An EM-Tracked Approach for Calibrating the 3D Pose of Flexible Endoscopes

Flexible endoscopes are ideal instruments for visualizing and diagnosing the inner surfaces of organs via a minimally invasive incision. Calibrating a flexible endoscope is a troublesome yet inevitable process in image-based tools tracking. Aiming to simplify the calibration process, we propose an electromagnetic (EM)-tracked calibration approach that does not require any predefined poses of the EM sensor. A three-stage calibration protocol was presented in an extensor. First, the orientation of the endoscope tube was derived by conducting a circular rotation of the endoscope around its axis utilizing a pair of tightly bearing stands. Second, the 3D position of the endoscope tip was acquired by having the tip come into contact with a flat plane. Third, the pose model of the bending section was derived and transformed into the local coordinate system of the EM sensor attached to the endoscope handle. To assess the accuracy of the proposed calibration approach, two experiments were designed and performed. Experimental results indicate accuracies of 0.09 ± 0.06 deg and 0.03 ± 0.19 deg in the estimation of the endoscope tube orientation and 0.52 ± 0.29, 0.33 ± 0.11, and 0.29 ± 0.17 mm in the x, y, and z estimations of the endoscope tip position, respectively. The proposed approach is accurate and easy to operate, does not require the employment of custom calibration markers, and can be used not only in surgical training systems but also in the endoscopic-based tools tracking.

How I do it: endoscopic evacuation of intraventricular lesions using a flexible endoscope in combination with an angiographic catheter

BACKGROUND

In intraventricular surgery using a flexible endoscope, the lesion is usually aspirated via the working channel. However, the surgical view during aspiration is extremely poor because the objective lens is located adjacent to the working channel.

METHOD

To address this issue, we developed a novel surgical procedure using an angiographic catheter. In this procedure, the catheter is inserted into the working channel, and the lesion is aspirated through the catheter. Besides, continuous intraventricular irrigation is performed via the gap between the catheter and the working channel.

CONCLUSION

This procedure maintains a clear view during surgery and reduces complications.

Endoscopic trans-Magendie foramen biopsy of the superior medullary velum: Technical note

BACKGROUND

Surgery of the fourth ventricle is challenging due to the presence of several surrounding delicate structures. Traditional approaches do not offer an easy visualization of these areas, especially those on the roof. Thanks to the most recent developments in neurosurgical endoscopy, it is possible to access the fourth ventricle via physiological pathways, avoiding unnecessary stress or damage to the nervous and vascular structures.

METHODS

We present the case of a patient with a lesion at the lingula-superior medullary velum, and an history of surgically resected lung and pancreatic adenocarcinomas. An endoscopic biopsy of the lesion through the foramen of Magendie was performed. The few reports on this endoscopic approach were also critically reviewed.

RESULTS

The retrograde endoscopic exploration through a suboccipital, trans-Magendie foramen approach using a flexible endoscope allowed the clear visualization of the superior medullary velum and the possibility to obtain diagnostic biopsies of the lesion with a minimally invasive technique.

CONCLUSIONS

The trans-Magendie navigation with a flexible endoscope is a safe and elegant technique to approach lesions located in any point of the fourth ventricle, particularly in its rostral portion.

Can a flexible surgical robot be used in the pediatric population: A feasibility study

OBJECTIVES

Transoral robotic surgery in adults confers excellent results and decreased morbidity. Application of these techniques has not yet been rigorously investigated in children. The goal of this study is to evaluate the feasibility of a flexible robotic surgical system in a pediatric population.

METHODS

This was a non-randomized, non-blinded, prospective clinical trial. An Investigational Device Exemption was obtained from the FDA. Patients 8-12 years old scheduled for tonsillectomy and adenoidectomy between February and December 2019 at an academic tertiary care children's hospital were included. Exclusion criteria included pulmonary or vascular conditions posing risks for extended anesthesia, or a smaller mouth opening than the instrumentation (28 mm × 15 mm). Tonsillectomy was completed with standard monopolar cautery. After the surgery was complete, the robot was utilized for evaluation and assessment of exposure. A pediatric anesthesiologist screened patients for tolerance of additional anesthesia (up to 15 min). A flexible robotic surgical system, the MedRobotics Flex® Robotic System, was used to visualize and access the tonsillar fossa, posterior pharynx, base of tongue, epiglottis and false vocal folds. Visualization and access were graded on a five-point Likert scale.

