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BackgroundRobot-assisted distal pancreatectomy (RDP) is increasingly used as an alternative to laparoscopic distal pancreatectomy (LDP) in patients with resectable pancreatic cancer but comparative multicenter studies confirming the safety and efficacy of RDP are lacking.MethodsAn international, multicenter, retrospective, cohort study, including consecutive patients undergoing RDP and LDP for resectable pancreatic cancer in 33 experienced centers from 11 countries (2010-2019). The primary outcome was R0-resection. Secondary outcomes included lymph node yield, major complications, conversion rate, and overall survival.ResultsIn total, 542 patients after minimally invasive distal pancreatectomy were included: 103 RDP (19%) and 439 LDP (81%). The R0-resection rate was comparable (75.7% RDP vs. 69.3% LDP, p = 0.404). RDP was associated with longer operative time (290 vs. 240 min, p < 0.001), more vascular resections (7.6% vs. 2.7%, p = 0.030), lower conversion rate (4.9% vs. 17.3%, p = 0.001), more major complications (26.2% vs. 16.3%, p = 0.019), improved lymph node yield (18 vs. 16, p = 0.021), and longer hospital stay (10 vs. 8 days, p = 0.001). The 90-day mortality (1.9% vs. 0.7%, p = 0.268) and overall survival (median 28 vs. 31 months, p = 0.599) did not differ significantly between RDP and LDP, respectively.ConclusionsIn selected patients with resectable pancreatic cancer, RDP and LDP provide a comparable R0-resection rate and overall survival in experienced centers. Although the lymph node yield and conversion rate appeared favorable after RDP, LDP was associated with shorter operating time, less major complications, and shorter hospital stay. The specific benefits associated with each approach should be confirmed by multicenter, randomized trials.

Background Benchmarking is an important tool for quality comparison and improvement. However, no benchmark values are available for minimally invasive spleen-preserving distal pancreatectomy, either laparoscopically or robotically assisted. The aim of this study was to establish benchmarks for these techniques using two different methods. Methods Data from patients undergoing laparoscopically or robotically assisted spleen-preserving distal pancreatectomy were extracted from a multicentre database (2006-2019). Benchmarks for 10 outcomes were calculated using the Achievable Benchmark of Care (ABC) and best-patient-in-best-centre methods. Results Overall, 951 laparoscopically assisted (77.3 per cent) and 279 robotically assisted (22.7 per cent) procedures were included. Using the ABC method, the benchmarks for laparoscopically assisted and robotically assisted spleen-preserving distal pancreatectomy respectively were: 150 and 207 min for duration of operation, 55 and 100 ml for blood loss, 3.5 and 1.7 per cent for conversion, 0 and 1.7 per cent for failure to preserve the spleen, 27.3 and 34.0 per cent for overall morbidity, 5.1 and 3.3 per cent for major morbidity, 3.6 and 7.1 per cent for pancreatic fistula grade B/C, 5 and 6 days for duration of hospital stay, 2.9 and 5.4 per cent for readmissions, and 0 and 0 per cent for 90-day mortality. Best-patient-in-best-centre methodology revealed milder benchmark cut-offs for laparoscopically and robotically assisted procedures, with operating times of 254 and 262.5 min, blood loss of 150 and 195 ml, conversion rates of 5.8 and 8.2 per cent, rates of failure to salvage spleen of 29.9 and 27.3 per cent, overall morbidity rates of 62.7 and 55.7 per cent, major morbidity rates of 20.4 and 14 per cent, POPF B/C rates of 23.8 and 24.2 per cent, duration of hospital stay of 8 and 8 days, readmission rates of 20 and 15.1 per cent, and 90-day mortality rates of 0 and 0 per cent respectively. Conclusion Two benchmark methods for mi

