Continuous Drainage Research Articles

Clinical Safety and Efficiency of the H-Port for Treatment of Leptomeningeal Metastasis.

To evaluate the usefulness of a cranial implantable chemoport, the H-port, as an alternative to the Ommaya reservoir for intraventricular chemotherapy/cerebrospinal fluid (CSF) access in patients with leptomeningeal metastasis (LM). One hundred fifty-two consecutive patients with a diagnosis of LM and who underwent H-port installation between 2015 and 2021 were evaluated. Adverse events associated with installation and intraventricular chemotherapy, and the rate of increased intracranial pressure (ICP) control via the port were evaluated for safety and efficacy. These indices were compared with published data of Ommaya (n=89), from our institution. Time-to-install and installation-related complications of intracranial hemorrhage (n=2) and catheter malposition (n=5) were not significantly different between the two groups. Intraventricular chemotherapy-related complications of CSF leakage occurred more frequently in the Ommaya than in the H-port group (13/89 vs. 3/152, respectively, p<0.001). Intracranial hemorrhage during chemotherapy occurred only in the Ommaya group (n=4). The CSF infection rate was not statistically different between groups (14/152 vs. 12/89, respectively). The ICP control rate according to reservoir type revealed a significantly higher ICP control rate with the H-port (40/67), compared with the Ommaya result (12/58, p<0.001). Analyzing the ICP control rate based on the CSF drainage method, continuous extraventricular drainage (implemented only with the H-port), found a significantly higher ICP control rate than with intermittent CSF drainage (33/40 vs. 6/56, respectively, p<0.0001). The H-port for intraventricular chemotherapy in patients with LM was superior for ICP control; it had equal or lower complication rates than the Ommaya reservoir.

Preventive effect of intermittent cerebrospinal fluid drainage for secondary chronic hydrocephalus after aneurysmal subarachnoid hemorrhage

BackgroundThe efficacy of intermittent cerebrospinal fluid (CSF) drainage compared with that of continuous CSF drainage in patients with subarachnoid hemorrhage (SAH) remains undetermined to date. Therefore, we investigated whether intermittent CSF drainage is effective in reducing secondary chronic hydrocephalus (sCH) after aneurysmal SAH.MethodsOverall, 204 patients (69 men and 135 women) treated for aneurysmal SAH between 2007 and 2022 were included in this study. Following SAH onset, 136 patients were managed with continuous CSF drainage, whereas 68 were managed with intermittent CSF drainage. Logistic regression analyses were used to calculate the age-adjusted and multivariate odds ratios for the development of sCH. The Cox proportional hazards regression model were used to compare the effects of intermittent and continuous CSF drainage on sCH development.ResultsOverall, 96 patients developed sCH among the 204 patients with SAH. In total, 74 (54.4%) of the 136 patients managed with continuous CSF drainage developed sCH, whereas 22 (32.4%) of the 68 patients managed with intermittent CSF drainage developed sCH. This demonstrated that the rate of sCH development was significantly lower among patients managed with intermittent CSF drainage. Compared with continuous CSF drainage, intermittent CSF drainage exhibited a multivariate odds ratio (95% confidential interval) of 0.25 (0.11–0.57) for sCH development. Intermittent CSF drainage was more effective (0.20, 0.04–0.95) in patients with severe-grade SAH than in those with mild-grade SAH (0.33, 0.12–0.95). Intermittent CSF drainage was ineffective in patients with acute hydrocephalus (8.37, 0.56–125.2), but it was effective in patients without acute hydrocephalus (0.11, 0.04–0.31).ConclusionsCompared with continuous CSF drainage, intermittent drainage is more effective in reducing sCH after aneurysmal SAH. Although intermittent drainage was ineffective in cases of co-occurrence of acute hydrocephalus, it was effective in reducing sCH development regardless of the severity of initial symptoms at SAH onset.

Chest wall reconstruction after the Clagett procedure and other types of open-window thoracostomy: a narrative review.

