Safely extending the indications of laparoscopic liver resection: When should we start laparoscopic major hepatectomy?

Association between surgical difficulty and tumor location based on subsegments of the Glisson branches in laparoscopic liver resection

Background

Laparoscopic liver resection has a steep learning curve, and multiple difficulty-scoring systems have been proposed to support safe implementation. Though the IWATE scoring system is widely used, the rationale for its tumor location score is unclear. The objective of our study was to establish a more accurate definition of tumor location based on subsegments of the Glisson branches.

Methods

We included 176 patients who underwent laparoscopic liver resection between January 2017 and February 2024, excluding those who underwent multiple or concomitant resections of other organs. Tumor location was defined by the most proximal subsegment of the Glisson branches (1sp, Spiegel; 1pc, para-caval; 1cp, caudate process; 3a, apical; 3b, basal; 4a; 4b; 5v, ventral; 5d, dorsal; 6v; 6d; 6 L, lateral; 7v; 7d; 8v; 8d).

Results

Within each segment, comparing operative time between subsegments showed significant differences, except for S1 (3a vs. 3b, p = 0.011; 4a vs. 4b, p = 0.001; 5v vs. 5d, p = 0.012; 6v vs. 6d vs. 6 L, p = 0.007; 7v vs. 7d, p = 0.003; 8v vs. 8d, p = 0.030). Blood loss significantly differed except for S1 (3a vs. 3b, p = 0.018; 4a vs. 4b, p = 0.002; 5v vs. 5d, p = 0.016; 6v vs. 6d vs. 6 L, p = 0.011; 7v vs. 7d, p = 0.013; 8v vs. 8d, p < 0.001). The incidence of postoperative complications did not differ significantly; however, hospital stay was significantly different only in S4 (4a vs. 4b, p = 0.049).

Conclusions

There are significant differences in the difficulty of laparoscopic liver resection among subsegments. More detailed scoring based on subsegments may improve accuracy, and we propose a new scoring system.

Indications for and limitations of laparoscopic anatomical liver resection: assessment of postoperative complications stratified by complexity of liver resection

BACKGROUND

Although complex anatomical liver resections are more often being performed laparoscopically, the short-term outcomes following laparoscopic anatomical liver resection (LALR), its optimal indications, and limitations remain unclear. This study aimed to clarify the indications for and limitations of LALR by assessing the short-term outcomes.

METHODS

This retrospective study included 233 patients who underwent LALR. The complexity of LALR was categorized into three levels: Grade I (low), grade II (moderate), and grade III (high). Short-term outcomes were compared among these groups, and the risk factors for severe morbidity were identified.

RESULTS

The patients' backgrounds were similar across the three groups. Intraoperative blood loss, Pringle maneuver time, and postoperative hospital stay were comparable between grade I (n = 59) and grade II (n = 65) LALR but were greater for grade III (n = 109). The transfusion and conversion rates were similar among the three groups. The operative time increased with the rise in difficulty grade. The rate of severe morbidity was 3.4% in grade I, 6.2% in grade II, and 16.5% in grade III LALR (P = 0.012). Multivariable analysis identified three perioperative risk factors for severe morbidity: Operative time of ≥ 540 min (odds ratio [OR] = 4.762, P = 0.009), intraoperative blood loss of ≥ 350 mL (OR = 3.982, P = 0.024), and preoperative serum albumin of ≤ 3.8 g/dL (OR = 3.518, P = 0.035).

CONCLUSIONS

Grade II LALR can be performed with the same level of safety as grade I LALR. However, grade III LALR has a higher complication rate than grades I and II LALR, and the risk increases further due to longer operative time and greater blood loss.

Short-term outcomes of laparoscopic central hepatectomy: a comparison with open surgery

PURPOSE

Laparoscopic liver resection has advantages over open liver resection, including reduced blood loss and shorter hospital stays. Laparoscopic central hepatectomy (CH) is a highly challenging procedure, and such outcomes can only be achieved with a high level of expertise in laparoscopic liver surgery. Laparoscopic CH remains challenging, with safety and efficacy unclear. This study retrospectively evaluated the intra- and short-term outcomes of laparoscopic versus open CH and assessed safety and efficacy of laparoscopic surgery.

METHODS

CH included anterior sectionectomy (AS) and central bisectionectomy (CBS) (excluding cases with biliary reconstruction). The study comprised 38 patients receiving CH in our department from January 2010 to November 2023.

RESULTS

The laparoscopic group included 14 cases and the open group 24. AS/CBS was performed in 14/10 open group cases and 6/8 laparoscopic group cases. Short-term surgical outcomes showed no significant between-group difference in operative time, but the laparoscopic group lost significantly less blood (250 vs. 985 mL; p = 0.001) and the transfusion rate was lower (14% vs. 46%; p = 0.004). Among postoperative outcomes, incidence of bile leakage was not significantly different (33% vs. 42%; p = 0.42), but the laparoscopic group had significantly less postoperative ascites (0% vs. 17%; p = 0.047), fewer surgical site infections (SSI) (0% vs. 21%; p = 0.02), and shorter postoperative hospital stay (14 vs. 30 days; p = 0.005). The risk factor for bile leakage in CH by univariate and multivariate analysis was tumor proximity to the right anterior Glissonean pedicle (OR = 6.84; 95% CI = 1.67-32.7; p = 0.01).

CONCLUSION

Laparoscopic CH could be performed safely. Compared to open surgery, laparoscopic CH was effective in reducing blood loss, postoperative ascites, SSIs, and shortening postoperative hospital stay. However, tumors close to the root of the right anterior Glissonean pedicle were considered a risk factor for postoperative bile leakage and require caution.

Utility of a novel scoring system for difficulty of pure laparoscopic hepatectomy for intrahepatic cholangiocarcinoma

Despite the growing adoption of laparoscopic hepatectomy (LH) for intrahepatic cholangiocarcinoma (ICC), there is no scoring system available designed to evaluate its surgical complexity. This paper aims to introduce a novel difficulty scoring system (DSS), designated as the Wei-DSS, exclusively tailored to assess the surgical difficulty of pure LH for ICC. We retrospectively collected clinical data from ICC patients who underwent pure LH at our institution, spanning from November 2018 to May 2024. Patients were categorized into two levels of Wei-DSS scores (low-difficulty [5-6], and high-difficulty [7-10]) determined by tumor characteristics, liver texture, resection extent and tumor marker levels. A total of 104 patients were enrolled in this study including a low-difficulty (LD) group comprising 47 patients and a high-difficulty (HD) group comprising 57 patients. Perioperative comparisons indicated that the HD group was significantly associated with a longer operation time (318.14 ± 125.89 min vs. 222.83 ± 119.03 min, P < 0.001), higher rates of intraoperative blood transfusions (59.6% vs. 27.7%, P = 0.001), and increased rates of postoperative complications (84.2% vs. 48.9%, P < 0.001) compared to the LD group. The receiver operating characteristic (ROC) curve analysis indicated that the Wei-DSS demonstrated superior predictive accuracy over the Major/Minor Classification for predicting postoperative complication rates (area under the curve [AUC] 0.702 vs. 0.622) and operating time (AUC 0.720 vs. 0.604 ). The Wei-DSS score may have the potential to assist surgeons in categorizing ICC patients with varying levels of surgical difficulty of LH, though it warrants further validations across multiple centers to solidify its efficacy and reliability.

OCRClassifier: integrating statistical control chart into machine learning framework for better detecting open chromatin regions

Open chromatin regions (OCRs) play a crucial role in transcriptional regulation and gene expression. In recent years, there has been a growing interest in using plasma cell-free DNA (cfDNA) sequencing data to detect OCRs. By analyzing the characteristics of cfDNA fragments and their sequencing coverage, researchers can differentiate OCRs from non-OCRs. However, the presence of noise and variability in cfDNA-seq data poses challenges for the training data used in the noise-tolerance learning-based OCR estimation approach, as it contains numerous noisy labels that may impact the accuracy of the results. For current methods of detecting OCRs, they rely on statistical features derived from typical open and closed chromatin regions to determine whether a region is OCR or non-OCR. However, there are some atypical regions that exhibit statistical features that fall between the two categories, making it difficult to classify them definitively as either open or closed chromatin regions (CCRs). These regions should be considered as partially open chromatin regions (pOCRs). In this paper, we present OCRClassifier, a novel framework that combines control charts and machine learning to address the impact of high-proportion noisy labels in the training set and classify the chromatin open states into three classes accurately. Our method comprises two control charts. We first design a robust Hotelling T2 control chart and create new run rules to accurately identify reliable OCRs and CCRs within the initial training set. Then, we exclusively utilize the pure training set consisting of OCRs and CCRs to create and train a sensitized T2 control chart. This sensitized T2 control chart is specifically designed to accurately differentiate between the three categories of chromatin states: open, partially open, and closed. Experimental results demonstrate that under this framework, the model exhibits not only excellent performance in terms of three-class classification, but also higher accuracy and sensitivity in binary classification compared to the state-of-the-art models currently available.

