Evaluating the learning curve for laparoscopic liver resection: a comparative study between standard and learning curve CUSUM

Technical aspects and learning curve of complex laparoscopic hepatectomy: how we do it

INTRODUCTION

Laparoscopic liver surgery has advanced significantly, offering benefits, such as reduced intraoperative complications and quicker recovery. However, complex laparoscopic hepatectomy (CLH) is technically demanding, requiring skilled surgeons. This study aims to share technical aspects, insightful tips, and outcomes of CLH at our center, focusing on the safety and learning curve.

METHODS

We reviewed all patients undergoing liver resection at our center from July 2017 to December 2023, focusing on those who underwent CLH. Of 135 laparoscopic liver resections, 63 (46.7%) were CLH. The learning curve of CLH was also assessed through linear and piecewise regression analyses considering the operation time and intraoperative blood loss.

RESULTS

Postoperative complications occurred only in 4.8% of patients, with a 90-day mortality rate of 3.2%. The mean operation time and blood loss significantly decreased after the first 20 operations, marking the learning curve's optimal cut-off. Significant improvements in R0 resection (p = 0.024) and 90-day mortality (p = 0.035) were noted beyond the learning curve threshold.

CONCLUSION

CLH is a safe and effective approach, with a relatively short learning curve of 20 operations. Future large-scale studies should further investigate the impact of surgical experience on CLH outcomes to establish guidelines for training programs.

Achieving Textbook Outcomes after Laparoscopic Resection in Posterosuperior Segments of the Liver: The Impact of the Learning Curve

Achieving textbook outcomes (TOs) improves the short-term and long-term performance of a hospital. Our objective was to assess TOs in the laparoscopic liver resection (LLR) of tumors in the PS (posterosuperior) section of the liver and identify the impact of the learning curve. We conducted a retrospective cohort study analyzing patients who underwent LLR for lesions located in the PS segments. Patients were divided into a TO and no-TO group. TOs were defined as negative margins, no transfusion, no readmission, no major complications, no 30-day mortality, and a length of stay ≤ 50th percentile. Patients' outcomes were assessed in two study periods before and after 2015. TOs were achieved in 47.6% (n = 117). In multivariable analysis, obesity (p = 0.001), shorter operation time (p < 0.001), less blood loss (p < 0.001), normal albumin (p = 0.003), and minor resection (p = 0.046) were significantly associated with achieving TOs. Although the 5-year recurrence-free survival rate (p = 0.096) was not significantly different, the 5-year overall survival rate was significantly greater in the TO group (p = 0.001). Body mass index > 25 kg/m2 (p = 0.020), age > 65 years (p = 0.049), and achievement of TOs (p = 0.024) were independently associated with survival. The proportion of patients who achieved a TO was higher after 2015 than before 2015 (52.3% vs. 36.1%; p = 0.022). TOs are important markers not only for assessing hospital and surgeon performance but also as predictors of overall survival. As the number of surgeons who achieve the learning curve increases, the number of patients with TOs will gradually increase with a subsequent improvement in overall survival.

The impact of hospital volume on liver resection: A systematic review and Bayesian network meta-analysis

BACKGROUND

This study aims to compare the outcomes of high-volume, medium-volume, and low-volume hospitals performing hepatic resections using a network meta-analysis.

METHODS

A literature search until June 2023 was conducted across major databases to identify studies comparing outcomes in high-volume, medium-volume, and low-volume hospitals for liver resection. Bayesian network meta-analysis was conducted, and surface under cumulative ranking area values, odds ratio, and mean difference with 95% credible intervals were reported for postoperative mortality, failure-to-rescue, morbidity, length of stay, and hospital costs.

RESULTS

Twenty studies comprising 248,707 patients undergoing liver resection were included. For the primary mortality outcome, overall and subgroup analyses were performed: group I: high-volume = 5 to 20 resections/year; group II: high-volume = 21 to 49 resections/year; group III: high-volume ≥50 resections/year. Results demonstrated a significant association between hospital volume and mortality (overall-high-volume versus medium-volume: odds ratio 0.66, 95% credible interval 0.49-0.87; high-volume versus low-volume: odds ratio 0.52, 95% credible interval 0.41-0.65; group I-high-volume versus low-volume: odds ratio 0.34, 95% credible interval 0.22-0.50; medium-volume versus low-volume: odds ratio 0.56, 95% credible interval 0.33-0.92; group II-high-volume versus low-volume: odds ratio 0.67, 95% credible interval 0.45-0.91), as well as length of stay (high-volume versus low-volume: mean difference -1.24, 95% credible interval -2.07 to -0.41), favoring high-volume hospitals. No significant difference was observed in failure-to-rescue, morbidity, or hospital costs across the 3 groups.

CONCLUSION

This study supports a positive relationship between hospital volume and surgical outcomes in liver resection. Patients from high-volume hospitals experience superior outcomes in terms of lower postoperative mortality and shorter lengths of stay than medium-volume and low-volume hospitals.

