Effect of Cold Versus Hot Snare Polypectomy on Colon Postpolypectomy Bleeding in Patients with End-Stage Renal Disease: A Retrospective Cohort Study.

BACKGROUND: Patients with end-stage renal disease (ESRD) who undergo polypectomy may experience postpolypectomy bleeding. To reduce the risk of delayed postpolypectomy bleeding among the general population, cold snare polypectomy (CSP) is recommended for removing colon polyps smaller than 1 cm. Nevertheless, only few studies have examined the effect of CSP on patients with ESRD. METHODS: We retrospectively analyzed the data of patients with ESRD who underwent colonoscopic polypectomy for polyps larger than 5 mm at a Taiwanese university hospital from January 2014 to January 2023. The main outcome was delayed postpolypectomy bleeding within 30 days. Multivariate analysis was conducted to adjust for major confounders. RESULTS: A total of 557 patients with ESRD underwent colonoscopic polypectomy during the study period: 201 underwent CSP and 356 underwent hot snare polypectomy (HSP). Delayed postpolypectomy bleeding occurred in 27 patients (4.8%). The rate of delayed postpolypectomy bleeding was lower in patients with ESRD who underwent CSP than in those who underwent HSP (1.9% vs. 6.4%, P = 0.022). The percentage of patients who did not experience postpolypectomy bleeding within 30 days after CSP remained lower than that observed after HSP (P = 0.019, log-rank test). Multivariate analysis demonstrated immediate postpolypectomy bleeding and HSP to be independent risk factors for delayed postpolypectomy bleeding. A nomogram prognostic model was used to predict the potential of delayed postpolypectomy bleeding within 30 days in patients with ESRD. CONCLUSIONS: Compared with HSP, CSP is more effective in mitigating the risk of delayed postpolypectomy bleeding in patients with ESRD.

Precise application of topical tranexamic acid to enhance endoscopic hemostasis for peptic ulcer bleeding: a randomized controlled study (with video).

BACKGROUND AND AIMS: Peptic ulcer recurrent bleeding occurs in 20% to 30% of patients after standard endoscopic hemostasis, particularly within 4 days after the procedure. The application of additional tranexamic acid (TXA) to the ulcer may enhance hemostasis. This study investigated the effectiveness of TXA powder application on bleeding ulcers during endoscopic hemostasis. METHODS: This study enrolled patients who had peptic ulcer bleeding between March 2022 and February 2023. After undergoing standard endoscopic therapy, the patients were randomly assigned to either the TXA group or the standard group. In the TXA group, an additional 1.25 g of TXA powder was sprayed endoscopically on the ulcer. Both groups then received 3 days of high-dose (8 mg/h) continuous infusion proton pump inhibitor therapy. Second-look endoscopy was conducted on days 3 to 4. The primary end point of early treatment failure was defined as ulcer recurrent bleeding within 4 days or major stigmata of recent hemorrhage on the second-look endoscopy. RESULTS: Sixty patients (30 in each group) with peptic ulcer bleeding and balanced baseline characteristics were randomly assigned to a treatment group. The early treatment failure rate was lower in the TXA group (6.7%) than in the standard group (30%) (P = .042). The freedom from treatment failure periods for 4 and 28 days was significantly longer in the TXA group than in the standard group (P = .023). No adverse events from TXA were recorded. CONCLUSIONS: The precise delivery of topical TXA alongside standard endoscopic hemostasis reduced the early treatment failure rate in patients with bleeding peptic ulcers. (Clinical trial registration number: NCT05248321.).

Safety and effectiveness of new embolization microspheres SCBRM for intermediate-stage hepatocellular carcinoma: A feasibility study.