Towards a Standardization of Learning Curve Assessment in Minimally Invasive Liver Surgery

OBJECTIVE

The aim was to analyze the learning curves of minimal invasive liver surgery(MILS) and propose a standardized reporting.

SUMMARY BACKGROUND DATA

MILS offers benefits compared to open resections. For a safe introduction along the learning curve, formal training is recommended. However, definitions of learning curves and methods to assess it lack standardization.

METHODS

A systematic review of PubMed, Web of Science, and CENTRAL databases identified studies on learning curves in MILS. The primary outcome was the number needed to overcome the learning curve. Secondary outcomes included endpoints defining learning curves, and characterization of different learning phases(competency, proficiency and mastery).

RESULTS

60 articles with 12'241 patients and 102 learning curve analyses were included. The laparoscopic and robotic approach was evaluated in 71 and 18 analyses and both approaches combined in 13 analyses. Sixty-one analyses (60%) based the learning curve on statistical calculations. The most often used parameters to define learning curves were operative time (n=64), blood loss (n=54), conversion (n=42) and postoperative complications (n=38). Overall competency, proficiency and mastery were reached after 34 (IQR 19-56), 50 (IQR 24-74), 58 (IQR 24-100) procedures respectively. Intraoperative parameters improved earlier (operative time: competency to proficiency to mastery: -13%, 2%; blood loss: competency to proficiency to mastery: -33%, 0%; conversion rate (competency to proficiency to mastery; -21%, -29%), whereas postoperative complications improved later (competency to proficiency to mastery: -25%, -41%).

CONCLUSIONS

This review summarizes the highest evidence on learning curves in MILS taking into account different definitions and confounding factors. A standardized three-phase reporting of learning phases (competency, proficiency, mastery) is proposed and should be followed.

Лапароскопическое изъятие левого латерального сектора печени у прижизненного донора.. [DOI: 10.61726/5567.2024.63.97.001]

В педиатрической практике трансплантация фрагментов печени позволяет достичь высоких результатов [Bowring M.G., 2020] и, при этом, полностью гарантировать безопасность родственных доноров. В то же время, при выполнении трансплантации «взрослый – ребенок», практически отсутствуют этические вопросы, поскольку, чаще всего, донором является один из родителей реципиента. Тем не менее, важной задачей остается создание условий для ускорения реабилитации и минимизации хирургической травмы у донора, в этой связи, внедрение миниинвазивных методов имеет особое значение. В последние два десятилетия миниинвазивные подходы к резекциям печени прочно вошли в арсенал крупных гепатобилиарных центров. Это стало возможным благодаря накопленному опыту открытой хирургии печени, а также технологическому прогрессу [Morise Z., 2017]. Однако, применение лапароскопического подхода у родственных доноров фрагментов печени по-прежнему остается предметом живого интереса в трансплантологических центрах всего мира. Первые сравнительные исследования оказались весьма обнадеживающими и продемонстрировали перспективность этого подхода [Broering D. C., 2018]. Накопление подобного опыта, анализ кривой обучения, стандартизация хирургической техники по-прежнему являются важными вопросами развития данного направления. В России лапароскопическое изъятие фрагмента печени для последующей трансплантации было впервые выполнено в ФГБУ «НМИЦ ТИО им. Академика В. И. Шумакова» в 2016 году. Также, в России впервые в мире произведено полностью лапароскопическое изъятие одновременно фрагмента печени и почки для последующей трансплантации детям [Готье С. В., 2016, Gautier S. V., 2019]. Цель исследования. Оптимизация хирургической техники и результатов лапароскопического изъятия левого латерального сектора у прижизненных доноров фрагмента печени на основании анализа накопленного опыта. Задачи исследования. 1. Сравнить результаты открытого и лапароскопического изъятия левого латерального сектора у прижизненных доноров. 2. Определить критерии селекции прижизненных доноров для лапароскопического изъятия левого латерального сектора печени. 3. Стандартизировать хирургическую технику выполнения лапароскопической латеральной секторэктомии печени. 4. Оценить результаты трансплантации левого латерального сектора, полученного открытым и лапароскопическим путём, у реципиентов. 5. Изучить кривую обучения выполнения лапароскопической латеральной секторэктомии печени у родственного донора. Научная новизна. На сегодняшний день, лапароскопическое изъятие левого латерального сектора печени у прижизненных доноров выполняется лишь в нескольких центрах в мире. Суммарный накопленный опыт по всему миру не превышает 500 операций. В настоящее время, по данным литературы, существует лишь несколько исследований, посвященных данной тематике. Проведение псевдорандомизации позволило объективизировать результаты и увеличить их достоверность. Изучение кривой обучения выполнения лапароскопической латеральной секторэктомии печени позволяет оценить потенциал внедрения данной методики в клинические центры. Новыми являются данные сравнительного анализа клинических результатов проведения открытого и лапароскопического изъятия левого латерального сектора печени у живых доноров, а также сравнительного анализа результатов трансплантаций у реципиентов, получивших соответствующие трансплантаты. Новыми являются разработанные рекомендации по селекции доноров для лапароскопического изъятия левого латерального сектора. Впервые разработаны алгоритмы, протоколы и рекомендации по выполнению хирургического вмешательства лапароскопической резекции левого латерального сектора печени у родственного донора. Практическая значимость исследования. Впервые в России на основании доказательной медицины установлена клиническая эффективность и безопасность лапароскопической левой латеральной секторэктомии у прижизненных доноров фрагмента печени. Разработана и стандартизирована хирургическая техника, позволяющая максимально снизить интра- и послеоперационные осложнения у доноров левого латерального сектора печени, а также получать трансплантаты высокого качества. Внедрение научных разработок в клиническую практику позволит: • обезопасить хиругическое пособие у доноров путем снижения интраоперационой кровопотери и минимизации хирургической травмы; • ускорить послеоперационную реабилитацию у доноров; • получить хороший косметический эффект после оперативного пособия. Методология и методы исследования. В исследовании проведен статистический анализ клинических данных, результатов оперативного вмешательства, лабораторных и инструментальных исследований до, во время и после резекции левого латерального сектора печени у родственных доноров и трансплантации левого латерального сектора детям. Проведен статистический анализ клинических данных, результатов трансплантаций левого латерального сектора печени у реципиентов, получивших трансплантат от доноров, оперированных открыто и лапароскопически. Основные положения, выносимые на защиту 1. Лапароскопическое изъятие левого латерального сектора является эффективным и безопасным методом, позволяющим уменьшить операционную травму и ускорить реабилитацию, а также получить хороший косметический эффект. 2. Результаты трансплантации левого латерального сектора печени детям от доноров, оперированных лапароскопически, сопоставимы с аналогичными от доноров, оперированных по классической открытой методике. 3. Унификация хирургической методики позволяет уменьшить длительность операции, а также позволяет добиться максимального снижения интра- и послеоперационных осложнений у доноров. 4. Более строгая селекция доноров для лапароскопического изъятия левого латерального сектора позволяет снизить риск интраоперационных осложнений на этапе становления методики и наработки хирургического опыта. Степень достоверности и апробация результатов Достоверность результатов определяется объемом проведенных исследований с использованием современных методов статистической обработки. Апробация работы состоялась 15 июля 2020 года на совместной конференции научных и клинических подразделений федерального государственного бюджетного учреждения «Национальный медицинский исследовательский центр трансплантологии и искусственных органов имени академика В.И. Шумакова» Министерства здравоохранения Российской Федерации (ФГБУ «НМИЦ ТИО им. ак. В.И. Шумакова» Минздрава России) и кафедры трансплантологии и искусственных органов Института клинической медицины имени Н.В. Склифосовского Федерального государственного автономного образовательного учреждения высшего образования Первый осковский государственный медицинский университет имени И.М. Сеченова Министерства здравоохранения Российской Федерации (Сеченовский Университет). Материалы диссертации доложены и обсуждены на III Российском национальном конгрессе «Трансплантация и донорство органов» (Москва 2017г.), на 15-м международном конгрессе по донорству органов (ISODP, Дубай, ОАЭ), на 10-м Всероссийском съезде трансплантологов (Москва, 2020 г.), и на международном съезде трансплантологического общества (The Transplantation Society, Сеул, Южная Корея, 2020г.). Внедрение результатов исследования в практику Результаты исследования используются в хирургическом отделении № 2 федерального государственного бюджетного учреждения «Национальный медицинский исследовательский центр трансплантологии и искусственных органов имени академика В.И. Шумакова» Министерства здравоохранения Российской Федерации, в отделении онкологии и детской хирургии федерального государственного бюджетного учреждения «Национальный медицинский исследовательский центр детской гематологии, онкологии и иммунологии имени Дмитрия Рогачёва» Министерства здравоохранения Российской Федерации, а также в образовательной программе кафедры трансплантологии и искусственных органов Института клинической медицины имени Н.В. Склифосовского Федерального государственного автономного образовательного учреждения высшего образования Первый осковский государственный медицинский университет имени И.М. Сеченова Министерства здравоохранения Российской Федерации (Сеченовский Университет). Личный вклад автора. Автор принимал непосредственное участие в разработке концепции и постановке задач исследования; в оперативных вмешательствах у родственных доноров печени и операциях по трансплантации печени; самостоятельно осуществлял сбор материала для исследования. Автором самостоятельно сформирована база данных, проведена статистическая обработка, анализ и интерпретация полученных результатов. Публикации по теме диссертации По теме диссертации опубликовано 15 научных работ, из них 3 статьи в центральных рецензируемых журналах, рекомендованных ВАК, а также 2 статьи в международных журналах.

