Natural orifice translumenal surgery: Flexible platform review

Lumen Apposition: A Changing Landscape in Therapeutic Endoscopy

The concept of endoscopic lumen apposition has seen a dramatic shift in the last several decades. Early natural orifice trans-luminal endoscopic surgery (NOTES) concepts have transformed into specialized lumen-apposing metal stents (LAMSs) and delivery devices, which provide endoscopists a minimally invasive alternative to surgical intervention. These LAMSs have become the bedrock of therapeutic endoscopy and provide treatment for a wide spectrum of gastrointestinal disorders. In this review, we summarize the changing landscape of therapeutic endoscopy by highlighting the use of LAMS and future directions as well as alternative devices to achieve lumen apposition.

Lumen Apposition: A Changing Landscape in Therapeutic Endoscopy

The concept of endoscopic lumen apposition has seen a dramatic shift in the last several decades. Early natural orifice trans-luminal endoscopic surgery (NOTES) concepts have transformed into specialized lumen-apposing metal stents (LAMSs) and delivery devices, which provide endoscopists a minimally invasive alternative to surgical intervention. These LAMSs have become the bedrock of therapeutic endoscopy and provide treatment for a wide spectrum of gastrointestinal disorders. In this review, we summarize the changing landscape of therapeutic endoscopy by highlighting the use of LAMS and future directions as well as alternative devices to achieve lumen apposition.

Development of a novel deployable arm for natural orifice transluminal endoscopic surgery

BACKGROUND

Natural orifice transluminal endoscopic surgery (NOTES) is aided by the instrument channel of an endoscope. Limited by the diameter of the endoscope, the construction of the operation triangle is affected. This paper presents a deployable arm that can increase the distance between the arms.

METHODS

The manipulation arm is composed of a continuum arm and a deployable arm. The deployable arm can be locked by a stay cable and a mechanical structure. The angle between the end-effectors and the common workspace of the two manipulation arms are comprehensively analysed. Through experiments, the design parameters are validated and justified.

RESULTS

The experiment shows that the deployment arm can maintain the deformation within 3.5 mm under a 300 g load, and the angle between the two end-effectors can be maintained within the range of [88°, 110°].

CONCLUSIONS

The novel deployment arms enlarge the angle between the end effectors, which significantly improves the flexibility of the arms.

Frontiers of Robotic Gastroscopy: A Comprehensive Review of Robotic Gastroscopes and Technologies

Simple Summary

With the rapid advancements of medical technologies and patients’ higher expectations for precision diagnostic and surgical outcomes, gastroscopy has been increasingly adopted for the detection and treatment of pathologies in the upper digestive tract. Correspondingly, robotic gastroscopes with advanced functionalities, e.g., disposable, dextrous and not invasive solutions, have been developed in the last years. This article extensively reviews these novel devices and describes their functionalities and performance. In addition, the implementation of artificial intelligence technology into robotic gastroscopes, combined with remote telehealth endoscopy services, are discussed. The aim of this paper is to provide a clear and comprehensive view of contemporary robotic gastroscopes and ancillary technologies to support medical practitioners in their future clinical practice but also to inspire and drive new engineering developments.

Abstract

Upper gastrointestinal (UGI) tract pathology is common worldwide. With recent advancements in robotics, innovative diagnostic and treatment devices have been developed and several translational attempts made. This review paper aims to provide a highly pictorial critical review of robotic gastroscopes, so that clinicians and researchers can obtain a swift and comprehensive overview of key technologies and challenges. Therefore, the paper presents robotic gastroscopes, either commercial or at a progressed technology readiness level. Among them, we show tethered and wireless gastroscopes, as well as devices aimed for UGI surgery. The technological features of these instruments, as well as their clinical adoption and performance, are described and compared. Although the existing endoscopic devices have thus far provided substantial improvements in the effectiveness of diagnosis and treatment, there are certain aspects that represent unwavering predicaments of the current gastroenterology practice. A detailed list includes difficulties and risks, such as transmission of communicable diseases (e.g., COVID-19) due to the doctor–patient proximity, unchanged learning curves, variable detection rates, procedure-related adverse events, endoscopists’ and nurses’ burnouts, limited human and/or material resources, and patients’ preferences to choose non-invasive options that further interfere with the successful implementation and adoption of routine screening. The combination of robotics and artificial intelligence, as well as remote telehealth endoscopy services, are also discussed, as viable solutions to improve existing platforms for diagnosis and treatment are emerging.

