Surgical Gesture Research Articles

The Alfieri’s edge-to-edge technique for mitral valve repair: from a historical milestone of cardiac surgery to the origin of the transcatheter era

After 30 years since its introduction, the edge-to-edge technique has become one of the most popular and adopted worldwide for surgical repair of mitral regurgitation. The success of this procedure could possibly be explained by its unique simplicity and high level of reproducibility. Indeed, it possesses the ability of being very versatile and it has been used in a wide spectrum of mitral valve pathologies and lesions: from degenerative to functional disease, from posterior to anterior leaflet lesions, including commissural defects. The rapidity of this easy surgical gesture has also enhanced its application in minimally invasive approaches. Finally, it has become a true milestone for the era of transcatheter correction of mitral regurgitation. Here, we describe the history and evolution of this breakthrough in the world of cardiac surgery.

A Novel Dissection Gesture Classification to Characterize Robotic Dissection Technique for Renal Hilar Dissection.

Deconstruction of robotic surgical gestures into semantic vocabulary yields an effective tool for surgical education. In this study we disassembled tissue dissection into basic gestures, created a classification system, and showed its ability to distinguish between experts and novices. Videos of renal hilum preparation during robotic assisted partial nephrectomies were manually reviewed to identify all discrete surgical movements. Identified dissection movements were classified into distinct gestures based on the consensus of 6 expert surgeons. This classification system was then employed to compare expert and novice dissection patterns during the renal hilum preparation. A total of 40 robotic renal hilum preparation videos were reviewed, representing 16 from 6 expert surgeons (100 or more robotic cases) and 24 from 13 novice surgeons (fewer than 100 robotic cases). Overall 9,819 surgical movements were identified, including 5,667 dissection movements and 4,152 supporting movements. Nine distinct dissection gestures were identified and classified into the 3 categories of single blunt dissection (spread, peel/push, hook), single sharp dissection (cold cut, hot cut and burn dissect) and combination gestures (pedicalize, 2-hand spread, and coagulate then cut). Experts completed 5 of 9 dissection gestures more efficiently than novices (p ≤0.033). In consideration of specific anatomical locations, experts used more peel/push and less hot cut while dissecting the renal vein (p <0.001), and used more pedicalize while dissecting the renal artery (p <0.001). Using this novel dissection gesture classification system, key differences in dissection patterns can be found between experts/novices. This comprehensive classification of dissection gestures may be broadly applied to streamline surgical education.

A High-Fidelity Hybrid Virtual Reality Simulator of Aneurysm Clipping Repair With Brain Sylvian Fissure Exploration for Vascular Neurosurgery Training.

Microsurgery clipping is one of the most challenging surgical interventions in neurosurgery. The opportunities to train residents are scarce, but the need for accumulating practice is mandatory. New simulating tools are needed for skill learning. The design, implementation, and assessment of a new hybrid aneurysm clipping simulator are presented. It consists of an ergonomic workstation with a patient head mannequin and a physics-based virtual reality simulation with bimanual haptic feedback. The simulator recreates scenarios of microsurgery from the patient fixation and the exploration of the brain lobes through Sylvian fissure and vascular structures to the aneurysm clipping. Skill metrics were introduced, including monitoring of gestures movements, exerted forces, tissue displacements, and precision in clipping. Two experimental conditions were tested: (1) simple clipping without brain tissue exploration and (2) clipping the aneurysm with brain Sylvian fissure exploration. Differences in the bimanual gestures were observed between both conditions. The quantitative measurements of tissue displacement of the brain lobes exhibited more tissue retrieval for the surgical gestures of neurosurgeons. Appraisal with questionnaires showed positive scores by neurosurgeons in all items evaluating the usability and realism of the simulator. The simulator was well accepted and feasible for training purposes. The analysis of the interactions with virtual tissues offers information to establish differential and common patterns between tested groups and thus useful metrics for skill evaluation of practitioners. Future work can lead to other tasks during the intervention and the inclusion of more clinical cases.

Haptic Intracorporeal Palpation Using a Cable-Driven Parallel Robot: A User Study.

