Endoscopic image enhancement with noise suppression

Stereoscopic endoscopes have been used increasingly in minimally invasive surgery to visualise the organ surface and manipulate various surgical tools. However, insufficient and irregular light sources become major challenges for endoscopic surgery. Not only do these conditions hinder image processing algorithms, sometimes surgical tools are barely visible when operating within low-light regions. In addition, low-light regions have low signal-to-noise ratio and metrication artefacts due to quantisation errors. As a result, present image enhancement methods usually suffer from heavy noise amplification in low-light regions. In this Letter, the authors propose an effective method for endoscopic image enhancement by identifying different illumination regions and designing the enhancement design criteria for desired image quality. Compared with existing image enhancement methods, the proposed method is able to enhance the low-light region while preventing noise amplification during image enhancement process. The proposed method is tested with 200 images acquired by endoscopic surgeries. Computed results show that the proposed algorithm can outperform state-of-the-art algorithms for image enhancement, in terms of naturalness image quality evaluator and illumination index.

Technique for reconstruction of large clival defects through an endoscopic-assisted tunneled retropharyngeal approach

BACKGROUND

Reconstruction of the clivus and posterior cranial base defects following endoscopic skull-base surgery can be particularly challenging. Commonly, defects in this region are repaired with pedicled mucoperichondrial flaps from the sinonasal cavity. Complex and large defects often require regional or free flaps, particularly when intranasal flaps have been exhausted. While there are no primary barriers to routing flaps into the clivus or nasopharynx in large open approaches, secondary surgical corridors are necessary during endoscopic cases for routing of free flaps. Routing of free-flap pedicles for endoscopic cranial base reconstruction has been described through secondary surgical corridors created through the maxillary sinus and infratemporal fossa. Here we describe the technique of a more direct pedicle route to the clivus through the retropharyngeal space.

METHODS

A patient with frank cerebrospinal fluid (CSF) rhinorrhea and extensive osteoradionecrosis of the clivus and craniocervical junction presented for treatment. Due to the size and location of the defect and previous exhaustion of candidate mucoperichondrial flaps, free-flap reconstruction was performed. A radial forearm free flap was tunneled through the prevertebral space into the nasopharynx and clivus and inserted with endoscopic-assisted techniques. The flap pedicle coursed through the retropharyngeal space to the neck vessels where arterial and venous anastomosis was established.

RESULTS

The CSF leak and clival defect were successfully repaired with this technique. Postoperative imaging demonstrated appropriate positioning of the flap as well as the location of the free-flap pedicle and anastomosis. Endoscopic evaluation at 6 months showed complete resurfacing of the previously exposed cranial base. In cadaveric dissection in 3 adult specimens, the pedicle length necessary to reach the inferior clivus and craniocervical junction from the closest recipient pedicle through a retropharyngeal route was an average of 6.5 cm vs an average of 16 cm through the transmaxillary approach.

CONCLUSION

The retropharyngeal space offers a direct route for tunneling free flaps for the repair of large clival defects during endoscopic skull-base surgery. Several advantages include a less circuitous pedicle route, mucosalization of the fascial flap, avoidance of midfacial degloving, and avoidance of potential disruption of the maxillary sinus.

[Application of endoscope assisted curved laryngoscope in laryngeal microsurgery of patients with difficulty laryngeal exposure]

Objective:To investigate the feasibility and clinical value of endoscope assisted curved laryngoscopy in laryngeal microsurgery of patients with difficulty laryngeal exposure. Method:The data of 28 patients with difficulty laryngeal exposure underwent microlaryngosurgery with endoscope assisted curved laryngoscopy technique were collected. Result:Surgeries with endoscope assisted curved laryngoscopy technique were completed successfully one-time in all patients. The fully exposure of glottis was 100%. All cases were followed up for 2 to 18 months. No residual disease or recurrence occurred and no obvious complication occurred. Conclusion:Endoscope assisted curved laryngoscopy technique is a useful solution to difficulty laryngeal exposure. It has satisfactory glottis exposure, clear surgical field and fewer complications which is worthy of promotion.

Digital Videoscopic Retrograde Intrarenal Surgeries for Renal Stones: Time-to-Maximal Stone Length Ratio Analysis

PURPOSE

To investigate 100 consecutive cases of videoscopic retrograde intrarenal surgery (RIRS) by a single surgeon and to evaluate factors associated with stone-free status and the learning curve thereof.

MATERIALS AND METHODS

We analyzed the results of videoscopic RIRS in 100 patients who underwent primary treatment for renal stones from January 2015 to August 2016. Videoscopic RIRS were performed with URF-V and URF-V2 flexible video uteroscopes (Olympus) or a Flex-Xc flexible ureterorenoscope (KARL STORZ). Non-contrast computed tomography was taken at 3 months postoperatively to confirm the absence of stones. The stone characteristics included the location, maximal stone length (MSL), stone heterogeneity index (SHI), and mean stone density (MSD). Fragmentation efficacy was calculated as operative time (min) divided by removed MSL (mm), and was evaluated in the sequential order of operations.

