EDITORIAL. ERCP outcomes: defining the operators, experience, and environments

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1 EDITORIAL ERCP outcomes: defining the operators, experience, and environments The outcome of ERCP is most commonly measured by success and complication rates. For most medical procedures, however, outcomes can be defined by many parameters along several axes. Other pertinent measures include degree of technical success, degrees and duration of clinical benefits, patient satisfaction, and expense. In a given patient these endpoints are influenced by numerous variables that can be defined by features of the patient, the disease state, the medical environment, the practitioners involved, the details of the procedure performed, and the occurrence, recognition, and response to early post-procedure consequences. Hence the input/outcome equation has infinite variation among patients. Clear definitions and better measures for the major variables in the outcome equation should improve our understanding of risk-benefit and costbenefit ratios, and thereby enhance medical decision making, patient counseling, training, research, and quality improvement. Efforts to reach a consensus regarding definitions for ERCP complications have already advanced the assessment of outcome. 1,2 For utility of application it is useful to group the variables by our temporal awareness of them during the process of care. Hence, preprocedure, intraprocedure, and postprocedure elements might be considered sequentially, despite their significant interrelatedness. Consideration of the anticipated outcomes at each interval may then influence subsequent advice or management. This becomes increasingly pertinent as prophylactic or therapeutic interventions, with varying thresholds of benefit (e.g., the use of gabexate or octreotide, to reduce postprocedure pancreatitis), are developed and characterized. This review addresses available data on the variables pertaining to the endoscopist, his/her training and experience, the setting in which the endoscopist practices, and the influence of these variables on various measures of outcome. Few studies specifically address these issues. Each of those available uses different measures for the same concept, and each seeks correlations with slightly different outcome measures. Nevertheless, data are accumulating from Presented at the ASGE Sponsored Workshop on Outcomes in ERCP, January 12-14, 2001, Atlanta, Georgia. Copyright 2002 by the American Society for Gastrointestinal Endoscopy /2002/$ /70/ doi: /mge Table 1. Procedural input variables pertaining to operator and experience Operator Training Technical* Didactic Year-trained Specialty Board certification Practice spectrum/type* Personality Rest Concurrent stress, demands Other *Data available. Situational elements. Experience Training Cumulative (lifetime) volumes* Ongoing volumes frequency of performance* Last analogous case Other several lines of investigation that confirm the intuitive relationship between outcome and experience. Operators and experience The parameters labeled operator and experience are inseparable terms truthfully meant to characterize the skill or competence of the endoscopist. What are the elements (breadth) and the extent (depth) of the skill set? This is a sensitive issue for which there are no absolute criteria. Numerous attributes pertaining to the individual endoscopist s experience could be used as proxies to infer or even represent skills. They are primarily among the known preprocedure variables in the outcome equation. Those elements for which data, although often limited, are available are designated in Table 1 with an asterisk. Some elements listed in Table 1 are situational, suggesting that the endoscopist brings a varying degree of skill to each procedure. Measurement of skills per procedure remains problematic. Ramirez et al. 3 and Cunningham et al. 4 found that the likelihood of successful cannulation increases when ERCP is repeated by the same endoscopist who performed an initial unsuccessful procedure. Similarly, Freeman and Cass 5 reported that participation of a second endoscopist of similar skill at the index procedure increases the likelihood of success. Although improvement in the success rate for cannulation may reflect operator characteristics specific to that occasion, it is also the result of familiarity with the anatomic problems in a given patient as well as altered patient tolerance or preparation. A second deficiency in the common measures of endoscopic skill is reliance on technical success as opposed to appraisal of cognitive ability. Compared with other endoscopic procedures, ERCP requires a greater degree of cognitive effort. Judgment and VOLUME 55, NO. 7, 2002 GASTROINTESTINAL ENDOSCOPY 953

