A guide for assessing the clinical relevance of findings in small bowel capsule endoscopy: analysis of 8064 answers of international experts to an illustrated script questionnaire

BACKGROUND AND AIM

Although recommended, the P-score used for assessing the pertinence / relevance of findings seen in small bowel (SB) capsule endoscopy (CE) is based on a low level of knowledge. The aim of this study was to evaluate the clinical relevance of the most frequent SBCE findings through an illustrated script questionnaire.

MATERIALS AND METHODS

Sixteen types of SBCE findings were illustrated four times each in three different settings (occult and overt obscure gastrointestinal bleeding and suspected Crohn's disease), and with a variable number (n = 1/n = 2-5/n ≥ 6), thus providing a questionnaire with 192 scenarios and 576 illustrated questions. Fifteen international experts were asked to rate the finding's relevance for each question as very unlikely (-2) / unlikely (-1) / doubtful (0) / likely (+1) / very likely (+2). The median score (≤-0.75, between -0.75 and 0.75, or ≥0.75) obtained for each scenario determined a low (P0), intermediate (P1) or high (P2) relevance, respectively.

RESULTS

8064 answers were analyzed. Participation and completion rates were 93% and 100%, respectively. In overt or occult OGIB, resultant P2 findings were 'typical angiectasia', 'deep ulceration', 'stenosis', and'blood', whatever their numbers, and 'superficial ulcerations' when multiple. While in suspected CD, consensus P2 lesions were 'deep ulceration' and 'stenosis' whatever their numbers, and 'aphthoid erosions' and 'superficial ulcerations' when multiple.

CONCLUSION

This study establishes a guide for the evaluation of relevance of SBCE findings. It represents a step forward for SB-CE interpretation and is intended to be used as a tool for teaching and academic research.

Repeat capsule endoscopy in suspected gastrointestinal bleeding

Objectives: This study aims to review the utility of repeat capsule endoscopy (CE) with on-going concern of small bowel (SB) bleeding following initial SB investigation with CE. Materials and methods: A specifically designed database of CE examinations performed over 13 years, with hospital records, was retrospectively interrogated for patients undergoing multiple CEs to investigate iron deficiency anaemia (IDA) or suspected SB bleeding. Results: 1335/2276 (58.7%) of CEs were performed to investigate IDA or SB bleeding; 92 were repeat CEs carried out for ongoing clinical concern. The median time interval between initial and repeat CE procedures was 466.5 (range 1-3066) days. Twenty-four patients had initially normal CE; on repeat examination, abnormalities were detected in 11/24 (45.8%). 3/21 (14.2%) of patients with angioectasia on first CE had alternative causes for IDA or GI bleeding detected on repeat CE. Six patients with active bleeding, without an identifiable source on initial CE, undergoing repeat CE had a cause isolated in 5/6 (83.3%). Changing CE device did not affect diagnostic yield (DY) compared to repeat CE using the same device (27.5% to 26.8%). Conclusions: It is known that CE can miss clinically relevant and serious lesions. Our results suggest that patients with an initially negative or inconclusive CE frequently have a cause of SB bleeding detected on repeat CE. The DY of repeat CE is highest in those with bleeding on their initial CE (83.3%) and lower in those with initially normal examinations (45.8%) or when an alternative cause, such as angioectasia is seen (14.2%).

Index serum hyaluronic acid independently and accurately predicts mortality in patients with liver disease

BACKGROUND

Hyaluronic acid is a recognised noninvasive marker of liver fibrosis. However, its prognostic ability has not been extensively studied.

AIMS

To investigate the ability of an index serum hyaluronic acid measurement to independently predict transplant-free survival in patients with liver disease of varying aetiology and severity.

METHODS

This was a retrospective single-centre cohort study. Serum hyaluronic acid was measured at the discretion of the attending clinicians, in patients attending the liver clinic, to assess disease severity. Patients with a hyaluronic acid measurement between 1995 and 2010 were identified. Patient characteristics at the point of hyaluronic acid measurement were recorded from medical records. Follow-up was from date of index hyaluronic acid measurement to date of death, date of transplant or censor date (July 01, 2015). Primary outcomes were all-cause and liver-related mortality. Kaplan-Meier analysis was used to compare survival in 3 patient groups with hyaluronic acid levels of <100 μg/L, 100-300 μg/L and >300 μg/L. Survival models were constructed using Cox proportional hazard and prediction accuracy was assessed by Harrell's C-statistic.

RESULTS

Five hundred and eighty nine patients fulfilled inclusion criteria. Median follow-up was 5.6 years (range 0.1-19.7). Transplant-free survival was significantly different between patients with hyaluronic acid <100 μg/L, 100-300 μg/L and >300 μg/L for liver-related as well as all-cause mortality (P < 0.001). Hyaluronic acid level was an independent predictor of survival (liver-related: HR 1.39, 95% CI 1.20-1.60, P < 0.001; all-cause: HR 1.04, 95% CI 1.02-1.06, P = 0.001). The liver-related prediction accuracy of hyaluronic acid was 0.74 (Standard error 0.03).

CONCLUSION

Index hyaluronic acid measurement can accurately and independently predict liver-related and all-cause mortality in patients with liver disease.

1H nuclear magnetic resonance spectroscopy-based metabonomic study in patients with cirrhosis and hepatic encephalopathy

AIM: To identify plasma metabolites used as biomarkers in order to distinguish cirrhotics from controls and encephalopathics.

METHODS: A clinical study involving stable cirrhotic patients with and without overt hepatic encephalopathy was designed. A control group of healthy volunteers was used. Plasma from those patients was analysed using ¹H - nuclear magnetic resonance spectroscopy. We used the Carr Purcell Meiboom Gill sequence to process the sample spectra at ambient probe temperature. We used a gated secondary irradiation field for water signal suppression. Samples were calibrated and referenced using the sodium trimethyl silyl propionate peak at 0.00 ppm. For each sample 128 transients (FID’s) were acquired into 32 K complex data points over a spectral width of 6 KHz. 30 degree pulses were applied with an acquisition time of 4.0 s in order to achieve better resolution, followed by a recovery delay of 12 s, to allow for complete relaxation and recovery of the magnetisation. A metabolic profile was created for stable cirrhotic patients without signs of overt hepatic encephalopathy and encephalopathic patients as well as healthy controls. Stepwise discriminant analysis was then used and discriminant factors were created to differentiate between the three groups.

