A flexible implant for acute intrapancreatic electrophysiology.

Microelectrode arrays (MEAs) have proven to be a powerful tool to study electrophysiological processes over the last decades with most technology developed for investigation of the heart or brain. Other targets in the field of bioelectronic medicine are the peripheral nervous system and its innervation of various organs. Beyond the heart and nervous systems, the beta cells of the pancreatic islets of Langerhans generate action potentials during the production of insulin. In vitro experiments have demonstrated that their activity is a biomarker for blood glucose levels, suggesting that recording their activity in vivo could support patients suffering from diabetes mellitus with long-term automated read-out of blood glucose concentrations. Here, we present a flexible polymer-based implant having 64 low impedance microelectrodes designed to be implanted to a depth of 10 mm into the pancreas. As a first step, the implant will be used in acute experiments in pigs to explore the electrophysiological processes of the pancreas in vivo. Beyond use in the pancreas, our flexible implant and simple implantation method may also be used in other organs such as the brain.

[New Technologies in Microsurgery: Potential, Indications and Economical Aspects - Report of the Consensus Workshop of the German-Speaking Society for Microsurgery of Peripheral Nerves and Vessels (DAM)]. / Neue Technologien in der Mikrochirurgie: Potential, Indikationen und ökonomische Aspekte ­ Konsensus-Bericht der Deutschsprachigen Arbeitsgemeinschaft für Mikrochirurgie der peripheren Nerven und Gefäße (DAM).

Recently, several new technologies to support microsurgeons have received European market approval. This article summarizes and discusses the impressions of an expert panel to classify the potential of new technologies in terms of benefits for the surgeon, specific indications and economic aspects during the 42nd Annual Meeting of the German-speaking Working Group for Microsurgery of Peripheral Nerves and Vessels (DAM) in Graz, Austria. In general, the expert panel addressed the principles and prerequisite for the successful establishment of new technologies and, in particular, novel optical and robotic systems. For this purpose, the current scientific literature was reviewed and initial clinical experience in the context of case series and retrospective studies was presented by the members of the expert panel. In the ensuing discussion, it was pointed out that it will first be necessary to identify patient subgroups in which the use of the new technologies is most likely to achieve a clinical benefit. Since clinical approval has already been granted for some systems, an approach can be developed for immediate clinical application from the simplest possible use to ever finer applications, i. e. from microsurgery to supermicrosurgery. Initially, funding for cost-intensive systems would presumably not be possible through revenue from standard care, but only through grants or subsidized clinical trials. In a final survey, the majority of meeting participants see the need for a price reduction of both visualization and surgical robotics technologies to enable widespread clinical establishment. Likewise, a majority of participants would prefer a combination of an exoscope or robotic microscope and a surgical robot for clinical use. The present consensus work addresses the development of a strategy for the effective establishment of new technologies, which should further increase the surgical quality of selected interventions.

Impact of preoperative body mass index and weight loss on morbidity and mortality following colorectal cancer-a retrospective cohort study.

PURPOSE: Body weight and preoperative weight loss (WL) are controversially discussed as risk factors for postoperative morbidity and mortality in colorectal cancer surgery. The objective of this study is to determine whether body mass index (BMI) or WL is associated with a higher postoperative complication rate. METHODS: In this retrospective cohort study, data analysis of 1241 consecutive patients undergoing colorectal cancer surgery in an 11-year period was performed. The main outcome measures were wound infections (WI), anastomotic leakages (AL), and in-house mortality. RESULTS: A total of 697 (56%) patients with colon and 544 (44%) with rectum carcinoma underwent surgery. The rate of WI for each location increased with rising BMI. The threshold value was 28.8 kg/m2. Obese patients developed significantly more WI than normal-weight patients did following rectal resection (18.0% vs. 8.2%, p = 0.018). Patients with preoperative WL developed significantly more AL following colon resections than did patients without preoperative WL (6.2% vs. 2.5%, p = 0.046). In-house mortality was significantly higher in obese patients following colon resections than in overweight patients (4.3% vs. 0.4%, p = 0.012). Regression analysis with reference to postoperative in-house mortality revealed neither increased BMI nor WL as an independent risk factor. CONCLUSIONS: Increased preoperative BMI is associated with a higher WI rate. AL rate after colon resection was significantly higher in patients showing preoperative WL. Preoperative BMI and WL are therefore risk factors for postoperative morbidity in this study. Nevertheless, this has to be further clarified by means of prospective studies. Trial registration DRKS00025359, 21.05.2021, retrospectively registered.

