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Background/aim: Laparoscopic hepatectomy (LH) requires accurate visualization and appropriate handling of hepatic veins and the Glissonean pedicle that suddenly appear during liver dissection. Failure to recognize these structures can cause injury, resulting in severe bleeding and bile leakage. This study aimed to develop a novel artificial intelligence (AI) system that assists in the visual recognition and color presentation of tubular structures to correct the recognition gap among surgeons., Patients and Methods: Annotations were performed on over 350 video frames capturing LH, after which a deep learning model was developed. The performance of the AI was evaluated quantitatively using intersection over union (IoU) and Dice coefficients, as well as qualitatively using a two-item questionnaire on sensitivity and misrecognition completed by 10 hepatobiliary surgeons. The usefulness of AI in medical education was qualitatively evaluated by 10 medical students and residents., Results: The AI model was able to individually recognize and colorize hepatic veins and the Glissonean pedicle in real time. The IoU and Dice coefficients were 0.42 and 0.53, respectively. Surgeons provided a mean sensitivity score of 4.24±0.89 (from 1 to 5; Excellent) and a mean misrecognition score of 0.12±0.33 (from 0 to 4; Fail). Medical students and residents assessed the AI to be very useful (mean usefulness score, 1.86±0.35; from 0 to 2; Excellent)., Conclusion: The novel AI presented was able to assist surgeons in the intraoperative recognition of microstructures and address the recognition gap among surgeons to ensure a safer and more accurate LH., (Copyright © 2023 International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Background/aim: Radiofrequency ablation (RFA) is used to treat primary and metastatic tumors in the liver. However, local recurrence after RFA is frequent and subsequent salvage hepatectomy is often ineffective due to difficulty in visualization of tumor margins., Patients and Methods: In the present retrospective clinical trial, seven patients from the Department of General and Gastro-enterological Surgery, Showa University School of Medicine underwent salvage hepatectomy for recurrent hepatocellular carcinoma (HCC) (n=2), colorectal liver metastasis (n=4) and lung-carcinoid liver metastasis (n=1), after RFA, between 2011 and 2020. Tumors were labeled with indocyanine green (ICG) and resected under fluorescence guidance. Resected specimens were evaluated under fluorescence microscopy as well as by standard histopathological techniques., Results: Pathological findings revealed negative tumor margins in all patients after fluorescence-guided surgery. Six of seven resected tumors had a fluorescent rim, including both HCC and liver metastasis. Fluorescence microscopy demonstrated that viable cancer tumor cells were located only on the inside of the fluorescent rim, and no malignant cells were detected within the fluorescent rim surrounding the tumor. Fluorescence microscopy showed that the tumor margin was secured if the fluorescence signal was completely resected., Conclusion: The present results demonstrate that ICG labeling of liver tumors recurring after RFA enabled complete resection under fluorescence guidance. The present study is the first clinical study to demonstrate that tumor types that generally cannot be completely resected with bright light are fully resectable under fluorescence guidance., (Copyright © 2022 International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Background: The Brisbane 2000 Terminology for Liver Anatomy and Resections, based on Couinaud's segments, did not address how to identify segmental borders and anatomic territories of less than one segment. Smaller anatomic resections including segmentectomies and subsegmentectomies, have not been well defined. The advent of minimally invasive liver resection has enhanced the possibilities of more precise resection due to a magnified view and reduced bleeding, and minimally invasive anatomic liver resection (MIALR) is becoming popular gradually. Therefore, there is a need for updating the Brisbane 2000 system, including anatomic segmentectomy or less. An online "Expert Consensus Meeting: Precision Anatomy for Minimally Invasive HBP Surgery (PAM-HBP Surgery Consensus)" was hosted on February 23, 2021., Methods: The Steering Committee invited 34 international experts from around the world. The Expert Committee (EC) selected 12 questions and two future research topics in the terminology session. The EC created seven tentative definitions and five recommendations based on the experts' opinions and the literature review performed by the Research Committee. Two Delphi Rounds finalized those definitions and recommendations., Results: This paper presents seven definitions and five recommendations regarding anatomic segmentectomy or less. In addition, two future research topics are discussed., Conclusions: The PAM-HBP Surgery Consensus has presented the Tokyo 2020 Terminology for Liver Anatomy and Resections. The terminology has added definitions of liver anatomy and resections that were not defined in the Brisbane 2000 system., (© 2021 Japanese Society of Hepato-Biliary-Pancreatic Surgery.)

