Ultrasound-guided modified subcostal transversus abdominis plane block and influence of recumbency position on dye spread in equine cadavers.
Abstract: To describe and evaluate an ultrasound-guided modified subcostal approach for the transversus abdominis plane (TAP) block in horse cadavers in lateral or dorsal recumbency. Methods: Prospective, experimental cadaveric study. Methods: Study of one preserved foal and eight fresh adult horse cadavers. Methods: The lateral and ventral abdominal wall of a preserved cadaver was dissected to identify the muscles and nerves. A unilateral standard TAP block technique was performed (60 mL of methylene blue dye-bupivacaine) on a fresh cadaver in right lateral recumbency. A modified subcostal technique was performed on the opposite side using a linear ultrasound transducer and in-plane approach. Injection points (two 30 mL dye) were at the level of the TAP (between the rectus abdominis and transversus abdominis muscles and ventral to the cutaneous trunci muscle) perpendicular to: 1) the mid-point between the xiphoid cartilage and umbilical scar; and 2) at a point between the caudal and middle thirds of the abdomen measured from the first injection point to the umbilical scar. The modified subcostal approach was performed in seven additional cadavers in both hemiabdomens, with three cadavers in lateral and four cadavers in dorsal recumbency. Ultrasound guidance was used with all injections. Results: The standard approach stained the sixteenth to eighteenth thoracic nerves (T16-T18). The modified subcostal approach performed in lateral recumbency provided greater spread (T9-T17) than dorsal recumbency (T12-T18) (p = 0.016). Conclusions: The modified subcostal TAP approach resulted in extensive staining exceeding the standard approach. The nerves stained are consistent with production of ventral abdominal wall anesthesia in horses. Clinical studies are needed to verify these findings.
Copyright © 2021 Association of Veterinary Anaesthetists and American College of Veterinary Anesthesia and Analgesia. Published by Elsevier Ltd. All rights reserved.
Publication Date: 2021-03-25 PubMed ID: 33903072DOI: 10.1016/j.vaa.2021.03.006Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
The study investigates a modified application of ultrasound-guided subcostal transversus abdominis plane (TAP) block in horse cadavers. The results suggest that this technique leads to wider dye spread, particularly when the cadaver is in a lateral recumbent position, suggesting it may be a more effective method for administering anesthesia in live horses.
Research Methodology
- The researchers conducted a detailed dissection on the abdominal wall of a preserved foal and eight fresh adult horse cadavers to identify muscles and nerves.
- A standard Transversus Abdominis Plane (TAP) block was performed on a fresh cadaver in right lateral recumbency using 60 mL of methylene blue dye-bupivacaine.
- A modified technique was implemented on the opposing side using a linear ultrasound transducer. The injection points were at the Transversus Abdominis Plane, between the rectus abdominis and the transversus abdominis muscles, and in the portion ventral to the cutaneous trunci muscle.
- The study was duplicated on seven additional cadavers; three placed in lateral and four in dorsal recumbency.
- Ultrasound guidance was employed with all injections to ensure precision.
Results
- The standard TAP block approach stained nerves T16 to T18.
- The new, modified subcostal approach resulted in more extensive spread, dyeing nerves T9 to T17 when in lateral recumbency.
- The dye spread was lesser when the cadaver was placed in dorsal recumbency, it stained nerves T12 to T18.
- This indicates that the subcostal TAP block approach, especially when applied in the lateral position, can result in a more extensive spread of anesthesia, potentially increasing its effectiveness.
Conclusions and Future Work
- The modified subcostal TAP technique demonstrated a more extensive nerve staining, implying that it might be more effective for producing ventral (front-centric) abdominal wall anesthesia in horses.
- However, before this modified approach can be recommended for clinical practice, it needs to be validated through clinical trials in live horses.
Cite This Article
APA
Freitag FAV, Amora DDS, Muehlbauer E, Dornbusch PT, Machado M, Montiani-Ferreira F, Prisco Farias EL, Valverde A, Duque Moreno JC.
(2021).
Ultrasound-guided modified subcostal transversus abdominis plane block and influence of recumbency position on dye spread in equine cadavers.
Vet Anaesth Analg, 48(4), 596-602.
https://doi.org/10.1016/j.vaa.2021.03.006 Publication
Researcher Affiliations
- Department of Veterinary Medicine, Federal University of Paraná, Curitiba, PR, Brazil; Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada.
- Department of Veterinary Medicine, Federal University of Paraná, Curitiba, PR, Brazil.
- Department of Veterinary Medicine, Federal University of Paraná, Curitiba, PR, Brazil.
- Department of Veterinary Medicine, Federal University of Paraná, Curitiba, PR, Brazil.
- Anatomy Department, Biological Science Sector, Federal University of Paraná, Curitiba, PR, Brazil.
- Department of Veterinary Medicine, Federal University of Paraná, Curitiba, PR, Brazil.
- Anatomy Department, Biological Science Sector, Federal University of Paraná, Curitiba, PR, Brazil.
- Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada.
- Department of Veterinary Medicine, Federal University of Paraná, Curitiba, PR, Brazil. Electronic address: anestesiologiavet@yahoo.com.br.
MeSH Terms
- Abdominal Muscles
- Animals
- Cadaver
- Horse Diseases
- Horses
- Nerve Block / veterinary
- Prospective Studies
- Ultrasonography, Interventional / veterinary
Citations
This article has been cited 5 times.- Nocera I, Moroni R, Fanelli D, Rota A, Di Franco C, Ungari C, Puccinelli C, Gandini M, Giusto G, Vannozzi I. Cryptorchidism in Equid: A Retrospective Study on Diagnostic Approach, Anaesthesia Management, Surgical Treatment and Outcomes. Animals (Basel) 2025 Oct 9;15(19).
- Moresco M, Camargo-Fontanela MA, Serighelli-Júnior G, Montiani-Ferreira F, Machado M, Duque-Moreno JC. Ultrasound-guided serratus plane injection using superficial and deep approaches in cat cadavers: anatomical and dye spread study. Vet Res Commun 2025 Oct 7;49(6):348.
- Sredenšek J, Brankovič J, Lampreht Tratar U, Čemažar M, Đokić M, Seliškar A. Evaluation of methylene blue solution distribution in the four-point transversus abdominis plane block technique in pigs: a pilot anatomical study. Front Vet Sci 2025;12:1574833.
- Aitken MR, Floriano DA, Hopster K. Open Approach to the Transversus Abdominis Plane in Horses: A Cadaver Feasibility Study. Vet Sci 2024 Jan 22;11(1).
- Gutiérrez Bautista ÁJ, Söbbeler FJ, Koch R, Viscasillas J, Kästner S. Assessment of an Ultrasound-Guided Rectus Sheath Block in Foals: A Cadaveric Study. Animals (Basel) 2023 Nov 21;13(23).
Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists
