INTRODUCTION

After      the       first     description      of         diagnostic       ERCP  by McCune et al. in 1968,¹ it was not long before biliary sphincterotomy was developed. Initial description of the technique of biliary sphincterotomy came simultaneously in 1974 from Kawai in Japan,² and Classen in Germany.³ The general construction of the sphincterotome was a single lumen catheter with an electrocautery wire that could be “bowed” when put under tension via traction.

The development of multilumen catheters soon followed, which allowed for separate lumens for the cutting wire and either contrast injection or guidewire placement (Figure 1).  Further refinements     of the bowing sphincterotome included triple lumen catheters (which could allow contrast injection with a guidewire in the catheter at the same time),  variations in cutting wire length  and sphincterotome tip geometry, and pre-curved catheters. Specialty variations of sphincterotomes have included rotatable design, bipolar cautery, ultra-tapered tips, and the reverse-orientation “Billroth II sphincterotome”. The general structure of the endoscopic sphincterotome has been remarkably stable for the past 20 years, and it is truly impressive that this rather straightforward and inexpensive device remains the workhorse of the advanced endoscopist’s toolbox when performing ERCP.

In the past, the term “papillotomy” was often used, although is rarely used anymore in favor of the term “sphincterotomy.”

Use of Abbreviations in this Article

For the sake of brevity and clarity, the following abbreviations will be used to describe the different variations of sphincterotomy:

ES  endoscopic sphincterotomy

bES  biliary sphincterotomy

mbES  minimal biliary sphincterotomy

pES  pancreatic sphincterotomy

mpES  minor papilla sphincterotomy

NKS  needle knife sphincterotomy

NKF needle knife fistulotomy

Indications for Endoscopic Biliary Sphincterotomy (bES)

The decision to perform bES is dependent on several factors including indication for the procedure, concomitant use of anti-coagulant or anti-platelet medications,  the presence or absence of         significant coagulopathy, and anatomical considerations such bile duct, and anatomical considerations. A longer sphincterotomy may be needed for removal of large biliary stones as opposed to a shorter length for placing a stent to palliate a biliary stricture or to facilitate device access into the bile duct.⁷

The most common indication for bES is for the management of choledocholithiasis.⁸ When anatomically feasible, a longer sphincterotomy is performed for management of larger common bile duct stones.⁹ However, bES in conjunction with papillary balloon dilation can obviate the need for a long sphincterotomy for removal of large bile duct stones.¹⁰ Management of iatrogenic or traumatic bile leaks is a common indication for ERCP.¹¹ Performing bES decreases the trans-papillary pressure gradient and facilitates preferential drainage of bile into the duodenum.^11,12 Functional biliary sphincter disorder, formerly referred to as sphincter of Oddi dysfunction (SOD), is another  indication for bES, although endoscopic management strategies for this set of as altered surgical anatomy or an intra-diverticular papilla.^4,5,6 The length of the sphincterotomy is tailored for the procedural indication, size of the conditions remain controversial, and many centers have abandoned the entire concept of SOD.13,14 According to the Rome IV criteria, patients with a dilated common bile duct and elevated liver  function          tests     (formerly        SOD    type     1)         should            undergo ERCP with bES. Other indications for bES are papillary stenosis, a type 3 choledochal cyst          (choledochocele),       sump   syndrome,       biliary            parasitic infections, and to facilitate access for biliary interventions, most importantly biliary stent placement.¹⁵

Contraindications for Endoscopic Biliary Sphincterotomy

An uncooperative patient is a contraindication for ERCP and bES. bES is classified as a          procedure with an elevated risk of bleeding according to the American Society for Gastrointestinal Endoscopy (ASGE) guidelines.¹⁶ However, minimal EBS (mbES) with papillary dilation  has been shown  to be safe in the setting of anti-platelet or anticoagulant use, although the indications for mbES are relatively uncommon.¹⁷ Although hepatic cirrhosis has been associated with higher rates of sphincterotomy bleeding,²⁶ this is not strictly considered an contraindication for bES. Altered patient anatomy such as a duodenal diverticulum or Billroth II gastrojejunostomy can increase the difficulty    of            bES,    however          the       procedure        can      be        safely performed in this setting.^7,15

Technique of Biliary Sphincterotomy (bES) Device selection

For cannulation of native papillae, most endoscopists favor the use of a bowing sphincterotome over a straight biliary catheter because the ability to bow the tip of the device can help achieve the proper angle for cannulation, and bES can be performed without the need for device exchange. Earlier sphincterotome designs had cutting wire lengths from 15mm to 40mm, and “nose length,” also referred to as “tip length,” up to 3-4cm. Most current sphincterotomes have short tips. Current models of bowing sphincterotomes have cutting wire lengths of 20, 25, or 30mm, and selection between these lengths is mainly user preference. Shorter cutting wires can be bowed with less of the tip of the device extended beyond the working channel, while longer cutting wires generate a more severe deformation of the sphincterotome during the act of bowing. Sphincterotomes can be “long wire” or “short wire” platforms, with the latter allowing physician-controlled guidewire manipulation for cannulation which has been found to be advantageous.¹⁸

Needle       knife    sphincterotomy           (NKS) was      first     described        in            1986    by        Huibrigtse       et         al.¹⁹  Historically, this was a rarely used technique, but it has gained more importance and adoption over the last several years. A needle-knife sphincterotome is a double or triple lumen catheter with a thin electrocautery needle at the tip that can be extended and withdrawn. It is mainly used in cases of difficult biliary cannulation after standard attempts at achieving duct access have failed.

Billroth-II anatomy is less frequently encountered anymore as surgical management of peptic ulcer disease has declined since introduction of potent antisecretory medications. Still, patients with Billroth-II anatomy are still encountered and a knowledge and understanding of how to perform biliary sphincterotomy in these patients is important. A dedicated Billroth-II sphincterotome is still available from Cook Medical (Bloomington,IN) but most modern endoscopists favor the use of a rotatable sphincterotome (Autotome, Boston Scientific, Marlborough, MA). Another effective technique in Billroth-II anatomy is to perform NKS over a previously placed biliary stent.

