The authors would like to express our gratitude for the support and technical experience shared by the personnel at the Biomedical Laboratory, Aalborg University Hospital, Denmark.

All animal experiments described were performed at Aalborg University Hospital, Denmark, in accordance with existing laws and under the approval of the Danish Animal Experiments Inspectorate (license no. 2020-15-0201-00401). Domestic swine, female, approximately 40 kg and 3 months of age, were used for this study. The details regarding the reagents and equipment used are listed in the Table of Materials.
1. Subject housing
<ol>
	<li>House subjects in groups ...

An Efficient High-Speed Pneumatic Drill Craniectomy to Access the Porcine Brain

<ol>
	<li>Mariager, T., Bjarkam, C., Nielsen, H., Bodilsen, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experimental+animal+models+for+brain+abscess:+a+systematic+review.">Experimental animal models for brain abscess: a systematic review.</a> Br J Neurosurg. , 1-8 (2022).</li><li>Bassols, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+pig+as+an+animal+model+for+human+pathologies:+A+proteomics+perspective.">The pig as an animal model for human pathologies: A proteomics perspective.</a> Proteomics Clin Appl. 8, 715-731 (2014).</li><li>Meurens, F., Summerfield, A., Nauwynck, H., Saif, L., Gerdts, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+pig:+A+model+for+human+infectious+diseases.">The pig: A model for human infectious diseases.</a> Trends Microbiol. 20 (1), 50-57 (2012).</li><li>Swindle, M. M., Makin, A., Herron, A. J., Clubb, F. J., Frazier, K. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Swine+as+models+in+biomedical+research+and+toxicology+testing.">Swine as models in biomedical research and toxicology testing.</a> Vet Pathol. 49 (2), 344-356 (2012).</li><li>Lind, N. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+use+of+pigs+in+neuroscience:+Modeling+brain+disorders.">The use of pigs in neuroscience: Modeling brain disorders.</a> Neurosci Biobehav Rev. 31 (5), 728-751 (2007).</li><li>Hoffe, B., Holahan, M. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+use+of+pigs+as+a+translational+model+for+studying+neurodegenerative+diseases.">The use of pigs as a translational model for studying neurodegenerative diseases.</a> Front Physiol. 10, 838 (2019).</li><li>Ettrup, K. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Basic+surgical+techniques+in+the+g&#246;ttingen+minipig:+Intubation,+bladder+catheterization,+femoral+vessel+catheterization,+and+transcardial+perfusion.">Basic surgical techniques in the g&#246;ttingen minipig: Intubation, bladder catheterization, femoral vessel catheterization, and transcardial perfusion.</a> J Vis Exp. (52), e2652 (2011).</li><li>Bjarkam, C. R., Glud, A. N., Orlowski, D., S&#248;rensen, J. C. H., Palomero-Gallagher, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+telencephalon+of+the+G&#246;ttingen+minipig,+cytoarchitecture+and+cortical+surface+anatomy.">The telencephalon of the G&#246;ttingen minipig, cytoarchitecture and cortical surface anatomy.</a> Brain Struct Funct. 222 (5), 2093-2114 (2017).</li><li>Hou, N., Du, X., Wu, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Advances+in+pig+models+of+human+diseases.">Advances in pig models of human diseases.</a> Animal Model Exp Med. 5 (2), 141-152 (2022).</li><li>Munk, M., Poulsen, F. R., Larsen, L., Nordstr&#246;m, C. H., Nielsen, T. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cerebral+metabolic+changes+related+to+oxidative+metabolism+in+a+model+of+bacterial+meningitis+induced+by+lipopolysaccharide.">Cerebral metabolic changes related to oxidative metabolism in a model of bacterial meningitis induced by lipopolysaccharide.</a> Neurocrit Care. 29 (3), 496-503 (2018).</li><li>Kyllar, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Radiography,+computed+tomography+and+magnetic+resonance+imaging+of+craniofacial+structures+in+pig.">Radiography, computed tomography and magnetic resonance imaging of craniofacial structures in pig.</a> J Vet Med C: Anat Histol Embryol. 43 (6), 435-452 (2014).</li><li>Mariager, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Continuous+evaluation+of+single-dose+moxifloxacin+concentrations+in+brain+extracellular+fluid,+cerebrospinal+fluid,+and+plasma:+A+novel+porcine+model.">Continuous evaluation of single-dose moxifloxacin concentrations in brain extracellular fluid, cerebrospinal fluid, and plasma: A novel porcine model.</a> J Antimicrobial Chemother. , (2024).</li></ol>

The authors have no conflicts of interest to declare.

