Microsurgical robotic system for the deep surgical field: development of a prototype and feasibility studies in animal and cadaveric models

Clinical, Preclinical, and Educational Applications of Robotic-Assisted Flap Reconstruction and Microsurgery: A Systematic Review

INTRODUCTION

Microsurgery and super-microsurgery allow for highly technical reconstructive surgeries to be performed, with repairs of anatomical areas of less than 1 mm. Robotic-assisted surgery might allow for further advances within microsurgery, providing higher precision, accuracy, and scope to operate in previously inaccessible anatomical areas. However, robotics is not well-established within this field. We provide a summary of the clinical and preclinical uses of robotics within flap reconstruction and microsurgery, educational models, and the barriers to widespread implementation.

METHODS

A systematic review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses was conducted of PubMed, Medline, and Embase. Preclinical, educational, and clinical articles were included.

RESULTS

One thousand five hundred and forty-two articles were screened; 87 articles met the inclusion criteria across flap harvest, flap/vessel pedicle dissection, vascular anastomosis, and nerve repair. The literature presents several potential benefits to the surgeon and patient such as high cosmetic satisfaction, minimally invasive access with reduced scarring (flap harvest), and low complication rates. Lack of haptic feedback was reported by authors to not impede the ability to perform vessel anastomosis; however, this required further investigation. A steep learning curve was identified, particularly for microsurgeons embarking upon robotic-assisted surgery.

CONCLUSION

Robotic-assisted surgery can potentially enhance microsurgery and flap reconstruction, with feasibility demonstrated within this review, up to anastomosis of 0.4 mm in diameter. However, there is a lack of sufficiently powered comparative studies, required to strengthen this statement. To increase accessibility to robotic surgery for plastic and reconstructive surgeons, educational opportunities must be developed with standardized assessment of skill acquisition.

The role of robotic surgery in neurological cases: A systematic review on brain and spine applications

The application of robotic surgery technologies in neurological surgeries resulted in some advantages compared to traditional surgeries, including higher accuracy and dexterity enhancement. Its success in various surgical fields, especially in urology, cardiology, and gynecology surgeries was reported in previous studies, and similar advantages in neurological surgeries are expected. Surgeries in the central nervous system with the pathology of millimeters through small working channels around vital tissue need especially high precision. Applying robotic surgery is therefore an interesting dilemma for these situations. This article reviews various studies published on the application of brain and spine robotic surgery and discusses the current application of robotic technology in neurological cases.

Using an Instrumented Hammer to Predict the Rupture of Bone Samples Subject to an Osteotomy

Osteotomies are common procedures in maxillofacial and orthopedic surgery. The surgeons still rely on their proprioception to control the progression of the osteotome. Our group has developed an instrumented hammer that was shown to provide information on the biomechanical properties of the tissue located around the osteotome tip. The objective of this study is to determine if this approach may be used to predict the rupture of a bone sample thanks to an instrumented hammer equipped with a force sensor. For each impact, an indicator τ is extracted from the signal corresponding to the variation of the force as a function of time. A linear by part regression analysis is applied to the curve corresponding to the variation of τ as a function of the distance d between the tip of the osteotome and the end of the sample. The experiments were conducted with plywood and bovine trabecular bone samples. The results show that τ starts increasing when the value of d is lower than 2.6 mm on average, which therefore corresponds to a typical threshold detection distance between the osteotome tip and the sample end. These findings open new paths for the development of this instrumented surgical hammer.

