Three-dimensional ultrasound image-guided robotic system for accurate microwave coagulation of malignant liver tumours

Robotic Assistance in Percutaneous Liver Ablation Therapies: A Systematic Review and Meta-Analysis

Objective

The aim of this systematic review and meta-analysis is to identify current robotic assistance systems for percutaneous liver ablations, compare approaches, and determine how to achieve standardization of procedural concepts for optimized ablation outcomes.

Background

Image-guided surgical approaches are increasingly common. Assistance by navigation and robotic systems allows to optimize procedural accuracy, with the aim to consistently obtain adequate ablation volumes.

Methods

Several databases (PubMed/MEDLINE, ProQuest, Science Direct, Research Rabbit, and IEEE Xplore) were systematically searched for robotic preclinical and clinical percutaneous liver ablation studies, and relevant original manuscripts were included according to the Preferred Reporting items for Systematic Reviews and Meta-Analyses guidelines. The endpoints were the type of device, insertion technique (freehand or robotic), planning, execution, and confirmation of the procedure. A meta-analysis was performed, including comparative studies of freehand and robotic techniques in terms of radiation dose, accuracy, and Euclidean error.

Results

The inclusion criteria were met by 33/755 studies. There were 24 robotic devices reported for percutaneous liver surgery. The most used were the MAXIO robot (8/33; 24.2%), Zerobot, and AcuBot (each 2/33, 6.1%). The most common tracking system was optical (25/33, 75.8%). In the meta-analysis, the robotic approach was superior to the freehand technique in terms of individual radiation (0.5582, 95% confidence interval [CI] = 0.0167-1.0996, dose-length product range 79-2216 mGy.cm), accuracy (0.6260, 95% CI = 0.1423-1.1097), and Euclidean error (0.8189, 95% CI = -0.1020 to 1.7399).

Conclusions

Robotic assistance in percutaneous ablation for liver tumors achieves superior results and reduces errors compared with manual applicator insertion. Standardization of concepts and reporting is necessary and suggested to facilitate the comparison of the different parameters used to measure liver ablation results. The increasing use of image-guided surgery has encouraged robotic assistance for percutaneous liver ablations. This systematic review analyzed 33 studies and identified 24 robotic devices, with optical tracking prevailing. The meta-analysis favored robotic assessment, showing increased accuracy and reduced errors compared with freehand technique, emphasizing the need for conceptual standardization.

Augmented Reality and Image-Guided Robotic Liver Surgery

Artificial intelligence makes surgical resection easier and safer, and, at the same time, can improve oncological results. The robotic system fits perfectly with these more or less diffused technologies, and it seems that this benefit is mutual. In liver surgery, robotic systems help surgeons to localize tumors and improve surgical results with well-defined preoperative planning or increased intraoperative detection. Furthermore, they can balance the absence of tactile feedback and help recognize intrahepatic biliary or vascular structures during parenchymal transection. Some of these systems are well known and are already widely diffused in open and laparoscopic hepatectomies, such as indocyanine green fluorescence or ultrasound-guided resections, whereas other tools, such as Augmented Reality, are far from being standardized because of the high complexity and elevated costs. In this paper, we review all the experiences in the literature on the use of artificial intelligence systems in robotic liver resections, describing all their practical applications and their weaknesses.

Automatic ultrasound scanning robotic system with optical waveguide-based force measurement

PURPOSE

The three-dimensional (3D) ultrasound (US) imaging realized by continuous scanning of a region is of great value for medical diagnosis and robot-assisted needle insertion. During scanning, the contact force and posture between the probe and skin of the patient are crucial factors that determine the quality of US imaging. We propose a robotic system for automatic scanning of curved surfaces with a stable contact force and vertical contact posture (the probe is parallel to the normal of the surface at the contact point).

METHODS

A 6-DOF robotic arm is used to hold and drive a two-dimensional (2D) US probe to complete automatic scanning. Further, a path-planning strategy is proposed to generate the scan path covering the selected area automatically. We also developed a novel force-measuring device based on optical waveguides to measure the distributed contact force and contact posture. Based on the measured force and posture, the robotic arm automatically adjusts the position and orientation of the probe and maintains a stable contact force and vertical contact posture at each scan point.

