The aer-o-scope: proof of concept of a pneumatic, skill-independent, self-propelling, self-navigating colonoscope

Painless colonoscopy: fact or fiction?

Although colonoscopy is a routinely performed procedure, it is not devoid of challenges, such as the potential for perforation and considerable patient discomfort, leading to patients postponing the procedure with several healthcare risks. This review delves into preprocedural and procedural solutions, and emerging technologies aimed at addressing the drawbacks of colonoscopies. Insufflation and sedation techniques, together with various other methods, have been explored to increase patient satisfaction, and thereby, the quality of endoscopy. Recent advances in this field include the prevention of loop formation, encompassing the use of variable-stiffness endoscopes, computer-guided scopes, magnetic endoscopic imaging, robotics, and capsule endoscopy. An autonomous endoscope that relies on self-propulsion to completely avoid looping is a potentially groundbreaking technology for the next generation of endoscopes. Nevertheless, critical techniques need to be refined to ensure the development of effective and efficient endoscopes.

Robotic Colonoscopy and Beyond: Insights into Modern Lower Gastrointestinal Endoscopy

Lower gastrointestinal endoscopy is considered the gold standard for the diagnosis and removal of colonic polyps. Delays in colonoscopy following a positive fecal immunochemical test increase the likelihood of advanced adenomas and colorectal cancer (CRC) occurrence. However, patients may refuse to undergo conventional colonoscopy (CC) due to fear of possible risks and pain or discomfort. In this regard, patients undergoing CC frequently require sedation to better tolerate the procedure, increasing the risk of deep sedation or other complications related to sedation. Accordingly, the use of CC as a first-line screening strategy for CRC is hampered by patients' reluctance due to its invasiveness and anxiety about possible discomfort. To overcome the limitations of CC and improve patients' compliance, several studies have investigated the use of robotic colonoscopy (RC) both in experimental models and in vivo. Self-propelling robotic colonoscopes have proven to be promising thanks to their peculiar dexterity and adaptability to the shape of the lower gastrointestinal tract, allowing a virtually painless examination of the colon. In some instances, when alternatives to CC and RC are required, barium enema (BE), computed tomographic colonography (CTC), and colon capsule endoscopy (CCE) may be options. However, BE and CTC are limited by the need for subsequent investigations whenever suspicious lesions are found. In this narrative review, we discussed the current clinical applications of RC, CTC, and CCE, as well as the advantages and disadvantages of different endoscopic procedures, with a particular focus on RC.

User interfaces for actuated scope maneuvering in surgical systems: a scoping review

BACKGROUND

A variety of human computer interfaces are used by robotic surgical systems to control and actuate camera scopes during minimally invasive surgery. The purpose of this review is to examine the different user interfaces used in both commercial systems and research prototypes.

METHODS

A comprehensive scoping review of scientific literature was conducted using PubMed and IEEE Xplore databases to identify user interfaces used in commercial products and research prototypes of robotic surgical systems and robotic scope holders. Papers related to actuated scopes with human-computer interfaces were included. Several aspects of user interfaces for scope manipulation in commercial and research systems were reviewed.

RESULTS

Scope assistance was classified into robotic surgical systems (for multiple port, single port, and natural orifice) and robotic scope holders (for rigid, articulated, and flexible endoscopes). Benefits and drawbacks of control by different user interfaces such as foot, hand, voice, head, eye, and tool tracking were outlined. In the review, it was observed that hand control, with its familiarity and intuitiveness, is the most used interface in commercially available systems. Control by foot, head tracking, and tool tracking are increasingly used to address limitations, such as interruptions to surgical workflow, caused by using a hand interface.

CONCLUSION

Integrating a combination of different user interfaces for scope manipulation may provide maximum benefit for the surgeons. However, smooth transition between interfaces might pose a challenge while combining controls.

Design, Analysis and Experimental Validation of a Novel 7-Degrees of Freedom Instrument for Laparoscopic Surgeries

Laparoscopic surgery is widely used for treating intra-abdominal conditions involving the gallbladder, pancreas, liver, intestines and reproductive organs. Conventional laparoscopy instruments used in manual surgeries usually have straight shafts and four degrees of freedom (DOF) plus grasping. However, these are insufficient for the complete rotation of the instrument tip. This makes it challenging to access difficult-to-reach organs inside the abdomen during the surgeries. A few robotic instruments available in the market have higher maneuverability but are expensive. Instruments incorporating cable-based mechanisms require replacement after a few sterilization cycles. This paper describes a novel, reusable and affordable multi-DOF laparoscopy instrument that provides two additional DOF: (a) wrist articulation about one axis (wristed yaw) and (b) rotation of the jaw after articulation (jaw roll). The wrist can articulate up to 45° and also roll after articulation. The additional degrees of freedom enable better maneuverability, functionality and reach than conventional laparoscopy instruments. Further, the new instrument employs only rigid links, providing better strength and minimal loss of function after multiple sterilizations. The complete design of the novel instrument, followed by its kinematic analysis and force calculations are explained in this paper, concluding with its manufacture and experimental validation.

Robotic, self-propelled, self-steerable, and disposable colonoscopes: Reality or pipe dream? A state of the art review

Robotic colonoscopes could potentially provide a comfortable, less painful and safer alternative to standard colonoscopy. Recent exciting developments in this field are pushing the boundaries to what is possible in the future. This article provides a comprehensive review of the current work in robotic colonoscopes including self-propelled, steerable and disposable endoscopes that could be alternatives to standard colonoscopy. We discuss the advantages and disadvantages of these systems currently in development and highlight the technical readiness of each system to help the reader understand where and when such systems may be available for routine clinical use and get an idea of where and in which situation they can best be deployed.

Robotic Autonomy for Magnetic Endoscope Biopsy

Magnetically actuated endoscopes are currently transitioning in to clinical use for procedures such as colonoscopy, presenting numerous benefits over their conventional counterparts. Intelligent and easy-to-use control strategies are an essential part of their clinical effectiveness due to the un-intuitive nature of magnetic field interaction. However, work on developing intelligent control for these devices has mainly been focused on general purpose endoscope navigation. In this work, we investigate the use of autonomous robotic control for magnetic colonoscope intervention via biopsy, another major component of clinical viability. We have developed control strategies with varying levels of robotic autonomy, including semi-autonomous routines for identifying and performing targeted biopsy, as well as random quadrant biopsy. We present and compare the performance of these approaches to magnetic endoscope biopsy against the use of a standard flexible endoscope on bench-top using a colonoscopy training simulator and silicone colon model. The semi-autonomous routines for targeted and random quadrant biopsy were shown to reduce user workload with comparable times to using a standard flexible endoscope.

