Leonard Knoedler

Leonard Knoedler


Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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7 September 2023 in International Journal of Surgery
Verified
Journal Article
Open access
SKSamuel Alfons Christoph Knoedler
Samuel Alfons Christoph Knoedler
RSRainer Schliermann
Rainer Schliermann
LKLeonard Knoedler
Leonard Knoedler
MWMengfan Wu
Mengfan Wu
FHFrederik Johannes Hansen
Frederik Johannes Hansen
Adriana C PanayiAdriana C Panayi
Adriana C Panayi
Background: Surgeons have historically used age as a preoperative predictor of postoperative outcomes. Sarcopenia, the loss of skeletal muscle mass due to disease or biological age, has been proposed as a more accurate risk predictor. The prognostic value of sarcopenia assessment in surgical patients remains poorly understood. Therefore, the authors aimed to synthesize the available literature and investigate the impact of sarcopenia on perioperative and postoperative outcomes across all surgical specialties. Methods: The authors systematically assessed the prognostic value of sarcopenia on postoperative outcomes by conducting a systematic review and meta-analysis according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, searching the PubMed/MEDLINE and EMBASE databases from inception to 1st October 2022. Their primary outcomes were complication occurrence, mortality, length of operation and hospital stay, discharge to home, and postdischarge survival rate at 1, 3, and 5 years. Subgroup analysis was performed by stratifying complications according to the Clavien–Dindo classification system. Sensitivity analysis was performed by focusing on studies with an oncological, cardiovascular, emergency, or transplant surgery population and on those of higher quality or prospective study design. Results: A total of 294 studies comprising 97 643 patients, of which 33 070 had sarcopenia, were included in our analysis. Sarcopenia was associated with significantly poorer postoperative outcomes, including greater mortality, complication occurrence, length of hospital stay, and lower rates of discharge to home (all P<0.00001). A significantly lower survival rate in patients with sarcopenia was noted at 1, 3, and 5 years (all P<0.00001) after surgery. Subgroup analysis confirmed higher rates of complications and mortality in oncological (both P<0.00001), cardiovascular (both P<0.00001), and emergency (P=0.03 and P=0.04, respectively) patients with sarcopenia. In the transplant surgery cohort, mortality was significantly higher in patients with sarcopenia (P<0.00001). Among all patients undergoing surgery for inflammatory bowel disease, the frequency of complications was significantly increased among sarcopenic patients (P=0.007). Sensitivity analysis based on higher quality studies and prospective studies showed that sarcopenia remained a significant predictor of mortality and complication occurrence (all P<0.00001). Conclusion: Sarcopenia is a significant predictor of poorer outcomes in surgical patients. Preoperative assessment of sarcopenia can help surgeons identify patients at risk, critically balance eligibility, and refine perioperative management. Large-scale studies are required to further validate the importance of sarcopenia as a prognostic indicator of perioperative risk, especially in surgical subspecialties.

23 October 2023 in Military Medical Research
Verified
Journal Article
Open access
PDF file
SKSamuel Alfons Christoph Knoedler
Samuel Alfons Christoph Knoedler
LKLeonard Knoedler
Leonard Knoedler
MKMartin Kauke-Navarro
Martin Kauke-Navarro
YRYuval Rinkevich
Yuval Rinkevich
Gabriel HundeshagenGabriel Hundeshagen
Gabriel Hundeshagen
Adriana C PanayiAdriana C Panayi
Adriana C Panayi
As the body’s integumentary system, the skin is vulnerable to injuries. The subsequent wound healing processes aim to restore dermal and epidermal integrity and functionality. To this end, multiple tissue-resident cells and recruited immune cells cooperate to efficiently repair the injured tissue. Such temporally- and spatially-coordinated interplay necessitates tight regulation to prevent collateral damage such as overshooting immune responses and excessive inflammation. In this context, regulatory T cells (Tregs) hold a key role in balancing immune homeostasis and mediating cutaneous wound healing. A comprehensive understanding of Tregs’ multifaceted field of activity may help decipher wound pathologies and, ultimately, establish new treatment modalities. Herein, we review the role of Tregs in orchestrating the regeneration of skin adnexa and catalyzing healthy wound repair. Further, we discuss how Tregs operate during fibrosis, keloidosis, and scarring.