RESULTS: Eighteen stabled cirrhotic patients, eighteen patients with overt hepatic encephalopathy and seventeen healthy volunteers were recruited. Patients with cirrhosis had significantly impaired ketone body metabolism, urea synthesis and gluconeogenesis. This was demonstrated by higher concentrations of acetoacetate (0.23 ± 0.02 vs 0.05 ± 0.00, P < 0.01), and b-hydroxybutarate (0.58 ± 0.14 vs 0.08 ± 0.00, P < 0.01), lower concentrations of glutamine (0.44 ± 0.08 vs 0.63 ± 0.03, P < 0.05), histidine (0.16 ± 0.01 vs 0.36 ± 0.04, P < 0.01) and arginine (0.08 ± 0.01 vs 0.14 ± 0.02, P < 0.03) and higher concentrations of glutamate (1.36 ± 0.25 vs 0.58 ± 0.04, P < 0.01), lactate (1.53 ± 0.11 vs 0.42 ± 0.05, P < 0.01), pyruvate (0.11 ± 0.02 vs 0.03 ± 0.00, P < 0.01) threonine (0.39 ± 0.02 vs 0.08 ± 0.01, P < 0.01) and aspartate (0.37 ± 0.03 vs 0.03 ± 0.01). A five metabolite signature by stepwise discriminant analysis could separate between controls and cirrhotic patients with an accuracy of 98%. In patients with encephalopathy we observed further derangement of ketone body metabolism, impaired production of glycerol and myoinositol, reversal of Fischer’s ratio and impaired glutamine production as demonstrated by lower b-hydroxybutyrate (0.58 ± 0.14 vs 0.16 ± 0.02, P < 0.0002), higher acetoacetate (0.23 ± 0.02 vs 0.41 ± 0.16, P < 0.05), leucine (0.33 ± 0.02 vs 0.49 ± 0.05, P < 0.005) and isoleucine (0.12 ± 0.02 vs 0.27 ± 0.02, P < 0.0004) and lower glutamine (0.44 ± 0.08 vs 0.36 ± 0.04, P < 0.013), glycerol (0.53 ± 0.03 vs 0.19 ± 0.02, P < 0.000) and myoinositol (0.36 ± 0.04 vs 0.18 ± 0.02, P < 0.010) concentrations. A four metabolite signature by stepwise discriminant analysis could separate between encephalopathic and cirrhotic patients with an accuracy of 87%.

CONCLUSION: Patients with cirrhosis and patients with hepatic encephalopathy exhibit distinct metabolic abnormalities and the use of metabonomics can select biomarkers for these diseases.

Randomised clinical study: comparison of acceptability, patient tolerance, cardiac stress and endoscopic views in transnasal and transoral endoscopy under local anaesthetic

BACKGROUND

Transnasal endoscopy (TNE) with ultrathin endoscopes has been advocated as an attractive alternative, for diagnostic upper endoscopy.

AIM

To assess tolerability, acceptability and quality of TNE, in comparison with standard upper endoscopy (SOGD, standard oesophago-gastro-duodenoscopy) under local anaesthetic.

METHODS

We prospectively recruited 157 patients (83 females/74 males) mean age 57 years. The Fujinon EG530N (5.9 mm) and EG530WR (9.4 mm) endoscopes were used. The endoscopist and all patients completed detailed questionnaires regarding tolerability, acceptance and quality of endoscopy using standard visual analogue scales (VAS). Oxygen saturation (SaO2 ), heart rate (HR) and systolic blood pressure (SBP) were recorded. Quality of biopsies was evaluated.

RESULTS

Analysis included 161 procedures (TNE:79, SOGD:82) with duodenal intubation achieved in all patients. VAS scores for patient comfort were significantly better in the TNE group (7.3 vs. 5.3 respectively, P < 0.001). Twenty patients with previous experience of standard endoscopy were randomised to TNE and 19 of them (95.5%) preferred the TNE. Gagging was significantly less in the TNE group (0.12 vs. 3.41 respectively, P < 0.001). Cardiovascular stress was significantly less in the TNE group irrespective of the degree of gagging or comfort. TNE biopsies were smaller, but adequate for definitive diagnosis, similarly to standard endoscopy.

CONCLUSIONS

Transnasal endoscopy is superior to SOGD in terms of comfort and patient acceptance with significantly less cardiovascular stress. TNE can routinely be used as alternative to SOGD under local anaesthetic, for diagnosis and should be preferentially offered in cardiorespiratory compromised patients.

Scoring system to identify patients at high risk of oesophageal cancer

BACKGROUND

Identification of a patient cohort at high risk of developing oesophageal cancer might enable a greater proportion of patients with curable disease stages to be identified and permit better use of investigative resources. The aim of this study was to develop a scoring system that identifies patients with dysphagia at greatest risk of having oesophageal cancer.

METHODS

Data on 435 patients with dysphagia were recorded. Univariable and multivariable analyses were performed to identify parameters predictive of cancer. These were used to create the Edinburgh Dysphagia Score (EDS), which was then validated in a second cohort of patients.

RESULTS

The EDS contained six parameters: age, sex, weight loss, duration of symptoms, localization of dysphagia and acid reflux. It stratified the development cohort into a group at higher risk, containing 39 of 40 patients with cancer, and a group at lower risk, comprising 36·0 per cent of referrals (sensitivity 97·5 per cent, negative predictive value 99·3 per cent). On validation, the EDS divided the referrals into a higher-risk group identifying all 26 cancers and a lower-risk group comprising 30·0 per cent of referrals.

CONCLUSION

From 574 referrals, the EDS correctly classified as higher risk all but one patient with cancer. Some 34·0 per cent of patients identified as lower risk could have been investigated less urgently. This simple scoring system permits sensitive prioritization of patients referred with dysphagia, and enables more efficient use of investigative resources.

Review article: omega-3 fatty acids - a promising novel therapy for non-alcoholic fatty liver disease

BACKGROUND

Non-alcoholic fatty liver disease affects 10-35% of the adult population worldwide; there is no consensus on its treatment. Omega-3 fatty acids have proven benefits for hyperlipidaemia and cardiovascular disease, and have recently been suggested as a treatment for non-alcoholic fatty liver disease.

AIMS

To review the evidence base for omega-3 fatty acids in non-alcoholic fatty liver disease and critically appraise the literature relating to human trials.

METHODS

A Medline and PubMed search was performed to identify relevant literature using search terms 'omega-3', 'N-3 PUFA', 'eicosapentaenoic acid', 'docosahexaenoic acid', 'non-alcoholic fatty liver disease' and 'NAFLD'.