RESULTS

A total of ten patients, eight males and two females, with obstructive sleep apnea (OSA) or sleep disordered breathing (SDB) were recruited in 2019. One patient did not complete the study due to equipment malfunction. The average patient demographics were: age 10.1 years (8.6-11.8 years), height 142.4 cm (127-164.9 cm), weight 47.5 kg (24.4-84.5 kg), and BMI 22.6 (13.9-31.0). Study time averaged 10.3 min (5-13 min). The tonsillar fossa, base of tongue, and posterior pharynx were visualized completely and easily accessed with the robotic instruments. The epiglottis and false vocal folds were visualized and accessed in 66% and 55% of patients, respectively. There were no adverse effects.

CONCLUSIONS

This study demonstrated that a flexible robotic surgical system is feasible for use in children 8-12 years of age when performing otolaryngology - head and neck surgery procedures of the oropharynx and larynx.

Snare-assisted flexible endoscope in trans-gastric endoscopic gallbladder-preserving surgery: A pilot animal study

BACKGROUND

Natural orifice transluminal endoscopic surgery (NOTES) gallbladder-preserving surgery by flexible endoscopy is an emerging technology. However, the gallbladder fails to obtain traction and positioning functions during the operation.

AIM

To evaluate the feasibility and safety of a new surgical method, “snare-assisted pure NOTES gallbladder-preserving surgery”.

METHODS

Eight miniature pigs were randomly divided into the experimental group [NOTES gallbladder-preserving surgery using the snare device, snare assisted (SA)] and the control group (NOTES gallbladder-preserving surgery without using the snare device, NC), with four cases in each group. The differences between the two groups of animals in operating time, operating workload, complications, adverse events, white blood cells, and liver function were determined.

RESULTS

No differences were found in the surgical success rate, gallbladder incision closure, white blood cell count, or liver function between the two groups. The total operating time, gallbladder incision blood loss, gallbladder disorientation time, gallbladder incision closure time, and workload scores on the National Aeronautics and Space Administration-Task Load Index were significantly reduced in the SA group (P < 0.05).

CONCLUSION

These results indicated that snare-assisted pure NOTES gallbladder-preservation surgery using standard endoscopic instruments reduced the difficulty of operation, shortened operation time, and did not increase complications in pigs. A new method for pure NOTES gallbladder-preservation surgery was provided.

Transcortical Endoscopic Removal of Residual Craniopharyngioma in the Third Ventricle: Surgical Video

Excision through craniotomy is used for pediatric craniopharyngioma removal. However, residual tumors can sometimes be found in the blind spot of the microscopic field, such as the third ventricle wall, back of the optic chiasm, and brainstem surface, during surgery. Video 1 demonstrates the surgery using a flexible endoscope for the removal of residual tumor located within the blind spot of the first resection. The written consent was obtained from the patient's family. A 4-year-old child complained of vomiting, and the radiologic findings showed obstructive hydrocephalus and a calcified suprasellar mass lesion that extended to the third ventricle. The tumor was treated with a right frontotemporal craniotomy. The pathologic diagnosis was craniopharyngioma. Postoperative magnetic resonance imaging showed residual tumor detected at the roof of the third ventricle, back of the optic chiasm, and interpeduncular fossa. The residual tumors were removed using a flexible endoscope via a transcortical, transventricular approach. Postoperative magnetic resonance imaging showed no residual tumors. Although histologically benign, craniopharyngiomas may be locally aggressive and their close proximity to vital structures makes them one of our controversial management dilemmas. Recurrence may occur following even a presumed total excision and radiation therapy. Residual tumors located in the third ventricle are resected through various approaches, such as the transsphenoidal or transcallosal approach. Our approach using a flexible endoscope was minimally invasive and useful for the removal of residual tumor of the third ventricle in craniopharyngioma surgery because the approach offered a wide field of view and visual angle and forceps could be applied according to the view.

Collective bacterial disinfection by opto-chemical treatment on mature biofilm in clinical endoscope

The present study proposes an innovative opto-chemical treatment using a basket-integrated optical device (BIOD) to disinfect mature bacterial biofilm on endoscope channels. A BIOD was designed to position an optical diffuser on the central axis of an endoscope channel and to distribute laser light concentrically to the bacterial biofilm on the channel surface. To apply thermal damage and oxidative stress to the bacterial biofilm, a low concentration of a crosslinking agent (glutaraldehyde ~0.5%) was combined with 808 nm infrared (IR) and 405 nm blue (BL) laser lights. The applied irradiances of IR and BL were 10 W/cm² and 1.6 W/cm² for Teflon channel model and 20 W/cm² and 3.2 W/cm² for a clinical model, respectively. Individual irradiation of either IR or BL for 180 s induced the maximum temperatures of 62 ± 2 °C and 53 ± 3 °C on the biofilm, respectively. The simultaneous opto-chemical treatment reduced a significant population of the bacterial biofilms (7.5-log₁₀ for Staphylococcus aureus and 7.1-log₁₀ for Pseudomonas aeruginosa), which were 2.9-fold and 3.9-fold higher than that of the standard treatment with 2% glutaraldehyde (GA) solution, respectively. The proposed opto-chemical disinfection method can help reduce multi-drug resistant bacteria and prevent cross-infection during the clinical usage of a flexible endoscope.

