PERSPECTIVES
Reflections on needle-knife papillotomy (with videos) John Baillie, MB, ChB, FASGE Morehead City, North Carolina, USA
Two generations of ERCP endoscopists have been indoctrinated into thinking that needle-knife papillotomy (NKP) is a dangerous procedure that should only be performed by experts. A report from Denmark looking at severe and fatal adverse events of ERCP resulting in litigation between 1992 and 1996 concluded that NKP “should still be regarded as a dangerous procedure.”1 Early published studies typically reported adverse event rates of NKP that were often double that of standard biliary sphincterotomy. A recent retrospective review of prospectively collected data on NKP continued to show a high postERCP pancreatitis (PEP) rate.2 However, in some expert hands, NKP apparently could be performed without excess morbidity from the beginning.3 In a recent study from Australia4 of 732 cases, 94 of which were deemed difficult, NKP increased the overall biliary cannulation rate to 97.7% at the cost of a 14.9% PEP rate. Statistical analysis revealed that the independent risk factor for PEP was not NKP, but rather the number of cannulation attempts, confirming what Freeman5 has been telling us for years: NKP used to finish the job gets blamed unfairly for PEP after the duodenal papilla is traumatized during failed cannulation attempts. Another confounding factor as one tries to follow the literature on NKP is the ever-changing ERCP landscape: when Vandervoort et al6 reported their study of adverse events of 1223 ERCPs in 2002, 45% were diagnostic and 55% were therapeutic. A 2006 prospective, multicenter study of risk factors for PEP included 48% diagnostic and 52% therapeutic cases, with an amazing 34% undergoing ERCP for suspected sphincter of Oddi dysfunction.7 Today, it is difficult to find a purely diagnostic indication for ERCP,
Reprint requests: John Baillie, MB, ChB, FASGE, Carteret Medical Group, PO Box 1648, Morehead City, NC 28557.
and the frequent use of sphincter of Oddi manometry is limited to a few academic centers, mainly in the United States. In the interests of full disclosure, I admit that in the past I, too, contributed to the “keep-out” literature on this subject.8 Until about 10 years ago, I did not offer third-year fellows learning ERCP the experience of NKP, and limited my teaching it to fourth year (advanced) fellows who showed particular aptitude for the procedure. Discussions with former trainees convinced me that we have limited training in NKP unfairly. As was recognized a long time ago,9 to be able to tackle the full spectrum of difficult-access cases and achieve a nearly 100% success rate, NKP is the sine qua non. Undoubtedly, many would-be NKP exponents have been intimidated over the years by the sight of experts performing unnecessarily large and aggressive needleknife incisions during live endoscopy courses, usually accompanied by the exhortation “don’t try this at home.” Such “heroic” NKPs are neither necessary nor desirable in everyday practice. Rather than discourage the use of NKP, we should show ERCP trainees how to use the technique selectively to increase their success rates for biliary and pancreatic access. This requires an understanding of the anatomy and the risks involved. For the purposes of this discussion, when I use the term NKP, I mean the free-hand technique using a needle-knife papillotome, which is essentially a bare wire advanced from the tip of a plastic sheath (Fig. 1). Unlike a standard sphincterotomy, NKP is a relatively uncontrolled technique that lacks the protections afforded by unidirectional cutting wire travel and orientation to the axis of the duct (Video 1, available online at www.giejournal.org). It is amazing to me that needle-knife papillotome design has remained virtually unchanged since its inception decades ago. Despite a lock on the device intended to fix the length of exposed wire, all NKP exponents are familiar with the frustrations of the “disappearing” wire: when the duodenoscope elevator is lifted, the plastic sheath is bent, and the wire tends to retract. What constitutes the ideal amount of wire exposed at the end of the sheath is a matter of personal preference, but too little and too much are both problematic. With too much wire, you lose control, with the very real risk of making too deep a cut; with too little wire, you cannot see what you are doing. Experts cannot even agree on whether the device should be used with
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Abbreviations: ASGE, American Society for Gastrointestinal Endoscopy; NKP, needle-knife papillotomy; PD, pancreatic duct; PEP, post-ERCP pancreatitis. DISCLOSURE: The author disclosed that he is a consultant to Cook Medical. Copyright ª 2014 by the American Society for Gastrointestinal Endoscopy 0016-5107/$36.00 http://dx.doi.org/10.1016/j.gie.2014.01.017 Received November 13, 2013. Accepted January 6, 2014. Current affiliation: Medical Gastroenterology, Carteret General Hospital, Morehead City, North Carolina, USA.
