ERCP and EUS in Management of Pancreatitis

Abstract

Interventional endoscopic procedures like Endoscopic Retrograde Cholangiopancreatography (ERCP) and endoscopic ultrasound (EUS) have a major role in the minimally invasive management of acute and chronic pancreatitis and their complications. These complications may be due to pancreaticolithiasis, main pancreatic duct strictures, trauma, infections, autoimmune pancreatitis and pancreatic neoplasms. ERCP and endoscopic ultrasound scan are important as both diagnostic and therapeutic interventions. The commonly managed complications by ERCP and EUS include; pancreatic duct stones, main pancreatic duct strictures, pancreatic pseudocysts and pancreatic walled off necrosis. These endoscopic interventions have the advantage of cosmesis, short hospital stay and can be safely used even in very sick, critical or elderly patients without necessarily increasing the morbidity and mortality associated with open surgical approaches.

1. Introduction

Endoscopic Retrograde Cholangiopancreatography (ERCP) has been employed in the diagnosis and management of biliary tract and pancreatic diseases over the years with the first diagnostic ERCP performed in 1968 by McCune and colleagues [1]. With the presence of less invasive diagnostic procedures such as Contrast enhanced Computed Tomography (CT), abdominal ultrasound, Endoscopic Ultrasound (EUS), Magnetic Resonance Cholangiopancreatography (MRCP) and better blood biomarkers, the popularity of ERCP as a diagnostic procedure has reduced overtime due to the ERCP-associated complications such as pancreatitis, bleeding which negatively impact its relevance as a routine diagnostic tool in pancreatic and bile duct pathologies. Preference has now shifted to the less risky non-invasive diagnostic procedures that involve no duct instrumentation.

The most common causes of acute pancreatitis are gallstones (40–70%) and alcohol (25–35%) [2]. ERCP is mainly utilized in management of gall stone pancreatitis especially among patients with cholangitis, biliary obstruction and pancreatic duct disruption. ERCP also has wide applications in the diagnosis of ductal changes in chronic pancreatitis with application of EUS in diagnosis of the parenchymal changes and intraductal stones with high accuracy. ERCP and EUS also have roles in diagnosis and management of various acute, subacute and chronic pancreatitis etiologies (such as intraductal gall stones, sphincter of Oddi dysfunction) and complications (such as pancreatic duct leaks, pancreatic pseudocysts) among others.

The potential benefits must be weighed against the associated risks of complications when selecting patients to undergo ERCP or its different therapeutic interventions.

2. Timing and role of ERCP in acute biliary pancreatitis

Acute biliary pancreatitis results from transient obstruction of the common bile duct by stones. Majority of the stones spontaneously pass into the duodenum followed by resolution of the acute pancreatitis [2]. In a few of the patients, persistent choledocholithiasis can lead to pancreatic duct and/or biliary tree obstruction resulting into severe/persistent pancreatitis and/or cholangitis with resolution and complication risk reduction on removal of the offending stones [3].

Stone can be extracted during ERCP by either balloon catheters or dormia stone extraction baskets after either endoscopic sphincterotomy (papillotomy) and/or endoscopic papillary balloon dilatation (sphincteroplasty). Papillary balloon dilatation is however not routinely recommended due to a lower technical success for stone clearance and a presumed increased risk of pancreatitis. It can however be considered in patients with coagulopathies or altered anatomy with smaller (<8 mm) stones [4]. Endoscopic sphincterotomy with stone extraction is associated with 80–90% success rate in common bile duct (CBD) stones treatment. In cases of irretrievable biliary stones, temporary biliary plastic or metallic stents can be placed to relieve the obstruction followed by a second attempt at stone removal combined with either mechanical or extracorporeal shock wave lithotripsy (ESWL). Failure of ERCP, EUS mechanical or ESWL ultimately means surgical intervention which can be open or laparoscopic cholecystectomy with choledocholithotomy to remove the CBD stones done during CBD exploration. For cases of ERCP with stenting, the stents may however, be associated with complications such as cholangitis and so should be removed or exchanged every 3–6 months. Definitive stenting is recommended in the elderly with a limited life expectancy and co-morbidities with caution due to the high rates of complications such as cholangitis with associated high mortality [4].