Application of robotic technologies in lower gastrointestinal tract endoscopy: A systematic review

BACKGROUND

Conventional optical colonoscopy is considered the gold standard investigation for colorectal tract pathology including colorectal malignancy, polyps and inflammatory bowel disease. Inherent limitations exist with current generation endoscopic technologies, including, but not limited to, patient discomfort, endoscopist fatigue, narrow field of view and missed pathology behind colonic folds. Rapid developments in medical robotics have led to the emergence of a variety of next-generation robotically-augmented technologies that could overcome these limitations.

AIM

To provide a comprehensive summary of recent developments in the application of robotics in lower gastrointestinal tract endoscopy.

METHODS

A systematic review of the literature was performed from January 1, 2000 to the January 7, 2021 using EMBASE, MEDLINE and Cochrane databases. Studies reporting data on the use of robotic technology in ex vivo or in vivo animal and human experiments were included. In vitro studies (studies using synthetic colon models), studies evaluating non-robotic technology, robotic technology aimed at the upper gastrointestinal tract or paediatric endoscopy were excluded. System ergonomics, safety, visualisation, and diagnostic/therapeutic capabilities were assessed.

RESULTS

Initial literature searching identified 814 potentially eligible studies, from which 37 were deemed suitable for inclusion. Included studies were classified according to the actuation modality of the robotic device(s) as electromechanical (EM) (n = 13), pneumatic (n = 11), hydraulic (n = 1), magnetic (n = 10) and hybrid (n = 2) mechanisms. Five devices have been approved by the Food and Drug Administration, however most of the technologies reviewed remain in the early phases of testing and development. Level 1 evidence is lacking at present, but early reports suggest that these technologies may be associated with improved pain and safety. The reviewed devices appear to be ergonomically capable and efficient though to date no reports have convincingly shown diagnostic or therapeutic superiority over conventional colonoscopy.

CONCLUSION

Significant progress in robotic colonoscopy has been made over the last couple of decades. Improvements in design together with the integration of semi-autonomous and autonomous systems over the next decade will potentially result in robotic colonoscopy becoming more commonplace.

Endorobots for Colonoscopy: Design Challenges and Available Technologies

Colorectal cancer (CRC) is the second most common cause of cancer death worldwide, after lung cancer (Sung et al., 2021). Early stage detection is key to increase the survival rate. Colonoscopy remains to be the gold standard procedure due to its dual capability to optically inspect the entire colonic mucosa and to perform interventional procedures at the same time. However, this causes pain and discomfort, whereby it requires sedation or anaesthesia of the patient. It is a difficult procedure to perform that can cause damage to the colonic wall in some cases. Development of new technologies aims to overcome the current limitations on colonoscopy by using advancements in endorobotics research. The design of these advanced medical devices is challenging because of the limited space of the lumen, the contorted shape, and the long tract of the large bowel. The force applied to the colonic wall needs to be controlled to avoid collateral effects such as injuries to the colonic mucosa and pain during the procedure. This article discusses the current challenges in the colonoscopy procedure, the available locomotion technologies for endorobots used in colonoscopy at a prototype level and the commercial products available.

Analytical Modeling of the Interaction Between Soft Balloon-Like Actuators and Soft Tubular Environment for Gastrointestinal Inspection

Accessing tubular environment is critical in medicine. For example, gastrointestinal tract related cancers are the leading causes of cancer deaths globally. To diagnose and treat these cancers, clinicians need accessing the gastrointestinal tract, for example, colon and small intestine, which are soft biological tubes. Soft balloon assisted locomotion is one of the promising methods for accessing bio-duct. It has been widely used in enteroscopy and other medical devices. However, the interaction between the balloon and the soft tube is seldom studied, such as the interaction pressure and the anchoring force. In this work, we present the first modeling of the interaction between soft balloon actuators and soft tubular environment. The free inflation model of soft balloon actuators was first presented. Then a constrained inflation model of the soft balloon in a soft tube was established. Finally, the anchoring force model between the soft balloon and the soft tube was developed. On average, the mean error of the predictions in these three models is 0.228 kPa (or 3.14%), 0.56 kPa (or 7.8%), and 0.22 N (or 14.7%), respectively. In the future, these models could be used for guiding balloon-actuator designs by minimizing the interaction pressure while maintaining sufficient anchoring force during the locomotion in soft tubes.

Robotic endoscopy. A review of the literature

Purpose

To present new endoscopic robotic devices in the context of minimally invasive procedures with high precision and automation.

Methods

Review of the literature by December 2018 on robotic endoscopy.

Results

We present the studies and investments for robotic implementation and flexible endoscopy evolution. We divided them into forceps manipulation platforms, active endoscopy and endoscopic capsule. They try to improve forceps handling and stability and to promote active movement.

Conclusion

The implementation and propagation of robotic models depend on doing what the endoscopist is unable to. The new devices are moving forward in this direction.

Navigation strategy for robotic soft endoscope intervention

BACKGROUND

Current soft endoscope intervention mainly depends on the skills of endoscopists, especially for the orientation of the endoscope within the human tortuous lumen. This dependence causes inefficient and time-consuming surgery.

METHODS

A human-robot cooperation navigation strategy is proposed to perform the intervention of soft endoscope. The navigation strategy firstly detects the cavity center by processing the image of endoscope, then an auto-orienting strategy is presented to automatically adjust the endoscope pointing to the detected cavity center.

RESULTS

Human phantom experiments are carried out to validate the effectiveness and feasibility of the navigation strategy. The results show that the cavity center is accurately extracted with whether the cavity is occluded or not and the auto-orienting strategy could well point the endoscope around the cavity center.

CONCLUSION

The proposed human-robot cooperation navigation strategy releases endoscopists from the time-consuming operations and improves the safety and automation of intervention procedures.

