Association of physiological reserve measures with adverse outcomes following liver transplantation

Background and Aim

The comparative utility of physiological reserve measures in predicting important clinical outcomes following liver transplantation (LT) requires further study. The aim of this work was therefore to compare the utility of physiological reserve measures in predicting early adverse clinical outcomes post‐LT.

Methods

A single‐center, retrospective cohort study of LT patients consecutively recruited between 1 January 2015, and 31 August 2020. Outcomes measured were sepsis and death within 12 months of LT, hospital length of stay (LOS), and intensive care LOS. Physiological reserve measures were handgrip strength, mid‐arm muscle circumference, and cardiopulmonary exercise testing (CPET) measures. Analysis was performed using univariate and multivariate logistic regression for sepsis and death, and univariate and multivariate Cox regression for hospital and intensive care LOS.

Results

Data were obtained for 109 subjects. Patients were predominantly (64%) male with a median (interquartile range [IQR]) age of 57 (49–63) and median (IQR) Model for End‐Stage Liver Disease score of 16 (11–21). In multivariate analysis, the odds of sepsis were lower in patients in the highest versus lowest tertile (odds ratio = 0.004; 95% confidence interval [CI] 0.00–0.13; P = 0.002). Hospital LOS was linearly associated with handgrip strength (hazard ratio [HR] = 1.03; 95% CI 1.00–1.06; P = 0.03) in multivariate analysis. Intensive care LOS was associated with peak VO₂ (HR 1.83; 95% CI 1.06–3.16; P = 0.03) and V_E/VCO₂ slope (HR 0.71; 95% CI 0.58–0.88; P = 0.002) in multivariate analysis.

Conclusion

Handgrip strength and CPET both identify candidates at high risk of adverse outcomes after LT.

Cardiovascular mortality following liver transplantation: predictors and temporal trends over 30 years

AIMS

There has been significant evolution in operative and post-transplant therapies following liver transplantation (LT). We sought to study their impact on cardiovascular (CV) mortality, particularly in the longer term.

METHODS AND RESULTS

A retrospective cohort study was conducted of all adult LTs in Australia and New Zealand across three 11-year eras from 1985 to assess prevalence, modes, and predictors of early (≤30 days) and late (>30 days) CV mortality. A total of 4265 patients were followed-up for 37 409 person-years. Overall, 1328 patients died, and CV mortality accounted for 228 (17.2%) deaths. Both early and late CV mortality fell significantly across the eras (P < 0.001). However, CV aetiologies were consistently the leading cause of early mortality and accounted for ∼40% of early deaths in the contemporary era. Cardiovascular deaths occurred significantly later than non-cardiac aetiologies (8.8 vs. 5.2 years, P < 0.001). On multivariable Cox regression, coronary artery disease [hazard ratio (HR) 4.6, 95% confidence interval (CI) 1.2-21.6; P = 0.04] and era of transplantation (HR 0.44; 95% CI 0.28-0.70; P = 0.01) were predictors of early CV mortality, while advancing age (HR 1.05, 95% CI 1.02-1.10; P = 0.005) was an independent predictors of late CV mortality. Most common modes of CV death were cardiac arrest, cerebrovascular events, and myocardial infarction.

CONCLUSION

Despite reductions in CV mortality post-LT over 30 years, they still account for a substantial proportion of early and late deaths. The late occurrence of CV deaths highlights the importance of longitudinal follow-up to study the efficacy of targeted risk-reduction strategies in this unique patient population.

Endoscopic cyst-gastrostomy for pancreatic pseudocysts: refining the indications

BACKGROUND

Pseudocysts are a common consequence of acute pancreatitis and require intervention if symptomatic. Endoscopic management is emerging as a safe and effective alternative to surgery, although its use is not yet widespread.

METHODS

We describe our experience of 10 consecutive unselected patients who underwent endoscopic ultrasound-guided cyst-gastrostomy and stent insertion at a tertiary referral centre. Technical aspects of the procedure are detailed with accompanying photographs.