TOETVA: a single surgeon's learning curve and a case report of CASTLE thyroid tumor

BACKGROUND

Owing to the lack of visible scars, the transoral endoscopic thyroidectomy vestibular approach (TOETVA) offers superior aesthetic outcomes compared to conventional thyroidectomy. Carcinoma showing thymus-like differentiation (CASTLE) represents a rare thyroid gland neoplasm. This study aimed to explore the TOETVA learning curve and present a case report of CASTLE.

METHODS

A study with precise 1:1 matching was conducted to assess the procedure safety and cancer control outcomes of TOETVA in comparison to conventional surgery between May 2020 and May 2023. Cumulative sum analysis was employed to optimally fit the learning curve. Subsequently, a case report of CASTLE treated with TOETVA surgery was presented.

RESULTS

The mean operative time was longer in the TOETVA group than in the open group. The TOETVA group had a higher incidence of skin numbness and excellent cosmetic outcomes compared to the open group. The learning curves for work area preparation, unilateral thyroid lobectomy, and the entire surgical process were 59, 28, and 50 cases, respectively. There were no differences between the learning and proficient groups, except for operative time, intraoperative blood loss, and drainage volume on the first postoperative day.

CONCLUSIONS

A comprehensive analysis of the TOETVA learning curve utilizing cumulative and analytical methods demonstrated the feasibility of TOETVA with regards to surgical integrity, safety, and oncological safety. This study's findings suggest that a surgeon's cumulative number of TOETVA cases exceeding 50 can reach the mastery stage. Moreover, diagnosing CASTLE is challenging and necessitates immunohistochemical detection of relatively specific markers associated with thymic epithelial tumors.

Open Versus Laparoscopic Right Hepatectomy for Hepatocellular Carcinoma Following Sequential TACE-PVE: A Multicentric Comparative Study

BACKGROUND

Right hepatectomy (RH) for hepatocellular carcinoma (HCC) is ideally preceded by transcatheter arterial chemoembolization (TACE) and portal vein embolization (PVE). Laparoscopic approach improves short-term outcome and textbook outcome (TO), which reflects the "ideal" surgical outcome, after RH. However, laparoscopic RH on an underlying diseased liver and after TACE/PVE remains a challenging procedure. The aim of this study was to compare the outcomes in patients who underwent laparoscopic liver resection (LLR) or open liver resection (OLR) following TACE/PVE.

PATIENTS AND METHODS

All patients with HCC who underwent RH after TACE/PVE in five French centers were retrospectively included. Outcomes were compared between the LLR group and the OLR group using propensity score matching (PSM). Quality of surgical care was defined by TO.

RESULTS

Between 2005 and 2019, 117 patients were included (41 in LLR group, 76 in OLR group). Overall morbidity was comparable (51% versus 53%, p = 0.24). In LLR group, TO was completed in 66% versus 37% in OLR group (p = 0.02). LLR and absence of clamping were the only factors associated with TO completion [hazard ratio (HR) 4.27, [1.77-10.28], p = 0.001]. After PSM, 5-year overall survival (OS) and progression-free survival (PFS) were 55% in matched LLR versus 77% in matched OLR, p = 0.35, and 13% in matched LLR versus 17% in matched OLR, p = 0.97. TO completion was independently associated with a better 5-year OS (65.2% versus 42.5%, p = 0.007).

CONCLUSION

Major LLR after TACE/PVE should be considered as a valuable option in expert centers to increase the chance of TO, the latter being associated with a better 5-year OS.

Outcomes of Laparoscopic Versus Open Liver Resection: A Case-control Study With Propensity Score Matching

BACKGROUND

This study aimed to evaluate the perioperative outcomes of patients with benign and malignant liver lesions scheduled for laparoscopic and open surgery using a propensity score-matched approach to analyze additional cofactors influencing outcomes.

PATIENTS AND METHODS

In this study, we retrospectively reviewed 270 patients who underwent laparoscopic or open liver resection at our institute between October 2016 and November 2021. Patients were divided into open and laparoscopic liver resection groups and compared according to the intention to treat principle. In the purification process for the nonrandom nature of the study, a matching analysis was performed at a 1:1 case-control ratio. The PS model included selected data on body mass index, additional data on the American Society of Anesthesiology score, cirrhosis, lesion <2 cm from the hilum, lesion <2 cm from the hepatic vein or inferior vena cava, and type of neoadjuvant chemotherapy.

RESULTS

The operation time and 30- and 90-day mortality rates were similar between the groups. The average length of hospital stay was 11 days in the open surgery group and 9 days in the laparoscopic surgery group after matching ( P =0.011). The 30-day morbidity rate was statistically different between the groups before and after matching, favoring the laparoscopic group ( P =0.001 and 0.006, respectively). After the propensity score-matched approch, the open group's Pringle time was shorter than that of the laparoscopic group. The total operative time was longer in the laparoscopic than in the open surgery group. This did not change after matching (300 vs. 240 min).