2 B Petersen Editorial decision making are, however, difficult to evaluate outside of structured examinations. In granting privileges to perform procedures, the practitioner s knowledge base is represented by training credentials and board certification. Training. There were significant differences in outcome measures of success and complications in relation to endoscopist experience in a survey of 10,000 cases reported by Bilbao et al. 6 in Those who had experience with 25 or fewer procedures had a 38% success rate for visualization of the biliary tree compared with 85% for endoscopists who had performed more than 200 procedures. The rate of procedurerelated complications was 3% for experienced endoscopists versus 7% to 15% for inexperienced endoscopists. Despite the limited numbers of procedures required for credentialing by many institutions, experience with 25 or fewer ERCP procedures would today be considered inadequate for independent practice. The American Society for Gastrointestinal Endoscopy (ASGE) designated a total of 100 procedures and 25 therapeutic procedures as minimum thresholds for the assessment of competence in ERCP. 7 The British Society of Gastroenterology selected 150 procedures as an appropriate minimum to be performed before competence can be evaluated. 8 The limited data available on numbers of procedures required to reach the threshold of competence, however, suggest that even greater experience is necessary to achieve acceptable outcomes. Jowell et al. 9 prospectively evaluated procedural competence in the performance of ERCP among gastroenterology fellows at various stages of training. Seventeen fellows were graded by 7 faculty members on both overall levels of competence and specific technical components during 1796 procedures performed over 24 months. Numbers of procedures necessary to achieve an 80% liklihood of success (defined as an acceptable score of excellent or adequate, compared with partial, failed, or not attempted ) for various aspects of ERCP were as follows: cholangiography, 160; pancreatography, 140; deep pancreatic duct cannulation, 160; stone extraction, 120; and stent insertion, 60 procedures. Thresholds for 80% likelihood of success at deep biliary cannulation and biliary sphincterotomy could not be generated with the numbers available. The probability of an acceptable score for deep biliary cannulation was 0.65 after 180 procedures (95% CI [0.53, 0.78]); for biliary sphincterotomy it was only 0.36 after 160 procedures (95% CI [0.08, 0.65]). On a more subjective scale, overall competence was deemed 80% probable after 137 procedures and 90% probable after 185 procedures. Among individual fellows, overall competence was reached by 2 of 10 after 120 procedures, 4 of 9 after 140 procedures, and 3 of 3 fellows after 180 to 200 procedures. Because all procedures were performed under the supervision and with the assistance of experienced endoscopists, complications could not be specifically attributed to fellows, and these data were not reported. Experience and historical controls. Beyond specific reference to training, experience is typically quantified by comparison of results for different time frames or between individuals or centers with different cumulative or current volumes of procedures. Comparisons between time frames, that is, use of historical controls, reflect not only evolving skills but also changes in instruments, accessories, and practice patterns. Several reports document improvements by comparison with historical control periods from the same center. In a study of the outcome for 394 endoscopic sphincterotomies performed over a 6-year period, Leese et al. 10 found that success with both sphincterotomy and clearance of stones from the bile duct improved with experience during the 6-year period. No comparative data were provided. Escourrou et al. 11 contrasted results for endoscopic sphincterotomy (ES) among 443 patients treated between 1975 and 1984 with results for 366 patients who underwent the procedure between 1985 and The mortality rate for procedurerelated complications decreased from 1.5% to 0.8% (p = 0.025) and the need for a second attempt to complete the ES declined from 8% to 4% of cases (p = 0.045). Differences between the 2 time frames were not significant for unsuccessful drainage after ES (4.5% vs. 2%), early complications (7% vs. 5%), late occurrence of acute cholecystitis (6.2% vs. 3.3%), and subsequent stenosis (3 cases in each interval). Even with 3 years of prior experience, Lambert et al. 12 identified statistically significant improvements in duct clearance ( 2 = 6.404, p = 0.011), complication rate ( 2 = 5.846, p = 0.016), and need for surgery ( 2 = , p = 0.001) during an 8-year experience with 602 patients