bluuebunny/crossref_metadata_2025 huggingface dataset:
Hot Spot Stress Analysis of a Two-Planar DTY Tubular Joint Subjected to Axial Loading
Authors: Prastianto R W , Adha I A , Hadiwidodo Y S , Rosyid D M , Mulyadi Y
Published: June 2023

Air Cooler Support Frame (ACSF) is one of the supporting structures in oil and gas field that consist of tubular and beam members. Currently, the existing common ACSF has a conventional design and could be overdesign. Therefore, the ACSF structure must be designed by considering local stress characteristics to obtain sustainable innovative design. Significant structural failure usually occurs in tubular joints because of the hot spot stress in the joint area. In this study, the ACSF structure was globally analysed to determine the critical joint which was a two-planar DTY joint, then it was locally modelled by using finite element method-based of ANSYS software for local stress analysis. The tubular joint has been modelled using solid elements including weld model and by creating fine meshing in the vicinity of the brace-chord intersection area for all braces. The axial loading is applied to investigate the local stress distribution along the brace-chord intersection line of the tubular joint for each brace. The result show that the hot spot stress of about 145 MPa for the DTY joint occurred in Brace 1 around the saddle area on the chord side under the axial tension loading.
Strength analysis of air cooler support frame (ACSF) platform due to corrosion
Authors: Rosyid D M , Prastianto R W , Wahda E L , Murdjito  , Sambodho K , Syarifudin M R
Published: June 2023

Design of an Air Cooler Support Frame (ACSF) platform installed at waters area must be sustainable and capable to withstand the environmental loads. In the estuary, corrosion due to seawater accumulates around the platform legs leads to reduce the strength of the structure. Therefore, this study was conducted to predict the platform’s strength under critical corrosion conditions during its working life. The analysis was carried out using the Finite Element Method. In the global analysis, the operating and environmental loads were applied. Then, various patterns in term of length and intensity of corrosion were adjusted to the corrosion zone’s elevation based on calculations from inspection data to determine the pattern that has the most significant effect to the platform’s strength. The most critical pattern of the corrosion was used in the model for local stress analysis. The results indicated that the appropriate corrosion model was applied to the ACSF Platform has a corrosion length pattern of about half of the leg length with an intensity of 40%. Also, the strength of the ACSF platform decreases after corrosion occurs. The stress in the corroded leg has exceeded the material allowable stress but still undergoes acceptable deformation.
A study into the effect of tip clearance on the performance of b-series and kaplan-series ducted propellers
Authors: Adietya B A , Aryawan W D , Utama I K A P
Published: June 2023

A study into the effect of tip clearance on ducted propellers was carried out. Two series of propellers, namely B-series and Kaplan-series, were used. The gap between tip of propeller and ducted was varied from 2mm to 5mm. The study was conducted numerically using computational fluid dynamics (CFD) approach. The solver is based on the Reynolds-Averaged Navier-Stokes (RANS) solutions and two turbulence modelling, i.e. k-ω SST by Menter and explicit algebraic stress model (EASM), were applied in order to find out the optimum results. This paper objective to discuss energy efficiency on ships by investigating variations of propeller tip clearances. Overall results showed that EASM demonstrated better score (particularly in term of thrust and efficiency) than the k-ω SST. The highest thrust, torque and efficiency were achieved at 3mm tip clearance for both series. Moreover, Kaplan-series showed better results than the B-series propeller indicating that the use of ducted propeller using Kaplan-series is more appropriate.
Session Assessment of Seaplane Operations: The Case of Marine Tourism Development on Gili Iyang Island, Indonesia
Authors: Shabrina N , Arianto D , Wardani K S , Qonita Z , Ispandiari A R , Hariyanto  , Gutami N I , Manti M F
Published: June 2023

The development of marine tourism in Indonesia aims to promote economic growth, enhance the well-being of the citizenry, and conserve the environment. Gili Iyang Island in East Java Province has the second highest oxygen concentration in the world and is a popular health tourism destination. The transportation industry plays a crucial role in facilitating access and connectivity between islands and other regions. Seaplanes are an alternative mode of transportation for reaching tourist destinations on small islands with limited land area that are surrounded by water. This study aims to determine the optimal conditions for reaching the island and the number of effective days for seaplane operations. In assessing seaplane operating factors, water conditions such as current speed (1), wind speed (2), waves height (3), and tides (4) have a significant impact. Therefore, seaplanes cannot effectively operate for an entire year. Using a comparative methodology, the characteristics of the seaplane mode of transportation in the waters of Gili Iyang will be examined to determine the optimal operational time. The results of the study indicate that the 19-seat seaplane can operate 258 days per year and recommend the use of air-sea transportation modes for the growth of tourism in Gili Iyang Island.
Melanonychia as a manifestation of chronic lead poisoning
Authors: Aguilar-Calderón Patrizia Elva , Reyes-Soto Mayra A , Sánchez-Meza Emmanuel , Brown-Herrera Alejandra , Ocampo-Candiani Jorge , Fernández Lucía T
Published: June 2023

First-contact clinicians and dermatologists should be aware of melanonychia as an atypical presentation of chronic lead poisoning in high-risk groups.
Predictors of sentinel lymph node metastasis in very thin invasive melanomas
Authors: Kakish Hanna , Sun James , Zheng David X , Ahmed Fasih Ali , Elshami Mohamedraed , Loftus Alexander W , Ocuin Lee M , Ammori John B , Hoehn Richard S , Bordeaux Jeremy S , Rothermel Luke D
Published: June 2023

Background

Melanomas < 0.8 mm in Breslow depth have less than a 5% risk for nodal positivity. Nonetheless, nodal positivity is prognostic for this group. Early identification of nodal positivity may improve the outcomes for these patients.

