Surgical Technique for the Implantation of a Wireless Telemetry Device on Pigs' Backs

Summary

A new surgical technique was developed for implanting telemetry devices in pigs that allows continuous monitoring without discomfort. The device is placed on the back, minimizing irritation and infection risk.

Abstract

Telemetry devices are essential for preclinical cardiovascular research, allowing for continuous monitoring of physiological parameters like electrocardiogram, temperature, and respiration in experimental animals without causing disruption. Traditional methods, such as intra-abdominal placement, can cause discomfort, particularly in pigs due to their habit of lying prone. To address this issue, a novel surgical technique was developed for implanting wireless telemetry devices in pigs, aimed at improving animal comfort and maintaining signal quality. This study involved 40 Yorkshire pigs (20-30 kg). The telemetry device was implanted in the back. A 2 inch incision was made lateral to the spine, followed by blunt dissection to create a pocket under the latissimus dorsi fascia. The pocket was treated with a vancomycin solution to prevent infection before device insertion. The leads were secured, and the site was closed in layers. All pigs showed strong, continuous telemetry signals after surgery. Over the 180-day follow-up period, only two cases of infection occurred: One was managed with antibiotics, and the other required device removal. No significant bleeding or loss of telemetry signal was observed, and all animals survived to the end of the study. This new technique offers a reliable method for implanting telemetry devices in pigs, reducing discomfort and infection risk while providing high-quality physiological data. It holds promise for broader use in preclinical cardiovascular research, improving both animal welfare and data reliability.

Introduction

Telemetry devices play a pivotal role in advancing the understanding of cardiovascular physiology, particularly in studies using an animal model of myocardial infarction. By enabling the continuous monitoring of physiological signals, including vital parameters and electrocardiogram (ECG) readings, these devices offer invaluable insights into the dynamic changes occurring during cardiac events. In preclinical studies, where animal models like pigs are instrumental in mimicking human cardiovascular responses, telemetry devices have become indispensable tools¹. The ability to record ECG continuously in unrestrained, freely moving animals provides....

Protocol

All animal procedures were approved by The Texas Heart Institute's Institutional Animal Care and Use Committee (IACUC). Animals were implanted with the EMKA easyTEL+L-EEEETA digital system (https://www.emkatech.com/product/easytel-large-animals/).

1. Preoperative preparations for experimental animals

1. Use Yorkshire pigs of either sex weighing between 20 kg and 30 kg. Do not feed the pigs 12-24 h before the start of anesthesia but allow access to water.

2. Sedation and anesthesia

1. Administer Telazol (tiletamine and zolazepam; 2-6 mg/kg intramuscula....

Results

The data presented in Table 1 show the reliability and safety of the surgical technique for dorsal implantation of telemetry devices in pigs. Successful ECG transmission was recorded in all 40 pigs (100%), confirming that the positioning of the device and lead configuration consistently enabled effective long-term signal acquisition. The absence of major bleeding events (0%; defined as ≥10 mL of blood loss) indicates the safety of the fascial pocket dissection and careful handling of vascular structures........

Discussion

A device-implantation procedure is described as a new invasive telemetric method of continuous ECG monitoring. This method ensures reliable recordings in animal experiments. Although the user manual for the EMKA device⁴ describes a surgical procedure for implanting the device in the abdomen of large animals such as dogs and pigs, intra-abdominal placement was not considered desirable because pigs typically lie on their abdomen, resulting in pressure on the peritoneum that could cause pain or disco.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
1 cc syringe	Vetone	V1 670097
10 cc syringe	Medline	SYR110010
12 cc syringe	Vetone	V1 670065
20 cc syringe	Nipro	JD+20L
20G needle	Medline	SYR100205
3 cc syringe	Nipro	JD+03L-NIJ
ACT cartridge	Medtronic	402-03
Alcohol	Vetone	V1 500205
Anesthesia circuit	Fisher & Paykel	RT210
Angiocath 14 Fr	BD	382269
Atropine sulfate	Vetone	V1 510221
Bariatric drape	Medline	DYNJP3105
Blade 10	Medline	MDS15010
Blade 11	Medline	MDS15011
Buprenorphine	PAR Pharmaceuticals	3003408B
Camera cover	Aspen Surgical	LT-C02
Cautery pen	Medline	ESPB3000
Cautery pen scratch pad	Medline	DYNJ01208
Coflex 2" tape	Vetwrap	1404BK
Curos cap protector	3M	CFF1-270
ECG electrodes	Medline	MDSM618305
EMKA easyTEL+L-EEEETA digital system	EMKA
Endotracheal tube	Jorvet	J0615J
Flunixin meglumine	Merck	65707
Injection cap	ICU Medical	C1000
Introducer catheter 5F	Abbott	406101
Introducer catheter 6F	Abbott	407845
Isoflurane	Vetone	MWI502017
IV Catheter Extension Set	Baxter	2C8612
IV Pump Set SmartSite	BD Alaris	2420-0007
Light cover	Medline	DYNJLHS2
Naxcel (ceftiofur)	Zoetis	25434
Needle counter	Medline	DYNJNC20F
Percutaneous entry needle	Cook	G00272
Permahand silk 2-0	Ethicon	C012D
PlasmaLyte	Baxter	2B2544
Povidone-iodine paint sticks	Aplicare	ORF20025S
Pressure monitoring transducer 1x1	Edwards Lifesciences	PX260
Pressure tubing 84"	Edwards Lifesciences	50P184
Saline	Baxter	2F7124
Shoe covers	Medline	NON29858
Skin stapler	Covidien	8886803712
Specimen cup	Medline	DYND30389
Sponge, 4"×4", X-ray detectable	Covidien	441002
Sponge, lap	Medline	MDS241518
Surgeon's cap	CardinalHealth	4359
Surgical gloves	Medline	MSG9065
Surgical gowns	Medline	DYNJP2001S
Surgical mask	Halyard	6211580
Table cover	Medline	DYNJP2311
Telazol	Zoetis	10004135
Tissue adhesive	3M	1469SB
Vancomycin	Fresenius Kabi	402254G
Vicryl 1	Ethicon	J480H
Vicryl 2-0	Ethicon	J869H