The Clagett procedure is one of the last treatment options for chronic stage pleural empyema. It involves the formation of an open-window in the thoracic wall to allow for continuous drainage and irrigation of the pleural cavity. Once the empyema has been resolved, reconstruction of the chest wall is sometimes challenging. This review aims to identify and summarize the options for reconstructing soft tissue defects of the chest wall following the Clagett procedure and other types of open-window thoracostomy. A narrative review was performed of the literature on PubMed, Cochrane Library, ClinicalTrials.gov, and Google Scholar, including all relevant studies published until January 2023. This review contains an overview of the reconstruction methods and the outcomes of the included studies on reconstructive options after the Clagett procedure and other types of open-window thoracostomy. A subdivision was made based on reconstruction type: pedicled flaps, free flaps, and the use of a vacuum-assisted closure (VAC) device. The advantages of pedicled flaps are reliable vascularization, better tissue match, reduced scarring, and shorter operation time compared to free flaps. However, when pedicled flaps are not available due to damage during previous surgeries or offer insufficient volume to obliterate the cavity, free flaps might be a solution. In cases where an open-window thoracostomy necessitates chest wall reconstruction, a pedicled flap is the preferred choice, followed by free flaps. Additionally, vacuum-assisted negative pressure wound therapy (VANPWT) techniques have shown potentially promising results (as an adjunct to surgical treatment).

Formation of a Long Filament Through the Connection of Two Filament Segments Observed by CHASE

We present imaging and spectroscopic diagnostics of a long filament during its formation with the observations from the Chinese Hα Solar Explorer and Solar Dynamics Observatory. The seed filament first appeared at about 05:00 UT on 2022 September 13. Afterward, it grew gradually and connected to another filament segment nearby, building up a long filament at about 20:00 UT on the same day. The CHASE Hα spectra show an obvious centroid absorption with mild broadening at the main spine of the long filament, which is interpreted as evidence of filament material accumulation. More interestingly, near the footpoints of the filament, persistent redshifts have been detected in the Hα spectra during the filament formation, indicating continuous drainage of filament materials. Furthermore, through inspecting the extreme-ultraviolet (EUV) images and magnetograms, it was found that EUV jets and brightenings appeared repeatedly at the junction of the two filament segments, where opposite magnetic polarities converged and canceled each other continuously. These results suggest the occurrence of intermittent magnetic reconnection that not only connects magnetic structures of the two filament segments but also supplies cold materials for the filament channel likely by the condensation of injected hot plasma, even though a part of the cold materials falls down to the filament footpoints at the same time.

Continuous wound irrigation and drainage for treating large contained duodenal perforation after EMR

Continuous wound irrigation and drainage for treating large contained duodenal perforation after EMR

Comparison of clinical and microbiological characteristics of community-acquired hypervirulent Klebsiella pneumoniae liver abscess in diabetic and non-diabetic patients.

Invasive infection caused by hypervirulent Klebsiella pneumoniae (HvKP) has been reported worldwide. Most of the patients are community population, related to diabetes mellitus (DM), chronic liver disease and other basic diseases, which prone to systemic migratory infection. In this study, we collected 377 patients with community acquired Klebsiella pneumoniae liver abscess in our hospital from January 2013 to December 2018, 65.8% of whom were male, and 49.6% had DM. Patients with DM are prone to eye and central nervous system (CNS) infection, which need continuous local abscess drainage during treatment. Among them, patients with poor blood glucose control have a higher rate of blood stream infections (BSI). 219 strains of HvKP were obtained, with K1/K2 Serotype accounted for 81.7%. The incidence of BSI in K2 patients was higher than that in K1 patients. The PCR results indicate that the carrying rate of virulence genes (rmpA、areo、kfu、allS、iroN、magA、uge、wcaG) in K1/K2 type strains is significantly higher than that in non K1/K2 type strains. ST23 and ST65 are the most common multilocus sequence typing (MLST), which belong to K1 and K2 Serotype respectively. All of HvKP strains showed high sensitivity to commonly used clinical antibiotics other than ampicillin, with 54.3% of the strains exhibiting high viscosity characteristics. Meanwhile, 35 classic Klebsiella pneumoniae (cKP) strains were collected, and their serum typing is mainly non K1/K2. The carrying rate of virulence genes and viscosity degree in HvKP are significantly higher than those in cKP. Primary liver abscess caused by HvKP is prone to multiple tissue and organ infections, but it shows higher sensitivity to most commonly used antibiotics in clinical practice except for ampicillin. After effective treatment, the overall prognosis of patients is better. This study analyzes the pathogenic characteristics of HvKP and elaborates on the clinical characteristics of patients, which can provide reference for clinical and scientific research work.

