Long-Term Catheterization of the Intestinal Lymph Trunk and Collection of Lymph in Neonatal Pigs

Summary

We present a surgical procedure to catheterize the intestinal lymph trunk in neonatal pigs to collect large quantities of lipid metabolism components from efferent lymph.

Abstract

Catheterization of the intestinal lymph trunk in neonatal pigs is a technique allowing for the long-term collection of large quantities of intestinal (central) efferent lymph. Importantly, the collection of central lymph from the intestine enables researchers to study both the mechanisms and lipid constitutes associated with lipid metabolism, intestinal inflammation and cancer metastasis, as well as cells involved in immune function and immunosurveillance. A ventral mid-line surgical approach permits excellent surgical exposure to the cranial abdomen and relatively easy access to the intestinal lymph trunk vessel that lies near the pancreas and the right ventral segment of the portal vein underneath the visceral aspect of the right liver lobe. The vessel is meticulously dissected and released from the surrounding fascia and then dilated with sutures allowing for insertion and subsequent securing of the catheter into the vessel. The catheter is exteriorized and approximately 1 L/24 hr of lymph is collected over a 7 day period. While this technique enables the collection of large quantities of central lymph over an extended period of time, the success depends on careful surgical dissection, tissue handling and close attention to proper surgical technique. This is particularly important with surgeries in young animals as the lymph vessels can easily tear, potentially leading to surgical and experimental failure. The video demonstrates an excellent surgical technique for the collection of intestinal lymph.

Introduction

The lymphatic system is an understudied area of physiology. Preclinical models of lymphatic catheterization occur in different animal species^1-8 and are used by pharmaceutical industries and research institutions to investigate mechanisms involved in lipid^8-12 and drug metabolism^13-15, cancer metastasis¹⁶ with experimental treatment¹⁷, and immune function^18-26. This study explores the use of intestinal lymph trunk catheterization in a domestic pig model to measure components of lipoprotein metabolism. Lipoprotein metabolism is involved in the production and secretion of chylomicrons, as well as changes ....

Protocol

All procedures on experimental animals described in both the video and manuscript were approved by the Institutional Animal Care and Use Committee and followed the guidelines set by the Canadian Council of Animal Care.

1. Surgical Anesthesia and Surgical Preparation of the Neonatal Pigs

1. In a separated anteroom, premedicate 25 kg pigs near the base of the neck with an intramuscular sedative-anesthetic drug cocktail containing: azaperone (0.3 mg/kg), ketamine hydrochloride (10 mg/kg), dexmedetomidine (15 µg/kg).
   Note: Add buprenorphine (0.005-0.02 mg/kg) in the pre-anesthetic drug cocktail for enhanced intra-operative ....

Results

Lymphatic catheterization of the intestinal lymphatic trunk of neonatal pigs allows collection of approximately 1 L/24 hr of central lymph over a 7 day period. The lymph collected in this experiments contained components of lipid metabolism, namely total lymph protein, ApoB48 lipoprotein, triglycerides, total protein, and cholesterol. Table 1 highlights representative amounts of these lipid components from pooled lymph samples of three pigs. Notably, lymph flow and lipid constituents are .......

Discussion

Collecting intestinal lymph is an excellent method to investigate mechanisms involved in lipid^8-12 and drug^13-15 metabolism, cancer metastasis^16,17, cell trafficking and immune function^18-26, in various experimental animal models. Indeed, the ability to harvest large quantities of either peripheral (afferent) and central (efferent and large trunk vessels) lymph over an extended period has been particularly important for understanding temporal changes that occur in cell populati.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Miller laryngoscope blade	Welch Allyn	68044	182 mm length
Surgivet advisor: Vital signs monitor	Surgivet	V9203
Rectal temperature probe	Surgivet	V3417
Mono-polar electrosurgery generator	Valley Lab
Metzenbaum scissors	Fine Science	14518-18
Tuffier retractor	Stevens	162-11-676
Mosquito forceps	Stevens	162-7-10
Kelly forceps-curved (14cm)	Stevens	162-7-38
Allis tissue forceps	Stevens	162-7-38
Forceps dressing-eye (10.2cm)	Stevens	162-18-780
Forceps dressing-Adison (12.1cm)	Stevens	162-17-2510
Needle Drivers	Stevens	162-V98-42
Iris scissors	Fine science	14058-11
Circulating water pump	Jorvet	J-783X
Maxitherm-Vinyl blanket	Jorvet	J-784C
Q tip applicators	Fisher Scientific	22-037-960
Catheterization  tubing (4.06 OD X 2.31 ID)	Braintree Scientific Inc.	MRE-160	Micro-Renethane implantation tubing
2-0 silk suture	Ethicon	LA556
2-0 polyglactin suture	Ethicon	J443H	2-0 vicryl
Large animal jacket	Lomir Biomedical Inc.	SSJ2YC
Polypropylene wash bottles	Fisher Scientific	03-409-22C	500 ml
Penicillin-Streptomycin	Sigma Aldrich	D4333
EDTA	Sigma Aldrich	60-00-4
Amphotericin B	Sigma Aldrich	A2411
Azaperone	Elanco Animal Health		Stresnil
Dexmedetomidine hydrochloride	Zoetis	6295	Dexdomitor
Isoflurane	Abbott Animal  Health	05260-5	IsoFlo
Ketamine hydrochloride	Zoetis	2626	Ketaset
Bupenorphine hydrochloride	Champion Alstoe Animal Health		DIN:02347510
6 mm Endotracheal tube	Jorvet	J-165d
10% Lidocaine spray	AstraZeneca		DIN:02003767
4 % Chlorhexidine surgical scrub	Partnar Animal Health	PCH-011	Diluted: 2.0% solution
3M Surgical steri- drape	3M Health Care	1040
SDS page gel	Invitrogen	EA0375BOX	3-8 % tris acetate
Polyvinylidene fluoride membrane	Millipore	IPVH00010	0.45 μm pore size
ApoB antibody	EMD Millipore	AB742	1:4000 dilution
Donkey anti-goat IgG-HRP	Santa Cruz Biotechnology	Sc-2304
ECL Prime Western Blotting Reagent	GE Healthcare LifeSciences	RPN2232
Triglyceride Kit	Wako Pure Chemicals	998-40391/994-40491
Total Cholesterol Kit	Wako Pure Chemicals	439-17501
Total Protein	Pierce	23225	Bicinchoninic Acid Assay