Background: The concept of minimally invasive anatomic liver resection (MIALR) is gaining popularity. However, specific technical skills need to be acquired to safely perform MIALR. The "Expert Consensus Meeting: Precision Anatomy for Minimally Invasive HBP Surgery (PAM-HBP Surgery Consensus)" was developed as a special program during the 32nd meeting of the Japanese Society of Hepato-Biliary-Pancreatic Surgery (JSHBPS)., Methods: Thirty-four international experts gathered online for the consensus. A Research Committee performed a comprehensive literature review, classifying studies according to the Scottish Intercollegiate Guidelines Network method. Based on the literature review and experts' opinions, tentative recommendations were drafted and circulated among experts using online Delphi Rounds. Finally, formulated recommendations were presented online in the Expert Consensus Meeting of the JSHBPS on February 23rd, 2021. The final recommendations were validated and finalized by the 2nd Delphi Round in May 2021., Results: Seven clinical questions were selected, and 22 recommendations were formulated. All recommendations reached more than 85% consensus among experts at the final Delphi Round., Conclusions: The Expert Consensus Meeting for safely performing MIALR has presented a set of clinical guidelines based on available literature and experts' opinions. We expect these guidelines to have a favorable effect on the safe implementation and development of MIALR., (© 2021 Japanese Society of Hepato-Biliary-Pancreatic Surgery.)

Background: In preparation for the upcoming consensus meeting in Tokyo in 2021, this systematic review aimed to analyze the current available evidence regarding surgical anatomy of the liver, focusing on useful landmarks, strategies and technical tools to perform precise anatomic liver resection (ALR)., Methods: A systematic review was conducted on MEDLINE/PubMed for English articles and on Ichushi database for Japanese articles until September 2020. The quality assessment of the articles was performed in accordance with the Scottish Intercollegiate Guidelines Network (SIGN)., Results: A total of 3169 manuscripts were obtained, 1993 in English and 1176 in Japanese literature. Subsequently, 63 English and 20 Japanese articles were selected and reviewed. The quality assessment of comparative series and case series was revealed to be usually low; only six articles were qualified as high quality. Forty-two articles focused on analyzing intersegmental/sectional planes and their relationship with specific hepatic landmark veins. In 12 articles, the authors aimed to investigate liver surface anatomic structures, while 36 articles aimed to study technological tools and contrast agents for surgical segmentation during ALR. Although Couinaud's classification has remained the cornerstone in daily diagnostic/surgical practices, it does not always portray the realistic liver segmentation and there has been no standardization on which a single strategy should be followed to perform precise ALR., Conclusions: A global consensus should be pursued in order to establish clear guidelines and proper recommendations to perform ALR in the era of minimally invasive surgery., (© 2021 Japanese Society of Hepato-Biliary-Pancreatic Surgery.)

Background: Ultrasonography (US) is widely used for pre-operative detection of liver tumors. However, US does not have high resolution and very small tumors, tumors located near the liver surface, or those in cirrhotic livers are often not detected., Case Report: A 47-year-old woman with a previous surgery for sigmoid colon cancer (T3N1bM0 Stage3b) showed a liver tumor on the surface of segment 2 by contrast-enhanced computed tomography (CT) and gadoliniumethoxybenzyldiethlenetriaminepen-taacetic acid (Gd-EOB-DTPA) magnetic resonance imaging (MRI). However, preoperative US could not identify a tumor lesion at the same site. The most likely preoperative diagnosis was metastasis from her sigmoid colon cancer and laparoscopic liver resection was performed. Intraoperative ultrasonography (IOUS) did not identify the tumor, but it was visualized with indocyanine green (ICG) fluorescence at the surface of segment 2. Laparoscopic liver resection was performed under fluorescence guidance. Pathological examination showed a pseudotumor with negative margins., Conclusion: ICG fluorescence imaging can allow visualization of liver tumors that are undetectable on US., (Copyright © 2021 International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Background/aim: To evaluate the complication rates and risk factors associated with transumbilical wounds and investigate the usefulness of an incision for organ removal in laparoscopic hepatectomy (Lap-H)., Patients and Methods: We enrolled 42 patients who underwent Lap-H excluding a small partial resection in our hospital between 2013 and 2018. The occurrences of superficial surgical site infection (SSI) and transumbilical port-site incisional hernia were recorded., Results: SSI was not observed, and hernia occurred in 3 patients (7.14%). Univariate analysis revealed that body mass index (BMI) (p=0.004) was significantly associated with the risk of hernia formation., Conclusion: High BMI is a risk factor for hernia formation in patients undergoing Lap-H with transumbilical incision; hence, wound closure should be performed carefully. The construction of the transumbilical wound for organ removal was feasible with rationality, with no need to create a new wound., (Copyright© 2020, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Purpose: The aim of this study was to compare the clinical outcomes between laparoscopic partial liver resection and open partial hepatectomy for tumors in the posterosuperior segments., Methods: The clinical outcomes of patients who underwent either laparoscopic (n = 20) or open (n = 44) resection in segments 7/8 of the liver were initially evaluated. Because of disparities in the background characteristics, a case-matched study (1:1) was conducted. In addition, a comparative study of the patients who met the institutional criteria for laparoscopic partial hepatectomy was performed., Results: In the case-matched study, the laparoscopic technique required a longer operation time (p = 0.001), but was associated with less intraoperative blood loss (p = 0.021), a lower incidence of major complications (p = 0.014), higher levels of serum albumin on postoperative days 3 and 7 (p = 0.031 and p = 0.035), and earlier discharge (p = 0.001) than open resection. The results of the latter study were similar to those of the case-matched analysis., Conclusions: Laparoscopic partial hepatectomy was a feasible procedure for treating tumors in the posterosuperior segments without compromising oncological safety and yielded better short-term outcomes than open techniques. In addition, this study provides concrete selection criteria for laparoscopic partial hepatectomy for difficult lesions.