Baillie
Reflections on needle-knife papillotomy
pure cutting current, blended (cutting and coagulating) current, or coagulating current alone. Even endoscopists with a rudimentary understanding of the physics of electrocautery should know that the current density at the tip of a fine wire is huge (being inversely related to the area of wire in contact with tissue). A really deep NKP cut is almost never desirable, with repeated cuts in the range of 2- to 3-mm depth being much safer and usually effective. Ideally, one should set the wire extension to that length. However, because a short length of wire at the end of the plastic sheath is difficult to see, we frequently have more wire than we need exposed during the procedure. The bile duct (choledochus) does not lie deep within the fold that runs down to the main duodenal papilla; in fact, it is quite superficial. When a deep cut results from injudicious application of a needle-knife papillotome, it risks penetrating the posterior wall of the duct and entering the retroduodenal space. One of the most hazardous situations in which to attempt NKP is when the bile duct is not dilated. A 2- to 3-mm diameter distal bile duct is a very small target, which is 1 reason why NKP should never be used as an alternative to skill in standard biliary cannulation. Most of us recognize a technically proficient biliary sphincterotomy performed with a pull papillotome (Video 1). However, far fewer of us know what constitutes an elegant NKP (Video 2, available online at www.giejournal.org). These days, there are very few purely diagnostic indications for ERCP. It should be superfluous to state that NKP should rarely be used for diagnostic access alone. Unfortunately, as evidenced by malpractice cases related to adverse events of NKP used for marginal indications, some of our colleagues still have not heard the message. True, there are situations in which experts need to access an obstructed biliary tree via a nondilated distal bile duct
(eg, jaundice caused by hilar biliary strictures); nonexperts are wise to refer such cases to a tertiary center and avoid a high-risk procedure. With the wealth of anatomic information available from modern cross-sectional abdominal imaging (especially CT and MRCP), such cases are not difficult to identify ahead of time. In the past, many patients with jaundice went directly to ERCP. As a result, endoscopists got some unpleasant surprises. In 2014, there is no excuse for not having anatomic information, even if only from transabdominal US, before cannulating a duodenal papilla. Not every patient with malignant obstructive jaundice needs preoperative biliary drainage. This should be a decision made by a multidisciplinary team, including a specialist surgeon, with all the necessary imaging available. The headlong rush to perform ERCP should be resisted, especially one that involves NKP. I would not presume to teach the art of NKP in a short commentary such as this. The trainee absolutely has to “be there,” ie, the ERCP suite, to share the experience with a skilled exponent. With this disclaimer firmly up front, I would, however, like to offer some observations from personal experience. (Because my own ERCP mentors chose not to share their NKP secrets with me, I take sole responsibility for the comments that follow.) First and foremost, the trainee must have sufficient experience in handling a duodenoscope to be comfortable making small inputs around the target (ie, the papillary fold). He or she must understand what causes, and how to apply, motion in all of the axes of the instrument (ie, up-down, right-left, twist [torque], and push-pull) and have a light touch on the elevator. Second, the trainee must understand the anatomy of the papillary fold and have a feel for the likely location of the choledochus. Like buying or selling a house, successful NKP is all about “location, location, and location.” With a deft hand, the white, wormlike structure that is the choledochus (Fig. 2) can actually be dissected free (this is rarely necessary, but it is a nice trick when it happens). Wandering off the axis of the duct is probably the most common cause for failing to access it by NKP. This is particularly likely when the anatomy of the duodenal papilla and its fold are distorted by a mass. Diverticula can also displace the papillary fold, but rarely obscure its axis. Making a needle-knife fistula into the bile duct within a diverticulum requires a steady hand (Fig. 3). Marking the anticipated axis of the duct with an endoscopic paint brush or marker (equipment makers: please note) would likely help to avoid NKP deviations. Unless the pancreatic duct (PD) is protected with a prophylactic stent, keeping the needle-knife away from the papillary opening is a good idea because the pancreas detests heat. Cutting upward from the papillary orifice (or close to it) is probably safer than cutting downward toward it. Boring a hole in a bulging papilla with a needle-knife (fistulotomy) is acceptable only if you have good evidence that there is a large, dilated bile duct beneath. This is where previous EUS examination of the duodenal wall can be very helpful.
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Volume 79, No. 5 : 2014 GASTROINTESTINAL ENDOSCOPY 823
Figure 1. Needle-knife papillotome.
Reflections on needle-knife papillotomy
Figure 2. Exposed choledochus (yellow arrow) after needle-knife papillotomy. A small needle-knife incision was made in the distal bile duct (green arrow).
Figure 3. Needle-knife papillotome creating biliary fistula within a diverticulum.
Baillie
Figure 4. Choledochocele (type III choledochal cyst) bulging into the lumen of the descending duodenum.
Figure 5. Choledochus revealed by small suprapapillary incision (anterior bile duct wall with tiny fistula [open arrow], pancreatic duct orifice [solid arrow]).
As EUS technology improves, I anticipate that one day all duodenoscopes will incorporate a small EUS probe at the tip that can be used for this exact purpose, allowing a “sweet spot” to be identified and marked for needle puncture. Experienced endoscopists usually have no difficulty recognizing a choledochocele (type III choledochal cyst) (Fig. 4), which is the ideal target of fistulotomy. One of the keys to success with NKP is a light touch. The great Dutch endoscopist, Kees Huibregtse, liked to compare incisions with a needle-knife to paint brush strokes. Metaphorically and literally, this is where the “art” of NKP comes into play. Pressure with the needle-knife tip should be avoided. A few light, superficial strokes in the axis of the duct will eventually expose the choledochus.