CONCLUSIONS

Laparoscopic surgery is a feasible and safe treatment option for patients with liver tumors, with promising results in terms of morbidity and hospital stay.

Implementation of minimally invasive Ivor Lewis esophagectomy: learning curve of a single high-volume center

Open esophagectomy is considered to be the main surgical procedure in the world for esophageal cancer treatment. Implementing a new surgical technique is associated with learning curve morbidity. The objective of this study is to determine the learning curve based on anastomotic leakage (AL) after implementing minimally invasive Ivor Lewis esophagectomy (MI-ILE) in January 2015. All 257 patients who underwent MI-ILE in a single high-volume center between January 2015 and December 2020 were retrospectively included in this study. The learning curve was evaluated using the standard CUSUM analysis with an expected AL rate of 11%. Secondary outcome parameters were postoperative complications, textbook outcome, and lymph node yield divided by the year of operation. Hierarchical binary logistic regression analysis was used to check for potential confounding variables. The CUSUM analysis showed a learning curve of 179 cases. The mean AL rate decreased from 33.3% in 2015 to 9.5% in 2020 (P = 0.007). There was an increase in the mean lymph node yield from 21 in 2018 to 28 in 2019 (P < 0.001) and textbook outcome from 37.3% in 2015 to 66.7% in 2020 (P = 0.005). A newly implemented MI-ILE has a learning curve of 179 patients based on a reference AL rate of 11% using the CUSUM method. Whether future generation surgeons will show similar learning curve numbers, implicating continuous development of different introduction programs of new techniques, will have to be the focus of future research.

The learning curve of laparoscopic rectal cancer surgery of millennial surgeons: Lessons for a safe implementation in low- and middle-income countries

Objective

This study aimed to analyse the learning curve (LC) in laparoscopic rectal cancer resections of 2 millennial surgeons during the implementation of the first laparoscopic rectal cancer surgery programme in low- and middle-income country (LMIC) cancer centre.

Methods

All consecutive patients operated by two millennial surgeons for primary rectal adenocarcinoma between January 2018 and March 2020 were included. The LC was analysed for operative duration and conversion to open surgery using both cumulative sum (CUSUM) and/or variable life-adjusted display (VLAD) charts.

Results

Eighty-four patients were included, 45 (53.6%) men with a mean age of 57.3 years. Abdominoperineal resection was performed in 31 (36.9%) cases and resections were extended to other organs in 20 (23.8%) patients. Thirteen patients (15.5%) had conversion to open surgery. Using CUSUM, Learning curve based on conversion was completed at 12 cases for the first surgeon versus 10 cases for the second. While using VLAD and learning curve-CUSUM (LC-CUSUM), the cases needed were 26 vs 24 respectively. The median operative duration was 314 min with a LC completed at cases (17 vs. 26), and (18 vs. 29) using, respectively, standard and LC-CUSUM.

Conclusions

This study shows a safe and short LC of millennial surgeons during the implementation of a laparoscopic rectal cancer surgery in an LMIC cancer centre, and the valuable use of modern statistical methods in the prospective assessment of LC safety during surgical training.

Hospital Volume and Textbook Outcomes in Minimally Invasive Hepatectomy for Hepatocellular Carcinoma

BACKGROUND

Hospital volume affects outcomes of patients who underwent resection for hepatocellular carcinoma (HCC). We sought to assess the impact of minimally invasive hepatectomy (MIH) volume on short- and long-term outcomes among patients with HCC.

METHODS

Patients who underwent MIH for HCC from 2010 to 2018 were identified from the National Cancer Database. Multivariable modeling with restricted cubic splines (RCS) was utilized to identify the MIH hospital volume threshold. Textbook outcome (TO) was defined as no conversion to open resection, negative margins after resection (R0), no extended length-of-stay, no readmission, and no 90-day mortality.

RESULTS

Among 3268 patients who underwent MIH for HCC, median age was 65.0 (IQR 59.0-72.0) and the majority was male (n = 2308, 70.6%). MIH hospital volume ranged from 1 to 87 cases, with a median of 13 (IQR 7-23). Overall, 2151 (60.9%) patients achieved TO after resection. While particularly high rates of achievement were found for no 90-day mortality (n = 3106, 95.0%), no readmission (n = 3153, 96.5%), and R0 resection (n = 3,017, 92.3%), other TO components including no conversion to open (n = 2778, 85.0%) and no prolonged LOS (n = 2584, 79.1%) were achieved less frequently. Patients treated at high-volume centers (≥50 MIH cases) were more likely to experience TO (high volume centers, n = 334, 68.7% vs. low volume centers, n = 1656, 59.5%, p < 0.001) and better long-term survival (5-year OS; high volume centers, 64.7% vs. low volume centers, 54.6%, p < 0.001).