Purpose: Laparoscopic liver resection is increasingly used to treat patients with hepatic tumor. However, during laparoscopic resection, information obtained by palpation using laparoscopic forceps or from intraoperative ultrasonography is extremely limited, which may pose a risk for positive surgical margins. This study aimed to investigate the feasibility and clinical application of near-infrared (NIR) fluorescence imaging to guide laparoscopic liver resection of a liver tumor and secure the surgical margins., Methods: A preliminary study in 25 patients was conducted. NIR imaging was used intraoperatively during laparoscopic liver resection. The liver tumors were preoperatively labeled by intravenously injecting the patients with indocyanine green dye (0.5 mg/kg), an NIR fluorescence agent. During the surgical procedure, the PINPOINT Endoscopic Fluorescence Imaging System was used to assess the surgical margin by using real-time endoscopic high-definition visible and NIR fluorescence imaging., Results: All tumors were identified and resected laparoscopically by using the PINPOINT system, and all resections successfully secured the surgical margin. The pathological findings of all tumors indicated negative margins, defined as R0., Conclusions: This technique showed the potential to improve the intraoperative identification and demarcation of tumors. Its use could potentially reduce the number of positive resection margins.

Purpose: Laparoscopic and thoracoscopic/laparoscopic hepatectomy is a safe procedure that has potential advantages over open surgery. However, deeply positioned liver tumors require expert laparoscopic and thoracoscopic/laparoscopic hepatectomy techniques. Using simulated preoperative three-dimensional virtual endoscopy (P3DVE) guidance, we demonstrate herein that a thoracoscopic approach (TA), thoracoscopic-laparoscopic approach (TLA), and laparoscopic approach (LA) are all feasible and safe routes for performing pure laparoscopic and thoracoscopic/laparoscopic resection of liver tumors located in the 4a, 7, and 8 liver subdiaphragmatic areas., Methods: Thirty-eight patients underwent laparoscopic and thoracoscopic/laparoscopic partial liver resection (TA 13 cases, TLA two cases, and LA 23 cases) of the subdiaphragmatic area at Showa University Hospital. All surgical approaches were preoperatively determined based on preoperative 3D virtual endoscopic simulation (P3DVES) visualization and findings using the image processing software SYNAPSE VINCENT(®)., Results: Laparoscopic and thoracoscopic/laparoscopic liver resection was successfully performed for all cases under P3DVE instruction. The mean operative times using TA, TLA, and LA approaches were 193, 185, and 190 min, respectively. Mean blood loss during TA, TLA, and LA was 179, 138, and 73 g, respectively. No patients required conversion to open surgery, and there were no deaths, although there were three cases of Clavien-Dindo grade I in TA along with three cases of grade I and one case of grade II in LA., Conclusions: TA, TLA, and LA routes performed under P3DVE instruction are feasible and safe to perform for pure laparoscopic and thoracoscopic/laparoscopic liver resection in selected patients with lesions located in the hepatic subdiaphragmatic area.

