Failure Of Drainage Research Articles

Defining failure of endoluminal biliary drainage in the era of endoscopic ultrasound and lumen apposing metal stents.

The role of endoscopy in pathologies of the bile duct and gallbladder has seen notable advancements over the past two decades. With advancements in stent technology, such as the development of lumen-apposing metal stents, and adoption of endoscopic ultrasound and electrosurgical principles in therapeutic endoscopy, what was once considered endoscopic failure has transformed into failure of an approach that could be salvaged by a second- or third-line endoscopic strategy. Incorporation of these advancements in routine patient care will require formal training and multidisciplinary acceptance of established techniques and collaboration for advancement of experimental techniques to generate robust evidence that can be utilized to serve patients to the best of our ability.

Arterial oxygen pressure during veno-venous extracorporeal membrane oxygenation may be increased by advancing the tip of the drainage cannula into the superior vena cava: a case report.

A simple and robust method for veno-venous extracorporeal membrane oxygenation (V-V ECMO) involves a drainage cannula into the inferior vena cava via the femoral vein (FV) and a reinfusion cannula into the right atrium (RA) via the internal jugular vein (IJV) (F-J configuration). However, with this method, the arterial oxygen (PaO2) is said to remain below 100mmHg.Since recently, in our ICU, to prevent drainage failure, we apply a modification from the commonly practiced F-J configuration by advancing the tip of the drainage cannula inserted via the FV into the superior vena cava (SVC) and crossing the reinfusion cannula inserted via the IJV in the RA (F(SVC)-J(RA) configuration). We experienced that this modification can be associated with unexpectedly high PaO2 values, which here we investigated in detail.Veno-arteriovenous ECMO was induced in a 65-year-old male patient who suffered from repeated cardiac arrest due to acute respiratory distress syndrome. His chest X-ray images showed white-out after lung rest setting, consistent with near-absence of self-lung ventilation. Cardiac function recovered and the system was converted to F(SVC)-J(RA) configuration, after which both PaO2 and partial pressure of pulmonary arterial oxygen values remained high above 200mmHg. Transesophageal echocardiography could not detect right-to-left shunt, and more efficient drainage of the native venous return flow compared to common F-J configuration may explain the increased PaO2.Although the F(SVC)-J(RA) configuration is a small modification of the F-J configuration, it seems to provide a revolutionary improvement in the ECMO field by combining robustness/simplicity with high PaO2 values.

Outcomes of a Second Ahmed Glaucoma Implant With Mitomycin-C in Pediatric Glaucoma After Initial Valve Failure.

After the failure of a glaucoma drainage device in children, implantation of a second Ahmed glaucoma valve with mitomycin-C allows a significant reduction of intraocular pressure and number of medications with good medium-term and long-term survival. The effectiveness of glaucoma drainage devices (GDD) is limited in time. There is little literature regarding the optimal management strategy after failure of a GDD in pediatric glaucoma. To report the outcomes of Ahmed glaucoma valve implantation (AGV) with mitomycin-C (MMC) after failure of a GDD in children. Retrospective chart review of patients with a history of at least 1 GDD receiving an AGV implantation with MMC between 2000 and 2019. We defined complete success as an IOP of 5-21mmHg without glaucoma medication and qualified success as a final IOP of 5-21mmHg with one or more glaucoma medication, without loss of vision. Twenty-one patients (22 eyes) met the inclusion criteria. The intraocular pressure and number of medications were significantly reduced. The probability of complete success was 47% [95% CI: 29%-75%] at 2 years and 34% [95% CI: 18%-65%] at 4 years. The probability of qualified success was 74% [95% CI: 56%-97%] at 2 years, and 54% [95% CI: 34%-84%] at 5 years. Failure happened in 10 eyes after a mean time of 4.3 years ±3.6 (6mo to 15y), 5 of which (23%) for severe complications or loss of vision. This study of implantation of a second valve with MMC reports a significant decrease in IOP and medications with medium-term and long-term success rates close to those reported for first valve implantation, although with a high risk of complications.

