bluuebunny/crossref_metadata_2025 huggingface dataset:
Probabilistic CO2 plume modelling
Authors: Tang David
Published: May 2024

The Offshore Petroleum and Greenhouse Gas Storage Act 2006 provides the legal framework for carbon dioxide (CO2) storage projects in Australian Commonwealth waters, with the associated regulations and guidelines requiring that applicants for a ‘declaration of an identified storage formation’ consider ‘all migration pathways of which the probability of occurrence is greater than 10%’. The overseas Society of Petroleum Engineer’s CO2 Storage Resources Management System goes further and discusses the concept of modelling not only the subsurface CO2 plume itself but also the attendant pressure effects and displaced formation water, which, in that scheme, comprise part of a wider ‘containment area’. These collective requirements necessitate that the eligible carbon storage resources be assessed probabilistically, a requirement that can result in sizable static and dynamic models that are computationally heavy to simulate. This computational complexity places inherent, practical limitations on using ‘conventional’ probabilistic workflows, such as Monte Carlo simulation or Latin hypercube sampling. To address this limitation, factorial experimental designs were employed in the modelling workflow. Factorial designs are widely used in settings where individual experiments are costly or require prolonged periods and, when implemented correctly, can uncover underlying uncertainty distributions using a minimum number of simulation cases. The efficacy and power of this approach is demonstrated using CO2 injection and migration models for a carbon storage project located in offshore Western Australia, which is in the early development stage. The ability to test potential sensitivities rapidly has proven to be critical in refining and defining the project’s ultimate carbon capture and storage development plan.
A speculative ridge within the Kidson Sub-basin – integrated interpretation from geophysical data
Authors: Zhan Y.
Published: May 2024

This paper presents an analysis of the basement geometry and its implications on the Kidson Sub-basin in the southern Canning Basin. Integration of seismic data primarily near the rim of the sub-basin with airborne electromagnetic data across its central portion reveals an east-northeast oriented ridge at Permian level, suggesting a possible elevated structure in the Ordovician and basement. The proposed ridge effectively separates the Kidson Sub-basin into two distinct parts, providing an explanation for facies and thickness variations observed in the Nambeet and Goldwyer formations, as well as the absence of the Willara Formation in the southeastern portion of the sub-basin. The presence of shallowing trends observed in seismic profiles along the southern flank of the ridge suggests the proximity of the basement high. The ridge is speculative and requires further work to verify its existence, potentially including passive and reflection seismic surveys across the structure. If confirmed, it might be a significant feature with far-reaching implications for the prospectivity of resources in the Kidson Sub-basin. The hydrocarbon sourced from the Nambeet, Goldwyer and Bongabinni formations in the NNW depocentre may have migrated via the extension of the Parallel Range Fault and be trapped in the footwall block over the ridge. Compared to the structures in the Fitzroy Trough, the traps within the Kidson Sub-basin are expected to maintain reasonable integrity and have good potential for petroleum accumulation and carbon sequestration in the thick Paleozoic succession.
Safeguard Mechanism reforms – how big and how much will it cost?
Authors: Gibb John , Forbes Anne , Simpson Luke
Published: May 2024

In an effort to reduce greenhouse gas emissions, the Australian government legislated the Safeguard Mechanism (SGM) in 2016. It is generally accepted that it had minimal impact, with no material reduction in greenhouse gas emissions resulting. In a move to address this, the legislation was amended, effective July 2023. These amendments rewrote the rules – baselines will reduce over time, the method of setting them will change, new concepts such as ‘international best practice’ will be introduced and new projects (including those already sanctioned, but not yet onstream) will be subject to tougher requirements. Our analysis will review the impact on the upstream projects currently covered by the SGM, and a select group of new projects. We will give our view on how the transition from the facility-specific to industry-average baselines impacts operators, and identify some of the potential winners and losers. Whilst first reporting is not due until the end of the 2024 financial year, there is still significant uncertainty on how the amended SGM will operate, specifically with regards to ‘industry best practice’. The paper will analyse what this could mean, and potential impacts. Is the SGM the roadmap to net zero that the industry is looking for? The work will leverage Wood Mackenzie’s asset by asset emissions data, and our unique insight into the economics of upstream developments. Ultimately, we will assess the trade-off that has been made by the Australian government – emissions for commerciality – and its long-term impact on the upstream sector.
A novel approach for geomechanical modelling in the absence of stress magnitude data
Authors: Rajabi Mojtaba , Ziegler Moritz , Ranjbarkarami Rasoul , Tavoosiiraj Parisa
Published: May 2024

