How to dissect the liver parenchyma: Excavation with cavitron ultrasonic surgical aspirator

Intraoperative artificial intelligence system identifying liver vessels in laparoscopic liver resection: a retrospective experimental study

BACKGROUND

The precise recognition of liver vessels during liver parenchymal dissection is the crucial technique for laparoscopic liver resection (LLR). This retrospective feasibility study aimed to develop artificial intelligence (AI) models to recognize liver vessels in LLR, and to evaluate their accuracy and real-time performance.

METHODS

Images from LLR videos were extracted, and the hepatic veins and Glissonean pedicles were labeled separately. Two AI models were developed to recognize liver vessels: the "2-class model" which recognized both hepatic veins and Glissonean pedicles as equivalent vessels and distinguished them from the background class, and the "3-class model" which recognized them all separately. The Feature Pyramid Network was used as a neural network architecture for both models in their semantic segmentation tasks. The models were evaluated using fivefold cross-validation tests, and the Dice coefficient (DC) was used as an evaluation metric. Ten gastroenterological surgeons also evaluated the models qualitatively through rubric.

RESULTS

In total, 2421 frames from 48 video clips were extracted. The mean DC value of the 2-class model was 0.789, with a processing speed of 0.094 s. The mean DC values for the hepatic vein and the Glissonean pedicle in the 3-class model were 0.631 and 0.482, respectively. The average processing time for the 3-class model was 0.097 s. Qualitative evaluation by surgeons revealed that false-negative and false-positive ratings in the 2-class model averaged 4.40 and 3.46, respectively, on a five-point scale, while the false-negative, false-positive, and vessel differentiation ratings in the 3-class model averaged 4.36, 3.44, and 3.28, respectively, on a five-point scale.

CONCLUSION

We successfully developed deep-learning models that recognize liver vessels in LLR with high accuracy and sufficient processing speed. These findings suggest the potential of a new real-time automated navigation system for LLR.

The CUSA Clarity Soft Tissue Removal Study: Clinical Performance Investigation of the CUSA Clarity Ultrasonic Surgical Aspirator System for Soft Tissue Removal During Liver Surgery

Background: Intraoperative blood loss has an unfavorable impact on the outcome of patients undergoing liver surgery. Today, the use of devices capable of minimizing this risk with high technical performance becomes mandatory. Into this scenario fits the CUSA® Clarity Ultrasonic Surgical Aspirator System. This prospective survey involving five liver surgery centers had the objective of investigating whether this innovative ultrasonic surgical aspirator is safe and effective in the transection of the liver parenchyma. Materials and Methods: This clinical study was a prospective, multicenter, single-arm Post-Market Clinical Follow-up study investigating 100 subjects who underwent liver surgery using the CUSA Clarity Ultrasonic Surgical Aspirator System at five centers during a period of 1 year and 8 months. After collecting all the patient's clinical information and instrument usage details, surgeons completed a brief survey giving their opinions on the performance of CUSA. Therefore, safety and efficacy outcomes were evaluated. Results: Surgeons had a 95% success rate in complete removal of the mass with an average overall operative time of 4 hours and 34 minutes. Overall, there were no complications or device deficiencies. Conclusion: The CUSA Clarity Ultrasonic Surgical Aspirator System performs well during liver surgery with a low complication rate. ClinicalTrials.gov Identifier: NCT04298268.

Hepatic Vein-Guided Approach in Laparoscopic Anatomic Liver Resection of the Ventral and Dorsal Parts of Segment 8

Laparoscopic ventral and dorsal segmentectomies 8 are an option for parenchymal-sparing liver resection. However, laparoscopic anatomic posterosuperior liver segment resection is technically demanding because of its deep location and the many variations in the segment 8 Glissonean pedicle (G8). In this study, we describe a hepatic vein-guided approach (HVGA) to overcome these limitations. For ventral segmentectomy 8, liver parenchymal transection was initiated at the ventral side of the middle hepatic vein (MHV) and continued exposing it toward the periphery. The G8 ventral branch (G8vent) was identified on the right side of the MHV. Following G8vent dissection, liver parenchymal transection was completed by connecting the demarcation line and G8vent stump. For dorsal segmentectomy 8, the anterior fissure vein (AFV) was exposed peripherally. The G8 dorsal branch (G8dor) was identified on the right side of the AFV. Following G8dor dissection, the right hepatic vein (RHV) was exposed from the root. Liver parenchymal transection was completed by connecting the demarcation line and RHV. Between April 2016 and December 2022, we performed laparoscopic ventral and dorsal segmentectomy 8 in fourteen patients. No complications (Clavien-Dindo classification, Grade ≥ IIIa) were observed. An HVGA is feasible and useful for standardizing safe laparoscopic ventral and dorsal segmentectomies 8.