RESULTS

Omega-3 fatty acids are important regulators of hepatic gene transcription. Animal studies demonstrate that they reduce hepatic steatosis, improve insulin sensitivity and reduce markers of inflammation. Clinical trials in human subjects generally confirm these findings, but have significant design inadequacies.

CONCLUSIONS

Omega-3 fatty acids are a promising treatment for non-alcoholic fatty liver disease which require to be tested in randomized placebo-controlled trials.

Review article: omega-3 fatty acids - a promising novel therapy for non-alcoholic fatty liver disease

BACKGROUND

Non-alcoholic fatty liver disease affects 10-35% of the adult population worldwide; there is no consensus on its treatment. Omega-3 fatty acids have proven benefits for hyperlipidaemia and cardiovascular disease, and have recently been suggested as a treatment for non-alcoholic fatty liver disease.

AIMS

To review the evidence base for omega-3 fatty acids in non-alcoholic fatty liver disease and critically appraise the literature relating to human trials.

METHODS

A Medline and PubMed search was performed to identify relevant literature using search terms 'omega-3', 'N-3 PUFA', 'eicosapentaenoic acid', 'docosahexaenoic acid', 'non-alcoholic fatty liver disease' and 'NAFLD'.

RESULTS

Omega-3 fatty acids are important regulators of hepatic gene transcription. Animal studies demonstrate that they reduce hepatic steatosis, improve insulin sensitivity and reduce markers of inflammation. Clinical trials in human subjects generally confirm these findings, but have significant design inadequacies.

CONCLUSIONS

Omega-3 fatty acids are a promising treatment for non-alcoholic fatty liver disease which require to be tested in randomized placebo-controlled trials.

Treating bleeding oesophageal varices with vasoactive agents: good value for money?

This article provides an editorial commentary to accompany the publication of an article on the economic evaluation of vasoactive agents used in the United Kingdom for acute bleeding oesophageal varices in patients with cirrhosis by Wechowski et al. From a clinical standpoint, the successful management of bleeding oesophageal varices should be based on definitive treatments such as therapeutic endoscopy or transjugular intrahepatic portosystemic stent shunt (TIPSS). Vasoactive agents such as terlipressin can be useful and potentially cost-effective additional therapy, however, particularly in patients where endoscopic treatment is likely to be delayed or is contraindicated.

The multidisciplinary team meeting improves staging accuracy and treatment selection for gastro-esophageal cancer

The object of this article is to assess current staging accuracies for individual modalities and to investigate the influence of the multidisciplinary team (MDT) on clinical staging accuracies and treatment selection for patients with gastro-esophageal cancer. Patients newly diagnosed with gastric or esophageal cancer and who were deemed suitable for surgical resection by the MDT were studied. Patients were staged with a combination of computerized tomography (CT), endoscopic ultrasound (EUS) and laparoscopic ultrasound (LUS). Additionally, the MDT determined an overall clinical stage for each patient after discussion at the MDT meeting. Treatments were selected according to this final clinical stage. Final histopathological staging (pTNM) was available for all patients and was used as the gold standard for determining staging accuracy. Suitability of treatment selection was assessed once final pTNM was available. One hundred and eighteen patients were studied. Endoscopic ultrasound was the most accurate individual staging modality for the loco-regional assessment of esophageal tumors (T stage accuracy 78%, N stage accuracy 70%). Laparoscopic ultrasound was the most accurate modality in T staging of gastric cancers (91%). The MDT stage was more accurate than each individual staging modality for T and N staging for both gastric and esophageal cancers (accuracy range: 88-89%) and was better for the assessment of nodal disease than each individual modality (CT P < 0.001, EUS P < 0.01, LUS P < 0.01). Overall staging accuracy as determined at the MDT meeting was increased and resulted in only 2/118 (2%) patients being under-treated. The MDT significantly improves staging accuracy for gastro-esophageal cancer and ensures that correct management decisions are made for the highest number of individual patients.

Review article: recent advances in the management of bleeding gastric varices

Gastric variceal bleeding can be challenging to the clinician. Tissue adhesives can control acute bleeding in over 80%, with rebleeding rates of 20-30%, and should be first-line therapy where available. Endoscopic ultrasound can assist in better eradication of varices. The potential risks of damage to equipment and embolic phenomena can be minimized with careful attention to technique. Variceal band ligation is an alternative to tissue adhesives for the management of acute bleeding, but not for secondary prevention due to a higher rate of rebleeding. Endoscopic therapy with human thrombin appears promising, with initial haemostasis rates typically over 90%. The lack of controlled studies for thrombin prevents universal recommendation outside of clinical trials. Balloon occluded retrograde transvenous obliteration is a recent technique for patients with gastrorenal shunts, although its use is limited to clinical trials. Transjugular intrahepatic portosystemic stent shunt is an option for refractory bleeding and secondary prophylaxis, with uncontrolled studies demonstrating initial haemostasis obtained in over 90%, and rebleeding rates of 15-30%. Non-cardioselective beta-blockers are an alternative to transjugular intrahepatic portosystemic stent shunt for secondary prophylaxis, although the evidence is limited. Shunt surgery should be considered in well-compensated patients. Splenectomy or embolization is an option in patients with segmental portal hypertension.

A biochemical prognostic model of outcome in paracetamol-induced acute liver injury

BACKGROUND

The aim of this study was to develop a prognostic model of outcome for patients with paracetamol induced acute liver injury based on admission parameters

METHODS

We used a cohort of 97 patients admitted to the Scottish Liver Transplant Unit between 1997 and 1998 to identify biochemical prognostic markers of outcome and thus create a prognostic model. Blood samples were taken on admission for analysis. The model was subsequently validated by testing it on a second cohort of 86 patients admitted between 1999 and 2000.

RESULTS

The following were identified as independent variables of poor prognosis (death/ transplant); phenylalanine, pyruvate, alanine, acetate, calcium, haemoglobin and lactate. A prognostic model was then constructed by stepwise forward logistic regression analysis: (400xPyruvate mmols/L)+(50xPhenylalanine (mmols/L)-(4 x Hemoglobin (g/dL). A value of <16 had an accuracy of 93% in predicting death correctly. When applied to the validation cohort this model had a positive predictive value of 91%, a negative predictive value of 94%, a sensitivity of 91%, and a specificity of 94%. On the same population overall, the positive and negative predictive value of the King's criteria were 94% and 93% respectively, whereas their sensitivity and specificity were 88% and 96% respectively.

CONCLUSIONS

Using admission characteristics our model is able to identify patients who die from paracetamol overdose fulminant hepatic failure as accurately as King's College criteria, but at a much earlier stage in their condition.