Many find performing a dry run (ie, simulating the cut without current flowing) helpful because it familiarizes the endoscopist with the landscape of the papilla. My personal preference is to make these needle-knife strokes cephalad (upward) rather than caudad (downward, toward the ampullary opening). Surprisingly, few ERCP endoscopists know what the intact choledochus looks like. The normal extrahepatic bile duct looks like a small shiny, almost translucent, worm (Fig. 5). When it is inflamed and thickened, as in chronic obstruction, it assumes a mother-of-pearl sheen (Fig. 6). Less predictable is what you may see when cutting through a tumor (eg, ampullary and head of pancreas cancer) into an obstructed bile duct. The temptation to cut deeper and deeper when you cannot locate the choledochus should be resisted. (Take my word
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Baillie
Reflections on needle-knife papillotomy
Figure 6. Chronically inflamed bile duct incised by a needle-knife papillotome. Note mother-of-pearl texture of the choledochus Here the incision is made by a combination of A, cephalad and B, caudad strokes with the needle knife.
for it: nothing good lives at the bottom of a deep hole in the medial wall of the descending duodenum.) When you have successfully accessed the bile duct by NKP, it is often safer and more effective to extend the initial opening with a standard pull papillotome, with the axis of the duct secured by using a guidewire. However, if you fail to access the bile duct, knowing when to abandon your NKP attempts is equally important. This is more easily said than done. What tells you that it is time to stop? I consider persistent bleeding that obscures the field of view one indication. Having a bad feeling about the procedure and patient agitation are others. As you are dealing with a very small target during NKP, it is imperative to control gut motility and patient-induced motion, such as retching. Increasingly, ERCPs are being performed with the patients under monitored anesthesia care, if not general anesthesia, sparing patients the distress of prolonged moderate sedation and creating a calmer work environment for the endoscopist. If the patient can tolerate continued biliary obstruction, stopping the procedure and bringing him or her back after a few days (allowing your incision to “mature”) can make all the difference. Sometimes on the second attempt, you are lucky and can go straight to the biliary orifice by following a trickle of bile. If the patient has acute cholangitis and needs urgent biliary decompression after a failed NKP, percutaneous (transhepatic) access by an interventional radiologist is the usual fall-back procedure. Where available, EUSdirected bile duct puncture and drainage may be a rescue option.10 However, despite enthusiastic advocates, Varadarajulu and Hawes11 opined recently in this journal that EUS-guided biliary drainage is “taxing” and “not ready” (for widespread use). When I learned to break boards during my martial arts training, it was expected to happen by osmosis (Fig. 7). It seemed like a point of honor not to ask how it was done. As a result, it was a painful process, with some hand and foot injuries along the way. NKP should not be learned this way! Training in NKP should be a graduated experience from easy to difficult. The easiest situation is papillotomy over a stent, which is usually just a small nick in the papillary fold (Fig. 8; Video 3, available online at www.giejournal.org). If you repeatedly enter the PD
Figure 7. Author (right) at his third Dan (degree) Black Belt graduation in U.S. Tae Kwon Do.
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during attempts to access the bile duct, placing a PD stent by using a guidewire and performing an NKP over it achieves the goal while reducing the risk of PEP. PD stenting also facilitates pancreatic sphincterotomy, both major and minor (Fig. 9). When attempting an NKP in the vicinity of the diverticula, stents provide extra protection against cuts straying off course (Fig. 10). Ironically, a free-hand NKP of a prominent papillary fold may be safer than repeatedly probing a small papilla. At the other end of the spectrum, cutting blind into friable ampullary tumors with a needle-knife can quickly become the endoscopic equivalent of the Wild West. How can trainees get experience in performing an NKP without involving actual patients? There are many ways to approach endoscopic training without involving patients, from inexpensive, but often unrealistic, static bench-top models to in vivo procedures on sedated animals. You can teach the NKP technique by using food from your
Reflections on needle-knife papillotomy
Figure 8. Needle-knife incision over a stent placed in the pancreatic duct.
Figure 9. Results of minor duodenal needle-knife papillotomy to treat symptomatic pancreas divisum. The incision was made down onto a straight, 5F plastic stent placed in the dorsal pancreatic duct.
Baillie
Figure 10. Needle-knife papillotomy performed over a biliary stent providing orientation within a duodenal diverticulum.
Figure 11. Author (left) performing endoscopy (EGD) on a young male cheetah (Herero) at London’s Whipsnade Zoo in 1985. Keeping this “patient” asleep was essential to the survival of the endoscopist and the veterinarian (right).