Usefulness of cranio-dorsal approach for laparoscopic left lateral sectionectomy

Most surgeons perform laparoscopic left lateral sectionectomy (Lap LLS) using the caudo-peripheral approach (C-P approach). However, recently, a cranio-dorsal approach (C-D approach) has been applied to various types of hepatectomy owing to its advantage of preventing split injury. No studies yet have compared the perioperative outcomes of Lap LLS using each approach. Therefore, this study aimed to determine whether the C-D approach is useful for Lap LLS by comparing its perioperative outcomes with the C-P approach. Data of patients who underwent Lap LLS in our institution between 2010 and 2022 for liver tumors were retrospectively collected. We compared the perioperative outcomes of Lap LLS using a conventional C-P approach, which transects hepatic parenchyma in the caudo-peripheral direction and a C-D approach, which transects hepatic parenchyma in the cranio-caudal direction. All surgeries were performed only by board-certified expert surgeons to minimize technical bias. Furthermore, the perioperative procedures employed at our institution remained unchanged throughout the study period. A total of 36 patients were included in the study (C-P approach, n = 25; C-D approach, n = 11). The C-D approach showed a significantly shorter operation time than the C-P approach (median, 225 min vs. 262 min, p = 0.04). In addition, the C-D approach showed significantly lower blood loss than the C-P approach (median, 20 mL vs. 100 mL, p < 0.01). Other parameters, such as morbidity and hospital stay, were comparable between groups. The C-D approach could offer better surgical outcomes than the conventional C-P approach.

Laparoscopic left hepatectomy in a goat as a training model for laparoscopic anatomic liver resection: results of training courses with a total of 70 goats

BACKGROUND

To create a suitable animal model for the training of laparoscopic anatomic liver resection, we performed left hepatectomy using a goat and found its suitability. We have since started using goats for wet-lab training and have gradually standardized the relevant procedures. Herein, we report our standardized training procedures using a goat and discuss its feasibility as a novel training model.

METHODS

The standardized wet-lab training courses of laparoscopic liver resection conducted on 62 tables with a total of 70 goats were reviewed. The training course began by encircling the hepatoduodenal ligament for the Pringle maneuver, which was repeated during the parenchymal dissection. Following partial liver resection of the left lateral section, left hepatectomy was performed by a standardized procedure for humans in which the liver was split, exposing the entire length of the middle hepatic vein trunk from the dorsal side after extrahepatic transection of the left Glissonean pedicle. If a goat deceased before initiating left hepatectomy, the training was restarted with a new goat. The surgical procedures were performed by surgeons of varying skill levels.

RESULTS

A total of 184 surgeons including 10 surgical residents participated in the training. Partial liver resection was initiated in 62 tables, with 8 (13%) dying during or after the procedure of partial liver resection. Subsequently, left hepatectomy was initiated in 61 and completed in 59 tables (98%), regardless of whether the goat survived or deceased, and was not completed in 2 tables (3%) due to time limitation. In 14 tables (23%), the goats deceased during the procedure, however, the procedure was completed. The causes of death were multifactorial, including massive bleeding, reperfusion injury after the Pringle maneuver, and carbon dioxide gas embolism.

CONCLUSIONS

Left hepatectomy in a goat is useful as a training model for laparoscopic anatomic liver resection.

The Use of Cavitron Ultrasonic Surgical Aspirator for High-Risk Neuroblastoma with Image-Defined Risk Factors in Children

Aim of the study: The cavitron ultrasonic surgical aspirator (CUSA) has gained popularity in adult surgical oncology, but its application in children is limited to liver surgery and neurosurgical procedures. The complete resection of neuroblastoma with image-defined risk factors (IDRFs) is still considered one of the most difficult procedures to achieve in pediatric surgical oncology, with a high morbidity rate and potential risk of intraoperative mortality. The aim of our study is to describe the application of ultrasonic dissection in neuroblastoma with IDRFs. Methods: A retrospective study was performed, analyzing patients operated on from 2000 to 2018. Patient characteristics, resection completeness, and postoperative surgical and oncology outcomes were analyzed. Main results: Twenty-six patients with high-risk neuroblastoma and IDRFs were operated on in the study period with a CUSA. A complete macroscopic resection was performed in 50% of patients, while the other half was operated on with minimal residual (<5 mL). Six post-operative complications occurred without the need for surgery (Clavien−Dindo < 3). The overall survival was 50%, with a median follow-up of 69.6 months (5.6−140.4). Conclusions: The application of the CUSA in neuroblastoma with IDRFs can be considered an effective and safe alternative technique to achieve a radical resection.