Geomechanics play an important role in any underground activity, such as carbon dioxide (CO2) and hydrogen (H2) geo-storage, owing to the considerable hazards linked to the injection and withdrawal of fluids into and from the subsurface. In order to quantify these risks, knowledge of full stress tensor is required. Yet, most of our stress information in the Australian target basins for geo-storage is limited to the stress orientations, while stress magnitude data is sparse. 3D geomechanical modelling has proved to be an invaluable tool for prediction of full stress tensor. Nevertheless, a model requires some stress magnitude data in order to tune the model to be representative of real stress state. In situations where stress magnitude data is lacking, this means that the model is susceptible to significant uncertainties. Herein, we present a novel strategy for stress modelling, which involves the utilisation of indirect data such as borehole breakouts, drilling-induced fractures, seismic activity records, and formation integrity tests to calibrate a 3D geomechanical model. We employ the northern Bowen Basin, an onshore basin in Queensland, Australia, as a case study for a comprehensive 3D geomechanical modelling approach. We assess all the indirect information in the model’s volume to narrow down the model predictions and find the most reliable stress state. This innovative approach is an important step forward in stress modelling of Australian basins, where lack of stress magnitudes is a great challenge for geomechanical assessment of geo-storage.
Case study using APDMS and RPEMS for SAWL pipes and benefits for offshore pipelay
Authors: Kathayat T. S. , Srivastava Atul , de Boer Jan , Mapara Bhavin , Gajjar Mahesh
Published: May 2024

This paper reviews an Automatic Pipe Dimension Measurement System (APDMS) and a Robotic Pipe End Measurement System (RPEMS) which can measure 19 and 9 parameters with the help of 72 and 6 measurement sensors respectively. APDMS and RPEMS are integrated into one optical measurement system, using laser triangulation, coupled with Systems, Applications and Products in Data Processing (SAP) integration and its own calibration modulus which provides an accurate solution to all pipe measurements. Two longitudinal submerged arc welded offshore projects were executed for an offshore pipe lay with close dimensional tolerances measured using the APDMS for one project and RPEMS for the other project. The radii data, assessed from the newly calculated common centre of all cross-sectional data, was used to line up the two adjacent pipes in a faster and more accurate way. By knowing the shape of the pipe ends based on this radii data, the best relative rotation of these two pipes can be determined and any misalignment will be verified and will stay within the requirements. The extensive database available for each pipe helped to match the line pipes with similar or close out-of-roundness at pipe ends resulting in good fitment of the pipes and ultimately quality welds, together with more pipe joints per day, resulting in a faster completion of the project. This paper shows the significance of using both systems.
The Bayu-Undan liquid CO2 import facilities – finding an effective solution
Authors: Weiter Ross , Toft Christopher
Published: May 2024

Carbon capture and storage (CCS) is widely considered to be one of the key enablers to decarbonising the economy. It is currently being implemented in a number of projects in gas, power, chemicals, cement, steel, and other industries. In the Asia–Pacific region, shipping of liquid carbon dioxide (LCO2) is widely seen as a key component of the CCS value chain. Shipping allows the emitters located in the industrial centres of Japan, Korea, and Singapore to access distant CO2 storage locations. The repurposing of the Bayu-Undan (BU) platforms and pipeline from gas production to CO2 injection presents a regional opportunity for the disposal of shipped CO2. Multiple LCO2 development concepts were assessed for unloading and storing the imported LCO2. Unloading can be carrier-to-shore, carrier-to-ship/barge, or carrier-to-platform; storage can be onshore, nearshore, offshore or no buffer storage at all with direct injection from carriers. These concepts required evaluation for technical functionality, maturity, complexity, operability, and availability. Imported LCO2 is too cold and low pressure to be transported or injected at the carrier transport conditions. The pressure needs to be boosted and temperature increased to meet the requirements of the injection system. This requires sources of power and heat. An evaluation of existing facilities, their condition, available space and spare capacity, and their constructability considerations revealed important opportunities and constraints. A study was carried out, which evaluated options for the BU LCO2 import using key evaluation criteria to select the most appropriate concept. This paper explores addressing the challenges involved.
Satellite based oil spill emergency response and recovery support
Authors: Pedersen Børre , Isaksen Hugo , Espeseth Martine M.
Published: May 2024

Oil spills at sea pose a complex and challenging problem. Detecting, reporting, and potentially acting on the spill are difficult tasks, especially if the information is only obtained from the perspective of a vessel. Near-real time and relevant information is crucial for effective management of an oil spill event. This paper demonstrates how satellite-based images, combined with methods for thickness extraction and oil drift trajectory, can provide end-users with actionable and timely information for emergency response and recovery support. The results show the high value of quick delivery and the importance of using multiple sensors and data sources during an emergency, which enhance situational awareness and decision making. We highlight the value of satellite imagery for oil detection and show how it can be used to document the polluter, identify relative oil thickness, model oil drift, and compare different sensors.
Opening versus shearing of a fluid-driven fault reactivation
Authors: Xiao Feng , Salimzadeh Saeed , Zhang Qian-Bing
Published: May 2024

