Short Drainage Research Articles

Shorter Drainage Tube to the Pancreatic Stump Reduces Pancreatic Fistula After Distal Pancreatectomy.

We investigated the relationship between the length of a prophylactic closed-suction drainage tube and clinically relevant postoperative pancreatic fistula (CR-POPF) in distal pancreatectomy (DP). The clinical data of 76 patients who underwent DP using a reinforced stapler for the division of the pancreas at Ehime University Hospital between December 2017 and May 2023 were retrospectively analyzed. Laparoscopic DP was performed in 41 patients (53.9%). Closed-suction drainage was performed using a 19Fr ExuFlow Round Drain with a vacuum bulb. The drainage tube length was defined as the distance between the peripancreatic stump site and the abdominal wall insertion site using abdominal radiography. CR-POPF was observed in 12 patients (15.8%). Univariate analyses demonstrated that male sex (P=0.020), American Society of Anesthesiologists Physical Status (P=0.017), current smoking (P=0.005), and drainage tube length (P<0.001) were significantly associated with CR-POPF. The optimal cut-off value of drainage tube length for CR-POPF was 220mm (area under the receiver operating characteristic curve=0.80). In multivariate analyses, drainage tube length (≥220mm) was the sole independent predictor for CR-POPF (odds ratio, 6.59; P=0.023). According to computed tomography performed ∼1 week after surgery, the median volume of peripancreatic fluid collection was significantly higher in the long drainage tube group than in the short drainage tube group (P<0.001). A drainage tube inserted at a shorter distance to the pancreatic stump may reduce the incidence of CR-POPF after DP.

Challenges and Opportunities in Oil Rim Reservoir Development

Low oil recovery is one of the common problems in the field development of thin oil rims associated with gas-condensate. The fast gas and water conning of the reservoirs are the main causes of sharp oil rate decline and low cumulative oil production per well. Low recovery efficiency is related to the oil saturated thickness and if oil saturation is less than 10 m, most of oil volumes in place are moved to transition zones. 3D numerical and streamline simulations are performed for the development of thin oil rims of one of the pay zones in Bokabil Formation of Haripur gas field. The development option with four vertical oil production wells and nine water injection wells has been proposed to cover the entire reservoir with the efficient sweeping. The simulation study of the dynamic model has revealed that vertical wells through the reservoir are able to make a short drainage path and produce insignificant quantity of oil and the production period is terminated shortly. As an alternative development option a rim shaped production well and a rim shaped water injection well is designed. The development option with a rim shaped production and an injection wells covers large drainage length and produce significant amount of oil. This option is technically and economically feasible. The Dhaka University Journal of Earth and Environmental Sciences, Centennial Special Volume June 2022: 85-88

Sedimentary architecture of a Late Cretaceous under‐filled rift basin, Canterbury Basin, New Zealand

AbstractThe Canterbury Basin in southeastern Zealandia was initiated during the late Albian (ca. 105 Ma) as a rift system, prior to the onset of seafloor spreading between Zealandia and eastern Gondwana at ca. 85 Ma. Basin‐fill architecture and sediment types have been determined from interpretation of 2D and 3D seismic‐reflection lines tied to five wells and compared to outcrop data from the literature. These data show that Cretaceous syn‐rift basin‐fill architecture was controlled by normal faulting, which produced basin and range topography that persisted for more that ca. 30 Myr after the cessation of faulting. Initial sedimentation was dominated by short drainage systems sourced from within the basin to produce alluvial fans along fault scarps, which inter‐fingered with axial‐flowing braided river conglomerates, coal measures and mudstone‐rich lake deposits in more central portions of the basins. Marine incursion of the basin from the east commenced during rifting and onset of Gondwana breakup, with maximum water depths achieved in the Oligocene. Post‐rifting, detrital sediments were mainly sourced locally from structural highs and augmented by pelagic sedimentation, which collectively draped and eventually buried most of the earlier‐formed horsts by the Early Eocene. The temporal persistence of basin and range topography reflected the low rates of erosion of horst blocks compared to the rates of fault displacement. The lack of substantial sediment input from outside of the rift basin was a key factor in the under‐filling of the Canterbury Basin. This research emphasises the key role played by sediment supply in rift basin filling. Despite an abundance of active faulting at initiation, some rift basins may fill slowly over tens of million years after rift cessation.

New Thoracotomy Closure, a Simple Way to Decrease Chronic Post-Operative Pain in Selected Patients-Blinded Prospective Study.

