The learning curve for laparoscopic pancreaticoduodenectomy by a proficient laparoscopic surgeon: A retrospective study at a single center

The learning curve for laparoscopic pancreaticoduodenectomy by a proficient laparoscopic surgeon: A retrospective study at a single center | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article The learning curve for laparoscopic pancreaticoduodenectomy by a proficient laparoscopic surgeon: A retrospective study at a single center Heng Wang, Xin Gao, Meng Liu, Xiaohan Kong, HongRui Sun, Zheyu Niu, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-3143153/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 03 Jan, 2024 Read the published version in BMC Surgery → Version 1 posted 8 You are reading this latest preprint version Abstract Background To explore the learning curve of single center laparoscopic pancreaticoduodenectomy(LPD) and evaluate the safety and efficacy of the operation at different stages. Method The clinical data of 120 cases of laparoscopic pancreatoduodenectomy performed by the same surgeon from June 2018 to June 2022 were reviewed and analyzed. The cumulative sum (CUSUM) analysis and the best fitting curve were used to draw the learning curve for the operation time and intraoperative blood loss, respectively. The two were mutually verified, and the number of surgeries needed to accumulate across the learning curve was analyzed. The clinical data, like operation time, intraoperative blood loss, length of stay, complications and other indicators were compared at different stages of the learning curve. Result The maximum turning point of the fitting curve was found in 35 cases by the cumulative sum method of operation time, after which the learning curve could be considered to have passed. The fitting curve obtained by the cumulative sum method of intraoperative blood loss was stable in 30 cases and proficient in 60 cases, which was basically consistent with the fitting curve of operation time. Taking 35 cases as the boundary, the learning curve is divided into learning improvement stage and mastering stage. There was no statistical significance in the general data of the two stage patients (P > 0.05).Hospitalization days decreased from 19 days to 15 days (P < 0.05);Pancreatic fistula decreased from 20.0% of grade B and 8.6% of grade C to 7.1% of grade B and 3.5% of grade C (P < 0.05), and the operative time decreased from (376.9 ± 48.2) minutes to (294.4 ± 18.7) minutes (P < 0.05).Intraoperative blood loss decreased from 375ml to 241ml(P < 0.05). Conclusion 35 patients with LPD can reach the proficiency stage and the perioperative indexes can be improved. Laparoscopic pancreatoduodenectomy The cumulative sum method༛Learning curve༛laparoscopic surgery Figures Figure 1 Figure 2 Introduction Laparoscopic pancreaticoduodenectomy(LPD)started in 1994 and is one of the most complex operations in general surgery [ 1 ]. With the development of endoscopic technology and the improvement of surgical level, more and more centers began to carry out LPD. Compared with open surgery, laparoscopic surgery has the advantages of less trauma, less intraoperative bleeding, shorter hospital stay, and faster postoperative recovery of patients[ 2 ][ 3 ]. But because of the complex structure around the pancreas, limited endoscopic field of view, limited operating angle and many other problems [ 4 ], LPD is only performed in some large and experienced medical centers. Compared with open pancreaticoduodenectomy (OPD), the efficacy of LPD has gradually become a focus of attention and debate among surgeons [ 5 ][ 6 ]. The mainstream view is that LPD has obvious advantages over OPD surgery [ 7 ], but there are also experts who offer the opposite view [ 8 ]. Multi-center studies have shown that in the early stage of LPD surgery, the short-term efficacy and prognosis of patients may not be ideal [ 9 ][ 10 ], which may be due to the neglect of the influence of the learning curve in the LPD surgery process. Therefore, it is of great significance to analyze and understand the learning curve during LPD surgery to guide surgeons to carry out surgery smoothly and reduce surgical complications. In this paper, the clinical data of 120 patients with LPD in a single center were retrospectively analyzed to explore the learning curve and evaluate the safety and efficacy of surgery at different stages. Data and methods General information : The clinical data of patients undergoing laparoscopic pancreaticoduodenectomy in the Department of Hepatobiliary Surgery, Shandong Provincial Hospital from June 2018 to June 2022 were retrospectively analyzed. Inclusion criteria: (1) Successful operation without laparotomy; (2) Preoperative imaging showed tumors around the pancreas head and ampulla without distant metastasis. Exclusion criteria: (1) absence of perioperative data; (2) conversion to laparotomy. Preoperative examination and preparation : (1) Preoperative examination: routine blood examination, liver function examination, blood biochemistry examination, electrocardiogram examination, chest radiograph examination, upper abdominal three-stage enhanced CT or MRI examination. If the patient is old or complicated with cardiopulmonary disease, cardiac ultrasound, lung function and other relevant tests should be performed according to the specific conditions. (2) Preoperative preparation: Informed consent for surgery was signed. If the total bilirubin was more than 400µmol/L before surgery, percutaneous hepatic aspiration and biliary drainage were performed to reduce yellow. Related to surgery : (1) Surgical methods: The 5-hole method was used to establish the abdominal operating hole, perforate the gastrocolic ligament, separate and dissect the omental sac to expose the pancreas, dissect the free gastric antrum and duodenal bulb, separate and ligate the right gastroepiploic vessel. The superior mesenteric vein was searched along the right gastromental vein to establish a tunnel behind the neck of the pancreas. The right blood vessel of the stomach was separated and ligated, and the gastric wall was severed 2cm from the pylorus with a cutter closure. The jejunum was severed approximately 15cm from the ligament Qu with a cutter closure. The capsule was cut open along the upper margin of the pancreas neck, lymph nodes around the common hepatic artery were dissected, the hepatoduodenal ligament was skeletal, the gastroduodenal artery was exposed and ligated, and neurolymphatic tissue was dissected. The lower segment of the hepatic duct was transected, the distal end was ligation and closed, and the gallbladder was excised. The lower margin of the pancreas was detached, and the neck of the pancreas was severed with an ultrasonic knife. The superior mesenteric vein and splenic vein were suspended. The uncinate process of the pancreas and its mesangium were removed near the right side of the superior mesenteric artery. The closed jejunum was lifted over the mesangium of the colon, and end-to-side anastomosis of the pancreatic duct and jejunum mucosa was performed. Pancreatoenterostomy was anastomized by "Hong's one-needle method", and support tubes were placed in the main pancreatic duct. End-to-side anastomosis of the hepatic duct and jejunum was performed approximately 8cm away from the anastomosis, and side-side gastrojejunal anastomosis was performed approximately 45cm away from the bilioenteric anastomosis. Double cannulae were prearranged for pancreaticojejunostomy and biliojejunostomy. A 3–5 cm incision was made along the midline of the upper abdomen to remove the specimen. (2) Intraoperative indicators: the time from the beginning of skin resection to the end of suture was calculated as the operating time, and the amount of intraoperative blood loss was recorded. (3) Postoperative indicators: incidence of pancreatic fistula, biliary fistula, gastric fistula, gastroparesis, postoperative exhaust and feeding time, postoperative bleeding, abdominal infection, reoperation and perioperative death were recorded. Perioperative time was defined as the time between admission and discharge. According to the 2016 update of the International Study Group on Pancreatic Surgery (ISGPS), postoperative pancreatic fistula(POPF) grade: the "Grade A pancreatic fistula" in the original grade is redefined as "biochemical leakage (BL)", which means that serum amylase is more than 3 times the upper limit of normal serum amylase in the institution. "Grade B pancreatic fistula" means continuous drainage for more than 3 weeks, or related clinical measures to control postoperative pancreatic fistula, or percutaneous or endoscopic drainage, or angiography due to bleeding, or infection without organ failure; "Grade C pancreatic fistula" means repeated surgery, or organ failure, or death [ 11 ][ 12 ][ 13 ]. Multiple linear regression Multiple linear regression methods were used to screen for factors affecting operating time. Assign independent variables to data that are classified variables, such as gender and main admission symptoms. Calculate standard operating time. CUSUM analysis was used to construct the learning fitting curve : CUSUM method is a time-weighted control graph method, which has been used for learning curve detection in recent years. This method first calculates the degree of deviation between the observed value of each sample and the target value, and calculates the accumulation and CUSUM by summing method. Formula is as follows: CUSUM= \({\sum }_{\text{i}\text{=1}}^{\text{n}}\text{（}\text{X}\text{i}\text{-}\text{u）}\) ,“Xi” represents