Geological injection of fluids plays a key role in addressing societal challenges such as renewable energy transition and climate crisis mitigation. However, frequent injection activities would disturb the stability of surrounding fault zones and furtherly induce seismicity. When fluid enters a fault, the competition among pressure front and slip front can play a role on the fault’s seismic behaviour. Fault’s stiffness as well as the rock’s Poisson’s ratio affects the shape of the slip and pressure front. In this study, the fault’s seismic behaviour has been extensively study through numerical modelling. The aim is to investigate the impact of deformable aperture and rock matrix’s Poisson’s ratio on the opening rupture and shear rupture of a pre-existing critically stressed fault. The parametric study shows that, with this initial stress state, the opening rupture grows slower than the shearing rupture, and the ratio between the front length is approximately 70%. A slip-weakening feature could boost this difference. Moreover, the variation between the front length along the y-direction and dip-direction of the fault increases with the increase of rock matrix’s Poisson’s ratio.
The case for integrated IMR programs: increasing operational efficiency with a holistic approach that reduces risk and carbon emissions
Authors: Henney Ka
Published: May 2024

This paper discusses the positive impact of adopting an integrated, customisable inspection, maintenance, and repair (IMR) approach when addressing subsea assets. Primary focus and expenditure are typically committed to the design, planning, and engineering of infrastructure. Of paramount importance, but often overlooked, are the ongoing health checks required of the subsea assets. These activities are regularly left until an issue is found, production is affected, or subsea asset data is required to enable decision making to ensure the lowest level of risk and maximise uptime. How the operations and maintenance approach used for subsea assets is best addressed using an integrated philosophy that streamlines not only contract management, but the collection and analysis of data is detailed. By supporting a more holistic view of assets not only by field, but regionally and globally, operators are best positioned to apply advanced technologies including machine learning for the development of risk-based inspection programs that provide insight into potential failures and anomalies. Building and adopting truly optimised IMR programs also reduces vessel days by leveraging already deployed assets, advanced technologies, and remote piloting to complete varied inspection tasks simultaneous to other ongoing operations, lowering emissions and risk associated with mobilisations and personnel on board. The impact of optimised inspection planning on users’ in-house resources is detailed. With internal experts dealing with IMR planning, analysis, and data management often stretched, adopting this forward-thinking approach to IMR has the potential to alleviate the burden associated with targeted planning and clearing backlogs that manage risk.
Post-stack 3D merging to fast-track regional interpretation – offshore Otway Basin case study
Authors: Gunning Merrie-Ellen , Wilkinson Scott , Chau Pei-Fei , Mitchell Cameron , Badry Jennifer
Published: May 2024

Ideally when combining legacy 3D seismic surveys, differences in acquisition parameters warrant full pre-stack reprocessing from field data. However, there are occasions where this is not possible due to time, financial or data access constraints; a valuable alternative is post-stack merging and enhancement of existing migrations. This case was to produce a regularised and seamless 3D dataset of the highest possible quality, for the offshore Otway Basin, within 2 months. The input migrated volumes varied by data extent, migration methodology, angle range and grid orientation. Fourteen input volumes totalling 8092 km2 were post-stack merged and processed to produce a continuous and consistent volume, enabling more efficient and effective interpretation of the region. The surveys were regularised onto a common grid, optimised for structural trends, prior to survey matching. A mis-tie analysis algorithm, applied over a time window optimised for interpretation of key events, was used to derive corrections for timing, phase and amplitude, using a reference. This was followed by time-variant spectral and amplitude matching to improve continuity between volumes. Additional enhancements including noise removal and lateral amplitude scaling were also applied. The final merged volume offers significant uplift over the inputs, providing better imaging of structure and events and dramatically improving the efficiency and quality of interpretation. This enables rapid reconnaissance of the area by explorers.
A new perspective on regional structural architecture across the offshore Otway Basin
Authors: Nicholson Chris , Abbott Steve , Bernardel George , Poudjom Djomani Yvette
Published: May 2024

Geoscience Australia has undertaken a regional seismic mapping study of the offshore Otway Basin extending across the explored inner basin to the frontier deep-water region. Seismic interpretation covers over 18,000 line-km of new and reprocessed data acquired in the 2020 Otway Basin seismic program and over 40,000 line-km of legacy 2D seismic data. We present new basin-scale isochore maps that show the distribution of the Cretaceous depocentres. Maps for the Lower Cretaceous Crayfish and Eumeralla supersequences, together with those recently published for the Upper Cretaceous Shipwreck and Sherbrook supersequences, complete the set of isochore maps for the main tectonostratigraphic basin intervals. Mapping of basement-involved faults has revealed structural fabrics that have influenced depocentre development. The tectonostratigraphic development of depocentres and maps of deep crustal units delineate crustal thinning trends related to late Cretaceous extension phases. This work highlights the need to review and update structural elements. For example, the boundary between the Otway and Sorell basins is now geologically constrained. The refinements to the tectonostratigraphic evolution of the Otway Basin presented here have important implications for the distribution and potential maturity of petroleum systems, especially with regard to heat flow associated with crustal extension.
Optimising CO2 storage resource utilisation: insights from the Otway Stage 4 field program
Authors: Watson Max , Nourollah Hadi , Bason David , Higgs Scott , Benson Sally , Cook Peter , Park Yong-Chan , Allison Mitch , Xue Ziqiu
Published: May 2024

