OBJECTIVETo investigate the effectiveness of microbubble-enhanced ultrasound (MEUS) for detecting perforators preoperatively in supraclavicular flap surgery.

METHODSFrom May 2009 to October 2013, there were 20 patients (26 flaps were involved) who planned to undergo supraclavicular artery based flap surgeries to recover the large-area defects in head and neck. The MEUS together with regular color Doppler ultrasound ( CDUS) were conducted preoperatively to determine the anatomical features of perforators branching from supraclavicular arteries (SCA). The perforator with wider caliber, faster flow speed, longer pedicles and closer pivot point was selected and the flap was designed according to the observed results.

RESULTSThere were 37 perforators of SCA detected by CDUS, whose calibers were ranging from 0.5 to 0.8 mm [Mean: (0.6 ± 0.1) mm]. There were 48 perforators of SCA detected by MEUS. Compared to CDUS, the caliber obtained from MEUS for same vessel is significantly increased [(0.7 ± 0.3) mm vs (0.6 ± 0.1) mm, P < 0.05]. According to the results of MEUS and three-dimensional reconstructive techniques, in at least 65.4% (17/26) of the flaps, thoracic branch of SCA (TBSA) has large caliber and good flow velocity which can be regarded as the predominant vessel and used as the pedicle of flap. The results of the operations confirmed the existences of all the marked vessels. 25 flaps were obtained according to the preoperative plans and one case used perforators of internal mammary artery as free flaps since the perforator of SCA was found improper. The contrast-related complication occurred in one patient which was manifested by gastrointestinal adverse effect like nausea and anorexia. The patient recovered 1 day later without treatment. All the patients have been followed up for 3 to 16 months (Mean: 8 months) with well-survived flaps.

CONCLUSIONSThe perforators of SCA demonstrated significant variations and preoperative mapping was vital for the success of surgery. MEUS is a valuable imaging modality for the preoperative assessment of the vascular supply for supraclavicular artery based flap.

Arteries ; diagnostic imaging ; Humans ; Mammary Arteries ; Microbubbles ; Neck ; surgery ; Perforator Flap ; Reconstructive Surgical Procedures ; Ultrasonography ; methods

Objective To evaluate the geometry of mitral valve and annulus in patients with mitral regurgitation, and to quantify the mitral annular remodeling and motion in ischemic mitral regurgitation (IMR) with mitral valve assessment (MVA) software. Methods Seventeen patients were divided into two groups: IMR group (n=10) and non-IMR group (n=7), and other 11 patients without significant mitral regurgitation (＜2+) and mitral structure abnormality were regarded as control group. The imaging was analyzed offline with Siemens MVA software to measure the annular diameters, annular circumference, anterior and posterior annular length, annular area (MAA) and non-planar angel (NPA). The dynamic changes during the cardiac cycle were calculated. Results Compared with control group, the posterior annular length and NPA significantly increased in IMR group (P＜0.05, P＜0.01). During the systole, the posterior annular and annular circumference paradoxically prolonged in IMR group compared with control group (median Δ posterior annular length: -2.71 mm/m2 vs 0.52 mm/m2, P＜0.05). In all patients of non-IMR group, the geometric character of mitral valve lesions shown in 3-dimensional echocardiography was accordant with surgical findings. Conclusion Three-dimensional echocardiography combined with MVA software provides a useful tool for assessment the geometric character of mitral valve lesions and quantification of mitral annulus remodeling, which is helpful to understand the mechanism of MR and guide surgical treatment.