Transarterial chemoembolization (TACE) is, currently, the recommended treatment for hepatocellular carcinoma (HCC). However, long-term chemoembolization triggers the inflammatory response and may lead to postembolization syndrome (PES). Although several types of degradable microspheres have been developed to reduce drug toxicity and PES incidence, the clinical outcomes remain unsatisfactory. Previously, we have developed a new type of spherical, calibrated, biodegradable, radiopaque microspheres (SCBRM) and demonstrated their safety and efficacy in a pig model. Thus, the goal of this feasibility study was to determine the clinical safety and efficacy of the new SCBRM in intermediate-stage HCC patients. In this study, 12 intermediate-stage HCC patients underwent TACE using SCBRM with a calibrated size of 100-250 µm. The disease control rates at 1 month and 3 months after TACE-SCBRM treatment were 100% and 75.0%, respectively. The objective response rates at 1 month and 3 months after treatment were 66.7% and 58.3%, respectively. Very few adverse events were observed with one patient developing nausea. One day after the treatment, alanine aminotransferase, alanine aminotransferase, and total bilirubin levels were slightly elevated in the patients, but all returned to baseline on day 7. The median and mean overall survival times were 33 months (interquartile range, 12.8-42.0) and 29.2 ± 14.3 months, respectively. The 1-year and 2-year survival rates were 91.7% and 58.3%, respectively. In conclusion, TACE with the new SCBRM microspheres is clinically safe and effective, and it represents a promising approach in the management of intermediate-stage HCC.

Mechanism of Artesunate in Reversing Epithelial-mesenchymal Transition and Akt /Snail Signaling Pathway in Colorectal Carcinoma / 中国实验方剂学杂志

Objective:To investigate the effects of artesunate （ART） on epithelial-mesenchymal transformation （EMT） of colorectal cancer HCT-8 cells，and explore the effects of ART on cell migration，invasion，EMT ability， and protein kinase B （Akt）/Snail signaling pathway of colorectal cancer. Method:3-（4-5-Dimethylthiazol-2-yl）2，5-diphenyltetrazolium bromide （MTT） assay was used to detect the effects of ART at different concentrations on the proliferation of HCT-8 cells. Wound healing assay and Transwell assay were used respectively to detect the effects of ART on migration and invasion of colorectal cancer cells. The effects of different concentrations of ART on the distribution of EMT-related proteins vimentin and E-cadherin in HCT-8 cells were detected by double-immunofluorescent staining. The effects of ART on protein expression levels of EMT markers E-cadherin，vimentin and N-cadherin in HCT-8 cells and the expression of Akt1， p-Akt1， and Snail1 in the Akt/Snail signaling pathway were determined by Western blot. Result:The dose-dependent inhibitory effects of ART on the proliferation of HCT-8 cells were determined and the inhibition rate was calculated. A dose-response curve was plotted accordingly. The half-maximal inhibitory concentration （IC₅₀） of ART on HCT-8 cells was （16.67±1.95） μmol·L^-1. The following four groups were set up： a control group （0 μmol·L^-1），and low-， medium-， and high-dose ART groups（2， 10， 50 μmol·L^-1）. Compared with the results in the control group，ART inhibited the migration and invasion of HCT-8 cells（<italic>P</italic><0.05）. Specifically， the expression of E-cadherin in HCT-8 cells was significantly up-regulated，and that of vimentin and N-cadherin was significantly down-regulated （<italic>P</italic><0.05）. The expression levels of p-Akt1 and Snail1 were significantly decreased after ART treatment，thus inhibiting EMT（<italic>P</italic><0.05）. Conclusion:The findings of this study suggested that ART inhibited the EMT-triggered migration and invasion of HCT-8 cells presumedly by inhibiting the activation of the Akt/Snail pathway to reverse EMT.

