200 research outputs found
The impact of reduction of doublet well spacing on the Net Present Value and the life time of fluvial Hot Sedimentary Aquifer doublets
This paper evaluates the impact of reduction of doublet well spacing, below the current West Netherlands Basin standard of 1000 to 1500 m, on the Net Present Value (NPV) and the life time of fluvial Hot Sedimentary Aquifer (HSA) doublets. First, a sensitivity analysis is used to show the possible advantage of such reduction on the NPV. The parameter value ranges are derived from West Netherlands Basin HSA doublet examples. The results indicate that a reduction of well spacing from 1400 to 1000 m could already influence NPV by up to 15%. This effect would be larger in more marginally economic HSA doublets compared to the West Netherlands Basin base case scenario. The possibility to reduce well spacing is supported by finite element production simulations, utilizing detailed facies architecture models. Furthermore, our results underline the necessity of detailed facies architecture models to assess the potential and risks of HSA doublets. This factor significantly affects doublet life time and net energy production of the doublet
Cerebral blood volume changes in negative BOLD regions during visual stimulation in humans at 7T
Trends in surgical techniques for the treatment of esophageal and gastroesophageal junction cancer: the 2022 update
The aim of this study was to evaluate the current practice in surgical techniques for esophageal and gastroesophageal junction cancer surgery worldwide and to compare the results to the previous surveys in 2007 and 2014. An online survey was sent out among surgical members of the International Society for Diseases of the Esophagus, the World Organization for Specialized Studies on Disease of the Esophagus, the International Gastric Cancer Association, the Association of Upper Gastrointestinal Surgery of Great Britain and Ireland and Dutch gastroesophageal surgeons via the network of the investigators. In total, 260 surgeons completed the survey representing 52 countries and 6 continents; Europe 56%, Oceania 14%, Asia 14%, South-America 9%, North-America 7%. Of the responding surgeons, 39% worked in a hospital that performed >51 esophagectomies per year. Total minimally invasive esophagectomy was the preferred technique (53%) followed by hybrid esophagectomy (26%) of which 7% consisted of a minimally invasive thoracic phase and 19% of a minimally invasive abdominal phase. Total open esophagectomy was preferred by 21% of the respondents. Total minimally invasive esophagectomy was significantly more often performed in high-volume centers compared with non-high-volume centers (P = 0.002). Robotic assistance was used in 13% during the thoracic phase and 6% during the abdominal phase. Minimally invasive transthoracic esophagectomy has become the preferred approach for esophagectomy. Although 21% of the surgeons prefer an open approach, 26% of the surgeons perform a hybrid procedure which may reflect further transition towards the use of total minimally invasive esophagectomy
Implementation of the robotic abdominal phase during robot-assisted minimally invasive esophagectomy (RAMIE): results from a high-volume center
BACKGROUND: Evidence on the added value of robotic-assistance in the abdominal phase during esophagectomy is scarce. In 2003, our center implemented the robotic thoracic phase for esophagectomy. In November 2018 the robot was also implemented in the abdominal phase. The aim of this study was to evaluate the implementation of the abdominal phase during robot-assisted minimally invasive esophagectomy (RAMIE). METHODS: Consecutive patients who underwent full RAMIE with intrathoracic anastomosis for esophageal cancer were included. Patients were extracted from a prospectively maintained institutional database. A cumulative sum (CUSUM) analysis was performed for abdominal operation time and abdominal lymph node yield. Intraoperative, postoperative and oncological outcomes including collected lymph nodes per abdominal lymph node station were reported. RESULTS: Between 2018 and 2021, 70 consecutive patients were included. The majority of the patients had an adenocarcinoma (n = 55, 77%) and underwent neoadjuvant chemo(radio)therapy (n = 65, 95%). The median operative time for the abdominal phase was 180 min (range 110-233). The CUSUM analysis for abdominal operation time showed a plateau at case 22. There were no intraoperative complications or conversions during the abdominal phase. The most common postoperative complications were pneumonia (n = 18, 26%) and anastomotic leakage (n = 14, 20%). Radical resection margins were achieved in 69 (99%) patients. The median total lymph node yield was 42 (range 23-83) and the median abdominal lymph node yield was 16 (range 2-43). The CUSUM analysis for abdominal lymph node yield showed a plateau at case 21. Most abdominal lymph nodes were collected from the left gastric artery (median 4, range 0-20). CONCLUSIONS: This study shows that a robotic abdominal phase was safely implemented for RAMIE without compromising intraoperative, postoperative and oncological outcomes. The learning curve is estimated to be 22 cases in a high-volume center with experienced upper GI robotic surgeons