This study describes a novel technique for skeletonization and isolation of Glissonean and venous branches during liver surgery using a harmonic scalpel (HS). Hepatic resections with HS were performed with the skeletonization and isolation technique in 50 patients (HS group). Variables evaluated were blood loss, operative time, biliary leak, and morbidity. The results were compared with 50 hepatic resections that were performed using a previously established technique: Cavitron ultrasonic surgical aspirator with electric cautery, ligatures, and hemoclips (NHS group). The HS group had shorter total operative times (285 versus 358 minutes; P = 0.01), less blood loss (389 versus 871 mL; P = 0.034), and less crystalloid infusion (2744 versus 3299 mL; P = 0.027) compared with the NHS group. Postoperative liver function and complication rates were similar when comparing the two groups. These data demonstrate that HS is a simple, easy, and effective instrument for the skeletonization and isolation of vessels during liver transection.

Background: Laparoscopic liver resection has recently gained wide acceptance for various liver tumors, thanks to advances in surgical techniques and devices. However, if the tumor is located in the subdiaphragmatic area of segments 7 and 8, resection is difficult. We demonstrate herein a novel technique for video-assisted thoracoscopic surgery hepatectomy (VATS-H) for liver tumors located in the subdiaphragmatic area., Methods: Five patients underwent VATS-H for a liver neoplasm. One port or two ports and two laparoscopic protectors were placed on the chest surrounding the tumor. Using intraoperative thoracoscopic ultrasonography (IOTU), the portion of the diaphragm located just above the tumor was cut and opened using laparoscopic coagulating shears. IOTU was performed on the liver surface, and the tumor margin was marked by electrocautery. For liver resection, microwave tissue coagulation or radiofrequency ablation was used for coagulation before liver transection and for coagulation of liver parenchyma during the transection., Results: The mean operating time was 137 min (range 95-185 min), and the mean operative blood loss was 43 g (range 0-200 g). No postoperative complications were encountered., Conclusions: VATS-H appears useful for resecting liver tumors located in the subdiaphragmatic area.

Background: Preoperative imaging is widely used and extremely helpful in hepatobiliary surgery. However, transfer of preoperative data to a intraoperative situation is very difficult. Surgeons need intraoperative anatomical information using imaging data for safe and precise operation in the field of hepatobiliary surgery. We have developed a new system for mapping liver segments and cholangiograms using intraoperative indocyanine green (ICG) fluorescence under infrared light observation., Method: The imaging technique for mapping liver segments and cholangiogram based on ICG fluorescence used an infrared-based navigation system. Eighty one patients with liver tumors underwent hepatectomy from 2006, January to 2009, March. In liver surgery, 1 ml of ICG was injected via the portal vein under observation by the fluorescent imaging system. Fourteen patients were underwent laparoscopic cholecystectomy for chronic cholecystitis with gallstones. In laparoscopic cholecystectomy, 5 ml of ICG was administered intravenously just before operation and the bile duct was observed using the infrared-based navigation system., Result: This new technique successfully identified stained subsegments and segments of the liver in 73 of 81 patients (90.1%). Moreover, clear mapping of liver segments was obtained even against a background of liver cirrhosis. Fluorescent cholangiography clearly showed the common bile duct and cystic duct in 10 of 14 patients (71.4%). No adverse reactions to the ICG were encountered., Conclusion: Application of this technique allows intraoperative identification of anatomical landmark in hepatobiliary surgery.

Background: Technetium-99m-galactosyl human serum albumin (GSA) scintigraphy provides an accurate estimation of the hepatic functional reserve but is not applied after a hepatectomy. The aim of this study was to elucidate the natural course of the remnant hepatic functional reserve (RHFR) after hepatectomy by GSA scintigraphy., Methods: Eighty-six patients (partial hepatic resection, Hr0 = 46; sectionectomy, Hr1 = 21; bisectionectomy, Hr2 = 19) classified as Child-Pugh class A before the hepatectomy were enrolled, and GSA scintigraphy to detect HH15 (uptake ratio of the heart at 15 min to that at 3 min) and LHL15 (uptake ratio of the liver at 15 min to the liver plus the heart at 15 min) was performed periodically before and after the hepatectomy. HH15, LHL15, and the percentages of patients that recovered to the preoperative levels of these entities were estimated. In addition, hematobiochemical tests and the remnant liver volume were also periodically monitored., Results: HH15 and LHL15 levels deteriorated until 2 months postoperatively (PO) after the procedure and subsequently recovered to the preoperative levels at 6 months PO in Hr0 patients. In Hr1 patients, but not in Hr2 patients, these levels also deteriorated until 3 months PO and had improved by 6 months after the surgery. Only 40% of the patients showed recovery to the preoperative levels by 6 months PO in the Hr0 group; furthermore, the percentage of patients who showed recovery to the preoperative levels by 6 months PO was under 40% in the Hr1 group and around 10% in the Hr2 group. However, the results of hematobiochemical tests and the remnant liver volume in all types of hepatectomies were rapidly normalized after the hepatectomy., Conclusions: Remnant hepatic functional reserve estimated by GSA scintigraphy revealed that a larger resected liver volume induced both more serious and continued remnant hepatic dysfunction in comparison to results shown by hematobiochemical tests, while the functional regeneration was also appreciably slower and more gradual in comparison to the volume regeneration.

