Stenting does not decompress the pancreatic duct as effectively as surgery in experimental chronic pancreatitis

Genetically induced vs. classical animal models of chronic pancreatitis: a critical comparison

Chronic pancreatitis (CP) is an utmost complex disease that is pathogenetically linked to pancreas-intrinsic ( e.g., duct obstruction), environmental-toxic ( e.g., alcohol, smoking), and genetic factors. Studying such a complex disease naturally requires validated experimental models. In the past 2 decades, the various animal models of CP usually addressed either the pancreas-intrinsic ( e.g., the caerulein model), the environmental-toxic ( e.g., diet-induced models), or the genetic component of CP. As such, these models were far from mirroring CP in its full spectrum, and the correct choice of models was vital for valid scientific conclusions on CP. The quest for mechanistic, genetic models gave rise to models based on gene modification and transgene insertion, such as the PRSS1 and the IL-1β/IL-1β models. Recently, we witnessed the development of highly exciting models that rely on the importance of autophagy in CP, that is, the murine pancreas-specific Atg5 and LAMP2 knockout models. Today, critical comparison of these several models is more important than ever for guiding research on CP in an efficient direction. The present review outlines the characteristics of the new genetic models in comparison with the well-known classic models for CP, notes the caveats in the choice of models, and also indicates novel directions for model development.-Klauss, S., Schorn, S., Teller, S., Steenfadt, H., Friess, H., Ceyhan, G. O., Demir, I. K. Genetically induced vs. classical animal models of chronic pancreatitis: a critical comparison.

Effect of naloxone-3-glucuronide and N-methylnaloxone on the motility of the isolated rat colon after morphine

The effect of the opioid antagonists naloxone-3-glucuronide and N-methylnaloxone on rat colon motility after morphine stimulation was measured. The rat model consisted of the isolated, vascularly perfused colon. The antagonists (10(-4) M, intraluminally) and morphine (10(-4) M, intra-arterially) were administered from 20 to 30 and from 10 to 50 min, respectively. Colon motility was determined by the luminal outflow. The antagonist concentrations in the luminal and venous outflow were measured by high-performance liquid chromatography. Naloxone-3-glucuronide and N-methylnaloxone reversed the morphine-induced reduction of the luminal outflow to baseline within 10 and 20 min, respectively. These antagonists were then excreted in the luminal outflow and could not be found in the venous samples. Naloxone, produced by hydrolysis or demethylation, was not detectable. In conclusion, highly polar naloxone derivatives peripherally antagonize the motility-lowering effect of morphine in the perfused isolated rat colon, are stable, and are not able to cross the colon-mucosal blood barrier.

Interventional endoscopic therapy in chronic pancreatitis including temporary stenting: a definitive treatment?

OBJECTIVE

In the past 15 years there have been tremendous advances in endoscopic management of chronic pancreatitis (CP). However, the value of endoscopic pancreatic stenting is still debatable.

MATERIAL AND METHODS

In 98 patients suffering from symptomatic CP (84 M, 14 F, 49+/-12, age range 23-83 years) endotherapy including temporary stenting of the pancreatic duct was performed. After final stent removal, indicating the primary end-point of endotherapy, 96 patients were followed for 35+/-28 (8 days-111) months. All data were assessed retrospectively.

RESULTS

As well as other endoscopic procedures, a total of 358 prostheses were inserted in the pancreatic duct and left in place for 3+/-1 (1 day-11) months. Total stent treatment time was 10+/-10 (6 days-49) months. At 46+/-27 (4-111) months after limited endotherapy, 57 patients had no need for secondary intervention, two-thirds were even without further pain sensations. In 22 patients, surgical treatment and in 17 patients further endoscopic therapy became necessary, which was significantly correlated with continued alcohol consumption.

CONCLUSIONS

Temporary stent placement as a part of interventional endoscopic therapy in CP shows a high rate of technical and long-term clinical success, with no need for secondary treatment in a remarkable number of patients. Continued cessation of alcohol consumption supports the treatment benefit significantly.

Long-term clinical outcome after endoscopic pancreatic ductal drainage for patients with painful chronic pancreatitis

BACKGROUND & AIMS

Endotherapy for patients with painful chronic pancreatitis (CP) gives early and midterm clinical results comparable with those of conventional surgery. The authors evaluated long-term clinical outcome after endoscopic pancreatic ductal drainage, focusing on pain and pancreatic endocrine/exocrine functions.