Evaluation Efficacy of Rhenium-188-Loaded Micro-particles for Radiotherapy in a Mouse Model of Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is one of the leading causes of mortality worldwide. The aim of the present study was to evaluate the distribution and the therapeutic effect of 188Re-Tin-colloid micro-particles in subcutaneous HCC-bearing mice. The synthesis and characterization of micro-particles labeled with the 188Re isotope were performed. The micro-particles were injected into the tumor site subcutaneously in the BNL HCC-bearing mice with three treatment groups, normal saline, 188Re micro-particles, and 188Re-Tin-colloid micro-particles. The results of biodistribution showed that major radioactivity (188Re) of 188Re-Tin-colloid micro-particles (18.69 ± 4.28 %ID/g) remained at the tumor sites, compared with 188Re micro-particles (0.21 ± 0.12 %ID/g), 24 h post injection. Following the injection of 188Re-Tin-colloid micro-particles for 14 days, all BNL tumors in mice were regressed during the observation period. By contrast, all of the mice treated with normal saline or 188Re micro-particles had died by 24 and 28 days, respectively. The 188Re-Tin-colloid micro-particles demonstrated high accumulation and therapeutic potential in the subcutaneous HCC-bearing mice.

Hepatocellular carcinoma-related cyclin D1 is selectively regulated by autophagy degradation system.

Dysfunction of degradation machineries causes cancers, including hepatocellular carcinoma (HCC). Overexpression of cyclin D1 in HCC has been reported. We previously reported that autophagy preferentially recruits and degrades the oncogenic microRNA (miR)-224 to prevent HCC. Therefore, in the present study, we attempted to clarify whether cyclin D1 is another oncogenic factor selectively regulated by autophagy in HCC tumorigenesis. Initially, we found an inverse correlation between low autophagic activity and high cyclin D1 expression in tumors of 147 HCC patients and three murine models, and these results taken together revealed a correlation with poor overall survival of HCC patients, indicating the importance of these two events in HCC development. We found that increased autophagic activity leads to cyclin D1 ubiquitination and selective recruitment to the autophagosome (AP) mediated by a specific receptor, sequestosome 1 (SQSTM1), followed by fusion with lysosome and degradation. Autophagy-selective degradation of ubiquitinated cyclin D1 through SQSTM1 was confirmed using cyclin D1/ubiquitin binding site (K33-238 R) and phosphorylation site (T286A) mutants, lentivirus-mediated silencing autophagy-related 5 (ATG5), autophagy-related 7 (ATG7), and Sqstm1 knockout cells. Functional studies revealed that autophagy-selective degradation of cyclin D1 plays suppressive roles in cell proliferation, colony, and liver tumor formation. Notably, an increase of autophagic activity by pharmacological inducers (amiodarone and rapamycin) significantly suppressed tumor growth in both the orthotopic liver tumor and subcutaneous tumor xenograft models. Our findings provide evidence of the underlying mechanism involved in the regulation of cyclin D1 by selective autophagy to prevent tumor formation. CONCLUSION: Taken together, our data demonstrate that autophagic degradation machinery and the cell-cycle regulator, cyclin D1, are linked to HCC tumorigenesis. We believe these findings may be of value in the development of alternative therapeutics for HCC patients. (Hepatology 2018;68:141-154).

A magnetic induction heating system with multi-cascaded coils and adjustable magnetic circuit for hyperthermia.

Based on the characteristics of cancer cells that cannot survive in an environment with temperature over 42 °C, a magnetic induction heating system for cancer treatment is developed in this work. First, the methods and analyses for designing the multi-cascaded coils magnetic induction hyperthermia system are proposed, such as internal impedance measurement of power generator, impedance matching of coils, and analysis of the system. Besides, characteristics of the system are simulated by a full-wave package for engineering optimization. Furthermore, by considering the safety factor of patients, a two-sectional needle is designed for hyperthermia. Finally, this system is employed to test the liver of swine in ex-vivo experiments, and through Hematoxylin and Eosin (H&E) stain and NADPH oxidase activity assay, the feasibility of this system is verified.

Hemostasis Plug for an Electromagnetic Thermotherapy and Its Application for Liver Laceration.

