Ultrasound-guided injection of the cranial tibial artery for stem cell administration in horses

Development of an ultrasound-guided proximo-medial approach for injection of the carpal flexor tendon sheath in horses and comparison with the conventional proximo-lateral ´blind` technique

The aim of this prospective case-control study was to describe and implement a reliable, accurate, and straightforward ultrasound-guided proximo-medial approach technique for injecting the carpal flexor tendon sheath in horses. The proximo-medial ultrasound-guided approach for intrathecal access to the carpal canal, as described in this study, was firstly developed on ten cadaveric limbs using an undiluted ionic iodinated contrast medium. Landmarks were identified, and the access point was established. Subsequently, the technique was validated in ten horses, and its efficacy was compared with the proximo-lateral ´blind` technique. For each injection, the following was recorded: successful injection (contrast within the carpal canal), number of attempts, and whether a structure other than the carpal sheath was penetrated. The ´blind` technique had a total accuracy of 70 % (7/10; 95 % confidence interval [CI]: CI 35 %-93 %), with inadvertent injection into the dorso-palmar pouch of the radiocarpal joint, carpal canal surrounding soft tissue, and intravenous injection being the most common issues associated with this approach. In contrast, the ultrasound-guided approach achieved an accuracy of 100 % (10/10; 95 % confidence interval [CI]: 69 %-100 %) for intrasynovial administration of the contrast medium. The ultrasound-guided proximo-medial approach for injecting the carpal sheath is an accurate and technically straightforward technique. This approach should be considered for synoviocentesis of the carpal sheath, particularly in horses with no evident effusion.

Vascularity evaluation of the equine tarsocrural and proximal intertarsal joint septum, and comparative analysis of two arthroscopic transection techniques

OBJECTIVE

To evaluate vascularity of the synovial membrane covered septum (SMS) separating the tarsocrural (TC) and proximal intertarsal (PIT) joints (Part 1) and compare two methods of transection, electrosurgical or Ferris Smith rongeur (FS rongeur) (Part 2).

STUDY DESIGN

Experimental study.

SAMPLE POPULATION

Part 1, 10 SMS (n = 5 horses). Part 2, six horses (n = 12 tarsi).

METHODS

In part 1, SMS harvested postmortem were each divided into eight regions of interest (ROIs), processed for histology, and immunostained with anti-α-actin antibody for blood vessel identification. Vascular density was calculated for each ROI. Data was compared within and between horses. In part 2, six horses underwent TC arthroscopy. Each limb was randomly assigned to undergo either electrosurgical or FS rongeur SMS transection. SMS transection and total operative time were recorded. Intraoperative hemorrhage was scored. Data was compared between both techniques.

RESULTS

Significant interindividual variations in SMS vascular density were detected (p = .02), but there were no differences among ROIs. No differences in the transection time were detected between electrosurgery (4.83 ± 0.54 min) and FS rongeur (4.33 ± 0.67 min). No differences were found in intraoperative hemorrhage scores between techniques.

CONCLUSION

Vascularity within the SMS varies among horses but not within its regions. Electrosurgical or FS rongeur transection of the medial SMS during tarsocrural arthroscopy is a rapid technique and improves surgical access to the dorsal compartment of the PIT.

Advances in Regional Vascular Injection Techniques for the Delivery of Stem Cells to Musculoskeletal Injury Sites

Vascular injections of stem cells are a pertinent alternative to direct intralesional injections when treating multiple or extensive lesions or with lesions impossible to reach directly. Extensive research using stem cell tracking has shown that intra-arterial injections without the use of a tourniquet should be preferred over venous or arterial regional limb perfusion techniques using a tourniquet. The median artery is used for the front limbs and the cranial tibial artery for the hind limbs. Proper efficacy studies are still lacking but early clinical work seems promising.

Contrast administration via ultrasound-guided injection of the cranial tibial artery results in contrast enhancement of the soft tissues of the metatarsus in horses undergoing CT

Delivery of mesenchymal stem cells (MSC) via intravascular techniques to treat diffuse and/or inaccessible soft tissue injuries has grown in popularity. The purpose of the current prospective, analytical pilot study was to utilize CT to validate this novel technique and provide additional evidence to support its use for injectate delivery to specific soft tissue structures. Of particular interest was the proximal suspensory ligament, which presents a challenging injection target. Six adult horses without lameness underwent CT of the distal hindlimbs. Scans were obtained prior to ultrasound-guided catheterization of the cranial tibial artery, in addition to early and delayed scans acquired following intra-arterial contrast administration. Region of interest analysis of the superficial and deep digital flexor tendons and suspensory ligament was used to assess contrast enhancement within these structures. Linear mixed models were used to determine statistical significance. Significant (P < 0.05) mean contrast enhancement was seen in all postinjection time points in all soft tissue structures of interest. This indicates that ultrasound-guided injection of the cranial tibial artery results in perfusion of injectate throughout the distal hind limb, including the major soft tissue structures of the metatarsus. This provides further support for this technique as a method of MSC delivery to multifocal or inaccessible injury of these structures, including the proximal suspensory ligament.

