Complications and recommended practices for electrosurgery in laparoscopy

Coagulant Protein-Free Blood Coagulation Using Catechol-Conjugated Adhesive Chitosan/Gelatin Double Layer

Since the discovery of polyphenolic underwater adhesion in marine mussels, researchers strive to emulate this natural phenomenon in the development of adhesive hemostatic materials. In this study, bio-inspired hemostatic materials that lead to pseudo-active blood coagulation, utilizing traditionally passive polymer matrices of chitosan and gelatin are developed. The two-layer configuration, consisting of a thin, blood-clotting catechol-conjugated chitosan (CHI-C) layer and a thick, barrier-functioning gelatin (Geln) ad-layer, maximizes hemostatic capability and usability. The unique combination of coagulant protein-free condition with CHI-C showcases not only coagulopathy-independent blood clotting properties (efficacy) but also exceptional clinical potential, meeting all necessary biocompatibility evaluation (safety) without inclusion of conventional coagulation triggering proteins such as thrombin or fibrinogen. As a result, the CHI-C/Geln is approved by the Ministry of Food and Drug Safety (MFDS, Republic of Korea) as a class II medical device. Hemostatic efficacy observed in multiple animal models further demonstrates the superiority of CHI-C/Geln sponges in achieving quick hemostasis compared to standard treatments. This study not only enriches the growing body of research on mussel-inspired materials but also emphasizes the potential of biomimicry in developing advanced medical materials, contributing a promising avenue toward development of readily accessible and affordable hemostatic materials.

A new knotless parametrial tissue ligation technique for safe total laparoscopic hysterectomy

OBJECTIVE

Parametrial tissue ligation during total laparoscopic hysterectomy (TLH) is important in large uteri with large vessels.

METHODS

A retrospective study was performed at Asan Medical Center for comparing TLH performed with a new knotless parametrial tissue ligation method and conventional laparoscopic-assisted vaginal hysterectomy (LAVH) from March 2019 to August 2021. For TLH, after anterior colpotomy, the parametrial tissue was ligated by anchoring the suture and making a loop in one direction three times using 1-0 V-LocTM 180 (Covidien, Mansfield, MA, USA) suture. Subsequently, the cranial part of the loop was cut using an endoscopic device.

RESULTS

A total of 119 and 178 patients were included in the TLH and LAVH groups, respectively. The maximal diameter of the uterus was larger in the TLH group (106.29±27.16 cm) than in the LAVH group (99.00±18.92 cm, P=0.01). The change in hemoglobin (Hb) level was greater in the LAVH group than in the TLH group (P<0.001). The weight of the removed uterus was greater in the TLH group than in the LAVH group (431.95±394.97 vs. 354.94±209.52 g; P=0.03). However, when the uterine weight was >1,000 g, the operative times and change in Hb levels were similar between the two groups. In both groups, no ureteral complications occurred during or after surgery.

CONCLUSION

Knotless parametrial tissue ligation using 1-0 V-LocTM 180 suture in TLH can be safely applied, even in cases with large uteri, without increased risks of ureteral injury or uterine bleeding.

Effect of longitudinal-bending elliptical ultrasonic vibration assistance on electrosurgical cutting and hemostasis

Electrosurgical devices are widely used for tissue cutting and hemostasis in minimally invasive surgery (MIS) for their high precision and low trauma. However, tissue adhesion and the resulting thermal injury can cause infection and impede the wound-healing process. This paper proposes a longitudinal-bending elliptical ultrasonic vibration-assisted (EUV-A) electrosurgical cutting system that incorporates an ultrasonic vibration in the direction of the cut by introducing an elliptical motion of the surgical tip. Compared with a solely longitudinal ultrasonic vibration-assisted (UV-A) electrosurgical device, the EUV-A electrode contacts the tissue intermittently, thus allowing for a cooler cut and preventing tissue accumulation. The experimental results reveal that the EUV-A electrode demonstrates better performance than the UV-A electrode for both anti-adhesion and thermal injury through in vitro experiments in porcine samples. The tissue removal mechanism of EUV-A electrosurgical cutting is modeled to investigate its anti-adhesion effect. In addition, lower adhesion, lower temperature, and faster cutting are demonstrated through in vivo experiments in rabbit samples. Results show that the EUV-A electrode causes lower thermal injury, indicative of faster postoperative healing. Finally, efficacy of the hemostatic effect of the EUV-A electrode is demonstrated in vivo for vessels up to 3.5 mm (equivalent to that of electrocautery). The study reveals that the EUV-A electrosurgical cutting system can achieve safe tissue incision and hemostasis.

Anterior Palatal Fistula Formation after Le Fort I Osteotomy in Conventional Orthognathic Surgery

The prevalence rate of maxillary ischemic complications following Le Fort I osteotomy was estimated to be about 1%. Understanding the local and systemic factors affecting maxillary perfusion before, during, and after the surgery can prevent the development of these complications. The present study investigated a case of anterior palatal fistula following the classic Le Fort I osteotomy.

Antiadhesion Superhydrophobic Bipolar Electrocoagulation Tweezers with High Conductivity and Stability

Irregularly shaped electrosurgical devices face significant challenges in electrosurgery due to serious blood and tissue adhesion. Superhydrophobic surfaces inspired by lotus leaves have attracted great attention for their promising antiadhesion properties. However, there are few methods for efficiently preparing superhydrophobic irregularly shaped bipolar electrocoagulation tweezers (BETs). Herein, we propose a simple and environmentally friendly method to fabricate antiadhesion superhydrophobic surfaces on BETs. The superhydrophobicity is obtained by combining laser texturing to form rough structures and low surface energy modification via stearic acid. The formation mechanism of superhydrophobicity is investigated through analyzing microstructures and chemical compositions by scanning electron microscopy, white-light interferometry, and X-ray photoelectron spectroscopy. The functionalized BET surfaces exhibit excellent water repellency with a contact angle of 159.6°, a roll-off angle of 1°, and a surface energy of 14.3 mJ/m2, possessing excellent antiadhesion properties against blood, chicken breast tissue, and pork tissue. Compared with ordinary BETs, the mass of blood, pork tissue, and chicken breast tissue adhered to the superhydrophobic BET is reduced by 97.70, 70.34, and 75.35%, respectively. Moreover, the superhydrophobic BETs have excellent conductivity and maintain good antiadhesion properties after low-temperature storage for 2 weeks, after being impacted by sand and blood and 30 cycles of tape peeling tests. With outstanding antiadhesion performance, the superhydrophobic BET may have promising application prospects in the electrosurgery field.

Development and application of a spray tip that enables electrocoagulation of a variety of tissues

BACKGROUND

Spray hemostasis is possible using a high-frequency power source from the tip of an electric scalpel; however, the difficulties regarding the uniformity and rapidity of the hemostasis surface remain. This study reports the development of a novel electrocoagulation device tip that can be used in endoscopic and robotic surgeries and can quickly coagulate and hemostat and easily adjust the extent of cauterization and hemostasis while minimizing the depth of thermal injury.

METHODS

The safety and efficacy of the hemostatic device were verified in a porcine model. A liver surface transection was conducted in vivo and the rapidity of the hemostatic effect of the device was observed. An extracted stomach, kidney, and liver were cauterized ex vivo by three operators with different surgical skills and the effects were analyzed pathologically. In addition, a sacrificed pig cadaver was used to achieve hemostasis at a renal transection site using the multi-spray endoscope tip.

