolimus treated and the control group. In the 10 mg/kg group the insulin amount in pancreas beta cells was significantly decreased, while the serum creatinine concentration was significantly increased. All other dosages showed no significant influence on function of insulin producing cells.

CONCLUSIONS

Tacrolimus in therapeutic dosages has no influence on the pancreas insulin production after 14 days of treatment. In contrast toxic tacrolimus dosages has a decreasing effect on insulin production, but is not associated with hypoinsulinemia. Only high doses of tacrolimus might induce glucose intolerance in transplanted patients.