Comparison of lateral thermal injury and healing of porcine skin incisions performed by CO2-laser, monopolar electrosurgery and radiosurgery: a preliminary study based on histological and immunohistochemical results

Injuries of Different Surgical Instruments on the Vocal Folds of Dogs

OBJECTIVE

This study aimed to compare the damage of vocal folds caused by four different surgical instruments: CO2 laser, electrosurgical knife, plasma radiofrequency ablation, and steel knife.

STUDY DESIGN

Randomized controlled study.

METHODS

The CO2 laser, electrosurgical knife, plasma radiofrequency ablation, steel knife, and other instruments were used to simulate the laryngeal microsurgery on experimental dogs. Both total vocal fold resection and punctate ablation were performed. On the day of surgery and 6 days later, the vocal fold tissue from the surgical site was removed for histological evaluation. The extent of vocal fold damage was assessed using the automatic digital pathological scanning system.

RESULTS

We detected varying degrees of damage to the laryngeal tissues. Only the steel knife caused epidermal defects on the vocal fold tissue, while other instruments produced thermal damage of different degrees. Furthermore, the steel knife also showed better and faster healing. The plasma radiofrequency ablation was found to cause more severe thermal burns to vocal folds than other surgical instruments (P < 0.05). Six days postsurgery the inflammatory reaction from the steel knife had basically subsided, with only hyperplasia and tissue repair visible microscopically, showing the best healing degree. On the other hand, the radiofrequency ablation group showed the heaviest inflammatory reaction, indicating relatively poor prognosis (P < 0.05).

CONCLUSION

Compared with the CO2 laser, the electrotome and steel knife showed less damage and better healing, while the plasma radiofrequency ablation showed the most obvious thermal burns to laryngeal and vocal tissues during surgery, with relatively poor healing.

Clinical and histological comparison of healing by steel scalpel, diode laser, and radiofrequency in palatal wound: An animal study

Background

Wound healing following periodontal soft tissue procedures can differ owing to different techniques, the feasibility of which can be determined through detailed macroscopic and microscopic observations.

Aims

This study aimed to clinically and histologically evaluate palatal wound healing in rats by secondary intention after excision using a steel scalpel, diode laser, and radiofrequency.

Materials and Methods

An excision was made in the edentulous anterior maxilla of 42 4-month-old male Wistar rats weighing 289-428 g. Part of the connective tissue was left in the surgical area to observe the dynamics of secondary intention wound healing. Three experimental groups were established: the steel scalpel, an 810-nm diode laser at a power output of 1.5 W in continuous mode, and a monopolar radiofrequency in a fully rectified waveform at 15 W. Clinical and histological analyses were performed on days 2, 4, and 7. Hemostasis, changes in body weight, defect size, epithelial gap, and inflammatory infiltration were evaluated.

Results

The epithelial gap closed completely in all groups on day 7. Bleeding occurred significantly more in the scalpel group (P < 0.001). No significant changes were observed in body weight between the groups. Macroscopically, the mean wound area decreased over time in all groups. Wound healing was significantly slower in the laser group on day 2 and in the radiofrequency group on days 4 and 7 (P < 0.001). Microscopically, the laser created the cleanest wound area, with minimal inflammatory infiltration and no thermal injury. More damage occurred in the connective tissue of the radiofrequency group. Wound healing was observed on day 7 in all groups.

Conclusions

Palatal wound healing with secondary intention yielded different outcomes in a rat model when different techniques were used. However, almost complete healing was observed in all wounds, which highlights the importance of the soft tissue left in the surgical area. Wound healing in periodontal soft tissue procedures is not compromised by different techniques, as long as the clinician has sufficient knowledge and experience.

Histologic and Immunohistochemical Evaluation of Radiosurgery in Strabismus Surgery in a Rabbit Model

PURPOSE

The aim of this study was to evaluate the use of monopolar radiosurgery (MRS) assisted strabismus surgery and to compare its histologic and immunohistochemical wound healing outcomes with conventional surgery.

MATERIALS AND METHODS

Superior rectus muscle resection was performed on 30 white rabbits with three different surgical muscle cutting techniques: monopolar radiosurgery (MRS group), conventional scissors preceded by bipolar electrocautery (BEC group), and conventional scissors with no cauterization (control group). Degree of tissue injury, bleeding, inflammation, and fibrosis, as well as wound healing rate (CD68+ cell number), were evaluated.

