Venous resection for pancreatic cancer, a safe and feasible option? A systematic review and meta-analysis

BACKGROUND

In pancreatic ductal adenocarcinoma patients with suspected venous infiltration, a R0 resection is most of the time not possible without venous resection (VR). To investigate this special kind of patients, this meta-analysis was conducted to compare mortality, morbidity and long-term survival of pancreatic resections with (VR+) and without venous resection (VR-).

METHODS

A systematic search was performed in Embase, Pubmed and Web of Science. Studies which compared over twenty patients with VR + to VR-for PDAC with ≥1 year follow up were included. Articles including arterial resections were excluded. Statistical analysis was performed with the random effect Mantel-Haenszel test and inversed variance method. Individual patient data was compared with the log-rank test.

RESULTS

Following a review of 6403 papers by title and abstract and 166 by full text, a meta-analysis was conducted of 32 studies describing 2216 VR+ and 5380 VR-. There was significantly more post-pancreatectomy hemorrhage (6.5% vs. 5.6%), R1 resections (36.7% vs. 28.6%), N1 resections (70.3% vs. 66.8%) and tumors were significantly larger (34.6 mm vs. 32.8 mm) in patients with VR+. Of all VR + patients, 64.6% had true pathological venous infiltration. The 90-day mortality, individual patient data for overall survival and pooled multivariate hazard ratio for overall survival were similar.

CONCLUSION

VR is a safe and feasible option in patients with pancreatic cancer and suspicion of venous involvement, since VR during pancreatic surgery has comparable overall survival and complication rates.

In the Era of the Leeds Protocol: A Systematic Review and A Meta-Analysis on the Effect of Resection Margins on Survival Among Pancreatic Ductal Adenocarcinoma Patients

BACKGROUND AND AIMS

A positive resection margin is considered to be a factor associated with poor prognosis after pancreatic ductal adenocarcinoma resection. However, analysis of the resection margin is dependent on the pathological slicing technique. The aim of this systematic review and meta-analysis was to study the impact of resection margin on the survival of pancreatic ductal adenocarcinoma patients whose specimens were analyzed using the axial slicing technique.

MATERIAL AND METHODS

A systematic search in the PubMed, Cochrane, and Embase datasets covering the time period from November 2006 to January 2019 was performed. Only studies with axial slicing technique (Leeds Pathology Protocol or Royal College of Pathology Protocol) were included in the final database. Meta-analysis between the marginal distance and survival was performed with the Inverse Variance Method in RevMan.

RESULTS

The systematic search resulted in nine studies meeting the inclusion criteria. The median survival for a resection margin 0 mm ranged from 12.3 to 23.4 months, for resection margin <0.5 mm 16 months, for resection margin <1 mm ranged from 11 to 27.5 months, for resection margin <1.5 mm ranged from 16.9 to 21.2 months, and for resection margin >2 mm ranged from 53.9 to 63.1 months. Five studies were eligible for meta-analysis. The pooled multivariable hazard ratio favored resection margin ⩾1 mm (hazard ratio: 1.32 and 95% confidence interval: 1.03-1.68, p = 0.03).

CONCLUSION

Resection margins ⩾1 mm seem to lead to better survival in pancreatic ductal adenocarcinoma patients than resection margin <1 mm. However, there is not enough data to evaluate the effect of oncologic therapy or to analyze the impact of other resection margin distances on survival.

Association of bacteria in pancreatic fistula fluid with complications after pancreatic surgery

Background

Pancreatic fistula (PF) is a common complication after pancreatic surgery. It is unclear how microbes in PF fluid affect outcomes and which microbes are present after pancreatoduodenectomy (PD) and distal pancreatectomy (DP). The aim of this study was to compare the microbiological spectrum of PF fluid after PD versus DP, and its association with postoperative complications.

Methods

Bacterial strains and antibiotic resistance rates of bacterial swabs obtained from the PF fluid of patients who underwent DP or PD were analysed. Cultured bacteria were classified as Enterobacterales and as ‘other intestinal and non‐intestinal microorganisms’ based on whether they are typically part of the normal human intestinal flora.