The Role of Cisternostomy and Cisternal Drainage in the Treatment of Aneurysmal Subarachnoid Hemorrhage: A Comprehensive Review.

Aneurysmal subarachnoid hemorrhage (aSAH) provokes a cascade reaction that is responsible for early and delayed brain injuries mediated by intracranial hypertension, hydrocephalus, cerebral vasospasm (CV), and delayed cerebral ischemia (DCI), which result in increased morbidity and mortality. During open microsurgical repair, cisternal access is achieved essentially to gain proximal vascular control and aneurysm exposition. Cisternostomy also allows brain relaxation, removal of cisternal clots, and restoration of the CSF dynamics through the communication between the anterior and posterior circulation cisterns and the ventricular system, with the opening of the Membrane of Liliequist and lamina terminalis, respectively. Continuous postoperative CSF drainage through a cisternal drain (CD) is a valuable option for treating acute hydrocephalus and intracranial hypertension. Moreover, it efficiently removes the blood and toxic degradation products, with a potential benefit on CV, DCI, and shunt-dependent hydrocephalus. Finally, the CD is an effective pathway to administer vasoactive, fibrinolytic, and anti-oxidant agents and shows promising results in decreasing CV and DCI rates while minimizing systemic effects. We performed a comprehensive review to establish the adjuvant role of cisternostomy and CD performed in cases of direct surgical repair for ruptured intracranial aneurysms and their role in the prevention and treatment of aSAH complications.

미세혈관 감압술에서의 뇌척수액 유출 예방을 위한 경막의 네 겹중첩 봉합

Background: Cerebrospinal fluid (CSF) leakage is one of major complication following cranial surgery. Many studies have been introducing surgical methods to prevent CSF leakage. Technique applying dural substitutes are being studied for its efficacy for preventing CSF leakage. We introduce four layer onlay stacking repair (FLOSR), effective dural closing technique for preventing CSF leak-age, while avoiding application of foreign material intradural space.&#x0D; Materials and Methods: Retrospective analysis of patients undergone microvascular decompres-sion (MVD) surgery for hemifacial spasm (HFS) and trigeminal neuralgia (TN) by a single surgeon in single center between September 2020 and September 2022 was done. MVD was done by retro-mastoid suboccipital approach. Number of patients who had CSF leakage, symptoms occurred by CSF leakage and treatment done for the patients were collected.&#x0D; Results: In this study, 355 patients underwent MVD for HFS and TN and 4 were excluded. Three patients of selected 351 patients who underwent MVD for HFS were suspected for CSF leakage which counts for approximately 0.9% of patients. All patients suspected for CSF leakage underwent MVD for HFS (3 of 3, 100%). Continuous lumbar drainage of 180-240 cc per day for 5 days was done and every patient had symptom improvement.&#x0D; Conclusions: FLOSR provided an effective method intra-operatively in preventing and lowering risk of severe CSF leakage after craniotomy by RMSOC (retromastoid suboccipital craniotomy) ap-proach without the risk of placing foreign materials inside dura.

The effect of unilateral chest drainage for transpulmonary pressure during mechanical ventilation

