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

A novel discrete linkage-type electrode for radiofrequency-induced intestinal anastomosis

INTRODUCTION

For decades, radiofrequency (RF)-induced tissue fusion has garnered great attention due to its potential to replace sutures and staples for anastomosis of tissue reconstruction. However, the complexities of achieving high bonding strength and reducing excessive thermal damage present substantial limitations of existing fusion devices.

MATERIALS AND METHODS

This study proposed a discrete linkage-type electrode to carry out ex vivo RF-induced intestinal anastomosis experiments. The anastomotic strength was examined by burst pressure and shear strength test. The degree of thermal damage was monitored through an infrared thermal imager. And the anastomotic stoma fused by the electrode was further investigated through histopathological and ultrastructural observation.

RESULTS

The burst pressure and shear strength of anastomotic tissue can reach 62.2 ± 3.08 mmHg and 8.73 ± 1.11N, respectively, when the pressure, power and duration are 995 kPa, 160 W and 13 s, and the thermal damage can be controlled within limits. Histopathological and ultrastructural observation indicate that an intact and fully fused stomas with collagenic crosslink can be formed.

CONCLUSION

The discrete linkage-type electrode presents favorable efficiency and security in RF-induced tissue fusion, and these results are informative to the design of electrosurgical medical devices with controllable pressure and energy delivery.

Histological evaluation of monopolar and bipolar radiofrequency microneedling treatment in a porcine model

BACKGROUND AND OBJECTIVE

Fractional radiofrequency microneedling (FRM) is widely used as an option for skin rejuvenation, however there is a lack of histological evidence for the various energy delivery systems available. The objective was to assess thermal denaturation of tissue and the wound healing response in monopolar mode versus bipolar mode. Histological analysis was performed to demonstrate the efficacy of automatic impedance feedback system in monopolar mode.

STUDY DESIGN AND METHODS

In this study, the acute thermal effects caused by monopolar FRM treatment to the dorsal skin of pigs were assessed histologically by hematoxylin & eosin (H&E) staining. Then, one session of either monopolar or bipolar FRM was used to treat one or the other side of the pig using varying power levels and pulse widths. The acute and chronic tissue reactions were assessed using H&E, immunofluorescence, and western blot analysis at 0, 14, 30, and 90 days after treatment. The efficacy of the impedance feedback system was also monitored histologically.

RESULTS

High-energy FRM treatment produced tissue loss and necrosis. The power level and pulse duration significantly affected the coagulation amount. Histopathology at 0, 14, 30, and 90 days showed that the skin tissue reaction was more pronounced for bipolar compared to monopolar FRM. Immunofluorescence showed the expression of TGF-β, Ki67, MMP3, and elastin increased dramatically with both modes, but were higher in the bipolar FRM treated side. The automatic impedance feedback system could effectively adjust the output energy.

CONCLUSIONS

We found that bipolar FRM produced greater thermal effects, more collagen coagulation, and more pronounced molecular changes compared with monopolar mode in a porcine animal model.

Current advancements in therapeutic approaches in orthopedic surgery: a review of recent trends

Recent advancements in orthopedic surgery have greatly improved the management of musculoskeletal disorders and injuries. This review discusses the latest therapeutic approaches that have emerged in orthopedics. We examine the use of regenerative medicine, including stem cell therapy and platelet-rich plasma (PRP) injections, to accelerate healing and promote tissue regeneration. Additionally, we explore the application of robotic-assisted surgery, which provides greater precision and accuracy during surgical procedures. We also delve into the emergence of personalized medicine, which tailors treatments to individual patients based on their unique genetic and environmental factors. Furthermore, we discuss telemedicine and remote patient monitoring as methods for improving patient outcomes and reducing healthcare costs. Finally, we examine the growing interest in using artificial intelligence and machine learning in orthopedics, particularly in diagnosis and treatment planning. Overall, these advancements in therapeutic approaches have significantly improved patient outcomes, reduced recovery times, and enhanced the overall quality of care in orthopedic surgery.