Results

A total of 847 patients had a pancreatic resection (PD 600; DP 247) between July 2007 and December 2016. Clinically relevant PF was detected in 131 patients (15·5 per cent). Bacterial swabs were obtained from 108 patients (DP 47; PD 61), of which 19 (17·6 per cent) were sterile. Enterobacterales were detected in 74 per cent of PF fluid swabs after PD, and in 34 per cent after DP. Infected, polymicrobial or multidrug‐resistant PF fluid was more common after PD (rates of 95, 50 and 48 per cent respectively) than after DP (66, 26 and 6 per cent respectively). Patients with higher grade complications (Clavien–Dindo grade IV–V) or grade C PF had more Enterobacterales and multidrug‐resistant Enterobacterales in the PF fluid after DP.

Conclusion

Enterobacterales and multidrug‐resistant bacteria are detected frequently after PD and DP, and are associated with more severe complications and PF in patients undergoing DP.

A rare case of perivascular epithelioid cell tumor (PEComa) of the pancreas diagnosed by endoscopic ultrasound

A 49-year-old woman consulted her general practitioner (GP) regarding epigastric pain that she had experienced for 2 months. Physical examination and laboratory results were unremarkable. An abdominal ultrasound indicated a solid pancreatic tumor, which was confirmed on subsequent CT and MRI. Endoscopic ultrasound (EUS) showed a well-defined heterogeneous, predominantly hypoechoic mass in the pancreatic body, so a neuroendocrine tumor (NET) was suspected. However, EUS-guided fine-needle aspiration (EUS-FNA) was performed and based on (immuno-)histochemical findings, the extremely rare diagnosis of a perivascular epithelioid cell tumor (PEComa) of the pancreas was made. Due to the malignant potential of pancreatic PEComas, laparoscopic left-sided pancreatectomy was performed. We present a case diagnosed by preoperative EUS-FNA highlighting the clinical and endosonographic features which help to distinguish it from its most important differential diagnosis, neuroendocrine tumors (NETs) of the pancreas.

Risk of malignancy in resected pancreatic mucinous cystic neoplasms

BACKGROUND

Pancreatic mucinous cystic neoplasms (MCNs) are rare mucin-producing cystic tumours defined by the presence of ovarian-type stroma. MCNs have a malignant potential and thus surgery is frequently performed. The aim of this cohort study was to define better the criteria for surgical resection in patients with MCN.

METHODS

This multicentre retrospective study included all resected MCNs between 2003 and 2015 in participating centres. Lesions without ovarian-type stroma were excluded. Patient characteristics, preoperative findings, histopathology findings and follow-up data were recorded.

RESULTS

The study included 211 patients; their median age was 53 (range 18-82) years, and 202 (95·7 per cent) were women. Median preoperative tumour size was 55 (range 12-230) mm. Thirty-four of the 211 (16·1 per cent) were malignant, and high-grade dysplasia (HGD) was found in a further 13 (6·2 per cent). One-third of MCNs in men were associated with invasive cancer, compared with 15·3 per cent in women. Five cases of malignant transformation occurred in MCNs smaller than 4 cm. All cases of malignancy or HGD were associated with symptoms or features of concern on preoperative cross-sectional imaging. In multivariable analysis, raised carbohydrate antigen 19-9 (odds ratio (OR) 10·54, 95 per cent c.i. 2·85 to 218·23; P < 0·001), tumour size (OR 4·23, 3·02 to 11·03; P = 0·001), mural nodules (OR 3·55, 1·31 to 20·55; P = 0·002) and weight loss (OR 3·40, 2·34 to 12·34; P = 0·034) were independent factors predictive of malignant transformation.