The optimised utilisation of storage resources and accelerated commercial carbon dioxide (CO2) storage development is vital for carbon capture and storage to play its important role in reducing emissions at scale. CO2CRC seeks to address this challenge through an international collaboration – the Otway Stage 4 field program – that demonstrates a suite of cost-effective reservoir management techniques with the potential to improve CO2 storage capabilities, particularly in lower-quality reservoirs, maturing them for commercial readiness. Aiming to enhance injectivity, improve sweep, increase model resolution, and develop performance monitoring capabilities, Otway 4 will substantially improve CO2 storage resource usage, furthering economical viability for decreasing CO2 emissions to the atmosphere. Otway Stage 4 includes acquisition and analysis of CO2 saturation and chemical data during plume migration and trapping, combined with investigation of fine-scale geological heterogeneity’s role in CO2 flow dynamics, to refine modelling workflows and, ultimately, develop strategies for optimising commercial CO2 storage; demonstrating whether CO2 microbubbles (MBs) significantly increase storage efficiency compared to standard CO2 injection, thereby unlocking previously untenable reservoirs for CO2 storage; enhancing seismic monitoring to comprehensively assess storage performance and MB behaviour, including quantitative derivation of CO2 saturation; and demonstrating the capability of Distributed Strain Sensing to quantitatively measure geomechanical changes associated with CO2 injection. In addition to Otway 4’s forward plans, laboratory and modelling work, including core flood analysis, to understand CO2 MB and surfactant behaviour at pore scale, dynamic modelling of CO2 flow through heterogeneous reservoir, and selecting suitable injection intervals at the Otway site are discussed.
Static contact angle, interfacial tension, and column height measurements for underground hydrogen storage
Authors: Muhammed Nasiru Salahu , Haq Bashirul , Shehri Dhafer Al , Qudrat Sayed
Published: May 2024

Geological porous media are key for large-scale hydrogen (H2) storage and production, where fluid interactions at interfaces and within rock formations are vital for effective gas containment. Although advancements have been achieved in comprehending structural trapping for estimating column height (CH), additional insights are required regarding how pore size impacts this estimation. Currently, CH estimates often consider seal rock potential, without including the capillary contribution from reservoir rock pore for structural trapping capacity assessment. This study measures the static contact angle (CA) on Wolfcamp (WC) Shale and interfacial tension (IFT) under modified drainage and imbibition conditions at temperatures of 30 and 50°C, pressures ranging from 500 to 3000 psia, and a salinity of 10 wt% sodium chloride. Subsequently, the static gas CH was calculated, accounting for contributions from the caprock pores alone and both the caprock and reservoir, to assess the structural sealing capacity of the caprock layer. The experimental procedures are comprehensively detailed in this paper. The outcome indicates that the static CA after drainage for H2)/brine/WC shale rises with pressure as the static CA after imbibition decreases. Both CAs decrease with increasing temperatures. For H2/brine systems, both drainage and imbibition IFTs decline with increasing pressure and temperature. Calculated CHs reveal that lower CAs substantially impact the gas trapping capacity beneath the caprock. In summary, this study highlights the preference for the drainage method in measuring IFT and CA to evaluate the potential structural trapping capacity of injected gas by the overlying caprock.
Changes in well control training to meet the challenge of reducing well control incidents
Authors: Sehnal Zdenek
Published: May 2024

The number of safety related incidents in the Oil and Gas industry has steadily declined over the past 20 years. However, the frequency of well control incidents has not followed the same trend. The Norwegian regulator (Petroleum Safety Authority) has recently documented this finding as related to the Norwegian sector of the North Sea. Globally, the International Association of Oil and Gas Producers (IOGP) Report 637 and recent data from Wild Well Control also support this conclusion – in fact, Wild Well Control data shows that the frequency of well control incidents may be increasing. The loss of experienced personnel due to reduced activity during the COVID-19 pandemic may have contributed to this. Now that activity is increasing again, the industry faces a challenge in recruiting skilled personnel. Current well control courses predominantly cover the well construction process, with minor emphasis on the whole life cycle of the well. However, a significant number (in some areas close to half) of well control incidents occur after the well construction process is completed. Based on analysis of the main contributory factors to well control incidents, IOGP has recently updated Report 476 ‘Recommendations for enhancements to well control training, examination and certification’. This paper reviews the changes to Report 476 and discusses how International Well Control Forum can contribute to reduce the well control incident rate with focus on the Well Control in Design and Lifecycle Management course.
Reducing risk of sexual harassment: a positive duty of care
Authors: Shaw Elizabeth
Published: May 2024

