Browsing by Subject "Lower extremity"

Now showing 1 - 3 of 3
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    Pseudomonas Aeruginosa Theft Biofilm Require Host Lipids of Cutaneous Wound
    (Wolters Kluwer, 2023) Sinha, Mithun; Ghosh, Nandini; Wijesinghe, Dayanjan S.; Mathew-Steiner, Shomita S.; Das, Amitava; Singh, Kanhaiya; El Masry, Mohamed; Khanna, Savita; Inoue, Hiroyuki; Yamazaki, Katsuhisa; Kawada, Manabu; Gordillo, Gayle M.; Roy, Sashwati; Sen, Chandan K.; Surgery, School of Medicine
    Objective: This work addressing complexities in wound infection, seeks to test the reliance of bacterial pathogen Pseudomonas aeruginosa (PA) on host skin lipids to form biofilm with pathological consequences. Background: PA biofilm causes wound chronicity. Both CDC as well as NIH recognizes biofilm infection as a threat leading to wound chronicity. Chronic wounds on lower extremities often lead to surgical limb amputation. Methods: An established preclinical porcine chronic wound biofilm model, infected with PA or Pseudomonas aeruginosa ceramidase mutant (PA ∆Cer ), was used. Results: We observed that bacteria drew resource from host lipids to induce PA ceramidase expression by three orders of magnitude. PA utilized product of host ceramide catabolism to augment transcription of PA ceramidase. Biofilm formation was more robust in PA compared to PA ∆Cer . Downstream products of such metabolism such as sphingosine and sphingosine-1-phosphate were both directly implicated in the induction of ceramidase and inhibition of peroxisome proliferator-activated receptor (PPAR)δ, respectively. PA biofilm, in a ceram-idastin-sensitive manner, also silenced PPARδ via induction of miR-106b. Low PPARδ limited ABCA12 expression resulting in disruption of skin lipid homeostasis. Barrier function of the wound-site was thus compromised. Conclusions: This work demonstrates that microbial pathogens must co-opt host skin lipids to unleash biofilm pathogenicity. Anti-biofilm strategies must not necessarily always target the microbe and targeting host lipids at risk of infection could be productive. This work may be viewed as a first step, laying fundamental mechanistic groundwork, toward a paradigm change in biofilm management.
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    Risk Factors for Unplanned Higher-Level Re-Amputation and Mortality after Lower Extremity Amputation in Chronic Limb-Threatening Ischemia
    (MDPI, 2024-07-10) Guerra, Andres; Guo, Michelle; Boyd, Riley M.; Zakharevich, Marina; Hoel, Andrew W.; Vavra, Ashley K.; Chung, Jeanette W.; Ho, Karen J.; Surgery, School of Medicine
    Background: The factors associated with unplanned higher-level re-amputation (UHRA) and one-year mortality among patients with chronic limb-threatening ischemia (CLTI) after lower extremity amputation are poorly understood. Methods: This was a single-center retrospective study of patients who underwent amputations for CLTI between 2014 and 2017. Unadjusted bivariate analyses and adjusted odds ratios (AOR) from logistic regression models were used to assess associations between pre-amputation risk factors and outcomes (UHRA and one-year mortality). Results: We obtained data on 203 amputations from 182 patients (median age 65 years [interquartile range (IQR) 57, 75]; 70.7% males), including 118 (58.1%) toe, 20 (9.9%) transmetatarsal (TMA), 37 (18.2%) below-knee (BKA), and 28 (13.8%) amputations at or above the knee. Median follow-up was 285 days (IQR 62, 1348). Thirty-six limbs (17.7%) had a UHRA, and the majority of these (72.2%) were following index forefoot amputations. Risk factors for UHRA included non-ambulatory status (AOR 6.74, 95% confidence interval (CI) 1.74–26.18; p < 0.10) and toe pressure < 30 mm Hg (AOR 4.89, 95% CI 1.52–15.78; p < 0.01). One-year mortality was 17.2% (n = 32), and risk factors included coronary artery disease (AOR 3.93, 95% CI 1.56–9.87; p < 0.05), congestive heart failure (AOR 4.90, 95% CI 1.96–12.29; p = 0.001), end-stage renal disease (AOR 7.54, 95% CI 3.10–18.34; p < 0.001), and non-independent ambulation (AOR 4.31, 95% CI 1.20–15.49; p = 0.03). Male sex was associated with a reduced odds of death at 1 year (AOR 0.37, 95% CI 0.15–0.89; p < 0.05). UHRA was not associated with one-year mortality. Conclusions: Rates of UHRA after toe amputations and TMA are high despite revascularization and one-year mortality is high among patients with CLTI requiring amputation.
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    The Lawnmower and the Pediatric Lower Extremity: A Catastrophic Combination
    (Open Science, 2024-02-26) Sathyanarayanan, Sairandri; Obinero, Chioma G.; Green, Jackson C.; Fallah, Kasra N.; Greives, Matthew R.; Chen, Wendy; Nguyen, Phuong D.; Surgery, School of Medicine
    Background: Lower extremity (LE) trauma within the pediatric population may be debilitating and have different implications and etiologies than in adults. Specifically, lawnmower injuries can cause catastrophic sequelae to the lower extremities, often requiring complex reconstruction or resulting in amputation. This study aims to present our experience with pediatric LE lawnmower injuries at one of the busiest level 1 trauma centers in the United States. Methods: An IRB-approved retrospective analysis was performed studying pediatric patients (age <18 years) who experienced LE trauma due to a lawnmower injury over a 5-year period (2012-2017). Patient demographics, perioperative data, and types of reconstruction were reviewed. Univariate analysis of the data was performed to examine trends in exposure and management of pediatric LE lawnmower injuries. Results: Twenty-three patients were identified with pediatric LE lawnmower injuries, of whom 82.6% were male. The patients had a median age of 6 years and a median Injury Severity Score (ISS) of 4. Over one-third (34.8%) of this cohort required immediate amputation. Additionally, 26.1% and 8.7% required local and free flap reconstruction, respectively. In comparison, only 3.6% and 2.3% of all traumatic pediatric LE injuries from the same time frame required local and free flaps, respectively. Conclusions: Lawnmower injuries to the LE can be devastating, causing long-term physical, emotional, and psychosocial consequences for pediatric patients and their families. The data in this study suggest that pediatric LE injuries from lawnmowers more often require complex reconstruction than other traumatic LE injuries. Rapid and effective decision-making by experienced surgeons is necessary to optimize the potential for limb salvage in pediatric LE lawnmower injuries. An algorithm of recommendations on when to transfer these types of injuries to more experienced tertiary centers is provided. Additional resources should be dedicated toward improving public awareness and industrial safety features to help prevent lawnmower injuries in pediatric patients.