Risk-Adjusted Assessment of the Learning Curve for Pure Laparoscopic Donor Hepatectomy for Adult Recipients

BACKGROUND

Studies on pure laparoscopic donor hepatectomy (PLDH) have been reported. However, only few studies have reported on the learning curve of PLDH. In this report, we aimed to determine the learning curve of PLDH in adult patients using cumulative sum (CUSUM) and risk-adjusted CUSUM (RA-CUSUM) analyses.

METHODS

The data of donors who underwent PLDH at a single center between December 2012 and May 2022 were retrospectively reviewed. The learning curve was evaluated using the CUSUM and RA-CUSUM methods based on surgery duration.

RESULTS

Forty-eight patients were finally included in the present study. The mean operation time was 393.6 ± 80.3 min. PLDH was converted to laparotomy in three cases (6.3%). According to the Clavien-Dindo classification, nine cases (18.8%) had higher-than-grade III postoperative complications and the most frequent complications were biliary complications. The CUSUM graph shows two peaks, at the 13th and 27th case. The multivariate analysis revealed that a body mass index ≥ 23 kg/m2 and intraoperative cholangiography were the only factors that were independently associated with longer operation time. Based on these results, an RA-CUSUM analysis was performed to assess the learning curve, which showed a decrease in the learning curve after 33 to 34 PLDH procedures.

CONCLUSIONS

A learning curve effect was demonstrated in this study after 33 to 34 PLDH procedures. There are relatively many biliary complications, and it is necessary to further examine the method of bile duct transection.

Delimiting Low Level of Difficulty Scoring System Based on the Extent of Resection Difficulty Scoring System for Laparoscopic Liver Resection

Background: The difficulty scoring system based on the extent of resection (DSS-ER) is a common tool for assessing the difficulty and risk of laparoscopic liver resection (LLR), but DSS-ER fails to comprehensively and accurately assess low level for beginners. Methods: The 93 cases of LLRs for primary liver cancer in the general surgery department of the Second Affiliated Hospital of Guangxi Medical University from 2017 to 2021 were retrospectively analyzed. The low level of DSS-ER difficulty scoring system was reclassified into three grades. The intraoperative and postoperative complications were compared among different groups. Results: There were significant differences in the operative time, blood loss, intraoperative allogeneic blood transfusion, conversion to laparotomy, and allogeneic blood transfusion among the different groups. Meanwhile, the postoperative complications were mainly pleural effusion and pneumonia, and the incidence of grade III was higher compared with other two grades. No significant difference existed in the postoperative biliary leakage and liver failure among three grades. Conclusions: This reclassified low level of DSS-ER difficulty scoring system has certain clinical value for LLR beginners to complete the corresponding learning curve.

Laparoscopic versus open resection of hepatocellular carcinoma in patients with cirrhosis

Hepatocellular carcinoma (HCC) is the sixth commonest malignancy worldwide, and the fourth-leading cause of cancer related death. Partial liver resection (LR) forms the mainstay of therapy for suitable patients with preserved liver function. In recent years, significant advances in surgical technology, refinement of operative techniques and improvements in peri-operative care have facilitated the widespread adoption of laparoscopic liver resection (LLR) with encouraging outcomes. Liver cirrhosis (LC) is present in up to 80% of patients with HCC, and adds a further dimension of complexity to LR. Cirrhotic patients have a propensity for greater intraoperative blood loss as well as increased postoperative complications such as refractory ascites and posthepatectomy liver failure. Tumor localization within the fibrotic parenchyma is challenging, giving rise to concerns about resection margin status. Patients are also at higher risk of developing metachronous lesions, which affects long-term survival. Presently, the exact role of LLR in HCC patients with underlying LC is not well-defined. Current evidence suggests that LLR offers a multitude of benefits in the short-term such as reduced blood loss and blood transfusion requirements and lower morbidity, when compared to open resection. Oncologic adequacy and long-term survival do not appear to be compromised. Special consideration must be given for LLR in patients with advanced cirrhosis, or those who require extensive major hepatectomies. We present here a brief review of the literature surrounding LLR for HCC on a background of LC.

An Ex Situ Cadaver Liver Training Model Continuously Pressurized to Simulate Specific Skills Involved in Laparoscopic Liver Resection: the Lap-Liver Trainer

BACKGROUND

Laparoscopic liver resection (LLR) requires delicate skills. The aim of the study was to develop a training model mimicking as much as possible intraoperative bleeding and bile leakage during LLR. We also assessed the educational value of the training model.

METHODS

The Lap-liver trainer (LLT) combined a continuously pressurized ex situ cadaver liver and a customized mannequin. The customized mannequin was designed by computer-aided design and manufactured by 3D printing. The left lateral sectionectomy (LLS) was chosen to assess the feasibility of a LLR with the LLT. Eighteen volunteers were recruited to perform LLS and to assess the educational value of the LLT using a Likert scale.

RESULTS

The customized mannequin consisted of a close laparoscopic training device based on a simplified reconstruction of the abdominal cavity in laparoscopic conditions. Ex situ cadaver livers were pressurized to simulate blood and bile supplies. Each expert surgeon (n = 3) performed two LLS. They were highly satisfied of simulation conditions (4.80 ± 0.45) and strongly recommended that the LLT should be incorporated into a teaching program (5.00 ± 0.0). Eight novice and 4 intermediate surgeons completed a teaching program and performed a LLS. Overall, the level of satisfaction was high (4.92 ± 0.29), and performing such a procedure under simulation conditions benefited their learning and clinical practice (4.92 ± 0.29).

CONCLUSIONS

The LLT could provide better opportunities for trainees to acquire and practice LLR skills in a more realistic environment and to improve their ability to deal with specific events related to LLR.

Cost analysis of robotic versus open hepatectomy: Is the robotic platform more expensive?

The robotic platform is perceived to be more expensive when compared to laparoscopic and open operations. We aimed to compare the perioperative costs of robotic vs. open hepatectomy for the treatment of liver tumors at our facility. We followed 370 patients undergoing robotic and open hepatectomy for benign and malignant liver tumors. Demographic, perioperative, cost and payment data were collected and analyzed. For illustrative purposes, the data were presented as median (mean ± SD). Two hundred sixty-seven robotic and 104 open hepatectomies were analyzed. There were no significant differences in perioperative variables between the two cohorts. The robotic group had a significantly lower estimated blood loss (EBL) (135 [208 ± 244.8] vs 300 [427 ± 502.5] ml, p < 0.0001), smaller lesion size (4 [5 ± 3.6] vs 5[6 ± 4.9] cm, p = 0.0052), shorter length of stay (LOS) (4 [4 ± 3.4] vs 6[8 ± 5.7] days, p < 0.0001) and decreased 90-day mortality (3 vs 7 p = 0.0028). There were no significant differences between the two groups any cost variable. The open group received significantly higher reimbursement ($29,297 [62,962 ± 75,377.96] vs $19,102 [38,975 ± 39,362.11], p < 0.001) and profit ($5005 [30,981 ± 79,541.09] vs $- 6682 [6146 ± 40,949.65], p < 0.001). Robotic hepatectomy is associated with lower EBL, shorter LOS and less mortality. There was no greater cost associated with the robotic platform despite a reduced reimbursement and profit.