Landmarks for Biliary Sphincterotomy (bES) What direction?

The direction of cut of the biliary sphincterotomy is along the long axis of the intraduodenal mound. This long axis is generally called the “12 o’clock direction”, invoking the directions of a clock      face     (Figure 2A       and      2B).     It          is acceptable       for the sphincterotomy incision to be carried out anywhere from an 11 o’clock to a 1 o’clock direction, although most avoid cutting in the 1 o’clock position if possible. Sphincterotomy outside of that “wedge” may carry an increased risk of pancreatitis, perforation, and/or bleeding.

How long?

Above  the orifice of the ampulla of Vater,  the distal common bile duct (CBD) is intraduodenal. This intraduodenal portion creates a “mound” of varying size in different patients. Sometimes the mound is quite prominent, or even bulging (Figure 3A).        This     can      occur   when   a stone   is         impacted at the papillary orifice or when there is diffuse dilation of the entire   common bile duct     (CBD). In some cases, an ampullary tumor can show a large ampullary bulge   (Figure 3B).     A         chledochocele (type    III        choledochal    cyst)    is another cause   for       a          bulging            ampulla           (Figure 3D).     In many   cases,  the mound is small. As a general rule, the extent of the biliary sphincterotomy can be taken to the entire length of the mound. Caution should be taken with very small papillae, as the mound is small and the length of cut necessarily needs to be shorter. Caution also should be exercised with sphincterotomy of ampullae that are on the edge     of         or         in         a          diverticulum   (Figure 4A       and 4B)      since the risk of perforation and bleeding is felt to be higher.²⁰ In cases such as these, consideration should be given for limited sphincterotomy or even mbES, followed by balloon sphincteroplasty, but most patients with a periampullary diverticulum can undergo a complete biliary sphincterotomy.¹⁷

Cautery settings

For most of the early years of bES, “blended” (cutting         and      coagulation) current was      used     through           the sphincterotome wire to create the cut. Care had to be taken to avoid cutting too fast (the dreaded “zipper           cut”),   which could   introduce         complications of bleeding or perforation. The introduction of a pulse cut mode in 1997 (EndoCut, ERBE, Tübingen, Germany)      was      almost revolutionary  for       the       field,   as “pulse cut” energy gradually took over as the preferred energy mode for biliary sphincterotomy. Modern endoscopic generators allow cutting and coagulating current to be used in an alternating manner during endoscopic sphincterotomy.

Troubleshooting

A common challenge is for the cutting wire to not be in the ideal 12 o’clock position prior to initiating the sphincterotomy. Generally, it is acceptable for the wire to be in the range of 11 o’clock to 1 o’clock, and to cut with the “side of the wire” to complete the sphincterotomy. However, if the orientation is still not adequate, sometimes the distal 3cm of the sphincterotome needs to be “groomed” to achieve the ideal direction. In the days before all sphincterotomes were “pre-curved” at the factory, endoscopists routinely groomed the tip of the sphincterotome.²¹ The other approach to improving sphincterotome wire orientation prior to cutting is to transition the endoscope from “short” to “long” position (Figure 5).    In         the            short    position,          the       endoscope       is         aligned along the lesser curvature of the stomach, in the long position the endoscope is aligned along the greater curvature of the stomach. Adjusting the endoscope position to the long position will typically correct an unacceptably rightward orientation and bring the cutting wire more into a more leftward, and hence safer, direction. If continued attempts at orienting the ampullary mound fail, one can also do a minimal biliary sphincterotomy followed by balloon sphincteroplasty.

Technique of Minimal Biliary

In some cases, one cannot make as long as a sphincterotomy as one would like. Anatomic causes of this situation include periampullary diverticulum, obscured ampullary landmarks, Billroth-II anatomy, or an extremely small papilla. Impaired coagulation causes include the patient actively taking anti-coagulants or anti-platelet agents which cannot be stopped, chronic renal failure, and hepatic cirrhosis with elevated INR not responsive to vitamin K replacement and/or thrombocytopenia. In these situations, mbES can be performed followed by balloon sphincteroplasty (Figure 6A, B, C,        D).       mbES  plus     balloon            sphincteroplasty         has an excellent safety record in regard to postprocedural bleeding, and still allows biliary therapy to be performed with a high degree of success. The mbES  is         quite            short    (about  2-3mm),          and      the       incision           very intentionally is not taken to its maximum. Dilation of         the       papillary         orifice is            accomplished  with a biliary balloon, the size of which is chosen to match the size of the distal CBD. An 8 or 10mm dilation balloon is most commonly used for biliary sphincteroplasty. The balloon is positioned across the           papillary            orifice and      2-3       mL      of         contrast           is         first     injected            into      the       balloon            to         facilitate         fluoroscopic            visualization.  Then    the       balloon            is         inflated           with            water to target diameter and held for 1-3 minutes, with longer dilation times favored for higher stone burden or larger diameter stones. The risk of a rare indication for pES. According to the Rome IV      criteria,           P-SOD can            be        defined            as         documented    episodes of recurrent acute pancreatitis, abnormal sphincter manometry study, and exclusion of other causes postbES bleeding is greatly lowered with the mbES technique.

Pancreatic Sphincterotomy Indications 

pES can be performed on both the major and minor papilla, depending on the indication for the procedure and ductal anatomy.²² Functional pancreatic    sphincter  of  Oddi disorder  (P-SOD)  is of pancreatitis such as alcohol, gallstones, medications, or metabolic derangements.¹⁴ There is a paucity of high-quality data regarding the efficacy  of pES for  P-SOD. A systematic review in 2006 revealed a

69% sustained symptomatic improvement from pES based on 5 non-randomized studies with 109 patients.²³ Prospective studies have shown an almost 50% recurrence rate of acute pancreatitis, despite undergoing pES in the setting of P-SOD.²⁴ Again, the entire concept of SOD is highly controversial and many centers have abandoned this notion.