refrigerator. But although using a hot needle-knife to carve up a pork chop or chicken breast is remarkably satisfying, it does not provide the credentials to perform NKP in live patients. Live animals are very expensive to use for endoscopic training. Even if you can ignore the moral and ethical issues involved, they require veterinary supervision and general anesthesia, few have GI anatomy mimicking that of humans, and some are just too dangerous to work with (Fig. 11). The pig is the most commonly used animal model for live ERCP training. For those who do not know that the pig’s duodenal papilla is less prominent that the human one and lies much closer to the pylorus, I guarantee that their first pig ERCP will be a humbling experience, as was mine. (By the way, the bile duct and pancreas drain from separate openings.) Ex vivo animal models (block dissections obtained from abattoirs) provide
a less expensive, but still fairly realistic environment in which to experiment with a needle-knife. Porcine tissue responds realistically to the application of electrocautery through a needle-knife or standard papillotome. The American Society for Gastrointestinal Endoscopy (ASGE) has pioneered endoscopic simulation, from static models to ex vivo animal ones with which therapeutic procedures such as NKP can be practiced in a safe, nonpatient environment. The ASGE’s annual Endofest meetings use this approach to training, and the recently opened ASGE IT&T Center in Downers Grove, Illinois, is providing a high-tech environment in which trainees and established endoscopists alike can hone their skills under expert supervision (Fig. 12). It has been repeatedly suggested that different tiers of ERCP training are appropriate for academia and community practice. I agree that a small cadre of experts based
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Baillie
Reflections on needle-knife papillotomy
NKP. Limiting the depth of cut is an obvious place to start, as are tools to localize the choledochus and facilitate dissection of the papillary fold to expose it. The “needleknife dinosaurs” missed a crucial evolutionary step somewhere in the early days of ERCP. They need to head over to the nearest tar pit and make way for a new generation of precision tools to access the biliary tree and pancreas. ACKNOWLEDGMENTS
Figure 12. The recently opened American Society for Gastrointestinal Endoscopy IT&T Center, in Downers Grove, Ill, includes a state-of-theart endoscopy simulation training laboratory. (Reproduced with permission from ASGE.)
in tertiary centers will continue to offer “high-end” ERCP procedures requiring extra training, regular practice, significant technical support, and specialized backup. For everyone else, the ERCP mission is similar: biliary stones, strictures and leaks, and basic pancreatic endotherapy. With the progressive decrease in the number of ERCPs performed over the past decade and its metamorphosis into an almost exclusively therapeutic modality, we need fewer, better trained ERCP endoscopists to ensure the best outcome for our patients wherever they are working. Supervised experience of NKP must be part of this training. Our trainees are more than ready to join this exclusive club.12 Although there are no data on the subject, the majority of those who currently perform NKP were probably self-taught. Those who have been using this technique safely for many years are pretty good at it. Let us make use of these seasoned experts to teach our trainees; I guarantee that they will answer the call. There are no ASGE or other guidelines from professional societies for NKP training. We need to correct this. We also need solid studies using the various teaching models to determine which ones are the most effective. As ERCP endoscopists evolve from basic competence to expertise, we should expect them to use NKP early rather than late in difficult cases. Combining ERCP and EUS training would maximize the anatomic information available to endoscopists faced with NKP decisions. Let us invite our partners in industry to step up to the plate and provide better, safer tools for
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The author is grateful to Dr Klaus Mergener (Tacoma, Wash) and Jill Haac, BS, Cook Medical, Inc (Winston-Salem, NC) for reviewing the manuscript and offering helpful comments. Dr Todd Baron of the Mayo Clinic (Rochester, Minn) kindly provided Video 2 which was edited from the original.
REFERENCES 1. Trap R, Adamsen S, Hart-Hansen O, et al. Severe and fatal complications after diagnostic and therapeutic ERCP: a prospective series of claims to insurance covering public hospitals. Endoscopy 1999;31: 125-30. 2. Katsinelos P, Gkagkalis S, Chatzimavoudis G, et al. Comparison of three types of precut technique to achieve common bile duct cannulations: a retrospective analysis on 274 cases. Dig Dis Sci 2012;57:3286-92. 3. Rabenstein T, Ruppert T, Schneider HT, et al. Benefits and risks of needle knife papillotomy. Gastrointest Endosc 1997;46:207-11. 4. Bailey AA, Bourke MJ, Kaffes AJ, et al. Needle-knife sphincterotomy: factors predicting its use and the relationship with post-ERCP pancreatitis (with video). Gastrointest Endosc 2010;71:266-71. 5. Freeman ML. Understanding risk factors and avoiding complications with endoscopic retrograde cholangiopancreatography. Curr Gastroenterol Rep 2003;5:145-55. 6. Vandervoort J, Soetikno RM, Tham TC, et al. Risk factors for complications after performance of ERCP. Gastrointest Endosc 2002;56:652-6. 7. Cheng CL, Sherman S, Watkins JL, et al. Risk factors for post-ERCP pancreatitis: a prospective, multicenter study. Am J Gastroenterol 2006;101:139-47. 8. Baillie J. Needle knife papillotomy revisited. Gastrointest Endosc 1997;46:282-4. 9. Rolhauser C, Johnson M, Al-Kawas FH. Needle knife papillotomy: a helpful and safe adjunct to endoscopic retrograde cholangiopancreatography in a selected population. Endoscopy 1998;30:691-6. 10. Sarkaria S, Sundararajan S, Kaheleh M. Endoscopic ultrasound access and drainage of the common bile duct. Gastrointest Endosc Clin N Am 2013;23:435-52. 11. Varadarajulu S, Hawes RH. EUS-guided biliary drainage: taxing and not ready. Gastrointest Endosc 2013;78:742-3. 12. Anastassiades CP, Saxena A. Precut needle-knife papillotomy in advanced endoscopic fellowship. Gastrointest Endosc 2013;77:637-40.