CONCLUSIONS

MIH hospital volume was associated with a higher likelihood of achieving TO and improved long-term survival among patients undergoing resection of HCC.

Modeling of Learning Processes Using Continuous-Time Markov Chain for Virtual-Reality-Based Surgical Training in Laparoscopic Surgery

Recent usage of Virtual Reality (VR) technology in surgical training has emerged because of its cost-effectiveness, time savings, and cognition-based feedback generation. However, the quantitative evaluation of its effectiveness in training is still not studied thoroughly. This paper demonstrates the effectiveness of a VR-based surgical training simulator in laparoscopic surgery and investigates how stochastic modeling represented as Continuous-time Markov-chain (CTMC) can be used to explicit the training status of the surgeon. By comparing the training in real environments and in VR-based training simulators, the authors also explore the validity of the VR simulator in laparoscopic surgery. The study further aids in establishing learning models of surgeons, supporting continuous evaluation of training processes for the derivation of real-time feedback by CTMC-based modeling.

A method for identifying the learning curve for the surgical stabilization of rib fractures

BACKGROUND

Surgical stabilization of rib fractures (SSRF) is an accepted efficacious treatment modality for patients with severe chest wall injuries. Despite increased adoption of SSRF, surgical learning curves are unknown. We hypothesized intraoperative duration could define individual SSRF learning curves.

METHODS

Consecutive SSRF operations between January 2017 and December 2021 at a single institution were reviewed. Operative time, as measured from incision until skin closure, was evaluated by cumulative sum methodology using a range of acceptable "missteps" to determine the learning curves. Misstep was defined by extrapolation of accumulated operative time data.

RESULTS

Eighty-three patients underwent SSRF by three surgeons during this retrospective review. Average operative times ranged from 135 minutes for two plates to 247 minutes for seven plates. Using polynomial regression of average operative times, 75 minutes for general procedural requirements plus 35 minutes per plate were derived as the anticipated operative times per procedure. Cumulative sum analyses using 5%, 10%, 15%, and 20% incident rates for not meeting expected operative times, or "missteps" were used. An institutional learning curve between 15 and 55 SSRF operations was identified assuming a 90% performance rate. An individual learning curve of 15 to 20 operations assuming a 90% performance rate was observed. After this period, operative times stabilized or decreased for surgeons A, B, and C.

CONCLUSION

The institutional and individual surgeon learning curves for SSRF appears to steadily improve after 15 to 20 operations using operative time as a surrogate for performance. The implementation of SSRF programs by trauma/acute care surgeons is feasible with an attainable learning curve.

LEVEL OF EVIDENCE

Therapeutic/Care Management; Level IV.

Learning Curve of USgHIFU Ablation for Uterine Fibroids: A Multi-Center Prospective Study

OBJECTIVES

To verify the stability of high-intensity focused ultrasound (HIFU) technology and the feasibility of training programs with learning curve cumulative summation (LC-CUSUM).

METHODS

A total of 12 physicians and 720 cases were equally assigned to the learning group and the control group, with 6 physicians and 360 cases per group. The learning group was treated by physicians without HIFU experience and the control group was treated by experienced physicians. Nonperfused volume (NPV) ratio was assessed by contrast-enhanced magnetic resonance imaging. Technical failure was defined as NPV ratio of uterine fibroids <70% and/or major complication, while <80% was set as a stricter standard of training qualification. LC-CUSUM was used to analyze the learning curve.

RESULTS

Physicians with or without HIFU experience in both groups achieved matchable NPV ratios, where a NPV ratio of 92.52% (16.06) was achieved by experienced physicians and 93.82% (16.95) by inexperienced physicians. No major complication was observed. The results of LC-CUSUM analysis showed that, with the standards of the NPV ratio of 70% or 80%, the learning group mastered the technique on the 11th case and the 16th case, respectively, while the control group was stable.

CONCLUSIONS

HIFU technology stayed stable in operation, with good safety and sound effectiveness, and was easy to learn. NPV ratio of 70% was considered as an appropriate indicator of training qualification. HIFU has remarkable prospects in achieving a NPV ratio of ≥80% without safety being compromised.

Evaluating the learning curve of high intensity focus ultrasound for breast fibroadenoma by CUSUM analysis: a multi-center study

OBJECTIVE

To explore the learning curve of high intensity focus ultrasound (HIFU) treatment for breast fibroadenoma.

METHODS

A database of 110 patients with 255 breast fibroadenomas who underwent HIFU treatment at two different clinical centers (Center 1 and 2) were retrospectively analyzed. The learning curves of HIFU treatment for breast fibroadenoma were drawn by CUSUM analysis in two centers, respectively. According to the inflection point of the learning curves, the treatment was divided into two groups: initial phase and consolidation phase. HIFU treatment parameters were compared between two groups. The effectiveness and safety results were also evaluated.