Alcoholic hepatitis: from pathogenesis to treatment

Alcoholic hepatitis is a serious complication of alcohol abuse due to its high mortality rates particularly at short term. It may complicate pre-existing alcoholic fatty liver or cirrhosis and is mainly diagnosed on clinical and laboratory grounds although liver biopsy is occasionally needed to exclude other pathology and confirm the diagnosis. Accumulating evidence suggests that cytokines and immunity are actively involved in its pathogenesis. Management includes abstinence and supportive care. Treatment with corticosteroids has been studied in several clinical trials with conflicting results. However, recent evidence supporting the beneficial effect of TNF-alpha inhibition provides an encouraging alternative. Here we summarise the current state in diagnosis and management of alcoholic hepatitis and briefly review the latest advances in pathophysiology that may lead to new therapeutic strategies for this difficult clinical condition.

DATA SOURCES

Medline 1966-2005, EMBASE/Excerpta Medica 1980-2005, The Cochrane Library (2005 Issue 2) and contact with authors of published reports.

Referral patterns and social deprivation in paracetamol-induced liver injury in Scotland

Paracetamol overdose is the commonest cause of acute liver failure in the UK, which has led to measures to restrict its sale. We aimed to establish whether changes in the referral of patients with paracetamol-induced acute liver failure have occurred since the introduction of legislation. We compared data from patients admitted to the Scottish Liver Transplantation Unit in 1992-98 with those admitted in 1998-2001. The incidence of paracetamol-induced liver failure, severity of patients' illness, and outcome did not differ between the groups. Patients with paracetamol-induced acute liver failure had higher Carstairs scores (1.99 [95% CI 1.33-2.65]; n=190) than patients with non-paracetamol acute liver failure (0.02 [-0.79 to 0.84]; n=68). We have shown an association between paracetamol-induced acute liver failure and social deprivation.

The simulated microgravity environment maintains key metabolic functions and promotes aggregation of primary porcine hepatocytes

The high aspect ratio vessel allows the culture of primary porcine hepatocytes in an environment of low shear stress and simulated microgravity. Primary porcine hepatocytes have been difficult to maintain in culture long term while preserving their metabolic functions. This study was carried out in order to characterise key metabolic functions of cell aggregates formed by primary porcine hepatocytes cultured in a high aspect ratio vessel for a predetermined period of 21 days. 10(8) porcine hepatocytes were loaded into the high aspect ratio vessel and continuously rotated during the experiments. 0.7 ml of the culture medium was sampled on days 1, 2, 4, 7, 10, 14 and 21. 1H nuclear magnetic resonance spectroscopy of the culture medium, using the presaturation technique, assessed the following: glucose metabolism, glutamine synthesis and ketogenesis. There was glucose breakdown anaerobically during the first 10 days as manifested by lactate production and pyruvate and threonine consumption. After day 10 there was significantly smaller lactate production (day 1 vs day 10 P < 0.01), and significantly smaller pyruvate (day 1 vs day 14 P < 0.03) and threonine consumption (day 1 vs day 10 P < 0.002), indicative of an aerobic metabolic pattern. Significantly more glutamate was produced after day 10 (day 1 vs day 10 P < 0.031), and more glutamine was consumed after day 14. There was a steadily diminishing production of acetate which reached a minimum on day 14 (day 2 vs day 14 P < 0.00014). After an initial 10 day period of acclimatisation cell aggregates formed in the high aspect ratio vessel switched from the anaerobic pattern of metabolism to the more efficient aerobic pattern, which was exhibited until the experiments were terminated. The high aspect ratio vessel is suitable for long-term culture of porcine hepatocytes and it is worthwhile carrying out scale-up feasibility studies.

Present medical management of Barrett's oesophagus

The management of Barrett's oesophagus should aim to treat symptoms, and prevent complications of reflux. Treatment of choice is a proton pump inhibitor, with the option of surgical treatment in younger patients. Uncertainties remain about the significance of short segment Barrett's oesophagus. Doubts also remain about the benefit and cost-effectiveness of conventional surveillance of Barrett's oesophagus; for patients with an annual cancer risk of 0.5% 5-yearly endoscopy and biopsies for patients without dysplasia represent the best strategy Novel modalities such as photodynamic therapy have shown encouraging results for high grade dysplasia or early cancer for patients unsuitable for surgery. Finally, agents such as cyclooxygenase-2 inhibitors hold promise for prevention of malignancy in Barrett's oesophagus.

Which hepatocyte will it be? Hepatocyte choice for bioartificial liver support systems

Liver failure, notwithstanding advances in medical management, remains a cause of considerable morbidity and mortality in the developed world. Although bioartificial liver (BAL) support systems offer the potential of significant therapeutic benefit for such patients, many issues relating to their use are still to be resolved. In this review, these issues are examined in terms of the functions required, the cells of choice in such a system, and the most appropriate environment to optimize the function of such cells. The major functions identified to date for a BAL are ammonia detoxification and biotransformation of toxic compounds, although this somewhat belies the complexity of the functions required. Two practical choices for cell type within such a system are xenogenic hepatocytes and immortalized human hepatocyte lines. Both these choices have drawbacks, such as the transmission of zoonoses and malignant infiltration, respectively. Finally, improvements in culture conditions, such as supplemented media, biodegradable scaffolds, and coculture, offer the possibility of prolonging the differentiated function of hepatocytes in a BAL.

Serum hyaluronan--a non-invasive test for diagnosing liver cirrhosis

INTRODUCTION

Hyaluronan is a glucosaminoglycan synthesized by the mesenchymal cells and degraded by hepatic sinusoidal endothelial cells by a specific receptor-mediated process. Elevated levels are associated with the sinusoidal capillarization that is seen in cirrhosis.

METHODOLOGY

Serum hyaluronan was measured, using a radiometric assay (Pharmacia, Sweden) in 221 patients with biopsy-proven chronic liver disease of a variety of aetiologies (alcohol n = 70, autoimmune chronic active hepatitis n = 23, primary biliary cirrhosis n = 17, hepatitis C n = 69, cryptogenic n = 15, various n = 27). All patients were fasted, and their liver function tests, full blood count, prothrombin time and Child-Pugh score were assessed at the time of the liver biopsy.