PFPaul F. Funk
Paul F. Funk
Cosima C. HochCosima C. Hoch
Cosima C. Hoch
SKSamuel Alfons Christoph Knoedler
Samuel Alfons Christoph Knoedler
LKLeonard Knoedler
Leonard Knoedler
SCSebastian Cotofana
Sebastian Cotofana
MAMichael Alfertshofer
Michael Alfertshofer
(1) Background: As the field of artificial intelligence (AI) evolves, tools like ChatGPT are increasingly integrated into various domains of medicine, including medical education and research. Given the critical nature of medicine, it is of paramount importance that AI tools offer a high degree of reliability in the information they provide. (2) Methods: A total of n = 450 medical examination questions were manually entered into ChatGPT thrice, each for ChatGPT 3.5 and ChatGPT 4. The responses were collected, and their accuracy and consistency were statistically analyzed throughout the series of entries. (3) Results: ChatGPT 4 displayed a statistically significantly improved accuracy with 85.7% compared to that of 57.7% of ChatGPT 3.5 (p < 0.001). Furthermore, ChatGPT 4 was more consistent, correctly answering 77.8% across all rounds, a significant increase from the 44.9% observed from ChatGPT 3.5 (p < 0.001). (4) Conclusions: The findings underscore the increased accuracy and dependability of ChatGPT 4 in the context of medical education and potential clinical decision making. Nonetheless, the research emphasizes the indispensable nature of human-delivered healthcare and the vital role of continuous assessment in leveraging AI in medicine.

20 August 2024 in Cells
Verified
Journal Article
Open access
PDF file
NANura Ahmad
Nura Ahmad
Alexandra Magdalena AnkerAlexandra Magdalena Anker
Alexandra Magdalena Anker
Silvan Maximilian KleinSilvan Maximilian Klein
Silvan Maximilian Klein
JDJillian Dean Dean
Jillian Dean Dean
LKLeonard Knoedler
Leonard Knoedler
Lukas PrantlLukas Prantl
Lukas Prantl
Scars may represent more than a cosmetic concern for patients; they may impose functional limitations and are frequently associated with the sensation of itching or pain, thus impacting both psychological and physical well-being. From an aesthetic perspective, scars display variances in color, thickness, texture, contour, and their homogeneity, while the functional aspect encompasses considerations of functionality, pliability, and sensory perception. Scars located in critical anatomic areas have the potential to induce profound impairments, including contracture-related mobility restrictions, thereby significantly impacting daily functioning and the quality of life. Conventional approaches to scar management may suffice to a certain extent, yet there are cases where tailored interventions are warranted. Autologous fat grafting emerges as a promising therapeutic avenue in such instances. Fundamental mechanisms underlying scar formation include chronic inflammation, fibrogenesis and dysregulated wound healing, among other contributing factors. These mechanisms can potentially be alleviated through the application of adipose-derived stem cells, which represent the principal cellular component utilized in the process of lipofilling. Adipose-derived stem cells possess the capacity to secrete proangiogenic factors such as fibroblast growth factor, vascular endothelial growth factor and hepatocyte growth factor, as well as neurotrophic factors, such as brain-derived neurotrophic factors. Moreover, they exhibit multipotency, remodel the extracellular matrix, act in a paracrine manner, and exert immunomodulatory effects through cytokine secretion. These molecular processes contribute to neoangiogenesis, the alleviation of chronic inflammation, and the promotion of a conducive milieu for wound healing. Beyond the obvious benefit in restoring volume, the adipose-derived stem cells and their regenerative capacities facilitate a reduction in pain, pruritus, and fibrosis. This review elucidates the regenerative potential of autologous fat grafting and its beneficial and promising effects on both functional and aesthetic outcomes when applied to scar tissue.