referred for removal of bile duct stones. Experience and procedure volumes. Several indices of procedure volume might be useful as proxies to designate the experience of individual operators or entire units. These include case volume during a specific interval (e.g., weekly, annual) and cumulative total volume for either a broadly defined type of procedure (e.g., ERCPs) or a specific maneuver or intervention (e.g., sphincterotomy). For some indices there are no studies in relation to outcome. For practical purposes, most studies have evaluated threshold numbers, above which differences have usually been minor or nonexistent. The volume of procedures performed by an individual and in a cen- 954 GASTROINTESTINAL ENDOSCOPY VOLUME 55, NO. 7, 2002

3 Editorial B Petersen ter are distinct but closely related. Available information will be reviewed separately as operator versus environment data. The specific evolution of skills during early experience has been evaluated in several studies. 13,14 Kald et al. 13 studied complications related to ES in 101 high-risk patients who underwent the procedure between 1981 and There were 7 complications and 3 deaths among 11 patients who underwent ES during the first year. Thereafter, 8 complications (9%) and a single death (1.1%) occurred among 90 patients. Cumulatively, the first 10 ES procedures performed by each of 3 endoscopists (total 30 ES) resulted in 8 complications; the next 10 ES procedures performed by each endoscopist resulted in a total of 4 complications, and for the third set of 10 ES procedures there were a total of 2 complications. Schlup et al. 14 used a cumulative sum method (cusum) to display and evaluate the progression of ERCP skills for a single endoscopist working in a remote low to medium volume referral center. 14 Over an 8-year period successful cannulation rates increased in biennial progression from 85% to 88%, 90%, and 96%. Graphical display of the data demonstrated a steep learning curve (slope) representing success rates consistently less than the target rate of 90% during the initial group of 50 procedures. This was followed by 70 procedures with fluctuating performance, and finally a flattening slope representing consistent success at or greater than the target after 130 to 150 procedures. Beyond 350 procedures, a further decline in the slope correlated with success rates around 95%. A similar pattern was evident in the cusum plot for therapeutic maneuvers, with substandard results during the first 50 procedures and acceptable performance after about 130. Freeman et al. 15 prospectively documented complications among 2347 patients who underwent endoscopic biliary sphincterotomy at 17 institutions in North America. The occurrence of any complication and the specific occurrence of pancreatitis or hemorrhage were correlated with multiple variables, including measures of endoscopist experience and procedure difficulty. On multivariate analysis lower case volume (<1 ES per week) was significantly associated with occurrence of post-es hemorrhage (OR = 2.17; 95% CI [1.12, 4.17], p = 0.002), but not with post-es pancreatitis. Low case volume was associated with overall complications in the univariate analysis but not subsequent multivariate analysis, likely because of case mix and use of advanced higher-risk maneuvers such as precut or needle knife sphincterotomy in the high volume centers. When only known preprocedure variables were assessed, multivariate analysis confirmed a significant association between low case volume and overall complications (OR = 1.43; 95% CI [1.07, 1.89], p = 0.01). Higher per-physician case volumes were also associated with successful precut sphincterotomy and biliary access at the same procedure (90% for higher volume endoscopists and 52% for low case volume endoscopists, p < 0.001). The associations between complications, procedure difficulty, and unit-specific data found in the Freeman study are presented in separate sections below. Patient and procedural factors not related to endoscopist skills are not reviewed. Davis et al. 16 prospectively evaluated associations between ERCP outcomes and practice setting as well as prior cumulative experience of the endoscopist. Forty-seven physicians performed 780 perioperative ERCPs for suspected bile duct stones before or after laparoscopic cholecystectomy. Physicians were grouped according to experience as follows: more than 200 cumulative procedures (11 physicians), less than 200 procedures (22 physicians), and academic expert (14 physicians). Practice settings were defined as communitybased (33 physicians) versus academic (14 physicians). Findings based on practice setting are reviewed in following sections. There were no significant differences in cannulation rates among the