Laparoscopic Ultrasound for Hepatocellular Carcinoma and Colorectal Liver Metastasis: An Overview

Transhepatic arterial approaches for ICG injection to guide laparoscopic anatomical hepatectomy: A case series study

BACKGROUND

Laparoscopic anatomical hepatectomy guided by near-infrared fluorescence imaging (NIR-FI) has been utilized extensively. However, it is difficult to resect "cone units" above the third branch of the Glissonean pedicle in the right posterior lobe using the laparoscopic positive or negative staining techniques. Therefore, we undertook a new laparoscopic segmentectomy based on the concept of "cone unit" assisted by interventional radiology combined with NIR-FI.

METHODS

Laparoscopic segmentectomy guided by NIR-FI via super-selective hepatic arteriography and trans-arterial injection of ICG was carried out on 13 patients with early-stage HCC between September 2020 and January 2022.11 of cases were successful, and relevant pathological characteristics and perioperative outcomes were retrospectively analyzed.

RESULTS

Two cases failed NIR-FI out of which one case involved over-staining to the non-target segment, and in the other case, which was to undergo laparoscopic segment V resection, only the ventral segment was stained while the imaging of the dorsal segment failed. In the intraoperative conditions, the tumor safe margin was 1.1 (0.7-1.55) cm, the interventional operation time was 50 (45.5-60.5) minutes, the operation time was 280 (242.5-307.5) minutes, the blood loss was 100 (50-200) ml, the postoperative hospital stay was 5 (4.5-5.5) days. No cases converted to laparotomy, and no serious postoperative complications developed.

CONCLUSIONS

NIR-FI through super-selective hepatic arteriography and trans-arterial injection of ICG can provide a clear and lasting navigation aid for laparoscopic segmentectomy, which may have positive implication for early-stage HCC with poor preoperative liver reserves.

Radiopaque Fiducials Guiding Laparoscopic Resection of Liver Tumors

BACKGROUND

Minimal invasive laparoscopic resection of liver tumors is less traumatic compared with open surgical resection and may be a better option for many patients. However, localization of intrahepatic tumors remains a challenge. Availability of hybrid operating rooms, equipped for high performance radiologic imaging, allows for new methods of surgical navigation.

METHODS

Twelve patients planned for laparoscopic resection of liver tumors were included. Before resection started, tumors were marked with radiopaque fiducials. Four fiducials were positioned with ultrasound within 1 cm of the tumor. Tumor and fiducials were localized with contrast enhanced cone beam computed tomography. Fluoroscopy with an overlay of cone beam computed tomography markings was projected side-by-side on the same screen as the laparoscopic view to visualize tumor location. The fiducials were eventually removed. Laparoscopic ultrasound, the standard method of localizing a tumor, was also used. The benefits of the 2 visualization methods were estimated by the operator. Procedure times, radiation doses and resection margins were recorded.

RESULTS

Fluoroscopy with radiopaque fiducials provided valuable information, complementing the laparoscopic ultrasound, particularly during the early phase of resection. In the later phase, mobilization of the tumor-containing liver segment caused significant displacement of the fluoroscopic overlay. The technique evolved during course of the study, with decreasing procedure times and radiation doses. Radical resection was achieved for all patients.

CONCLUSIONS

Radiopaque fiducials and fluoroscopy can complement laparoscopic ultrasound for guiding resection of liver tumors. Combining radiologic and optical imaging in a hybrid operating suit may facilitate development of augmented reality techniques for surgical navigation.

