Primary Radical Research Articles

Selective Coupling of 1,2-Bis-Boronic Esters at the more Substituted Site through Visible-Light Activation of Electron Donor-Acceptor Complexes.

1,2‐Bis‐boronic esters are useful synthetic intermediates particularly as the two boronic esters can be selectively functionalized. Usually, the less hindered primary boronic ester reacts, but herein, we report a coupling reaction that enables the reversal of this selectivity. This is achieved through the formation of a boronate complex with an electron‐rich aryllithium which, in the presence of an electron‐deficient aryl nitrile, leads to the formation of an electron donor–acceptor complex. Following visible‐light photoinduced electron transfer, a primary radical is generated which isomerizes to the more stable secondary radical before radical‐radical coupling with the arene radical‐anion, giving β‐aryl primary boronic ester products. The reactions proceed under catalyst‐free conditions. This method also allows stereodivergent coupling of cyclic cis‐1,2‐bis‐boronic esters to provide trans‐substituted products, complementing the selectivity observed in the Suzuki–Miyaura reaction.

Selective Coupling of 1,2‐Bis‐Boronic Esters at the more Substituted Site through Visible‐Light Activation of Electron Donor–Acceptor Complexes

Abstract1,2‐Bis‐boronic esters are useful synthetic intermediates particularly as the two boronic esters can be selectively functionalized. Usually, the less hindered primary boronic ester reacts, but herein, we report a coupling reaction that enables the reversal of this selectivity. This is achieved through the formation of a boronate complex with an electron‐rich aryllithium which, in the presence of an electron‐deficient aryl nitrile, leads to the formation of an electron donor–acceptor complex. Following visible‐light photoinduced electron transfer, a primary radical is generated which isomerizes to the more stable secondary radical before radical‐radical coupling with the arene radical‐anion, giving β‐aryl primary boronic ester products. The reactions proceed under catalyst‐free conditions. This method also allows stereodivergent coupling of cyclic cis‐1,2‐bis‐boronic esters to provide trans‐substituted products, complementing the selectivity observed in the Suzuki–Miyaura reaction.

Superoxide Radicals in the Execution of Cell Death.

Superoxide is a primary oxygen radical that is produced when an oxygen molecule receives one electron. Superoxide dismutase (SOD) plays a primary role in the cellular defense against an oxidative insult by ROS. However, the resulting hydrogen peroxide is still reactive and, in the presence of free ferrous iron, may produce hydroxyl radicals and exacerbate diseases. Polyunsaturated fatty acids are the preferred target of hydroxyl radicals. Ferroptosis, a type of necrotic cell death induced by lipid peroxides in the presence of free iron, has attracted considerable interest because of its role in the pathogenesis of many diseases. Radical electrons, namely those released from mitochondrial electron transfer complexes, and those produced by enzymatic reactions, such as lipoxygenases, appear to cause lipid peroxidation. While GPX4 is the most potent anti-ferroptotic enzyme that is known to reduce lipid peroxides to alcohols, other antioxidative enzymes are also indirectly involved in protection against ferroptosis. Moreover, several low molecular weight compounds that include α-tocopherol, ascorbate, and nitric oxide also efficiently neutralize radical electrons, thereby suppressing ferroptosis. The removal of radical electrons in the early stages is of primary importance in protecting against ferroptosis and other diseases that are related to oxidative stress.

Robot-Assisted Prostate-Specific Membrane Antigen-Radioguided Surgery in Primary Diagnosed Prostate Cancer.

