Model-based individual life-spanning documentation in visceral surgery: a proof of concept.

INTRODUCTION: Surgical documentation has many implications. However, its primary function is to transfer information about surgical procedures to other medical professionals. Thereby, written reports describing procedures in detail are the current standard, impeding comprehensive understanding of patient-individual life-spanning surgical course, especially if surgeries are performed at a timely distance and in diverse facilities. Therefore, we developed a novel model-based approach for documentation of visceral surgeries, denoted as 'Surgical Documentation Markup-Modeling' (SDM-M). MATERIAL AND METHODS: For scientific evaluation, we developed a web-based prototype software allowing for creating hierarchical anatomical models that can be modified by individual surgery-related markup information. Thus, a patient's cumulated 'surgical load' can be displayed on a timeline deploying interactive anatomical 3D models. To evaluate the possible impact on daily clinical routine, we performed an evaluation study with 24 surgeons and advanced medical students, elaborating on simulated complex surgical cases, once with classic written reports and once with our prototypical SDM-M software. RESULTS: Leveraging SDM-M in an experimental environment reduced the time needed for elaborating simulated complex surgical cases from 354 ± 85 s with the classic approach to 277 ± 128 s. (p = 0.00109) The perceived task load measured by the Raw NASA-TLX was reduced significantly (p = 0.00003) with decreased mental (p = 0.00004) and physical (p = 0.01403) demand. Also, time demand (p = 0.00041), performance (p = 0.00161), effort (p = 0.00024), and frustration (p = 0.00031) were improved significantly. DISCUSSION: Model-based approaches for life-spanning surgical documentation could improve the daily clinical elaboration and understanding of complex cases in visceral surgery. Besides reduced workload and time sparing, even a more structured assessment of individual surgical cases could foster improved planning of further surgeries, information transfer, and even scientific evaluation, considering the cumulative 'surgical load.' CONCLUSION: Life-spanning model-based documentation of visceral surgical cases could significantly improve surgery and workload.

Audio-based event detection in the operating room.

PURPOSE: Even though workflow analysis in the operating room has come a long way, current systems are still limited to research. In the quest for a robust, universal setup, hardly any attention has been given to the dimension of audio despite its numerous advantages, such as low costs, location, and sight independence, or little required processing power. METHODOLOGY: We present an approach for audio-based event detection that solely relies on two microphones capturing the sound in the operating room. Therefore, a new data set was created with over 63 h of audio recorded and annotated at the University Hospital rechts der Isar. Sound files were labeled, preprocessed, augmented, and subsequently converted to log-mel-spectrograms that served as a visual input for an event classification using pretrained convolutional neural networks. RESULTS: Comparing multiple architectures, we were able to show that even lightweight models, such as MobileNet, can already provide promising results. Data augmentation additionally improved the classification of 11 defined classes, including inter alia different types of coagulation, operating table movements as well as an idle class. With the newly created audio data set, an overall accuracy of 90%, a precision of 91% and a F1-score of 91% were achieved, demonstrating the feasibility of an audio-based event recognition in the operating room. CONCLUSION: With this first proof of concept, we demonstrated that audio events can serve as a meaningful source of information that goes beyond spoken language and can easily be integrated into future workflow recognition pipelines using computational inexpensive architectures.

Prospective clinical cohort study: low incidence of Barrett esophagus but high rate of reflux disease at 5-year follow-up after sleeve gastrectomy versus Roux-en-Y gastric bypass.

