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The use of high-frequency (HF) generators for HF surgical treatment of biological tissue has become an indispensable part of today's surgical applications of all kinds. Generally, HF alternating electric currents between 300 kHz and 1 MHz are used to induce hemostasis by heating at the cellular level. This effect can be attributed to Joule heating, in which a current dissipated conductor converts the electrical energy into thermal energy. However, sound evidence on the reliability and effectiveness of application-specific HF generator modes is not sufficiently available. Usually, the evidence takes place empirically by means of preclinical or clinical studies. Nevertheless, a corresponding empirical data collection is time- and cost-intensive. Therefore, physiological and statistical modeling provides the opportunity to relate tissue response to the applied electrical energy to obtain a prediction of the tissue reaction. In this contribution, we establish a monopolar coagulation model of an already well-known model approach based on Pennes bioheat equation. Additionally, the vaporization of tissue water at the water boiling point is considered. Furthermore, a variation of temperature-dependent tissue parameters was performed to analyze their impact on the model output. The simulation results demonstrate that the initial electrical conductivity has the greatest influence on the temperature distribution as well as on the time until the tissue temperature reached the boiling point of water. In contrast, the tissue water content has the least impact on the model output. Depending on the desired coagulation effect, HF power control as a function of electrical conductivity or its reciprocal, tissue resistance, must be added next in an improved model.

Laparoscopic cyst enucleation has its advantages and limitations in treatment of gastrointestinal tract (GIT) duplications. It allows to avoid bowel resection in such locations as ileocecal valve. We introduced laparoscopic cyst enucleation with further bowel plasty using cyst muscle layer and without monopolar coagulation, for cyst dissection we used straight scissors. Our study included 20 children with GIT duplications, who underwent cyst enucleation from 2018 to 2021. Laparoscopy was performed in all cases with various cyst locations (stomach – 2, duodenum – 3, small bowel – 14, ileocecal area – 1). Mean age of surgery was 40 ± 35,3 days (min 6 days, max 150 days). Mean operation time was 84,4 ± 27,35 min (min – 40 min, max – 160 min). We had no intraoperative complications. All patients received parenteral feeding for 3–5 days after the operation. Postoperative complications occurred in 3 cases: bowel perforation which required enterostomy (10%) and bowel volvulus required resection (5%). To our opinion, perforations occurred due to monopolar coagulation used for cyst enucleation in these children. No complications were observed in patients who underwent enucleation by straight scissors. Mean postoperative hospital stay was 15.6 ± 10.48 days (min – 4 days, max – 58 days). We observed neither stenosis nor any other complications in the long-term follow-up. Laparoscopic cyst enucleation is a feasible and safe approach for GIT duplications. It allows to avoid bowel resection, and the use of straight scissors instead of monopolar coagulation provides less postoperative complications such as perforation. III. • The laparoscopy cyst enucleation is not a wide spread method due to a high level of complications occurrence. • The laparoscopy cyst enucleation is by straight scissors with closing the cyst bed by cyst muscle layer is a feasible and safe method. • The routine ultrasound examination reveals duplication cysts before complications manifested. [ABSTRACT FROM AUTHOR]

A three-dimensional (3-D) electrothermal coupled finite element (FE) model was used to simulate and analyze the effects of the electrosurgical power-on setting on the temperature distribution and thermal damage in biological tissue during coagulation. The discussed parameters include the power-on–off durations, contact distance between the electrosurgical blade and tissue surface, and inclination angle of the blade during cutting. The results indicate that under the condition of a constant input electrical energy, the maximal temperature decreased when the power-on time was shortened and the power-off (pause) duration was increased. The two contact distances between the blade and tissue (0 and 0.25 mm) did not show a significant temperature difference; however, the tissue temperature increased with increasing blade inclination angle. We concluded that using a normal cut angle and set at a multiple shorter-time power-on with intermittent power-off operation procedure can reduce the risk of thermal damage during monopolar electrosurgery. [ABSTRACT FROM AUTHOR]

Background: Gold standard treatment of symptomatic cholelithiatis is laparoscopic cholicystectomy. No doubt, some minor biliary complication may occur by using monopolar hook,that is because of its thermal effect. In other way,use of ultrasonically activated harmonic scalpel,ie, (Ethicon Endo Surgery INC-Johnson & Johnson Medical SPA, Somerville, NJ) in laparoscopic cholecystectomies is increasing day bye day,for the purpose of dissecting gallbladder,vessels, and the cystic duct, because it reduces the risk of thermal injuries at operative field. Patients and Methods: This Comparative Study was conducted in surgical department of Ghulam Muhammad Mahar Medical Collage Hospital and Hira Medical Centre Sukkur during a period of last two years from july 2009 to june 2011. In duration of 2-years, we selected 92 patients, in which the, division and dissection of the cystic artery and duct is wholy soly done by Harmonic scalpal. We compared this group of patients with the data of a homogenous control group of patients, in which monopolar electrodiathermy and clips were used, in respect of average length of hospital stay, surgical time duration, and post operative complication. Results: Harmonic scalpel usage in surgery results shorter operative time but, there is no significant difference between operative and post operative complication in both group of patients. Conclusion: Harmonic scalpel has multiple function (coagulation, cutting, coaptation, and cavitation), so it is safe, effective and reliable instrument for gallblader surgery, specially in complicated cases. By using this instrument, you can save opertive time, anaesthesia time, operation theatre booking time, and operative as well as post operative complication. [ABSTRACT FROM AUTHOR]

Abstract: Many authors emphasize the advantages of laparoscopic techniques in their experience, including the excellent cosmetic results, reduced postoperative pain, rapid functional recovery, lower incidence of adhesions, wound infections and believe that laparoscopic appendectomy is a reliable operation for treating acute appendicitis. Laparoscopic appendectomy has become a standard procedure in the treatment of acute appendicitis in our department since it was introduced in 2003. There are 414 patients underwent laparoscopic appendectomy and 37 patients underwent open appendectomy in our department in 2008. More than 2000 laparoscopic appendectomies were performed in our department during 2003–2009. However, open appendectomy is still the standard procedure in many Taiwan and worldwide hospitals. One of the reasons is that the operating costs incurred for laparoscopic appendectomy are higher than that of open appendectomy. We describe, herein, an access technique utilizing existing instrumentation that is reliable and easy. [Copyright &y& Elsevier]