Hepatic thermal injury promotes colorectal cancer engraftment in C57/black 6 mice.

Treatment options for liver metastases (primarily colorectal cancer) are limited by high recurrence rates and persistent tumor progression. Surgical approaches to management of these metastases typically use heat energy including electrocautery, argon beam coagulation, thermal ablation of surgical margins for hemostasis, and preemptive thermal ablation to prevent bleeding or to effect tumor destruction. Based on high rates of local recurrence, these studies assess whether local effects of hepatic thermal injury (HTI) might contribute to poor outcomes by promoting a hepatic microenvironment favorable for tumor engraftment or progression due to induction of procancer cytokines and deleterious immune infiltrates at the site of thermal injury. To test this hypothesis, an immunocompetent mouse model was developed wherein HTI was combined with concomitant intrasplenic injection of cells from a well-characterized MC38 colon carcinoma cell line. In this model, HTI resulted in a significant increase in engraftment and progression of MC38 tumors at the site of thermal injury. Furthermore, there were local increases in expression of messenger ribonucleic acid (mRNA) for hypoxia-inducible factor-1α (HIF1α), arginase-1, and vascular endothelial growth factor α and activation changes in recruited macrophages at the HTI site but not in untreated liver tissue. Inhibition of HIF1α following HTI significantly reduced discreet hepatic tumor development (P = 0.03). Taken together, these findings demonstrate that HTI creates a favorable local environment that is associated with protumorigenic activation of macrophages and implantation of circulating tumors. Discrete targeting of HIF1α signaling or inhibiting macrophages offers potential strategies for improving the outcome of surgical management of hepatic metastases where HTI is used.

Characteristics of Esophageal Injury in Ablation of Atrial Fibrillation Using a High-Power Short-Duration Setting.

BACKGROUND: The mechanism of esophageal thermal injury (ETI; esophageal mucosal injury and periesophageal nerve injury leading to gastric hypomotility) remains unknown when using a high-power short-duration (HP-SD) setting. This study sought to evaluate the characteristics of esophageal injuries in atrial fibrillation ablation using a HP-SD setting. METHODS: After exclusion of 5 patients with their esophagus at the right portion of left atrium and 21 patients with additional ablations such as box isolation and low voltage area ablation in left atrium posterior wall, 271 consecutive patients (62±10 years, 56 women) who underwent pulmonary vein isolation by radiofrequency catheter ablation were analyzed. In the 101 patients, a HP-SD setting at 45 to 50 W with an Ablation Index module was used (HP-SD group). In the remaining 170 patients before introduction of the HP-SD setting, a conventional power setting of 20 to 30 W with contact force monitoring was used (conventional group). We performed esophagogastroduodenoscopy after pulmonary vein isolation in all patients and investigated the incidence and characteristics of ETI. RESULTS: Although the incidence of ETI was significantly higher in the HP-SD group compared with the conventional group (37% versus 22%, P=0.011), the prevalence of esophageal lesions did not differ between the groups (7% versus 8%). Multivariate logistic regression analysis revealed that the use of the HP-SD setting (odds ratio, 6.09, P<0.001), and the parameters that suggest anatomic proximity surrounding the esophagus, were independent predictors of ETI. However, the majority of ETI in the HP-SD group was gastric hypomotility, and the thermal injury was limited to the shallow layer of the periesophageal wall using the HP-SD setting. CONCLUSIONS: Although the use of the HP-SD setting was a strong predictor of ETI, it could avoid deeper thermal injuries that reach the esophageal mucosal layer.

A Case Report of Heterotopic Ossification Caused by High-Voltage Electric Injury.