Impact of tumor size on the difficulty of minimally invasive liver resection

INTRODUCTION

We performed this study in order to investigate the impact of tumour size on the difficulty of MILR, as well as to elucidate the optimal tumour size cut-off/s to distinguish between 'easy' and 'difficult' MILRs.

MATERIALS AND METHODS

This is retrospective review of 603 consecutive patients who underwent MILR between 2006 and 2019 of which 461 met the study inclusion criteria. We first conducted an exploratory analysis to visualize the associations between tumor size and various surrogates of laparoscopic difficulty in order to determine to optimal tumor size cutoff for stratification. Visual inspection of flexible spline-based models as well as quantitative evidence determined that perioperative outcomes differed between patients with tumor size of 30-69 mm and tumours ≥70 mm. These cutoffs were used for further downstream analyses.

RESULTS

The cohort of 461 patients was divided into 3 groups based on tumour diameter size. Patients with larger tumours experienced longer operating times ((PGroup 2 vs 1<0.001, PGroup 3 vs 1<0.001, PGroup 3 vs 2<0.001), higher blood loss (PGroup 2 vs 1<0.001, PGroup 3 vs 1<0.001, PGroup 3 vs 2<0.001), as well as significantly longer hospital stay (PGroup 2 vs 1<0.001, PGroup 3 vs 1<0.001, PGroup 3 vs 2<0.001). There was a monotonic trend towards increasing blood transfusion rates (P = 0.006), overall morbidity (P = 0.029) and 90-day mortality rates (P = 0.047) with increasing tumour size.

CONCLUSION

Although tumour size of 30 mm serves as an optimal cut-off for predicting difficult resections as per the Iwate criteria, a trichotomy (<30 mm, 30-69 mm, ≥70 mm) may provide additional granularity. Further large-scale prospective studies are needed to corroborate these findings.

Standardized single-incision plus one-port laparoscopic left lateral sectionectomy: a safe alternative to the conventional procedure

Purpose

Laparoscopic left lateral sectionectomy (LLLS) is a feasible and safe procedure with a relatively smooth learning curve. However, single-incision LLLS requires extensive surgical experience and advanced techniques. The aim of this study is to report the standardized single-incision plus one-port LLLS (reduced port LLLS, RPLLLS) technique and evaluate its safety, feasibility, and effectiveness for junior surgeons.

Methods

Between January 2008 and November 2020, the clinical records of 49 patients who underwent LLLS, divided into the conventional LLLS (n = 37) and the RPLLLS group (n = 12), were retrospectively reviewed. The patient characteristics, pathologic results, and operative outcomes were evaluated.

Results

A history of previous abdominal surgery in the RPLLLS group was significantly high (56.8% vs. 91.7%, p = 0.552). Notably, junior surgeons performed 62.2% of the conventional LLLSs and 58.4% of the standardized RPLLLSs. There were no significant differences between the two groups in terms of median operative time (121.0 vs. 113.5, p = 0.387), median blood loss (13.0 vs. 8.5, p = 0.518), median length of hospital stays (7.0 vs. 7.0, p = 0.408), and morbidity rate (2.7% vs. 0%, p = 0.565), respectively.

Conclusion

This standardized RPLLLS is a feasible and safe alternative to conventional LLLS and may become the ideal training procedure for both junior surgeons and surgeons aiming to learn more complex procedures.

Evolution and trends in the adoption of laparoscopic liver resection in Singapore: Analysis of 300 cases

ABSTRACT Introduction: The introduction of laparoscopic surgery has changed abdominal surgery. We evaluated the evolution and changing trends associated with adoption of laparoscopic liver resection (LLR) and the experience of a surgeon without prior LLR experience. Methods: A retrospective review of 310 patients who underwent LLR performed by a single surgeon from 2011 to 2020 was conducted. Exclusion criteria were patients who underwent laparoscopic liver surgeries such as excision biopsy, local ablation, drainage of abscesses and deroofing of liver cysts. There were 300 cases and the cohort was divided into 5 groups of 60 patients. Results: There were 288 patients who underwent a totally minimally invasive approach, including 28 robotic-assisted procedures. Open conversion occurred for 13 (4.3%) patients; the conversion rate decreased significantly from 10% in the initial period to 3.3% subsequently. There were 83 (27.7%) major resections and 131 (43.7%) resections were performed for tumours in the difficult posterosuperior location. There were 152 (50.7%) patients with previous abdominal surgery, including 52 (17.3%) repeat liver resections for recurrent tumours, and 60 patients had other concomitant operations. According to the Iwate criteria, 135 (44.7%) were graded as high/expert difficulty. Major morbidity (>grade 3a) occurred in 12 (4.0%) patients and there was no 30-day mortality. Comparison across the 5 patient groups demonstrated a significant trend towards older patients, higher American Society of Anesthesiologists (ASA) score, increasing frequency of LLR with previous abdominal surgery, increasing frequency of portal hypertension and huge tumours, decreasing blood loss and decreasing transfusion rate across the study period. Surgeon experience (≤60 cases) and Institut Mutualiste Montsouris (IMM) high grade resections were independent predictors of open conversion. Open conversion was associated with worse perioperative outcomes such as increased blood loss, transfusion rate, morbidity and length of stay. Conclusion: LLR can be safely adopted for resections of all difficulty grades, including major resections and for tumours located in the difficult posterosuperior segments, with a low open conversion rate. Keywords: Laparoscopic hepatectomy, laparoscopic liver resection, robotic hepatectomy, robotic liver resection, Singapore

Statistical Process Control Charts for Monitoring Next-Generation Sequencing and Bioinformatics Turnaround in Precision Medicine Initiatives

Purpose

Precision oncology, such as next generation sequencing (NGS) molecular analysis and bioinformatics are used to guide targeted therapies. The laboratory turnaround time (TAT) is a key performance indicator of laboratory performance. This study aims to formally apply statistical process control (SPC) methods such as CUSUM and EWMA to a precision medicine programme to analyze the learning curves of NGS and bioinformatics processes.

Patients and Methods

Trends in NGS and bioinformatics TAT were analyzed using simple regression models with TAT as the dependent variable and chronologically-ordered case number as the independent variable. The M-estimator "robust" regression and negative binomial regression were chosen to serve as sensitivity analyses to each other. Next, two popular statistical process control (SPC) approaches which are CUSUM and EWMA were utilized and the CUSUM log-likelihood ratio (LLR) charts were also generated. All statistical analyses were done in Stata version 16.0 (StataCorp), and nominal P < 0.05 was considered to be statistically significant.

Results

A total of 365 patients underwent successful molecular profiling. Both the robust linear model and negative binomial model showed statistically significant reductions in TAT with accumulating experience. The EWMA and CUSUM charts of overall TAT largely corresponded except that the EWMA chart consistently decreased while the CUSUM analyses indicated improvement only after a nadir at the 82^nd case. CUSUM analysis found that the bioinformatics team took a lower number of cases (54 cases) to overcome the learning curve compared to the NGS team (85 cases).

Conclusion

As NGS and bioinformatics lead precision oncology into the forefront of cancer management, characterizing the TAT of NGS and bioinformatics processes improves the timeliness of data output by potentially spotlighting problems early for rectification, thereby improving care delivery.

Initial experience with a robotic hepatectomy program at a high-volume laparoscopic center: single-center experience and surgical tips

Background

Despite the development of laparoscopic surgery, there are still inherent limitations associated with conventional laparoscopic instruments such as restrictions in movement and an inability for articulation. Robotic surgery may help to overcome the limitations of conventional laparoscopic surgery. The aim of this study was to present our initial experience with robotic hepatectomy (RH) and discuss the steps required to develop an RH program at a high-volume laparoscopic hepatectomy (LH) center.

Methods

We retrospectively reviewed prospectively collected data for 14 consecutive patients who underwent RH between 2017 and 2018. Clinicopathological characteristics and perioperative outcomes were compared with those reported in previous studies. The operation time of each procedure was analyzed to assess RH proficiency based on experience.

