Duct Diameter Research Articles

Comparison of C-reactive Protein Versus White Blood Cell Count in Early Detection of Major Complications Post Whipple Procedure—A Prospective Study

Introduction: Whipple’s (pancreatoduodenectomy) surgery carries significant post-operative morbidity even in specialised centres. We share our findings by comparing the inflammatory markers C-reactive protein (CRP) and white blood cell count (WBC) in early detection of post-operative complications. Material and Methods: In this prospective study, 56 patients who underwent the Whipple procedure in our institution between January 2021 and December 2022 were evaluated. Demographic characteristics, pre-and post-operative CRP and WBC levels, intraoperative parameters like pancreatic texture and duct diameter, intraoperative blood loss, postoperative complications, length of stay and final histopathology were evaluated. The receiver operator characteristics curve (ROC) was drawn, and the area under the curve was calculated. Results: Among the 32 (57.2%) patients who developed complications, 6 (10.7%) had major and 26 (46.4%) had minor complications. ROC curves revealed greatest area under curve value for POD5 CRP (AUC-1.000; P <.01) followed by POD3 (AUC-0.999; P < .01) and then POD7 (AUC-0.995; P < .01). For WBC, the greatest value was found only on POD5 (AUC-0.742; P = .003) followed by POD7 (AUC-0.716; P < .009), but not on POD3 (AUC-0.607; P = .19). Conclusion: C-reactive protein was better than white blood cell counts in the early detection of postoperative complications.

Correlation between axial and coronal common bile duct diameters in computed tomography: a retrospective study of 1064 patients

BackgroundThe measurement of the common bile duct (CBD) diameter is essential for evaluating bile duct pathologies. The axial plane of computed tomography (CT) images is the established method for CBD diameter measurement. However, modern software enables easy reconstruction of axial CT images into the coronal plane, allowing for CBD diameter measurement in this plane. This study aimed to investigate the correlation between measurements in the axial and coronal planes.ResultsThe three reviewers demonstrated fair reliability in measuring CBD diameter in axial and coronal planes, with intraclass correlation coefficients of 0.776 and 0.799, respectively. A positive correlation was observed between the two diameters (r = 0.943), with 88.9% of axial diameter variation explained by coronal diameter and approximately 0.29 + (0.94 × coronal diameter) (R2 = 0.889, p < 0.001). When a cutoff value of 7 mm was used to predict an abnormal axial diameter, the agreement between axial and coronal CBD diameters was substantial (Kappa = 0.715) with discordance between the two measurements identified in 6.2% of cases (66/1064) when a) coronal diameter < 7 mm but axial measurement ≥ 7 mm (39/1064; 3.7%) and b) coronal diameter ≥ 7 mm but axial measurement < 7 mm (27/1064; 2.5%). In univariable linear regression and multivariable analyses, the strongest independent factors associated with increased axial CBD diameter were presence of focal CBD lesion, age ≥ 60 years, and cholecystectomy.ConclusionThere was a strong positive correlation between axial and coronal CBD diameters with substantial agreement when using a 7-mm cutoff and fair reliability in their measurements.

Impact of Modified Blumgart Anastomosis on Pancreatic Fistula and Pancreaticojejunostomy Time During Laparoscopic Pancreaticoduodenectomy: Single-Center Experience.