Background and Objectives: Chronic post-thoracotomy pain syndrome (PTPS) is a very common and uncomfortable complication, occurring frequently after thoracic operations, leading to the necessity of further medication and hospitalizations. One important risk factor in developing chronic pain is the chest closure technique, which can lead to chronic intercostal nerve damage. This study proposes an alternative nerve-sparring closure technique to standard peri-costal sutures, aimed toward minimizing the risk of chronic pain in selected patients. Materials and Methods: We performed a prospective randomized study on 311 patients operated for various thoracic pathology over a period of 12 months, evaluating incision types, chest closure technique, and number of drains with drainage duration. The patients were divided into three groups: peri-costal (PC), proposed extra-costal (EC), and simple (SC) suture, respectively. Pain was measured on day 1, 2, 5, 7, and at 6 months post-operatively using the Visual Analogic Scale. Results: No significant differences in pain level were recorded in the first two post-operative days between the PC and EC groups. However, a significant decrease in pain level was observed on day 5 and at 6 months post-operatively, with a mean level of 3.5 ± 1.8, 1.2 ± 1 for the EC group compared to a mean value of 5.3 ± 1.6, 3.2 ± 1.5, respectively. No significant differences were observed regarding other evaluated variables. Conclusions: The lower recorded pain scores in patients with extra-costal chest closure are a strong argument to use this technique. Its ease of use is similar to the classic peri-costal closure, and the time needed to perform it is not significantly increased. The association of this technique with less invasive procedures and short drainage duration limits chronic post-operative pain. This procedure may represent an option for decreasing healthcare costs associated with the management of PTPS.

Substrate colonization by an emulsion drop prior to spreading

In classical wetting, the spreading of an emulsion drop on a surface is preceded by the formation of a bridge connecting the drop and the surface across the sandwiched film of the suspending medium. However, this widely accepted mechanism ignores the finite solubility of the drop phase in the medium. We present experimental evidence of a new wetting mechanism, whereby the drop dissolves in the medium, and nucleates on the surface as islands that grow with time. Island growth is predicated upon a reduction in solubility near the contact line due to attractive interactions between the drop and the surface, overcoming Ostwald ripening. Ultimately, wetting is manifested as a coalescence event between the parent drop and one of the islands, which can result in significantly large critical film heights and short hydrodynamic drainage times prior to wetting. This discovery has broad relevance in areas such as froth flotation, liquid-infused surfaces, multiphase flows and microfluidics.

Safety and Efficacy of Early Tube Removal Following Percutaneous Transhepatic Gallbladder Drainage: an Observational Study.

Background:There are currently no guidelines concerning the advisability and timing of tube removal following percutaneous transhepatic gallbladder drainage (PTGBD). The present study aimed to assess the feasibility and risks of early removal of the PTGBD tube under the scenario of subsiding inflammation, patent cystic and common bile ducts, and absence of intraperitoneal leakage.Methods:Patient background and outcomes were assessed retrospectively in 701 cases of acute cholecystitis treated with PTGBD. The median times until tube removal and tube dislodgement and the cumulative rates of tube dislodgement were calculated.Results:Tube removal was performed in 275 patients after a median time of 16 days (range: 6 to 213 d); biliary peritonitis was observed in 2 patients following tube removal. Tubes were removed in 8 and 35 patients within 7 and 10 days, respectively. Tube dislodgement was observed in 82 patients after a median time of 12 days (range: 1 to 125 d).Conclusion:The present study suggests that drainage tube removal is safe and effective when performed after a short drainage period of 7 to 10 days if the criteria for the removal of the drainage tube were met.

Improvement of Soft Soil Using Linear Distributed Floating Stone Columns under Foundation Subjected to Static and Cyclic Loading

A stone column is one of the soil improvement methods that are mainly used for improving the geotechnical behavior of soft soils. For deep improvement of soft soil, the floating stone columns are considered the best and effective economically which provide lateral confinement and drainage and longitudinal skin friction. In this study, six tests were carried out on the natural soft soil of undrained shear strength of 5.5 kPa improved by single and two linear distributed floating stone columns. The stone column dimensions are 30 mm in diameter and 180 mm in length and the stone column material is sand of high internal friction angle of 48°. The natural and improved soil samples are tested under isolated raft foundation of dimensions 120×120 mm subjected to vertical static and cyclic loading of frequency 2Hz and continued for 50 seconds. The results showed a significant improvement in soil bearing capacity when reinforced with stone columns despite the small area replacement ratio, where the bearing capacity of improved soil increased by 120 to 145%. The compressibility of improved soil decreased by 57 to 86% in comparison with that of natural soft soil. Also, the floating stone columns reduced the porewater pressure, where the stone columns considered efficient in providing short drainage pathways. This can be one of the reasons why soil reinforced with floating stone columns hold higher cyclic and static stresses regardless the end bearing of stone columns.