Intraoperative palpation is a surgical gesture jeopardized by the lack of haptic feedback which affects robotic minimally invasive surgery. Restoring the force reflection in teleoperated systems may improve both surgeons' performance and procedures' outcome. A force-based sensing approach was developed, based on a cable-driven parallel manipulator with anticipated seamless and low-cost integration capabilities in teleoperated robotic surgery. No force sensor on the end-effector is used, but tissue probing forces are estimated from measured cable tensions. A user study involving surgical trainees (n = 22) was conducted to experimentally evaluate the platform in two palpation-based test-cases on silicone phantoms. Two modalities were compared: visual feedback alone and both visual + haptic feedbacks available at the master site. Surgical trainees' preference for the modality providing both visual and haptic feedback is corroborated by both quantitative and qualitative metrics. Hard nodules detection sensitivity improves (94.35 ± 9.1% vs 76.09 ± 19.15% for visual feedback alone), while also exerting smaller forces (4.13 ± 1.02 N vs 4.82 ± 0.81N for visual feedback alone) on the phantom tissues. At the same time, the subjective perceived workload decreases. Tissue-probe contact forces are estimated in a low cost and unique way, without the need of force sensors on the end-effector. Haptics demonstrated an improvement in the tumor detection rate, a reduction of the probing forces, and a decrease in the perceived workload for the trainees. Relevant benefits are demonstrated from the usage of combined cable-driven parallel manipulators and haptics during robotic minimally invasive procedures. The translation of robotic intraoperative palpation to clinical practice could improve the detection and dissection of cancer nodules.

Robot-based assistance in middle ear surgery and cochlear implantation: first clinical report.

Middle ear surgery may benefit from robot-based assistance to hold micro-instruments or an endoscope. However, the surgical gesture performed by one hand may perturb surgeons accustomed to two-handed surgery. A robot-based holder may combine the benefits from endoscopic exposure and a two-handed technique. Furthermore, tremor suppression and accurate tool control might help the surgeon during critical surgical steps. The goal of this work was to study the safety of an otological robot-based assistant under clinical conditions in a limited series of patients. The RobOtol system has been used as an endoscope or a micro instrument holder for this series. Eleven cases were operated on with the robot as an endoscope holder for chronic otitis. Twenty-one cases were operated on with the robot as a micro-instrument holder for otosclerosis (9 cases), transtympanic tube placement (2 cases), or cochlear implantation (10 cases). No complications related to the robot manipulation occurred during surgery nor in postoperative. In the chronic otitis group, all perforations were sealed and 3-month postoperative pure-tone average air-bone gap (PTA ABG) was 15 ± 2.6dB. In the otosclerosis group, 1-month post-op PTA ABG was 10 ± 1dB. For cochlear implantation cases, a scala tympani insertion, a vestibular scala translocation occurred and a full scala vestibuli insertion was observed in 7, 2 and 1 case, respectively. The RobOtol system has reached the clinical stage. It could be used safely and with accurate control as an endoscope holder or a micro instrument holder in 32 cases.

Coracoid tunnels in open and arthroscopic treatment of acromioclavicular dislocation: an experimental cadaveric study.

Treatment of acromioclavicular joint (ACJ) dislocation is not encoded uniquely. Type I and II injuries are usually treated conservatively, while types IV, V and VI surgically. Controversy still exists over the treatment of type III injuries. In the operative approach, there is no agreement on the best surgical technique. Our purpose is to compare the mini-open and arthroscopic approach focusing on the evaluation of the anatomical precision of the coracoid drilling. This is a controlled laboratory study. Ten fresh-frozen cadaveric shoulders were randomly assigned to the two techniques in order to compare them. We performed essential surgical gestures to drill the tunnel using MINAR® System (mini-open) and Dog-Bone® (ARTHREX, arthroscopic). The anatomical specimens were then subjected to CT-scan investigation. We statistically evaluated the precision of these two techniques analyzing DICOM files using two parameters. Parameter 1 evaluates the tunnel entry area on the superior side of the coracoid. Parameter 2 describes the orientation of the tunnel. There are no statistically significant differences (95% confidence level) between arthroscopic and mini-open approach about the precision in the location of the coracoid hole, regarding the entry area (p = 1.00) and the orientation (p = 0.196). The evidences collected enable the orthopedic surgeon to choose equally between the two techniques in the treatment of AC joint dislocation toward precision.