Background/Objectives: The aim of this study is to evaluate the impact of modified Blumgart anastomosis methods during pancreaticojejunostomy (PJ) on the incidence of clinically relevant postoperative pancreatic fistula (POPF) after laparoscopic pancreaticoduodenectomy (LPD). Methods: This is a retrospective cohort study analyzing data of patients who underwent LPD from 2018 to 2022. The primary endpoint was the incidence of grade B and C POPF based on the International Study Group on Pancreatic Fistula criteria and PJ anastomosis time. Incidence of postoperative complications (Clavien-Dindo classification grade ≥ III) was also investigated. Results: A total of 148 patients, 99 patients in a modified Blumgart group and 49 patients in a continuous suture group, were enrolled. There were no statistically significant differences in the general and intraoperative characteristics found between the two groups (p > 0.05). There was no significant difference in pancreas texture (p = 0.397) and diameter of pancreatic duct (p = 0.845). Grade B and C POPF occurred in five patients (5.1%) in the modified Blumgart group and three patients (6.1%) in the continuous suture group with no statistical difference (p = 0.781). A total of eleven patients (11.1%) in the modified Blumgart group and four patients (8.2%) in the continuous suture group had postoperative complication (Clavien-Dindo Classification grade 3 or more). Mortality within 90 days was 2 (2%) and 0 (0%), respectively. The PJ anastomosis times in the modified Blumgart group and continuous suture group were 28.8 ± 5.94 min and 35 ± 7.71 min, respectively (p = 0.003). Conclusions: This study suggests that modified Blumgart PJ showed shorter anastomosis time with comparable outcome to continuous suture methods in LPD.

The Utilization of Acetaminophen for Managing PGE1-Induced Fever in Neonates with Critical Congenital Heart Disease.

We aimed to retrospectively evaluate the use of acetaminophen, which may be a risk factor for the ductal canal, in the treatment of fever due to prostaglandin E1 (PGE1) infusion in newborns with critical congenital heart disease (CCHD). The study included newborns who were followed-up in our neonatal intensive care unit with the diagnosis of critical congenital heart disease, developed fever due to PGE1 infusion and had acetaminophen administered for antipyretic treatment. The patent ductus arteriosus diameters of the patients were evaluated by echocardiographic imaging before intravenous acetaminophen treatment and at the end of the day of acetaminophen treatment. PGE1 fever was observed in 10 (6%) of 156 infants with ductus-dependent congenital heart disease. Intravenous acetaminophen treatment administered as an antipyretic in these infants did not cause the narrowing or closure of the ductal canal diameter, which would lead to clinical decompensation if it was closed, and the patients remained hemodynamically stable until surgery. It can be considered that controlled and rapidly administered intravenous acetaminophen therapy in the management of fever in neonates with congenital heart disease who develop fever as a side effect of high-dose intravenous PGE1 infusion therapy (≥0.3 mcg/kg/min) may prevent hemodynamic decompensation in these critically ill infants, and as a secondary outcome, it can be speculated that avoiding rapid daily increases in PGE1 maintenance infusion doses may be necessary to limit the number of paracetamol administrations in these infants.

Stent misdeployment and factors associated with failure in endoscopic ultrasound-guided choledochoduodenostomy: analysis of the combined datasets from two randomized trials.

Stent misdeployment (SMD) is a feared and poorly characterized technical challenge of endoscopic ultrasound (EUS)-guided choledochoduodenostomy (CDS) using lumen-apposing stents. We aimed to ascertain the rate of stent misdeployment in EUS-CDS for malignant distal biliary obstruction (MDBO) and describe its outcomes while identifying variables associated with its occurrence. This was a post hoc analysis of two randomized controlled trials comparing EUS-CDS vs. endoscopic retrograde cholangiopancreatography in MDBO. The primary end point was rate of SMD, classified as misdeployment of the distal flange (type I), proximal flange (type II), contralateral bile duct wall injury (type III), or double mucosal puncture (type IV). Multivariable analysis was performed to identify variables associated with SMD and/or technical failure, and with clinical failure or stent dysfunction. 152 patients were included. Technical success was 93.4 %. SMD occurred in 11 patients (7.2 %; 95 %CI 3.1 %-11.4 %): 8 type I, 1 type II, and 2 type III. Endoscopic salvage of SMD was successful in 81.8 %. Misdeployment led to adverse events in four patients (two mild, two moderate), giving an overall SMD-related adverse event rate of 2.6 % (95 %CI 0.7 %-6.6 %). On multivariable analysis, extrahepatic bile duct diameter of ≤ 15 mm was associated with increased odds of SMD and/or technical failure. SMD was relatively common in EUS-CDS and was associated with an extrahepatic bile duct diameter of ≤ 15 mm. The majority of misdeployments could be rescued endoscopically with low risk for adverse events.

