Pancreatic endoprostheses in chronic pancreatitis: criteria to predict stent occlusion

Sex Differences in the Exocrine Pancreas and Associated Diseases

Differences in pancreatic anatomy, size, and function exist in men and women. The anatomical differences could contribute to the increase in complications associated with pancreatic surgery in women. Although diagnostic criteria for pancreatitis are the same in men and women, major sex differences in etiology are reported. Alcohol and tobacco predominate in men, whereas idiopathic and obstructive etiologies predominate in women. Circulating levels of estrogens, progesterone, and androgens contribute significantly to overall health outcomes; premenopausal women have lower prevalence of cardiovascular and pancreatic diseases suggesting protective effects of estrogens, whereas androgens promote growth of normal and cancerous cells. Sex chromosomes and gonadal and nongonadal hormones together determine an individual's sex, which is distinct from gender or gender identity. Human pancreatic disease etiology, outcomes, and sex-specific mechanisms are largely unknown. In rodents of both sexes, glucocorticoids and estrogens from the adrenal glands influence pancreatic secretion and acinar cell zymogen granule numbers. Lack of corticotropin-releasing factor receptor 2 function, a G protein-coupled receptor whose expression is regulated by both estrogens and glucocorticoids, causes sex-specific changes in pancreatic histopathology, zymogen granule numbers, and endoplasmic reticulum ultrastructure changes in acute pancreatitis model. Here, we review existing literature on sex differences in the normal exocrine pancreas and mechanisms that operate at homeostasis and diseased states in both sexes. Finally, we review pregnancy-related pancreatic diseases and discuss the effects of sex differences on proposed treatments in pancreatic disease.

The Role of Endoscopic and Surgical Treatment in Chronic Pancreatitis

Chronic pancreatitis is a long-term illness leading to hospital admissions and readmission. This disease is often caused by heavy alcohol consumption and smoking. Patients with chronic pancreatitis suffer from acute or chronic pain episodes, recurrent pancreatitis, and complications, such as pseudocysts, biliary duct strictures, and pancreatic duct fistulas. Pancreatic duct strictures and stones may increase intraductal pressure and cause pain. Endoscopic therapy is aiming at decompressing the pressure and relieving the pain, most commonly with pancreatic duct stents and pancreatic duct stone retrieval. Early surgery is another option to treat the pain. In addition, endotherapy has been successful in treating complications related to chronic pancreatitis. The therapy should be individually chosen in a multidisciplinary meeting. Endoscopic therapy and surgery as treatment options for chronic pancreatitis are discussed in this review.

Narcotic Independence After Pancreatic Duct Stenting Predicts Narcotic Independence After Lateral Pancreaticojejunostomy for Chronic Pancreatitis

OBJECTIVE

This study aimed to determine if the improved pain response to endoscopic retrograde cholangiopancreatogrphy (ERCP) and pancreatic stent placement (EPS) predicts pain response in patients with chronic pancreatitis after modified lateral pancreaticojejunostomy (LPJ).

METHODS

A multi-institutional, retrospective review of patients who underwent successful EPS before LPJ between 2001 and 2010 was performed. The primary outcome was narcotic independence (NI) within 2 months after ERCP or LPJ.

RESULTS

A total of 31 narcotic-dependent patients with chronic pancreatitis underwent successful EPS before LPJ. Ten (32%) achieved post-LPJ NI (median follow-up, 8.5 months; interquartile range [IQR], 2-38 months). Eight (80%) of 10 patients with NI post-ERCP achieved NI post-LPJ. Two (10%) without NI post-ERCP achieved NI post-LPJ. Narcotic independence post-EPS was associated strongly with NI post-LPJ with an odds ratio of 38 (P = 0.0025) and predicted post-LPJ NI with a sensitivity, specificity, positive predictive value, and negative predictive value of 80%, 90.5%, 80%, and 90.5%, respectively.