Equations and methodologies of inlet drainage system discharge coefficients: A review

Abstract Accurate determination of grate inlet discharge coefficients is crucial in reducing modeling uncertainties and mitigating urban flooding hazards. This review critically examines the methods, equations, and recommendations for determining the weir/orifice discharge coefficients, based on the inlet parameters and flow conditions. Reviewing previous studies for inlets showed that the discharge coefficient of rectangular inlets under subcritical flow ranges from 0.53 to 0.6 for weirs and from 0.4 to 0.46 for orifices, while in grated circular inlets, it falls between 0.115 and 0.372 for weirs and between 0.349 and 2.038 for orifices. For circular non-grated inlets under subcritical flow, the weir and orifice coefficients are in the range of 0.493–0.587 and 0.159–0.174, respectively. However, the orifice discharge coefficients of grated and non-grated inlets with unknown Froude number range between 0.14–0.39 and 0.677–0.82, respectively. For supercritical flow, the weir and orifice discharge coefficients of grated and non-grated rectangular inlets are 0.03–0.47 and 1.67–2.68, respectively. Previous studies showed that it is recommended to correlate the discharge coefficients with the approaching flow and Froude number under subcritical and supercritical flows, respectively. Yet, additional studies are recommended for a better understanding of the limits and parameters governing the flow transitional stage between weir and orifice and between subcritical and supercritical conditions. Moreover, further research is required to determine the weir and orifice discharge coefficients of circular inlets under supercritical flow as well as the orifice discharge coefficient range of rectangular non-grated inlets under subcritical flow. Finally, it is recommended to increase the road surface roughness to reduce Froude number, and thereby, increase discharge coefficients of street inlets. The aim of this review is to help inlet designers and authorities promote sustainable cities with resilient urban drainage systems and reduce the environmental, economic, health, and social impacts of urban drainage failure.

Hounsfield Units as an Independent Predictor of Failed Percutaneous Drainage of Spinal Tuberculosis Paraspinal Abscess Under Computed Tomography Guidance.

To investigate the value of Hounsfield units (HUs) as an independent predictor of failed percutaneous drainage of spinal tuberculosis paraspinal abscess under computed tomography (CT) guidance. A retrospective analysis was conducted on 61 patients who underwent CT-guided percutaneous drainage for spinal tuberculosis paraspinal abscess between October 2017 and October 2020. Preoperative CT scans were used to measure the HUs of the abscess. Patients were categorized into successful drainage (n = 49) and failed drainage (n = 12) groups. Statistical analysis involved independent sample t-tests and chi-square tests to compare between the 2 groups. Binary logistic regression was performed to identify independent predictive factors for drainage failure. Receiver operating characteristic (ROC) curves were employed to ascertain risk factor thresholds and diagnostic performance. Among the patients, 49 experienced successful drainage while 12 faced drainage failure. The mean HUs of abscesses in the failed drainage group were significantly higher than those in the successful drainage group (p < 0.001). ROC analysis revealed an area under the curve of 0.897 (95% confidence interval, 0.808-0.986) for predicting drainage failure based on HUs. The optimal HU cutoff value for predicting drainage failure was 22.3, with a sensitivity of 91.7% and specificity of 69.4%. HUs are an independent predictor of failed percutaneous drainage of spinal tuberculosis paraspinal abscess under CT guidance. The HU value of 22.3 can be used as an initial screening threshold for predicting the success or failure of drainage.

Experimental study on overtopping dam-break of a tailing reservoir under extreme conditions.