There is consensus among different meta-analyses and guidelines on the role and timing of early ERCP with endoscopic sphincterotomy (ES) in case of acute biliary pancreatitis in the presence of cholangitis and/or persistent cholestasis. However there is obvious lack of agreement on the role and timing of ERCP in mild or severe predicted acute biliary pancreatitis in the absence of cholangitis or persistent cholestasis [5]. Neoptolemus J.P. et al. [6] conducted a randomized controlled trial involving 121 patients with suspected biliary acute pancreatitis using the modified Glasgow system for severity stratification. Early ERCP done within 72 hours plus Endoscopic sphincterotomy for those with common bile duct stones was associated with reduction in complications and shorter hospital stay significantly among those with severe acute pancreatitis when compared with those on conventional treatment. The reduction in complications was still noticed even after excluding those with associated cholangitis. However, no difference in mortality was noted. Another randomized control trial by Fan S T et al. [7] randomized 195 patients with acute pancreatitis to two arms, either early ERCP done within 24 hours after admission with endoscopic papillotomy for ampullary and common bile duct stones or conservative treatment and selective ERCP with or without endoscopic papillotomy in those that deteriorated. Early ERCP with/without endoscopic papillotomy was associated with reduction in biliary sepsis in both patients with mild or severe acute pancreatitis with no major differences in incidence of local or systemic complications between the two groups. The mortality rate was however lower in the early ERCP with or without endoscopic papillotomy group [7]. Another study by Folsch et al. [8] demonstrated no reduction in complications or mortality with early ERCP within 72 hours among patients with acute biliary pancreatitis with no obstruction. This study suggests that early ERCP is only beneficial among patients with acute pancreatitis complicated by acute cholangitis and biliary tree obstruction, and not in severe acute pancreatitis complicated in the absence of the above complications.

Based on meta-analysis, early ERCP with sphincterotomy (within 24–72 hours) had an overall significant reduction in complication rate among patients with biliary pancreatitis (41.8% versus 31.3%, P = 0.03, k = 3) significantly among those with severe disease (57.1% versus 18.2%, P = 0.0001, k = 2) with no overall significant effect on the mortality rate (7.2% versus 6.4%, P = 0.46, k = 3) [9]. Similar findings were noted in a meta-analysis by Moretti et al. when comparing early ERCP vs. conservative management in acute biliary pancreatitis. Early ERCP was associated with reduction in complications and mortality rates by 31% and 6% respectively with significant reduction in complication rates among patients with severe pancreatitis compared to mild pancreatitis (pooled rate difference of 38.5% vs. 1.8%) [10].

ERCP should not be routinely performed in patients with acute biliary pancreatitis due to its invasiveness and risk for complications. Early ERCP has been demonstrated to reduce complication rates among patients with severe acute biliary pancreatitis in the absence of cholangitis or biliary obstruction unlike among patients with mild disease. Early ERCP +ES may be considered among patients with acute biliary pancreatitis with severe biliary pancreatitis rather than among patients with mild acute biliary pancreatitis unless when having standard indications for ERCP + ES such as cholangitis, biliary obstruction [11]. However, proponents of early conservative management argue that early routine ERCP may lead to unnecessary ERCPs with related complications as the offending gallstone has passed in majority of the cases at the time of diagnosis [12, 13] and also with looming uncertainty of whether early ERCP improved prognosis of acute gallstone pancreatitis. Early ERCP is also technically difficult in acute pancreatitis due to ampulla and duodenal edema. It is therefore recommended by the ESGE that ERCP with or without endoscopic sphincterotomy among patients with acute biliary pancreatitis without cholangitis be reserved for patients with persistent biliary obstruction after a period of conservative management regardless of the severity [14, 15]. Cholecystectomy can be performed later after ERCP + ES (usually 4 to 6 weeks) to prevent recurrence of the acute pancreatitis [9]. Among patients with mild acute biliary pancreatitis, early laparoscopic cholecystectomy with intraoperative cholangiography is recommended. If intraoperative cholangiography reveals common bile duct stones with failed laparoscopic clearance of the stones, then post-operative ERCP should be performed [9].

Less invasive imaging modalities such as EUS and MRCP should be used to screen for choledocholithiasis in suspicious cases in the absence of cholangitis and/or jaundice.