RESULTS

An increase in the number of tip terminals expanded the cauterization surface and shortened the cauterization time. In parenchymatous organs, uniform cauterization was possible without increasing the depth of thermal injury. The cauterization depth did not depend on the operator's skill, and the spray coagulation was safe. The variable spray tip allowed for simple hemostasis during open and laparoscopic surgeries.

CONCLUSIONS

This novel electrocoagulation device tip can be developed as a forceps that can change the spray range and can be used during laparoscopic and robotic surgeries.

A dual-view multi-resolution laparoscope for safer and more efficient minimally invasive surgery

Minimally invasive surgery (MIS) is limited in safety and efficiency by the hand-held nature and narrow fields of view of traditional laparoscopes. A multi-resolution foveated laparoscope (MRFL) was invented to address these concerns. The MRFL is a stationary dual-view imaging device with optical panning and zooming capabilities. It is designed to simultaneously capture and display a zoomed view and supplemental wide view of the surgical field. Optical zooming and panning capabilities facilitate repositioning of the zoomed view without physically moving the system. Additional MRFL features designed to improve safety and efficiency include its snub-nosed endoscope, tool-tip auto tracking, programmable focus profiles, unique selectable display modalities, foot pedal controls, and independently controlled surgeon and assistant displays. An MRFL prototype was constructed to demonstrate and test these features. Testing of the prototype validates its design architecture and confirms the functionality of its features. The current MRFL prototype functions adequately as a proof of concept, but the system features and performance require further improvement to be practical for clinical use.

Capacitive coupling leading to electrical skin burn injury during laparoscopic surgery

Purpose

Trocar-site burns occurring during laparoscopic surgery have been reported in various cases, and several efforts to reduce them are underway. This study aimed to analyze the effect of capacitive coupling on trocar site by observing electrical and histological changes for electrical skin burn injury.

Methods

To measure the electrical changes relating to capacitive coupling, the temperature, current, voltage, and impedance around the trocar were measured when an open circuit and a closed circuit were formed using insulation intact instruments and repeated after insulation failure. After the experiment, the tissue around the trocar was collected, and microscopic examination was performed.

Results

When open circuits were formed with the intact insulation, the impedance was significantly reduced compared to the cases of closed circuits (142.0 Ω vs. 109.3 Ω, p = 0.040). When the power was 30 W and there was insulation failure, no significant difference was measured between the open circuit and the closed circuit (147.7 Ω vs. 130.7 Ω, p = 0.103). Collagen hyalinization, nuclear fragmentation, and coagulation necrosis suggesting burns were observed in the skin biopsy at the trocar insertion site.

Conclusion

This study demonstrated that even with a plastic trocar and electrosurgical instruments that have intact insulation, if an open circuit is formed, capacitive coupling increases, and trocar-site burn can occur. When using electrocautery, careful manipulation must be taken to avoid creating an open circuit to prevent capacitive coupling related to electrical skin burn.

High-throughput multi-resolution foveated laparoscope for minimally invasive surgery

Feasibility and clinical utility of a multi-resolution foveated laparoscope (MRFL) was previously tested in a porcine surgical study. The study revealed several clinical limitations of the system including moisture proofing, working distance, image quality, low light performance, color accuracy, size, and weight. In this paper, we discuss the root causes of these limitations and strategies to correct them, present the design and prototyping of a new high throughput multi resolution foveated laparoscope (HT-MRFL), and demonstrate the HT-MRFL prototype performance in comparison to the MRFL and simulated performance metrics.

Comparing the safety and effectiveness of dedicated radiofrequency transseptal wires to electrified metal guidewires

Background

Application of electrocautery to a metal guidewire is used by some operators to perform transseptal puncture (TSP). Commercially available dedicated radiofrequency (RF) guidewires may represent a better alternative. This study compares the safety and effectiveness of electrified guidewires to a dedicated RF wire.

Methods

TSP was performed on freshly excised porcine hearts using an electrified 0.014″ or 0.032″ guidewire under various power settings and was compared to TSP using a dedicated RF wire with 5 W power (0.035″ VersaCross RF System, Baylis Medical). The primary endpoint was the number of attempts required to achieve TSP. Secondary endpoints included the rate of TSP failure, TSP consistency, the effect of the distance between the tip of the guidewire and the tip of the dilator, and effect of RF power output level. Qualitative secondary endpoints included tissue puncture defect appearance, thermal damage to the TSP guidewire or dilator, and tissue temperature using thermal imaging.

Results

The RF wire required on average 1.10 ± 0.47 attempts to cross the septum. The 0.014″ electrified guidewire required an overall mean of 2.17 ± 2.36 attempts (2.0 times as many as the RF wire; p < .01), and the 0.032″ electrified guidewire required an overall mean of 3.90 ± 2.93 attempts (3.5 times as many as the RF wire; p < .01). Electrified guidewires had a higher rate of TSP failure, and caused larger defects and more tissue charring than the RF wire. Thermal analysis showed higher temperatures and a larger area of tissue heating with electrified guidewires than the RF wire.

Conclusion

Fewer RF applications were required to achieve TSP using a dedicated RF wire compared to an electrified guidewire. Smaller defects and lower tissue temperatures were also observed using the RF wire. Electrified guidewires required greater energy delivery and were associated with equipment damage and tissue charring, which may present a risk of thrombus, thermal injury, or scarring.

Temperature profile and residual heat of monopolar laparoscopic and endoscopic dissection instruments

BACKGROUND

Endoscopic and laparoscopic electrosurgical devices (ED) are of great importance in modern medicine but can cause adverse events such as tissue injuries and burns from residual heat. While laparoscopic tools are well investigated, detailed insights about the temperature profile of endoscopic knives are lacking. Our aim is to investigate the temperature and the residual heat of laparoscopic and endoscopic monopolar instruments to increase the safety in handling ED.

METHODS

An infrared camera was used to measure the temperature of laparoscopic and endoscopic instruments during energy application and to determine the cooling time to below 50 °C at a porcine stomach. Different power levels and cutting intervals were studied to investigate their impact on the temperature profile.

RESULTS

During activation, the laparoscopic hook exceeded 120 °C regularly for an up to 10 mm shaft length. With regards to endoknives, only the Dual Tip Knife showed a shaft temperature of above 50 °C. The residual heat of the laparoscopic hook remained above 50 °C for at least 15 s after activation. Endoknives cooled to below 50 °C in 4 s. A higher power level and longer cutting duration significantly increased the shaft temperature and prolonged the cooling time (p < 0.001).

CONCLUSION

Residual heat and maximum temperature during energy application depend strongly on the chosen effect and cutting duration. To avoid potential injuries, the user should not touch any tissue with the laparoscopic hook for at least 15 s and with the endoknives for at least 4 s after energy application. As the shaft also heats up to over 120 °C, the user should be careful to avoid tissue contact during activation with the shaft. These results should be strongly considered for safety reasons when handling monopolar ED.