Early postoperative endoscopic evaluation of rectal anastomoses: a prospective cross-sectional study.

BACKGROUND: Reported incidence of anastomotic leakage (AL) of rectal anastomoses is up to 29% with an overall mortality up to 12%. Nevertheless, there is no uniform evidence-based diagnostic procedure for early detection of AL. The objective of this prospective clinical trial was to demonstrate the diagnostic value of early postoperative flexible endoscopy for rectal anastomosis evaluation. METHODS: Flexible endoscopy between 5 and 8th postoperative day was performed consecutively in 90 asymptomatic patients. Sample size calculation was made using the two-stage Simon design. Diagnostic value was measured by management change after endoscopic evaluation. Anastomoses were categorized according to a new classification. Study is registered in German Clinical Trials Register (DRKS00019217). RESULTS: Of the 90 anastomoses, 59 (65.6%) were unsuspicious. 20 (22.2%) were suspicious with partial fibrin plaques (n = 15), intramural hematoma and/or local blood coagulum (n = 4) and ischemic area in one. 17 of these anastomoses were treated conservatively under monitoring. In three a further endoscopic re-evaluation was performed and as consequence one patient underwent endoscopic vacuum therapy. 11 (12.2%) AL were detected. Here, two could be treated conservatively under monitoring, four with endoscopic vacuum therapy and five needed revision surgery. No intervention-related adverse events occurred. A change in postoperative management was made in 31 (34.4%) patients what caused a significant improvement of diagnosis of AL (p < 0.001). CONCLUSIONS: Early postoperative endoscopic evaluation of rectal anastomoses is a safe procedure thus allows early detection of AL. Early treatment for suspicious anastomoses or AL could be adapted to avoid severe morbidity and mortality.

Evaluation of different setting configurations with a new developed telemedical interface of a parallel kinematic robotic system - An experimental development study.

BACKGROUND: For development of a minimally invasive intracorporal micromanipulator, a master-slave telemanipulation system was required. METHODS: Different input positions for a tablet-based input device with a heads-up centred screen were evaluated. Personal preference was assessed using a questionnaire. Then, the most ergonomic and intuitive position was compared to a surgical reference position based on laparoscopic sigmoid resection. RESULTS: After comparing a 45°, 75° (pitch) and 60°/20° (pitch/yaw) to a 60° reference position no significant differences in processing time and number of failures could be demonstrated. Study participants indicated the 60°/20° position as the most comfortable in the questionnaire. This was therefore compared with the laparoscopic reference position, both sitting and standing. Here, the laparoscopic sitting position was perceived to be the most ergonomic. CONCLUSIONS: The developed input device offers a maximum of flexibility and individualisation to reach ergonomic and intuitive conditions. General recommendations regarding an optimal setting cannot be given, based on our results.

[Laparoscopic Heller Myotomy in the Treatment of Achalasia]. / Laparoskopische Heller-Myotomie zur Therapie der Achalasie.