RESULTS

The novel force-measuring device is easy to fabricate, integrates with the probe and has the capacity of measuring the force distributed on the contact surface and estimating the contact posture. The experimental results of automatic scanning of a US phantom and parts of the human body demonstrate that the proposed system performs well in automatically scanning curved surfaces, maintaining a stable contact force and vertical contact posture and producing a good quality 3D US volume.

CONCLUSION

An automatic US scanning robotic system with an optical waveguide-based force-measuring device was developed and tested successfully. Experimental results demonstrated the feasibility of the proposed system to scan the human body.

Ultrasound-guided needle insertion robotic system for percutaneous puncture

PURPOSE

Ultrasound (US)-guided percutaneous puncture technology can realize real-time, minimally invasive interventional therapy without radiation. The location accuracy of the puncture needle directly determines the precision and safety of the operation. It is a challenge for novices and young surgeons to perform a free-hand puncture guided by the ultrasound images to achieve the desired accuracy. This work aims to develop a robotic system to assist surgeons to perform percutaneous punctures with high precision.

METHODS

An US-guided puncture robot was designed to allow the mounting and control of the needle to achieve localization and insertion. The US probe fitted within the puncture robot was held by a passive arm. Moreover, the puncture robot was calibrated with a novel calibration method to achieve coordinate transformation between the robot and the US image. The system allowed the operators to plan the puncture target and puncture path on US images, and the robot performed needle insertion automatically. Five groups of puncture experiments were performed to verify the validity and accuracy of the proposed robotic system.

RESULTS

Assisted by the robotic system, the positioning and orientation accuracies of the needle insertion were 0.9 ± 0.29 mm and 0.76 ± 0.34°, respectively. These are improved compared with the results obtained with the free-hand puncture (1.82 ± 0.51 mm and 2.79 ± 1.32°, respectively). Moreover, the proposed robotic system can reduce the operation time and number of needle insertions (14.28 ± 3.21 s and one needle insertion, respectively), compared with the free-hand puncture (25.14 ± 6.09 s and 1.96 ± 0.68 needle insertions, respectively).

CONCLUSION

A robotic system for percutaneous puncture guided by US images was developed and demonstrated. The experimental results indicate that the proposed system is accurate and feasible. It can assist novices and young surgeons to perform the puncture operation with increased accuracy.

A novel microwave tool for robotic liver resection in minimally invasive surgery

Introduction: During the last two decades, many surgical procedures have evolved from open surgery to minimally invasive surgery (MIS). This limited invasiveness has motivated the development of robotic assistance platforms to obtain better surgical outcomes. Nowadays, the da Vinci robot is a commercial tele-robotic platform widely used for different surgical applications.Material and methods: In this work, the da Vinci Research Kit (dVRK), namely the research version of the da Vinci, is used to manipulate a novel microwave device in a teleoperation scenario. The dVRK provides an open source platform, so that the novel microwave tool, dedicated to prevention bleeding during hepatic resection surgery, is mechanically integrated on the slave side, while the software interface is adapted in order to correctly control tool pose. Tool integration is validated through in-vitro and ex-vivo tests performed by expert surgeons, meanwhile the coagulative efficacy of the developed tool in a perfused liver model was proved in in-vivo tests.Results and conclusions: An innovative microwave tool for liver robotic resection has been realized and integrated into a surgical robot. The tool can be easily operated through the dVRK without limiting the intuitive and friendly use, and thus easily reaching the hemostasis of vessels.

Fabrication of 3D plotted scaffold with microporous strands for bone tissue engineering

Scaffold porosity has played a key role in bone tissue engineering aimed at effective tissue regeneration, by promoting cell attachment, proliferation, and osteogenic differentiation for new bone formation.

Customized Three-Dimensional Printing Spacers for Bone Positioning in Orthognathic Surgery for Correction and Prevention of Facial Asymmetry