Spherical and Non-Spherical Combined Two Degree-of-Freedom Rotational Parallel Mechanism for a Microsurgical Robotic System

Microsurgery, often performed for anastomosis of small vessels and nerves, requires micro-manipulations of small tissues and thus requires highly specialized surgical skills. Robotic technology has great potential to assist with microsurgical treatments because of the high accuracy provided by robots; however, implementation remains challenging because the technical requirements of robotic surgery are far different from those in industry. One of the greatest challenges is that two surgical tools (e.g., tweezers) must be precisely and deftly moved around the surgical area in seven degrees of freedom (DOF) using one DOF to grasp each tool, and these tools are used in close proximity to each other. Additionally, high accuracy and rigidity at the tool tip are imperative for successful performance of the microsurgical procedure. In this study, we propose a new rotational two-DOF parallel mechanism that has the inherent advantages of a parallel mechanism, namely accuracy and rigidity, within a newly proposed spherical and non-spherical combined parallel structure to prevent collision of the two mechanisms in a dual-arm setup for microsurgery. The prototype was evaluated by performing a series of mechanical tests, and microsurgical suturing was performed by a microsurgical robotic system. The series of evaluations demonstrated the feasibility of the proposed mechanism.

Virtual reality simulation of robotic transsphenoidal brain tumor resection: Evaluating dynamic motion scaling in a master-slave system

Background

Integrating simulators with robotic surgical procedures could assist in designing and testing of novel robotic control algorithms and further enhance patient‐specific pre‐operative planning and training for robotic surgeries.

Methods

A virtual reality simulator, developed to perform the transsphenoidal resection of pituitary gland tumours, tested the usability of robotic interfaces and control algorithms. It used position‐based dynamics to allow soft‐tissue deformation and resection with haptic feedback; dynamic motion scaling control was also incorporated into the simulator.

Results

Neurosurgeons and residents performed the surgery under constant and dynamic motion scaling conditions (CMS vs DMS). DMS increased dexterity and reduced the risk of damage to healthy brain tissue. Post‐experimental questionnaires indicated that the system was well‐evaluated by experts.

Conclusion

The simulator was intuitively and realistically operated. It increased the safety and accuracy of the procedure without affecting intervention time. Future research can investigate incorporating this simulation into a real micro‐surgical robotic system.

Toward Improving Safety in Neurosurgery with an Active Handheld Instrument

Microsurgical procedures, such as petroclival meningioma resection, require careful surgical actions in order to remove tumor tissue, while avoiding brain and vessel damaging. Such procedures are currently performed under microscope magnification. Robotic tools are emerging in order to filter surgeons' unintended movements and prevent tools from entering forbidden regions such as vascular structures. The present work investigates the use of a handheld robotic tool (Micron) to automate vessel avoidance in microsurgery. In particular, we focused on vessel segmentation, implementing a deep-learning-based segmentation strategy in microscopy images, and its integration with a feature-based passive 3D reconstruction algorithm to obtain accurate and robust vessel position. We then implemented a virtual-fixture-based strategy to control the handheld robotic tool and perform vessel avoidance. Clay vascular phantoms, lying on a background obtained from microscopy images recorded during petroclival meningioma surgery, were used for testing the segmentation and control algorithms. When testing the segmentation algorithm on 100 different phantom images, a median Dice similarity coefficient equal to 0.96 was achieved. A set of 25 Micron trials of 80 s in duration, each involving the interaction of Micron with a different vascular phantom, were recorded, with a safety distance equal to 2 mm, which was comparable to the median vessel diameter. Micron's tip entered the forbidden region 24% of the time when the control algorithm was active. However, the median penetration depth was 16.9 μm, which was two orders of magnitude lower than median vessel diameter. Results suggest the system can assist surgeons in performing safe vessel avoidance during neurosurgical procedures.

Feasibility study on robot-assisted retinal vascular bypass surgery in an ex vivo porcine model

PURPOSE

To describe a new robot-assisted surgical system for retinal vascular bypass surgery (RVBS) and to compare the success rate with freehand RVBS.