RESULTS

The inflection points of the learning curves were the 60^th treatment in Center 1 and the 65^th treatment in Center 2. The screening time, treatment time, sonication time and hyperechoic scale change time were significantly shorter in consolidation phase than those in initial phase of the two centers (p < 0.05). There were no differences in non-perfused volume (NPV) ratio and energy effect factor (EEF) between the two groups in Center 1, while in Center 2, these above-mentioned results in consolidation phase led to a greater improvement than those in initial phase. There was no difference of Visual Analogue Scale (VAS) scores and no adverse event observed in both centers.

CONCLUSION

HIFU treatment for breast fibroadenoma was effective and safe. The learning curve of HIFU treatment for breast fibroadenoma can be completed after treating 60-65 tumors without increasing the safety risk.

Four-year experience with more than 1000 cases of total laparoscopic liver resection in a single center

BACKGROUND

Laparoscopic liver resection (LLR) has become a safe surgical procedure that needs additional summarization.

AIM

To review 4 years of total LLR surgeries, exceeding 1000 cases, which were performed at a single center.

METHODS

Patients who underwent LLR at West China Hospital of Sichuan University between January 2015 and December 2018 were identified. Surgical details, including the interventional year, category of liver disease, and malignant liver tumors prognosis, were evaluated. The learning curve for LLR was evaluated using the cumulative sum method. The Kaplan-Meier method was used to perform survival analysis.

RESULTS

Ultimately, 1098 patients were identified. Hepatocellular carcinoma (HCC) was the most common disease that led to the need for LLR at the center (n = 462, 42.08%). The average operation time was 216.94 ± 98.51 min. The conversion rate was 1.82% (20/1098). The complication rate was 9.20% (from grade II to V). The 1-year and 3-year overall survival rates of HCC patients were 89.7% and 81.9%, respectively. The learning curve was grouped into two phases for local resection (cases 1-106 and 107-373), three phases for anatomical segmentectomy (cases 1-44, 45-74 and 75-120), and three phases for hemihepatectomy (cases 1-17, 18-48 and 49-88).

CONCLUSION

LLR may be considered a first-line surgical intervention for liver resection that can be performed safely for a variety of primary, secondary, and recurrent liver tumors and for benign diseases once technical competence is proficiently attained.

Learning Curve of Laparoscopic Kasai Portoenterostomy in a Tertiary Hospital with Low Caseload of Biliary Atresia

Background: Laparoscopic Kasai portoenterostomy (KPE) is generally considered to be technically challenging. A scarcity of studies has particularly focused on the learning curve (LC) of this technique. The present study was aimed to objectively evaluate the LC of laparoscopic KPE in a medical center with relatively low caseload of biliary atresia (BA). Materials and Methods: Thirty-five consecutive pediatric patients treated with laparoscopic KPE for BA by the same surgeon team between 2012 and 2018 were retrospectively enrolled in the present study. Operative time (OT) was selected as the surrogate marker. Cumulative sum (CUSUM) analysis was applied to describe the LC of laparoscopic KPE. Results: The turning point of the CUSUM curve occurred at the 21st case, which divided the curve into two distinct phases, phase 1 (the initial 21 cases) and phase 2 (the remaining 14 cases). The curve was best modeled as a second-order polynomial with equation CUSUM in minutes equal to -0.9161 × case number² + 32.097 × case number + 7.8217 (R² = 0.981). Age at surgery, sex, weight, and preoperative liver function were well balanced between the two phases (each P > .05). The OT was significantly decreased in phase 2 compared with phase 1 (P < .0001). Furthermore, the rates of early jaundice clearance and 2-year native liver survival were higher in phase 2. The rate of postoperative cholangitis was comparable between the two phases. Conclusions: Two characteristic phases of the LC for laparoscopic KPE were identified using CUSUM analysis and represented the initial learning period and the subsequent period of technical mastery, respectively. Surgeons are possible to acquire competency of laparoscopic KPE in relatively low-case centers.

Minimally Invasive Liver Surgery: A Snapshot from a Major Dutch HPB and Transplant Center

BACKGROUND

Minimally invasive liver surgery (MILS) has been progressively adopted on a nationwide scale. The aim of this study is to investigate MILS implementation in a high-volume Dutch hepato-pancreato-biliary and transplant center, which is considered a moderate to low-volume center from a European standpoint.

METHODS

All patients who underwent MILS at Erasmus Medical Center between April 2010 and December 2021 were retrospectively reviewed. Patients' surgical outcomes were compared after stratification according to resections' difficulty and liver cirrhosis.

