Leakage Rate Research Articles

A new small target defect detection algorithm for solar panels based on improved YOLOV7

ABSTRACT Surface Defect Detection (SDD) is an important means to ensure product quality in industrial production. Accompanied by the rapid development of artificial intelligence technology, the surface defect detection algorithm based on convolutional neural network (CNN) has gradually replaced the traditional machine vision and manual inspection methods. However, due to the small morphology of some defects in solar panels, this brings certain challenges to industrial defect detection. Therefore, this paper investigates a surface defect detection based on YOLOV7 for the small target in solar panels. Firstly, the coordinate attention mechanism is used to improve the model’s attention to distinguishable defect features. Secondly, a two-way weighted feature pyramid is utilised to replace the PANet in order to improve the feature fusion effect of the detection model. Finally, Soft Non-Maximum Suppression (Soft NMS) is used in post-processing to reduce the leakage rate of the detection model. The proposed method is tested on a self-built dataset of surface defects detection on solar panels, and the experimental results verify that the accuracy of the model in this paper is better than other advanced methods.

Fluorescence angiography with indocyanine green for low anterior resection in patients with rectal cancer: a prospective before and after study.

Inadequate bowel perfusion is among risk factors for colorectal anastomotic leaks. Perfusion can be assessed with indocyanine green fluorescence angiography (ICG) during colon resections. Possible benefits from its systematic use in high-risk patients with rectal cancer remain inconsistent. This study aimed to evaluate the surgical modifications induced by ICG assessment during rectal cancer surgery and associated anastomotic leaks. This prospective before and after cohort study was conducted in a single Canadian high-volume colorectal surgery center. Eligible patients were undergoing alow anterior resection for rectal cancer below 15cm from the anal margin. Stapled and handsewn coloanal anastomoses were included. The experimental group was recruited prospectively, undergoing surgery using fluorescence angiography with ICG. The control group was built retrospectively from consecutive patients who had been operated on without ICG, prior to its implementation. Each cohort included 113 patients. The use of ICG led to modifications from initial surgical plan in 10.6% of patients, with no occurrence of anastomotic leaks in this specific group. When comparing leak rates, using ICG seemed to be protective, but this could not be statistically proven, overall (13.3% vs. 6.2%, p = 0.07), nor for handsewn coloanal anastomoses (11.8% vs. 5.9%, p = 0.67). A lack of power could explain such non-significant results, especially with low overall anastomotic leak rates recorded. ICG influenced ultimate proximal resection margin in a clinically relevant proportion of cases. It might be associated with reduced leak rates although not formally proven with this data. This technology is safe and easy to apply in high-volume colorectal centers.

A method for enhancing the accuracy of industrial bearing surface defect detection

ABSTRACT Deep learning models often encounter challenges when detecting surface defects on industrial bearings, including inaccurate feature extraction caused by random shapes and multi-scale defects, as well as high leakage rates of small objects in complex multi-object scenes. To address these challenges, a YOLOv8n-based method (YOLOv8-IWDD) is proposed for detecting bearing surface defects. Firstly, the ImplicitHead detection head is introduced, which utilises implicit addition and multiplication to highlight key features. This enhancement improves feature extraction, resulting in improved detection accuracy for small objects, especially in complex multi-object scenarios, and effectively reduces missed detections. Secondly, the Inner-WIoU loss function optimises bounding box localisation, enabling the model to better handle randomly shaped defects, accelerate convergence, and enhance localisation accuracy. In addition, dynamic label assignment and dynamic sampling strategies are proposed to achieve flexible adjustment of sample assignment and sampling method, which further improves the detection accuracy and robustness. These strategies enhance the model’s robustness in handling multi-scale and complex shape defects. The experimental results show that YOLOv8-IWDD improves mAP0.5 by 2.9%, mAP0.5:0.95 by 9.4%, precision by 2.2%, and recall by 6.5% compared with the YOLOv8n model. The method achieves promising results in detecting surface defects on industrial bearings.

