Robotic surgery for the sinuses and skull base: what are the possibilities and what are the obstacles?

The Party Wall: Redefining the Indications of Transcranial Approaches for Giant Pituitary Adenomas in Endoscopic Era

The evolution of endoscopic trans-sphenoidal surgery raises the question of the role of transcranial surgery for pituitary tumors, particularly with the effectiveness of adjunct irradiation. This narrative review aims to redefine the current indications for the transcranial approaches for giant pituitary adenomas in the endoscopic era. A critical appraisal of the personal series of the senior author (O.A.-M.) was performed to characterize the patient factors and the tumor's pathological anatomy features that endorse a cranial approach. Traditional indications for transcranial approaches include the absent pneumatization of the sphenoid sinus; kissing/ectatic internal carotid arteries; reduced dimensions of the sella; lateral invasion of the cavernous sinus lateral to the carotid artery; dumbbell-shaped tumors caused by severe diaphragm constriction; fibrous/calcified tumor consistency; wide supra-, para-, and retrosellar extension; arterial encasement; brain invasion; coexisting cerebral aneurysms; and separate coexisting pathologies of the sphenoid sinus, especially infections. Residual/recurrent tumors and postoperative pituitary apoplexy after trans-sphenoidal surgery require individualized considerations. Transcranial approaches still have a critical role in giant and complex pituitary adenomas with wide intracranial extension, brain parenchymal involvement, and the encasement of neurovascular structures.

Continuum robots for endoscopic sinus surgery: Recent advances, challenges, and prospects

PURPOSE

Endoscopic sinus surgery (ESS) has been recognized as an effective treatment modality for paranasal sinus diseases. Over the past decade, continuum robots (CRs) for ESS have been studied, but there are still some challenges. This paper presents a review on the scientific studies of CRs for ESS.

METHODS

Based on the analysis of the anatomical structure of the paranasal sinus, the requirements of CRs for ESS are discussed. Recent studies on rigid robots, handheld flexible robots, and CRs for ESS are presented. Surgical path planning, navigation, and control are also included.

RESULTS

Concentric tube CRs and cable-driven CRs have great potential for applications in ESS. The CRs incorporated with multiple replaceable arms with different functions are preferable in ESS.

CONCLUSION

Further study on navigation and control is required to improve the performance of CRs for ESS.

MemoBox: A mechanical follow-the-leader system for minimally invasive surgery

With the increase in Natural Orifice Transluminal Endoscopic Surgery procedures, there is an increasing demand for surgical instruments with additional degrees of freedom, able to travel along tortuous pathways and guarantee dexterity and high accuracy without compromising the surrounding environment. The implementation of follow-the-leader motion in surgical instruments allows propagating the decided shape through its body and moving through curved paths avoiding sensitive areas. Due to the limited operational area and therefore the instrument size, the steerable shaft of these instruments is usually driven by cables that are externally actuated. However, a large number of degrees of freedom requires a great number of actuators, increasing the system complexity. Therefore, our goal was to design a new memory system able to impose a follow-the-leader motion to the steerable shaft of a medical instrument without using actuators. We present a memory mechanism to control and guide the cable displacements of a cable-driven shaft able to move along a multi-curved path. The memory mechanism is based on a programmable physical track with a mechanical interlocking system. The memory system, called MemoBox, was manufactured as a proof-of-concept demonstration model, measuring 70 mm × 64 mm × 6 mm with 11 programmable elements and featuring a minimum resolution of 1 mm. The prototype shows the ability to generate and shift complex 2D pathways in real-time controlled by the user.

A miniature robotic steerable endoscope for maxillary sinus surgery called PliENT

In endoscopic maxillary sinus surgery, the maxillary sinus is accessed through the nasal cavity which constitutes a narrow and tortuous pathway. However, surgeons still use rigid endoscopes and rigid, straight or pre-bent instruments for this procedure. Resection of the uncinate process and creation of a medial antrostomy is warranted to access the pathology inside the maxillary sinus and depending on the location of the pathology (lateral, inferior or anterior wall), additional resection of healthy tissue and/or functional structures like the lacrimal duct and/or inferior turbinate is necessary to gain optimal access. In order to avoid this additional resection, a functional single-handed, steerable endoscope for endoscopic maxillary sinus surgery has been designed and built. This endoscope is, to our knowledge, the most slender active steerable endoscope ever reported for maxillary sinus surgery. The performance of the endoscope was validated by two surgeons on a cadaver. An increased field of view was found in comparison to currently used endoscopes. As a direct consequence, a reduced need for resection of healthy tissue was confirmed.

