57 research outputs found

    Planetary Soil Simulant Characterisation: NU-LHT-2M Study Case to Support Oxygen Extraction Lab Tests with a Low-Temperature Carbothermal Process

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    Since the landing on the lunar surface, the lunar regolith has begun to interact in different ways with landed elements, such as the wheels of a rover, astronaut suits, drills, and plants for extracting oxygen or manufacturing objects. Therefore, a strong effort has been required on Earth to fully characterise these kinds of interactions and regolith utilisation methods. This operation can only be performed by using regolith simulants, soils that are reproduced with the Earth’s rocks and minerals to match the real features. This article presents the main guidelines and tests for obtaining the properties of a generic simulant in terms of composition, physical and mechanical properties, solid–fluid interaction, and thermal properties. These parameters are needed for the designing and testing of payloads under development for planned lunar surface missions. The same tests can be performed on lunar, martian, or asteroid simulants/soils, both in laboratory and in situ. A case study is presented on the lunar simulant NU-LHT-2M, representative of the lunar highlands. The tests are performed in the context of an in situ resource utilisation (ISRU) process that aims to extract oxygen from the lunar regolith using a low-temperature carbothermal reduction process, highlighting the main regolith-related criticalities for an in situ demonstrator plant

    Evolution of laparoscopic left lateral sectionectomy without the Pringle maneuver: through resection of benign and malignant tumors to living liver donation

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    BACKGROUND: Laparoscopic left lateral sectionectomy (LLS) has gained popularity in its use for benign and malignant tumors. This report describes the evolution of the authors' experience using laparoscopic LLS for different indications including living liver donation. METHODS: Between January 2004 and January 2009, 37 consecutive patients underwent laparoscopic LLS for benign, primary, and metastatic liver diseases, and for one case of living liver donation. Resection of malignant tumors was indicated for 19 (51%) of the 37 patients. RESULTS: All but three patients (deceased due to metastatic cancer disease) are alive and well after a median follow-up period of 20 months (range, 8-46 months). Liver cell adenomas (72%) were the main indication among benign tumors, and colorectal liver metastases (84%) were the first indication of malignancy. One case of live liver donation was performed. Whereas 16 patients (43%) had undergone a previous abdominal surgery, 3 patients (8%) had LLS combined with bowel resection. The median operation time was of 195 min (range, 115-300 min), and the median blood loss was of 50 ml (range, 0-500 ml). Mild to severe steatosis was noted in 7 patients (19%) and aspecific portal inflammation in 11 patients (30%). A median free margin of 5 mm (range, 5-27 mm) was achieved for all cancer patients. The overall recurrence rate for colorectal liver metastases was of 44% (7 patients), but none recurred at the surgical margin. No conversion to laparotomy was recorded, and the overall morbidity rate was 8.1% (1 grade 1 and 2 grade 2 complications). The median hospital stay was 6 days (range, 2-10 days). CONCLUSIONS: Laparoscopic LLS without portal clamping can be performed safely for cases of benign and malignant liver disease with minimal blood loss and overall morbidity, free resection margins, and a favorable outcome. As the ultimate step of the learning curve, laparoscopic LLS could be routinely proposed, potentially increasing the donor pool for living-related liver transplantation

    Robotic versus Laparoscopic Surgery for Spleen-Preserving Distal Pancreatectomies: Systematic Review and Meta-Analysis

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    Background: When oncologically feasible, avoiding unnecessary splenectomies prevents patients who are undergoing distal pancreatectomy (DP) from facing significant thromboembolic and infective risks. Methods: A systematic search of MEDLINE, Embase, and Web Of Science identified 11 studies reporting outcomes of 323 patients undergoing intended spleen-preserving minimally invasive robotic DP (SP-RADP) and 362 laparoscopic DP (SP-LADP) in order to compare the spleen preservation rates of the two techniques. The risk of bias was evaluated according to the Newcastle–Ottawa Scale. Results: SP-RADP showed superior results over the laparoscopic approach, with an inferior spleen preservation failure risk difference (RD) of 0.24 (95% CI 0.15, 0.33), reduced open conversion rate (RD of −0.05 (95% CI −0.09, −0.01)), reduced blood loss (mean difference of −138 mL (95% CI −205, −71)), and mean difference in hospital length of stay of −1.5 days (95% CI −2.8, −0.2), with similar operative time, clinically relevant postoperative pancreatic fistula (ISGPS grade B/C), and Clavien–Dindo grade ≥3 postoperative complications. Conclusion: Both SP-RADP and SP-LADP proved to be safe and effective procedures, with minimal perioperative mortality and low postoperative morbidity. The robotic approach proved to be superior to the laparoscopic approach in terms of spleen preservation rate, intraoperative blood loss, and hospital length of stay