The objective of this study was to evaluate the safety and feasibility of 99mTc-based prostate-specific membrane antigen (PSMA) robot-assisted-radioguided surgery to aid or improve the intraoperative detection of lymph node metastases during primary robot-assisted radical prostatectomy (RARP) for prostate cancer (PCa). Methods: Men with primary high-risk PCa (≥ cT3a, International Society of Urological Pathology (ISUP) grade group ≥ 3 or prostate-specific antigen of ≥ 15 ng/mL) with potential lymph node metastasis (Briganti nomogram risk > 10% or on preoperative imaging) were enrolled in the study. Patients underwent staging 68Ga-PSMA PET/CT scanning. Preoperatively, a 99mTc-labeled PSMA ligand (99mTc PSMA I&S; 500 MBq) was administered followed by SPECT/CT. A RARP including extended pelvic lymph node dissection was performed, with intraoperative tracing of PSMA-avid tissues using a prototype DROP-IN γ-probe. Resected specimens were also measured ex vivo. Histopathologic concordance with probe findings was evaluated. A radiotracer count of ≥ 1.5 times the background reference (invivo), and ≥ 10 (absolute count) in the ex vivo setting, was considered positive. Results: Twelve patients were included (median age, 68 y, and prostate-specific antigen, 9.15 ng/mL). Most of the patients harbored ISUP 5 PCa (75%) and had avid lymph nodes on preoperative PSMA PET (64%). The DROP-IN probe aided resection of PSMA-avid (out-of-template) lymph nodes and residual disease at the prostate bed. Eleven metastatic lymph nodes were identified by the probe that were not observed on preoperative 68Ga-PSMA PET/CT. Of the 74 extraprostatic tissue specimens that were resected, 22 (29.7%) contained PCa. The sensitivity, specificity, positive predictive value, and negative predictive value of inpatient use of the γ-probe were 76% (95% CI, 53%-92%), 69% (95% CI, 55%-81%), 50%, and 88%, respectively. Ex vivo, the diagnostic accuracy was superior: 76% (95% CI, 53%-92%), 96% (95% CI, 87%-99%), 89%, and 91%, respectively, for sensitivity, specificity, positive predictive value, and negative predictive value. Of the missed lymph nodes invivo (n = 5) and ex vivo (n = 5), 90% were micrometastasis (≤3 mm). No complications greater than Clavien-Dindo Grade I occurred. Conclusion: Robot-assisted 99mTc-based PSMA-radioguided surgery is feasible and safe in the primary setting, optimizing the detection of nodal metastases at the time of RARP and extended pelvic lymph node dissection. Further improvement of the detector technology may optimize the capabilities of robot-assisted 99mTc-based PSMA-radioguided surgery.

Heterogeneous activation of H2O2/Na2S2O8 with iron ore from water distribution networks for pollutant removal.

In this study, we investigated using the main composition of pipe deposits from water distribution networks as catalyst to activate dual-oxidant H2O2/Na2S2O8 system to produce radicals for perchloroethylene and chloramphenicol removal. According to the results, the degradation efficiency of perchloroethylene by H2O2/Na2S2O8 system was 92.05% within 8 h. Due to the slow conversion between ≡Fe3+ and ≡Fe2+, the hydroxylamine was introduced to reduce reaction time. As for the results, the degradation efficiency of chloramphenicol in the H2O2/Na2S2O8 system with hydroxylamine assistance was 73.31% within 100 min. Meanwhile, several key affecting factors and the kinetic models were investigated. The primary radicals were identified by electron paramagnetic resonance and radical scavenging tests. Eleven degradation products were confirmed by high-resolution liquid chromatography-mass spectrometry. The result of this study provided the theoretical basis for resource utilization of pipe deposits in water treatment in case of emerging contamination events.

In Situ EPR Spin Trapping and Competition Kinetics Demonstrate Temperature-Dependent Mechanisms of Synergistic Radical Production by Ultrasonically Activated Persulfate.