Resection of a recurrent medulloblastoma in the anterior middle part of the aqueduct with a flexible endoscope: a case report

Resection or biopsy of intraventricular brain tumors using an endoscope has become common, but the limitations of these procedures are not clear. Manipulation to access a tumor that arises from the blind angle of the rigid endoscope, such as the anterior part of the aqueduct, is limited. We report here that we successfully resected a recurrent medulloblastoma in the anterior part of the aqueduct using only a flexible endoscope. This method appears to be suitable for poorly vascularized and suctionable tumors that arise in the blind angle of a rigid endoscope.

New perspectives in the endoscopic treatment of brain purulent collections: targets, techniques, results in a case series, and overview of the literature

BACKGROUND

Purulent intracranial infections are threatening conditions. Different surgical approaches have been described, respecting the rationale of evacuating the fluid component of the purulent collection. Emerging evidence supports the use of the endoscope for the treatment of cerebral abscesses and subdural empyemas; especially the peculiarities of flexible endoscopes could potentially offer a more effective and conclusive management as compared with the drainage through catheters. We describe our experience in the treatment of intracranial purulent collections with flexible endoscopy, comparing it with the most recent literature.

METHODS

Ten patients affected by intracranial suppuration were treated with endoscopy at our institution. The neurosurgical technique is thoroughly described. The related literature is reviewed, providing a comprehensive overview on the endoscopic treatment of intracranial suppuration so far.

RESULTS

All the patients had a good clinical outcome, with no peri-operative complications. The postoperative scans showed significant radiological improvement, with important reduction of the pus volume. In all cases, the microbiological cultures showed positivity.

CONCLUSIONS

In our experience, the use of the flexible scope proved feasible and effective in the treatment of intracranial purulent collections. Visual awareness of the internal capsule is not limited to a direct inspection of the fluid pus; it rather allows an active removal of the more solid (and perhaps more microbiologically significant) fibrinoid component, and also assists in final bleeding control and in assessing the extent of the evacuation. The steering capabilities of the fiberscope are particularly suitable for such purposes, allowing sampling the solid internal layer of the pyogenic membrane, and potentially shedding light on the actual clinical significance of this component of the abscess.

Novel Endoscopic Technique for Inserting a Sheath into a Slit Ventricle: The Water-Slide Technique

BACKGROUND

The efficacy and safety of endoscopic procedures for slit ventricle syndrome (SVS) have been presented in recent studies. However, inserting a sheath into a target ventricle is essential in the beginning of endoscopic procedures for SVS, and this maneuver is challenging owing to the quite narrow ventricular space. We report a novel flexible endoscopic technique, the water-slide technique, that can effectively guide a sheath into a slit ventricle without the use of other adjunctive devices, such as a neuronavigation system and an ultrasound machine.

METHODS

Ten endoscopic procedures using the water-slide technique were performed in 9 patients with SVS. All patients had undergone ventriculoperitoneal shunt placement. Using the technique, the sheath was first placed on the flexible endoscope. The endoscope was then inserted into the lateral ventricle along the tract around the pre-existing ventricular catheter with irrigation of artificial cerebrospinal fluid via the working channel of the endoscope. After the endoscope reached the ventricle, the sheath was inserted into the ventricle along the endoscope. The endoscope was then used as a stylet. The endoscopic procedure was performed afterward. Continuous irrigation of artificial cerebrospinal fluid via the working channel is important when using this technique.

RESULTS

In all cases, the sheath was successfully introduced to the slit ventricle without the use of adjunctive devices. There were no postoperative complications correlated with the maneuver.

CONCLUSIONS

This novel endoscopic technique is effective and safe for inserting a sheath into a target ventricle in the management of SVS.

Transanal total mesorectal excision (TaTME) using flexible endoscope with laparoscopic assistance: a pilot study in porcine models

BACKGROUND

Transanal total mesorectal excision (TaTME) is routinely performed to excise low rectal tumors. TaTME often relies on transanal endoscopic microsurgery (TEM) or transanal minimally invasive surgery (TAMIS) platform, all using rigid endoscopes. Our study reported a novel approach to TaTME which was completed using flexible endoscope, and we named it F-TaTME.