Robotic- assisted minimally invasive Ivor-Lewis handsewn anastomosis technique and outcomes from a large-volume European centre
In minimally invasive transthoracic esophagectomy, intrathoracic anastomoses are usually performed with stapling devices to avoid a technically challenging handsewn technique in the upper mediastinum. Few have published about handsewn anastomotic techniques due to the technically demanding requirements for suturing with rigid instruments in the thoracic cavity. With robot-assisted minimally invasive esophagectomy (RAMIE), the robot provides increased dexterity, enabling construction of a hand-sewn intrathoracic anastomosis. This study aimed to evaluate the outcomes of our technique for hand-sewn intrathoracic anastomosis in RAMIE, following the initial learning phase between 2016 and 2018 in UMC Utrecht. Patients who underwent RAMIE with a robot-assisted hand-sewn intrathoracic anastomosis were included in this retrospective study. Data were extracted from a prospectively maintained institutional database. Key technique steps included esophageal stay-sutures, use of barbed sutures for the anastomosis, placement of tension-releasing stitches, and covering of the anastomosis with omentum. The primary outcome was anastomotic leakage; secondary outcomes included anastomotic stricture rate and duration of anastomosis construction. Between 1 November 2019 and 30 May 2023, 89 consecutive patients were included. Anastomotic leakage (defined by the Esophageal Complications Consensus Group) occurred in 11 patients (12.4%), which involved a grade I leak in four patients (4.5%), grade II leak in one patient (1.1%), and grade III leakage in six patients (6.7%). The median duration of anastomosis creation was 33 minutes (range, 23-55 minutes). Stricture rate was 32.6% (29 patients) at 1 year post-operatively for which dilation was needed for all patients. This study shows that a robot-assisted hand-sewn intrathoracic anastomosis in RAMIE is feasible, safe, and reliable
Indocyanine green fluorescence in robot-assisted minimally invasive esophagectomy with intrathoracic anastomosis: a prospective study
Indocyanine green fluorescence angiography (ICG-FA) allows for real-time intraoperative assessment of the perfusion of the gastric conduit during esophagectomy. The aim of this study was to investigate the effect of the implementation of ICG-FA during robot-assisted minimally invasive esophagectomy (RAMIE) with an intrathoracic anastomosis. In this prospective cohort study, a standardized protocol for ICG-FA was implemented in a high-volume center in December 2018. All consecutive patients who underwent RAMIE with an intrathoracic anastomosis were included. The primary outcome was whether the initial chosen site for the anastomosis on the gastric conduit was changed based on ICG-FA findings. In addition, ICG-FA was quantified based on the procedural videos. Out of the 63 included patients, the planned location of the anastomosis was changed in 9 (14%) patients, based on ICG-FA. The median time to maximum intensity at the base of the gastric conduit was shorter (25 s; range 13-49) compared to tip (34 s; range 12-83). In patients with anastomotic leakage, the median time to reach the FImax at the tip was 56 s (range 30-83) compared to 34 s (range 12-66) in patients without anastomotic leakage (p = 0.320). The use of ICG-FA resulted in an adaptation of the anastomotic site in nine (14%) patients during RAMIE with intrathoracic anastomosis. The quantification of ICG-FA showed that the gastric conduit reaches it maximum intensity in a base-to-tip direction. Perfusion of the entire gastric conduit was worse for patients with anastomotic leakage, although not statistically different
Effects of Noise Bandwidth and Amplitude Modulation on Masking in Frog Auditory Midbrain Neurons