the observed value for each patient (using operative time and intraoperative blood loss), “n” represents the surgical sequence number, “u” represents the mean value of this observation. The surgical serial number is taken as the abscissa, CUSUM value as the ordinate, and the fitting curve drawing is calculated, with P < 0.05 judge fitting success to the fit of the fitting coefficient \({R}^{2}\) judgment, the best model choose \({R}^{2}\) most close to 1. Statistical processing SPSS25.0 software was used for statistical analysis. The learning curve is drawn using R software version 4.1.2.. Measurement data conforming to the normal distribution use (x̄ ± s) representation, and t- test was used for comparison between groups. Measurement data with non-normal distributions were represented by M(Q1,Q3) , and the rank sum test was used for comparison between groups. Frequency data (classified data) is represented by the number of cases (%), and comparison between groups using test or Fisher's exact probability method. All results were considered statistically significant with P < 0.05. Results General information: Out of the 120 patients who underwent laparoscopic pancreatoduodenectomy, 69 were male and 51 were female, with an average age of (59.5 ± 8.9) years. A total of 25 patients were diagnosed with pancreatic cancer. It is noteworthy that no conversion to laparotomy was performed during the procedure. For further details, please refer to Table 1 . Table 1 Basic clinical features and baseline of patients with LPD Clinical factor LPD(n = 120) gender male 69(57.5%) female 51(42.5%) Age (years) 59.5 ± 8.9 Main admission symptom jaundice 79(65.8%) Abdominal pain 15(12.5%) other 26(21.7%) hypertension no 103(85.8%) yes 17(14.2%) diabetes no 112(93.3%) yes 8(6.7%) Smoking history no 81(67.5%) yes 39(32.5%) Drinking history no 89(74.2%) yes 31(25.8%) History of pancreatitis no 116(96.7%) yes 4(3.3%) History of abdominal operation no 105(87.5%) yes 15(12.5%) Major tumor size (cm) 2.5 ± 0.9 American Society of Anesthesiologists (ASA) score ≤ 2 43(35.8%) ＞2 77(64.2%) Pathological findings cholangiocarcinoma 40(33.3%) Periampullary carcinoma 16(13.3%) Pancreatic cancer 25(20.8%) Carcinoma of duodenal papilla 32(26.7%) Pancreatic neuroendocrine carcinoma 7(5.8%) The cumulative sum method and Learning curve fitting: CUSUM graph of learning curve, See Figs. 1 and 2 . Operation time learning curve fitting curve equation is: CUSUM(n) = 1 \(\times {10}^{-6}{n}^{5}\) -0.0003 \({n}^{4}\) +0.0331 \({n}^{3}-\) 2.6579 \({n}^{2}\) +108.28 \(n\) +233.9(n is the number of surgical cases). The five highest \({R}^{2}\) to the power curve fitting coefficient (P < 0.05, \({R}^{2}\) = 0.9949), the fitting curve culminate in 35 cases. The fitting equation of intraoperative blood loss learning curve is: CUSUM(n)=5× \({10}^{-5}{n}^{4}\) -0.0098 \({n}^{3}\) -0.2378 \({n}^{2}\) +72.958 \(n\) +1834.6. Highest quartic equation fitting coefficient R2 (P < 0.05, \({R}^{2}\) = 0.9409), 30 cases of fitting curve is stable, 60 patients to master, and the surgery time the results are basically identical. Taking 35 cases as nodes, they were divided into 1 ~ 35 cases for the improvement stage of LPD learning.35 cases and later for the proficient application stage. Comparison of general data in the two stages: General data in the two stages, including gender, age, admission symptoms, hypertension, diabetes, smoking history, drinking history and postoperative pathological types, were not statistically significant, as shown in Table 2 . Table 2 Comparison of general data of patients in the two stages Learning improvement stage (n = 35) Proficiency stage (n = 85) t / χ 2 value P value gender 0.58 0.446 male 22(62.9%) 47(55.3%) female 13(37.1%) 38(44.7%) Age(years) 58.1 ± 8.8 60.0 ± 8.9 -1.17 0.245 Main admission symptom 2.09 0.352 choleplania 25(71.4%) 54(63.5%) abdominal pain 2(5.7%) 13(15.3%) others 8(22.9%) 18(21.7%) hypertension 0.31 0.581 no 31(88.6%) 72(84.7%) yes 4(11.4%) 13(15.3%) Diabetes mellitus 0.07 0.788 no 33 (94.3%) 79(92.9%) yes 2(5.7%) 6(7.1%) smoking history 1.04 0.308 no 26(74.3%) 55(64.7%) yes 9(25.7%) 30(35.3%) Drinking history 0.23 0.633 no 33(94.1%) 62(72.9%) yes 8(22.9%) 23(27.1%) History of pancreatitis 0.87 0.351 no 33(94.3%) 83(97.6%) yes 2(5.7%) 2(2.4%) history of abdominal operation 0.14 0.704 no 30(85.7%) 75(88.2%) yes 5(14.3%) 10(11.8%) Main tumor size (cm) 2.4 ± 1.1 2.5 ± 0.9 -0.94 0.351 American Society of Anesthesiologists (ASA) score 1.05 0.303 ≤ 2 15(42.9%) 28(32.9%) ＞2 20(57.1%) 57(67.1%) pathological findings 4.22 0.377 cholangiocarcinoma 11(31.4%) 29(34.1%) Periampullary carcinoma 7(20.0%) 9(10.6%) pancreatic cancer 4(11.4%) 21(24.7%) Carcinoma of duodenal papilla 11(31.4%) 21(24.7%) Pancreatic neuroendocrine cancer 2(5.7%) 5(5.9%) Comparison of perioperative effects in the two stages: The number of days from postoperative to discharge (15 days vs 19 days, P < 0.05), operation time (294.4 ± 18.7 minutes vs 376.9 ± 48.2 minutes, P < 0.05), intraoperative blood loss (241 ml vs 375 ml, P < 0.05), pancreatic fistula (Grade B pancreatic fistula 7.1%, grade C pancreatic fistula 3.5% vs Grade B pancreatic fistula 20.0%, grade C pancreatic fistula 8.6%, P < 0.05), anal vent time (P < 0.05) and postoperative feeding time (P < 0.05) were significantly less than the LPD learning improvement stage compared with the proficient application stage. There were no significant differences in biliary fistula, gastrointestinal fistula, gastroparesis, postoperative bleeding, reoperation and perioperative death between the two groups (P > 0.05). See Table 3 for details. Table 3 Comparison of perioperative effects between the two stages Clinical factor Mode of operation t / χ 2 value P value Learning improvement stage (n = 35) Proficiency stage (n = 75) Days from surgery to discharge (days) 19.4 ± 2.6 14.9 ± 3.2 7.436 < 0.05 Operation time (minutes) 376.9 ± 48.2 294.4 ± 18.7 13.568 < 0.05 Intraoperative blood loss (ml) 375.1 ± 194.3 241 ± 123.8 4.511 < 0.05 Pancreatic fistula 6.046 0.049 No pancreatic fistula or biochemical leakage 25(71.4%) 76(89.4%) Grade B pancreatic fistula 7(20.0%) 6(7.1%) Grade C pancreatic fistula 3(8.6%) 3(3.5%) Biliary fistula 2.801 0.094 no 29(82.9%) 79(92.9%) yes 6(17.1%) 6(7.1%) Gastrointestinal fistula 0.001 0.972 no 33(94.3%) 80(94.1%) yes 2(5.7%) 5(5.9%) gastroplegia 0.869 0.351 no 33(94.3%) 83(97.6%) yes 2(5.7%) 2(2.4%) Anal exhaust time (days) 3.1 ± 0.9 2.7 ± 0.8 2.269 0.027 Postoperative feeding time (days) 3.3 ± 0.8 2.7 ± 0.8 3.482 0.001 Postoperative bleeding 3.280 0.070 no 30(85.7%) 81(95.3%) yes 5(14.3%) 4(4.7%) abdominal infection 6.965 0.008 no 28(80.0%) 81(95.3%) yes 7(20.0%) 4(4.7%) Reoperation 0.674 0.412 no 30(85.7%) 80(94.1%) yes 5(14.3%) 5(5.9%) Perioperative death 0.035 0.852 no 33(97.1%) 85(98.8%) yes 1(2.9%) 1(1.2%) Discussion After extensive development, endoscopic surgery has become a widely used treatment for tumors in various organs, with recognized safety and advantages. LPD was first published in 1994, but its development has been relatively slow. In recent years, LPD has been widely performed in major medical centers, but its safety remains controversial, and there is no consensus reached in clinical practice due to frequent anastomotic reconstructions, critical postoperative complications, concerns about a lack of radical curative effect in malignant tumors, and limitations in endoscopy technology [ 14 ].It has been pointed out in the literature that there is a common learning curve in the surgical process of surgeons [ 15 ][ 16 ]. Jennifer F Tseng pointed out that three trained surgeons showed improvement in operation time, intraoperative blood loss and other aspects after 60 PD cases were accumulated [ 17 ]. Mohamed Abdelgadir Adam pointed out that the incidence of postoperative perioperative complications such as pancreatic fistula and postoperative bleeding in the LPD group was higher than that in the OPD group [ 18 ], possibly because the surgeons had not yet crossed the learning curve. Studies both domestic and international reveal varying learning curves across different centers. Some centers have indicated a case number of 40 throughout the learning curve [ 19 ], while others point to multi-center studies with a case number of 49, where postoperative pancreatic fistula incidence appears to decrease at different stages of the learning curve [ 9 ]. Currently, an increasing number of medical centers are interested in performing laparoscopic pancreaticoduodenectomy (LPD), resulting in a rise in the number of procedures executed annually. However, the procedure remains challenging and carries potential risks. Acknowledging the presence of a learning curve is pivotal in guiding surgeons to progress from skill enhancement to mastery. While numerous studies have been conducted on LPD learning curves both domestically and internationally, few offer reference significance for individual centers or surgeons. Additionally, most studies involve surgeons with limited experience in laparoscopic surgery prior to LPD, potentially due to a shortage of high-volume research centers. There is a scarcity of data on the learning curve for LPD performed by surgeons with thousands of prior laparoscopic surgeries. This may explain why the surgeon in the current study required fewer procedures to surmount the learning curve and signifies that having adequate laparoscopic surgical experience can potentially shorten the learning curve before performing LPD. Variations in patient demographics, perioperative