There is a high risk of dam breakage in tailing reservoirs under extreme conditions. Once a dam breaks, it causes serious pollution to the surrounding ecological environment. To explore the effects of a tailings dam break under extreme conditions (flood conditions, drainage failure, flood discharge failure, and dam saturation), the mechanism underlying an overtopping dam break must be accurately understood. In this study, fine-grained tailings and perlite were selected to create composite model sand, and a prototype tailing reservoir was restored at a scale of 1:200. Furthermore, the dam-break process and results were analyzed and summarized by performing an overtopping dam-break test on the tailing reservoir under extreme conditions. The results show that the tailing discharge process has a high sand content, strong sand-carrying capacity, and high speed. The amount of model sand discharge accounted for 15.13% of the total storage capacity, and the amount of tailings deposition in the downstream area accounted for 95.21% of the discharge, which were both greater than the results of similar physical model tests and actual tailings dam failure accidents. An overtopping dam break in a tailing pond is a progressively destructive process. The dam break mechanism can be divided into two stages: prior breach penetration and subsequent breach horizontal expansion. In the process of a tailings dam break, the motion state of the tailings particles is transformed between the bed-load and suspended-load movement states. These results can provide important reference for the reinforcement of mine management and the formulation of preventive measures, which are essential to improving the safety of tailings reservoirs and protecting the ecological environment.

Factors predicting technical failure of endoscopic transpapillary gallbladder drainage for acute cholecystitis.

Endoscopic transpapillary gallbladder drainage (ETGBD) is a highly technical procedure, but few studies have evaluated factors that predict its technical success. Therefore, in this study, we sought to identify predictors of technically successful ETGBD. One hundred and eighty-two patients who underwent ETGBD for acute cholecystitis at our hospital were retrospectively investigated. Factors associated with technical failure were identified by focusing on clinical characteristics, anatomical features (direction of the cystic duct branch and course of the cystic duct), and procedural factors (cystic duct and gallbladder with or without contrast and cystic duct injury). The technical success rate was 84.6% (154/182) and the clinical success rate was 96.1% (148/154). The adverse event rate was 11.0% (20/182; cystic duct injury in 13 patients, pancreatitis in six, and liver abscess in one. Univariate and multivariate analyses identified the right cranial direction and spiral-type course of the cystic duct to be significant anatomical features and cystic duct injury to be a significant procedural feature contributing to the technical failure of ETGBD. ETGBD is a highly practical procedure for patients with acute cholecystitis. However, difficulty is encountered in some cases because of anatomical and procedural factors. Our results suggest that ETGBD may be difficult and thus should not be performed in cases with the right cranial direction or spiral-type course of the cystic duct or those with cystic duct injury.

Complications of Cerebral Spinal Fluid Drainage in Thoracoabdominal Aortic Procedures