Future of Endoscopic Spine Surgery: Insights from Cutting-Edge Technology in the Industrial Field

In the evolving landscape of spinal surgery, technological advancements play a pivotal role in enhancing surgical outcomes and patient experiences. This paper delves into the cutting-edge technologies underpinning endoscopic spine surgery (ESS), specifically highlighting the innovations in scope cameras, RF equipment, and drills. The modern scope camera, with its capability for high-resolution imaging, offers surgeons unparalleled visualization, enabling precise interventions. Radiofrequency (RF) equipment has emerged as a crucial tool, providing efficient energy delivery for tissue modulation without significant collateral damage. Drills, with their enhanced torque and adaptability, allow for meticulous bone work, ensuring structural integrity. As minimally invasive spine surgery (MISS) becomes the standard, the integration and optimization of these technologies are paramount. This review captures the current state of these tools and anticipates their continued evolution, setting the stage for the next frontier in spinal surgery.

Comparative healing of swine skin following incisions with different surgical devices

Background

Electrosurgical technology is widely used in surgical dissection and hemostasis, but the generated heat creates thermal injury to adjacent tissues and delays wound healing. The plasma blade (PB) applies pulsed radiofrequency (RF) to generate electrical plasma along the edge of a thin, flat, insulated electrode, minimizing collateral tissue damage. This study aimed to evaluate wound healing in swine skin following incision with a new surgical system that applies low-temperature plasma (NTS-100), a foreign PB, conventional electrosurgery (ES), and a scalpel blade.

Methods

In vitro porcine skin and an in vivo porcine skin model were used in this study. Full-thickness skin incisions 3 cm in length were made on the dorsum of each animal for each of the 5 surgical procedures at 0, 21, 28, 35, and 42 days. The timing of the surgical procedures allowed for wound-healing data points at 1, 2, 3, and 6 weeks accordingly. Local operating temperature and blood loss were quantified. Wounds were harvested at designated time points, tested for wound tensile strength, and examined histologically for scar formation and tissue damage.

Results

Local operating temperature was reduced significantly with NTS-100 (cut mode 83.12±23.55 °C; coagulation mode 90.07±10.6 °C) compared with PB (cut mode 94.46±11.48 °C; coagulation mode 100.23±6.58 °C, P<0.05) and ES (cut mode 208.99±34.33 °C, P<0.01; coagulation mode 233.37±28.69 °C, P<0.01) in vitro. Acute thermal damage from NTS-100 was significantly less than ES incisions (cut mode: 247.345±42.274 versus 495.295±103.525 µm, P<0.01; coagulation mode: 351.419±127.948 versus 584.516±31.708 µm, P<0.05). Bleeding, histological scoring of injury, and wound strength were equivalent for the NTS-100 and PB incisions.

Conclusions

The local operating temperature of NTS-100 was lower than PB, and NTS-100 had similarly reliable safety and efficacy.

The use of bipolar coagulation forceps prevented salivary fistula in patients with parotidectomy: a retrospective study

Background

Salivary fistula is a relatively common complication in patients who have undergone a parotidectomy. The purpose of this study was to investigate the effects of bipolar coagulation forceps use on salivary fistulas.

Methods

From March 2015 to June 2020, 177 patients who underwent a parotidectomy in the Department of Oral and Maxillofacial Surgery at the Second Xiangya Hospital of Central South University were recruited. The patients were divided into an experimental group and a control group based on whether bipolar coagulation forceps or sutures were used, respectively.

Results

The drainage output of the experimental group was significantly lower than that of the control group (p = 0.04). The duration of dressing pressure applied in the experimental group was significantly shorter than that in the control group (p = 0.0003). Moreover, the incidence of salivary fistula in the experimental group (9.8%, 8/82) was notably lower than that in the control group (34.7%, 33/95) (p < 0.0001). In the logistic regression model for salivary fistula development, both the use of bipolar coagulation forceps (p = 0.0021) and drainage output (p = 0.0237) were associated with the presence of salivary fistulas.

Conclusions

Our findings indicate that the use of bipolar coagulation forceps decreases the incidence of salivary fistula in patients who have undergone a parotidectomy. The use of bipolar coagulation forceps is a safe, effective, and convenient method to prevent salivary fistulas in patients who undergo a parotidectomy.

Trial registration: Current Controlled Trials ChiCTR2100044722, Date: 26/03/2021, Retrospectively registered.

Eradication of Benign Skin Lesions of the Face by Voltaic Arc Dermabrasion (Atmospheric Plasma): Postoperative Pain Assessment by Thermal Infrared Imaging

Objectives

The face aging processes are associated with physiologic and biochemical alteration that produces wrinkles, skin pigmentation and benign growths. The aim of this study was to evaluate the clinical efficacy of voltaic arc dermabrasion with plasma to remove benign facial skin lesions.