Surgery

This chapter provides a comprehensive background from basic to applied knowledge of surgical anatomy which is necessary for the surgical treatment of cholangiocarcinoma (CCA) patients. Significant advances that have been made in the surgical treatment of CCA were examined. For instance, in-depth details are provided for appropriate preoperative assessment and treatment to optimize patient status and to improve the outcome of surgical treatment(s). Comprehensive details are provided for the surgical techniques and outcomes of treatments for each type of CCA with clear illustrations and images. This chapter also describes the role of minimally invasive surgery and liver transplantation in CCA treatment.

Laparoscopic liver resection with "ultrasonic scalpel mimic CUSA" technique

BACKGROUND

Liver parenchymal transection is the most critical step for laparoscopic liver resection (LLR). Ultrasonic scalpel (Harmonic) is a common used energy instrument in LLR; however, it is only recommended for superficial layer transection and the Cavitron Ultrasonic Surgical Aspirator (CUSA) is recommended for deep layer dissection. We herein introduce the "Harmonic mimic CUSA" technique for LLR.

METHODS

We retrospectively reviewed the medical records of the patients who underwent LLR using CUSA or the "Harmonic mimic CUSA" for parenchymal transection between July 2018 and October 2020 at West China Hospital of Sichuan University. Observation indicators included general demographic information, operative time, intraoperative blood loss, blood transfusion volume, complication rate, hospital stay, and the costs. Perioperative data was compared between the two groups by propensity score matching analysis (PSM).

RESULTS

A total of 298 patients, including 192 in Harmonic group and 106 in CUSA group, were enrolled in this study. After a 1:1 PSM, 99 patients using "Harmonic mimic CUSA" were matched with 99 patients via CUSA for parenchymal transection in LLRs. The Harmonic group had significantly less intraoperative blood loss (mean, 150 ml vs. 250 ml, P < 0.001), shorter operative time (mean 170 min vs. 250 min, P < 0.001) and less costs (mean 6723$ vs. 8307$, P < 0.001). The conversion to laparotomy, length of postoperative hospital stay, complications were comparable between the two groups. There perioperative mortality was nil.

CONCLUSION

The "Harmonic mimic CUSA" technique is safe, simple and feasible for LLR, which may be an alternative to CUSA for LLR.

Dorsal vs ventral approach to the middle hepatic vein during laparoscopic left hemihepatectomy: multicenter retrospective observational study

BACKGROUND

Left hemihepatectomy requires exposure of the middle hepatic vein (MHV) at the cutting-surface. Two procedures are used to approach the MHV: a conventional ventral approach and a laparoscopy-specific dorsal approach. This multicenter retrospective observational study aimed to evaluate the perioperative outcomes of these two procedures.

METHODS

Clinical records of 38 consecutive patients that underwent laparoscopic left hemihepatectomy in four university hospitals between 2016 and 2021 were retrospectively reviewed. Outcome measurements were operative blood loss, operating time, trend of postoperative laboratory data within 7 days after hepatectomy, and postoperative complications. Quality of MHV exposure was also evaluated and compared by three-grade evaluation (excellent/good/poor) using recorded still images of the cut-surface of the remnant liver (n = 35).

RESULTS

Dorsal and ventral approaches were performed in 9 and 29 patients, respectively. Median operating time was 316 min (dorsal) and 314 min (ventral) (P = 0.71). Median operative blood loss was 45 ml (dorsal) and 105 ml (ventral) (P = 0.10). Two patients in the ventral approach group had bleeding in excess of 500 ml, which was not seen in the dorsal approach group. Excellent/good/poor MHV appearance on the cutting-surface was observed in 5/3/1 patients in the dorsal approach group, respectively, and in 7/8/11 patients in the ventral approach group, respectively (P = 0.03). In the ventral approach group, significant increases of aspartate aminotransferase (on postoperative day 1 and day 4/5) and of alanine aminotransferase (on postoperative day 2/3 and 4/5) were observed (P < 0.05). Postoperative complications were observed only in the ventral approach group (n = 3).