BACKGROUND: Achalasia refers to a primary oesophageal motility disorder characterised by the absence of peristalsis and incomplete or complete lack of relaxation of the lower oesophageal sphincter. The cardinal symptom is dysphagia. The therapeutic goal is surgical or interventional repair of the oesophageal outflow tract at the level of the oesophagogastric junction. INDICATION: We present the case of a 24-year-old patient with dysphagia accompanied by regurgitations, odynophagia as well as an unintentional weight loss over two years. METHODS: The video describes the preoperative imaging as well as endoscopic findings and demonstrates the technique of laparoscopic Heller myotomy followed by Dor fundoplication. CONCLUSIONS: Concerning the therapy of classic achalasia, laparoscopic Heller myotomy followed by Dor fundoplication - despite controversies regarding peroral endoscopic myotomy as an alternative therapeutic option - can be considered as an established standard procedure.

Reducing Degrees of Freedom in Surgical Suturing: Implications for Minimally Invasive Device Development-A Prospective Experimental Study.

Open surgery allows the use of all 6 degrees of freedom (DOF; x-y-z and roll-pitch-yaw), whereas laparoscopy requires working under limitation to 4 axes. We present a prospective experimental study evaluating translational and rotational DOF restriction in surgical suturing tasks. An experimental platform included a kinematic structure that limited the maneuverability of the surgical instruments. The subjects (n=20) worked in a randomized order using (1) 6DOF, (2) 4DOF with 3 translational and 1 rotational DOF (4TRANS), and (3) 4DOF with 1 translational and 3 rotational DOF (4ROT). The time required to perform each task was recorded. Suturing and knot tying were significantly faster under 6DOF compared with 4ROT (both P<0.001) and 4TRANS (both P<0.001). Assessment of subjective difficulty and impairment showed most favorable results for 6DOF. The advantage of rotational compared with translational DOF should be considered in the development of future surgical devices.

Long-term results of the custom- made hip endoprostheses Evolution K® and Adaptiva®: A prospective cohort study.

The aim of our study is to evaluate clinical long-term results and determine changes in periprosthetic bone density of the custom-made hip prostheses Evolution-K ® and Adaptiva ® . Periprosthetic bone density were evaluated by means of DEXA (LunariDXA- Prodigy® bone densitometer) with a long-term follow-up of 16 (15-18) years (Evolution-K®) in 24 patients and 13 (13-15) years (Adaptiva®) in 41 patients. Evolution- K® had a survival rate of 92% and yielded 79/100 points in Harris Hip Score, a mediocre result. Adaptiva® had a survival rate of 99% and achieved a good score of 88/100 points. Bone density measurements demonstrated the greatest loss of bone density in the proximal regions of interest (ROI) for both prosthesis types (Evolution-K®: -25.8% ROI 1, -40.3% ROI 7; -8.3% ROI 2, -10.4% ROI 6; Adaptiva®: -29.8% ROI 7, -6.8% ROI 6, +14.3% ROI 3, +3.1% ROI 4). Adaptiva® yielded a good clinical result as compared to Evolution-K® with only average clinical results. Both prostheses clearly showed signs of "stress shielding". Here, the Adaptiva® achieved reduced bone density loss as compared to the Evolution-K®.

Detection of adverse events leading to inadvertent injury during laparoscopic cholecystectomy using convolutional neural networks.

Uncontrolled movements of laparoscopic instruments can lead to inadvertent injury of adjacent structures. The risk becomes evident when the dissecting instrument is located outside the field of view of the laparoscopic camera. Technical solutions to ensure patient safety are appreciated. The present work evaluated the feasibility of an automated binary classification of laparoscopic image data using Convolutional Neural Networks (CNN) to determine whether the dissecting instrument is located within the laparoscopic image section. A unique record of images was generated from six laparoscopic cholecystectomies in a surgical training environment to configure and train the CNN. By using a temporary version of the neural network, the annotation of the training image files could be automated and accelerated. A combination of oversampling and selective data augmentation was used to enlarge the fully labeled image data set and prevent loss of accuracy due to imbalanced class volumes. Subsequently the same approach was applied to the comprehensive, fully annotated Cholec80 database. The described process led to the generation of extensive and balanced training image data sets. The performance of the CNN-based binary classifiers was evaluated on separate test records from both databases. On our recorded data, an accuracy of 0.88 with regard to the safety-relevant classification was achieved. The subsequent evaluation on the Cholec80 data set yielded an accuracy of 0.84. The presented results demonstrate the feasibility of a binary classification of laparoscopic image data for the detection of adverse events in a surgical training environment using a specifically configured CNN architecture.

