Color-coded laparoscopic liver resection using artificial intelligence: A preliminary study.

Tashiro and colleagues demonstrated for the first time that an artificial intelligence system can precisely identify intrahepatic vascular structures during laparoscopic liver resection in real time through color coding under bleeding and indocyanine green fluorescent imaging. The system supports real-time navigation and offers potentially safer laparoscopic or robotic liver surgery.

Development of a Novel Artificial Intelligence System for Laparoscopic Hepatectomy.

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.

Laparoscopic Anatomical Liver Resection Using Liver Mapping of Incidental Indocyanine Green Fluorescence due to Cholestasis.

BACKGROUND/AIM: Indocyanine green (ICG) fluorescence is useful in laparoscopic hepatectomy (LH) for tumor identification and staining, as well as determination of resection margins. At our Institution, patient-specific, three-dimensional simulations and rehearsal of surgical strategies are carried out preoperatively. We describe cases in which ICG administered preoperatively became stagnated and fluoresced in an area similar to the preoperatively established resection area and the pathological findings in these cases. PATIENTS AND METHODS: Four patients who underwent LH at our hospital between 2020 and 2023 (due to hepatocellular carcinoma in two and colorectal liver metastasis in two) were enrolled in the present study. The ICG-fluorescing liver segments were resected laparoscopically and their pathological characteristics were examined using a fluorescence microscope. RESULTS: In four cases, the areas of ICG fluorescence seen intraoperatively were due to stasis of preoperatively administered ICG, which fortuitously was equivalent to the planned resection area in the preoperative patient-specific simulation. The fluorescent areas were resected; there were no cases of bile leakage or recurrence. Fluorescence microscopy revealed areas with diffuse ICG fluorescence in normal hepatocytes on the tumor's peripheral side. CONCLUSION: It was suggested that resection of the liver area that was fluorescent due to stagnation of preoperatively administered ICG was rational and justified both anatomically and oncologically. This resection may also contribute to the prevention of bile leakage and recurrence.

Simultaneous tumor identification, cholangiography, and securing surgical margin for recurrence of hepatocellular carcinoma using the Medical Imaging Projection System.

BACKGROUND: Indocyanine green (ICG) fluorescence-guided surgery is a real-time navigation technology for tumor detection, securing surgical margins, segmentation mapping, and cholangiography in liver surgery [1]. According to recent reports, the Medical Imaging Projection System (MIPS) may be a useful new real-time navigation technology for open anatomical liver resection [2]. However, the efficacy of MIPS for tumor identification, cholangiography, and securing surgical margins is uncertain. In this report, we introduce MIPS-assisted liver resection for real-time navigation during simultaneous tumor identification, cholangiography, and securing surgical margins. METHODS: A 76-year-old man presented with a 30 × 30 mm recurrent hepatocellular carcinoma on the transection plane after right anterior sectionectomy. Eight radiofrequency ablations were performed after the first hepatectomy. Preoperative computed tomography and three-dimensional simulation revealed a tumor near the posterior Glissonean branch. One day before surgery, 2.5 mg/body ICG was administered. We analyzed whether MIPS could simultaneously facilitate tumor identification, cholangiography, and securing surgical margins. The relationship between fluorescent imaging and the surgical margin was evaluated with a fluorescent microscope [3]. RESULTS: Simultaneous tumor identification, cholangiography, and securing the surgical margins were demonstrated by adjusting the image projection of MIPS, and R0 resection was achieved without biliary injury (Figs. 1 and 2). The operative time and estimated blood loss were 287 minutes and 394 mL, respectively. He was discharged on postoperative day 12 without any complications. CONCLUSION: MIPS could be useful for real-time navigation for tumor identification, cholangiography, and securing surgical margins during liver surgery. The threshold of fluorescent intensity should be set for optimal image projection.

Clinical Treatment of Perioperative Disseminated Intravascular Coagulation in Patients Who Underwent Gastrointestinal and Hepato-Biliary-Pancreatic Surgery.