Collaborative Robotic Assistant Platform for Endonasal Surgery: Preliminary In-Vitro Trials

Endonasal surgery is a minimally invasive approach for the removal of pituitary tumors (sarcomas). In this type of procedure, the surgeon has to complete the surgical maneuvers for sarcoma resection with extreme precision, as there are many vital structures in this area. Therefore, the use of robots for this type of intervention could increase the success of the intervention by providing accurate movements. Research has focused on the development of teleoperated robots to handle a surgical instrument, including the use of virtual fixtures to delimit the working area. This paper aims to go a step further with a platform that includes a teleoperated robot and an autonomous robot dedicated to secondary tasks. In this way, the aim is to reduce the surgeon’s workload so that he can concentrate on his main task. Thus, the article focuses on the description and implementation of a navigator that coordinates both robots via a force/position control. Finally, both the navigation and control scheme were validated by in-vitro tests.

A Surgical Robotic System for Treatment of Pelvic Osteolysis Using an FBG-Equipped Continuum Manipulator and Flexible Instruments

This paper presents the development and experimental evaluation of a redundant robotic system for the less-invasive treatment of osteolysis (bone degradation) behind the acetabular implant during total hip replacement revision surgery. The system comprises a rigid-link positioning robot and a Continuum Dexterous Manipulator (CDM) equipped with highly flexible debriding tools and a Fiber Bragg Grating (FBG)-based sensor. The robot and the continuum manipulator are controlled concurrently via an optimization-based framework using the Tip Position Estimation (TPE) from the FBG sensor as feedback. Performance of the system is evaluated on a setup that consists of an acetabular cup and saw-bone phantom simulating the bone behind the cup. Experiments consist of performing the surgical procedure on the simulated phantom setup. CDM TPE using FBGs, target location placement, cutting performance, and the concurrent control algorithm capability in achieving the desired tasks are evaluated. Mean and standard deviation of the CDM TPE from the FBG sensor and the robotic system are 0.50 mm, and 0.18 mm, respectively. Using the developed surgical system, accurate positioning and successful cutting of desired straight-line and curvilinear paths on saw-bone phantoms behind the cup with different densities are demonstrated. Compared to the conventional rigid tools, the workspace reach behind the acetabular cup is 2.47 times greater when using the developed robotic system.

A Method Based on 3D Shape Analysis Towards the Design of Flexible Instruments for Endoscopic Maxillary Sinus Surgery

The emergence of steerable flexible instruments has widened the uptake of minimally invasive surgical techniques. In sinus surgery, such flexible instruments could enable the access to difficult-to-reach anatomical areas. However, design-oriented metrics, essential for the development of steerable flexible instruments for maxillary sinus surgery, are still lacking. This paper proposes a method to process measurements and provides the instrument designer with essential information to develop adapted flexible instruments for limited access surgery. This method was applied to maxillary sinus surgery and showed that an instrument with a diameter smaller than 2.4 mm can be used on more than 72.5% of the subjects' set. Based on the statistical analysis and provided that this flexible instrument can bend up to [Formula: see text] it is estimated that all areas within the maxillary sinus could be reached through a regular antrostomy without resorting to extra incision or tissue removal in 94.9% of the population set. The presented method was partially validated by conducting cadaver experiments.

Active Endoscope Preserving Image Orientation for Endonasal Skull Base Surgery

Endonasal Skull Base Surgery has some advantages over conventional methods; however, some issues such as the need to replace the endoscope due to the fixed view, and possible invasiveness during insertion make the procedure difficult. To solve these problems, this paper proposes an active endoscope mechanism with several benefits. First, its variable direction of view can cover the wide ranges. Second, it provides a forward view, lessening the danger of damaging critical tissues while the endoscope is being inserted. Third, it can change the direction of view within a very small radius of 6.5 mm, so it can be used in a small cavity and work together with other surgical tools. We have designed the endoscope, which has 4 mm diameter. It is a simple tilting and rotation mechanism of 2-degree of freedom (DOF). It implements kinematics control to make it intuitive to operate. The image sensor attached to the distal end is fixed mechanically so that the image orientation is preserved in the direction of gravity. The experiments showed the user could intuitively control the endoscope with the master device and observe the target without swapping the endoscope. Future tests will examine clinical aspects and combination work with surgical instruments.

An active endoscope with small sweep volume that preserves image orientation for arthroscopic surgery

BACKGROUND

Microsurgery is generally performed in narrow spaces with limited movement. Endoscopes that allow for angle changes have been developed using elastic materials, but they require a large bending space. We propose a new endoscope with a small sweep volume for angle changes.

METHODS

We fabricated a prototype with a thumb-operated joystick. The image sensor is attached to the tooltip. The image signal is input to a motor control board which computes inverse kinematics and transforms it into joint angle values. Each axis is positioned according to these values.