Lower incidence of late tamponade after cardiac surgery by extended chest tube drainage

Objectives. To ascertain whether extended chest tube drainage decreases the occurrence of late tamponade after cardiac surgery. Design. All patients undergoing cardiac surgery at the Tampere University Heart Hospital, Tampere, Finland, between the 23rd of October 2015 and the 17th of August 2016 were included. The first 260 consecutive patients were treated according to a short drainage protocol, in which the mediastinal chest tubes were removed during the first postoperative day unless producing >50ml/h, and the following 224 consecutive patients by an extended drainage protocol, in which the mediastinal chest tubes were kept at least until the second postoperative day, and thereafter if producing >50ml/4h. The incidence of late tamponade and the length and course of postoperative hospitalization, including the development of complications, were compared. Results. The occurrence of late cardiac tamponade was 8.8% following the short drainage protocol and 3.6% after the extended drainage protocol, p = .018. There were no statistically significant differences in the demographics, medical history, or the procedures performed between the study groups. The in-hospital mortality rate was 3.5%, the stroke rate was 2.1%, and the deep sternal wound infection rate was 1.7%, with no statistically significant differences between the groups. There were no differences in the need for reoperations for bleeding, infection rate, need for pleurocentesis, occurrence of atrial fibrillation, or the length of hospitalization between the groups. Conclusions. Longer mediastinal chest tube drainage after cardiac surgery is associated with a significantly lower incidence of late cardiac tamponade.

Non-Darcy Flow in Hydraulic Flushing Hole Enlargement-Enhanced Gas Drainage: Does It Really Matter?

In recent years, the non-Darcy flow has seen a significant increase in interest in conventional and unconventional gas developments. The nonlinear behavior can be described by adding a quadratic term of the velocity with the permeability-dependent β factor in Darcy’s law. The methods for improving permeability such as the hydraulic flushing hole enlargement (HFHE) technique can remarkably enhance the coal permeability thus changing the β factor. However, few studies have been done previously to seek how this non-Darcy flow impacts the permeability-enhanced gas drainage. In this study, a fully coupled coal deformation and damage, the non-Darcy flow of free methane gas in the fractures, and Fickian diffusion of adsorbed methane in the coal matrix model were developed. The Klinkenberg effect has been taken into account as a reference object. A series of simulation scenarios were carried out to evaluate and compare the influences of the non-Darcy effect, gas-coal interaction effect, and Klinkenberg effect on the HFHE-enhanced gas drainage. Results of the simulation illustrate that the HFHE technique can significantly improve the gas drainage efficiency by permeability enhancement. But the HFHE-enhanced gas drainage is unique to the other gas developments with high or low flow rates; a slight pressure gradient and short drainage time make the non-Darcy effect fail to generate cumulative influence on the HFHE-enhanced gas drainage.

Controlling variables and emission factors of methane from global rice fields

Abstract. Rice cultivation has long been known as one of the dominant anthropogenic contributors to methane (CH4) emissions, yet there is still uncertainty when estimating its emissions at the global or regional scale. An increasing number of rice field measurements have been conducted globally, which allow us to reassess the major variables controlling CH4 emissions and develop region- and country-specific emission factors (EFs). The results of our statistical analysis show that the CH4 flux from rice fields was closely related to organic amendments, the water regime during and before the rice-growing season, soil properties and agroecological conditions. The average CH4 fluxes from fields with single and multiple drainage were 71 % and 55 % that of continuously flooded rice fields. The CH4 flux from fields that were flooded in the previous season were 2.4 and 2.7 times that of fields previously drained for a short and long season, respectively. Rice straw applied at 6 t ha−1 in the preseason can decrease CH4 emissions by half when compared to that applied shortly before rice transplanting. The global default EF was estimated to be 1.19 kg CH4 ha−1 day−1 with a 95 % confidence interval of 0.80 to 1.76 kg CH4 ha−1 day−1 for continuously flooded rice fields without organic amendment and with a preseason water status of short drainage. The lower EFs were found in countries from South Asia (0.85 kg CH4 ha−1 day−1) and North America (0.65 kg CH4 ha−1 day−1) relative to other regions, indicative of geographical variations at sub-regional and country levels. In conclusion, these findings can provide a sound basis for developing national inventories and mitigation strategies of CH4 emission from rice fields.