Diversity of Picea omorika (Pančić) Purk. Populations Based on Morpho-anatomical Needle Traits and Bioclimatic Parameters

Picea omorika (Pančić) Purkyne is a well-known endemic conifer species. However, there have been few morpho-anatomical studies to date. Several years ago, preliminary population studies of P. omorika were published, but with the inclusion of additional populations, it became necessary to confirm whether the southernmost population from Mileševka Canyon, also known as var. vukomanii, (Pavlović and Matović 1994), remains distinct from the others. Two-year-old needles from the lower third of the crown were collected in late autumn from seven natural populations of P. omorika from Serbia and from the border with Bosnia and Herzegovina. The variability of ten morpho-anatomical traits and the cross-sectional anatomy of Serbian spruce needles were examined in seven natural populations in Serbia. Needle length was measured with a digital calliper, and the nine other needle traits, needle width, needle thickness, vascular bundle diameter, resin ducts diameter, number of resin ducts, distance between vascular bundle and resin duct, cuticle and epidermal thickness, hypodermal thickness, and hypodermal width, were examined under a light microscope. For most of the traits studied, the Štula population had the highest values, whereas the Bilo population had the lowest. Needles with triangular sections are most common in the southern part of Mt. Tara, while elliptical and rhomboidal sections are characteristic in populations at the edge of the distribution range in Serbia. Multivariate analyses separated populations into two main groups. Both principal component analysis and discriminant analysis indicated population overlap, while cluster analysis identified three main groups. Multivariate analysis of bioclimatic data and a correlation study of morpho-anatomical traits were also performed. Based on bioclimatic parameters, individuals in the populations from Mileševka and Štula showed the most distinct characteristics. Mantel and partial Mantel tests confirmed no correlation between the complete set of morphological traits and bioclimatic parameters, even after adjusting for regional differences.

Pancreatic Fistula Following Pancreatoduodenectomy: A Focus on Drain Amylase Dynamics and Surgical Variables

Introduction: Postoperative pancreatic fistula (POPF) remains one of the most challenging complications following pancreatoduodenectomy, contributing significantly to morbidity and mortality. This study explores the relationship between clinical, biochemical, and surgical factors and the development of POPF, with a focus on identifying predictors. Methods: This observational study was conducted in Dhaka Medical College &amp; Hospital (DMCH), Dhaka, from January 2023 to December 2023. 30 patients with the Whipples procedure were selected as study subjects by purposive simple random sampling technique. Analysis was done manually by MS Word &amp; MS Excel worksheet and SPSS. The unpaired t-test and Chi-square test were done for data analysis. Result: POPF was significantly associated with a smaller main pancreatic duct diameter (≤3 mm, p = 0.006) and soft pancreatic texture (p = 0.00005). Elevated drain fluid amylase levels, particularly on postoperative day 5, highlighted its role in the early detection of POPF. Periampullary carcinoma was the most common diagnosis overall, though only chronic pancreatitis showed a significant association with POPF (p = 0.032). The duct-to-mucosa anastomotic technique significantly reduced the risk of POPF compared to the dunking method (p = 0.00001). Other variables, including blood loss and procedure type, were not significantly linked to POPF development. Conclusion: This study highlights that postoperative pancreatic fistula (POPF) following pancreatoduodenectomy is strongly influenced by factors such as small main pancreatic duct diameter (≤3 mm), soft pancreatic texture, and the anastomotic technique used. Elevated drain fluid amylase levels in the early postoperative period emerged as a reliable marker for POPF risk.