Volume 79, No. 5 : 2014 GASTROINTESTINAL ENDOSCOPY 827
Reflections on needle-knife papillotomy (with videos) John Baillie, MB, ChB, FASGE Morehead City, North Carolina, USA
Two generations of ERCP endoscopists have been indoctrinated into thinking that needle-knife papillotomy (NKP) is a dangerous procedure that should only be performed by experts. A report from Denmark looking at severe and fatal adverse events of ERCP resulting in litigation between 1992 and 1996 concluded that NKP “should still be regarded as a dangerous procedure.”1 Early published studies typically reported adverse event rates of NKP that were often double that of standard biliary sphincterotomy. A recent retrospective review of prospectively collected data on NKP continued to show a high postERCP pancreatitis (PEP) rate.2 However, in some expert hands, NKP apparently could be performed without excess morbidity from the beginning.3 In a recent study from Australia4 of 732 cases, 94 of which were deemed difficult, NKP increased the overall biliary cannulation rate to 97.7% at the cost of a 14.9% PEP rate. Statistical analysis revealed that the independent risk factor for PEP was not NKP, but rather the number of cannulation attempts, confirming what Freeman5 has been telling us for years: NKP used to finish the job gets blamed unfairly for PEP after the duodenal papilla is traumatized during failed cannulation attempts. Another confounding factor as one tries to follow the literature on NKP is the ever-changing ERCP landscape: when Vandervoort et al6 reported their study of adverse events of 1223 ERCPs in 2002, 45% were diagnostic and 55% were therapeutic. A 2006 prospective, multicenter study of risk factors for PEP included 48% diagnostic and 52% therapeutic cases, with an amazing 34% undergoing ERCP for suspected sphincter of Oddi dysfunction.7 Today, it is difficult to find a purely diagnostic indication for ERCP,
Reprint requests: John Baillie, MB, ChB, FASGE, Carteret Medical Group, PO Box 1648, Morehead City, NC 28557.
and the frequent use of sphincter of Oddi manometry is limited to a few academic centers, mainly in the United States. In the interests of full disclosure, I admit that in the past I, too, contributed to the “keep-out” literature on this subject.8 Until about 10 years ago, I did not offer third-year fellows learning ERCP the experience of NKP, and limited my teaching it to fourth year (advanced) fellows who showed particular aptitude for the procedure. Discussions with former trainees convinced me that we have limited training in NKP unfairly. As was recognized a long time ago,9 to be able to tackle the full spectrum of difficult-access cases and achieve a nearly 100% success rate, NKP is the sine qua non. Undoubtedly, many would-be NKP exponents have been intimidated over the years by the sight of experts performing unnecessarily large and aggressive needleknife incisions during live endoscopy courses, usually accompanied by the exhortation “don’t try this at home.” Such “heroic” NKPs are neither necessary nor desirable in everyday practice. Rather than discourage the use of NKP, we should show ERCP trainees how to use the technique selectively to increase their success rates for biliary and pancreatic access. This requires an understanding of the anatomy and the risks involved. For the purposes of this discussion, when I use the term NKP, I mean the free-hand technique using a needle-knife papillotome, which is essentially a bare wire advanced from the tip of a plastic sheath (Fig. 1). Unlike a standard sphincterotomy, NKP is a relatively uncontrolled technique that lacks the protections afforded by unidirectional cutting wire travel and orientation to the axis of the duct (Video 1, available online at www.giejournal.org). It is amazing to me that needle-knife papillotome design has remained virtually unchanged since its inception decades ago. Despite a lock on the device intended to fix the length of exposed wire, all NKP exponents are familiar with the frustrations of the “disappearing” wire: when the duodenoscope elevator is lifted, the plastic sheath is bent, and the wire tends to retract. What constitutes the ideal amount of wire exposed at the end of the sheath is a matter of personal preference, but too little and too much are both problematic. With too much wire, you lose control, with the very real risk of making too deep a cut; with too little wire, you cannot see what you are doing. Experts cannot even agree on whether the device should be used with
822 GASTROINTESTINAL ENDOSCOPY Volume 79, No. 5 : 2014
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Abbreviations: ASGE, American Society for Gastrointestinal Endoscopy; NKP, needle-knife papillotomy; PD, pancreatic duct; PEP, post-ERCP pancreatitis. DISCLOSURE: The author disclosed that he is a consultant to Cook Medical. Copyright ª 2014 by the American Society for Gastrointestinal Endoscopy 0016-5107/$36.00 http://dx.doi.org/10.1016/j.gie.2014.01.017 Received November 13, 2013. Accepted January 6, 2014. Current affiliation: Medical Gastroenterology, Carteret General Hospital, Morehead City, North Carolina, USA.