IntroductionChest tube drainage is usually performed through an underwater seal at a level of 10–20 cmH2O. Based on the definition of transpulmonary pressure, continuous chest drainage creates continuous negative pressure, decreasing pleural surface pressure and increasing transpulmonary pressure. We investigated how unilateral chest drainage could affect the tidal volume or driving pressure during mandatory mechanical ventilation.MethodsThis study was an experimental study using a lung-thoracic model and anesthesia ventilator. Tidal volume was set to 300 mL with pressure-controlled ventilation or volume-controlled ventilation. Left tidal volume and right tidal volume were measured independently using respirometers with positive end-expiratory pressure (PEEP) levels of 0, 10, and 20 cmH2O. Simultaneously, left negative pressure of the chest drainage was changed to 0, 10, and 20 cmH2O.ResultsIn all conditions, a tidal volume of 300 mL was achieved. In both pressure-controlled ventilation and volume-controlled ventilation, the left tidal volume increased with the application of chest drainage at 10 cmH2O when the PEEP level was 0 cmH2O, but left tidal volume decreased with the application of chest drainage at 20 cmH2O. Furthermore, when PEEP was 10 cmH2O, the left tidal volume decreased in proportion to the pressure of thoracic drainage. The right tidal volumes changed inversely with their counterpart left tidal volumes.ConclusionUnilateral chest drainage caused unbalanced ventilation of the left and right lungs regardless of pressure-controlled ventilation or volume-controlled ventilation.

RETRACTED: Dewi et al. Efficacy of Intermittent and Continuous Subglottic Secretion Drainage in Preventing the Risk of Ventilator-Associated Pneumonia: A Meta-Analysis of Randomized Control Trials. Medicina 2023, 59, 283.

The journal retracts the article entitled "Efficacy of Intermittent and Continuous Subglottic Secretion Drainage in Preventing the Risk of Ventilator-Associated Pneumonia: A Meta-Analysis of Randomized Control Trials" [...].

A One-Dimensional Nonlinear Consolidation Analysis of Double-Layered Soil with Continuous Drainage Boundary

Based on the soil nonlinearity assumptions proposed by Mesri, the one-dimensional nonlinear consolidation of double-layered soil is investigated. To better align with engineering reality, a continuous drainage boundary is introduced, bolstering the reliability of the derived solution through comparison against existing findings. Subsequently, the consolidation behavior of double-layered soil is analyzed for the soil permeability, compressibility, nonlinear parameters, and interface parameters. The outcomes elicit a positive correlation between the consolidation rate of the double-layered soil and both the ratio of permeability coefficient from the lower to upper soil layers and the value of the interface parameter. Furthermore, it is observed that a lower compressibility coefficient ratio between the lower and upper soil layers, along with a reduced ratio of compression index to penetration index, both contribute to an increased consolidation rate within the context of double-layered soil. The one-dimensional nonlinear consolidation of double-layered soil is intricate, intertwined with the relative permeability and compressibility of soil layers, and the influence of nonlinear parameters and drainage boundary configuration. Integrating these factors is crucial for analyzing the consolidation traits of double-layered soil, leading to a more precise portrayal of the consolidation behavior of coastal soft soils.

Mobility in Post-Surgical Knee Arthroplasty with Compression Bandage VS Drainage

Introduction: Post-surgical management of total knee arthroplasty (TKA) includes compressive bandaging or continuous suction drainage. The arches of mobility are evaluated through some validated scales such as the Knee Society Score (KSS) questionnaire, the recovery of these is still uncertain between one management and another for not finding statistically significant differences or presenting a small sample in studies already carried out. Objective: To compare the mobility arches of patients with compressive bandage vs. continuous suction drainage undergoing TKA. Methods: Prospective, longitudinal, comparative, analytical study; patients &gt;55 years old undergoing TKA were included. They were grouped according to compressive bandage or continuous suction drainage and the arches of mobility before and after surgery were compared. Results: 68 patients were registered, 41 (60.2 %) women and 27 (39.8 %) men with a mean age of 66.5 ± 8.3 years. Compressive bandage was applied to 34 patients and continuous suction drainage to the rest. Post-surgery the final score of the questionnaire was 82.76± 8.30 for the compressive bandage group vs. continuous suction drainage 72± 12.80 (p= &lt;0.001), which translates better evolution in bandage group. Conclusions: The data of the present study suggest that compressive bandaging as a post TKA may result in better patient functionality according to mobility arcs being necessary other studies for validation.