This case report described the diagnosis and treatment of a patient with ectopic bone injury due to high-pressure electric shock. A 24-year-old male patient suffered from burns that covered 50% of TBSA, including on limbs and torso, after coming into contact with 10-kV high-voltage electricity. A repeated Meek micrografting technique (MEEK) was applied for wound healing; skin grafts were cut into micrografts and expanded at a ratio of 1:4 to cover large areas after burn trauma. After the injury, right elbow redness, fever, pains, and joint movement disorder were reported by the patient, which might be attributed to excessive exercises and acute scarring. However, these symptoms were not treated immediately. Six months after the injury, his right elbow joint showed 90° locking and a restricted 5° movement capacity. X-ray examination revealed a new bone formation at the inner tibia shin. In addition, 3D CT showed the formation of right tibia, the ruler bone, and the skull of the humming bridge. Under general anesthesia, the right elbow joint was released, the medial collateral ligament was repaired, and the hinge external fixator was fixed. A large number of hyperplastic bone masses were found at the right elbow joint during surgery, specifically in the foot bone hawk's beak nest. No complications after surgery were observed. X-ray examination in February showed disappearance of the bone bridge and normal relationship of the right elbow joint. This case study revealed that electric shock injury could lead to ectopic bone formation, and much attention should be paid on any changes that indicate aseptic inflammation, such as redness, swelling, fever, and pain during the treatment process. Finally, identification of the scar constriction phase could indicate surgical treatment in order to promote the limb rehabilitation process.

Successful, Full-Thickness Skin Graft in a Bald Eagle (Haliaeetus leucocephalus).

A subadult, male bald eagle (Haliaeetus leucocephalus) was evaluated after being found unable to fly, with large eschars on the dorsal head and right stifle. Because of the appearance and location, the lesions were believed to be caused by an electrical injury. Treatment included oral antibiotics, nonsteroidal anti-inflammatory drugs, pain medication, surgical debridement of the eschars, and trephining of the affected inner table of the cranium. A full-thickness skin graft was performed to expedite wound healing and minimize holding time. After 6 weeks, the bird had new feather growth on its dorsal head and was released. This is the first report, to our knowledge, of a nonmesh, full-thickness skin graft in an avian species. Full-thickness skin grafts should be considered as a surgical option in juvenile or adult avian patients with large dorsal head wounds.

A Histologic Perspective on Electrical and Thermal Burn-Injured Human Skin.

OBJECTIVE: To analyze specific spectroscopic (FT-Raman) and thermal (limiting oxygen index) aspects of skin samples exposed to electrical injury compared with thermal injury. METHODS: An observational case-control study was conducted at the Dr Stanislaw Sakiel Center for Burns Treatment in Siemianowice, Silesia, Poland. A scanning electron microscope was used to diagnose and illustrate the topography of skin samples from electrical and thermal burns and the morphologic effects on damaged versus undamaged skin surfaces. In particular, researchers attempted to detect spectroscopic and thermal changes at the molecular level, namely, specific biomarkers of tissue degeneration and their regeneration under the influence of the applied modifiers (antioxidants and orthosilicic acid solutions). RESULTS: Modification with L-ascorbic acid and hydrogel of orthosilicic acid caused an increase in the intensity of the amide I Raman peaks, whereas modification with sodium ascorbate and orthosilicic acid resulted in the separation of the band protein side chains (1,440-1,448 cm), which is a part of tissue regeneration. The best result was obtained when the skin was treated with 7% orthosilicic acid (limiting oxygen index, 26%). CONCLUSIONS: Antioxidant treatment may be advantageous in minimizing injury in patients with thermal burns but not always in electrical burns.

Reconstruction of the Distal Leg and Foot Using Free Anterolateral Thigh Flaps in Patients With High-Voltage Electrical Burns.

In a patient with a high-voltage electrical burns, the extent of burning is greatest at the entrance and exit points of the electric current. As the exit point is usually the ankle and/or foot, these areas may be the most severely damaged. As local tissue is limited in this region, free tissue transfer is usually required for reconstruction. Eleven anterolateral thigh free flaps were placed for the reconstruction of foot and ankle defects caused by electrical burns. When the defects were large, we placed the flaps with two or three perforators. In six patients, recipient vessels were prepared in the trauma region or immediately adjacent thereto. Reconstructions were performed at an average of 23.18 days after the burns, and the average hospitalization time was 42.27 days. Patients with burns on the dorsum of the foot often required toe amputations. In patients who underwent direct reconstruction (without debridement), re-operations were required because of graft loss in other burnt areas. The foot and ankle are the regions most damaged by electrical burns. Vessels in the trauma zone or immediately proximal thereto can serve as recipient vessels. Even when the defect is sizeable, a large anterolateral thigh flap with multiple perforators can be harvested. No vascular problem was encountered during early or late reconstruction. The free flap is very reliable when used to reconstruct foot tissue defects caused by electrical burns.

The effect of oral N-acetylcystein on prevention of extensive tissue destruction in electrical burn injury.