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 packaging and clean method contribute to insulation failure of electrosurgical instruments

With the rapid development of medical technology, the use of electrosurgical instruments is dramatically increased in various types of surgery. However, the damage of the insulation layer of the reusable electrosurgical instrument often causes surgical accidents. The procedures of packaging and cleaning contribute to many damages to insulating layer of reusable electrosurgical instruments.Various types of reusable electrosurgical instruments were detected for insulation failures, conduction failures, short-circuit by using a high-voltage detector, DIATEG (Morgate company). In addition, reusable electrosurgical instruments were detected for insulation failures after packaging and cleaning by different procedures.13.1% (129/740) electrosurgical instruments had an insulation test failure; 6.2% (9/146) monopolar wires were with conduction failure; and 7.7% (16/207) bipolar wires were with short-circuit. Different packaging and cleaning procedures contribute to various degrees of damages to insulating property of reusable electrosurgical instruments.Insulation failure was a wide problem of reusable electrosurgical instruments, while fixed packaging method and mild cleaning procedures result in fewer damages to insulating property of reusable electrosurgical instruments.

Electrosurgery Use During Post-Mohs Micrographic Surgery Repair and Complication Rates-How Important is a Dry Field?

BACKGROUND

Electrosurgery is used to achieve hemostasis during surgery. There are no studies exploring the effects of the use or avoidance of electrodessication during Mohs micrographic surgery (MMS) repair. Given the growing concerns for tissue aerosolization, occupational smoke exposure, and spread of infectious diseases, it is important to determine the importance of electrical hemostasis.

MATERIALS AND METHODS

In this retrospective study, electronic medical records of a single, tertiary, academic dermatology practice were reviewed. All MMS cases that underwent surgical repair from January 1 to December 31, 2019, by 2 dermatologic surgeons (one who used electrodessication during repair and one who did not) were included. Patient demographic data, information regarding the procedures, and complications occurring 90 days after MMS were recorded.

RESULTS

One hundred ninety-eight cases of MMS repair used electrodessication, whereas 193 cases did not. There was no significant difference in the demographic makeup, MMS procedure, or 90-day complication rates between the 2 groups. No major adverse events were MMS-related.

CONCLUSION

The use or avoidance of electrodessication during MMS repair was not associated with increased 90-day postoperative complications, suggesting that a greater tolerance of moderate oozing at a surgical site during MMS repair is reasonable to minimize electrosurgical tissue damage and occupational smoke exposure.

Application of multi-component fluid model in studies of the origin of skin burns during electrosurgical procedures

This paper reports on safety challenges regarding spark created when the applied electric field exceeds the dielectric breakdown strength as a source of complication during electrosurgery. Despite the unquestionable benefits of electrosurgery, such as minimal chances of infection and fast recovery time, the interaction of the electrosurgical tool with the tissue may result in tissue damage and force feedback to the tool. Some risks of complications often depend on a surgeon's knowledge of instruments and safety aspects of technical equipment that can be eliminated by clarifying the causation and conditions of their development. Current trends in electrosurgery include computational algorithms and methods to control the effect of delivered energy to the patient. For this study, calculations were performed by using the COMSOL simulation package based on a multi-component plasma fluid model. The emphasis is put on conditions that lead to the breakdown of the dielectric medium. It was found that breakdown occurs most easily when both electrodes are cylindrical. For configurations with one or two spherical electrodes, breakdown voltages are higher up to 25% and 48%, respectively. With decreasing the cathode radius, the breakdown voltage may decrease even to 41%. On the other hand, the temperature increase lowers the breakdown voltage. Also, electrical asymmetries appear to be a response to the non-symmetry of the electric field between the electrodes causing differences in the breakdown voltage between 36% and 70%. The results presented here could be very useful for the design of surgical devices to prevent potential complications of electrosurgical procedures.

Electrosurgical unit: Iatrogenic injuries and medico-legal aspect. Italian legal rules, experience and article review

BACKGROUND

The use of the electrosurgical unit (ESU) is well-established in the surgical practice. The Authors, to better understand the genesis of injuries connected to the use of electrosurgical instruments, conducted an in-depth literature review pertaining to this topic.

MATERIALS AND METHOD

Using the most important medical databases, a research of experimental studies in the last 20 years was conducted.

RESULTS

The analysis of the mechanisms responsible for the lesions showed that high energy devices remain as the most common cause of injury. Adverse events are mainly given by thermal injuries; cases of electromagnetic interference are also described in patients with pacemakers or sacral nerve stimulator and spinal stimulators as well as cases of fire of the endotracheal tube in the course of tracheostomy for the use of the electrosurgical unit in an environment with a high concentration of oxygen or anesthetic gases. Also reported in the literature are individual cases of fires caused by sparks from the electrosurgical handpiece also for the use of disinfectants and/or in relation to surgical drapes.

CONCLUSION

In order to clearly define the medical-legal aspects, focusing on the professional responsibility of the surgical and nursing staff, the authors' attention was brought to the need for an effective prevention plan that highlights not only the importance of an accurate procedural knowledge in order to safety use the electrosurgical instruments, but also the need for a system that monitors any complications or adverse events resulting from the use of such instruments.

Hand Skin Burn as a Complication of Electrosurgery Use in Prone Position in Surgery: A Case Report

Electrosurgery is one of the advances in the surgical field and used commonly. Modern electrosurgical units considered relatively safe. Although rare, inadvertent skin burns due to electrosurgery caused by different mechanisms were reported in the literature. Positioning the patient in prone is required for some surgeries and utilizing this position in a proper manner is essential to avoid complications. We present a case of a 47-year-old female patient who underwent uneventful spinal surgery in a prone position. The patient complained of pain in fingers postoperatively that revealed third-degree skin burn. Plastic surgery was involved in the treatment of burns and the patient followed regularly until fully healed. This case study aims to prompt awareness among surgeons and the staff of the operation-room regarding the unintended burn of patients caused by aberrant circuit related to electrosurgery in prone position.

A continuum thermomechanical model for the electrosurgery of soft hydrated tissues using a moving electrode

Electrosurgical radio-frequency heating of tissue is widely applied in minimally invasive surgical procedures to dissect tissue with simultaneous coagulation to obtain hemostasis. The tissue effect depends on the cumulative heating that occurs in the vicinity of the moving blade electrode. In this work, a continuum thermomechanical model based on mixture theory, which accounts for the multiphase nature of soft hydrated tissues and includes transport and evaporation losses, is used to capture the transient heating effect of a moving electrode. The model takes into account the dependence of electrical conductivity and the evaporation rate on the water content in the tissue, as it changes in response to heating. Temperature prediction is validated with mean experimental temperature measured during in situ experiments performed on porcine liver tissue at different power settings of the electrosurgical unit. The model is shown to closely capture the temperature variation in the tissue for three distinct scenarios; with no visible cutting or coagulation damage at a low 10 W power setting, with coagulation damage but no tissue cutting at an intermediate power setting of 25 W, and with both coagulation and tissue cutting at a higher power setting of 50 W. Furthermore, an Arrhenius model is shown to capture tissue damage observed in the experiments. Increase in applied power was found to correlate with tissue cutting and concentrated damage near the electrode, but had little effect on the observed coagulation damage width. The proposed model provides, for the first time, an accurate tool for predicting temperature rise and evolving damage resulting from a moving electrode in pure-cut electrosurgery.