IMPORTANCE Understanding the learning curve of a new complex surgical technique helps to reduce potential patient harm. Current series on the learning curve of minimally invasive distal pancreatectomy (MIDP) are mostly small, single-center series, thus providing limited data. OBJECTIVE To evaluate the length of pooled learning curves of MIDP in experienced centers. DESIGN, SETTING, AND PARTICIPANTS This international, multicenter, retrospective cohort study included MIDP procedures performed from January 1, 2006, through June 30, 2019, in 26 European centers from 8 countries that each performed more than 15 distal pancreatectomies annually, with an overall experience exceeding 50 MIDP procedures. Consecutive patients who underwent elective laparoscopic or robotic distal pancreatectomy for all indications were included. Data were analyzed between September 1, 2021, and May 1, 2022. EXPOSURES The learning curve for MIDP was estimated by pooling data from all centers. MAIN OUTCOMES AND MEASURES The learning curvewas assessed for the primary textbook outcome (TBO), which is a composite measure that reflects optimal outcome, and for surgical mastery. Generalized additive models and a 2-piece linear model with a break point were used to estimate the learning curve length of MIDP. Case mix-expected probabilities were plotted and compared with observed outcomes to assess the association of changing case mix with outcomes. The learning curve also was assessed for the secondary outcomes of operation time, intraoperative blood loss, conversion to open rate, and postoperative pancreatic fistula grade B/C. RESULTS From a total of 2610 MIDP procedures, the learning curve analysis was conducted on 2041 procedures (mean [SD] patient age, 58 [15.3] years; among 2040 with reported sex, 1249 were female [61.2%] and 791 male [38.8%]). The 2-piece model showed an increase and eventually a break point for TBO at 85 procedures (95% CI, 13-157 procedures), with a plateau TBO rate at 70%. T

Background: The European registry for minimally invasive pancreatic surgery (E-MIPS) collects data on laparoscopic and robotic MIPS in low-and high-volume centers across Europe.Methods: Analysis of the first year (2019) of the E-MIPS registry, including minimally invasive distal pancreatectomy (MIDP) and minimally invasive pancreatoduodenectomy (MIPD). Primary outcome was 90-day mortality.Results: Overall, 959 patients from 54 centers in 15 countries were included, 558 patients underwent MIDP and 401 patients MIPD. Median volume of MIDP was 10 (7-20) and 9 (2-20) for MIPD. Median use of MIDP was 56.0% (IQR 39.0-77.3%) and median use of MIPD 27.7% (IQR 9.7-45.3%). MIDP was mostly performed laparoscopic (401/558, 71.9%) and MIPD mostly robotic (234/401, 58.3%). MIPD was performed in 50/54 (89.3%) centers, of which 15/50 (30.0%) performed >= 20 MIPD annually. This was 30/ 54 (55.6%) centers and 13/30 (43%) centers for MIPD respectively. Conversion rate was 10.9% for MIDP and 8.4% for MIPD. Overall 90 day mortality was 1.1% (n = 6) for MIDP and 3.7% (n = 15) for MIPD.Conclusion: Within the E-MIPS registry, MIDP is performed in about half of all patients, mostly using laparoscopy. MIPD is performed in about a quarter of patients, slightly more often using the robotic approach. A minority of centers met the Miami guideline volume criteria for MIPD.

BACKGROUND: Robot-assisted distal pancreatectomy (RDP) is increasingly used as an alternative to laparoscopic distal pancreatectomy (LDP) in patients with resectable pancreatic cancer but comparative multicenter studies confirming the safety and efficacy of RDP are lacking.METHODS: An international, multicenter, retrospective, cohort study, including consecutive patients undergoing RDP and LDP for resectable pancreatic cancer in 33 experienced centers from 11 countries (2010-2019). The primary outcome was R0-resection. Secondary outcomes included lymph node yield, major complications, conversion rate, and overall survival.RESULTS: In total, 542 patients after minimally invasive distal pancreatectomy were included: 103 RDP (19%) and 439 LDP (81%). The R0-resection rate was comparable (75.7% RDP vs. 69.3% LDP, p = 0.404). RDP was associated with longer operative time (290 vs. 240 min, p < 0.001), more vascular resections (7.6% vs. 2.7%, p = 0.030), lower conversion rate (4.9% vs. 17.3%, p = 0.001), more major complications (26.2% vs. 16.3%, p = 0.019), improved lymph node yield (18 vs. 16, p = 0.021), and longer hospital stay (10 vs. 8 days, p = 0.001). The 90-day mortality (1.9% vs. 0.7%, p = 0.268) and overall survival (median 28 vs. 31 months, p = 0.599) did not differ significantly between RDP and LDP, respectively.CONCLUSIONS: In selected patients with resectable pancreatic cancer, RDP and LDP provide a comparable R0-resection rate and overall survival in experienced centers. Although the lymph node yield and conversion rate appeared favorable after RDP, LDP was associated with shorter operating time, less major complications, and shorter hospital stay. The specific benefits associated with each approach should be confirmed by multicenter, randomized trials.