RESULTS

The tooltip sweeping volume was 104 mm³ . Surgeons at the Asan Medical Center used our endoscope to obtain images of the biceps tendon and subscapularis joints of a cadaver.

CONCLUSION

Currently, a low-resolution image sensor is attached to endoscope tooltips. In the future, we will develop a high-resolution image module equipped with an ultra-small complementary metal oxide semiconductor sensor.

Endonasal endoscopic transsphenoidal approach robot prototype: A cadaveric trial

BACKGROUND

The Endonasal Endoscopic Transsphenoidal Surgery (EETS) is a minimally invasive procedure to approach and remove pituitary tumors and other sellar lesions. The process causes less pain, faster recovery, and provides further minimal invasive access in critical cases. However, a slight deviation of tools from the target area can be fatal to the patients. The aim of this study is to design and develop a prototype robot to demonstrate neurosurgical robot-assisted EET approach.

METHODS

The effectiveness of a prototype robot in executing a minimally invasive EET surgery was studied in 6 cadavers. The robot was associated with a multi-information integrated technique for surgery including QR code tracking. The robot was controlled and driven by the neurosurgeon.

RESULTS

The standard procedure of EET was followed and the robot carried out the first stage of EET under the supervision of neurosurgeon. Finally, the sellar was reached by the neurosurgeon. The result was determined by qualitative analysis and was confirmed by the neurosurgeon. The time for the entire EET surgical procedure showed marked reduction compared to the traditional EET approach.

CONCLUSION

The robot design was found to be technically feasible and hence can be used for assisting the EET procedure. The robot used was able to assist the neurosurgeon correctly to approach the sinus.

Robotic Skull Base Surgery

Robotic surgery has become more common in otolaryngologic surgery since the introduction of the da Vinci robotic system, but has played a limited role in anterior and central skull base surgery, largely because of technical limitations of existing robots. Current robotic technology has been used in creative ways to access the skull base, but was not designed to navigate these complex anatomic constraints. Novel robots should target many of the limitations of current robotic technology, such as maneuverability, inability to suture, lack of haptic feedback, and absent integration with image guidance.

A Cooperative Human-Robot Interface for Constrained Manipulation in Robot-Assisted Endonasal Surgery

Endoscopic endonasal surgery (EES) is a minimally invasive technique for removal of pituitary adenomas or cysts at the skull base. This approach can reduce the invasiveness and recovery time compared to traditional open surgery techniques. However, it represents challenges to surgeons because of the constrained workspace imposed by the nasal cavity and the lack of dexterity with conventional surgical instruments. While robotic surgical systems have been previously proposed for EES, issues concerned with proper interface design still remain. In this paper, we present a cooperative, compact, and versatile bimanual human-robot interface aimed to provide intuitive and safe operation in robot-assisted EES. The proposed interface is attached to a robot arm and holds a multi-degree-of-freedom (DOF) articulated forceps. In order to design the required functionalities in EES, we consider a simplified surgical task scenario, with four basic instrument operations such as positioning, insertion, manipulation, and extraction. The proposed cooperative strategy is based on the combination of force based robot control for tool positioning, a virtual remote-center-of-motion (VRCM) during insertion/extraction tasks, and the use of a serial-link interface for precise and simultaneous control of the position and the orientation of the forceps tip. Virtual workspace constraints and motion scaling are added to provide safe and smooth control of our robotic surgical system. We evaluate the performance and usability of our system considering reachability, object manipulability, and surgical dexterity in an anatomically realistic human head phantom compared to the use of conventional surgical instruments. The results demonstrate that the proposed system can improve the precision, smoothness and safety of the forceps operation during an EES.

Work-related musculoskeletal disorders among endoscopic transsphenoidal surgeons: a systematic review of prevalence and ergonomic interventions

Endoscopic transsphenoidal surgery is a surgical technique introduced in the last 20 years for the treatment of skull base pathologies and, in particular, pituitary tumours. Although the prevalence of work-related musculoskeletal disorders is usually significantly higher in endoscopists and minimally invasive surgeons compared to other surgical and medical specialties, reviews on the prevalence of disorders among neurosurgeons dedicated to endoscopic transsphenoidal surgery are not available. This article performs a systematic review to identify the work-related musculoskeletal disorders among transsphenoidal neurosurgeons, their prevalence and the ergonomic interventions proposed to reduce risk factors and prevent disorders. The results show that the ergonomics of transsphenoidal neurosurgeons is an under-investigated topic. Indeed, specific prevalence data are not available. In addition, only a few papers suggest interventions and guidelines, but without objective assessment of the outcomes to confirm the ergonomic benefit. Based on these gaps in the literature, a future research agenda is proposed.

Anatomical Workspace Study of Endonasal Endoscopic Transsphenoidal Approach

Purpose

To determine the workspace through an anatomical dimensional study of the skull base to further facilitate the design of the robot for endonasal endoscopic transsphenoidal (EET) surgery.