Emerging next-generation robotic colonoscopy systems towards painless colonoscopy

Advances in the field of robotics have allowed modern technology to be integrated into medicine and that can minimize patients suffering from the side effects that are inherent to procedures for improving their quality of life. Conventional devices that are used for colonoscopies are rigid and require a high level of expertise from endoscopists to perform the procedure. Advances in robot-assisted colonoscopic systems now produce softer, more slender, automated designs that no longer require the operator to use forceful pushing to advance the colonoscope inside the colon, reducing risks to the patient of perforation and pain. It is challenging to reprocess these scopes for reuse as the materials used can be damaged during decontamination, leading to the possible risks of cross-infection by pathogenic microorganisms when reused by patients. An ideal solution is to eliminate these contamination risks to patients by adopting sterile, single-use scopes straight from the manufacturer's package to the patient. With this idea in mind, emerging developments that push the boundaries in this area will benefit patients and encourage the public to participate in and adhere better to colonoscopy screening to reduce the development of colorectal cancer. Thus, in light of these concerns and challenges, to encourage patients undergoing colorectal screening to comply with colonoscopy procedures that they are less invasive, changes in the design and materials are necessary. One of the more promising technological advances in this area is the advent of robotic colonoscopy.

Soft Robotics in Medical Applications

Soft robotics are robotic systems made of materials that are similar in softness to human soft tissues. Recent medical soft robot designs, including rehabilitation, surgical, and diagnostic soft robots, are categorized by application and reviewed for functionality. Each design is analyzed for engineering characteristics and clinical significance. Current technical challenges in soft robotics fabrication, sensor integration, and control are discussed. Future directions including portable and robust actuation power sources, clinical adoptability, and clinical regulatory issues are summarized.

Occupation-associated health hazards for the gastroenterologist/endoscopist

Advances in the field of endoscopy have allowed gastroenterologists to obtain detailed imaging of anatomical structures and to treat gastrointestinal diseases with endoscopic therapies. However, these technological developments have exposed endoscopists and staff to hazards such as musculoskeletal injuries, exposure to infectious agents, and ionizing radiation. We aimed to review the occupational hazards for the gastroenterologist and endoscopist. Using PubMed, Medline, Medscape, and Google Scholar, we identified peer-reviewed articles with the keywords “occupational hazards,” “health hazards,” “occupational health hazards,” “endoscopy,” “gastroenterologist,” “infectious agents,” “musculoskeletal injuries,” and “radiation.” Strategies for reducing exposure to infectious agents, radiation, and the risk of musculoskeletal injuries related to gastroenterology include compliance with established standard measures, the use of thyroid shields and radioprotective eyewear, and ergonomic practices. We conclude that educating endoscopic personnel and trainees in these practices, in addition to further research in these areas, will likely lead to the development of more efficient and user-friendly workspaces that are safer for patients and personnel.

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.

Can technology increase adenoma detection rate?

Colorectal cancer is the third most common cancer worldwide and the second most common cause of cancer-related death in Europe and North America. Colonoscopy is the gold standard investigation for the colon but is not perfect, and small or flat adenomas can be missed which increases the risk of patients subsequently developing colorectal cancer. Adenoma detection rate is the most widely used marker of quality, and low rates are associated with increased rates of post-colonoscopy colorectal cancer. Standards of colonoscopy and adenoma detection vary widely between different endoscopists. Interventions to improve adenoma detection rate are therefore required. Many devices have been purported to increase adenoma detection rate. This review looks at current available evidence for device technology to improve adenoma detection rate during colonoscopy.

A hydraulically driven colonoscope

BACKGROUND

Conventional colonoscopy requires a high degree of operator skill and is often painful for the patient. We present a preliminary feasibility study of an alternative approach where a self-propelled colonoscope is hydraulically driven through the colon.

METHODS

A hydraulic colonoscope which could be controlled manually or automatically was developed and assessed in a test bed modelled on the anatomy of the human colon. A conventional colonoscope was used by an experienced colonoscopist in the same test bed for comparison. Pressures and forces on the colon were measured during the test.

RESULTS

The hydraulic colonoscope was able to successfully advance through the test bed in a comparable time to the conventional colonoscope. The hydraulic colonoscope reduces measured loads on artificial mesenteries, but increases intraluminal pressure compared to the colonoscope. Both manual and automatically controlled modes were able to successfully advance the hydraulic colonoscope through the colon. However, the automatic controller mode required lower pressures than manual control, but took longer to reach the caecum.

CONCLUSIONS

The hydraulic colonoscope appears to be a viable device for further development as forces and pressures observed during use are comparable to those used in current clinical practice.

A novel self-propelled disposable colonoscope is effective for colonoscopy in humans (with video)

BACKGROUND AND AIMS

The self-propelled disposable colonoscope (SPDC) with a 360° view is designed to enhance visualization, minimize risks of perforation and infection transmission, and shorten operator training time associated with conventional colonoscopy (CC). We evaluated SPDC efficacy for cecal intubation and safety.

METHODS

Prospective patients presenting for colorectal cancer screening underwent SPDC immediately followed by CC. Initial patients necessary for SPDC operators to achieve proficiency comprised the training cohort. Subsequent enrolled patients comprised the study cohort. SPDC colonoscopy was performed up to the cecum, where anatomic landmarks were photographed and mucosal suction marks were placed. During SPDC withdrawal, polyps were recorded and similarly marked. On the second pass (by using CC), any potential mucosal damage and suction marks from the SPDC as well as polyps were recorded. Main endpoints included SPDC cecal intubation rates, confirmed by anatomic landmarks and residual marks seen on subsequent CC, and frequency and severity of adverse events and mucosal damage with SPDC. The secondary endpoint was subjective procedure proficiency, evaluated by the operator based on the training cohort. The tertiary endpoint was documenting pathologies visualized with SPDC.

RESULTS

Fifty-six of 58 enrolled subjects completed the study. Proficiency with SPDC was attained after 8 to 10 procedures. Cecal intubation was successful in 98.2% (55/56 subjects; 95% confidence interval [CI], 90.4%-99.9%), including 100% (95% CI, 90.7%-100%) of the study cohort and 94.4% (95% CI, 72.7%-99.9%) of the training cohort. No mucosal damage or adverse events were reported. SPDC detected 87.5% of polyps seen in tandem CC, including all polyps larger than 5 mm.

CONCLUSIONS

SPDC was highly successful, simple to use, and safe in achieving complete colonoscopy (cecal intubation). (

CLINICAL TRIAL REGISTRATION NUMBER

0692-12-TLV.).

Quantitative assessment of colorectal morphology: Implications for robotic colonoscopy

This paper presents a method of characterizing the distribution of colorectal morphometrics. It uses three-dimensional region growing and topological thinning algorithms to determine and visualize the luminal volume and centreline of the colon, respectively. Total and segmental lengths, diameters, volumes, and tortuosity angles were then quantified. The effects of body orientations on these parameters were also examined. Variations in total length were predominately due to differences in the transverse colon and sigmoid segments, and did not significantly differ between body orientations. The diameter of the proximal colon was significantly larger than the distal colon, with the largest value at the ascending and cecum segments. The volume of the transverse colon was significantly the largest, while those of the descending colon and rectum were the smallest. The prone position showed a higher frequency of high angles and consequently found to be more torturous than the supine position. This study yielded a method for complete segmental measurements of healthy colorectal anatomy and its tortuosity. The transverse and sigmoid colons were the major determinant in tortuosity and morphometrics between body orientations. Quantitative understanding of these parameters may potentially help to facilitate colonoscopy techniques, accuracy of polyp spatial distribution detection, and design of novel endoscopic devices.

