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The Effects of Irreversible Electroporation on the Achilles Tendon: An Experimental Study in a Rabbit Model.

Song Y, Zheng J, Yan M, Ding W, Xu K, Fan Q, Li Z - PLoS ONE (2015)

Bottom Line: A total of 140 six-month-old male New Zealand rabbits were used.Histopathological and biomechanical evaluations were performed to examine the effects of electroporation ablation and radiofrequency ablation over time.This advantage could have a significant impact on the field of tumor ablation near vital tendons or ligaments.

View Article: PubMed Central - PubMed

Affiliation: Orthopedics Oncology Institute of Chinese PLA and Department of Orthopedics, Tangdu Hospital, Fourth Military Medical University, Xi'an, Shaanxi, P.R. China; Department of General Surgery, NO. 202 Hospital of PLA, Shenyang, Liaoning, P.R. China.

ABSTRACT

Background: To evaluate the potential effects of irreversible electroporation ablation on the Achilles tendon in a rabbit model and to compare the histopathological and biomechanical changes between specimens following electroporation ablation and radiofrequency ablation.

Methods: A total of 140 six-month-old male New Zealand rabbits were used. The animals were randomly divided into two groups, 70 in the radiofrequency ablation group and 70 in the electroporation group. In situ ablations were applied directly to the Achilles tendons of rabbits using typical electroporation (1800 V/cm, 90 pulses) and radiofrequency ablation (power control mode) protocols. Histopathological and biomechanical evaluations were performed to examine the effects of electroporation ablation and radiofrequency ablation over time.

Results: Both electroporation and radiofrequency ablation produced complete cell ablation in the target region. Thermal damage resulted in tendon rupture 3 days post radiofrequency ablation. In contrast, electroporation-ablated Achilles tendons preserved their biomechanical properties and showed no detectable rupture at this time point. The electroporation-ablated tendons exhibited signs of recovery, including tenoblast regeneration and angiogenesis within 2 weeks, and the restoration of their integral structure was evident within 12 weeks.

Conclusions: When applying electroporation to ablate solid tumors, major advantage could be that collateral damage to adjacent tendons or ligaments is minimized due to the unique ability of electroporation ablation to target the cell membrane. This advantage could have a significant impact on the field of tumor ablation near vital tendons or ligaments.

No MeSH data available.


Related in: MedlinePlus

H&E staining of the rabbit ATs following sham operation, RFA and IRE ablation in longitudinal section.(RFA-3 d) Coagulative necrosis induced nuclear pyknosis and karyorrhexis (arrow head); (IRE-1 w) complete IRE ablation and removal of tenocytes; (IRE-2 w) regeneration of blood capillaries (black arrow) and tenoblasts (hollow arrow). The scale bars represent 50 μm.
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pone.0131404.g004: H&E staining of the rabbit ATs following sham operation, RFA and IRE ablation in longitudinal section.(RFA-3 d) Coagulative necrosis induced nuclear pyknosis and karyorrhexis (arrow head); (IRE-1 w) complete IRE ablation and removal of tenocytes; (IRE-2 w) regeneration of blood capillaries (black arrow) and tenoblasts (hollow arrow). The scale bars represent 50 μm.

Mentions: In the control group, H&E staining revealed that the collagen fibers were wavy but parallel to the major axis of the tendon. Sparse tenocytes with flat nuclei were distributed in the interspaces of dense fibers (Fig 4). TEM revealed a transverse band on each parallel collagen fibril and narrow interfibrillar crannies. However, in the RFA group, disintegration, liquefaction and coagulative necrosis with nuclear pyknosis and karyorrhexis were evident 3 d after ablation. Collagen fibrils were difficult to distinguish from the tangled mass of degenerative extracellular matrix (ECM). However, the architecture of collagen fibrils appeared to have remained intact during the initial 2 w after IRE (Fig 5). In the IRE group, the cell structure apparently disappeared 3 d after ablation, leaving a large number of condensed and abnormal nuclei. There was a well-demarcated margin between the ablated and non-ablated regions (Fig 6). The combination of 1800 V/cm and 90 pulses was sufficient to ablate all cells within the target region 1 week post-IRE (Figs 4 and 7A). The IRE-2 w specimen was characterized by the regeneration of tenoblasts and blood capillaries. Several round or oval-shaped tenoblasts were observed migrating from the peripheral non-ablated region, as well as from the ingrowing endotenon towards the intermediate region. In the IRE-6 w specimens, the collagen fibrils were slightly separated by small interfibrillar gaps, and their average diameter had decreased (Figs 5 and 7C). The number of cells per square millimeter and the individual cell area were both at high levels from 4 w to 6w (Fig 7A and 7B). Modeling and maturation of the AT were evident in IRE group between 12 w and 24 w. Over time, collagen realignment and cellular distribution gradually returned to control levels.