Improved multi-resolution foveated laparoscope with real-time digital transverse chromatic correction

A multi-resolution foveated laparoscope (MRFL) with autofocus and zooming capabilities was previously designed to address the limiting trade-off between spatial resolution and field of view during laparoscopic minimally invasive surgery. The MRFL splits incoming light into two paths enabling simultaneous capture of the full surgical field and a zoomed-in view of the local surgical site. A fully functional prototype was constructed to demonstrate and test the autofocus, zooming capabilities, and clinical utility of this new laparoscope. The test of the prototype in both dry lab and animal models was successful, but it also revealed several major limitations of the prototype. In this paper, we present a brief overview of the aforementioned MRFL prototype design and results, and the shortcomings associated with its optical and mechanical designs. We then present several methods to address the shortcomings of the existing prototype with a modified optical layout and redesigned mechanics. The performances of the new and old system prototypes are comparatively analyzed in accordance with the design goals of the new MRFL. Finally, we present and demonstrate a real-time digital method for correcting transverse chromatic aberration to further improve the overall image quality, which can be adapted to future MRFL systems.

Stray energy transfer in single-incision robotic surgery

INTRODUCTION

Stray energy transfer from surgical monopolar radiofrequency energy instruments can cause unintended thermal injuries during laparoscopic surgery. Single-incision laparoscopic surgery transfers more stray energy than traditional laparoscopic surgery. There is paucity of published data concerning stray energy during single-incision robotic surgery. The purpose of this study was to quantify stray energy transfer during traditional, multiport robotic surgery (TRS) compared to single-incision robotic surgery (SIRS).

METHODS

An in vivo porcine model was used to simulate a multiport or single-incision robotic cholecystectomy (DaVinci Si, Intuitive Surgical, Sunnyvale, CA). A 5 s, open air activation of the monopolar scissors was done on 30 W and 60 W coag mode (ForceTriad, Covidien-Medtronic, Boulder, CO) and Swift Coag effect 3, max power 180 W (VIO 300D, ERBE USA, Marietta, GA). Temperature of the tissue (°C) adjacent to the tip of the assistant grasper or the camera was measured with a thermal camera (E95, FLIR Systems, Wilsonville, OR) to quantify stray energy transfer.

RESULTS

Stray energy transfer was greater in the SIRS setup compared to TRS setup at the assistant grasper (11.6 ± 3.3 °C vs. 8.4 ± 1.6 °C, p = 0.013). Reducing power from 60 to 30 W significantly reduced stray energy transfer in SIRS (15.3 ± 3.4 °C vs. 11.6 ± 3.3 °C, p = 0.023), but not significantly for TRS (9.4 ± 2.5 °C vs. 8.4 ± 1.6 °C, p = 0.278). The use of a constant voltage regulating generator also minimized stray energy transfer for both SIRS (0.7 ± 0.4 °C, p < 0.001) and TRS (0.7 ± 0.4 °C, p < 0.001).

CONCLUSIONS

More stray energy transfer occurs during single-incision robotic surgery than multiport robotic surgery. Utilizing a constant voltage regulating generator minimized stray energy transfer for both setups. These data can be used to guide robotic surgeons in their use of safe, surgical energy.

Thermal effects of monopolar electrosurgery detected by real-time infrared thermography: an experimental appendectomy study

Background

Monopolar energy (ME) is routinely used in appendectomy. This study aimed to investigate the degree of lateral thermal spread generated by ME and to evaluate the thermal injury sustained by the close-lying tissues.

Methods

Appendectomy with a monopolar Maryland dissector was performed in 8 rabbits (at 30 and 60 W power settings). A high-resolution infrared camera was used to record tissue heating during the intervention. After autopsy macroscopic changes were evaluated and tissue samples were subjected to myeloperoxidase (MPO) assay and histological examination.

Results

No significant differences in the extent of thermal spread, MPO activity and histological signs of inflammation were observed between groups. Regardless of the power settings, the heat spread exceeded 2 cm laterally along the mesoappendix when application time exceeded 3 s. The spread of heat through tubular structures in both groups caused a significant temperature rise in the nearby intestinal loop, resulting in perforation (n = 3) and necrosis (n = 1).

Conclusions

Application time is critical in thermal spread during appendectomy aided by ME. Tubular anatomic structures can enhance thermal injury on distant tissues. The observed effects of ME bear clinical relevance that need further investigation.

Monopolar stray energy in robotic surgery

INTRODUCTION

Stray energy transfer from monopolar radiofrequency energy during laparoscopy can be potentially catastrophic. Robotic surgery is increasing in popularity; however, the risk of stray energy transfer during robotic surgery is unknown. The purpose of this study was to (1) quantify stray energy transfer using robotic instrumentation, (2) determine strategies to minimize the transfer of energy, and (3) compare robotic stray energy transfer to laparoscopy.

METHODS

In a laparoscopic trainer, a monopolar instrument (L-hook) was activated with DaVinci Si (Intuitive, Sunnyvale, CA) robotic instruments. A camera and assistant grasper were inserted to mimic a minimally invasive cholecystectomy. During activation of the L-hook, the non-electric tips of the camera and grasper were placed adjacent to simulated tissue (saline-soaked sponge). The primary outcome was change in temperature from baseline (°C) measured nearest the tip of the non-electric instrument.

RESULTS

Simulated tissue nearest the robotic grasper increased an average of 18.3 ± 5.8 °C; p < 0.001 from baseline. Tissue nearest the robotic camera tip increased (9.0 ± 2.1 °C; p < 0.001). Decreasing the power from 30 to 15 W (18.3 ± 5.8 vs. 2.6 ± 2.7 °C, p < 0.001) or using low-voltage cut mode (18.3 ± 5.8 vs. 3.1 ± 2.1 °C, p < 0.001) reduced stray energy transfer to the robotic grasper. Desiccating tissue, in contrast to open air activation, also significantly reduced stray energy transfer for the grasper (18.3 ± 5.8 vs. 0.15 ± 0.21 °C, p < 0.001) and camera (9.0 ± 2.1 vs. 0.24 ± 0.34 °C, p < 0.001).

CONCLUSIONS

Stray energy transfer occurs during robotic surgery. The assistant grasper carries the highest risk for thermal injury. Similar to laparoscopy, stray energy transfer can be reduced by lowering the power setting, utilizing a low-voltage cut mode instead of coagulation mode and avoiding open air activation. These practical findings can aid surgeons performing robotic surgery to reduce injuries from stray energy.

Dynamic Impedance Monitoring for Large Diameter Vessel Sealing Using Bipolar Electrosurgery

Vessel sealing using bipolar electrosurgery is becoming a common practice in modern operating rooms. Despite all the advantages such as faster operation, less bleeding, and shorter postsurgery recovery time, side effects including sticking, charring, and rebleeding still occur, leading to increased surgery time and sometimes fatal complications. Tissue impedance during the electrosurgical process has been used to determine the electrical power of the process. However, little has been done to understand the dynamic tissue impedance and its effectiveness in monitoring the vessel sealing process. Moreover, the samples used in previous studies all had small diameters of 2–5 mm. In this study, an experimental setup was developed to perform vessel sealing tests using large-diameter blood vessel samples with mimicking blood flow. The tissue impedance during the heating process was obtained. Burst pressures after sealing were measured. A finite element simulation model was developed to understand the dynamic impedance behavior. It is seen that the tissue impedance increases rapidly in the beginning of the heating process and remains at a level that is several orders of magnitude higher than the initial value. This rapid impedance increase indicates protein denaturing, thus can be used to monitor the electrosurgical vessel sealing process. An impedance-based monitoring algorithm was developed, with which a burst pressure at least twice the normal human systolic blood pressure was achieved.