Baillie
Reflections on needle-knife papillotomy
pure cutting current, blended (cutting and coagulating) current, or coagulating current alone. Even endoscopists with a rudimentary understanding of the physics of electrocautery should know that the current density at the tip of a fine wire is huge (being inversely related to the area of wire in contact with tissue). A really deep NKP cut is almost never desirable, with repeated cuts in the range of 2- to 3-mm depth being much safer and usually effective. Ideally, one should set the wire extension to that length. However, because a short length of wire at the end of the plastic sheath is difficult to see, we frequently have more wire than we need exposed during the procedure. The bile duct (choledochus) does not lie deep within the fold that runs down to the main duodenal papilla; in fact, it is quite superficial. When a deep cut results from injudicious application of a needle-knife papillotome, it risks penetrating the posterior wall of the duct and entering the retroduodenal space. One of the most hazardous situations in which to attempt NKP is when the bile duct is not dilated. A 2- to 3-mm diameter distal bile duct is a very small target, which is 1 reason why NKP should never be used as an alternative to skill in standard biliary cannulation. Most of us recognize a technically proficient biliary sphincterotomy performed with a pull papillotome (Video 1). However, far fewer of us know what constitutes an elegant NKP (Video 2, available online at www.giejournal.org). These days, there are very few purely diagnostic indications for ERCP. It should be superfluous to state that NKP should rarely be used for diagnostic access alone. Unfortunately, as evidenced by malpractice cases related to adverse events of NKP used for marginal indications, some of our colleagues still have not heard the message. True, there are situations in which experts need to access an obstructed biliary tree via a nondilated distal bile duct
(eg, jaundice caused by hilar biliary strictures); nonexperts are wise to refer such cases to a tertiary center and avoid a high-risk procedure. With the wealth of anatomic information available from modern cross-sectional abdominal imaging (especially CT and MRCP), such cases are not difficult to identify ahead of time. In the past, many patients with jaundice went directly to ERCP. As a result, endoscopists got some unpleasant surprises. In 2014, there is no excuse for not having anatomic information, even if only from transabdominal US, before cannulating a duodenal papilla. Not every patient with malignant obstructive jaundice needs preoperative biliary drainage. This should be a decision made by a multidisciplinary team, including a specialist surgeon, with all the necessary imaging available. The headlong rush to perform ERCP should be resisted, especially one that involves NKP. I would not presume to teach the art of NKP in a short commentary such as this. The trainee absolutely has to “be there,” ie, the ERCP suite, to share the experience with a skilled exponent. With this disclaimer firmly up front, I would, however, like to offer some observations from personal experience. (Because my own ERCP mentors chose not to share their NKP secrets with me, I take sole responsibility for the comments that follow.) First and foremost, the trainee must have sufficient experience in handling a duodenoscope to be comfortable making small inputs around the target (ie, the papillary fold). He or she must understand what causes, and how to apply, motion in all of the axes of the instrument (ie, up-down, right-left, twist [torque], and push-pull) and have a light touch on the elevator. Second, the trainee must understand the anatomy of the papillary fold and have a feel for the likely location of the choledochus. Like buying or selling a house, successful NKP is all about “location, location, and location.” With a deft hand, the white, wormlike structure that is the choledochus (Fig. 2) can actually be dissected free (this is rarely necessary, but it is a nice trick when it happens). Wandering off the axis of the duct is probably the most common cause for failing to access it by NKP. This is particularly likely when the anatomy of the duodenal papilla and its fold are distorted by a mass. Diverticula can also displace the papillary fold, but rarely obscure its axis. Making a needle-knife fistula into the bile duct within a diverticulum requires a steady hand (Fig. 3). Marking the anticipated axis of the duct with an endoscopic paint brush or marker (equipment makers: please note) would likely help to avoid NKP deviations. Unless the pancreatic duct (PD) is protected with a prophylactic stent, keeping the needle-knife away from the papillary opening is a good idea because the pancreas detests heat. Cutting upward from the papillary orifice (or close to it) is probably safer than cutting downward toward it. Boring a hole in a bulging papilla with a needle-knife (fistulotomy) is acceptable only if you have good evidence that there is a large, dilated bile duct beneath. This is where previous EUS examination of the duodenal wall can be very helpful.
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Volume 79, No. 5 : 2014 GASTROINTESTINAL ENDOSCOPY 823
Figure 1. Needle-knife papillotome.
Reflections on needle-knife papillotomy
Figure 2. Exposed choledochus (yellow arrow) after needle-knife papillotomy. A small needle-knife incision was made in the distal bile duct (green arrow).
Figure 3. Needle-knife papillotome creating biliary fistula within a diverticulum.
Baillie
Figure 4. Choledochocele (type III choledochal cyst) bulging into the lumen of the descending duodenum.
Figure 5. Choledochus revealed by small suprapapillary incision (anterior bile duct wall with tiny fistula [open arrow], pancreatic duct orifice [solid arrow]).
As EUS technology improves, I anticipate that one day all duodenoscopes will incorporate a small EUS probe at the tip that can be used for this exact purpose, allowing a “sweet spot” to be identified and marked for needle puncture. Experienced endoscopists usually have no difficulty recognizing a choledochocele (type III choledochal cyst) (Fig. 4), which is the ideal target of fistulotomy. One of the keys to success with NKP is a light touch. The great Dutch endoscopist, Kees Huibregtse, liked to compare incisions with a needle-knife to paint brush strokes. Metaphorically and literally, this is where the “art” of NKP comes into play. Pressure with the needle-knife tip should be avoided. A few light, superficial strokes in the axis of the duct will eventually expose the choledochus.
