Epithelial and connective tissue healing following electrosurgical incisions in human gingiva

Comparison of Radiofrequency and Electrocautery With Conventional Scalpel Incisions

PURPOSE

The disadvantages of conventional scalpels, including insufficient control of bleeding, prompted us to search for new alternative methods such as electrosurgery and radiosurgery. In this study, the conventional scalpel was compared with radiosurgery and electrosurgery for wound healing with assessment of lateral heat production, inflammation, and instrument performance.

MATERIALS AND METHODS

Incisions were made in the palatal mucosa of 42 Wistar rats using a scalpel, electrocautery instrument, or radiofrequency instrument. Postoperative hemostasis, tissue coagulation, and tissue sticking were measured, and pain evaluation through weight loss was recorded. Gingival biopsy specimens from the surgical area were obtained at the time of surgery and 2, 4, 7, and 14 days postoperatively and were evaluated immunohistochemically for inducible nitric oxide synthase and heat shock protein 70. Kruskal-Wallis, 1-way analysis of variance, and Mann-Whitney U tests were used for statistical evaluation.

RESULTS

The rats in the electrosurgery and radiosurgery groups had aggressively greater weight loss when compared with the scalpel group in the first 7 days. Hemostasis was better in the electrocautery group, tissue coagulation was greater in the radiofrequency group (P < .001), and tissue sticking was lesser in the scalpel group (P < .001) compared with the other groups. Inducible nitric oxide synthase expression and heat shock protein 70 expression were similar in all 3 groups.

CONCLUSIONS

Electrosurgery performed better regarding hemostasis, whereas a scalpel was superior in terms of tissue sticking and tissue coagulation. Radiosurgery was superior regarding hemostasis when compared with a conventional scalpel, but it was not as successful as electrosurgery.

Molecular resonance tonsillectomy in children: comparative study over standard techniques in an 11-year study

OBJECTIVES

Learn the molecular resonance (MR) technology for tonsillectomy. An analysis of outcomes of MR compared to standard cold-knife (CK) and monopolar cautery (MPC) for pediatric tonsillectomy offers new possibilities, lowering postoperative morbidity.

STUDY DESIGN

Eleven-year, prospective, randomized, 3-group trial.

SETTING

Tertiary care pediatric institution.

SUBJECTS AND METHODS

Eight hundred and seventy-three children undergoing adenotonsillectomy were randomly assigned to MR (n = 283), CK (n = 279), or MPC (n = 279) techniques. Outcome measures included intraoperative time, blood loss, postoperative pain, weight loss, and histopathologic examination on excised tonsils.

RESULTS

Histopathologic evaluation revealed reduced thermal injury with MR over MPC (43 µm vs 186, P < .001), statistically associated with reduced muscular, blood vessel, and nerve fiber damage compared to CK (P < .001). Blood loss was minimal in MR. Significant reduced pain scores were related to MR (P < .002). Two MR, 15 CK, and 12 MPC patients experienced delayed bleeding.

CONCLUSION

MR for pediatric tonsillectomy resulted in reduced histopathologic thermal injury, lower pain scores, and reduced postoperative morbidity compared with CK and MPC techniques in an 11-year study.

Tonsillectomy in children: a five-factor analysis among three techniques--reporting upon clinical results, anesthesia time, surgery time, bleeding, and cost

OBJECTIVES

Improved technology claims better clinical results for adenotonsillectomy (T&A) in children, and promoters of each technique announce many virtues over one another, year after year. However, cost remains one variable that is not always thoroughly addressed. In this study, monopolar cautery (MPC) T&A was compared with coblation (CAT) and molecular resonance (MR) techniques in a pediatric population.

STUDY DESIGN

Prospective analysis of 96 patients (32 for each surgical modality: MPC, MR, or CAT).

SETTING

Tertiary care pediatric institution.

SUBJECTS AND METHODS

Clinical results, anesthesia and surgery time, bleeding, and cost among these three established techniques were compared. P-values of P < .05 were considered significant for all comparisons.

RESULTS

The CAT and MPC had similar operative times (mean 19.2 and 21.1 minutes, respectively, P = NS), whereas the MR group had overall saving of 7.8 minutes in surgery (P < .05). In terms of cost of technology, the cost of the MPC and MR groups was 90.6% and 83.7% less than the CAT group, respectively.

CONCLUSIONS

This study demonstrated that MR technique of T&A enabled the surgical team to save a significant amount of time, whereas CAT added substantial costs, compared to MR and standard cautery techniques.

Molecular resonance vs. coblation tonsillectomy in children

BACKGROUND

Quantum molecular resonance coagulation is an innovative technology that uses molecular resonance to cut and coagulate precisely, cleanly, and hemostatically at low tissue temperature levels. This technology offers a new possibility for tonsillectomy.

OBJECTIVES

To compare molecular resonance (MRT) with coblation (CAT) devices for pediatric tonsillectomy.