Safety Profile of the New Harmonic Focus: Different Emissivity and Temperature Behavior Between the Active and the Inactive Blade

Ultrasonic devices disperse less energy in the tissues. The new Harmonic Focus+ (HF+) seems to be more efficient but thermal damages have been reported. This study examined the temperature and the emissivity profile of the active and passive blades of the HF+, on a pig tissue model at different power settings. The FLIR System B series thermal imaging camera has been used on various biological pig tissues to evaluate the emissivity of the ultrasonic device. The active blade heats up faster than the passive one and the increase in power increases the speed of the temperature raising only on the active blade. Increasing the power setting reduces the dissection time and the temperature of both blades. Active blade temperatures of <60°C are obtained with cutting times close to 5 seconds; with these cutting times, the inactive blade does not exceed 30°C. The HF+ emissivity profiles demonstrate that the behavior of the inactive blade is significantly different from the active one. To prevent thermal damages, keep the active blade toward the operator, do not exceed 5 seconds of activation, use the maximum power, and avoid the use of the instrument as a dissector immediately after its activation.

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.

A Surgical Instrument Cover for the Prevention of Thermal Injuries During Laparoscopic Operations

INTRODUCTION

Accidental thermal injuries are infrequent, nonetheless, dangerous complications in laparoscopic surgery. Burns are produced because of direct contact, lack of instrument insulation and capacitive coupling. Biological fluids on the surface of laparoscopic instruments behave as electric conductors on the sheath and may be responsible for accidental thermal injuries. Our hypothesis is that using an insulator device may prevent those injuries.

MATERIALS AND METHODS

After evaluating different materials for dielectric properties, costs, and temperature increase tolerance, we selected polytetrafluoroethylene (PTFE) to develop a sleeve that works as an electrical insulator when applied on the sheath of laparoscopic instruments. Efficacy of this PTFE cover in reducing conduction of electricity was tested on both reusable and disposable laparoscopic instruments.

RESULTS

Electric conduction of the laparoscopic instrument sheaths was tested using an ex vivo model that reproduces the abdominal environment in basal conditions and in presence of blood. Electric conduction of laparoscopic instruments was measured before and after the placement of the PTFE cover. We measured a significant difference in electric resistance on the sheath's surface without and with blood, revealing a weak electrical conduction: infinity versus a median value of 251.11 Mohm, respectively.

CONCLUSIONS

This ex vivo study demonstrated that a PTFE sleeve may reduce electricity conduction of laparoscopic instruments. A pilot in vivo study is planned to test its safety and efficacy.

Contemporary use of ultrasonic versus standard electrosurgical dissection in laparoscopic nephrectomy: Safety, efficacy and cost

Objective

To assess the safety, efficacy and cost-effectiveness of ultrasonic dissection (USD) compared with standard monopolar electrosurgery (ES) in laparoscopic nephrectomy (LN).

Patients and methods

Retrospective analysis of patients’ records who underwent elective LN was performed. Patients were divided in to two groups: USD and ES groups depending on the energy source used during LN. The preoperative (demographics, indication for surgery), intraoperative (conversion to open surgery, operative time, estimated blood loss [EBL], complications), and postoperative (morbidity/mortality, volume of drainage, hospital stay, cost) data were collected and analysed.

Results

Between February 2004 and February 2008, 136 patients were included. The indications for nephrectomy were: inflammatory (51 patients), non-inflammatory (64), and tumours (21). The two groups were similar for preoperative data. The conversion rate to open surgery (12.5%) and mean operative time did not differ significantly between the groups. However, intraoperative mean EBL was significantly less with USD, at 140.8 mL vs 182.6 mL for ES. There were no differences in postoperative parameters and morbidity. USD was significantly more expensive than ES (59 000 vs 26 000 Indian Rupees).

Conclusions

ES is a safe and feasible tool like USD in LN when used with caution. USD facilitates completion of difficult cases and reduces intraoperative blood loss. However, the majority of LNs can be completed safely with ES. ES is sturdy and cheap; therefore, selective use of USD appears to be the most cost-effective policy in the developing world.

Clinical Impact of Iatrogenic Small Bowel Perforation Secondary to Laparoscopic Cholecystectomy: A Single-center Experience

OBJECTIVE

Bowel, vascular, and biliary injuries during laparoscopic cholecystectomy (LC) have to be addressed with high priority. The focus of this study was on small bowel injury (SBI) and its impact on clinical management.

METHODS

We report 5 cases of SBI in a retrospective database of 2062 consecutive LC between January 2004 and December 2017.

RESULTS

We report isolated iatrogenic SBI in 0.24% (5 of 2062) after LC. We identified 3 cases with SBI associated with the technique of Hasson or related problems with intraoperative relaxation toward the end of the LC. All 5 patients needed at least 1 reoperation. There was no mortality in this series and all patients with iatrogenic SBI got discharged from the clinic in good health. Nevertheless, 3 of 5 patients (60%) with SBI filed a law suit.

CONCLUSIONS

Isolated iatrogenic SBI is a rare but dreaded complication after LC with high impact on patient's health and prone for medicolegal claims. Strict precaution on thorough relaxation throughout the operation, meticulous handling of closing technique of the fascial layer and "eternal vigilance" are mandatory to reduce risks of SBI after LC.

Improving anti-adhesion performance of electrosurgical electrode assisted with ultrasonic vibration

The electrosurgical electrode currently stands out as one of the most commonly used tools in minimally invasive surgery. In order to facilitate tissue cutting and accelerate wound healing, tissue adhesion to the electrosurgical electrode is considered as an extremely urgent problem to be solved. In this paper, a novel ultrasonic vibration assisted (UV-A) electrosurgical electrode is firstly proposed to overcome the problem of tissue sticking. The anti-adhesion effects were evaluated by measuring the adhesion force and the weight of tissue adhesion using the electrosurgical electrode with and without UV-A comparatively. Experimental results show that the average adhesion force and the tissue adhesion mass with UV-A were decreased by approximately 60% and 70% respectively, accompanied by smaller thermal injury area compared with that without UV-A. Moreover, the underlying mechanism of anti-adhesion effect with UV-A was revealed by investigating the influence of ultrasonic vibration on electric current, tissue removal and spark discharge. This research suggests that UV-A is a promising and practical method for improving the anti-adhesion performance of electrosurgical electrode.

Risk management for surgical energy-driven devices used in the operating room

Complications related to energy sources in the operating room are not well-recognized or published, despite occasionally dramatic consequences for the patient and the responsible surgeon. The goal of this study was to evaluate the risks and consequences related to use of energy sources in the operating room.

PATIENTS AND METHODS

Between 2009 and 2015, 876 adverse events related to health care (AERHC) linked to energy sources in the operating room were declared in the French experience feedback data base "REX". We performed a descriptive analysis of these AERHC and analyzed the root causes of these events and of the indications for non-elective repeat operations, for each energy source.