RESULTS

The mean age of the total patient was 60.0±14.0 years. The mean MSL was 13.1±6.2 mm. The average MSD was 734.2±327.6 Hounsfield unit (HU) and the SHI was 241.0±120.0 HU. The mean operation time was 65.1±45.7 min considering each renal unit. The stone-free rate at 3 months post-surgery was 87%. The estimated cut-off of the time-to-MSL ratio below 5 min/mm was 50. Multivariate analyses indicated a lower MSD [odds ratio (OR): 0.998; 95% confidence interval (CI): 0.996-0.999; p=0.047) and the last 50 cases (OR: 5.408, 95% CI: 1.337-30.426; p=0.030) as independent predictors of stone-free status after videoscopic RIRS.

CONCLUSION

Low MSDs and the last 50 cases were significant predictors of stone-free rate in videoscopic RIRS.

Endoscopic meatus scoring scale versus sniff test to predict insertability before transnasal endoscopy: A prospective, randomized study

BACKGROUND AND AIM

Sniff test is a common method before unsedated transnasal esophago-gastro-duodenoscopy (UT-EGD) to select a nostril insertion site. Yet there is no objective method to select a more specific meatus insertion tract for anesthesia and insertion. We devised an endoscopic meatus scoring scale by anterior meatuscopy to select the most optimal meatus insertion tract. We hypothesized that meatuscopy instead of sniff test might improve tolerance and reduce adverse events during nasal anesthesia and UT-EGD.

METHODS

A prospective randomized controlled trial to compare patient tolerance and adverse events.

RESULTS

A total of 359 patients were assessed and finally 310 patients were analyzed. There were no statistical differences in patient characteristics and insertion failure rates. Pain scores during nasal anesthesia, nasal insertion/exsertion, UT-EGD, and overall tolerance were significantly lower in the meatuscopy group than sniff test group. Compared with the sniff tested patients, the meatuscopied patients had significantly lower epistaxis rates during insertion/exsertion, better visual capacity after decongestive anesthesia, and shorter total procedure time. A significantly higher proportion of the meatuscopied than sniff tested patients would like to receive the same procedure next time. Nasal discharge, nasal pain, epistaxis, and blowing out blood clots occurred significantly less frequent in the meatuscopy group than sniff test group. More sniff tested than meatuscopied patients had headache, delayed epistaxis, and sinusitis although they were not statistically significant.

CONCLUSION

Selection of an optimal meatus insertion tract by an anterior meatuscopy causes lesser nasal pain, epistaxis, and post-procedural side effects in nasal anesthesia and UT-EGD than the conventional sniff test.

Effectiveness of tip rotation in fibreoptic bronchoscopy under different experimental conditions: an in vitro crossover study

Background

Proper manipulation of fibreoptic bronchoscopes is essential for successful tracheal intubation or diagnostic bronchoscopy. Failure of proper navigation and rotation of the fibrescope may lead to difficulties in advancing the fibrescope and might also be responsible for (unnecessary) difficulties and delays in fibreoptic tracheal intubation, with subsequent hypoxaemia. The present study, therefore, aimed to assess the effectiveness of tip rotation in flexible bronchoscopes in different experimental conditions.

Methods

Five differently sized pairs of fibrescopes (outer diameters of 2.2, 2.4, 3.5, 4.2, and 5.2 mm) were inserted into paediatric airway manikins via an appropriately sized laryngeal mask and were turned clockwise or anticlockwise at the fibrescope body or cord to 45, 90, and 180°, with the cord held either straight or bent. The primary outcome measure was the ratio of rotation measured at the tip over the rotation performed with the fibrescope body or cord.

Results

Overall, the 'body' turn was significantly less effective when a bent cord was present (mean difference ranging from 29.8% (95% confidence interval 8.8-50.9) to 117.4% (93.6-141.2). This difference was diminished when the 'cord' turn was performed. Smaller fibrescopes, with outer diameters of 2.2 and 2.4 mm, were inferior with respect to the transmission of 'body' rotation to the tip.

Conclusions

'Cord' turning of the fibrescope appears to be more effective in rotating the tip than a turn of the fibrescope 'body' only. Straightening the fibrescope cord and combined 'body' and 'cord' turning are recommended.

Real-time geometry-aware augmented reality in minimally invasive surgery

The potential of augmented reality (AR) technology to assist minimally invasive surgery (MIS) lies in its computational performance and accuracy in dealing with challenging MIS scenes. Even with the latest hardware and software technologies, achieving both real-time and accurate augmented information overlay in MIS is still a formidable task. In this Letter, the authors present a novel real-time AR framework for MIS that achieves interactive geometric aware AR in endoscopic surgery with stereo views. The authors' framework tracks the movement of the endoscopic camera and simultaneously reconstructs a dense geometric mesh of the MIS scene. The movement of the camera is predicted by minimising the re-projection error to achieve a fast tracking performance, while the three-dimensional mesh is incrementally built by a dense zero mean normalised cross-correlation stereo-matching method to improve the accuracy of the surface reconstruction. The proposed system does not require any prior template or pre-operative scan and can infer the geometric information intra-operatively in real time. With the geometric information available, the proposed AR framework is able to interactively add annotations, localisation of tumours and vessels, and measurement labelling with greater precision and accuracy compared with the state-of-the-art approaches.