Spinal cord ischemia is a devastating complication of thoracoabdominal aortic procedures. Prophylactic cerebral spinal fluid (CSF) drainage has been shown to reduce the rates of postoperative neurologic deficit. Recent articles have cited a high rate of complications secondary to CSF drain placement, ranging from 7.6% to 9%, with the most worrisome being intracranial hemorrhage (ICH) and have concluded that the risks of drain use may outweigh the benefits. A single-center retrospective cohort study was conducted to investigate our rates of CSF drain-related complications. Patients were included if they underwent a thoracic or thoracoabdominal aortic procedure and had a CSF drain placed in the perioperative period. Patients with pre-existing neurologic deficits or who presented with aortic rupture were excluded. Major complications were defined as permanent paraplegia, ICH, epidural hematoma or abscess, meningitis, or catheter retention requiring a reoperation. Minor complications that were tracked included transient parasthesia, CSF leak, post-dural puncture headache, asymptomatic blood in the CSF, drain failure, and catheter retention not requiring a reoperation. There were 129 patients in the 15-year period who received a CSF drain for spinal cord protection (Table I). Of these, 122 patients (94.6%) had prophylactic CSF drains, 4 had drains placed postoperatively, and 3 patients had both preoperative and postoperative drains. The most common indication for surgery was thoracoabdominal aortic aneurysm (n = 57; 44.2%) (Table I), and the majority of cases were performed endovascularly (n = 72; 55.8%). There were five occurrences of permanent paraplegia for a rate of 3.9% (Table II). There were no cases of ICH nor other major complications due to spinal drain placement. The rate of minor complications was 26.4%, with the most common being transient parasthesia (n = 13; 10.1%) (Table II). No association was found between complication rates and either indication for procedure or type of operation. The rate of minor complications in this cohort is comparable to prior literature, but our major complication rates due to spinal drain insertion were found to be lower, with no incidence of ICH. The rate of permanent paraplegia in the cohort was 3.9%, which is similar to previous studies. The lack of spinal drain placement complications may be due to a well-defined spinal drain protocol at our center and the small group of dedicated anesthesiologists working with vascular surgery. Further research is required to determine which patients benefit most from prophylactic CSF drainage.Table IPatient characteristicsFull cohort (N = 129)Basic demographicsAge, mean (SD), years65.7 (12.3)Gender, No. (%) Male73 (56.6) Female56 (43.4)BMI, mean (SD)29.1 (6.4)Comorbidities, No. (%) Hypertension101 (78.3) Dyslipidemia60 (46.5) Coronary artery disease30 (23.3) COPD29 (22.4) Chronic kidney disease27 (20.9) Diabetes mellitus20 (15.5)Smoking history, No. (%) Current smoker44 (34.1) Prior smoker52 (40.3)Previous aortic operation, No. (%)64 (49.6)Aortic characteristics, No. (%) TAAA57 (44.2)Extent I25 (43.8)Extent II5 (8.8)Extent III16 (28.1)Extent IV11 (19.3)Mean size (SD), cm6.3 (1.2) Acute aortic syndrome, No. (%)40 (31.0)Acute dissection18 (45.0)PAU13 (32.5)IMH9 (22.5)Chronic dissection, No. (%)31 (24.0)Other indication, No. (%)1BMI, Body mass index; COPD, chronic obstructive pulmonary disease; IMH, intramural hematoma; PAU, penetrating aortic ulcer; SD, standard deviation; TAAA, thoracoabdominal aortic aneurysm. Open table in a new tab Table IIStudy outcomesFull cohort (n = 129)TAAA (n = 57)AAS (n = 40)Chronic dissection (n = 31)Major complications, No. (%)5 (3.9)0 (0)3 (7.5)2 (6.5) Permanent paraplegia5 (3.9)0 (0)3 (7.5)2 (6.5) Epidural hematoma0 (0)0 (0)0 (0)0 (0) Epidural abscess0 (0)0 (0)0 (0)0 (0) ICH0 (0)0 (0)0 (0)0 (0) Meningitis0 (0)0 (0)0 (0)0 (0) Catheter reoperation0 (0)0 (0)0 (0)0 (0)Minor complications, No. (%)34 (26.4)14 (24.6)12 (30.0)8 (25.8) Temporary parasthesia13 (10.1)7 (12.3)4 (10.0)2 (6.5) Asymptomatic bleed8 (6.2)1 (1.8)3 (7.5)4 (12.9) PDPH6 (4.7)3 (5.3)2 (5.0)1 (3.2) Drain failure5 (3.9)2 (3.5)2 (5.0)1 (3.2) CSF leak2 (1.6)1 (1.8)1 (2.5)0 (0) Catheter nonoperative0 (0)0 (0)0 (0)0 (0)AAS, Acute aortic syndrome; CSF, cerebrospinal fluid; ICH, intracranial hemorrhage; PDPH, post-dural puncture headache; TAAA, thoracoabdominal aortic aneurysm. Open table in a new tab

Postoperative management using a digital drainage system for massive air leakage after pulmonary resection.