CONCLUSIONS

Narcotic independence after EPS is associated with NI after LPJ. Failure to achieve NI post-ERCP predicts failure to achieve NI post-LPJ. These results support the need for larger studies to confirm the predictive value of pancreatic duct stenting for better selection of chronic pancreatitis patients who will benefit from LPJ.

Endoscopic therapy in chronic pancreatitis: current perspectives

Endoscopic therapy in chronic pancreatitis (CP) aims to provide pain relief and to treat local complications, by using the decompression of the pancreatic duct and the drainage of pseudocysts and biliary strictures, respectively. This is the reason for using it as first-line therapy for painful uncomplicated CP. The clinical response has to be evaluated at 6-8 weeks, when surgery may be chosen. This article reviews the main possibilities of endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic ultrasound (EUS) therapies. Endotherapy for pancreatic ductal stones uses ultrasound wave lithotripsy and sometimes additional stone extractions. The treatment of pancreatic duct strictures consists of a single large stenting for 1 year. If the stricture persists, simultaneous multiple stents are applied. In case of unsuccessful ERCP, the EUS-guided drainage of the main pancreatic duct (MPD) or a rendezvous technique can solve the ductal strictures. EUS-guided celiac plexus block has limited efficiency in CP. The drainage of symptomatic or complicated pancreatic pseudocysts can be performed transpapillarily or transgastrically/transduodenally, preferably by EUS guidance. When the biliary stricture is symptomatic or progressive, multiple plastic stents are indicated. In conclusion, as in many fields of symptomatic treatment, endoscopy remains the first choice, either by using ERCP or EUS-guided procedures, after consideration of a multidisciplinary team with endoscopists, surgeons, and radiologists. However, what is crucial is establishing the right timing for surgery.

Pancreatic and biliary stents

Biliary and pancreatic stents are used in a variety of benign and malignant conditions including strictures and leaks and in the prevention of post-ERCP pancreatitis.Both plastic and metal stents are safe, effective, and easy to use. SEMSs have traditionally been used for inoperable malignant disease. Covered SEMSs are now being evaluated for use in benign disease. Increasing the duration of patency of both plastic and metal stents remains an important area for future research.

Endoscopic therapy in chronic pancreatitis

Chronic pancreatitis (CP) is a debilitating disease that can result in chronic abdominal pain, malnutrition, and other related complications. The main aims of treatment are to control symptoms, prevent disease progression, and correct any complications. A multidisciplinary approach involving medical, endoscopic, and surgical therapy is important. Endoscopic therapy plays a specific role in carefully selected patients as primary interventional therapy when medical measures fail or in patients who are not suitable for surgery. Endoscopic therapy is also used as a bridge to surgery or as a means to assess the potential response to pancreatic surgery. This review addresses the role of endoscopic therapy in relief of obstruction of the pancreatic duct (PD) and bile du ct, closure of PD leaks, and drainage of pseudocysts in CP. The role of endoscopic ultrasound-guided celiac plexus block for pain in chronic pancreatitis is also discussed.

Treatment of pancreatic strictures

The diagnosis and treatment of patients with pancreatic strictures presents a multitude of clinical challenges. The etiology of pancreatic strictures is varied, including benign strictures subsequent to acute pancreatitis, trauma, postsurgical, post-endoscopic retrograde cholangiopancreatography (ERCP), and malignancy. Patients with strictures usually present with symptoms of recurrent pancreatitis, abdominal pain, weight loss, and/or steatorrhea. The absence of a prior history of pancreatitis or surgery increases the likelihood of malignancy. High-quality imaging studies of the pancreas, CT, MRI/magnetic resonance cholangiopancreatography, or endoscopic ultrasound (EUS) scanning are utilized for better definition. Imaging detects an associated mass and/or demonstrates the ductal anatomy. Invasive procedures such as ERCP are performed to better define the causal relationships of the patient's symptoms or to obtain tissue diagnosis. Treatment goals include ameliorating symptoms, dilating the stricture, and ruling out cancer. The risk of malignancy underlies much of the intervention, which includes serology, cytologic analysis, and serial imaging. EUS has become the procedure of choice to rule out a mass, to evaluate the parenchyma for evidence of chronic pancreatitis, and to obtain fine-needle biopsies for tissue confirmation. In symptomatic patients or patients with indeterminate strictures, ERCP is used for direct pancreatography, tissue acquisition, and endoscopic treatment. Endotherapy includes sphincterotomy, dilation, and stenting to provide drainage. We view ERCP as the optimal first-line treatment modality. ERCP offers the potential of curative treatment and is less invasive than surgery, especially as some patients' symptoms are not severe enough to justify surgery. If patients do not experience relief of symptoms after several sessions of endoscopic therapy, surgery is the logical next step for definitive, long-term treatment.

