Endovascular Perforation Model for Subarachnoid Hemorrhage Combined with Magnetic Resonance Imaging (MRI)

Summary

Here we present a standardized SAH mouse model, induced by endovascular filament perforation, combined with magnetic resonance imaging (MRI) 24 h after operation to ensure the correct bleeding site and exclude other relevant intracranial pathologies.

Abstract

The endovascular filament perforation model to mimic subarachnoid hemorrhage (SAH) is a commonly used model - however, the technique can cause a high mortality rate as well as an uncontrollable volume of SAH and other intracranial complications such as stroke or intracranial hemorrhage. In this protocol, a standardized SAH mouse model is presented, induced by endovascular filament perforation, combined with magnetic resonance imaging (MRI) 24 h after operation to ensure the correct bleeding site and exclude other relevant intracranial pathologies. Briefly, C57BL/6J mice are anesthetized with an intraperitoneal ketamine/xylazine (70 mg/16 mg/kg body weight) injection and placed in a supine position. After midline neck incision, the common carotid artery (CCA) and carotid bifurcation are exposed, and a 5-0 non-absorbable monofilament polypropylene suture is inserted in a retrograde fashion into the external carotid artery (ECA) and advanced into the common carotid artery. Then, the filament is invaginated into the internal carotid artery (ICA) and pushed forward to perforate the anterior cerebral artery (ACA). After recovery from surgery, mice undergo a 7.0 T MRI 24 h later. The volume of bleeding can be quantified and graded via postoperative MRI, enabling a robust experimental SAH group with the option to perform further subgroup analyses based on blood quantity.

Introduction

Subarachnoid hemorrhage (SAH) is caused by the rupture of an intracranial aneurysm and poses a life-threatening emergency, associated with substantial morbidity and mortality, accounting for approx. 5% of strokes^1,2. SAH patients present with severe headaches, neurological dysfunction, and progressive disturbance of consciousness³. Around 30% of SAH patients die within the first 30 days after the initial bleeding event⁴. Clinically, 50% of patients experience delayed brain injury (DBI) after early brain injury. DBI is characterized by delayed cerebral ischemia an....

Protocol

The experiments were performed in accordance with the guidelines and regulations set forth by Landesamt fuer Gesundheit und Soziales (LaGeSo), Berlin, Germany (G0063/18). In this study, C57Bl/6J male (8-12 weeks old) mice with a weight of 25 ± 0.286 g (average ± s.e.m.) were used.

1. Animal preparation

1. Induce anesthesia by injecting ketamine (70 mg/kg) and xylazine (16 mg/kg) intraperitoneally. Maintain normal body temperature, contributing to quick induc.......

Discussion

In summary, a standardized SAH mouse model induced by endovascular filament perforation operation is presented with minor invasion, short operative time, and acceptable mortality rates. MRI is conducted 24 h postoperatively to ensure the correct bleeding site and the exclusion of other relevant intracranial pathologies. Furthermore, we classified different SAH bleeding grades and measured bleeding volumes, allowing further subgroup analyses based on bleeding grade.

Adequate positioning of the .......

Materials

Name	Company	Catalog Number	Comments
Eye cream	Bayer	815529836	Bepanthen
Images analysis software	ImageJ		Bundled with Java 1.8.0_172
Ligation suture (5-0)	SMI		Silk black USP
Light source for microscope	Zeiss	CL 6000 LED
Ketamine	CP-pharma	797-037	100 mg/mL
MRI	Bruker	Pharmascan 70/16	7 Tesla
MRI images acquired software	Bruker		Bruker Paravision 5.1
Paracetamol (40 mg/mL)	bene Arzneimittel	4993736
Prolene filament (5-0)	Erhicon	EH7255
Razor	Wella	HS61
Surgical instrument (Fine Scissors)	FST	14060-09
Surgical instrument (forceps#1)	AESCULAP	FM001R
Surgical instrument (forceps#2)	AESCULAP	FD2855R
Surgical instrument (forceps#3)	Hammacher	HCS 082-12
Surgical instrument (Needle holder)	FST	91201-13
Surgical instrument (Vannas Spring Scissors)	FST	15000-08
Surgical microscope	Zeiss	Stemi 2000 C
Ventilation monitoring	Stony Brook		Small Animal Monitoring & Gating System
Wounding suture(4-0)	Erhicon	CB84D
Xylavet	CP-pharma	797-062	20 mg/mL