BACKGROUND: Benchmarking is an important tool for quality comparison and improvement. However, no benchmark values are available for minimally invasive spleen-preserving distal pancreatectomy, either laparoscopically or robotically assisted. The aim of this study was to establish benchmarks for these techniques using two different methods.METHODS: Data from patients undergoing laparoscopically or robotically assisted spleen-preserving distal pancreatectomy were extracted from a multicentre database (2006-2019). Benchmarks for 10 outcomes were calculated using the Achievable Benchmark of Care (ABC) and best-patient-in-best-centre methods.RESULTS: Overall, 951 laparoscopically assisted (77.3 per cent) and 279 robotically assisted (22.7 per cent) procedures were included. Using the ABC method, the benchmarks for laparoscopically assisted and robotically assisted spleen-preserving distal pancreatectomy respectively were: 150 and 207 min for duration of operation, 55 and 100 ml for blood loss, 3.5 and 1.7 per cent for conversion, 0 and 1.7 per cent for failure to preserve the spleen, 27.3 and 34.0 per cent for overall morbidity, 5.1 and 3.3 per cent for major morbidity, 3.6 and 7.1 per cent for pancreatic fistula grade B/C, 5 and 6 days for duration of hospital stay, 2.9 and 5.4 per cent for readmissions, and 0 and 0 per cent for 90-day mortality. Best-patient-in-best-centre methodology revealed milder benchmark cut-offs for laparoscopically and robotically assisted procedures, with operating times of 254 and 262.5 min, blood loss of 150 and 195 ml, conversion rates of 5.8 and 8.2 per cent, rates of failure to salvage spleen of 29.9 and 27.3 per cent, overall morbidity rates of 62.7 and 55.7 per cent, major morbidity rates of 20.4 and 14 per cent, POPF B/C rates of 23.8 and 24.2 per cent, duration of hospital stay of 8 and 8 days, readmission rates of 20 and 15.1 per cent, and 90-day mortality rates of 0 and 0 per cent respectively.CONCLUSION: Two

[EN] Background Whereas the usefulness of radiofrequency (RF) energy as haemostatic method in liver surgery has become well established in the last decades, its intentional application on resection margins with the aim of reducing local recurrence is still debatable. Our goal was to compare the impact of an additional application of RF energy on the top of the resection surface, namely additional margin coagulation (AMC), on local recurrence (LR) when subjected to a subcentimeter margin. Methods We retrospectively analyzed 185 patients out of a whole cohort of 283 patients who underwent radical hepatic resection with subcentimetric margin. After propensity score adjustment, patients were classified into two balanced groups according to whether RF was applied or not. Results No significant differences were observed within groups in baseline characteristics after PSM adjustment. The LR rate was significantly higher in the Control than AMC Group: 12 patients (14.5%) vs. 4 patients (4.8%) (p = 0.039). The estimated 1, 3, and 5-year LR-free survival rates of patients in the Control and AMC Group were: 93.5%, 86.0%, 81.0% and 98.8%, 97.2%, 91.9%, respectively (p = 0.049). Univariate Cox analyses indicated that the use of the RF applicator was significantly associated with lower LR (HR = 0.29, 95% confidence interval 0.093¿0.906, p = 0.033). The Control Group showed smaller coagulation widths than the AMC group (p < 0.001). Conclusions An additional application of RF on the top of the resection surface is associated with less local hepatic recurrence than the use of conventional techniques.