Accident-induced liver trauma is a significant human health concern, as this organ is readily injured during periods at which the abdominal region is compromised. In this work, electromagnetic thermotherapy was successfully developed and employed in vitro and in vivo to treat livers that had been lacerated. Briefly, a new hemostasis plug was integrated with an electromagnetic thermotherapy system (ETS) to perform surgery on lacerated livers. The high-frequency, alternating electromagnetic field (EMF) was generated by the ETS and was shown to induce a pre-set temperature increase within the hemostasis plug embedded in the target tissue. In order to prevent overheating and maintain a constant hemostasis temperature, a temperature feedback control system was utilized. The effect of the intensity of the EMF on the heating capacity of the ETS-hemostasis system was first explored. Furthermore, the relationship between the coagulation zone and operating temperature were investigated in vitro. By utilizing the temperature feedback control system, the hemostasis plug could be heated to a specific temperature for efficient hemostasis. With this approach, the optimal treatment temperature and time were investigated for liver laceration. Lacerated livers from New Zealand white rabbits were successfully treated with the hemostasis plug and ETS within a short period of time. When compared with the traditional perihepatic packing approach, the volume of blood loss from liver laceration surgeries treated by ETS has been dramatically reduced by 83%, suggesting a high therapeutic potential for this system.

Development of biodegradable radiopaque microsphere for arterial embolization-a pig study.

AIM: To develop a new type of calibrated, biodegradable, and imaging detectable microsphere and evaluated its embolization safety and efficacy on pig's liver and spleen. METHODS: Six kinds of pharmaceutical excipient were combined and atomized to form our microsphere. Twenty-four male Lanyu pigs weighing 25-30 kg were used. The arteries of spleen and liver were embolized with Gelfoam, Embosphere, or our microsphere. The serum biochemical tests, computed tomography (CT), liver perfusion scan, and tissue microscopy examination were done to evaluate the safety and efficacy of embolization. RESULTS: Radiopaque microspheres with a size ranging from 300 to 400 µm were produced. Embolization of hepatic and splenic artery of pigs with our microsphere significantly reduced the blood flow of liver and resulted in splenic infarction. The follow-up CT imaging and the microscopic examination showed intraarterial degradation of Gelfoam and microsphere. The blood tests demonstrated insignificant changes with regards to liver and renal functions. CONCLUSION: Our microspheres, with the unique characteristics, can be used for transcatheter arterial embolization with effects equivalent to or better than Gelfoam and Embosphere in pigs.

Transarterial chemoembolization using gelatin sponges or microspheres plus lipiodol-doxorubicin versus doxorubicin-loaded beads for the treatment of hepatocellular carcinoma.

OBJECTIVE: To retrospectively compare treatment of hepatocellular carcinoma (HCC) with transarterial chemoembolization (TACE) using gelatin sponges or microspheres plus lipiodol-doxorubicin vs. doxorubicin-loaded drug-eluting beads (DEB). MATERIALS AND METHODS: A total of 158 patients with HCC received TACE from November 2010 to November 2011 were enrolled in this study, including 64 (40.5%) received TACE with lipiodol-doxorubicin and gelatin sponges (group A), 41 (25.9%) received TACE with lipiodol-doxorubicin and microspheres (group B), and 53 (33.5%) received TACE with doxorubicin-loaded DEB (group C). Tumor response and adverse events (AEs) were evaluated. RESULTS: No significant difference was found at baseline among the three groups. The doxorubicin dosage in group C was significantly (p < 0.001) higher compared to the dose used in groups A or B (median, 50 mg vs. 31 mg or 25 mg). Significantly (p < 0.001) more patients in group C achieved complete response compared to those in groups A or B (32.1% vs. 6.3% or 2.4%). Significantly (p < 0.001) less patients in group C had progressive disease compared to those in groups A or B (34.0% vs. 57.8% or 68.3%). Minor AEs were more common in groups A and B compared to group C, with rates of 54.7%, 34.1%, and 5.7%, respectively. CONCLUSION: In patients with HCC, TACE with DEB offers better safety and efficacy profiles compared to either TACE with gelatin sponges or TACE with microspheres.

