Landmarks and techniques to perform minimally invasive liver surgery: A systematic review with a focus on hepatic outflow

A pilot study of virtual liver segment projection technology in subsegment-oriented laparoscopic anatomical liver resection when indocyanine green staining fails (with video)

BACKGROUND

Precision surgery for liver tumors favors laparoscopic anatomical liver resection (LALR), involving the removal of specific liver segments or subsegments. Indocyanine green (ICG)-negative staining is a commonly used method for defining resection boundaries but may be prone to failure. The challenge arises when ICG staining fails, as it cannot be repeated during surgery. In this study, we employed the virtual liver segment projection (VLSP) technology as a salvage approach for precise boundary determination. Our aim was to assess the feasibility of the VLSP to be used for the determination of the boundaries of the liver resection in this situation.

METHODS

Between January 2021 and June 2023, 12 consecutive patients undergoing subsegment-oriented LALR were included in this pilot series. The VLSP technology was utilized to define the resection boundaries at the time of ICG-negative staining failure. Routine surgical parameters and short-term outcomes were evaluated to assess the safety of VLSP in this procedure. In addition, its feasibility was assessed by analyzing the accuracy between the predicted resected liver volume (PRLV) and actual resected liver volume (ARLV).

RESULTS

Of the 12 enrolled patients, the mean operation time was 444.58 ± 101.70 min (range 290-570 min), with a mean blood loss of 125.00 ± 96.53 ml (range 50-400 mL). One patient (8.3%) was converted to laparotomy for subsequent parenchymal transection, four (33.3%) received blood transfusions and four (33.3%) had postoperative complications. All patients received an R0 resection. The Pearson correlation coefficient (r) between PRLV and ARLV was 0.98 (R2 = 0.96, p < 0.05), and the relative error (RE) was 8.62 ± 6.66% in the 12 patients, indicating agreement.

CONCLUSION

Failure of intraoperative ICG-negative staining during subsegment-oriented LALR is possible, and VLSP may be an alternative to define the resection boundaries in such cases.

Laparoscopic left hemihepatectomy guided by indocyanine green fluorescence: A cranial-dorsal approach

BACKGROUND

Advancements in laparoscopic technology and a deeper understanding of intrahepatic anatomy have led to the establishment of more precise laparoscopic hepatectomy (LH) techniques. The indocyanine green (ICG) fluorescence navigation technique has emerged as the most effective method for identifying hepatic regions, potentially overcoming the limitations of LH. While laparoscopic left hemihepatectomy (LLH) is a standardized procedure, there is a need for innovative strategies to enhance its outcomes.

AIM

To investigate a standardized cranial-dorsal strategy for LLH, focusing on important anatomical markers, surgical skills, and ICG staining methods.

METHODS

Thirty-seven patients who underwent ICG fluorescence-guided LLH at Qujing Second People's Hospital between January 2019 and February 2022 were retrospectively analyzed. The cranial-dorsal approach was performed which involves dissecting the left hepatic vein cephalad, isolating the Arantius ligament , exposing the middle hepatic vein, and dissecting the parenchyma from the dorsal to the foot in order to complete the anatomical LLH. The surgical methods, as well as intra- and post-surgical data, were recorded and analyzed. Our hospital's Medical Ethics Committee approved this study (Ethical review: 2022-019-01).

RESULTS

Intraoperative blood loss during LLH was 335.68 ± 99.869 mL and the rates of transfusion and conversion to laparotomy were 13.5% and 0%, respectively. The overall incidence of complications throughout the follow-up (median of 18 months; range 1-36 months) was 21.6%. No mortality or severe complications (level IV) were reported.

CONCLUSION

LLH has the potential to become a novel, standardized approach that can effectively, safely, and simply expose the middle hepatic vein and meet the requirements of precision surgery.

Augmented Reality Navigation Plus Indocyanine Green Fluorescence Imaging Can Accurately Guide Laparoscopic Anatomical Segment 8 Resection

BACKGROUND

Laparoscopic anatomical Segment 8 (S8) resection is a highly challenging hepatectomy. Augmented reality navigation (ARN), which could be combined with indocyanine green (ICG) fluorescence imaging, has been applied in various complex liver resections and may also be applied in laparoscopic anatomical S8 resection. However, no study has explored how to apply ARN plus ICG fluorescence imaging (ARN-FI) in laparoscopic anatomical S8 resection, or explored its accuracy.