RESULTS

Hyaluronan levels (microg/l) were significantly higher in patients with liver cirrhosis (cirrhosis n = 127, mean 440, 95% CI 367-515) (P < 0.0001) compared with hepatic fibrosis (n = 23, mean 144, 95% CI 69-190), chronic hepatitis (n = 60, mean 63, 95% CI 37-91) and fatty liver (n = 11, mean 107, 95% CI 37-177). Within the cirrhotic population, there was no significant difference in hyaluronan levels between different aetiologies, but hyaluronan level increased proportionally to the severity of cirrhosis. Overall, a hyaluronan level > 100 microg/l had a 78% specificity and 83% sensitivity for diagnosing cirrhosis, while the specificity was increased to 96% for all patients with hyaluronan levels > 300 microg/l. The highest specificity and sensitivity were seen at a cut-off value of 100 microg/l in patients with alcohol-associated liver disease (89%, 87%) and hepatitis C (93%, 72%) respectively. Within patient cohorts, there was a significant correlation (P < 0.01) between hyaluronan and albumin, platelet count and bilirubin, but not with alanine aminotransferase.

CONCLUSION

Measurement of fasted serum hyaluronan reliably differentiated cirrhotic from non-cirrhotic liver disease and can be regarded as a useful test in the diagnosis of liver cirrhosis, particularly when a liver biopsy is contraindicated.

Low serum retinol levels are associated with hepatocellular carcinoma in patients with chronic liver disease

BACKGROUND

Retinol and other vitamin A derivatives affect the differentiation and growth of many tissues and have anti-tumour properties.

AIM

To investigate serum retinol levels in patients with liver disease and hepatocellular carcinoma (HCC) and to assess its importance as a risk factor for the development of HCC.

METHODS

Serum retinol levels were measured in healthy volunteers and 175 patients (34 with chronic hepatitis C, 117 with cirrhosis, and 24 with HCC.

RESULTS

The serum retinol levels (mean +/- s.e.) in ng/mL, were 972.1 +/- 37.7 in the control group and 647 +/- 41.1 in patients with chronic hepatitis C. Serum retinol levels in patients with cirrhosis and HCC were lower than in patients with cirrhosis alone (365.8 +/- 43.1 vs. 438.9 +/- 22.1, P < 0.04). In particular, there was a more significant difference in serum retinol levels between Child-Pugh grade A patients with cirrhosis and Child-Pugh grade A patients with cirrhosis/HCC (serum retinol levels 532.4 +/- 26.7 vs. 366.1 +/- 86.4, P < 0.03). There was a significant difference in serum retinol levels between normal controls and all patients' groups (P < 0.001). There were significantly lower serum retinol levels in cholestatic Child-Pugh grade A patients with cirrhosis compared with noncholestatic Child-Pugh grade A patients with cirrhosis/HCC (411.5 +/- 30.3 vs. 579.7 +/- 32.7, P < 0.0004). Sixty percent of patients with Child-Pugh grade A cirrhosis/HCC had serum retinol levels below 350 ng/mL compared with only 18.4% of cirrhotics without HCC (chi 2-test, P=0.01). No correlation was found between serum retinol levels and alpha FP or any other liver function tests, apart from serum albumin, which showed a positive correlation (r=0.61 P < 0.018).

CONCLUSIONS

There was a progressive reduction in serum retinol levels from controls to patients with liver cirrhosis. Those patients with cirrhosis and HCC had significantly lower values than patients with cirrhosis alone. Serum retinol levels may be a risk factor for the development of HCC.

An improved ex vivo method of primary porcine hepatocyte isolation for use in bioartificial liver systems

INTRODUCTION

Primary porcine hepatocytes are commonly, used in bioartificial liver devices and for in vitro studies of hepatocyte function. Although in vivo isolation of porcine hepatocytes can give high yield and viability, such methods are time-consuming and expensive, requiring specialist surgical facilities.

AIM

To develop a simple, low-cost, high viability, high yield, reproducible ex vivo method for obtaining functional porcine hepatocytes for use in bioartificial liver systems.

METHODS

Weanling piglets (12 kg) were killed with pentobarbitone sodium, the infra-hepatic inferior vena cava was clamped and the supra-hepatic inferior vena cava cannulated. The whole liver was retrogradely perfused in situ with cold saline and excised, followed by an ex vivo open-loop and re-circulating perfusion method (at 37 degrees C) in five steps. The liver was disrupted, sequentially filtered in washing buffer, purified by centrifugation and resuspended in Williams E medium. Viability and cell number were assessed using trypan blue exclusion. The cells were subsequently cultured in serum-free chemically-defined medium and function was assessed.

RESULTS

The time interval from when the animals were killed to the final cell wash was 105+/-5 min (n = 20). Cell viability was 85+/-6% with a yield of (2.4+/-0.5) x 10(10) from 12+/-1 kg piglets using 0.03% (w/v) collagenase (n = 20). Hepatocytes from all isolations were successfully plated and grown in monolayer culture. In freshly isolated hepatocytes (day 0) total protein content (TP) was 1.2+/-0.1 mg/10(6) cells (n = 5) and 1.2+/-0.3 mg/10(6) cells (n = 5) for day 2 monolayer cultures, corresponding to approximately 9x10(6) hepatocytes per dish. The percentage of total LDH released into the medium was 13+/-4% for day 0 and 8+/-4% at day 2; conversely, intracellular LDH activities were 87+/-4% and 92+/-4% of the total, respectively. The urea synthesis rate was 196+/-36 nmol/h/mg total protein at day 0 (n = 5) and 292+/-62 nmol/h/mg protein (n = 9) at day 2. The total P450 content was 99+/-11 pmol/mg total protein for fresh cells (n = 5) and maintained at 89+/-35 pmol/mg total protein in day 2 cultures.

CONCLUSIONS

This ex vivo method provides a high viability, high yield, cost-effective and rapid technique for isolating functional porcine hepatocytes with high plating efficiency, which compares favourably with results obtained using complex in vivo techniques.

Cerebral near infrared spectroscopy for the measurement of indocyanine green elimination in cirrhosis

BACKGROUND

Indocyanine green (ICG) clearance is a useful indicator of hepatic function but most measurement methods are invasive.

AIM

To validate a less invasive technique using cerebral near infrared spectrophotometry (NIRS) to measure ICG elimination, and to compare it with the established methods for the determination of ICG clearance in a group of normal controls and patients with cirrhosis.

METHOD

NIRS was used to measure ICG elimination in 41 cirrhotic patients and nine healthy volunteers. The first 13 of the cirrhotic patients also had their ICG clearance measured by the conventional spectrophotometric technique.

RESULTS

NIRS ICG elimination rate (ICG-k) and spectrophotometry ICG-k values correlated strongly (r= 0. 828, P < 0.001, n=13). There was a significant reduction in the mean NIRS-k in cirrhotic patients and within Child-Pugh classes A, B, and C (P < 0.001).