Cleaning of occluded pancreatic duct endoprostheses: a new indication for extracorporeal shock wave lithotripsy?

BACKGROUND

Pancreatic duct stenting is widely performed for bridging main pancreatic duct obstruction in patients with chronic pancreatitis. The major limitation is early stent occlusion, making regular stent exchange necessary.

OBJECTIVE

To date, no measures are available to prevent stent occlusion. The aim of this study was to evaluate the cleansing effect of shock wave application (SWA) on occluded pancreatic duct stents in vitro.

DESIGN

In vitro study.

PATIENTS

We analyzed occlusion rates of 25 plastic endoprostheses removed from 21 patients with chronic pancreatitis.

INTERVENTION

We administered 350 shock wave pulses every 10 mm along the prosthesis, which was stored in a latex balloon filled with gas-free physiologic saline solution, by using a pressure of 42 megapascals.

MAIN OUTCOME MEASUREMENTS

After SWA, the occlusion rate was measured again, and the cleansing rate was calculated in comparison with the native prosthesis.

RESULTS

The mean (± SD) occlusion rate was significantly reduced (64.7 ± 28.7 [15%-100%]) before SWA vs 9.8 ± 25.3 [0-100%]) after SWA; P = .038). In 16 of 25 prostheses (64%), cleaning was complete. Four of the remaining 9 prostheses (16%) showed satisfactory cleaning of 95%, on average. Residual clogging material was found mainly at the duodenal tip and the middle of the stent. No significant association was found between patient-related or stent-related parameters and the cleansing effect of SWA.

LIMITATIONS

In vitro study design.

CONCLUSION

SWA is effective in cleaning occluded pancreatic endoprostheses in vitro. Prolongation of stent placement seems possible if regular SWA is performed. Extracorporeal shock wave lithotripsy therefore might become a new indication for patients under treatment with pancreatic endoprostheses.

Low symptomatic premature stent occlusion of multiple plastic stents for benign biliary strictures: comparing standard and prolonged stent change intervals

BACKGROUND

Benign biliary strictures are typically managed endoscopically whereby an increasing size or number of plastic stents is placed at ERCP. Stents are often changed every 3 to 4 months based on the known median patency of a single biliary stent, but patency data for multiple biliary stents are lacking.

OBJECTIVE

To assess the incidence of occlusion-free survival of multiple plastic biliary stents and the rate of premature occlusion if left in longer than 6 months.

DESIGN

Retrospective.

SETTING

Tertiary-care medical center (Charleston, SC).

PATIENTS

Consecutive patients who received multiple plastic stents for benign nonhilar biliary strictures from 1994 to 2008 were identified.

INTERVENTIONS

Exchange of multiple plastic biliary stents within 6 months (group 1) or 6 months or longer (group 2) after placement.

MAIN OUTCOME MEASUREMENTS

Symptomatic stent occlusion.

RESULTS

Seventy-nine patients with nonhilar extrahepatic benign biliary stricture underwent 125 ERCPs with multiple plastic biliary stents. Stents were scheduled for removal/exchange within 6 months in 52 patients (86 ERCPs) compared with after 6 months in 22 patients (26 ERCPs). The median interval between multiple stent placement and removal/exchange was 90 days for group 1 and 242 days for group 2. Premature stent occlusion occurred in 4 of 52 (7.7%) patients in group 1 versus 1 of 22 (4.5%) in group 2, with significantly longer occlusion-free survival in group 2 (log-rank P < .0001).