RESULTS

In CS group, hemorrhage scores were significantly higher than those in the other groups (MRS group: Z = 5.182; p < 0.001 and BEC group: Z = 4.463; p < 0.001) and MRS group had lower scores than BEC group; however, the difference was not significant (Z = 1.423; p = 0.211). The tissue injury score in BEC group was higher when compared with MRS, and the difference was statistically significant (p = 0.028). Median inflammation scores at days 1 and 21 were lowest in MRS group, but the difference was not statistically significant among groups (day 1; p = 0.115, day 21; p = 0.095). The median fibrosis score was higher in the control group, when compared with MRS, and the difference was statistically significant (muscle-sclera; p = 0.011 and muscle-conjunctiva: p = 0.003). The macrophage score (number of CD68+ cells) was lowest in CS group; however, the difference was not significant (p = 0.657).

CONCLUSIONS

Monopolar radiosurgery is a novel method for strabismus surgery and provides equivalent hemostasis effects and wound healing properties, compared with conventional methods, and enhances surgeon comfort, as muscle incisions are made in one step with clean surgical area.

Evaluating the utility of a CO2 surgical laser for piglet castration to reduce pain and improve wound healing: a pilot study

CO₂ surgical lasers are widely used for procedures in veterinary and human medicine. There is evidence to suggest surgery using a CO₂ laser reduces pain and swelling and improves healing time compared with surgery with a scalpel. Millions of piglets in North America are surgically castrated each year using a scalpel. Therefore, piglet welfare may be improved by making refinements to the surgical procedure. The objectives of this preliminary study were to determine the ability of a CO₂ surgical laser to (1) reduce pain and (2) improve wound healing of piglets undergoing surgical castration. Two-day-old male Yorkshire × Landrace piglets were used and randomly assigned to 1 of 3 treatments (n = 10 piglets/treatment group): surgical castration with the CO₂ laser, surgical castration with a scalpel, or sham (uncastrated control). Piglets were video recorded in their pens for 1 hr preprocedure and from 0 to 2, 6 to 8, and at 24 hr postprocedure for behavior scoring. Surgical site images were collected at baseline, 0, 8, 24, 48, 72, 96, 120, 144, and 168 hr postcastration for wound healing assessment. Infrared thermography images of the surgical site were also taken at baseline, 0, 0.5, 8, and 24 hr postprocedure to assess inflammation. Finally, blood was collected from each piglet at baseline and 0.5 hr postcastration to assess cortisol levels, prostaglandin E metabolite and pig-major acute phase protein concentration. Laser-castrated piglets displayed more pain behaviors across the observation period than scalpel-castrated piglets (P = 0.05). Laser-castrated piglets also displayed significantly more agonistic behavior than both scalpel-castrated piglets (P = 0.005) and sham piglets (P = 0.036); yet, laser-castrated piglets had significantly lower temperatures at the site of incision compared with scalpel-castrated piglets (P = 0.0211). There was no significant difference in wound healing or any of the blood parameters assessed between laser-castrated and scalpel-castrated piglets. There was evidence of thermal tissue damage on the scrotum of piglets that were castrated using the CO₂ laser. This may have resulted in the unremarkable healing time and the increased pain behavior observed in this study. The surgical laser technique should be refined before conclusions can be made regarding the utility of a CO₂ laser for piglet castration.

Pilonidal sinus disease: Preliminary case-control study on heat-related wound dehiscence

Background

Pilonidal disease is a morbid condition of the young population, that could impair quality of life with a high cost for the health care system. No consensus exists on optimal surgical treatment, even if several techniques have been proposed. In this preliminary case-control study we compared excision by knife and diathermy to investigate if wound dehiscence could be related to heat spreading during excision of the sinus.

Materials and method

Between January 2017 and February 2018, 29 patients underwent to sinus excision.16 patients underwent sinus excision by diathermy (named “Hot” group, case-group) while 13 patients underwent excision by the knife as the control group (named “Cold” group). The temperature data were recorded for both groups. Were considered primary and secondary outcomes.