care protocols, and hospital levels may cause learning curves to differ among centers. Hence, learning curves establish based on the experience of individual surgeons, centers, anastomosis methods, and standardized perioperative treatment offer useful guidance for surgeons seeking to navigate the LPD learning curve. Numerous studies have reported on the learning curve of LPD. However, the customary broken-line chart is limited to operation time and the inflection point of the chart is often deemed as the cut-off point of the learning phase. Regrettably, this approach is highly subjective and lacks statistical support as it overlooks the influence of the patients' preoperative conditions on the operation duration [ 4 ][ 20 ]. In this study, the CUSUM method was employed to establish a learning curve. After accurately fitting the curve, multiple regression analysis was conducted to eliminate the impact of patients' preoperative factors on operating time and obtain the benchmark operation duration. Ultimately, 35 patients were selected as nodes, which were verified by the learning curve of intraoperative blood loss. The CUSUM-derived learning curve not only highlights the inflection point of the operating time's descent but also considers whether the benchmark operating duration continues to decrease beyond the inflection point. The findings of this study indicate that during the progression from the stage of improved learning to that of skilled application, the duration of operation gradually decreases while the incidence of pancreatic fistula shows a corresponding reduction. The statistical analysis of these results is significant, and reveals a correlation between operation time and short-term complications, in contrast to the conclusions drawn by Wang's investigation [ 14 ]. With the advancements in technical proficiency, the volume of intraoperative blood loss has gradually reduced. The adoption of the ERAS concept has resulted in a shortened postoperative feeding period. With the increased understanding of postoperative pancreatic fistula and biliary leakage and the refinement of treatment techniques, the percentage of abdominal infections during the skilled application phase has decreased. There were no significant differences in other perioperative complications such as postoperative bleeding and reoperation between the two groups. Currently, statistical data on the long-term survival rate and progression-free survival rate of patients after LPD is not available in our center due to the relatively short amount of time since we began performing the procedure. Further studies and continued follow-ups will enable us to determine the long-term efficacy of LPD. The learning curve of a single center and surgeon discussed in this study may differ from the findings of other centers. Future multi-center and large sample learning curve analyses are expected to provide more valuable information for surgeons performing LPD surgeries. Conclusion By utilizing CUSUM analysis, it has been concluded that experienced laparoscopic surgeons tend to reach the maximum turning point of their learning curve for operation time around the 35th case. Moreover, the curve fitting of intraoperative blood loss is relatively stable at 30 cases and proficient at 60 cases, which is lower than the typical number of operations needed to surpass the learning curve in the global medical community. Abbreviations LPD laparoscopic pancreaticoduodenectomy CUSUM cumulative sum OPD open pancreaticoduodenectomy BL biochemical leakage Declarations Ethics approval and consent to participate The research was endorsed by the Ethics Committee of Shandong Provincial Hospital（SWYX:NO.2022-147）, and all participants were duly informed and provided written consent. The study was performed in accordance with the Declaration of Helsinki. Consent for publication Not applicable. Conflict of Interest The authors hereby declare that no conflicts of interest exist. Fund programs This study was supported by the Natural Science Foundation of Shandong Province (ZR2020MH259). Authors' contributions WH, GX carried out the experimental design, conducted statistical analysis, and was responsible for manuscript writing for this study; LM, XH K, and HR S are tasked with data collection; ZY N, CQ M conduct a critical evaluation of the scholarly content presented in the article; HQ Z, L J guided the research; Z X performed the surgery. Acknowledgements We express our gratitude towards all the participants and supporters of this research. Availability of data and materials The datasets and analytical data utilized in this experiment are not currently publicly available, but they may be made accessible to corresponding authors upon request. References GAGNER M. LAPAROSCOPIC PYLORUS-PRESERVING PANCREATICODUODENECTOMY [J]. 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Cite Share Download PDF Status: Published Journal Publication published 03 Jan, 2024 Read the published version in BMC Surgery → Version 1 posted Editorial decision: Major revision 16 Oct, 2023 Reviews received at journal 27 Aug, 2023 Reviewers agreed at journal 27 Aug, 2023 Reviewers invited by journal 27 Aug, 2023 Editor assigned by journal 27 Aug, 2023 Editor invited by journal 26 Jul, 2023 Submission checks completed at journal 26 Jul, 2023 First submitted to journal 05 Jul, 2023 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-3143153","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":221696676,"identity":"e3c76493-4ef3-41e2-878a-477399db502a","order_by":0,"name":"Heng Wang","email":"","orcid":"","institution":"Shandong University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Heng","middleName":"","lastName":"Wang","suffix":""},{"id":221696677,"identity":"008cd3c4-3b27-4027-a61d-ebbb7cc1a3c1","order_by":1,"name":"Xin Gao","email":"","orcid":"","institution":"Shandong University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Xin","middleName":"","lastName":"Gao","suffix":""},{"id":221696678,"identity":"8684eb04-69d3-4700-8b29-a3482852b9c1","order_by":2,"name":"Meng Liu","email":"","orcid":"","institution":"Shandong First Medical University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Meng","middleName":"","lastName":"Liu","suffix":""},{"id":221696679,"identity":"aac232e3-9180-48e1-9a38-3f1d8a350f20","order_by":3,"name":"Xiaohan Kong","email":"","orcid":"","institution":"Shandong First Medical University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Xiaohan","middleName":"","lastName":"Kong","suffix":""},{"id":221696680,"identity":"85907486-12e4-47b9-9aa7-c3beb35a6fad","order_by":4,"name":"HongRui Sun","email":"","orcid":"","institution":"Shandong First Medical University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"HongRui","middleName":"","lastName":"Sun","suffix":""},{"id":221696681,"identity":"7ff8323e-64be-41db-8406-9983b6348e12","order_by":5,"name":"Zheyu Niu","email":"","orcid":"","institution":"Qilu Synva Pharmaceutical Co. Ltd","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Zheyu","middleName":"","lastName":"Niu","suffix":""},{"id":221696682,"identity":"f57d704c-93ce-4fd5-bdb6-305599bf50a2","order_by":6,"name":"Huaqiang Zhu","email":"","orcid":"","institution":"Shandong Provincial Hospital Affiliated to Shandong First MedicalUniversity","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Huaqiang","middleName":"","lastName":"Zhu","suffix":""},{"id":221696683,"identity":"e95594fb-5090-4146-b443-80e5572ab2d4","order_by":7,"name":"Jun Lu","email":"","orcid":"","institution":"Shandong Provincial Hospital Affiliated to Shandong First MedicalUniversity","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Jun","middleName":"","lastName":"Lu","suffix":""},{"id":221696685,"identity":"4ba2e3a4-f54e-4fba-8d4e-b55211de5354","order_by":8,"name":"Xu Zhou，","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAy0lEQVRIiWNgGAWjYDACCTBpw8PG3nyAIYEELWly/DzHEkjScthYckaOAXHukp/dfEyat405ccOZM58/PNxhx8Df3o3fMsY5x9IkZ7axJW443rtNIvFMMoPEmbMb8Gphlsgxk/jYxgO05ew2hsQ2ZgYDiVz8WthAWhLbJBI33Mh5/CGxrZ6wFh6ILQYg7zMA9R4mrEVCIi3Zcsa5BFAgg6w7zkPQL/Izkg/e5in7D4rKxx9/tlXL8bf34teC6VLSlI+CUTAKRsEowAoAoitGN7jKafUAAAAASUVORK5CYII=","orcid":"","institution":"Shandong Provincial Hospital Affiliated to Shandong First MedicalUniversity","correspondingAuthor":true,"submittingAuthor":false,"prefix":"","firstName":"Xu","middleName":"","lastName":"Zhou，","suffix":""},{"id":221696687,"identity":"af5c8fcb-91f2-4b98-970d-522fefeb367b","order_by":9,"name":"Chaoqun Ma","email":"","orcid":"","institution":"Shandong Provincial Hospital Affiliated to Shandong First MedicalUniversity","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Chaoqun","middleName":"","lastName":"Ma","suffix":""}],"badges":[],"createdAt":"2023-07-05 16:14:16","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-3143153/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-3143153/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1186/s12893-023-02270-6","type":"published","date":"2024-01-03T15:01:38+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":40842295,"identity":"d8bda82f-4c82-4a82-aa2e-e664fbcb6ed9","added_by":"auto","created_at":"2023-07-31 19:18:04","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":46497,"visible":true,"origin":"","legend":"\u003cp\u003eCUSUM learning curve of operative time\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-3143153/v1/a86066cdda9916d6a0a67f09.png"},{"id":40842294,"identity":"84829069-1520-43f0-9467-c4cb1f566f4f","added_by":"auto","created_at":"2023-07-31 19:18:04","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":61703,"visible":true,"origin":"","legend":"\u003cp\u003eCUSUM learning curve of intraoperative blood loss\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-3143153/v1/14cbc23ee4421d52a2be320d.png"},{"id":49315577,"identity":"75acc169-defe-4dea-ac11-ceb18125b918","added_by":"auto","created_at":"2024-01-08 15:08:55","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":496275,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-3143153/v1/9c131637-431e-4e54-bd90-34349be17729.