CONCLUSIONS

The dorsal approach could achieve safe and precise anatomical left hemihepatectomy with operation time and operative blood loss comparable to the conventional ventral approach.

Intrahepatic Glissonean Approach for Laparoscopic Bisegmentectomy 7 and 8 With Root-Side Hepatic Vein Exposure

BACKGROUND

Laparoscopic anatomic liver resections of the posterosuperior segments are technically demanding procedures.^1-5 The segments are located in a deep-seated area of the liver surrounded by the ribs and the diaphragm, making forceps manipulation difficult. To overcome this limitation, an intrahepatic Glissonean approach and exposure of the hepatic veins from the root side was applied.^6-10 The authors describe the technical aspects of performing a bisegmentectomy 7-8.

METHODS

Liver parenchymal transection was initiated from the ventral aspect of the root of the middle hepatic vein, which often runs in the intersegmental plane, identifying the Glissonean pedicle of segment 8 (G8). After dissection of the G8, segmentectomy 8 was performed through identification of the ischemic area. After complete mobilization of the right lobe, the Glissonean pedicle of segment 7 (G7), which runs relatively near the liver surface,^{9, 10} was marked using ultrasonography. After division of the G7, a wide dissection between the caudate lobe and segment 7 was performed and connected to the previously dissected plane from the dorsal side of the right hepatic vein (RHV). Finally, bisegmentectomy 7-8 was performed with RHV resection because of tumor invasion.

RESULTS

The operation time was 510 min, and the estimated blood loss was 150 ml. The patient was discharged on postoperative day 10 without any complications.

CONCLUSIONS

Application of the intrahepatic Glissonean approach and exposure of the major hepatic veins from their roots using unique laparoscopic principles allows a safe performance of bisegmentectomy 7-8.

International multicentre propensity score-matched analysis comparing robotic versus laparoscopic right posterior sectionectomy

BACKGROUND

Minimally invasive right posterior sectionectomy (RPS) is a technically challenging procedure. This study was designed to determine outcomes following robotic RPS (R-RPS) and laparoscopic RPS (L-RPS).

METHODS

An international multicentre retrospective analysis of patients undergoing R-RPS versus those who had purely L-RPS at 21 centres from 2010 to 2019 was performed. Patient demographics, perioperative parameters, and postoperative outcomes were analysed retrospectively from a central database. Propensity score matching (PSM) was performed, with analysis of 1 : 2 and 1 : 1 matched cohorts.

RESULTS

Three-hundred and forty patients, including 96 who underwent R-RPS and 244 who had L-RPS, met the study criteria and were included. The median operating time was 295 minutes and there were 25 (7.4 per cent) open conversions. Ninety-seven (28.5 per cent) patients had cirrhosis and 56 (16.5 per cent) patients required blood transfusion. Overall postoperative morbidity rate was 22.1 per cent and major morbidity rate was 6.8 per cent. The median postoperative stay was 6 days. After 1 : 1 matching of 88 R-RPS and L-RPS patients, median (i.q.r.) blood loss (200 (100-400) versus 450 (200-900) ml, respectively; P < 0.001), major blood loss (> 500 ml; P = 0.001), need for intraoperative blood transfusion (10.2 versus 23.9 per cent, respectively; P = 0.014), and open conversion rate (2.3 versus 11.4 per cent, respectively; P = 0.016) were lower in the R-RPS group. Similar results were found in the 1 : 2 matched groups (66 R-RPS versus 132 L-RPS patients).

CONCLUSION

R-RPS and L-RPS can be performed in expert centres with good outcomes in well selected patients. R-RPS was associated with reduced blood loss and lower open conversion rates than L-RPS.

Cranio-caudal approach to hepatic veins in laparoscopic central bisectionectomy (with Video)

BACKGROUND

Laparoscopic central bisectionectomy (Couinaud's segment IV, V, and VIII) needs exposure of the RHV and MHV on the surface of the remnant and the resecting side, respectively. Avoiding venous injury is mandatory and laparoscopy-specific cranio-caudal approach to hepatic veins might be helpful [1]. We present this procedure in performing laparoscopic central bisectionectomy.