Slower swimming promotes chemotactic encounters between bacteria and small phytoplankton

Chemotaxis enables marine bacteria to increase encounters with phytoplankton cells by reducing their search times, provided that bacteria detect noisy chemical gradients around phytoplankton. Gradient detection depends on bacterial phenotypes and phytoplankton size: large phytoplankton produce spatially extended but shallow gradients, whereas small phytoplankton produce steeper but spatially more confined gradients. To date, it has remained unclear how phytoplankton size and bacterial swimming speed affect bacteria's gradient detection ability and search times for phytoplankton. Here, we compute an upper bound on the increase in bacterial encounter rate with phytoplankton due to chemotaxis over random motility alone. We find that chemotaxis can substantially decrease search times for small phytoplankton, but this advantage is highly sensitive to variations in bacterial phenotypes or phytoplankton leakage rates. By contrast, chemotaxis toward large phytoplankton cells reduces the search time more modestly, but this benefit is more robust to variations in search or environmental parameters. Applying our findings to marine phytoplankton communities, we find that, in productive waters, chemotaxis toward phytoplankton smaller than 2 μm provides little to no benefit, but can decrease average search times for large phytoplankton (∼20 μm) from 2 wk to 2 d, an advantage that is robust to variations and favors bacteria with higher swimming speeds. By contrast, in oligotrophic waters, chemotaxis can reduce search times for picophytoplankton (∼1 μm) up to 10-fold, from a week to half a day, but only for bacteria with low swimming speeds and long sensory timescales. This asymmetry may promote the coexistence of diverse search phenotypes in marine bacterial populations.

HMB/Arg/Gln may improve short-term outcomes after esophagectomy in patients with thoracic esophageal cancer.

The wound healing effects of a specialized amino acid supplement containing calcium beta-hydroxy-beta-methylbutyrate, L-arginine, and L-glutamine (HMB/Arg/Gln) have been reported. This study aimed to investigate the effectiveness of HMB/Arg/Gln in the perioperative management of patients with thoracic esophageal cancer. This retrospective cohort study included 131 patients who underwent esophagectomy for thoracic esophageal cancer between January 2016 and November 2023. Postoperative infectious complications (PICs) were compared between patients who received HMB/Arg/Gln for 7days before surgery (n = 95) and those who did not (control group, n = 36). Among the 111 male and 20 female patients (median age 68years, range 38-84years), stage I disease was found in 37 patients, stage II in 26, stage III in 61, and stage IVa in 7. Of the 131 patients, 36 (27.5%) had PICs, with PICs occurring in 20 (21%) of the HMB/Arg/Gln group and 16 (44.4%) of the control group. The PIC rate was significantly lower in the HMB/Arg/Gln than in the control group (p = 0.007). Propensity score matching analysis showed lower rates of anastomotic leakage (5.5% vs. 22.2%; p = 0.04) and Clavien-Dindo grade III or higher PICs (5.5% vs. 27.8%; p = 0.011) in the HMB/Arg/Gln than in the control group. The healing time for anastomotic leakage was shorter in the HMB/Arg/Gln (18days, range 7-25days) than in the control group (25days, range 21-56days) (p = 0.033). HMB/Arg/Gln supplementation was associated with reduced risk of anastomotic leakage and PIC severity following esophagectomy.

Evaluating the impact of enhanced recovery after surgery protocols following oesophagectomy: a systematic review and meta-analysis of randomised clinical trials.