PATIENTS AND METHODS

This study is a post hoc analysis that included 31 patients undergoing laparoscopic anatomical S8 resection from the clinical NaLLRFI trial, and the resected liver volume was measured in each patient. The perioperative parameters of safety and feasibility, as well as the accuracy analysis outcomes were compared.

RESULTS

There were 16 patients in the ARN-FI group and 15 patients underwent conventional laparoscopic hepatectomy without ARN or fluorescence imaging (non-ARN-FI group). There was no significant difference in baseline characteristics between the two groups. Compared with the non-ARN-FI group, the ARN-FI group had lower intraoperative bleeding (median 125 vs. 300 mL, P = 0.003). No significant difference was observed in other postoperative short-term outcomes. Accuracy analysis indicated that the actual resected liver volume (ARLV) in the ARN-FI group was more accurate.

CONCLUSIONS

ARN-FI was associated with less intraoperative bleeding and more accurate resection volume. These techniques may address existing challenges and provide rational guidance for laparoscopic anatomical S8 resection.

Laparoscopic Anatomical Liver Resection of Segment VIII by Using ICG Fluorescence Positive Staining Under the Guidance of Laparoscopic Ultrasonography

BACKGROUND

Anatomical segmentectomy is a surgical procedure that completely removes a territory (or territories) of the third-order portal venous branches of a Couinaud segment (Wakabayashi et al. in J Hepatobil Pancreat Sci 29(1):82-98, 2022. https://doi.org/10.1002/jhbp.899 ). Laparoscopic segmentectomy of S8 is considered technically challenging because of the Precise dissection of the Glissonean pedicle of S8, and exposure of the middle and right hepatic veins are required (Ome et al. in J Am Coll Surg 230(3):e13-e20, 2020; Wakabayashi et al. in Ann Surg 261(4):619-29, 2015. https://doi.org/10.1097/sla.0000000000001184 ; Monden et al. in J Hepatobil Pancreat Sci 29(1):66-81, 2022. https://doi.org/10.1002/jhbp.898 ). This report describes a new approach, which can reduce unwanted damage to normal tissues and complications.

METHODS

A 53-year-old man who has suffered from hepatitis B for 10 years was admitted for the treatment of two nodular tumors located in segment VIII. The surgical procedure began with the percutaneous injection of 5 mL, 0.025 mg/mL of ICG into the S8 portal branch by using an 18G PTCD needle under the guidance of laparoscopic ultrasound (Xu et al. in Surg Endosc 34(10):4683-4691, 2020. https://doi.org/10.1007/s00464-020-07691-5 ; Wang et al. in Ann Surg 274(1):97-106, 2021. https://doi.org/10.1097/sla.0000000000004718 ; Aoki et al. in J Am Coll Surg 230(3):e7-e12, 2020. https://doi.org/10.1016/j.jamcollsurg.2019.11.004 ), followed by liver transection on the cranial side of the liver, which used the ICG fluorescence images for exposing the roots of the middle and right hepatic veins and dissecting and ligating S8 portal pedicle. The excision specimen was sent for histopathological diagnosis.

RESULTS

It took 200 min for the operation and 60 min for the total Pringle maneuver. The estimate of blood loss was 110 mL. The final histopathologic results of the two nodules were hepatocellular carcinoma (HCC). The patient was discharged on postoperative Day 6 with no complications.

CONCLUSIONS

Laparoscopic anatomical liver resection of S8 has been demonstrated to be feasible. Under the guidance of laparoscopic ultrasonography, ICG positive staining was proven to be optimal for Anatomical segmentectomy.

Study of the Intersegmental Veins Between S5 and S8 Based on 3D Reconstruction

BACKGROUND

Anatomic resection (AR) is a surgical method for treating hepatocellular carcinoma, and identifying intersegmental planes between segments 5 (S5) and 8 (S8) remains challenging. This study aims to find reliable intersegmental veins (IVs) between them as anatomical landmarks using 3D reconstruction analysis.