Evaluation of Deep Learning Models for Identifying Surgical Actions and Measuring Performance

When evaluating surgeons in the operating room, experienced physicians must rely on live or recorded video to assess the surgeon's technical performance, an approach prone to subjectivity and error. Owing to the large number of surgical procedures performed daily, it is infeasible to review every procedure; therefore, there is a tremendous loss of invaluable performance data that would otherwise be useful for improving surgical safety. To evaluate a framework for assessing surgical video clips by categorizing them based on the surgical step being performed and the level of the surgeon's competence. This quality improvement study assessed 103 video clips of 8 surgeons of various levels performing knot tying, suturing, and needle passing from the Johns Hopkins University-Intuitive Surgical Gesture and Skill Assessment Working Set. Data were collected before 2015, and data analysis took place from March to July 2019. Deep learning models were trained to estimate categorical outputs such as performance level (ie, novice, intermediate, and expert) and surgical actions (ie, knot tying, suturing, and needle passing). The efficacy of these models was measured using precision, recall, and model accuracy. The provided architectures achieved accuracy in surgical action and performance calculation tasks using only video input. The embedding representation had a mean (root mean square error [RMSE]) precision of 1.00 (0) for suturing, 0.99 (0.01) for knot tying, and 0.91 (0.11) for needle passing, resulting in a mean (RMSE) precision of 0.97 (0.01). Its mean (RMSE) recall was 0.94 (0.08) for suturing, 1.00 (0) for knot tying, and 0.99 (0.01) for needle passing, resulting in a mean (RMSE) recall of 0.98 (0.01). It also estimated scores on the Objected Structured Assessment of Technical Skill Global Rating Scale categories, with a mean (RMSE) precision of 0.85 (0.09) for novice level, 0.67 (0.07) for intermediate level, and 0.79 (0.12) for expert level, resulting in a mean (RMSE) precision of 0.77 (0.04). Its mean (RMSE) recall was 0.85 (0.05) for novice level, 0.69 (0.14) for intermediate level, and 0.80 (0.13) for expert level, resulting in a mean (RMSE) recall of 0.78 (0.03). The proposed models and the accompanying results illustrate that deep machine learning can identify associations in surgical video clips. These are the first steps to creating a feedback mechanism for surgeons that would allow them to learn from their experiences and refine their skills.

Neurophysiological Monitoring During Large Femoral and Pelvic Tumoral Resections

Background: Oncological femoral or pelvic resections and reconstruction have become an alternative to large amputations. However, one of the frequent risks is the neurological injury. The use of intraoperative evoked potentials allows its control in order to modify the surgical gestures. The purpose of this study was to evaluate the results of intraoperative neurophysiologic monitoring in large reconstructive arthroplasty surgeries. Case presentation: A prospective study (2012-2018) was performed, including 8 patients with 6 complete resections of the femur and 2 resections of the pelvis. In all cases, intraoperative lumbar plexus monitoring was performed using evoked potentials in order to analyze variations during surgery as well as a postoperative control. 100% could be correctly monitored throughout the surgery. In 4 cases, intraoperative anomalies were detected requiring modification of the surgery. Of these, postoperatively only one nerve injury persisted: a complete sciatic nerve injury due to an intraoperative vascular injury. Conclusion: Intraoperative neurophysiological monitoring is a very useful resource in large oncological resection, allowing detection of nerve distress due to manipulation or excessive limb traction during reconstruction. The use of somatosensory evoked potentials in large oncological resections can predict and minimize the risk of relevant postoperative nerve complications

Surgical Performance Analysis and Classification Based on Video Annotation of Laparoscopic Tasks.

