Conversion in laparoscopic cholecystectomy for acute cholecystitis

Scopul lucrării. Colecistectomia laparoscopică a devenit o operație curentă în practica chirurgicală zilnică și este considerată în prezent un standard de aur, oferind posibilitatea de a rezolva aproape toate litiazele veziculare simptomatice. În anumite cazuri totuși, condițiile tehnice particulare creează riscuri specifice, ce impun conversia la tehnica deschisă.Materiale și metodă. Studiul nostru se întinde pe o perioada de 5 ani, fiind incluși următorii factori: forma anatomopatologică, motivele și rata conversiei, complicațiile postoperatorii și durata medie de spitalizare.Rezultate. În perioada decembrie 2018- decembrie 2022 au fost efectuate 3576 de colecistectomii laparoscopice din care 2848 au fost realizate pentru colecistita acută (79,6%). Din punct de vedere al formelor anatomopatologice au predominat colecistitele acute catarale (52%), urmate de cele flegmonoase (37%) și gangrenoase (11%). Rata conversiei a fost de 5,4% (156 cazuri), cu o tendință constantă la descreștere corelată cu îmbunătățirea experienței echipei chirurgicale. Printre cele mai întâlnite cauze ce au dus la conversie putem enumera: anatomie incertă datorită proceselor inflamatorii importante (62 de pacienți), fibroza la nivelul triunghiului Calot (43 de cazuri), dar și alte cauze (hemoragie, ciroză hepatică, sindrom aderențial – 51 de cazuri ). La pacienții la care s-a realizat conversia, complicațiile postoperatorii au fost întâlnite în 18% din cazuri, durata medie de spitalizare a fost de 13 zile, cu o mortalitate de 1,28%.Concluzii. Conversia în colecistectomia laparoscopică pentru colecistita acută reprezintă o dovadă a maturității chirurgicale şi nu trebuie considerată un eșec al tehnicii laparoscopice, fiind salutată în situații în care avantajul abordului laparoscopic este depăsit de riscurile unor situații întâlnite în practică.Aim of study. Laparoscopic cholecystectomy is now the “gold standard” operation for patients with gallstones disease. However, a number of patients require conversion to open cholecystectomy for the safe completion of the procedure, generally being certified that untransparency in operative field, unclear anatomical proportion , are the most frequent causes of conversion and postoperative complications.Materials and methods. From 3576 patients who underwent laparoscopic cholecystectomy between 2018-2022, we selected a lot of 2848 cases of acute cholecystitis and evaluated the conversion rate encountered. The patients were selected according to the morphopatological form of cholecystitis as: catarrhal cholecystitis – 52% (1436 cases), phlegmonous cholecystitis - 37% (1275 cases) and gangrenous cholecystitis – 11% (896 cases). The conversion rate was 5,4% (156 cases) Results. In this paper the modalities, the technical particularities and the causes that can lead to conversion in laparoscopic cholecystectomy for acute cholecystitis are discussed.Conclusions. Laparoscopic cholecystectomies can be safely performed for almost all patients with acute cholecystitis by an experienced surgical team, although unclear anatomy secondary to inflammation remains the most common reason for conversion leading to higher rate of postoperative complications and a longer hospital stay, the overall impact of acute cholecystitis on the operative outcome has decreased with time

Multilevel Spiral Axicon for High-Order Bessel–Gauss Beams Generation

This paper presents an efficient method to generate high-order Bessel–Gauss beams carrying orbital angular momentum (OAM) by using a thin and compact optical element such as a multilevel spiral axicon. This approach represents an excellent alternative for diffraction-free OAM beam generation instead of complex methods based on a doublet formed by a physical spiral phase plate and zero-order axicon, phase holograms loaded on spatial light modulators (SLMs), or the interferometric method. Here, we present the fabrication process for axicons with 16 and 32 levels, characterized by high mode conversion efficiency and good transmission for visible light (λ = 633 nm wavelength). The Bessel vortex states generated with the proposed diffractive optical elements (DOEs) can be exploited as a very useful resource for optical and quantum communication in free-space channels or in optical fibers

Carbon nanotubes growth from C2H2 and C2H4/NH3 by catalytic LCVD on supported iron-carbon nanocomposites

We report about the synthesis of carbon nanotubes by catalytic LCVD (C-LCVD), using a CW CO2 laser and alternatively, C2H2/ C2H4/NH3 and C2H2/C2H4-containing gas mixtures. Different core-shell Fe-C nanocomposites (as synthesized and toluene extracted) were used employed as catalysts. The nanotubes grown from Fe-C residue demonstrate the lowest mean diameters. Prevalent curled and coiled morphologies are obtained for the CNTs grown in the presence of ammonia. (c) 2006 Elsevier B.V. All rights reserved

Investigation of wet etching technique for selective patterning of ferroelectric zirconium-doped hafnium oxide thin films for high-frequency electronic applications

This paper presents the area-selective wet etching (ASWE) method as a novel approach to have a selective patterning of a 6.8 nm-thick zirconium-doped hafnium oxide (HZO) thin film, to improve the performance of a metal ferroelectric metal (MFM)-like structure. According to the electromagnetic simulations of microwave phase shifters with patterned HZO thin films, it is underlined the importance to have selectively targeted areas covered with HZO instead of full-coverage wafers, to gain a further increase in the microwave performance of low-voltage tunable high-frequency components. The impact of the ASWE method on the morpho-structural properties was studied using various investigation tools in a non-destructive manner. X-ray reflectivity (XRR) has been employed at different immersion times, up to 120 s. Based on the extended Fast Fourier Transform (FFT) analysis, as well as from the simulation of the experimental curves in the framework of parallel-tempering algorithm, the determination of the etching rate became possible. X-ray diffraction (XRD), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS) clearly indicated the complete removal of HZO after etching processes at 180 s. The method is fast, reliable, and low-cost, thus filling the actual gap in providing the necessary ferroelectric thin films exclusively in selected areas of interest