Enhanced Recovery After Surgery (ERAS) protocols are evidence-based care improvement pathways which are perceived to expedite patient recovery following surgery. Their utility in the setting of oesophagectomy remains unclear. The aim of this study was to perform a systematic review and meta-analysis of randomised clinical trials (RCTs) to evaluate the impact of ERAS protocols on recovery following oesophagectomy compared to standard care. A systematic review was performed in accordance with preferred reporting items for systematic reviews and meta-analyses guidelines. Meta-analysis was performed using Review Manager (Version 5.4). Six RCTs including 850 patients were included in this meta-analysis. Overall complication rate (Odds Ratio (OR): 0.35, Confidence Interval (CI): 0.21, 0.59, P < 0.0001), pulmonary complications (OR: 0.40, CI: 0.24, 0.67, P = 0.0005), post-operative length of stay (LOS) (OR -1.88, CI -2.05, -1.70, P < 0.00001) and time to post-operative flatus (OR: -5.20, CI: -9.46, -0.95, P = 0.02) favoured the ERAS group. There was no difference noted for anastomotic leak (OR: 0.55, CI: 0.24, 1.28, P = 0.17), cardiac complications (OR: 0.86, CI: 0.30, 2.46, P = 0.78), gastrointestinal complications (OR: 0.51, CI: 0.23, 1.17, P = 0.11), wound complications (OR: 0.85, CI: 0.28, 2.58, P = 0.78), mortality (OR: 1.37, CI: 0.26, 7.4, P = 0.71), and 30-day re-admission rate (OR: 1.29, CI: 0.30, 5.47, P = 0.73) between ERAS and standard care groups. ERAS implementation improved post-operative complications, LOS, and time to flatus following oesphagectomy. These results support the robust adoption of ERAS in patients indicated to undergo oesphagectomy.

Treatment Quality of Rectal Cancer Patients in Certified Colorectal Cancer Centers Versus Non-Certified Hospitals: A Comparative Analysis.

Background/Objectives: The certification of hospitals as colorectal cancer centers aims to improve treatment quality, but evidence supporting its effectiveness remains limited. This study evaluated the impact of certification on treatment outcomes for rectal cancer patients in Germany. Methods: We conducted a retrospective analysis of 14,905 patients with primary rectal cancer (UICC Stages I-III) treated at 271 hospitals. Treatment outcomes were compared between certified colorectal cancer centers (3624 patients in 55 hospitals) and non-certified hospitals (11,281 patients in 216 hospitals). Additionally, a subset analysis examined outcomes before and after certification within the same institutions. Results: Certified centers demonstrated higher utilization of preoperative imaging (endorectal ultrasound: 70.7% vs. 58.2%, p < 0.001; pelvic MRI: 39.1% vs. 28.5%, p < 0.001) and lower rates of intraoperative complications (4.6% vs. 6.2%, p < 0.001). Surgical quality indicators, including M.E.R.C.U.R.Y. classification (Grade 1: 86.5% both groups, p = 0.620) and anastomotic leakage rates (11.3% vs. 11.9%, p = 0.407), were comparable between certified and non-certified hospitals. Despite treating patients with more favorable tumor stages, certified centers showed no significant advantage in 5-year overall survival (82.8% vs. 82.0%, p = 0.880) or 30-day mortality (2.6% both groups, p = 0.869). Hospital stays were marginally shorter in certified centers (19.46 vs. 20.24 days, p < 0.001). Conclusions: While certification was associated with improved adherence to diagnostic protocols and reduced intraoperative complications, it did not significantly impact surgical quality or long-term survival outcomes. These findings suggest that certification alone may not guarantee superior treatment quality, as hospitals participating in quality assurance programs achieved comparable results without formal certification.

Evaluation on H2, N2, He &amp; CH4 diffusivity in rock and leakage rate by diffusion in underground gas storage

Evaluation on H2, N2, He &amp; CH4 diffusivity in rock and leakage rate by diffusion in underground gas storage

Impact of Surgeon Specialization on Outcomes in Emergency Colorectal Surgery: A Systematic Review and Meta-analysis.