PATIENT

A 45-year-old female was admitted to our hospital with a 6 cm HCC in the segment VIII and IV. Her comorbid disease was non-cirrhotic HBV hepatitis (Child-Pugh grade A) and diabetes (untreated).

METHOD

After cholecystectomy, G₄ branches were dissected and cut by extra- or intra-hepatic approach. Hilar plate was dissected and the G_ant was encircled and occluded by a vascular clip. Afterwards, exposure of the MHV was started at its root on IVC [2,3] and extended in cranio-caudal direction [1]. After sufficient space was obtained around the G_ant, the G_ant and the MHV were cut. Parenchymal transection between right anterior and right posterior sections was also started form the root of the RHV to its cranio-caudal direction. Liver resection was finished with full exposure of the RHV.

RESULTS

The operating time was 380 minutes, and the blood loss volume was 30 ml. Postoperative CT image showed exposure of the RHV and umbilical portion of Glissonean branch, and no fluid retention.

CONCLUSION

Laparoscopy-specific cranio-caudal approach to hepatic veins may be useful to avoid split injury of venous branches [4], especially if the hepatectomy requires complete exposure of hepatic vein, such as central bisectionectomy.

How-I-do-it: laparoscopic left medial sectionectomy utilizing a cranial approach to the middle hepatic vein and Laennec's capsule

Background

Laparoscopic anatomic liver resection is technically demanding, given the need to safely isolate the Glissonean pedicles and expose the hepatic veins (HVs) on the liver parenchyma cut surface. Laennec’s capsule is observed around the Glissonean pedicles and root of the HVs. However, its existence, particularly on the peripheral side of the HVs, remains controversial. Herein, we describe Laennec’s capsule-related histopathological findings around the HVs and a safe laparoscopic left medial sectionectomy utilizing Laennec’s capsule.

Methods

The extrahepatic Glissonean approach was performed by connecting Gates II and III, in accordance with Sugioka’s Gate theory. Liver parenchymal transection commenced along the demarcation line, which is between the medial and lateral sections, and the G4 was dissected during transection. Subsequently, via the outer-Laennec approach, the middle hepatic vein (MHV) was exposed from the root side in cranial view, while Laennec’s capsule was preserved. Parenchymal transection was completed while connecting the MHV with the demarcation line. We obtained the membrane surrounding the HVs and performed histopathological examinations.

Results

Six patients underwent laparoscopic left medial sectionectomy from February 2012 to November 2020. There were no cases involving complications (Clavien–Dindo classification; grade II or higher), open-surgery conversion, transfusion, or surgery-related death. The histopathological findings showed Laennec’s capsule surrounding both the trunk of the major HVs and the peripheral side of the HVs.

Conclusions

A cranial approach to the major HVs utilizing Laennec’s capsule is a feasible and advantageous procedure for laparoscopic left medial sectionectomy. We propose that Laennec’s capsule surrounds the entire length of the HVs.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00423-021-02282-x.

Arantius' Ligament Approach to Middle Hepatic Vein in Laparoscopic Extended Medial Segmentectomy (with Video)

BACKGROUND

Under laparoscopy-specific caudal and lateral view, Aranitius' ligament could be the landmark for the root of the venous trunks in the left hepatic lobe.1-3 We performed laparoscopic hepatic extended medial segmentectomy including the middle hepatic vein (MHV) using the Arantius' approach.

METHODS

An 86-year-old man was referred to our hospital for hepatocellular carcinoma, 4.5 cm in size, located in the medial hepatic segment (Video 1). After pneumoperitoneum and placement of four working ports, the Arantius' ligament was exposed, isolated, and divided. The liver parenchyma underneath the Arantius' ligament was opened to widely expose the root of the MHV, umbilical fissure vein (UFV), and left hepatic vein (LHV). After dividing the Glissonean branches for segment 4 (G4), the parenchymal tissue between MHV and LHV was divided. The trunk of the MHV was fully exposed and was divided using the endo-stapling device. Parenchymal resection was further proceeded along the dorsal side of the MHV, and the planned hepatectomy was completed.

RESULTS

The operation time was 337 min, and the estimated blood loss was 400 g. His postoperative course was uneventful, and he was discharged on postoperative day 10.

CONCLUSIONS

The significance of Arantius' ligament approach is short-cut exposure of the MHV as the anatomical landmark during the initial process of the surgery under laparoscopy-specific caudal and lateral view, and is a reasonable technique in extended medial segmentectomy including the MHV.