Ultrasound coupled with activated persulfate can synergistically degrade aqueous organic contaminants. Here, in situ electron paramagnetic resonance spin trapping was used to compare radicals produced by ultrasonically activated persulfate (US-PS) and its individual technologies, ultrasound alone (US) and heat-activated persulfate (PS), with respect to temperature. Radicals were trapped using 5,5-dimethyl-1-pyrroline-N-oxide, DMPO, to form detectable nitroxide adducts. Using initial rates of radical adduct formation, and compared to US and PS, US-PS at 40 and 50 °C resulted in the largest synergistic production of radicals. Radicals generated from US were reasonably consistent from 40 to 70 °C, indicating that temperature had little effect on cavitational bubble collapse over this range. However, synergy indexes calculated from initial rates showed that ultrasonic activation of persulfate at the bubble interface changes with temperature. From these results, we speculate that higher temperatures enhance persulfate uptake into cavitation bubbles via nanodroplet injection. DMPO-OH was the predominant adduct detected for all conditions. However, competition modeling and spin trapping in the presence of nitrobenzene and atrazine probes showed that SO4•- predominated. Therefore, the DMPO-OH signal is derived from SO4•- trapping with subsequent DMPO-SO4- hydrolysis to DMPO-OH. Spin trapping is effective in quantifying total radical adduct formation but limited in measuring primary radical speciation in this case.

Photoredox Organocatalysis for the Enantioselective Synthesis of 1,7-Dicarbonyl Compounds.

We describe an asymmetric organocatalytic method to synthesize 1,7-dicarbonyl compounds containing a β-stereocenter. The chemistry relies on the formation of γ-keto radicals, generated upon oxidative ring opening of cyclobutanols mastered by an organic photoredox catalyst. These nonstabilized primary radicals are stereoselectively intercepted by an iminium ion intermediate, formed upon activation of aliphatic and aromatic enals by a chiral secondary amine catalyst. This organocatalytic photoredox method served to prepare scaffolds found in natural products and drug molecules.

Spin trapping analysis of the thermal degradation of polypropylene

The thermal degradation mechanism of poly(propylene) (PP) fabric from room temperature to 220 °C was analyzed using the electron spin resonance (ESR) spin-trapping technique. This method was adopted to prolong the lifetime of the short-lived radical intermediates generated by thermal degradation with the object of inspecting their molecular structure. A spin-trapping reagent, 2,4,6-tri‑tert-butylnitrosobenzene (TTBNB), was impregnated into the PP fabric using supercritical CO2 (scCO2) treatment in the presence of a co-solvent. The impregnation efficiency and effect were evaluated using proton nuclear magnetic resonance (1H NMR) spectroscopy, Fourier-transform infrared (FT-IR) spectroscopy, and scanning electron microscopy (SEM). ESR analysis showed that the degradation of PP is initiated from the tertiary carbon positions via two pathways: homolysis to generate ·CH3 and −CH2−·CH−CH2− radicals, and hydrogen abstraction to generate −CH2−·C(CH3)−CH2− radicals. These radicals are also attacked by oxygen to form hydroperoxides, which then decompose to form the alkoxy radicals −CH2−CH(O·)−CH2− and −CH2−C(CH3)(O·)−CH2−. These radicals are involved in the subsequent β-scission reactions that produce primary and secondary carbon radicals. Alkoxy radicals also take part in the β-scission reactions involving the main chain carbon radicals, which have a hydroxyl group in the β-position, and in hydrogen abstraction from a five-membered ring at temperatures higher than the melting-point to produce an α‑hydroxyl carbon radical, ·CH(OH)−. These inferred processes involved in the thermal degradation of PP fabric were supported by other methods of analysis, including differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and dynamic mechanical analysis (DMA).

Preparation and characterization of a magnetic microsphere synthesized from sucrose allyl ether for transcatheter arterial embolization

The polymerization of allyl monomers has been reported as notoriously difficult because of degradative chain transfer induced by the allyl radical as a primary radical with resonance-stabilized structure. A favorable approach is to produce polymers from inert monomers by using photodriven radical–mediated cyclization reaction (PRMC). In this study, Fe3O4 at sucrose allyl ether (Fe3O4@SAE) magnetic microspheres with sucrose as the skeleton and encapsulated nanomagnetic particles was prepared by PRMC. Its morphology and performance were characterized by using microscope, infrared, thermogravimetric and differential scanning calorimetry, scanning electron microscope/energy-dispersive spectrometer, and vibrating sample magnetometer. The feasibility as an embolic agent was evaluated by catheter transportability and cell compatibility. The results show that Fe3O4@SAE (sucrose allyl ether) magnetic microspheres have an average particle size of 371 μm, regular spherical shape, good dispersion, basically non-toxicity, and good cell compatibility. It has a certain degree of magnetism and can use alternating magnetic fields to achieve targeted embolization.