RESULTS

A total of 212 cases were included. Major liver resections were performed in 24 patients (11%), while minor resections were performed in 188 patients (89%). Among those, 177 (94%) resections were classified as technically minor and 11 (6%) as technically major. Major morbidity was reported in 14/177 patients (8%) after technically minor resections and in 3/24 patients (13%) after major resections. Anatomically and technically major resections had higher intraoperative blood losses (425 (0-2100) vs. 240 (50-110) vs. 100 (0-2400) mL; p-value < 0.001) and longer hospital stay (6 (3-25) vs. 5 (2-9) vs. 3 (1-44); p-value < 0.001) when compared with the technically minor counterpart. Perioperative outcomes were similar when comparing cirrhotic MILS with the non-cirrhotic cohort.

CONCLUSION

MILS program implementation can lead to encouraging surgical outcomes even in low- to moderate-volume centers. Although low procedural volume might be predictive of impaired outcomes, long-standing experience in the HPB and liver transplant field could mitigate low-case volume effects on surgical outcomes.

Postoperative Outcomes After Laparoscopic Liver Resections in Low and High-Volume Centers: A Multicentric Case-Matched Comparative Study

BACKGROUND

Laparoscopic liver resection (LLR) is the gold standard for liver resections. Despite its feasibility and safety in high-volume centers (HVC), its performance is controversial in low-volume centers (LVCs). We aimed to evaluate the results of LLR performed in LVC.

METHODS

Patients who underwent LLR between 2013 and 2019 in three LVCs were compared after case-matching with those in an HVC using the Institut Mutualiste Montsouris LLR Difficulty Score (IMMLDS).

RESULTS

Seventy-six patients treated in three LVCs were matched to 152 in HVCs for age, body mass index, and resection type. The incidence of LLR significantly increased in LVCs over time (2013-2016 vs. 2017-2019) (21.2% vs. 39.3%; p = 0.002 and) while abdominal drainage rate decreased (77.4% vs. 51.1%; p = 0.003). In IMMLDS group I (60 vs. 120 patients), higher Pringle maneuver (43.3% vs. 2.5%; p < 0.0001), median blood loss (175 ml vs. 50 ml; p < 0.0001), abdominal drainage (58.3% vs. 6.6%; p < 0.0001), and conversion rate (8.3% vs. 1.6%, p = 0.04) were observed in LVCs. The overall postoperative morbidity was comparable (Clavien I-II: p = 0.54; Clavien > II: p = 0.71). In IMMLDS groups II-III, Pringle maneuver (56.5% vs. 3.1%; p < 0.0001), blood loss (350 ml vs. 175 ml; p = 0.02), and abdominal drainage (75% vs. 28.3%; p = 0.004) were different; however, postoperative morbidity was not. The surgical difficulty notwithstanding, length of stay (group I: p = 0.13; group II-III: p = 0.93) and R0 surgical margin (group I: p = 0.3; group II-III p = 0.39) were not different between LVCs and HVCs.

CONCLUSIONS

LLR performed at an LVC can be feasible and safe with acceptable morbidity.

Learning curves in minimally invasive hepatectomy: systematic review and meta-regression analysis

BACKGROUND

Minimally invasive hepatectomy (MIH) has become an important option for the treatment of various liver tumours. A major concern is the learning curve required. The aim of this study was to perform a systematic review and summarize current literature analysing the learning curve for MIH.

METHODS

A systematic review of the literature pertaining to learning curves in MIH to July 2019 was performed using PubMed and Scopus databases. All original full-text articles published in English relating to learning curves for both laparoscopic liver resection (LLR), robotic liver resection (RLR), or a combination of these, were included. To explore quantitatively the learning curve for MIH, a meta-regression analysis was performed.

RESULTS

Forty studies relating to learning curves in MIH were included. The median overall number of procedures required in studies utilizing cumulative summative (CUSUM) methodology for LLR was 50 (range 25-58) and for RLR was 25 (16-50). After adjustment for year of adoption of MIH, the CUSUM-derived caseload to surmount the learning curve for RLR was 47.1 (95 per cent c.i. 1.2 to 71.6) per cent; P = 0.046) less than that required for LLR. A year-on-year reduction in the number of procedures needed for MIH was observed, commencing at 48.3 cases in 1995 and decreasing to 23.8 cases in 2015.

CONCLUSION

The overall learning curve for MIH decreased steadily over time, and appeared less steep for RLR compared with LLR.

Clinical outcome and repair integrity after arthroscopic rotator cuff repair significantly improved during the surgeon's learning curve

HYPOTHESIS AND BACKGROUND

Whether learning curve could affect the surgical outcome after arthroscopic rotator cuff repair is still unknown. The purpose of this study was to evaluate surgical learning curve for clinical outcome and retear rate after arthroscopic rotator cuff repairs that were performed by the beginner shoulder surgeon. We hypothesized that clinical outcome and retear rate would improve over time with the accumulation of a surgeon's experience.