Application of CT radiomics in investigating the anatomical basis of chronic dacryocystitis

Objective:To explore the relevant anatomical factors in the pathogenesis of chronic dacryocystitis based on CT radiomics. Methods:A retrospective analysis was conducted on the general data and sinus CT materials of 85 patients with chronic dacryocystitis（case group） admitted to our department from December 2020 to December 2023, and 85 individuals undergoing physical examination（control group） during the same period. The differences in anatomical parameters between the two groups were compared to study the morphological characteristics of the nasolacrimal duct in patients with chronic dacryocystitis. Univariate and multivariate logistic regression analyses were used to explore the relevant anatomical factors in the pathogenesis of chronic dacryocystitis. Results:There were statistically significant differences（P<0.05） in the proportion of combined nasal septal deviation, the distance between the anterior and posterior ridges of the lacrimal fossa, the angle between the long axis of the nasolacrimal duct and the projection on the midsagittal plane, the maximum transverse diameter of the bony nasolacrimal duct, the maximum cross-sectional area of the bony nasolacrimal duct, and the thickness of the frontal process of the maxilla between the two groups. There were no statistically significant differences（P>0.05） in whether there was a combined high-position nasal septal deviation, whether there was a combined non-high-position nasal septal deviation, and whether there was a combined pneumatized middle turbinate. Multivariate analysis showed that nasal septal deviation, the distance between the anterior and posterior ridges of the lacrimal fossa, the angle between the long axis of the nasolacrimal duct and the projection on the midsagittal plane, and the maximum cross-sectional area of the bony nasolacrimal duct are independent anatomical factors affecting the pathogenesis of chronic dacryocystitis. Conclusion:Nasal septal deviation, a large distance between the anterior and posterior ridges of the lacrimal fossa, a large angle between the long axis of the nasolacrimal duct and the projection on the midsagittal plane, and a small maximum transverse diameter of the bony nasolacrimal duct are important anatomical bases for the pathogenesis of chronic dacryocystitis, providing a basis for an in-depth understanding of the disease occurrence.

Dilated common bile duct diameter as an indicator of bacteremia in patients with symptomatic common bile duct stones

BackgroundThe optimal timing and selection for blood culture collection in patients with acute cholangitis remains unclear. The relationship between common bile duct (CBD) diameter and the incidence of bacteremia in patients with CBD stones was elucidated. MethodsThis single-center retrospective observational study included patients with symptomatic CBD stones who presented to the emergency department between January 2019 and December 2021. The primary endpoint was the incidence of bacteremia. The patients were divided into two groups based on bacteremia complications. The patient characteristics and CBD diameters were compared between the two groups to identify factors associated with bacteremia. ResultsIn total, 270 patients were analyzed, with bacteremia identified in 134 patients (50 %), and the median CBD diameter was 10.7 mm (IQR, 8.7–13.7). The CBD diameter was significantly larger in patients with bacteremia (median 12.4 mm [IQR, 9.9–15.7] vs. 9.7 mm [IQR, 8.2–11.7], P < 0.001) in univariate analysis. Multivariable analysis revealed that the CBD diameter was significantly associated with bacteremia (OR: 1.25, 95 % CI: 1.14–1.38, P < 0.010). The area under the ROC curves, representing the diagnostic accuracy of CBD diameter for indicating bacteremia, was 0.72 (95 % CI, 0.66–0.78) with a cut-off value of 11.2 mm. ConclusionCBD dilation in patients with symptomatic CBD stones is significantly correlated with bacteremia. The CBD diameter cannot be assessed as the sole tool for detecting bacteremia; however, CBD dilation could be an indicator of bacteremia, assisting in the treatment strategy, regardless of the initial severity of cholangitis.

Optimal indication of adding pancreatic juice cytology in the diagnosis of malignant intraductal papillary mucinous neoplasm of the pancreas.