Catalytic cleavage and functionalization of bulky and inert Csp3–Csp3 bonds via a relayed proton-coupled electron transfer strategy

Catalytic cleavage and functionalization of unstrained carbon–carbon bonds represent a formidable challenge for synthetic chemistry. Despite tremendous advances in transition-metal catalysis and photoredox radical chemistry, methods for the cleavage of sterically crowded inert C sp3 –C sp3 bonds remain underdeveloped. Here we describe the direct, photoredox cleavage of hindered C sp3 –C sp3 bonds of alcohols under neutral conditions. A relayed proton-coupled electron transfer (PCET) strategy is employed that overcame the previous requirement of a Brønsted base. Heavily branched alcohols with a high oxidation potential ( E ox½ > +2 V versus saturated calomel electrode) are cleaved and functionalized with remarkable efficiency and versatility. A simple, non-substituted phenyl group can promote a relayed PCET process to deliver primary, secondary, and tertiary alkyl radicals under neutral conditions. • Proton-coupled electron transfer • C–C cleavage of alcohols • Alkyl radicals • Various radicalophiles Liao et al. report a Fukuzumi acridinium salt as a catalyst for the C–C bond cleavage of linear primary, secondary, and tertiary carbinols under neutral conditions. The resulting transient alkyl radical species can be intercepted using various radicalophiles, including electron-deficient alkenes, an electrophilic SCF 3 reagent, and a range of heteroaryls.

Degradation of tetracycline by FeNi-LDH/Ti3C2 photo-Fenton system in water: From performance to mechanism

Recently, photo-Fenton technology has been widely used to degrade tetracycline (TC) because of its great efficiency and wide application range. Herein, Fe–Ni layered double hydroxides (FeNi-LDH)/Ti3C2 photo-Fenton system was constructed in this study. The results showed the introduction of Ti3C2 solved some problems of FeNi-LDH such as poor conductivity, easy aggregation, and high recombination rate of photoelectron. Benefiting from these advantages, FeNi-LDH/Ti3C2 exhibited excellent TC removal rate of 94.7% while pure FeNi-LDH was only 54%. Besides, FeNi-LDH/Ti3C2 possessed strong pH tolerance (2–11) and the removal efficiency was still up to 82% after the four-cycle experiment. Furthermore, the quenching experiments revealed the reaction mechanism, where ∙OH and ·O2− were the primary active radicals for degrading TC. Last, the results of the simulated wastewater treatment and the inorganic ion interference tests showed that FeNi-LDH/Ti3C2 possessed practical application potential. In brief, this study shows that FeNi-LDH/Ti3C2 can offer a certain theoretical basis for the actual development of hydrotalcite in heterogeneous photo-Fenton systems.

Algae-derived metal-free boron-doped biochar as an efficient bioremediation pretreatment for persistent organic pollutants in marine sediments

Aquatic systems are important sinks of persistent organic pollutants (POPs), such as polycyclic aromatic hydrocarbons (PAHs). In this study, boron-doped biochar (B-BAB) was prepared from pristine brown algae (Sargassum duplicatum) and boric acid using a facile pyrolysis method. The B-BAB was then used as catalyst for the activation of peroxymonosulfate (PMS) for bioremediation-based sediment decontamination. The effect of catalyst dosage and initial pH of the B-BAB/PMS system on PAH removal were studied. At an initial pH of 3.0, 93% of the PAH was degraded within 12 h in the presence of 1.0 g/L of B-BAB and 1 × 10−4 M of PMS, while the removal of 2-, 3-, 4-, 5-, and 6-ring PAHs was 53, 86, 81, 83, and 91%, respectively. Results demonstrated that B-BAB has superior catalytic capacity for PMS activation and significantly improved the efficacy of PAH removal. Interaction between boric and nitrogen species on the graphitized carbon framework, through the primary radical (SO4•– and HO•) and nonradical (1O2) reactions in the B-BAB/PMS system was key to efficient PAHs removal. High PAH removal capability and favorable changes in benthic bacterial communities of the B-BAB/PMS process suggested that PMS-advanced oxidation process (AOP) treatment enhanced the biological richness and microbiota diversity of the sediments, which were initially dominated by Proteobacteria and Epsilonbacteraeota, including genera related to Woeseia and Sulfurovum. Overall, the present study significantly expanded knowledge on the metal-free nature of carbocatalysis-boosting B-BAB/PMS removal of POPs. The B-BAB/PMS system may be useful to realizing the application of green technologies for future water environment bioremediation campaigns.