Learning curves, potential and speed in training of laparoscopic skills: a randomised comparative study in a box trainer.

BACKGROUND: The effectiveness of practical surgical training is characterised by an inherent learning curve. Decisive are individual initial starting capabilities, learning speed, ideal learning plateaus, and resulting learning potentials. The quantification of learning curves requires reproducible tasks with varied levels of difficulty. The hypothesis of this study is that the use of three-dimensional (3D) vision is more advantageous than two-dimensional vision (2D) for the learning curve in laparoscopic training. METHODS: Forty laparoscopy novices were recruited and randomised to a 2D Group and a 3D Group. A laparoscopy box trainer with two standardised tasks was used for training of surgical tasks. Task 1 was a positioning task, while Task 2 called for laparoscopic knotting as a more complex process. Each task was repeated at least ten times. Performance time and the number of predefined errors were recorded. 2D performance after 3D training was assessed in an additional final 2D cycle undertaken by the 3D Group. RESULTS: The calculated learning plateaus of both performance times and errors were lower for 3D. Independent of the vision mode the learning curves were smoother (exponential decay) and efficiency was learned faster than precision. The learning potentials varied widely depending on the corresponding initial values and learning plateaus. The final 2D performance time of the 3D-trained group was not significantly better than that of the 2D Group. The final 2D error numbers were similar for all groups. CONCLUSIONS: Stereoscopic vision can speed up laparoscopic training. The 3D learning curves resulted in better precision and efficiency. The 3D-trained group did not show inferior performance in the final 2D cycle. Consequently, we encourage the training of surgical competences like suturing and knotting under 3D vision, even if it is not available in clinical routine.

[Robotic Assisted Proctocolectomy with Ileal Pouch-Anal Anastomosis in a Case of Suspected Hereditary Polyposis]. / Roboterassistierte Proktokolektomie mit ileopouchanaler Anastomose bei Verdacht auf hereditäre Polyposis.

BACKGROUND: Various forms of hereditary polyposis have been described in the literature. Classical familial adenomatous polyposis (FAP) is a rare, autosomal dominantly inherited disease which is caused by a germline mutation in the adenomatous polyposis coli gene (APC). Patients with this diagnosis successively develop multiple polyps of the colon. Left untreated, FAP almost inevitably leads to malignant transformation. INDICATION: We present the case of a 37-year-old patient with histologically confirmed, stenotic adenocarcinoma of the descending colon and an initially suspected hereditary polyposis due to multiple polyps in the descending and sigmoid colon. METHODS: The video describes the preoperative imaging as well as endoscopic findings and demonstrates the technique of a two-stage, robotically assisted proctocolectomy with ileal pouch-anal anastomosis (IPAA) and the creation of a temporary loop ileostomy. CONCLUSIONS: With respect to the surgical treatment of classic FAP, restorative proctocolectomy (RPC) with ileal J-pouch construction can be regarded as an established standard procedure, despite controversy regarding various technical aspects. Minimally invasive strategies should be considered as an equivalent option compared to conventional techniques.

Impact of haptic feedback on applied intracorporeal forces using a novel surgical robotic system-a randomized cross-over study with novices in an experimental setup.