Orthognathic surgery is a powerful tool for correction of facial asymmetry and malocclusion. The goal is to achieve good dental function and facial aesthetics. Three-dimensional simulation is used for surgical planning, and bone gaps could be created to achieve facial balance. In this study, customized "spacers" were made using computer-aided design and three-dimensional printing for guides for use during surgery. With the final three-dimensional plan, the skull images were exported to 3-Matic software, where spacers were designed according to the bone gaps. Three-dimensionally-printed spacers were made and used to facilitate positioning and fixation. Consecutive patients with facial asymmetry were recruited in this prospective study. The postoperative outcome was assessed using a visual analogue scale and the three-dimensional facial surface area discrepancy index for subjective and objective evaluation. There were 12 patients and a total of 19 spacers for the Le Fort I and mandibular ramus segments. The spacers worked nicely during the bone fixation process. Mean preoperative and postoperative visual analogue scale scores were 4.83 and 7.14, with a statistically significant improvement for facial symmetry (p = 0.018). Mean preoperative and postoperative facial surface area discrepancy index was 0.95 and 0.98, and the correction of asymmetry was significant (p = 0.009). There were no related surgical complications. All patients were satisfied with the correction of facial asymmetry and malocclusion. The custom-made, three-dimensionally-printed spacers help to achieve surgical precision to correct and prevent facial asymmetry in orthognathic surgery. CLINICAL QUESTION/LEVEL OF EVIDENCE:: Therapeutic, IV.

A kernel smoothing algorithm for ablation visualization in ultrasound elastography

Three-dimensional visualization of tumor ablation procedures have significant clinical value because the ability to accurately visualize ablated volumes can help clinicians gauge the extent of ablated tissue necrosis and plan future treatment steps. Better control over ablation volume can prevent recurrence of tumors treated using ablative procedures. This paper presents a kernel based smoothing algorithm called MatérnSmooth to reconstruct shear wave velocity maps from data acquired through ultrasound electrode vibration elastography. Shear wave velocity estimates are acquired on several intersecting imaging planes that share a common axis of intersection collinear with the ablation needle. An objective method of choosing smoothing parameters from underlying data is outlined through simulations. Experimental validation was performed on data acquired from a tissue mimicking phantom. Volume estimates were found to be within 20% of the true value.

Tissue Engineering for the Temporomandibular Joint

Tissue engineering potentially offers new treatments for disorders of the temporomandibular joint which frequently afflict patients. Damage or disease in this area adversely affects masticatory function and speaking, reducing patients' quality of life. Effective treatment options for patients suffering from severe temporomandibular joint disorders are in high demand because surgical options are restricted to removal of damaged tissue or complete replacement of the joint with prosthetics. Tissue engineering approaches for the temporomandibular joint are a promising alternative to the limited clinical treatment options. However, tissue engineering is still a developing field and only in its formative years for the temporomandibular joint. This review outlines the anatomical and physiological characteristics of the temporomandibular joint, clinical management of temporomandibular joint disorder, and current perspectives in the tissue engineering approach for the temporomandibular joint disorder. The tissue engineering perspectives have been categorized according to the primary structures of the temporomandibular joint: the disc, the mandibular condyle, and the glenoid fossa. In each section, contemporary approaches in cellularization, growth factor selection, and scaffold fabrication strategies are reviewed in detail along with their achievements and challenges.

A novel planning solution for semi-autonomous aspiration of Baker's cysts

BACKGROUND

A Baker's cyst is a pathological structure located near a kneepit, which causes discomfort and reduces mobility of the knee. It is commonly treated with aspiration, which often requires MRI scanning and US guidance. The aim of this study was to propose a novel planning solution for semi-autonomous aspiration of the Baker's cyst using only MRI imaging.

METHODS

The proposed method requires minimal user input and offers automatic cyst segmentation with collision-free path planning for the assumed robotic structure with four degrees of freedom.

RESULTS

The prepared software was tested on four image sets obtained from patients eligible for cyst aspiration. It was possible to accurately segment the cyst in the considered cases. The collision-free path planning method was investigated in numerical scenarios.

CONCLUSIONS

The simulations verified the proposed software solution. Future work will be devoted to experimental verification of the path planning procedure.

Advances in local ablation of malignant liver lesions

Local ablation of liver tumors matured during the recent years and is now proven to be an effective tool in the treatment of malignant liver lesions. Advances focus on the improvement of local tumor control by technical innovations, individual selection of imaging modalities, more accurate needle placement and the free choice of access to the liver. Considering data found in the current literature for conventional local ablative treatment strategies, virtually no single technology is able to demonstrate an unequivocal superiority. Hints at better performance of microwave compared to radiofrequency ablation regarding local tumor control, duration of the procedure and potentially achievable larger size of ablation areas favour the comparably more recent treatment modality; image fusion enables more patients to undergo ultrasound guided local ablation; magnetic resonance guidance may improve primary success rates in selected patients; navigation and robotics accelerate the needle placement and reduces deviation of needle positions; laparoscopic thermoablation results in larger ablation areas and therefore hypothetically better local tumor control under acceptable complication rates, but seems to be limited to patients with no, mild or moderate adhesions following earlier surgical procedures. Apart from that, most techniques appear technically feasible, albeit demanding. Which technology will in the long run become accepted, is subject to future work.