CONCLUSIONS

Small indeterminate MCNs with no symptoms or features of concern may safely be observed as they have a low risk of malignant transformation.

bis-(p-hydroxyphenyl)-pyridyl-2-methane (BHPM)-the active metabolite of the laxatives bisacodyl and sodium picosulfate-enhances contractility and secretion in human intestine in vitro

BACKGROUND

Stimulant laxatives are widely used to treat constipation. We investigated in human small and large intestinal preparations the effects of bis-(p-hydroxyphenyl)-pyridyl-2-methane (BHPM), the active metabolite of the laxatives bisacodyl and sodium picosulfate on smooth muscle tone and epithelial secretion.

METHODS

Circular and longitudinal muscle tone of small or large intestinal preparations were recorded with isometric force transducers. Epithelial ion flux (I_SC ) and tissue resistance was measured with Ussing chamber technique after apical and basolateral BHPM application to large intestinal mucosa/submucosa preparations. Studies were performed in macroscopically normal specimens from 79 patients.

KEY RESULTS

BHPM concentration-dependently (0.5-5 μM) increased the tone of circular and longitudinal muscle from small to large intestine. The effect was strongest in large intestinal longitudinal muscle and smallest in small intestinal circular muscle. Increase in muscle tone was prevented by the L-type Ca⁺⁺ channel blocker nifedipine but insensitive to the nerve blocker tetrodotoxin. Apical or basolateral BHPM concentration-dependently decreased or increased I_SC, respectively. The K_Ca 1.1 (BK) channel blocker iberiotoxin reversed apical I_SC decrease whereas tetrodotoxin reversed basolateral I_SC increase. BHPM had no effect on tissue resistance or nerve-mediated secretory or muscle response with one exception: at the highest concentration basolateral BHPM reduced nerve-mediated secretion.

CONCLUSIONS AND INTERFERENCES

BHPM enhanced mucosal secretion and muscle contractility. Results suggested that the laxative effect of BHPM was a consequence of the increase in muscle tone as well as an increased K⁺ secretion when acting luminally and a nerve-driven Cl^- and HCO₃^- secretion once acting basolaterally after absorption.

Meta-analysis of the impact of neoadjuvant therapy on patterns of recurrence in pancreatic ductal adenocarcinoma

Background

Neoadjuvant therapy may increase the rate of radical tumour resection in patients with pancreatic cancer. Its impact on tumour recurrence has not been investigated fully. This study aimed to assess the impact of neoadjuvant therapy on patterns of recurrence.

Methods

A systematic review was performed of articles identified through the PubMed, Scopus, Embase, Ovid and Google Scholar databases that analysed the relationship between neoadjuvant therapy and recurrence published to January 2016. The main endpoint was overall tumour recurrence. Other endpoints included local recurrence, any kind of distant, hepatic, pulmonary or peritoneal metastasis.

Results

A total of 4257 citations were reviewed. Twelve observational studies comprising 1365 patients were analysed. Neoadjuvant therapy significantly reduced the risk of overall (risk ratio (RR) 0·82, 95 per cent c.i. 0·74 to 0·90; P < 0·001) and local (RR 0·42, 0·32 to 0·55; P < 0·001) recurrence. Neoadjuvant therapy did not reduce the risk of any kind of distant (RR 1·02, 0·91 to 1·14; P = 0·78), hepatic (RR 0·86, 0·68 to 1·10; P = 0·23), pulmonary (RR 0·99, 0·37 to 2·66; P = 0·98) or peritoneal (RR 0·88, 0·57 to 1·38; P = 0·58) metastasis.

Conclusion

Neoadjuvant therapy reduced the risk of local recurrence but not that of distant metastasis.

Meta-analysis of outcomes following resection of the primary tumour in patients presenting with metastatic colorectal cancer

BACKGROUND

It is not clear whether resection of the primary tumour (when there are metastases) alters survival and/or whether resection is associated with increased morbidity. This systematic review and meta-analysis assessed the prognostic value of primary tumour resection in patients presenting with metastatic colorectal cancer.

METHODS

A systematic review of MEDLINE/PubMed was performed on 12 March 2016, with no language or date restrictions, for studies comparing primary tumour resection versus conservative treatment without primary tumour resection for metastatic colorectal cancer. The quality of the studies was assessed using the MINORS and STROBE criteria. Differences in survival, morbidity and mortality between groups were estimated using random-effects meta-analysis.

