scholarly journals Six-Month Outcomes of Clinically Relevant Meniscal Injury in a Large-Animal Model

2021 ◽  
Vol 9 (11) ◽  
pp. 232596712110354
Author(s):  
Sonia Bansal ◽  
Kyle D. Meadows ◽  
Liane M. Miller ◽  
Kamiel S. Saleh ◽  
Jay M. Patel ◽  
...  

Background: The corrective procedures for meniscal injury are dependent on tear type, severity, and location. Vertical longitudinal tears are common in young and active individuals, but their natural progression and impact on osteoarthritis (OA) development are not known. Root tears are challenging and they often indicate poor outcomes, although the timing and mechanisms of initiation of joint dysfunction are poorly understood, particularly in large-animal and human models. Purpose/Hypothesis: In this study, vertical longitudinal and root tears were made in a large-animal model to determine the progression of joint-wide dysfunction. We hypothesized that OA onset and progression would depend on the extent of injury-based load disruption in the tissue, such that root tears would cause earlier and more severe changes to the joint. Study Design: Controlled laboratory study. Methods: Sham surgeries and procedures to create either vertical longitudinal or root tears were performed in juvenile Yucatan mini pigs through randomized and bilateral arthroscopic procedures. Animals were sacrificed at 1, 3, or 6 months after injury and assessed at the joint and tissue level for evidence of OA. Functional measures of joint load transfer, cartilage indentation mechanics, and meniscal tensile properties were performed, as well as histological evaluation of the cartilage, meniscus, and synovium. Results: Outcomes suggested a progressive and sustained degeneration of the knee joint and meniscus after root tear, as evidenced by histological analysis of the cartilage and meniscus. This occurred in spite of spontaneous reattachment of the root, suggesting that this reattachment did not fully restore the function of the native attachment. In contrast, the vertical longitudinal tear did not cause significant changes to the joint, with only mild differences compared with sham surgery at the 6-month time point. Conclusion: Given that the root tear, which severs circumferential connectivity and load transfer, caused more intense OA compared with the circumferentially stable vertical longitudinal tear, our findings suggest that without timely and mechanically competent fixation, root tears may cause irreversible joint damage. Clinical Relevance: More generally, this new model can serve as a test bed for experimental surgical, scaffold-based, and small molecule–driven interventions after injury to prevent OA progression.

Author(s):  
Yak-Nam Wang ◽  
Andrew A. Brayman ◽  
Keith T. Chan ◽  
Keith Richmond ◽  
Wayne L. Monsky ◽  
...  

AbstractBackgroundAbscess formation is a host defense mechanism to contain the spread of infection. Abscesses can affect any part of the body and are common sequelae to complications of trauma, surgery, systemic infections and other disease states. Most models for abscesses are in small animals. Pursuant to the goal of developing more advanced treatments for abscesses, we sought to develop a large animal model which would reasonably mimic a fluid-filled human abscess.MethodsDomestic swine were inoculated with a bimicrobial mixture of Bacteroides fragilis (B. fragilis) and Escherichia coli (E. coli) supplemented with an irritant (dextran). Inoculations were performed under ultrasound guidance in the muscle, subcutaneously or intradermally within the same animal. Fourteen days after inoculation, lesions were imaged with ultrasound, resected and prepared for histological evaluation.ResultsInjection of bimicrobial (aerobic and anaerobic) bacterial mixtures at multiple sites in a pig produced multiple lesions with histological features similar to encapsulated and multiloculated/multichamber abscesses often observed clinically in humans. Important salient features include the formation of a connective tissue capsule surrounding histologically nearly amorphous pus.ConclusionsThis paper provides the first description of a pig model for multiloculated abscesses. This animal model could potentially enable the evaluation of new technologies to replace or augment the current standard of care (image-guided percutaneous abscess drainage with antibiotics).


Analgesia ◽  
1995 ◽  
Vol 1 (4) ◽  
pp. 598-602 ◽  
Author(s):  
L.D. Napier ◽  
Z. Mateo ◽  
D.A. Yoshishige ◽  
B.A. Barron ◽  
J.L. Caffrey

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Premila D. Leiphrakpam ◽  
Hannah R. Weber ◽  
Andrea McCain ◽  
Roser Romaguera Matas ◽  
Ernesto Martinez Duarte ◽  
...  