The oil and gas sector has made progress towards becoming safer and more respectful for all employees. However, recent public reports, including the Western Australian Parliament’s ‘Enough is Enough’, and increasing engagement from National Offshore Petroleum Safety and Environmental Management Authority (NOPSEMA), continue to demonstrate that sexual harassment remains pervasive across the industry – 32% of people still experience sexual harassment in their workplace. The social, physical, psychological, and financial costs of sexual harassment are devastating, both to individuals and employers. The damage can carry long-term business and reputational consequences. All Australian employers are under a new, legally enforceable positive duty to take ‘reasonable and proportionate measures’ to prevent sexual harassment. It requires proactive steps to ensure sexual harassment is prevented from happening in the first place. Vicarious liability provisions have been expanded so that employers can now be held accountable – even if no complaints are lodged. Employers require a clear framework to ensure they are meeting their positive duty obligations. There are three key areas that can enable the oil and gas sector to strategically leverage their compliance activities, maximising benefits for their business and for their people. These key areas include: (1) capability and engagement of leaders and management; (2) understanding the risk factors and drivers of sexual harassment for the industry, and for individual organisations; and (3) understanding employee experiences of psychological safety, culture, and behaviours.
2023 PESA business environment review
Authors: Wild Erin , Adeyinfa Emmanuel , Farrant Adrian
Published: May 2024

In 2023, the world faced increased local and global headwinds in achieving the goal of net zero emissions by 2050 due to geopolitical factors, global economic variables, advancing technology, and evolving policies and regulations. Despite a 22% rise in global investments for renewable energy, the world fell short of the 76% required for a Net Zero Emissions Pathway by 2050. There was a collective return to fossil fuels, particularly natural gas and liquefied natural gas (LNG), to meet the demand for secure and affordable energy amid global energy supply shocks. As a result of sustained elevated energy prices governments and energy companies are having to consider all three elements of the energy trilemma – affordability, sustainability, and security – in a more balanced way. The energy industry responded to these challenges by increasing investments in gas-oriented resources and the emergence of investments into the critical minerals value chain, indicating a historic convergence of multiple industries to address the global energy transition. Investment in new energy technologies to support decarbonisation continued, albeit at a slower pace than required. The energy transition also accelerated the decommissioning responsibilities of upstream energy producers for their mature infrastructure assets. As Australia and other countries globally, strive to deliver on net zero ambitions, the oil and gas sector continues to grapple with the delicate balancing act of providing reliable, affordable, secure and sustainable sources of energy, which only continues to emphasise the need for fossil fuels during this energy transition.
A preliminary assessment of regional CO2 storage potential in the onshore northern Perth Basin
Authors: Ellis Louisa , Thomas Charmaine , Cass Julie , Mory Arthur , Brooks Deidre
Published: May 2024

The Geological Survey of Western Australia (GSWA) is creating a new carbon dioxide (CO2) geological storage atlas for Western Australia. The atlas will incorporate the latest state-wide datasets to provide a regional assessment of the potential for CO2 sequestration across the Perth, Southern Carnarvon, Northern Carnarvon (onshore and State waters), Canning and Officer basins. Multi-1D modelling of subsurface temperature in the northern Perth Basin incorporates newly collated temperature data, updated regional depth maps, and stratigraphic revisions. This modelling captures lateral subsurface temperature variations that are incorporated into isothermal depth and temperature maps identifying reservoir units within the optimum temperature–pressure window for CO2 storage. Isopach maps of associated sealing units indicate where they are of adequate thickness to contain CO2. Modelled present-day temperature maps of seven key reservoir units reveal promising CO2 storage prospectivity, with all postulated reservoir units having significant extents within optimum CO2 storage temperature and pressure ranges. Whereas older reservoir units are prospective for CO2 storage towards the margins of the basin, younger reservoir units in the shallower part of the succession are only prospective in or near the Dandaragan Trough, the deepest part of the basin. The critical upper temperature limit of 31.1°C is shallower in the north and west of the basin, where the modelled geothermal gradient is higher. All state-wide raw and interpreted datasets including temperature and depth maps will be published and available for download on the GSWA Western Australian Petroleum and Geothermal Information Management System website.
Innovation and opportunity through regulatory change
Authors: McCarrey Sue , Blair Graham , Grebe Cameron
Published: May 2024

Adapting to change and seizing opportunities is a constant process for all involved in offshore energy, government and industry alike. The offshore energy sector continues to adapt approaches and adopt new ways of doing business as community expectations and the regulatory framework continue to evolve. As industry explores new frontiers in carbon capture and storage and infrastructure reuse for renewables, the historic challenges of legacy wells and decommissioning remain at the forefront of planning considerations. Recognising this changing landscape, the regulator has undergone its own evolution from investigations to drive change and enhance safety standards through to consultation best practice based on cultural awareness. This change has been driven by a refocusing of priorities and increased emphasis on where the greatest regulatory impact can be achieved. This paper outlines critical learnings from the past year – what industry is doing well and ongoing opportunities for improvement, the changes being implemented by the regulator and what they mean for industry, and what lies ahead for the offshore sector in the broader legislative and regulatory regime.
Laparoscopic Magnetic Sphincter Augmentation for Symptomatic Gastroesophageal Reflux After Roux-en-Y Gastric Bypass: Outcome in 13 Patients
Authors: Moser Schaub E , Fringeli Y , Kessler U , Zehetner J
Published: May 2024

Background

Gastroesophageal reflux disease (GERD) represents a common burden after bariatric procedures, particularly after laparoscopic sleeve gastrectomy (LSG). While GERD after LSG is usually treated with conversion to Roux-en-Y gastric bypass (RYGB), there are limited surgical options to manage medically refractory GERD after RYGB due to the altered anatomy. The use of magnetic sphincter augmentation (MSA) is one option, but the literature on this topic remains scarce.