METHODS

We retrospectively evaluated 57 patients who underwent multidetector-row CT scans from September 2021 to January 2023. The portal vein watershed of S5 and S8 and hepatic veins were reconstructed using 3D reconstruction analysis software. We counted and analyzed the IVs running within the intersegmental plane between S5 and S8, examined their features, and analyzed the location of the junctions between IVs and middle hepatic veins (MHVs).

RESULTS

Among the 57 patients, 43 patients (75.4%) had IVs between S5 and S8. Most patients (81.4%) had a single IV joining the MHV, while 13.9% had two IVs, one joining the MHV and the other joining the right hepatic vein (RHV). The majority of IV-MHV junctions were found in the lower part of the MHVs. The most clearly identifiable junctions between the IVs and MHVs occurred slightly below the midpoint of the horizontal planes of the second hepatic portal and the center of the gallbladder bed.

CONCLUSION

Our study identified IVs between S5 and S8 in the liver as potential anatomical landmarks during AR for hepatocellular carcinoma surgery. We found three types of IVs and provided insights on how to locate their junctions with MHVs for easier surgical navigation. However, individual anatomical variations must be considered, and preoperative 3D reconstruction and personalized surgical planning are crucial for success. More research with larger sample sizes is needed to validate our findings and establish the clinical significance of these IVs as landmarks for AR.

Laparoscopic left hemihepatectomy guided by real-time indocyanine green fluorescence imaging using the arantius-first approach

BACKGROUND AND OBJECTIVE

Laparoscopic hepatectomy approaches, including major hepatectomy, were rapidly developed in the past decade. However, standard laparoscopic left hemihepatectomy (LLH) is still only performed in high-volume medical centres. In our series, we describe our technical details and surgical outcomes of LLH.

METHODS

Thirty-nine patients who underwent LLH in our institute were enrolled in the study. Among these, 13 patients underwent LLH guided by real-time ICG fluorescence imaging using the Arantius-first approach (ICG-LLH group), and the other 26 underwent conventional LLH (conventional LLH group). Demographic characteristics and perioperative data were retrospectively collected and analysed. We compared the technical and postoperative short-term outcomes of the two groups.

RESULTS

There were no significant differences in the demographic or clinicopathological characteristics of the patients in the two groups. ICG-LLH required significantly fewer pringle manoeuvres (1 vs. 3 times, p < 0.0001), had a shorter parenchyma dissection time (26 vs. 78 min, p < 0.001), and required fewer vessel clips (18 vs. 28, p < 0.001). Although there was no significant difference, the ICG-LLH group had less bile leakage (0 vs. 5, p = 0.09) and less blood loss (120 vs. 165, p = 0.119). There were no significant differences in the overall complication or R0 resection rates between the two groups.

CONCLUSION

Our data demonstrate that laparoscopic left hemihepatectomy guided by real-time ICG fluorescence imaging using the Arantius-first approach is safe and feasible in selected patients, thus improving the fluency of the surgical procedure and postoperative short-term outcomes.

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.

Hepatic vein anatomy related to Laennec's capsule for liver resection

BACKGROUND

Laennec's capsule is the proper membrane covering the entire surface of the liver parenchyma, including around the Glissonean pedicles and hepatic veins. Laennec's capsule around the hepatic veins has been clinically reported to comprise two layers: the hepatic and cardiac Laennec's capsules. However, where the cardiac Laennec's capsule is derived from and the two capsules' separability are still unclear. This study aimed to investigate the anatomy of the two capsules using cadaveric specimens.

METHODS

Histopathological examinations of autopsy specimens from four cadavers were conducted. Each specimen was sliced in the longitudinal section to include the pericardium, right hepatic vein (RHV), and inferior vena cava (IVC). Additionally, long-axis specimens of the RHV were obtained to determine the separability of the capsules and to examine the extent to which the capsules extended along the RHV. Laennec's capsule was estimated using elastic fiber staining.

RESULTS

The cardiac Laennec's capsule is derived from the pericardium (parietal and visceral) and diaphragm and runs parallel with the IVC and hepatic veins associated with the hepatic Laennec's capsule. The two capsules were separable micro- and macroscopically. The hepatic Laennec's capsule was observed from the root to the peripheral side and the cardiac Laennec's capsule from the root to the middle side of the hepatic vein.