Many find performing a dry run (ie, simulating the cut without current flowing) helpful because it familiarizes the endoscopist with the landscape of the papilla. My personal preference is to make these needle-knife strokes cephalad (upward) rather than caudad (downward, toward the ampullary opening). Surprisingly, few ERCP endoscopists know what the intact choledochus looks like. The normal extrahepatic bile duct looks like a small shiny, almost translucent, worm (Fig. 5). When it is inflamed and thickened, as in chronic obstruction, it assumes a mother-of-pearl sheen (Fig. 6). Less predictable is what you may see when cutting through a tumor (eg, ampullary and head of pancreas cancer) into an obstructed bile duct. The temptation to cut deeper and deeper when you cannot locate the choledochus should be resisted. (Take my word
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Reflections on needle-knife papillotomy
Figure 6. Chronically inflamed bile duct incised by a needle-knife papillotome. Note mother-of-pearl texture of the choledochus Here the incision is made by a combination of A, cephalad and B, caudad strokes with the needle knife.
for it: nothing good lives at the bottom of a deep hole in the medial wall of the descending duodenum.) When you have successfully accessed the bile duct by NKP, it is often safer and more effective to extend the initial opening with a standard pull papillotome, with the axis of the duct secured by using a guidewire. However, if you fail to access the bile duct, knowing when to abandon your NKP attempts is equally important. This is more easily said than done. What tells you that it is time to stop? I consider persistent bleeding that obscures the field of view one indication. Having a bad feeling about the procedure and patient agitation are others. As you are dealing with a very small target during NKP, it is imperative to control gut motility and patient-induced motion, such as retching. Increasingly, ERCPs are being performed with the patients under monitored anesthesia care, if not general anesthesia, sparing patients the distress of prolonged moderate sedation and creating a calmer work environment for the endoscopist. If the patient can tolerate continued biliary obstruction, stopping the procedure and bringing him or her back after a few days (allowing your incision to “mature”) can make all the difference. Sometimes on the second attempt, you are lucky and can go straight to the biliary orifice by following a trickle of bile. If the patient has acute cholangitis and needs urgent biliary decompression after a failed NKP, percutaneous (transhepatic) access by an interventional radiologist is the usual fall-back procedure. Where available, EUSdirected bile duct puncture and drainage may be a rescue option.10 However, despite enthusiastic advocates, Varadarajulu and Hawes11 opined recently in this journal that EUS-guided biliary drainage is “taxing” and “not ready” (for widespread use). When I learned to break boards during my martial arts training, it was expected to happen by osmosis (Fig. 7). It seemed like a point of honor not to ask how it was done. As a result, it was a painful process, with some hand and foot injuries along the way. NKP should not be learned this way! Training in NKP should be a graduated experience from easy to difficult. The easiest situation is papillotomy over a stent, which is usually just a small nick in the papillary fold (Fig. 8; Video 3, available online at www.giejournal.org). If you repeatedly enter the PD
Figure 7. Author (right) at his third Dan (degree) Black Belt graduation in U.S. Tae Kwon Do.
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during attempts to access the bile duct, placing a PD stent by using a guidewire and performing an NKP over it achieves the goal while reducing the risk of PEP. PD stenting also facilitates pancreatic sphincterotomy, both major and minor (Fig. 9). When attempting an NKP in the vicinity of the diverticula, stents provide extra protection against cuts straying off course (Fig. 10). Ironically, a free-hand NKP of a prominent papillary fold may be safer than repeatedly probing a small papilla. At the other end of the spectrum, cutting blind into friable ampullary tumors with a needle-knife can quickly become the endoscopic equivalent of the Wild West. How can trainees get experience in performing an NKP without involving actual patients? There are many ways to approach endoscopic training without involving patients, from inexpensive, but often unrealistic, static bench-top models to in vivo procedures on sedated animals. You can teach the NKP technique by using food from your
Reflections on needle-knife papillotomy
Figure 8. Needle-knife incision over a stent placed in the pancreatic duct.
Figure 9. Results of minor duodenal needle-knife papillotomy to treat symptomatic pancreas divisum. The incision was made down onto a straight, 5F plastic stent placed in the dorsal pancreatic duct.
Baillie
Figure 10. Needle-knife papillotomy performed over a biliary stent providing orientation within a duodenal diverticulum.
Figure 11. Author (left) performing endoscopy (EGD) on a young male cheetah (Herero) at London’s Whipsnade Zoo in 1985. Keeping this “patient” asleep was essential to the survival of the endoscopist and the veterinarian (right).