A primary indication for pES is in the endoscopic management of chronic pancreatitis. Commonly, pES is utilized in conjunction with other endoscopic modalities such as pancreatic stricture dilation, balloon extraction of pancreatic stones, pancreatoscopy           and      pancreatic       duct     (PD)    stent placement to facilitate drainage and stricture remodeling.²⁵ All of these are widely accepted indications for pES.

Pancreas divisum is a congenital condition resulting from an embryologic failure of fusion of the dorsal and ventral aspects of the pancreas. Acquired pancreas divisum can be seen in some cases of pancreatic duct obstruction in the head of the pancreas.^27,28 In both situations, the majority of pancreatic drainage is via the pancreatic duct of Santorini and thence through the minor papilla.²⁹ Pancreatic ductal obstruction in conjunction with minor papillary stenosis has been implicated in recurrent acute pancreatitis, chronic pancreatitis, and chronic pancreatic-type pain syndrome.³⁰ Endoscopic mpES has been utilized for the management of pancreas divisum. An early study by           Lehman           et         al.        showed            a          significant benefit from    mpES in patients with recurrent acute pancreatitis in distinction to those with chronic pancreatitis or chronic pain.³¹ However, a 2012 literature review showed a widely variable range of symptomatic improvement after mpES, ranging from 58-92%.³² Contraindications to pancreatic sphincterotomy are similar to bES including uncontrolled coagulopathy or patient instability. Given the heightened risk of pancreatitis related to pES and mpES, these procedures should be performed by interventional endoscopists   with     a          significant       level    of training in pancreatic endoscopic therapy.

Major Papilla Pancreatic Sphincterotomy

The direction of pancreatic sphincterotomy at the major papilla is generally in the 12 to 1 o’clock direction. The length of the incision is different from biliary sphincterotomy because the PD dives deep into the retroperitoneal space as opposed to the case of the distal bile duct which has an intraduodenal segment prior to entering the retroperitoneal space.

Some         ERCP  specialists       find     it          easier  to         do        a pancreatic sphincterotomy after a previous biliary sphincterotomy, since the septum is exposed, and a more precise view of the pancreatic sphincter is available   (FIG    7A and      B).       The      septum is         incised a          few millimeters and the results examined.

One approach to pES is to cut a few millimeters, then push in the sphincterotome 1-2cm, halfbow the cutting wire, and then draw out the half-bowed sphincterotome. This is called the “sizing maneuver”. If a bowed sphincterotome can be pulled out with little resistance, then this can be considered as an adequate pancreatic sphincterotomy. If there is still resistance to pulling through a bowed sphincterotome, then the pES can be taken another 1-2mm, and the sizing maneuver repeated as needed. Excessive deep cutting of the PD sphincter may result in duodenal perforation.

Previous bES is not a requirement for doing pES, however. A pES can be performed with an intact biliary sphincter. The direction of the cut is 12 to 1 o’clock, and the sizing maneuver described above can be performed to estimate adequacy of the pES.

Another method of performing pES is needle knife incision over a previously placed pancreatic stent. In this technique, a needle knife incision is performed along the course of a PD stent. The procedure is somewhat easier after previous bES. The pancreatic sphincter can be visualized and cut with the needle knife. For pES over a PD stent, the sizing maneuver is not performed (since a bowingtype         sphincterotome  is not  employed).

Minor Papilla Pancreatic Sphincterotomy (mpES)

Minor papilla pancreatic sphincterotomy (mpES)  is performed in cases of pancreas divisum anatomy with recurrent acute pancreatitis, and on occasion for pancreatic endotherapy in non-divisum anatomy, but with a completed obstructed main PD of the duct of Wirsung (“acquired pancreas divisum”).²⁸    Like     pES     at         the       major  papilla, mpES can be performed with either a bowing sphincterotome, or with a needle knife over a previously placed PD stent. Also similar to pES at the major papilla, stepwise incisions are performed with a bowing sphincterotome, or a needle knife over a previously placed PD stent. The sizing maneuver is also possible at the minor papilla if the bowing sphincterotome is used. In some cases of divisum, particularly in acquired    divisum,          the       orifice of         the       minor  papilla may be quite stenotic, and although a guidewire can be advanced into the dorsal PD, a sphincterotome cannot           be        advanced         through           the       tight            orifice, making            correct placement of the cutting wire impossible. In these rare cases, a needle-knife sphincterotomy can be performed using the guidewire as a guide. This can open the sphincter enough to eventually get either a bowing sphincterotome into position, or to place a 4 or 5 French pancreatic stent, over which a needle knife mpES can be performed.

Transpancreatic Biliary Sphincterotomy for Biliary Access

A technique has been described by Goff describing biliary access after performing a limited pancreatic sphincterotomy.³³ This technique may be applied if there is difficulty obtaining selective access  to the bile duct. In this situation, the guidewire has been deeply inserted into the main pancreatic duct, and the bowing sphincterotome is used to make a somewhat pancreatic sphincterotomy while pulling the sphincterotome in a biliary direction i.e. towards 11 o’clock. This often will open the distal bile duct, which can then be cannulated with the      assistance        of a          floppy wire.    The endoscopist     may elect to place a temporary pancreatic stent (for example, 4 French x 11cm)  after    this      access maneuver, but this is not universally performed.

Needle Knife Biliary Sphincterotomy (NKS) and Needle Knife Fistulotomy (NKF)

Needle knife biliary sphincterotomy is an essential tool for all ERCP specialists. The ability to perform the NKS technique can greatly increase the rate of successful deep biliary cannulation in patients who have failed prior cannulation attempts with standard techniques. NKS is typically used in cases of failed biliary deep cannulation, although it may be used as a primary technique in ampullae that contain an impacted stone, or when the papillary orifice is pointing   in an unfavorable direction.  There is a related technique, called needle knife fistulotomy     (NKF), in  which  the  initial  site  of  cutting is  above, rather  than  at,  the  papillary orifice (Figure 8). Some   practitioners   favor   NKF    over     NKS because of a belief that this can lower the incidence of post-ERCP      pancreatitis (PEP). Emerging        data     suggests that NKS or NKF-associated PEP may be more related to previous unsuccessful cannulation attempts rather than the NKS itself. The authors prefer NKS in most situations, reserving NKF in cases of very bulging ampullae or in situations where  the papillary orifice is not easily  found   or standard tools cannot be properly oriented.