Study Design

Voltaic arc dermabrasion plasma technique was used to remove the facial benign skin lesions. The study involved 45 patients (26 females;19 males) treated for benign facial skin lesions with voltaic arc dermabrasion also called plasma exeresis technique. The subjects age ranged between 43 and 65 years. The clinical observations and comparison of pretreatment and post-treatment photographs of the treated regions were performed by a joint examiner at each follow-up visit.

Results

During plasma irradiation, the average temperature of the skin was 290.3 ± 21.7 °C, while immediately after it was 90.6 ± 21.8 °C. Overall clinical improvement was 100% in six lesions with complete resolution of all lesions. Three patients observed a transient post-inflammatory pigmentation with a peak at 1 month after VAD treatment, gradually fading spontaneously over 2 to 3 months.

Conclusions

The voltaic arc dermabrasion technique (atmospheric plasma) should be considered for lesions, especially relatively superficial ones, and small lesions that are located on the face.

Level of Evidence IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

An evaluation of electrocoagulation and thermal diffusion following radiofrequency microneedling using an in vivo porcine skin model

BACKGROUND

Few studies exist that examined the role of radiofrequency microneedling (RFMN) in skin electrocoagulation. This research utilized a porcine model to understand bipolar dermal delivery from an RFMN device.

AIMS

The objective of this study was to elucidate and compare the dermal thermal effects of a RFMN device producing 1 and 2 MHz signal amplitudes, with respective voltage and current gradients, utilizing noninsulated and insulated needles by examining the histologic effects on porcine skin.

METHODS

Two separate animal studies were conducted to evaluate the electrocoagulation and thermal diffusion effects using the RFMN device. The electrocoagulation effects were assessed histologically using hematoxylin and eosin (H&E) staining, and heating effects were assessed through thermal imaging.

RESULTS

Histology results of the thermal injury induced by insulated needles demonstrated that 2 MHz resulted in a narrow and concentrated coagulation zone as compared to 1 MHz. Further, the 1 MHz insulated needle resulted in ovular shaped tissue coagulation as compared to 2 MHz tissue coagulation that was columnar. Finally, full thermal diffusion occurs seconds after the set RF conduction time.

CONCLUSION

The findings showed that 1 MHz insulated needle produces larger coagulations with an increase in power level, the 1 MHz noninsulated array was comparable to the 2 MHz insulated array with similar histologic features, and heat dissipates seconds after the set conduction time.

[Eyelid surgery : Eyelid surgical techniques from a histopathological perspective]

Eyelid surgery and histopathology are closely related, especially in tumor surgery. Based on histological specimens from the archive of the Department of Ophthalmopathology, Eye Centre Freiburg, this article deals with the search for traces following eyelid surgery, and explains the respective clinical relevance for ophthalmologists involved in surgical and conservative treatment. Thermal, electrical and mechanical impacts on the tissue during tumor removal lead to histologically detectable artifacts. These must be kept to a minimum by the surgeon in order to ensure histological assessability and avoid adverse consequences for the patient. During the subsequent eyelid reconstruction, the eyelid architecture is changed depending on the surgical technique. Thus, after Hughes' operation a degeneration of the meibomian glands is histologically noticeable, which should be taken into account in the clinical aftercare of the patients. Suture material can lead to foreign body granulomas, which can be clinically misinterpreted as tumor recurrence. In contrast to foreign material, transplanted autologous tissue, such as cartilage or oral mucosa in the case of eyelid malposition, usually does not lead to chronic inflammation.

Intraoperative tumor margin assessment using diffuse reflectance spectroscopy: the effect of electrosurgery on tissue discrimination using ex vivo animal tissue models

Using an intraoperative margin assessment technique during breast-conserving surgery (BCS) helps surgeons to decrease the risk of positive margin occurrence. Diffuse reflectance spectroscopy (DRS) has the potential to discriminate healthy breast tissue from cancerous tissue. We investigated the performance of an electrosurgical knife integrated with a DRS on porcine muscle and adipose tissue. Characterization of the formed debris on the optical fibers after electrosurgery revealed that the contamination is mostly burned tissue. Even with contaminated optical fibers, both tissues could still be discriminated with DRS based on fat/water ratio. Therefore, an electrosurgical knife integrated with DRS may be a promising technology to provide the surgeon with real-time guidance during BCS.