Results

Of the 14 patients, 12 patients (85.7%) underwent robotic major hepatectomy. Median patient age was 54.5 years, while median body mass index (BMI) was 25.2 kg/m². The median operation time was 360 (range: 145–544) min. The median estimated blood loss (EBL) was 300 (range: 50–1,400) mL. Conversion to open surgery was not required in any case. The median length of hospital stay was 5 (range: 4–14) days. Major complications occurred in 2 patients (14.2%), although both recovered without sequelae. The time required for hilar dissection, docking, and parenchymal transection gradually decreased after the first two cases of RH.

Conclusions

From our initial experience, RH might be considered as a feasible procedure in the liver resection, even in major hepatectomy. In addition, surgeons with sufficient experience in LH could rapidly adapt for RH. However, we have to make a system for education and monitoring of this innovative surgery for the patients’ safety.

Learning process of laparoscopic liver resection and postoperative outcomes: chronological analysis of single-center 15-years' experience

BACKGROUND

Limited studies have reported the actual learning process of laparoscopic liver resection (LLR). This study aimed to chronologically evaluate our 15 years' experience of LLR.

METHODS

All consecutive LLRs between 2006 to 2020 were retrospectively analyzed. The time period was divided into three groups; first (2006-2010), second (2011-2015), and third (2016-2020) period. The primary endpoint of this study was a composite of overall (Clavien-Dindo grade ≥ II) or major (grade ≥ IIIa) postoperative complications within 30 days. Using the IWATE criteria (four difficulty levels based on six indices), LLR was categorized as basic (< 7 points) and advanced (≥ 7 points) one. All analyses were performed based on the intention-to-treat principles.

RESULTS

During the study period, a total of 382 LLRs were gradually performed (first period, n = 54; second period, n = 114, and third period, n = 214). Low incidences of overall and major complications were maintained (9.3, 10.5, and 7.0%, p = 0.514, and 1.9, 2.6, and 2.3%, p = 1.000). Meanwhile, pure LLRs (i.e., LLRs without hand-assisted or hybrid approach) and advanced LLRs were increasingly performed in 25 (46.3%), 71 (62.3%), and 205 (95.8%) patients (p < 0.001) and 3 (5.6%), 18 (15.8%), and 58 (27.1%) patients (p < 0.001), respectively.

CONCLUSIONS

This study suggests that stepwise approach from basic to advanced procedures and use of hand-assisted or hybrid approach during the early phases for starting LLR practice may allow for maintaining low morbidity in specialized center.

Laparoscopic liver resection for huge (≥10 cm) hepatocellular carcinoma: A coarsened exact-matched single-surgeon study

INTRODUCTION

Laparoscopic liver resection (LLR) is increasingly being utilised worldwide for the management of both benign and malignant liver tumours. However, there is limited data to date regarding the safety and feasibility of this approach for huge (≥10 cm) hepatocellular carcinomas (HCCs). We present here our early experience performing LLR for huge HCCs.

METHODS

We conducted a retrospective review of 280 consecutive patients who underwent LLR by a single surgeon from 2012 to August 2020.15 patients had a preoperative radiological diagnosis of huge (≥10 cm) HCC. Coarsened exact-matched (CEM) weighting was used to compare them to 101 patients who underwent LLR for non-huge HCC.

RESULTS

After CEM-weighting, both groups were well-balanced for baseline variables. There was no difference in the rates of open conversion. The huge HCC patients had a higher mean Iwate difficulty score than the non-huge HCC patients (9.13 vs 6.53, p = 0.007). As such, the median operating time for the huge HCC group was longer (360 min vs 240min, p = 0.049). However, there were no significant differences in estimated blood loss, proportion of patients requiring blood transfusion, utilization of Pringle maneuver or median Pringle duration. Post-operatively, there were no significant differences in median LOS, overall and major morbidity rates, and 90-day mortality rates between both groups. Median resection margins were also similar for both cohorts.

CONCLUSION

LLR may be performed successfully for selected patients with huge HCC, with encouraging perioperative outcomes and no compromise in oncologic efficacy.

[Advantages and future perspectives of laparoscopic liver surgery]

BACKGROUND

Laparoscopic liver surgery (LLS) is increasingly utilized worldwide due to several potential advantages over open liver surgery.

OBJECTIVE

Analysis and presentation of the advantages and disadvantages of LLS in comparison to open surgery.

MATERIAL AND METHODS

Analysis of clinically relevant factors of minimally invasive liver surgery in comparison to open liver surgery in the current literature.

RESULTS

In addition to obvious cosmetic advantages, the current literature shows advantages regarding length of hospital stay and quality of life after LLC. In contrast to major liver resections, parenchyma-preserving resections often appear cost-neutral due a shorter postoperative hospital stay compared to conventional liver resections. In addition to particular personnel requirements, LLS also has technical prerequisites, such as a dedicated intraoperative ultrasound system. Furthermore, contrast-enhanced laparoscopic examinations are possible and ultrasound information can be fused with preoperative imaging. Virtual reality technology and 3‑dimensional printing are currently under investigation to improve the intraoperative anatomical orientation of LLS.

CONCLUSION

The current literature reveals significant advantages for LLS so that this procedure should be further developed in Germany in order to offer this technique to as many patients as possible.

Efficacy of Laparoscopic Hepatectomy versus Open Surgery for Hepatocellular Carcinoma With Cirrhosis: A Meta-analysis of Case-Matched Studies

Background

The role of laparoscopic hepatectomy (LH) in hepatocellular carcinoma (HCC) with cirrhosis remains controversial and needs to be further assessed. The present meta-analysis aimed to compare the surgical and oncological outcomes of LH with those of open hepatectomy (OH) for HCC with cirrhosis.

Methods

The PubMed, Embase, and Cochrane Library databases were searched for studies comparing LH and OH until Mar 2021. Weighted mean differences (WMDs), odds ratios (ORs), and hazard ratios (HRs) were calculated for continuous, dichotomous, and long-term variables, respectively, with 95% confidence intervals (CIs). Subgroup analysis was performed according to different resection types: major resection and minor resection. The meta-analysis was performed using the STATA 12.0.

Results

A total of 16 case-matched studies (784 patients in the LH group and 1,191 patients in the OH group.) were included in this meta-analysis. In terms of primary outcomes, LH was associated with decreased overall complication rate (OR 0.57; 95% CI 0.46 to 0.71; P <0.01), major complication rate (OR 0.52; 95% CI 0.33 to 0.82; P < 0.01), postoperative mortality (OR 0.27; 95% CI 0.11 to 0.66; P  <0.01), 1-y overall survival (OS) rate (HR 0.48; 95% CI 0.31 to 0.73; P <0.01), 2-y OS (HR 0.61; 95% CI 0.45 to 0.83; P < 0.01), and 5-y OS (0.67; 95% CI 0.53 to 0.85; P < 0.01). With respect to secondary outcomes, blood loss (WMD −69.16; 95% CI −101.72 to −36.61; P < 0.01), length of hospitalization (LOH) (WMD −2.65; 95% CI −3.41 to −1.89; P < 0.01), minor complication rate (OR 0.70; 95% CI 0.53 to 0.94; P = 0.02), postoperative liver failure (OR 0.60; 95% CI 0.38 to 0.95; P = 0.03), and postoperative ascites (OR 0.44; 95% CI 0.28 to 0.72; P < 0.01) was lower in LH than in OH. No significant differences in operation time (P = 0.07), transfusion rate (P = 0.05), 1-, 2-, and 5-year DFS rate (1-year, P = 0.08; 2-year, P = 0.08; 5-year, P = 0.23) were noted between LH and OH. Subgroup analysis based on minor resection revealed that LH had similar favored outcomes in comparison with those in the overall pooled analysis. However, LH had a longer operation time than OH in the setting of major resection (P < 0.01).

Conclusion

LH is technically feasible and safe for selected HCC patients with cirrhosis. LH can achieve favored short-term and long-term oncological outcomes in minor liver resection. Laparoscopic major hepatectomy (LMH) seems to offer some advantages over the open approach; however concerns about surgical and oncological safety remain. More evidence on LMH is warranted before expanding its indication to patients with cirrhosis.