BACKGROUND: Gastroesophageal reflux disease seems more frequent after laparoscopic sleeve gastrectomy (LSG) than Roux-en-Y gastric bypass (LRYGB). Retrospective case series have raised concerns about a high incidence of Barrett esophagus (BE) after LSG. OBJECTIVE: This prospective clinical cohort study compared the incidence of BE ≥5 years after LSG and LRYGB. SETTING: St. Clara Hospital, Basel, and University Hospital, Zürich, Switzerland. METHODS: Patients were recruited from 2 bariatric centers where preoperative gastroscopy is standard practice and LRYGB is preferred for patients with preexisting gastroesophageal reflux disease. At follow-up ≥5 years after surgery, patients underwent gastroscopy with quadrantic biopsies from the squamocolumnar junction and metaplastic segment. Symptoms were assessed using validated questionnaires. Wireless pH measurement assessed esophageal acid exposure. RESULTS: A total of 169 patients were included, with a median 7.0 ± 1.5 years after surgery. In the LSG group (n = 83), 3 patients had endoscopically and histologically confirmed de novo BE; in the LRYGB group (n = 86), there were 2 patients with BE, 1 de novo and 1 preexisting (de novo BE, 3.6% versus 1.2%; P = .362). At follow-up, reflux symptoms were reported more frequently by the LSG group than by the LRYGB group (51.9% versus 10.5%). Similarly, moderate-to-severe reflux esophagitis (Los Angeles grade B-D) was more common (27.7% versus 5.8%) despite greater use of proton pump inhibitors (49.4% versus 19.7%), and pathologic acid exposure was more frequent in patients who underwent LSG than in patients who underwent LRYGB. CONCLUSIONS: After at least 5 years of follow-up, a higher incidence of reflux symptoms, reflux esophagitis, and pathologic esophageal acid exposure was found in patients who underwent LSG compared with patients who underwent LRYGB. However, the incidence of BE after LSG was low and not significantly different between the 2 groups.

The impact of prior endoscopic or surgical therapy on open Zenker's diverticulum surgery: analysis on a large single center cohort : Comparison of primary and revisional open surgery for Zenker's diverticulum.

BACKGROUND: Endoscopic treatment of Zenker's diverticulum is an attractive minimally invasive alternative compared to the classic open approach. However, increased recurrence rate were reported. In case of relapse, endoscopic therapy might be repeated, or alternatively open surgery is performed. This study aimed to identify potential differences in the outcomes between primary or secondary surgical treatment in Zenker's diverticulum. METHODS: From January 2003 to April 2019, 227 subsequent patients underwent surgical diverticulectomy and cervical myotomy at the surgical department of TUM. 41 of 227 patients had received previous therapy, either open or endoscopic. Perioperative parameters in priorly untreated patients were retrospectively compared to those after previous therapy (mostly endoscopic) with special regard to perioperative data and postoperative complications. Univariate and multivariate regression analyses were performed to identify predictors for postoperative complications. RESULTS: We could show that the number of complications (p = 0.047) in pretreated patients is significant higher as well as the severity after Clavien-Dindo (p = 0.025). Stapler line leakage, wound infections, and operative revision rate was higher also pretreated group. Pretreatment and surgery time showed a significant association with postoperative complications in univariate analysis. In multivariate analysis, pretreatment remained a significant independent predictor of complications. CONCLUSION: The present data indicate that endoscopic therapy might represent a risk factor for postoperative complications in case of relapse surgery. Therefore primary open surgery should be debated in patients with an increased high risk of relapse.

Long-term outcome of patients with epiphrenic diverticula: A retrospective single-center analysis over 20 years.

BACKGROUND: Epiphrenic diverticula are extremely rare. Evidence-based treatment recommendations are scarce. The primary study outcome was to examine whether surgical treatment in patients with epiphrenic diverticula leads to improved quality of life by outweighing the perioperative risks compared with conservative treatment. METHODS: All patients with an epiphrenic diverticula at our institution between 2001 and 2021 were retrospectively reviewed and followed-up using a specific questionnaire, including the Eating Assessment Tool, and Gastrointestinal Quality of Life Index quality-of-life scores. RESULTS: Of 51 patients with epiphrenic diverticula, 28 had surgery and 23 had conservative treatment. The most common symptom at presentation was dysphagia. Although 16 patients underwent open surgery, 12 had minimally invasive procedures. A prophylactic stent was applied intraoperatively in 6 patients. The morbidity rate in surgically treated patients was 50% (14/28), with a leakage in 43% (12/28; 33% for prophylactic stenting). Mortality was nil. At a median follow-up of 139 months, patients with surgery had better outcomes than those without (ie, less dysphagia [6/12 vs 11/12; P = .025]), a less likely pathologic Eating Assessment Tool score (4/12 vs 9/12; P = .041), and a nonsignificant better Gastrointestinal Quality of Life Index score (122 vs 112; P = .929). The rate of recurrence/progression of symptoms was significantly higher for conservatively treated patients (11/18 vs 6/27 for any surgery; P = .008), as well as for patients with minimally invasive procedure (5/12 vs 1/15 for open surgery; P = .030). CONCLUSION: Despite the high perioperative morbidity, surgical treatment of epiphrenic diverticula leads to an improved long-term quality of life and lower recurrence rates than conservative treatment.