The technique of NKS and NKF is the same, differing only in the initial site of initiation of the incision. For both techniques, a long mucosal incision is carried out in the same direction as a standard wire guided sphincterotome performed with a bowing sphincterotome. The cut is taken in the 11-12 o’clock direction until most of the mucosa overlying the intraduodenal mound is incised. In some cases of a very bulging ampulla, the initial incision may gain access to the bile duct, and this event is heralded by a large discharge of bile. More commonly, however, the technique of NKS is a two-step process: initial mucosal incision followed      by        identification  and      cutting into      the exposed intraduodenal bile duct (the “Huibregtse technique”).

The initial mucosal incision should be long enough to expose the underlying biliary structures in the intraduodenal segment. After the initial mucosal incision is made, the edges of the cut can be seen to retract laterally, exposing the inner structures. We have found that success is more predictably achieved by taking a “visual approach” to identifying the bile duct after adequate initial mucosal incision. The needle knife device is used to make a vertical incision into a tubular structure that might be found. This tubular structure typically is white or tan in colon with a “matte” rather      than glossy  surface (Figure 9).        In         cases   of         non-dilated distal bile ducts (for example, with malignant        biliary obstruction),   the       intraduodenal  bile duct is quite narrow, and visualization may be challenging. Making stepwise vertical incisions followed by gentle probing with the guidewire in the presumed biliary direction will often allow biliary access. If not, repeating some more short vertical incisions followed by more gentle probing with the guidewire is the next step. In some cases, despite repeated incisions and probing, deep biliary cannulation cannot be achieved. In such cases, it may be reasonable to stop cannulation attempts, and bring the patient back on a different day for a repeat attempt at biliary access. At the time of repeat   ERCP, the biliary orifice is         often    obvious,          and cannulation is achieved promptly. If the biliary endoscopist is comfortable with NKS, it is important to not over-persist with regular cannulation attempts before changing to NKS. One reason for this is that persistence can increase the risk of PEP. Another reason is that persistent cannulation attempts prior to NKS can actually decrease the success rate of subsequent successful NKS. This appears to be due to tissue edema or even inadvertent submucosal injections which obscures the submucosal structures after initial incision.

NKS can be performed as a “freehand” procedure or can be performed following placement of a pancreatic duct stent. Both techniques are reasonable and in experienced hands, safe.

Adverse Events Related to Endoscopic Sphincterotomy

It is paramount for an endoscopist performing ERCP to be familiar with adverse events associated with NKS, to take necessary preventative steps, and to promptly recognize and manage any adverse events that do arise.³⁴ Post-sphincterotomy hemorrhage (PSH) occurs at a rate of 1-48%.³⁵ PSH     is            defined according to timing and severity.  Immediate PSH occurs during the index ERCP, while delayed PSH can occur hours to days later.^5,35 Cotton et al. described mild PSH as clinical evidence of bleeding with less than  3  gm/dL drop in  hemoglobin without need for transfusion, moderate PSH as requiring less than 4 units of packed red blood cells without need for angiography or surgery, and severe PSH as requiring 5 units or more of packed red blood cells or the need for angiographic or surgical intervention.^5,35 In practice, however, any PSH that requires blood transfusion is considered to be           significant. Freeman et al.’s landmark study⁸ found that definite risk factors for PSH     are       pre-procedural coagulopathy, use of anti-coagulants within 3 days of performing ES, ascending cholangitis as an indication for ERCP, immediate bleeding during initial ES, and low endoscopic case volumes on the part of the sphincterotomy. The tissue effect that one is looking      for       (aside  from            cessation         of         bleeding)         is         creation of a submucosal “bleb” with injection. Use of a metal sheath injection needle (CarrLocke   injection            needle, Steris,  Mentor OH)     is         advantageous as there is less likelihood that the needle sheath will deform or “kink” as compared with plastic sheathed needles.

Thermal therapy to treat bleeding with bipolar cautery, monopolar cautery, argon plasma coagulation, and hemostatic clips have been used for control of PSH.^35,38 However, manipulation of clips or stiff hemostasis probes can be quite challenging through a duodenoscope. More recently, placement of fully covered self-expanding metal stents has been shown to treat PSH by creating a tamponade effect on the sphincterotomy site. Stent placement is highly  efficacious as both a primary modality for PSH or as a rescue therapy when other therapies fail.39,40 A feared complication of ES is perforation, the incidence of which is approximately 1% based on older data, but is probably much less in the current era.⁴¹        A classification  of ERCP-related  perforations was proposed by Stapfer et al.⁴² Type I injury is duodenal wall trauma from the duodenoscope and is typically located on the duodenal wall

opposite to the ampulla. Type II injury is a periampullary perforation related to ES and is the most common type ranging from 15-68% of cases.⁴³ Type III injuries are ductal in location and related to instrumentation such as wire perforation. Type IV injury represents retroperitoneal air alone.

Patient-related factors for sphincterotomy perforation    are       biliary sphincter disorder           (SOD) and      a dilated common bile duct. Procedural related risk factors are performing a pre-cut sphincterotomy and longer sphincterotomy length.⁴⁴ Retroperitoneal perforations can be graded based on the consensus definition        by Cotton et         al.:       mild    is         low      volume            leakage of contrast with medical treatment less than 3 days, moderate is with medical treatment 4-10 days, and severe is medical treatment lasting longer than 10 days with possible percutaneous or surgical intervention.⁵ In common practice, the Cotton classification  is no longer  used.               