BACKGROUND: Most currently used surgical robots have no force feedback; the next generation displays forces visually. A novel single-port robotic surgical system called FLEXMIN has been developed. Through an outer diameter of 38 mm, two instruments are teleoperated from a surgeon's control console including true haptic force feedback. One additional channel incorporates a telescope, another is free for special instrument functions. METHODS: This randomized cross-over study analyzed the effect of haptic feedback on the application of intracorporeal forces. In a standardized experiment setup, the subjects had to draw circles with the surgical robot as gently as possible. The applied forces, the required time spans, and predefined error rates were measured. RESULTS: Without haptic feedback, the maximum forces (median/IQR) were 6.43 N/2.96 N. With haptic feedback, the maximum forces were lower (3.57 N/1.94 N, p < 0.001). Also, the arithmetic means of the force progression (p < 0.001) and their standard deviations (p < 0.001) were lower. Not significant were the shorter durations and lower error rates. No sequence effect of force or duration was detected. No characteristic learning or fatigue curve was observed. CONCLUSIONS: In the experiment setup, the true haptic force feedback can reduce the applied intracorporeal robotic force to one-half when considering the aspects maximum, means, and standard deviation. Other test tasks are needed to validate the influence of force feedback on surgical efficiency and safety.

Surgeons' participation in the development of collaboration and management competencies in undergraduate medical education.

The teaching of professional roles in medical education is an interdisciplinary concern. However, surgeons require specific standards of professionalism for certain context-based situations. In addition to communication, studies require collaboration, leadership, error-/conflict-management, patient-safety and decision-making as essential competencies for surgeons. Standards for corresponding competencies are defined in special chapters of the German National Competency-based Learning Objectives for Undergraduate Medical Education (NKLM; chapter 8, 10). The current study asks whether these chapters are adequately taught in surgical curricula. Eight German faculties contributed to analysing mapping data considering surgical courses of undergraduate programs. All faculties used the MERlin mapping platform and agreed on procedures for data collection and processing. Sub-competency and objective coverage, as well as the achievement of the competency level were mapped. Overall counts of explicit citations were used for analysis. Collaboration within the medical team is a strongly represented topic. In contrast, interprofessional cooperation, particularly in healthcare sector issues is less represented. Patient safety and dealing with errors and complications is most emphasized for the Manager/Leader, while time management, career planning and leadership are not addressed. Overall, the involvement of surgery in teaching the competencies of the Collaborator and Manager/Leader is currently low. However, there are indications of a curricular development towards explicit teaching of these roles in surgery. Moreover, implicitly taught roles are numerous, which indicates a beginning awareness of professional roles.

Therapy of pessary-induced rectovaginal fistula and pelvic organ prolapse in elderly patients by vaginal approach and modified LeFort colpocleisis: a case series.

PURPOSE: Pelvic organ prolapse (POP) presents a common benign condition in women associated with reduced quality of life (QoL). The use of pessaries is considered a first-line treatment of POP. However, pessaries can cause perforations into adjacent organs resulting in fistulas. We present a series of three cases of rectovaginal fistulas (RVF) due to pessary perforation. METHODS: Three consecutive cases of pessary-induced RVF in patients with POP stage IV were assessed between September 2016 and September 2019. Consensus for therapeutic strategy was reached by an interdisciplinary board. RESULTS: The RVF were located in the posterior vaginal wall and had a diameter of up to 60 mm. In one of three patients, a two-step approach was chosen with the ostomy being performed at the same time as fistula closure and modified LeFort colpocleisis. It was followed by ostomy closure 3 months later. In two patients, a three-step approach was chosen with the ostomy performed separately due to a local tissue inflammation around RVF. Neither fistula nor POP recurrences have occurred so far. CONCLUSION: Combined temporary gastrointestinal diversion, RVF closure and POP therapy can be performed as a two- or three-stage approach. Lack of evidence and standardized algorithms in RVF therapy make further clinical studies essential. We encourage the preoperative assessment of any case of complex rectovaginal fistula by an interdisciplinary board for determining an individualized treatment.

The impact of guided instrument insertion during laparoscopy: a randomized study with novices in an optical box trainer.