To elucidate clinical outcomes using a digital drainage system (DDS) for massive air leakage (MAL) after pulmonary resection. A total of 135 consecutive patients with pulmonary resection air leakage of > 100ml/min on the DDS were evaluated retrospectively. In this study, MAL was defined as ≥ 1000ml/min on the DDS. We analyzed the clinical characteristics and surgical outcomes of patients with MAL compared with non-MAL (101-999ml/min). Using the DDS data, the duration of the air leak was plotted with the Kaplan‒Meier method and compared using the log-rank test. MAL was detected in 19 (14%) patients. The proportions of heavy smokers (P = 0.04) and patients with emphysematous lung (P = 0.03) and interstitial lung disease (P < 0.01) were higher in the MAL group than in the non-MAL group. The MAL group had a higher persistence rate of air leakage at 120h after surgery than the non-MAL group (P < 0.01) and required significantly more frequent pleurodesis (P < 0.01). Drainage failure occurred in 2 (11%) and 5 (4%) patients from the MAL and non-MAL groups, respectively. Neither reoperation nor 30-day surgical mortality was observed in patients with MAL. MAL was able to be treated conservatively without surgery using the DDS.

V-016 TAPP APPROACH FOR A GIANT INGUINOSCROTAL HERNIA

Abstract Aim We present the case of a patient with giant inguinoscrotal hernia and the laparoscopic approach performed. Material &amp; Methods 54yo Male, no medical history except for BMI41. He is evaluated in outpatient clinic for asymptomatic left inguinoscrotal hernia of ten years of evolution. He denies digestive symptoms. Difficulty in urination without symptoms of obstruction. On examination, 20×15cm left not reducible inguinoscrotal hernia extending to the mid-thigh. Minimally invasive approach, TransAbdominal PrePeritoneal, was performed. The content of the hernia is a long portion of sigma and a large amount of fat from the greater omentum. After returning them to the abdominal cavity with the help of pressure from the outside, the TAPP technique was performed without incident, with localization of elements of the spermatic cord. Polypropylene mesh 12×15cm fixed with tackers and cyanoacrylate is placed. Results the patient was discharged on the 4thPO day with no incidents. Subsequently he developed a large seroma that required percutaneous drainage and heart failure that caused large scrotal edema, resolved with diuretic treatment. Ten months later there is no recurrence. Conclusions Giant inguinoscrotal hernia is a surgical challenge. Anterior or posterior approach, open or minimally invasive, can be performed. Sometimes intestinal resection and/or orchiectomy is required. The need for preoperative conditioning with botulinum toxin and even pneumoperitoneum can be considered. We presume that, when possible, the minimally invasive posterior approach is the best technique for these large defects since it provides the best surgical field in the most resistant plane for inguinal hernia repair.

Therapeutic Lymphangiogenesis Is a Promising Strategy for Secondary Lymphedema.

Secondary lymphedema is caused by lymphatic insufficiency (lymphatic drainage failure) following lymph node dissection during the surgical treatment or radiation therapy of breast or pelvic cancer. The clinical problems associated with lymphedema are reduced quality of life in terms of appearance and function, as well as the development of skin ulcers, recurrent pain, and infection. Currently, countermeasures against lymphedema are mainly physical therapy such as lymphatic massage, elastic stockings, and skin care, and there is no effective and fundamental treatment with a highly recommended grade. Therefore, there is a need for the development of a fundamental novel treatment for intractable lymphedema. Therapeutic lymphangiogenesis, which has been attracting attention in recent years, is a treatment concept that reconstructs the fragmented lymphatic network to recover lymphatic vessel function and is revolutionary to be a fundamental cure. This review focuses on the translational research of therapeutic lymphangiogenesis for lymphedema and outlines the current status and prospects in the development of therapeutic applications.

