A histologic and electronic evaluation of electrosurgical currents: nonfiltered full-wave modulated vs. filtered current

The linear cutting stapler may reduce surgical time and blood loss with muscle transection: a pilot study

Because of skeletal muscle's density and vascularity, its transection with standard electrocautery can be tedious. In a pilot study we asked whether a linear cutting stapling device decreased surgical time, blood loss, transfusion rates, and complications in patients undergoing above-knee amputation when compared to traditional electrocautery. We retrospectively reviewed 11 patients with above-knee amputation cases using a linear cutting stapling device over a 10-year period and compared those to 13 patients in whom we used electrocautery. The patients treated with the linear cutting stapling device had an average of 97 minutes of surgical time, 302 cc blood loss, and 1.55 units transfusion, compared to an average 119 minutes, 510 cc, and 2.15 units, respectively, with the electrocautery cases. Despite the trends, these parameters, as well as major complications, were similar in these two small groups. In skeletal muscle transection, we believe the linear cutting stapler is a reasonable and potentially cost-effective technical alternative to electrocautery, possibly resulting in less blood loss and shorter surgical time with similar rates of complications.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Improved wound healing with a modified electrosurgical electrode

Previous studies comparing standard electrosurgical (ES) electrode and steel scalpel (SS) wound healing have reported poor initial tensile strength, a delay in reaching maximum tensile strength and an increased inflammatory response in the ES wounds. The hypothesis that a smaller needle (modified) electrode would give better wound healing than a standard electrode was tested. Using histology as a parameter of wound healing, incisions created by a modified electrode, a standard electrode and a steel scalpel were compared. Sixty Sha Sha mice were divided into 10 groups. Standardised dorsal skin incisions were made using steel scalpel, standard and modified electrosurgical cutting electrodes. Mice were sacrificed on days 0, 1, 2, 3, 5, 7, 9, 14, 28 and 42. The incised skin was processed for standard and immunohistochemical staining. The standard ES wound had significantly higher numbers of polymorphonuclear leukocytes in comparison to the SS and modified ES wounds (p less than or equal to 0.01). However, macrophage numbers were found to be significantly lower in the ES wounds when compared to the SS wounds on days two and five (p less than or equal to 0.05). The fibroblast response was delayed by up to two days in the ES wounds when compared to the SS wounds. Epithelialisation was completed by day two in the SS and modified ES groups but was only complete by day three in the standard ES group (p less than or equal to 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Electrosurgery--a biological approach

Electrosurgery has been used in dentistry for more than 50 years. Both opponents and advocates of electrosurgery have presented a variety of clinical studies in favour of their respective opinions, which are discussed in the following review. In some studies, wounds created by electrosurgical techniques were observed through the healing stages, in comparison to those following incision by a surgical blade, with no significant difference being discovered. Other studies reported that the histologic response of oral connective tissue to electrosurgery was adverse in some animal and human models. However, neither of these groups used methods that allowed documentation or control of operating variables. A critical evaluation of controlled clinical studies shows that adverse responses of (connective) tissue, epithelium, bone, cementum, and periodontal attachment are related to an excessive lateral heat production during the procedure. With electrosurgery, the clinician can control the inherent variables. Waveform, frequency, size of the electrode, time of contact and cooling periods are some of those considered to be of importance in the studies. On the basis of the research reports, clinical guidelines have been developed to give practical advice to the clinician using electrosurgery. Providing that these safeguards are adhered to, scientific evidence supports the biological compatibility of electrosurgery for intraoral surgical procedures.

A comparison of healing and pain following excision of inflammatory papillary hyperplasia with electrosurgery and blade-loop knives in human patients

Twenty human patients participated in a study designed to compare electrosurgery with blade-loop knives for the excision of inflammatory papillary hyperplasia in a split-mouth study. Questionnaires were used to assess pain and patient preference during a 2-week postoperative period, and photographs were made to chronicle the healing process. Healing occurred at approximately the same rate following each procedure. The majority of subjects did not perceive a difference in discomfort with either technique on the day of surgery or at any time during follow-up. Of those who did have a preference, a significant majority favored electrosurgery on the day of treatment. This preference became statistically insignificant on the second postoperative day and beyond.