Methods

There were 120 cases having a paranasal sinus CT scan in the database. The internal volumes of the nasal cavities (NC), the volumes of the sphenoid sinuses (SS), and the distance between the anterior nasal spine and base of the sellar (d-ANS-BS) were measured.

Results

The Pearson correlation coefficient (PCC) between the relevant distances and the volumes of the right NC was 0.32; between the relevant distances and the volumes of the left NC was 0.43; and between the relevant distances and volumes of NC was 0.41; with a statistically significant difference (p < 0.001). All PCCs had a statistically significant meaningful difference (p < 0.05).

Conclusion

The volume of NCs were significantly correlated with distances (p < 0.05). The safest and shortest distance to guide the robotic arm length in the EET approach could be represented by d-ANS-BS. This result was also used as primary information for further robotic design.

A validation study of a virtual-based haptic system for endoscopic sinus surgery training

BACKGROUND

The development of endoscopic sinus surgery (ESS) training simulators for clinical environment applications has reduced the existing shortcomings in conventional teaching methods, creating a standard environment for trainers and trainees in a more accurate and repeatable fashion.

MATERIALS AND METHODS

In this research, the validation study of an ESS training simulator has been addressed. It is important to consider components that guide trainees to improve their hand movements control in the orbital floor removal in an ESS operation. Therefore, we defined three tasks to perform: pre-experiment learning, training, and evaluation. In these tasks, the critical regions introduced in the virtual training environment are forbidden to be touched. Recruiting 20 participants, divided into two groups, we investigated the performance metrics: quality (the percentage of the realism for the generated force for orbital floor removal and the usefulness of the proposed training system for the surgical educational curricula.), efficiency (time, path length), and safety (touching the goal and forbidden wall).

RESULTS

All recruited participants answered a post-evaluation questionnaire regarding their perceptions of training system realism, potential educational benefits, and practiced skills. We investigate the differences between groups' performance metrics by utilizing the analysis of variance-Kruskal-Wallis test. Acquired results indicate that training before the actual process of the surgery has a significant effect on the accuracy and validity of the process for surgeons.

CONCLUSIONS

Utilizing a standardized environment, trainers and trainees are able to carry out a process with regular features. In addition to traditional education methods, trainees can learn the risk of surgical operations. The training simulators can, also, provide a standard method for assessing the skills of surgical and medical students.

Foot-Controlled Robot-Enabled EnDOscope Manipulator (FREEDOM) for Sinus Surgery: Design, Control, and Evaluation

Despite successful clinical applications, teleoperated robotic surgical systems face particular limitations in the functional endoscopic sinus surgery (FESS) in terms of incompatible instrument dimensions and robot set-up. The endoscope remains manually handled by an assistant when the surgeon performs bimanual operations. This paper introduces the development of the Foot-controlled Robot-Enabled EnDOscope Manipulator (FREEDOM) designed for FESS. The system features clinical considerations that inform the design for providing reliable and safe endoscope positioning with minimal obstruction to the routine practice. The robot structure is modular and compact to ensure coaxial instrument manipulation through the nostril for manual procedures. To avoid rigid endoscope motions, a new compliant endoscope holder is proposed that passively limits the lens-tissue contact forces under collisions for patient-side protection. To facilitate hands-free endoscope manipulation that imposes minimal distractions to the surgeon, a foot-wearable interface is further designed to relieve the assistant's workload. The foot control method owns a short learning curve (mean 3.4 mins), and leads the task to be more ergonomic and surgeon-centered. Cadaver and clinical studies were both conducted to evaluate the surgical applicability of the FREEDOM to assist endoscope manipulation in FESS. The system was validated to be safe (IEC-60601-1) and easy for set up (mean 3.6 mins), from which the surgeon could perform various three-handed procedures alone in FESS without disrupting the routine practice.

Phenomenological tissue fracture modeling for an Endoscopic Sinus and Skull Base Surgery training system based on experimental data

The ideal simulator for Endoscopic Sinus and Skull Base Surgery (ESSS) training must be supported by a physical model and provide repetitive behavior in a controlled environment. Development of realistic tissue models is a key part of ESSS virtual reality (VR)-based surgical simulation. Considerable research has been conducted to address haptic or force feedback and propose a phenomenological tissue fracture model for sino-nasal tissue during surgical tool indentation. Mechanical properties of specific sino-nasal regions of the sheep head have been studied in various indentation and relaxation experiments. Tool insertion at different indentation rates into coronal orbital floor (COF) tissue is modeled as a sequence of three events: deformation, fracture, and cutting. The behavior in the deformation phase can be characterized using a non-linear, rate-dependent modified Kelvin-Voigt model. A non-linear model for tissue behavior prior to the fracture point is presented. The overall model shows a non-positive dependency of maximum force on tool indentation rate, which indicates faster tool insertion velocity decreases the maximum final fracture force. The tissue cutting phase has been modeled to characterize the force necessary to slice through the COF. The proposed model in this study can help develop VR-based ESSS base simulators in otolaryngology and ophthalmology surgeries. Such simulators are useful in preoperative planning, accurate surgical simulation, intelligent robotic assistance, and treatment applications.