METHODS

This retrospective study consisted of 200 consecutive patients who had arthroscopic rotator cuff repairs, performed by a single surgeon between 2011 and 2018. We included symptomatic rotator cuff tears involving the supraspinatus/infraspinatus and/or subscapularis tendon and follow-up magnetic resonance imaging evaluations of repair integrity 6 months after surgery. Surgeon's learning was evaluated with calculation of cumulative retear rate and cumulative summation (CUSUM) analysis. Clinical outcomes and the retear rates were compared between group A (the first-half 100 patients) and group B (the latter-half of 100 patients).

RESULTS

The mean follow-up period was 21 months (range, 12-55). The overall retear rate was 13% (26 patients). The CUSUM analysis showed that after patient number 97, the curve was maintained below the level of acceptable failure rate, suggesting the competency was obtained consistently. Comparing between groups, retear rate showed significant decrease from 18% in group A to 8% in group B (P = .036). Notably, retear rate in small to medium-sized tears (<3 cm) significantly decreased from 26% (12 of 46 patients) in group A to 2% (1 of 49 patients) in group B (P = .001). However, analysis in large to massive tears (≥3 cm) failed to show difference between groups (30%, 6 of 20, in group A and 25%, 6 of 24, in group B; P = .711). In multivariate analysis, higher fatty infiltration of the supraspinatus muscle (P = .008), more severe muscle atrophy of the teres minor (P = .010), and belonging to group A (P = .011) were associated with retear.

CONCLUSION

Clinical outcomes and retear rate after arthroscopic rotator cuff repairs significantly improved during the learning curve period of a beginner shoulder surgeon.

Short-term outcomes of laparoscopic versus open hepatectomy in the elderly patient: systematic review and meta-analysis

BACKGROUND AND AIM

Favorable outcomes of laparoscopic hepatectomy (LH) over open hepatectomy (OH) have been demonstrated. LH offers less postoperative morbidity, less blood loss, and shorter hospital stay, while maintaining oncological safety. Only limited evidence about outcomes of LH in elderly is currently available. Therefore, this study aimed to compare short term outcomes of LH to OH for patients >65 years.

METHODS

A systematic review and meta-analysis were performed according to Cochrane guidelines. Embase, PubMed, Cochrane Library, and Google Scholar were searched to identify eligible studies. Studies were included if they compared LH to OH, and focused on an elderly population, or had a majority of patients >65 years. Perioperative and postoperative outcomes were analyzed.

RESULTS

Thirteen studies with 1174 patients (LH:532, OH:642) were included for analysis. When compared to OH, elderly undergoing LH had significantly less postoperative complications (risk ratio [RR]0.52; 95% confidence interval (CI):0.43-0.63), less blood loss (mean difference [MD]-198.58; 95% CI:-299.88 to -97.28), and shorter length of stay (MD-4.83; 95%CI:-7.91 to -1.84), while oncological safety was non-inferior (RR1.04; 95%CI:1.00-1.08).

CONCLUSIONS

Within the elderly population LH seems to be superior to OH, concerning short-term outcomes. However, for broader applicability more trials are needed including more difficult and major resections.

Liver resection safety in a developing country: Analysis of a collective learning curve

AIM OF THE STUDY

To analyze the collective learning curve in the performance of safe liver resections, using the decrease of severe postoperative complications (SPC) as a proxy for overall safety competency.

MATERIAL AND METHODS

This was a retrospective analysis of a prospective database in the setting of a liver surgery program implementation in a tertiary center in Morocco. The 100 first consecutive cases of elective liver resections starting from January 1st, 2018 were included in the analysis. SPC were defined as CD>IIIa during the first 90 postoperative days. We used a cumulative sum (CUSUM) technique to determine the number of cases required to achieve safety competency. We then compared case characteristics before and after the learning curve completion.

RESULTS

SPC occurred in 15 cases (15%), including 5 deaths (5%). The CUSUM chart revealed a learning curve completion at the 49th case, marked by an inflection point towards the decrease in SPC (24.5% vs 5.9%; P=0.009). In period 2 (after), cases were associated with less diabetes, less synchronous digestive resection, more cirrhosis, and more prolonged preoperative chemotherapy. The rates of major resection (30.6% vs 29.9%; P=0.89) and biliary reconstruction were comparable, as were the operating time, and estimated blood loss.

CONCLUSION

Approximately 50 cases were required to complete the learning curve and improve the overall safety of liver resection. In our setting, the learning curve chronology was consistent with collective measures, including team stabilization and protocol development.