Invasive lobular carcinoma of the breast with colonic metastasis: a case series of three patients

BackgroundAlthough metastatic spread of breast cancer to the gastrointestinal tract is very rare, it is more likely to occur in invasive lobular carcinoma (ILC) than in ductal carcinoma. Colonic metastasis is particularly rare, and the treatment strategies for these cases are not clearly defined. Herein, we report three cases of ILC with various abdominal symptoms associated with colonic metastasis.Case presentationCase 1 A 70-year-old female patient with vomiting and melena was referred to our hospital. Endoscopic examination revealed a Dieulafoy ulcer in the rectum and an elevated lesion in the descending colon. She also had two breast nodules, and was diagnosed as ILC with colonic metastasis. Considering her general condition, the best supportive care (BSC) was offered. The patient died 4 months after confirmation of the diagnosis. Case 2 An 80-year-old female patient presented with diarrhea and vomiting. She was diagnosed with ILC with colonic metastasis, and a coloscopy revealed stenosis of the transverse colon with a metastatic lesion. Ileosigmoid bypass surgery was performed for intestinal obstruction, and systemic treatment for breast cancer was initiated. The patient developed peritoneal carcinomatosis and died 1 year and 2 months after surgery. Case 3 A 56-year-old female patient underwent left total mastectomy for ILC, and laparoscopic transverse colectomy was conducted for a colonic lesion 9 years and 2 months after. The diagnosis as colonic metastasis was not confirmed at that time. Two years and 2 months later, torose lesions were detected in the hepatic flexural and descending colon, and histopathological findings indicated that all colon tumors, including the previously resected tumor, were metastatic spread of ILC. Systemic treatment was continued, but the transverse colonic lesion penetrated the abdominal wall, and an abscess formed 2 years and 11 months after the resection. The fistula improved by continuous suction drainage following ileostomy but recurred, and the patient died 3 years and 8 months after colectomy.ConclusionsColonic metastases from breast cancer can trigger various abdominal symptoms, and the prognosis in these cases is generally poor. In selected cases, surgical treatment for abdominal symptoms and subsequent systemic therapy can contribute to a prolonged prognosis.

A sandwich-like silk fibroin/polysaccharide composite dressing with continual biofluid draining for wound exudate management

Optimal wound healing requires a wet microenvironment without over-hydration. Inspired by capillarity and transpiration, we have developed a sandwich-like fibers/sponge dressing with continuous exudate drainage to maintain appropriate wound moisture. This dressing is prepared by integrating a three-layer structure using the freeze-drying method. Layer I, as the side that contacts with the skin directly, consists of a hydrophobic silk fibroin membrane; Layer II, providing the pumping action, is made of superabsorbent chitosan-konjac glucomannan sponge; Layer III, accelerating evaporation sixfold compared to natural evaporation, is constructed with a graphene oxide soaked hydrophilic cellulose acetate membrane. Animal experiments showed that the composite dressing had superior wound-healing characteristics, with wounds decreasing to 24.8% of their original size compared to 28.5% for the commercial dressing and 43.2% for the control. The enhanced wound healing can be ascribed to the hierarchical porous structure serves as the fluid-driving factor in this effort; the hydrophilicity of a membrane composed of silk fibroin nanofibers is adjustable to regulate fluid-transporting capacity; and the photothermal effect of graphene oxide guarantees exudates that have migrated to the top layer to evaporate continuously. These findings indicate the unidirectional wicking dressing has the potential to become the next generation of clinical dressings.

Safety of endoscopic ultrasound-guided hepaticogastrostomy in patients with malignant biliary obstruction and ascites.

Endoscopic ultrasound (EUS)-guided hepaticogastrostomy (EUS-HGS) is useful for patients with biliary cannulation failure or inaccessible papillae. However, it can lead to serious complications such as bile peritonitis in patients with ascites; therefore, development of a safe method to perform EUS-HGS is important. Herein, we evaluated the safety of EUS-HGS with continuous ascitic fluid drainage in patients with ascites. Patients with moderate or severe ascites who underwent continuous ascites drainage, which was initiated before EUS-HGS and terminated after the procedure at our institution between April 2015 and December 2022, were included in the study. We evaluated the technical and clinical success rates, EUS-HGS-related complications, and feasibility of re-intervention. Ten patients underwent continuous ascites drainage, which was initiated before EUS-HGS and terminated after completion of the procedure. Median duration of ascites drainage before and after EUS-HGS was 2 and 4 days, respectively. Technical success with EUS-HGS was achieved in all 10 patients (100%). Clinical success with EUS-HGS was achieved in 9 of the 10 patients (90 %). No endoscopic complications such as bile peritonitis were observed. In patients with ascites, continuous ascites drainage, which is initiated before EUS-HGS and terminated after completion of the procedure, may prevent complications and allow safe performance of EUS-HGS.