RESULTS

Six patients made an uneventful recovery. Four patients developed complications, of which one was successfully salvaged by endoscopy and three required surgery.

CONCLUSION

We discuss technical and patient factors which may have contributed to these complications in the context of current literature, and in particular, found that the presence of necrosis was associated with higher morbidity, both in our series and in others. In our experience, endoscopic ultrasound-guided cyst-gastrostomy is best employed in simple, mature pseudocysts without necrotic debris, and we recommend this procedure only after a detailed assessment of the pseudocyst in a specialist hepatobiliary unit.

Cirrhosis and microvascular invasion predict outcomes in hepatocellular carcinoma

BACKGROUND

Liver resection (LR) and liver transplantation (LT) are two modalities offering potential for cure in patients with hepatocellular carcinoma (HCC). The objective of this study was to evaluate the long-term survival of patients with HCC treated with LT and LR and to analyse variables influencing these outcomes.

METHODS

Patients referred to the South Australian Liver Transplant Unit and Hepatopancreatobiliary Unit at Flinders Medical Centre from January 1992 to September 2009 with a diagnosis of HCC who underwent LT or LR were included in the study. Histopathological parameters analysed included size, number and grade of tumour, microscopic vascular invasion and presence or absence of cirrhosis in remnant liver.

RESULTS

Eighty-five patients with a median age of 58 years (range 26-85 years) underwent LT or LR. Median follow-up was 40 months in both groups. Overall, 5-year actuarial survival for all patients with HCC in both groups was 55%. LR patients were significantly older (P < 0.001) than LT patients. Their tumours were larger (P < 001) and more often solitary (P < 0.001) compared with the LT group. In multivariate analysis, age >60 (P < 0.02), histopathological evidence of vascular invasion (P < 0.02) and presence of cirrhosis (P < 0.02) were associated with a significantly reduced survival. Patients without vascular invasion and cirrhosis had an actuarial 5-year survival >70%.

CONCLUSIONS

Our study indicates that LT (within University of California, San Francisco criteria) and LR can lead to acceptable long-term survival outcomes in patients with HCC. Microscopic vascular invasion and cirrhosis were the most significant prognostic factors impacting on survival.

Predicting patient survival after pancreaticoduodenectomy for malignancy: histopathological criteria based on perineural infiltration and lymphovascular invasion

BACKGROUND

Accurate and simple prognostic criteria based on histopathology following pancreaticoduodenectomy would be helpful in assessing prognosis and considering and evaluating adjuvant therapy. This study analysed the histological parameters influencing outcome following pancreaticoduodenectomy for periampullary malignancy.

METHODS

A total of 110 pancreaticoduodenectomies were performed from 1998 to 2008. The median age of patients was 69 years (range 20-89 years). The median follow-up was 4.9 years. Of the procedures, 87% (96) were performed for malignancies and the remainder (n= 14) for benign aetiologies. Of the 96 malignancies, 60 were pancreatic adenocarcinoma and the rest were ampullary (14), cholangio (9), duodenal (9) carcinomas and others. Statistical analysis was performed using log-rank and Cox regression multivariate analyses.

RESULTS

Patients who underwent resection had 1-, 3- and 5-year survival rates of 70%, 46% and 41%, respectively. The 1-, 3- and 5-year survival rates for periampullary cancers other than pancreatic adenocarcinoma were 83%, 69% and 61%, respectively; those for pancreatic adenocarcinoma were 62%, 31% and 27%, respectively (P < 0.003). Poor tumour differentiation (P < 0.02), tumour size >3 cm (P < 0.04), margin <or=2 mm (P < 0.02), nodal involvement (P < 0.003), perineural infiltration (P < 0.0001) and lymphovascular invasion (P < 0.002) were associated with poorer prognosis. In a multivariate analysis, histologically identified perineural infiltration (P < 0.03) and lymphovascular invasion (P= 0.05) were significant factors influencing outcome. Five-year survival was 77% in patients negative for both factors and 15% in patients positive for both (P < 0.0001). In the pancreatic adenocarcinoma subgroup, patients who were negative for both factors had a 5-year survival of 71%, whereas those who were positive for both had a 5-year survival of 16% (P < 0.02).