Application of Indocyanine Green Fluorescence as an Adjuvant to Laparoscopic Ultrasound in Minimally Invasive Liver Resection

Background: Indocyanine green (ICG) fluorescence imaging has been extensively used in a variety of applications in visceral surgery. In minimally invasive liver resections, the detection of small superficial hepatic lesions using an intravenous injection of ICG before surgery represents a promising application. Methods: We analyzed 18 consecutive patients who underwent laparoscopic liver resection for superficial malignant tumors, namely 11 patients with hepatocellular carcinoma (HCC), 5 patients with colorectal liver metastases (CRLM), 1 patient with intrahepatic cholangiocarcinoma (ICC), and 1 patient with thyroid cancer metastasis, using ICG fluorescence as an adjuvant tool to intraoperative laparoscopic ultrasound (LUS). Results: An optimal ICG 15-minute clearance retention rate (R15 < 10%) and ICG plasma disappearance rate (<18%/minute) were present in 11 patients (61.1%) and in 14 patients (77.7%), respectively. Liver tumors were 29 in total, including 14 HCCs (48.3%), 13 CRLMs (44.8%), 1 ICC (3.4%), and 1 thyroid cancer metastasis (3.4%). Twenty-nine tumors (100%) were correctly visualized with ICG/fluorescence, as compared with 21 tumors identified with LUS (72.4%). After complete liver mobilization, ICG staining allowed to identify more superficial lesions (early HCC and small CRLM) in posterolateral segments (Segments 6 and 7) as compared with LUS (14 versus 10 lesions). In addition, in segments usually treated laparoscopically (e.g., left lateral segments), ICG was superior to LUS (10 versus 6 lesions) to identify superficial early HCC in patients with macronodular cirrhosis. Conclusions: ICG visual feedback might substitute the tactile feedback of the hand and might in some cases act as a "booster" of LUS for superficial hepatic lesions.

Registration of Untracked 2D Laparoscopic Ultrasound to CT Images of the Liver Using Multi-Labelled Content-Based Image Retrieval

Laparoscopic Ultrasound (LUS) is recommended as a standard-of-care when performing laparoscopic liver resections as it images sub-surface structures such as tumours and major vessels. Given that LUS probes are difficult to handle and some tumours are iso-echoic, registration of LUS images to a pre-operative CT has been proposed as an image-guidance method. This registration problem is particularly challenging due to the small field of view of LUS, and usually depends on both a manual initialisation and tracking to compose a volume, hindering clinical translation. In this paper, we extend a proposed registration approach using Content-Based Image Retrieval (CBIR), removing the requirement for tracking or manual initialisation. Pre-operatively, a set of possible LUS planes is simulated from CT and a descriptor generated for each image. Then, a Bayesian framework is employed to estimate the most likely sequence of CT simulations that matches a series of LUS images. We extend our CBIR formulation to use multiple labelled objects and constrain the registration by separating liver vessels into portal vein and hepatic vein branches. The value of this new labeled approach is demonstrated in retrospective data from 5 patients. Results show that, by including a series of 5 untracked images in time, a single LUS image can be registered with accuracies ranging from 5.7 to 16.4 mm with a success rate of 78%. Initialisation of the LUS to CT registration with the proposed framework could potentially enable the clinical translation of these image fusion techniques.

Hyperspectral evaluation of hepatic oxygenation in a model of total vs. arterial liver ischaemia

Liver ischaemia reperfusion injury (IRI) is a dreaded pathophysiological complication which may lead to an impaired liver function. The level of oxygen hypoperfusion affects the level of cellular damage during the reperfusion phase. Consequently, intraoperative localisation and quantification of oxygen impairment would help in the early detection of liver ischaemia. To date, there is no real-time, non-invasive, and intraoperative tool which can compute an organ oxygenation map, quantify and discriminate different types of vascular occlusions intraoperatively. Hyperspectral imaging (HSI) is a non-invasive optical methodology which can quantify tissue oxygenation and which has recently been applied to the medical field. A hyperspectral camera detects the relative reflectance of a tissue in the range of 500 to 1000 nm, allowing the quantification of organic compounds such as oxygenated and deoxygenated haemoglobin at different depths. Here, we show the first comparative study of liver oxygenation by means of HSI quantification in a model of total vascular inflow occlusion (VIO) vs. hepatic artery occlusion (HAO), correlating optical properties with capillary lactate and histopathological evaluation. We found that liver HSI could discriminate between VIO and HAO. These results were confirmed via cross-validation of HSI which detected and quantified intestinal congestion in VIO. A significant correlation between the near-infrared spectra and capillary lactate was found (r = − 0.8645, p = 0.0003 VIO, r = − 0.7113, p = 0.0120 HAO). Finally, a statistically significant negative correlation was found between the histology score and the near-infrared parameter index (NIR) (r = − 0.88, p = 0.004). We infer that HSI, by predicting capillary lactates and the histopathological score, would be a suitable non-invasive tool for intraoperative liver perfusion assessment.