Application Effect of Continuous Lumbar Cistern Fluid Drainage Combined With Decompressive Craniectomy in the Treatment of Severe Craniocerebral Injury

To analyze the application effect of continuous lumbar cistern fluid drainage combined with decompressive craniectomy in the treatment of severe craniocerebral injury. A total of 87 patients with severe craniocerebral injury admitted to our hospital between March 2016 and March 2021 were retrospectively enrolled. They were divided into two groups according to the decompression methods applied, with 42 patients who received standard decompressive craniectomy assigned to the control group and 45 patients who received continuous lumbar cistern fluid drainage combined with standard decompressive craniectomy assigned to the observation group. The primary indicators that were monitored and compared between the two group included the amount of time for patient CT imaging to be clear of subarachnoid hemorrhage, the length-of-stay, the duration of post-operative intubation, the mannitol dose, scores for Glasgow Coma Scale (GCS), prognosis, the incidence of cerebral edema and cerebral infarction, and complications. The secondary indicators that were monitored and compared included intracranial pressure, cerebrospinal fluid antinucleosome protein SP100, and red blood cell count of the two groups before treatment and after continuous drainage for 7 days. The amount of time for CT imaging to be clear of subarachnoid hemorrhage and the length-of-stay of the observation group were shorter than those of the control group, the mannitol dose of the observation group was lower than that of the control group, the incidence of cerebral edema and the incidence of complications of the observation group were lower than those of the control group, and the rate of patients with good prognosis in the observation group was higher than that in the control group ( P<0.05). There was no significant difference in the rate of poor prognosis or mortality between the two groups ( P>0.05). The duration of postoperative intubation of the observation group was (8.24±1.09) d, while that of the control group was (9.22±1.26) d, and the difference between the two groups was statistically significant ( t=3.887, P<0.05). There were 2 cases (4.44%) of cerebral infarction in the observation group, with the infarct volume being (8.36±1.87) cm 3, while there were 9 cases (21.43%) of cerebral infarction in the control group, with the infarct volume being (8.36±1.87) cm 3, and there were statistically significant differences in the incidence and volume of cerebral infarction between the two groups ( χ 2=5.674, t=9.609, P<0.05). After treatment, the intracranial pressure and red blood cell count decreased in both groups and the intracranial pressure, cerebrospinal fluid SP100, and red blood cell count of the observation group were significantly lower than those of the control group ( P<0.05). The cerebrospinal fluid SP100 of the observation group decreased after treatment in comparison with the level before treatment ( P<0.05), while the pre- and post-treatment levels of the control group did not demonstrate any significant difference. Continuous lumbar cistern fluid drainage in patients with severe craniocerebral injury effectively shortens the time required for the body to recover, significantly reduces the level of intracranial pressure, improves the levels of cerebral edema and cerebral infarction, and has a high degree of safety for prognosis and recovery.

Cough-induced chylothorax in a two-year-old boy – case report and review of the literature

BackgroundChylothorax is a very rare form of pleural effusion in children, especially after the neonatal period, and predominantly occurs secondary to cardiothoracic surgery. It can lead to significant respiratory distress, immunodeficiency, and malnutrition. Effective treatment strategies are therefore required to reduce morbidity.Case presentationA previously healthy two-year old boy was admitted with history of heavy coughing followed by progressive dyspnea. The chest X-ray showed an extensive opacification of the right lung. Ultrasound studies revealed a large pleural effusion of the right hemithorax. Pleural fluid analysis delivered the unusual diagnosis of chylothorax, most likely induced by preceded excessive coughing. After an unsuccessful treatment attempt with a fat-free diet and continuous pleural drainage for two weeks, therapy with octreotide was initiated. This led to complete and permanent resolution of his pleural effusion within 15 days, without any side effects.ConclusionsSevere cough may be a rare cause of chylothorax in young children. Octreotide seems to be an effective and safe treatment of spontaneous or traumatic chylothorax in children.There is, however, a lack of comprehensive studies for chylothorax in children and many issues concerning diagnostic strategies and treatment algorithms remain.

