Inguinal Cannulation for Establishing Extracorporeal Circulation in Adult Porcine Model

Summary

This article describes the establishment of extracorporeal circulation via inguinal cannulation and explains the advantages and disadvantages associated with this technique.

Abstract

Due to the similar size ratios, adult porcine models are suitable for cardiovascular and circulatory physiology studies on extracorporeal circulation. As standard, the connection to the cardiopulmonary bypass (CBP) is established via a sternotomy and cannulation of large vessels. However, problems can arise during methodical implementation, for example, due to a small situs, vessels that are difficult to see, or vascular anomalies with a small aorta. An iatrogenic aortic rupture can lead to the termination of the experiment. Therefore, there is a need for further, safe access via the inguinal vessels. A heart-lung machine with a disposable set (hollow fiber oxygenator with a perfusion capacity of up 3,5 l/min) is used in the in vivo trial. For inguinal cannulation, the femoral artery and vein are dissected in the right groin. A 14-16 French (Fr.). Edwards Heartport cannula and a 22-Fr. SAP femoral cannula is used for cannulation. Cannulation is performed using the Seldinger technique. Inguinal cannulation resulted in significantly fewer aborted experiments in the large animal trials and allowed better relief of the heart during dissection. Inguinal cannulation to establish an extracorporeal circulation in a large animal model trial represents a safe approach. It results in minimal trauma to the aorta and improved visibility in the thorax. In addition, this access enables minimally invasive cardiac surgery. The focus is also on the ethical aspects of animal experiments and the associated experimental success.

Introduction

In vivo pig models are suitable for cardiovascular and circulatory physiology studies due to their comparable anatomical and physiological properties. Establishment of extracorporeal circulation is also unproblematic due to the size and weight ratios. This means that extensive studies on various issues can be carried out in vivo. This applies in particular to studies on the use of a heart-lung machine and the associated establishment of an extracorporeal circuit^1,2. The goal of the method presented here is to provide an experimental platform for extracorporeal circulation in pigs using groin ....

Protocol

All large-animal experiments on pigs (age 3-4 months; sex: male and female; weight 40-60 kg; domestic pigs), after thorough review, were approved by the Karlsruhe Regional Council on October 10, 2022, under file number 35.-9185.81/G-96/22. This is a terminal procedure; all animals were euthanized at the end of the procedure.

1. Anesthesia and animal preparation

1. Premedication is always carried out at our faculty in the Interfaculty Biomedical Research Facility. Premedicate the laboratory animal with 0.075 mL/kg midazolam hydrochloride (5 mg/mL) and 0.225 mL/kg ketamine (100 mg/mL) before taking it to the operatin....

Results

The change in cannulation type for establishing extracorporeal circulation, from thoracic central cannulation to inguinal cannulation, did not result in iatrogenic aortic rupture in animal experiments (Table 1). The background to this is an animal study in which 18 pigs per group were operated on. In the first 15 procedures, six pigs suffered iatrogenic aortic rupture after central cannulation, which is why the experiment was discontinued. The mortality rate was 40%. In the remaining 21 procedures, the c.......

Discussion

Experimental cardiac surgery is indispensable today. Possible objectives include assessing left ventricular pump function under the administration of various drugs and their pharmacokinetic properties, optimizing surgical procedures, and optimizing perfusion in extracorporeal circulation. Adult pig models are very well suited for this purpose due to their cardiovascular and physiological characteristics.

In extracorporeal circul.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Dexpanthenol 5%	Bayer	PZN AT-2424276	Anaesthesia
HLM Set Trilly AF Kinder	Eurosets	AG71155	Heart lung machines disposable set
Ketamin 5mg/ml	Pfizer	PZN 01395650	Anaesthesia
Mersilene 0	Ethicon	R844	pericardial stay sutures
Midazolam 5mg/5ml	Hameln	PZN 05918501	Anaesthesia
Perkutanes Einführkit 100 cm	Maquet	PIK 100	Arterial puncture set
Piritramid 15mg/ml	Piramal	PZN 01312724	Anaesthesia
Polypropylene 4,0 RB-1 (Prolene)	ETHICON	8710H	Tobacco pouch seam on the vessel
PotiSite Arterial Perfusion Cannula 16 Fr.	Edwards	FLK0012	Arterial inguinal cannula
Propofol 1% 200mg/20ml	Fresenius KABI	PZN 18116200	Anaesthesia
RAP Femoral Venous Cannula 22 Fr.	LivaNova	200-100	Venous inguinal cannula
Revas Access Kit Dual Lumen 180 cm	Freelife	FLK0012	Venous puncture set
Seide 75 cm	Resorba	G850N	to fix the cannula around the vessel
Sevofluran 100% /V/V) 250ml	SEVOrane	PZN 03796821	Anaesthesia
Silikon-Loops 2,5 mm blue	SERAG Wiessner	SL27	for the preparation of the vein
Silikon-Loops 2,5 mm red	SERAG Wiessner	SL26	for the preparation of the artery
Sterofundin ISO 1/1 E ISO	B/BRAUN	PZN 01078955	Volume
Tourniquet Kit 7 Fr.	Medtronic	79005	for attaching the cannulas to the vessel