Robotic stereotaxic system based on 3D skull reconstruction to improve surgical accuracy and speed

BACKGROUND

Some experimental approaches in neuroscience research require the precise placement of a recording electrode, pipette or other tool into a specific brain area that can be quite small and/or located deep beneath the surface. This process is typically aided with stereotaxic methods but remains challenging due to a lack of advanced technology to aid the experimenter. Currently, procedures require a significant amount of skill, have a high failure rate, and take up a significant amount of time.

NEW METHOD

We developed a next generation robotic stereotaxic platform for small rodents by combining a three-dimensional (3D) skull profiler sub-system and a full six degree-of-freedom (6DOF) robotic platform. The 3D skull profiler is based on structured illumination in which a series of horizontal and vertical line patterns are projected onto an animal skull. These patterns are captured by two two-dimensional (2D) CCD cameras which reconstruct an accurate 3D skull surface profile based on structured illumination and geometrical triangulation. Using the reconstructed 3D profile, the skull can be repositioned using a 6DOF robotic platform to accurately align a surgical tool.

RESULTS

The system was evaluated using mechanical measurement techniques, and the accuracy of the platform was demonstrated using agar brain phantoms and animal skulls. Additionally, a small and deep brain nucleus (the medial nucleus of the trapezoid body) were targeted in rodents to confirm the targeting accuracy.

CONCLUSIONS

The new stereotaxic system can accomplish "skull-flat" rapidly and precisely and with minimal user intervention, and thus reduces the failure rate of such experiments.

A variable-stiffness continuum manipulators by an SMA-based sheath in minimally invasive surgery

BACKGROUND

Due to its unique dexterity and safety, continuum manipulators have been widely used in small constrained environment. However, its flexibility also brings negative effects such as poor stiffness and low strength. This paper presents a novel variable-stiffness sheath for continuum manipulators applied in minimally invasive surgery.

METHODS

We present a variable-stiffness sheath based on shape memory alloy (SMA) for each module of the continuum manipulators. The stiffness of the sheath can be continuously adjusted depending on the voltage between both ends of the sheath, along with the phase transformation of SMA between austenite and martensite.

RESULTS

The experimental results demonstrate that the stiffness of the sheath and single module are able to increase up to 223.1% and 139.2%, separately, which verify the correctness of the proposed variable stiffness method.

CONCLUSION

The robot integrated with the variable-stiffness sheath is demonstrated to possess a fine capacity of variable stiffness.

A foldable manipulator with tunable stiffness based on braided structure

Minimally invasive surgery (MIS) has recently seen a surge in clinical applications due to its potential benefits over open surgery. In MIS, a long manipulator is placed through a tortuous human orifice to create a channel for surgical tools and provide support when they are operated. Currently the relative large profile and low stiffness of the manipulators limit the effectiveness and accuracy of MIS. Here we propose a new foldable manipulator with tunable stiffness. The manipulator takes a braided skeleton to enable radial folding, whereas membrane is used to seal the skeleton so as to adjust stiffness through creating negative pressure. We demonstrated experimentally, numerically, and analytically that, a flexible and a rigid state were obtained, and the ratio of bending stiffness in the rigid state to that in the flexible state reached 6.85. In addition, the manipulator achieved a radial folding ratio of 1.95. The proposed manipulator shows great potential in the design of surgical robots for MIS. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B, 2019.

A novel variable-stiffness flexible manipulator actuated by shape memory alloy for minimally invasive surgery

This article presents a novel variable-stiffness flexible manipulator for minimally invasive surgery. Each module of the proposed manipulator contains a variable-stiffness mechanism actuated by proactive deformation of shape memory alloy. Due to low driving current, apparent mechanical deformation, suitable phase transformation temperature and biocompatibility of shape memory alloy wire actuation, it is well suited for the manipulator applied in minimally invasive surgery, where variable stiffness is urgently required. In this article, the conceptual design, elastic modulus model, thermo-electric model, stiffness controlling method and finite element method simulation for a single module of the proposed variable-stiffness flexible manipulator are presented. Moreover, the memory shape setting experiment of shape memory alloy wire and fabrication of the single module are carried out. Finally, stiffness characterizations of the mechanism and the single module are studied separately, theoretically and experimentally.