Urban Drainage: The Challenges and Failure Assessment Using AHP, Addis Ababa, Ethiopia

Urban drainage infrastructures are facing critical challenges due to a lack of integrated asset management, periodic maintenance, improper design, and construction methodologies. The objective of this study is to understand the urban drainage challenges and assess the failure causes and their impacts to recommend possible mitigation measures. Drainage failure causes and impacts are analyzed using the analytical hierarchy process (AHP) qualitative multicriteria decision model after conducting technical group discussions, interviews, and technical field surveys. The assessment was performed by taking representative samples from both cross- and longitudinal drainage infrastructures. The AHP analysis results showed that approximately 35.5% and 28.6% of failure causes are debris and various solid wastes for cross- and longitudinal drainage structures with correlation coefficients of 0.93 and 0.95, respectively. The result showed that design and construction defects are the second major failure causes. The research results showed that urbanization has a direct relationship with major drainage failure causes, resulting from man-made debris and solid waste clogging. On the other hand, drainage failure caused by siltation, drifts, and vegetation is higher in newly developing semi-urban and agricultural areas. The number of barrels in cross-drainage structures also contribute significantly to cross-drainage failure by creating a flow barrier due to the intermediate columns. The drainage failure impact assessment result showed that both cross- and longitudinal drainage failures primarily impact road pavement following transport disruption and traffic accidents, accounting for 38.5%, 18%, and 16%, respectively. Our research recommended that the mitigation measures for drainage failure are proper asset management and maintenance, appropriate construction supervision, and awareness creation, with weights of 36.3%, 15.5%, and 15.3%, respectively. As a drainage problem mitigation measure, the longitudinal drainage analysis results showed that the provision of a combination of cross-fall slopes, gutter slopes, and local depressions at the inlets can contribute to an increase in the trapping efficiency of the drainage system by 50%, which can reduce surface flooding substantially.

Abstract No. 56 Comparing Outcomes of Percutaneous Biliary Drainage Catheters in Right versus Left Hepatic Approaches

Determine if there is a difference in complications associated with right or left hepatic percutaneous biliary drain placement in patients with benign or malignant biliary etiology. This retrospective study included patients with benign or malignant biliary stricture and treated with percutaneous biliary drainage at a single institution from 7/28/2004 to 3/30/2021. Three hundred fifty-seven patients met inclusion criteria, seventy-seven on the left and two hundred and eighty on the right, with a mean age of 65.1 years. Complications associated with the initial drain placement or during subsequent intervention were collected and categorized. Perioperative complications included surgery, infection, hemorrhage, and drain failure. Complications during treatment with a percutaneous biliary drain included death, chills, catheter displacement, cholangitis, biliary stones, drain malfunction, fever resolving without treatment, and pericatheter leakage. Complications were also grouped as major or minor. Statistical analyses were performed using logistic regression analysis and P values less than 0.05 were considered significant. Major interventional and treatment complication rates showed no statistical significance between left and right drains. The rate of minor interventional and treatment complications also showed no statistical significance between right and left drains. However, when cholangitis was analyzed individually, right sided hepatobiliary drains demonstrated a statistically significant increase in complication rates. Current literature describes safety of right biliary drain placement when compared with left, despite current equivocal study analyses. This large group analysis describes no statistically significant difference in complications between right and left hepatobiliary drains aside from slightly higher incidence of cholangitis for right sided drains.

Is Cystogastrostomy a Definitive Operation for Pancreatitis Associated Pancreatic Fluid Collections?

Pancreatic-enteric drainage procedures have become standard therapy for symptomatic pancreatic pseudocysts and walled-off pancreatic necrosis. The need for pancreatic resection after cyst-enteric drainage procedure in the event of recurrence is not well studied. This study aimed to quantify the percentage of patients requiring resection due to recurrence after surgical cystogastrostomy and identify predictors of drainage failure. A single-institution retrospective review was conducted to identify all patients undergoing surgical cystogastrostomy between 2012 and 2020. Demographic, disease, and treatment characteristics were identified. Failure of surgical drainage was defined as the need for subsequent pancreatic resection due to recurrence. Characteristics between failure and nonfailure groups were compared with identifying predictors of treatment failure. Twenty-four cystogastrostomies were performed during the study period. Three patients (12.5%) required a subsequent distal pancreatectomy after surgical drainage. There was no difference in comorbidities between drainage alone and failure of drainage groups. Mean cyst size seemed to be larger in patients that underwent drainage alone versus those that needed subsequent resection (15.2 vs 10.3cm, P =0.05). Estimated blood loss at initial operation was similar between groups (126 vs 166mL, P =0.36). Surgical pancreatic drainage was successful in the initial management of pancreatic fluid collections. We did not identify any predictors of failure of initial drainage. There was a trend suggesting smaller cyst size may be associated with cystgastrostomy failure. Resection with distal pancreatectomy for walled-off pancreatic necrosis and pancreatic pseudocysts can be reserved for cases of failure of drainage.