Robotic Endoscope Control - State of the Art of Voice Control and Other Options for Laparoscopic Camera Robot Guidance.

In video-based surgery (VBS), the surgeon is no longer the master of his or her view. Visualization of the surgical field is mediated by a video camera guided by an assistant. The separation of visualization and surgical activities leads to significant drawbacks. Early in the history of VBS, active camera holders controlled directly by the surgeon were introduced to replace the human camera assistant. However, despite remarkable technological advances over the past 25 years, robotic camera guidance systems (RCGS) still play only a marginal role. This is less due to inadequate mechanical designs or kinematics, and mainly due to inadequate human-machine interaction. In most cases, a simple task-shift is required that increases the surgeon's mental workload instead of reducing it. The current state of the art in robotic camera guidance, as represented by the SOLOASSIST II RCGS (AKTORmed, Neutraubling, Germany), includes a sophisticated combination of direct manual control, joystick navigation and high-quality voice control that provides the most intuitive surgeon-machine interaction currently available. An in-depth analysis of further clinical needs and promising developments in operating room integration suggests that the addition of context sensitivity could actually enhance the assistive effect of RCGS, making them potentially superior to the average human camera guidance.

Systematic Review and Meta-Analysis on Colorectal Anastomotic Techniques.

Purpose: Anastomosis creation after resective gastrointestinal surgery is a crucial task. The present review examines the techniques and implants currently available for anastomosis creation and analyses to which extent they already address our clinical needs, with a special focus on their potential to enable further trauma minimization in visceral surgery. Methods: A multi-database research was conducted in MEDLINE, Scopus, and Cochrane Library. Comparative controlled and uncontrolled clinical trials dealing with anastomosis creation techniques in the intestinal tract in both German and English were included and statistically significant differences in postoperative complication incidences were assessed using the RevMan5.4 Review Manager (Cochrane Collaboration, Oxford, UK). Results: All methods and implant types were analyzed and compared with respect to four dimensions, assessing the techniques' current performances and further potentials for surgical trauma reduction. Postoperative outcome measures, such as leakage, stenosis, reoperation and mortality rates, as well as the tendency to cause bleeding, wound infections, abscesses, anastomotic hemorrhages, pulmonary embolisms, and fistulas were assessed, revealing the only statistically significant superiority of hand-suture over stapling anastomoses with respect to the occurrence of obstructions. Conclusion: Based on the overall complication rates, it is concluded that none of the anastomosis systems addresses the demands of operative trauma minimization sufficiently yet. Major problems are furthermore either low standardization potentials due to dependence on the surgeons' levels of experience, high force application requirements for the actual anastomosis creation, or large and rigid device designs interfering with flexibility demands and size restrictions of the body's natural access routes. There is still a need for innovative technologies, especially with regard to enabling incisionless interventions.

Kidney Transplantation After Rescue Allocation-the Eurotransplant Experience: A Retrospective Multicenter Outcome Analysis.