A radiologist's point of view in the presurgical and intraoperative setting of colorectal liver metastases

Multidisciplinary management of patients with metastatic colorectal cancer requires in each phase an adequate choice of the most appropriate imaging modality. The first challenging step is liver lesions detection and characterization, using several imaging modality ultrasound, computed tomography, magnetic resonance and positron emission tomography. The criteria to establish the metastases resectability have been modified. Not only the lesions number and site but also the functional volume remnant after surgery and the quality of the nontumoral liver must be taken into account. Radiologists should identify the liver functional volume remnant and during liver surgical procedures should collaborate with the surgeon to identify all lesions, including those that disappeared after the therapy, using intraoperative ultrasound with or without contrast medium.

Laboratory test of Single Landmark registration method for ultrasound-based navigation in laparoscopy using an open-source platform

Purpose

Test the feasibility of the novel Single Landmark image-to-patient registration method for use in the operating room for future clinical trials. The algorithm is implemented in the open-source platform CustusX, a computer-aided intervention research platform dedicated to intraoperative navigation and ultrasound, with an interface for laparoscopic ultrasound probes.

Methods

The Single Landmark method is compared to fiducial landmark on an IOUSFAN (Kyoto Kagaku Co., Ltd., Japan) soft tissue abdominal phantom and T2 magnetic resonance scans of it.

Results

The experiments show that the accuracy of the Single Landmark registration is good close to the registered point, increasing with the distance from this point (12.4 mm error at 60 mm away from the registered point). In this point, the registration accuracy is mainly dominated by the accuracy of the user when clicking on the ultrasound image. In the presented set-up, the time required to perform the Single Landmark registration is 40% less than for the FLRM.

Conclusion

The Single Landmark registration is suitable for being integrated in a laparoscopic workflow. The statistical analysis shows robustness against translational displacements of the patient and improvements in terms of time. The proposed method allows the clinician to accurately register lesions intraoperatively by clicking on these in the ultrasound image provided by the ultrasound transducer. The Single Landmark registration method can be further combined with other more accurate registration approaches improving the registration at relevant points defined by the clinicians.

Glissonian approach combined with major hepatic vein first for laparoscopic anatomic hepatectomy

BACKGROUND

Laparoscopic anatomic hepatectomy remains challenging because of the complex interior structures of the liver. Our novel strategy includes the Glissonian approach and the major hepatic vein first, which serves to define the external and internal landmarks for laparoscopic anatomic hepatectomy.

METHODS

Eleven cases underwent laparoscopic anatomic hepatectomy, including three right hepatectomies, three left hepatectomies, three right posterior hepatectomies, and two mesohepatectomies. The Glissonian approach was used to transect the hepatic pedicles as external demarcation. The major hepatic vein near the hepatic portal was exposed and served as the internal landmark for parenchymal transection. The liver parenchyma below and above the major hepatic vein was transected along the major hepatic vein. Fifty-nine subjects were used to compare the distance between the major hepatic vein and secondary Glisson pedicles among different liver diseases.

RESULTS

The average operative time was 327 min with an estimated blood loss of 554.55 mL. Only two patients received three units of packed red blood cells. The others recovered normally and were discharged on postoperative day 7. The distance between right posterior Glissonian pedicle and right hepatic vein was shorter in the patients with cirrhosis than that without cirrhosis, and this distance was even shorter in patients with hepatocellular carcinoma.