Prompt recognition of a perforation is of utmost importance to minimize leakage of enteral contents into the retroperitoneal space. The use of carbon dioxide   insufflation is         essential          when   performing      ERCP  (Figure 10)       as         this      has been    shown  to         be        associated with less pain, abdominal distention, and adverse events.^45,46 Medical management of a perforation includes supportive care, bowel rest, and intravenous antibiotics.⁴⁷ There is limited evidence for the use of endoscopic clips for the closure of sphincterotomy related perforations.^48,49 When a peri-ampullary perforation is recognized, immediate diversion of biliary contents should be initiated by placing a biliary stent, or on rare occasions a nasobiliary drain.⁵⁰ Surgical management is required when patients do not respond to medical and endoscopic modalities or when the presentation is delayed and there is  significant retroperitoneal contamination.⁵⁰ Fortunately, surgery is rarely required in these situations. Post-ERCP  pancreatitis (PEP)^51,52 has been associated with biliary and pancreatic sphincterotomy. The likelihood of developing PEP is related to a combination of operator, patient, and procedural related factors and the contribution of sphincterotomy itself is unclear. For example, although NKS has been implicated in the development of PEP, this may be due to the delayed use of this technique resulting in multiple failed cannulation attempts rather than the NKS itself.⁵³ In a systematic review and meta-analysis of randomized controlled trials, early pre-cut NKS did not increase the risk for pancreatitis.⁵⁴ The management of acute post-ERCP pancreatitis is comparable with other etiologies of acute pancreatitis.

Other reported complications of endoscopic biliary sphincterotomy are ascending cholangitis and delayed papillary stenosis.^8,55 Papillary stenosis of   the       biliary orifice after    ES       can      result   in         biliary symptoms and choledocholithiasis.⁵⁶ There do not    appear to         be        any      significant long-term        biliary problems, including the development of biliary malignancy, in patients that have undergone biliary sphincterotomy, even more than 25 years later. Patients who have undergone biliary sphincterotomy and have intact gallbladders are at risk for later acute cholecystitis, probably due to bacterial access to the gallbladder, but only if gallbladder stones are present. The            complication   rate      specifically     for       pES     is            approximately 10%.⁵⁷ Recurrent acute pancreatitis may be a complication related to post-ES pancreatic papillary stenosis.²⁵

Training and Competency in Endoscopic Sphincterotomy

Competency in bES requires formal training and an adequate number of supervised procedures. Most gastroenterology trainees will not attain this level of competency during their general gastroenterology fellowship and an additional year of advanced endoscopic training is optimal.⁵⁸ The minimum number of procedures for independent practice will vary depending on the exposure and individual skill of the trainee, however, there have been standards proposed by various endoscopy organizations.

As per the ASGE, a minimum of 200 proctored ERCP procedures and 80 biliary sphincterotomies should be performed prior to independent practice.⁵⁹ The European Society for Gastrointestinal Endoscopy and the UK Joint Advisory Group both suggest a minimum of 300 proctored ERCP examinations during training, however, neither group specifies the number of bES needed for independent practice.^60,61 Finally, the Canadian Association for Gastroenterology recommends a minimum of 200 supervised ERCP procedures with 80 biliary sphincterotomies performed in the training setting.⁶²

Despite the published standards for bES training, the true minimum number needed for competency remains unclear. A 2019 multi-center cohort study involving 32 advanced endoscopy programs in the United States reported that 120 bES are required for competency based on a standardized assessment tool.⁶³ However, a prior study by the same authors in 2016 revealed a broad range of case numbers needed to attain competency in basic ERCP skills. Furthermore, none of the trainees in this study were determined to be proficient in bES, thus contributing to the lack of clarity on training metrics for this subject.⁶⁴ Pre-cut needle-knife sphincterotomy (NKS), needle-knife fistulotomy (NKF), and trans-pancreatic sphincterotomy (TPS) are important skills for the “full service” ERCP specialist.65 Despite numerous studies assuring the safety and efficacy of these techniques, the learning curve is less well studied.65-67 For NKS, the reported learning curve has been widely variable, ranging from 13 to 100 cases for competence.68,69 Similarly, for NKF there is a wide reported range of cases from 20 to 100 prior to gaining mastery.70,71 For performance of pancreatic endotherapy, mastery of pES is an important skill for an ERCP specialist. However, there are no standardized guidelines regarding gaining competency for pES. Therefore, it is preferable for pES to be performed by endoscopists with specialized training in pancreatic endoscopic therapy.

CONCLUSION

ES is a vital tool for all interventional endoscopists who plan to perform ERCP with biliary and pancreatic interventions. One must be wellinformed on the accepted indications and adverse events related to this procedure. An advanced endoscopist must be skilled at treating complications related to ES. Furthermore, additional endoscopic training to perform ES should be pursued prior to independent practice, ideally in the setting of a formal advanced endoscopy training program. Additionally, one must understand when an ES in not technically feasible due to medical and anatomic considerations. 

The minimal sphincterotomy plus papillary balloon dilation technique is very important in cases when biliary sphincterotomy is necessary, but the patient has an uncorrectable coagulopathy, is concurrently using of anticoagulant or antiplatelet medications, or has anatomic constraints to full sphincterotomy. When traditional access to the bile or pancreatic ducts is not technically feasible, it is imperative that one is skilled in the use of pre-cut ES techniques such as NKS to help facilitate cannulation. Pancreatic sphincterotomy of the major or minor papilla is also an important technique but should be restricted to ERCP practitioners with special expertise in pancreatic endotherapy.