Background and Objectives:Current approaches in surgical skills assessment employ virtual reality simulators, motion sensors, and task-specific checklists. Although accurate, these methods may be complex in the interpretation of the generated measures of performance. The aim of this study is to propose an alternative methodology for skills assessment and classification, based on video annotation of laparoscopic tasks.Methods:Two groups of 32 trainees (students and residents) performed two laparoscopic tasks: peg transfer (PT) and knot tying (KT). Each task was annotated via a video analysis software based on a vocabulary of eight surgical gestures (surgemes) that denote the elementary gestures required to perform a task. The extracted metrics included duration/counts of each surgeme, penalty events, and counts of sequential surgemes (transitions). Our analysis focused on trainees’ skill level comparison and classification using a nearest neighbor approach. The classification was assessed via accuracy, sensitivity, and specificity.Results:For PT, almost all metrics showed significant performance difference between the two groups (p < 0.001). Residents were able to complete the task with fewer, shorter surgemes and fewer penalty events. Moreover, residents performed significantly fewer transitions (p < 0.05). For KT, residents performed two surgemes in significantly shorter time (p < 0.05). The metrics derived from the video annotations were also able to recognize the trainees’ skill level with 0.71 – 0.86 accuracy, 0.80 – 1.00 sensitivity, and 0.60 – 0.80 specificity.Conclusion:The proposed technique provides a tool for skills assessment and experience classification of surgical trainees, as well as an intuitive way for describing what and how surgemes are performed.

GPS guided reverse shoulder arthroplasty.

Background and aim of the work:The reverse shoulder arthroplasty (RSA) has risen exponentially, this has entailed an increasing number of complications and reoperations. In RSA, loads are transferred directly to the glenoid component. As a result, failure of the glenoid component is one of the most common complications. CT 3D preoperative planning, patient-specific and the possibility of performing a more precise and controlled surgical gesture in the operating room are increasingly important. The use of the GPS navigation on CT 3D planning has proved to be useful above all in terms of accuracy, reliability and the possibility of reproducing the planned gesture preoperatively.Methods:This study analyzes the precision, safety, and reproducibility of the GPS system for the reverse shoulder prosthesis tested on 6 scapulohumeral cadaver specimens, subsequently subjected to anatomical dissection to verify the correct positioning of the glenoid components and the percentage of appropriateness in the field of planning previously virtually assumed.Results:Postoperative macroscopic dissection revealed no central peg perforated or screws malpositioned, no leaking from the bone or injury to the adjacent neurovascular structures. The average length of the screws was 42 mm (range 36 mm to 46 mm) for the lower screw and 40 mm for the upper one (range 36 mm to 42 mm).Conclusions:This cadaver study has shown that GPS navigation offers greater efficiency in baseplate and screws placement and can avoid intra- and postoperative complications. (www.actabiomedica.it)

Long-Term Results of ACL Reconstruction Using a Nonanatomic Double-Bundle Technique with Extra-Articular Reinforcement.

Extra-articular procedures for the improvement in rotational stability after anterior cruciate ligament (ACL) reconstruction have gained popularity in the last decade. This surgical gesture hoped to improve resistance to the high tensional forces affecting the ACL graft during cutting and pivoting movements of the lower extremity and eventually prevent ACL reconstruction failure. We performed this study to analyze the long-term results of patients undergoing ACL reconstruction using a nonanatomic double-bundle technique with an additional extra-articular augmentation. All the cases that underwent an ACL reconstruction using a nonanatomic double-bundle technique with an extra-articular reinforcement during the period between 1992 and 1997 were reviewed. The inclusion criteria for this study included a minimum follow-up of 10 years and age between 14 and 45 years at the time of the surgery. Forty patients were included in this series (34 males and 6 females). The mean Lysholm score after a minimum follow-up period of 10 years was 92.3 (standard deviation [SD], 9.4). The average preoperative Tegner score of the participants was 7.0 (SD, 1.1). This score decreased to 5.7 (SD, 1.2) at the end of follow-up. Follow-up X-rays were reviewed to assess the degenerative changes in the three knee compartments. Degenerative changes ≥ Kellgren-Lawrence grade 2 were observed in our six (15%) patients, all of them in the medial knee compartment. With these results, we conclude that double-bundle nonanatomic ACL reconstruction combined with an extra-articular reinforcement resembling the anterolateral ligament offers good overall long-term results, with relatively low rates of osteoarthritis.