METHODS

The feasibility of rectum resection using F-TaTME was evaluated in five pigs. Firstly, the superior rectal artery and vein were managed under the assistance of laparoscopy. Secondly, the flexible endoscope was used to complete the full-thickness rectotomy and rectal mobilization. Finally, the specimen was removed and the manual colon-rectal anastomosis was performed under direct vision.

RESULTS

F-TaTME was accomplished in all 5 pigs. The mean procedure time was 136.6 min (97-162 min). The mean length from the lower edge of the lesion to circumferential dissection line was 1.4 cm (1.0-1.8 cm) and mean length of exteriorized rectum was 12.6 cm (11-14 cm). No injury to colorectal wall, adjacent pelvic or abdominal organs was found.

CONCLUSIONS

Our preliminary data suggested that F-TaTME may be a feasible method for TaTME.

Challenges in achieving effective high-level disinfection in endoscope reprocessing

Endoscope reprocessing is often ineffective, and microbes frequently remain on endoscopes after the use of high-level disinfectants (HLDs). Several factors impact reprocessing effectiveness, including non-adherence to guidelines, use of damaged endoscopes, use of insoluble products during endoscopy, insufficient cleaning, contaminated rinse water, and inadequate drying before storage. Our team suspected that issues with HLD chemistries and monitoring could also contribute to reprocessing failures. We conducted a mixed-methods analysis of published literature, our interviews with frontline personnel, and evidence from our previous studies. The evidence showed that reusable HLDs commonly failed tests for minimum effective concentration (MEC) before their maximum usage periods. MEC tests also detected failures associated with single-use HLDs that did not fully deploy. These failures were due to product issues, process complexities, and personnel non-adherence with guidelines and manufacturer instructions. HLDs will likely continue to be used for the foreseeable future. More research is needed to assess real-world practice patterns related to the high-level disinfection step and MEC testing and to establish more realistic usage periods for reusable HLD chemistries. Manufacturers and researchers should evaluate the ability of technological solutions and engineered safeguards to overcome human error. Recognition of the need for quality improvement is growing, and infection preventionists should take action to build on this momentum and collaborate with manufacturers, endoscopists, and reprocessing personnel to improve the effectiveness of high-level disinfection.

Flexible endoscopic assistance in the surgical management of vestibular schwannomas

Endoscopic-assisted techniques have extensively been applied to vestibular schwannoma (VS) surgery allowing to increase the extent of resection, minimize complications, and preserve facial nerve and auditory functions. In this paper, we retrospectively analyze the effectiveness of flexible endoscope in the endoscopic-assisted retrosigmoid approach for the surgical management of VS of various sizes. The authors conducted a retrospective analysis on 32 patients who underwent combined microscopic and flexible endoscopic resection of VS of various sizes over a period of 16 months. Flexible endoscopic-assisted retrosigmoid approach was performed in all cases, and in 6 cases, flexible and rigid endoscopic control were used in combination to evaluate the differences between the two surgical instruments. The surgical results were additionally compared with a previous case series of 141 patients operated for VS of various sizes without endoscopic assistance. Gross-total resection was achieved in 84% of the cases and near-total resection was accomplished in the rest of them. Excellent or good facial nerve function was observed in all except one case with a preoperative severe facial palsy. Hearing preservation surgery (HPS) was attempted in 11 cases and accomplished in 9 (81.8%). A tumor remnant was endoscopically identified in the fundus of the IAC in all cases (100%). Endoscopic assistance increased the rate of total removal and no intrameatal residual tumor was seen at radiological follow-up. Comparative analysis with a surgical cohort of patients operated with the sole microsurgical technique showed a significative association between endoscopic assistance and intracanalicular extent of resection. Combined microsurgical and flexible endoscopic assistance provides remarkable advantages in the pursuit of maximal safe resection of VS and preservation of facial nerve and auditory functions, minimizing the risk of post-operative complications.