METHODS

Of 110 patients with painful CP endoscopically treated between October 1987 and December 1989, 56 long-surviving patients were followed-up for 14.4 years (SD, .6 y); 40 patients died and 14 patients were lost to follow-up evaluation. Technical results included decreased ductal dilation and stone clearance. Clinical results included the rate of hospitalizations for pain before and after endotherapy, the need for surgery, the course of endocrine/exocrine insufficiencies, and late mortality.

RESULTS

Complete or partial technical success initially was obtained in 48 of 56 long-surviving patients. Long-term clinical success (< or =5 hospitalizations for pain during follow-up evaluation, without surgery) was obtained for 37 of 56 patients. At a mean follow-up time of 14.4 years, 44 patients had avoided surgery and the annual rate of hospitalizations for pain decreased significantly (before endotherapy: 0.98 [+/-1.36] vs 0.40 [+/-0.51] for the 3 years thereafter vs 0.14 [+/-0.22] for the last 11 years of follow-up evaluation; P < .001). Short duration of disease before initial therapy and absence of smoking at the last follow-up evaluation were associated with long-term clinical success.

CONCLUSIONS

Endotherapy provides long-term benefits for about two thirds of patients with painful CP. Good clinical outcome was associated with cessation or absence of smoking, whereas alcohol abuse increased the risks for diabetes mellitus, steatorrhea, and mortality.

Endoscopic management of chronic pancreatitis

Endoscopic management of CP is generally safe, minimally invasive, and often effective for years, does not hinder further surgery, and can be repeated. It should be applied as a first-line approach to improving the clinical condition of patients with this chronic disease. The best results are obtained when endoscopic treatment is performed early in the course of CP. Proper patient selection, adequate expertise, and a supporting multidisciplinary infrastructure are essential. New technologies will continue to be developed and to extend the scope of therapeutic pancreatic endoscopy.

Effect of pancreaticojejunostomy on fibrosis, pancreatic blood flow, and interstitial pH in chronic pancreatitis: a feline model

OBJECTIVE

To study the relation between fibrosis, pancreatic blood flow (PMBF), interstitial pH (pHi), and the effects of pancreaticojejunostomy (PJ) in chronic pancreatitis.

BACKGROUND

Chronic pancreatitis is associated with low PMBF and pHi, suggesting the existence of underlying ischemia.

METHODS

In cats, the main pancreatic duct was partially obstructed and the animals were studied 2, 4, 6, and 8 weeks later. PJ was performed after 2 and 4 weeks of ductal obstruction and studied 4 weeks later. PMBF and pH were measured before and after stimulation with secretin and cholecystokinin. pHi was measured with microelectrodes, PMBF by hydrogen gas clearance. Histologic analysis of the pancreas with Sirius red (collagen stain) and fast green FCF (noncollagen protein) stains allowed semiquantitative analysis of the ratio between collagen and total protein (C/TP).

RESULTS

With the evolution of chronic pancreatitis, there is a progressive increase in the collagen content and C/TP ratio, a reduction in basal PMBF and pHi, and loss of the normal response to stimulation. Early PJ restores collagen content, C/TP ratio, and basal and stimulated PMBF and pHi to normal. PJ performed in established CP returns the C/TP ratio to normal, improves basal PMBF, and restores the normal hyperemic response to secretion. Basal pHi is improved and the "acid tide" associated with secretin returns, but there is still no response to cholecystokinin.

CONCLUSIONS

Pancreaticojejunostomy restores the elevated collagen and C/TP ratio to normal and reverses the ischemia present in CP. The authors speculate that restoration of PMBF and its normal response to stimulation allows "regeneration" and restoration of secretory function.

Pancreatic surgery

According to epidemiologic studies, the incidence of acute and chronic pancreatitis and carcinoma of the pancreas are increasing worldwide. This is the result not only of improved diagnostic methods introduced in the last decades (eg, contrast-enhanced computed tomography, "all-in-one" magnetic resonance imaging, single-photon emission computed tomography, and endoscopic retrograde cholangiopancreatography) but also of changes in the environment and nutritional behavior. Once a specific diagnosis has been made, the first-choice interventions in acute and chronic inflammatory pancreatic diseases are predominantly organ-and organ function-preserving surgical procedures. In pancreatic cancer, extended radical surgery and multimodal therapies seem to offer the most benefit. This article provides an overview of recently published articles focusing on surgical treatment options in acute and chronic pancreatitis and carcinoma of the pancreas.