BACKGROUND: During laparoscopic operations, the trocars are often out of the viewing field of the laparoscope. Blind insertion of laparoscopic instruments is potentially dangerous especially when they are pointed or hot. A guidance of the instrument to the target point has the potential to improve the safety of instrument insertion. METHODS: In this study, the effect of a mechanical and an optical tool for guided instrument insertion into the abdominal cave was evaluated. The controlled prospective randomized study measured safety and efficiency of instrument insertion by 60 novices in an inanimate standardized box trainer. A post-test questionnaire based on the NASA Task Load Index prompted for the subjective impressions of the subjects. RESULTS: Instrument insertion with optical guidance showed a shorter (p = 0.002) insertion time (median 87.5 s for nine insertions) compared with blind insertion (median 112.0 s for nine insertions). The error number with optical guidance (median 0.5) was lower (p = 0.064) compared with blind insertion (median 1.0). The mechanical guidance showed a shorter (p = 0.001) insertion time (median 89.0 s for nine insertions) and less (p = 0.044) touch errors (median 0) compared with blind insertion. The results of the two guidance tools (mechanical vs. optical guidance) showed no significant difference. In the questionnaire, 89% of the novices subjectively judged the mechanical guidance tool better than blind insertion. The assessments of optical compared to mechanical guidance turned out quite similar. CONCLUSIONS: In the experimental setup, instrument insertion with a guidance tool performed faster and safer compared with blind insertion. The subjective assessments confirmed the benefit of instrument guidance.

TuThor: an innovative new training model for video-assisted thoracic surgery.

OBJECTIVES: Video-assisted thoracic surgery (VATS) is a complex technique requiring dedicated surgical training. Platforms for such training are scarce and often rely on the use of live animals, which raises ethical concerns. The objective of this study was to develop a box trainer that is dedicated for VATS training and able to reproduce bleeding scenarios. METHODS: The developed Tuebingen Thorax Trainer comprises 5 components that are mounted on a human anatomy-like thoracic cavity containing a porcine organ complex. Any standard thoracoscopic instrument can be used. The organ complex is attached to a perfusion module. We assessed the applicability of the system in four 1-day VATS training courses at the Tuebingen Surgical Training Center. Assessment was performed using a questionnaire handed out to all participants. RESULTS: Forty participants have been trained with the Tuebingen Thorax Trainer at our institution since November 2016. Thirty-five (87.5%) participants stated that the Tuebingen Thorax Trainer is an adequate model for VATS training. The ex vivo organ complex was reported to be realistic with regards to the level of detail and scale (76%). A large proportion of participants (27.5%) were experienced with VATS and reported having performed >50 procedures before taking the training course. CONCLUSIONS: This new training device allows realistic training for VATS procedures. 'Stagnant hydrostatic perfusion' permits simulation of reproducible bleeding scenarios. The device is low in production costs and offers a strong resemblance to the clinical scenario. It reduces the use of animal models and contributes to the efforts in making surgical skills training for VATS more accessible.

Novel box trainer for taTME - prospective evaluation among medical students.

BACKGROUND: Transanal total mesorectal excision (taTME) has been subject to extensive research and increasing clinical application. It allows further reduction of trauma by accessing via a natural orifice. Manifold platforms and instruments have been introduced and heterogeneity in surgical techniques exists. Because of the technique's complexity there is a persistent need for dedicated training devices and concepts. MATERIALS AND METHODS: The key steps of taTME were analyzed and a box trainer with three modules resembling these steps was designed and manufactured. Twenty-one surgically inexperienced medical students performed five repetitions of the three tasks with the new box trainer. Time and error count were analyzed for assessment of a learning curve. RESULTS: A significant reduction of processing time could be demonstrated for tasks 1-3 (p < 0.001; p < 0.001; p = 0.001). The effect size was high for comparison of repetition 1 and 5 and decreased over the course (task 1: r = 0.88 vs. r = 0.21; task 2: r = 0.86 vs. r = 0.23; task 3: r = 0.74 vs. r = 0.44). Also, a significant reduction of errors was demonstrated for tasks 1 and 2. The decrease of effect size was analogously demonstrated. CONCLUSIONS: The trainer might help to reduce the use of animal models for testing of platforms and instruments as well as gaining first-hand experience in transanal rectal resection.