Results

the cold group has worse outcomes in operative time and blood loss, but better results in post-operative pain at first day and first control, number of weekly and total dressings until healing, time for full wound recovery, days to return to work, patient feeling feedback and scar aspect. Wounds healed within 8–12 days were 84.6% in the Cold group and 18.8% in the Hot one. I° Dindo-Clavien complications were respectively 15.4% and 100.0% for the Cold and Hot group. No differences were recorded for II° Dindo-Clavien complications and in days of hospitalization.

Conclusion

cold excision of the sinus pilonidalis has better results both in terms of precarious healing and quality of life, probably because the tissues are not subjected to diathermocoagulation damage and therefore the healing occurs more quickly. (United States National Institutes of Health, www.clinicaltrial.gov, number NCT 03764657, www.researchregistry.com UIN 5003).

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Pilonidal sinus disease.

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Cold and Hot surgical procedures.

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Wounds healed within 8–12 days were 84.6% in the Cold group and 18.8% in the Hot one. I° Dindo-Clavien complications were 15.4% for the Cold and 100.0% for the Hot group.

Terminal Deoxynucleotidyl Transferase-Mediated Deoxyuridine Triphosphate Nick End Labeling (TUNEL) Assay to Characterize Histopathologic Changes Following Thermal Injury

Background

Despite the wide application of lasers and radiofrequency (RF) surgery in dermatology, it is difficult to find studies showing the extent of damage dependent on cell death.

Objective

We evaluated histopathologic changes following in vivo thermal damage generated by CO₂ laser, 1,444 nm long-pulsed neodymium:yttrium-aluminum-garnet (LP Nd:YAG) laser and RF emitting electrosurgical unit.

Methods

Thermal damage was induced by the above instruments on ventral skin of rat. Specimens were stained with hematoxylin and eosin, along with a terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL) assay, to highlight the degree of irreversible cellular injury.

Results

The volume of vaporization was largest with the CO₂ laser. Area of cell death area identified by TUNEL assay, when arranged from widest to narrowest, was 1,444 nm LP Nd:YAG laser, CO₂ laser, and RF emitting electrosurgical unit.

Conclusion

This histopathologic evaluation of the acute characterization of injury across devices may be advantageous for attaining better treatment outcomes.

Healing of canine skin incisions made with monopolar electrosurgery versus scalpel blade

OBJECTIVE

To determine the influence of monopolar electrosurgery in cutting mode set at 10, 20, or 30 W on surgery time, hemostasis, and healing of cutaneous wounds compared to scalpel incisions.

STUDY DESIGN

Randomized blinded control trial.

ANIMALS

Dogs (n = 15).

METHODS

Four skin incisions were created on either side of the dorsal midline with a scalpel, or monopolar electrosurgery at 10, 20, and 30 W. Surgical time and incisional bleeding were measured. Each incision was assessed daily for edema, erythema and discharge, and complications. Healing was evaluated via histology at 7 days. Results were analyzed for significance at P ≤ .05.

RESULTS

Surgical time and hemostasis were improved in all electrosurgery groups. Erythema was reduced in all electrosurgical incisions for days 1-4, but was greater in wounds created via electrosurgery at 20 W than those made with a scalpel blade by day 7. No difference was noted in the degree of edema or presence of wound discharge. All histologic variables of tissue healing were lower in electrosurgical incisions than scalpel incisions (P < .001). Ten incisional complications occurred, all associated with electrosurgery.

CONCLUSIONS

The use of monopolar electrosurgery at 10, 20, and 30 W in a cutting waveform improved hemostasis and surgical time when incising canine skin, but delayed healing and increased complications within the first 7 days compared to scalpel incisions.

Electrosurgery: part II. Technology, applications, and safety of electrosurgical devices

Electrosurgical currents can be delivered to tissue in monopolar or bipolar and monoterminal or biterminal modes, with the primary difference between these modes being their safety profiles. A monopolar electrosurgical circuit includes an active electrode and a dispersive (return) electrode, while there are 2 active electrodes in bipolar mode. In monoterminal mode, there is an active electrode, but there is no dispersive electrode connected to the patient's body and instead the earth acts as the return electrode. Biterminal mode uses a dispersive electrode connected to the patient's body, has a higher maximum power, and can be safer than monoterminal mode in certain situations. Electrosurgical units have different technologies for controlling the output power and for providing safety. A thorough understanding of these technologies helps with a better selection of the appropriate surgical generator and modes.