physician groups. Experience did correlate with sphincterotomy success, independent of practice setting. The least experienced group had a success rate of 88% compared with 97% and 100% for the groups with greater experience (p = 0.003). Indications, findings, and complications did not correlate with experience, the latter occurring in 6% and 10% of cases for the 2 groups with greater experienced and 12% for the least experienced group. Rabenstein et al. 17 in a smaller single center study of post-es complications identified a strong association between low-volume operators (<40 ES/year) and complications, despite procedure success rates equivalent to those for higher-volume endoscopists. In slight variance from the results of other studies, lowprocedure volume was associated with acute pancreatitis by multivariate analysis (OR = 3.8; 95% CI [1.44, 10.00], p = 0.007), whereas overall complications were only associated by univariate analysis. Intraprocedure variables. Procedural factors that are usually identified as contributing to outcome include combinations of anatomic and pathologic findings plus the diagnostic or therapeutic maneuvers selected. Other intraprocedure variables that reflect on the duration or difficulty of the procedure are undoubtedly influenced by the skills and experience of the endoscopist and the unit. They may serve, therefore, as surrogate measures of endoscopist skills; examples include subjective or graded assess- VOLUME 55, NO. 7, 2002 GASTROINTESTINAL ENDOSCOPY 955

4 B Petersen Editorial ments of cannulation difficulty, procedure duration, number of unintended pancreatic duct injections, success or failure of a given maneuver, and frequency of ancillary maneuvers such as needle knife sphincterotomy. The latter maneuver reportedly carries a higher risk, 15,18-21 which is difficult to apportion between the prior failed access and the mode of incision. Significant variations in case mix further complicate the attribution of such variables to the endoscopist alone, as inexperienced endoscopists generally forgo such maneuvers, whereas experienced centers may use needle knife sphincterotomy for both diagnostic and therapeutic purposes. Freeman et al. 15 graded difficulty of cannulation subjectively on a scale of 1 to 3. Using this and other indirect indices of difficulty, these investigators demonstrated the following: (1) overall complications were associated with a higher difficulty score (OR = 3.05; 95% CI [1.83, 5.08], p < 0.001), precut sphincterotomy (OR 3.61; 95% CI [1.78, 7.34], p < 0.001), and combined percutaneous-endoscopic procedures (OR = 3.40; 95% CI [1.04, 11.13], p = 3.40); (2) pancreatitis was associated with a higher difficulty score (for difficult vs. easy, OR = 2.40; 95% CI [1.07, 5.36], p < 0.001]), precut sphincterotomy (OR = 4.34; 95% CI [1.73, 10.88], p < 0.001), and a greater number of pancreatic duct injections (for 4 vs. no injections, OR = 1.35; 95% CI [1.04, 1.75], p < 0.001), but not with use of a guidewire for cannulation; and, (3) hemorrhage was not associated with any of the direct or indirect indices of difficulty. Johnson et al. 22 further elucidated the elements that might contribute to the increased risk of difficult procedures. These indirectly relate to endoscopist skills, although skill and experience were not specifically addressed. Both subjective difficulty and more than 10 pancreatic duct injections were related to acute pancreatitis by univariate analysis. Despite a trend, longer fluoroscopy times were not statistically associated with increased complications. Environment The environment in which an endoscopist practices undoubtedly influences both absolute and relative outcomes. Distinguishing features commonly mentioned include procedure volumes within a unit, number of operators among whom a given volume is distributed, funding as a public versus private facility, academic versus private practice setting, community versus referral setting, participation of fellows in general or advanced training, equipment availability, institutional mix of patient services, and patient mix of diseases and comorbidities. To date, few studies have investigated outcomes as they relate to specific descriptors of the practice setting other than volumes. Measures of institutional experience tend to reflect individual operator experience. Freeman et al. 15 presented data associating various outcomes with 5 high-volume versus 12 lowervolume centers (centers in which individuals perform more or less than 1 ES per week). In centers with greater volumes, there were fewer difficult cannulations (p < 0.001), fewer inadvertent pancreatic injections (p < 0.001), fewer failures to achieve access or drainage subsequent to ES (p < 0.001), fewer episodes of hemorrhage (p = 