The Effects of Irreversible Electroporation on the Achilles Tendon: An Experimental Study in a Rabbit Model.

Song Y, Zheng J, Yan M, Ding W, Xu K, Fan Q, Li Z - PLoS ONE (2015)

H&E staining of the rabbit ATs following sham operation, RFA and IRE ablation in longitudinal section.(RFA-3 d) Coagulative necrosis induced nuclear pyknosis and karyorrhexis (arrow head); (IRE-1 w) complete IRE ablation and removal of tenocytes; (IRE-2 w) regeneration of blood capillaries (black arrow) and tenoblasts (hollow arrow). The scale bars represent 50 μm.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4482699&req=5

pone.0131404.g004: H&E staining of the rabbit ATs following sham operation, RFA and IRE ablation in longitudinal section.(RFA-3 d) Coagulative necrosis induced nuclear pyknosis and karyorrhexis (arrow head); (IRE-1 w) complete IRE ablation and removal of tenocytes; (IRE-2 w) regeneration of blood capillaries (black arrow) and tenoblasts (hollow arrow). The scale bars represent 50 μm.
Mentions: In the control group, H&E staining revealed that the collagen fibers were wavy but parallel to the major axis of the tendon. Sparse tenocytes with flat nuclei were distributed in the interspaces of dense fibers (Fig 4). TEM revealed a transverse band on each parallel collagen fibril and narrow interfibrillar crannies. However, in the RFA group, disintegration, liquefaction and coagulative necrosis with nuclear pyknosis and karyorrhexis were evident 3 d after ablation. Collagen fibrils were difficult to distinguish from the tangled mass of degenerative extracellular matrix (ECM). However, the architecture of collagen fibrils appeared to have remained intact during the initial 2 w after IRE (Fig 5). In the IRE group, the cell structure apparently disappeared 3 d after ablation, leaving a large number of condensed and abnormal nuclei. There was a well-demarcated margin between the ablated and non-ablated regions (Fig 6). The combination of 1800 V/cm and 90 pulses was sufficient to ablate all cells within the target region 1 week post-IRE (Figs 4 and 7A). The IRE-2 w specimen was characterized by the regeneration of tenoblasts and blood capillaries. Several round or oval-shaped tenoblasts were observed migrating from the peripheral non-ablated region, as well as from the ingrowing endotenon towards the intermediate region. In the IRE-6 w specimens, the collagen fibrils were slightly separated by small interfibrillar gaps, and their average diameter had decreased (Figs 5 and 7C). The number of cells per square millimeter and the individual cell area were both at high levels from 4 w to 6w (Fig 7A and 7B). Modeling and maturation of the AT were evident in IRE group between 12 w and 24 w. Over time, collagen realignment and cellular distribution gradually returned to control levels.

Bottom Line: A total of 140 six-month-old male New Zealand rabbits were used.Histopathological and biomechanical evaluations were performed to examine the effects of electroporation ablation and radiofrequency ablation over time.This advantage could have a significant impact on the field of tumor ablation near vital tendons or ligaments.

View Article: PubMed Central - PubMed

Affiliation: Orthopedics Oncology Institute of Chinese PLA and Department of Orthopedics, Tangdu Hospital, Fourth Military Medical University, Xi'an, Shaanxi, P.R. China; Department of General Surgery, NO. 202 Hospital of PLA, Shenyang, Liaoning, P.R. China.

ABSTRACT

Background: To evaluate the potential effects of irreversible electroporation ablation on the Achilles tendon in a rabbit model and to compare the histopathological and biomechanical changes between specimens following electroporation ablation and radiofrequency ablation.

Methods: A total of 140 six-month-old male New Zealand rabbits were used. The animals were randomly divided into two groups, 70 in the radiofrequency ablation group and 70 in the electroporation group. In situ ablations were applied directly to the Achilles tendons of rabbits using typical electroporation (1800 V/cm, 90 pulses) and radiofrequency ablation (power control mode) protocols. Histopathological and biomechanical evaluations were performed to examine the effects of electroporation ablation and radiofrequency ablation over time.

Results: Both electroporation and radiofrequency ablation produced complete cell ablation in the target region. Thermal damage resulted in tendon rupture 3 days post radiofrequency ablation. In contrast, electroporation-ablated Achilles tendons preserved their biomechanical properties and showed no detectable rupture at this time point. The electroporation-ablated tendons exhibited signs of recovery, including tenoblast regeneration and angiogenesis within 2 weeks, and the restoration of their integral structure was evident within 12 weeks.

Conclusions: When applying electroporation to ablate solid tumors, major advantage could be that collateral damage to adjacent tendons or ligaments is minimized due to the unique ability of electroporation ablation to target the cell membrane. This advantage could have a significant impact on the field of tumor ablation near vital tendons or ligaments.

No MeSH data available.


Related in: MedlinePlus