Preparation and therapeutic evaluation of (188)Re-thermogelling emulsion in rat model of hepatocellular carcinoma.

Radiolabeled Lipiodol(®) (Guerbet, Villepinte, France) is routinely used in hepatoma therapy. The temperature-sensitive hydrogel polyethylene glycol-b-poly-DL-lactic acid-co-glycolic acid-b-polyethylene glycol triblock copolymer is used as an embolic agent and sustained drug release system. This study attempted to combine the polyethylene glycol-b-poly-DL-lactic acid-co-glycolic acid-b-polyethylene glycol hydrogel and radio-labeled Lipiodol to form a new radio-thermogelling emulsion, rhenium-188-N,N'-1,2-ethanediylbis-L-cysteine diethyl-ester dihydrochloride-Lipiodol/hydrogel ((188)Re-ELH). The therapeutic potential of (188)Re-ELH was evaluated in a rodent hepatoma model. Rhenium-188 chelated with N,N'-1,2-ethanediylbis-L-cysteine diethyl-ester dihydrochloride was extracted with Lipiodol to obtain rhenium-188-N,N'-1,2-ethanediylbis-L-cysteine diethyl-ester dihydrochloride-Lipiodol ((188)Re-EL), which was blended with the hydrogel in equal volumes to develop (188)Re-ELH. The (188)Re-ELH phase stability was evaluated at different temperatures. Biodistribution patterns and micro-single-photon emission computed tomography/computed tomography images in Sprague Dawley rats implanted with the rat hepatoma cell line N1-S1 were observed after in situ tumoral injection of ~3.7 MBq (188)Re-ELH. The therapeutic potential of (188)Re-EL (48.58±3.86 MBq/0.1 mL, n=12) was evaluated in a 2-month survival study using the same animal model. The therapeutic effects of (188)Re-ELH (25.52±4.64 MBq/0.1 mL, n=12) were evaluated and compared with those of (188)Re-EL. The responses were assessed by changes in tumor size and survival rates. The (188)Re-ELH emulsion was stable in the gel form at 25°C-35°C for >52 hours. Biodistribution data and micro-single-photon emission computed tomography/computed tomography images of the (188)Re-ELH group indicated that most activity was selectively observed in hepatomas. Long-term (188)Re-ELH studies have demonstrated protracted reductions in tumor volumes and positive effects on the survival rates (75%) of N1-S1 hepatoma-bearing rats. Conversely, the 2-month survival rate was 13% in the control sham group. Therapeutic responses differed significantly between the two groups (P<0.005). Thus, the hydrogel enhanced the injection stability of (188)Re-EL in an animal hepatoma model. Given the synergistic results, direct (188)Re-ELH intratumoral injection is a potential therapeutic alternative for hepatoma treatment.

Electromagnetic thermotherapy for deep organ ablation by using a needle array under a synchronized-coil system.

Thermal ablation by using electromagnetic thermotherapy (EMT) has been a promising cancer modality in recent years. It has relatively few side effects and has therefore been extensively investigated for a variety of medical applications in internal medicine and surgery. The EMT system applies a high-frequency alternating electromagnetic field to heat up the needles which are inserted into the target tumor to cause tumor ablation. In this study, a new synchronized-coil EMT system was demonstrated, which was equipped with two synchronized coils and magnetic field generators to provide a long-range, penetrated electromagnetic field to effectively heat up the needles. The heating effect of the needles at the center of the two coils was first explored. The newly designed two-section needle array combined with the synchronized-coil EMT system was thus demonstrated in the in vitro and in vivo animal experiments. Experimental data showed that the developed system is promising for minimally invasive surgery since it might provide superior performance for thermotherapy in cancer treatment.