CONCLUSION

Measurement of ICG elimination by the NIRS method is at least as reliable as the conventional spectrophotometric technique in normals and in patients with cirrhosis. This technique merits further development for use as a bedside, less invasive liver function test.

The effect of polymorphisms in tumor necrosis factor-alpha, interleukin-10, and transforming growth factor-beta1 genes in acute hepatic allograft rejection

BACKGROUND

The occurrence of acute rejection in orthotopic liver transplantation is unpredictable. The role of cytokines in the process of rejection is not entirely clear. We investigated polymorphisms in the genes encoding tumor necrosis factor (TNF)-alpha, interleukin (IL)-10, and transforming growth factor (TGF)-beta1, which affect the amount of cytokine produced in vitro, in a liver transplant population to determine any association with acute rejection.

METHOD

DNA was extracted from whole blood of liver transplant patients. After amplification with polymerase chain reactions, the polymorphisms at TNF-alpha -308, IL-10 -1082, and TGF-beta1 +869 and +915 were determined using sequence-specific oligonucleotide probes. Acute cellular rejection was a clinical and histological diagnosis.

RESULTS

Acute cellular rejection requiring treatment occurred in 68 (48%) of 144 patients. Acute cellular rejection was significantly associated with the TNF-alpha -308 A/A genotype (P<0.02). There was no significant association with either IL-10 or TGF-beta1 polymorphisms in acute rejection.

CONCLUSION

Patients with a homozygous TNF-alpha -308 genotype A/A are more likely to suffer from acute cellular rejection after liver transplantation.

Plasma nitrites/nitrates in HCV infection and hepatocellular carcinoma

OBJECTIVE

Nitric oxide (NO) is produced in response to inflammatory and mitogenic stimuli and may have a role in carcinogenesis. However, the role of NO in hepatitis C-associated hepatocellular carcinoma (HCC) is unclear. In this study, we investigated the potential role of NO in HCC complicating hepatitis C virus (HCV) infection.

METHOD

We measured plasma nitrites/nitrates as being representative for NO release in blood of patients with chronic hepatitis C without cirrhosis (n = 20), cirrhosis of different aetiologies (n = 30) including HCV, HCC (n = 22) and in healthy controls (n = 8), by an enzyme-linked immunosorbent assay.

RESULTS

Plasma NO levels in patients with chronic hepatitis C without cirrhosis (32.3+/-8.94 micromol/l) were not significantly different from those in healthy control subjects (35.5+/-15.12 micromol/l). Also, there were no statistical differences between plasma NO levels in patients on alpha-interferon (alpha-IFN) therapy (n = 10) (31.60+/-10.55 micromol/l) and in non-treated patients (n = 10) (33.00+/-7.51 micromol/l) within the group of chronic hepatitis C. Plasma NO levels in patients with cirrhosis (42.36+/-26.86 micromol/l) were significantly higher than those with chronic hepatitis C (P < 0.001). The cause of cirrhosis had no effect on plasma NO levels. Plasma NO levels in patients with HCC (49.40+/-49.11 micromol/l) were significantly higher than those with liver cirrhosis (P < 0.03). No significant correlation was found between plasma NO and serum ALT (alanine aminotransferase) levels. There were positive correlations between plasma NO levels and alkaline phosphatase (r = 0.528) (P = 0.0001), bilirubin (r = 0.244) (P = 0.039) and GGT (gamma glutamyltransferase) (r = 0.255) (P = 0.030).

CONCLUSION

The results of this study demonstrate that patients with chronic hepatitis C without cirrhosis have the same plasma NO levels as controls, and that alpha-IFN therapy had no effect on NO production in these patients. However, patients with HCC have elevated plasma NO levels compared with patients with cirrhosis. These data support the concept that NO is elevated in cirrhosis and HCC, but HCV infection does not appear to be responsible for the increase of NO in these patients. The severity of liver disease may be an important factor.

Animal models of fulminant hepatic failure: a critical evaluation

Few conditions in medicine are more dramatic or more devastating than acute liver failure. Our understanding and treatment of this condition have been limited by the lack of satisfactory animal models. The most widely used models consist of surgical anhepatic and devascularization procedures and hepatotoxins, such as galactosamine and acetaminophen. Potential disadvantages with surgical models are their inability to recreate the inflammatory milieu that exists in acute liver failure and their reliance on surgical expertise. Models using hepatotoxins are free of such constraints. Galactosamine-induced hepatotoxicity is more predictable than acetaminophen, but its cost and lack of a human equivalent clinical syndrome has restricted its use. Acetaminophen-based models offer the greatest potential but have proven the most difficult to develop because of difficulties with reproducibility and refractory anemia. Although progress has been made, research must continue in this area to establish an animal model with minimal disadvantages that would accurately reflect the clinical syndrome seen in humans.

Massive T wave changes following a combined kidney and liver transplant in a young female with cirrhosis

We report the case of a young female with PSC-associated cirrhosis and chronic renal failure who developed clinical and electrocardiographic signs consistent with acute myocardial infarction after a combined kidney and liver transplant. Cardiac investigations at that time were negative and she is currently asymptomatic one year post-transplant with resolution of most of her ECG abnormalities. Although the cause of her symptoms and ECG abnormalities is not immediately apparent, this case illustrates the difficulties in interpreting abnormal cardiac investigations in transplanted patients with liver cirrhosis who may have a background of subclinical cardiac disease.

Indocyanine green clearance reflects reperfusion injury following liver transplantation and is an early predictor of graft function

BACKGROUND/AIMS

Primary graft dysfunction is difficult to predict. We have previously shown that indocyanine green clearance measured at 24 h following orthotopic liver transplantation predicts graft survival and outcome. We prospectively evaluated the use of indocyanine green clearance (with a cut-off value of 200 ml/min) as a marker of graft function following orthotopic liver transplantation and investigated its relationship with the markers of reperfusion injury during orthotopic liver transplantation.

METHODS

In all patients indocyanine green clearance was measured at 24 h. Repeated blood samples were taken before, during the anhepatic and reperfusion phase and up to 12 h following orthotopic liver transplantation to measure the levels of neutrophil elastase and reactive oxygen intermediates. All patients studied had normal hepatic arterial pulse on Doppler-ultrasound post orthotopic liver transplantation.