BACKGROUND: Electric burn patients usually suffer permanent injury and sequelae. Salvage of the zone of stasis is an important topic in the treatment of burn patients. N-Acetylcysteine (NAC), as an antioxidant, has effect on the saving zone of stasis and extensive rhabdomyolisis. The aim of this study was therefore to evaluate the effect of oral NAC on tissue destruction indicators in an electric burn rat model. MATERIAL AND METHODS: An experimental study was conducted with thirty six male Wistar albino rats divided into 2 groups. Group A (n=18) and group B (n=18) were electrical burn injury groups without and with NAC therapy, respectively. The extent of burn wounds were evaluated by planimetry using a digital wound measuring device. Blood samples were obtained to analyze creatine kinase (CK) levels as a marker of extensive rhabdomiolysis on the first hour after electric injury (baseline) and on the 7th day to see the antioxidant effect of NAC. RESULTS: A significant decrease in tissue destruction was seen by the necrotic area on day 7 in the NAC therapy group compared to the control group (mean 2.26±1.05cm2 versus mean 7.12±3.30cm2 respectively; p=0.001), which was confirmed by the level of serum CK (day 7: group A, mean 140±51U/L versus Group B, mean 102±6U/L; p=0.007). CONCLUSION: A decrease in electric burn necrotic area and tissue damage in the group using NAC treatment was demonstrated. NAC might have a beneficial effect in the treatment of electrical burns. Further experimental and clinical studies with NAC treatment are necessary to confirm these results.

Targeted release of stromal cell-derived factor-1α by reactive oxygen species-sensitive nanoparticles results in bone marrow stromal cell chemotaxis and homing, and repair of vascular injury caused by electrical burns.

Rapid repair of vascular injury is an important prognostic factor for electrical burns. This repair is achieved mainly via stromal cell-derived factor (SDF)-1α promoting the mobilization, chemotaxis, homing, and targeted differentiation of bone marrow mesenchymal stem cells (BMSCs) into endothelial cells. Forming a concentration gradient from the site of local damage in the circulation is essential to the role of SDF-1α. In a previous study, we developed reactive oxygen species (ROS)-sensitive PPADT nanoparticles containing SDF-1α that could degrade in response to high concentration of ROS in tissue lesions, achieving the goal of targeted SDF-1α release. In the current study, a rat vascular injury model of electrical burns was used to evaluate the effects of targeted release of SDF-1α using PPADT nanoparticles on the chemotaxis of BMSCs and the repair of vascular injury. Continuous exposure to 220 V for 6 s could damage rat vascular endothelial cells, strip off the inner layer, significantly elevate the local level of ROS, and decrease the level of SDF-1α. After injection of Cy5-labeled SDF-1α-PPADT nanoparticles, the distribution of Cy5 fluorescence suggested that SDF-1α was distributed primarily at the injury site, and the local SDF-1α levels increased significantly. Seven days after injury with nanoparticles injection, aggregation of exogenous green fluorescent protein-labeled BMSCs at the injury site was observed. Ten days after injury, the endothelial cell arrangement was better organized and continuous, with relatively intact vascular morphology and more blood vessels. These results showed that SDF-1α-PPADT nanoparticles targeted the SDF-1α release at the site of injury, directing BMSC chemotaxis and homing, thereby promoting vascular repair in response to electrical burns.

Effect of Differing Parameters on Irreversible Electroporation in a Porcine Model.

INTRODUCTION AND OBJECTIVE: Irreversible electroporation (IRE) is a new ablative technology to treat small renal masses. We evaluated differed ablation settings on lesion size and temperature changes in a porcine model. MATERIALS AND METHODS: After Institutional Animal Care and Use Committee approval, 36 laparoscopy-guided and 16 open ablations were performed on 13 domestic female pigs. Ablation parameters studied were voltage (1000 V/cm, 1500 V/cm, or 2000 V/cm), probe exposure (1.0 or 1.5 cm), and lesion size over time (survival) (0-, 7-, or 14 day). Temperature changes were monitored during open ablations with differed settings. Gross lesion size was measured, and histologic analysis with hematoxylin and eosin and nicotinamide adenine dinucleotide staining was performed. RESULTS: The 1000 V/cm ablations had no gross or histologic lesions. A factorial analysis of variance demonstrated that day (p = 0.56), exposure (p = 0.33), and voltage (p = 0.06) did not demonstrate statistical significance for affecting lesion size. For 1.0 cm probe exposure, 2000 V/cm did more closely approximate expected lesion size (p = 0.02) compared with 1500 V/cm. While significance was not seen for 1.5 cm probe exposure, 2000 V/cm often exceeded expected lesion volume. Only 1 of 4 temperature sensors, located adjacent to one of the IRE probes, noted a significant increase with increased voltage. However, all maximum temperatures remained less than 70°C. CONCLUSIONS: Variation in lesion volume was seen with different ablation settings in this porcine model. Maximal energy and probe exposure settings should be utilized to ensure full coverage of target volume/mass, potentially without concern for thermal injury to renal collecting system or nearby structures.