Objectives

To determine the degree to which ulceration and other high-risk features predict sentinel lymph node (SLN) positivity for very thin melanomas.

Methods

The National Cancer Database was reviewed from 2012 to 2018 for patients with melanoma with Breslow thickness < 0.8 mm. Data were analysed from 7 July 2022 through to 25 February 2023. Patients were excluded if data regarding their ulceration status or SLN biopsy (SLNB) performance were unknown. We analysed patient, tumour and health system factors for their effect on SLN positivity. Data were analysed using χ2 tests and logistic regressions. Overall survival (OS) was compared by Kaplan–Meier analyses.

Results

Positive nodal metastases were seen in 876 (5.0%) patients who underwent SLNB (17 692). Factors significantly associated with nodal positivity on multivariable analysis include lymphovascular invasion [odds ratio (OR) 4.5, P < 0.001], ulceration (OR 2.6, P < 0.001), mitoses (OR 2.1, P < 0.001) and nodular subtype (OR 2.1, P < 0.001). Five-year OS was 75% and 92% for patients with positive and negative SLN, respectively.

Conclusions

Nodal positivity has prognostic significance for very thin melanomas. In our cohort, the rate of nodal positivity was 5% overall in these patients who underwent SLNB. Specific tumour factors (e.g. lymphovascular invasion, ulceration, mitoses, nodular subtype) were associated with higher rates of SLN metastases and should be used to guide clinicians in choosing which patients will benefit from SLNB.
Patient-Derived 3D Models for Preclinical Drug Response Evaluation in Neuroblastoma
Authors: Gros S J , Huo Z , Bilang R , Supuran C , von der Weid N , Holland-Cunz S , Martin I , Muraro M
Published: June 2023

Background

Neuroblastoma is the most common solid childhood tumor outside the central nervous system. Metastatic and relapsed disease in neuroblastoma patients still has a poor prognosis. New treatment methods to improve therapy and outcomes for patients with advanced neuroblastoma are urgently needed. However, clinical trials currently only allow for testing few substances in even fewer patients. This increases the need to improve and advance preclinical tumor models to preselect favorable candidates for novel therapeutics.

Aims

This study investigates the advantages and limitations of using bioreactor-based perfused 3D models in for preclinical drug testing in solid tumors exemplified in neuroblastoma.

Methods

We established perfused bioreactor-based 3D models using neuroblastoma cell lines and tissue slice-culture and evaluated cell viability. Several inhibitors against hypoxia-related factors, associated with tumor progression, were tested including Aqb011 against aquaporin 1 (AQP1) and SLC-0111 against carbonic-anhydrase IX (CAIX). Isothermal microcalorimetry was used for measuring real time thermogenesis in 3D cell and tissue constructs.

Results

3D neuroblastoma cell constructs presented with similar morphological features compared to neuroblastoma cells in intact tumor tissue featuring small, round and blue cells. Perfused neuroblastoma slice-culture maintained its primary structure in the bioreactor for up to 10 days. Both 3D neuroblastoma cell constructs and neuroblastoma tissue responded to inhibition with significant decrease of thermogenesis measured by microcalorimetry, if the correlating hypoxic factor (AQP1 or CAXI) was expressed. The AQP1 inhibitor Aqb011 and the CAIX inhibitor SLC-0111 decrease heat production of 3D neuroblastoma cultures.

Conclusions

We newly establish two preclinical models for neuroblastoma cells and tissue in a 3D structure. Drug response monitoring can be applied in these models using isothermal microcalorimetry. Monitoring times can be increased by use of the perfused bioreactor. Our models are an important first step to preclinically evaluate new drugs using patient-derived tumor tissue exemplified for neuroblastoma.
Sniffing Out Pseudomonas Aeruginosa Wound Infections with Vitamin B12: A Simple and Selective Colorimetric Biosensor for Early Diagnosis
Authors: Li Z , Ren Q , Shishaeva L
Published: June 2023

Background

The vacuum-assisted closure (VAC) system is a useful tool to promote wound healing. However, due to its occlusive system, the wound is often prone to Pseudomonas aeruginosa (PA) infections. Early detection and initiation of treatment is essential to limit the damage (e.g., saving a skin graft), but the black sponge occludes the wound and prevents its visual assessment leading to delayed diagnosis. Fortunately, each bacterium emits a spectrum of specific volatile organic compounds that can be used for detection. For PA, the signature compound is hydrogen cyanide.

Aims

We aimed to develop a colorimetric biosensor for “naked-eye” detection of PA that takes advantage of the negative pressure created by the VAC to collect hydrogen cyanide.

Methods

We used aquocyanocobinamide, a derivative of vitamin B12, as a colorimetric chemosensor of biological cyanide. By binding cyanide, the color of the sensor changes from orange to violet, which can be quantified with UV-VIS spectroscopy. The sensor was delivered onto the carrier material polyvinyl acetate. Its sensitivity was assessed using laboratory strains and clinical isolates of PA in-vitro and on an ex vivo skin model.

Results

UV-VIS spectroscopy readings of the sensor were calibrated for the cyanide concentration 0-250ppm. Cyanide produced by 30 laboratory and 20 clinical PA isolates were quantified based on the colorimetric changes of the sensor. While the sensor detected all PA strains, it did not falsely react to other wound pathogens such as Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli and Enterococci, suggesting a high specificity. In a proof-of-principle experiment, the colorimetric change of the sensor was detected by eye after 3 hours incubation with a PA culture.