Colorectal emergencies represent a large proportion of acute general surgical workload and carry significant mortality. Identify the influence of surgeon specialization on mortality and other outcomes in emergency colorectal surgery. Systematic searches of Ovid MEDLINE, Ovid Embase, and Cochrane electronic databases were performed for studies published from January 1, 1990, to August 27, 2023. Studies investigating outcomes in emergency colorectal surgery for adults, comparing colorectal against noncolorectal surgeon specialization, were included. Exclusion criteria were: 1) publications studying primarily pediatric populations; 2) studies incorporating patients who had undergone surgery before 1990; and 3) studies only published in abstract form or non-English language. Primary outcomes were 30-day mortality and in-hospital mortality. Secondary outcomes were rates of anastomotic leak, reintervention, primary anastomosis, and laparoscopic approach. Of 7676 studies identified, 155 were selected for full-text review and 21 were included for quantitative analysis. Eleven studies showed improved 30-day (OR 0.64; 95% CI, 0.60-0.68; p < 0.0001) and in-hospital mortality (OR 0.66; 95% CI, 0.49-0.89; p = 0.007) with colorectal specialization. There was a significantly higher rate of primary anastomosis (OR 2.95; 95% CI, 2.02-4.31; p < 0.0001) and use of laparoscopic surgery (OR 2.38; 95% CI, 1.42-4.00; p = 0.001) among specialized colorectal surgeons. Specialization was also associated with a significant reduction in any stoma formation (OR 0.52; 95% CI, 0.28-0.98; p = 0.04). No significant difference was observed for anastomotic leak (OR 0.70; 95% CI, 0.45-1.07; p = 0.10) or reintervention rates (OR 0.78; 95% CI, 0.55-1.10; p = 0.16). Heterogeneity exists within the included patient populations and definitions of colorectal specialization observed in different countries. Emergency colorectal surgery undertaken by specialized colorectal surgeons is associated with significantly improved postoperative mortality, lower rates of stoma formation, and increased rates of primary anastomosis and minimally invasive surgery. CRD42022300541.

Stent vs Stentless Ileal Conduits After Radical Cystectomy: Is There a Difference in Early Postoperative Outcomes?

Placing ureteral stents at the ureteroileal anastomosis for radical cystectomy with ileal conduit (RCIC) has long been common practice. Recently, some providers have begun omitting stents. We sought to investigate differences in perioperative and 30-day outcomes between patients who underwent RCIC with and without stents placed at the ureteroileal anastomosis. We identified RCICs performed between 2019 and 2021 in the National Surgical Quality Improvement Program database and corresponding Cystectomy-Targeted Participant Use File. Baseline demographics, comorbidities, and operative parameters were compared via Pearson's χ2 and t tests between stented and stentless RCICs. Outcomes of interest, including rates of UTIs, acute kidney injury, renal failure requiring dialysis, ileoileal anastomotic leaks, ureteral obstruction, urinary leak or fistula formation, reoperations, and 30-day hospital readmissions, were compared using Pearson's χ2. All statistical tests were 2-tailed with P < .05 considered significant. A total of 5418 RCICs were identified. Four hundred ninety-eight (9.2%) were stentless. There were no differences in baseline demographics or comorbidities. Significantly fewer stented patients had robotic-assisted operations (23% vs 29%, P < .01). Stented patients had lower rates of urinary leak or fistula formation (3.1% vs 4.8%, P = .04). There was no significant difference in 30-day rates of UTIs, acute kidney injuries, renal failure, ileoileal anastomotic leaks, ureteral obstruction, reoperations, and readmissions. Limitations include retrospective design and lack of longitudinal tracking past 30 days. Stentless patients had noninferior outcomes compared to stented patients in most important 30-day outcomes. Our analysis suggests that stents may not be necessary in ileal conduit urinary diversion procedures.

Modified posterior pelvic exenteration combined with ileocecal resection for locally advanced endometrial cancer.