RESULTS

Five different energy sources were used, producing 876 declared AERHC: monopolar electrocoagulation: 614 (70%) AERHC, advanced bipolar coagulation (thermofusion): 137 (16%) AERHC, ultrasonic devices: 69 (8%) AERHC, traditional bipolar electrocoagulation: 32 AERHC, and cold light: 24 AERHC. The adverse events reported were skin burns (27.5% of AERHC), insulation defects (16% of AERHC), visceral burns or perforation (30% of AERHC), fires (11% of AERHC), bleeding (7.5% of AERHC) and misuse or miscellaneous causes (8% of AERHC). For the five energy sources, the root causes were essentially misuse, imperfect training and/or cost-related reasons regarding equipment purchase or maintenance. One hundred and forty-six non-elective procedures (17% of AERHC) were performed for complications related to the use of energy sources in the operating room.

CONCLUSION

This study illustrates the risks related to the use of energy sources on the OR and their consequences. Most cases were related to persistent misunderstanding of appropriate usage within the medical and paramedical teams, but complications are also related to administrative decisions concerning the purchase and maintenance of these devices.

Fundamental Use of Surgical Energy (FUSE): An Essential Educational Program for Operating Room Safety

Operating room (OR) safety has become a major concern in patient safety since the 1990s. Improvement of team communication and behavior is a popular target for safety programming at the institutional level. Despite these efforts, essential safety gaps remain in the OR and procedure rooms. A prime example is the use of energy-based devices in ORs and procedural areas. The lack of fundamental understanding of energy device function, design, and application contributes to avoidable injury and harm at a rate of approximately 1 to 2 per 1000 patients in the US. Hundreds of OR fires occur each year in the US, some causing severe injury and even death. Most of these fires are associated with the use of energy-based surgical devices.In response to this safety issue, the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) developed the Fundamental Use of Surgical Energy (FUSE) program. This program includes a standardized curriculum targeted to surgeons, other physicians, and allied health care professionals and a psychometrically designed and validated certification test. A successful FUSE certification documents acquisition of the basic knowledge needed to safely use energy-based devices in the OR. By design FUSE fills a void in the curriculum and competency assessment for surgeons and other procedural specialists in the use of energy-based devices in patients.

Hand-to-hand coupling and strategies to minimize unintentional energy transfer during laparoscopic surgery

BACKGROUND

Energy-based devices are used in nearly every laparoscopic operation. Radiofrequency energy can transfer to nearby instruments via antenna and capacitive coupling without direct contact. Previous studies have described inadvertent energy transfer through bundled cords and nonelectrically active wires. The purpose of this study was to describe a new mechanism of stray energy transfer from the monopolar instrument through the operating surgeon to the laparoscopic telescope and propose practical measures to decrease the risk of injury.

METHODS

Radiofrequency energy was delivered to a laparoscopic L-hook (monopolar "bovie"), an advanced bipolar device, and an ultrasonic device in a laparoscopic simulator. The tip of a 10-mm telescope was placed adjacent but not touching bovine liver in a standard four-port laparoscopic cholecystectomy setup. Temperature increase was measured as tissue temperature from baseline nearest the tip of the telescope which was never in contact with the energy-based device after a 5-s open-air activation.

RESULTS

The monopolar L-hook increased tissue temperature adjacent to the camera/telescope tip by 47 ± 8°C from baseline (P < 0.001). By having an assistant surgeon hold the camera/telescope (rather than one surgeon holding both the active electrode and the camera/telescope), temperature change was reduced to 26 ± 7°C (P < 0.001). Alternative energy devices significantly reduced temperature change in comparison to the monopolar instrument (47 ± 8°C) for both the advanced bipolar (1.2 ± 0.5°C; P < 0.001) and ultrasonic (0.6 ± 0.3°C; P < 0.001) devices.

CONCLUSIONS

Stray energy transfers from the monopolar "bovie" instrument through the operating surgeon to standard electrically inactive laparoscopic instruments. Hand-to-hand coupling describes a new form of capacitive coupling where the surgeon's body acts as an electrical conductor to transmit energy. Strategies to reduce stray energy transfer include avoiding the same surgeon holding the active electrode and laparoscopic camera or using alternative energy devices.

The Art of Electrosurgery: Trainees and Experts

The benefits of electrosurgery have been acknowledged since the early 1920s, and nowadays more than 80% of surgical procedures involve devices that apply energy to tissues. Despite its widespread use, it is currently unknown how the operator’s choices with regard to instrument selection and application technique are related to complications. As such, the manner in which electrosurgery is applied can have a serious influence on the outcome of the procedure and the well-being of patients. The aim of this study is to investigate the variety of differences in usage of electrosurgical devices. Our approach is to measure these parameters to provide insight into application techniques. A sensor was developed that records the magnitude of electric current delivered to an electrosurgical device at a frequency of 10 Hz. The sensor is able to detect device activation times and a reliable estimate of the power-level settings. Data were recorded for 91 laparoscopic cholecystectomies performed by different surgeons and residents. Results of the current measurement data show differences in the way electrosurgery is applied by surgeons and residents during a laparoscopic cholecystectomy. Variations are seen in the number of activations, the activation time, and the approach for removal of the gallbladder. Analysis showed that experienced surgeons have a longer activation time than residents (3.01 vs 1.41 seconds, P < .001) and a lower number of activations (102 vs 123). This method offers the opportunity to relate application techniques to clinical outcome and to provide input for the development of a best practice model.

Diathermy versus scalpel in transverse abdominal incision in women undergoing repeated cesarean section: A randomized controlled trial

AIM

The aim of this study was to evaluate the volume of blood loss, wound incision time and wound complication according to use of scalpel or electrosurgery during the creation of transverse abdominal incisions during repeated cesarean section (CS).

MATERIAL AND METHODS

A randomized controlled trial was carried out at Ain Shams University Maternity Hospital. We recruited 130 women with a history of one previous CS at the time of their planned lower-segment CS. Participants were randomized to anterior abdominal wall opening from subcutaneous tissue till the peritoneum by either the use of scalpel with disposable blade (No. 22) or diathermy using the standard diathermy pen electrode. The main outcome measures were the volume of blood loss from skin incision to the end of the peritoneal incision, the operative time and wound complication.

RESULTS

We observed a highly significant difference between the two groups in blood loss (median [interquartile range], 11 [8-15.25] g for the diathermy group vs 20 [18-23] g for the scalpel group, P < 0.001) and skin-to-peritoneum incision time (median [interquartile range], 7 [5-7.25] min for the diathermy group vs 10 [7-11] min for the scalpel group, P < 0.001). The postoperative pain was less in the diathermy group but wound complications showed no statistical difference.

CONCLUSION

The use of diathermy in the opening of anterior abdominal wall during CS decreases blood loss and operative time but has no impact on postoperative pain or wound complications.

Diathermy awareness among surgeons-An analysis in Ireland

INTRODUCTION

Diathermy is an integral part of many modern surgical procedures. While diathermy is generally accepted as 'safe', electrosurgery-induced injuries are among the more common causes for malpractice litigation. The purpose of this study was to evaluate the awareness among surgeons of the principles, risks, precautions and appropriate use of diathermy.

METHODS

All surgeons employed from Senior House Officer (SHO) to Consultant grade in two teaching hospitals were surveyed. Sixty-three surgeons were asked to complete an anonymous questionnaire, which recorded level of training and addressed competence in principles, hazards, and precautions to be taken with diathermy.

RESULTS

Eight Consultants, 5 Specialist Registrars, 19 Registrars and 13 SHO's responded (71% response). All but three subspecialties were represented. Eighty-two percent (37/45) had no formal diathermy training. Despite 89% (40/45) of surgeons regarding diathermy as a safe instrument, 56% felt they had inadequate understanding of the principles and failed to demonstrate an appropriate awareness of the potential risks. Fifty seven percent exhibited a dangerous lack of awareness in managing equipment not yielding the desired effect and 22% were unaware of any patient groups requiring special caution. Only 42% wanted formal training.