Technological and Ideological Innovations in Endoscopic Skull Base Surgery

BACKGROUND

Endoscopic skull base surgery has evolved over the last several decades due to technological advances and operative techniques. Several innovations that are not yet mainstream may have significant impact on the future of endoscopic skull base surgery.

METHODS

Current literature pertaining to innovations in endoscopic skull base surgery was retrieved using PubMed, Embase, Web of Science, and Google Scholar.

RESULTS

Several recent innovations may play an influential role in the advancement of endoscopic skull base surgery, including fluorescent dyes such as indocyanine green fluorescence, fluorescein, and 5-aminolevulinic acid, 3-dimensional endoscopes, robotic surgery, and intraoperative magnetic resonance imaging.

CONCLUSIONS

Several technologies are under current investigation with the hope to improve future outcomes in endoscopic skull base surgery. Additional research and evolution are necessary and will require intense scrutiny before becoming standard of care.

Current surgical practices of robotic-assisted tissue repair and reconstruction

This paper systematically reviewed and analyzed the recent publications of robotic-assisted surgeries in the field of tissue repair and reconstruction. Surgical robots can elevate skin flap more accurately and shorten the time of tissue harvest. In addition, robotic-assisted surgery has the advantage of minimal tissue trauma and thus forms minimal scar. The utilization of surgical robots reduces the occurrence of complications after oral radical tumor resection while achieving cosmetic sutures. Robotic-assisted radical mastectomy could radically remove invasive breast cancer lesions and achieve breast reconstruction in the first stage through the small incisions in the operation areas. Surgical robots enable precise microvascular anastomosis and reduce tissue edema in the surgical field. Robotic-assisted technology can help appropriately locate the target tissues at different angles during sinus and skull base surgeries and accurately place tissues during urethroplasty. The robotic-assisted technology provides a new platform for surgical innovation in the field of tissue repair and reconstruction. However, the uncertainty in the survival rate after tumor radical surgery, the increase of operating time, and the high costs are barriers for its clinical application in tissue repair and reconstructive surgery. Nevertheless, robotic-assisted technology has already demonstrated an impact on the field of tissue repair and reconstruction in a meaningful way.

[Robotic Surgery - Who is The Boss?]

In the head and neck region, great potential is seen in robot-assisted surgery (RAS). Mainly in cancer surgery, the use of robotic systems seems to be of interest. Until today, two robotic systems (DaVinci® und FLEX®) have gained approval for clinical use in the head and neck region, and multiple other systems are currently in pre-clinical testing. Although, certain groups of patients may benefit from RAS, no unbiased randomized clinical studies are available. Until today, it was not possible to satisfactorily prove any advantage of RAS as compared to standard procedures. The limited clinical benefit and the additional financial burden seem to be the main reasons, why the comprehensive application of RAS has not been realized so far.This review article describes the large variety of clinical applications for RAS in the head and neck region. In addition, the financial and technical challenges, as well as ongoing developments of RAS are highlighted. Special focus is put on risks associated with RAS and current clinical studies. We believe, that RAS will find its way into clinical routine during the next years. Therefore, medical staff will have to increasingly face the technical, scientific and ethical features of RAS.

An Innovate Robotic Endoscope Guidance System for Transnasal Sinus and Skull Base Surgery: Proof of Concept

Objective  Advanced transnasal sinus and skull base surgery remains a challenging discipline for head and neck surgeons. Restricted access and space for instrumentation can impede advanced interventions. Thus, we present the combination of an innovative robotic endoscope guidance system and a specific endoscope with adjustable viewing angle to facilitate transnasal surgery in a human cadaver model. Materials and Methods  The applicability of the robotic endoscope guidance system with custom foot pedal controller was tested for advanced transnasal surgery on a fresh frozen human cadaver head. Visualization was enabled using a commercially available endoscope with adjustable viewing angle (15-90 degrees). Results  Visualization and instrumentation of all paranasal sinuses, including the anterior and middle skull base, were feasible with the presented setup. Controlling the robotic endoscope guidance system was effectively precise, and the adjustable endoscope lens extended the view in the surgical field without the common change of fixed viewing angle endoscopes. Conclusion  The combination of a robotic endoscope guidance system and an advanced endoscope with adjustable viewing angle enables bimanual surgery in transnasal interventions of the paranasal sinuses and the anterior skull base in a human cadaver model. The adjustable lens allows for the abandonment of fixed-angle endoscopes, saving time and resources, without reducing the quality of imaging.