RESULTS

Of 37 412 initially screened articles, 56 retrospective studies with 148 151 patients met the inclusion criteria. Primary tumour resection led to an improvement in overall survival of 7·76 (95 per cent c.i. 5·96 to 9·56) months (risk ratio (RR) for overall survival 0·50, 95 per cent c.i. 0·47 to 0·53), but did not significantly reduce the risk of obstruction (RR 0·50, 95 per cent c.i. 0·16 to 1·53) or bleeding (RR 1·19, 0·48 to 2·97). Neither was the morbidity risk altered (RR 1·14, 0·77 to 1·68). Heterogeneity between the studies was high, with a calculated I² of more than 50 per cent for most outcomes.

CONCLUSION

Primary tumour resection may provide a modest survival advantage in patients presenting with metastatic colorectal cancer.

Tryptase potentiates enteric nerve activation by histamine and serotonin: Relevance for the effects of mucosal biopsy supernatants from irritable bowel syndrome patients

BACKGROUND

We previously showed that mucosal biopsy supernatants from irritable bowel syndrome patients activated neurons despite low concentrations of tryptase, histamine, and serotonin which individually would not cause spike discharge. We studied the potentiating responses between these mediators on excitability of enteric neurons.

METHODS

Calcium-imaging was performed using the calcium-sensitive dye Fluo-4 AM in human submucous plexus preparations from 45 individuals. Histamine, serotonin, and tryptase were applied alone and in combinations to evaluate nerve activation which was assessed by analyzing increase in intracellular Ca²⁺ ([Ca²⁺ ]_i ), the proportion of responding neurons and the product of both defined as Ca-neuroindex (NI). Protease activated receptor (PAR) 2 activating peptide, PAR2 antagonist and the serine protease-inhibitor FUT-175 were used to particularly investigate the role of proteases.

KEY RESULTS

Histamine or serotonin (1 μmol/L each) evoked only few small responses (median NI [25%/75%]: 0 [0/148]; 85 [0/705] respectively). Their combined application evoked statistically similar responses (216 [21/651]). Addition of the PAR2 activator tryptase induced a significantly higher Ca-NI (1401 [867/4075]) compared to individual application of tryptase or to coapplied histamine and serotonin. This synergistic potentiation was neither mimicked by PAR2 activating peptide nor reversed by the PAR2 antagonist GB83, but abolished by FUT-175.

CONCLUSIONS & INFERENCES

We observed synergistic potentiation between histamine, serotonin, and tryptase in enteric neurons, which is mediated by proteolytic activity rather than PAR2 activation. This explained neuronal activation by a cocktail of these mediators despite their low concentrations and despite a relatively small PAR2-mediated response in human submucous neurons.

[Resection of main duct and mixed type IPMN ≥5 mm]

The incidence of cystic pancreatic lesions is steadily increasing due to the technical advances in imaging. Within the group of cystic pancreatic lesions intraductal papillary mucinous neoplasms (IPMNs) depict an important entity. Due to a possible progression to malignancy the clinical strategy has to be well chosen. For primary diagnostic work-up imaging by magnetic resonance imaging (MRI) with MR cholangiopancreatography (MRCP) and computed tomography (CT) scanning is recommended. Additional information can be gained by endosonography and a biopsy of the cystic lesion, allowing analysis of biomarkers, such as GNAS and KRAS mutation as wells as NLR. These can help to differentiate between IPMN and other cystic lesions although the clinical importance for the diagnosis of main duct (MD) and mixed IPMN is limited. The current guidelines (Fukuoka and EU guidelines) recommend resection of MD and mixed IPMN following oncological standards. For the definition of MD-IPMN, a duct dilatation between 5-10 mm is needed when following the current guidelines; however, current publications claim an even lower cut-off of ≥5 mm due to the risk of malignant progression. Intraoperative frozen sections are recommended to evaluate the margins status and extended resection is recommended for residual high-grade dysplasia. Surveillance of potentially at risk patients is recommended at regular intervals of 6-12 months while patients with malignant IPMN should be followed according to pancreatic cancer protocols. A screening for extrapancreatic malignancy is not indicated.