CONCLUSION

Our results show a dearth of awareness among surgeons regarding diathermy. Given our findings, we urge a shift in attitude towards diathermy, with surgeons adopting a more cautious and safe approach to diathermy use. We recommend that formal training be introduced as a hospital based initiative.

Iatrogenic Burns of the Neckline in a Patient with Tetraparesis During Tracheotomy

The paper presents a case of an atypical iatrogenic complication after tracheotomy analyzed on the basis of the case dossier materials submitted to the authors by the court of justice to prepare a forensic medical opinion concerning the correctness of the medical procedure. A 37-year-old woman was brought by the ambulance service to the hospital with acute respiratory failure due to post-tracheostomy tracheal stenosis. Tracheotomy was performed on an emergency basis. The patient suffered severe burns of the chest and neck. The experts concluded that the most probable cause of the incident was electrocautery-induced ignition of the disinfectant used for cleaning the skin before the surgery. It was established that with correct handling of the procedure, the aforementioned incident should not have taken place. Therefore, it cannot be regarded as a normal complication inherent in the risk associated with the procedure, but as a consequence of a medical error.

Single-incision laparoscopic surgery increases the risk of unintentional thermal injury from the monopolar "Bovie" instrument in comparison with traditional laparoscopy

BACKGROUND

Single-incision laparoscopic surgery (SILS) places multiple instruments in close, parallel proximity, an orientation that may have implications in the production of stray current from the monopolar "Bovie" instrument. The purpose of this study was to compare the energy transferred during SILS compared to traditional four-port laparoscopic surgery (TRD).

METHOD

In a laparoscopic simulator, instruments were inserted via SILS or TRD setup. The monopolar generator delivered energy to a laparoscopic L-hook instrument for 5-s activations on 30-Watts coag mode. The primary outcome (stray current) was quantified by measuring the heat of liver tissue held adjacent to the non-electrically active 10-mm telescope tip and Maryland grasper in both the SILS and TRD setups. To control for the potential confounder of stray energy coupling via wires outside the surgical field, the camera cord and active electrode wires were oriented parallel or completely separated.

RESULTS

SILS and TRD setups create similar amounts of stray current as measured by increased tissue temperature at the non-electrically active telescope tip (41 ± 12 vs. 39 ± 10 °C; p = 0.71). Stray current was greater in SILS compared to TRD at the tip of the non-electrically active Maryland forceps (38 ± 9 vs. 20 ± 10 °C; p < 0.01). Separation of the active electrode and camera cords did not change the amount of stray energy in the SILS orientation for either telescope (39 ± 10 °C bundled vs. 36 ± 10 °C separated; p = 0.40) or grasper (38 ± 9 °C bundled vs. 34 ± 11 °C separated; p = 0.19) but did in the TRD orientation (41 ± 12 bundled vs. 24 ± 10 separated; p < 0.01). When SILS was compared to TRD with the cords separated, SILS increased stray energy at both the telescope tip and grasper tip (36 ± 10 vs. 24 ± 10 °C; p < 0.01 and 34 ± 11 vs. 17 ± 8 °C; p < 0.01).

CONCLUSION

SILS increases stray energy transfer nearly twice as much as TRD with the use of the monopolar instrument. Strategies to mitigate the amount of stray energy in the TRD setup such as separation of the active electrode and camera cords are not effective in the SILS setup. These practical findings should enhance surgeons using the SILS approach of increased stray energy that could result in injury.

Delayed Perforation of the Large Bowel due to Thermal Injury during Laparoscopic Cholecystectomy

We report a case of delayed perforation of the large bowel because of thermal injury during a laparoscopic cholecystectomy. A 78-year-old male with symptomatic cholelithiasis underwent a difficult laparoscopic cholecystectomy because of multiple adhesions resulting from two previous cholecystitis episodes. The patient recovered well after surgery and was discharged on post-operative day 2. On postoperative day 10, the patient returned to the hospital with peritonitis. An exploratory laparotomy revealed perforation of the wall of the hepatic flexure of the large bowel, which was centred in a necrotic area 1 cm in diameter. The perforation was sutured and a temporary ileostomy performed, which was closed at a later date. The patient was doing well at a 10-month follow-up review. A delayed rupture of any part of the bowel after laparoscopic surgery can be potentially fatal if not treated during an emergency exploratory laparotomy, even if the clinical signs are not severe.

Electrocautery effect on intestinal vascularisation in a murine model

BACKGROUND

The use of electrocautery devices is associated with complications such as perforation or fistulisation when used near intestinal structures. This is likely due to its effect on vascularisation of the bowel wall. To test this hypothesis we established a murine model to quantify the effect of electrocautery injury on the intestinal microvascularisation.

METHODS

Sprague-Dawley rats were subjected to five electrocautery injuries on the small bowel in coagulation mode (30 W intensity) and in cut mode (40 W, 80 W and 200 W intensities) for durations of 1, 2 and 5 s. 5 mg/kg of fluorescein was injected intravenously, the injured bowel segments harvested and the rat sacrificed. The segments were analysed to measure the fluorescence of injured bowel compared to adjacent unharmed tissue.

RESULTS

A significant decrease in bowel wall microvascularisation occurred with increasing intensity (coag 30 W/cut 40 W versus cut 200 W 1 s: p < 0.05) and duration of electrocautery injury (cut 40 W 1/2 s versus 5 s: p < 0.05). There was a 40% perforation rate when decreased bowel wall microvascularisation was 25% or more. Despite similar electrocautery injury, a significantly greater microvascularisation decrease was observed in jejunum compared to ileum (p < 0.05).

CONCLUSION

We successfully established a murine model to quantify the decrease of bowel wall microvascularisation associated with electrocautery use. Unsurprisingly, the decrease in microvascularisation is greater with higher intensity and duration of electrocautery and is associated with more perforations in the experimental model. The jejunum seems more vulnerable to electrocautery injury than the ileum. These observations support caution when using electrocautery devices near intestinal structures.

Separating the Laparoscopic Camera Cord From the Monopolar "Bovie" Cord Reduces Unintended Thermal Injury From Antenna Coupling: A Randomized Controlled Trial

OBJECTIVE(S)

The monopolar "Bovie" is used in virtually every laparoscopic operation. The active electrode and its cord emit radiofrequency energy that couples (or transfers) to nearby conductive material without direct contact. This phenomenon is increased when the active electrode cord is oriented parallel to another wire/cord. The parallel orientation of the "Bovie" and laparoscopic camera cords cause transfer of energy to the camera cord resulting in cutaneous burns at the camera trocar incision. We hypothesized that separating the active electrode/camera cords would reduce thermal injury occurring at the camera trocar incision in comparison to parallel oriented active electrode/camera cords.

METHODS

In this prospective, blinded, randomized controlled trial, patients undergoing standardized laparoscopic cholecystectomy were randomized to separated active electrode/camera cords or parallel oriented active electrode/camera cords. The primary outcome variable was thermal injury determined by histology from skin biopsied at the camera trocar incision.