Chronic Pseudomonas aeruginosa biofilm infection impairs murine S100A8/A9 and neutrophil effector cytokines-implications for delayed wound closure?

The impact of Pseudomonas aeruginosa biofilm infections in chronic wounds and clinical implication for healing is receiving increased attention. However, the pathophysiology of host/pathogen interplay is not fully understood. By further revealing the mechanisms, necessary new treatment strategies may be identified. Since the background for chronic wounds is diverse, representative animal models are important. We assessed host response and spontaneous wound closure in the relatively resistant C3H/HeN and the susceptible BALB/c mouse strain. Full-thickness burn wounds were inflicted in 108 mice. Pseudomonas aeruginosa biofilm (106 colony forming units) was injected subcutaneously in 72 mice, euthanised day 4, 7 or 10 days post-infection. Wounds were analysed for neutrophil host response markers: S100A8/A9, keratinocyte-derived chemokine and granulocyte-colony stimulating factor. Total peripheral blood leucocyte and polymorphonuclear count were assessed in parallel. Histopathology evaluated wound inflammatory burden. Photoplanimetry described macroscopical wound closure. Stable chronic wound infection was established in all challenged mice. Pseudomonas aeruginosa biofilm suppressed neutrophil host response in wounds. C3H/HeN mice achieved earlier systemic inflammatory control and healed faster than BALB/c mice. Pseudomonas aeruginosa biofilms perturb host defence thereby inducing a steady state of chronic infection which may impair wound healing. These results indicate therapeutic options for immune modulation of biofilm-infected wounds.

Stray energy transfer during endoscopy.

INTRODUCTION: Endoscopy is the standard tool for the evaluation and treatment of gastrointestinal disorders. While the risk of complication is low, the use of energy devices can increase complications by 100-fold. The mechanism of increased injury and presence of stray energy is unknown. The purpose of the study was to determine if stray energy transfer occurs during endoscopy and if so, to define strategies to minimize the risk of energy complications. METHODS AND PROCEDURES: A gastroscope was introduced into the stomach of an anesthetized pig. A monopolar generator delivered energy for 5 s to a snare without contacting tissue or the endoscope itself. The endoscope tip orientation, energy device type, power level, energy mode, and generator type were varied to mimic in vivo use. The primary outcome (stray current) was quantified as the change in tissue temperature (°C) from baseline at the tissue closest to the tip of the endoscope. Data were reported as mean ± standard deviation. RESULTS: Using the 60 W coag mode while changing the orientation of the endoscope tip, tissue temperature increased by 12.1 ± 3.5 °C nearest the camera lens (p < 0.001 vs. all others), 2.1 ± 0.8 °C nearest the light lens, and 1.7 ± 0.4 °C nearest the working channel. Measuring temperature at the camera lens, reducing power to 30 W (9.5 ± 0.8 °C) and 15 W (8.0 ± 0.8 °C) decreased stray energy transfer (p = 0.04 and p = 0.002, respectively) as did utilizing the low-voltage cut mode (6.6 ± 0.5 °C, p < 0.001). An impedance-monitoring generator significantly decreased the energy transfer compared to a standard generator (1.5 ± 3.5 °C vs. 9.5 ± 0.8 °C, p < 0.001). CONCLUSION: Stray energy is transferred within the endoscope during the activation of common energy devices. This could result in post-polypectomy syndrome, bleeding, or perforation outside of the endoscopist's view. Decreasing the power, utilizing low-voltage modes and/or an impedance-monitoring generator can decrease the risk of complication.

Five seconds of 50-60 W radio frequency atrial ablations were transmural and safe: an in vitro mechanistic assessment and force-controlled in vivo validation.