Prion disease and recommended procedures for flexible endoscope reprocessing - a review of policies worldwide and proposal for a simplified approach

Several guidelines recommend specific treatments for endoscopes, procedures of quarantine for endoscopes, or additional treatments for the endoscope washer disinfector (EWD) in suspected or confirmed cases of Creutzfeldt-Jakob disease (CJD) or variant CJD (vCJD) but vary in many details. This study therefore reviewed guidelines on reprocessing flexible endoscopes after use in patients with suspected or confirmed prion disease. In addition, a literature search was performed in Medline on prion, CJD, vCJD, chemical inactivation, transmission healthcare, epidemiology healthcare, concentration tissue human and endoscope. Thus far, no case of CJD or vCJD transmitted by flexible endoscope has been reported. In animals it has been shown that oral uptake of 0.1-5 g of bovine spongiform encephalopathy (BSE)-infected brain homogenate is necessary for transmission. The maximum prion concentration in other tissues (e.g., terminal ileum) is at least 100-fold lower. Automated cleaning of endoscopes alone results in very low total residual protein ≤5.6 mg per duodenoscopes. Recommendations vary between countries, sometimes with additional cleaning, use of alkaline cleaners, no use of cleaners with fixative properties, use of disinfectants without fixative properties or single-use disinfectants. Sodium hydroxide (1 M) and sodium hypochlorite (10,000 and 25,000 mg/L) are very effective in preventing transmission via contaminated wires implanted into animal brains, but their relevance for endoscopes is questionable. Based on circumstantial evidence, it is proposed to consider validated reprocessing as appropriate in the case of delayed suspected prion disease when immediate bedside cleaning, routine use of alkaline cleaners, no fixative agents anywhere prior to disinfection and single use brushes and cleaning solutions can be assured.

Flexible Endoscopic-Assisted Microsurgical Radical Resection of Intracanalicular Vestibular Schwannomas by a Retrosigmoid Approach: Operative Technique

The efficacy of endoscopic techniques in the surgical management of intracanalicular vestibular schwannomas (ICVSs) has been underlined in recent studies. An endoscopic- assisted retrosigmoid approach (EARSA) appears to be particularly suitable for achieving complete resection of an ICVS. In this study, we describe the surgical treatment of 3 cases of ICVS with an EARSA, highlighting the advantages and limitations of flexible endoscopy in accomplishing a safe radical resection with hearing preservation. Three patients with an ICVS underwent surgery via a flexible endoscopic-assisted microneurosurgical retrosigmoid approach. Flexible endoscopic assistance allowed the identification of residual tumor located in the most lateral portion of the fundus of the internal auditory canal in all cases. Endoscopic controls and further microsurgical resection were attempted, and complete surgical resection was achieved in all cases without the occurrence of postoperative facial or auditory nerve dysfunction. Flexible endoscopy appears to be particularly useful and safe in the surgical management of ICVS by microneurosurgery via an EARSA.

A Novel Dissection Method Using a Flexible Neuroendoscope for Resection of Tumors Around the Aqueduct of Sylvius

BACKGROUND

Flexible endoscopes have both a wide range of movement and a wide field of view and are therefore widely used for endoscopic third ventriculostomy and biopsy. However, tumor resection around the aqueduct of Sylvius using flexible endoscopes has scarcely been reported.

CASE DESCRIPTION

We report 2 cases of tumor resection around the aqueduct of Sylvius. The first case is a 38-year-old man presenting with progressive headache, nausea, and diplopia. Magnetic resonance imaging (MRI) revealed a 1.4 cm nonenhancing mass at the entry of the aqueduct of Sylvius and occlusive hydrocephalus. We performed tumor resection and endoscopic third ventriculostomy (ETV) simultaneously. His symptoms disappeared after the operation. Final pathologic diagnosis was ancient schwannoma. The second case is a 78-year-old woman presenting with progressive disturbance of consciousness (coma). MRI showed 0.7 cm nonenhancing mass at the entry of the aqueduct of Sylvius and occlusive hydrocephalus. We performed tumor resection and ETV similarly. Her consciousness improved after the operation. Final tumor diagnosis was cavernous malformation. In both cases there was no additional neurologic deficit after the surgery.

CONCLUSIONS

By using a flexible endoscope for tumor dissection, resection of a tumor without a neck, which cannot be removed through aspiration alone, becomes possible. To our knowledge, the presented cases are the first to describe the effectiveness of complete resection of a tumor in the third ventricle using flexible endoscopy.

NOViSE: a virtual natural orifice transluminal endoscopic surgery simulator

Purpose

Natural orifice transluminal endoscopic surgery (NOTES) is a novel technique in minimally invasive surgery whereby a flexible endoscope is inserted via a natural orifice to gain access to the abdominal cavity, leaving no external scars. This innovative use of flexible endoscopy creates many new challenges and is associated with a steep learning curve for clinicians.