Robotic Transnasal Endoscopic Skull Base Surgery: Systematic Review of the Literature and Report of a Novel Prototype for a Hybrid System (Brescia Endoscope Assistant Robotic Holder)

BACKGROUND

Although robotics has already been applied to several surgical fields, available systems are not designed for endoscopic skull base surgery (ESBS). New conception prototypes have been recently described for ESBS. The aim of this study was to provide a systematic literature review of robotics for ESBS and describe a novel prototype developed at the University of Brescia.

METHODS

PubMed and Scopus databases were searched using a combination of terms, including Robotics OR Robot and Surgery OR Otolaryngology OR Skull Base OR Holder. The retrieved papers were analyzed, recording the following features: interface, tools under robotic control, force feedback, safety systems, setup time, and operative time. A novel hybrid robotic system has been developed and tested in a preclinical setting at the University of Brescia, using an industrial manipulator and readily available off-the-shelf components.

RESULTS

A total of 11 robotic prototypes for ESBS were identified. Almost all prototypes present a difficult emergency management as one of the main limits. The Brescia Endoscope Assistant Robotic holder has proven the feasibility of an intuitive robotic movement, using the surgeon's head position: a 6 degree of freedom sensor was used and 2 light sources were added to glasses that were therefore recognized by a commercially available sensor.

CONCLUSIONS

Robotic system prototypes designed for ESBS and reported in the literature still present significant technical limitations. Hybrid robot assistance has a huge potential and might soon be feasible in ESBS.

Development of a snake-like dexterous manipulator for skull base surgery

Petrous apex lesions constitute considerable surgical challenges due to their location in the skull base and close relationship with critical structures such as inner ear, carotid arteries, facial nerves and jugular bulb. These lesions often cannot be treated completely with rigid tools due to the limited accessibility. We are aiming to develop a snake-like manipulator to assist surgeons with the infralabyrinthine treatment of petrous apex lesions with increased dexterity. This snake-like dexterous manipulator (SDM) with 3.3 mm outer diameter and 40 mm working length was designed including a tool channel with a diameter of 1.8 mm and an endoscope channel with a diameter of 0.7 mm. The SDM can be actuated in one plane and two directions enabling the C- and S-shaped bends and rotated around its longitudinal axis. The constant curvature modeling was implemented to predict the deflection in one direction. Experiments were carried out with optical microscope to find out different bending modes. Experimental bending modes were in a good agreement with the theoretical ones in terms of the bending behavior. However tip position prediction showed discrepancies up to 1 mm in X and 2 mm in Z axes.

Toward Medical Devices With Integrated Mechanisms, Sensors, and Actuators Via Printed-Circuit MEMS

Recent advances in medical robotics have initiated a transition from rigid serial manipulators to flexible or continuum robots capable of navigating to confined anatomy within the body. A desire for further procedure minimization is a key accelerator for the development of these flexible systems where the end goal is to provide access to the previously inaccessible anatomical workspaces and enable new minimally invasive surgical (MIS) procedures. While sophisticated navigation and control capabilities have been demonstrated for such systems, existing manufacturing approaches have limited the capabilities of millimeter-scale end-effectors for these flexible systems to date and, to achieve next generation highly functional end-effectors for surgical robots, advanced manufacturing approaches are required. We address this challenge by utilizing a disruptive 2D layer-by-layer precision fabrication process (inspired by printed circuit board manufacturing) that can create functional 3D mechanisms by folding 2D layers of materials which may be structural, flexible, adhesive, or conductive. Such an approach enables actuation, sensing, and circuitry to be directly integrated with the articulating features by selecting the appropriate materials during the layer-by-layer manufacturing process. To demonstrate the efficacy of this technology, we use it to fabricate three modular robotic components at the millimeter-scale: (1) sensors, (2) mechanisms, and (3) actuators. These modules could potentially be implemented into transendoscopic systems, enabling bilateral grasping, retraction and cutting, and could potentially mitigate challenging MIS interventions performed via endoscopy or flexible means. This research lays the ground work for new mechanism, sensor and actuation technologies that can be readily integrated via new millimeter-scale layer-by-layer manufacturing approaches.