METHODS

A robot-assisted system for retinal microsurgery was constructed to include two independent robotic arms. A 23-gauge light probe and an intraocular forceps were affixed to the arm end effectors to perform the intraocular manipulation. Harvested porcine eyes were introduced to be established animal models of closed-sky eyeballs after that pars plana vitrectomy using temporary keratoprosthesis was performed by a skilful surgeon. Retinal vascular bypass surgery (RVBS) was performed by an inexperienced ophthalmologist to test the ease of use. A stainless steel wire (45-μm pipe diameter) was used as an artificial vessel. Before RVBS, the wires were prepositioned at the retinal surface of the eyes. The Control group (n = 20) underwent freehand RVBS, and the Experimental group (n = 20) underwent robot-assisted RVBS. To create the simulated bypass, the distal end of the wire was inserted into the selected vessel and advanced ~4 mm away from the optic disc. If successful, then the proximal wire end was inserted and advanced ~2 mm towards the optic disc. The difference in the success rate for the freehand and robot-assisted procedures was analysed by the chi-square test.

RESULTS

The success rate for the freehand RVBS was 5% (1/20 eyes). In contrast, the robot-assisted success rate was 35% (7/20) of eyes (p < 0.05).

CONCLUSION

This study demonstrated the feasibility of robot-assisted RVBS in ex vivo porcine eyes. The robotic system increased the accuracy and stability of manipulation by eliminating freehand tremor, leading to a higher surgical success rate.

Cooperative robot assistant for vitreoretinal microsurgery: development of the RVRMS and feasibility studies in an animal model

PURPOSE

The purpose of the study was to describe the development of a robotic aided surgical system named RVRMS (robotic vitreous retinal microsurgery system) and to evaluate the capability for using it to perform vitreoretinal surgery.

METHODS

The RVRMS was designed and built to include the key components of two independent arms. End-effectors of each arm fix various surgical instruments and perform intraocular manipulation. To evaluate properly the RVRMS, robot-assisted 23-gauge surgical tasks including endolaser for retinal photocoagulation, pars plana vitrectomy (PPV), retinal foreign body removal and retinal vascular cannulation were performed in two different sizes of an animal model. Endolaser was performed in the eye of a living Irish rabbit and the other tasks were done in a harvested porcine eye. For each evaluation, the duration and the successful completion of the task was assessed.

RESULTS

Robot-assisted vitreoretinal operations were successfully performed in nine rabbit eyes and 25 porcine eyes without any iatrogenic complication such as retinal tear or retinal detachment. In the task of using an endolaser, three rows of burns around the induced retinal hole were performed in nine rabbit eyes with half size intervals of laser spots. Nine procine eyes underwent PPV followed by successful posterior vitreous detachment (PVD) induction assisted with triamcinolone acetonide (TA). Nine porcine eyes completed removal of a fine stainless steel wire, which was inserted into prepared retinal tissue. Finally, retinal vascular cannulation with a piece of stainless steel wire (6mm length, 45 μm pipe diameter and one end cut to ∼30° slope) was successfully achieved in seven porcine eyes. The average duration of each procedure was 10.91±1.22 min, 11.68±2.11min, 5.90±0.46 min and 13.5±6.2 min, respectively.

CONCLUSIONS

Maneuverability, accuracy and stability of robot-assisted vitreoretinal microsurgery using the RVRMS were demonstrated in this study. Wider application research of robotic surgery and improvement of a robotic system should be continued.

Medical Engineering and Microneurosurgery: Application and Future

Robotics and medical engineering can convert traditional surgery into digital and scientific procedures. Here, we describe our work to develop microsurgical robotic systems and apply engineering technology to assess microsurgical skills. With the collaboration of neurosurgeons and an engineering team, we have developed two types of microsurgical robotic systems. The first, the deep surgical systems, enable delicate surgical procedures such as vessel suturing in a deep and narrow space. The second type allows for super-fine surgical procedures such as anastomosing artificial vessels of 0.3 mm in diameter. Both systems are constructed with master and slave manipulator robots connected to local area networks. Robotic systems allowed for secure and accurate procedures in a deep surgical field. In cadaveric models, these systems showed a good potential of being useful in actual human surgeries, but mechanical refinements in thickness and durability are necessary for them to be established as clinical systems. The super-fine robotic system made the very intricate surgery possible and will be applied in clinical trials. Another trial included the digitization of surgical technique and scientific analysis of surgical skills. Robotic and human hand motions were analyzed in numerical fashion as we tried to define surgical skillfulness in a digital format. Engineered skill assessment is also feasible and should be useful for microsurgical training. Robotics and medical engineering should bring science into the surgical field and training of surgeons. Active collaboration between medical and engineering teams and academic and industry groups is mandatory to establish such medical systems to improve patient care.