Volume-controlled versus short drainage after inguinofemoral lymphadenectomy in vulvar cancer patients: A Dutch nationwide prospective study

ObjectiveInguinofemoral lymphadenectomy for patients with vulvar squamous cell carcinoma is associated with a high incidence of postoperative wound complications, which may be influenced by inguinal drain management. The aim of this nationwide prospective study (MAMBO: Morbidity And Measurement of the BOdy) was to assess the feasibility and the incidence of complications after volume-controlled versus short drainage. MethodsThe MAMBO study consisted of two observational studies in all eight oncology centers in the Netherlands, conducted between 2012 and 2016. In the first study, the drain was removed when the production was <30ml/24h, except in the first 48h, and after a maximum of 28days (MAMBO-IA). In the second study, the drain was removed five days postoperatively regardless of production (MAMBO-IB). We assessed the complications within eight weeks after surgery using logistic regression to compare the incidence of one or more complications between the two drainage protocols, adjusting for possible confounders. ResultsWe included 77 patients (139 groins) for volume-controlled drainage and 64 patients (112 groins) for short drainage. Volume-controlled drainage was associated with significant less lymphocele formation. Moreover, we found no difference in wound infection or primary wound breakdown. The estimated incidence of one or more complications was 46% per groin after volume-controlled drainage versus 75% after short drainage, (RD 29% (95% CI 8, 49) p=0.006). ConclusionsThis prospective study shows that volume-controlled drainage is associated with significantly less complications compared to short drainage. We therefore recommend volume-controlled drainage after inguinofemoral lymphadenectomy in patients with vulvar squamous cell carcinoma.

Thermal Volume Changes and Creep in the Callovo-Oxfordian Claystone

The Callovo-Oxfordian (COx) claystone is considered as a potential host rock for high-level radioactive waste disposal at great depth in France. Given the exothermic nature of radioactive wastes, a temperature elevation planned to be smaller than 100 °C will affect the host rock around the disposal cells. To gain better understanding of the thermal volumetric response of the COx claystone, a new thermal isotropic compression cell was developed with particular attention devoted to monitoring axial and radial strains. To do so, a high-precision LVDTs system ensuring direct contact between the LVDT stem and the claystone sample through the membrane was developed. A short drainage length (10 mm) was also ensured so as to allow full saturation of the sample under stress conditions close to in situ, and fully drained conditions during compression. High-precision strain monitoring allowed to observe a volumetric creep under stress conditions close to in situ. A drained heating test under constant stress carried out afterwards up to 80 °C exhibited a thermoelastic expansion up to a temperature of 48 °C, followed by thermoplastic contraction at higher temperature. Creep volume changes, that appeared to be enhanced by temperature, were modelled by using a simple Kelvin–Voigt model, so as to estimate the instantaneous response of the COx claystone and to determine its thermal expansion coefficient. The temperature at which the transition between thermal expansion and contraction appeared is close to the maximum burial temperature of the Callovo-Oxfordian claystone, estimated at 50 °C. This is in agreement with what has been already observed on the Opalinus Clay by Monfared et al. (2012) that was interpreted as a thermal hardening phenomenon, showing that the material kept the memory of the highest temperature supported during its geological history.

Investigation of the change in soil fabric during cone penetration in silt using 2D measurements

Interpretation of CPTU testing in silt is non-trivial because of the partially drained conditions that are likely to occur during penetration. A better understanding of the pore pressure generation/dissipation is needed in order to obtain reliable design parameters. Following a previous study using X-ray computed tomography (micro-CT) with volumetric digital image correlation (3D-DIC) that clearly showed the formation of distinct dilation and compression areas around the cone; the present work takes a closer look at those areas in order to link volumetric behavior to changes in soil fabric. High-resolution 2D backscattered electron images of polished thin sections prepared from frozen samples at the end of penetration are used. The images have a spatial resolution of 0.4 µm/pixel that allow a clear identification of grains and pore spaces. Image processing techniques are developed to quantify local porosity and obtain the statistical distribution of the particle orientation for the zones around the cone tip and shaft. It is shown that the formation of compaction regions is related to the ability of the grains to rearrange and align along a well-defined preferred orientation forming a more closed-fabric characterized by high anisotropy values, while zones of dilation are associated with a more open packing with grains randomly oriented and with large voids within. These observations suggested that for a saturated soil, water will move from a compressive zone to a neighboring dilative zone, creating a short drainage path. By shedding light on the link between soil fabric and drainage patterns, this study contributes toward a better understanding of the measured macro-response during CPTU tests on silt.

