Hasil untuk "Surgery"

A. Stout, M. R. Murray

D. Sutherland, R. Olshen, L. Cooper et al.

F. Niessen, P. Spauwen, J. Schalkwijk et al.

K. Kondo, Y. Monden

M. Owings, L. Kozak

B. Atkins, N. Athanasou, J. Deeks et al.

O. Farges, J. Belghiti, R. Kianmanesh et al.

C. Gutt, J. Encke, J. Köninger et al.

A. Nicholson, M. C. Lowe, J. Parker et al.

André Guaraci DeVito-Moraes, Isabela Souza Vardasca, Miguel Peñarrocha-Diago et al.

This study investigates the mechanical and optical properties of monolithic zirconia used in dentistry, focusing on how different concentrations of yttrium oxide and varied sintering times affect the material. A critical trade-off in ceramics has been reported in the literature, in which increased crystalline content (like in zirconia) leads to higher mechanical strength but lower aesthetic translucency. However, detailed information on this trade-off process for different types of zirconia is lacking. A total of seven types of zirconia varying in yttria content (3 mol% to 5 mol%) were tested across four sintering protocols available in a laboratory zirconia sintering device: Slow (12 h), Standard (8 h), Fast (3.5 h), and Ultrafast (1.15 h). The primary findings indicate that while a higher yttria concentration correlates with lower flexural strength and high translucency, the sintering time generally did not compromise mechanical strength or color variation across most samples. Nevertheless, the Fast and Ultrafast protocols did significantly reduce the translucency of zirconia with a high concentration of yttrium oxide.

U. Khot, A. Lang, K. Murali et al.

G. Pettersson, S. Hussain

The 2016 American Association for Thoracic Surgery (AATS) guidelines for surgical treatment of infective endocarditis (IE) are question based and address questions of specific relevance to cardiac surgeons. Clinical scenarios in IE are often complex, requiring prompt diagnosis, early institution of antibiotics, and decision-making related to complications, including risk of embolism and timing of surgery when indicated. The importance of an early, multispecialty team approach to patients with IE is emphasized. Management issues are divided into groups of questions related to indications for and timing of surgery, pre-surgical work-up, preoperative antibiotic treatment, surgical risk assessment, intraoperative management, surgical management, surveillance, and follow up. Standard indications for surgery are severe heart failure, severe valve dysfunction, prosthetic valve infection, invasion beyond the valve leaflets, recurrent systemic embolization, large mobile vegetations, or persistent sepsis despite adequate antibiotic therapy for more than 5-7 days. The guidelines emphasize that once an indication for surgery is established, the operation should be performed as soon as possible. Timing of surgery in patients with strokes and neurologic deficits require close collaboration with neurological services. In surgery infected and necrotic tissue and foreign material is radically debrided and removed. Valve repair is performed whenever possible, particularly for the mitral and tricuspid valves. When simple valve replacement is required, choice of valve-mechanical or tissue prosthesis-should be based on normal criteria for valve replacement. For patients with invasive disease and destruction, reconstruction should depend on the involved valve, severity of destruction, and available options for cardiac reconstruction. For the aortic valve, use of allograft is still favored.

F. Rubino, M. Gagner, P. Gentileschi et al.

Sun-wook Kim, Ho-Seong Han, Hee-Won Jung et al.

K. Peeters, R. Tollenaar, C. Marijnen et al.

C. Akins, D. C. Miller, M. Turina et al.

Boris Penev, Hallmon Hughes, Katherine Scarpino et al.

Introduction: The trigeminocardiac reflex (TCR), a physiologic response to irritation of the branches of the trigeminal nerve, was first described in humans in 1870. Gastric hypermotility, hypotension, bradycardia, and even asystole have been reported in response to surgical manipulation of the trigeminal nerve and its branches, but literature is limited in patients not undergoing surgery. Although effects are generally transient and benign, TCR can present a significant diagnostic and therapeutic challenge in patients undergoing surgical manipulation of the trigeminal nerve and its branches. Case Report: We describe a case of severe bradycardia secondary to facial trauma causing hemodynamic compromise and diagnostic uncertainty. Conclusion: This case highlights a possible case of TCR, as well as therapeutic considerations, in a patient presenting to the emergency department with severe facial trauma.

Yuto Takada, Hiroshi Doi, Yuko Kinoshita et al.