Design optimization of neuroendoscopic continuum instruments for third ventriculostomy and tumor biopsy

A simulation-based approach to the design of procedure-specific dexterous neuroendoscopic continuum instruments for endoscopic third ventriculostomy and tumor biopsy is proposed. Given pre-operative CT and MRI images, the algorithm returns instrument design specifications including lengths, curvatures and alternative positions for the surgical incision while respecting anatomical boundaries. This methodology proposes a novel clinically-guided geometric representation of surgical targets specific to this indication. The additional constraints imposed by the presence of surgical trocars and endoscopes are also considered. Finally, we conclude with a clinical example to demonstrate the proposed approach.

Hand-held multi-DOF robotic forceps for neurosurgery designed for dexterous manipulation in deep and narrow space

Neurosurgical procedures require precise and dexterous manipulation of a surgical suture in narrow and deep spaces in the brain. This is necessary for surgical tasks such as the anastomosis of microscopic blood vessels and dura mater suturing. A hand-held multi-degree of freedom (DOF) robotic forceps was developed to aid the performance of such difficult tasks. The diameter of the developed robotic forceps is 3.5 mm, and its tip has three DOFs, namely, bending, rotation, and grip. Experimental results showed that the robotic forceps had an average needle insertion force of 1.7 N. Therefore, an increase in the needle insertion force is necessary for practical application of the developed device.

Current Capabilities and Development Potential in Surgical Robotics

Commercial surgical robots have been in clinical use since the mid-1990s, supporting surgeons in various tasks. In the past decades, many systems emerged as research platforms, and a few entered the global market. This paper summarizes the currently available surgical systems and research directions in the broader field of surgical robotics. The widely deployed teleoperated manipulators aim to enhance human cognitive and physical skills and provide smart tools for surgeons, while image-guided robotics focus on surpassing human limitations by introducing automated targeting and treatment delivery methods. Both concepts are discussed based on prototypes and commercial systems. Through concrete examples the possible future development paths of surgical robots are illustrated. While research efforts are taking different approaches to improve the capacity of such systems, the aim of this survey is to assess their maturity from the commercialization point of view.

Robotics in keyhole transcranial endoscope-assisted microsurgery: a critical review of existing systems and proposed specifications for new robotic platforms

BACKGROUND

Over the past decade, advances in image guidance, endoscopy, and tube-shaft instruments have allowed for the further development of keyhole transcranial endoscope-assisted microsurgery, utilizing smaller craniotomies and minimizing exposure and manipulation of unaffected brain tissue. Although such approaches offer the possibility of shorter operating times, reduced morbidity and mortality, and improved long-term outcomes, the technical skills required to perform such surgery are inevitably greater than for traditional open surgical techniques, and they have not been widely adopted by neurosurgeons. Surgical robotics, which has the ability to improve visualization and increase dexterity, therefore has the potential to enhance surgical performance.

OBJECTIVE

To evaluate the role of surgical robots in keyhole transcranial endoscope-assisted microsurgery.

METHODS

The technical challenges faced by surgeons utilizing keyhole craniotomies were reviewed, and a thorough appraisal of presently available robotic systems was performed.

RESULTS

Surgical robotic systems have the potential to incorporate advances in augmented reality, stereoendoscopy, and jointed-wrist instruments, and therefore to significantly impact the field of keyhole neurosurgery. To date, over 30 robotic systems have been applied to neurosurgical procedures. The vast majority of these robots are best described as supervisory controlled, and are designed for stereotactic or image-guided surgery. Few telesurgical robots are suitable for keyhole neurosurgical approaches, and none are in widespread clinical use in the field.