CONCLUSIONS

The existence of the two layers of Laennec's capsule around the hepatic veins was confirmed histologically and they were separable. Identification and decollement of these layers would contribute to establishing safe and feasible anatomic liver resection techniques.

Latest Findings on Minimally Invasive Anatomical Liver Resection

Minimally invasive liver resection (MILR) is being widely utilized owing to recent advancements in laparoscopic and robot-assisted surgery. There are two main types of liver resection: anatomical (minimally invasive anatomical liver resection (MIALR)) and nonanatomical. MIALR is defined as a minimally invasive liver resection along the respective portal territory. Optimization of the safety and precision of MIALR is the next challenge for hepatobiliary surgeons, and intraoperative indocyanine green (ICG) staining is considered to be of considerable importance in this field. In this article, we present the latest findings on MIALR and laparoscopic anatomical liver resection using ICG at our hospital.

Extrahepatic approach for taping the common trunk of the middle and left hepatic veins or the left hepatic vein alone in laparoscopic hepatectomy (with videos)

BACKGROUND

Outflow control is difficult, and techniques required for effectively handling intraoperative hemorrhage during laparoscopic hepatectomy have not previously been adequately reported.

METHODS

Sixteen patients underwent surgery, of which 15 underwent laparoscopic left hepatectomy and one underwent laparoscopic partial hepatectomy of the caudate lobe. Encircling and taping of the common trunk of the middle (MHV) and left hepatic veins (LHV) was performed in 12 patients, and that of the LHV alone in four patients. Surgical techniques based on anatomical landmarks and histological findings are presented with videos. Histological confirmation of the anatomical landmarks for these procedures was performed in fresh cadavers to understand the anatomical structures and layers involved.

RESULTS

The median procedure duration was 15 (6-25) minutes. All procedures were performed safely with no major bleeding. Histological findings showed fibrous connective tissue between the tunica adventitia of the inferior vena cava (IVC) and the Laennec's capsule of the liver. The layer of dissection was along the tunica adventitia of the IVC.

CONCLUSIONS

The surgical techniques for encircling and taping of the common trunk of the MHV and LHV and the LHV alone based on anatomical landmarks were feasible and could allow for efficient outflow control in laparoscopic hepatectomy.

Treatment of hepatic venous system hemorrhage and carbon dioxide gas embolization during laparoscopic hepatectomy via hepatic vein approach

With the improvement of laparoscopic surgery, the feasibility and safety of laparoscopic hepatectomy have been affirmed, but intraoperative hepatic venous system hemorrhage and carbon dioxide gas embolism are the difficulties in laparoscopic hepatectomy. The incidence of preoperative hemorrhage and carbon dioxide gas embolism could be reduced through preoperative imaging evaluation, reasonable liver blood flow blocking method, appropriate liver-breaking device, controlled low-center venous pressure technology, and fine-precision precision operation. In the case of blood vessel rupture bleeding in the liver vein system, after controlling and reducing bleeding, confirm the type and severity of vascular damage in the liver and venous system, take appropriate measures to stop the bleeding quickly and effectively, and, if necessary, transfer the abdominal treatment in time. In addition, to strengthen the understanding, prevention and emergency treatment of severe CO2 gas embolism in laparoscopic hepatectomy is also the key to the success of surgery. This study aims to investigate the methods to deal with hepatic venous system hemorrhage and carbon dioxide gas embolization based on author's institutional experience and relevant literature. We retrospectively analyzed the data of 60 patients who received laparoscopic anatomical hepatectomy of hepatic vein approach for HCC. For patients with intraoperative complications, corresponding treatments were given to cope with different complications. After the operation, combined with clinical experience and literature, we summarized and discussed the good treatment methods in the face of such situations so that minimize the harm to patients as much as possible.

Caudodorsal approach combined with in situ split for laparoscopic right posterior sectionectomy

BACKGROUND

Laparoscopic right posterior sectionectomy (LRPS) was technically challenging and lack of standardization. There were some approaches for LRPS, such as caudal approach and dorsal approach. During our practice, we initiated pure LRPS using the caudodorsal approach with in situ split and present several advantages of this method.