Flexible robotic endoscopy: current and original devices

Two current major research topics concern the incorporation of flexible robotic endoscopy systems developed for natural-orifice translumenal endoscopic surgery (NOTES), primarily for the purpose of remote forceps operation, into endoscopic submucosal dissection (ESD) and other flexible endoscopic treatments and the use of robots for the manipulation of flexible endoscopes themselves with the aim of enabling the remote insertion of colonoscopes, etc. However, there are still many challenges that remain to be addressed; the ideal robotic endoscope has not yet been realized. This article reviews the ongoing developments and our own efforts in the area of flexible robotic endoscopy.

Theoretical investigation of transgastric and intraductal approaches for ultrasound-based thermal therapy of the pancreas

Background

The goal of this study was to theoretically investigate the feasibility of intraductal and transgastric approaches to ultrasound-based thermal therapy of pancreatic tumors, and to evaluate possible treatment strategies.

Methods

This study considered ultrasound applicators with 1.2 mm outer diameter tubular transducers, which are inserted into the tissue to be treated by an endoscopic approach, either via insertion through the gastric wall (transgastric) or within the pancreatic duct lumen (intraductal). 8 patient-specific, 3D, transient, biothermal and acoustic finite element models were generated to model hyperthermia (n = 2) and ablation (n = 6), using sectored (210°–270°, n = 4) and 360° (n = 4) transducers for treatment of 3.3–17.0 cm³ tumors in the head (n = 5), body (n = 2), and tail (n = 1) of the pancreas. A parametric study was performed to determine appropriate treatment parameters as a function of tissue attenuation, blood perfusion rates, and distance to sensitive anatomy.

Results

Parametric studies indicated that pancreatic tumors up to 2.5 or 2.7 cm diameter can be ablated within 10 min with the transgastric and intraductal approaches, respectively. Patient-specific simulations demonstrated that 67.1–83.3% of the volumes of four sample 3.3–11.4 cm³ tumors could be ablated within 3–10 min using transgastric or intraductal approaches. 55.3–60.0% of the volume of a large 17.0 cm³ tumor could be ablated using multiple applicator positions within 20–30 min with either transgastric or intraductal approaches. 89.9–94.7% of the volume of two 4.4–11.4 cm³ tumors could be treated with intraductal hyperthermia. Sectored applicators are effective in directing acoustic output away from and preserving sensitive structures. When acoustic energy is directed towards sensitive structures, applicators should be placed at least 13.9–14.8 mm from major vessels like the aorta, 9.4–12.0 mm from other vessels, depending on the vessel size and flow rate, and 14 mm from the duodenum.

Conclusions

This study demonstrated the feasibility of generating shaped or conformal ablative or hyperthermic temperature distributions within pancreatic tumors using transgastric or intraductal ultrasound.

Natural orifice transluminal endoscopic surgery with a snake-mechanism using a movable pulley

BACKGROUND

Natural orifice transluminal endoscopic surgery is an emerging technique. We aimed to develop an advanced surgical robot mechanism for natural orifice surgery.

METHODS

We propose the active-controlled overtube-type platform with multiple channels for an endoscopic camera and surgical tools. To make such a platform, we suggest an advanced snake mechanism comprising movable pulleys to make a snake mechanism with multiple degrees of freedom and high operating force.

RESULTS

The stiffness and maneuverability of the active-controlled platform appeared satisfactory. Using prototypes and ex vivo experiments, we confirmed that the mechanism was suitable for a snake-like robotic platform for natural orifice surgery.

CONCLUSIONS

The suggested snake mechanism using movable pulleys has the advantages of stiffness and maneuverability. This new mechanism can be an alternative platform for natural orifice surgery.

Minimally Invasive Surgery for the Treatment of Colorectal Cancer

BACKGROUND

Reduction in operative trauma along with an improvement in endoscopic access has undoubtedly occupied surgical minds for at least the past 3 decades. It is not at all surprising that minimally invasive colon surgery has come a long way since the first laparoscopic appendectomy by Semm in 1981. It is common knowledge that the recent developments in video and robotic technologies have significantly furthered advancements in laparoscopic and minimally invasive surgery. This has led to the overall acceptance of the treatment of benign colorectal pathology via the endoscopic route. Malignant disease, however, is still primarily treated by conventional approaches.

METHODS AND RESULTS

This review article is based on a literature search pertaining to advances in minimally invasive colorectal surgery for the treatment of malignant pathology, as well as on personal experience in the field over the same period of time. Our search was limited to level I and II clinical papers only, according to the evidence-based medicine guidelines. We attempted to present our unbiased view on the subject relying only on the evidence available.