There are several retrospective studies which have suggested that optimal cytoreductive surgery for stage IV endometrial cancer improves survival [1-3]. In addition, some investigators have reported that achieving maximal cytoreduction to a visibly disease-free outcome in the abdominal cavity for endometrial cancer with distant metastases can extend patients' survival [4]. Due to the anatomic proximity of the rectosigmoid colon to the female pelvic organs and its involvement in locally advanced endometrial cancer, an en bloc resection of the uterus, adnexa, and rectosigmoid, also known as a modified posterior pelvic exenteration (MPPE), is performed to achieve optimal cytoreduction [5,6]. Additionally, if the tumor has infiltrated the ileal end and/or cecum, ileocecal resection can be added. I report the details of the technique for this surgery requiring intestinal reconstruction. We routinely placed a transanal drainage tube after a MPPE to decrease the rate of anastomotic leakage and the need for a diverting stoma [7]. No visible tumors were observed after surgery. No intraoperative or early postoperative complications occurred. The patient did not have an impediment in her postoperative bladder and bowel function. Concerning the extent of hysterectomy during surgery, the procedure was performed as described in that of a class II hysterectomy [8]. This might partly explain the preservation of these function. Subsequently, she was treated with 6 cycles of doxorubicin and cisplatin chemotherapy. Two years after surgery, she is alive with no evidence of recurrence. The patient provided informed consent for use of this video.

European multicentre analysis of the implementation of robotic complete mesocolic excision for right-sided colon tumours.

Complete mesocolic excision (CME) is an oncologically driven technique for treating right colon cancer. While laparoscopic CME is technically demanding and has been associated with more complications, the robotic approach might reduce morbidity. The aim of this study was to assess the safety of stepwise implementation of robotic CME. A multicentre retrospective analysis of prospectively collected data on robotic right colectomy was performed at five European tertiary centres. Patients were classified for type of surgery: R-RHC (standard right colectomy), R-impCME (learning cases towards robotic CME defined as R-RHC with one but not all the hallmarks of CME) or R-CME (robotic CME). Primary outcomes were overall and severe 30-day complication rates before and after propensity score matching (PSM) analysis. Five hundred and fifty-one consecutive patients undergoing robotic surgery for (pre)malignant lesions of the right colon between 2010 and 2020 were included: R-RHC (n = 101), R-impCME (n = 135) and R-CME (n = 315). Baseline characteristics differed for American Society of Anesthesiologists score (p = 0.0012) and preoperative diagnosis of adenocarcinoma (p < 0.001). Procedure time increased by surgical complexity (p < 0.001). Vascular event rates did not differ, with no superior mesenteric vein injuries. Conversion, complication and anastomotic leak rates, time to flatus/soft diet and length of stay (LOS) did not differ. While R-RHC was performed for a lower rate of malignancies (p < 0.001), lymph node yield was significantly higher in R-CME (p < 0.001). After PSM, analyses on 186 patients documented no differences in overall and severe 30-day complication rate, conversion rate, LOS or 30-day mortality. R-CME can be implemented without increasing the overall or 30-day severe complication rate.

Effects of cellulose nanofibrils on the mechanical and thermal properties of phase change foams based on polyethylene glycol/cellulose nanofibrils/waterborne polyurethane.

Incorporating phase change materials (PCM) into three-dimensional porous network structures could effectively address the leakage problem. In this study, by investigating the effects of different cellulose nanofibrils (CNF) contents on the mechanical and thermal properties of polyethylene glycol (PEG)/CNF/waterborne polyurethane (WPU) phase change foams, a series of leak-proof, lightweight, and stable PEG/CNF/WPU phase change foams were synthesized. Utilizing CNFs as porous support materials could effectively mitigate the leakage of PCMs. Meanwhile, the incorporation of WPU dispersions leads to the formation of CNFs/WPU composite network structure, which enhances the mechanical strength of the phase change foams and further reduces the leakage of PEG. The morphological, crystallographic, chemical, mechanical, and thermal characteristics of PEG/CNF/WPU phase change foams with varying CNF concentrations were comprehensively assessed using field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), mechanical testing, and differential Scanning calorimetry (DSC). The research results indicate that phase change latent heat of PEG/CNF/WPU phase change foam containing 0.8 wt% CNF reached 150.54 J·g-1 and demonstrated superior compressive strength, compressive yield stress, and compressive modulus with a remarkably low leakage rate of just 8.57 % after enduring a 30-day leakage test.

COLOR IV: a multicenter randomized clinical trial comparing intracorporeal and extracorporeal ileocolic anastomosis after laparoscopic right colectomy for colon cancer.