A novel internal cold circulation radiofrequency-assisted device for liver transection

PURPOSE

To evaluate the safety and efficacy of a new internal cold circulation bipolar radiofrequency compared with Habib-4X bipolar radiofrequency device in the resection of liver tumors.

METHODS

A total of 85 patients with hepatocellular carcinoma who received radiofrequency-assisted liver resection from February 2017 to January 2020 were retrospectively enrolled in our study, in which 45 patients received the new internal cold circulation bipolar radiofrequency (New-RF) and 40 patients received Habib-4X bipolar radiofrequency (Habib-4X). Primary outcome measures were the speed of liver transection, the width of coagulation tissue, hemorrhage volume, blood transfusion rate, and operation time.

RESULTS

The baseline characteristics of patients in the New-RF and Habib-4X groups had no significant difference (p > 0.05). Compared to Habib-4X, the New-RF had a faster average speed of liver transection (4.81 ± 1.20 cm²/min vs 3.64 ± 1.08 cm²/min, p < 0.001), a narrower width of coagulation tissue (1.42 ± 0.23 cm² vs 1.81 ± 0.20 cm², p < 0.001), a less operation time (55.04 ± 16.12 min vs 64.02 ± 15.09 min, p = 0.010), a lower rate of needle path bleeding (13.3% vs 35.0%, p = 0.019), and a lower carbonization rate of electrode needle (22.2% vs 77.8%, p < 0.001). Hemorrhage during the transection (85.0 ml vs 105.0 ml, p = 0.438) and hemorrhage per square centimeter (3.28 ± 0.86 ml/cm² vs 3.60 ± 1.12 ml/cm², p = 0.141) in the New-RF group were smaller than those in Habib-4X group with no significant difference.

CONCLUSION

The new internal cold circulation bipolar radiofrequency was a safe and efficacious auxiliary device for liver resection with a faster speed of resection, lower carbonization rate of electrode needle, and more precise range of coagulation.

Double cone-unit laparoscopic hepatic resection using indocyanine green negative counterstaining (with video)

A hepatic cone-unit represents an anatomical unit dominated by a smaller Glissonean pedicle. Anatomical resection of a tumor located in an intersegmental plane is challenging, but could be achieved effectively by performing multiple cone-unit resection. We performed double cone-unit laparoscopic resection of hepatocellular carcinoma located on the intersegmental plane between segments 6a, b. The liver parenchyma covering the posterior Glissonean pedicle was divided along Rouviere's sulcus, the Glissonean branches of segments 6a, b were isolated and ligated, and indocyanine green (ICG) negative counterstaining was performed. The hepatic parenchyma was dissected along the demarcation line to identify the right hepatic vein and the double cone-unit resection was then completed with a negative surgical margin. Thus, double cone-unit laparoscopic hepatectomy with ICG negative counterstaining may be a feasible option for tumors located in an intersegmental plane.

Laparoscopic left ventral hepatic segmentectomy (with video)

BACKGROUND

The anatomical resection of Segment 3 and 4 of the liver under conventional laparotomy was reported [1]. We present the laparoscopic approach for this type of resection.

METHOD

Laparoscopic left ventral hepatic segmentectomy [2] including the Segment 3 (S3) and the ventral Segment 4 (S4v), preserving the Segment 2 (S2) and the dorsal Segment 4 (S4d), was performed for the hepatocellular carcinoma located at the root of the Glissonean pedicle of the S3.

VIDEO

After the pneumoperitoneum and the mobilization of the left lateral segment, the Glissonean pedicle for the left ventral segment was controlled and occluded. The demarcation line between the left ventral segment and the Segment 2 (S2), the dorsal Segment 4 (S4d) and the Segment 5 (S5) was confirmed using indocyanine green-fluorescence imaging [3]. The hepatic parenchymal resection was started along the demarcation line between the S3 and S2 on the dorsal lateral segment [4], followed by the division of the Glissonean pedicle of the left ventral segment. Further parenchymal division between the S4v and S4d, and that between the S4v and S5 resulted in the completion of the laparoscopic left ventral hepatic segmentectomy.

RESULTS

The operative time was 221 minutes and the intraoperative blood loss was 10 ml. The postoperative course was uneventful and the patient was discharged 7days after the surgery.

CONCLUSIONS

The left ventral hepatic segmentectomy could be among the standard choices of laparoscopic anatomical resection for a tumor located around the top of the umbilical portion in selected HBP institutes.