BACKGROUND: At Eurotransplant (ET), kidneys are transferred to "rescue allocation" (RA), whenever the standard allocation (SA) algorithms Eurotransplant Kidney Allocation System (ETKAS) and Eurotransplant Senior Program (ESP) fail. We analyzed the outcome of RA. METHODS: Retrospective patient clinical and demographic characteristics association analyses were performed with graft outcomes for 2422 recipients of a deceased donor renal transplantation (DDRT) after RA versus 25 481 after SA from 71 centers across all ET countries from 2006 to 2018. RESULTS: Numbers of DDRTs after RA increased over the time, especially in Germany. RA played a minor role in ESP versus ETKAS (2.7% versus 10.4%). RA recipients and donors were older compared with SA recipients and donors, cold ischemia times were longer, waiting times were shorter, and the incidence of primary nonfunction was comparable. Among ETKAS recipients, HLA matching was more favorable in SA (mean 3.7 versus 2.5). In multivariate modeling, the incidence of graft loss in ETKAS recipients was reduced in RA compared with SA (subdistribution hazard ratio, 0.80; 95% confidence interval [0.70-0.91], P < 0.001), whereas other outcomes (mortality, death with functioning graft (DwFG)) were not significantly different. None of the 3 outcomes were significantly different when comparing RA with SA within the ESP program. CONCLUSIONS: Facing increased waiting times and mortality on dialysis due to donor shortage, this study reveals encouragingly positive DDRT outcomes following RA. This supports the extension of RA to more patients and as an alternative tool to enable transplantation in patients in countries with prohibitively long waiting times or at risk of deterioration.

How to Cope with Big Data in Functional Analysis of the Esophagus.

INTRODUCTION: Esophageal motility disorders have a severe impact on patients' quality of life. While high-resolution manometry (HRM) is the gold standard in the diagnosis of esophageal motility disorders, intermittently occurring muscular deficiencies often remain undiscovered if they do not lead to an intense level of discomfort or cause suffering in patients. Ambulatory long-term HRM allows us to study the circadian (dys)function of the esophagus in a unique way. With the prolonged examination period of 24 h, however, there is an immense increase in data which requires personnel and time for evaluation not available in clinical routine. Artificial intelligence (AI) might contribute here by performing an autonomous analysis. METHODS: On the basis of 40 previously performed and manually tagged long-term HRM in patients with suspected temporary esophageal motility disorders, we implemented a supervised machine learning algorithm for automated swallow detection and classification. RESULTS: For a set of 24 h of long-term HRM by means of this algorithm, the evaluation time could be reduced from 3 days to a core evaluation time of 11 min for automated swallow detection and clustering plus an additional 10-20 min of evaluation time, depending on the complexity and diversity of motility disorders in the examined patient. In 12.5% of patients with suggested esophageal motility disorders, AI-enabled long-term HRM was able to reveal new and relevant findings for subsequent therapy. CONCLUSION: This new approach paves the way to the clinical use of long-term HRM in patients with temporary esophageal motility disorders and might serve as an ideal and clinically relevant application of AI.

5th-Generation Mobile Communication: Data Highway for Surgery 4.0.

INTRODUCTION: 5th generation cellular mobile communications (5G) is one of the main requirements for the digital future. The new standard will offer high bandwidths (10GB/s), low latency (<1ms), and a high quality of service. It is not yet known whether 5G performance is sufficient for demanding eHealth applications (e.g., telemedicine). MATERIAL AND METHODS: We evaluated 5G performance in two different medical applications (person/asset track & tracing and video data transmission for telesurgery) to appraise the impact of this new technology. In addition, a Delphi study was conducted evaluating the expectations and acceptance of 5G in the medical field in general. RESULTS: Delphi study revealed that 5G has great potential for the future information transfer in the healthcare domain, and an increase of research activities for 5G applications in hospitals is needed. Clinical evaluation proved technical feasibility and accuracy of the 5G track & trace prototype solution. For the telepresence use case, the video stream data rate varied between 900KB-1MB/s (7.2-8 Mb/s). The data rate of the robotic control command varied between 2.4-7.2KB/s (19.2-57.6Kb/s). Delay time (latency) ranged between 2-60ms depending on the transmitted data packet length. Seventy-five percent of data packets were processed after 30ms. CONCLUSION: 5G data transmission volume, rate, and latency met the requirements for real-time track & trace and telemedicine applications. Especially for the latter, 5G data transmission offers a high potential and further research should be carried out.

24-hour monitoring of transient lower esophageal sphincter relaxation events by long-term high-resolution impedance manometry in normal volunteers: The "mirror phenomenon".