AIMS: Longer procedural time is associated with complications in radiofrequency atrial fibrillation ablation. We sought to reduce ablation time and thereby potentially reduce complications. The aim was to compare the dimensions and complications of 40 W/30 s setting to that of high-power ablations (50-80 W) for 5 s in the in vitro and in vivo models. METHODS AND RESULTS: In vitro ablations-40 W/30 s were compared with 40-80 W powers for 5 s. In vivo ablations-40 W/30 s were compared with 50-80 W powers for 5 s. All in vivo ablations were performed with 10 g contact force and 30 mL/min irrigation rate. Steam pops and depth of lung lesions identified post-mortem were noted as complications. A total of 72 lesions on the non-trabeculated part of right atrium were performed in 10 Ovine. All in vitro ablations except for the 40 W/5 s setting achieved the critical lesion depth of 2 mm. For in vivo ablations, all lesions were transmural, and the lesion depths for the settings of 40 W/30 s, 50 W/5 s, 60 W/5 s, 70 W/5 s, and 80 W/5 s were 2.2 ± 0.5, 2.3 ± 0.5, 2.1 ± 0.4, 2.0 ± 0.3, and 2.3 ± 0.7 mm, respectively. The lesion depths of short-duration ablations were similar to that of the conventional ablation. Steam pops occurred in the ablation settings of 40 W/30 s and 80 W/5 s in 8 and 11% of ablations, respectively. Complications were absent in short-duration ablations of 50 and 60 W. CONCLUSION: High-power, short-duration atrial ablation was as safe and effective as the conventional ablation. Compared with the conventional 40 W/30 s setting, 50 and 60 W ablation for 5 s achieved transmurality and had fewer complications.

Safety and effectiveness of endobiliary radiofrequency ablation according to the different power and target temperature in a swine model.

BACKGROUND AND AIM: Endobiliary radiofrequency ablation (EB-RFA) is a new endoscopic palliation and adjunctive tool. Although EB-RFA is performed worldwide, a possibility of iatrogenic thermal injury leading to perforation or bleeding still remains. Therefore, we aimed to assess the effects of thermal and coagulation injury after in vivo EB-RFA using a new catheter with a temperature sensor in a swine model. METHODS: Twelve mini pigs were divided into four groups according to power (33 mm 10 W electrode vs. 18 mm 7 W electrode) and RFA target temperature (75°C vs. 80°C). All mini pigs underwent endoscopic retrograde cholangiography and target temperature controlled EB-RFA for 120 s. Additional cholangiogram was taken immediately after RFA, and all pigs were sacrificed after 24 h to assess the macroscopic/microscopic RFA injury. RESULTS: Microscopic maximal injury depth and ablation area of EB-RFA using a 33-mm 10 W RFA electrode were significantly deeper and larger than those of EB-RFA using an 18-mm 7 W electrode (median; 2.7 vs. 2.1 mm, P = 0.004, 48.9 vs. 36.2 mm2 , P = 0.016). However, there were no significant differences in microscopic ablation parameters between two different RFA target temperatures (75°C vs. 80°C). In addition, a post-RFA cholangiogram and assessment of the resected specimen at 24 h after the RFA showed no adverse events such as perforation or bleeding. CONCLUSIONS: EB-RFA using a temperature controlled RFA catheter successfully ablates the bile duct wall without adverse events in a swine model.

Electrical burns: Highlights from a 5-year retrospective analysis.

BACKGROUND: Electrical burns are the third most common cause of burn injuries, after scald and flame burns. In spite of decreasing mortality rates as advancements are made in treatment modalities and medical equipment, significant complications and socioeconomic consequences still accompany electrical burns. Analyzed in the present study were data from patients hospitalized for electrical burns between 2008 and 2012 in the Samsun Training and Research Hospital, the only burn care center in the Black Sea region of Turkey. METHODS: Data from 94 patients (84 males, 10 females) hospitalized for electrical burns between 2008 and 2012 were retrospectively evaluated. Patient age, gender, occupation, presence of coexisting trauma, burn degree, burned percentage of total body surface area (TBSA), voltage of the electric current (low or high), medical cost (per day and total), and infection rates were analyzed. RESULTS: Mean patient age was 26.4±13.2 years. Ten patients were female (10.6%) and 84 were male (89.4%). High-voltage burns were sustained by 47 patients (50%) and low-voltage burns by 42 (44.7%); the remaining 5 were flash burns. Mean burned TBSA was 21.8±19.8% in high-voltage injuries and 11.9±6.9% in low-voltage injuries. Seven patients had accompanying soft tissue lacerations, major bone fractures, or epidural hematomas. Findings of infection were encountered in 31 patients (32.9%), and appropriate treatments were initiated according to culture results. Mean duration of hospitalization was 21.3±19.8 days in patients with high-voltage burns and 8.6±6.2 days in patients with low-voltage burns. Mean hospital stay was 2.5-fold longer, and total medical costs were 4-fold higher in patients with high-voltage burns. CONCLUSION: Young adult males who were injured in industrial accidents constituted the majority of high-voltage burn patients. Incidence of these injuries may be reduced by improvements in training regarding the safe use of electrical devices, and correct installation and safe maintenance of power grids, as well as by a review of occupational safety regulations.