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"The learning curve for laparoscopic pancreaticoduodenectomy by a proficient laparoscopic surgeon: A retrospective study at a single center","fulltext":[{"header":"Introduction","content":"\u003cp\u003eLaparoscopic pancreaticoduodenectomy(LPD)started in 1994 and is one of the most complex operations in general surgery [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. With the development of endoscopic technology and the improvement of surgical level, more and more centers began to carry out LPD. Compared with open surgery, laparoscopic surgery has the advantages of less trauma, less intraoperative bleeding, shorter hospital stay, and faster postoperative recovery of patients[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e][\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. But because of the complex structure around the pancreas, limited endoscopic field of view, limited operating angle and many other problems [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e], LPD is only performed in some large and experienced medical centers. Compared with open pancreaticoduodenectomy (OPD), the efficacy of LPD has gradually become a focus of attention and debate among surgeons [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e][\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. The mainstream view is that LPD has obvious advantages over OPD surgery [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e], but there are also experts who offer the opposite view [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Multi-center studies have shown that in the early stage of LPD surgery, the short-term efficacy and prognosis of patients may not be ideal [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e][\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e], which may be due to the neglect of the influence of the learning curve in the LPD surgery process. Therefore, it is of great significance to analyze and understand the learning curve during LPD surgery to guide surgeons to carry out surgery smoothly and reduce surgical complications. In this paper, the clinical data of 120 patients with LPD in a single center were retrospectively analyzed to explore the learning curve and evaluate the safety and efficacy of surgery at different stages.\u003c/p\u003e"},{"header":"Data and methods","content":"\u003cp\u003e \u003cb\u003eGeneral information\u003c/b\u003e: The clinical data of patients undergoing laparoscopic pancreaticoduodenectomy in the Department of Hepatobiliary Surgery, Shandong Provincial Hospital from June 2018 to June 2022 were retrospectively analyzed. Inclusion criteria: (1) Successful operation without laparotomy; (2) Preoperative imaging showed tumors around the pancreas head and ampulla without distant metastasis. Exclusion criteria: (1) absence of perioperative data; (2) conversion to laparotomy.\u003c/p\u003e \u003cp\u003e\u003cb\u003ePreoperative examination and preparation\u003c/b\u003e: (1) Preoperative examination: routine blood examination, liver function examination, blood biochemistry examination, electrocardiogram examination, chest radiograph examination, upper abdominal three-stage enhanced CT or MRI examination. If the patient is old or complicated with cardiopulmonary disease, cardiac ultrasound, lung function and other relevant tests should be performed according to the specific conditions. (2) Preoperative preparation: Informed consent for surgery was signed. If the total bilirubin was more than 400\u0026micro;mol/L before surgery, percutaneous hepatic aspiration and biliary drainage were performed to reduce yellow.\u003c/p\u003e \u003cp\u003e \u003cb\u003eRelated to surgery\u003c/b\u003e: (1) Surgical methods: The 5-hole method was used to establish the abdominal operating hole, perforate the gastrocolic ligament, separate and dissect the omental sac to expose the pancreas, dissect the free gastric antrum and duodenal bulb, separate and ligate the right gastroepiploic vessel. The superior mesenteric vein was searched along the right gastromental vein to establish a tunnel behind the neck of the pancreas. The right blood vessel of the stomach was separated and ligated, and the gastric wall was severed 2cm from the pylorus with a cutter closure. The jejunum was severed approximately 15cm from the ligament Qu with a cutter closure. The capsule was cut open along the upper margin of the pancreas neck, lymph nodes around the common hepatic artery were dissected, the hepatoduodenal ligament was skeletal, the gastroduodenal artery was exposed and ligated, and neurolymphatic tissue was dissected. The lower segment of the hepatic duct was transected, the distal end was ligation and closed, and the gallbladder was excised. The lower margin of the pancreas was detached, and the neck of the pancreas was severed with an ultrasonic knife. The superior mesenteric vein and splenic vein were suspended. The uncinate process of the pancreas and its mesangium were removed near the right side of the superior mesenteric artery. The closed jejunum was lifted over the mesangium of the colon, and end-to-side anastomosis of the pancreatic duct and jejunum mucosa was performed. Pancreatoenterostomy was anastomized by \"Hong's one-needle method\", and support tubes were placed in the main pancreatic duct. End-to-side anastomosis of the hepatic duct and jejunum was performed approximately 8cm away from the anastomosis, and side-side gastrojejunal anastomosis was performed approximately 45cm away from the bilioenteric anastomosis. Double cannulae were prearranged for pancreaticojejunostomy and biliojejunostomy. A 3\u0026ndash;5 cm incision was made along the midline of the upper abdomen to remove the specimen. (2) Intraoperative indicators: the time from the beginning of skin resection to the end of suture was calculated as the operating time, and the amount of intraoperative blood loss was recorded. (3) Postoperative indicators: incidence of pancreatic fistula, biliary fistula, gastric fistula, gastroparesis, postoperative exhaust and feeding time, postoperative bleeding, abdominal infection, reoperation and perioperative death were recorded. Perioperative time was defined as the time between admission and discharge. According to the 2016 update of the International Study Group on Pancreatic Surgery (ISGPS), postoperative pancreatic fistula(POPF) grade: the \"Grade A pancreatic fistula\" in the original grade is redefined as \"biochemical leakage (BL)\", which means that serum amylase is more than 3 times the upper limit of normal serum amylase in the institution. \"Grade B pancreatic fistula\" means continuous drainage for more than 3 weeks, or related clinical measures to control postoperative pancreatic fistula, or percutaneous or endoscopic drainage, or angiography due to bleeding, or infection without organ failure; \"Grade C pancreatic fistula\" means repeated surgery, or organ failure, or death [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e][\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e][\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e \u003cstrong\u003eMultiple linear regression\u003c/strong\u003e \u003cp\u003eMultiple linear regression methods were used to screen for factors affecting operating time. Assign independent variables to data that are classified variables, such as gender and main admission symptoms. Calculate standard operating time.\u003c/p\u003e \u003c/p\u003e \u003cp\u003e \u003cb\u003eCUSUM analysis was used to construct the learning fitting curve\u003c/b\u003e: CUSUM method is a time-weighted control graph method, which has been used for learning curve detection in recent years. This method first calculates the degree of deviation between the observed value of each sample and the target value, and calculates the accumulation and CUSUM by summing method. Formula is as follows: CUSUM=\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\({\\sum }_{\\text{i}\\text{=1}}^{\\text{n}}\\text{（}\\text{X}\\text{i}\\text{-}\\text{u）}\\)\u003c/span\u003e\u003c/span\u003e,\u0026ldquo;Xi\u0026rdquo; represents the observed value for each patient (using operative time and intraoperative blood loss), \u0026ldquo;n\u0026rdquo; represents the surgical sequence number, \u0026ldquo;u\u0026rdquo; represents the mean value of this observation. The surgical serial number is taken as the abscissa, CUSUM value as the ordinate, and the fitting curve drawing is calculated, with P\u0026thinsp;\u0026lt;\u0026thinsp;0.05 judge fitting success to the fit of the fitting coefficient \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\({R}^{2}\\)\u003c/span\u003e\u003c/span\u003e judgment, the best model choose \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\({R}^{2}\\)\u003c/span\u003e\u003c/span\u003e most close to 1.