The use of mixed reality in the preoperative planning of colorectal surgery: Preliminary experience with a narrative review

New advanced technologies have recently been developed and preliminarily applied to surgery, including virtual reality (VR), augmented reality (AR) and mixed reality (MR). We retrospectively review all colorectal cases in which we used holographic 3D reconstruction from February 2020 to December 2022. This innovative approach was used to identify vascular anomalies, pinpoint tumor locations, evaluate infiltration into neighboring organs and devise surgical plans for both training and educating trainee assistants. We have also provided a state-of-the-art analysis, briefly highlighting what has been stated by the scientific literature to date. VR facilitates training and anatomical assessments, while AR enhances training and laparoscopic performance evaluations. MR, powered by HoloLens, enriches anatomic recognition, navigation, and visualization. Successful implementation was observed in 10 colorectal cancer cases, showcasing the effectiveness of MR in improving preoperative planning and its intraoperative application. This technology holds significant promise for advancing colorectal surgery by elevating safety and reliability standards.

Laparoscopic Radical Nephrectomy with Transperitoneal Approach for Large Renal Tumors: Standardized Surgical Technique and Outcomes

Background: Minimally invasive surgery is used only in selected cases of renal masses greater than 7 cm, and few studies exist in this setting. This study aimed to evaluate the safety and effectiveness of a laparoscopic surgical approach for the treatment of large renal tumors using a standardized technique. Materials and Methods: Data of patients who underwent laparoscopic nephrectomy (LN) using the transperitoneal approach were retrospectively evaluated from December 2019 to September 2022. The study population was divided into two groups: patients with renal masses <7 cm (Group A) and those with renal masses ≥7 cm in diameter (Group B). The intraoperative and postoperative outcomes were compared. Results: Forty patients were enrolled (16 in Group A and 24 in Group B) in this study. Although significant difference in terms of age and American Society of Anesthesiologists score were detected, the two groups did not differ in mean operative time (130 minutes standard deviation [SD] ± 64 versus 148 minutes DS ± 56; P = .376), intraoperative complications (0% versus 8.3%; P = .508), need for postoperative transfusion (12% versus 12%; P > .999), and length of stay (3.38 DS ± 0.62 days versus 3.92 DS ± 2.47; P = .313). One patient had a local recurrence and died ∼13 months after surgery. Furthermore, 2 patients developed trocar-site incisional hernia in Group B. Conclusion: In this cohort of patients, LN for large renal tumors appeared to be safe and feasible. Larger mass dimension does not appear to influence the outcomes when the surgery is performed using a standardized technique by experienced surgeons.

A Systematic Review on the Role of Matrix Metalloproteinases in the Pathogenesis of Inguinal Hernias

The recurrence rate in patients who undergo surgery for abdominal wall hernias (AWHs) is high. AWHs have been hypothesized to be a disease of the extracellular matrix, which is supported by evidence showing a high incidence of AWHs in patients with connective tissue disorders. This study aimed to investigate the most recent literature studies describing the levels of several matrix metalloproteinases (MMPs) in the blood and fascia, with the objective of better clarifying the pathogenetic role of matrix metalloproteinases (MMPs) and their inhibitors in inguinal hernias (IHs). A systematic literature search was conducted using the PubMed, Scopus, and Web of Science electronic databases to identify eligible studies. The identified studies were included in the analysis, and a qualitative synthesis of the results is provided to describe the most recent findings. Seventeen studies were included. An association between MMP-2 and direct IHs has also been demonstrated. MMP-1, MMP-2, MMP-9, MMP-12, and MMP-13 levels were increased in both the serum and fascia of patients with IHs. The analysis of inhibitors showed an increase in tissue inhibitors of metalloproteinases (TIMPs), specifically TIMP-1 in IHs, particularly in direct hernias, and a reduction in TIMP-2 in the biopsy samples of the transversalis fascia. In contrast, a reduction in TIMP-1 and an increase in TIMP-2 levels have been reported only in the serum of patients with IHs. Metalloproteinases play a crucial role in the pathogenesis of IHs. The analysis of other molecules, such as TIMPs or their correlation with specific genes, is enhancing our understanding of the pathophysiology of IHs. However, more prospective studies, including comprehensive clinical and laboratory data collection, are required to confirm the relationship between the studied biomarkers and the risk of IHs.

Steam reduction of CO2 on Pd/TiO2 catalysts: a comparison between thermal and photocatalytic reactions

The performances of Pd/TiO₂ catalysts in the steam reduction of CO₂ were analyzed in a photocatalytic and in a thermo-catalytic system. The comparison showed the superiority of the photocatalytic route.

Photocatalytic reduction of CO2 over platinised Bi2WO6-based materials

Bi₂WO₆ and Bi₂WO₆–TiO₂ were synthesized, platinised and evaluated in the photocatalytic reduction of CO₂. The methane yield was greatly improved by platinisation and TiO₂ addition. Blue phosphors enhanced the system stability.

Controlled growth of CNT in mesoporous AAO through optimized conditions for membrane preparation and CVD operation

Anodic aluminium oxide (RAAO) membranes with a mesoporous structure were prepared under strictly controlling experimental process conditions, and physically and chemically characterized by a wide range of experimental techniques. Commercial anodic aluminium oxide (CAAO) membranes were also investigated for comparison. We demonstrated that RAAO membranes have lower content of both water and phosphorus and showed better porosity shape than CAAO. The RAAO membranes were used for template growth of carbon nanotubes (CNT) inside its pores by ethylene chemical vapour deposition (CVD) in the absence of a catalyst. A composite material, containing one nanotube for each channel, having the same length as the membrane thickness and an external diameter close to the diameter of the membrane holes, was obtained. Yield, selectivity and quality of CNTs in terms of diameter, length and arrangement (i.e. number of tubes for each channel) were optimized by investigating the effect of changing the experimental conditions for the CVD process. We showed that upon thermal treatment RAAO membranes were made up of crystallized allotropic alumina phases, which govern the subsequent CNT growth, because of their catalytic activity, likely due to their Lewis acidity. The strict control of experimental conditions for membrane preparation and CNT growth allowed us to enhance the carbon structural order, which is a critical requisite for CNT application as a substitute for copper in novel nano-interconnects.

Hydrocarbon decomposition in alumina membrane: an effective way to produce carbon nanotubes bundles

Carbon nanotubes were synthesised within the pores of an alumina membrane. The membrane had 200 nm diameter pores and 60 microm thickness, and ethylene was used as carbon source. Membrane dissolution by HF results in a bundle of parallel open tubes, aligned without macroscopic defects. The external diameter of the tubes is uniform and there is no evidence of any amorphous carbon. Wall thickness control was obtained by varying the reaction time, length by the thickness of alumina membrane, and external tube diameter by the membrane pore size. Scanning (SEM) and transmission (TEM) electron microscopy, atomic force microscopy (AFM), X-ray diffraction, thermogravimetric analysis (TG) and surface area evaluation by nitrogen adsorption were used for the characterization of membrane and nanotubes.