Local and Circulating Endothelial Cells Undergo Endothelial to Mesenchymal Transition (EndMT) in Response to Musculoskeletal Injury.

Endothelial-to-mesenchymal transition (EndMT) has been implicated in a variety of aberrant wound healing conditions. However, unambiguous evidence of EndMT has been elusive due to limitations of in vitro experimental designs and animal models. In vitro experiments cannot account for the myriad ligands and cells which regulate differentiation, and in vivo tissue injury models may induce lineage-independent endothelial marker expression in mesenchymal cells. By using an inducible Cre model to mark mesenchymal cells (Scx-creERT/tdTomato + ) prior to injury, we demonstrate that musculoskeletal injury induces expression of CD31, VeCadherin, or Tie2 in mesenchymal cells. VeCadherin and Tie2 were expressed in non-endothelial cells (CD31-) present in marrow from uninjured adult mice, thereby limiting the specificity of these markers in inducible models (e.g. VeCadherin- or Tie2-creERT). However, cell transplantation assays confirmed that endothelial cells (ΔVeCadherin/CD31+/CD45-) isolated from uninjured hindlimb muscle tissue undergo in vivo EndMT when transplanted directly into the wound without intervening cell culture using PDGFRα, Osterix (OSX), SOX9, and Aggrecan (ACAN) as mesenchymal markers. These in vivo findings support EndMT in the presence of myriad ligands and cell types, using cell transplantation assays which can be applied for other pathologies implicated in EndMT including tissue fibrosis and atherosclerosis. Additionally, endothelial cell recruitment and trafficking are potential therapeutic targets to prevent EndMT.

Effects of N-acetylcysteine and ethyl pyruvate on ischemia-reperfusion injury in experimental electrical burn model.

OBJECTIVES: This study was planned as a histopathologic evaluation of the effectiveness of ethyl pyruvate (EP) and N-acetylcysteine (NAC) in reducing electric burn-related organ damage in an experimental model. METHODS: Four groups of 7 female Wister rats were established. The first was a sham group, the second an electrical burn control group receiving 600 V, the third group received NAC therapy of 20 mg/kg 1 hour after 600 V electrical burn, and the fourth group received 50 mg/kg EP 1 hour after 600 V electrical burn. Heart, kidney, striated muscle, brain, and lung tissues obtained 24 hours postprocedurally were subjected to histopathologic examination, and injury scores were determined. The values determined were then subjected to statistical analysis. RESULTS: Electrical fire caused significant damage in heart, striated muscle, kidney, and brain tissues. A statistically significant decrease in injury scores in total striated muscle and heart tissue was observed in the 2 treatment groups administered NAC or EP compared to the control group (P= .001). Total kidney injury scores among the groups were significantly lower in the NAC and EP groups compared to the control group (P= .002 and P= .001, respectively). Brain injury examination revealed a significant decrease in injury scores with NAC and EP therapy, both antioxidant agents, in terms of neuron degeneration (P= .004 and P= .001, respectively). CONCLUSIONS: Electrical burn was observed to cause injury in heart, striated muscle, kidney, and brain tissue. This injury was reduced by the administration of NAC and EP.

Influences of high-voltage electrical burns on the pulmonary microcirculation in rabbits.