Autophagy-preferential degradation of MIR224 participates in hepatocellular carcinoma tumorigenesis.

Autophagy and microRNA (miRNA) are important regulators during cancer cell tumorigenesis. Impaired autophagy and high expression of the oncogenic microRNA MIR224 are prevalent in hepatocellular carcinoma (HCC); however, the relationship between the 2 phenomena remains elusive. In this study, we are the first to reveal that autophagy selectively regulates MIR224 expression through an autophagosome-mediated degradation system. Based on this finding, we further demonstrated that in hepatitis B virus (HBV)-related HCC, aberrant autophagy (low autophagic activity) results in accumulation of MIR224 and decreased expression of the target gene Smad4, which leads to increased cell migration and tumor formation. Preferential recruitment of MIR224 into the autophagosome was clearly demonstrated by a) miRNA in situ hybridization under confocal microscopy, and b) immunogold labeling of MIR224 under electron microscopy compared with a ubiquitously expressed microRNA MIRlet7e/let-7. Furthermore, we found that off-label use of amiodarone, an antiarrhythmic agent, effectively suppressed HCC tumorigenesis through autophagy-mediated MIR224 degradation both in vitro and in vivo. In summary, we identified amiodarone as a new autophagy inducer, which may provide an alternative approach in HCC therapy through a novel tumor suppression mechanism.

Electromagnetic thermotherapy system with needle arrays: a practical tool for the removal of cancerous tumors.

Thermotherapy has been a promising method to treat tumor. In recent years, electromagnetic thermotherapy (EMT) has been extensively investigated and holds the potential for a variety of medical applications including for cancer treatment when combined with minimally invasive surgery approach. In this study, an alternating electromagnetic frequency was provided by an EMT system to heat up stainless steel needle arrays which were inserted into the target tumor to a high temperature, therefore leading to local ablation of the tumor. A new two-section needle-array apparatus was further demonstrated to encompass the tumor to prevent the tumor cells to spread after the treatment process. By using the needle-array insertion apparatus, there is no limitation of the treatment area; this method could, therefore, be applied for tumors that are larger than 6 cm. It was first successfully demonstrated in the in vitro experiments on porcine livers. Then an in vivo experiment was directly conducted on pigs. The two-section needle array incorporated with the needle-array apparatus and EMT was demonstrated to be promising for no-touch isolation treatment of cancerous tumors.

An electromagnetic thermotherapy system with a deep penetration depth for percutaneous thermal ablation.

Thermal ablation has been a promising method to remove the cancerous tissues. Electromagnetic-based thermotherapy has been extensively investigated for a variety of medical applications recently. In this study, a prototype electromagnetic thermotherapy system has been developed with a new coil design and a two-section needle. The coil can generate an alternating electromagnetic field (EMF) with a deep penetration depth to remotely heat the needle which is located up to 15 cm away, enabling percutaneous thermal ablation. Several important parameters, including the heating effects of the needle at different positions, the intensity of the EMF and the induced temperature distribution on the surrounding tissue, are first explored. An in vitro animal experiment has also been performed which shows EMF-induced ablation in a porcine liver by the needle. Furthermore, an in vivo experiment on an animal model (a New Zealand white rabbit) is also conducted in the study. Thus, the two-section needle combined with the coil-generated EMF has been demonstrated to be a promising thermotherapy system for percutaneous thermal ablation.

Autophagy suppresses tumorigenesis of hepatitis B virus-associated hepatocellular carcinoma through degradation of microRNA-224.