References

1. ^{McCune WS, Shorb PE, Moscovitz H. Endoscopic cannulation of the ampulla of Vater: a preliminary report. Ann Surg 1968;167:752–756.}
2. ^{Kawai K, Akasaka Y, Murakami K, Tada M, Koli Y. Endoscopic sphincterotomy of the ampulla of Vater. Gastrointest Endosc 1974;20:148–151.}
3. ^{Classen M, Demling L. Endoskopische Sphinkterotomie der Papilla Vateri und Steinextraktion aus dem Ductus choledochus. Dtsch Med Wochenschr 1974;99:496–497.}
4. ^{Adler DG, Baron TH, Davila RE, et al. ASGE guideline: the role of ERCP in diseases of the biliary tract and the pancreas.
   Gastrointest Endosc. 2005;62(1):1-8. doi:10.1016/j. gie.2005.04.015}
5. ^{Cotton PB, Lehman G, Vennes J, et al. Endoscopic sphincterotomy complications and their management: an attempt at consensus. Gastrointest Endosc. 1991;37(3):383393. doi:10.1016/s0016-5107(91)70740-2}
6. ^{Dumonceau JM, Kapral C, Aabakken L, et al. ERCPrelated adverse events: European Society of Gastrointestinal
   Endoscopy (ESGE) Guideline. Endoscopy. 2020;52(2):127-149. doi:10.1055/a-1075-4080}
7. ^{Köksal AŞ, Eminler AT, Parlak E. Biliary endoscopic sphincterotomy: Techniques and complications. World J Clin Cases. 2018;6(16):1073-1086. doi:10.12998/wjcc.v6.i16.1073}
8. ^{Freeman ML, Nelson DB, Sherman S, et al. Complications of endoscopic biliary sphincterotomy. N Engl J Med. 1996;335(13):909-918. doi:10.1056/ NEJM199609263351301}
9. ^{Ryozawa S, Itoi T, Katanuma A, et al. Japan Gastroenterological Endoscopy Society guidelines for endoscopic sphincterotomy. Dig Endosc. 2018;30(2):149-173. doi:10.1111/den.13001}
10. ^{Minami A, Hirose S, Nomoto T, Hayakawa S. Small sphincterotomy combined with papillary dilation with large balloon permits retrieval of large stones without mechanical lithotripsy. World J Gastroenterol. 2007;13(15):2179-2182. doi:10.3748/wjg.v13.i15.2179}
11. ^{Kaffes AJ, Hourigan L, Luca ND, Byth K, Williams SJ, Bourke MJ. Impact of endoscopic intervention in 100 patients with suspected postcholecystectomy bile leak. Gastrointest Endosc. 2005;61(2):269-275. doi:10.1016/S0016-5107(04)02468-X}
12. ^{Davids PH, Rauws EA, Tytgat GN, Huibregtse K. Postoperative bile leakage: endoscopic management. Gut. 1992;33(8):1118-1122. doi:10.1136/gut.33.8.1118}
13. ^{Cotton PB, Durkalski V, Romagnuolo J, et al. Effect of endoscopic sphincterotomy for suspected sphincter of Oddi dysfunction on pain-related disability following cholecystectomy: the EPISOD randomized clinical trial. JAMA. 2014;311(20):2101. doi:10.1001/jama.2014.5220}
14. ^{Cotton PB, Elta GH, Carter CR, Pasricha PJ, Corazziari ES. Rome IV. Gallbladder and sphincter of Oddi disorders.
    Gastroenterology. 2016;150:1420-1429. doi:10.1053/j.gastro.2016.02.033}
15. ^{Dayyeh BKA, Baron TH. Endoscopic sphincterotomy: Indications, techniques, and adverse events. Tech Innov Gastrointest Endosc. 2019;0(0). doi:10.1016/j.tgie.2012.04.001}
16. ^{Acosta RD, Abraham NS, Chandrasekhara V, et al. The management of antithrombotic agents for patients undergoing GI endoscopy. Gastrointest Endosc. 2016;83(1):3-16. doi:10.1016/j.gie.2015.09.035}
17. ^{Mok SRS, Arif M, Diehl DL, Khara HS, Ho HC, Elfant AB. Safety and efficacy of minimal biliary sphincterotomy with papillary balloon dilation (m-EBS+EPBD) in patients using clopidogrel or anticoagulation. Endosc Int Open. 2017;5(3):E157-E164. doi:10.1055/s-0042-120225}
18. ^{Srinivasan I, Freeman ML. Guidewire trauma: a key component of post-ERCP pancreatitis that is best controlled by the endoscopist. Am J Gastro. 2016 1;111:1848-50.}
19. ^{Huibregtse K, Katon RM, Tytgat GN. Precut papillotomy via fine-needle knife papillotome: a safe and effective technique. Gastrointest Endosc. 1986 Dec 1;32(6):403-5.}
20. ^{Mu P, Yue P, Li F, Lin Y, Liu Y, Meng W, Zhou W, Li X. Does periampullary diverticulum affect ERCP cannulation and post-procedure complications? An up-to-date metaanalysis. The Turk J Gastro. 2020 Mar;31(3):193.}
21. ^{Seibert DG, Matulis SR. Consistent improvement in sphincterotome orientation with manual grooming. Gastrointest Endosc. 1995;42(4):325-9.}
22. ^{Sherman S, Lehman GA. Endoscopic pancreatic sphincterotomy: techniques and complications. Gastrointest Endosc Clin N Am. 1998;8(1):115-124.}
23. ^{Sgouros SN, Pereira SP. Systematic review: sphincter of Oddi dysfunction – non-invasive diagnostic methods and long-term outcome after endoscopic sphincterotomy – Aliment Pharm and Therap. 2006;24:237-246}
24. ^{Coté GA, Imperiale TF, Schmidt SE, et al. Similar efficacies of biliary, with or without pancreatic, sphincterotomy in treatment of idiopathic recurrent acute pancreatitis. Gastroenterology. 2012;143(6):1502-1509.e1. doi:10.1053/j. gastro.2012.09.006}
25. ^{Buscaglia JM. Pancreatic sphincterotomy: Technique, indications, and complications. World J Gastroenterol. 2007;13(30):4064. doi:10.3748/wjg.v13.i30.4064}
26. ^{Mashiana HS, Dhaliwal AS, Sayles H, et al. Endoscopic retrograde cholangiopancreatography in cirrhosis – a systematic review and meta-analysis focused on adverse events. World J Gastrointest Endosc. 2018;10(11):354-366. doi:10.4253/wjge.v10.i11.354}