BACKGROUND: It is unclear how effective recombinant thrombomodulin (rTM) treatment is in disseminated intravascular coagulation (DIC) during the perioperative period of gastrointestinal and hepato-biliary-pancreatic surgery. The current study aimed to evaluate the therapeutic outcomes of rTM for perioperative DIC. METHODS: We enrolled 100 consecutive patients diagnosed with perioperative DIC after gastrointestinal surgery, and hepato-biliary-pancreatic including emergency procedures, between January 2012 and May 2021. Patients received routine rTM treatment immediately after DIC diagnosis. Then, the DIC, Sequential Organ Failure Assessment (SOFA), and Acute Physiology and Chronic Health Evaluation (APACHE) II scores were calculated and used for evaluation. The outcomes of rTM treatment and the predictors of survival were evaluated. RESULTS: The causative diseases of DIC were as follows: perforated peritonitis, n = 38; intestinal ischemia, n = 23; intra-abdominal abscess, n = 13; anastomotic leakage, n = 7; pneumonia, n = 7; cholangitis, n = 4; and others, n = 6. The 30-day mortality rate was 18.0%. There were significant differences in the platelet count (13.78 vs 10.41, P = .032) and the SOFA score (5.22 vs 9.89, P<.0001) at the start of DIC treatment between the survivor and non-survivor groups (day 0). The survivor group had a significantly lower DIC score (3.13 vs 4.93, P = .0006) and SOFA score (4.94 vs 12.14, P < .0001) and a higher platelet count (13.50 vs 4.34, P < .0001) than the non-survivor group on day 3. CONCLUSIONS: Comprehensive and systemic treatment is fundamentally essential for DIC, in which rTM may play an important role in the treatment of perioperative DIC.

Laparoscopic Resection of a Hepatic Epithelioid Angiomyolipoma Revealed by Indocyanine Green Fluorescence Imaging.

Indocyanine green fluorescence imaging (ICG-FI)-a sensitive tool for detecting tumor localization in laparoscopic surgery-produces false positive results for benign liver tumors. This report is the first case of hepatic angiomyolipoma (HAML) treated laparoscopically with ICG-FI. We present the case of a 31-year-old woman with a liver tumor that was a 13-mm mass in the anterior superior segment. Though a benign tumor was suspected, malignant potential could not be ruled out. Therefore, minimally invasive laparoscopic resection using ICG-FI was planned. ICG, intravenously injected preoperatively, revealed the tumor's existence. Pure laparoscopic hepatectomy with ICG-FI was performed for excisional biopsy, during which the tumor was resected with adequate surgical margins, followed by histological confirmation of HAML. In conclusion, it is suggested that laparoscopic resection with ICG-FI is an effective minimal invasive surgery for tumors that are difficult to detect, such as HAML, leading to a safe surgical margin.

Indocyanine Green Labeling of Tumors in the Liver Recurring After Radiofrequency Ablation Enables Complete Resection by Fluorescence-guided Surgery.

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.

Relationship Between Remnant Pancreatic Volume and Endocrine Function After Pancreaticoduodenectomy.

BACKGROUND: Decreased pancreatic volume (PV) is a predictive factor for diabetes mellitus (DM) after surgery. There are few reports on PV and endocrine function pre- and post-surgery. We investigated the correlation between PV and insulin secretion. METHODS: Seventeen patients underwent pancreaticoduodenectomy (PD) Pre- and post-surgery PV and C-peptide index (CPI) measurements were performed. Additionally, the correlation between PV and CPI was analyzed. RESULTS: The mean preoperative PV (PPV) was 55.1 ± 31.6 mL, postoperative remnant PV (RPV) was 25.3±17.3 mL, and PV reduction was 53%. The mean preoperative C-peptide immunoreactivity (CPR) was 1.39 ± .51 and postoperative CPR was .85±.51. The mean preoperative CPI was 1.29±.72 and postoperative CPI was .73 ± .48. Significant correlations were observed between RPV and post CPR (ρ = .507, P = .03) and post CPI (ρ = .619, P = .008). DISCUSSION: There was a significant correlation between RPV and CPI after PD. A smaller RPV resulted in lower insulin secretion ability, increasing the potential risk of new-onset DM after PD.

Determinative Structural Features Identified With Probe-based Confocal Endomicroscopy for the Accurate Diagnosis of Gallbladder Malignancy.

BACKGROUND: Probe-based confocal laser endomicroscopy (pCLE) can visualize microscopic structures at high resolution but has not yet yielded definitive diagnostic features of gallbladder malignancy, as opposed to benign changes. PATIENTS AND METHODS: A total of 73 patients had their gallbladder evaluated with pCLE performed on resected benign and malignant gallbladder surgical specimens, which were sprayed with fluorescein. Malignant and benign features of pCLE findings were identified on the basis of Miami and Paris Classifications. Standard histopathological diagnoses and individual patient pCLE findings of gallbladder lesions were correlated. RESULTS: Of the 73 consecutive patients that had their gallbladder evaluated ex vivo with pCLE, 11 were identified with gallbladder malignancy. pCLE identified features of gallbladders examined ex vivo, including the presence of thick dark bands and dark clumps, which together correlated with histopathologically-determined biliary malignancy at 100% sensitivity. Thick white bands and visualized epithelium, also identified with pCLE, together correlated with histopathologically-determined malignancy at 100% specificity. CONCLUSION: pCLE can be used for real-time differentiation of cancerous/non-cancerous regions in the gallbladder using the diagnostic criteria identified in the present study.