Laparoscopic versus open resection of intrahepatic cholangiocarcinoma: nationwide analysis

BACKGROUND

The relevance of laparoscopic resection of intrahepatic cholangiocarcinoma (ICC) remains debated. The aim of this study was to compare laparoscopic (LLR) and open (OLR) liver resection for ICC, with specific focus on textbook outcome and lymph node dissection (LND).

METHODS

Patients undergoing LLR or OLR for ICC were included from two French, nationwide hepatopancreatobiliary surveys undertaken between 2000 and 2017. Patients with negative margins, and without transfusion, severe complications, prolonged hospital stay, readmission or death were considered to have a textbook outcome. Patients who achieved both a textbook outcome and LND were deemed to have an adjusted textbook outcome. OLR and LLR were compared after propensity score matching.

RESULTS

In total, 548 patients with ICC (127 LLR, 421 OLR) were included. Textbook-outcome and LND completion rates were 22.1 and 48.2 per cent respectively. LLR was independently associated with a decreased rate of LND (odds ratio 0.37, 95 per cent c.i. 0.20 to 0.69). After matching, 109 patients remained in each group. LLR was associated with a decreased rate of transfusion (7.3 versus 21.1 per cent; P = 0.001) and shorter hospital stay (median 7 versus 14 days; P = 0.001), but lower rate of LND (33.9 versus 73.4 per cent; P = 0.001). Patients who underwent LLR had lower rate of adjusted TO completion than patients who had OLR (6.5 versus 17.4 per cent; P = 0.012).

CONCLUSION

The laparoscopic approach did not substantially improve quality of care of patients with resectable ICC.

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.

Dorsal approach with Glissonian approach for laparoscopic right anatomic liver resections

BACKGROUND

Laparoscopic anatomic hepatectomy (LAH) has gradually become a routine surgical procedure. However, how to expose the whole hepatic vein and avoid the hepatic vein laceration is still a challenge because of the caudate lobe, particularly in right hepatectomy. We adopted a dorsal approach combined with Glissionian appraoch to perform laparoscopic right anatomic hepatectomy (LRAH).

METHODS

Twenty patients who underwent LRAH from January 2017 to November 2018 were retrospectively analysed. Of these patients, seven patients underwent laparoscopic right hemihepatectomy (LRH group), seven patients who underwent laparoscopic right posterior hepatectomy (LRPH group), and six patients who underwent laparoscopic hepatectomy for segment 7 (LS7 group). The paracaval portion of caudate lobe could be transected firstly through dorsal approach and the corresponding major hepatic vein could be exposed from its root to the peripheral branches safely. Due to exposure along the major hepatic vein trunk, the remaining liver parenchyma could be quickly transected from dorsal to cranial side.

RESULTS

The mean age of the patients was 53.8 years and the male: female ratio was 8:12. The median operation time was 306.0 ± 58.2 min and the mean estimated volume of blood loss was 412.5 ± 255.4 mL. The mean duration of postoperative hospital stay was 10.2 days. The mean Pringle maneuver time was 64.8 ± 27.7 min. Five patients received transfusion of 2-4 U of red blood cells. Two patients suffered from transient hepatic dysfunction and one suffered from pleural effusion. None of the patients underwent conversion to an open procedure. The operative duration, volume of the blood loss, Pringle maneuver time, and postoperative hospital stay duration did not differ significantly among the LRH, LRPH, and LS7 groups (P > 0.05).

CONCLUSIONS

Dorsal approach combined with Glissonian approach for right lobe is feasible and effective in laparoscopic right anatomic liver resections.

Operative Time, Age, and Serum Albumin Predict Surgical Morbidity After Laparoscopic Liver Surgery

Background. Laparoscopic liver resection (LLR) has emerged as a considerable alternative to conventional liver surgery. However, the increasing complexity of liver resection raises the incidence of postoperative complications. The aim of this study was to identify risk factors for postoperative morbidity in a monocentric cohort of patients undergoing LLR. Methods. All consecutive patients who underwent LLR between 2015 and 2019 at our institution were analyzed for associations between complications with demographics and clinical and operative characteristics by multivariable logistic regression analyses. Results. Our cohort comprised 156 patients who underwent LLR with a mean age of 60.0 ± 14.4 years. General complications and major perioperative morbidity were observed in 19.9% and 9.6% of the patients, respectively. Multivariable analysis identified age>65 years (HR = 2.56; P = .028) and operation time>180 minutes (HR = 4.44; P = .001) as significant predictors of general complications (Clavien ≥1), while albumin<4.3 g/dl (HR = 3.66; P = .033) and also operative time (HR = 23.72; P = .003) were identified as predictors of major postoperative morbidity (Clavien ≥3). Conclusion. Surgical morbidity is based on patient- (age and preoperative albumin) and procedure-related (operative time) characteristics. Careful patient selection is key to improve postoperative outcomes after LLR.

Middle and left hepatic vein trunk control during laparoscopic liver resection (with video)

BACKGROUND

While inflow control can be easily applied by Pringle maneuver, outflow control of the left liver has not been formally described. We report here a safe and reproductible technique of middle and left hepatic veinous trunk control (MLHVC) before parenchymal transection during laparoscopic left hepatectomy.

METHODS

A retrospective review of laparoscopic liver resection was conducted from January 2013 to March 2018 from our prospective database. All cases of laparoscopic left hepatectomy (LLH) were included, and intra- and postoperative outcomes data collected. We collected cases where the middle and left hepatic vein trunk control has been attempted and clamping used, and we analyzed outcomes associated with this maneuver.

RESULTS

MLHVC was attempted in 28 cases (77.8) of the 36 LLH identify in a monocentric study. It was technically not feasible only in 3 cases (8.3%) and clamping applied in 15 cases (41.7%). No significant intraoperative unexpected event occurred.

CONCLUSION

We present here a technique for left liver outflow control that can be safely added to the armamentarium of laparoscopic liver surgery.

Analysis of perioperative outcomes following laparoscopic repeat liver resection compared to laparoscopic primary liver resection based on a single surgeon's experience: A 1:2 propensity score-matched study

BACKGROUND

We report a single surgeon experience with laparoscopic repeat liver resection (LRLR), and analyse short-term outcomes relative to laparoscopic primary liver resection (LPLR).

METHODS

Two-hundred and twenty-two laparoscopic liver resections were performed from 2012 to 2019 of which 33 were LRLR. 1:2 propensity-score matching was done to compare 32 LRLR with 64 LPLR cohort. We further analyzed the first 16 LRLR cases compared to the subsequent 17 cases.

RESULTS

32 LRLR cases were matched to 64 LPLR cases. Apart from a higher frequency of Pringle maneuver in the LPLR cohort (p = 0.006), there were no differences in other perioperative outcomes. There were more posterosuperior located tumours (75.0% vs 17.6%, p = 0.003) and higher median difficulty score (8.50 vs 5.00, p = 0.025) in the initial 16 LRLR cases compared to the next 17. The earlier group had higher median blood loss (250.00 ml vs 50.00 ml, p = 0.012), but other outcomes were similar.

CONCLUSION

LRLR may be safely performed in selected patients with no difference in key perioperative outcomes compared to LPLR.

Surgical outcomes of 118 complex laparoscopic liver resections: a single- center experience

BACKGROUND

Indications for laparoscopic liver resection (LLR) are continuously expanding. The Japanese Society of Hepato-Biliary-Pancreatic Surgery defines highly difficult hepatectomy as a procedure involving one or more sections (except for left lateral sectionectomy) or anatomical segmentectomy. This study aimed to assess the outcomes of complex LLR procedures and compare their technical difficulties, about which only a little is known to date.

METHODS

We performed a retrospective review of the operative outcomes of 118 consecutive patients who underwent pure laparoscopic complex hepatectomy. The surgical outcomes, including operative times, blood loss amounts, and postoperative morbidity rates, were compared among complex LLR procedures.

RESULTS

The overall median operative time was 280 minutes, and the median intraoperative blood loss was 86 mL. Two patients required conversion to open laparotomy (1.7%). The postoperative major morbidity rate was 11.0% Posterosuperior segmentectomy, right hemihepatectomy, and anterior sectionectomy required the longest operative times. Anterior and posterior sectionectomy resulted in the highest blood loss, and right hemihepatectomy and anterior sectionectomy resulted in the most complications.

CONCLUSIONS

The surgical difficulties associated with complex LLR procedures vary. It is critical to recognize the specific risks and cautionary points to ensure patient safety and provide proper systemic training to surgeons.