27. ^{Cotton PB. Congenital anomaly of pancreas divisum as cause of obstructive pain and pancreatitis. Gut. 1980;21(2):105-doi:10.1136/gut.21.2.105}
28. ^{Warshaw AL, Cambria RP. False pancreas divisum. Acquired pancreatic duct obstruction simulating the congenital anomaly. Ann Surg. 1984;200(5):595-599. doi:10.1097/00000658-198411000-00007}
29. ^{Michailidis L, Aslam B, Grigorian A, Mardini H. The efficacy of endoscopic therapy for pancreas divisum: a meta-analysis. Ann Gastroenterol. 2017;30(5):550-558. doi:10.20524/aog.2017.0159}
30. ^{M Delhaye CM, re. Pancreatic ductal system obstruction and acute recurrent pancreatitis. World J Gastroenterol. 2008;14(7):1027-1033. doi:10.3748/wjg.14.1027}
31. ^{Lehman GA, Sherman S, Nisi R, Hawes RH. Pancreas divisum: results of minor papilla sphincterotomy. Gastrointest Endosc. 1993;39(1):1-8. doi:10.1016/s0016-5107(93)70001-2}
32. ^{Fujimori N, Igarashi H, Asou A, et al. Endoscopic approach through the minor papilla for the management of pancreatic diseases. World J Gastrointest Endosc. 2013;5(3):81-88.}
33. ^{Goff JS. Long-term experience with the transpancreatic sphincter pre-cut approach to biliary sphincterotomy. Gastrointest Endosc. 1999 Nov 1;50(5):642-5.}
34. ^{Chandrasekhara V, Khashab MA, Muthusamy VR, et al. Adverse events associated with ERCP. Gastrointest Endosc. 2017;85(1):32-47. doi:10.1016/j.gie.2016.06.051}
35. ^{Ferreira LEVVC, Baron TH. Post-sphincterotomy bleeding: who, what, when, and how. Am J Gastro. 2007;102(12):28502858.}
36. ^{Wilcox CM, Canakis J, Mönkemüller KE, Bondora AW, Geels W. Patterns of bleeding after endoscopic sphincterotomy, the subsequent risk of bleeding, and the role of epinephrine injection. Am J Gastroenterol. 2004;99(2):244-248. doi:10.1111/j.1572-0241.2004.04058.x}
37. ^{Leung JWC, Chan FKL, Sung JJY, Chung SCS. Endoscopic sphincterotomy-induced hemorrhage: A study of risk factors and the role of epinephrine injection. Gastrointest Endosc. 1995;42(6):550-554. doi:10.1016/S0016-5107(95)70009-9}
38. ^{Baron TH, Norton ID, Herman L. Endoscopic hemoclip placement for post-sphincterotomy bleeding. Gastrointest Endosc. 2000;52(5):662.doi:10.1067/mge.2000.108621}
39. ^{Cochrane J, Schlepp G. Comparing endoscopic intervention against fully covered self-expanding metal stent placement for post-endoscopic sphincterotomy bleed (CEASE Study). Endosc Int Open. 2016;04(12):E1261-E1264. doi:10.1055/s-0042-118227}
40. ^{Canena J, Liberato M, Horta D, Romão C, Coutinho A. Short-term stenting using fully covered self-expandable metal stents for treatment of refractory biliary leaks, postsphincterotomy bleeding, and perforations. Surg Endosc. 2013;27(1):313-324. doi:10.1007/s00464-012-2368-3}
41. ^{Christensen M, Matzen P, Schulze S, Rosenberg J. Complications of ERCP: a prospective study. Gastrointest Endosc.2004;60(5):721-731. doi:10.1016/s0016-5107(04)02169-8}
42. ^{Stapfer M, Selby RR, Stain SC, et al. Management of duodenal perforation after endoscopic retrograde cholangiopancreatography and sphincterotomy. Ann Surg.
    2000;232(2):191-198. doi:10.1097/00000658-200008000-00007}
43. ^{Trikudanathan G, Hoversten P, Arain M, Attam R, Freeman M, Amateau S. The use of fully-covered selfexpanding metallic stents for intraprocedural management of post-sphincterotomy perforations: a single-center study (with video). Endosc Int Open. 2018;06(01):E73-E77. doi:10.1055/s-0043-121884}
44. ^{Enns R, Eloubeidi MA, Mergener K, et al. ERCP-related perforations: risk factors and management. Endoscopy. 2002;34(4):293-298. doi:10.1055/s-2002-23650}
45. ^{Bretthauer M, Seip B, Aasen S, Kordal M, Hoff G, Aabakken L. Carbon dioxide insufflation for more comfortable endoscopic retrograde cholangiopancreatography: a randomized, controlled, double-blind trial. Endoscopy. 2007;39(01):58-64. doi:10.1055/s-2006-945036}
46. ^{Lee JH, Kedia P, Stavropoulos SN, Carr-Locke D. AGA Clinical Practice Update on Endoscopic Management of Perforations in Gastrointestinal Tract: Expert Review. Clin Gastroenterol Hepatol. 2021;19(11):2252-2261.e2. doi:10.1016/j.cgh.2021.06.045}
47. ^{Kumbhari V, Sinha A, Reddy A, et al. Algorithm for the management of ERCP-related perforations. Gastrointest Endosc. 2016;83(5):934-943. doi:10.1016/j.gie.2015.09.039}
48. ^{Katsinelos P, Paroutoglou G, Papaziogas B, Beltsis A, Dimiropoulos S, Atmatzidis K. Treatment of a duodenal perforation secondary to an endoscopic sphincterotomy with clips. World J Gastroenterol. 2005;11(39):6232-6234. doi:10.3748/wjg.v11.i39.6232}
49. ^{Baron TH, Gostout CJ, Herman L. Hemoclip repair of a sphincterotomy-induced duodenal perforation. Gastrointest Endosc. 2000;52(4):566-568. doi:10.1016/S0016-5107(00)70032-0}
50. ^{Howard TJ, Tan T, Lehman GA, et al. Classification and management of perforations complicating endoscopic sphincterotomy. Surgery. 1999;126(4):658-665. doi:10.1016/ S0039-6060(99)70119-4}