3. Microlithiasis

Microlithiasis/biliary sludge is a controversial etiology for acute pancreatitis. Biliary sludge is detected in 75% of the patients with recurrent idiopathic acute pancreatitis [16, 17]. Abdominal ultrasound has low sensitivity in diagnosis of biliary sludge. Bile analysis with microscopic examination for cholesterol crystals is the gold standard for diagnosing biliary sludge with however a sensitivity of 66% [18].

The bile for analysis can be obtained directly through common bile duct aspiration at ERCP or by duodenal aspiration of bile after cholecystokinin stimulation. EUS can also be utilized in diagnosis of microlithiasis/biliary sludge with a higher sensitivity and also applicability in evaluating other causes of idiopathic acute pancreatitis [18]. ERCP should be done 4–6 weeks after the initial presentation when the pancreatitis has resolved and if microlithiasis is detected, cholecystectomy or biliary sphincterotomy can be considered as management options depending on the patient’s surgical risk [19].

4. Sphincter of Oddi dysfunction

Sphincter of Oddi Dysfunction (SOD) is the most frequent cause of idiopathic recurrent acute pancreatitis with a prevalence rate between 15–72% among patients with idiopathic recurrent pancreatitis using ERCP with raised SOD basal pressures at sphincter of Oddi manometry (SOM) as the gold standard for diagnosis and 50–87% among those with chronic pancreatitis [18, 20]. The pathogenesis of pancreatitis in SOD involves increase in the intrapancreatic ductal pressures. The elevation in the intraductal pressure results from either anatomic obstruction of the Sphincter of Oddi by fibrosis and/or inflammation or from functional obstruction caused by sphincter muscle spasms.

Endoscopic therapies such as pancreatic and biliary sphincterotomy can be employed in treating pancreas divisum and/or sphincter of Oddi dysfunction especially in patients with recurrent acute pancreatitis. These therapies are however associated with a significant risk of precipitating acute pancreatitis and hemorrhage, and so should be performed in specialized units and with careful patient selection [3, 21].

Endoscopic injection of botulinum toxin decreases pancreatitis episodes in 80% of patients with acute idiopathic pancreatitis. However, the effect is short-lived with also concerns regarding side effects. Dual sphincterotomy has been demonstrated to have lower rates of pancreatitis recurrence compared to either biliary or pancreatitic sphincterotomy alone.

Temporary pancreatic stent placement is recommended to prevent post-procedure pancreatitis [19, 21].

5. Pancreas divisum

Pancreas divisum (PD) is the most common anatomical variant of the pancreatic duct with an incidence of approximately 10% in the general population and symptomatic in only 5% of the patients [22]. PD has been shown to be a predisposing factor for chronic and recurrent pancreatitis and an incidental finding in idiopathic pancreatitis. However, its exact etiological role in pancreatitis is not well understood and still under study [23].

Contrast-enhanced CT and contrast-enhanced MRCP can be used in the diagnosis of PD with improved sensitivities with secretin provocation for better visualization of the ducts.

Endoscopic Ultrasound (EUS) has also been reported to have a high diagnostic accuracy for PD with a sensitivity of 87–95% with secretin enhancement (S-EUS) offering marginal benefit. Absence of a “stack sign” and the presence of a “crossed duct sign” are considered to be indicative of PD. ERCP is seldom used if no therapeutic interventions are intended due to the associated risks [23].

Therapeutic interventions are reserved for patients with recurrent attacks of acute pancreatitis, incases of a single episode of severe pancreatitis in the absence of any other identifiable etiology or in chronic pancreatitis with a modifiable target such as a stone, dilated dorsal duct or stricture [23]. Endoscopic and surgical therapies can be employed on the management of PD. Endoscopic therapy includes minor papilla endoscopic sphincterotomy, minor papilla orifice balloon dilatation and trans minor papilla dorsal duct stenting.

Papillary endotherapy is associated with an increased risk of post-procedural pancreatitis and therefore prophylactic temporary pancreatic stenting is recommended in addition to peri-procedural non-steroidal anti-inflammatory drugs (NSAIDs) are recommended to reduce the risk. Long-term dorsal pancreatic duct stenting though effective, is associated with possible complications such as occlusion, ductal perforation, acute pancreatitis and proximal or distal stent migration.