Response and Mechanism of Coal Fine Production to Differential Fluid Action in the Baode Block, Ordos Basin

The Baode Block in the Ordos Basin is currently one of the most successfully developed and largest gas field of low–medium rank coal in China. However, the production of coal fine has affected the continuous and stable drainage and efficient development of this area. The special response and mechanism of differential fluid action during the drainage process is one of the scientific issues that must be faced to solve this production problem. In view of this, the evolution laws of a reservoir’s macro–micro physical characteristics under different fluid conditions (fluid pressure, salinity) have been revealed, and the response mechanism of coal fine migration-induced reservoir damage has been elucidated through a nuclear magnetic resonance online displacement system. The results indicated that pores at different scales exhibited varying patterns with increasing displacement pressure. The proportion of the mesopore and transition pore is not affected by salinity and is positively correlated with displacement pressure. When the salinity is between 3000 mg/L and 8000 mg/L, the proportion of macropore and micropore showed parabolic changes with increasing displacement pressure, and there was a lowest point. The evolution law of pore fractal dimension and permeability change rate under the action of different fluids jointly showed that there was an optimal salinity for the strongest reservoir sensitivity enhancement effect. The mechanical and chemical effects of fluid together determined the damage degree of coal reservoir induced by coal fine migration.

Nonlinear consolidation analysis of saturated multi‐layered soil with continuous drainage boundary

AbstractContinuous drainage boundary is widely accepted to overcome the shortcoming of the traditional assumption of fully permeable or impermeable drainage boundary in consolidation theories. This study presents an analytical solution for one‐dimensional small‐strain nonlinear consolidation of saturated multi‐layered soil with constant consolidation coefficients under continuous drainage boundary condition. The proposed solution is validated by comparison with the existing solutions in literature, which shows that the existing solutions are special cases of this solution. A parametric study performed on saturated four‐layered soil with continuous drainage boundary indicates that the interface parameter and the loading stress ratio have great influences on the nonlinear consolidation of saturated multi‐layered soil. The present solution can be effectively applied to provide more reasonable design for soil foundation.

Postoperative constrictive pericarditis caused rupture of lymphatic collaterals: a rare etiology of chylothorax

BackgroundChylothorax after cardiovascular surgery is primarily caused by direct injury to the thoracic duct or its branches, and occurs in early postoperative period. In the present case, we describe a rare case of chylothorax manifesting three months after surgery secondary to constrictive pericarditis.Case presentationA 71-year-old man underwent mitral valve replacement, tricuspid valve annuloplasty, and the maze procedure. He developed acute perioperative myocardial infarction on postoperative day one due to plaque rupture in the left anterior descending artery and underwent percutaneous coronary intervention. Although the patient was discharged on postoperative day 36, he required readmission on postoperative day 83 because of right side chylothorax associated with constrictive pericarditis. Lymphangiography revealed thoracic duct interruption and development of lymphatic collateral vessels via the right hilum. Single-photon emission computed tomography revealed abnormal tracer accumulation in the right hilum, suggesting a lymphatic leakage site. A catheter study indicated biventricular dip and plateau patterns with a reduced cardiac index (1.6 L/min/m2) and elevated central venous pressure (18 mmHg). Conservative treatment for chylothorax, including a low-fat diet and continuous drainage with chest tube, was unsuccessful. Drainage of chyle at approximately 500 mL/day continued. On hospitalization day 50, complete pericardiectomy via median sternotomy was performed because the patient’s cardiac function deteriorated. The central venous pressure dramatically decreased, and the chylothorax gradually subsided. There was no recurrence of symptoms 1 year postoperatively.ConclusionsChylothorax associated with constrictive pericarditis subsequent to cardiac surgery is extremely rare. Although conservative management failed, the present case was successfully treated via pericardiectomy alone and did not require any additional precedures, such as thoracic duct ligation via a right thoracotomy.