The demonstrated procedure involves several critical steps. Firstly, the accurate planning of the craniectomy&#39;s location is crucial due to the composition of the porcine skull. Since the thickness of the porcine frontal bone increases at the lateral edges, placing the opening too laterally11 can make it difficult to reach the dura mater during drilling. Additionally, locating the opening correctly within the midline is important to reduce the risk of unintended damage to the underlying dorsal ...

In general, animal models are used when practical and/or ethical limitations prohibit the use of human patients to examine diseases or test surgical methods. Novel animal models are generally established to provide new knowledge with translational value to human conditions. Rodents are often utilized due to practical and financial considerations, but they have limited translational value to humans, especially due to substantial anatomical differences1. Pigs, however, offer several advantages compared to rodents. Not only do pigs share several key anatomical, physiological, metabolic, and genetic features with humans, but the size of the porcine organ systems can be weight-matched to resemble human organs2,3. This gives pigs a unique role among surgical animal models and in procedural training4. Although the use of porcine models requires certain practical and financial capabilities compared to the use of rodents, pigs offer both a financially and ethically more acceptable option compared to the use of non-human primates.
The porcine brain is of particular interest in translational neuroscience research. Firstly, the architecture of the pig brain is similar to that of the human brain, as both are white matter-predominant and gyrencephalic3,5,6. Secondly, the larger brain size in pigs compared to rodents permits the use of surgical equipment and various imaging modalities equivalent to those used in clinical settings7,8. Consequently, various porcine models have been used extensively in neuroscience research over recent decades9. The majority of these porcine CNS models, however, require direct analysis of brain tissue, which can be obtained in various ways (e.g., implantation of catheters or electrodes, tissue biopsies, etc.)10. Since most of these modalities require some degree of instrumentalization and direct access to the brain, different approaches for surgical access must be considered.
This method involves performing an anterior craniectomy through the frontal bone on a sedated 3-month-old female Danish Landrace pig. The overall purpose of this manuscript is to describe a method for exposing a large proportion of the ventral porcine brain through a craniectomy using a pneumatic high-speed drill. The first step is to place the subject in a suitable position with an elevated head. Since the porcine cranium is quite different from that of humans, the second step involves planning the placement of the craniectomy using various anatomical landmarks. The third step is to access the underlying dura mater covering both hemispheres without damaging it.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>10 mL plastic syrringes</td>
			<td>Becton, Dickinson and Company</td>
			<td>303219</td>
			<td></td>
		</tr>
		<tr>
			<td>107 Microdialysis pump</td>
			<td>M Dialysis</td>
			<td>P000127</td>
			<td>&#160;107 Microdialysis Pump</td>
		</tr>
		<tr>
			<td>2 mL plastic syrringes</td>
			<td>Becton, Dickinson and Company</td>
			<td>300928</td>
			<td></td>
		</tr>
		<tr>
			<td>25 mm, 18 G needles</td>
			<td>Becton, Dickinson and Company</td>
			<td>304100</td>
			<td></td>
		</tr>
		<tr>
			<td>Bair Hugger heater</td>
			<td>3M</td>
			<td>B5005241003</td>
			<td></td>
		</tr>
		<tr>
			<td>Bair Hugger heating blanket</td>
			<td>3M</td>
			<td>B5005241003</td>
			<td></td>
		</tr>
		<tr>
			<td>Batery for microdialysis pump</td>
			<td>M Dialysis</td>
			<td>8001788</td>
			<td>Battery 6V, 106 &#38; MD Pump</td>
		</tr>
		<tr>
			<td>Dissector</td>
			<td>Karl Storz</td>
			<td>223535</td>
			<td>Flattended 3 mm dissector</td>
		</tr>
		<tr>
			<td>Endotracheal tube size 6.5</td>
			<td>DVMed</td>
			<td>DVM-107860</td>
			<td>Cuffed endotracheal tube</td>
		</tr>
		<tr>
			<td>Euthasol Vet</td>
			<td>Dechra Veterinary Products A/S</td>
			<td>380019</td>
			<td>phentobarbital for euthanazia, 400 mg/mL</td>
		</tr>
		<tr>
			<td>Farabeuf Rougine</td>
			<td>Mahr Surgical</td>
			<td></td>
			<td>Flat headed rougine (12 mm)</td>
		</tr>
		<tr>
			<td>Foley Catheter 12 F</td>
			<td>Becton, Dickinson and Company</td>
			<td>D175812E</td>
			<td>Catherter with in-built thermosensor</td>
		</tr>
		<tr>
			<td>Intravenous sheath</td>
			<td>Coris Avanti</td>
			<td></td>
			<td>Avanti Cordis Femoral Sheath 6 F</td>
		</tr>
		<tr>
			<td>Microdialysis brain catheters</td>
			<td>M Dialysis</td>
			<td>P000050</td>
			<td>membrane length 10 mm -shaft 100 mm 4/pkg</td>
		</tr>
		<tr>
			<td>Microdialysis syringe</td>
			<td>M Dialysis</td>
			<td>8010191</td>
			<td>&#160;106 Pump&#160;Syringe 20/pkg</td>
		</tr>
		<tr>
			<td>Microvials for microdialysis sampling</td>
			<td>M Dialysis</td>
			<td>P000001</td>
			<td>Microvials 250/pkg</td>
		</tr>
		<tr>
			<td>Operating table</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Pneumatic high-speed drill</td>
			<td>Medtronic</td>
			<td></td>
			<td>Medtronic Midas Rex 7 drill</td>
		</tr>
		<tr>
			<td>Primus respirator</td>
			<td>Dr&#228;ger</td>
			<td></td>
			<td>Respirator with in-built vaporiser for supplementary Sevofluran anesthesia</td>
		</tr>
		<tr>
			<td>Rounded diamond drill</td>
			<td>Medtronic</td>
			<td>7BA40D-MN</td>
			<td></td>
		</tr>
		<tr>
			<td>Self-retaining retractor</td>
			<td>World Precission Instruments</td>
			<td>501722</td>
			<td>Weitlander retractor, self-retaining, 14 cm blunt</td>
		</tr>
		<tr>
			<td>Sterile Saline</td>
			<td>Fresnius Kabi</td>
			<td>805541</td>
			<td>1000 mL</td>
		</tr>
		<tr>
			<td>Sterile surgical swaps</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Surgical scalpel no 24</td>
			<td>Swann Morton</td>
			<td>5.03396E+12</td>
			<td>Swann Morton Sterile Disposable Scalpel No. 24</td>
		</tr>
		<tr>
			<td>Zoletil Vet</td>
			<td>Virbac</td>
			<td></td>
			<td>Medical mixture for induction of anesthesia</td>
		</tr>
	</tbody>
</table>