Comprehensive review on endonasal endoscopic sinus surgery

Endonasal endoscopic sinus surgery is the standard procedure for surgery of most paranasal sinus diseases. Appropriate frame conditions provided, the respective procedures are safe and successful. These prerequisites encompass appropriate technical equipment, anatomical oriented surgical technique, proper patient selection, and individually adapted extent of surgery. The range of endonasal sinus operations has dramatically increased during the last 20 years and reaches from partial uncinectomy to pansinus surgery with extended surgery of the frontal (Draf type III), maxillary (grade 3-4, medial maxillectomy, prelacrimal approach) and sphenoid sinus. In addition there are operations outside and beyond the paranasal sinuses. The development of surgical technique is still constantly evolving. This article gives a comprehensive review on the most recent state of the art in endoscopic sinus surgery according to the literature with the following aspects: principles and fundamentals, surgical techniques, indications, outcome, postoperative care, nasal packing and stents, technical equipment.

Effect of training frequency on the learning curve on the da Vinci Skills Simulator

BACKGROUND

The purpose of this study was to evaluate the effect of training on the performance outcome with the da Vinci Skills Simulator.

METHODS

Forty novices were enrolled in a prospective training curriculum. Participants were separated into 2 groups. Group 1 performed 4 training sessions and group 2 had 2 training sessions over a 4-week period. Five exercises were performed 3 times consecutively. On the last training day, a new exercise was added.

RESULTS

A significant skills gain from the first to the final practice day in overall performance, time to complete, and economy of motion was seen for both groups. Group 1 had a significantly better outcome in overall performance, time to complete, and economy of motion in all exercises. There was no significant difference found regarding the new exercise in group 1 versus group 2 in nearly all parameters.

CONCLUSION

Longer time distances between training sessions are assumed to play a secondary role, whereas total repetition frequency is crucial for improvement of technical performance. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1762-E1769, 2016.

[Nasosinusal malignant tumors: about 32 cases and literature reviews]

Sous l’appellation tumeurs malignes naso-sinusiennes est regroupé un vaste éventail de tumeurs, aux histologies et localisations variées, mais aux tableaux cliniques souvent similaires. Le diagnostic de ces tumeurs est difficile, nécessitant une approche multidisciplinaire, à savoir oto-rhino-laryngologique, radiologique et anatomopathologique. Notre étude rétrospective concerne 32 cas de tumeurs malignes naso-sinusiennes, colligées au service d’ORL de l’hôpital militaire Avicenne de Marrakech, entre Janvier 2004 et Décembre 2014. L’analyse des données a noté que la fréquence des tumeurs épithéliales (75% des cas) était supérieure à celle des tumeurs non épithéliales (25% des cas), avec en tête de file l’adénocarcinome de l’ethmoïde (31,25%) et le carcinome épidermoïde du sinus maxillaire (18,75%). Ces tumeurs surviennent le plus souvent chez le sujet âgé avec une moyenne d’âge de 52 ans et une répartition équitable entre les deux sexes. Le délai de consultation moyen était de 12 mois avec une symptomatologie dominée par un syndrome nasosinusien (71,8%), associé dans certains cas à des signes ophtalmologiques (12,5%) ou neurologiques (15,6%). Tous nos patients ont bénéficié d’un examen clinique notamment endoscopique, d’une exploration radiologique des tumeurs et de leurs extensions, et d’une confirmation diagnostique par un examen anatomopathologique. Le traitement a consisté en une exérèse chirurgicale de la tumeur dès que cela était possible, soit dans 81,3% des cas (26 patients), généralement complété par un traitement adjuvant radio-chimiothérapique (77%). Le suivi à un an de nos patients a permis de noter une bonne évolution pour 08 d’entre eux (25%), une récidive dans 6 cas (18,75%), le décès de neuf patients (28,1%), et l’absence d’information concernant les autres cas (28,1%).

HelixFlex: bioinspired maneuverable instrument for skull base surgery

Endoscopic endonasal surgery is currently regarded as the 'gold standard' for operating on pituitary gland tumors, and is becoming more and more accepted for treatment of other skull base lesions. However, endoscopic surgical treatment of most skull base pathologies, including certain pituitary tumors, is severely impaired by current instruments lack of maneuverability. Especially, gaining access to, and visibility of, difficult-to-reach anatomical corners without interference with surrounding neurovascular structures or other instruments, is a challenge. In this context there is the need for instruments that are able to provide a stable shaft position, while both the orientation and the position of the end-effector can be independently controlled. Current instruments that allow for this level of maneuverability are usually mechanically complex, and hence less suitable for mass production. This study therefore focuses on the development of a new actuation technique that allows for the required maneuverability while reducing the construction complexity. This actuation technique, referred to as multi-actuation, integrates multiple cable routings into a single steerable structure. Multi-actuation has been successfully integrated and tested in a handheld prototype instrument called HelixFlex. HelixFlex contains a 4 degrees of freedom maneuverable 5.8 mm (diameter) tip and shows promising results concerning its maneuverability and potential rigidity.