The Learning Curve for Thermal Ablation of Liver Cancers: 4,363-Session Experience for a Single Central in 18 Years

This study aimed to explore the special efforts required to achieve proficiency in performing thermal ablation of liver cancers, including tumors in difficult locations, and clarify the effects of handing-down teaching on the corresponding process. Major complications of patients receiving percutaneous thermal ablation of liver cancer were analyzed. Polynomial fitting was used to describe the connection between major complication rates and special experience. Learning curve of major complications was plotted both for the whole group and for each operator, respectively. Tumors in difficult locations were further studied. A total of 4,363 thermal ablation sessions were included in this study. 143 of 4,363 patients had major complications, corresponding to an incidence rate of 3.27%. 806 thermal ablation sessions were performed for tumors in difficult locations. The major complication rate of these sessions is 6.33%. According to the trend of the learning curve of the 4363 patients, the experience of the whole group can be classified into five stages, that is, the high-risk, relatively stable, unstable, proficient and stable periods. A learning curve for an individual operator can be classified into the high-risk, proficient and stable periods. The major complication rates for the chronologically first, second and third operator of the group are 3.23, 3.35, and 3.31%, respectively. The special experience needed to bypass the first stage corresponds to 410, 510, and 440 sessions, the second stage, 1850, 850, and 870 sessions, by the three operators, respectively. The major complication rates for the tumors in difficult locations for the first, second and third operator were 7.04, 5.53, and 5.98%, respectively. For the tumors in difficult locations, the special experience needed to bypass the first stage corresponds to 150, 130, and 140 sessions, the second stage, 290, 175, and 185 sessions, by the three operators, respectively. In conclusion, the learning process of an operator percutaneous thermal ablation for liver cancer can be classified into three stages. The major complication rate for tumors in difficult locations were higher than that for all tumors. Handing-down teaching can make an operator arrive at the third stage earlier but not the second stage.

A falciform ligament flap surface sealing technique for laparoscopic and robotic-assisted liver surgery

Whether sealing the hepatic resection surface after liver surgery decreases morbidity is still unclear. Nevertheless, various methods and materials are currently in use for this procedure. Here, we describe our experience with a simple technique using a mobilized falciform ligament flap in minimally invasive liver surgery (MILS). We retrospectively analyzed the charts from 46 patients who received minor MILS between 2011 and 2019 from the same surgical team in a university hospital setting in Germany. Twenty-four patients underwent laparoscopic liver resection, and 22 patients received robotic-assisted liver resection. Sixteen patients in the laparoscopic group and fourteen in the robotic group received a falciform ligament flap (FLF) to cover the resection surface after liver surgery. Our cohort was thus divided into two groups: laparoscopic and robotic patients with (MILS + FLF) and without an FLF (MILS-FLF). Twenty-eight patients (60.9%) in our cohort were male. The overall mean age was 56.8 years (SD 16.8). The mean operating time was 249 min in the MILS + FLF group vs. 235 min in the MILS-FLF group (p = 0.682). The mean blood loss was 301 ml in the MILS + FLF group vs. 318 ml in the MILS-FLF group (p = 0.859). Overall morbidity was 3.3% in the MILS + FLF group vs. 18.8% in the MILS-FLF group (p = 0.114). One patient in the MILS-FLF group (overall 2.2%), who underwent robotic liver surgery, developed bile leakage, but this did not occur in the MILS + FLF group. Covering the resection surface of the liver after minor minimally invasive liver resection with an FLF is a simple and cost-effective technique that does not prolong surgical time or negatively affect other perioperative parameters. In fact, it is a safe add-on step during MILS that may reduce postoperative morbidity. Further studies with larger cohorts will be needed to substantiate our proof of concept and results.

Impact of First Assistant Surgeon Experience on the Perioperative Outcomes of Laparoscopic Hepatectomies

Introduction: This study aims to evaluate the impact of first assistant surgeon experience on the outcomes of laparoscopic hepatectomies in a university-affiliated teaching hospital. Methods: This is a retrospective study comparing outcomes of laparoscopic hepatectomies with first assistant surgeons of varying experience levels. Three hundred and eighty-five consecutive laparoscopic hepatectomies performed in a tertiary university-affiliated teaching hospital from 2012 to 2018 were included and stratified into three cohorts-Group 1 in which assistants were residents, Group 2 for fellows, and Group 3 for attendings. Baseline clinicopathologic variables and outcome measures were analyzed using the augmented inverse probability of treatment weighting approach, which is a propensity score-based method that combines aspects of covariate adjustment and inverse probability weighting. Results: Group 3 comprised a greater proportion of advanced- and expert-level surgeries based on the Iwate criteria; 33.8%, 32.2%, and 46.0% of patients underwent advanced- and expert-level surgeries in Groups 1, 2, and 3, respectively. Group 3 had consistently higher operative times as well as more frequent use and longer duration of Pringle's maneuver (P < .05). The median operative times for Groups 1, 2, and 3 were 195, 195, and 290 minutes, respectively. Pringle's maneuver was applied in 26.9%, 33.9%, and 60.2% of patients with a corresponding median duration of 35, 36, and 45 minutes, respectively. None of the other perioperative and postoperative outcomes demonstrated statistically significant differences. Conclusion: With an appropriate selection of cases, participation of residents as first assistants in laparoscopic hepatectomies can be encouraged without compromise in perioperative outcomes.