This study describes a simplified surgical procedure and technique for performing cavernous nerve stimulation with the isolation of the nerve-electrode complex using silicone glue and intracavernous pressure measurement.
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Method Article
Cavernous Nerve Stimulation and Recording of Intracavernous Pressure in a Rat
In This Article
Summary
Abstract
The stimulation of the cavernous nerve (CN) and measurement of intracavernous pressure (ICP) have been used extensively to test and evaluate therapies for erectile dysfunction. However, the methods used vary between laboratories, and pitfalls still exist. The goal of this study was to describe a surgical technique that would provide a reliable and reproducible model. By exposing the ischiocavernosus muscle at its point of insertion on the ischial tuberosity, the penile crus could be cannulated with minimal dissection and injury to the structures involved in erectile function. Repeated stimulation of the CN, without the need for lifting and drying, was achieved by using a 125 µm bipolar silver electrode and biocompatible silicon glue to isolate the electrode-nerve complex. This method prevents neuropraxia by reducing stretching and drying the nerve and provides complete isolation of the nerve, negating electrical leakage and preventing stimulation of alternative pathways.
Introduction
In vivo study of erectile function in experimental animals started in 1863 with the pioneering experimental work of Eckhard1. Electrostimulation of the pelvic nerves was used to induce the increased ICP in dogs. Throughout the 20th century, similar experimental protocols were used in larger animals such as dogs, monkeys, cats and rabbits. Evaluating erectile function in a rat was first developed by Quinlan et al. in 19892. The method has since been modified and updated by several other groups34. Today, the rat is the most widely used animal mode....
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Protocol
Animals were housed in the University of Southern Denmark Animal Care Facility as per institutional guidelines. All animal experiments were carried out in accordance with the National Institutes of Health guide for the care and use of laboratory animals. This is an acute, non-survival surgery procedure.
1. Preparation of Tubing, Electrode, and Instruments for the Surgical Procedure
- Use the following microsurgical instruments: surgical scissors, angled micro scissors, a tissue forceps, a pair of Dumont #7 and #5 curved micro forceps, a micro needle holder, and retractors.
Note: As this is an acute pr....
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Results
The use of this protocol with the recommended stimulation settings, under inhalation anesthesia with isoflurane 2.0% oxygen 0.8 L/min, should produce results as shown in Figure 11 and Figure12, where there is multiple back to back stimulations between 75-80 mm Hg. Figure 13 shows the same stable response over a 20-min stimulation with the response stable at 73-77 mm Hg. Test the line for ICP meas.......
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Discussion
The principal goal of this study was to describe a simplified surgical technique of penile crus cannulation for ICP recording and isolation of the CN for electrostimulation. We introduced modifications to the dissection of the cavernous body to simplify the surgery and provide reproducible recordings of the increase of the ICP with CN stimulation. With a 1 cm vertical skin incision, lateral to the base of the penis, using the palpable ischial tuberosity as guidance, we achieved good exposure of the ischiocavernosus muscl.......
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Disclosures
The authors have nothing to disclose.
Acknowledgements
The authors have no acknowledgements.
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Materials
| Name | Company | Catalog Number | Comments |
|---|---|---|---|
| Adson forceps | Fine Science Tool | 11006-12 | |
| Dumont #7 forceps | Fine Science Tool | 11271-30 | |
| Dumont #5 forceps | Fine Science Tool | 11273-20 | |
| ToughCut Mayo scissor | Fine Science Tool | 14110-15 | |
| Miniature Vannas Spring scissor | Fine Science Tool | 15006-09 | |
| Ultra Fine Hemostat | Fine Science Tool | 13020-12 | |
| Crile Hemostat | Fine Science Tool | 13004-14 | |
| Kwik-Sil Adhesive | World Precision Instruments | KWIK-SIL | |
| Teflon coated silver wire 0.125 mm | World Precision Instruments | AGT0510 | |
| Elastic wire retractors | Custom made | ||
| Scalpel blade | Fine Science Tool | 10023-00 | |
| PE-50 tubing | Warner Instruments | 64-0753 | |
| 23 G Needle | Kruuse | 121272 | |
| SD-9 Square Pulse Stimulator | Somatco | 1077/183 | |
| Blood pressure transducer and cable | World Precision Instruments | BLPR2 | |
| Raucotupf Cotton-tipped Applicators | Lohmann-Raucher | 11966 | |
| Pro-ophta Ocular Sticks | Lohmann-Raucher | 16515 | |
| NaCl 0,9 % 100 mL | Local pharmacy | ||
| Heparin | Local pharmacy | ||
| 25 mL Syringe | Odense University Hospital | ||
| Vet eye ointment - Viscotears | Local pharmacy | ||
| silver wires | Science Products GmbH, Heidelberg, Germany | ||
| Silicon Glue | Kwik-Sil, World Precision Instruments, Sarasota, FL, USA |
References
- Eckhard, C. Untersuchungen über die Erektion des Hundes In: Beiträge zur Anatomie und Physiologie. , Vol. Band III Giessen: Ferber 123-166 (1863).
- Quinlan, D. M., Nelson, R. J., Partin, A. W., Mostwin, J. L., Walsh, P. C. The rat as a model for the study of penile erection. J Urol. ....
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