CONCLUSION

Focusing on advances in colorectal minimally invasive surgery, it has to be stated that there are still a number of unanswered questions regarding the surgical management of malignant diseases with this approach. These questions do not only relate to the area of boundaries set for the use of minimally invasive techniques in this field but also to the exact modality best suited to the treatment of every particular case whilst maintaining state-of-the-art oncological principles.

Kinematic Design of a Novel Spatial Remote Center-of-Motion Mechanism for Minimally Invasive Surgical Robot

To deliver more value to the healthcare industry, a specialized surgical robot is needed in the minimally invasive surgery (MIS) field. To fill this need, a compact hybrid robotic wrist with four degrees of freedom (DOFs) is developed for assisting physicians to perform MIS. The main body of the wrist is a 2DOF parallel mechanism with a remote center-of-motion (RCM), which is located outside the mechanism. From the mechanical point of view, it is different from existing 2DOF spherical mechanisms, since there is no physical constraint on the RCM. Other DOFs of the wrist are realized by a revolute joint and a prismatic joint, which are serially mounted on the movable platform of the parallel mechanism. The function of these DOFs is to realize the roll motion and the in-out translation of the surgical tool. Special attention is paid to the parallel RCM mechanism. The detailed design is provided and the kinematic equations are obtained in the paper. Further, the Jacobian matrix is derived based on the kinematic equations. Finally, the paper examines the singularity configurations and implements the condition number analysis to identify the kinematic performance of the mechanism.

A micro-optical system for endoscopy based on mechanical compensation paradigm using miniature piezo-actuation

The goal of the study was to investigate the feasibility of a novel miniaturized optical system for endoscopy. Fostering the mechanical compensation paradigm, the modeled optical system, composed by 14 lenses, separated in 4 different sets, had a total length of 15.55mm, an effective focal length ranging from 1.5 to 4.5mm with a zoom factor of about 2.8×, and an angular field of view up to 56°. Predicted maximum lens travel was less than 3.5mm. The consistency of the image plane height across the magnification range testified the zoom capability. The maximum predicted achromatic astigmatism, transverse spherical aberration, longitudinal spherical aberration and relative distortion were less than or equal to 25μm, 15μm, 35μm and 12%, respectively. Tests on tolerances showed that the manufacturing and opto-mechanics mounting are critical as little deviations from design dramatically decrease the optical performances. However, recent micro-fabrication technology can guarantee tolerances close to nominal design. A closed-loop actuation unit, devoted to move the zoom and the focus lens sets, was implemented adopting miniaturized squiggle piezo-motors and magnetic position encoders based on Hall effect. Performance results, using a prototypical test board, showed a positioning accuracy of less than 5μm along a lens travel path of 4.0mm, which was in agreement with the lens set motion features predicted by the analysis. In conclusion, this study demonstrated the feasibility of the optical design and the viability of the actuation approach while tolerances must be carefully taken into account.

From passive tool holders to microsurgeons: safer, smaller, smarter surgical robots

Within only a few decades from its initial introduction, the field of surgical robotics has evolved into a dynamic and rapidly growing research area with increasing clinical uptake worldwide. Initially introduced for stereotaxic neurosurgery, surgical robots are now involved in an increasing number of procedures, demonstrating their practical clinical potential while propelling further advances in surgical innovations. Emerging platforms are also able to perform complex interventions through only a single-entry incision, and navigate through natural anatomical pathways in a tethered or wireless fashion. New devices facilitate superhuman dexterity and enable the performance of surgical steps that are otherwise impossible. They also allow seamless integration of microimaging techniques at the cellular level, significantly expanding the capabilities of surgeons. This paper provides an overview of the significant achievements in surgical robotics and identifies the current trends and future research directions of the field in making surgical robots safer, smaller, and smarter.

Natural orifice transluminal endoscopic surgery for intra-abdominal emergency conditions

BACKGROUND

Patient benefits from natural orifice transluminal endoscopic surgery (NOTES) are of interest in acute-care surgery. This review provides an overview of the historical development of NOTES procedures, and addresses their current uses and limitations for intra-abdominal emergency conditions.

METHODS

A PubMed search was carried out for articles describing NOTES approaches for appendicectomy, percutaneous gastrostomy, hollow viscus perforation and pancreatic necrosectomy. Pertinent articles were reviewed and data on available outcomes synthesized.