Conclusions

The presence of Pseudomonas aeruginosa can be quickly and reliably detected by our vitamin B12-based colorimetric biosensor. Its incorporation inside the VAC-system can allow physicians to detect PA wound infections early on.
Mesothelial Cell Recruitment Towards Sites of Post-Surgical Adhesion Formation in the Peritoneal Cavity
Authors: Bayer J , Büchi I , Candinas D , Keogh-Stroka D , Zindel J
Published: June 2023

Background

Abdominal surgeries are often inevitable and live-saving procedures, however, they can be associated with post-surgical complications, such as the formation of irreversible scar bands called peritoneal adhesions. Adhesions in the peritoneal cavity can lead to serious health burden by causing small bowel obstruction, infertility, and chronic pelvic pain. Unfortunately, no effective treatment for adhesion patients exists today. Mesothelial cells and mesothelial cell-derived mesenchymal myofibroblasts have been identified as key players in the pathogenesis of adhesions, and thus represent a novel target for pharmacological interventions.

Aims

Our aim is to study the molecular mechanisms of mesothelial cell recruitment towards peritoneal adhesion sites, which could serve as potential drug targets to effectively prevent the formation of adhesions.

Methods

By exploiting genetic lineage tracing and experimental animal surgery, we have established a surgical-transgenic mouse model system that allows us to study mesothelial cell recruitment during processes of scar-free wound healing and wound healing associated with adhesion formation. To identify candidate molecules predominantly required for the recruitment of mesothelial cells towards adhesion sites, we apply an untargeted transcriptomics-based research strategy (spatial transcriptomics, single cell RNA sequencing).

Results

Histological characterization of our mouse model showed that over seven days post-surgery increasing numbers of mesothelial or mesothelial cell-derived cells accumulate at adhesion sites whereas their numbers stay constant in wounds healing without scar formation. Along with these findings, we have determined candidate molecules potentially triggering mesothelial cell migration towards sites of adhesion formation and will next test their proposed function in vivo and in vitro.

Conclusions

Mesothelial cells and mesothelial cell-derived mesenchymal myofibroblasts particularly accumulate at sites of adhesion formation. Therapeutic targeting of the recruitment mechanism of these cells might represent a novel strategy to prevent post-surgical adhesion formation in the peritoneal cavity.
Insights into DNA Damage in Regenerating Young and Aged Mouse Livers
Authors: Asensio Aldave A , Dommann N , Rossetti G , Karamichali A , Dionellis V , Keogh A , Candinas D , Halazonetis T , Stroka D
Published: June 2023

Background

The maintenance of genome stability is a key process to slow aging. One of the mechanisms ensuring this stability is the correct coordination of origins of replication (ORI), resulting in the successful transmission of DNA. Previously, we mapped and compared ORI firing between young and aged mice in vivo, using a regenerating liver mouse model. We confirmed a decreased hepatocyte ORI efficiency in aged mice, known to have impaired liver regeneration. ORI firing proved to be fully rescued when blocking the aged mice's ATR serine/threonine-protein kinase, suggesting that the DNA replication checkpoint actively mediates ORI firing impairment upon DNA damage detection.

Aims

To explore DNA damage differences between young and aged mice regenerating livers.

Methods

To induce proliferation, mice were subjected to partial hepatectomy (PH) and liver sections were harvested at different timepoints. Immunohistochemistry staining (IHC) were used to address proliferation and DNA damage, using Ki67 and serine 139 phosphorylated histone H2AX (g-H2AX) as markers, respectively.

Results

We confirmed a lack of Ki67 signal in young and aged mice prior to PH. The signal takes off at 24-28h post-PH and reaches its peak at 36-48h, which is significantly lower in aged mice. After 48h post-PH, young hepatocytes’ Ki67 reaches its basal level 120h post-PH. However, aged hepatocytes’ Ki67 is maintained at low levels overtime. Next, we compared DNA damage kinetics between young and aged mice livers. Both mouse groups present an increase of g-H2AX upon PH, higher in young mice. The g-H2AX signal decreases in young hepatocytes after 48h post-PH until disappearing 120h post PH. Aged mice hepatocytes maintain the g-H2AX rates overtime after 48h post-PH.

Conclusions

Our data suggests that hepatocytes develop DNA damage upon proliferation, which is able to be resolved in young mice hepatocytes but remains present in aged livers, ultimately leading to impaired liver regeneration.
Feasibility and Safety of Intraoperative Bile Duct Clearance by Sphincter Oddi Balloon Dilatation: A Prospective Observational Pilot Study
Authors: Prevost G A , Huber C , Schnell B , Candinas D , Wiest R , Schnüriger B
Published: June 2023

Background

Concomitant cholecysto- and choledocholithiasis is common. Standard treatments are ERCP followed by cholecystectomy or laparoendoscopic rendez-vous. ERCP has drawbacks such as post-ERCP-pancreatitis (5%) or -bleeding (5%) and potentially more than one intervention to address common bile duct (CBD) stones. Safety and feasibility of an intraoperative antegrade transcystic single-stage approach during cholecystectomy with papillary balloon dilation and pushing of concrements to the duodenum has not been evaluated prospectively.

Aims

The aim of the study was to evaluate this procedure regarding safety and stone clearance rate.

Methods

Prospective single centre intervention study. 80 consecutive patients admitted to our institution between 1/2021 and 4/2022 with suspected or confirmed choledocholithiasis (stones ≤ 6 mm) and known cholecystolithiasis were included. Success of the procedure was defined as lack of filling defects in the intraoperative control cholangiography and absence of symptoms at 6 weeks follow up. Simon's two stage design was used to determine sample size. Aiming for 95% positive outcomes (no pancreatitis) and tolerating at most 15% negative outcomes, power analysis revealed 57 participants (80% power, alpha 0.05).