CONCLUSION

New robotic platforms in minimally invasive neurosurgery must possess clear and unambiguous advantages over conventional approaches if they are to achieve significant clinical penetration.

Robotic Skull Base Surgery via Supraorbital Keyhole Approach

BACKGROUND:

The supraorbital keyhole approach has been used in anterior skull base tumor and aneurysm surgery. However, there are debates regarding the safety and limitations of this kind of approach.

OBJECTIVE:

To determine the feasibility and potential benefits of surgical robotic technology in minimally invasive neurosurgery.

METHODS:

Two fresh cadaver heads were studied with the da Vinci Surgical System with 0° and 30° stereoscopic endoscopes to visualize neuroanatomy. The ability of the system to suture and place clips under the keyhole approach was tested.

RESULTS:

The da Vinci Surgical System was used throughout the supraorbital transeyebrow keyhole approach. With the use of standard microdissection techniques, the optic nerve, optic chiasm, carotid artery, and third cranial nerve were visualized. The sylvian fissure was then exposed from the proximal sylvian membrane to the distal M1 segment. With the EndoWrist microforceps, suturing can be achieved smoothly to close a defect created on the M2 artery. Although the benefits in adjusting clips during aneurysm surgery could be provided by an articulating applier, a proper robotic applier is not currently available.

CONCLUSION:

The minimally invasive supraorbital keyhole surgery can be achieved with the da Vinci Surgical System in cadaver models. This system provides neurosurgeons with broader vision and articulable instruments, which standard microsurgical systems do not provide. Further studies are necessary to evaluate the safety and benefits of using the da Vinci Surgical System in minimally invasive neurosurgery.

Frameless robotically targeted stereotactic brain biopsy: feasibility, diagnostic yield, and safety

Object

Frameless stereotactic brain biopsy has become an established procedure in many neurosurgical centers worldwide. Robotic modifications of image-guided frameless stereotaxy hold promise for making these procedures safer, more effective, and more efficient. The authors hypothesized that robotic brain biopsy is a safe, accurate procedure, with a high diagnostic yield and a safety profile comparable to other stereotactic biopsy methods.

Methods

This retrospective study included 41 patients undergoing frameless stereotactic brain biopsy of lesions (mean size 2.9 cm) for diagnostic purposes. All patients underwent image-guided, robotic biopsy in which the SurgiScope system was used in conjunction with scalp fiducial markers and a preoperatively selected target and trajectory. Forty-five procedures, with 50 supratentorial targets selected, were performed.

Results

The mean operative time was 44.6 minutes for the robotic biopsy procedures. This decreased over the second half of the study by 37%, from 54.7 to 34.5 minutes (p < 0.025). The diagnostic yield was 97.8% per procedure, with a second procedure being diagnostic in the single nondiagnostic case. Complications included one transient worsening of a preexisting deficit (2%) and another deficit that was permanent (2%). There were no infections.

Conclusions

Robotic biopsy involving a preselected target and trajectory is safe, accurate, efficient, and comparable to other procedures employing either frame-based stereotaxy or frameless, nonrobotic stereotaxy. It permits biopsy in all patients, including those with small target lesions. Robotic biopsy planning facilitates careful preoperative study and optimization of needle trajectory to avoid sulcal vessels, bridging veins, and ventricular penetration.

Force detecting gripper and flexible micro manipulator for neurosurgery

In order to realize a less invasive robotic neurosurgery for the deeply seated tumor, a force detecting gripper with a flexible micro manipulator has been developed. Gripping force applied on the gripper is detected by strain gages fit on the gripper clip. Signal is conducted to the amplifier by the cables through the inner pipe of the manipulator. In order to approach to the deeply seated tumor through a narrow hole, a micro manipulator which can flex at the end part to face the gripper for the target and can rotate the closing direction of the gripper at the end of the manipulator has been developed. Some operation test showed that the developed manipulator can approach flexibly to the target, and the taking out force of a target on the soft material was detected clearly.