Current state of micro-robots/devices as substitutes for screening colonoscopy: assessment based on technology readiness levels

BACKGROUND

Previous reports have described several candidates, which have the potential to replace colonoscopy, but to date, there is still no device capable of fully replacing flexible colonoscopy in the management of colonic disorders and for mass adult population screening for asymptomatic colorectal cancer.

MATERIALS AND METHODS

NASA developed the TRL methodology to describe and define the stages of development before use and marketing of any device. The definitions of the TRLS used in the present review are those formulated by "The US Department of Defense Technology Readiness Assessment Guidance" but adapted to micro-robots for colonoscopy. All the devices included are reported in scientific literature. They were identified by a systematic search in Web of Science, PubMed and IEEE Xplore amongst other sources. Devices that clearly lack the potential for full replacement of flexible colonoscopy were excluded.

ASSESSMENT OF THE CURRENT SITUATION

The technological salient features of all the devices included for assessment are described briefly, with particular focus on device propulsion. The devices are classified according to the TRL criteria based on the reported information. An analysis is next undertaken of the characteristics and salient features of the devices included in the review: wireless/tethered devices, data storage-transmission and navigation, additional functionality, residual technology challenges and clinical and socio-economical needs.

CONCLUSIONS

Few devices currently possess the required functionality and performance to replace the conventional colonoscopy. The requirements, including functionalities which favour the development of a micro-robot platform to replace colonoscopy, are highlighted.

Feasibility of joystick guided colonoscopy

The flexible endoscope is increasingly used to perform minimal invasive interventions. A novel add-on platform allows single-person control of both endoscope and instrument at the site of intervention. The setup changes the current routine of handling the endoscope. This study aims to determine if the platform allows effective and efficient manipulation to position the endoscope at potential intervention sites throughout the bowel. Five experts in flexible endoscopy first performed three colonoscopies on a computer simulator using the conventional angulation wheels. Next they trained with the joystick interface to achieve their personal level of intubation time with low pain score. 14 PhD students (novices) without hands-on experience performed the same colonoscopy case using either the conventional angulation wheels or joystick interface. Both novice groups trained to gain the average expert level. The cecal intubation time, pain score and visualization performance (% of bowel wall) were recorded. All experts reached their personal intubation time in 6 ± 6 sessions. Three experts completed their learning curve with low pain score in 8 ± 6 sessions. The novices required 11 ± 6 sessions using conventional angulation wheels, and 12 ± 6 sessions using the joystick interface. There was no difference in the visualization performance between the novice and between the expert groups. This study shows that the add-on platform enables endoscope manipulation required to perform colonoscopy. Experts need only a relatively short training period. Novices are as effective and as efficient in endoscope manipulation when comparing the add-on platform with conventional endoscope control.

The endoscopy evolution: 'the superscope era'

Developments to the design of the flexible endoscope are transforming the field of gastroenterology. There is a drive to improve colonic adenoma detection rates leading to advancements in the design of the colonoscope. Novel endoscopes now allow increased visualisation of colonic mucosa, including behind colonic folds, and aim to reduce pain associated with the procedure. In addition, a shift in surgical paradigm towards minimally invasive endoluminal surgery has meant innovations in flexible platforms are being sought. There are a number of limitations of the basic endoscope. These include a lack of stability and triangulation of instruments. Modifications to the flexible endoscope design form the basis of a number of newly developed and research platforms, some of which are discussed in this review.

Soft material adhesion characterization for in vivo locomotion of robotic capsule endoscopes: Experimental and modeling results

The objective of this work is to validate an experimental method and nondimensional model for characterizing the normal adhesive response between a polyvinyl chloride based synthetic biological tissue substrate and a flat, cylindrical probe with a smooth polydimethylsiloxane (PDMS) surface. The adhesion response is a critical mobility design parameter of a Robotic Capsule Endoscope (RCE) using PDMS treads to provide mobility to travel through the gastrointestinal tract for diagnostic purposes. Three RCE design characteristics were chosen as input parameters for the normal adhesion testing: pre-load, dwell time and separation rate. These parameters relate to the RCE׳s cross sectional dimension, tread length, and tread speed, respectively. An inscribed central composite design (CCD) prescribed 34 different parameter configurations to be tested. The experimental adhesion response curves were nondimensionalized by the maximum stress and total displacement values for each test configuration and a mean nondimensional curve was defined with a maximum relative error of 5.6%. A mathematical model describing the adhesion behavior as a function of the maximum stress and total displacement was developed and verified. A nonlinear regression analysis was done on the maximum stress and total displacement parameters and equations were defined as a function of the RCE design parameters. The nondimensional adhesion model is able to predict the adhesion curve response of any test configuration with a mean R(2) value of 0.995. Eight additional CCD studies were performed to obtain a qualitative understanding of the impact of tread contact area and synthetic material substrate stiffness on the adhesion response. These results suggest that the nondimensionalization technique for analyzing the adhesion data is sufficient for all values of probe radius and substrate stiffness within the bounds tested. This method can now be used for RCE tread design optimization given a set of environmental conditions for device operation.

Review of musculoskeletal injuries and prevention in the endoscopy practitioner

Practitioners of endoscopy often experience musculoskeletal pain and injury (most often in the back, neck, shoulders, hands, wrists, and thumbs) that are associated with the minute and repetitive strain that is placed on these areas during endoscopic procedures. This review of the current documentation of endoscopy-related pain and injuries among practitioners finds that such problems are widespread and specific in kind as well as strongly correlated with high procedure volume and procedure duration. Research on the nature and impact of cumulative trauma and overuse syndromes in other professions such as dentistry, pianists, production labor, and athletics is brought to bear on the work of the endoscopist. A more thorough understanding of the nature and prevalence of work-related pain and injury sustained by endoscopists should inform further development of ergonomic practices and equipment design. This article reviews current recommendations for ergonomic design in the endoscopy procedure space and finds that reported compliance with those recommendations is quite low. Strategies for the management of the risk of musculoskeletal injuries related to the practice of endoscopy include compliance with currently recommended ergonomic practices, education of trainees in ergonomic technique when practicing endoscopy, and research toward the modification and development of more ergonomic endoscopes and procedure spaces.