Positive pancreatic juice cytology (PJC) is an important finding when considering surgical resection in patients with intraductal papillary mucinous neoplasm (IPMN); however, guidelines do not recommend endoscopic retrograde cholangiopancreatography (ERCP) for PJC. This study aimed to clarify the findings worthy of adding PJC for diagnosing high-grade dysplasia (HGD) and invasive carcinoma (IC) in patients with IPMN. Patients with IPMN who underwent preoperative PJC and surgical resection at Hiroshima University Hospital were enrolled, and the diagnostic yield of malignant IPMN based on PJC and clinical and imaging findings and the incidence of post-ERCP pancreatitis (PEP) were retrospectively analyzed. Of the 129 eligible patients, 61 (47%) had malignant tumors (29 HGD and 32 IC). The diagnostic yields of PJC were as follows: 33%, 97%, 91%, 62%, and 67% for sensitivity, specificity, and positive predictive value, and negative predictive value, respectively. Multivariate analysis revealed that an abrupt change in the pancreatic duct caliber was an independent predictive factor of true-positive PJC (hazard ratio: 15.81, P=0.001), with a diagnostic sensitivity of 86% for PJC in these patients. The incidence rate of PEP was 19%, and the pancreatic body and tail lesions, main pancreatic duct diameter <10mm, and placement of a nasopancreatic drainage catheter were significant risk factors for PEP. Although PJC is generally not recommended for patients with IPMN, it is worth considering for the determination of treatment strategies in patients with abrupt changes in the caliber of the pancreatic duct with distal pancreatic atrophy.

Laparoscopic lateral pancreaticojejunostomy in the current era: A narrative review.

Chronic pancreatitis is a benign disease which causes recurrent abdominal pain and loss of pancreatic function. Lateral pancreaticojejunostomy (LPJ) is a commonly performed drainage procedure for this condition. While usually performed through an open approach, there have been few cases of laparoscopic approaches for this condition. A literature review was conducted to understand the current status of laparoscopic longitudinal pancreatojejunostomy (LLPJ). We conducted a comprehensive literature search using PubMed, Embase and Cochrane Library to find the articles published until 1 st October 2023. We excluded studies involving paediatric patients or robotic assisted surgeries. Our evaluation focussed on pain relief scores, morbidity, hospital stay length, mortality rates and the development of endocrine and exocrine deficiencies in the patients. The patients in the analysis had a mean age of 36.5 and a male to female ratio of 1.4:1. The mean main pancreatic duct diameter was 11.5 mm. Tropical pancreatitis was identified as the primary cause. The surgical procedure was performed using 4 ports with minimal bleeding and a 13% morbidity rate. The conversion rate was 15%. The average operative time was 260 min and the mean hospital stay was 5.7 days. The results for pain control were excellent, as 90% of patients did not report pain in most series at the end of 3 years. The laparoscopic surgical management of chronic calcific pancreatitis with LPJ offers a safe and effective solution for pain relief in carefully chosen patients. However, further comprehensive studies with large sample sizes are essential to establish a more conclusive comparison between LLPJ and open surgery.

Evaluation of dimensional changes of the nasolacrimal canal after rapid maxillary expansion: A cone-beam computed tomography study

ObjectiveThe aim of this study is to evaluate the nasolacrimal canal dimensionally and volumetrically after treatment in patients who underwent rapid maxillary expansion. Materials and methodsA total of 19 patients (12 females, 7 males) with maxillary transverse deficiency, who underwent rapid maxillary expansion were included in the study. Cone beam computed tomography images were analyzed to measure the volume, anteroposterior diameter, transverse diameter, length, and angle of the nasolacrimal duct before and after treatment. ResultsThe average age of the patients was 13.8 ± 1.69 years. Statistically significant increases in the volume, anteroposterior diameter, transverse diameter, length, and angle of the nasolacrimal canal were observed after treatment for both the right and left sides. No significant difference was found nasolacrimal canal dimensionally and volumetrically except angle on the left and right side of male and female patients. No significant differences were found in the changes between male and female patients. ConclusionRapid maxillary expansion resulted in significant dimensional and volumetric increases in the nasolacrimal canal. Although no prior studies have linked maxillary transverse deficiency to nasolacrimal canal obstruction, the findings suggest that RME may be a viable treatment for nasolacrimal canal obstruction under appropriate conditions.