On the Thermo-Hydro-Mechanical Behaviour of a Sheared Callovo-Oxfordian Claystone Sample with Respect to the EDZ Behaviour

To better understand the impact of temperature elevation on the response of the excavation damaged zone around repository cells and galleries for radioactive waste disposal, the combined effects of shear and temperature elevation were investigated in the laboratory on the Callovo-Oxfordian claystone. To do so, a hollow cylinder thermal triaxial cell with short drainage path specifically developed for low permeability rocks was used. Once properly saturated under stress conditions close to in situ, the specimen was sheared along a constant effective mean stress path mimicking the stress path followed during gallery excavation. The shear stress was afterwards released and an undrained heating test was performed on the sheared specimen. It was observed that the temperature increase under undrained conditions led to a thermal increase in pore water pressure resulting in a decrease in mean effective stress that brought back the sheared specimen to failure, evidencing a thermally induced failure. Steady state radial permeability tests performed at various stages of the test demonstrated that the overall permeability of the sheared specimen was comparable to that before shearing, confirming the excellent self-sealing properties of the Callovo-Oxfordian claystone. This shows that, in spite of being possibly remobilised by temperature elevation, the EDZ will keep an overall permeability constant equal to that of the massive rock, keeping the same isolation properties.

Video assisted thoracoscopic excision of mediastinal ectopic parathyroid adenomas: a UK regional experience.

To report the first series of video-assisted thoracoscopic surgery (VATS) resection of mediastinal ectopic parathyroid adenomas (MEPAs) in the UK. A case series of seven cases undergoing VATS between 2004 and 2009 to treat single gland hyperparathyroidism. Methylene blue (MB) was used in 5/7 cases immediately before exploration to identify the adenomas. Carbon dioxide (CO2) up to pressures of 10 mmHg was used safely to deflate the lung in two cases. There were five women and two men with a mean age of 53 years (range, 27-72 years). Histopathology confirmed successful resection of the parathyroid adenoma in 6/7 cases. There was one conversion to open thoracotomy due to bleeding from the azygos vein resulting from excessive traction. Despite marked MB uptake, this patient proved to have tuberculoid adenopathy and no parathyroid tissue was identified. Postoperative plasma calcium returned to normal in 6/7 patients and parathyroid hormone (PTH) level in 6/7 patients. The median hospital stay was 2 days and there was no mortality in this series. MEPAs can be safely resected using VATS with minimal surgical morbidity, short drainage time and short hospital stay. CO2 insufflation and the intraoperative use of MB are safe and help to accurately localise the ectopic adenoma. VATS should be considered as the first-line approach for resection of MEPAs.

Dating of debris flow fan complexes from Lantau Island, Hong Kong, China: The potential relationship between landslide activity and climate change

Five debris flow fan complexes bordering the coastal foothills of western Lantau Island, Hong Kong, have been the subject of a stratigraphic and dating study to explore the potential relationship between past periods of climate change and landslide activity. Luminescence (OSL) ages from the fan complexes, supported by a few calibrated radiocarbon (14C) ages on duplicate samples, suggest six main periods of accumulation: 28,000–20,000ka, 14,500–10,500ka, 5800–5000ka, 4370–4230ka, 3560–3320ka, and 1350–1050ka. The younger periods (<10,000ka) appear to be dominated by relatively thin (0.5–1.5m) units deposited mainly by debris flood events whereas the older periods are dominated by thicker (1.0–3.5m) units deposited by debris flow events. We hypothesise that immediately prior to the Last Glacial Maximum (LGM, i.e., 21,000ka), the climate was cool and dry. Upland areas were probably devoid of vegetation, providing favourable conditions for sediment production in source areas. These debris-laden source areas are likely to have been mobilised during periodic rainstorm activity, rapidly channelised over relatively short drainage courses, and then deposited as thick, sediment-rich, debris flow deposits along the coastal foothills. During the early to middle Holocene, the climate was warmer and more humid. Pluvial conditions dominated; forests occupied the upland source areas, leading to possibly reduced sediment yields, more frequent flash floods and deposition dominated by debris floods. Compared with recent studies on the weathering and erosion history of the Pearl River Delta, our landslide age data are indicative of a potential link between increased landslide activity and intensification of the East Asian monsoon during the early to middle Holocene.