CONCLUSION

The Glissonian approach with the major hepatic vein first is easy and feasible for laparoscopic anatomic hepatectomy, especially in patients with hepatocellular carcinoma and cirrhosis.

A learning curve for laparoscopic liver resection: an effective training system and standardization of technique

The incidence of laparoscopic liver resection (LHx) has been increased in the past decade. There have been some reports about some advantages of LHx, in both short and long-term outcomes after operation. The use of a minor LHx was regarded as a standard surgical practice, and some peri-operative complications hindered worldwide increase of LHx in the Second International Consensus Conference on LHx at Morioka. However, no suggestions were described in terms with how to provide the best teaching and training necessary to shorten the learning curve for inexperienced surgeons using a new surgical technique while continuing to maintain a low rate of morbidity from the very beginning. This study includes a literature review of published research which looked at a learning curve for LHx. As well, it proposes a new step-wise training method for inexperienced surgeons and standardization of a technique for LHx focusing especially on laparoscopic left hepatectomy (LLHx).

Anthropomorphic liver phantom with flow for multimodal image-guided liver therapy research and training

Purpose

The objective of this study was to develop a multimodal, permanent liver phantom displaying functional vasculature and common pathologies, for teaching, training and equipment development in laparoscopic ultrasound and navigation.

Methods

Molten wax was injected simultaneously into the portal and hepatic veins of a human liver. Upon solidification of the wax, the surrounding liver tissue was dissolved, leaving a cast of the vessels. A connection was established between the two vascular trees by manually manipulating the wax. The cast was placed, along with different multimodal tumor models, in a liver shaped mold, which was subsequently filled with a polymer. After curing, the wax was melted and flushed out of the model, thereby establishing a system of interconnected channels, replicating the major vasculature of the original liver. Thus, a liquid can be circulated through the model in a way that closely mimics the natural blood flow.

Results

Both the tumor models, i.e., the metastatic tumors, hepatocellular carcinoma and benign cyst, and the vessels inside the liver model, were clearly visualized by all the three imaging modalities: CT, MR and ultrasound. Doppler ultrasound images of the vessels proved the blood flow functionality of the phantom.

Conclusion

By a two-step casting procedure, we produced a multimodal liver phantom, with open vascular channels, and tumor models, that is the next best thing to practicing imaging and guidance procedures in animals or humans. The technique is in principle applicable to any organ of the body.

The practice of laparoscopic liver surgery in Belgium: a national survey

BACKGROUND

Laparoscopic liver surgery (LLS) gained popularity bringing several advantages including decreased morbidity and reduction of length of hospital stay compared to open.

METHODS

To understand practice and evolution of LLS in Belgium, a 20-questions survey was sent to all members of the Royal Belgian Society for Surgery, the Belgian Section of Hepato-Pancreatic and Biliary Surgery and the Belgian Group for Endoscopic Surgery.

RESULTS

Thirty-seven surgical units representing 61 surgeons performing LLS in Belgium responded: 50% from regional hospitals, 28% from university and 22% from peripheral hospitals. Replies from high volume centers (>50 liver-surgery/year) were 19%. More than 25% of liver procedures were performed laparoscopically in 35% of centers. LLS is adopted since more than 15-years in 14.5% of centers with an increasing rate reported in 59%. Low relevance of LLS in the hospital organization (26.5%) and lack of time in surgical schedules (12%) or of specific training (9%) are the main barriers for further diffusion. More than 80% of the responders agreed to participate to a national prospective registry.

CONCLUSION

LLS is mainly performed in experienced HPB units with an increasing interest in peripheral centers. A prospective national registry will be useful by providing real data in terms of indications, morbidity and overall evolution.