\u003c/p\u003e \u003cp\u003e \u003cstrong\u003eStatistical processing\u003c/strong\u003e \u003cp\u003eSPSS25.0 software was used for statistical analysis. The learning curve is drawn using R software version 4.1.2.. Measurement data conforming to the normal distribution use (x̄ ± s) representation, and \u003cem\u003et-\u003c/em\u003e test was used for comparison between groups. Measurement data with non-normal distributions were represented by \u003cem\u003eM(Q1,Q3)\u003c/em\u003e, and the rank sum test was used for comparison between groups. Frequency data (classified data) is represented by the number of cases (%), and comparison between groups using test or Fisher's exact probability method. All results were considered statistically significant with P\u0026thinsp;\u0026lt;\u0026thinsp;0.05.\u003c/p\u003e \u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eGeneral information: Out of the 120 patients who underwent laparoscopic pancreatoduodenectomy, 69 were male and 51 were female, with an average age of (59.5\u0026thinsp;\u0026plusmn;\u0026thinsp;8.9) years. A total of 25 patients were diagnosed with pancreatic cancer. It is noteworthy that no conversion to laparotomy was performed during the procedure. For further details, please refer to Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eBasic clinical features and baseline of patients with LPD\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eClinical factor\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLPD(n\u0026thinsp;=\u0026thinsp;120)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003egender\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003emale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e69(57.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003efemale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e51(42.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge (years)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e59.5\u0026thinsp;\u0026plusmn;\u0026thinsp;8.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMain admission symptom\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ejaundice\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e79(65.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAbdominal pain\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e15(12.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eother\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e26(21.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ehypertension\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eno\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e103(85.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eyes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e17(14.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ediabetes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eno\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e112(93.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eyes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e8(6.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSmoking history\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eno\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e81(67.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eyes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e39(32.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDrinking history\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eno\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e89(74.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eyes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e31(25.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHistory of pancreatitis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eno\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e116(96.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eyes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e4(3.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHistory of abdominal operation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eno\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e105(87.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eyes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e15(12.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMajor tumor size (cm)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e2.5\u0026thinsp;\u0026plusmn;\u0026thinsp;0.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAmerican Society of Anesthesiologists (ASA) score\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u0026le;\u0026thinsp;2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e43(35.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e＞2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e77(64.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePathological findings\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003echolangiocarcinoma\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e40(33.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePeriampullary carcinoma\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e16(13.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePancreatic cancer\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e25(20.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCarcinoma of duodenal papilla\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e32(26.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePancreatic neuroendocrine carcinoma\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e7(5.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eThe cumulative sum method and Learning curve fitting: CUSUM graph of learning curve, See Figs.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e and \u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. Operation time learning curve fitting curve equation is: CUSUM(n)\u0026thinsp;=\u0026thinsp;1\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\times {10}^{-6}{n}^{5}\\)\u003c/span\u003e\u003c/span\u003e-0.0003\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\({n}^{4}\\)\u003c/span\u003e\u003c/span\u003e+0.0331\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\({n}^{3}-\\)\u003c/span\u003e\u003c/span\u003e2.6579\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\({n}^{2}\\)\u003c/span\u003e\u003c/span\u003e+108.28\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(n\\)\u003c/span\u003e\u003c/span\u003e+233.9(n is the number of surgical cases). The five highest\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\({R}^{2}\\)\u003c/span\u003e\u003c/span\u003e to the power curve fitting coefficient (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05, \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\({R}^{2}\\)\u003c/span\u003e\u003c/span\u003e = 0.9949), the fitting curve culminate in 35 cases. The fitting equation of intraoperative blood loss learning curve is: CUSUM(n)=5\u0026times;\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\({10}^{-5}{n}^{4}\\)\u003c/span\u003e\u003c/span\u003e-0.0098\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\({n}^{3}\\)\u003c/span\u003e\u003c/span\u003e-0.2378\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\({n}^{2}\\)\u003c/span\u003e\u003c/span\u003e+72.958\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(n\\)\u003c/span\u003e\u003c/span\u003e+1834.6. Highest quartic equation fitting coefficient R2 (P \u0026lt; 0.05, \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\({R}^{2}\\)\u003c/span\u003e\u003c/span\u003e = 0.9409), 30 cases of fitting curve is stable, 60 patients to master, and the surgery time the results are basically identical. Taking 35 cases as nodes, they were divided into 1 ~ 35 cases for the improvement stage of LPD learning.35 cases and later for the proficient application stage.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eComparison of general data in the two stages: General data in the two stages, including gender, age, admission symptoms, hypertension, diabetes, smoking history, drinking history and postoperative pathological types, were not statistically significant, as shown in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eComparison of general data of patients in the two stages\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eLearning improvement stage\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;35)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eProficiency stage\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;85)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cem\u003et\u003c/em\u003e/\u003cem\u003eχ\u003c/em\u003e\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e \u003cp\u003evalue\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e \u003cp\u003evalue\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003egender\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.58\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.446\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003emale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e22(62.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e47(55.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003efemale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e13(37.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e38(44.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge(years)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e58.1\u0026thinsp;\u0026plusmn;\u0026thinsp;8.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e60.0\u0026thinsp;\u0026plusmn;\u0026thinsp;8.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-1.17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.245\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003eMain admission symptom\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e2.