HPB SO35 - Outcomes of Transcystic Laparoscopic Common Bile Duct Exploration at the time of Laparoscopic Cholecystectomy in patients with small common bile duct diameter

Abstract Background Laparoscopic Cholecystectomy with Laparoscopic Common Bile Duct Exploration (LC+LCBDE) is a single stage therapeutic option for management of choledocholithiasis. There have been limited publications regarding the feasibility of transcystic LCBDE in patients with small (≤8mm) common bile ducts (CBD). This study seeks to examine the outcomes for patients with small ducts who underwent LC+LCBDE via a transcystic approach (LCBDE-t) in a district general hospital over a thirty-month period. Method Prospectively collected data regarding all patients who underwent LC+LCBDE-t over a period from January 2022 to June 2024 was retrospectively reviewed. Data including indication for surgery, CBD diameter, length of stay, complication rate, and readmission rate were determined from Electronic Care Records. Data were analysed using Microsoft Excel. Results 76 patients were identified. CBD diameter (almost all as measured at pre-operative Magnetic Resonance Cholangiopancreatography [MRCP]) ranged from 3.5mm to 8mm (average 6.32). One patient required conversion to open surgery due to difficulties with the LC element of the operation. Median postoperative length of stay was 1 day (range 0-32 days) and readmission rate was 5.33%. Five patients experienced a complication beyond Clavien-Dindo Grade II, with the most serious two being a bile leak and a postoperative bleed, both of which required further surgery. One patient required subsequent Endoscopic Retrograde Cholangiopancreatography (ERCP) for retained CBD stones. Conclusion LCBDE is a safe and effective management option for patients in the setting of choledocholithiasis with small CBD diameter. Small CBD should not necessarily be a deterrent to consideration of transcystic LCBDE as a therapeutic option in appropriately selected patients.

Centerline-guided reinforcement learning model for pancreatic duct identifications.

Pancreatic ductal adenocarcinoma is forecast to become the second most significant cause of cancer mortality as the number of patients with cancer in the main duct of the pancreas grows, and measurement of the pancreatic duct diameter from medical images has been identified as relevant for its early diagnosis. We propose an automated pancreatic duct centerline tracing method from computed tomography (CT) images that is based on deep reinforcement learning, which employs an artificial agent to interact with the environment and calculates rewards by combining the distances from the target and the centerline. A deep neural network is implemented to forecast step-wise values for each potential action. With the help of this mechanism, the agent can probe along the pancreatic duct centerline using the best possible navigational path. To enhance the tracing accuracy, we employ landmark-based registration, which enables the generation of a probability map of the pancreatic duct. Subsequently, we utilize a gradient-based method on the registered data to extract a probability map specifically indicating the centerline of the pancreatic duct. Three datasets with a total of 115 CT images were used to evaluate the proposed method. Using image hold-out from the first two datasets, the method performance was 2.0, 4.0, and 2.1mm measured in terms of the mean detection error, Hausdorff distance (HD), and root mean squared error (RMSE), respectively. Using the first two datasets for training and the third one for testing, the method accuracy was 2.2, 4.9, and 2.6mm measured in terms of the mean detection error, HD, and RMSE, respectively. We present an algorithm for automated pancreatic duct centerline tracing using deep reinforcement learning. We observe that validation on an external dataset confirms the potential for practical utilization of the presented method.

Association of cytochrome P450 CYP2C9 (rs1057910) gene polymorphism and ibuprofen response in preterm neonates diagnosed with patent ductus arteriosus

Background Patent ductus arteriosus (PDA) closure is one of the most significant changes necessary to transition to extrauterine life. The failure of closure in preterm infants has been associated with a variety of complications. Aim and objectives This study aim to investigate the correlation between cytochrome P450 CYP2C9 gene polymorphism and the response to ibuprofen treatment in preterm neonates with PDA. Subjects and methods This prospective study was conducted on 64 preterm neonates with patent ductus arteriosus (hsPDA). The neonates were treated with ibuprofen and diagnosed using clinical and echocardiographic examinations. The study was carried out at the Neonatal Intensive Care Unit (NICU), Pediatric Department, Kasr Alainy and ElMounira Pediatric Hospitals, Cairo University, in June 2018. Results A statistically significant difference in respiratory rate was observed between both groups ( p = 0.047). Additionally, there was a significant difference in the duration of treatment with ibuprofen ( p = 0.021). Treatment with ibuprofen had no impact on renal function parameters. The platelet count decreased after treatment with no statistical difference. Conclusion Use of Oral ibuprofen is a highly effective treatment for HsPDA in preterm neonates, demonstrating a remarkable success rate of 92.2% and fewer adverse effects. Whilst no correlation between the CYP2C9 (rs1057910) gene polymorphism and the efficacy of oral ibuprofen response, Other factors affecting the response of oral ibuprofen and subsequent PDA closure include gestational age, birth weight, Apgar score at 5 min, ductal diameter, RDS, and sepsis.