51. ^{Cheng CL, Sherman S, Watkins JL, et al. Risk Factors for Post-ERCP Pancreatitis: A Prospective Multicenter Study. Am J Gastroenterol. 2006;101(1):139-147. doi:10.1111/ j.1572-0241.2006.00380.x}
52. ^{Chen JJ, Wang XM, Liu XQ, et al. Risk factors for postERCP pancreatitis: a systematic review of clinical trials with a large sample size in the past 10 years. Eur J Med Res. 2014;19(1):26. doi:10.1186/2047-783X-19-26}
53. ^{Bailey AA, Bourke MJ, Kaffes AJ, Byth K, Lee EY, Williams SJ. Needle-knife sphincterotomy: factors predicting its use and the relationship with post-ERCP pancreatitis (with video). Gastrointest Endosc. 2010;71(2):266-271. doi:10.1016/j.gie.2009.09.024}
54. ^{Sundaralingam P, Masson P, Bourke MJ. Early precut sphincterotomy does not increase risk during endoscopic retrograde cholangiopancreatography in patients with difficult biliary access: a meta-analysis of randomized controlled trials. Clin Gastroenterol Hepatol. 2015;13(10):1722-1729. e2. doi:10.1016/j.cgh.2015.06.035}
55. ^{Rösch W, Riemann JF, Lux G, Lindner HG. Long-term follow-up after endoscopic sphincterotomy. Endoscopy. 1981;13(04):152-153. doi:10.1055/s-2007-1021671}
56. ^{Prat F, Malak NA, Pelletier G, et al. Biliary symptoms and complications more than 8 years after endoscopic sphincterotomy for choledocholithiasis. Gastroenterology.
    1996;110(3):894-899. doi:10.1053/gast.1996.v110. pm8608900}
57. ^{Asbun HJ, Rossi RL, Heiss FW, Shea JA. Acute relapsing pancreatitis as a complication of papillary stenosis after endoscopic sphincterotomy. Gastroenterology.
    1 9 9 3 ; 1 0 4 ( 6 ) : 1 8 1 4 – 1 8 1 7 . d o i : 1 0 . 1 0 1 6 / 0 0 1 6 -5085(93)90663-w}
58. ^{Wani S, Keswani RN, Petersen B, et al. Training in EUS and ERCP: standardizing methods to assess competence.
    Gastrointest Endosc. 2018;87(6):1371-1382. doi:10.1016/j. gie.2018.02.009}
59. ^{Faulx AL, Lightdale JR, Acosta RD, et al. Guidelines for privileging, credentialing, and proctoring to perform GI endoscopy. Gastrointest Endosc. 2017;85(2):273-281. doi:10.1016/j.gie.2016.10.036}
60. ^{Johnson G, Webster G, Boškoski I, et al. Curriculum for ERCP and endoscopic ultrasound training in Europe: European Society of Gastrointestinal Endoscopy (ESGE) position statement. Endoscopy. 2021;53(10):1071-1087. doi:10.1055/a-1537-8999}
61. ^{Siau K, Keane MG, Steed H, et al. UK Joint Advisory Group consensus statements for training and certification in endoscopic retrograde cholangiopancreatography. Endosc Int Open. 2022;10(1):E37-E49. doi:10.1055/a-1629-7540}
62. ^{Springer J, Enns R, Romagnuolo J, Ponich T, Barkun AN, Armstrong D. Canadian credentialing guidelines for endoscopic retrograde cholangiopancreatography. Can J Gastroenterol J Can Gastroenterol. 2008;22(6):547-551. doi:10.1155/2008/582787}
63. ^{Wani S, Han S, Simon V, et al. Setting minimum standards for training in EUS and ERCP: results from a prospective multicenter study evaluating learning curves and competence among advanced endoscopy trainees. Gastrointest Endosc. 2019;89(6):1160-1168.e9. doi:10.1016/j.gie.2019.01.030}
64. ^{Wani S, Hall M, Wang AY, et al. Variation in learning curves and competence for ERCP among advanced endoscopy trainees by using cumulative sum analysis.
    Gastrointest Endosc. 2016;83(4):711-719.e11. doi:10.1016/j. gie.2015.10.022}
65. ^{Swan MP, Alexander S, Moss A, Williams SJ, Ruppin D, Hope R, Bourke MJ. Needle knife sphincterotomy does not increase the risk of pancreatitis in patients with difficult biliary cannulation. Clin Gastroenterol Hepatol. 2013;11(4):430-436.e1. doi:10.1016/j.cgh.2012.12.017}
66. ^{Pécsi D, Farkas N, Hegyi P, et al. Transpancreatic sphincterotomy has a higher cannulation success rate than needle-knife precut papillotomy – a meta-analysis. Endoscopy. 2017;49(9):874-887. doi:10.1055/s-0043-111717}
67. ^{Lim JU, Joo KR, Cha JM, et al. Early use of needle-knife fistulotomy is safe in situations where difficult biliary cannulation is expected. Dig Dis Sci. 2012;57(5):1384-1390. doi:10.1007/s10620-012-2030-x}
68. ^{Li JW, Ang TL, Kam JW, Kwek ABE, Teo EK. The learning curve for needle knife precut sphincterotomy revisited. United Eur Gastroenterol J. 2017;5(8):1116-1122. doi:10.1177/2050640617701808}
69. ^{Akaraviputh T, Lohsiriwat V, Swangsri J, Methasate A, Leelakusolvong S, Lertakayamanee N. The learning curve for safety and success of precut sphincterotomy for therapeutic ERCP: a single endoscopist’s experience. Endoscopy. 2008;40(6):513-516. doi:10.1055/s-2007-995652}
70. ^{Lopes L, Dinis-Ribeiro M, Rolanda C. Gaining competence in needle-knife fistulotomy – can I begin on my own? Endosc Int Open. 2016;04(04):E383-E388. doi:10.1055/s-0041-109399}
71. ^{Fernandes J, Canena J, Alexandrino G, et al. Outcomes of single-endoscopist-performed needle-knife fistulotomy for selective biliary access in 842 consecutive patients: learning curve and changes over a 14-year period in a retrospective study. Scand J Gastroenterol. 2021;56(11):1363-1370.doi:10.1080/00365521.2021.1958369}

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