STUDY DESIGN

Prospective, two-group, randomized trial in a tertiary care pediatric institution. One hundred fifty-seven children for whom tonsillectomy was indicated were randomly assigned to receive MRT (n = 79) or CAT (n = 78). Main outcome measures included intraoperative time, blood loss, postoperative pain, and weight loss. Histopathologic examination was performed on all excised tonsils. Patients, parents, and pathologist were blinded to surgical modality.

RESULTS

Histopathologic evaluation revealed significantly reduced thermal injury with MRT than with CAT (43 microns vs. 126, respectively, P < .001), and was statistically associated with reduced muscular, blood vessel, and nerve fiber damage. No intraoperative blood loss was observed in patients following MRT. Statistically significant reduced pain scores were related to the MRT (P < .002). In addition, the MRT method showed a quick return to normal diet with even weight gain during the 10-day postoperative period. One child in the CAT group experienced delayed bleeding and required readmission.

CONCLUSIONS

Molecular resonance for pediatric tonsillectomy resulted in significantly reduced histopathologic thermal injury and lower pain scores compared with coblation. Further studies are advised to support these data.

Blunt dissection versus electronic molecular resonance bipolar dissection for tonsillectomy: operative time and intraoperative and postoperative bleeding and pain

OBJECTIVE

To compare operative time, intraoperative and postoperative bleeding and pain using two different techniques for tonsillectomy: electronic molecular resonance bipolar tonsillectomy and blunt dissection tonsillectomy.

METHODS

From January 2005 to December 2006, a prospective, randomised study was performed in 800 children, aged from 3 to 10 years, admitted to the ENT (Ear Nose Throat) Unit of Giannina Gaslini Institute, Genoa, Italy to undergo tonsillectomy. Patients were randomised into two surgical groups, Group A (electronic molecular resonance tonsillectomy, EMRBT) and Group B (blunt dissection tonsillectomy). Operative time, intraoperative blood loss and postoperative complications were recorded. During 10 days after surgery, children and their parents were also asked to provide a rating of the patients' current pain intensity using a visual analogue scale. In this period, the parents were also asked to note the analgesic drugs administered.

RESULTS

Duration of surgery and blood loss were significantly much lower in the group undergoing electronic molecular resonance bipolar tonsillectomy (p<0.0001). Postoperative pain scores resulted significantly different between the two methods on days 5 (p=0.05) and 8 (p=0.001) in evaluations by mothers. Moreover, in evaluations by patients pain scores resulted significantly different between the two methods on days 3 (p=0.02), 8 (p=0.005) and 9 (p=0.01). We found no difference between boys and girls in pain scores in the 10 days considered, nor between children older than 5 yrs and children younger than or aged 5 years. No statistically significant differences between the two techniques were found in the use of analgesics in all postoperative evaluations.

CONCLUSIONS

This study showed that the use of electronic molecular resonance bipolar tonsillectomy, compared to blunt dissection, has several advantages. Reduced operative time and intraoperative bleeding make EMRBT more cost effective and allow an increased number of operations. Concerning postoperative pain, the two techniques did not present significant differences in the use of analgesics. The number of postoperative bleeding episodes was also similar in the two groups of patients.

Safety of electronic molecular resonance adenoidectomy

Adenoidectomy is one of the most frequent operations in children. In order to reduce hospital stay costs, today, this procedure is performed as day surgery. Even though adenoidectomy is not considered risky, some minor complications may occur, the most important being bleeding (0.5-8% incidence). The surgical technique used can influence considerably postoperative pain and time to recovery. This aspect is essential in the management of day surgery patients, for whom the need of safe and rapid maneuvers associated with early recovery determines the choice of the surgical procedure. Recently, we developed a surgical technique based on the use of an electronic molecular resonance tool associated with bendable suction electrocautery. This study was carried out on 600 patients, divided into two groups, the first undergoing ablation using the molecular resonance tool and the second undergoing curette adenoidectomy. The two groups were homogeneous for age, sex, surgical indications, and grade of adenoid hypertrophy. The following parameters were considered: duration of surgery, importance of intraoperative bleeding, time to cicatrization, incidence of bleeding complications. Duration of surgery and intra- and postoperative bleeding were much lower in the first group than in the group undergoing traditional adenoidectomy. In addition, rhinopharyngeal complete cicatrization, defined as absolute absence of pseudomembrane, was much quicker in the first group, as assessed by postoperative endoscopy. Another major advantage offered by the molecular resonance tool is the accuracy of surgery performed under visual control in a practically bloodless field. To sum up, this method, thanks to its technical features and safety, is particularly indicated in children and in patients with coagulation disorders.

Histology of laser- and high-frequency-electrosurgical incisions in the palate of pigs

The histological effects of CO2-laser-, Nd-YAG-laser- and electrosurgical incisions were investigated in the oral mucosa of pigs. Laser- as well as electrosurgery caused necrosis by thermal effects. Undermining vacuolisation in the stratum basale and denaturation of collagenous fibers in the lamina propria were typical findings. The CO2-laser incisions were trough-like with a sharply bordered coagulation. The Nd-YAG-laser produced exclusively coagulation but no incision. Electrosurgery yielded radiating coagulation and the best ratio of depth of incision to width of coagulation.