Robotics in Colonoscopy

Colorectal cancer is the second leading cause of mortality in men and women in the United States. While there is a definite advantage regarding the use of colonoscopies in screening, there is still a lack of widespread acceptance of colonoscopy use in the general public. This is evident by the fact that up to 75% of patients diagnosed with colorectal cancer present with locally advanced disease. In order to make colonoscopy and in turn colorectal cancer screening a patient friendly and a comfortable test some changes in tool are necessary. The conventional colonoscope has not changed much since its development. There are several new advances in colorectal screening practices. One of the most promising new advances is the advent of robotic endoscopic techniques.

Colonoscopy with magnetic control system to navigate the forepart of colonoscope shortens the cecal intubation time

BACKGROUND

Colonoscopy is considered the most effective method for diagnosing colorectal diseases, but its application is sometimes limited due to invasiveness, patient intolerance, and the need for sedation.

OBJECTIVE

The aim of this study was to improve the problem of loop formation and shorten the cecal intubation time of colonoscopy by using a magnetic control system (MCS).

METHODS

Two experienced gastroenterologists, three trainees, and a novice repeated colonoscopy without or with MCS on three colonoscopy training model simulator cases. These cases were divided into introductory (case 2) and challenging levels (cases 4 and 5). The cecal intubation times were recorded.

RESULTS

For all cases, the average cecal intubation times for the experienced gastroenterologists with MCS were significantly shorter than without MCS (case 2: 52.45 vs. 27.65 s, p < 0.001; case 4: 166.7 vs. 120.55 s, p < 0.01; case 5: 130.35 vs. 100.2 s, p < 0.05). Those of the trainees also revealed significantly shorter times with MCS (case 2: 67.27 vs. 51 s, p < 0.01; case 4: 253.27 vs. 170.97 s, p < 0.001; case 5: 144.1 vs. 85.57 s, p < 0.001).

CONCLUSION

Conducting colonoscopy with MCS is safe and smooth, and shortens the cecal intubation time by navigating the forepart of the colonoscope. In addition, all diagnostic and therapeutic benefits of conventional colonoscopy are retained.

Mechanical analysis of insertion problems and pain during colonoscopy: why highly skill-dependent colonoscopy routines are necessary in the first place... and how they may be avoided

BACKGROUND

Colonoscopy requires highly skill-dependent manoeuvres that demand a significant amount of training, and can cause considerable discomfort to patients, which increases the use of sedatives. Understanding the underlying fundamental mechanics behind insertion difficulties and pain during colonoscopy may help to simplify colonoscopy and reduce the required extent of training and reliance on sedatives.

METHODS

A literature search, anatomical studies, models of the colon and colonoscope, and bench tests were used to qualitatively analyze the fundamental mechanical causes of insertion difficulties and pain. A categorized review resulted in an overview of potential alternatives to current colonoscopes.

RESULTS

To advance a colonoscope through the colon, the colon wall, ligaments and peritoneum must be stretched, thus creating tension in the colon wall, which resists further wall deformation. This resistance forces the colonoscope to bend and follow the curves of the colon. The deformations that cause insertion difficulties and pain (necessitating the use of complex conventional manoeuvres) are the stretching of ligaments, and stretching of colon wall in the transverse and longitudinal directions, and the peritoneum.

CONCLUSIONS

Four fundamental mechanical solutions to prevent these deformations were extracted from the analysis. The current results may help in the development of new colonoscopy devices that reduce - or eliminate - the necessity of using highly skill-dependent manoeuvres, facilitate training and reduce the use of sedatives.

New platforms and devices in colonoscopy

Gastrointestinal endoscopy is a rapidly evolving field. Techniques in endoscopy continue to become more sophisticated, as do the devices and platforms, particularly in colonoscopy and endoscopic resection. This article reviews new platforms for endoscopic imaging of the colon, and discusses new endoscopic accessories and developments in endoscopic resection.

Experimental assessment of a novel robotically-driven endoscopic capsule compared to traditional colonoscopy

BACKGROUND

Despite colonoscopy represents the conventional diagnostic tool for colorectal pathology, its undeniable discomfort reduces compliance to screening programmes.

AIMS

To evaluate feasibility and accuracy of a novel robotically-driven magnetic capsule for colonoscopy as compared to the traditional technique.

METHODS

Eleven experts and eleven trainees performed complete colonoscopy by robotic magnetic capsule and by conventional colonoscope in a phantom ex vivo model (artificially clean swine bowel). Feasibility, overall accuracy to detect installed pins, procedure elapsed time and intuitiveness were measured for both techniques in both operator groups.

RESULTS

Complete colonoscopy was feasible in all cases with both techniques. Overall 544/672 pins (80.9%) were detected by experimental capsule procedure, while 591/689 pins (85.8%) were detected within conventional colonoscopy procedure (P=ns), thus establishing non-inferiority. With the experimental capsule procedure, experts detected 74.2% of pins vs. 87.6% detected by trainees (P<0.0001). Overall time to complete colon inspection by robotic capsule was significantly higher than by conventional colonoscopy (556±188s vs. 194±158s, respectively; P=0.0001).

CONCLUSION

With the limitations represented by an ex vivo setting (artificially clean swine bowel and the absence of peristalsis), colonoscopy by this novel robotically-driven capsule resulted feasible and showed adequate accuracy compared to conventional colonoscopy.

Renewed attention for overtube-assisted colonoscopy to prevent incomplete endoscopic examination of the colon

BACKGROUND

Colonoscopy is the standard examination to detect mucosal pathology in the colon. However, failure to complete colonoscopy may reach more than 10% in population-based endoscopy practices. The reasons for incomplete conventional colonoscopy are diverse and result in missed diagnosis of colonic polyps and carcinoma.

OBJECTIVE

Recent endoscopic developments have shown that the use of specialized overtubes may help to reach the cecum in the case of a difficult colonoscopy, even with less discomfort. Several types of overtubes are currently available, whereas other types are being developed and clinically evaluated. The current review highlights the development of overtubes for colonoscopy and the available clinical data on overtube-assisted colonoscopy in the case of incomplete conventional colonoscopy.

DATA SOURCES

Data were derived from a PubMed search through November 2012.

STUDY SELECTION

Available clinical literature data on recent developments in overtube-assisted colonoscopy were studied.