A Gesture Recognition Algorithm for Hand-Assisted Laparoscopic Surgery.

Minimally invasive surgery (MIS) techniques are growing in quantity and complexity to cover a wider range of interventions. More specifically, hand-assisted laparoscopic surgery (HALS) involves the use of one surgeon’s hand inside the patient whereas the other one manages a single laparoscopic tool. In this scenario, those surgical procedures performed with an additional tool require the aid of an assistant. Furthermore, in the case of a human–robot assistant pairing a fluid communication is mandatory. This human–machine interaction must combine both explicit orders and implicit information from the surgical gestures. In this context, this paper focuses on the development of a hand gesture recognition system for HALS. The recognition is based on a hidden Markov model (HMM) algorithm with an improved automated training step, which can also learn during the online surgical procedure by means of a reinforcement learning process.

Revisión bibliográfica de la técnica de fenol y sus modificaciones

La matricectomía química mediante fenolización es probablemente la técnica más empleada en la resolución quirúrgica de la onicocriptosis. A pesar de ser una técnica podológica por excelencia y del vasto conocimiento empírico existente respecto a su uso, algunos gestos quirúrgicos realizados en su ejecución, así como los diferentes protocolos de curación continúan siendo objeto de debate y controversia entre los diferentes autores y la evidencia científica es aún limitada pese a la popularidad de la técnica. En el presenta artículo realizamos una revisión bibliográfica actualizada de los artículos más relevantes que ha sido publicados para defender diferentes modificaciones y en base a las mismas planteamos algunas ideas que pueden ser utilizadas en el diseño de estudios científicos prospectivos que contribuyan a ampliar el campo de conocimientos de la Podología y el nivel de evidencia científica de uno de los tratamientos más específicos y populares en nuestra profesión.

Vesicoureteral antireflux surgery with Lich–Gregoir technique without vesical drainage: Long-term results

ObjectiveTo describe our long-term experience with patients with vesicoureteral reflux (VUR) who underwent conventional surgery without postoperative bladder drainage. Material and methodsRetrospective review of 45 patients surgically treated by extravesical Lich–Gregoir's ureterovesical reimplantation without postoperative bladder drainage between 2010 and 2013. Results37 women (82.2%) and 8 men (17.8%). 28 patients with unilateral reflux, and 17 patients with bilateral reflux with a total of 62 operated kidneys. The mean age at surgery was 6 years (2–11 years).The main cause of surgical indication was the persistence of reflux in patients older than 6 years (73.3%); with grade III VUR (75.6%) being the most frequent. The mean surgical time was 44min (35–70) for unilateral reimplantation, and 70min (53–98) for bilateral ones.All patients presented spontaneous urination in the immediate postoperative period, without pain, no hematuria, full incontinence, and without a bladder balloon. None required bladder catheter placement, and hospital discharge was indicated between 7 and 36h postoperatively (mean 11h).All continued with spontaneous micturitions, without postvoid residual or voiding dysfunction during the 5-year follow-up. ConclusionThe thorough selection of the patients, the detailed surgical gestures, the bladder emptying without instrumentation of the urethra, together with a correct use of analgesics and early ambulation allowed excellent outcomes obtained in these patients managed with a short hospital stay and without bladder drainage, also demonstrating the safety of the procedure at 5 years of follow-up.

Recognition of Endovascular Manipulations using Recurrent Neural Networks.

The ability to accurately recognize elementary surgical gestures is a stepping stone to automated surgical assessment and surgical training. In this paper, a long short-term memory (LSTM) recurrent neural network is applied to the task of recognizing six typical manipulations in percutaneous coronary intervention (PCI). The manipulation mentioned above is referring to the atomic surgical operation, also called surgeme in many research. Instead of using the video data or kinematic data of surgical instruments, we propose to use the kinematic data of the operator's hand acquired by our wearable data glove to recognize the manipulations. To establish a baseline for comparison, a method based on Hidden Markov Model (HMM) is applied because HMM is frequently used in the tasks of surgical sequence learning. Two cross-validation schemes are used in our experiments, they both illustrate that our LSTM-based method far outperforms the HMM-based method. To our knowledge, this is the first paper to apply the LSTM recurrent neural network in the field of PCI.