Aims

To present mid- to long-term outcome of patients treated with MSA for GERD after RYGB.

Methods

We performed a retrospective single-centre analysis of data from patients who underwent laparoscopic MSA for GERD between August 2015 and December 2023, and who had previously RYGB. Outcomes were persistence/recurrence of GERD symptoms, use of proton pump inhibitors (PPIs) and need for redo surgery related to MSA complications or recurrent GERD.

Results

Of the 312 MSA procedures performed for GERD, we identified 13 patients who underwent laparoscopic MSA after RYGB. There were 10 female patients (77%), with mean age of 42.6 ± 13.7 years and mean BMI of 27.2 ± 2.7 kg/m2. Seven patients (54%) had de novo GERD. All MSA procedures included hiatoplasty. Median follow-up was 40 months (range 7-72) and median time between RYGB and MSA placement was 42 months (range 8-242). One patient (8%) required endoscopic dilatation due to persistent postoperative dysphagia. Two patients (15%) needed redo surgery: 1 redo hiatoplasty with adhaesiolysis and 1 conversion to esophagojejunostomy with implant removal. There was no erosion or migration of the MSA implant. Overall satisfactory control of reflux with discontinuation or reduction of PPIs was achieved in 9 patients (69%).

Conclusion

The use of MSA to manage refractory GERD after RYGB is a safe option and was effective in 69% of patients but is limited to patients with intact oesophageal motility.
Robotic-Assisted Inguinal Hernia Repair with The Dexter System™: A Prospective Multicentre Clinical Investigation
Authors: Gantner L , Mignot H , Pochhammer J , Grieder F , Breitenstein S
Published: May 2024

Background

Robot-assisted transabdominal preperitoneal inguinal hernia repair (rTAPP) is established as safe and feasible with various robotic platforms. The Dexter robotic system is an open platform with a sterile surgeon’s console, two robotic instrument arms, and one robotic endoscope arm.

Aims

We conducted a prospective multicentre study (ClinicalTrials.gov NCT05873582) to assess the safety and performance of this new robotic platform.

Methods

Three centres in France, Germany, and Switzerland participated. The primary objectives of the study were to document the successful completion of the rTAPP procedures and to collect data on the occurrence of adverse events and device-related events perioperatively and up to 30 days post-surgery. The procedures were performed by three surgeons with varying levels of experience in robotic systems, including novice, intermediate and expert.

Results

Fifty patients were operated for inguinal hernia repair (33 unilateral, 17 bilateral). The mean age and BMI of the patients were 60 years (±15) and 25.7 kg/cm2 (±3.3), respectively. All surgeries were successfully completed as planned using three standard laparoscopy trocars sized 10/12mm. Each procedure was performed with robotic assistance, and there were no conversions to open surgery. No intra-operative complications, device deficiency, or adverse events of Clavien-Dindo Grade III to V occurred. The mean skin-to-skin operative time was 55 min (±14) for unilateral hernia repair and 95 min (±22) for bilateral hernia repair. The mean robotic console time was 34 min (±12) for unilateral hernia and 68 min (±21) for bilateral hernia repairs. The patients were discharged within 1day (± 1 day) after surgery.

Conclusion

Our rTAPP experience with the Dexter system confirms feasibility, safety, and comparable operative times to other robotic platforms. This study demonstrates the practicality and safety of the robotic techniques, positioning the Dexter system as a valuable tool in hernia repair.
Randomised Controlled Pilot Trial on GHOST Ileostomy versus Conventional Loop Ileostomy in Patients Undergoing low Anterior Resection for Rectal Cancer
Authors: Probst P , Klotz R , Diener M K , Knebel P , Hüttner F J
Published: May 2024

Background

Anastomotic leakage is the most important complication after colorectal surgery. In patients undergoing low anterior resection with total mesorectal excision (LAR/TME) a loop ileostomy is fashioned to protect the low anastomosis. Ghost ileostomy is a pre-stage ileostomy, which can be converted to a diverting ileostomy, if anastomotic leakage is suspected. If there are no signs of anastomotic leakage an actual ileostomy can be avoided.

Aims

The objective was to evaluate whether ghost ileostomy is a safe alternative to a conventional loop ileostomy.

Methods

GHOST was a randomised controlled pilot trial without formal hypothesis. Patients undergoing LAR/TME for rectal cancer were intraoperatively randomised to receive a ghost ileostomy or loop ileostomy. Patients were followed prospectively for 6 months. Comprehensive complication index, transformation of ghost ileostomy into loop ileostomy, presence of an ostomy at 6 months, Wexner score and quality of life were assessed.