RESULTS

Emergency conditions in surgery tax the patient's cardiovascular and respiratory systems, and fluid and electrolyte balance. The operative intervention itself leads to an inflammatory response and blood loss, thus adding to the physiological stress. NOTES provides a minimally invasive alternative access to the peritoneal cavity, avoiding abdominal wall incisions. A clear advantage to the patient is evident with the implementation of an endoscopic approach to deal with inadvertently displaced percutaneous endoscopic gastrostomy tubes and perforated gastroduodenal ulcer. The NOTES approach appears less invasive for patients with infected pancreatic necrosis, in whom it allows surgical debridement and avoidance of open necrosectomy. Transvaginal appendicectomy is the second most frequently performed NOTES procedure after cholecystectomy. The NOTES concept has provided a change in perspective for intramural and transmural endoscopic approaches to iatrogenic perforations during endoscopy.

CONCLUSION

NOTES approaches have been implemented in clinical practice over the past decade. Selected techniques offer reduced invasiveness for patients with intra-abdominal emergencies, and may improve outcomes. Steady future development and adoption of NOTES are likely to follow as technology improves and surgeons become comfortable with the approaches.

Articulated Manipulator With Multiple Instruments for Natural Orifice Transluminal Endoscopic Surgery

This paper presents an articulated manipulator with multiple instruments for natural orifice endoscopic transluminal endoscopic surgery (NOTES). This robotic system is made up of four major components, namely a multifunctional manipulator, a robot-connecting arm, an articulated drive mechanism, and a surgeon control console. The manipulator, capable of changing instruments in situ at the surgical site, was developed to reduce infection risk, improve surgical workflow, and encourage solo surgery by providing surgeons with all the required instruments. The robot-connecting arm serves as an experimental platform for future bimanual robot configurations. To facilitate stable positioning and optimal orientation of the robot, the articulated drive mechanism was also created. The surgeon control console provides a user-friendly platform to receive system input from surgeons. Benchtop testing showed adequate articulation and tool-tip forces for accomplishment of typical tasks in abdominal surgery. This system leverages the benefits both of cable-wire actuation systems and of direct motor embedding on different components to achieve better tool triangulation, higher instrument grasping force, and improved positioning at the surgical site.

Mechatronic design of a fully integrated camera for mini-invasive surgery

This paper describes the design features of an innovative fully integrated camera candidate for mini-invasive abdominal surgery with single port or transluminal access. The apparatus includes a CMOS imaging sensor, a light-emitting diode (LED)-based unit for scene illumination, a photodiode for luminance detection, an optical system designed according to the mechanical compensation paradigm, an actuation unit for enabling autofocus and optical zoom, and a control logics based on microcontroller. The bulk of the apparatus is characterized by a tubular shape with a diameter of 10 mm and a length of 35 mm. The optical system, composed of four lens groups, of which two are mobile, has a total length of 13.46 mm and an effective focal length ranging from 1.61 to 4.44 mm with a zoom factor of 2.75×, with a corresponding angular field of view ranging from 16° to 40°. The mechatronics unit, devoted to move the zoom and the focus lens groups, is implemented adopting miniature piezoelectric motors. The control logics implements a closed-loop mechanism, between the LEDs and photodiode, to attain automatic control light. Bottlenecks of the design and some potential issues of the realization are discussed. A potential clinical scenario is introduced.

A modular magnetic platform for Natural Orifice Transluminal Endoscopic Surgery

Modern surgery is currently developing NOTES (Natural Orifice Translumenal Endoscopic Surgery) robotic approaches to enable scarless surgical procedures. Despite of the variegated devices proposed, they still have several limitations. In this work, we propose a surgical platform composed of specialized modules, in order to provide the overall system with adequate stability, dexterity and force generation. The concept behind the platform, the main modules and their performance are described to highlight the system potential to outperform current NOTES procedures.

Emerging robotic platforms for minimally invasive surgery

Recent technological advances in surgery have resulted in the development of a range of new techniques that have reduced patient trauma, shortened hospitalization, and improved diagnostic accuracy and therapeutic outcome. Despite the many appreciated benefits of minimally invasive surgery (MIS) compared to traditional approaches, there are still significant drawbacks associated with conventional MIS including poor instrument control and ergonomics caused by rigid instrumentation and its associated fulcrum effect. The use of robot assistance has helped to realize the full potential of MIS with improved consistency, safety and accuracy. The development of articulated, precision tools to enhance the surgeon's dexterity has evolved in parallel with advances in imaging and human-robot interaction. This has improved hand-eye coordination and manual precision down to micron scales, with the capability of navigating through complex anatomical pathways. In this review paper, clinical requirements and technical challenges related to the design of robotic platforms for flexible access surgery are discussed. Allied technical approaches and engineering challenges related to instrument design, intraoperative guidance, and intelligent human-robot interaction are reviewed. We also highlight emerging designs and research opportunities in the field by assessing the current limitations and open technical challenges for the wider clinical uptake of robotic platforms in MIS.