Methods

We developed NOViSE—the first force-feedback-enabled virtual reality simulator for NOTES training supporting a flexible endoscope. The haptic device is custom-built, and the behaviour of the virtual flexible endoscope is based on an established theoretical framework—the Cosserat theory of elastic rods.

Results

We present the application of NOViSE to the simulation of a hybrid trans-gastric cholecystectomy procedure. Preliminary results of face, content and construct validation have previously shown that NOViSE delivers the required level of realism for training of endoscopic manipulation skills specific to NOTES.

Conclusions

VR simulation of NOTES procedures can contribute to surgical training and improve the educational experience without putting patients at risk, raising ethical issues or requiring expensive animal or cadaver facilities. In the context of an experimental technique, NOViSE could potentially facilitate NOTES development and contribute to its wider use by keeping practitioners up to date with this novel surgical technique. NOViSE is a first prototype, and the initial results indicate that it provides promising foundations for further development.

Electronic supplementary material

The online version of this article (doi:10.1007/s11548-016-1401-8) contains supplementary material, which is available to authorized users.

Flexible Endoscopic Aspiration for Intraventricular Casting Hematoma

BACKGROUND

Conventionally, patients suffering a massive intraventricular hemorrhage have undergone external ventricular drainage. However, long-term or repeated drainage increases the risk of complications due to infections or shunt dependency. Neuroendoscopic surgery may offer some advantages over more conventional procedures.

METHODS

Thirteen patients suffering intraventricular hematoma associated with intracerebral hemorrhage, treated in our hospital between April 2011 and March 2014, were reviewed retrospectively. Casting hematomas in the ventricles were manually aspirated using a flexible endoscope. The timing of the operation, period of post-endoscopic ventricular drainage, additional internal shunt surgery, 3-month post-surgical outcome, and critical complications were evaluated.

RESULTS

Two patients (treated during our earliest use of endoscope) who underwent surgery on the 7th and 16th day post-onset required subsequent cerebrospinal shunt surgery. In contrast, of the 11 patients who underwent endoscopic surgery on the day of onset, only 1 patient required an additional, third ventriculostomy due to a secondary obstruction of the aqueduct by adhesive fibrous membranes. After 3 months, all six patients with mRS scores of 2-3 satisfied all the following criteria: initial Glasgow Coma Scale scores higher than 8, flexible endoscopic surgeries performed on the day of onset, and period of ventricular drainage of less than 4 days.

CONCLUSIONS

Early surgical intervention using a flexible endoscope and short period of post-surgical drainage can be highly effective for patients suffering from casting intraventricular hematomas associated with intracerebral hemorrhage. The advantages of this treatment may be a less invasive procedure, ICP control in the acute phase, breaking away from ventricular drainage in the early stage, and prevention of hydrocephalus or intracranial infectious complications in the long term.

Increasing potential risks of contamination from repetitive use of endoscope

BACKGROUND

Medical devices inserted into the human body can be divided into single-use devices and reusable medical devices (RMDs) depending on the method of use. RMDs are applied to >1 patient, and users reprocess them prior to repeat use. Therefore, reprocessing of RMDs has become more difficult, and issues related to infection risk have become more prevalent.

METHODS

Research was performed to compare differences in surface alterations between not-aged (NA) samples and accelerated-aging (AA) samples. NA and AA samples were exposed to potential contaminants and treated with the same cleaning conditions. Then the residual contaminants were analyzed, and adhesion characteristics were investigated.

RESULTS

Significant differences between the 2 sample groups were observed in the pattern of physical surface alterations. Similar to the endoscope for clinical use, a deep crack was found in the surface of the AA sample. According to the binding affinity test, highly likely potential contaminants were found more frequently on AA samples.

CONCLUSION

The results suggest the necessity of limiting the duration of time that RMDs may be used, considering the potential risk of infection from repetitive use of RMDs, and also raised the possibility of applying this simulation model of AA. This methodology can be applied to various RMDs, including endoscopes.

Embryonic natural orifice transluminal endoscopic surgery in the treatment of severe acute pancreatitis complicated by abdominal compartment syndrome

BACKGROUND

The study aimed to estimate the value of embryonal natural orifice transluminal endoscopic surgery (ENOTES) in treating severe acute pancreatitis (SAP) complicated with abdominal compartment syndrome (ACS).

METHODS

The patients, who were randomized into an ENOTES group and an operative group, underwent ENOTES and laparotomy, respectively. The results and complications of the two groups were compared.