Validation of the Updated Alternate Fistula Risk Score for Prediction of Postoperative Pancreatic Fistula After Pancreatoduodenectomy.

Postoperative pancreatic fistula (POPF) remains a significant challenge following pancreatoduodenectomy (PD), contributing to morbidity and mortality. Various risk assessment models have been established to predict the likelihood of POPF. An updated alternate fistula risk score (ua-FRS) has been recently refined and validated within European cohorts. However, the validation of this score in South Asian cohorts remains relatively unexplored. This study aims to validate the applicability of ua-FRS for the prediction of POPF in patients undergoing PD in the South Asian population, particularly Nepal. This cross-sectional, observational study was conducted by a single team across three tertiary care centers in Kathmandu, Nepal from July 2021 to October 2023. A total of 98 patients were studied in terms of their sex, body mass index (BMI), diameter of the main pancreatic duct (MPD), pancreatic consistency, pathological site, and estimated blood loss. The accuracy of ua-FRS for the prediction of postoperative pancreatic fistula after pancreatoduodenectomy was evaluated using the receiver operative characteristics curve. Univariate analysis revealed that sex, pancreatic gland texture, the diameter of the main pancreatic duct, the site of pathology, and BMI were statistically significant factors. However, in the multivariate analysis, only BMI and the diameter of the MPD retained their statistical significance, with p-values less than 0.005. The ua-FRS demonstrated high sensitivity and specificity in predicting postoperative pancreatic fistula, as evidenced by an area under the curve (AUC) of 0.802. The ua-FRS has validation in the context of the South Asian population to predict POPF following PD, offering a reliable tool to guide perioperative management.

Comprehensive CFD Analysis of Base Pressure Control Using Quarter Ribs in Sudden Expansion Duct at Sonic Mach Numbers

This study aims to assess the effect of rib size, shape, and location in a suddenly expanded flow at sonic Mach number. Flow from a converging nozzle is exhausted into a larger area of duct diameter of 18 mm. The geometric parameters considered are the area ratio, duct length, rib radius, and inertia parameters, which are considered the level of expansion at critical Mach number. In the present study, duct lengths were from 1D to 6D, rib radii considered were 1 mm to 3 mm, and rib locations were 0.5D, 1D, 1.5D, 2D, and 3D. Results show that when the ribs are placed near the reattachment point with a 3 mm radius, they are efficient and capable of reducing the suction in the recirculation zone and the base pressure, which was lower than the ambient pressure in the absence of ribs, is assorted larger than the back pressure. If the requirement is to equate the pressure at the base to ambient pressure, then a 2 mm radius is the right choice. Furthermore, the 1 mm rib cannot reduce the suction in the base region, and base pressure remains sub-atmospheric for the entire range of rib locations, as well as the NPRs of the present study. When the orientation of the ribs is changed, and the flow interacts with the flat surface instead of the curved surface, there is a marginal change in the flow pattern, and there is no significant change in the base pressure values.

High-Risk Biliary Anastomosis During Robotic Pancreaticoduodenectomy: Initial Experience with Biodegradable Biliary Stent.