This study was performed to investigate the effects of high-voltage electrical burns (HEB) on the pulmonary microcirculation in rabbits. Total of 120 rabbits were randomly divided into control and HEB group using a random number table. HEB model was developed with a voltage regulator and experimental transformer. Laser Doppler perfusion imager was utilized to monitor and quantify the blood perfusion in pulmonary microcirculation. The microvascular morphologic changes of the lung were observed using light microscopy and transmission electron microscope (TEM). The lung wet/dry weight ratio and the PaO2 were determined. The values of blood perfusion in rabbit pulmonary microcirculation in the HEB group were decreased at 5 min, but increased at 1 h after burn (P <  0.01) and then decreased gradually. Light microscopy reveals microthrombus formation in pulmonary venules and bleeding in venous capillaries in HEB group. We found the number of microvilli in the capillary endothelial cells decreased, the rough endoplasmic reticulum expanded and severe degranulation occurred, the mitochondrial cristae fused or disappeared, and severe edema surrounded the capillary endothelial cells by TEM. The values of lung wet/dry weight ratio were higher and the PaO2 were lower than that of before burn group (P <  0.01). These results demonstrated that microcirculatory disorders play a major role in the development of progressive lung damage after high-voltage electrical burns.

Precordial skin burns after endoscopic submucosal dissection for gastric tube cancer.

BACKGROUND AND AIM: Endoscopic submucosal dissection (ESD) is useful as a minimally invasive treatment option for early gastric cancer. ESD is also used in the management of postoperative remnant gastric cancers in the stomach and gastric tube cancers. Perforation and delayed bleeding have been the main complications of ESD reported in the management of gastric tube cancer. However, in the current literature, there is no description of precordial skin burns caused by electrical coagulation. METHODS: While we treated 22 patients with gastric tube cancers by ESD from 2005 to 2014, we experienced five skin burns in four patients after ESD. We retrospectively analyzed clinical characteristics of precordial skin burn as a complication of ESD. RESULTS: All skin burns occurred in patients reconstructed using a presternal route, whose incidence of precordial skin burn was 55.6%. In all cases, lesions were located in the upper or middle third of gastric tubes irrespective of their direction. Skin burn developed on postoperative day (POD) 1 or POD 2, taking 4-7 days to heal and was accompanied by high fever in 60% of cases. CONCLUSION: The present study suggests that when carrying out ESD for gastric tube cancer using the presternal route, it is necessary to consider the occurrence of a precordial skin burn as a possible complication.

Biomedical electrosurgery devices containing nanostructure for minimally invasive surgery: reduction of thermal injury and acceleration of wound healing for liver cancer.

The aim of the present study was to investigate the thermal injury in the liver after a minimally invasive electrosurgery technique with a copper-doped diamond-like carbon (DLC-Cu) surface coating. To effectively utilize electrosurgery in a clinical caner setting, it is necessary to suppress the thermal injury to adjacent tissues. The surface morphologies of DLC-Cu thin films were characterized using scanning electron microscopy and transmission electron microscopy. Three-dimensional liver models were reconstructed using magnetic resonance imaging to simulate the electrosurgical procedure. Our results indicated that the temperature decreased significantly when minimally electrosurgery with nanostructured DLC-Cu thin films was used, and that it continued to decrease with increasing film thickness. In an animal model, thermography revealed that the surgical temperature was significantly lower in the minimally invasive electrosurgery with DLC-Cu thin film (DLC-Cu-SS) compared to untreated electrosurgery. In addition, DLC-Cu-SS created a relatively small thermal injury area and lateral thermal effect. These results indicated that the biomedical nanostructure coating reduced excessive thermal injury, and uniformly distributed temperature in the liver.

Pedicled full-thickness abdominal flap combined with skin grafting for the reconstruction of anterior chest wall defect following major electrical burn.

Successful reconstruction of extensive anterior chest wall defect following major electrical burn represents a very challenging surgery. Herein we report the first case using pedicled full-thickness abdominal flap combined with skin grafting to treat this injury with severe infection and exposure of pericardium and ribs in a Chinese patient. Following the performance of chest debridement to remove necrotic and infected tissues and the injection of broad-spectrum antibiotics to reduce infection, a pedicled full-thickness abdominal flap was used to cover the exposed pericardium and ribs, and skin grafting from the right leg of the patient was done to cover the exposed vital tissues. The patient was followed up for a total of 3·5 years, and satisfactory cosmetic and functional outcomes were obtained without complications. This report provides an effective method for the surgeons who encounter similar cases where reconstruction of extensive anterior chest wall is required.