A rare case of synchronous appendiceal and cecal cancer.

Primary appendiceal cancer is rare, and difficult to diagnose pre-operatively because lack of specific symptoms. This report presents a rare case of synchronous colon and appendiceal cancer. A 50-year-old man was referred to our hospital due to endoscopic submucosal resection (ESD) for early cecal cancer. ESD was performed, and the pathological examination revealed tubular adenocarcinoma with deep submucosal invasion. Laparoscopic ileocecal resection was performed as additional resection after ESD of cecal cancer. There were no obvious abnormalities around the ileocecal region in the preoperative examination. Postoperative pathological examination incidentally revealed a mucosal papillary adenocarcinoma of the appendix, with no residual lesion in the ESD scar. The patient was discharged on the seventh postoperative day. Synchronous appendiceal and colon cancer is extremely rare in past reports. Here, we report the case details and review previous case reports.

Indocyanine Green Fluorescence Image-guided Laparoscopic Hepatectomy Enabled Resection of a Tumor Invisible With Ultrasonography.

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.

The Efficacy of Intraoperative Fluorescent Imaging Using Indocyanine Green for Cholangiography During Cholecystectomy and Hepatectomy.

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.

Use of Transumbilical Incision as an Organ Removal Site in Laparoscopic Pancreatectomy.

BACKGROUND/AIM: To evaluate complications and risk factors associated with transumbilical incision as an organ removal site in laparoscopic pancreatectomy (LP). PATIENTS AND METHODS: In total, 52 patients who underwent LP between 2009 and 2017 were included in this study. The development of superficial surgical site infection (SSI) and transumbilical port-site incisional hernia was recorded. RESULTS: None of the patients had SSI. However, three (5.77%) presented with transumbilical incisional hernia. No variables were significantly associated with the risk of transumbilical incisional hernia. CONCLUSION: No evident risk factors correlated with hernia formation. Hence, incisional hernia might have occurred at a certain probability. In some cases, it was caused by technical problems. However, the use of transumbilical incision as an organ removal site was feasible, and a new incision for organ removal alone was not required.

Experience of the pancreas duodenectomy for so-called carcinosarcoma of the common bile duct:a case report and review of literature.

A 79-year-old man presented with malaise and jaundice at a local hospital. His blood tests showed severe inflammation, liver failure, and high expression of several tumour markers. Radiological findings revealed dilated common and intrahepatic bile ducts and a lower bile duct constricted by a soft tissue mass. Histological findings by endoscopy showed a suspected adenocarcinoma, which was determined as class IV by cytology. The patient was referred to our hospital for surgical treatment. He underwent pancreaticoduodenectomy and the final diagnosis was so-called carcinosarcoma of the bile duct. He had liver metastasis and died at 26 postoperative months.

Intraoperative Shear Wave Elastography as a Quantitative Predictor of Pancreatic Fibrosis and Exocrine Function.

BACKGROUND/AIM: Soft pancreatic texture is a risk factor for postoperative pancreatic fistula (POPF). However, conventional evaluation of pancreatic texture is largely dependent on subjective assessment and lacks quantitative parameters. The study aimed to use ultrasonic shear wave elastography (SWE) to evaluate pancreatic stiffness to determine if the intraoperative SWE measurement could be a quantitative predictor for POPF. PATIENTS AND METHODS: Fifteen patients scheduled for pancreaticoduodenectomy were included. Both pre- and intra-operative measurement of the pancreatic SWE index (SWEI) were evaluated. Relationships between intraoperative and preoperative SWEI, pathological fibrosis of the resected pancreatic specimen, postoperative exocrine function of the remnant pancreas, and the incidence of POPF were evaluated. RESULTS: The intraoperative SWEI was correlated with the preoperative SWEI, pathological fibrosis of pancreatic tissue, and pancreatic exocrine function. CONCLUSION: Intraoperative SWE measurement of pancreatic elasticity may be useful as a quantitative method for evaluating pancreatic fibrosis and exocrine function.