BACKGROUND:Socket-shield technique can effectively maintain labial soft and hard tissues,but the incidence of postoperative complications such as exposure and displacement of root shield is relatively high.It is speculated that the root shield may be exposed and displaced due to excessive load after long-term function of dental implants. OBJECTIVE:Through three-dimensional finite element analysis,we aim to study the influence of varying root shield thicknesses on the stress distribution,equivalent stress peaks,and displacement in the root shield,periodontal ligaments,implant,and surrounding alveolar bone under normal occlusal loading.We also attempt to analyze the correlation between the thickness of the root shield and occurrence of mechanical events such as root shield exposure,displacement,and fracture. METHODS:Cone-beam CT data of a patient who met the indication standard of socket-shield technique for maxillary central incisor were retrieved from database.Reverse engineering techniques were used to build models of the maxillary bone and root shield,while forward engineering was used to create models for the implant components based on their parameters.Models depicting various root shield thicknesses(0.5,1.0,1.5,and 2.0 mm)were created using Solidworks 2022 software.ANSYS Workbench 2021 software was then used to simulate and analyze the effects of varying root shield thicknesses on stress distribution,equivalent stress peaks,and displacement of the root shields,periodontal ligaments,implants,and surrounding alveolar bone under normal occlusion. RESULTS AND CONCLUSION:(1)In all root shield models,the stress was concentrated on the palatal cervical side,both sides of the edges and the lower edge of the labial side.As the thickness of the root shield increased,the equivalent stress peak and displacement showed a decreasing trend.The 0.5 mm thickness model produced a stress concentration of 176.20 MPa,which exceeded the yield strength(150 MPa)of tooth tissue.(2)The periodontal ligament stress in each group was concentrated in the neck margin and upper region.With the increase of root shield thickness,the equivalent stress peak and displacement of periodontal ligament showed a decreasing trend.(3)Implant stress in all models was concentrated in the neck of the implant and the joint of the implant-repair abutment,and the labial side was more concentrated than the palatal side.With the increase of root shield thickness,the equivalent stress peak of the implant in the model showed an increasing trend.(4)In each group of models,stress of cortical bone concentrated around the neck of the implant and the periphery of the root shield,and the labial side was more concentrated than the palatal side.With the increase of the thickness of the root shield,the equivalent stress peak around the root shield decreased;the peak value of the equivalent stress of the bone around the neck of the implant showed an increasing trend.In the model,the stress of cancellous bone was mainly concentrated around the neck of the lip of the implant,the top of the thread,the root tip and the lower margin of the root shield,and the labial side was more concentrated than the palatal side.With the increase of the thickness of the root shield,the peak value of the equivalent stress of the bone around the root shield in the model showed a decreasing trend.The minimum principal stress of cortical bone in each group of models was concentrated around the neck of the implant,exhibiting a fan-shaped distribution.As the thickness of the root shield increased,the minimum principal stress of cortical bone showed an increasing trend.(5)These results indicate that different thicknesses of the root shield have different biomechanical effects.The root shield with a thickness of 0.5 mm is easy to fracture.For patients with sufficient bone width,the root shield with a thickness of 2.0 mm is an option to reduce the risk of complications such as root shield exposure,fracture,and displacement.Meanwhile,it should be taken into account to protect the periodontal ligament in the preparation process,and rounding treatments ought to be carried out on both sides and the lower edge of the root shield.

Cerium oxide nanoparticles (CeO₂ NPs), as the oxides of the most abundant elements in rare earths, have been widely used in biomedical and industrial production and other fields that are closely related to human life. China is a large country in resources and production of rare earth, and the impact of CeO₂ NPs on human health has been increasingly concerned. In response to the possible health risks of CeO₂ NPs, researchers begin to focus on their toxic effects on living organisms, especially on the reproductive system. The male reproductive system is not only responsible for producing sperm and regulating the secretion of testosterone, but also plays a key role in maintaining male sexual characters and function. Any adverse effects on the male reproductive system may lead to reduced fertility and reproductive dysfunction. Some studies have shown that long-term exposure to CeO₂ NPs may lead to gonadal damage, sex hormone disorders, and other problems in male animals. Therefore, an in-depth study of the potential effects of CeO₂ NPs on the male reproductive system is of great scientific significance and practical value. In this study, we reviewed the male reproductive toxicity of CeO₂ NPs in terms of spermatogenic cells, spermatozoa structure, blood-testis barrier, hypothalamic-pituitary-gonadal axis, and functional changes in epididymis, and analyzed the effects of the size and shape of physicochemical parameters of CeO₂ NPs on the toxicity to male reproductive system. The findings will provide a theoretical basis and scientific evidence for the rational use of CeO₂ NPs.