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.352\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003echoleplania\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e25(71.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e54(63.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eabdominal pain\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2(5.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e13(15.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eothers\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e8(22.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e18(21.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ehypertension\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.31\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.581\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eno\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e31(88.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e72(84.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eyes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e4(11.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e13(15.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDiabetes mellitus\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.07\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.788\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eno\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e33 (94.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e79(92.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eyes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2(5.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e6(7.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003esmoking history\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.308\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eno\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e26(74.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e55(64.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eyes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e9(25.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e30(35.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDrinking history\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.633\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eno\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e33(94.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e62(72.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eyes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e8(22.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e23(27.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003eHistory of pancreatitis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.87\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.351\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eno\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e33(94.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e83(97.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eyes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2(5.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2(2.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003ehistory of abdominal operation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.704\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eno\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e30(85.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e75(88.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eyes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e5(14.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e10(11.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003eMain tumor size (cm)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.4\u0026thinsp;\u0026plusmn;\u0026thinsp;1.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2.5\u0026thinsp;\u0026plusmn;\u0026thinsp;0.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e-0.94\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.351\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c3\" namest=\"c1\"\u003e \u003cp\u003eAmerican Society of Anesthesiologists (ASA) score\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e1.05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.303\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026le;\u0026thinsp;2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e15(42.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e28(32.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e＞2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e20(57.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e57(67.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003epathological findings\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4.22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.377\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003echolangiocarcinoma\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e11(31.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e29(34.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePeriampullary carcinoma\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e7(20.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e9(10.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003epancreatic cancer\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e4(11.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e21(24.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCarcinoma of duodenal papilla\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e11(31.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e21(24.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePancreatic\u003c/p\u003e \u003cp\u003eneuroendocrine cancer\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2(5.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e5(5.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eComparison of perioperative effects in the two stages: The number of days from postoperative to discharge (15 days vs 19 days, P\u0026thinsp;\u0026lt;\u0026thinsp;0.05), operation time (294.4\u0026thinsp;\u0026plusmn;\u0026thinsp;18.7 minutes vs 376.9\u0026thinsp;\u0026plusmn;\u0026thinsp;48.2 minutes, P\u0026thinsp;\u0026lt;\u0026thinsp;0.05), intraoperative blood loss (241 ml vs 375 ml, P\u0026thinsp;\u0026lt;\u0026thinsp;0.05), pancreatic fistula (Grade B pancreatic fistula 7.1%, grade C pancreatic fistula 3.5% vs Grade B pancreatic fistula 20.0%, grade C pancreatic fistula 8.6%, P\u0026thinsp;\u0026lt;\u0026thinsp;0.05), anal vent time (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05) and postoperative feeding time (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05) were significantly less than the LPD learning improvement stage compared with the proficient application stage. There were no significant differences in biliary fistula, gastrointestinal fistula, gastroparesis, postoperative bleeding, reoperation and perioperative death between the two groups (P\u0026thinsp;\u0026gt;\u0026thinsp;0.05). See Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e for details.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eComparison of perioperative effects between the two stages\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eClinical factor\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003eMode of operation\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003et\u003c/em\u003e/\u003cem\u003eχ\u003c/em\u003e\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e \u003cp\u003evalue\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e \u003cp\u003evalue\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLearning improvement stage (n\u0026thinsp;=\u0026thinsp;35)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eProficiency stage (n\u0026thinsp;=\u0026thinsp;75)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDays from surgery to discharge (days)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e19.4\u0026thinsp;\u0026plusmn;\u0026thinsp;2.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e14.9\u0026thinsp;\u0026plusmn;\u0026thinsp;3.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e7.436\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.05\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOperation time (minutes)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e376.9\u0026thinsp;\u0026plusmn;\u0026thinsp;48.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e294.4\u0026thinsp;\u0026plusmn;\u0026thinsp;18.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e13.568\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.05\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIntraoperative blood loss (ml)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e375.1\u0026thinsp;\u0026plusmn;\u0026thinsp;194.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e241\u0026thinsp;\u0026plusmn;\u0026thinsp;123.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e4.511\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.05\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePancreatic fistula\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e6.046\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.049\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo pancreatic fistula or biochemical leakage\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e25(71.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e76(89.