Laparoscopic Liver Surgery Guided by Virtual Real-time CT-Guided Volume Navigation.

BACKGROUND: Recently, virtual navigation system has been applied to hepatic surgery, enabling better visualization of intrahepatic vascular branches and location of tumor. Intraoperative ultrasonography (IOUS) is the most common form of image guidance during liver surgery. However, during laparoscopic hepatectomies (LH), IOUS has several limitations and its reliability has been poorly evaluated. The objective of this work is to evaluate VRCT (virtual real-time CT-guided volume navigation) during LH. This system aims to provide accurate anatomical orientation for surgeons enhancing the safety of LH. METHODS: Twenty-seven hepatic neoplasms were resected laparoscopically at our institution under reference guidance of VRCT. During operation, electromagnetic tracking of the surgical instrument was used for navigating the direction of accurate liver transection. RESULTS: Twenty-six (96.3%) of the 27 lesions (mean diameter 11 mm) were successfully performed under VRCT guidance. Average registration time was < 2 min. Average setup time was approximately 7 min per procedure. VRCT allows the surgeon to navigate liver transection with acceptable accuracy. The mean error was 12 mm. All surgical margins were negative and the mean histologic resection margin was 9 mm. CONCLUSIONS: VRCT-guided LH is feasible and provides valuable real-time anatomical feedback during hepatic resections. Advancement of such systems to improve accuracy might greatly compensate for the limitation of laparoscopic IOUS.

Preventing clinically relevant pancreatic fistula with combination of linear stapling plus continuous suture of the stump in laparoscopic distal pancreatectomy.

BACKGROUND: Pancreatic fistula is one of the serious complications for patients undergoing distal pancreatectomy, which leads to significant morbidity. The aim of our study is to compare linear stapling closure plus continuous suture with linear stapling closure alone during laparoscopic distal pancreatectomy (LDP) in terms of clinically relevant postoperative pancreatic fistula (POPF) rate. METHODS: Twenty-two patients underwent LDP at our institution between 2011 and 2013. Twelve patients had linear stapling closure with peri-firing compression (LSC) alone compared with ten patients who had linear stapling closure, peri-firing compression plus continuous suture (LSC/CS) for stump closure of remnant pancreas in LDP. Biochemical leak and clinically relevant POPF were compared between both groups. RESULTS: POPF occurred in 4 of 12 (33.3%) patients with linear stapling closure while no patient developed a clinically relevant POPF in the triple combination of linear stapling, peri-firing compression plus continuous suture group (p = 0.043).1 patient (8.3%) in the LSC group and 5 patients (50%) in the LSC/CS group had evidence of a biochemical leak. There were no significant differences in operative time (188.3 vs 187.0 min) and blood loss (135 vs. 240 g) between both groups but there was a significantly of shorter length of hospital stay (11.9 vs. 19.9 days) in LSC/CS group (p = 0.037). There was no mortality in either group. CONCLUSIONS: The triple combination of linear stapling, peri-firing compression plus continuous suture in LDP has effectively prevented occurrence of clinically relevant ISGPF POPF. TRIAL REGISTRATION: The study was retrospectively registered September 30, 2019 at Showa University Ethics Committee as IRB protocol numbers 2943.

Usefulness of a Transumbilical Incision for Organ Removal in Laparoscopic Hepatectomy.

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.

An Improved Encapsulation Method for Cryopreserving Hepatocytes for Functional Transplantation Using a Thermo-reversible Gelation Polymer.

BACKGROUND/AIM: Thermo-reversible gelation polymer (TGP) can be converted into a gel state upon warming and liquid upon cooling. The present study aimed to demonstrate a new method for cryopreservation and encapsulation of rat hepatocytes using a TGP and their successful transplantation. MATERIALS AND METHODS: The isolated rat hepatocytes were microencapsulated using TGP, and stored in liquid nitrogen. After cryopreservation, hepatocytes were cultured. Moreover, hepatocytes were transplanted into the spleen without a TGP capsule. RESULTS: The viability of hepatocytes that were cryopreserved in TGP was 71.2±2.3%. The hepatocytes demonstrated adequate survival, maintained their hepatic function in culture, and expressed albumin after transplantation to the rat spleen. CONCLUSION: We demonstrated a cryopreservation method of rat hepatocyte encapsulation using a TGP gel in the hydrogel state which subsequently allowed successful transplantation of unencapsulated hepatocytes in a sol state TGP gel at low temperature.