Surgical therapy includes surgical minor papilla sphincterotomy or surgical minor papilla sphincteroplasty.

For both endoscopic and surgical therapies, the response rate to therapy is higher in the recurrent pancreatitis group compared to chronic pancreatitis and the chronic pancreatic-type abdominal pain (76–80% Vs 42%- 69% Vs 33–54% with endotherapy and 83% Vs 67% Vs 52% with surgical therapy) [23]. Due to comparable response rates with both endoscopic and surgical therapies, endoscopic therapy is recommended as first line due to a more favorable complication and mortality rate. Surgery is preserved for patients with failed minor papilla cannulation, endotherapy or have altered anatomy such as Bilroth II anatomy [23].

6. Pancreatic and biliary tumors

Pancreatic and biliary tree tumors may present with acute or chronic pancreatitis due to obstruction of the pancreatic duct.

ERCP and EUS have applications in the diagnosis and management of ampullary tumors and intraductal papillary mucinous tumors of the pancreas. ERCP can help with visualization and biopsy sample collection from tumors involving the ampulla and periampullary region. EUS also can be utilized in evaluation of pancreatic and biliary tree masses causing pancreatitis and ultrasound-guided sample collection. Curative or palliative interventions such as endoscopic snare ampullectomy or ablative therapy can also be performed endoscopically. Recurrent pancreatitis for example in intraductal papillary mucinous tumors can be minimized by sphincterotomy with stenting.

7. Pancreatic duct leaks and pancreatic fluid collections

Pancreatic duct disruptions occur in both acute and chronic pancreatitis and in some cases in case of pancreatic trauma. Pancreatic duct leaks can complicate acute pancreatitis as a result of ductal epithelial disruptions by the inflammatory process and in chronic pancreatitis, as a result of ductal obstruction from inflammatory strictures and intraductal stones [24]. Pancreatic duct leaks may have variable presentations such as pancreatic fluid collections e.g. pseudocysts, pancreatic ascites, external pancreatic fistulas, disconnected duct syndrome among others. Pancreatic fluid collections may also result as a complication of pancreatic necrosis.

Diagnosis may be made using cross-sectional imaging studies such as Computed Tomograpgy (CT), secretin-enhanced MRCP or ultrasonography. Due to the associated risk of causing or worsening pancreatitis, ERCP is not employed for primary diagnostic purposes but rather for therapeutic interventions. EUS-guided Fine Needle Aspiration can be used to obtain pancreatic pseudocyst fluid for analysis for amylase levels, carcino-embryonic antigen (CEA) and cytology to differentiate pseudocyst from cystic neoplasms [24].

Pancreatic duct leaks may be effectively managed by endoscopic trans-papillary pancreatic duct stenting with a stent that bridges the leak diverting pancreatic fluid drainage from the ductal disruption to the duodenum.

Pancreatic pseudocysts occur as complications of acute or chronic pancreatitis and are usually asymptomatic except in a few cases. Pseudocysts and other pancreatic fluid collections can be managed endoscopically with a success rate of 70–97% [23, 25] and complication rate of 5–19% with complications such as hemorrhage and recurrence [26].

Endoscopic transluminal or trans-papillary drainage options with or without ultrasound are effective in draining these cysts and are usually performed 4 to 6 weeks after the acute pancreatitis episode resolves [23, 24]. Pancreatic pseudocysts can be drained via endoscopically created cysto-gastrostomies or cysto-enterostomies with subsequent stent placement. EUS is helpful in identification and preventing trauma to blood vessels during the procedure and also in situations where there is no visible bulge from the cyst in the gastrointestinal lumen. Though less popular recently, pancreatic fluid collections can also be managed with transmural or trans-papillary placement of plastic stents [25].

8. Pancreatic strictures

Pancreatic strictures can be diagnosed radiologically by CT and MRI/MRCP with supplementation with Endoscopic Ultrasound, secretin-enhanced MRCP, pancreatic function tests especially in the early stages with limited structural changes [27]. ESGE recommends treating painful dominant main pancreatic duct (MPD) strictures with insertion of a single stent across the dominant MPD stricture for one uninterrupted year. Dominant pancreatic strictures are defined by presence of at least one of the following characteristics: upstream MPD dilatation ≥ 6 mm in diameter, prevention of contrast medium outflow alongside a 6-Fr catheter inserted upstream from the stricture, or abdominal pain during continuous infusion of a naso-pancreatic catheter inserted upstream from the stricture with 1 L saline for 12 – 24 hours. Pancreatic duct stents decompress the MPD and persistently dilate the stricture relieving pain and may improve the exocrine pancreatic function [14]. Numerous studies have demonstrated pain relief [28]. In a meta-analysis involving 1498 patients, 88% had immediate pain relief and 67% had long-term pain relief with endotherapy for pancreatic strictures with a 7.85% complication rate [29].