RESULTS

All patients with indocyanine green clearance >200 ml/min recovered following orthotopic liver transplantation and remained well up to 3 months of follow up. Four patients had an indocyanine green clearance <200 ml/min; three were re-transplanted for graft failure within 3 days of the transplant, while one survived after prolonged intensive support and hospitalization. Indocyanine green clearance significantly correlated with reactive oxygen intermediates production and neutrophil elastase during orthotopic liver transplantation (r=-0.61, p<0.002 and r=-0.66, p<0.0009, respectively). Indocyanine green clearance was also significantly correlated with alanine aminotransferase and prothrombin time at 24 h post-transplantation (r=-0.35, p<0.02 and r=-0.4, p<0.0077, respectively).

CONCLUSION

Indocyanine green reflects the degree of reperfusion injury and is a good early marker of primary graft function. Indocyanine green clearance over 200 ml/min is associated with favorable outcome.

Intrahepatic proliferation of 'naive' and 'memory' T cells during liver allograft rejection: primary immune response within the allograft

Liver allograft rejection is mediated by a primary response of T lymphocytes, followed by infiltration of the graft with a mixed inflammatory reaction. Using single and double label immunocytochemistry, we examined the proliferation index and the phenotype of leukocytes on liver biopsies from 10 patients with acute rejection before and after treatment with i.v. steroids, 10 patients with chronic rejection, 10 patients without rejection posttransplant, and 15 nongrafted, nonimmunosuppressed patients. Proliferation of mononuclear leukocytes (assessed by expression of Ki-67, a nuclear antigen associated with the cell cycle) inside the allograft was a prominent feature of acute and chronic rejection and was down-regulated by steroid treatment. Leukocytes in cell cycle were located predominantly in the portal tracts at the site of the inflammatory infiltrate. The majority of 'naive' (CD45RA+) and 'memory' (CD45RO+) CD4+ T lymphocytes were also periportally distributed. In contrast, CD8+ T lymphocytes, CD57+ natural killer cells, and CD68+ macrophages were located intraparenchymally throughout the liver lobules, whereas CD20+ B lymphocytes were only present in some of the portal tracts. Predominantly CD4+ and occasionally CD8+ lymphocytes were proliferating (assessed by double staining). The proliferating CD4+ cells were of both naive (CD4+, CD45RA+) and memory (CD4+, CD45RO+) phenotypes. To our knowledge, this is the first description of proliferating naive T lymphocytes in situ in liver allografts. These findings suggest that there may be a primary immune response generated within the allograft as well as in draining lymphatic tissue. This implicates not only intrahepatic proliferation of T lymphocytes as a prominent feature of rejection, but also suggests that the liver has a special immunological status comparable to that of lymphatic tissue.

Review article: the management of acute liver failure

Acute liver failure (ALF) is a relatively uncommon but dramatic clinical syndrome with high mortality rates, in which a previously normal liver fails within days or weeks. Paracetamol overdose remains the major cause of ALF in the UK, while viral hepatitis is the commonest cause world-wide. Cerebral oedema is the leading cause of death in patients with ALF. Despite advances in intensive care and the development of new treatment modalities, ALF remains a condition of high mortality best managed in specialist centres. Orthotopic liver transplantation is the only new treatment modality that has made a significant impact in improving outcome. Bioartificial liver support systems and hepatocyte transplantation are new promising treatment options that may change the management of ALF in the future.

Peripheral eosinophil count both before and after liver transplantation predicts acute cellular rejection

Acute cellular rejection is common after orthotopic liver transplantation and an important cause of graft dysfunction. Eosinophils, potent mediators of tissue damage, have been implicated in the pathogenesis of acute rejection. We studied 55 patients, all of whom had a protocol biopsy 7 days after transplantation and whose peripheral eosinophil count was monitored daily for 11 days after transplantation. Patients were divided clinicopathologically into two groups: group A, without rejection, group B, with rejection. Group B (36% of patients) developed rejection within the 11-day study period. The pretransplant eosinophil count was significantly higher in group B, compared with group A (0.31 +/- 0.08 v 0.10 +/- 0.01 (x10(9)/L), p < .001). After transplantation, the eosinophil count fell to low levels in both groups. By day 3 there was a statistically significant rise in the eosinophil count in group B compared with group A, with a maximum at day 7 [0.51 +/- 0.06 v 0.26 +/- 0.03 (x10(9)/L) p < .001]. After treatment with steroids, the eosinophil count dropped to values similar to those in group A and remained low thereafter in 16 of 20 patients. Four patients had a second episode of rejection; in each of these, eosinophils were raised again and decreased with resolution of the rejection. An eosinophil count threshold of 0.13 (x10(9)/L) before transplantation and 0.33 (x10(9)/L) on day 7 after transplantation predicted the development of rejection (sensitivity 72/70%, specificity 66/63%, negative predictive value 82/79%). We conclude that a raised eosinophil count is associated with acute rejection. The raised eosinophil count before transplantation in group B suggests that these patients are predisposed to acute rejection, and earlier intervention may be indicated.

Graft dysfunction following liver transplantation: role of free radicals

BACKGROUND/AIMS

Following orthotopic liver transplantation primary graft non-function occurs in about 10% of patients, and survival depends on early retransplantation. The aetiology has yet to be defined, but reperfusion injury as a result of free radical production has been considered as a possible mechanism. In this study we looked for evidence of free radical generation intraoperatively and assessed the relationship between free radical production and graft function.

METHODS/RESULTS

Twenty-one patients (M:F 10:11, mean age; 53 +/- 3.8 years) who underwent liver transplantation for end-stage liver disease were studied. Free radical activity increased significantly following reperfusion, as shown by: (i) the diene conjugated method, where the percentage molar ratio increased from a baseline of 10.87 +/- 0.78% to 24.42 +/- 7.8% (p < 0.01), and (ii) by electron paramagnetic resonance, where a more than a twofold rise in radical concentration was detected (p < 0.05). The increase in free radical activity detected by the diene conjugated method was significantly higher in patients with poor outcome as compared with those who had uneventful recovery (p < 0.01).

CONCLUSION

Free radical activity is increased following reperfusion of liver graft during transplantation, and the magnitude of the rise is related to the severity of graft dysfunction.

Investigation and management of acute diarrhoea

Acute diarrhoea is a common but debilitating symptom with diverse aetiology. The aim of this review is to consider the important pathogens, diagnostic approaches and management of acute diarrhoea.

Middle cerebral artery blood flow velocity in patients with cirrhosis

BACKGROUND

Brain dysfunction is common in patients with advanced liver disease; it is often manifested as hepatic encephalopathy, but its cause is not clearly understood.