SURGICAL TREATMENT OPTIONS IN COMPLICATED COLO-RECTAL CANCERS OPERATED IN EMERGENCY

Globally, the colo-rectal cancer is the 4th in frequency of all neoplasia and in Romania is the 2nd, with a yearly tendency of increasing the number of new cases. The poor symptomatology in the inchoate stages and also the deficiency of effective screening programs lead to frequently late presentation of patients, with tumors in complicated stages, when the surgical operations, very often can no longer have a curative intention. We will present the results of a retrospective study during 10 years (2007-2016) that included 431 patients with complicated colo-rectal cancers, admitted and operated in the 2nd Surgery Clinic of the Clinical Emergency County Hospital “Sf. Ap. Andrei” from Galati, Romania. In 133 cases (30,9%), most of them occlusive, it was practiced in emergency a left iliac anus, leaving the tumor in its place. The Hartmann operation was practiced in 97 cases (22,5%). Anytime it was possible, we practiced operations with radical intentions, like: right hemicolectomy, in 46 cases (10,7%), left hemicolectomy, in 13 cases (3%), segmentary colectomy with anastomosis, in 30 cases (6,9%). Regarding the surgical operations in emergency, many of them don’t have a radical intention, taking into account the local invasion of the tumors and the metastasis. In these situations, a first surgical gesture is required, as an intervention that is meant to save the patient’s life, solving only the complication.

Une clinique de l’apotemnophilie

IntroductionThe term of apotemnophily was used for the first time by Money in 1977 to name patients who desire an amputation of a healthy limb. CaseWe present a case report of a thirty-two years old military woman, who was hospitalized in a neurology service because of a chronic pain syndrome. The disorders began with a knee trauma complicated by chronic pain causing multiple complaints. At first sight, we are challenged by her desire to amputate her lower limb. DiscussionA literature review highlights controversial positions regarding the nosographic place of apotemnophily: initially classified within paraphilias, the desire to amputation of a healthy limb was later identified by some authors as a body integrity and identity disorders and then studied as a neurological disorder. The clinic of our patient open minded our diagnostic reasoning to other clinical entities such as a depressive disorder with melancholic and psychotic characteristics, an illness anxiety disorder, a body dysmorphic disorder. ConclusionBeyond the controversies, the main risk for these patients is to meet a doctor who decides to treat them with a mutilatory surgical gesture. The therapeutic challenge is to create the conditions of reception of this complaint and to hear the identity claim that it carries. The multidisciplinary approach associating psychiatrist, clinical psychologist and sometimes surgeons when it's appropriate, must prevent medical nomadism and must try to relieve the patient from the suffering of identity.

Resultados a largo plazo de cirugía antirreflujo vesicoureteral con técnica de Lich-Gregoir sin drenaje vesical

ObjectiveTo describe our long-term experience with patients with vesicoureteral reflux (VUR) who underwent conventional surgery without postoperative bladder drainage. Material and methodsRetrospective review of 45 patients surgically treated by extravesical Lich-Gregoir's ureterovesical reimplantation without postoperative bladder drainage between 2010 and 2013. Results37 women (82.2%) and 8 men (17.8%). 28 patients with unilateral reflux, and 17 patients with bilateral reflux with a total of 62 operated kidneys. The mean age at surgery was 6 years (2 to 11 years).The main cause of surgical indication was the persistence of reflux in patients older than 6 years (73.3%); with grade III VUR (75.6%) being the most frequent. The mean surgical time was 44minutes (35-70) for unilateral reimplantation, and 70minutes (53-98) for bilateral ones.All patients presented spontaneous urination in the immediate postoperative period, without pain, no hematuria, full incontinence, and without a bladder balloon. None required bladder catheter placement, and hospital discharge was indicated between 7 and 36hours postoperatively (mean 11h).All continued with spontaneous micturitions, without postvoid residual or voiding dysfunction during the 5-year follow-up. ConclusionThe thorough selection of the patients, the detailed surgical gestures, the bladder emptying without instrumentation of the urethra, together with a correct use of analgesics and early ambulation allowed excellent outcomes obtained in these patients managed with a short hospital stay and without bladder drainage, also demonstrating the safety of the procedure at 5 years of follow-up.