11 February 2023 in Journal of Clinical Medicine
Verified
Journal Article
Open access
PDF file
SKSamuel Alfons Christoph Knoedler
Samuel Alfons Christoph Knoedler
HBHelena Baecher
Helena Baecher
Cosima C. HochCosima C. Hoch
Cosima C. Hoch
DODoha Obed
Doha Obed
DMDany Y. Matar
Dany Y. Matar
Adriana C PanayiAdriana C Panayi
Adriana C Panayi
Background: Orthognathic surgery (OS) is a frequently performed procedure for the correction of dentofacial deformities and malocclusion. Research on OS is mostly limited to single-surgeon experience or single-institutional reports. We, therefore, retrospectively analyzed a multi-institutional database to investigate outcomes of OS and identify risk factors for peri- and postoperative complications. Methods: We reviewed the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database (2008–2020) to identify patients who underwent OS for mandibular and maxillary hypo- and hyperplasia. The postoperative outcomes of interest included 30-day surgical and medical complications, reoperation, readmission, and mortality. We also evaluated risk factors for complications. Results: The study population included 674 patients, 48% of whom underwent single jaw surgery, 40% double jaw surgery, and 5.5% triple jaw surgery. The average age was 29 ± 11 years, with an equal gender distribution (females: n = 336; 50%, males: n = 338; 50%). Adverse events were relatively rare, with a total of 29 (4.3%) complications reported. The most common surgical complication was superficial incisional infection (n = 14; 2.1%). While the multivariable analysis revealed isolated single lower jaw surgery (p = 0.03) to be independently associated with surgical complication occurrence, it also identified an association between the outpatient setting and the frequency of surgical complications (p = 0.03) and readmissions (p = 0.02). In addition, Asian ethnicity was identified as a risk factor for bleeding (p = 0.003) and readmission (p = 0.0009). Conclusion: Based on the information recorded by the ACS-NSQIP database, our analysis underscored the positive (short-term) safety profile of OS. We found OS of the mandible to be associated with higher complication rates. The calculated risk role of OS in the outpatient setting warrants further investigation. A significant correlation between Asian OS patients and postoperative adverse events was found. Implementation of these novel risk factors into the surgical workflow may help facial surgeons refine their patient selection and improve patient outcomes. Future studies are needed to investigate the causal relationships of the observed statistical correlations.

4 December 2023 in International Journal of Surgery
Verified
Journal Article
Open access
SKSamuel Alfons Christoph Knoedler
Samuel Alfons Christoph Knoedler
MKMartin Kauke-Navarro
Martin Kauke-Navarro
LKLeonard Knoedler
Leonard Knoedler
SFSarah Friedrich
Sarah Friedrich
DMDany Y. Ba Matar
Dany Y. Ba Matar
Adriana C PanayiAdriana C Panayi
Adriana C Panayi
Background: Breast cancer mortality and treatment differ across racial groups. It remains unclear whether such disparities are also reflected in perioperative outcomes of breast cancer patients undergoing mastectomy. Study design: The authors reviewed the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database (2008–2021) to identify female patients who underwent mastectomy for oncological purposes. The outcomes were stratified by five racial groups (white, Black/African American, Asian, American Indian/Alaska Native, and Native Hawaiian/Pacific Islander) and included 30-day mortality, reoperation, readmission, surgical and medical complications, and non-home discharge. Results: The study population included 222 947 patients, 68% (n=151 522) of whom were white, 11% (n=23 987) Black/African American, 5% (n=11 217) Asian, 0.5% (n=1198) American Indian/Alaska Native, and 0.5% (n=1018) Native Hawaiian/Pacific Islander. While 136 690 (61%) patients underwent partial mastectomy, 54 490 (24%) and 31 767 (14%) women received simple and radical mastectomy, respectively. Overall, adverse events occurred in 17 222 (7.7%) patients, the largest portion of which were surgical complications (n=7246; 3.3%). Multivariable analysis revealed that being of Asian race was protective against perioperative complications [odds ratio (OR)=0.71; P<0.001], whereas American Indian/Alaska Native women were most vulnerable to the complication occurrence (OR=1.41; P<0.001). Black/African American patients had a significantly lower risk of medical (OR=0.59; P<0.001) and surgical complications (OR=0.60; P<0.001) after partial and radical mastectomy, respectively, their likelihood of readmission (OR=1.14; P=0.045) following partial mastectomy was significantly increased. Conclusion: The authors identified American Indian/Alaska Native women as particularly vulnerable to complications following mastectomy. Asian patients experienced the lowest rate of complications in the perioperative period. The authors’ analyses revealed comparable confounder-adjusted outcomes following partial and complete mastectomy between Black and white races. Their findings call for care equalization in the field of breast cancer surgery.