LIMITATIONS

Retrospective study at a single tertiary referral center.

CONCLUSION

Multiple plastic biliary stents for benign nonhilar strictures were associated with a low rate of premature symptomatic stent occlusion at more than 6 months and a longer occlusion-free survival.

Update on endoscopic treatment of chronic pancreatitis

Endoscopic therapy has been increasingly recognized as the effective therapy in selected patients with chronic pancreatitis. Utility of endotherapy in various conditions occurring in chronic pancreatitis is discussed. Its efficacy, limitations, and alternatives are addressed. For the best management of these complex entities, a multidisciplinary approach involving expertise in all pancreatic specialties is essential to achieve the goal.

Endoscopic treatment as first-line therapy for pancreatic ascites and pleural effusion

BACKGROUND

Ascites and pleural effusion are well recognized complications of pancreatic diseases. Drug therapy of these is limited by high cost, prolonged hospitalization and failure rates; surgery is invasive and is associated with considerable morbidity and mortality.

OBJECTIVE

To analyze the data on patients with pancreatic ascites and/or pleural effusion treated endoscopically over a ten-year period.

METHODS

Patients with symptomatic ascites/pleural effusion for at least 3 weeks with a fluid amylase level of > 1000 S units/dl and underlying pancreatic disease were included. The interventions were a 5 mm sized pancreatic sphincterotomy and placement of a 7 Fr pancreatic stent. Somatostatin/octreotide and parenteral nutrition were not used after endoscopic therapy.

RESULTS

Of the 28 patients included (22 men), 17 (60.7%) had chronic pancreatitis. The causes were tropical pancreatitis (13, 46.4%), alcohol abuse (10, 35.7%), idiopathic acute pancreatitis (4, 14.3%) and resective surgery for gastric cancer (1, 3.6%). Ascites alone was seen in 15, pleural effusion alone in 6 and both in 7 patients. Ten patients (35.7%) had 14 pseudocysts. Endotherapy was successful in 27 (96.4%). Twenty-six (92.8%) patients had complete resolution of ascites/effusion over a median 5 weeks. The stents were removed 3-6 weeks later without any recurrence over the next 6-36 (median = 17) months. Complications (7, 25%) included severe pain in 2 (7.1%) and fever in 5 (17.8%) of which 3 (10.7%) had infection of residual fluid collections. No patient died.

CONCLUSION

Endoscopic therapy offers an excellent therapeutic alternative in patients with pancreatic ascites and pleural effusion.

Endotherapy for pain in chronic pancreatitis

Pain is the most distressing symptom of chronic pancreatitis. Although the pathogenesis of pain is still poorly understood, an increase in intraductal pressure may be the dominant factor. The management of pain can involve medical, endoscopic, neurolytic, and surgical therapies. Endotherapy includes pancreatic sphincterotomy, extraction of stones, placement of stent, and dilatation of strictures, sometimes preceded or followed by extracorporeal shock-wave lithotripsy. Several studies have now shown that endotherapy provides partial or complete relief of pancreatic pain in a majority of patients with an acceptable frequency of early and late complications. Endotherapy should now graduate from an experimental form of treatment to a realistic treatment option in patients with chronic or relapsing pain, particularly in the setting of calcific chronic pancreatitis.

Chronic pancreatitis

PURPOSE OF REVIEW

As in previous reviews in this journal, this review is focused on the most important new observations in chronic pancreatitis made in the past year and the beginning of this year.

RECENT FINDINGS

Important observations include the following: first, the natural history and course of chronic pancreatitis; second, that smoking enhances the risk of chronic pancreatitis; third, possible new function tests in combination with imaging procedures; fourth, the superiority of surgery compared with endotherapy for long-term pain relief; fifth, new insights in autoimmune pancreatitis.

SUMMARY

All in all, little progress has recently been made in the field of diagnosis and therapy of chronic pancreatitis. There are some studies in the field of endotherapy and autoimmune pancreatitis that are promising however.