INTERVENTION

A descriptive comparison was made of currently available endoscopy systems used for overtube-assisted colonoscopy.

MAIN OUTCOME MEASURES

The primary outcomes measured were the feasibility and safety of different endoscopy systems to perform overtube-assisted colonoscopy.

RESULTS

Several overtube-assisted colonoscopy systems have recently been developed to complete colonoscopy in the case of difficult conventional colonoscopy. Literature data show excellent feasibility to reach the cecum with very low complication rates and good patient tolerance for the different overtube systems.

LIMITATIONS

The majority of available studies are uncontrolled case series describing 7 to 110 patients undergoing overtube-assisted colonoscopy with only 1 direct comparison between 2 overtube systems.

CONCLUSIONS

Overtube-assisted colonoscopy has been shown to be useful in performing colonoscopy by increasing the cecal intubation rate and patient tolerance and by decreasing the need for sedation. There is no standardized superior overtube system at this moment.

Advanced endoscopic technologies for colorectal cancer screening

Colorectal cancer is the third most common cancer in men and the second most common cancer in women worldwide. Diagnosing colorectal has been increasingly successful due to advances in technology. Flexible endoscopy is considered to be an effective method for early diagnosis and treatment of gastrointestinal cancer, making it a popular choice for screening programs. However, millions of people who may benefit from endoscopic colorectal cancer screening fail to have the procedure performed. Main reasons include psychological barriers due to the indignity of the procedure, fear of procedure related pain, bowel preparation discomfort, and potential need for sedation. Therefore, an urgent need for new technologies addressing these issues clearly exists. In this review, we discuss a set of advanced endoscopic technologies for colorectal cancer screening that are either already available or close to clinical trial. In particular, we focus on visual-inspection-only advanced flexible colonoscopes, interventional colonoscopes with alternative propulsion mechanisms, wireless capsule colonoscopy, and technologies for intraprocedural bowel cleansing. Many of these devices have the potential to reduce exam related patient discomfort, obviate the need for sedation, increase diagnostic yield, reduce learning curves, improve access to screening, and possibly avert the need for a bowel preparation.

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.

Advanced technologies for gastrointestinal endoscopy

The gastrointestinal tract is home to some of the most deadly human diseases. Exacerbating the problem is the difficulty of accessing it for diagnosis or intervention and the concomitant patient discomfort. Flexible endoscopy has established itself as the method of choice and its diagnostic accuracy is high, but there remain technical limitations in modern scopes, and the procedure is poorly tolerated by patients, leading to low rates of compliance with screening guidelines. Although advancement in clinical endoscope design has been slow in recent years, a critical mass of enabling technologies is now paving the way for the next generation of gastrointestinal endoscopes. This review describes current endoscopes and provides an overview of innovative flexible scopes and wireless capsules that can enable painless endoscopy and/or enhanced diagnostic and therapeutic capabilities. We provide a perspective on the potential of these new technologies to address the limitations of current endoscopes in mass cancer screening and other contexts and thus to save many lives.

Overview of upcoming advances in colonoscopy

Although colonoscopy is a very commonly carried out procedure, it is not without its problems, including a risk of perforation and significant patient discomfort, especially associated with looping formation. Furthermore, looping formation may prevent a complete colonoscopy from being carried out in certain patients. The conventional colonoscope has not changed very much since its original introduction. We review promising technologies that are being promoted as a way to address the problems with current colonoscopy. There are some methods to prevent looping formation, including overtube, variable stiffness, computer-guided scopes, Aer-O-Scope, magnetic endoscopic imaging and the capsule endoscope. In recent years, with the progress of microelectromechanical and microelectronic technologies, many biomedical and robotic researchers are developing autonomous endoscopes with miniaturization of size and integration functionality that represent state of the art of the micro-robotic endoscope. The initial results by using aforementioned methods seem promising; however, there are some conflicting reports of clinical trials with the overtube colonoscope, the computer-guided scope and the variable stiffness colonoscope. There are also some limitations in the use of the Aer-o-scope and the capsule endoscope. The autonomous endoscope is based on a self-propelling property that is able to avoid looping completely. This novel technology could potentially become the next generation endoscope; however, there are still critical techniques to be approached in order to develop the effective and efficient novel endoscope.

Evolving techniques in colonoscopy

PURPOSE OF REVIEW

This review summarizes recent clinical studies of colonoscopy technique and new technologies.

RECENT FINDINGS

Water immersion reduces pain and sedation doses in unsedated and lightly sedated colonoscopy. Cap-fitted colonoscopy makes insertion faster and improves detection of lesions behind folds, but the latter effect is operator-dependent. A single controlled trial showed improved detection with the Third Eye Retroscope, but the two arms of the study were not controlled for withdrawal time. Chromoendoscopy increases detection of diminutive adenomas, but adds time to the colonoscopy procedure. Electronic chromoendoscopy methods (narrow band imaging, Fujinon Intelligent ChromoEndoscopy, i-scan, and autofluorescence) have been either unsuccessful in improving detection or require more study. However, these methods and several other methods (chromoendoscopy with magnification, confocal laser microscopy, and endocytoscopy) allow accurate real time determination of polyp histology.

SUMMARY

Water immersion is a clear advance in unsedated colonoscopy. Cap-fitted colonoscopy is a promising method for both practical and effective visualization of the proximal sides of haustral folds. Electronic chromoendoscopy has been largely ineffective at improving polyp detection, but is effective (as are confocal laser microscopy and endocytoscopy) for diagnosis of polyp histology.

High cecal intubation rates with a new computer-assisted colonoscope: a feasibility study

OBJECTIVES

The acceptability of colonoscopy as a screening test is limited by several factors including patient discomfort. A new self-propelled colonoscope, the Invendo SC20 (Invendo Medical GmbH), may be helpful in reducing sedation. It consists of a sheathed endoscope contained within an "inverted sleeve," and having an instrument channel and an electrohydraulic bendable tip; it is steered using a handheld device and propelled by a motorized drive unit. This study assessed the safety and efficacy of this new endoscope in volunteers undergoing colorectal cancer (CRC) screening.

METHODS

Paid healthy volunteers aged 50-70 years and eligible for screening colonoscopy were included. Total colonoscopy using carbon dioxide insufflation or water instillation on demand was attempted, with all procedures being started without sedation. The main outcome parameters were safety and the cecal intubation rate.