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGrade B pancreatic fistula\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e7(20.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6(7.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGrade C pancreatic fistula\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3(8.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3(3.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBiliary fistula\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2.801\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.094\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eno\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e29(82.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e79(92.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eyes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6(17.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6(7.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGastrointestinal fistula\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.972\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eno\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e33(94.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e80(94.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eyes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2(5.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5(5.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003egastroplegia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.869\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.351\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eno\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e33(94.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e83(97.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eyes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2(5.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2(2.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAnal exhaust time (days)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3.1\u0026thinsp;\u0026plusmn;\u0026thinsp;0.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.7\u0026thinsp;\u0026plusmn;\u0026thinsp;0.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2.269\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.027\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePostoperative feeding time (days)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3.3\u0026thinsp;\u0026plusmn;\u0026thinsp;0.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.7\u0026thinsp;\u0026plusmn;\u0026thinsp;0.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e3.482\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePostoperative bleeding\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e3.280\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.070\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eno\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e30(85.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e81(95.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eyes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5(14.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4(4.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eabdominal infection\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e6.965\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.008\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eno\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e28(80.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e81(95.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eyes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e7(20.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4(4.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eReoperation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.674\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.412\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eno\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e30(85.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e80(94.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eyes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5(14.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5(5.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePerioperative death\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.035\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.852\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eno\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e33(97.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e85(98.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eyes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1(2.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1(1.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eAfter extensive development, endoscopic surgery has become a widely used treatment for tumors in various organs, with recognized safety and advantages. LPD was first published in 1994, but its development has been relatively slow. In recent years, LPD has been widely performed in major medical centers, but its safety remains controversial, and there is no consensus reached in clinical practice due to frequent anastomotic reconstructions, critical postoperative complications, concerns about a lack of radical curative effect in malignant tumors, and limitations in endoscopy technology [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e].It has been pointed out in the literature that there is a common learning curve in the surgical process of surgeons [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e][\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. \u003cspan type=\"BoldUnderline\" class=\"BoldUnderline\" name=\"Emphasis\"\u003eJennifer F Tseng\u003c/span\u003e pointed out that three trained surgeons showed improvement in operation time, intraoperative blood loss and other aspects after 60 PD cases were accumulated [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. \u003cspan type=\"BoldUnderline\" class=\"BoldUnderline\" name=\"Emphasis\"\u003eMohamed Abdelgadir Adam\u003c/span\u003e pointed out that the incidence of postoperative perioperative complications such as pancreatic fistula and postoperative bleeding in the LPD group was higher than that in the OPD group [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e], possibly because the surgeons had not yet crossed the learning curve.\u003c/p\u003e \u003cp\u003eStudies both domestic and international reveal varying learning curves across different centers. Some centers have indicated a case number of 40 throughout the learning curve [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e], while others point to multi-center studies with a case number of 49, where postoperative pancreatic fistula incidence appears to decrease at different stages of the learning curve [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. Currently, an increasing number of medical centers are interested in performing laparoscopic pancreaticoduodenectomy (LPD), resulting in a rise in the number of procedures executed annually. However, the procedure remains challenging and carries potential risks. Acknowledging the presence of a learning curve is pivotal in guiding surgeons to progress from skill enhancement to mastery. While numerous studies have been conducted on LPD learning curves both domestically and internationally, few offer reference significance for individual centers or surgeons. Additionally, most studies involve surgeons with limited experience in laparoscopic surgery prior to LPD, potentially due to a shortage of high-volume research centers. There is a scarcity of data on the learning curve for LPD performed by surgeons with thousands of prior laparoscopic surgeries. This may explain why the surgeon in the current study required fewer procedures to surmount the learning curve and signifies that having adequate laparoscopic surgical experience can potentially shorten the learning curve before performing LPD. Variations in patient demographics, perioperative care protocols, and hospital levels may cause learning curves to differ among centers. Hence, learning curves establish based on the experience of individual surgeons, centers, anastomosis methods, and standardized perioperative treatment offer useful guidance for surgeons seeking to navigate the LPD learning curve.\u003c/p\u003e \u003cp\u003eNumerous studies have reported on the learning curve of LPD. However, the customary broken-line chart is limited to operation time and the inflection point of the chart is often deemed as the cut-off point of the learning phase. Regrettably, this approach is highly subjective and lacks statistical support as it overlooks the influence of the patients' preoperative conditions on the operation duration [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e][\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. In this study, the CUSUM method was employed to establish a learning curve. After accurately fitting the curve, multiple regression analysis was conducted to eliminate the impact of patients' preoperative factors on operating time and obtain the benchmark operation duration. Ultimately, 35 patients were selected as nodes, which were verified by the learning curve of intraoperative blood loss. The CUSUM-derived learning curve not only highlights the inflection point of the operating time's descent but also considers whether the benchmark operating duration continues to decrease beyond the inflection point.