Hand-eye calibration using a target registration error model

Surgical cameras are prevalent in modern operating theatres and are often used as a surrogate for direct vision. Visualisation techniques (e.g. image fusion) made possible by tracking the camera require accurate hand-eye calibration between the camera and the tracking system. The authors introduce the concept of 'guided hand-eye calibration', where calibration measurements are facilitated by a target registration error (TRE) model. They formulate hand-eye calibration as a registration problem between homologous point-line pairs. For each measurement, the position of a monochromatic ball-tip stylus (a point) and its projection onto the image (a line) is recorded, and the TRE of the resulting calibration is predicted using a TRE model. The TRE model is then used to guide the placement of the calibration tool, so that the subsequent measurement minimises the predicted TRE. Assessing TRE after each measurement produces accurate calibration using a minimal number of measurements. As a proof of principle, they evaluated guided calibration using a webcam and an endoscopic camera. Their endoscopic camera results suggest that millimetre TRE is achievable when at least 15 measurements are acquired with the tracker sensor ∼80 cm away on the laparoscope handle for a target ∼20 cm away from the camera.

Design and evaluation of an augmented reality simulator using leap motion

Advances in virtual and augmented reality (AR) are having an impact on the medical field in areas such as surgical simulation. Improvements to surgical simulation will provide students and residents with additional training and evaluation methods. This is particularly important for procedures such as the endoscopic third ventriculostomy (ETV), which residents perform regularly. Simulators such as NeuroTouch, have been designed to aid in training associated with this procedure. The authors have designed an affordable and easily accessible ETV simulator, and compare it with the existing NeuroTouch for its usability and training effectiveness. This simulator was developed using Unity, Vuforia and the leap motion (LM) for an AR environment. The participants, 16 novices and two expert neurosurgeons, were asked to complete 40 targeting tasks. Participants used the NeuroTouch tool or a virtual hand controlled by the LM to select the position and orientation for these tasks. The length of time to complete each task was recorded and the trajectory log files were used to calculate performance. The resulting data from the novices' and experts' speed and accuracy are compared, and they discuss the objective performance of training in terms of the speed and accuracy of targeting accuracy for each system.

Impact of Successful Choanal Atresia Repair on the Nasal Mucosa: A Preliminary Study

Introduction  The main histological features of the nasal mucosa in choanal atresia are distorted cilia, marked increase of mucous submucosal glands associated with marked reduction of goblet cell density, and lymphocytic cellular infiltration.

Objective  To study the nasal mucosal changes in cases of choanal atresia after successful repair compared with pre-repair mucosal histological features.

Methods  Tissue samples were taken from the inferior turbinate of 3 patients (1 bilateral and 2 unilateral) who were successfully operated. Then, the biopsies were subjected to histopathological, histochemical and immunohistochemical studies. After that, the results were compared with pre-repair findings in the choanal atresia side and in the normal side.

Results  Four biopsies (4 repaired choanal atresia sides) of the mucosa of the inferior turbinate revealed that 1 patient (who had a bilateral choanal atresia repaired), after achieving a patent choana for 8 months, had not completely recovered a normal nasal mucosa. The other 2 patients, after 18 and 23 months of achieving a patent choana, showed normal nasal cavities.

Conclusion  The main histological features of the nasal mucosa in choanal atresia could be reversed by surgery, making the patients regain their choanal patency, with their mucosae changing back to normal gradually with time.

Laparoscopic Acetabular Fracture Fixation after Three-dimensional Modelling and Printing

Current surgical treatment of acetabular fractures is open reduction and internal fixation and requires a large incision resulting in considerable blood loss and a potentially long duration of recovery. We report a case of an acetabular fracture that received laparoscopic internal fixation after three-dimensional (3D) modelling and printing of the acetabulum. A 43 year old male fell from a height of 3 m resulting in a right acetabulum anterior column fracture. Thin section computed tomography scanning with 0.6 mm increments and subsequent 3D reconstruction was performed, and a 3D model of the acetabulum and fracture was printed. The steel reconstruction plate was prebent in vivo and placed into the optimized position based on the 3D modelling and the optimized insert orientation and measured screw length were determined. The fracture was reduced and the plate placed laparoscopically without complications, and the patient had excellent functional recovery. Acetabular fractures are complex injuries, and while minimally invasive surgical techniques are used in many fields, they are not common for the treatment of acetabular fractures. 3D modelling is commonly used in medicine, and although 3D printing is used in some fields, it has not found widespread use in orthopedics.

GuideWire Migrating into Murphy's Eye of Endotracheal Tube: An Unusual Complication of Percutaneous Dilational Tracheostomy

Percutaneous dilational tracheostomy (PDT) is a frequently carried out bedside procedure in a critical care setting. It is usually performed under fiberoptic endoscopic guidance. Studies with PDT performed with endoscopic guidance have reported lower complication rates than studies performed with “blind” PDT. We report a case where PDT was performed without endoscopic assistance and the j-shaped guidewire got stuck in the Murphy's eye of endotracheal tube causing difficulty in railroading of tracheostomy tube (TT).