Purpose: Bile duct injury is one of the most serious complications of laparoscopic cholecystectomy. Intraoperative indocyanine green (ICG) cholangiography is a safe and useful navigation modality for confirming the biliary anatomy. ICG cholangiography is expected to be a routine method for helping avoid bile duct injuries. Patients and Methods: We examined 25 patients who underwent intraoperative cholangiography using ICG fluorescence. Two methods of ICG injection are used: intrabiliary injection (percutaneous transhepatic gallbladder drainage [PTGBD], gallbladder [GB] puncture and endoscopic nasobiliary drainage [ENBD]) at a dosage of 0.025 mg during the operation or intravenous injection with 2.5 mg ICG preoperatively. Results: There were 24 patients who underwent laparoscopic cholecystectomy and 1 patient who underwent hepatectomy. For laparoscopic cholecystectomy, the average operation time was 127 (50– 197) minutes, and estimated blood loss was 43.2 (0– 400) g. The ICG administration route was intravenous injections in 12 cases and intrabiliary injection in 12 cases (GB injection: 3 cases, PTGBD: 8 cases, ENBD:1 case). The course of the biliary tree was able to be confirmed in all cases that received direct injection into the biliary tract, whereas bile structures were recognizable in only 10 cases (83.3%) with intravenous injection. The postoperative hospital stay was 4.6 (3– 9) days, and no postoperative complications (Clavien–Dindo ≧IIIa) were observed. For hepatectomy, a tumor located near the left Glissonian pedicle was resected using a fluorescence image guide. Biliary structures were fluorescent without injury after resecting the tumor. No adverse events due to ICG administration were observed, and the procedure was able to be performed safely. Conclusion: ICG fluorescence imaging allows surgeons to visualize the course of the biliary tree in real time during cholecystectomy and hepatectomy. This is considered essential for hepatobiliary surgery to prevent biliary tree injury and ensure safe surgery. [ABSTRACT FROM AUTHOR]

Background. In fulminant hepatic failure (FHF), the ability of surviving hepatocytes to proliferate is diminished. Therefore, it is important that medical therapy cause no further impairment of liver regeneration. In FHF, intracranial hypertension secondary to brain edema is the most common cause of brain injury and death and glycerol is used in some countries to treat this complication. Glycerol has been long known to suppress the growth of various cell types. We therefore decided to examine the effect of glycerol on hepatocyte proliferation in vitro and in vivo in rats subjected to partial (2/3) hepatectomy. Additionally, we investigated the effect of glycerol on the proliferation of HepG2 cells.Materials and methods. Mitogen-induced primary rat hepatocytes were cultured in a hormonally defined Dulbecco''s modified Eagle''s medium containing increasing amounts of glycerol (0.5, 1.0, 2.0, 4.0%). HepG2 cells were cultured in minimal essential medium/10% FBS. After 2 days, HepG2 cells were exposed to glycerol (1.0–2.0–4.0%) and harvested after 48 h. Control dishes contained no glycerol. Cell proliferation was measured by the incorporation of [3H]thymidine and/or bromodeoxyuridine (BrdU). In vivo, Sprague–Dawley rats were subjected to standard partial 2/3 hepatectomy and assigned to intraportal administration of either 400 μl of glycerol or saline. Rats were killed after 1, 2, 3, 5, and 7 days. Liver weight/body weight ratio and BrdU uptake were measured.Results. In all cultures tested, glycerol suppressed the growth of cells in a dose-dependent manner. In vivo, a single intraportal dose of glycerol slowed the liver regenerative response.Conclusions. This study demonstrated that glycerol has a potent growth-inhibitory effect on hepatocyte proliferation in vivo and in vitro. Remarkably, glycerol inhibited the proliferation of liver cancer cells as well. The results of this study have important clinical implications. [Copyright &y& Elsevier]