RESULTS

A total of 61 volunteers participated (34 men and 27 women; mean age 57.5 years). The cecum was reached in 60 volunteers (cecal intubation rate of 98.4%). The median time to reach the cecum was 15 min (range 7-53.5). Sedation was given in three individuals (4.9%). On withdrawal (median time 15 min), the material for histological evaluation was obtained from 33 polyps (mean size 4.8 mm) in 23 people by biopsy forceps or snare. No device-related complications were encountered.

CONCLUSIONS

A new computer-assisted colonoscope, controlled using a handheld device, showed excellent cecal intubation rates during screening examinations, with sedation required in only ~ 5% of screenees. Further clinical and comparative studies are warranted.

Functional evaluation of the endotics system, a new disposable self-propelled robotic colonoscope: in vitro tests and clinical trial

OBJECTIVE

Currently, the best method for CRC screening is colonoscopy, which ideally (where possible) is performed under partial or deep sedation. This study aims to evaluate the efficacy of the Endotics System, a new robotic device composed of a workstation and a disposable probe, in performing accurate and well-tolerated colonoscopies. This new system could also be considered a precursor of other innovating vectors for atraumatic locomotion through natural orifices such as the bowel. The flexible probe adapts its shape to the complex contours of the colon, thereby exerting low strenuous forces during its movement. These novel characteristics allow for a painless and safe colonoscopy, thus eliminating all major associated risks such as infection, cardiopulmonary complications and colon perforation.

METHODS

An experimental study was devised to investigate stress pattern differences between traditional and robotic colonoscopy, in which 40 enrolled patients underwent both robotic and standard colonoscopy within the same day.

RESULTS

The stress pattern related to robotic colonoscopy was 90% lower than that of standard colonoscopy. Additionally, the robotic colonoscopy demonstrated a higher diagnostic accuracy, since, due to the lower insufflation rate, it was able to visualize small polyps and angiodysplasias not seen during the standard colonoscopy. All patients rated the robotic colonoscopy as virtually painless compared to the standard colonoscopy, ranking pain and discomfort as 0.9 and 1.1 respectively, on a scale of O to 10, versus 6.9 and 6.8 respectively for the standard device.

CONCLUSIONS

The new Endotics System demonstrates efficacy in the diagnosis of colonic pathologies using a procedure nearly completely devoid of pain. Therefore, this system can also be looked upon as the first step toward developing and implementing colonoscopy with atraumatic locomotion through the bowel while maintaining a high level of diagnostic accuracy;

The intelligent, painless, "germ-free" colonoscopy: A Columbus' egg for increasing population adherence to colorectal cancer screening?

Colorectal cancer (CRC) represents a major cause of morbidity and mortality. Although it is widely accepted that CRC screening in average risk populations lowers CRC incidence and mortality, a disappointedly low adherence rate to both faecal occult blood testing and colonoscopy-based screening programs has been observed in Italy and in other European countries. Main reasons for the low acceptance of colonoscopy-based CRC screening has been ascribed to lack of recommendations given by general practitioners, fear of discomfort or complications, embarrassment, and avoidance of unpleasant preparation. New advances in endoscopic technology such as colon capsule and robotic colonoscopy might represent the ideal tool for CRC screening since they reduce or eliminate procedure-related pain and discomfort. Moreover, no disinfection between procedures is required. Motion of the new probes along the gastrointestinal tract is achieved either in passive modality by utilizing the gut peristalsis (colon capsule) or in active "intelligent" modality by means of computer-assisted propulsion (robotic colonoscopy). In this review, the preliminary clinical results obtained with the new devices are summarized. It is expected that the new instruments will be soon available in clinical practice with the hope of increasing adherence to CRC screening programs.

Endotics system vs colonoscopy for the detection of polyps

AIM

To compare the endotics system (ES), a set of new medical equipment for diagnostic colonoscopy, with video-colonoscopy in the detection of polyps.

METHODS

Patients with clinical or familial risk of colonic polyps/carcinomas were eligible for this study. After a standard colonic cleaning, detection of polyps by the ES and by video-colonoscopy was performed in each patient on the same day. In each single patient, the assessment of the presence of polyps was performed by two independent endoscopists, who were randomly assigned to evaluate, in a blind fashion, the presence of polyps either by ES or by standard colonoscopy. The frequency of successful procedures (i.e. reaching to the cecum), the time for endoscopy, and the need for sedation were recorded. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the ES were also calculated.

RESULTS

A total of 71 patients (40 men, mean age 51.9 ± 12.0 years) were enrolled. The cecum was reached in 81.6% of ES examinations and in 94.3% of colonoscopies (P = 0.03). The average time of endoscopy was 45.1 ± 18.5 and 23.7 ± 7.2 min for the ES and traditional colonoscopy, respectively (P < 0.0001). No patient required sedation during ES examination, compared with 19.7% of patients undergoing colonoscopy (P < 0.0001). The sensitivity and specificity of ES for detecting polyps were 93.3% (95% CI: 68-98) and 100% (95% CI: 76.8-100), respectively. PPV was 100% (95% CI: 76.8-100) and NPV was 97.7% (95% CI: 88-99.9).

CONCLUSION

The ES allows the visualization of the entire colonic mucosa in most patients, with good sensitivity/specificity for the detection of lesions and without requiring sedation.

Pedrosa MC, Farraye FA, Shergill AK, Banerjee S, Desilets D, Diehl DL, Kaul V, Kwon RS, Mamula P, Rodriguez SA, Varadarajulu S, Song LMWK, Tierney WM. Minimizing occupational hazards in endoscopy: personal protective equipment, radiation safety, and ergonomics

The ASGE Technology Committee provides reviews of existing, new, or emerging endoscopic technologies that have an impact on the practice of GI endoscopy. Evidence-based methodology is used, by using a MEDLINE literature search to identify pertinent clinical studies on the topic and a MAUDE (U.S. Food and Drug Administration Center for Devices and Radiological Health) database search to identify the reported complications of a given technology. Both are supplemented by accessing the "related articles" feature of PubMed and by scrutinizing pertinent references cited by the identified studies. Controlled clinical trials are emphasized, but in many cases, data from randomized, controlled trials are lacking. In such cases, large case series, preliminary clinical studies, and expert opinions are used. Technical data are gathered from traditional and Web-based publications, proprietary publications, and informal communications with pertinent vendors. Technology Status Evaluation Reports are drafted by 1 or 2 members of the ASGE Technology Committee, reviewed and edited by the committee as a whole, and approved by the Governing Board of the ASGE. When financial guidance is indicated, the most recent coding data and list prices at the time of publication are provided. For this review, the MEDLINE database was searched through August 2009 for articles related to personal protection equipment by using the key words "personal protection equipment" (exp Protective Clothing/ or exp Protective Devices/ or exp Masks/ or exp Occupational Exposure/'') "infection control" paired with "Endoscopy." For the radiation section, the following key words were used: "radiation and endoscopy," "radiation and ERCP," and "radiation safety." For the ergonomics section, the following key words were used: "ergonomics of endoscopy," "endoscopist injury," "medical ergonomics," "endoscopy and musculoskeletal strain," "musculoskeletal injury and endoscopists," "occupational diseases and endoscopy," "cumulative trauma disorder and endoscopy," "repetitive strain injury and endoscopy." Technology Status Evaluation Reports are scientific reviews provided solely for educational and informational purposes. Technology Status Evaluation Reports are not rules and should not be construed as establishing a legal standard of care or as encouraging, advocating, requiring, or discouraging any particular treatment or payment for such treatment.