Results

57/80 patients (71%) fulfilled the inclusion criteria. While there was no postoperative pancreatitis, 2 patients (3.5%) had asymptomatic amylasemia 4h postoperatively. Stone clearance was achieved in 54 patients (94%). The main reason for failed stone clearance was the inability to push the guide wire along the concrement into the duodenum. Median number of CBD-stones was 1 (1-6). Median stone diameter was 4 mm (0.1-6 mm). Median intervention time was 28 min (14-129 min).

Conclusions

Intraoperative bile duct clearance by balloon dilation of the sphincter Oddi appears to be safe and highly feasible. Its overall superiority to the current standards requires evaluation in a randomized controlled trial.
Anti-Recem18 Antibody Levels are Associated with Lesion Size and Determine Follow-Up after Resection of Hepatic Alveolar Echinococcosis
Authors: Gloor S , Jiang W , Maurer M , Gottstein B , Oberli A , Hagemann J , Hotz J F , Candinas D , Lachenmayer A , Grüner B , Beldi G
Published: June 2023

Background

Best monitoring practices for patients after resection of hepatic alveolar echinococcosis remain unclear.

Aims

The current study tested if assessment of anti-recEm18 allows for postsurgical patient surveillance.

Methods

A retrospective study with patients undergoing liver resection for alveolar echinococcosis at the University Hospital Berne from December 2002 to December 2020 and at the University Hospital and Medical Center Ulm from January 2011 to December 2017 was performed. Analysis was directed to determine a potential association of pre- and postoperative values of anti-recEm18 with clinical outcomes.

Results

Among 147 patients who underwent liver resection for alveolar echinococcosis in curative intent, perioperative results of recEm18-serology were available in 88 patients. In patients without residual disease, the postoperative anti-recEm18 value after 12 months dropped to a mean of 2 AU/ml (standard deviation: 4 AU/ml). Three trajectories of anti-recEm18 were identified based on a threshold of 10 AU/ml: “Em18-low” (n = 31, 35%) with anti-recEm18 values below 10 AU/ml pre- and postoperatively, “responders” (n = 53, 60%) with preoperative values above 10 AU/ml and a postoperative decrease of more than 80% of the initial anti-recEm18 and “residual disease” (n = 4, 5%) with the postoperative presence of residual disease. The decline of anti-recEm18 in “responders” reached a plateau after 11.4 months at which levels decreased by 80%. The only recurrence in the entire population was identified by a secondary increase of anti-recEm18. Anti-recEm18 levels had a linear correlation to the maximum lesion diameter (R2 = 0.558).

Conclusions

Anti-recEm18 antibody levels correlate with the lesion size preoperatively and response to surgery postoperatively. Anti-recEm18 allows to be applied as serological surveillance marker during postoperative follow-up in patients with elevated preoperative anti-recEm18 levels.
Impact of Cirrhosis on the Choice of Liver Resection in Patients with Hepatocellular Carcinoma
Authors: Zeindler J , Hess G F , von Heesen M , Aegerter N , Reber C , Schmitt A , Muenst S , Bolli M , Soysal S D , Kollmar O
Published: June 2023

Background

Hepatocellular carcinoma (HCC) usually occurs within an underlying chronic liver disease such as cirrhosis with limited liver function. Liver resection is an effective treatment option. Most studies investigating the benefits of anatomic (ALR) versus non-anatomic (NALR) liver resections in cirrhotic HCC patients involve Asian populations with different underlying chronic liver diseases.

Aims

NALR limits the resection of liver parenchyma, and therefore could reduce postoperative liver failure, while the effects on survival rates remain unclear. European data are desperately needed.

Methods

This is a retrospective and prospective multicentre cohort study, including all patients undergoing liver resection for HCC between 2009 and 2020 from 3 specialised centres in Switzerland and Germany. Patients were stratified for cirrhosis and no cirrhosis. Complications and survival rates were analysed using univariate and multivariate Cox regression models.

Results

298 patients were included. Median follow-up time was 52.76 months. 158/298 (53%) patients presented with cirrhosis. Cirrhotic patients after ALR (n=64/158) showed a significantly longer ICU stay (p=0.017) and postoperative in-hospital stay (p=0.007) compared to after NALR (n=94/158), while the NALR group showed significantly more postoperative complications (p<0.001), but the rate of liver insufficiency was not significantly different after NALR versus ALR (p=0.846). Overall survival (OS) and recurrence free survival (RFS) in cirrhotic versus non-cirrhotic patients were not significantly different (adjusted HR 0.78 (95% CI 0.53-1.15, p=0.21) and adjusted HR 0.82 (95% CI 0.64-1.24, p=0.27), respectively). A trend towards better OS and RFS could be observed favouring NALR in cirrhotic patients (for OS adjusted HR 0.55 (95% CI 0.28-1.07, p=0.08) and for RFS adjusted HR 0.55 (95% CI 0.30-1.01, p=0.06)).

Conclusions

European patients with cirrhosis could benefit from NALR regarding longer OS and RFS. NALR is associated with a significantly higher complication rate compared to ALR, but not with a higher rate of postoperative liver insufficiency.
Watchful Waiting after Definitive Radiochemotherapy in Patients with Esophageal Cancer: Independent Predictors for Recurrence
Authors: Gerber S , Berger M D , Hemmatazad H , Candinas D , Haltmeier T , Borbély Y
Published: June 2023

Background

Treatment of Esophageal Cancer (EC) consists of neoadjuvant radiochemotherapy (RCT) followed by resection. However, esophagectomy is associated with considerable morbidity in patients already burdened with comorbidities, malnutrition, and unhealthy lifestyle.