CONCLUSIONS

The presence of perineural infiltration and lymphovascular invasion on histopathology is highly significant in predicting 5-year outcomes after pancreaticoduodenectomy for periampullary and pancreatic malignancies.

Perioperative morbidity affects long-term survival in patients following liver resection for colorectal metastases

BACKGROUND

Hepatic resection is the treatment of choice in patients with colorectal liver metastases. Perioperative morbidity is associated with decreased long-term survival in several cancers. The aim of this study was to assess the impact of perioperative morbidity and other prognostic factors on the outcome of patients undergoing liver resection for colorectal metastases.

METHODS

One hundred ninety seven patients undergoing liver resection with curative intent were investigated. The influence of prognostic factors, such as complications, tumor stage, margins, age, sex, number of lesions, transfusion, portal inflow obstruction, and era and type of resection, was assessed using univariate and multivariate analysis. Complications were graded using an objective surgical complication classification.

RESULTS

The 5-year survival rate was 38%, with a median follow up of 4.5 years. The disease-free survival rate at 5 years was 23%. The perioperative morbidity and mortality rates were 30 and 2.5%, respectively. The median survival of patients with perioperative complications was 3.2 years, compared to 4.4 years in those patients without complications (p < 0.01). For patients with positive resection margins, the median survival was 2.1 years, compared 4.4 years in patients with a margin (p = 0.019).

CONCLUSION

Perioperative morbidity and a positive resection margin had a negative impact on long-term survival in patients following liver resection for colorectal metastases.

Effects of cholecystokinin and secretin on pancreatic duct pressure and pancreatic blood flow in Australian brush-tailed possums

AIM: To investigate the effects of cholecystokinin (CCK) and secretin on pancreatic duct pressure (PDP) and pancreatic blood flow (PBF) in Australian brush-tailed possums.

METHODS: CCK and secretin (5 mg/kg) were intravenously injected into 6 brush-tailed possums respectively. Pancreatic duct of the possums were cannulated and PDP was measured by Maclab recording system separately. PBF was measured using laser Doppler flowmetry.

RESULTS: Five minutes after CCK and secretin injection, PDP increased from 16.2 ± 1.8 and 16.8 ± 1.7 mmHg to 18.9 ± 2.1 and 25.6 ± 1.9 mmHg, and maintained high levels (17.6 ± 2.4 mmHg and 21.5 ± 2.5 mmHg) at the 15^th minute (P < 0.002 and P < 0.001); PBF increased from 0.58 ± 0.09 and 0.55 ± 0.04 mL/100 g to 0.75 ± 0.11 and 0.85 ± 0.12 mL/100 g, respectively, at the beginning after CCK and secretin injection. However, CCK and secretin made a continual PDP increase along with PBF decrease till maintaining a low level (0.51 ± 0.09 mL/100 g and 0.39 ± 0.11 mL/100 g, P < 0.001) within 15 minutes, but the influence of secretin was more significant than that of CCK (P < 0.05).

CONCLUSION: PDP can be increased by CCK and secretin injection, resulting in an increase of PBF, which may be the initial factor in the pathogenesis and development of acute biliary pancreatitis.

Scorpion venom stimulates biliary/duodenal motility and pancreatic exocrine secretion

Scorpion envenomation causes severe upper abdominal pain associated with nausea and vomiting. Although scorpion venom (SV) stimulates pancreatic and gastric secretion in animal models, its effects on duodenal and biliary motility have not been reported. The aim of this study was to determine the effects of SV on sphincter of Oddi (SO), duodenal and gall bladder motility and pancreatic amylase output. Anaesthetized Australian possums (n = 21) were infused with SV via intravenous or closed intra-arterial routes. Blood pressure, SO, duodenal and gall bladder motility were continuously monitored for 4 h. Trans-sphincteric flow (TSF), an indicator of bile duct resistance, was measured concurrently. The amylase output in pancreatic juice was also measured. SV infusion resulted in profound transient increase in blood pressure, SO motility and a significant decrease in TSF. No significant differences were noted in SO basal pressure changes. A transient increase in gall bladder tone, duodenal contraction amplitude and frequency, and amylase output were noted. Following the peak in blood pressure, amylase output, SO, gall bladder and duodenal motility were depressed. SV induces a rapid but transient increase in biliary and duodenal motility that is associated with stimulation of pancreatic amylase output. These changes may contribute to gastrointestinal symptoms associated with early phases of envenomation.