0.002), fewer severe complications (p = 0.01), and fewer overall complications (p = 0.03), but no significant difference in rates of pancreatitis. For the 6 private practices, complication rates were lower compared with the 11 university-affiliated centers, but this was not significant on multivariate analysis. Davis et al. 16 in their study of perioperative ERCP identified a significant difference in procedure timing in relation to the surgery based on practice type, with 69% of community-based procedures being performed before surgery and 59% of procedures in the academic center being performed after surgery (relative risk for preoperative procedure in the community = 1.67; 95% CI [1.34, 2.02]). This was in part a reflection of referral bias because 77% of community-based ERCPs were performed in the same setting as the cholecystectomy, whereas 76% of ERCPs in the academic center were subsequent to a postoperative referral from another center. For preoperative procedures the only difference with respect to indication was a higher proportion of procedures for pancreatitis in the academic setting (p = 0.01). Among preoperative patients there were no differences in findings in relation to setting. For postoperative procedures, the indications did not differ between community and academic settings. However, there were differences in findings: more stones were identified in the community setting (50% vs. 29%, p = 0.001) and more strictures were found in academic centers (19% vs. 10%, p = 0.027); again, this is likely because of referral bias. In contrast to the data outlined above on cumulative experience and outcome, the practice setting did not correlate with success of cannulation or ES. A nonsignificant trend was noted for lower postprocedure complication rates among academic (6%) versus community-based centers (10%-12%). Loperfido et al. 21 documented major complications among 2769 patients undergoing either diagnostic or therapeutic ERCP at 9 hospitals in Italy. There were 6 low-volume small centers (<150 procedures/year) and 3 higher volume large centers (>200 procedures/year). Two hospitals were university affiliated, 5 were major district hospitals, and GASTROINTESTINAL ENDOSCOPY VOLUME 55, NO. 7, 2002

5 Editorial B Petersen were small hospitals. Performance of ERCP at lowvolume centers was associated by multivariate analysis with higher overall risks for major complications (OR = 2.90; 95% CI [1.97, 4.28], p < ), cholangitis (OR = 4.71; 95% CI [1.91, 11.65], and bleeding (OR = 2.95; 95% CI [1.25, 6.96]), and by univariate analysis with death, and pancreatitis. Unlike the many other studies in which precut approaches are concentrated in referral centers, Loperfido et al. 21 noted a higher frequency of precut techniques in the low-volume centers, where they contributed to the higher complication rates. Technical failures were more common in small centers (p < ) and there was also a higher rate of repeat procedures in these institutions (p < ). When an ERCP fails to visualize the desired duct, further attempts are often indicated. The incremental benefit of further efforts in the same environment was discussed above. 3-5 Similarly, several studies have documented the benefits of referral to a tertiary center for the subsequent attempt at visualization of the clinically relevant duct. Choudari et al. 23 reviewed 562 such procedures. At the referral center, access was successfully achieved in 96.4%; advanced cannulation techniques were used in 41%. Complications occurred in 10.6% of cases. Rollhauser et al. 24 reported results for 104 procedures repeated in a referral center. Advanced techniques were used in 55%; access was achieved in 95%, and complications occurred in 12.6% of cases. Although the data are limited, these results are similar to those for repeated efforts in the original, albeit tertiary, center. Underlying indications and their associated risk, as well as availability of advanced techniques for access and subsequent therapy, should be considered when making the decision to repeat the procedure or refer the patient to another center. Summary A potpourri of associations has been identified for the common ERCP outcomes of success/failure, overall complication rates, and the specific complications of pancreatitis, hemorrhage, and cholangitis. Generally consistent results demonstrate improved success rates for endoscopists with cumulative experience of 150 to 200 procedures or case volumes of more than 40 to 50 sphincterotomies per year. Whether these 2 indicators of experience track together is not known. Similarly, prospective evaluation of fellows in training suggests that over 200 procedures are required to reach an acceptable level of competence in the performance of essential maneuvers. Global or specific complications have been less consistently associated with experience, although most studies suggest an association, and the major prospective studies concur in this regard. 