In this context, a watch and wait (WW) strategy has gained importance in patients with complete response to RCT and has been adopted by our center a decade ago.

Aims

To investigate independent predictors for recurrence in patients with EC undergoing WW.

Methods

We retrospectively analyzed data of all patients with potentially curable EC and complete response to RCT from 01/2014–12/2020 at a tertiary university hospital. Patients underwent staging (computed tomography (CT), upper endoscopy with ultrasound and biopsies (EUS), and positron-emission tomography (PET)), followed by RCT with restaging six weeks after completion. Routine follow-up consisted of EUS every three and CT every six months. Clinical data were extracted from electronic medical records. Factors associated with recurrence were adjusted for patient- and tumor-characteristics in multivariate regression analysis.

Results

A total of 40 patients were included. Of these, 22 (55%) had cancer recurrence. Tumor type was squamous cell carcinoma in 24 (60%) and adenocarcinoma in 16 (40%), respectively. T3-stage was most frequent (n=26, 65%), 35 (88%) patients were nodal-positive. Mean age was 67 years (SD 8.8), 30 (75%) patients were male. Recurrence occurred after a mean of 413 days (SD 171). Multivariate analysis revealed a circumferential tumor extent >50% in staging (OR 15.229, p=0.017) and dysphagia at restaging (OR 6.336, p=0.023) as independent risk factors for recurrence.

Conclusions

The current study revealed tumor extent and dysphagia as independent risk factors for recurrence. These predictors may help in the early identification of patients with EC recurrence, thus contributing to a personalized follow-up.
Laparoscopic Hiatal Hernia Repair with RefluxStop: Outcomes in 30 Patients with a Minimal Follow-Up of 12 Months
Authors: Fringeli Y , Kessler U , Linas I , Zehetner J
Published: June 2023

Background

Laparoscopic hiatal hernia repair with RefluxStop is an innovative technique to treat patients with gastroesophageal reflux disease (GERD). While feasibility and safety of this technique have already been demonstrated, consistent 12-months follow-up data is lacking.

Aims

To report 12-months outcomes and complications of a novel surgical anti-reflux technique with RefluxStop.

Methods

Among the 60 patients who underwent hiatal hernia surgery with RefluxStop since 2020 at our institution, we performed a retrospective chart review of the first 30 patients who achieved a minimal follow-up of 12 months. Follow-up data were reviewed until December 2022. Primary outcome was the clinical improvement of GERD related symptoms (heartburn and regurgitation) at 3 and 12 months after surgery. Secondary outcomes were need for dilatations and occurrence of implant related complications.

Results

The median follow-up was 19.5 months (range, 13-31). Preoperatively, 23 patients (76.7%) presented with esophageal dysmotility, and the median length of the concomitant hiatal hernia was 4cm (range, 2-8). Mean GERD-HRQL score (0-75 points) was 37.6 ± 15.8 before surgery, 4.2 ± 7.1 at 3 months, and 4.4 ± 6.9 at 12 months (p<0.001). Three patients (10%) required postoperatively balloon dilatation due to persistent dysphagia. One patient experienced an asymptomatic partial migration of the implant, one patient presented with a recurrence of hiatal hernia after 2 years who required surgical repair, and in one case the implant was removed after 16 months to due persisting left thoracic pain.

Conclusions

This study confirmed excellent clinical outcomes beyond 1 year with significant improvement of reflux symptoms in all patients.
Gut Microbiota Conditioning Promotes Anti-Tumor Immunity and Responsiveness to Immunological Checkpoint Blockade in Colorectal Cancer
Authors: Basso C , Cianfarani A , Djordjevic J , Sorrenti E , Galafassi J , Roesel R , Christoforidis D , Majno-Hurst P E , Iezzi G
Published: June 2023

Background

Colorectal cancer (CRC) infiltration by T lymphocytes is associated with prolonged survival. However, immune infiltration spontaneously occurs in <20% of tumors and no therapies able to promote it are currently available. CRC tissue is populated by gut bacteria translocated across the neoplastic epithelium. We previously showed that direct contact between tumor cells and bacteria induces overexpression of genes encoding immune cell-recruiting chemokines in tumor cells, and we identified a panel of bacterial species associated with enhanced chemokine expression, high T cell infiltration and favorable prognosis.

Aims

In this project we tested the ability of identified bacterial species to boost T-cell infiltration and promote tumor regression in orthotopic CRC experimental models.

Methods

Luciferase-expressing mismatch repair (MMR)-proficient or -deficient murine CRC cells from established cell lines were injected intra-cecum in syngeneic mice. Tumor growth was monitored by bioluminescence. Bacterial species of interest, defined as Operational Taxonomic Units (OTUs), were cultured under anaerobic conditions, and, following tumor development, were administered to tumor-bearing mice by oral gavage. In specific experiments, bacteria administration was combined with immunological checkpoint blockade (ICB), based on injection of anti-PD-1 antibodies. Immune cell infiltration was evaluated by flow cytometry, following tumor harvesting and enzymatic tissue digestion.

Results

In MMR-deficient tumors, known to be immunogenic and responsive to immunotherapy, administration of the bacterial species OTU8, was sufficient to reduce tumor growth. In MMR-proficient tumors, scarcely infiltrated by immune cells and poorly responsive to ICB, OTU8, did not per se affect tumor growth, but enhanced infiltration by cytotoxic CD8+ T cells, ultimately leading, in combination with anti-PD-1 antibodies, to tumor growth inhibition.