Anisotropic magnetic field effects in the re-oxidation of cryptochrome in the presence of scavenger radicals.

The avian compass and many other of nature's magnetoreceptive traits are widely ascribed to the protein cryptochrome. There, magnetosensitivity is thought to emerge as the spin dynamics of radicals in the applied magnetic field enters in competition with their recombination. The first and dominant model makes use of a radical pair. However, recent studies have suggested that magnetosensitivity could be markedly enhanced for a radical triad, the primary radical pair of which undergoes a spin-selective recombination reaction with a third radical. Here, we test the practicality of this supposition for the reoxidation reaction of the reduced FAD cofactor in cryptochrome, which has been implicated with light-independent magnetoreception but appears irreconcilable with the classical radical pair mechanism (RPM). Based on the available realistic cryptochrome structures, we predict the magnetosensitivity of radical triad systems comprising the flavin semiquinone, the superoxide, and a tyrosine or ascorbyl scavenger radical. We consider many hyperfine-coupled nuclear spins, the relative orientation and placement of the radicals, their coupling by the electron-electron dipolar interaction, and spin relaxation in the superoxide radical in the limit of instantaneous decoherence, which have not been comprehensively considered before. We demonstrate that these systems can provide superior magnetosensitivity under realistic conditions, with implications for dark-state cryptochrome magnetoreception and other biological magneto- and isotope-sensitive radical recombination reactions.

Activation of sulfite by ferric ion for the degradation of 2,4,6-tribromophenol with the addition of sulfite in batches

In this work, the removal of 2,4,6-tribromophenol (TBP) by ferric ion-activated sulfite [Fe(III)/S(IV)] process was systematically investigated with determining the intermediate products and evaluating the influences of some operational conditions and water matrices. Our results show that batching addition of S(IV) benefits the S(IV) utilization efficiency and TBP removal, with SO 4 •‒ being the primary reactive radical accounting for TBA degradation. The maximum TBP removal in the Fe(III)/S(IV) process was observed at pH 4.0 and oxygen is essential in this process. With increasing Fe(III) and S(IV) dosages from 0.05 and 0.1 mmol/L to 0.2 and 2.0 mmol/L, respectively, TBP removal followed trends of first increase then decrease. As the acute toxicity of the TBP solution was significantly reduced, the Fe(III)/S(IV) process was believed to be a good choice in the treatment of TBP. Graphical Abstract The combined process of ferric ion and sulfite [S(IV)] has been firstly applied to degrade 2,4,6-tribromophenol with dosing S(IV) in batches, in which sulfate radical plays the dominant role with transforming the most bromine contained in the 2,4,6-tribromophenol into bromide. .

Role of Functional Groups in the Monomer Molecule on the Radical Polymerization in the Presence of Graphene Oxide. Polymerization of Hydroxyethyl Acrylate under Isothermal and Non-Isothermal Conditions.