Tracheobronchial foreign body removal in infants who had very small airways: A prospective clinical trial

BACKGROUND AND AIMS

Tracheobronchial foreign body aspiration is a life-threatening emergency. Using a rigid bronchoscope with optical forceps is the most effective method for foreign body removal. However, occasionally for some infants these instruments could not be used, as they may be too large for their small airways. Here, they present the apnea technique with only an optical forceps for foreign body removal in infants with very small airways.

METHODS

Foreign bodies were removed using only an optical forceps for infants who had very small diameter airways. After general anesthesia, the suspension laryngoscope was set just above the vocal cord, and the inserted ventilation tube was pulled out, followed by a new one being inserted through the suspension laryngoscope and placed at the trachea. With the oxygen saturation at 100%, we pulled out the ventilation tube and inserted the optical forceps with an endoscope. After that, the foreign body was removed by the optical forceps.

RESULTS

The foreign body removal using only an optical forceps is technically feasible for an infant. The mean operation time was 40.33 ± 8.06 min, and the hospital stay was 2.25 ± 0.62 days. When we pulled out the ventilation tube, the O₂ saturation mean time (apnea time) was 106.25 ± 14.30 sec. In 12 infants, the foreign body was removed completely without a need for a second procedure.

CONCLUSIONS

The apnea technique for the removal of foreign body from the airway, using only an optical forceps with an endoscope, is useful in infants who had very small airways.

Methodological proposal for validation of the disinfecting efficacy of an automated flexible endoscope reprocessor

OBJECTIVE

to elaborate and apply a method to assess the efficacy of automated flexible endoscope reprocessors at a time when there is not an official method or trained laboratories to comply with the requirements described in specific standards for this type of health product in Brazil.

METHOD

the present methodological study was developed based on the following theoretical references: International Organization for Standardization (ISO) standard ISO 15883-4/2008 and Brazilian Health Surveillance Agency (Agência Nacional de Vigilância Sanitária - ANVISA) Collegiate Board Resolution (Resolução de Diretoria Colegiada - RDC) no. 35/2010 and 15/2012. The proposed method was applied to a commercially available device using a high-level 0.2% peracetic acid-based disinfectant.

RESULTS

the proposed method of assessment was found to be robust when the recommendations made in the relevant legislation were incorporated with some adjustments to ensure their feasibility. Application of the proposed method provided evidence of the efficacy of the tested equipment for the high-level disinfection of endoscopes.

CONCLUSION

the proposed method may serve as a reference for the assessment of flexible endoscope reprocessors, thereby providing solid ground for the purchase of this category of health products.

OBJETIVO

propor e aplicar um método para a avaliação da eficácia de processadoras automáticas de endoscópios flexíveis, em um momento em que ainda não existe no Brasil um método oficial, nem tampouco laboratórios capacitados que contemplem os requisitos das normas específicas aplicáveis a esse tipo de produto para a saúde.

MÉTODO

caracterizou-se como pesquisa metodológica e foi desenvolvido com base em três referenciais teóricos: norma técnica International Organization for Standardization (ISO) - ISO 15883-4/2008, Resolução de Diretoria Colegiada (RDC) nº35/2010 e RDC nº15/2012 da Agência Nacional de Vigilância Sanitária (ANVISA). Aplicou-se o método proposto em um equipamento específico, comercialmente disponível, utilizando desinfetante de alto nível à base de ácido peracético 0,2%.

RESULTADOS

o método de avaliação proposto mostrou-se robusto, à medida que as recomendações das legislações pertinentes ao equipamento avaliado foram incorporadas, com algumas adaptações para sua exequibilidade. A aplicação do método proposto permitiu atestar a eficácia do equipamento utilizado na desinfecção de alto nível de endoscópios.

CONCLUSÃO

o método pode servir de referência para a avaliação de reprocessadoras de endoscópios flexíveis, subsidiando a aquisição dessa categoria de produtos para a saúde.

OBJETIVO

elaborar y aplicar un método para evaluar la eficacia de reprocesadores automatizados de endoscopios flexibles en un momento en el que no hay un método oficial o laboratorios capacitados para cumplir con los requisitos descritos en las normas específicas para este tipo de producto para la salud en Brasil.

MÉTODO

el presente estudio metodológico fue desarrollado en base a las siguientes referencias teóricas: Organización Internacional de Normalización (International Organization for Standardization - ISO) norma ISO 15883-4/2008 y Agencia Nacional de Vigilancia de la Salud de Brasil (Agência Nacional de Vigilância Sanitária - ANVISA) Resolución del Directorio Colegiado (Resolução de Diretoria Colegiada - RDC) № 35/2010 y 15/2012. El método propuesto se aplicó a un dispositivo comercialmente disponible usando un desinfectante al 0,2% a base de ácido peracético de alto nivel.

RESULTADOS

el método de evaluación propuesto se evaluó como fuerte después de que las recomendaciones formuladas en la legislación pertinente se incorporaron con algunos ajustes para garantizar su factibilidad. La aplicación del método propuesto proporciona evidencia de la eficacia de los equipos de prueba para la desinfección de alto nivel de endoscopios.