Conclusions

We demonstrated that administration of defined bacteria promotes endogenous immune responses against CRC. Gut microbiota conditioning might represent an innovative therapeutic strategy to enhance responsiveness to ICB and to broaden its indication beyond MMR-deficient tumors.
Robotic Versus Open Incisional Ventral Hernia Repair with Sublay Mesh in Overweight Patients: A Case-Control Analysis of Clinical Outcomes and Costs
Authors: Douissard J , Gramolini L , Dupuis A , Mareschal J , Chevallay M , Hagen M , Toso C
Published: June 2023

Background

Robotic incisional hernia repair (RIHR) with sublay mesh is gaining traction as a minimally-invasive alternative to open retro-rectus reconstruction (OIHR). Obesity is a known risk factor for complications following hernia repair.

Aims

The objective of this study is to compare the clinical outcomes and costs of RIHR versus OIHR with sublay mesh in overweight patients.

Methods

Patients with a body mass index (BMI) of 25-35 kg/m2 who underwent OIHR or RIHR with sublay mesh over a 2 years’ period were included. Recurrent hernias after mesh repair were excluded. The main outcome was length of hospital stay (LOS). Secondary outcomes included surgical site complications (SSC), visual analog pain score (VAS), analgesic methods, and general complications.

Results

Ninety patients were included, 45 in each group. The mean length of stay (LOS) was significantly shorter in RIHR (6.8 days ± 4.6 vs. 2.3 days ± 2, p < 0.001), as were VAS at day 0 (3.0 ± 2.7 vs. 1.7 ± 1.8, p = 0.005) and day 1 (4.2 ± 2.2 vs. 2.4 ± 1.8, p < 0.001), with a significant reduction in morphine consumption and epidural analgesia. The mean operative time was 163 min. ± 65 in OIHR and 191 min. ± 94 in RIHR (p = 0.06), despite a higher proportion of component separation in the robotic group (18% vs 33.3%, p = 0.005). The open group had higher rates of SSC (20% vs 2.2%, p = 0.015) and general complications (40% vs 13.3%, p = 0.004). General costs per diagnosis showed a mean reduction of 4797 CHF in the robotic group, mostly due to reduced hospitalization costs (9364 CHF vs. 3472 CHF).

Conclusions

The robotic approach improved post-operative outcomes of incisional hernia repair with sublay mesh compared to the open approach in overweight patients, without significantly increasing operative time and costs.
The Impact of the Gastric Pouch and Gastro-Jejunostomy Size after Laparoscopic Roux-En-Y Gastric Bypass - A Prospective, CT-Volumetry Based Study
Authors: Lazaridis I , Kraljevic M , Köstler T , Mattiello D , Andreou A , Zingg U , Delko T
Published: June 2023

Background

Some patients who undergo laparoscopic Roux-en-Y gastric bypass (LRYGB) may present with insufficient weight loss or weight regain. Anatomical factors that may lead to failure of LRYGB include the size of the gastric pouch and the diameter of the gastro-jejunostomy.

Aims

This study explores the gastric pouch size and the size of the gastro-jejunostomy after LRYGB and investigates their impact on weight loss, appetite and quality of life (QoL).

Methods

Patients undergoing LRYGB in a single centre underwent computed tomography (CT) with oral contrast one day and one year after LRYGB. Volumetry of the gastric pouch and calculation of the size of the gastro-jejunostomy was performed. Appetite was assessed pre-operatively and one year after LRYGB using the Edmonton Appetite Assessment questionnaire. QoL was assessed pre-operatively one year after surgery using the GIQLI and BAROS questionnaires.

Results

61 patients were included. Of those, 55 patients (90.2%) underwent CT one year after LRYGB. The mean preoperative Body Mass Index was 40.7±3.97kg/m2. The mean Excess weight loss (%EWL) one year after surgery was 82.1±21.5%. There was no significant change in mean gastric pouch size one day and one year after LYRGB (15.73±11.8cm3 and 14.4±11.5cm3, respectively, p=0.55). The mean size of the gastrojejunostomy increased significantly from 2.63cm2 to 3.60cm2 (p<0.0001). Mean GIQLI and BAROS values improved significantly one year after LRYGB, but no significant changes in the mean Edmonton Appetite Assessment values were found. %EWL and improvement in GIQLI and BAROS values one year after surgery did not correlate with the initial size of the gastric pouch and the increase of the size of the gastro-jejunostomy.

Conclusions

One year after LRYGB, the size of the gastro-jejunostomy increased significantly, but no difference in the gastric pouch volume was found. Both gastric pouch volume and dilatation of the gastro-jejunostomy did not correlate with weight loss and QoL outcomes.
The Intraoperative Dorsal Tangential View and the Radial Groove View of the Distal Radius to Detect Dorsal Screw Protrusion in Volar Plating: Teaching Effect and Value in Clinical Practise
Authors: Fässler D , Pozzi L , Doert A , Schläppi M , Meier C
Published: June 2023

Background

Dorsal screw tip protrusion (DSTP) with extensor tendon injury is a well-known complication of volar plating for distal radius fractures. The dorsal tangential view (DTV) and the radial groove view (RGV) have been recommended to detect DSTP. The value of these views depends on their quality and reproducibility.

Aims

It was the aim of this study to investigate the quality of these views before and after teaching of the involved surgeons.

Methods

All adult patients treated with volar plating for distal radius fractures between 10/2019 and 10/2020 were included. Prior to their first case in the study period, all involved surgeons were instructed in a standardized manner how to perform technically correct DTV and RGV. Patients from an earlier period served as controls. Image quality was rated independently by two investigators. Detection of DSTP based on fluoroscopy was documented and protruding screws were exchanged. The impact of teaching was assessed. Furthermore, reliability of DTV and RGV to detect DSTP was compared to postoperative ultrasound.