Ultrasound-Guided Transplantation of Mesenchymal Stem Cells Improves Adriamycin Nephropathy in Rats Through the RIPK3/MLKL and TLR-4/NF-κB Signaling

Bone marrow stromal cell (BMSC) treatment has been shown to be beneficial for Adriamycin nephropathy (ADR). However, the low transplantation rate is still the key factor that affects this strategy. This study is the first to investigate the efficacy and potential mechanism of ultrasound-guided transrenal arterial transfer of BMSCs for the treatment of ADR in rats. The ADR rat model was established by two injections of doxorubicin. In addition, the rats were randomly divided into four groups (10 rats per group): the normal group (no treatment), the medium control group (treated with medium), the Adriamycin group (treated with phosphate buffer), and the BMSC group (treated with BMSCs). After 4 weeks, the levels of serum creatinine (SCr), blood urea nitrogen (BUN), and urine albumin (ALb) were measured. In addition, pathological changes in kidney tissue were evaluated by pathological sectioning and electron microscopy. Western blotting was used to determine the levels of proteins in rat kidneys. Ultrasound-guided renal artery transplantation of BMSCs reduced the levels of SCr, BUN, and ALb and improved the pathological structure of rat kidneys compared with those in the Adriamycin group. This treatment inhibited renal cell necrosis by reducing the expression of receptor-interacting Serine/threonine Kinase 3 (RIPK3) and Mixed lineage kinase domain-like pseudokinase (MLKL) and inhibited renal inflammation and fibrosis by reducing the expression of Toll-Like receptor 4 (TLR4) and nuclear factor κB (NF-κB). Our study shows that ultrasound-guided transrenal artery transplantation of BMSCs can improve adriamycin-induced renal injury in rats by regulating the RIPK3/MLKL and TLR-4/NF-κB pathways and inhibiting renal necrosis, inflammation, and fibrosis.

Regenerative Medicine for Equine Musculoskeletal Diseases

Simple Summary

Lameness due to musculoskeletal disease is the most common diagnosis in equine veterinary practice. Many of these orthopaedic disorders are chronic problems, for which no clinically satisfactory treatment exists. Thus, high hopes are pinned on regenerative medicine, which aims to replace or regenerate cells, tissues, or organs to restore or establish normal function. Some regenerative medicine therapies have already made their way into equine clinical practice mainly to treat tendon injures, tendinopathies, cartilage injuries and degenerative joint disorders with promising but diverse results. This review summarises the current knowledge of commonly used regenerative medicine treatments and critically discusses their use.

Abstract

Musculoskeletal injuries and chronic degenerative diseases commonly affect both athletic and sedentary horses and can entail the end of their athletic careers. The ensuing repair processes frequently do not yield fully functional regeneration of the injured tissues but biomechanically inferior scar or replacement tissue, causing high reinjury rates, degenerative disease progression and chronic morbidity. Regenerative medicine is an emerging, rapidly evolving branch of translational medicine that aims to replace or regenerate cells, tissues, or organs to restore or establish normal function. It includes tissue engineering but also cell-based and cell-free stimulation of endogenous self-repair mechanisms. Some regenerative medicine therapies have made their way into equine clinical practice mainly to treat tendon injures, tendinopathies, cartilage injuries and degenerative joint disorders with promising results. However, the qualitative and quantitative spatiotemporal requirements for specific bioactive factors to trigger tissue regeneration in the injury response are still unknown, and consequently, therapeutic approaches and treatment results are diverse. To exploit the full potential of this burgeoning field of medicine, further research will be required and is ongoing. This review summarises the current knowledge of commonly used regenerative medicine treatments in equine patients and critically discusses their use.

Stem Cells in Veterinary Medicine-Current State and Treatment Options

Regenerative medicine is a branch of medicine that develops methods to grow, repair, or replace damaged or diseased cells, organs or tissues. It has gained significant momentum in recent years. Stem cells are undifferentiated cells with the capability to self—renew and differentiate into tissue cells with specialized functions. Stem cell therapies are therefore used to overcome the body's inability to regenerate damaged tissues and metabolic processes after acute or chronic insult. The concept of stem cell therapy was first introduced in 1991 by Caplan, who proposed that massive differentiation of cells into the desired tissue could be achieved by isolation, cultivation, and expansion of stem cells in in vitro conditions. Among different stem cell types, mesenchymal stem cells (MSC) currently seem to be the most suitable for therapeutic purposes, based on their simple isolation and culturing techniques, and lack of ethical issues regarding their usage. Because of their remarkable immunomodulatory abilities, MSCs are increasingly gaining recognition in veterinary medicine. Developments are primarily driven by the limitations of current treatment options for various medical problems in different animal species. MSCs represent a possible therapeutic option for many animal diseases, such as orthopedic, orodental and digestive tract diseases, liver, renal, cardiac, respiratory, neuromuscular, dermal, olfactory, and reproductive system diseases. Although we are progressively gaining an understanding of MSC behavior and their mechanisms of action, some of the issues considering their use for therapy are yet to be resolved. The aim of this review is first to summarize the current knowledge and stress out major issues in stem cell based therapies in veterinary medicine and, secondly, to present results of clinical usage of stem cells in veterinary patients.

Stem Cells in Equine Veterinary Practice-Current Trends, Risks, and Perspectives

With this Editorial, we introduce the Special Issue "Adipose-Derived Stem Cells and Their Extracellular Microvesicles (ExMVs) for Tissue Engineering and Regenerative Medicine Applications" to the scientific community. In this issue, we focus on regenerative medicine, stem cells, and their clinical application.