Effect of preoperative biliary drainage on bacterial flora in bile of patients with periampullary cancer

BACKGROUND

Patients with obstructive jaundice due to periampullary tumours may undergo preoperative biliary drainage (PBD). The effect of PBD on the microbiome of the biliary system and on postoperative outcome remains unclear.

METHODS

A single-centre retrospective study of patients with obstructive jaundice due to periampullary cancer, treated between July 2007 and July 2015, was undertaken. Intraoperative bile samples were obtained for microbiological analysis after transection of the common bile duct. Postoperative complications were registered.

RESULTS

Of 290 patients treated, intraoperative bile samples were present for 172 patients (59·3 per cent) who had PBD and 118 (40·7 per cent) who did not. Contamination of bile was increased significantly in patients who underwent stenting (97·1 per cent versus 18·6 per cent in those without stenting; P < 0·001). PBD resulted in a shift in the biliary microbiome from Escherichia coli in non-stented patients (45 per cent versus 19·2 per cent in stented patients; P = 0·009) towards increased contamination with Enterococcus faecalis (9 versus 37·7 per cent respectively; P = 0·008) and Enterobacter cloacae (0 versus 20·4 per cent; P = 0·033). This shift was associated with a high incidence of bacterial resistance against ampicillin-sulbactam (63·6 per cent versus 18 per cent in patients with no PBD; P < 0·001), piperacillin-tazobactam (30·1 versus 0 per cent respectively; P = 0·003), ciprofloxacin (28·5 versus 5 per cent; P = 0·047) and imipenem (26·6 versus 0 per cent; P = 0·011). The rate of wound infection was higher in patients with a positive bile culture (21·0 per cent versus 6 per cent in patients with sterile bile; P = 0·002). Regression analysis revealed the presence of Enterococcus faecium (odds ratio 2·83, 95 per cent c.i. 1·17 to 6·84; P = 0·021) and Citrobacter species (odds ratio 5·09, 1·65 to 15·71; P = 0·005) as independent risk factors for postoperative wound infection.

CONCLUSION

There are fundamental differences in the biliary microbiome of patients with periampullary cancer who undergo PBD and those who do not. PBD induces a shift of the biliary microbiome towards a more aggressive and resistant spectrum, which requires a differentiated perioperative antibiotic treatment strategy.

Effect of hyoscine butylbromide (Buscopan®) on cholinergic pathways in the human intestine

BACKGROUND

Hyoscine butylbromide (HBB, Buscopan(®) ) is clinically used to treat intestinal cramps and visceral pain. Various studies, mainly on animal tissues, suggested that its antimuscarinic action is responsible for its spasmolytic effect. However, functional in vitro studies with human tissue have not been performed so far.

METHODS

We wanted to provide a comprehensive study on the mode of action of HBB in human intestinal samples and investigated HBB (1 nmol L(-1) -10 μmol L(-1)) effects on muscle activity with isometric force transducers and calcium imaging, on epithelial secretion with Ussing chamber technique and on enteric neurons using fast neuroimaging.

KEY RESULTS

Hyoscine butylbromide concentration dependently reduced muscle contractions, calcium mobilization, and epithelial secretion induced by the muscarinic agonist bethanechol with IC50 values of 429, 121, and 224 nmol L(-1), respectively. Forskolin-induced secretion was not altered by HBB. Cholinergic muscarinic muscle and epithelial responses evoked by electrical nerve stimulation were inhibited by 1-10 μmol L(-1) HBB. Moreover, HBB significantly reduced the bethanechol-induced action potential discharge in enteric neurons. Interestingly, we observed that high concentrations of HBB (10 μmol L(-1)) moderately decreased nicotinic receptor-mediated secretion, motility, and nerve activity.