RESULTS

Enterocinesia was observed earlier in the ENOTES group than in the operative group. Acute Physiology and Chronic Health Evaluation II (APACHE II) score of patients in the ENOTES group was lower than that of the operative group on the 1st, 3rd and 5th post-operative day (P<0.05). The cure rate was 96.87% in the ENOTES group, which was statistically different from 78.12% in the operative group (P<0.05). There were significant differences in complications and mortality between the two groups (P<0.01).

CONCLUSION

Compared with surgical decompression, ENOTES associated with flexible endoscope therapy is an effective and minimal invasive procedure with less complications.

The transnasal VideoPanendoscopy (ViP): diagnostics of the upper aerodigestive tract using an anatomically correct model from the model to the patient

Endoscopy of the upper aerodigestive tract (UADT) develops rapidly. New endoscopes in combination with special imaging techniques allow complete examinations of the UADT in an ambulatory setting. Therefore, it is necessary to educate and train young physicians in a standardized protocol. A special anatomical training model has been designed to allow a stepwise endoscopy training course. It can be used by specialists who would like to take advantage of transnasal VideoPanendoscopy for examination of suitable candidate patients. This method offers advantages for ENT doctors, gastroenterologists as well as endoscopic surgeons.

Correlation between the growth of bacterial biofilm in flexible endoscopes and endoscope reprocessing methods

BACKGROUND

The purpose of this article was to investigate bacterial biofilm formed on endoscopes and to explore the possible correlation between endoscope reprocessing procedures and bacterial biofilm growth on endoscope channels.

METHODS

Sixty-six endoscope suction and biopsy channels and 13 water and air channels were collected from 66 hospitals throughout China. Scanning electron microscopy was used to observe biofilm growth on the internal surface of these channels. Questionnaires were mailed to 66 endoscopy centers to investigate reprocessing procedures for endoscopes.

RESULTS

Obvious biofilm growth was detected on 36 suction and biopsy channels (36/66, 54.6%) and 10 water and air channels (10/13, 76.9%). The percentage of manual cleaning in group B (n = 36, without detection of biofilms) was 92.3% (33/36), whereas it was 50.0% (15/30) in group A (n = 30, with detection of biofilms). Follow-up of group A (n = 30) showed that no biofilm was detected, whereas biofilm was detected in group B. The difference was statistically significant (P = .001). The proportion of detergent reuse in group B was 92.3% (33/36), and it was 61.5% in group A (18/30) (P = .005). The proportion of alcohol-air drying in group B was 38.9% (14/36), and it was 76.7% (23/30) in group A (P = .002).

CONCLUSION

The formation of endoscopic biofilm during clinical practice may be related to reuse of detergent, manual cleaning, and incomplete drying.

Is peracetic acid suitable for the cleaning step of reprocessing flexible endoscopes?

The bioburden (blood, protein, pathogens and biofilm) on flexible endoscopes after use is often high and its removal is essential to allow effective disinfection, especially in the case of peracetic acid-based disinfectants, which are easily inactivated by organic material. Cleaning processes using conventional cleaners remove a variable but often sufficient amount of the bioburden. Some formulations based on peracetic acid are recommended by manufacturers for the cleaning step. We performed a systematic literature search and reviewed the available evidence to clarify the suitability of peracetic acid-based formulations for cleaning flexible endoscopes. A total of 243 studies were evaluated. No studies have yet demonstrated that peracetic acid-based cleaners are as effective as conventional cleaners. Some peracetic acid-based formulations have demonstrated some biofilm-cleaning effects and no biofilm-fixation potential, while others have a limited cleaning effect and a clear biofilm-fixation potential. All published data demonstrated a limited blood cleaning effect and a substantial blood and nerve tissue fixation potential of peracetic acid. No evidence-based guidelines on reprocessing flexible endoscopes currently recommend using cleaners containing peracetic acid, but some guidelines clearly recommend not using them because of their fixation potential. Evidence from some outbreaks, especially those involving highly multidrug-resistant gram-negative pathogens, indicated that disinfection using peracetic acid may be insufficient if the preceding cleaning step is not performed adequately. Based on this review we conclude that peracetic acid-based formulations should not be used for cleaning flexible endoscopes.

Cervical and retrosternal approach to the left thoracic cavity using a flexible endoscope

OBJECTIVES

Mediastinoscopy remains the gold standard for surgical exploration of the mediastinum. The use of this approach to access the left thoracic cavity could be complicated by vascular or neurological lesion. The aim of this experimental work was to describe a new approach to the left thoracic cavity through a cervical incision and retrosternal space using a flexible endoscope as a unique instrument.