Channel-like 360° Isthmocele Treatment with a 16F Mini-Resectoscope: A Step-by-step Technique

To show the technique of hysteroscopic channel-like 360° repair of a cesarean scar defect performed with a Gubbini 16F miniresectoscope (GUBBINI system; Tontarra Medizintechnik, Tuttlingen, Germany). A step-by-step demonstration of the surgical technique using slides, pictures, and a video (an instructive video [Video 1]). A university hospital (Bologna University Hospital, Sant'Orsola-Malpighi Polyclinic, Bologna, Italy). A 35-year-old woman with a history of a previous cesarean section complaining of pelvic pain and postmenstrual spotting. With the vaginoscopic approach, the isthmocele was localized; a high-frequency 90° angled circular loop electrode and pure cutting current of 100 W were used to resect the fibrotic tissue of the proximal (step 1) and distal (step 2) part of the niche. We performed resection not only of the fibrotic tissue underneath the niche but also of the inflamed tissue placed around the niche and on the opposite site (the so-called channel-like 360° endocervical ablation). A high-frequency angled ball electrode was used to obtain focused coagulation of all residual inflamed tissue still present on the niche surface and on the cervical canal walls (step 3); the aim of this step is to facilitate the re-epithelialization of the cervical canal walls by the paraphysiological endocervical epithelium. The procedure was ended by controlling any bleeding of the endocervical vessels by reducing the inflow and pressure of the distending medium and by focused electrocauterization with a ball electrode (step 4). The operative time was 14 minutes. The small diameter of a 16F resectoscope and the use of a miniaturized loop without cervical dilation allow the operative procedures to be performed without cervical dilation and without anatomic distortion of the defect, reducing the risk of complications. The small diameter of the sheaths also makes the surgical gesture faster with an easier and faster approach to the niche compared with isthmocele hysteroscopic standard surgery. The presence of a uterine scar defect is usually asymptomatic or refers to postmenstrual spotting with dark red or brown discharge, dysmenorrhea, dyspareunia, chronic pelvic pain, infertility, or a dull sensation after menstruation. Several factors may play a role in isthmocele development such as a low uterine incision, a deficient suturing technique of the uterine incision, and patient-related factors that impair wound healing or increase inflammation or adhesion formation. Different techniques were used as reconstructive therapies of the cesarean scar defect including laparoscopic or robot-assisted laparoscopic excision, vaginal repair, or hysteroscopic treatment. All of these procedures remove or ablate the niche fibrotic tissue with the aim of relieving symptoms. Asymptomatic cases should not be treated. According to the most recent literature, hysteroscopic repair of a cesarean scar represents an effective and safe surgical option in cases of a symptomatic isthmocele. The persistence of symptoms has been reported in up to 18% of cases, so adequate counseling should be performed before the procedure.

Medical gesture recognition using dynamic arc length warping

Hand gesture recognition is a promising research area often used in applications of human–computer interactions in the medical field. In this paper, we present a novel approach to differentiate gestures based on an arc-length parametrization and a curvature analysis of 3D trajectories. This new method called dynamic arc length warping (DALW) can outperform classic multi dimensional-dynamic time warping (MD-DTW) algorithm as it is invariant to sensor location and more tolerant to temporal distortions. Experimental validation of the algorithm is presented using different gestures and sensors in biomedical applications: an exoskeleton apparatus, surgical gestures captured by an instrumented laparoscopic device and finally, a birth simulator with an instrumented forceps. A basic perceptron multilayer neural network was implemented in order to perform the classification. Results involve an average increase of 7.14% in the classification rates by using DALW distance, compared to the classical MD-DTW.