CONCLUSIÓN

el método propuesto puede servir de referencia para la evaluación de reprocesadores de endoscopios flexibles, proporcionando de este modo bases sólidas para la compra de esta categoría de productos de salud.

[Clinical application of iodine solution staining in the diagnosis of early laryngeal cancer with electronic endoscope]

Objective:To discuss the feasibility and clinical application value of the laryngeal iodine staining under the electronic fiber laryngoscope.Method:Will meet the inclusion criteria of 90 patients, randomly divided into three groups, set to a, b, c group.a ,all patients in the a group were examined by electronic fiber mirror, NBI mode and 0.5% Lugol liquid iodine staining method in three ways. b, all patients in the b group were examined by electronic fiber mirror, NBI mode and 1.0% Lugol liquid iodine staining method in three ways. c,all patients in the c group were examined by electronic fiber mirror, NBI mode and 1.5% Lugol liquid iodine staining method in three ways. The location and range of positive lesions were recorded in each person of the three groups, positive lesions were biopsy, if the positive lesion is repeated, the site can only take a biopsy. As a diagnostic gold standard, the results of the other tests were compared with the results of other tests. And to observe the color of iodine in the throat, all patients were followed up for 24 hours in the presence of dyspnea, severe pain in the throat and other symptoms, and 24 hours after the examination again electronic fiber optic examination. Biopsy was performed in all patients, as gold standard. Using chi square test, inspection standardP <0.05.Result:As the solution of the iodine concentration increased, the rate of the laryngeal was cancer gradually increased. Ninety people take part in the experiment, no one has serious complications. All the patients have no significant inflammation on the mucous membrane of the throat and the subglottic airway afer 24 hours, by the electronic fiber laryngoscope. 1% and the following concentration of Lugol solution for iodine staining, sensitivity to the diagnosis of early laryngeal cancer was higher than that of electronic fiber,the two methods were compared, and the statistical analysis was performed(P >0.05). No statistical significance. There was no significant difference in the diagnosis of early laryngeal cancer. Contrast between iodine stain with 1.5% Lugol solution and electronic fiber sus pension, after statistical calculation(P <0.05);both are statistically significant, and the difference is significant.Comparison of iodine stain with 1.5% Lugol solution and NBI examination, make statistical analysis,P >0.05, there was no significant difference between the both.Conclusion:The 1.5% and below the concentration of the iodine staining under the electronic fiber laryngoscope can be safely applied to inspect the throat, and 1.5% Lugol iodine solution in the diagnosis of laryngeal cancer in the early stage of laryngeal cancer is better than using electronic, and has a certain value in clinical application.

Endoscopic removal of bullets from the cranial ridge junction region via transoral and transnasal approaches: Two case reports and review of literature

Endoscopes in otolaryngology may facilitate accessing the lumens and sites such as upper cervical spine with minimally invasive surgical exposure. Here, we present 2 interesting cases of youth who underwent endoscopic removal of bullets in the cranial ridge junction region.The first case was a 20-year-old young man who underwent a gunshot in the face. A CT scan showed that a metallic foreign body located inside the right lateral body of Atlas that presented a comminuted fracture. The second case a 36-year-old man who also underwent a gunshot in the face. CT scan showed a foreign body lodged in the soft tissues before the right anterior arch of Atlas cone (C1) that presented a fracture. The bullets in these 2 patients were removed under the endoscopes with minimal damage, respectively. The patients were discharged without neck activity obstacle.The advantage of endoscopic technique is obvious because limited visualization does not damage surrounding tissues, thus decreasing surgical complications. This was an interesting experience of surgical operation in this region.

Use of adaptive hybrid filtering process in Crohn's disease lesion detection from real capsule endoscopy videos

The aim of this Letter is to present a new capsule endoscopy (CE) image analysis scheme for the detection of small bowel ulcers that relate to Crohn's disease. More specifically, this scheme is based on: (i) a hybrid adaptive filtering (HAF) process, that utilises genetic algorithms to the curvelet-based representation of images for efficient extraction of the lesion-related morphological characteristics, (ii) differential lacunarity (DL) analysis for texture feature extraction from the HAF-filtered images and (iii) support vector machines for robust classification performance. For the training of the proposed scheme, namely HAF-DL, an 800-image database was used and the evaluation was based on ten 30-second long endoscopic videos. Experimental results, along with comparison with other related efforts, have shown that the HAF-DL approach evidently outperforms the latter in the field of CE image analysis for automated lesion detection, providing higher classification results. The promising performance of HAF-DL paves the way for a complete computer-aided diagnosis system that could support the physicians' clinical practice.

Foot-controlled robotic-enabled endoscope holder for endoscopic sinus surgery: A cadaveric feasibility study

OBJECTIVES/HYPOTHESIS

To evaluate the feasibility of a unique prototype foot-controlled robotic-enabled endoscope holder (FREE) in functional endoscopic sinus surgery.

STUDY DESIGN

Cadaveric study.

METHODS

Using human cadavers, we investigated the feasibility, advantages, and disadvantages of the robotic endoscope holder in performing endoscopic sinus surgery with two hands in five cadaver heads, mimicking a single nostril three-handed technique.