Electrosurgery and wound healing: a review of the literature

This literature review and discussion has presented evidence that some additional research needs to be done in this area. Particular attention should be paid to control certain variables: kind and type of waveform, shape and size of electrode, and speed of the electrode through the tissue so that meaningful results may be given to the dental profession. The evaluation of the literature seems to show that when the variables are controlled, untoward results of wound healing after electrosurgery seem unwarranted.

Lateral heat production secondary to electrosurgical incisions

Adverse healing responses, including necrosis of soft tissue and sequestration of alveolar bone, have been reported following the use of electrosurgery for intraoral incisions. These responses are usually attributed to excessive heat accumulation during the surgical procedure. The purpose of this investigation was to measure temperature changes in subadjacent connective tissue during intraoral electrosurgical incisions in palatal mucosa of miniature swine. Results indicate that single electrosurgical incisions should be accomplished at a speed of approximately 7 mm. per second and that successive incisions should be separated by a cooling interval of 8 to 10 seconds to avoid generation of heat sufficient to initiate an adverse healing response.

Healing of electrosurgical incisions in gingiva: early histologic observations in adult men

The healing of electrosurgical incisions in the gingivae of adult men was investigated at 6-hour intervals. Clinical observation indicated that incisions healed progressively until 72 hours, when they were barely discernible. Clinical evidence of inflammation associated with the wounds was negligible. At a light microscopic level, initial reaction to electrosurgical incisions included disruption of the surface epithelium and denaturation of the connective tissue lateral to the incision. The zone of denatured connective tissue remained for the entire 72-hour period of this study. Young fibroblasts and vascular proliferation were evident in the connective tissue at 30 hours. Epithelium exhibited complete bridging of the wound surface in some specimens as early as 30 hours after incision. All specimens had an intact epithelial surface at 48 hours. Mild-to-moderate accumulations of inflammatory cells, consisting primarily of lymphocytes, surrounded the wound edges. Acute inflammation with polymorphonuclear leukocytic infiltration was not observed, except for moderate accumulation at 6 to 12 hours. Subepithelial hematoma formation within the connective tissue was evident in four of the size specimens at 72 hours.

Effect of retraction procedures on the periodontium in humans

On the basis of wound healing and gingival recession caused by the three procedures, the copper-band retraction method was the most satisfactory. This tentative conclusion is based on the following reasons: 1. Retraction methods must be evaluated relative to the impression procedure and fit of the restoration. The long-range effects of the marginal fit are probably the most important factor for enhancing periodontal health. 2. This study involved only healthy periodontia of adolescent patients. Different healing might be observed in tissues characterized by gingivitis or periodontitis. 3. A broader study involving a greater range of procedures and conditions is recommended to evaluate each retraction technique. 4. This study involved teeth which had an adequate zone of attached gingiva. More complicated healing and perhaps altered sequences might be observed if the procedures were performed on gingival margins of alveolar mucosa, thin gingival walls, or areas of root prominence and thin cortical bone.

A method to measure operating variables in electrosurgery

Variables affecting tissue response to electrosurgical wounding have been identified and discussed. An electronic measuring device was designed and built to record actual power generated at the active electrode during surgical use of an electrosurgery instrument. In addition, this electronic device measures the amount of time the active electrode is in contact with tissue. Coupled with an electrosurgery unit producing a documented waveform and an electrosurgery electrode having a controlled-depth gauge, variables affecting tissue response to electrosurgery wounding may be measured.

Histologic evaluation of electrosurgery with varying frequency and waveform

This investigation was designed to determine the differences in tissue alteration produced by electrosurgical machines with different carrier frequencies and waveforms. Histologic analysis showed that: 1. The machine with full-wave rectification and the lowest frequency of operation (machine I, 1.7 MHz) produced significantly greater tissue alteration in the superficial tissue layers than the full-wave rectification machines with higher frequencies of operation. 2. The continuous-output waveform produced significantly less tissue alteration in the superficial tissue layers than the modulated type at the same frequency of operation. 3. Histologically, the experimental defect showed a band of coagulation necrosis approximately 50 mu wide along the margin of the incision. Tissue destruction decreased laterally and inferiorly from the surface of the defect. 4. The experimental defect was similar in shape to the physical form of the cutting electrode.