Diode laser surgery versus electrocautery in the treatment of inflammatory fibrous hyperplasia: a randomized double-blind clinical trial

OBJECTIVES

To compare the efficacy and safety of diode laser and electrocautery techniques for inflammatory fibrous hyperplasia (IFH) removal.

MATERIALS AND METHODS

In this randomized double-blind clinical trial, 40 individuals were randomly allocated to two groups: group 1 (G1) consisted of 20 individuals assigned to treatment with diode laser and group 2 (G2) consisted of 20 individuals assigned to treatment with electrocautery. The following transoperative parameters were evaluated: bleeding, temperature, and surgical technique parameters (energy deposited on tissue, flow rate, and time of incision). The postoperative parameters evaluated were as follows: pain, functional alterations (chewing, speaking), analgesic medication intake, swelling, healing of the wound area, and patient satisfaction.

RESULTS

Among the 40 individuals included in the study, four (two in G1 and two in G2) did not complete the entire follow-up. Therefore, 36 individuals (18 in G1 and 18 in G2) participated. Participants in G1 and in G2 had similar demographic characteristics. No difference regarding the trans- or postoperative parameters evaluated was observed between G1 and G2 (p > 0.05). Also, no difference regarding the time for healing was observed between groups.

CONCLUSIONS

Diode laser seems to be as effective and safe as electrocautery when applied under similar conditions for IFH removal.

CLINICAL RELEVANCE

IFH corresponds to 65% of the lesions observed in denture wearers. This study shows that under similar conditions diode laser is as effective and safe as electrocautery for removal of IFH.

Controlling depth of electrosurgery after curettage of skin tumors-an in vitro study

BACKGROUND

Depth of tissue injury in electrosurgery depends on generator power, electrode size, speed of electrode movement on tissue, and current delivery method. We sought to evaluate the depth of tissue injury associated with different methods of electrocoagulation in an effort to make electrocoagulation more reproducible.

METHODS

A knife-shaped electrode was used to apply an electrosurgical current to the surface of a piece of bovine liver. Different electrosurgical methods were performed. Cross sections of the liver were then studied for tissue effect.

RESULTS

Fulguration provided only superficial coagulation. Contact electrocoagulation and electrodesiccation using the flat side of the electrode provided significantly deeper levels of coagulation and were associated with less smoke than fulguration. Desiccation provided the deepest tissue effect.

CONCLUSIONS

Electrofulguration can be used for superficial tissue destruction. For deeper coagulation, a relatively larger electrode can be used in contact mode. Slower movement of the electrode on tissue in contact mode is associated with desiccation and the deepest level of tissue destruction.

Combination of Low-Temperature Electrosurgical Unit and Extractive Electrospray Ionization Mass Spectrometry for Molecular Profiling and Classification of Tissues

Real-time molecular navigation of tissue surgeries is an important goal at present. Combination of electrosurgical units and mass spectrometry (MS) to perform accurate molecular visualization of biological tissues has been pursued by many research groups. Determination of molecular tissue composition at a particular location by surgical smoke analysis is now of increasing interest for clinical use. However, molecular analysis of surgical smoke is commonly lacking molecular specificity and is associated with significant carbonization and chemical contamination, which are mainly related to the high temperature of smoke at which many molecules become unstable. Unlike traditional electrosurgical tools, low-temperature electrosurgical units allow tissue dissection without substantial heating. Here, we show that low-temperature electrosurgical units can be used for desorption of molecules from biological tissues without thermal degradation. The use of extractive electrospray ionization technique for the ionization of desorbed molecules allowed us to obtain mass spectra of healthy and pathological tissues with high degree of differentiation. Overall, the data indicate that the described approach has potential for intraoperative use.

A SYSTEMATIC REVIEW ON CURRENT RESEARCH TRENDS IN ELECTROSURGICAL SYSTEMS

The use of electrosurgery (also referred to as radiosurgery) is a type of surgery that uses electrical currents in order to perform the surgery. This type of surgery dates back to more than 100 years. For over five decades, different reviews have been conducted in the field of electrosurgery. This has led to a dramatic increase in interest in electrosurgery, resulting to an incredible intervention in microvascular surgery that has provoked the most noteworthy use of radio frequency instruments. The controlled and exact use of these radio frequency electrical current on delicate tissue sites to be cut is accomplished by methods for deliberately composed anodes. This is a persistently advancing field with dynamic research going on in various new applications. There are different sorts of surgery, which can be delivered with high recurrence instruments such as Diathermy, Bipolar, and Monopolar. This paper performs a systematic review by extracting information from a wide variety of research papers in electrosurgery topics. The purpose of a systematic review is to classify and categorize the field of electrosurgery in an unbiased way, listing the current existing trends in electrosurgery, can lead to the classification and understanding of electrosurgery as a whole, and to predict the future direction of the field by analyzing the research interest over the last couple of years.