BACKGROUND: The aim of this study was to investigate the frequency and circadian changes in transient lower esophageal sphincter relaxations (TLESRs) in normal volunteers using 24-hour high-resolution impedance manometry (HRIM). METHODS: Fifteen volunteers underwent HRIM. TLESRs were recorded during the mealtime, 2-hour postprandial, daytime, and supine periods. The catheter was firmly secured to the nose, and subjects went home, ate normal meals, and continued routine daily activities. KEY RESULTS: Successful recordings were obtained in 11 volunteers. Overall, 1083 TLESRs were documented; the average occurrence was 4.2/h, and the duration was 21.0 ± 5.2 seconds. The majority of the TLESRs occurred during the 2-hour postprandial (42.7%) and daytime (31.5%) periods, while 10.2% and 15.6% occurred during the mealtime and supine periods, respectively. Eight hundred and eighty-six (81.8%) TLESRs were associated with reflux. Overall, 25.5% of TLESRs were preceded by partial secondary peristalsis (PSP), while 74.5% were preceded by nothing. Terminating events included primary peristalsis (PP; 40.3%), PSP (42.8%), full secondary peristalsis (FSP; 8.2%), or nothing (8.7%). Both preceding and terminating events periodically changed throughout the four periods. One hundred and twelve (10.3%) TLESRs with both preceding and terminating events of PSP, presenting as a "mirror phenomenon," were documented. The majority of these TLESRs occurred during the supine (70.5%). CONCLUSIONS & INFERENCES: Transient lower esophageal sphincter relaxations are common physiological motor events in normal volunteers; these events have certain circadian rhythms, as do the events that precede and terminate TLESR events. A special "mirror phenomenon" is observed when both the preceding and terminating events are PSP.

Pharyngeal pH monitoring in gastrectomy patients - what do we really measure?

AIM: Diagnosis of laryngopharyngeal reflux (LPR) has dramatically increased over the last years. For diagnosis of gastroesophageal reflux, a newly designed pharyngeal probe (Dx-pH) was recently introduced. It is also recommended to guide therapy decision in antireflux surgery. However, diagnostic results are questionable. Therefore, we establish a reliable reference group with asymptomatic patients after total gastrectomy and, thus, complete extinction of gastric acid production. METHODS: Pharyngeal pH monitoring was performed in 10 consecutive patients with history of total gastrectomy. All patients were off proton pump inhibitor (PPI) therapy and followed a non-acid diet during the complete measurement period. RESULTS: All procedures were performed without any complication. Six of the 10 asymptomatic gastrectomy patients (60%) had pathological results derived from the validated reference values (Ryan score) in pharyngeal pH monitoring. CONCLUSION: Pathological pH values assessed by the Dx-pH device, usually interpreted as pathological aerosolized acidic gastroesophageal and/or laryngopharyngeal reflux, are obviously dissociated from gastric acid production. Further studies are required to determine diagnostic value of the new system. Therefore, the pharyngeal pH monitoring system seems currently not to be useful to guide any diagnostic or therapeutic decisions, in particular if surgical therapy is considered.

Endoluminal perforation of a magnetic antireflux device.

BACKGROUND: The history of surgical antireflux treatment is coined by the search for better alternatives to Nissen fundoplication. Implantable devices are one option, beginning with the "Angelchik" prosthesis 30 years ago. However, this procedure was left soon because of the high rate of foreign body connected problems (migration, perforation). A modern approach is a magnetic sphincter augmentation device (LINX Reflux Management System, Torax Medical, Shoreview, MN, USA), a magnetic chain which is implanted laparoscopically. Advantages reported are simplicity to apply and good results in reflux control, with up to now only rare complication rates as reported in the literature (Lipham et al. in Dis Esophagus, 2014). METHODS: We report one case of erosion of the esophagus by a LINX system resulting in severe dysphagia. RESULTS: A complete endoluminal removal could be achieved by a prototype OTSC-clip remover. Complete remission could be achieved. The technique is presented in detail (video). CONCLUSIONS: In principle, total endoscopic removal of the LINX device is feasible in case of major erosion.