Automatic Multiple-Needle Surgical Planning of Robotic-Assisted Microwave Coagulation in Large Liver Tumor Therapy

The “robotic-assisted liver tumor coagulation therapy” (RALTCT) system is a promising candidate for large liver tumor treatment in terms of accuracy and speed. A prerequisite for effective therapy is accurate surgical planning. However, it is difficult for the surgeon to perform surgical planning manually due to the difficulties associated with robot-assisted large liver tumor therapy. These main difficulties include the following aspects: (1) multiple needles are needed to destroy the entire tumor, (2) the insertion trajectories of the needles should avoid the ribs, blood vessels, and other tissues and organs in the abdominal cavity, (3) the placement of multiple needles should avoid interference with each other, (4) an inserted needle will cause some deformation of liver, which will result in changes in subsequently inserted needles’ operating environment, and (5) the multiple needle-insertion trajectories should be consistent with the needle-driven robot’s movement characteristics. Thus, an effective multiple-needle surgical planning procedure is needed. To overcome these problems, we present an automatic multiple-needle surgical planning of optimal insertion trajectories to the targets, based on a mathematical description of all relevant structure surfaces. The method determines the analytical expression of boundaries of every needle “collision-free reachable workspace” (CFRW), which are the feasible insertion zones based on several constraints. Then, the optimal needle insertion trajectory within the optimization criteria will be chosen in the needle CFRW automatically. Also, the results can be visualized with our navigation system. In the simulation experiment, three needle-insertion trajectories were obtained successfully. In the in vitro experiment, the robot successfully achieved insertion of multiple needles. The proposed automatic multiple-needle surgical planning can improve the efficiency and safety of robot-assisted large liver tumor therapy, significantly reduce the surgeon’s workload, and is especially helpful for an inexperienced surgeon. The methodology should be easy to adapt in other body parts.

Diopside modified porous polyglycolide scaffolds with improved properties

In this research, diopside was incorporated into PGA scaffolds for enhancing mechanical and biological properties. The porous scaffolds were fabricated via selective laser sintering.

The assistant function of three-dimensional information for I125 particle implantation

The purpose of this study was to explore the assistant function of 3-D information for I125 particle implantation of multineedle intervention under the guidance of ultrasound. The assistant function of 3-D information was verified by a simulation experiment system which consists of an ultrasound probe, an abdominal phantom, the preoperative computed tomography image of a patient, the electromagnetic tracking device, and the self-developed 3-D image navigation software with a practical and friendly graphical user interface. The simulation particle implantation experiments were divided into the two groups. The first group of experiments was performed with the aid of 3-D information. Seven days later, the second group of experiments was carried out with the aid of 2-D information. We made the statistical analysis of the experimental results obtained by nine medical students, nine interventional radiologists, and nine attending physicians. With the assistance of 3-D information, the percentage of tumor coverage increased (p < 0.01), the operation time shortened (p < 0.01), and the number of insertions reduced (p < 0.01). The assistant function of 3-D information for particle implantation of multineedle intervention under the guidance of ultrasound was technically feasible and effective.

Practice guidelines for ultrasound-guided percutaneous microwave ablation for hepatic malignancy

Primary liver cancer and liver metastases are among the most frequent malignancies worldwide, with an increasing number of new cases and deaths every year. Traditional surgery is only suitable for a limited proportion of patients and imaging-guided percutaneous thermal ablation has achieved optimistic results for management of hepatic malignancy. This synopsis outlines the first clinical practice guidelines for ultrasound-guided percutaneous microwave ablation therapy for hepatic malignancy, which was created by a joint task force of the Society of Chinese Interventional Ultrasound. The guidelines aim at standardizing the microwave ablation procedure and therapeutic efficacy assessment, as well as proposing the criteria for the treatment candidates.