Real-time oncological guidance using diffuse reflectance spectroscopy in electrosurgery: the effect of coagulation on tissue discrimination

In breast surgery, a lack of knowledge about what is below the tissue surface may lead to positive tumor margins and iatrogenic damage. Diffuse reflectance spectroscopy (DRS) is a spectroscopic technique that can distinguish between healthy and tumor tissue making it a suitable technology for intraoperative guidance. However, because tumor surgeries are often performed with an electrosurgical knife, the effect of a coagulated tissue layer on DRS measurements must be taken into account. It is evaluated whether real-time DRS measurements obtained with a photonic electrosurgical knife could provide useful information of tissue properties also when tissue is coagulated and cut. The size of the coagulated area is determined and the effect of its presence on DR spectra is studied using ex vivo porcine adipose and muscle tissue. A coagulated tissue layer with a depth of 0.1 to 0.4 mm is observed after coagulating muscle with an electrosurgical knife. The results show that the effect of coagulating adipose tissue is negligible. Using the fat/water ratio's calculated from the measured spectra of the photonic electrosurgical knife, it was possible to determine the distance from the instrument tip to a tissue transition during cutting. In conclusion, the photonic electrosurgical knife can determine tissue properties of coagulated and cut tissue and has, therefore, the potential to provide real-time feedback about the presence of breast tumor margins during cutting, helping surgeons to establish negative margins and improve patient outcome.

Interactive thermal tissue reactions of 7-MHz intense focused ultrasound and 1-MHz and 6-MHz radiofrequency on cadaveric skin

BACKGROUND

Intense focused ultrasound (IFU) and radiofrequency (RF) systems generate thermal tissue reactions in multiple zones in the skin, with the microscopic features thereof varying according to energy sources and treatment parameters.

OBJECTIVE

To evaluate interactive thermal tissue reactions of IFU and RF in cadaveric skin.

METHODS

Thermal reaction patterns generated by IFU, invasive bipolar RF, and non-invasive monopolar RF treatments were analyzed in cadaveric skin of the inner thigh. Additionally, combination treatment, including IFU and invasive bipolar RF, IFU and non-invasive monopolar RF, invasive bipolar RF and IFU, and non-invasive monopolar RF and IFU, was delivered to cadaveric skin and microscopically evaluated.

RESULTS

Combination treatment with 1.5-mm IFU followed by 1.5-mm invasive RF elicited multiple thermal injury zones of coagulation and ablation in the mid to lower dermis. Therein, IFU-induced thermal reactions were indistinguishable from RF-induced thermal reactions. Non-invasive RF treatment on IFU-pretreated cadaveric tissue specimens exhibited greater degrees of thermal injury, with wider and deeper penetration, compared to non-invasive RF treatment alone. Furthermore, RF-pretreated tissues showed marked differences in the patterns of IFU-induced thermal tissue reactions.

CONCLUSION

Our data suggest that combination treatments with IFU and RF elicit various patterns of interactive thermal tissue reactions.

Comparison of the Thermal Spread of Three Different Electrosurgical Generators on Rat Uterus: A Preliminary Experimental Study

BACKGROUND/AIMS

The objective of this study was to compare the depth and width of thermal spread caused on rat uterine tissue after application of 3 different electrosurgical generators.

METHODS

Alsa Excell 350 MCDSe (Unit A), Meditom DT-400P (Unit M), and ERBE Erbotom VIO 300 D (Unit E) electrosurgical units (ESUs) were used. The number of Wistar Hannover rats required to obtain valid results was 10. The primary objective of the study was to compare the 3 ESUs using the same instrument and the same waveform. The secondary objective of the study was to compare the differences between monopolar and bipolar systems of each ESU separately using the same waveform.

RESULTS

The thermal spread caused by each ESU using monopolar instruments with continuous and interrupted waveforms was significantly different. Among the 3 devices, Unit A caused the largest thermal uterine tissue spread. On the other hand, Unit E caused the most superficial thermal tissue spread, and the smallest thermal spread among all ESUs.