METHODOLOGY

Intracranial blood flow velocity parameters, including peak systolic velocity, end diastolic velocity and mean velocity of both middle cerebral arteries were measured by transcranial Doppler ultrasonography in 37 patients with cirrhosis without encephalopathy (16 Child's A, 10 Child's B and 11 Child's C) and 12 normal controls. The cause was alcohol-related in 24 and non-alcohol-related in 13.

RESULTS

No significant differences in any of the Doppler parameters were detected in Child's group A when compared with controls. However, a statistically significant decrease in middle cerebral artery blood flow velocity was evident when Child's B and C patients without clinically apparent encephalopathy were compared with controls irrespective of the cause. Our results demonstrate that intracranial blood flow is abnormal in patients with advanced liver disease without clinically apparent encephalopathy.

The platelet count as a predictor of variceal hemorrhage in primary biliary cirrhosis

BACKGROUND

Variceal bleeding is a common, life-threatening complication of primary biliary cirrhosis (PBC) that remains difficult to predict.

OBJECTIVE

The aim of this study was to identify whether certain biochemical and hematological parameters may be used as predictors of variceal bleeding in patients with PBC.

METHODS

Cox proportional hazard regression analysis was used to test whether various prognostic factors were significantly associated with the time of first bleeding in 63 patients with proven PBC, of whom 11 had subsequent bleeding.

RESULTS

Both the first available platelet count and the bilirubin level were of significant value in predicting variceal bleeding, but only the platelet count was an independent predictor of bleeding. In the group of patients who subsequently bled, there was a progressive drop in the platelet count over the follow-up period, with a proportional increase in the risk of bleeding; a platelet count below 200 x 10(9)/L was strongly associated with variceal bleeding (p < 0.001). None of the patients with platelet count above 200 x 10(9)/L bled over a total of 136 patient-years follow-up. In the group who did not bleed, no change in platelet count was identified during follow up.

CONCLUSION

We conclude that the platelet count can be used as a predictor of variceal bleeding in PBC.

The effect of alcohol on acid secretion by the bovine gall bladder in vitro

OBJECTIVES

To determine whether acid secretion by gall bladder mucosa is influenced by alcohol and whether hydrogen ion output is increased when the gall bladder is perfused with moderate concentrations of alcohol.

METHODS

Fifty bovine gall bladders were studied. Twenty-five served as controls and 25 were perfused (in groups of five) with varying concentrations of alcohol (w/v): 0.05, 0.1, 0.2, 0.5 and 1.0%. Acid output was measured over 1 h and the results expressed as the mean.

RESULTS

There was no significant difference between acid production by control gall bladders and those perfused with 0.05% alcohol (24.30 +/- 8.7 versus 18.95 x 8.41 nmol/h), but the acid output was significantly increased when the mucosa was exposed to 0.1 and 0.2% alcohol concentrations (50.28 +/- 10.2 and 29.34 +/- 9.1 nmol/h; P < 0.001 and P < 0.0004, respectively). Perfusion with alcohol concentrations of 0.5 and 1.0%, significantly inhibited mucosal acid output (2.60 +/- 2.0 and -1.70 +/- 1.2 nmol/h; P < 0.0001 and P < 0.0001, respectively).

CONCLUSION

This study shows that perfusion of bovine gall bladder mucosa in vitro with moderate concentrations of alcohol stimulates acid output. This observation is important for assessing the link between alcohol and the risk of gallstone formation.

Hand skin temperature changes in patients with chronic liver disease

Previous studies have shown that changes in the peripheral circulation occur in patients with liver disease. We have investigated the temperature of the hands of 26 patients and 13 controls using a liquid crystal contact thermography system. Significant differences in resting hand temperature and appearance were observed when the patients were categorised according to Child's score. The appearance depended upon the severity of liver disease; Child's A patients have warm hands of normal thermographic appearance; Child's B patients have cold hands with an abnormal thermographic appearance; whilst Child's C patients have warm hands with an abnormal thermographic appearance. After right-hand ice-cold water immersion, right-hand recovery was abnormally slow in Child's B & C groups compared with Child's A patients and controls. In addition, there was left-hand reflex vasoconstriction during the right-hand warm-up period in those with severe liver disease. With regard to autonomic function, no significant difference in right-hand temperature, thermographic appearance or warm-up rate was detected between those with and those without autonomic neuropathy. These results indicate that autonomic nervous system dysfunction is not the predominant cause of these changes.

Autonomic function in cirrhosis assessed by cardiovascular reflex tests and 24-hour heart rate variability

OBJECTIVES

To assess the prevalence of autonomic dysfunction in cirrhosis and to observe the effect of disease severity on autonomic dysfunction.

METHODS

Seventy patients with cirrhosis (Child's class A, 42; Child's class B, 10; and Child's class C, 15) (45 alcoholic, 15 primary biliary cirrhosis, five chronic active hepatitis, and eight idiopathic) underwent standard cardiovascular reflex tests. In addition, in 40 patients, 24-h ECG RR variability tests were performed to detect autonomic dysfunction.

RESULTS

Forty-two of 70 (60%) patients had abnormalities of cardiovascular reflex function of varying severity, whereas 24 of 34 (70%) had 24-h RR counts with the 95% age-related tolerance. The prevalence of abnormality increased with increasing severity of liver disease but not with different etiologies.

CONCLUSION

Irrespective of etiology, there is a high prevalence of autonomic dysfunction in cirrhosis, and it is related to disease severity: the mechanism is unknown.

A pilot study of indocyanine green clearance as an early predictor of graft function

Primary graft dysfunction occurs in up to 10% of liver transplant recipients and is the major reason for early mortality and retransplantation. The conventionally used markers of early graft function--i.e., correction of acidosis, glucose requirement, consumption of potassium, serum alanine transaminase (ALT), prothrombin time (PT), bile flow, resolution of encephalopathy and haemodynamic instability can be very misleading as they are dependent on numerous other factors. The aim of this study was to assess the use of indocyanine green clearance (ICG) as a measure of graft function. Peripheral ICG clearance was measured 18-24 hr after liver transplantation in twenty-three consecutive patients (24 transplants). Doppler ultrasonography confirmed normal hepatic arterial blood flow. Correlations between ICG clearance and other markers of graft function and outcome were sought. The mean ICG clearance was 406 mls/min (SD 137.5). A threshold value of 200 ml/min reliably predicted outcome. Significant correlations were found between ICG clearance and times to normalization of PT (P < 0.02) and to the correction of acidosis (P < 0.05). No correlation was found with ALT, PT, bile flow, glucose requirement, or consumption of potassium. ICG clearance measured on the day after liver transplantation accurately reflects graft function and may be used to predict graft survival and final outcome.