A case of a patient who developed a radiation recall reaction (RRR) triggered by coronavirus disease 2019 (COVID-19) infection following surgery and chemoradiotherapy for carcinoma of the buccal mucosa is reported. A 75-year-old woman presented in October 2023 with pyrexia and erythema extending from the left cheek to the anterior chest area. In December 2021, she had undergone surgery to remove a carcinoma of the left buccal mucosa (pT2N0M0), followed by left comprehensive neck dissection for delayed cervical lymph node metastasis in June 2022, with subsequent adjuvant chemoradiotherapy. Her course was uneventful until September 2023, when she developed COVID-19. Twenty-three days after COVID-19 infection had been confirmed, she developed systemic pyrexia with erythema and a heat sensation from her left cheek to the left anterior chest. On presentation, her temperature was 39 ºC, and she had a mild sore throat. Erythema and a heat sensation were apparent from the left cheek to the neck and anterior chest, corresponding to the previously irradiated area. Laboratory tests showed a white blood cell count of 11,760/μl, and C-reactive protein of 16.0 mg/dl. Computed tomography did not show any obvious abscess formation or infection source. An RRR was diagnosed, and she was admitted for treatment with intravenous sulbactam/ampicillin and intravenous hydrocortisone sodium succinate. Five days after admission, the inflammatory reaction had improved, and she was discharged. Her subsequent course has been uneventful, with no flareup of the RRR. This case is presented along with a review of relevant literature.

Xuanyu Chen, Zhangfu Li, Chao Zheng et al.

Abstract Objective This study aims to investigate changes in matrix metalloproteinase (MMP) and tissue inhibitor of metalloproteinase (TIMP) levels in the intervertebral discs of New Zealand white rabbits under simulated overload and microgravity conditions, focusing on the expression of MMP1, MMP3, and TIMP1. The findings aim to provide a theoretical foundation for preventing and delaying lumbar disc degeneration in these environments. Methods Overload was simulated using an animal centrifuge, and microgravity was mimicked through tail suspension. A randomized single-blind method was applied to divide 120 age- and weight-matched New Zealand white rabbits into six groups: control groups (30 d, 60 d, 90 d) and overload/microgravity groups (30 d, 60 d, 90 d), with 20 rabbits per group. The expression of MMP1, MMP3, and TIMP1 in the lumbar intervertebral discs was measured and analyzed using statistical methods, including chi-square tests and t-tests, across different exposure times. Results In the experimental groups, MMP1 and MMP3 expression levels were significantly higher than those in the corresponding control groups at all time points (P < 0.01). MMP1 and MMP3 levels progressively increased with longer exposure durations, showing statistically significant differences (P < 0.01). TIMP1 expression was significantly higher in the 30-day and 60-day experimental groups than in the control group (P < 0.01), but decreased in the 90-day group, indicating a late-stage imbalance in the MMP/TIMP1 ratio. Conclusion Simulated overload and microgravity conditions lead to elevated MMP1, MMP3, and TIMP1 expression in lumbar intervertebral discs, promoting accelerated disc degeneration.

Gokhan Canko, Ozge Doganay Ozyilmaz

Abstract Statement of problem Recent advancements in digital technology have revolutionized implant dentistry, particularly with additively manufactured subperiosteal jaw implants (AMSJIs). These implants allow patient-specific designs that adapt to anatomical requirements. However, optimizing stress distribution remains a challenge. Purpose This study evaluated the stress distribution in AMSJIs and surrounding bone by analyzing different framework materials (PEEK and Co-Cr), anterior wing designs (I- and Y-shaped), and cantilever extensions using three-dimensional finite element analysis. Methods A model was created from a patient with an atrophic, edentulous maxilla. Biomechanical evaluation of eight maxillary implant scenarios was performed under a 200 N force applied at a 45° oblique angle. Stress distribution in the bone, implants, screws, and prosthetic frameworks, as well as prosthetic displacement, was analyzed. Results The lowest implant stress (444.5 MPa) was observed in the Co-Cr group without a cantilever using an I-shaped design, whereas the highest stress (623.0 MPa) occurred in the Co-Cr group with a cantilever using a Y-shaped design. Prosthetic displacement was greater in cantilevered groups, with PEEK exhibiting more displacement than Co-Cr. Conclusions The optimal stress distribution was achieved with the I-shaped design without a cantilever, using Co-Cr. Stress levels were significantly influenced by framework material, wing design, and cantilever presence, underscoring the importance of design and material selection. Clinical significance While stress remained within physiological limits in all cases, avoiding cantilevers and selecting a rigid material can optimize Y-shaped designs. PEEK demonstrated favorable properties in cantilevered designs, but its long-term effects on soft tissue and implants warrant further clinical trials.