Risk factors for failure of tandem ureteral stents drainage for malignant ureteral obstruction

Risk factors for failure of tandem ureteral stents drainage for malignant ureteral obstruction

Predictive and prognostic factors associated with unliquefied pyogenic liver abscesses.

Poor liquefaction of pyogenic liver abscesses, which makes drainage impossible at the time of diagnosis, is not infrequent. The impact of poor liquefaction and subsequent drainage failure on clinical outcomes is unknown. We conducted a retrospective study with all patients diagnosed with liver abscesses from July 2017 through June 2020. Late drainage (LD) was defined as drainage performed ≥48h after diagnosis due to poor liquefaction. Logistic regression was performed to identify the factors associated with late or non-drainage (LD/ND). The Cox proportional hazard model was used to identify the variables related to abscess recurrence by 90 days after diagnosis. A total of 153 patients were included. Thirty (19.6%) patients underwent LD and 54 (35.3%) did not undergo drainage. Other than non-cystic appearance, LD/ND was associated with smaller size (adjusted odds ratio [aOR] 0.85, 95% confidence interval [CI] 0.73-0.98, p=0.031) and culture-negativity (aOR 2.69, 95% CI 1.14-6.67, p=0.027). Current hepatopancreaticobiliary malignancy was the only significant predictor of 90-day recurrence. Neither LD/ND (OR, 0.56; 95% CI, 0.13-2.41; p=0.426) nor LD (OR, 1.26; 95% CI, 0.23-5.55; p=0.719) was associated with recurrence by 90 days. The incidence of late complications was reduced by drainage, without a reduction in the duration of hospitalization. Several clinical features were associated with undrainable liver abscesses. Neither LD/ND nor ND had an adverse impact on clinical outcomes.

Characterization of the Liquid–Lubricant Interface in a Dovetail Cavity for a Viscous Laminar Flow

Lubricant-infused surfaces (LISs) have application in diverse fields based on their liquid-repellent properties. In bulk flow, LISs, however, are susceptible to drainage failure caused by external shear imposed at the liquid–lubricant interface. In this study, the shear-flow-induced lubricant depletion in a dovetail-shaped cavity microchannel has been numerically examined. Lubricant is exposed to five external liquids with different viscosities (μr = 0.2–1) in the laminar range (100 ≤ Re ≤ 1000). Temporal variations in the lubricant depletion from the microchannel and cavities were observed with time. Meniscus shapes were characterized for flows at different viscosity ratios. The results show that when the lubricant is kept fixed, a less viscous external liquid aids in better lubricant retention. Due to the shear imparted, three stable and two failure meniscus shapes have been distinguished. The results are further supported by vortex formation within the cavity and interface velocities contributing to meniscus shapes based on the magnitude of external shear. Additionally, it was evident that, as the viscosity ratio was reduced, the effect of the cavity opening was no longer dependent on the flow rate. It was envisaged that the results will help in the design of a robust LIS system.

Predicting the Success of Catheter Drainage in Infected Necrotising Pancreatitis: A Cross-Sectional Observational Study.