CONCLUSIONS

Surgeons should note that different ESUs used with the same power output might create different thermal effects especially in the monopolar configuration within the same waveform, for the same duration, and with the same instrument.

Adjuvant Therapy for Revision Rhinoplasty of Contracted Nose Using Polydeoxyribonucleotide and Invasive Bipolar Radiofrequency

Supplemental Digital Content is available in the text.

Most cases of severely contracted nose require revision rhinoplasty and septoplasty, wherein preoperative and/or intraoperative expansion of nasal soft tissue is necessary for tension-free revision surgery. The present study aimed to evaluate the efficacy and safety of pre- and postoperative adjuvant therapy using polydeoxyribonucleotide (PDRN) and invasive, pulsed-type, bipolar, alternating current radiofrequency (RF) for revision surgery of a contracted nose. In total, 30 patients were treated with 16 sessions (8 preoperative sessions and 8 postoperative sessions) of intralesional injection of PDRN and invasive RF treatment using microneedle electrodes at 1-week intervals. One week after the final combined pretreatment using PDRN and invasive bipolar RF, the skin of contracted noses was sufficiently softened, and nasal skin mobility was notably improved in all the patients. During revision rhinoplasty and septoplasty, the contracted nasal skin in each patient was adequately released for proper covering of the nasal tip without tension. Postoperatively, 8 sessions of adjuvant therapy elicited marked clinical improvements in persistent nasal tip dimpling and contracture, septal deviation, and warping from the incomplete recovery of nasal contracture after revision surgery. In conclusion, our pre- and postoperative adjuvant therapies using PDRN and invasive bipolar RF remarkably improved the therapeutic outcomes of revision rhinoplasty and septoplasty for contracted skin of the nose without major side effects.

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.

Mohs Micrographic Surgery for the Management of Cutaneous Malignancies

Mohs micrographic surgery is a specialized form of skin cancer surgery in which the Mohs surgeon acts as both surgeon and pathologist. The procedure is characterized by its histopathologic margin control and ability to spare tissue, particularly in cosmetically sensitive locations. Mohs surgery is known for both limiting the size of the final defect and its high cure rate. In this review, the authors highlight indications for the procedure, detail the technique itself, discuss cutaneous tumors for which Mohs micrographic surgery is indicated, and present the economic benefit of Mohs surgery.

Electrosurgical Smoke: Ultrafine Particle Measurements and Work Environment Quality in Different Operating Theatres

Air cleanliness in operating theatres (OTs) is an important factor for preserving the health of both the patient and the medical staff. Particle contamination in OTs depends mainly on the surgery process, ventilation principle, personnel clothing systems and working routines. In many open surgical operations, electrosurgical tools (ESTs) are used for tissue cauterization. ESTs generate a significant airborne contamination, as surgical smoke. Surgical smoke is a work environment quality problem. Ordinary surgical masks and OT ventilation systems are inadequate to control this problem. This research work is based on numerous monitoring campaigns of ultrafine particle concentrations in OTs, equipped with upward displacement ventilation or with a downward unidirectional airflow system. Measurements performed during ten real surgeries highlight that the use of ESTs generates a quite sharp and relevant increase of particle concentration in the surgical area as well within the entire OT area. The measured contamination level in the OTs are linked to surgical operation, ventilation principle, and ESTs used. A better knowledge of airborne contamination is crucial for limiting the personnel’s exposure to surgical smoke. Research results highlight that downward unidirectional OTs can give better conditions for adequate ventilation and contaminant removal performances than OTs equipped with upward displacement ventilation systems.

Electromagnetic Initiation and Propagation of Bipolar Radiofrequency Tissue Reactions via Invasive Non-Insulated Microneedle Electrodes

Radiofrequency (RF) energy can be emitted into the skin, either non- or invasively, via a monopolar mode that utilizes an active electrode and a grounded electrode or via a bipolar mode that employs two active electrodes. In this experimental study of RF tissue reactions, bipolar RF energy was emitted in vivo to micropig skin at varying microneedle penetration depths, signal amplitudes, and conduction times. Immediately after RF treatment, skin samples exhibited RF-induced coagulation columns of thermal injury, separately generated around each microneedle in the dermis. In ex vivo bovine liver tissue, the thermal coagulation columns were found to be concentrated maximally around the pointed tips of each electrode. After a RF conduction time of 2 seconds, the individual areas of thermal coagulation began to converge with neighboring RF-induced coagulation columns; the convergence of coagulation columns was found to start from the tips of neighboring electrodes.