Robotic catheter ventriculostomy: feasibility, efficacy, and implications

OBJECT

Robotic applications hold great promise for improving clinical outcomes and reducing complications of surgery. To date, however, there have been few widespread applications of robotic technology in neurosurgery. The authors hypothesized that image-guided robotic placement of a ventriculostomy catheter is safe, highly accurate, and highly reproducible.

METHODS

Sixteen patients requiring catheter ventriculostomy for ventriculoperitoneal (VP) shunt or reservoir placement were included in this retrospective study. All patients underwent image-guided robotic placement of a ventricular catheter, using a preoperatively defined trajectory.

RESULTS

All catheters were placed successfully in a single pass. There were no catheter-related hemorrhages and no injuries to adjacent neural structures. The mean distance of the catheter tip from the target was 1.5 mm. The mean operative times were 112 minutes for VP shunt placement and 42.3 minutes for reservoir placement. The mean operative times decreased over the course of the study by 49% for VP shunts and by 19% for reservoir placement.

CONCLUSIONS

The robotic placement of a ventriculostomy catheter using a preplanned trajectory is safe, highly accurate, and highly reliable. This makes single-pass ventriculostomy possible in all patients, even in those with very small ventricles, and may permit catheter-based therapies in patients who would otherwise be deemed poor surgical candidates because of ventricle size. Robotic placement also permits careful preoperative study and optimization of the catheter trajectory, which may help minimize the risks to bridging veins and sulcal vessels.

The analysis of intraoperative neurosurgical instrument movement using a navigation log-file

BACKGROUND

The purpose of this study was to define the technical requirements of future (tele)robotic neurosurgical systems. We aimed to analyse the movements of surgical instruments during neurosurgical procedures.

METHODS

A commercially available neuronavigation system (StealthStation TREON(plus), Medtronic, USA) was used to determine the position and orientation of the surgical instrument. A custom-made log-mode was implemented in the software to file instrument coordinates intraoperatively. Data was collected during the debulking of malignant primary brain tumours, temporal epilepsy surgery and skull base tumour surgery.

RESULTS

Maximum tip displacement velocity varied, per procedure, in the range 6.6-12.7 cm/s and maximum rotational speed 21-40 degrees/s. Maximum instrument orientation differences within the volume of movement varied. The largest differences were detected during temporal epilepsy surgery (73 degrees and 52 degrees in the coronal and axial planes, respectively), while the smallest differences were detected in the debulking of an intraventricular tumour.

CONCLUSIONS

In this study, we have demonstrated the feasibility of motion analysis in image-guided neurosurgery. To mimic ordinary open neurosurgery, future neurosurgical (tele)robotic systems should at least support translational speeds up to 12.7 cm/s, rotational speeds up to 40 degrees/s and differences in instrument orientation of up to 73 degrees.

Robotic ocular surgery

BACKGROUND

Bimanual, three-dimensional robotic surgery has proved valuable for a variety of surgical procedures.

AIMS

To examine the use of a commercially available surgical robot for ocular microsurgery.

METHODS

Using a da Vinci surgical robot, ocular microsurgery was performed with repair of a corneal laceration in a porcine model. The experiments were performed on harvested porcine eyes placed in an anatomical position using a foam head on a standard operating room table. A video scope and two, 360 degrees -rotating, 8-mm, wrested-end effector instruments were placed over the eye with three robotic arms. The surgeon performed the actual procedures while positioned at a robotic system console that was located across the operating room suite. Each surgeon placed three 10-0 sutures, and this was documented with still and video photography.

RESULTS

Ocular microsurgery was successfully performed using the da Vinci surgical robot. The robotic system provided excellent visualisation, as well as controlled and delicate placement of the sutures at the corneal level.

CONCLUSIONS

Robotic ocular microsurgery is technically feasible in the porcine model and warrants consideration for evaluation in controlled human trials to deploy functioning remote surgical centres in areas without access to state-of-the-art surgical skill and technology.