METHODS

From April 2018 to December 2021, consecutive patients who underwent pure LRPS using the caudodorsal approach with in situ split at our institution entered into this retrospective study. The key point of the caudodorsal approach was that the right hepatic vein was exposed from peripheral branches toward the root and the parenchyma was transected from the dorsal side to ventral side. Specially, the right perihepatic ligaments were not divided to keep the right liver in situ before parenchymal dissection for each case.

RESULTS

11 patients underwent pure LRPS using the caudodorsal approach with in situ split. There were 9 hepatocellular carcinoma, 1 sarcomatoid hepatocellular carcinoma, and 1 hepatic hemangioma. Five patients had mild cirrhosis and 1 had moderate cirrhosis. All the procedures were successfully completed laparoscopically. The median operative time was 375 min (range of 290-505 min) and the median blood loss was 300 ml (range of 100-1000 ml). Five patients received perioperative blood transfusion, of which 1 patient received autologous blood transfusion and 2 patients received blood transfusion due to preoperative moderate anemia. No procedure was converted to open surgery. Two patients who suffered from postoperative complications, improved after conservative treatments. The median postoperative stay was 11 days (range of 7-25 days). No postoperative bleeding, hepatic failure, and mortality occurred.

CONCLUSION

The preliminary clinical effect of the caudodorsal approach with in situ split for LRPS was satisfactory. Our method was feasible and expected to provide ideas for the standardization of LRPS. Further researches are required due to some limitations of this study.

Standardization of laparoscopic anatomic liver resection of segment 2 by the Glissonean approach

BACKGROUND

Anatomic liver resection (ALR) has been established to eliminate the tumor-bearing hepatic region with preservation of the remnant liver volume for liver malignancies. Recently, laparoscopic ALR has been widely applied; however, there are few reports on laparoscopic segmentectomy 2. This study aimed to present the standardization of laparoscopic segmentectomy 2 with surgical outcomes.

METHODS

This study included seven patients who underwent pure laparoscopic segmentectomy 2 by the Glissonean approach from January 2020 to December 2021. Four of them had hepatocellular carcinoma, two had colorectal liver metastasis, and one had hepatic angiomyolipoma, which was preoperatively diagnosed with hepatocellular carcinoma. In all patients, preoperative three-dimensional (3D) simulation images from dynamic CT were reconstructed using a 3D workstation. The layer between the hepatic parenchyma and the Glissonean pedicle of segment 2 (G2) was dissected to encircle the root of G2. After clamping or ligation of the G2, 2.5 mg of indocyanine green was injected intravenously to identify the boundaries between segments 2 and 3 with a negative staining method under near-infrared light. Parenchymal transection was performed from the caudal side to the cranial side according to the demarcation on the liver surface, and the left hepatic vein was exposed on the cut surface if possible.

RESULTS

The mean operative time for all patients was 281 min. The mean blood loss was 37 mL, and no transfusion was necessary. Estimated liver resection volumes significantly correlated with actual liver resection volumes (r = 0.61, P = 0.035). After the operation, one patient presented with asymptomatic deep venous and pulmonary thrombosis, which was treated with anticoagulant therapy. The mean length of hospital stay was 8.9 days.

CONCLUSION

Laparoscopic segmentectomy 2 by the Glissonean approach is a feasible and safe procedure with the preservation of the nontumor-bearing segment 3 for liver tumors in segment 2.

Counterclockwise modular laparoscopic anatomical mesohepatectomy using combined glissonean pedicle (Takasaki approach) and hepatic vein-guided approaches

Background

Although laparoscopic anatomical hepatectomy (LAH) is widely adopted today, laparoscopic anatomic mesohepatectomy (LAMH) for patients with hepatocellular carcinoma (HCC) remains technically challenging.

Methods

In this study, 6 patients suffering from solitary liver tumors located in the middle lobe of the liver underwent counterclockwise modular LAMH using combined Glissonean pedicle (Takasaki approach) and hepatic vein-guided approaches. In this process, the Glissonean pedicle approach (Takasaki approach) was first used to transect the liver pedicles of segment right anterior (G58) and segment 4 (G4). Second, the hepatic vein-guided approach was performed along the umbilical fissure vein (UFV) to sever the liver parenchyma from the caudal to cranial direction, and the middle hepatic vein (MHV) and anterior fissure vein (AFV) were then disconnected at the root. Last, the hepatic vein-guided approach was once more performed along the ventral side of the right hepatic vein (RHV) to transect the liver parenchyma from the cranial to anterior direction, and the middle lobe of the liver, including the tumor, was removed completely. The entire process was applied in a counterclockwise fashion, and the exposure or transection sequence was G58, and G4, followed by UFV, MHV, AFV, and finally, the liver parenchyma along the ventral side of RHV.