Endothelin-1 stimulates sphincter of Oddi motility and decreases trans-sphincteric flow: a possible mechanism contributes to cholestasis in disease states

Endothelin-1 (ET-1) is a potent stimulator of gallbladder contractility. Its role in modulation of sphincter of Oddi (SO) motility and trans-sphincteric flow (TSF) has not been evaluated. To characterize the effects of ET-1 on SO motility and TSF, 10 anaesthetized Australian possums (in vivo, n = 6) were given graded doses of ET-1 (5-200 pmol kg-1) via closed intra-arterial injection. Blood pressure, TSF and SO motility (basal pressure, phasic amplitude, contraction frequency) were analysed. For in vitro studies, eight SO rings were subjected to 10-12-10-7 mol L-1 cumulative concentrations of ET-1 in organ bath and SO motility was measured. Data are expressed as mean +/- SEM. Statistical analysis used anova. ET-1 induced a dose-related increase in blood pressure with a maximal increase of 37.5 +/- 2.5 mmHg at 200 pmol kg-1, (P < 0.001). ET-1 also increases SO basal pressure (P < 0.001) and contraction frequency (P < 0.0001). However, the contraction amplitude was not significantly affected. ET-1 decreased TSF in a dose-related manner (P < 0.001) with cessation of TSF at the highest dose (P < 0.001). In vitro studies showed a significant increase in mean SO motility index, and frequency of contractions at higher ET-1 concentrations (10-9-10-7 mol L-1). ET-1 is a potent stimulator of SO motility resulting in a reduction in TSF.

Effects of acute pancreatic duct obstruction on pancreatic perfusion: implication of acute pancreatic duct decompression

BACKGROUND

Acute pancreatitis can result in pancreatic ischaemia and necrosis. Pancreatic duct (PD) obstruction may be the first step causing ischaemia in acute pancreatitis. Nitric oxide donors can attenuate acute pancreatitis through improvement in compromised pancreatic perfusion (PP). In this study, we determined if (1) PD obstruction altered PP and (2) PD decompression or L-arginine administration reversed this change.

METHODS

Fifteen Australian possums were randomly assigned to two groups: Animals in group A (n = 6) were subjected to 30 min of PD obstruction and 60 min of PD decompression. Animals in group B (n = 9) were subjected to 120 min PD ligation and 60 min PD decompression. A subset group B (n = 6) were subjected to intravenous L-arginine (100 microg/kg) at the end of 120 min of ligation and at the end of PD decompression. The PP (Laser Doppler fluxmetry), PD pressure and blood pressure were continuously monitored.

RESULTS

PD pressure increased from 2.9 +/- 2.5 to 18.1 +/- 4.9 mmHg following PD ligation. PP was reduced to 67.1% +/- 4.5% (P<0.01) and 46.2% +/- 7.5% (P<0.001) of baseline following 30 and 120 min of PD ligation, respectively. Following 60 min of PD decompression, PP was restored to 89.1% +/- 13.4% (P<0.02) of the baseline in the 30-min group. However, following 120 min PD ligation, PP remained depressed. L-arginine administration after 120 min of PD ligation transiently increased PP from 46.2% +/- 7.5% to 81.1% +/- 8.6% (P<0.03) of baseline. This effect was reproduced if L-arginine was administered at the end of decompression (P<0.05).

CONCLUSION

In patients with acute pancreatitis due to obstructive causes, early decompression of the PD may prevent early pancreatic ischaemia.