\u003c/p\u003e \u003cp\u003eThe findings of this study indicate that during the progression from the stage of improved learning to that of skilled application, the duration of operation gradually decreases while the incidence of pancreatic fistula shows a corresponding reduction. The statistical analysis of these results is significant, and reveals a correlation between operation time and short-term complications, in contrast to the conclusions drawn by Wang's investigation [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. With the advancements in technical proficiency, the volume of intraoperative blood loss has gradually reduced. The adoption of the ERAS concept has resulted in a shortened postoperative feeding period. With the increased understanding of postoperative pancreatic fistula and biliary leakage and the refinement of treatment techniques, the percentage of abdominal infections during the skilled application phase has decreased. There were no significant differences in other perioperative complications such as postoperative bleeding and reoperation between the two groups. Currently, statistical data on the long-term survival rate and progression-free survival rate of patients after LPD is not available in our center due to the relatively short amount of time since we began performing the procedure. Further studies and continued follow-ups will enable us to determine the long-term efficacy of LPD. The learning curve of a single center and surgeon discussed in this study may differ from the findings of other centers. Future multi-center and large sample learning curve analyses are expected to provide more valuable information for surgeons performing LPD surgeries.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eBy utilizing CUSUM analysis, it has been concluded that experienced laparoscopic surgeons tend to reach the maximum turning point of their learning curve for operation time around the 35th case. Moreover, the curve fitting of intraoperative blood loss is relatively stable at 30 cases and proficient at 60 cases, which is lower than the typical number of operations needed to surpass the learning curve in the global medical community.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eLPD \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; laparoscopic pancreaticoduodenectomy\u003c/p\u003e\n\u003cp\u003eCUSUM \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; cumulative sum\u003c/p\u003e\n\u003cp\u003eOPD \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;open pancreaticoduodenectomy\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eBL \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; biochemical leakage\u0026nbsp;\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe research was endorsed by the Ethics Committee of Shandong Provincial Hospital（SWYX:NO.2022-147）, and all participants were duly informed and provided written consent. The study was performed in accordance with the Declaration of Helsinki.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of Interest\u003c/strong\u003e\u0026nbsp; \u0026nbsp;\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe authors hereby declare that no conflicts of interest exist.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFund programs\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was supported by the Natural Science Foundation of Shandong Province (ZR2020MH259).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026apos; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWH, GX carried out the experimental design, conducted statistical analysis, and was responsible for manuscript writing for this study; LM, XH K, and HR S are tasked with data collection; ZY N, CQ M conduct a critical evaluation of the scholarly content presented in the article; HQ Z, L J guided the research; Z X performed the surgery.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe express our gratitude towards all the participants and supporters of this research.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets and analytical data utilized in this experiment are not currently publicly available, but they may be made accessible to corresponding authors upon request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eGAGNER M. 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Langenbecks Archives of Surgery. 2017;402(5):853\u0026ndash;61. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s00423-016-1541-x\u003c/span\u003e\u003cspan address=\"10.1007/s00423-016-1541-x\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-surgery","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bsur","sideBox":"Learn more about [BMC Surgery](http://bmcsurg.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bsur/default.aspx","title":"BMC Surgery","twitterHandle":"@BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Laparoscopic pancreatoduodenectomy, The cumulative sum method༛Learning curve༛laparoscopic surgery","lastPublishedDoi":"10.21203/rs.3.rs-3143153/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-3143153/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eTo explore the learning curve of single center laparoscopic pancreaticoduodenectomy(LPD) and evaluate the safety and efficacy of the operation at different stages.\u003c/p\u003e\u003ch2\u003eMethod\u003c/h2\u003e \u003cp\u003eThe clinical data of 120 cases of laparoscopic pancreatoduodenectomy performed by the same surgeon from June 2018 to June 2022 were reviewed and analyzed. The cumulative sum (CUSUM) analysis and the best fitting curve were used to draw the learning curve for the operation time and intraoperative blood loss, respectively. The two were mutually verified, and the number of surgeries needed to accumulate across the learning curve was analyzed. The clinical data, like operation time, intraoperative blood loss, length of stay, complications and other indicators were compared at different stages of the learning curve.\u003c/p\u003e\u003ch2\u003eResult\u003c/h2\u003e \u003cp\u003eThe maximum turning point of the fitting curve was found in 35 cases by the cumulative sum method of operation time, after which the learning curve could be considered to have passed. The fitting curve obtained by the cumulative sum method of intraoperative blood loss was stable in 30 cases and proficient in 60 cases, which was basically consistent with the fitting curve of operation time. Taking 35 cases as the boundary, the learning curve is divided into learning improvement stage and mastering stage. There was no statistical significance in the general data of the two stage patients (P\u0026thinsp;\u0026gt;\u0026thinsp;0.05).Hospitalization days decreased from 19 days to 15 days (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05);Pancreatic fistula decreased from 20.0% of grade B and 8.6% of grade C to 7.1% of grade B and 3.5% of grade C (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05), and the operative time decreased from (376.9\u0026thinsp;\u0026plusmn;\u0026thinsp;48.2) minutes to (294.4\u0026thinsp;\u0026plusmn;\u0026thinsp;18.7) minutes (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05).Intraoperative blood loss decreased from 375ml to 241ml(P\u0026thinsp;\u0026lt;\u0026thinsp;0.05).\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003e35 patients with LPD can reach the proficiency stage and the perioperative indexes can be improved.\u003c/p\u003e","manuscriptTitle":"The learning curve for laparoscopic pancreaticoduodenectomy by a proficient laparoscopic surgeon: A retrospective study at a single center","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2023-07-31 19:17:59","doi":"10.21203/rs.3.rs-3143153/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Major revision","date":"2023-10-16T04:02:01+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2023-08-28T03:03:55+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"9f926dd0-1d17-4e90-8250-0d81b5083780","date":"2023-08-28T00:33:40+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2023-08-27T15:13:40+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2023-08-27T15:07:04+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2023-07-26T10:09:20+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2023-07-26T09:40:56+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Surgery","date":"2023-07-05T16:00:20+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-surgery","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bsur","sideBox":"Learn more about [BMC Surgery](http://bmcsurg.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bsur/default.aspx","title":"BMC Surgery","twitterHandle":"@BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"fa572363-f77a-4261-93f0-af50c4609bae","owner":[],"postedDate":"July 31st, 2023","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2024-01-08T15:04:47+00:00","versionOfRecord":{"articleIdentity":"rs-3143153","link":"https://doi.org/10.1186/s12893-023-02270-6","journal":{"identity":"bmc-surgery","isVorOnly":false,"title":"BMC Surgery"},"publishedOn":"2024-01-03 15:01:38","publishedOnDateReadable":"January 3rd, 2024"},"versionCreatedAt":"2023-07-31 19:17:59","video":"","vorDoi":"10.1186/s12893-023-02270-6","vorDoiUrl":"https://doi.org/10.1186/s12893-023-02270-6","workflowStages":[]},"version":"v1","identity":"rs-3143153","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-3143153","identity":"rs-3143153","version":["v1"]},"buildId":"7rjqhiLT3MXkJMwkYKINL","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}