Abstract Background Acute respiratory distress syndrome (ARDS) is multifactorial and can result from sepsis, trauma, or pneumonia, amongst other primary pathologies. It is one of the major causes of death in critically ill patients with a reported mortality rate up to 45%. The present study focuses on the development of a large animal model of smoke inhalation-induced ARDS in an effort to provide the scientific community with a reliable, reproducible large animal model of isolated toxic inhalation injury-induced ARDS. Methods Animals (n = 21) were exposed to smoke under general anesthesia for 1 to 2 h (median smoke exposure = 0.5 to 1 L of oak wood smoke) after the ultrasound-guided placement of carotid, pulmonary, and femoral artery catheters. Peripheral oxygen saturation (SpO2), vital signs, and ventilator parameters were monitored throughout the procedure. Chest x-ray, carotid, femoral and pulmonary artery blood samples were collected before, during, and after smoke exposure. Animals were euthanized and lung tissue collected for analysis 48 h after smoke inhalation. Results Animals developed ARDS 48 h after smoke inhalation as reflected by a decrease in SpO2 by approximately 31%, PaO2/FiO2 ratio by approximately 208 (50%), and development of bilateral, diffuse infiltrates on chest x-ray. Study animals also demonstrated a significant increase in IL-6 level, lung tissue injury score and wet/dry ratio, as well as changes in other arterial blood gas (ABG) parameters. Conclusions This study reports, for the first time, a novel large animal model of isolated smoke inhalation-induced ARDS without confounding variables such as cutaneous burn injury. Use of this unique model may be of benefit in studying the pathophysiology of inhalation injury or for development of novel therapeutics.


2021 ◽  
Vol 10 (Supplement_1) ◽  
Author(s):  
J Josiassen ◽  
OKL Helgestad ◽  
NLJ Udesen ◽  
A Banke ◽  
PH Frederiksen ◽  
...  

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): The Danish Heart Foundation Unrestricted research grant from Abiomed Background No strong evidence exists regarding the treatment of cardiogenic shock (CS) caused by acute right ventricular (RV) failure which has mainly consisted of vasoactive drugs. There is expert agreement that treatment with the recently developed Impella RP is feasible, but no previous studies have compared vasoactive treatment strategies with the Impella RP in terms of cardiac unloading and end-organ perfusion. Hypothesis Treatment with the Impella RP device will be associated with lower RV myocardial workload (pressure-volume area) compared to vasoactive treatment strategies and can furthermore be achieved without compromising organ perfusion. Methods CS was induced by a stepwise injection of polyvinyl alcohol microspheres into the right coronary artery in twenty adult female Danish landrace pigs weighing 75-80 kg. After induction of CS, the pigs were allocated to one of the two interventions for 180 minutes: 1) vasoactive therapy comprised a continuous infusion of norepinephrine (0.1 µg/kg/min) for the first 30 minutes, supplemented by an infusion of milrinone (0.4 µg/kg/min) for the remaining 150 minutes or 2) immediate insertion of and treatment with the Impella RP.  The results are presented as median [Q1;Q3]. Results Treatment with the Impella RP was associated with a lower RV workload compared to the vasoactive group, while no difference was observed with regards to left ventricular workload among intervention groups, Figure 1. Renal venous oxygen saturation increased to a similar degree following both interventions compared to the state of CS. A trend towards a higher cerebral venous oxygen saturation was observed with norepinephrine compared to Impella RP (Impella RP 51 [47;61] % vs Norepinephrine 62 [57;71] % ; p = 0.07), which became significantly higher with the addition of milrinone (Impella RP 45 [32;63] % vs Norepinephrine +Milrinone 73 [66;81] %; p = 0.002). Conclusion In this large animal model of profound CS caused by predominantly RV failure the Impella RP unloaded the failing RV. The vasoactive treatment, however, caused a higher cerebral venous oxygen saturation, while both interventions increased renal venous oxygen saturation to a similar degree. Abstract Figure 1


2000 ◽  
Vol 69 (Supplement) ◽  
pp. S405
Author(s):  
I. Fourneau ◽  
S. H. Yap ◽  
T. Roskams ◽  
L. Flendrig ◽  
R. Chamuleau ◽  
...  

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