Results

The counterclockwise modular LAMH using combined Glissonean pedicle (Takasaki approach) and hepatic vein-guided approaches was feasible in all 6 cases. The median duration of the operation was 275 ± 35.07 min, and the mean estimated blood loss was 283.33 ml. All of the 6 patients recovered smoothly. The Clavien-Dindo Grade I-II complications rate was up to 33.33%, mainly characterized by postoperative pain and a small amount of ascites. No Clavien-Dindo Grade III-V complications occurred, and the mean postoperative hospital stay was 6.83 ± 1.47 days. Follow-up results showed that the average disease-free survival (DFS) was 12.17 months, and the 21-months OS rate, DFS rate and tumor recurrent rate were 100%, 83.33% and 16.67% respectively.

Conclusions

Counterclockwise modular LAMH using combined Glissonean pedicle (Takasaki approach) and hepatic vein-guided approaches takes the advantages of the two approaches, is a novel protocol for LAMH. It is thought to be technically feasible for patients with a centrally located solitary HCC. The oncologic feasibility of this technique needs to be investigated based on long-term follow-up. A multicenter, large-scale, more careful study is necessary.

Laparoscopic Left Hemihepatectomy Using the Hilar Plate-First Approach (with Video)

BACKGROUND

Effective inflow and outflow control of the liver is essential for a safe hepatectomy. Detachment of the hilar plate is a fundamental technique in the Glissonean approach. The hilar plate is situated near the middle hepatic vein, which runs in the midplane of the liver, and serves as a landmark during hemihepatectomy. In this study, we describe the technical details and surgical outcomes of laparoscopic left hemihepatectomy using the hilar plate-first approach.

METHODS

The key procedures of the hilar plate-first approach included the following: (1) detachment of the hilar plate for the left Glissonean approach, (2) the middle hepatic vein approach from the hilar plate, (3) parenchymal transection along the ischemic line and middle hepatic vein, and (4) transection of the left Glissonean pedicle at the ventral aspect of the Arantius ligament.

RESULTS

Between September 2020 and September 2021, 12 patients underwent laparoscopic left hemihepatectomy using the hilar plate-first approach. The median operation time was 227 min (range 140-350 min), and the median estimated blood loss was 82.5 ml (range 50-150 ml). The median length of postoperative hospital stay was 7 days (range 5-10 days). No major complications, including biliary complications, were observed.

CONCLUSION

The hilar plate-first approach contributes to the standardization of surgical techniques for laparoscopic left hemihepatectomy. This technique is a safe and effective approach for the inflow and outflow systems of the left hemiliver.

All the Routes for Laparoscopic Liver Segment VIII Resection: A Comprehensive Review of Surgical Techniques

Liver surgery is highly demanding for anatomical, physiological and technical reasons, and minimally invasive approaches have been implemented at a slower rate. Today, laparoscopic liver resection is a standard of care in many occasions, yet specific operations remain particularly challenging and generally performed in open surgery. In particular, SVIII resection may be considered one of the most difficult due to anatomical characteristics including its sub-diaphragmatic position, the deep-lying Glissonean pedicle and the close contact with the inferior vena cava and right and middle hepatic veins. Many techniques have risen to overcome technical difficulties, and today laparoscopic SVIII resection has been demonstrated to be feasible. This review provides a complete picture of current approaches, focusing on all techniques reported so far with critical appraisal of each, discussing and explaining benefits and pitfalls.

Anatomy of the Middle Hepatic Vein Tributaries to Promote Safer Hepatic Vein-Guided Liver Resection

BACKGROUND

In laparoscopic anatomic liver resection, an increasingly common procedure, the hepatic vein-guided approach is widely used although the hepatic vein tributaries can be a major source of bleeding in the event of inadvertent injury. This report describes the anatomy of the middle hepatic vein (MHV) including its tributaries based on reconstructed three-dimensional computed tomography images and provides anatomic data to enable safe middle hepatic vein-guided liver resection.