New endoscopy devices to improve population adherence to colorectal cancer prevention programs

Despite recent advances in medicine, colorectal cancer (CRC) remains one of the greatest hazards for public health worldwide and especially the industrialized world. It has been well documented with concrete data that regular screening colonoscopy aimed at early detection of precancerous polyps can help decrease the incidence of CRC. However, the adherence of the general population to such screening programs has been shown to be lower than that expected, thus allowing CRC to remain a major threat for public health. Various reasons have been suggested to explain the disappointing compliance of the population to CRC screening programs, some of them associated with colonoscopy per se, which is viewed by many people as an unpleasant examination. Governments, medical societies, individual gastroenterologists, as well as the medical industry are working in order to improve endoscopic devices and/or to improve standard colonoscopy. The aim is to improve the acceptance of the population for this method of CRC screening, by providing a painless and reliable examination of the colon. This review focuses on some of the latest improvements in this field.

An optimal micropatterned end-effecter for enhancing frictional force on large intestinal surface

We present a simple surface modification method for enhancing the frictional properties on soft, viscoelastic tissue of large intestine by integrating micropatterned structures with controlled shape and geometry. The micropatterned end-effecter (EE) was fabricated onto micromachined EE body (20 mm long, 2 mm diameter cylinders) in the forms of line, box, pyramid, and bottle shape by utilizing capillary molding technique with UV-curable poly(urethane acrylate) (PUA) polymer. To evaluate the frictional behavior of micropatterned EE, we employed a biotribotester, for easy loading and test of a biological organ specimen. It was found that the frictional properties of micropatterned EE are heavily dependent upon the shape of microstructure. The patterned EE with parallel lines (to the direction of locomotion) showed better frictional performance (average frictional coefficient approximately 1.53 and maximum approximately 3.98) compared with other micropatterned EEs (average frictional coefficient 0.72-0.94 and maximum 1.78-2.49) and nonpatterned EE (average frictional coefficient approximately 0.58 and maximum approximately 1.51). In addition, various geometric parameters (e.g., height, width, and space) as well as operating conditions (e.g., contact load and sliding speed) were systematically investigated for probing optimal anchoring function of the parallel line patterned EE.

Screening for colorectal cancer, where are we now?

The most important disadvantage of the currently available colonoscopes is the need for bowel preparation. Preparation less virtual would be an attractive option. The cost of the new endoscopic methods for colorectal cancer screening is another issue, and needs to be reduced to less than US$200 if large-scale use is intended. Proof of concept for the new endoscopes has been achieved, although significant improvements are still required before colonoscopy can be replaced.

Cecal intubation rate with the double-balloon endoscope after incomplete conventional colonoscopy: a study in 45 patients

BACKGROUND AND AIM

Conventional colonoscopy is the gold standard for colorectal cancer screening. However, a failure rate to complete conventional colonoscopy of more than 10% is reported in the literature. We evaluated whether the therapeutic Fujinon double-balloon endoscope EN-450T5/20 is a valuable tool to intubate the cecum and to carry out all conventional endoscopic procedures after incomplete conventional colonoscopy.

METHODS

Forty-five consecutive patients with prior incomplete conventional colonoscopy were prospectively enrolled. All but three procedures were carried out under conscious sedation with the patient in the left lateral decubitus position without fluoroscopic guidance.

RESULTS

The cecum was reached in 42 of 45 patients (93%) and in 62% additional therapeutic interventions were carried out. Double-balloon colonoscopy required less conscious sedation compared to conventional colonoscopy. No external abdominal compression nor fluoroscopic control was used. The insertion depth of the double-balloon endoscope did not exceed the working length of a conventional colonoscope.

CONCLUSIONS

The present study illustrates that the concept of double-balloon endoscopy is a valuable alternative to reach the cecum after prior incomplete conventional colonoscopy, especially due to redundant colon and colonic loop formation. The procedure requires less conscious sedation and no fluoroscopic control, but allows all conventional endoscopic interventions.

Perspectives of colorectal cancer screening in Germany 2009

Adequate screening methods can decrease colorectal cancer (CRC) mortality. The guaiac test for fecal occult-blood (FOBT) is part of the German CRC Screening Program since 1970 and has evidence level Ia. In randomized multicenter-studies FOBT has an average sensitivity of 24% and decreases CRC mortality up to 30%. Immunological tests for human haemoglobin (iFOBT) show better performance characteristics than guaiac FOBT, with augmented sensitivity and specificity. However, the single tests show wide differences in diagnostic performance and iFOBT is not yet covered by insurance companies although it should replace the guaiac test for CRC screening. Visual colonoscopy, which was introduced to the German National Cancer Screening Program in 2002, is the gold standard for the diagnosis of colorectal neoplasia. From 2003 to 2007 more than 2.8 million examinations have been documented in Germany. The prevalence of adenomas is around 20% and of CRC about 0.7% to 1.0% of the screenings. Seventy percent of the carcinomas detected during screening are in an early stage (UICC I and II). Furthermore, screening colonoscopy is a cost saving procedure with a low complication rate (0.25% overall). Insurance companies save 216€ for each screening colonoscopy mainly by prevention of neoplasia due to polypectomy. In Germany, virtual colonography by computed tomography (CT) or magnetic resonance imaging still lacks standardization of the hard and software. In experienced centres the sensitivity for CRC and large polyps of CT colonography is comparable to colonoscopy but in meta-analyses the ranking is lower. New technologies like computer-aided colonoscopies with sheath or double balloon techniques are coming up as well as capsule colonoscopy, which sensitivity for large polyps is about 70%. Advised by his physician, the patient can choose his most acceptable examination method from this whole set of screening tools.