RESULTS

The FREE robot is relatively easy to use. Setup was quick, taking less than 3 minutes from docking the robot at the head of the bed to visualizing the middle meatus. The unit is also relatively small, takes up little space, and currently has four degrees of freedom. The learning curve for using the foot control was short. The use of both hands was not hindered by the presence of the endoscope in the nasal cavity. The tremor filtration also aided in the smooth movement of the endoscope, with minimal collisions.

CONCLUSION

The FREE endoscope holder in an ex-vivo cadaver test corroborated the feasibility of the robotic prototype, which allows for a two-handed approach to surgery equal to a single nostril three-handed technique without the holder that may reduce operating time. Further studies will be needed to evaluate its safety profile and use in other areas of endoscopic surgery.

LEVEL OF EVIDENCE

NA. Laryngoscope, 126:566-569, 2016.

Bacterially Antiadhesive, Optically Transparent Surfaces Inspired from Rice Leaves

Because of the growing prevalence of antimicrobial resistance strains, there is an increasing need to develop material surfaces that prevent bacterial attachment and contamination in the absence of antibiotic agents. Herein, we present bacterial antiadhesive materials inspired from rice leaves. "Rice leaf-like surfaces" (RLLS) were fabricated by a templateless, self-masking reactive-ion etching approach. Bacterial attachment on RLLS was characterized under both static and dynamic conditions using Gram-negative Escherichia coli O157:H7 and Gram-positive Staphylococcus aureus. RLLS surfaces showed exceptional bacterial antiadhesion properties with a >99.9% adhesion inhibition efficiency. Furthermore, the optical properties of RLLS were investigated using UV-vis-NIR spectrophotometry. In contrast to most other bacterial antiadhesive surfaces, RLLS demonstrated optical-grade transparency (i.e., ≥92% transmission). We anticipate that the combination of bacterial antiadhesion efficiency, optical grade transparency, and the convenient single-step method of preparation makes RLLS a very attractive candidate for the surfaces of biosensors; endoscopes; and microfluidic, bio-optical, lab-on-a-chip, and touchscreen devices.

Posterosuperior extension of caudal septal incision for endoscopic septoplasty

BACKGROUND

Endoscopic septoplasty provides several advantages over traditional headlight septoplasty in terms of better visualization. However, surgeons may experience frequent soiling of the endoscope lens by blood from the incision site and awkwardness in finding adequate space for the endoscope and dissectors in narrow septal mucosal tunnels. Here, we propose a simple and safe modification for endoscopic septoplasty.

METHODS

A total of 21 patients underwent endoscopic septoplasty using a new modification. Briefly, a posterosuperior extension incision was made along the dorsal septum at the superior end of the caudal septal incision, and a posteroinferior-based septal mucosal flap was developed and placed laterally over the inferior turbinate during surgery.

RESULTS

The new modification reported here provided clear endoscopic visualization and a comfortable working space from making the incision to closing the wound. In addition, no significant complications related to this modification, such as increased operation time, intraoperative or postoperative bleeding, delayed wound healing, synechia, nasal septal perforation, and reduced olfaction, were observed.

CONCLUSION

Adding a posterosuperior extension incision to the caudal septal incision might be a safe and efficient modification for endoscopic septoplasty.

Colour-reproduction algorithm for transmitting variable video frames and its application to capsule endoscopy

Presented is a new power-efficient colour generation algorithm for wireless capsule endoscopy (WCE) application. In WCE, transmitting colour image data from the human intestine through radio frequency (RF) consumes a huge amount of power. The conventional way is to transmit all R, G and B components of all frames. Using the proposed dictionary-based colour generation scheme, instead of sending all R, G and B frames, first one colour frame is sent followed by a series of grey-scale frames. At the receiver end, the colour information is extracted from the colour frame and then added to colourise the grey-scale frames. After a certain number of grey-scale frames, another colour frame is sent followed by the same number of grey-scale frames. This process is repeated until the end of the video sequence to maintain the colour similarity. As a result, over 50% of RF transmission power can be saved using the proposed scheme, which will eventually lead to a battery life extension of the capsule by 4-7 h. The reproduced colour images have been evaluated both statistically and subjectively by professional gastroenterologists. The algorithm is finally implemented using a WCE prototype and the performance is validated using an ex-vivo trial.

Urine Flow Dynamics Through Prostatic Urethra With Tubular Organ Modeling Using Endoscopic Imagery

Voiding dysfunction is common in the aged male population. However, the obstruction mechanism in the lower urinary tract and critical points for obstruction remains uncertain. The aim of this paper was to develop a system to investigate the relationship between voiding dysfunction and alteration of the shape of the prostatic urethra by processing endoscopic video images of the urethra and analyzing the fluid dynamics of the urine stream. A panoramic image of the prostatic urethra was generated from cystourethroscopic video images. A virtual 3-D model of the urethra was constructed using the luminance values in the image. Fluid dynamics using the constructed model was then calculated assuming a static urethra and maximum urine flow rate. Cystourethroscopic videos from 11 patients with benign prostatic hyperplasia were recorded around administration of an alpha-1 adrenoceptor antagonist. The calculated pressure loss through the prostatic urethra in each model corresponded to the prostatic volume, and the improvements of the pressure loss after treatment correlated to the conventional clinical indices. As shown by the proposed method, the shape of the prostatic urethra affects the transporting urine fluid energy, and this paper implies a possible method for detecting critical lesions responsible for voiding dysfunction. The proposed method provides critical information about deformation of the prostatic urethra on voiding function. Detailed differences in the various types of relaxants for the lower urinary tract could be estimated.