Results

Thirty patients were equally randomised. The CCI was 30.7 (± 17.7) in the ghost ileostomy group compared to 29.7 (± 18.6) in the loop ileostomy group at 6 months (p=0.889). The ghost ileostomy was converted into a loop ileostomy in 6 of 15 (40.0%) patients. At 6 months after low anterior resection, 6 (40.0%) patients in the ghost ileostomy group and 7 (46.7%) patients in the ileostomy group still had an ileostomy. There was no mortality and no need for creation of a terminal ostomy within the trial. Neither postoperative function assessed by the Wexner score, nor the overall quality of life showed significant differences.

Conclusion

Ghost ileostomy seems to be a viable and safe option to a more selective approach regarding creation of an ileostomy in patients undergoing LAR/TME. However, the difficult patient selection with exclusion of patients at high risk of anastomotic leakage limits its widespread application and should be optimised in future trials.
Dysregulated MicroRNAs Contribute to Chemotherapy-Resistance of Pleural Mesothelioma
Authors: Kirschner M B , Schläpfer F , Meerang M , Opitz I
Published: May 2024

Background

Dysregulated expression of microRNAs has been shown to contribute to response to chemotherapeutic agents in several cancers, including pleural mesothelioma (PM). In previous work, we found expression of several tissue-microRNAs to correlate with patient’s response to cisplatin-pemetrexed.

Aims

We want to understand how altering the expression of these microRNAs affects cell growth and chemo response.

Methods

PM cell lines MSTO-211H (biphasic), H28, Meso-1, Mero-82 (epithelioid) and non-malignant MeT-5A were reverse transfected with synthetic microRNA mimics for 15 candidates. Following transfection, cell growth, colony forming ability, and migratory potential were assessed using standard assays. Furthermore, transfected cells were exposed to increasing concentrations of cisplatin to evaluate sensitivity to these drugs.

Results

Overexpression of seven candidate microRNAs resulted in growth inhibition in all investigated PM cell lines five days post transfection. The strongest effects were observed for miR-380-5p, miR-221-3p, miR-210, miR-625-3p, and miR-19b, which reduced cell growth to 30-60%. Growth of non-malignant MeT-5A cells remained largely unaffected (Fig. A). Overexpression of those microRNAs also resulted in a strong reduction of colony forming ability (Fig. B), while an effect on wound healing capacity (migration) could not be observed. Finally, we found that especially overexpression of miR-221-3p, miR-625-3p and miR-19b was able to sensitise cells towards cisplatin, with the strongest effect observed in MSTO-211H for miR-221-3p (IC50 from 17.6µM to 2.7µM) and miR-19b (IC50 from 17.6µM to 0.7µM), and in Mero-82 for miR-625-3p (IC50 from 3.75µM to 0.8µM) (Fig. C).

Conclusion

We show that overexpression of several microRNAs has the potential to alter PM cell growth and colony forming ability. Furthermore, microRNA overexpression can sensitise cells towards cisplatin, although the degree of sensitisation varies between different cell lines. Current analyses focus on the response towards the cisplatin/pemetrexed doublet and on the effect on cell cycle and expression of associated genes.
Accuracy in Navigated Percutaneous Sacroiliac Screw Fixation: A Systematic Review and Meta-Analysis
Authors: Haveman R , van de Wall B , Haefeli P , Beeres F , Babst R , Link B C
Published: May 2024

Background

Percutaneous sacroiliac screw placement is a challenging procedure in patients with pelvic fractures. To overcome these challenges, navigated techniques have emerged as an alternative to conventional 2D fluoroscopy for guiding screw placement. However, it remains to be seen whether navigated techniques truly have a beneficial effect on accuracy, radiation exposure and occurrence of complications.

Aims

We performed a meta-analysis to investigate whether navigated techniques are superior to conventional 2D fluoroscopy in percutaneous sacroiliac screw fixation.

Methods

The electronic databases were searched for both randomized clinical trials and observational studies comparing percutaneous sacroiliac screw fixation with 2D fluoroscopy to new navigated techniques (2D or 3D fluoroscopic navigation with a c-arm, computer assisted ultrasound navigation, O-Arm navigation, mobile CT navigation, robotic navigation). Effects were pooled and presented as odds ratio, mean difference, and standardized mean difference with corresponding 95% confidence interval.

Results

In total 18 studies were included. New navigated techniques had a higher accuracy (81% versus 91% with MD 10%, 95% CI 5-14%). The greatest benefit in accuracy was found in studies with more advanced navigated techniques (O-Arm, mobile CT or robotic navigation). Also, fluoroscopy time (MD 72.13 seconds, 95% CI 7.73;92.91) and fluoroscopy frequency (MD 17.22 images in total, 95% CI 7.73;26.70) were lower for new navigated techniques. Radiation dose was higher for new navigated techniques (SMD 0.50, 95% CI 0.01;0.99). Surgery duration showed no significant difference. Similar results were found among in vitro studies. Complications were rare in both groups.