Functional groups in a monomer molecule usually play an important role during polymerization by enhancing or decreasing the reaction rate due to the possible formation of side bonds. The situation becomes more complicated when polymerization takes place in the presence of graphene oxide since it also includes functional groups in its surface. Aiming to explore the role of functional groups on polymerization rate, the in situ bulk radical polymerization of hydroxyethyl acrylate (HEA) in the presence or not of graphene oxide was investigated. Differential scanning calorimetry was used to continuously record the reaction rate under both isothermal and non-isothermal conditions. Simple kinetic models and isoconversional analysis were used to estimate the variation of the overall activation energy with the monomer conversion. It was found that during isothermal experiments, the formation of both inter- and intra-chain hydrogen bonds between the monomer and polymer molecules results in slower polymerization of neat HEA with higher overall activation energy compared to that estimated in the presence of GO. The presence of GO results in a dissociation of hydrogen bonds between monomer and polymer molecules and, thus, to higher reaction rates. Isoconversional methods employed during non-isothermal experiments revealed that the presence of GO results in higher overall activation energy due to the reaction of more functional groups on the surface of GO with the hydroxyl and carbonyl groups of the monomer and polymer molecules, together with the reaction of primary initiator radicals with the surface hydroxyl groups in GO.

RECONSTRUCTION OF TWO DISCRETE SURGICAL DEFECTS IN HEAD AND NECK IN THE ABSENCE OF FREE FLAPAVAILABILITY-AN INSTITUTIONAL EXPERIENCE

Introduction: Operable oral and oropharyngeal tumors with extra nodal extension inltrating the skin at level II to V require resection of primary and extended radical neck dissection can result in a defect at both primary and neck with intervening normal tissue. Ideally they need to be reconstructed with a chimeric free ap but in cases where it was not possible, locoregional aps were utilized. Aim-To discuss and compare our experience with various methods to reconstruct two discrete defects. Materials And Methods: This is a retrospective study from the Head Neck Oncology Dept of a Kidwai Memorial Institute Of Oncology, Bangalore, India between March 2016 – August 2021. A total of 14 were included in this study and divided into 3 groups. Group-1 included Pectoralis Major Myocutaneous Flap (PMMC) in a dual island technique, group-2 included reconstruction with combination of two locoregional aps. Group-3 included reconstruction with PMMC with split skin graft(SSG) covering for external defect. Results: The time taken to raise a dual-islanded PMMC and for PMMC with split thickness skin grafting an average is 50minutes compared to group-2- 90minutes. The time for insertion into the defects were one-and-a -half times more in the group-2 than other groups. No patients in group 1 and group 2 had a delay in receiving adjuvant treatment, whereas 50% of patient in group-3 could not receive adjuvant radiotherapy on time due to delayed wound healing. Conclusion- any of the three options can be considered for reconstruction of two discrete defects. PMMC with dual island technique found to be the most effective one with shorter operating time and with the least complication rate.

Generation and reactivity of vinyltelluryl radical.

Vinyltelluryl radical was prepared by high-vacuum flash pyrolysis from the corresponding divinylditelluride and trapped in an argon matrix at 10 K. The title compound was characterized by IR and UV/Vis spectroscopy, and all experimental data match well with density functional theory at the UB3LYP/def2-QZVPP level. According to UB3LYP/def2-QZVPP computations, the spin density is mainly localized on the Te atom. The vinylogy principle for the vinyltelluryl radical is not applicable due to the lack of delocalization of spin density. Upon irradiation of the matrix with light (λ = 365 nm), the vinyltelluryl radical rearranges to a H-Te˙⋯acetylene complex. Doping the matrix with molecular oxygen leads to the hitherto unknown vinyltelluro peroxy radical. The latter isomerizes to the more thermodynamically stable vinyltelluroyl radical by irradiation with light at λ = 523 nm.

Effect of Number of Retrieved Lymph Nodes on Prognosis in FIGO Stage IA1-IIA2 Cervical Cancer Patients Treated With Primary Radical Surgery.