Background Management of acute necrotising pancreatitis is often challenging for clinicians. Secondary infection of the necrotic collections leads to sepsis and warrants intervention. Minimally invasive techniques like catheter drainage have recently been proposed over more risky and morbid traditional open procedures. Factors that can predict successful catheter drainage of the necrotic pancreatic collection are still unclear and not well established. Materials and methods This study is designed as a retrospective cross-sectional observational study to investigate the association of 21 factors in predicting successful catheter drainage. Data from 30 patients admitted with acute necrotising pancreatitis treated with catheter drainage were collected and analysed. Twenty-one factors, including demographic variables, disease severity factors, drainage criteria, and morphological criteria on imaging, were studied for their predictive association with successful outcomes. Univariate analysis was done for each variable against the outcome. The study was conducted between December 2012 to March 2017. P-value <0.05 was considered statistically significant. Results Patients with no organ involvement responded better to primary catheter drainage. Patients with BMI>25 and multi-organ failure were poor candidates for primary catheter drainage. Clinically unwell patients with a Bedside Index for Severity in Acute Pancreatitis (BISAP) score of ≥4 had a negative outcome on catheter drainage and usually ended up in a surgical procedure or eventually succumbed to the disease. Other variables included in our study did not statistically associate with the success or failure of percutaneous catheter drainage. Conclusion BMI >25, multiple organ failure, and BISAP score ≥ 4 are independent negative predictors for the success of catheter drainage in infected necrotising pancreatitis. No organ failure showed a positive predictor for successful catheter drainage. Further studies are required to explore these predictive factors in a larger sample size to predict the success of catheter drainage in infected pancreatic necrosis.

Investigation on Drained Mechanical Properties of Sandy Soil after Internal Erosion with an Erosion-Stress Coupling Apparatus

Internal erosion is one of the important causes of soil damage. In this paper, an erosion-stress coupling apparatus was developed to investigate the mechanical property of soil after internal erosion. Main efforts were devoted to rebuilding pressure cell so that soils can be eroded under confining pressure and deviator pressure. The hydraulic gradient is controlled by using the water-head control method which can provide up to 40 m water-head. The volume change of the sample can also be accurately measured by the volume controller. The eroded particles were collected by the eroded soil collection system. Triaxial consolidation drained shear tests after internal erosion were performed on gap graded soils. It was found that the drainage failure strength and drainage internal friction angle of soil after internal erosion under confining pressure decreased with the increase of fine particle loss. Based on the experimental data, amodified Duncan-Chang model considering fine particle loss was introduced. Numerical modelling of vertical displacement of dam was carried out by using the modified Duncan-Chang model, and it was found that when the fine particle loss exceeds 10%, the displacement increases significantly.

Efficacy and safety of endoscopic ultrasound guided drainage of pseudocysts and walled-off necrosis after failure of percutaneous drainage.

Endoscopic Ultrasound (EUS) represents the gold standard for initial drainage of pancreatic fluid collections (PFC) due to various etiologies. However, data concerning salvage EUS drainage after initial percutaneous drainage are limited. The purpose of our study was to evaluate the clinical outcomes and safety of EUS-guided drainage of pancreatic collections after failure of percutaneous drainage. This retrospective study was conducted in a single, tertiary university center from August 2013 to January 2020. Indication was pancreatic collection after acute pancreatitis with PFC requiring EUS-guided drainage after failure of percutaneous drainage. Twenty-two patients with PFC after acute pancreatitis were included (mean age 64.1 ± 11.3years) of which 4/22 (18.2%) had pancreatic pseudocyst and 18/22 (81.8%) presented with a walled-off necrosis. Seventy-six interventions were performed among the 22 patients. Lumen-Apposing Metal Stent (LAMS) were used in 5/22 (22.7%) and double pigtail plastic stents in 17/22 (77.3%) of interventions with a median number intervention of 3 per patient (range 1 to 7). Technical success rate was 98.7% (75/76) with an overall clinical success of 81.8% (18/22). Procedure related adverse events rate was 9.1% (2/22) including one bleeding and one pancreatic fistula. Two non-procedure related deaths were observed. EUS-guided pancreatic collection drainage is clinically effective and safe after clinical/technical failure of radiological percutaneous management.