    Laparoscopic ICG-guided RALPPS procedure for HCC on cirrhosis with 3D reconstruction implementation: a case report

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    We present a fully laparoscopic partial RALPPS (radiofrequency-assisted liver partition with portal vein ligation for staged hepatectomy) on a cirrhotic 71-year-old man with a bifocal hepatocellular carcinoma. The patient’s liver was preoperatively studied through a CT-guided 3D-reconstruction. During stage-1, the right portal vein was ligated and injected with alcohol distally; the vascular limit between the right and left anterior sectors was defined through the systemic infusion of indocyanine green for a negative staining. Hence, laparoscopic ablations, guided by luminescence and checked with intraoperative ultrasounds, were performed. After 55 days, the future liver remnant increased from 28.6% to 46.3%, allowing a laparoscopic RALPPS stage-2. Fully laparoscopic RALPPS technique shows several advantages compared to the original procedure, especially in patients with cirrhosis. The avoidance of liver transection during stage-1 reduced blood loss and intraabdominal adhesions, and it eliminated the risk of biliary fistulae and allowed an easier liver transection during stage-2

    Perioperative thromboprophylaxis in liver transplant patients

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    Improvements in surgical and anesthetic procedures have increased patient survival after liver transplantation (LT). However, the perioperative period of LT can still be affected by several complications. Among these, thromboembolic complications (intracardiac thrombosis, pulmonary embolism, hepatic artery and portal vein thrombosis) are relatively common causes of increased morbidity and mortality. The benefit of thromboprophylaxis in general surgical patients has already been established, but it is not the standard of care in LT recipients. LT is associated with a high bleeding risk, as it is performed in a setting of already unstable hemostasis. For this reason, the role of routine perioperative prophylactic anticoagulation is usually restricted. However, recent data have shown that the bleeding tendency of cirrhotic patients is not an expression of an acquired bleeding disorder but rather of coexisting factors (portal hypertension, hypervolemia and infections). Furthermore, in cirrhotic patients, the new paradigm of ''rebalanced hemostasis'' can easily tip towards hypercoagulability because of the recently described enhanced thrombin generation, procoagulant changes in fibrin structure and platelet hyperreactivity. This new coagulation balance, along with improvements in surgical techniques and critical support, has led to a dramatic reduction in transfusion requirements, and the intraoperative thromboembolic-favoring factors (venous stasis, vessels clamping, surgical injury) have increased the awareness of thrombotic complications and led clinicians to reconsider the limited use of anticoagulants or antiplatelets in the postoperative period of LT

    The role of minimally invasive surgery in the treatment of HCC

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    Liver surgery is the first-line treatment for hepatocellular carcinoma (HCC). Minimally invasive liver resection (MILS) has become an attractive option thanks to reduced intraoperative blood losses, shortened length of hospital stay, and similar oncological outcomes when compared to open liver resection. Nonetheless, the safety of MILS is still debated in challenging situations, such as in cirrhotic patients, difficult tumor locations, multiple or large tumors, and repeat resection. The aim of this review is to discuss current indications of laparoscopic liver resection for HCC treatment in the light of its outcomes, focusing on technical aspects of minimally invasive anatomic liver resection and state of the art of MILS in challenging situations

    Selecting the Best Approach for the Treatment of Multiple Non-Metastatic Hepatocellular Carcinoma

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    According to the Barcelona Clinic Liver Cancer (BCLC) staging system, the optimal strategy for patients with multiple HCC within the Milan Criteria is liver transplantation (LT). However, LT cannot be offered to all the patients due to organ shortages and long waiting lists, as well as because of the advanced disease carrying a high risk of poor outcomes. For early stages, liver resection (LR) or thermal ablation (TA) can be proposed, while trans-arterial chemoembolization (TACE) still remains the treatment of choice for intermediate stages (BCLC-B). Asian guidelines and the National Comprehensive Cancer Network suggest LR for resectable multinodular HCCs, even beyond Milan criteria. In this scenario, a growing body of evidence shows better outcomes after surgical resection when compared with TACE. Trans-arterial radioembolization (TARE) and stereotaxic body radiation therapy (SBRT) can also play an important role in this setting. Furthermore, the role of minimally invasive liver surgery (MILS) specifically for patients with multiple HCC is still not clear. This review aims to summarize current knowledge about the best therapeutical strategy for multiple HCC while focusing on the role of minimally invasive surgery and on the most attractive future perspectives
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