Design of a Multitasking Robotic Platform with Flexible Arms and Articulated Head for Minimally Invasive Surgery

This paper describes a multitasking robotic platform for Minimally Invasive Surgery (MIS). The device is designed to be introduced through a standard trocar port. Once the device is inserted to the desired surgical site, it can be reconfigured by lifting an articulated section, and protruding two tendon driven flexible arms. Each of the arms holds an interchangeable surgical instrument. The articulated section features a 2 Degrees-of-Freedom (DoF) universal joint followed by a single DoF yaw joint. It incorporates an on-board camera and LED light source at the distal end, leaving a Ø3mm channel for an additional instrument. The main shaft of the robot is largely hollow, leaving ample space for the insertion of two tendon driven flexible arms integrated with surgical instruments. The ex-vivo and in-vivo experiments demonstrate the potential clinical value of the device for performing surgical tasks through single incision or natural orifice transluminal procedures.

Robotics in endoscopy

PURPOSE OF REVIEW

The increasing complexity of intralumenal and emerging translumenal endoscopic procedures has created an opportunity to apply robotics in endoscopy. Computer-assisted or direct-drive robotic technology allows the triangulation of flexible tools through telemanipulation. The creation of new flexible operative platforms, along with other emerging technology such as nanobots and steerable capsules, can be transformational for endoscopic procedures. In this review, we cover some background information on the use of robotics in surgery and endoscopy, and review the emerging literature on platforms, capsules, and mini-robotic units.

RECENT FINDINGS

The development of techniques in advanced intralumenal endoscopy (endoscopic mucosal resection and endoscopic submucosal dissection) and translumenal endoscopic procedures (NOTES) has generated a number of novel platforms, flexible tools, and devices that can apply robotic principles to endoscopy. The development of a fully flexible endoscopic surgical toolkit will enable increasingly advanced procedures to be performed through natural orifices.

SUMMARY

The application of platforms and new flexible tools to the areas of advanced endoscopy and NOTES heralds the opportunity to employ useful robotic technology. Following the examples of the utility of robotics from the field of laparoscopic surgery, we can anticipate the emerging role of robotic technology in endoscopy.

Light Sources for Single-Access Surgery

Background. Minimally invasive surgical techniques such as single access and natural orifice translumenal endoscopic surgery (NOTES) aim to reduce the number of external scars on the patient but impose restrictions on the space available for the light source within the endoscope and, therefore, the size of the field of view that can be sufficiently illuminated. Materials and Methods. This article presents and compares a number of illumination methods (xenon, light-emitting diodes, laser/phosphor, supercontinuum laser) that could be applied in single-access, robotic, and NOTES procedures. The luminance, spectral content, and intensity profile of each source was measured. Standardized images of each illuminating an abdominal simulator were assessed by a group of surgeons to provide an initial clinical impression. Results. The xenon source was found to have the highest luminance when used with a standard laparoscopic light cable, but this was significantly reduced when used with a small cable suitable for single-access applications. The supercontinuum laser–based light source had brightness comparable to the xenon, which was supported by the surgical test group observations. Conclusions. The supercontinuum fiber probe is a potential alternative to xenon light sources for use in single-access surgery with its comparable luminance, small diameter, flexibility, and even illumination. An initial in vivo test is described, providing a guide for future development.

NOTES-Natural orifice transluminal endoscopic surgery: Why not?

Since natural orifice transluminal endoscopic surgery (NOTES) was first described by Anthony Kalloo, it has attracted tremendous interest from surgeons and gastroenterologist all around the world. This special issue of the World Journal of Gastrointestinal Surgery explores the current possibilities and future potential of the most disruptive revolution in the field of surgery represented by the NOTES approach. In the future, new technologies developed for this approach and deeper insight into several gastrointestinal diseases will lead to the design of completely new interventional procedures and change the way we will operate, bringing us to the previously unimaginable goal of “no scar surgery”.