Right-sided colon cancer is a prevalent malignancy. The standard surgical treatment for this condition is laparoscopic right hemicolectomy, with ileocolic anastomosis being a crucial step in the procedure. Recently, intracorporeal ileocolic anastomosis has garnered attention for its minimally invasive benefits. However, there remains a paucity of rigorously designed, large-scale, international multicenter randomized controlled trials to definitively assess the safety and efficacy of intracorporeal ileocolic anastomosis in laparoscopic right hemicolectomy for right-sided colon cancer. This study is an international, multicenter, randomized, controlled, open-label, non-inferiority trial designed to compare the safety and efficacy of intracorporeal versus extracorporeal ileocolic anastomosis in patients with right-sided colon cancer undergoing right hemicolectomy. The primary endpoint is the anastomotic leakage rate within 30days post-surgery. The main secondary endpoint is the 3-year disease-free survival rate post-surgery. A comprehensive quality assurance protocol will be established before the trial begins, including CT review, pathological evaluation, and the standardization and assessment of surgical techniques. This study aims to evaluate the safety and efficacy of intracorporeal ileocolic anastomosis following right hemicolectomy in patients with right-sided colon cancer. The anticipated outcome is that intracorporeal ileocolic anastomosis will show an anastomotic leakage rate and a 3-year disease-free survival rate comparable to those of extracorporeal anastomosis, while offering the added benefit of faster postoperative recovery.

Experimental Study to Determine the Leakage Area of Single-Leaf Smoke Control Doors in the Design of Pressure Differential Systems

On the occasion of building fires, the risk of smoke, which adversely influences escape conditions, must be minimised. One way to reduce the risk is, for example, to pressurise the escape route in order to limit the infiltration of smoke. Careful determination of the design parameters of the pressurisation system is of great importance. This study will propose a new leakage area for single-leaf smoke control doors based on the analysis of the leakage area of the doors in the EN 12101-13 standard, estimating the leakage rate through closed doors. This value is half the currently recommended value, regardless of the opening direction. The determination of the leakage area is supported by measurements in pressurised smoke-free lobbies with single-leaf smoke control doors opening into and outwards from a pressurised space. The measurements are performed using the fans of the lobbies’ pressurisation systems to provide the required air volume. The suitability of this method has also been tested using blower door assembly measurements. The newly proposed leakage area takes into account the increased air tightness of the smoke control doors, thereby ensuring that the optimum air volume to be supplied by the pressurisation system can be determined. The results of this research suggest an appropriate leakage area value for designers when using the calculation method proposed by the applicability of the investigated standard.

Postoperative bile leak after hepato-pancreato-biliary surgery in malignant biliary obstruction: rates, treatments, and outcomes in a high-volume tertiary referral center

BackgroundBiliary leakage is a serious complication of hepato-pancreato-biliary operations, increasing morbidity and mortality, and challenging clinicians.ObjectiveThis study aims to evaluate the incidence of bilioenteric anastomotic leakage, treatment options, and their outcomes at a high-volume tertiary referral center.MethodsA retrospective cohort study was conducted to analyze the outcomes of patients who underwent biliary anastomosis formation between 2016 and 2021. Data from patients with malignant biliary obstruction was analyzed collectively and in two homogenous cohorts: distal malignant (DM) group with distal biliary obstruction undergoing pancreatic head resection, proximal malignant (PM) group with perihilar biliary obstruction undergoing perihilar biliary resection without liver resection.Results724 patients were found. After exclusions, 410 remained in the DM and 41 in the PM group. In the DM group the leak rate was 5.6% (23/410). Mortality was 3.9%, in patients with anastomotic failure 26% (6/23) vs no failure 2.6% (10/387) (p‹0.0001). Leak rate in the ASA III and ASA I-II patients were 52.2% (12/23) vs 48.8% (11/23), (p = 0.597). Leak rates were higher in the PM group 14,6% (6/41), mortality was 4.9% (2/41). All leaks in the PM group occurred in ASA III patients (6/6). No statistically significant associations were found between leak rates and factors such as patient age, preoperative serum bilirubin levels, preoperative or intraoperative biliary drainage, cholangitis, blood transfusion, postoperative pancreatic fistula, or bile duct dilation in either group. Bile leaks (n = 29) were treated conservatively (n = 9) with percutaneous transhepatic drainage (n = 3) or reoperation with (n = 16) or without (n = 10) external biliary drainage. Clinical success rates were slightly higher after reoperation with external drainage.ConclusionThis study identified perihilar resection as a risk factor for biliary leakage and trends indicating higher leak rates among patients with advanced comorbidities (ASA III), elevated preoperative bilirubin levels, non-dilated bile ducts, cholangitis or postoperative pancreatic fistula but these associations did not reach statistical significance, likely due to the limited sample size. In the management of anastomotic leakage, conservative and minimally invasive methods are effective; however, most cases required relaparotomy combined with external biliary drainage.