METHODS

Following simulation modeling of the hepatic vasculatures, reconstructed MHV data was pooled from 35 healthy liver donors. Yields of the MHV tributaries were analyzed to enable MHV-guided liver resection.

RESULTS

A total of 252 tributaries were identified in the 35 donors. The MHV yielded fewer tributaries from its anterior and posterior aspects than from its right-side and left-side aspects (40 [15.9%], 13 [5.2%], 93 [36.9%], and 106 [42.1%], respectively). The MHV tributaries from the anterior and posterior aspects were smaller in diameter than those from the right-side and left-side aspects (median, 3.0, 2.0, 4.8, and 4.0 mm, respectively).

DISCUSSION

Our simulation revealed that MHV dissection from the anterior or posterior aspect poses a lower risk of injury to the MHV tributaries compared to dissection from either lateral aspect. In addition, MHV dissection from the anterior or posterior aspect allows for safer identification and isolation of the thick MHV tributaries originating from the lateral aspects. Ideally, the anterior or posterior aspect of the MHV should be accessed and exposed before the lateral aspects are dissected to minimize the risk of MHV tributary injury.

Minimally invasive anatomic liver resection: Results of a survey of world experts

BACKGROUND

Although the number of minimally invasive liver resections (MILRs) has been steadily increasing in many institutions, minimally invasive anatomic liver resection (MIALR) remains a complicated procedure that has not been standardized. We present the results of a survey among expert liver surgeons as a benchmark for standardizing MIALR.

METHOD

We administered this survey to 34 expert liver surgeons who routinely perform MIALR. The survey contained questions on personal experience with liver resection, inflow/outflow control methods, and identification techniques of intersegmental/sectional planes (IPs).

RESULTS

All 34 participants completed the survey; 24 experts (70%) had more than 11 years of experience with MILR, and over 80% of experts had performed over 100 open resections and MILRs each. Regarding the methods used for laparoscopic or robotic anatomic resection, the Glissonean approach (GA) was a more frequent procedure than the hilar approach (HA). Although hepatic veins were considered essential landmarks, the exposure methods varied. The top three techniques that the experts recommended for identifying IPs were creating a demarcation line, indocyanine green negative staining method, and intraoperative ultrasound.

CONCLUSION

Minimally invasive anatomic liver resection remains a challenging procedure; however, a certain degree of consensus exists among expert liver surgeons.

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.

Expert Consensus Guidelines: How to safely perform minimally invasive anatomic liver resection

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.

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.

Laparoscopic Anatomic Liver Resection of the Dorsal Part of Segment 8 Using an Hepatic Vein-Guided Approach

BACKGROUND

Laparoscopic anatomic liver resection is considered highly challenging, especially in segment 8 (S8), owing to the limited angle of the laparoscope and limited manipulation of the surgical instrument1^,2. Additionally, resection is technically difficult when approaching the more peripheral branches since the Glissonean pedicle of S8 has several variations3 and is far from the hepatic hilum. The hepatic vein (HV)-guided approach involves entering from the cranial side of the liver while overcoming these difficulties with the unique view and techniques of laparoscopy4^,5. We describe laparoscopic anatomic resection of the dorsal part of S8 using the HV-guided approach for hepatocellular carcinoma.

METHODS

The drainage vein of segment 8 (V8), which often runs between the ventral and dorsal parts of S86^,7, was exposed from the confluence of the middle HV to the periphery. The dorsal Glissonean branch of S8 (G8dor) was identified by deep dissection of the parenchyma on the right side of the V8. The right HV (RHV) was exposed toward the periphery after dissecting the G8dor. Liver parenchymal dissection was completed by connecting the demarcation line and the RHV.

RESULTS

The total operation time was 319 min, estimated blood loss was 5 mL, and the patient was discharged on postoperative day 6 with no complications.

CONCLUSION

Laparoscopic anatomic resection of the dorsal parts of S8 could be safely performed by exposing the HVs from their roots and using the HVs as a landmark to identify the intrahepatic Glissonean pedicles.