refrigerator. But although using a hot needle-knife to carve up a pork chop or chicken breast is remarkably satisfying, it does not provide the credentials to perform NKP in live patients. Live animals are very expensive to use for endoscopic training. Even if you can ignore the moral and ethical issues involved, they require veterinary supervision and general anesthesia, few have GI anatomy mimicking that of humans, and some are just too dangerous to work with (Fig. 11). The pig is the most commonly used animal model for live ERCP training. For those who do not know that the pig’s duodenal papilla is less prominent that the human one and lies much closer to the pylorus, I guarantee that their first pig ERCP will be a humbling experience, as was mine. (By the way, the bile duct and pancreas drain from separate openings.) Ex vivo animal models (block dissections obtained from abattoirs) provide
a less expensive, but still fairly realistic environment in which to experiment with a needle-knife. Porcine tissue responds realistically to the application of electrocautery through a needle-knife or standard papillotome. The American Society for Gastrointestinal Endoscopy (ASGE) has pioneered endoscopic simulation, from static models to ex vivo animal ones with which therapeutic procedures such as NKP can be practiced in a safe, nonpatient environment. The ASGE’s annual Endofest meetings use this approach to training, and the recently opened ASGE IT&T Center in Downers Grove, Illinois, is providing a high-tech environment in which trainees and established endoscopists alike can hone their skills under expert supervision (Fig. 12). It has been repeatedly suggested that different tiers of ERCP training are appropriate for academia and community practice. I agree that a small cadre of experts based
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NKP. Limiting the depth of cut is an obvious place to start, as are tools to localize the choledochus and facilitate dissection of the papillary fold to expose it. The “needleknife dinosaurs” missed a crucial evolutionary step somewhere in the early days of ERCP. They need to head over to the nearest tar pit and make way for a new generation of precision tools to access the biliary tree and pancreas. ACKNOWLEDGMENTS
Figure 12. The recently opened American Society for Gastrointestinal Endoscopy IT&T Center, in Downers Grove, Ill, includes a state-of-theart endoscopy simulation training laboratory. (Reproduced with permission from ASGE.)
in tertiary centers will continue to offer “high-end” ERCP procedures requiring extra training, regular practice, significant technical support, and specialized backup. For everyone else, the ERCP mission is similar: biliary stones, strictures and leaks, and basic pancreatic endotherapy. With the progressive decrease in the number of ERCPs performed over the past decade and its metamorphosis into an almost exclusively therapeutic modality, we need fewer, better trained ERCP endoscopists to ensure the best outcome for our patients wherever they are working. Supervised experience of NKP must be part of this training. Our trainees are more than ready to join this exclusive club.12 Although there are no data on the subject, the majority of those who currently perform NKP were probably self-taught. Those who have been using this technique safely for many years are pretty good at it. Let us make use of these seasoned experts to teach our trainees; I guarantee that they will answer the call. There are no ASGE or other guidelines from professional societies for NKP training. We need to correct this. We also need solid studies using the various teaching models to determine which ones are the most effective. As ERCP endoscopists evolve from basic competence to expertise, we should expect them to use NKP early rather than late in difficult cases. Combining ERCP and EUS training would maximize the anatomic information available to endoscopists faced with NKP decisions. Let us invite our partners in industry to step up to the plate and provide better, safer tools for
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The author is grateful to Dr Klaus Mergener (Tacoma, Wash) and Jill Haac, BS, Cook Medical, Inc (Winston-Salem, NC) for reviewing the manuscript and offering helpful comments. Dr Todd Baron of the Mayo Clinic (Rochester, Minn) kindly provided Video 2 which was edited from the original.
REFERENCES 1. Trap R, Adamsen S, Hart-Hansen O, et al. Severe and fatal complications after diagnostic and therapeutic ERCP: a prospective series of claims to insurance covering public hospitals. Endoscopy 1999;31: 125-30. 2. Katsinelos P, Gkagkalis S, Chatzimavoudis G, et al. Comparison of three types of precut technique to achieve common bile duct cannulations: a retrospective analysis on 274 cases. Dig Dis Sci 2012;57:3286-92. 3. Rabenstein T, Ruppert T, Schneider HT, et al. Benefits and risks of needle knife papillotomy. Gastrointest Endosc 1997;46:207-11. 4. Bailey AA, Bourke MJ, Kaffes AJ, et al. Needle-knife sphincterotomy: factors predicting its use and the relationship with post-ERCP pancreatitis (with video). Gastrointest Endosc 2010;71:266-71. 5. Freeman ML. Understanding risk factors and avoiding complications with endoscopic retrograde cholangiopancreatography. Curr Gastroenterol Rep 2003;5:145-55. 6. Vandervoort J, Soetikno RM, Tham TC, et al. Risk factors for complications after performance of ERCP. Gastrointest Endosc 2002;56:652-6. 7. Cheng CL, Sherman S, Watkins JL, et al. Risk factors for post-ERCP pancreatitis: a prospective, multicenter study. Am J Gastroenterol 2006;101:139-47. 8. Baillie J. Needle knife papillotomy revisited. Gastrointest Endosc 1997;46:282-4. 9. Rolhauser C, Johnson M, Al-Kawas FH. Needle knife papillotomy: a helpful and safe adjunct to endoscopic retrograde cholangiopancreatography in a selected population. Endoscopy 1998;30:691-6. 10. Sarkaria S, Sundararajan S, Kaheleh M. Endoscopic ultrasound access and drainage of the common bile duct. Gastrointest Endosc Clin N Am 2013;23:435-52. 11. Varadarajulu S, Hawes RH. EUS-guided biliary drainage: taxing and not ready. Gastrointest Endosc 2013;78:742-3. 12. Anastassiades CP, Saxena A. Precut needle-knife papillotomy in advanced endoscopic fellowship. Gastrointest Endosc 2013;77:637-40.
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