The single surgeon learning curve of laparoscopic liver resection: A continuous evolving process through stepwise difficulties

The aim of the study was to evaluate the single-surgeon learning curve (SSLC) in laparoscopic liver surgery over an 11-year period with risk-adjusted (RA) cumulative sum control chart analysis.Laparoscopic liver resection (LLR) is a challenging and highly demanding procedure. No specific data are available for defining the feasibility and reproducibility of the SSLC regarding a consistent and consecutive caseload volume over a specified time period.A total of 319 LLR performed by a single surgeon between June 2003 and May 2014 were retrospectively analyzed. A difficulty scale (DS) ranging from 1 to 10 was created to rate the technical difficulty of each LLR. The risk-adjusted cumulative sum control chart (RA-CUSUM) analysis evaluated conversion rate (CR), operative time (OT) and blood loss (BL). Perioperative morbidity and mortality were also analyzed.The RA-CUSUM analysis of the DS identified 3 different periods: P1 (n = 91 cases), with a mean DS of 3.8; P2 (cases 92-159), with a mean DS of 5.3; and P3 (cases 160-319), with a mean DS of 4.7. P2 presented the highest conversion and morbidity rates with a longer OT, whereas P3 showed the best results (P < 0.001). Fifty cases were needed to achieve a significant decrease in BL. The overall morbidity rate was 13.8%; no perioperative mortality was observed.According to our analysis, at least 160 cases (P3) are needed to complete the SSLC performing safely different types of LLR. A minimum of 50 cases can provide a significant decrease in BL. Based on these findings, a longer learning curve should be anticipated to broaden the indications for LLR.

Superselective intra-arterial hepatic injection of indocyanine green (ICG) for fluorescence image-guided segmental positive staining: experimental proof of the concept

BACKGROUND

Intraoperative liver segmentation can be obtained by means of percutaneous intra-portal injection of a fluorophore and illumination with a near-infrared light source. However, the percutaneous approach is challenging in the minimally invasive setting. We aimed to evaluate the feasibility of fluorescence liver segmentation by superselective intra-hepatic arterial injection of indocyanine green (ICG).

MATERIALS AND METHODS

Eight pigs (mean weight: 26.01 ± 5.21 kg) were involved. Procedures were performed in a hybrid experimental operative suite equipped with the Artis Zeego^®, multiaxis robotic angiography system. A pneumoperitoneum was established and four laparoscopic ports were introduced. The celiac trunk was catheterized, and a microcatheter was advanced into different segmental hepatic artery branches. A near-infrared laparoscope (D-Light P, Karl Storz) was used to detect the fluorescent signal. To assess the correspondence between arterial-based fluorescence demarcation and liver volume, metallic markers were placed along the fluorescent border, followed by a 3D CT-scanning, after injecting intra-arterial radiological contrast (n = 3). To assess the correspondence between arterial and portal supplies, percutaneous intra-portal angiography and intra-arterial angiography were performed simultaneously (n = 1).

RESULTS

Bright fluorescence signal enhancing the demarcation of target segments was obtained from 0.1 mg/mL, in matter of seconds. Correspondence between the volume of hepatic segments and arterial territories was confirmed by CT angiography. Higher background fluorescence noise was found after positive staining by intra-portal ICG injection, due to parenchymal accumulation and porto-systemic shunting.

CONCLUSIONS

Intra-hepatic arterial ICG injection, rapidly highlights hepatic target segment borders, with a better signal-to-background ratio as compared to portal vein injection, in the experimental setting.

Laparoscopic detection and resection of occult liver tumors of multiple cancer types using real-time near-infrared fluorescence guidance

BACKGROUND

Tumor recurrence after radical resection of hepatic tumors is not uncommon, suggesting that malignant lesions are missed during surgery. Intraoperative navigation using fluorescence guidance is an innovative technique enabling real-time identification of (sub)capsular liver tumors. The objective of the current study was to compare fluorescence imaging (FI) and conventional imaging modalities for laparoscopic detection of both primary and metastatic tumors in the liver.