Conclusion

This meta-analysis demonstrated a higher accuracy of screw positioning, lower fluoroscopic frequency and time for navigated percutaneous sacroiliac screw fixation compared to conventional 2D fluoroscopy. Complications are acceptably low for both groups. Future studies should focus on which of the navigated techniques is the best and whether the implementation costs of a new technique outweigh its benefits.
LATE ONSET FABRY’S DISEASE MIMICKING HYPERTROPHIC CARDIOMYOPATHY
Authors: Allocca G , Centa M , Bagato F , Sitta N , Gallucci M , Carraro G , Vitturi N , De Michieli L , Rivetti L , Bullian F , Mantovan R
Published: May 2024

Fabry disease (FD) is rare genetic syndrome which determines a lysosomal storage disorder caused by pathogenic variants in the alpha–galactosidase A (GLA) gene that lead to alpha–galactosidase A (AGAL– A) enzyme activity disfunction.The fenotipic effect is a left ventricular hypertrophy (LVH) that is frequently misdiagnosed as hypertrophic cardiomyopathy (HCM).This disease in still unfamiliar for the most part of cardiologists cause of the fenotipic familiarities with other more common and wellknown diseases and according to recent data the prevalence of FD among unexplained LVH is 0.93%.These characteristics drive to a heavy under diagnosis of a disease with many therapy chances. The prompt initiation of these treatments, subsequently an early diagnosis, is actually considered the best strategy to improve the natural course of the disease.The critical evaluation of the clinical history and basic cardiomiopaty assessments could drive the cardiologist to the diagnosis.Precisely, we present an example of three family pedigree discovered in a couple of months subsequently the unmasking of proband male patients with decennary misdiagnosis of HCM. The ambulatory suspect of non sarcomeric disease in LVH drove us to critically reexaminate EKGs and previous CMR scans finding respectively PR shortage associated with right bundle block and basal inferolateral late gadolinium enhancement (figure 1). In a proband it is not possible to perform MRI with gadolinium due to the presence of renal failure and the diagnostic suspicion arose by analyzing the T1 mapping signal (figure 2).The score ID FABRY–HCM were applied resulting suggestive too.Having thus corroborated the suspicion, blood spot tests were performed finally detecting a very low AGAL–A activity. The following GLA genetic tests identified the tipical mutation of late onset Fabry’s disease (p.N215Ser). Fulfilling the consensus criteria for the therapy initiation, the patients were treated with enzyme replacement therapy. We completed families predigree identifying other six famale gene mutation carriers with almost preserved AGAL–A activity. The diagnosis of FD allowed us to perform the specific therapy in affected patients hopefully effecting their quality of life and their prognosis and to bring out healthy carriers.The initial suspect questioning a previous diagnosis starting to simple clinical and routine strumental elements were crucial.
MACHINE LEARNING APPROACH FOR PREDICTION OF CLINICAL OUTCOMES IN ANTICOAGULATED PATIENTS WITH ATRIAL FIBRILLATION
Authors: Bernardini A , Bindini L , Antonucci E , Berteotti M , Giusti B , Testa S , Palareti G , Milli M , Frasconi P , Marcucci R
Published: May 2024

Background

Despite the availability of different risk scores, the accuracy of actual prediction tools for outcomes in patients with atrial fibrillation (AF) remains modest. Although Machine Learning (ML) has been used to predict outcomes in the AF population, evidences about outcome prediction in a population entirely on oral anticoagulation is lacking.

The aim of this study is to use ML to predict outcomes in anticoagulated patients with atrial fibrillation, processing data from the Italian AF START–2 Register.

Methods and aims

Different ML models were applied to predict all–cause death, cardiovascular (CV) death, major bleeding and stroke in anticoagulated patients with nonvalvular AF. Overall population, Vitamin K Antagonists (VKA) and Direct Oral Anticoagulants (DOACs) populations were considered for the analyses.

Results

11078 AF patients (male n=6029, 54.3%) were enrolled with a median follow–up period of 1.5 years [IQR 1.0–2.6]. Patients on VKA were 5135 (46.4%), while 5943 (53.6%) were on DOACs. During the follow–up, 785 patients died, of which 169 (21.6%) due to CV causes; 240 major bleeding events were recorded, and 50 strokes occurred. Using Multi–Gate Mixture of Experts (MmoE), a cross–validated AUC of 0.779 ± 0.016 and 0.745 ± 0.022 were obtained, respectively, for the prediction of all–cause death and CV death in the overall population. The best ML model outperformed CHA2DSVA2SC and HAS–BLED for all–cause death prediction (p<0.001 for both). When compared to HAS–BLED, Gradient Boosting improved major bleeding prediction in DOACs patients compared to HAS–BLED score (0.711 vs. 0.586, p<0.001). Body mass index, age, glomerular filtration rate, platelet count and hemoglobin levels resulted the most important variables for ML prediction.

Conclusions

In patients with AF, ML models showed good discriminative ability to predict all–cause death, regardless of the type of anticoagulation strategy, and major bleeding on DOAC therapy, outperforming CHA2DS2VASC and the HAS–BLED scores for risk prediction in these populations. Anemia, platelet count, and BMI emerged as new potential risk predictors in anticoagulated AF patients. The applications of ML prediction models in clinical practice could improve the risk assessment and subsequent management of anticoagulated patients with AF.