Instructive head-mounted display system: pointing device using a vision-based finger tracking technique applied to surgical education

Introduction

The head-mounted display (HMD) system is a novel personalized imaging monitoring system for use in a medical setting.

Aim

To support interactive intraoperative communication among HMD wearers, we integrated vision-based finger tracking into our system as a pointing device.

Material and methods

Our vision-based finger tracking system is composed of a commercially available real-time video camera, which is mounted on the modern HMD, and computer software that enables tracking of the tip of the operator's index finger and superimposing the marker on the endoscopic view.

Results

We used this system in an experimental demonstration. The operator used the finger-tracking pointer to explain the intraoperative findings of transurethral resection for bladder cancer to medical students.

Conclusions

This finger tracking system-based pointing device can function as a supportive tool for the HMD system, enabling interactive instruction and communication between the operator and other attending physicians or medical students.

Retrograde intrarenal surgery monotherapy versus shock wave lithotripsy for stones 10 to 20 mm in preschool children: a prospective, randomized study

PURPOSE

We compared the outcome of retrograde intrarenal surgery monotherapy vs shock wave lithotripsy for stones 10 to 20 mm in preschool children.

MATERIALS AND METHODS

This prospective study included 60 children with a mean ± SD age of 2.4 ± 1.3 years. Patients were randomly divided into 2 groups. Group 1 underwent shock wave lithotripsy and group 2 underwent retrograde intrarenal surgery as monotherapy. Retrograde intrarenal surgery was started using a 7.5Fr semirigid ureteroscope (Storz®) and the holmium laser, and completed by the Flex X™2 flexible ureterorenoscope. A ureteral access sheath was not used and only hydrodilatation was performed. Patients were evaluated preoperatively by ultrasound and plain abdominopelvic x-ray. Followup was 3 months.

RESULTS

The stone-free rate after a single session treatment was 70% and 86.6% in groups 1 and 2, respectively. Mean operative time was 27.9 ± 3.5 and 40 ± 7.8 minutes, mean fluoroscopy exposure time was 60 ± 42 and 50 ± 35 seconds, and mean hospital stay was 6 ± 2 and 12 ± 8 hours, respectively. No major complication occurred in either group and no child in either group received blood transfusion. Nine group 1 patients needed a second shock wave lithotripsy session, of whom 2 required a third session. At 3 months the overall stone-free rate was 93.3% and 96.6% in groups 1 and 2, respectively.

CONCLUSIONS

Retrograde intrarenal surgery is an option for treating medium sized renal stones in preschool children with results comparable to those of shock wave lithotripsy and a safe short-term outcome.

Comparison of haemodynamic responses to intubation: Flexible fibreoptic bronchoscope versus bonfils rigid intubation endoscope

Background:

The flexible fibreoptic bronchoscope and bonfils rigid intubation endoscope are being widely used for difficult intubations.

Methods:

The haemodynamic response to intubation under general anaesthesia was studied in 60 adult female patients who were intubated using either flexible fibreoptic bronchoscope or bonfils rigid intubation endoscope (30 in each group). Non-invasive blood pressure and heart rate (HR) was recorded before induction of anaesthesia, immediately after induction, at the time of intubation and, thereafter, every minute for the next 5 min. The product of HR and systolic blood pressure (rate pressure product) at every point of time was also calculated.

Statistical Analyses:

Graph pad prism, 5.0 statistical software, independent t test and repeated measure ANOVA test were used.

Results:

Both bonfils rigid intubation endoscope and flexible fibreoptic bronchoscope required a similar time (less than 1 min) for orotracheal intubation. After intubation, there was a significant increase in HR, blood pressure and rate pressure product (P<0.001) in both the groups compared with the baseline and post-induction values. There was no significant difference in HR, blood pressure and rate pressure product at any of the measuring points or in their maximum values during observation between the two groups. The time required for recovery of systolic blood pressure and HR to post-induction value (±10%) was not significantly different between the two groups (more than 2 min).

Conclusion:

In female adults under general anaesthesia, bonfils rigid intubation endoscope and flexible fibreoptic bronchoscope require a similar time for successful orotracheal intubation and cause a similar magnitude of haemodynamic response.

Improvement in Cormack and Lehane grading with laparoscopic assistance during tracheal intubation

BACKGROUND

To use laparoscope as an easily available and easy to use alternative option to videolaryngoscope.

AIMS

The aim of the study was to assess the improvement in the glottic view using a conventional direct laryngoscope (DL) assisted by a laparoscope with its endovision system along with the time taken for tracheal intubation.

SETTINGS AND DESIGN

A prospective, double blind, randomized, controlled study was conducted in a tertiary care centre.