RESULTS

Eighty-four patients participated. Baseline demographics were similar in the groups for age, sex, preoperative diagnosis, operative time, and blood loss. Thermal injury at the camera trocar incision was lower in the separated versus parallel group (31% vs 57%; P = 0.027).

CONCLUSIONS

Separation of the laparoscopic camera cord from the active electrode cord decreases thermal injury from antenna coupling at the camera trocar incision in comparison to the parallel orientation of these cords. Therefore, parallel orientation of these cords (an arrangement promoted by integrated operating rooms) should be abandoned. The findings of this study should influence the operating room setup for all laparoscopic cases.

Optical design and system engineering of a multiresolution foveated laparoscope

The trade-off between the spatial resolution and field of view is one major limitation of state-of-the-art laparoscopes. In order to address this limitation, we demonstrated a multiresolution foveated laparoscope (MRFL) which is capable of simultaneously capturing both a wide-angle overview for situational awareness and a high-resolution zoomed-in view for accurate surgical operation. In this paper, we focus on presenting the optical design and system engineering process for developing the MRFL prototype. More specifically, the first-order specifications and properties of the optical system are discussed, followed by a detailed discussion on the optical design strategy and procedures of each subsystem. The optical performance of the final system, including diffraction efficiency, tolerance analysis, stray light and ghost image, is fully analyzed. Finally, the prototype assembly process and the final prototype are demonstrated.

Continuously zoom imaging probe for the multi-resolution foveated laparoscope

In modern minimally invasive surgeries (MIS), standard laparoscopes suffer from the tradeoff between the spatial resolution and field of view (FOV). The inability of simultaneously acquiring high-resolution images for accurate operation and wide-angle overviews for situational awareness limits the efficiency and outcome of the MIS. A dual view multi-resolution foveated laparoscope (MRFL) which can simultaneously provide the surgeon with a high-resolution view as well as a wide-angle overview was proposed and demonstrated to have great potential for improving the MIS. Although experiment results demonstrated the high-magnification probe has an adequate magnification for viewing surgical details, the dual-view MRFL is limited to two fixed levels of magnifications. A fine adjustment of the magnification is highly desired for obtaining high resolution images with desired field coverage. In this paper, a high magnification probe with continuous zooming capability without any mechanical moving parts is demonstrated. By taking the advantages of two electrically tunable lenses, one for optical zoom and the other for image focus compensation, the optical magnification of the high-magnification probe varies from 2 × to 3 × compared with that of the wide-angle probe, while the focused object position stays the same as the wide-angle probe. The optical design and the tunable lens analysis are presented, followed by prototype demonstration.

Antenna coupling explains unintended thermal injury caused by common operating room monitoring devices

INTRODUCTION

Unintended thermal injury from patient monitoring devices (eg, electrocardiogram pads, neuromonitoring leads) results in third-degree burns. A mechanism for these injuries is not clear. The monopolar "bovie" emits radiofrequency energy that transfers to nearby, nonelectrically active cables or wires without direct contact by capacitive and antenna coupling. The purpose of this study was to determine if, and to what extent, radiofrequency energy couples to common patient monitoring devices.

MATERIALS AND METHODS

In an ex vivo porcine model, monopolar radiofrequency energy was delivered to a handheld "bovie" pencil. Nonelectrically active neuromonitoring and cardiac-monitoring leads were placed in proximity to the monopolar pencil and its cord. Temperature changes of tissue touched by the monitoring lead were measured using a thermal camera immediately after a 5-second activation. The energy-device cords were then separated by 15 cm, the power was reduced from 30 W coag to 15 W coag and different cord angulation was tested. An advanced bipolar device, a plasma-based device, and an ultrasonic device were also tested at standard settings.

RESULTS

The neuromonitoring lead increased tissue temperature at the insertion site by 39 ± 13°C (P<0.001) creating visible char at the skin. The electrocardiogram lead raised tissue temperature by 1.3 ± 0.5°C (P<0.001). Decreasing generator power from 30 W to 15 W and separating the bovie cord from the neuromonitoring cord by 15 cm significantly reduced the temperature change (39 ± 13°C vs. 26±5°C; P<0.001 and 39 ± 13°C vs. 10 ± 5°C; P<0.001, respectively). Lastly, monopolar energy increased tissue temperatures significantly more than argon beam energy (34 ± 15°C), advanced bipolar energy (0.2 ± 0.4°C), and ultrasonic energy (0 ± 0.3°C) (all P<0.001).

CONCLUSIONS

Stray energy couples to commonly used patient monitoring devices resulting in potentially significant thermal injury. The handheld bovie cord transfers energy via antenna coupling to neuromonitoring leads that can raise tissue temperatures over 100°F (39°C) using standard settings. The most effective ways to decrease this energy coupling is to reduce generator power, increase the separation between wires, or utilize lower voltage energy devices such as ultrasonic or bipolar energy.

Insulation failure in electrosurgery instrumentation: a prospective evaluation

BACKGROUND

The use of electrosurgery has expanded to a wide variety of surgical specialities, but it has also been accompanied by its share of complications, including thermal injuries to nontargeted tissues, caused by a break or defect in the insulation of the instrument's coat. The purpose of this study was to determine the prevalence and the location of insulation failures (IFs) in electrosurgical instruments, then to assess the necessity of routine IF testing.

METHODS

Electrosurgical instruments were visually inspected and checked for IF using a high-voltage detector. Two different detectors were used during two testing sessions: DTU-6 (Petel company) and DIATEG (Morgate company). Laparoscopic and non-laparoscopic instruments were determined to have IF if current crossed the instrument's insulation, signaled by an alarm sound.

RESULTS

A total of 489 instruments were tested. The overall prevalence of IFs was 24.1 % with only visual inspection and 37.2 % with the IF detector. Among the 489 instruments, 13.1 % were visually intact, but had an electric test failure. DTU-6 and DIATEG detectors showed comparable efficiency in detection of overall IFs and for laparoscopic and non-laparoscopic instruments. The median location of IFs was more pronounced for laparoscopic instruments (50.4 %) and the distal location for non-laparoscopic instruments (40.4 %).

CONCLUSION

Accidental burns are a hidden problem and can lead to patient complications. In Central Sterilization Service Department, prevention currently includes only visual control of electrosurgery instrumentation, but testing campaigns are now necessary in order to identify maximum instruments' defects.

Application of platelet rich fibrin for management of an electrosurge induced osteonecrosis involving maxillary alveolus

BACKGROUND

Application of principles of electrocautery for hemostasis dates back to prehistoric times. Its modern implementation in various fields of general and head and neck surgeries have been well documented. However its usage in minor oral surgical procedures has gained popularity only recently. Complications associated with electro-surgery in the dental field are relatively rare and there is insufficient literature on its management.

CASE REPORT

We present a case report on management of an electrosurgery induced osteonecrosis involving maxillary alveolus of left premolars.

DISCUSSION

Inadvertent contact of the electrosurgery tip on bone can result in necrosis making it necessary to remove the sequestrum and graft the defect. Platelet rich fibrin in combination with bone grafts have been well documented to provide successful periodontal regeneration.

CLINICAL IMPLICATIONS

Our aim of presenting this report is to create awareness among the health care providers regarding electrosurgical injuries. To our knowledge, this is the first time platelet rich fibrin has been used in the management of intraoral electrosurgical injury. Combining bone grafts with platelet rich fibrin is a good alternative as it can be done with relative ease and predictable outcome.