Histologic evaluation of the width of soft tissue necrosis adjacent to carbon dioxide laser incisions

This study evaluated the width of tissue necrosis lateral to carbon dioxide laser incisions on human intraoral excisional biopsy specimens. Measurements were made on specimens including epithelium, muscle, dense and loose connective tissue, and salivary gland. Results showed a mean width of tissue necrosis of 86 microns in epithelium, 85 microns in muscle, 51 microns in loose connective tissue, 96 microns in dense connective tissue, and 41 microns in salivary gland. The range of thermal necrosis in different tissue types is probably based on the water content within each type. A cellular partially homogenized zone of reversible thermal damage up to 500 microns in width was visible adjacent to the zone of thermal necrosis. The relatively narrow width of tissue necrosis with this technique may account for the claimed superior properties of laser-induced wounds compared with those created by electrosurgery.

Self-sterilization of the electrosurgery electrode

Sterilization of the electrode used in electrosurgery has been assumed to occur at the instant of contact of the energized electrode tip to a grounded source. This study evaluated whether the time of electrode activation or the amount of energy delivered is important in the self-sterilization process. Standard bacteriologic culturing techniques were employed to assess sterility of the electrode tip following activation. Total time of application of the current and the energy used were recorded on audiotape and later tabulated. The data indicate that the time of energizing and the energy units used are critical in the sterilization of the electrode tip. These results confirm that self-sterilization of the electrosurgery electrode tip occurs, but full confidence is not realized with the time intervals commonly employed in clinical practice. The electrode tip must be considered a potential source of bacterial contamination of electrosurgically managed dental procedures.

Vascular thermocoagulation-perivascular nerve lesions. An ultrastructural report on the choice between monopolar and bipolar electrocoagulation

High-frequency coagulation is used with advantage for a number of purposes, including the production of haemostasis during surgery. The morphological changes which thermocoagulation produces in or near the wall of an artery remain, however, largely unknown; and systematic research in the subject is long overdue. As might be expected from clinical experience, the local effects of monopolar thermocoagulation are much more severe and far-reaching than those caused by the bipolar method. For these reasons the bipolar coagulation technique is to be preferred wherever possible.

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.

Histologic evaluation of gingival response to an electrosurgical blade

Lateral heat production during the use of electrosurgical procedures in the oral cavity causes denaturation of the connective tissue adjacent to the incision line. This study evaluated the denatured zone following electrosurgery incision in dog gingiva with a traditional tungston wire electrode and a no. 15 surgical blade adapted for electrosurgery use. The effects of using a passive electrode during surgical procedures and using an "autosensor" circuit to control power adjustment were also evaluated. It was found that a surgical blade adapted for electrosurgery produces a zone of denatured tissue that is not statistically different from that produced with a wire electrode. Moreover, no differences were noted between incisions produced with manual power adjustment and those with power controlled by the "autosensor" circuit. A significantly wider zone of denatured tissue was produced when incisions were made without a passive electrode in place.

Histometric evaluation of interproximal bone responses to electrosurgical mucoperiosteal incisions in dogs

The periosteal and endosteal interproximal bone remodeling activity following clinically simulated blade and electrosurgical mucoperiosteal incisions was investigated by histologic and morphometric analyses. Undecalcified histologic sections were prepared and evaluated using standard bone morphometric techniques. Periosteal and endosteal bone surfaces subjacent to incisions were examined and the percentages of forming, resorbing, and quiescent surfaces, and the number of osteoclasts per millimeter of bone surface, were calculated. Based on indices of bone remodeling activity, the potentials for activation of interproximal bone remodeling by clinically appropriate blade and electrosurgery incisions in dogs appear to be similar.

Subjacent heat production during tissue excision with electrosurgery

A study was designed to document heat production subjacent to tissue excision by electrosurgery. In Phase I of the study, 20 electrosurgery excisions were made with a loop electrode in the palatal mucosa of miniature swine. Subjacent heat production was measured with implantation thermistors. Temperature measurements adjacent to 20 single incisions made with a needle electrode were used for comparison. Energy used and duration of active electrode contact with the tissue were recorded for each procedure with an electronic measuring device. In Phase II, 20 sets of excisions consisting of three successive excisions were performed. The following intraexcisional cooling periods were used for four sets each: 1 second, 5 seconds, 8 seconds, 10 seconds, and 15 seconds. Results indicate that single electrosurgery excisions with a loop electrode generate more energy than incisions made with a needle electrode. Subjacent heat production, however, is not significantly different. Cooling intervals of at least 15 seconds between successive electrosurgery excisions made with a loop electrode are necessary to prevent heat build-up of a magnitude capable of initiating destructive alveolar changes.

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.