Oncological outcome of carcinomas in the rectosigmoid junction compared to the upper rectum or sigmoid colon - A retrospective cohort study.

INTRODUCTION: Although carcinomas of the rectosigmoid junction are frequent, specific data on these tumors are sparse because assignment either to the colon or rectum is common. The objective of this study is to determine whether carcinomas of the rectosigmoid junction can be assigned to the sigmoid colon or to the upper rectum in terms of tumor characteristics and oncological outcome. MATERIALS AND METHODS: 337 consecutive patients undergoing resection of carcinomas in the sigmoid colon, the rectosigmoid junction and the upper third of the rectum were analyzed retrospectively and additionally followed-up for oncological outcome. RESULTS: 185 patients (54.9%) showed carcinoma in the sigmoid colon, 41 (12.2%) in the rectosigmoid junction and 111 (32.9%) in the upper rectum. Synchronous liver metastases (rectosigmoid junction 31.7%, sigmoid colon 16.2%, upper rectum 11.7%; P = 0.01), lymphovascular invasion (rectosigmoid junction 46.3%, sigmoid colon 25.4%, upper rectum 32.4%; P = 0.03) and pN2 (rectosigmoid junction 31.7%, sigmoid colon 10.3%, upper rectum 13.5%; P = 0.002) were more common in carcinomas of the rectosigmoid junction. The median follow-up period was 44 (22-75.5) months. Five-year overall survival was 44.6% in patients with carcinomas in the rectosigmoid junction, 70.9% in the sigmoid colon, and 70.2% in the upper rectum. CONCLUSION: Carcinomas of the rectosigmoid junction reveal a deviant behavioral pattern compared to its adjacent bowel segments.

Watchful Waiting after Radiochemotherapy in Rectal Cancer: When Is It Feasible?

A "watch and wait" strategy in rectal cancer is increasingly considered in patients who achieve an excellent response to radiotherapy. While a growing number of studies have shown the feasibility of this strategy in selected patients, the optimal therapeutic regimen to maximize response rates still needs to be established. Furthermore, accurate response prediction and the management of minor residual findings after radiotherapy remain a matter of debate. Finally, concerns regarding the long-term oncological safety of the "watch and wait" approach have been expressed. Therefore, the present review aims to address the open questions in the context of a "watch and wait" strategy and focuses on the diagnosis of a clinical complete response and the ideal management thereafter.

[First Robotic Assisted Resection of a Retrorectal Tailgut Cyst - Video Case Report of a 27-Year-Old Female Patient]. / Roboterassistierte Resektion einer retrorektalen Tailgut-Zyste ­ erstbeschreibender Videofallbericht einer 27-jährigen Patientin.

PURPOSE: Tailgut cysts are a rare form of retrorectal tumours. They are also referred to as cystic hamartomas and predominantly affect female patients. Malignant transformation is thought to occur in 2 - 10% of cases, but there is scant further evidence. Besides the risk of malignant transformation, the feared complications include infection, difficulties in defecation, or potential dystocia necessitating in sano resection. INDICATION: We describe the case of a 27-year-old female patient presenting with a prolapsing round structure during defaecation. MRI, endosonography and transrectal drainage were carried out to exclude malignancy. We performed resection of the retrorectal tailgut cyst by robotic surgery. To the authors knowledge, this access has not previously been described for tailgut cyst resection. METHOD: Our video shows preoperative diagnostic testing, endoscopic drainage and robotic resection of the tailgut cyst. An intraoperative lesion of the dorsal rectum was successfully closed by suture. CONCLUSIONS: Different surgical techniques have been described for tailgut cyst resection. That with the widest application is posterior/sacral access, followed by abdominal and transrectal techniques. There are no published reports of robotic resection. We chose the robotic approach, as this is the surgeon's preferred technique for minimally invasive surgery of the pelvis.