Sensitivity Analysis of Scallop Damper Seal Design Parameters for Leakage and Static Performance

The leakage characteristics and static stiffness of scallop damper seals have a significant impact on rotor vibration and stability. A parameter sensitivity analysis model for geometrical parameters in scallop damper seals was developed using a design of experiments (DOE) approach. The method employed a central composite design, integrating factorial, axial, and center points to assess non-linear effects efficiently. And the effects of radial clearance, cavity depth, and length–diameter ratios on leakage performance and rotor stability were investigated. The leakage rate, flow-induced force, and static stiffness coefficient for 15 different combinations of geometric parameters at eccentricities of 0.2 and 0.4 were numerically calculated. The results show that eccentricity has little effect on leakage and its parameter sensitivity. Larger cavity depths and length–diameter ratios are beneficial for seal leakage performance. The tangential force increases with increasing eccentricity but decreases with increasing radial clearance, while it first decreases and then increases with the increase in the cavity depth and length–diameter ratios. Additionally, the radial force decreases with the increase in the length-to-diameter ratio and increases first and then decreases with the increase in radial clearance. The parameter level in this study is defined as the ratio of the actual parameter value to the maximum parameter value. Static direct stiffness reaches its maximum value at a radial clearance level of 30.2%. It remains positive within a cavity depth range of 92.3~100%, as well as a length–diameter ratio range of 0~20.3%. The static cross-coupled stiffness gradually decreases with the increase in radial clearance but first decreases and then increases with the increase in the cavity depth or length–diameter ratio levels. The research results presented in this paper can serve as a reference for the analysis of the performance and design of scallop damper seals.

Short-term surgical outcomes of rectal adenocarcinoma surgical treatment in Latin America: a multicenter, retrospective assessment in 49 centers from 12 countries

IntroductionRectal cancer is a prevalent disease that requires multidisciplinary management. Results of treatment of patients suffering from this malignancy in Latin America have been scarcely reported before.MethodsA retrospective, multicenter study was conducted to report preoperative and operative characteristics of patients intervened for rectal cancer in centers from Latin America during 2015–2022, and the short-term results of treatment were analyzed. The study was open to any center receiving rectal cancer patients, irrespective of volume. The main study outcome was 30-day postoperative complications including any deviation from the normal postoperative course (Clavien Dindo I to V).ResultsA total of 2044 patients from 49 centers in 12 Latin American countries were included, with a mean age of 63 years. Twenty-five percent of patients were operated in low-volume centers. Twenty-nine percent of patients had a tumor located in the low rectum, and only 53% of patients had preoperative MRI for local staging. A total of 1052 patients (52%) received neoadjuvant therapy before surgery. Eighty-six percent of patients were operated by a specialized colorectal surgeon, and 31% of patients were intervened using a conventional approach. A total of 29.9% of patients presented a postoperative complication. The anastomotic leak rate was 8.9%. Fifty-eight percent of pathology reports had less than 12 lymph nodes harvested, and 22.9% of reports did not include mesorectal quality. In the multivariate analysis, neoadjuvant therapy (OR: 1.44, p-value: 0.023), urgent procedures (OR: 3.73, p-value: 0.049), intraoperative complications (OR: 2.21, p-value: 0.046), advanced tumors (OR: 1.39, p-value: 0.036), and prolonged surgery (OR: 1.74, p-value: 0.004) were found to be independently related to suffering postoperative complications.ConclusionsThis study includes information about the approach and results of rectal cancer management in Latin America at a large scale. In the future, this information can be used as a bridge to identify areas of improvement among rectal cancer patients’ treatment in the region.