accessing the porcine brain via high-speed pneumatic drill craniectomy

The use of pigs as an experimental animal model is especially relevant in neuroscience research, as the porcine and human central nervous systems (CNS) share many important functional and architectural properties. Consequently, pigs are expected to have an increasingly important role in future research on various neurological diseases. Here, a method to perform an anterior craniectomy through the porcine frontal bone is described. After a midline incision and subsequent exposure of the porcine frontal bone, anatomical landmarks are used to ensure the optimal location of the craniectomy. By careful and gradual thinning of the frontal bone with a rounded drill, a rectangular opening to the dura mater and underlying cerebral hemispheres is achieved. The presented method requires certain surgical materials, including a pneumatic high-speed drill, and some degree of surgical experience. Potential complications include unintended lesions of the dura mater or dorsal sagittal sinus. However, the method is simple, time-efficient, and offers a high degree of reproducibility for researchers. If performed correctly, the technique exposes a large portion of the unaffected pig brain for various neuromonitoring or analyses.

Author Spotlight: A Reproducible and Efficient Method for Accessing Porcine Brain via Craniectomy

Accessing the Porcine Brain via High-Speed Pneumatic Drill Craniectomy

The prone position of the pig&#39;s head provides optimal access for the surgeon during the procedure, and the use of stabilizing sandbags reduces the risk of unintended shifts in the pig&#39;s head position while drilling.
During this demonstration, the superficial anatomical landmarks of the pig&#39;s superior skull (both superior orbital crests and the nuchal crest) (Figure 1 and Figure 3) were used to precisely identify the center...

This protocol describes performing a craniectomy using a high-speed pneumatic drill on a 3-month-old Danish Landrace pig. The access is made through the frontal bone and reveals the ventral dura mater and underlying cerebral hemispheres. This procedure allows for access to a large portion of the pig brain.

The use of pigs as an experimental animal model is especially relevant in neuroscience research, as the porcine and human central nervous systems (CNS) ...

accessing-the-porcine-brain-via-high-speed-pneumatic-drill-craniectomy

Research

JoVE Journal

Neuroscience

Performing Craniectomy on a Pig Using a High-Speed Pneumatic Drill to Access the Brain

124 Views.  Aalborg University Hospital.  This protocol describes performing a craniectomy using a high-speed pneumatic drill on a 3-month-old Danish Landrace pig. The access is made through the frontal bone and reveals the ventral dura mater and underlying cerebral hemispheres. This procedure allows for access to a large portion of the pig brain.

An Efficient High-Speed Pneumatic Drill Craniectomy to Access the Porcine Brain

Summary