Multiple side-by-side stents and self-expandable metal stents (SEMSs) can be used for refractory strictures. Fully covered SEMSs have been demonstrated to offer better pain relief results over the uncovered and partially covered types, though further studies need to be conducted due to the associated potential complications [14]. Endoscopic ultrasonography can facilitate drainage of symptomatic MPD obstruction with failed trans-papillary approach with either the Rendezvous technique (puncturing the MPD through the gastric or duodenal wall and advancing a guidewire into the MPD to proceed with trans-papillary drainage) or through transmural drainage through a stent [14].

Malignancy should be ruled out before stent dilatation therapy.

9. Role of EUS and ERCP in the diagnosis of chronic pancreatitis

The diagnosis of chronic pancreatitis is based on altered pancreatic morphology and function. However, there is variation in the imaging findings using different modalities among patients with clinical features suggestive of chronic pancreatitis which sometimes delays diagnosis.

The American College of Gastroenterology (ACG) recommends cross-sectional imaging such as MRI or CT as first-line in the diagnosis of chronic pancreatitis in combination with careful history, physical examination, exposure risk, direct and/or indirect pancreatic function tests. These are preferred over ERCP and EUS due to the less invasiveness, objectivity, availability and cost differences. Endoscopic ultrasound can however be utilized if the findings from the cross-sectional imaging are in question. If EUS is inconclusive, secretin-enhanced magnetic resonance cholangiopancreatography (s-MRCP) or secretin- enhanced EUS are recommended [30]. A systematic review and meta-analysis on diagnostic performance of imaging modalities in chronic pancreatitis compared the sensitivity and specificity estimates of EUS, ERCP, MRI and CT, with no significant differences noted. Sensitivities for ERCP, EUS, MRI and CT reported were 82%; 95%CI: 76–87%), 81% (95%CI: 70–89%), 78% (95%CI: 69–85%), and 75% (95%CI: 66–83%), respectively and specificities, 94%; 95%CI: 87–98%), 90%; 95%CI: 82–95%), 96%; 95%CI: 90–98%) and 91%; 95% CI: 81–96%) respectively [31]. In the same study, abdominal ultrasonography was reported to have the lowest accuracy in diagnosing chronic pancreatitis. EUS can detect pancreatic parenchymal and ductal changes with high sensitivity and specificity producing high resolution ultrasonographic images due to the close proximity of the pancreas to the gastric and duodenal lumen.

A total of ten EUS criteria have been proposed by the International Working Group for Minimum Standard Terminology in Gastrointestinal Endoscopy for diagnosing chronic pancreatitis including five parenchymal criteria (hyperechoic foci, hyperechoic strands, parenchymal lobularity, cysts, calcifications) and five ductal criteria (pancreatic duct dilation, pancreatic duct irregularity, hyperechoic pancreatic duct walls, visible pancreatic side branches, intraductal calcifications) [32]. Diagnostic probability depends on the number of criteria observed, presence of two or less rules out chronic pancreatitis, presence of five or more criteria provides and definitive diagnosis, and presence of two to five criteria is indeterminate requiring pancreatic function tests. Some of the pancreatic changes seen during EUS have however been also associated with advanced age, smoking, obesity in the absence of chronic pancreatitis. EUS is operator dependant with poor inter-observer agreement which affects the reliability and standardization of EUS interpretation [33].

The Rosemont criteria was developed by a group of 32 experienced endosonographers in an attempt to harmonize and standardize the EUS based diagnosis of chronic pancreatitis. Ductal and parenchymal EUS findings are divided into major A, major B and minor criteria with different weight to different findings. Based on the number and character of positive EUS criteria, EUS evaluation is classified as “consistent with CP”, “suggestive of CP”, “indeterminate for CP”, or “normal” [34]. However, the Rosemont criteria does not improve the inter-observer agreement compared to the standard EUS criteria [34] (Tables 1 and 2).