Robot-Assisted Neck Dissection Through a Modified Facelift Incision

Objectives:

The aim of this study is to describe the feasibility as well as oncologic outcomes of robot-assisted neck dissection (RAND) through a modified facelift incision in an American population.

Study Design:

Retrospective case series.

Setting:

University tertiary care hospital.

Methods:

All patients who underwent RAND between November 2012 and December 2014 were included. Medical records were reviewed for demographics, medical histories, staging, operative information, postoperative hospital course and complications, and oncologic outcomes.

Results:

There were 11 RANDs identified among 10 patients. Five patients had known nodal metastasis at the time of surgery. Two patients had been previously irradiated. The average time of surgery was 284.4 ± 72.3 minutes, including other associated procedures. The average lymph node yield was 28.5 ± 9.3 nodes. There were no major complications. Average follow-up was 19.4 months. There was 1 supraclavicular recurrence in a previously irradiated patient. All patients are currently alive and without evidence of disease.

Conclusions:

Robot-assisted neck dissection is a safe and feasible procedure that can be performed by surgeons with familiarity with neck dissection and robot-assisted surgery and who have been trained in RAND. Appropriate oncologic outcomes can be obtained in a patient wishing to avoid a noticeable scar.

An experimental feasibility study on robotic endonasal telesurgery

BACKGROUND

Novel robots have recently been developed specifically for endonasal surgery. They can deliver several thin, tentacle-like surgical instruments through a single nostril. Among the many potential advantages of such a robotic system is the prospect of telesurgery over long distances.

OBJECTIVE

To describe a phantom pituitary tumor removal done by a surgeon in Nashville, Tennessee, controlling a robot located approximately 800 km away in Chapel Hill, North Carolina, the first remote telesurgery experiment involving tentacle-like concentric tube manipulators.

METHODS

A phantom pituitary tumor removal experiment was conducted twice, once locally and once remotely, with the robotic system. Robot commands and video were transmitted across the Internet. The latency of the system was evaluated quantitatively in both local and remote cases to determine the effect of the 800-km distance between the surgeon and robot.

RESULTS

We measured a control and video latency of < 100 milliseconds in the remote case. Qualitatively, the surgeon was able to carry out the experiment easily and observed no discernable difference between the remote and local cases.

CONCLUSION

Telesurgery over long distances is feasible with this robotic system. In the longer term, this may enable expert skull base surgeons to help many more patients by performing surgeries remotely over long distances.

First use of a computer-assisted operator-controlled flexible endoscope for transoral surgery

Transoral robotic surgery (TORS) has become an accepted treatment option for head and neck cancer. However, anatomical limitations and a relevant financial burden require alternative developments in this field. To this end, a patient presenting with a T2 squamous cell carcinoma of the lower lateral oropharyngeal wall was effectively treated with a new Conformité Européene-certified, computer-assisted, operator-controlled flexible endoscope (Flex). Intraoperative visualization and tissue handling were acceptable and safe. Transoral surgery with the flexible endoscope was safely conducted in a clinical setting. The introduction of alternative TORS systems will increase competition, drive scientific improvement, and reduce financial expenses.

Current trends in robotic surgery for otolaryngology

As minimally invasive surgery has become common in head and neck surgery, the role of robotic surgery has expanded from thyroid surgery and transoral robotic surgery (TORS) of the oropharynx and supraglottic to other areas. Surgeons have advanced the limits of TORS, adapting lasers to the Da Vinci robot for glottic cancer, and combining existing techniques for transoral supraglottic laryngectomy and hypopharyngectomy to perform transoral total laryngectomy. Skull base approaches have been reported with some success in case reports and cadaver models, but the current instrument size and configuration limit the applicability of the current robotic system. Surgeons have reported reconstruction of the head and neck via local and free flaps. Using the previously reported approaches for thyroidectomy via modified facelift incision, neck dissection has also been reported. Future applications of robotic surgery in otolaryngology may be additionally expanded, as several new robotic technologies are under development for endolaryngeal work and neurotology.

A Telerobotic System for Transnasal Surgery

Mechanics-based models of concentric tube continuum robots have recently achieved a level of sophistication that makes it possible to begin to apply these robots to a variety of real-world clinical scenarios. Endonasal skull base surgery is one such application, where their small diameter and tentacle like dexterity are particularly advantageous. In this paper we provide the medical motivation for an endonasal surgical robot featuring concentric tube manipulators, and describe our model-based design and teleoperation methods, as well as a complete system incorporating image-guidance. Experimental demonstrations using a laparoscopic training task, a cadaver reachability study, and a phantom tumor resection experiment illustrate that both novice and expert users can effectively teleoperate the system, and that skull base surgeons can use the robot to achieve their objectives in a realistic surgical scenario.