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Ranjbartehrani P, Ramirez DA, Schmidlin F, Etheridge M, Iaizzo PA, Shao Q, Bischof JC. Nerve Protection During Prostate Cryosurgery. Ann Biomed Eng 2023; 51:538-549. [PMID: 36088432 DOI: 10.1007/s10439-022-03059-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 08/13/2022] [Indexed: 11/30/2022]
Abstract
Cryosurgery is a minimally invasive approach to the treatment of focal prostate cancer (PCa). A major complication is the cryoinjury to the cavernous nerve in the neurovascular bundle (NVB). This nerve cryoinjury halts conduction of action potentials (APs) and can eventually result in erectile dysfunction and therefore diminished quality of life for the patient. Here, we propose the application of cryoprotective agents (CPA) to the regions of the nerves in the NVB, prior to prostate cryosurgery, to minimize non-recoverable loss of AP conduction. We modeled a cryosurgical procedure based on data taken during a clinical case and applied ex-vivo porcine phrenic nerves and rat sciatic nerve with temperature profile of NVB. The APs were measured before and after the CPA exposures and during 3 h of recovery. Comparisons of AP amplitude recovery with various CPA compositions reveal that certain CPAs (e.g., 5% DMSO + 7.5% Trehalose and 5% M22 for porcine and rat nerves, respectively) showed little or no toxicity and effective cryoprotection from freezing (on average 48% and 30% of recovered AP, respectively). In summary, we demonstrate that neural conduction can be preserved after exposure to freezing conditions if CPAs are properly selected and deployed onto the nerve.
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Affiliation(s)
- Pegah Ranjbartehrani
- Department of Mechanical Engineering, University of Minnesota, 111 Church Street SE, Minneapolis, MN, 55455, USA
| | - David A Ramirez
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, USA
| | - Franz Schmidlin
- Urology Center Hirslanden Grangettes Group, Geneva, Switzerland
| | - Michael Etheridge
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, USA
| | - Paul A Iaizzo
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, USA.,Department of Surgery, University of Minnesota, Minneapolis, USA.,Institute for Engineering in Medicine, University of Minnesota, Minneapolis, USA
| | - Qi Shao
- Department of Mechanical Engineering, University of Minnesota, 111 Church Street SE, Minneapolis, MN, 55455, USA. .,Institute for Engineering in Medicine, University of Minnesota, Minneapolis, USA.
| | - John C Bischof
- Department of Mechanical Engineering, University of Minnesota, 111 Church Street SE, Minneapolis, MN, 55455, USA. .,Department of Biomedical Engineering, University of Minnesota, Minneapolis, USA. .,Institute for Engineering in Medicine, University of Minnesota, Minneapolis, USA.
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Burchiel KJ, Russell LC. Glycerol neurolysis: neurophysiological effects of topical glycerol application on rat saphenous nerve. J Neurosurg 1985; 63:784-8. [PMID: 4056882 DOI: 10.3171/jns.1985.63.5.0784] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The effect of topical glycerol application on normal and previously injured saphenous nerves was tested in 20 Sprague-Dawley rats. Anhydrous glycerol treatment of five normal nerves showed a rapid loss of C-fiber conduction within 5 minutes of application, while after 10 to 30 minutes, a complete conduction blockade in all fiber types was produced. The effect of anhydrous glycerol on both spontaneous firing from the neuroma and impulse propagation within the nerve was examined in 11 rats that had undergone saphenous neurotomy 7 days previously. In these animals, cessation of spontaneous action potential production from the neuroma was the earliest electrophysiological change noted, followed by loss first of C-fiber, then of A-fiber conduction. Graded concentrations of glycerol (25%, 50%, 75%, and 100%) were used in four rats with saphenous neuromas, which allowed selective blockade of spontaneous action potential generation and C-fiber conduction with minimal effect on A-fibers. The neurophysiological mechanism of glycerol neurolysis appears to be a nonspecific conduction blockade of large and small fibers, which is established within minutes of its application. Spontaneous firing within damaged axons, which may play a role in a variety of cranial and peripheral nerve sensorimotor syndromes, is also exquisitely sensitive to glycerol application.
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