Background: The studies which address the impact of costs of robotic vs. laparoscopic approach on quality of life (cost-effectiveness studies) are scares in general surgery. Methods: The Spanish national study on cost-effectiveness differences among robotic and laparoscopic surgery (ROBOCOSTES) is designed as a prospective, multicentre, national, observational study. The aim is to determine in which procedures robotic surgery is more cost-effective than laparoscopic surgery. Several surgical operations and patient populations will be evaluated (distal pancreatectomy, gastrectomy, sleeve gastrectomy, inguinal hernioplasty, rectal resection for cancer, Heller cardiomiotomy and Nissen procedure). Discussion: The results of this study will demonstrate which treatment (laparoscopic or robotic) and in which population is more cost-effective. This study will also assess the impact of previous surgical experience on main outcomes.

[EN] Purpose To compare the size of the coagulation (CZ) and periablational (PZ) zones created with two commercially available devices in clinical use for radiofrequency (RFA) and microwave ablation (MWA), respectively. Methods Computer models were used to simulate RFA with a 3-cm Cool-tip applicator and MWA with an Amica-Gen applicator. The Arrhenius model was used to compute the damage index (omega). CZ was considered when omega > 4.6 (>99% of damaged cells). Regions with 0.6

This is an Accepted Manuscript of an article published by Taylor & Francis in International Journal of Hyperthermia on Jan 01 2019, available online: http://www.tandfonline.com/10.1080/02656736.2019.1627585, [EN] Introduction: Endoluminal sealing of the pancreatic duct by glue or sutures facilitates the management of the pancreatic stump. Our objective was to develop a catheter-based alternative for endoluminal radiofrequency (RF) sealing of the pancreatic duct. Materials and methods: We devised a novel RF ablation technique based on impedance-guided catheter pullback. First, bench tests were performed on ex vivo models to tune up the technique before the in vivo study, after which endoluminal RF sealing of a similar to 10 cm non-transected pancreatic duct was conducted on porcine models using a 3 Fr catheter. After 30 days, sealing effectiveness was assessed by a permeability test and a histological analysis. Results: The RF technique was feasible in all cases and delivered similar to 5 W of power on an initial impedance of 308 +/- 60 ohm. Electrical impedance evolution was similar in all cases and provided guidance for modulating the pullback speed to avoid tissue sticking and achieve a continuous lesion. During the follow-up the animals rate of weight gain was significantly reduced (p < 0.05). Apart from signs of exocrine atrophy, no other postoperative complications were found. At necropsy, the permeability test failed and the catheter could not be reintroduced endoluminally, confirming that sealing had been successful. The histological analysis revealed a homogeneous exocrine atrophy along the ablated segment in all the animals. Conclusions: Catheter-based RF ablation could be used effectively and safely for endoluminal sealing of the pancreatic duct. The findings suggest that a fully continuous lesion may not be required to obtain complete exocrine atrophy.

[EN] Purpose: To develop computer models to mimic the impedance-controlled pulsing protocol implemented in radiofrequency (RF) generators used for clinical practice of radiofrequency ablation (RFA), and to assess the appropriateness of the models by comparing the computer results with those obtained in previous experimental studies.Methods: A 12-min RFA was modelled using a cooled electrode (17G, 3cm tip) inserted in hepatic tissue. The short (transverse) diameter of the coagulation zone was assessed under in vivo (with blood perfusion (BP) and considering clamping) and ex vivo (at 21 degrees C) conditions. The computer results obtained by programming voltage pulses were compared with current pulses.Results: The differences between voltage and current pulses were noticeable: using current instead of voltage allows larger coagulation zones to be created, due to the higher energy applied by current pulses. If voltage pulses are employed the model can accurately predict the number of roll-offs, although the waveform of the applied power is clearly not realistic. If current voltages are employed, the applied power waveform matches well with those reported experimentally, but there are significantly fewer roll-offs. Our computer results were overall into the ranges of experimental ones.Conclusions: The proposed models reproduce reasonably well the electrical-thermal performance and coagulation zone size obtained during an impedance-controlled pulsing protocol.