Short-term Outcomes of "Difficult" Laparoscopic Liver Resection at Specialized Centers: Report From INSTALL (International Survey on Technical Aspects of Laparoscopic Liver Resection)-2 on 4478 Patients

OBJECTIVE

To define the current status of "difficult" LLR, a global database was created and investigated.

BACKGROUND

In the Second International Consensus Conference in 2014, minor LLR was considered as a standard practice and major LLR remained an innovative procedure. Since then, no updates on worldwide trends have been available.

METHODS

A questionnaire on all consecutive patients who underwent difficult LLR (major hepatectomy, posterosuperior segmentectomy, sectionectomy, living donor hepatectomy, tumor size ≥10 cm, Child-Pugh grade ≥B, combined with biliary reconstruction, and Iwate criteria difficulty score ≥7) in 2014-2018 was distributed via email to 65 high-volume LLR centers worldwide. Individual data on patient and tumor demographics, surgical information, and short-term outcomes were obtained to create a large-scale international registry for analyses.

RESULTS

Overall, 58 centers in 19 countries performed 4478 difficult LLR (median, 58.5; range, 5-418) during the study period. Hepatocellular carcinoma accounted for ≥40% of all indications. Half of the patients underwent major hepatectomy, followed by sectionectomy, posterosuperior segmentectomy, and living donor hepatectomy. In the vast majority of procedures, Clavien-Dindo grade ≥IIIa complication rates of ≈10% and 90-day mortality rates of ≈1% were achieved. Left or right trisectionectomy had the worst Clavien-Dindo grade ≥IIIa complication rate of ≥10% and 90-day mortality rate of 5%-10%. No significant correlation was observed between center volume and short-term outcomes.

CONCLUSIONS

Total 4478 patients underwent difficult LLR worldwide in 2014-2018. Most procedures are safe and feasible when conducted in specialized centers.

Safety and feasibility of robotic major hepatectomy for novice surgeons in robotic liver surgery: A prospective multicenter pilot study

BACKGROUND

Robotic liver resection has not yet been widely implemented. We aimed to evaluate the feasibility and safety of robotic major liver resection by performing a prospective multicenter study.

METHODS

From July 2017 to December 2018, five surgeons from five tertiary hospitals who were novices in robotic liver resection but experienced in open and laparoscopic liver resection performed 46 cases of robotic major anatomical liver resections. Perioperative clinical data and surgical data, including detailed procedure times were prospectively collected. All operations were performed according to a protocol for unify surgical techniques and instruments.

RESULTS

Twenty-two cases of left hemihepatectomy, one case of extended left hemihepatectomy, 14 cases of right hemihepatectomy, two cases of right anterior sectionectomy, six cases of right posterior sectionectomy, and one case of central bisectionectomy were performed. The most common indications were hepatocellular carcinoma (21 cases) followed by intrahepatic duct stones (10 cases), intrahepatic cholangiocellular carcinoma (7 cases), liver metastases (3 cases), intraductal papillary neoplasms (2 cases), sarcoma (1 case), mucinous cystic neoplasm (1 case), and hemangioma (1 case). Surgical resection margins for all tumor cases were negative. The mean operation time was 378.58 ± 124.31 (190-696) minutes and the estimated intraoperative blood loss was 276.67 ± 397.41 mL (range, 10-2600 mL). Overall complications developed in 16 cases (34.8%). There were three cases of severe surgical complications (Clavien-Dindo classification of III or more). Only one of 46 cases was converted to conventional open left hemihepatectomy because of bleeding. The mean hospital stay was 7.3 ± 2.5 (4-18) days.

CONCLUSIONS

The results of this study indicate that robotic anatomic major liver resection can be safely performed by robotic beginners who are advanced open and laparoscopic liver surgeons.

Learning Curve in Laparoscopic Liver Resection, Educational Value of Simulation and Training Programmes: A Systematic Review

BACKGROUND

The laparoscopic approach is widely accepted as the procedure of choice for abdominal surgery. However, laparoscopic liver resection (LLR) has advanced slowly due to the significant learning curve (LC), and only few publications have dealt with advanced training in LLR.

METHODS

Two reviewers conducted systematic research through MEDLINE and EMBASE with combinations of the following keywords: (learning curve OR teaching OR training OR simulation OR education) AND (liver OR hepatic) AND (laparoscopic OR laparoscopy). Robotic-assisted, hand-assisted and hybrid LLRs were excluded.

RESULTS

Nineteen studies were retrieved. Overall, the level of evidence was low. Thirteen articles assessed the LC during real-life LLR, and six articles focussed on simulation and training programmes in LLR. The LC in minor LLR comprised 60 cases overall, and 15 cases for standardised left lateral sectionectomy. For major LLR (MLLR), the LC was 50 cases for most studies, but was reported to be 15-20 cases in more recent studies, provided MLLR is performed progressively in selected patients. However, there was heterogeneity in the literature regarding the number of minor LLRs required before MLLR, with 60 minor LLRs reported as the minimum. Six studies showed a potential benefit of simulation and training programmes in this field. The gradual implementation of LLR combined with simulation-based training programmes could reduce the clinical impact of LC.

CONCLUSIONS

The LC in LLR is a long process, and MLLR should be gradually implemented under the supervision of experienced surgeons. Training outside the operating room may reduce the LC in real-life situations.

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.

Glucocorticoid use and ischemia-reperfusion injury in laparoscopic liver resection: Randomized controlled trial

AIM

Laparoscopic liver resection (LLR) is increasingly carried out worldwide. However, there are concerns regarding ischemia-reperfusion injury caused by pneumoperitoneum and the Pringle maneuver. It is not clear whether perioperative use of glucocorticoids lowers the risk of ischemia-reperfusion hepatic injury in LLR as has been reported for open liver resection. The aim of the present study was to investigate the role of perioperative glucocorticoid use in improving hepatic function and surgical outcomes after LLR.

METHODS

In this double-blind, randomized controlled trial (UMIN000013823), we enrolled 130 patients who presented to our institution for LLR between April 2014 and October 2018. Six patients were excluded, resulting in 124 patients being randomized to either the glucocorticoid or the control group. Preoperatively, patients in the glucocorticoid group received 500 mg methylprednisolone in saline solution, patients in the control group saline solution only. Surgical outcomes and blood parameters were compared between the two groups.

RESULTS

The Pringle maneuver could not be carried out in 24 patients, resulting in 50 patients in each group being included in the analysis. Postoperatively, total, direct and indirect bilirubin, and C-reactive protein and interleukin-6 levels were significantly lower, albumin levels were significantly higher, and prothrombin time was significantly shorter in the glucocorticoid than in the control group. Surgical outcomes were not significantly different between the groups.

CONCLUSION

This first report on preoperative glucocorticoid use in LLR showed that it significantly improved postoperative liver function and thus might enhance the safety of LLR.

Laparoscopic liver resection for liver tumours in proximity to major vasculature: A single-center comparative study

BACKGROUND

With growing popularity and experience in laparoscopic liver surgery, the options for more difficult procedures increase. Only small case series have been published regarding laparoscopic liver resection (LLR) for tumours in proximity to major vessels (MVs). The aim was to compare outcomes of LLR for tumours located less or more than 15 mm from MVs.

METHODS

This was a retrospective analysis of a prospectively collected database of consecutive LLR (October 2011-August 2017). Proximity to MVs (PMV) was defined as lesions located within 15 mm to the caval vein, hepatic veins and portal vein (main trunk and first branches). The control group were all lesions located more than 15 mm from MVs.

RESULTS

Some 60/235 LLR were performed for lesions in proximity to major vasculature (24%). In the PMV group, median IWATE Difficulty Score was higher (8.5 (IQR: 6.0-9.0) VS 5.0 (IQR: 3.0-6.0), p < 0.001) as was the use of CUSA® (45.0% VS 8.6%, p < 0.001) and Pringle manoeuvre (8.3% VS 1.7%; p = 0.028). Operative time was longer (180min (IQR: 140-210) VS 120min (IQR: 75-150), p < 0.001) and blood loss was higher (190 ml (IQR: 100-325) VS 75 ml (IQR: 50-220), p < 0.001) in the PMV group. There was no difference in perioperative blood transfusion (3.3% VS 1.7%, p = 0.60) or postoperative morbidity (15.0% VS 14.3%, p = 0.89). There was no mortality in both groups. On mean follow-up of 21 months, no significant differences could be found in disease free (p = 0.77) and overall survival (p = 0.12).

CONCLUSION

In experienced hands, LLR of lesions in proximity to MVs is safe and feasible with acceptable short and long-term results.