Background:The influence of the number of removed lymph nodes (RLNs) on patients with early-stage cervical cancer (ESCC) is still questionable. The objective of this study was to explore the prognostic value of RLNs on ESCC patients.Methods:A retrospective study was performed including all ESCC patients who underwent radical surgery from January 2016 to December 2018. Cox regression analysis was performed to verify the correlation between the number of RLNs and the prognosis (recurrence-free survival [RFS], disease-specific survival [DSS]) of ESCC. According to the guidelines, all the patients were divided into high-risk and non-high-risk groups. The optimal cut-off values of RLNs were determined by receiver operating characteristic curve analysis and Youden index and further the prognostic value of them was explored.Results:A total 1101 patients were enrolled. The number of RLNs was an independent prognostic influence factor of the prognosis of ESCC (P < .001 for RFS, P < .001 for DSS). The optimal cut-off values of RLNs (40 in the high-risk group and 23 in the non-high-risk group) were significantly associated with the prognosis of ESCC, in the high-risk group (P < .001 for RFS, P = .002 for DSS) and non-high-risk group (P < .001 for RFS, P < .001 for DSS), respectively.Conclusions:More extensive lymph node dissection (RLNs ⩾ 40) could benefit the high-risk ESCC patients. However, in the non-high-risk group, moderate lymph node dissection (RLNs ≈23) could also benefit them and may reduce the incidence of related complications. Those findings may help to determine the scope of lymph node dissection in ESCC patients before operation.

Transtumoral endoprothesis in surgery of colorectal cancer, complicated with colonic obstruction: advantages and disadvantages. A review of the literature

A multifactorial analysis of the literature data on the treatment of acute tumor colonic obstruction using minimally invasive endoscopic surgical technology was carried out. On the basis of the analysis of special publications, the effectiveness of stenting of the large intestine, as a minimally invasive endoscopic method of decompression, is presented. Indications and contraindications for colorectal stenting, advantages and disadvantages, possibilities and prospects of endoscopic decompression of the colon are described in detail. It is postulated that stenting, used in acute tumor obstruction of the colon as a «bridge to surgery», being a worthy alternative to classical colostomy, allows an effective antegrade decompression of the colon and prepares the patient to surgical treatment with the performance of oncological justified primary radical and one-stage restorative operations in more optimal conditions with minimal risk. It is shown that in the late stages of the malignant process and in the presence of neresect-leucorrhoea colorectal cancer, as well as in the presence of absolute contraindications to a radical surgeon Colon stenting can serve as the final treatment for inoperable patients.

Cervical conization before primary radical hysterectomy has a protective effect on disease recurrence in early cervical cancer: A two-center matched cohort study according to surgical approach

ObjectiveTo ascertain whether cervical conization before radical hysterectomy (RH) has a protective effect on survival outcomes in early cervical cancer, taking into account the surgical approach. MethodsFrom cervical cancer cohorts of two institutions, we identified node-negative, margin-negative, parametria-negative, 2009 FIGO stage IB1 cervical cancer patients who received primary Type C RH between July 2006 and June 2020. Patients were divided into conization group (n = 144) and control group (n = 434). We conducted three independent 1:1 propensity score matching processes for histology, lymphovascular space invasion, cervical tumor size, and surgical approach (all patients, those who underwent open surgery, and those who underwent minimally invasive surgery [MIS]). Survival outcomes were compared. ResultsOverall, the conization group had less cervical tumor size and received MIS more frequently (P = 0.010) and adjuvant treatment less often (P = 0.002) versus the controls. After matching, the conization group showed significantly better disease-free survival (DFS) versus control (3-year DFS rate, 94.2% vs. 86.3%; P = 0.012), but similar overall survival. Among the open RH matched patients (n = 96), no difference in DFS was observed between the conization and control groups (P = 0.984). In contrast, among the MIS RH matched patients (n = 192), the conization group showed significantly better DFS versus control (3-year DFS rate, 95.7% vs. 82.9%; P = 0.005). In multivariate analysis adjusting for cervical tumor size and adjuvant treatment, conization was identified as an independent favorable prognostic factor for DFS (adjusted HR, 0.318; 95% CI, 0.134–0.754; P = 0.009). ConclusionsPreoperative cervical conization might reduce the disease recurrence rate in early cervical cancer patients who undergo primary MIS RH.