CONCLUSIONS & INFERENCES

The results demonstrated the strong antimuscarinic action of HBB whereas the nicotinic antagonism at higher concentrations plays at most a moderate modulatory role. The muscle relaxing effect of HBB and its inhibition of muscarinic nerve activation likely explain its clinical use as an antispasmodic drug. Our results further highlight a so far unknown antisecretory action of HBB which warrants further clinical studies on its use in secretory disorders.

Ginger and its pungent constituents non-competitively inhibit activation of human recombinant and native 5-HT3 receptors of enteric neurons

BACKGROUND

Beneficial effects of ginger in the treatment of gastrointestinal (GI) problems and chemotherapy-induced nausea and vomiting are well accepted. In rodents, the action of ginger seems to be mediated by the inhibition of 5-HT3 receptors, which are established targets to combat emesis and irritable bowel syndrome.

METHODS

Heterologously expressed human 5-HT3 A or 5-HT3 AB receptors were characterized by means of Ca(2+) influx studies using HEK293 cells. Complementing Ca(2+) measurements in Fluo-4-AM-stained whole-mount preparations of the human submucous plexus were carried out. Furthermore, [3H]GR65630 binding assays were performed to reveal the mode of action of ginger and its pungent compounds.

KEY RESULTS

We show for the first time that ginger extracts and its pungent arylalkane constituents concentration-dependently inhibit activation of human 5-HT3 receptors. Ginger extracts inhibited both receptors with increasing content of pungent compounds, confirming that these are part of ginger's active principle. Inhibition potencies of the arylalkanes 6-gingerol and 6-shogaol on both receptors were in the low micromolar range. A lipophilic ginger extract and 6-gingerol had no influence on 5-HT potency, but reduced the 5-HT maximum effect, indicating non-competitive inhibition. The non-competitive action was confirmed by [(3) H]GR65630 binding, showing that the ginger extract did not displace the radioligand from 5-HT3 A and 5-HT3 AB receptors. The potential relevance of the inhibitory action of ginger on native 5-HT3 receptors in the gut was confirmed in whole-mount preparations of the human submucous plexus. While a general neurotoxic effect of 6-gingerol was ruled out, it inhibited the 2-methyl-5-HT-mediated activation of 5-HT3 receptors residing on enteric neurons.

CONCLUSIONS & INFERENCES

Our findings may encourage the use of ginger extracts to alleviate nausea in cancer patients receiving chemotherapy and to treat functional GI disorders.

Prophylactic glycine administration attenuates pancreatic damage and inflammation in experimental acute pancreatitis

BACKGROUND/AIMS

Acute pancreatitis (AP) is characterized by premature zymogen activation, systemic inflammatory response resulting in inflammatory infiltrates, sustained intracellular calcium, neurogenic inflammation and pain. The inhibitory neurotransmitter and cytoprotective amino acid glycine exerts a direct inhibitory effect on inflammatory cells, inhibits calcium influx and neuronal activation and therefore represents a putative therapeutic agent in AP.

METHODS

To explore the impact of glycine, mild AP was induced in rats by supramaximal cerulein stimulation (10 μg/kg BW/h) and severe AP by retrograde injection of sodium taurocholate solution (3%) into the common biliopancreatic duct. 100/300 mmol glycine was administered intravenously before induction of AP. To elucidate the effect of glycine on AP, we determined pathomorphology, pancreatic cytokines as well as proteases, serum lipase and amylase, pancreatic and lung MPO activity and pain sensation.

RESULTS

Glycine administration resulted in a noticeable improvement of pathomorphological alterations in AP, such as a reduction of necrosis, inflammatory infiltrates and cytoplasmic vacuoles in cerulein pancreatitis. In taurocholate pancreatitis, glycine additionally diminished pancreatic cytokines and MPO activity, as well as serum lipase and amylase levels.

CONCLUSIONS

Glycine reduced the severity of mild and much more of severe AP by attenuating the intrapancreatic and systemic inflammatory response. Therefore, glycine seems to be a promising tool for prophylactic treatment of AP. and IAP.