Parenchyma	Duct
Hyperechoic foci with acoustic shadows (major A); body/tail	Stones in the duct (major A)
Honeycomb-like lobulation (major B); body/tail	Irregular duct (minor); body/tail
Lobulation without honeycombing (minor); body/tail	Dilated side ducts (minor); body/tail
Hyperechoic foci without acoustic shadows (minor); body/tail	Dilated main duct (minor); body/tail
Cysts (minor)	Hyperechoic contours on the main duct (minor); body/tail
Echo-dense septa (minor); body/tail

Table 1.

Rosemont criteria for endoscopic ultrasound diagnosis of chronic pancreatitis [34].

Assessment	Criteria
Consistent with CP	A. 1 major A + ≥ 3 minor; B. 1 major A + 1 major B; C. 2 major A
Suggestive of CP	A. 1 major A + < 3 minor; B. 1 major B + ≥ 3 minor; C. ≥ 5 minor
Indeterminate for CP	A. 3 to 4 minor, no major; B. Major B +/− < 3 minor
Normal	A. <3 minor, no major

Table 2.

Interpretation of the Rosemont criteria [34].

Diagnosis of early chronic pancreatitis presents a clinical challenge. EUS has been shown to detect some of the early features of chronic pancreatitis not detected by other imaging modalities [35]. ERCP remains a last-line diagnostic test and should be rarely used outside of therapeutic purposes.

Currently, histology is the gold standard for diagnosing early and late stages of chronic pancreatitis but not routinely done due to considerations of safety in obtaining samples from the pancreas. EUS is useful in obtaining pancreatic biopsies for histopathological diagnosis of chronic pancreatitis and other causative factors like pancreatic masses, autoimmune hepatitis. EUS-guided Fine Needle Aspiration (FNA) or Fine Needle Biospy (FNB) can be utilized to obtain biopsies for cytological and histological evaluation especially for cystic and mass lesions [36, 37, 38, 39].

10. ERCP complications

ERCP alone or with the different therapeutic interventions is associated with different complications including pancreatitis, hemorrhage, infections, perforation and cardiopulmonary events. Other miscellaneous complications such as ileus, pneumothorax, pneumomediastinum, portal venous air, stent migration, liver abscess, biliary or pancreatic duct fistulae among others have also been reported but are very rare [40]. Their severity can range from mild to severe requiring hospitalization and possible permanent disability or death [41].

Three well studied interventions have demonstrated effectiveness in reduction of post-ERCP pancreatitis. These include:

10.1 Guidewire cannulation

Cannulation of the bile duct and pancreatic duct using a guidewire inserted through a catheter has been shown to significantly reduce the incidence of post-ERCP pancreatitis when compared with the conventional contrast cannulation [42, 43, 44]. Guidewire cannulation reduces post-ERCP pancreatitis by avoiding hydrostatic injury to the pancreas that may occur contrast injection and by reducing the need for precut sphincterotomy.

10.2 Pancreatic duct stents

In a meta-analysis evaluating 4 randomized prospective trials by Andriulli et al. [45] pancreatic duct stent placement had a twofold reduction in the incidence of post-ERCP pancreatitis (24.1% vs. 12%; P = 0.009; odds ratio: 0.44, 95% confidence interval: 0.24–0.81). Pancreatic duct stent insertion is technically difficult and there is need for follow-up evalutation to ensure passage or removal and associated with potential pancreatic ductal injuries. Insertion failure rates ranging from 4 to 10% have been reported and a higher incidence of severe pancreatitis among patients with failed pancreatic duct stenting [45, 46, 47].

10.3 Rectal non-steroidal anti-inflammatory drugs (NSAIDs)

Several drugs have been investigated for pharmaco-prophylaxis of post-ERCP pancreatitis. Of all drugs investigated, rectal NSAIDs have proved to be most effective at preventing post-ERCP pancreatitis [48, 49, 50, 51, 52, 53, 54, 55, 56].