Background and Objectives: Biliary fistulas (BFs) occur in approximately 3-8% of patients undergoing pancreaticoduodenectomy (PD), and the bile duct diameter ≤ 5 mm is the most important risk factor. The aim of this study was to evaluate the efficacy of biodegradable biliary stents (BSs) in reducing complications in patients undergoing robotic pancreaticoduodenectomy (RPD) with a bile duct diameter of ≤5 mm. Materials and Methods: A retrospective single-centre observational study was conducted. Patients undergoing RPD after the completion of the robotic biliary anastomosis learning curve were included in this study. Only patients with a bile duct diameter ≤ 5 mm were included in the analysis. A prospectively held database was used. The intraoperative time for biliary anastomosis was extracted from surgical videos. Results: Of 30 patients, 20 received no biliary stent (nBS) and 10 received a biodegradable stent (BS). The decision to use a stent was based on product availability. The median operative time for biliary anastomosis was significantly shorter in the BS group compared to the nBS group, at 15 min versus 24 min (p < 0.001). Three patients in the nBS group developed a BF, whereas none were observed in the BS group. No stent migration was observed in any of the patients. Conclusions: The use of biodegradable biliary stents in high-risk biliary anastomosis in RPD appears to effectively reduce the incidence of BFs and may serve as a viable strategy to mitigate early biliary complications. The use of biodegradable stents facilitates a faster and easier biliary anastomosis. These findings suggest a potential benefit of using biodegradable stents in complex biliary reconstruction. However, larger studies are needed to confirm these results.

Experimental investigation on the vented flame and pressure behaviour of hydrogen-air mixtures

To explore the changes in pressure and flame propagation inside and outside the vessel when the pipe diameter does not match the vent diameter, and to check the conservatism of standards NFPA 68 and EN 14491 for this case, an experimental apparatus was utilized to investigate the influences of static activation pressure (0.7–1.75 bar) and vent diameter (30–70 mm) on the deflagration behavior of hydrogen–air mixtures (Φ: 0.6–1.4). The vented pressure, flame propagation, and pressure–flame interaction characteristics of hydrogen–air mixtures were observed and analyzed. Additionally, the conservatism of the calculated venting area under the experimental conditions of NPFA 68 and EN 14491 was verified. The results indicated that under an equivalence ratio of 0.6, the pressure-time curve inside the container exhibited only one peak (Pmax11). In the stoichiometric and fuel-rich states, the pressure-time curve inside the container exhibited two peaks attributed to the decrease in venting efficiency due to the secondary explosion inside the pipe, increasing the turbulence intensity within the container. When the static activation pressure is 0.7 bar, the pressures of the three vent diameters of 30, 50 and 70 dropped by 11.34%, 24.38% and 26.86% respectively. And the Pmax11 at Φ = 1.0 and Φ = 1.4 are similar, while this phenomenon is not observed for other vent diameters. When the vent diameter was inconsistent with the duct diameter. the calculations of both standards were conservative. However, under these testing conditions (vent diameter: 30–70 mm, static activation pressure: 0.7–1.75 bar), the NPFA 68 calculations yield a conservatism range of 3.3–11, whereas EN14491 ranges from 1.6 to 15.7. The NPFA 68 results were more stable and concentrated, making these conditions more suitable for industry safety design in hydrogen venting.

Seismic Performance of Precast Drift-Hardening Concrete Walls Connected by Grout-Sheath Duct.

In order to find a suitable size of sheath duct and a reliable construction method for precast walls, a cast-in-place and five 1/2 scale precast drift-hardening concrete walls reinforced with weakly bonded ultra-high strength SBPDN rebars were fabricated and tested under reserved lateral load and constant compression. The experimental variables were the diameter of sheath ducts (45 mm, 100 mm, and 120 mm), embedded length (20d and 35d; d is the nominal diameter of SBPDN rebars), axial load ratio (0.075 and 0.15), and the construction method. The experimental observations, hysteresis behaviors, envelope curves, residual deformation, crack propagation, and energy dissipation were compared in the study. Moreover, a formula was applied to calculate the bond strength of the sheath duct. The experimental and calculated results revealed that increasing the axial load ratio and embedment length could not enhance the bond strength of the sheath ducts, and increasing the diameter decreased the bond strength significantly. Anchored the SBPDN rebars in smaller sheath ducts separately was a more stable connection method for precast concrete shear walls and provided sufficient drift-hardening capability, even at a large drift level (over 3%).