Results

A total of 124 patients were included in the study group, 125 patients served as controls. Interobserver agreement for the image quality was 97% for DTV and 98% for RGV. Image quality significantly improved with teaching (p<0.001). Correct images were observed in 81% vs. 58% for DTV and 81% vs. 53% for RGV. From a total of 571 evaluated screws intraoperative fluoroscopy identified 24 DSTP (4.2%) in 23 patients (18.5%). Postoperative ultrasound revealed 4 DSTP (0.8-1.2mm; 0.7%) in 4 patients (3.2%).

Conclusions

Teaching surgeons how to perform technically good DTV and RGV leads to a significant improvement of image quality. DTV and RGV are reliable tools to detect DSTP. However, despite correct views, some minor dorsal cortex penetrations may be missed. Thus, early further investigations are recommended in patients with extensor tendon irritation.
Carpal Tunnel Syndrome and Trigger Digit: An Early Symptom of Cardial Amyloidosis
Authors: Kallenbach B , Höfflinghaus T , Höller S , Dietrich M , Sproedt J
Published: June 2023

Background

Amyloidosis is a disease with misfolded protein deposits. The subform transthyretin amyloidosis (ATTR) presents with heart failure, atrial fibrillation and bundle branch block, often requiring pacing. Soft tissue deposits may occur, causing trigger digit (TD) and carpal tunnel syndrome (CTS). These may be an initial symptom of systemic amyloidosis with cardiac manifestation, they precede cardiac amyloidosis on average 5-9 years. Studies showed positivity of up to 22.5% for ATTR in tenosynovial biopsies in CTS-patients identified by a screening algorithm. ATTR is found in around 25% of autopsies at 80 years and older, with underestimated prevalence in the general population.

Aims

Early detection is crucial in treating systemic amyloidosis. Therefore, biopsies taken during carpal tunnel release (CTR) and trigger release (TR) can contribute significantly to its diagnosis.

Methods

Patients admitted in 2022 to our hospital were examined prospectively and biopsied if macroscopic intraoperative synovial hyperplasia was present. Histologic examination was done with Congo red staining and immunohistologic examination for ATTR. Patients tested positive for ATTR were offered a cardiologic follow-up.

Results

118 patients (63 CTS, 55 TD) were included in the study, 40 (34%) underwent partial synovectomy. Of these, 3 patients (7.5%) were positive for ATTR. 1 patient had an unremarkable cardiologic examination, 1 patient declined, 1 patient is pending.

Conclusions

Early detection of amyloidosis by CTR and TR is a topic of increasing relevance. In our study, the positivity rate was lower than in others. However, there was different patient selection, e.g., according to macroscopic findings instead of a screening algorithm. The observation period is insufficient to record any cardiac results; a follow-up in 5-10 years would be appropriate. Current therapy for amyloidosis aims to delay the disease progress by preventing deposit formation, with no therapy degrading pre-existing deposits. Thus, early detection is crucial for disease outcome and justifies additional screening cost.
Improving the Early Outcome of Digital Replantation: Technical Tricks Learned in a US Fellowship
Authors: Früh F , Safa B , Watt A , Pridgen B , Lin W , Buntic R , Buncke G
Published: June 2023

Background

Despite stable numbers of upper limb amputations there is a decline in replantation in Europe. This results in lacking experience, decreasing success rates, and fewer attempts. Training in high-volume centers is crucial for hand surgeons performing upper extremity replantation.

Aims

This abstract highlights the experience in a US microsurgery fellowship.

Methods

Upper extremity revascularization and replantation cases during a 10 month - period were retrospectively reviewed. Overall, the fellow was exposed to 29 cases: 2 hand, 5 thumb and 9 digitial replantations as well as 13 thumb and digital revascularizations. Primary outcome was the survival of the injured body part. Secondary outcomes were total case time, number of repaired arteries/veins, the use of vein grafts, and early free flap coverage. Whenever possible, all microsurgical steps including vessel debridement and anastomosis were performed under tourniquet.

Results

Success rate was 21/29 (72%). Failure was limited to avulsion or crush injuries. Mean surgery time for revascularization was 92 min (range, 45-134 min) per digit. Mean surgery time for thumb and single digit replantation was 133 min (range, 62-270 min) and for the two hand replantations 180 min and 300 min, respectively. Routinely, only 1 dominant artery was repaired. Forearm or saphenous vein grafts were used in 14/29 cases. Only in 3/23 cases > 1 vein was repaired and in 3 cases interpositional vein grafts were used for dorsal vein reconstruction. One venous flow-through flap was used and a dorsal hand soft tissue defect was covered with a fascio-cutaneous free flap 5 days after replantation.

Conclusions

Replantation remains a challenge for hand surgeons. The thoughtful use of a tourniquet with vessel debridement in a bloodless field is key to maximize the efficiency of replantation. Furthermore, the liberate use of vein grafts and venous flow-through flaps helps moving outside the trauma zone, thus increasing the likelihood of upper limb salvage.
Mid- to Long-Term Clinical and Radiological Outcome after Perilunate Injuries
Authors: Riederer J , Kellenberger C , Häfeli M , Cordier T , Wirtz C , Schibli S , Felsbourg J
Published: June 2023

Background

Perilunate dislocations (PLD) and perilunate fracture dislocations (PLFD) are rare but severe injuries to the wrist, usually resulting from a high-energy trauma occurring in sports injuries, motor vehicle accidents, falls or machine related accidents. Treatment of choice is early reduction with carpal transfixation, fracture fixation and refixation of the injured ligaments.