METHODS

Sixty patients with American Society of Anesthesiologists (ASA) physical status I and II requiring general anaesthesia and tracheal intubation for elective surgery were included in the study. The patients were anaesthetized, paralysed, DL was performed and Cormack and Lehane grade (C and L) noted, followed by the introduction of the laparoscope alongside the flange of the Macintosh laryngoscope and a further C and L grading done as seen on monitor. Demographic data, ASA physical status, airway assessment, mouth opening, modified Mallampatti class, jaw protrusion, thyromental and sternomental distances, optimal external laryngeal manipulation, time taken for intubation, pulse oximetry, blood on; tracheal tube, lip, dentition or mucosal trauma, sore throat, hoarseness of voice, excessive secretions and regurgitation were recorded.

STATISTICAL ANALYSIS

Statistical analysis was done using statistics package for social sciences software (17.0 version). A P-value less than 0.05 was considered statistically significant.

RESULTS

Eighty-three percent of the patients showed improvement in glottic view after laparoscopic assistance. Eighty-one and 85% of the patients with C and L grade II and III respectively on DL had an improved glottic view with this technique. The mean time to intubate was 37 seconds.

CONCLUSIONS

Laparoscopic assistance provided a better glottic view than DL in most patients (83%). It has a potential advantage over standard DL in difficult intubation.

Robotic neurosurgery: a preliminary study using an active vision-guided robotic arm for bone drilling and endoscopic manoeuvres

BACKGROUND

Surgical robots have been appearing in operating rooms over the past decade, and neurosurgery has been one of the pioneers in this area. In neurosurgery, the clinical use of robots has been limited to stereotactic procedures and endoscopic manoeuvres, although the brain is a unique organ and well-suited for robotic application. The aim of this study was to assess the ability of our vision-guided robotic system to perform basic neurosurgical procedures.

METHODS

THE STUDY WAS DIVIDED INTO TWO PARTS: bone drilling and endoscopic manoeuvres. The robotic system was instructed to recognise targets on artificial skull models placed in different positions (supine, lateral, sitting, and prone) and to make burr holes. A total of 10 selected burr holes were used to assess the capability of the robot to insert an endoscope.

RESULTS

The accuracy ranged 0.1-1.0 mm with repeatability ranged 0.03-0.92 mm.

CONCLUSION

Generally, the present robotic system is able to perform the surgical tasks. However, further study is needed to refine the robotic system, including the safety mechanisms.

Gasless endoscopic thyroidectomy via an anterior chest wall approach using a flap-lifting system

PURPOSE

Endoscopic thyroidectomy (ET) requires a proper working space for adequate visualization of anatomical structures and proper instrument manipulation. The purpose of this prospective study was to estimate the feasibility and safety of ET using an anterior chest wall approach without gas insufflation.

MATERIALS AND METHODS

The working space was created under a direct and endoscopic view through a 3-cm incision on the anterior chest wall. A retracting device was then inserted to establish the working space, and subsequent procedures were performed endoscopically. All data were reviewed using a prospective database.

RESULTS

We performed 30 ETs in patients with benign thyroid tumors from December 2003 to December 2005. The procedures were completed successfully in 29 patients (mean operative time: 160.6 min; range: 90-345 min). One patient with ET was converted to open thyroidectomy secondary to substernal extension of the tumor. None of the patients developed permanent postoperative hypocalcemia or recurrent laryngeal nerve paralysis. Three patients exhibited some degree of transient recurrent laryngeal nerve palsy.

CONCLUSION

These data suggest that gasless ET using an anterior chest wall approach is safe and feasible in selected patients for treating benign thyroid tumors. This technique may offer good operative working space when performed by surgeons with relatively low-volume ET practices.

Significance of non-erosive minimal esophageal lesions in gastro-esophageal reflux disorder

BACKGROUND

Non-erosive reflux disorder, which represents more than 60% of gastro-esophageal reflux disorders, lacks objective parameters for diagnosis. The purpose of this study was to evaluate the correlation between non-erosive minimal lesions at the lower esophagus and gastro-esophageal reflux disorder.

METHODS

Patients were asked to answer a symptom questionnaire. The endoscopic findings were either graded by LA classification or recorded as non-erosive minimal lesions. Patients with minimal lesions were treated with rabeprazole or a placebo and responses were evaluated at weeks 1 and 4.

RESULTS

In 8 centers, 3454 patients were screened. In patients with heartburn or acid regurgitation as the most bothersome symptom, 23.7% had endoscopy negative reflux disorder, 40.1% showed minimal lesions, and 36.20% had mucosal break esophagitis. Thirty-four percent of patients with minimal lesions and 39.1% of patients with LA 'grade A' mild esophagitis reported typical reflux symptoms as their main symptom. In patients with minimal lesions, medication with rabeprazole reduced symptoms significantly at weeks 1 and 4, but not with the placebo.

CONCLUSION

Patients with non-erosive minimal esophageal lesions had similar reflux symptoms comparable to those with mild erosive reflux esophagitis, and reflux symptoms were improved with a short-term proton pump inhibitor. Thus, non-erosive minimal esophageal lesion constitutes a great part of gastro-esophageal reflux disorder.