Natural auditory scenes such as frog choruses consist of multiple sound sources (i.e., individual vocalizing males) producing sounds that overlap extensively in time and spectrum, often in the presence of other biotic and abiotic background noise. Detection of a signal in such environments is challenging, but it is facilitated when the noise shares common amplitude modulations across a wide frequency range, due to a phenomenon called comodulation masking release (CMR). Here, we examined how properties of the background noise, such as its bandwidth and amplitude modulation, influence the detection threshold of a target sound (pulsed amplitude modulated tones) by single neurons in the frog auditory midbrain. We found that for both modulated and unmodulated masking noise, masking was generally stronger with increasing bandwidth, but it was weakened for the widest bandwidths. Masking was less for modulated noise than for unmodulated noise for all bandwidths. However, responses were heterogeneous, and only for a subpopulation of neurons the detection of the probe was facilitated when the bandwidth of the modulated masker was increased beyond a certain bandwidth – such neurons might contribute to CMR. We observed evidence that suggests that the dips in the noise amplitude are exploited by TS neurons, and observed strong responses to target signals occurring during such dips. However, the interactions between the probe and masker responses were nonlinear, and other mechanisms, e.g., selective suppression of the response to the noise, may also be involved in the masking release
Surgical treatment of esophago-tracheobronchial fistulas after esophagectomy
The aim of this study was to evaluate the surgical treatment of esophago-tracheobronchial fistulas (ETBFs) that occurred after esophagectomy with gastric conduit reconstruction in a tertiary referral center for esophageal surgery. All patients who underwent surgical repair for an ETBF after esophagectomy with gastric conduit reconstruction were included in a tertiary referral center. The primary outcome was successful recovery after surgical treatment for ETBF, defined as a patent airway at 90 days after the surgical fistula repair. Secondary outcomes were details on the clinical presentation, diagnostics, and postoperative course after fistula repair. Between 2007 and 2022, 14 patients who underwent surgical repair for an ETBF were included. Out of 14 patients, 9 had undergone esophagectomy with cervical anastomosis and 5 esophagectomy with intrathoracic anastomosis after which 13 patients had developed anastomotic leakage. Surgical treatment consisted of thoracotomy to cover the defect with a pericardial patch and intercostal flap in 11 patients, a patch without interposition of healthy tissue in 1 patient, and fistula repair via cervical incision with only a pectoral muscle flap in 2 patients. After surgical treatment, 12 patients recovered (86%). Mortality occurred in two patients (14%) due to multiple organ failure. This study evaluated the techniques and outcomes of surgical repair of ETBFs following esophagectomy with gastric conduit reconstruction in 14 patients. Treatment was successful in 12 patients (86%) and generally consisted of thoracotomy and coverage of the defect with a bovine pericardial patch followed by interposition with an intercostal muscle
Evidence-based PET for thoracic tumours
AbstractFluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) is a robust imaging tool that is currently used in daily clinical practice for the evaluation of thoracic malignancies. This chapter provides an overview of the current evidence-based data on the usefulness of PET/CT for the evaluation of patients with thoracic tumours including lung cancer, pleural and thymic tumours, and esophageal cancer
A multi-disciplinary commentary on preclinical research to investigate vascular contributions to dementia
Although dementia research has been dominated by Alzheimer's disease (AD), most dementia in older people is now recognised to be due to mixed pathologies, usually combining vascular and AD brain pathology. Vascular cognitive impairment (VCI), which encompasses vascular dementia (VaD) is the second most common type of dementia. Models of VCI have been delayed by limited understanding of the underlying aetiology and pathogenesis. This review by a multidisciplinary, diverse (in terms of sex, geography and career stage), cross-institute team provides a perspective on limitations to current VCI models and recommendations for improving translation and reproducibility. We discuss reproducibility, clinical features of VCI and corresponding assessments in models, human pathology, bioinformatics approaches, and data sharing. We offer recommendations for future research, particularly focusing on small vessel disease as a main underpinning disorder
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