Aims

As reports on mid- to long-term outcome are scarce, we aimed to investigate clinical and radiological outcome of open treatment after a minimal follow-up of 2 years.

Methods

Patients treated for PLD and PLFD in our institution were identified back to 2008. Inclusion criteria were PLD and PLFD who underwent open surgery, had a minimal follow-up of 2 years and were available for a follow-up. Clinical examination included ROM and grip strength. PRWE, quick DASH, SF-12 and the single assessment numeric evaluation (SANE) score were used as PROMs. Dorso-palmar and lateral X-rays were done and assessed for carpal height, inter- and radio-carpal angles and degenerative changes.

Results

Of 54 identified patients, 29 patients could be located and contacted. By the date of abstract submission 15 patients after PLFD and 9 after PLD had been followed-up in our clinic. Mean follow-up was 93 months (24-170). Mean F/E was 43/0/51° for the affected and 68/0/66° for the healthy wrist, P/S 77/0/73° and 79/0/79°, R/U 24/0/34° and 27/0/44°. Mean grip strength was 41kp and 61kp. Mean score for PRWE was 13.2, qDASH 14.2%, SF-12 physical score 50.9, mental score 55.1 and SANE 86%. 11 patients showed slight to moderate degenerative changes. Carpal height (Nattrass Index) showed a mean of 1.45.

Conclusions

Although the affected wrists showed reduced ROM and SANE scores, patients were mostly satisfied with the outcome and only exhibited little pain. Open reduction and fixation of PLD and PLFD reliably lead to satisfactory results even in the long-term.
Training with a Novel Digitally Enhanced Hands-On Surgical Training (DEHST) Enhances the Performance During Intramedullary Nail Distal Interlocking
Authors: Pastor T , Cattaneo E , Gueorguiev B , Windolf M , Buschbaum J
Published: June 2023

Background

Freehand distal interlocking of intramedullary nails remains a challenging task. This surgical step is the most difficult part performed at the end of the operation and may have a catastrophic influence on patients’ outcome of not performed precisely. Recently, the AO Research Institute developed a new training device for Digitally Enhanced Hands-on Surgical Training (DEHST), potentially improving surgical skills needed for this surgical step. The device already yielded high scores in terms of face and construct validity in the first step of the validation cascade.

Aims

To evaluate weather training with DEHST enhances the performance of novices without surgical experience in free-hand distal nail interlocking compared to a non-trained group of novices.

Methods

20 novices were assigned in two groups and performed distal interlocking of a tibia nail in an artificial bone model under a real C-arm. Group 1: DEHST trained novices (virtual locking of five nail holes during one hour of training). Group 2: untrained novices without DEHST training. Time, number of x-rays, nail hole roundness, critical events and success rates were compared between the groups.

Results

Time to complete the task (sec) and x-ray exposure (µGcm2) were significantly lower in Group1 414.7 (290–615) and 17.8 (9.8–26.4) compared to Group2 623.4 (339–1215) and 32.6 (16.1–55.3); p=0.041 and 0.003. Perfect circle roundness (%) was 95.0 (91.1–98.0) in Group 1 and 80.8 (70.1–88.9) in Group 2; p<0.001. In Group 1 90% of the participants achieved successful completion of the task (hit the nail with the drill), whereas only 60% of the participants in group 2 achieved this; p=0.121.

Conclusions

Training with DEHST significantly enhances the performance of novices without surgical experience in distal interlocking of intramedullary nails. Besides radiation exposure and operation time the complication rate during the operation can be significantly reduced.
Clearing of Polytrauma Patients for Early Definitive Fracture Fixation: A Systematic Literature Review
Authors: Roman R , Klingebiel F K L , Halvachizadeh S , Kalbas Y , Pape H C
Published: June 2023

Background

Early patient assessment is important for surgical decision making in severely injured patients. Moreover it is known that early fracture fixation is beneficial, such as those in stable condition or those who respond well to resuscitation.

Aims

The aim of this systematic review is to identify parameters that indicate risk factors for an unfavorable outcome and early complications. In addition, we aim to improve decision making and separate patients who would benefit from early versus staged definitive surgical fixation.

Methods

A systematic review was performed of peer-reviewed articles in English or German published between January 1, 2000, and May 15 2022 (PUBMED) according to PRISMA guidelines. The primary outcome was the pathophysiologic response to polytrauma, including coagulopathy, shock/hemorrhage, hypothermia, and soft tissue injury to determine the treatment strategy with the least number of complications. Articles that had used quantitative parameters to distinguish between stable and unstable patients were combined.

Results

The initial systematic search for MeSH criteria yielded 1550 publications deemed relevant to the following topics (coagulopathy (n = 37), hemorrhage/shock (n = 7), hypothermia (n = 11), soft tissue injury (n = 24)). Thresholds for stable, borderline, unstable, and in extremis conditions were defined according to the existing literature as follows: Coagulopathy; International Normalized Ratio (INR) and viscoelastic methods (VEM)/blood/shock; lactate, systolic blood pressure and hemoglobin, hypothermia; thresholds in degrees Celsius/soft tissue trauma: traumatic brain injury, thoracic and abdominal trauma, and musculoskeletal trauma.

Conclusions

In this systematic literature review, we summarize the publications by focusing on the different pathways that stimulate pathophysiologic cascades and distant organ damage. We propose that these parameters can be used for clinical decision making within the concept of safe definitive surgery (SDS) in the treatment of severely injured patients.