METHODS

Patients undergoing laparoscopic resection of a malignant hepatic tumor were eligible for inclusion. Patients received standard of care, including preoperative CT and/or MRI. In addition, 10 mg indocyanine green was intravenously administered 1 day prior to surgery. After introduction of the laparoscope, inspection, FI, and laparoscopic ultrasonography (LUS) were performed. Histopathological examination of resected suspect tissue was considered the gold standard.

RESULTS

Twenty-two patients suspected of having hepatocellular carcinoma (n = 4), cholangiocarcinoma (n = 2) or liver metastases from colorectal carcinoma (n = 12), uveal melanoma (n = 2), and breast cancer (n = 2) were included. Two patients were excluded because their surgery was unexpectedly postponed several days. Twenty-six malignancies were resected in the remaining 20 patients. Sensitivity for various modalities was 80 % (CT), 84 % (MRI), 62 % (inspection), 86 % (LUS), and 92 % (FI), respectively. Three metastases (12 %) were identified solely by FI. All 26 malignancies could be detected by combining LUS and FI (100 % sensitivity).

CONCLUSION

This study demonstrates added value of FI during laparoscopic resections of several hepatic tumors. Although larger series will be needed to confirm long-term patient outcome, the technology already aids the surgeon by providing real-time fluorescence guidance.

Discrimination of liver malignancies with 1064 nm dispersive Raman spectroscopy

Raman spectroscopy has been widely demonstrated for tissue characterization and disease discrimination, however current implementations with either 785 or 830 nm near-infrared (NIR) excitation have been ineffectual in tissues with intense autofluorescence such as the liver. Here we report the use of a dispersive 1064 nm Raman system using a low-noise Indium-Gallium-Arsenide (InGaAs) array to discriminate highly autofluorescent bulk tissue ex vivo specimens from healthy liver, adenocarcinoma, and hepatocellular carcinoma (N = 5 per group). The resulting spectra have been combined with a multivariate discrimination algorithm, sparse multinomial logistic regression (SMLR), to predict class membership of healthy and diseased tissues, and spectral bands selected for robust classification have been extracted. A quantitative metric called feature importance is defined based on classification outputs and is used to guide the association of spectral features with biological indicators of healthy and diseased liver tissue. Spectral bands with high feature importance for healthy and liver tumor specimens include retinol, heme, biliverdin, or quinones (1595 cm(-1)); lactic acid (838 cm(-1)); collagen (873 cm(-1)); and nucleic acids (1485 cm(-1)). Classification performance in both binary (normal versus tumor, 100% sensitivity and 89% specificity) and three-group cases (classification accuracy: normal 89%, adenocarcinoma 74%, hepatocellular carcinoma 64%) indicates the potential for accurately separating healthy and cancerous tissues and suggests implications for utilizing Raman techniques during surgical guidance in liver resection.

Robot-integrated intraoperative ultrasound: Initial experience with hepatic malignancies

PURPOSE

A new robotic surgery tool allows intraoperative ultrasound to be performed using a fully robotic technique. Herein, we evaluate the feasibility and reliability of robotically integrated ultrasound to guide resection of malignant hepatic tumors.

MATERIAL AND METHODS

A consecutive series of ultrasound-guided robotic resections of primary and secondary hepatic malignancies was analyzed in terms of perioperative data and specimen evaluation, focusing on the reliability of the new robot-integrated ultrasound probe.

RESULTS

Ten consecutive patients underwent 15 robotic liver resections. Two patients were resected to excise primary hepatocellular cancers and eight underwent resections of liver metastases. R0 resections were achieved for all lesions. The median operative time was 247 min, and blood loss was limited. No mortality occurred.

CONCLUSIONS

Our present analysis confirmed the reliability of fully robotic liver resection guided via robotically integrated ultrasonic assessment. Robotic surgery, particularly hepatic resection, may benefit greatly from better manageability, and the fact that the surgeon can directly manage both the operative and the diagnostic parts of the procedure.