METHODS

We conducted an experimental work on 12 refrigerated and non-embalmed cadavers. Through a cervical incision, we dissected the retrosternal space to the level of Louis angle and then opened the left mediastinal pleura. We introduced the flexible endoscope through this pleural window into the left thoracic cavity. We defined three distances between the borders of the endoscope entry point, the phrenic nerve and the mammary artery: Distance 1: between the medial edge of the endoscope entrance point and the medial edge of the left mammary artery, Distance 2: between the top of the endoscope entrance point and the penetration of phrenic nerve in the left thoracic cavity and Distance 3: between the lateral edge of the entrance point of the endoscope and the medial edge of the phrenic nerve. To measure these distances, we performed a left postero-lateral thoracotomy.

RESULTS

Procedure was successfully executed in 10 of the 12 studied subjects. The mean distances 1, 2 and 3 were 17.1 (range 2-40), 39.5 (17-80) and 19.1 mm (10-40), respectively. The minimal Distance 1 was in two subjects 0.2 and 0.5 mm.

CONCLUSIONS

This approach avoids the para-aortic and supra-aortic zone; this access could be less dangerous than already described access techniques. Despite the limits of our work on cadavers, and the two failures in the application of the access, the mean distances we calculated show the potential safety of our approach concerning the phrenic nerve and the mammary artery. An experimental protocol on living animals is currently underway with the aim of confirming the safety of our approach.

Endoscope-assisted retrosigmoid resection of a medium size vestibular schwannoma tumor model: a cadaveric study

OBJECTIVE

To demonstrate a flexible endoscope assisted technique to perform microsurgical resection using a retrosigmoid approach of an artificial polymer tumor model that mimics a medium size (15-20mm diameter) vestibular schwannoma.

METHODS

Twelve bilateral retrosigmoid dissections were performed in 6 glutaraldehyde embalmed, colored silicone injected, adult cadaveric heads. Using a standard retrosigmoid approach, we first implanted the tumor model at the cerebellopontine angle (CPA) and then we resected the tumor under simultaneous endoscopic and microscopic visualizations. The resection was performed by first creating a corridor by removing the lower portion of the tumor and then by inserting through the same corridor the flexible endoscope mounted on a surgical instrument in order to accomplish early visualization of the VII-VIII complex. This early visualization of the VII-VIII complex made possible expeditious removal of the model with preservation of the VII-VIII complex.

RESULTS

We were able to successfully implant the artificial tumor in all the specimens. The post-tumor implantation CT scan confirmed the optimal CPA location of the model with its intra-porus extension. The exposure of the facial and the adjoining neuro-vascular structures was excellent during all stages of the surgical removal and was accomplished with minimal cerebellar retraction, under intermittent endoscopic-assisted control. Early visualization of the facial and vestibular cochlear nerves complex led to unhindered removal of the tumor model.

CONCLUSIONS

The endoscopic-assisted microsurgical removal of a tumor model simulating a medium size vestibular schwannoma was feasible in our tumor model study emulating real surgery. Visualization of the acousticofacial bundle at the early stage of the surgical removal should theoretically decrease the risk of its inadvertent injuries as well as facilitate complete removal of the tumor. Clinical studies to validate this laboratory study are necessary.

[Flexible endoscope in thoracic surgery: CITES or cVATS?]

Early pain and persistent parietal disorders remains a major unresolved problem in thoracic surgery. Thoracotomy and the use of multiple ports in most Video Assisted Thoracic Surgery (VATS) procedures are the major cause of this persistent pain. For the last decade, a few publications describing the use of either single incision VATS and cervical thoracic approaches have been reported without significant results in comparison with current used techniques. Intercostals compression during surgery and early after by intercostals chest tube placement, are probably the major cause of postoperative pain. Flexible endoscope is currently used in several surgeries and will take more and more importance in our daily use in thoracic surgery. Instrument flexibility allows its use through minimally invasive approaches and offers a very interesting intra-thoracic navigation. We describe here the first use in France of a flexible endoscope in thoracic surgery through a single cervical incision to perform simultaneous exploration and biopsies of the mediastinum and right pleura using the original approach of Cervical Incision Thoracic Endoscopic Surgery (CITES).

Removal of foreign bodies from esophagus with flexible endoscope - a case report

To present a case of impacted artificial denture in esophagus and its removal by flexible endoscope. A 28 year old male presented with history of ingesting his denture 2 h back. It was removed by flexible endoscope and flexible fibre optic forceps. Though rigid endoscopic removal of foreign body is safe and effective, but often requires general anaesthesia. The flexible fibre optic endoscopic removal, which can be done under local anaesthesia in outpatient department is a suitable alternative.