The microenvironment in chronic pancreatitis and pancreatic cancer induces neuronal plasticity

BACKGROUND

Pancreatic neuropathy in chronic pancreatitis (CP) and pancreatic cancer (PCa) is characterized by pancreatic neuropathy, i.e. increased neural density and hypertrophy, which are associated with neuropathic pain. To better understand the mechanism of these neuropathic alterations, we aimed at achieving an in-vitro simulation of the intrapancreatic neuroplasticity.

METHODS

Dissociated myenteric plexus (MP) and dorsal root ganglia (DRG) neurons of newborn rats were treated with normal human pancreas (NP), CP or PCa tissue extracts. Furthermore, MP and DRG neurons were cultured in supernatants from different pancreatic cancer cell lines (PCC) and human pancreatic stellate cells (hPSC) obtained from either CP or PCa tissues. For analysis, the neurite density, outgrowth, neuronal branching capacity and perikaryonal size were quantified.

KEY RESULTS

Myenteric plexus and DRG neurons grown in CP and PCa tissue extracts built denser networks than in NP extracts. Both neuronal types showed a strong neurite outgrowth, more complex branching pattern and a somatic hypertrophy in CP and PCa extracts. Pancreatic cancer cell supernatants induced a prominent neurite outgrowth, increased neurite density and perikaryonal hypertrophy in MP and DRG neurons. Supernatants of CP-derived hPSC strongly stimulated neurite outgrowth. Glial density in MP cultures was strikingly increased by PCa tissue extracts.

CONCLUSIONS & INFERENCES

Intrapancreatic microenvironment in CP and PCa induces neuroplastic alterations under in-vitro conditions, leading to increased neural density and hypertrophy. Thus, due to its neurotrophic attributes, the intrapancreatic microenviroment in CP and PCa seems to be a key player in the generation of pancreatic neuropathy and neuroplasticity.

Endothelin receptor antagonists are not beneficial in the therapy of acute experimental pancreatitis

BACKGROUND AND AIM

Due to increased capillary permeability and the early appearance of vasoactive and toxic agents, patients suffering from necrotizing pancreatitis frequently develop a systemic inflammatory response syndrome (SIRS). Endothelin, a potent vasoconstrictor, is thought to play a major role in these changes via the regulation of microcirculation. An improved outcome of acute experimental necrotizing pancreatitis by blocking the endothelin receptors ETA and ETB, either selectively (only ETA) or unselectively (ETA and ETB), has been suggested. The aim of this study was to investigate further the beneficial effects of new, highly potent endothelin-receptor (ET-R) antagonists in acute experimental pancreatitis.

METHODS

The influence of the selective ET-RA antagonist BSF208075 (1 mg/kg) on mortality was studied in three severity groups of acute necrotizing pancreatitis (retrograde injection of 4%, 5% and 6% of sodium taurocholate into the main pancreatic duct). The effects of the selective ET-RA antagonists LU135252 (LU13) and BSF208075 (BSF20) and of the unselective endothelin receptor (ET-R(A/B)) antagonist BSF420627 (BSF42) were additionally analyzed in 4% taurocholate-induced necrotizing pancreatitis. Furthermore, the significance of variable doses of the endothelin receptor antagonist LU13 (1 mg/kg, 3 mg/kg and 100 mg/kg) was determined in a 4% sodium taurocholate model and in a cerulein pancreatitis model.

RESULTS

Prophylactic ET-R antagonism increased the mortality rate in the 4% sodium taurocholate-induced pancreatitis. No reduction in pancreatic damage after induction of taurocholate pancreatitis was found by ET-R blockage. Application of ET-R antagonists had no beneficial influence in ascites development. However, administration of LU13 (100 mg/kg) resulted in a non-significant increase in pancreatic oedema, whereas peritoneal necrosis was not affected.

CONCLUSION

The selective and unselective ET-R antagonists BSF20, BSF42 and LU13 failed to improve survival and pancreatic damage during acute experimental pancreatitis. Therefore, previously reported beneficial effects of ET-R antagonists in experimental acute pancreatitis have to be critically evaluated before conclusions for further clinical development are made.