11. Therapeutic role of ERCP and EUS in chronic pancreatitis

Chronic pancreatitis is a long standing painful inflammatory condition leading to progressive and irreversible pancreatic parenchymal damage and if not treated may result in either exocrine, endocrine insufficiency or both. This condition can be debilitating and severely affect the quality of life of these patients since most of them are either in and out of hospital, are on pain relieving medications, some may need enzyme supplementation and those that ultimately develop diabetes mellitus will have to be on oral hypoglycemic medications or insulin injections for life. Chronic pancreatitis may lead to stricture formation at the ampullary region leading to upstream dilatation of both the CBD and main pancreatic duct [57].

This ampullary strictures can also lead to both choledocholithiasis and main pancreatic duct stone formation further worsening the patient’s symptoms. Other common complications of chronic pancreatitis include; pancreatic inflammatory space occupying lesions, pancreatic pseudocysts, walled of pancreatic necrosis can occur in either acute, subacute and rarely chronic pancreatitis. In cases where there is no known identifiable cause of chronic pancreatitis, empiric therapy is initiated targeting to pain, exocrine and endocrine pancreatic insufficiencies. Failure of empiric therapy will most likely lead to identifiable causes or complications of chronic pancreatitis like main pancreatic duct stones, dominant pancreatic duct stricture, pancreatic pseudocysts, walled of pancreatic necrosis and sometimes benign or malignant pancreatic neoplasms [58].

Pancreatic ductal stones can be spontaneously expelled. But when they persist ERCP + ES with or without stenting is done, the stones are extracted during ERCP and incase of failure of stone extraction by dormie baskets or stone extraction balloon catheters, mechanical or ESWL can be attempted. If the endotherapy options fail then open or laparoscopic surgical intervention is done.

Dominant pancreatic ductal strictures are managed based on the location and etiology, short strictures at the ampullar can be treated with either ERCP + ES with stenting or ampullectomy in case of small ampullary lesions causing ampullary strictures. Distal pancreatic ductal strictures will warrant endoscopically placing the stents across the stricture either via trans-papillary approach or a rendezvous approach. Failure in endotherapy will necessitate surgical intervention [59].

Pancreatic pseudocyst if asymptomatic and small are managed conservatively for at least 4 to 6 weeks. Large symptomatic pancreatic pseudocysts can be drained endoscopically during ERCP via the trans-papillary approach with stent insertion. They can also be drained via the trans-mural approach with the aid of endoscopic ultrasound guidance into the stomach, duodenum or proximal jejunum. EUS identifies the pseudocyst, maturity of the cyst wall, vascularity of the surrounding structures and helps in guided and safe creation of the cysto-gastrostomy or cysto-enterostomy with stent insertion. Endoscopic placement of the stent across the endoscopically created cysto-enterostomy ensures adequate pseudocysts drainage hence minimizing recurrence. Ultrasound guided percutaneous drainage can be done but increases the chances of a persistent pancreatico-cutaneous fistula formation. In case of failure of endoscopic drainage, open or laparoscopic surgical intervention can be done. Walled off pancreatic necrosis in the setting of chronic pancreatitis can be drained in the same way as pancreatic pseudocysts. The endoscope can be inserted into the cavity of the pancreatic necrosis cavity and the necrosectomy is done under direct vision after dilatation of the cysto-enterostomy. Stents are left across the cysto-enterostomy. Failure of endoscopic interventions may then warrant open or laparoscopic surgical intervention [60].

Endoscopic ultrasound in important in diagnosis of benign or malignant pancreatic neoplasms, sample can be taken for histological diagnosis and then a decision on the most appropriate management approach is chosen. Benign small asymptomatic pancreatic lesions less than 2 cm can be followed up with repeat EUS 3–6 months intervals. For symptomatic benign and malignant pancreatic lesions irrespective of the size will need endoscopic, laparoscopic or open resection with aim of obtaining clear resection margins post intervention. Small symptomatic lesions at the ampullar may undergo endoscopic ampullectomy but large lesions will necessitate surgical intervention [61].

12. Conclusion

ERCP and EUS are important in the management of both acute and chronic pancreatitis and its complications after failed empiric therapy. Endotherapy has the advantage of cosmesis, short hospital stay and decreased morbidity and mortality. Where endotherapy is unsuccessful or the cause of the pancreatitis is a large symptomatic malignant lesion, laparoscopic or surgical intervention will surfice.

Conflict of interest

None.