Real-Time Fluorescence Imaging for Thoracic Duct Identification during Oesophagectomy: A Systematic Review of the Literature.

Postoperative chylothorax is a serious complication after oesophagectomy. Real-time identification of the thoracic duct (TD) could prevent injury or facilitate prompt management when it occurs. Intraoperative TD lymphography with indocyanine green (ICG) is a novel technique that may help prevent chyle leaks following thoracic surgery. A systematic search of PubMed, Embase, MEDLINE, Scopus, and the Cochrane Library for studies published until July 2024 evaluating ICG for TD identification during oesophagectomy was performed. Studies were included in the review if they assessed intraoperative TD identification with ICG to prevent chyle leakage in patients undergoing oesophagectomy. Nine of 265 screened papers were included in the present review, with 3 reporting comparative techniques of TD identification between patients. Only 1 study had a control group without ICG administration. TD was identified in 281 of the 303 patients who received ICG. Chyle leak incidence was 0.66% in the ICG group. The mean observation time of TD after ICG administration was 162 minutes. Most of the included patients received neoadjuvant treatment before surgery. Different application routes of ICG have been reported, with the most prominent one being through the inguinal region under ultrasound guidance. Real- time TD identification with ICG might be a valuable tool for avoiding injury or managing it intraoperatively. To our knowledge, this is the first systematic review on this complex topic. However, as no randomized controlled trials have been published, sufficient evidence is needed to determine whether the aforementioned method can sufficiently reduce the chyle leak rate.

Impacts of COVID‐19 pandemic on short‐term outcomes of low anterior resection performed in hospitals with different surgical volumes

AbstractAimTo evaluate the impact of the coronavirus disease (COVID‐19) pandemic on short‐term outcomes of low anterior resection (LAR) across hospitals classified by surgical volume.MethodsData of patients who underwent elective LAR for rectal cancer between 2018 and 2022 were obtained from the National Clinical Database of Japan. Hospitals were categorized into high‐, medium‐, and low‐volume groups. Each group was constituted to represent approximately one‐third of all surgeries performed between 2018 and 2019. The standardized morbidity/mortality ratios (SMRs) of Clavien–Dindo grade ≥3 (CD ≥ 3) complications were the primary endpoint. The secondary endpoints included anastomotic leakage, pneumonia, and surgical mortality.ResultsThis study analyzed 91 800 cases of elective LAR, with 10.5% experiencing CD ≥ 3 complications, 8.8% anastomotic leakage, 0.9% pneumonia, and 0.5% surgical mortality. Despite COVID‐19, SMRs of CD ≥ 3 complications decreased from 2018 to 2022 across all groups. However, increases in the rates and SMRs of CD ≥ 3 complications were observed in low‐volume hospitals around mid‐2020, followed by a decline. Anastomotic leakage showed similar trends. The rates and SMRs of pneumonia and surgical mortality remained unchanged. Notably, anastomotic leakage rates were 7.6%, 8.9%, and 10.0% in high‐, medium‐, and low‐volume hospitals, respectively, indicating superior outcomes in high‐volume hospitals.ConclusionEarly COVID‐19 waves may have disproportionately affected low‐volume hospitals. However, the decline in SMRs of CD ≥ 3 complications from 2018 to 2022 across all three groups suggests the robustness and resilience of surgical services for rectal cancer in Japan. The potential disparity in short‐term outcomes among hospitals is a new concern.