[EN] Purpose: To track the saline during infusion with a 15 G needle into healthy pig livers at high and low infusion rates for 300 s. Methods: In each experiment, the needle was inserted into a single lobe of the liver to a depth of at least 2 cm following its longer axis. Two sets of experiments were defined: 1) low infusion rate of 0.1 mL/min (n = 6) and 2) high infusion rate of 1 mL/min (n = 6). Cine CT scans were carried out and three transverse planes were defined around the infusion point (IP), which corresponds with needle tip. Two assessments were performed: 1) a dynamic plane study focused on the time progress of the saline distribution on a single plane, which provided the Mean Percentage of Grayscale Intensity (MPG!): and 2) a volumetric study focused on the three dimensional distribution of the saline around IP at the end of the experiment, which provided the High Intensity Volume Ratio (HIVR). Results: The saline solution was conspicuous around the IP and shortly after heterogeneously inside the vessels. At the high infusion rate, the saline became conspicuous not only much sooner (evident at 20 s) but farther away (mean value of MPGI over 2%, up to 17 mm from the IP) and at a much higher intensity (mean value of MPGI over 10% up to 4 mm from the IP). The lower the radial distance to the IP, the greater the difference in HIVR between both groups. Conclusions: The high infusion rate leads to a faster, wider and a more marked presence of saline than the low rate. The rapid drainage into the hepatic veins may explain the heterogeneous distribution. (C) 2012 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

This is a copy of an article published in the Journal of Endourology ©2011 copyright Mary Ann Liebert, Inc.; Journal of Endourology is available online at: http://www.liebertpub.com/end, [EN] Materials and Methods: We performed a comparative experimental study between a new radiofrequency (RF)-assisted device consisting of a handheld instrument that simultaneously conducts coagulation and cutting tasks without hilar clamping vs a standard technique with hilar clamping. A porcine model was used (10 animals per group) with survival of 17 days. Results: The estimated blood loss with the new device was significantly lower than with the standard technique (15.5 +/- 23.7 vs 79.4 +/- 76.3 mL). Although transection time was longer with the new device (10.7 +/- 13.7 vs 2.1 +/- 1.2 min), the total operative time was significantly shorter (35.3 +/- 13.7 vs 60.2 +/- 10.5 min). Evidence of localized urinary extravasation (urinoma) was identical in both groups (five cases). The group subjected to the new device, however, showed a significantly higher number of cases of leakage after conducting the methylene-blue test: eight (80%) cases vs only one (11%) with the standard technique. Necrosis depth was significantly greater with the new device (6.6 +/- 0.9 vs <1 mm). Conclusions: The experimental results suggest that the proposed RF-assisted device provides adequate hemostatic control during transection of the renal parenchyma without additional instruments or surgical maneuvers and could therefore be a valuable adjunct for LPN without vascular clamping. The device was unsuccessful in effectively sealing the collecting system.

In this article some recent data concerning the approach on radiofrequency ablation (RFA) of liver tumors are reviewed. Specifically, several critical statements between surgical and percutaneous approach are raised and discussed: (1) Open approach may lead to a higher complication rate; (2) Temporary occlusion of hepatic inflow during surgical approach may lead to a higher rate of ablation of the liver tumors; (3) Surgical approach may permit better targeting of the tumor to be ablated. (4) Surgical approach may discover additional liver tumors. Finally, several conclusions and recommendations are also addressed.

Background: Radiofrequency (RF) ablation is used to obtain local control of unresectable tumors in liver, kidney, prostate, and other organs. Accurate data on expected size and geometry of coagulation zones are essential for physicians to prevent collateral damage and local tumor recurrence. The aim of this study was to develop a standardized terminology to describe the size and geometry of these zones for experimental and clinical RF. Methods: In a first step, the essential geometric parameters to accurately describe the coagulation zones and the spatial relationship between the coagulation zones and the electrodes were defined. In a second step, standard terms were assigned to each parameter. Results: The proposed terms for single-electrode RF ablation include axial diameter, front margin, coagulation center, maximal and minimal radius, maximal and minimal transverse diameter, ellipticity index, and regularity index. In addition a subjective description of the general shape and regularity is recommended. Conclusions: Adoption of the proposed standardized description method may help to fill in the many gaps in our current knowledge of the size and geometry of RF coagulation zones.