15,17,21 Pancreatitis appears to be less associated with pure measures of experience than with various indices of difficulty. Difficulty, which also correlates with other negative outcomes, probably reflects a blend of patient and endoscopist elements. The practice environment appears to influence outcomes predominantly through case mix and volumes. From the little that is known about training environments it appears that the case mix and the responsible instructor influence outcome more than the participation of a fellow. The influence of the operator, his or her experience, and the environment on outcomes beyond success rates and complications has not been studied extensively. Recommendations Are these data pertinent to our present healthcare delivery system? Should they influence the design of training programs, granting of privileges to perform ERCP, or the selection of endoscopists by either patients or payers? To some extent they already do. In the last decade many training programs dropped the pretense of providing ample ERCP training to all fellows. So-called third-tier or advanced endoscopy training programs proliferated, then declined in importance as the length of training was increased with the addition of a compulsory third year, during which only a subset of fellows are offered significant training in ERCP. Applicants to fellowship programs should avoid the temptation to assess training opportunities on the basis of provision of advanced skills, such as ERCP, to all fellows in the program. Similarly, training programs should avoid the temptation to promise such training to individuals beyond the number that can be adequately trained in relation to the volume of available procedures. Exposure to manipulation of sideviewing instruments and to the principles of ERCP, including indications, contraindications, interpretation of basic findings, complications, and their management should suffice for general gastroenterology training. Exposure should not be equated with license to practice advanced procedures, however. Advanced training in the context of a 3-year fellowship or an additional advanced year of training is now a defacto expectation for those entering academic or major endoscopic referral practices. This does not apply to the majority of practice settings in the United States however. Many hospitals, including those in urban and suburban areas, require only minimum experience (15-30 procedures) for granting privileges to perform ERCP, most do not differentiate privileges among types of ERCP procedures, and proctoring programs for assessment of skills before granting privileges are rare. Because hospitals and VOLUME 55, NO. 7, 2002 GASTROINTESTINAL ENDOSCOPY 957

6 B Petersen Editorial health systems have increasing responsibility for the competence of those practicing within their environment, these standards should be improved. Threshold numbers, such as those reviewed above, offer some guidance to those granting privileges. Prudent fellows seek, and professional groups provide, a mentor for new members lacking significant experience. Limited privileges should be granted for performance of specific procedures with an experienced colleague until experience in terms of numbers of procedures is sufficient for independent practice. Similarly, biannual recredentialing should be predicated on continued performance of adequate numbers of procedures to maintain competence. Such a threshold is not defined for those with previously established skills; however, common sense dictates that some minimum be established. Finally, although ASGE guidelines rightly state that threshold numbers do not certify competence, they remain important as objective measures of minimum training. The ASGE should consider an increase in the numbers of procedures required for attainment of minimal competence in ERCP to a level that more closely approximates the available data. The figures, albeit incomplete, are there and available to regulators, plaintiffs, and payers. No doubt they will eventually bolster mandates if they are not preemptively interpreted and judiciously applied by training programs, hospitals, and our specialty society itself. Bret T. Petersen, MD Mayo Clinic Rochester, Minnesota REFERENCES 1. Cotton PM, Lehman G, Vennes J, Russell RCG, Meyers WC, Liquory C, et al. Endoscopic sphincterotomy complications and their management: an attempt at consensus. Gastrointest Endosc 1991;37: Freeman ML. Procedure-specific outcomes assessment for endoscopic retrograde cholangiopancreatography. 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