UNLABELLED: In hepatocellular carcinoma (HCC), dysregulated expression of microRNA-224 (miR-224) and impaired autophagy have been reported separately. However, the relationship between them has not been explored. In this study we determined that autophagy is down-regulated and inversely correlated with miR-224 expression in hepatitis B virus (HBV)-associated HCC patient specimens. These results were confirmed in liver tumors of HBV X gene transgenic mice. Furthermore, miR-224 was preferentially recruited and degraded during autophagic progression demonstrated by real-time polymerase chain reaction and miRNA in situ hybridization electron microscopy after extraction of autophagosomes. Our in vitro study demonstrated that miR-224 played an oncogenic role in hepatoma cell migration and tumor formation through silencing its target gene Smad4. In HCC patients, the expression of low-Atg5, high-miR-224, and low-Smad4 showed significant correlation with HBV infection and a poor overall survival rate. Autophagy-mediated miR-224 degradation and liver tumor suppression were further confirmed by the autophagy inducer amiodarone and miR-224 antagonist using an orthotopic SD rat model. CONCLUSION: A noncanonical pathway links autophagy, miR-224, Smad4, and HBV-associated HCC. These findings open a new avenue for the treatment of HCC.

Using modern teaching strategies to teach upper abdominal sonography to medical students.

BACKGROUND: Upper abdominal sonography can help physicians to confirm the diagnosis of various hepatobiliary diseases. Teaching sonography skills to medical students is important because it may enhance their level of knowledge and overall development during their gastroenterology section rotation. Sonographic imaging is abstract and students can be easily confused when scanning the abdominal structures from different sites and directions. We used several modern teaching strategies to facilitate the learning of sonography skills. METHODS: The year five medical students beginning a gastroenterology section rotation for their first-year clerkship were taught abdominal sonography skills. Abstract sonographic images were related to concrete objects and the surrounding structures were further indicated. Each of the images was given a specific name and was sorted according to the scanning site. A mnemonics system was designed to help students to memorize the names of these images. A badge was created to recognize the achievement of being able to complete a basic upper abdominal sonography. Students were free (i.e., not obligated) to request a demonstration opportunity to show their skills within 2 weeks after receiving tutelage. We recorded the number of students who received training and were able to successfully complete the task; these individuals then received a badge to be pinned onto their white coats. RESULTS: Sixty-three of 68 students (92.6%) requested evaluation and all of them passed. CONCLUSION: We have greatly simplified the process of learning about upper abdominal sonography by using andragogy to enhance learning, mnemonics to help memory, and a pin-badge reward system to stimulate incentives.

Partial nephrectomy without renal ischemia using an electromagnetic thermal surgery system in a porcine model.

OBJECTIVE: To test the feasibility of partial nephrectomy using needle arrays under alternating current (AC) electromagnetic field without renal artery clamping. METHODS: We performed an experimental study for partial nephrectomy without renal artery clamping in a porcine model, comparing a new thermal surgery system consisting of an AC electromagnetic field generator and stainless steel needle arrays (using 10 pigs) vs an ultrasonic Harmonic Scalpel (on 8 pigs). Two cm of the upper pole of the kidneys were resected, and then the feasibility, operation time, blood loss, biochemical parameters, pathology, and complications were observed for 14 days. RESULTS: There was no difference by weight in the mean percentage of kidney removed between the 2 groups (8.1 ± 3.4% vs 12.7 ± 5.5%). The estimated blood loss for the partial nephrectomy with electromagnetic thermal surgery system was significantly less compared to the ultrasonic Harmonic Scalpel (53.0 ± 73.0 vs 188.8 ± 49.3 mL). Transection time was shorter with the electromagnetic thermal surgery system (10 vs 12 minutes). Bleeding from the cut surface after partial nephrectomy was noted in 2 pigs (electromagnetic surgery group) and 8 pigs (control group); all the bleeding was controlled with additional monopolar electrocoagulation and sutures. No urinoma was identified in either group when a second laparotomy was performed 2 weeks later. CONCLUSION: Our study of a partial nephrectomy in a porcine model demonstrates that the heat generated by the electromagnetic thermal surgery system is sufficient to coagulate renal parenchyma and to seal off the blood vessels without pedicle clamping.