Quantitative evaluation of intact peripheral nerve structures after utilization of CO2 laser, electrocautery, and scalpel

Effect of Nerve-Cutting Technique on Nerve Microstructure and Neuroma Formation

Background Peripheral neuroma formation results from partial or complete nerve division. Elucidating measures to prevent the development of peripheral neuromas is of clinical importance. The aim of this study was to determine the effect of various surgical nerve-cutting techniques on nerve microstructure and resultant neuroma formation. Methods Twenty Sprague-Dawley rats were randomly assigned to one of the following nerve-cutting techniques: No. 15 scalpel blade with tongue depressor, micro-serrated scissors, nerve-cutting guide forceps with straight razor, and bipolar cauterization. The right sciatic nerve was transected using the assigned nerve-cutting technique. Neuromas were harvested 6 weeks postoperatively, and samples were obtained for histologic analysis. The contralateral sciatic nerve was transected at euthanasia and analyzed with histology and with scanning electron microscopy in a subset of the rats. Results Fifteen of the 20 rats survived the 6-week experiment. Scanning electron microscopy of the No. 15 scalpel blade group showed the most visual damage and disorganization whereas the nerve-cutting guide forceps and micro-serrated scissors groups resulted in a smooth transected surface. Bipolar cauterization appeared to enclose the fascicular architecture within a sealed epineurium. Each neuroma was significantly larger than contralateral controls. There were no significant differences in neuroma caliber between nerve transection groups. No substantial differences in microstructure were evident between transection groups. Conclusion Despite disparate microscopic appearances of the cut surfaces of nerves using various nerve-cutting techniques, we found no significant differences in the caliber or incidence of neuroma formation based on nerve-cutting technique. Nerve-cutting technique used when transecting peripheral nerves may have little bearing on the formation or size of resultant neuroma formation.

Relieving Pain in Oral Lesions of Pemphigus Vulgaris Using the Non-ablative, Non-thermal, CO2 Laser Therapy (NTCLT): Preliminary Results of a Novel Approach

Introduction: Pemphigus vulgaris (PV) is a chronic, serious autoimmune mucocutaneous bullous disease. Oral lesions in PV may be extremely painful. This pain may adversely affect the patients' oral intake and quality of life. This before-after clinical trial was designed to assess the pain relieving effects of single session of non-ablative, non-thermal CO₂ laser therapy (NTCLT) in oral lesions of PV. Methods: Fifty painful oral lesions of fourteen patients with PV were illuminated by CO₂ laser (power: 1 W, scanning the lesions with rapid circular motion of the handpiece) passing through a thick layer of transparent gel with high water content. The pain severity of the oral lesions was reported by the patients up to the fourth postoperative day. They were also asked to continue their existing systemic treatment during the course of this study as a precondition for the participation. Results: The severity of contact and non-stimulate (non-contact) pain declined immediately and significantly after NTCLT (P < 0.001). The pain relieving effect was sustained during the four successive days of follow-up. The procedure was pain free and no kind of analgesics was required. Following NTCLT, there were no visible thermal complications such as destruction, ablation or irritation of the oral lesions. Conclusion: The results of the trial proposed that single session of NTCLT could immediately and significantly relieve pain in oral lesions of PV, without any visible thermal complications.

Histopathological and electrophysiological study of CO(2), Er:YAG, and CO (2) + Er:YAG laser effect on peripheral nerve

BACKGROUND

The purpose of this study was to investigate the morphological, histopathological, and electrophysiological changes of peripheral nerve after CO(2) (carbon dioxide), Er:YAG (erbium:yttrium aluminum garnet), and CO(2) + Er:YAG laser irradiation. There have been no comparative reports on CO(2), Er:YAG, and CO(2) + Er:YAG laser effects on peripheral nerve.

METHODS

Thirty Wistar albino rats were randomly assigned to three groups. Group I received CO(2), group II Er:YAG, and group III CO(2) + Er:YAG laser irradiation. Contralateral untreated sciatic nerves from the same animals were used as controls. The effect of laser on the peripheral nerve was assessed morphologically, histopathologically, and electrophysiologically after 6 weeks of laser irradiation.

RESULTS

No significant difference was observed between the treated and the untreated nerves.

CONCLUSION

The overall findings indicated that CO(2), Er:YAG, and CO(2) + Er:YAG lasers may be used safely in nerve tissue surgery.

Evaluation of short-term limb function following unilateral carbon dioxide laser or scalpel onychectomy in cats

OBJECTIVE

To evaluate short-term postoperative forelimb function after scalpel and laser onychectomy in cats.

DESIGN

Randomized, prospective study.

ANIMALS

20 healthy adult cats.

PROCEDURES

Cats were randomly assigned to the laser (n = 10) or scalpel (10) onychectomy group. Unilateral left forelimb onychectomy was performed. In the scalpel group, a tourniquet was used during surgery and a bandage was applied after surgery. Pressure platform gait analysis was performed prior to and 1, 2, 3, and 12 days after onychectomy. Peak vertical force (PVF), vertical impulse, and the ratio of the PVF of the left forelimb to the sum of the remaining limbs (PVF ratio) were used as outcome measures.

RESULTS

The laser onychectomy group had significantly higher ground reaction forces on days 1 and 2 and significantly higher PVF ratio on day 12, compared with the scalpel group. Similarly, significant differences were found in change in ground reaction forces on days 1 and 2 and the PVF ratio on day 12, compared with day -1. No cats required rescue analgesia during the course of the study. One cat in the laser group had signs of depression and was reluctant to walk on day 2 after surgery, had physical examination findings consistent with cardiac insufficiency, and was euthanized.

CONCLUSIONS AND CLINICAL RELEVANCE

Cats had improved limb function immediately after unilateral laser onychectomy, compared with onychectomy with a scalpel, tourniquet, and bandage. This improved limb function may result from decreased pain during the 48 hours following unilateral laser onychectomy.

CO2 laser in oral graft-versus-host disease: a pilot study

This paper is the first to report the benefits of CO2 laser treatment for pain control in severe oral chronic graft-versus-host disease (GVHD). A CO2 laser device was used during 17 treatment sessions in four patients. The CO2 laser was applied over the mucosal lesions using 1 W for 2-3 s/1 mm(2). This treatment resulted in a consistent and significant decrease in pain, measured using a standard visual analogue scale. These results suggest that the CO2 laser can be used for the alleviation of pain in oral chronic GVHD.