Improvements of marine clay slurries using chemical–physical combined method (CPCM)

In this paper, the effectiveness, applicability and validity of chemical–physical combined methods (CPCMs) for treatment of marine clay (MC) slurries were evaluated. The method CPCM1 combines chemical stabilization and vacuum preloading (VP), while CPCM2 is similar to CPCM1 but includes both the application of surcharge and use of geo-bags to provide confinement during surcharge preloading. The key advantage of CPCM2 using geo-bags is that the surcharge can be immediately applied on the chemically stabilized slurries. Two types of geo-bags were investigated under simulated land filling and dyke conditions, respectively. The test results show that the shear strength (cu) of treated slurry by CPCM2 is generally much higher than that by CPCM1. Besides, the use of CPCM2 can significantly reduce the treatment time due to the short drainage paths created by geo-bags. Overall, CPCM2 allows faster consolidation and higher preloading that help to achieve higher mechanical properties of the stabilized slurry. There are consistent relationships between cU and water content of slurries treated by CPCM2. Several important observations were also made based on comparisons of experimental data.

The Thermal Volume Changes of the Callovo–Oxfordian Claystone

There are very few data on the thermoplastic behaviour of claystones, while their knowledge is necessary in understanding long-term behaviour of high-level radioactive waste confining systems. In this paper, a number of thermomechanical parameters of the Callovo–Oxfordian claystone, the possible host rock of radioactive waste in France, are presented. These parameters were obtained from experiments performed on a hollow cylinder cell. The short drainage path of this device allows a good saturation in a reasonably short time; also, the good drainage conditions and reasonable homogeneity of pore pressure during the tests in such a low-permeability material. The saturation procedure was performed under in-site stresses prior to testing to reduce the swelling effect during hydration. The thermomechanical experimental programme conducted here evidenced a plastic contraction of the claystone during drained heating under in-situ stress conditions, like in normally consolidated soils. Previous loading induced a dilating–contracting response comparable to that of overconsolidated clays. Finally, whereas the elastic response appeared to be temperature independent, the plastic compressibility investigated through a drained isothermal isotropic compression test at 80 °C increased compared to that at 25 °C. These first results should be confirmed by further thermomechanical investigation on claystones.

Research on Influencing Factors of Drainage Performance in Engineering

In order to control the seepage and eliminate the adverse effects, influencing factors of drainage in engineering are discussed in this paper. The drainage holes are simulated by rod element to study the influence of drainage performance on angle and length. Compared the drainage performance of drainage galleries in different location, the optimal assembly is obtained. Meanwhile, drainage performance is analyzed by different permeability coefficient and anisotropy of rock and soil mass. The results show that: (1) Drainage flow of small angle and short drainage hole is close to big angle and long one, the small angle flows more than the big angle when increasing the same length. (2) Shallow drainage galleries can significantly drop the free surface and the deep one can greatly decrease the pore water pressure. Drainage galleries built at the upstream side and bottom, as the optimum assembly, can enormously change the seepage field. (3) For anisotropy materials, the horizontal drainage performance is better than vertical when Ky/Kx decreases. On the contrary, vertical is superior to the horizontal. Increasing vertical permeability coefficient is benefit to drainage.

On the THM behaviour of a sheared Boom clay sample: Application to the behaviour and sealing properties of the EDZ

In this study the effect of the temperature increase on the hydro-mechanical properties of sheared Boom clay samples is investigated. Two samples of Boom clay are resaturated in a new hollow cylinder triaxial cell with a short drainage path and then sheared by performing an axisymmetric triaxial loading. The effect of the undrained heating under deviatoric stress is studied on the first sample. It is shown that undrained temperature increase leads to an increase of pore water pressure and consequently to a decrease of the effective mean stress which brings the sample to failure. For an initially sheared sample, the failure occurs along the existing shear band which behaves as a weakness plane in the sample. The responses of the local strain measurement transducers clearly show the sliding of rigid blocks when failure occurs in the sample. The effect of the presence of a shear band on the permeability of the other Boom clay sample is investigated at ambient temperature and at 80 °C. It is shown that the presence of a shear band does not affect significantly the permeability. These results confirm the good self sealing properties of Boom clay at ambient and at high temperature.