Laparoscopic versus open liver resection in the posterosuperior segments: a sub-group analysis from the OSLO-COMET randomized controlled trial

BACKGROUND

Laparoscopic liver resection in the posterosuperior segments is technically challenging. This study aimed to compare the perioperative outcomes for laparoscopic and open resection of colorectal liver metastases located in the posterosuperior segments.

METHODS

This was a subgroup analysis of the OSLO-COMET randomized controlled trial, where 280 patients were randomly assigned to open or laparoscopic parenchyma-sparing liver resections of colorectal metastases. Patients with tumors in the posterosuperior segments were identified, and perioperative outcomes and health related quality of life (HRQoL) were compared.

RESULTS

We identified a total of 136 patients, 62 in the laparoscopic and 74 in the open group. The postoperative complication rate was 26% in the laparoscopic and 31% in the open group. The blood loss was less in the open group (500 vs. 250 ml, P = 0.006), but the perioperative transfusion rate was similar. The operative time was similar, while postoperative hospital stay was shorter in the laparoscopic group (2 vs. 4 days, P < 0.001). HRQoL was significantly better after laparoscopy at 1 month.

CONCLUSION

In patients undergoing laparoscopic or open liver resection of colorectal liver metastases in the posterosuperior segments, laparoscopic surgery was associated with shorter hospital stay and comparable perioperative outcomes.

Multicentre analysis of the learning curve for laparoscopic liver resection of the posterosuperior segments

BACKGROUND

Laparoscopic liver resection demands expertise and a long learning curve. Resection of the posterosuperior segments is challenging, and there are no data on the learning curve. The aim of this study was to evaluate the learning curve for laparoscopic resection of the posterosuperior segments.

METHODS

A cumulative sum (CUSUM) analysis of the difficulty score for resection was undertaken using patient data from four specialized centres. Risk-adjusted CUSUM analysis of duration of operation, blood loss and conversions was performed, adjusting for the difficulty score of the procedures. A receiver operating characteristic (ROC) curve was used to identify the completion of the learning curve.

RESULTS

According to the CUSUM analysis of 464 patients, the learning curve showed an initial decrease in the difficulty score followed by an increase and, finally, stabilization. More patients with cirrhosis or previous surgery were operated in the latest phase of the learning curve. A smaller number of wedge resections and a larger number of anatomical resections were performed progressively. Dissection using a Cavitron ultrasonic surgical aspirator and the Pringle manoeuvre were used more frequently with time. Risk-adjusted CUSUM analysis showed a progressive decrease in operating time. Blood loss initially increased slightly, then stabilized and finally decreased over time. A similar trend was found for conversions. The learning curve was estimated to be 40 procedures for wedge and 65 for anatomical resections.

CONCLUSION

The learning curve for laparoscopic liver resection of the posterosuperior segments consists of a stepwise process, during which accurate patient selection is key.

Developments and perspectives of laparoscopic liver resection in the treatment of hepatocellular carcinoma

Laparoscopic liver resection (LLR) was introduced in the early 1990s, initially for partial resection of the anterolateral segments, from where it has expanded in a stepwise fashion. Movement restriction makes bleeding control demanding. Managing pneumoperitoneum pressure with inflow control can inhibit venous bleeding and create a dry surgical field for easier hemostasis. Since the lack of overview leads to disorientation, simulation and navigation with imaging studies have become important. Improved direct access to the liver inside the rib cage can be obtained in LLR, reducing destruction of the associated structures and decreasing the risk of refractory ascites and liver failure, especially in patients with a cirrhotic liver. Although LLR can be performed as bridging therapy to transplantation for severe cirrhosis, its impact on expanding the indications of liver resection (LR) and the consequent survival benefits must be evaluated. For repeat LR, LLR is advantageous by producing fewer adhesions and reducing the need for adhesiolysis. The laparoscopic approach facilitates better access in a small operative field between adhesions. Further evaluations are needed for repeat anatomical resection, since alterations of the anatomy and surrounding scars and adhesions of major vessels have a larger impact.

Robotic versus laparoscopic liver resection in complex cases of left lateral sectionectomy

BACKGROUND

Laparoscopic liver resection is recommended as the standard operation for left lateral sectionectomy (LLS). Robotic liver resection is theoretically better than laparoscopic liver resection in complex cases of liver resection. However, in a complex case of LLS, whether robotic LLS (R-LLS) is still better than laparoscopic LLS (L-LLS) is unclear. This study aims to assess the perioperative outcomes of R-LLS and L-LLS in the overall and in the subgroup of complex cases of LLS.

METHODS

From January 2015 to June 2017, the data on consecutive patients who underwent R-LLS were retrospectively compared with those who underwent L-LLS. Based on defined criteria for complex cases, the subgroup of such patients who underwent R-LLS were compared with the subgroup of patients who underwent L-LLS. The patient characteristics and surgical outcomes in the whole groups and subgroups of patients were analyzed.

RESULTS

The overall R-LLS and L-LLS groups showed no significance differences in operative time, intraoperative blood loss, postoperative hospital stay, blood transfusion and morbidity rates. The overall medical costs were significantly higher in the R-LLS group than in the L-LLS group (12786.4 vs. 7974.3 USD; p < 0.001). On subgroup analysis of the complex cases, the estimated blood loss was significantly less in the R-LLS subgroup than the L-LLS subgroup (131.9 vs. 320.8 ml, p = 0.003). The two subgroups showed no significant differences in postoperative hospital stay (4.7 vs. 5.3 days; p = 0.054) and operative times (126.4 vs. 110.8 min; p = 0.379). The R-LLS subgroup had significantly higher overall medical costs than the L-LLS subgroup (13536.9 vs. 9186.7 USD, p = 0.006).

CONCLUSION

The overall R-LLS group was comparable to the overall L-LLS group in perioperative outcomes. Although the overall medical costs in the robotic subgroup was higher, R-LLS might be a better choice for the subgroup of patients with complex cases when compared to L-LLS.

Highlights, limitations and future challenges of laparoscopic resection for colorectal liver metastases

The liver is the most common site for metastatic colorectal cancer (CRLM). Despite advances in oncologic treatment, resection of metastases is still the only curative option. Although laparoscopic surgery for primary colorectal cancer is well documented and widely used, laparoscopic surgery for liver metastases has developed more slowly. However, in spite of some difficulties, laparoscopic approach demonstrated strong advantages including minimal parietal damage, decreased morbidity (reduced blood loss and need for transfusion, fewer pulmonary complications), and simplification of subsequent iterative hepatectomy. Up to now, more than 9 000 laparoscopic procedures have been reported worldwide and long-term results in colorectal liver metastases seem comparable to the open approach. Only one recent randomized controlled trial has compared the laparoscopic and the open approach. The purpose of the present update was to identify the barriers limiting widespread acceptance of laparoscopic approach, the benefits and the limits of laparoscopic hepatectomies in CRLM.

A Comparison of the Learning Curves of Laparoscopic Liver Surgeons in Differing Stages of the IDEAL Paradigm of Surgical Innovation: Standing on the Shoulders of Pioneers

OBJECTIVE

To compare the learning curves of the self-taught "pioneers" of laparoscopic liver surgery (LLS) with those of the trained "early adopters" in terms of short- and medium-term patient outcomes to establish if the learning curve can be reduced with specific training.

SUMMARY OF BACKGROUND DATA

It is expected that a wider adoption of a laparoscopic approach to liver surgery will be seen in the next few years. Current guidelines stress the need for an incremental, stepwise progression through the learning curve in order to minimize harm to patients. Previous studies have examined the learning curve in Stage 2 of the IDEAL paradigm of surgical innovation; however, LLS is now in stage 3 with specific training being provided to surgeons.

METHODS

Using risk-adjusted cumulative sum analysis, the learning curves and short- and medium-term outcomes of 4 "pioneering" surgeons from stage 2 were compared with 4 "early adapting" surgeons from stage 3 who had received specific training for LLS.

RESULTS

After 46 procedures, the short- and medium-term outcomes of the "early adopters" were comparable to those achieved by the "pioneers" following 150 procedures in similar cases.

CONCLUSIONS

With specific training, "early adapting" laparoscopic liver surgeons are able to overcome the learning curve for minor and major liver resections faster than the "pioneers" who were self-taught in LLS. The findings of this study are applicable to all surgical specialties and highlight the importance of specific training in the safe expansion of novel surgical practice.