Evaluation of skull bone viability and effect of early surgical intervention in electrical contact burns using 18 F-Sodium Fluoride PET-CT imaging.

OBJECTIVE: Electrical contact burns of the scalp cause serious morbidity and mortality. Early necrotic bone debridement and flap cover are crucial for successful wound closure. 18 F Sodium Fluoride (NaF), with high bone-to-soft tissue activity ratio, is useful for bone viability assessment. This study evaluated the role of 18 F NaF PET-computed tomography (CT) in objectively defining the extent and depth of nonviable calvarial bone, to guide adequate bone debridement. METHOD: Of 20 patients referred to our institute with electrical contact burns of the scalp during a 2-year period, 15 were enrolled in the study. Two weeks after the initial management, tracer uptake pattern was noted on 18 F NaF PET-CT of the head and exposed bone measured. Surgical bone debridement was based on scan findings, followed by wound closure. All patients underwent clinical evaluation and follow-up scan 3 months after surgery. RESULTS: Eight patients showed a central photopenic area in the exposed bone (maximum standardized uptake value [SUVmax] of 0.76 ± 0.14 with mean maximum dimensions 4.10 ± 1.76/2.67 ± 1.54 cm). High tracer uptake (SUVmax, 9.66 ± 6.03) was seen peripheral to the exposed bone (mean maximum dimensions, 8.14 ± 3.03/4.75 ± 1.61 cm). Postoperatively, there was no significant change in tracer uptake in the central debrided region or peri-debridement bone area under the flap. Clinically all patients showed a well-healed flap. CONCLUSION: 18 F NaF PET-CT appears useful for objective evaluation of skull bone viability and planning necrotic bone debridement in patients with electrical contact burns. However, additional studies with longer patient follow-up are required to validate these results.

[Modern integrated approach to surgical treatment of patients with defects and deformations following high-voltage electrical injury]. / Sovremennyi kompleksnyi podkhod v khirurgicheskom lechenii patsientov s defektami i deformatsiyami v rezul'tate vysokovol'tnoi elektrotravmy.

OBJECTIVE: To develop the algorithm for correction of defects following high-voltage electrical trauma with revascularized autografts, to assess the incidence and risk factors of postoperative complications. MATERIAL AND METHODS: Surgical interventions were performed in 16 men. Autografts were selected considering localization of defect and preoperative ultrasound data on perfusion of donor and recipient areas. We applied a sample with temporary compression of the vessels and ultrasound scanning of arteries and veins (a small-sized Doppler sound indicator of blood flow velocity - MINIDOP, BIOSS). RESULTS: Nine patients underwent microsurgical transplantation of revascularized flaps. Six patients with electrical trauma of the upper extremities underwent transplantation of free skin autografts and transposition of flexor and extensor muscles of the fingers in various combinations. In 1 patient, simultaneous microsurgical graft transplantation and plasty with local tissues were carried out. Microsurgical transplantation of thoracodorsal flap was performed in 2 patients with maxillofacial defect (with preliminary deepidermization of the flap in one case). In 3 patients with traumatic amputation of the penis, 2 patients underwent phalloplasty with a thoracodorsal flap and prefabrication of a radial forearm graft at the first stage. At the next stage, urethroplasty with a prefabricated radial forearm graft was performed. In 1 patient, closure of the penis defect was carried out using scrotal flaps. CONCLUSION: An integrated surgical approach, the use of free revascularized autografts and adequate postoperative management ensure high-quality aesthetic and functional restoration, improvement of the quality of life and social adaptation of patients with defects and deformations following high-voltage electrical injury.

[Imaging judgment of soft tissue and vascular injuries in limbs with high-voltage electric burn and its clinical significance].

The injury mechanism of high-voltage electric burn in limbs is complex and special. The soft tissue and vascular injuries caused by high-voltage electric burn are serious and concealed. It is difficult to judge the severity and extent of injury before surgery, which affects the diagnosis and treatment effects and remains a major problem in burn field. In recent decades, a series of clinical studies have been conducted by scholars at home and abroad, using various imaging methods for the judgment of soft tissue and vascular injuries, which have their own advantages and disadvantages. According to the principle of accuracy, precision, safety, and easy operation, magnetic resonance imaging and magnetic resonance angiography are required at the same time in general for the imaging judgment of soft tissue and vascular injuries in limbs with high-voltage electric burn. The B-mode ultrasonography shall be performed if a precise judgment of vascular injury is needed.

Esophageal injury associated with catheter ablation for atrial fibrillation: Determinants of risk and protective strategies.

Catheter ablation has become an important element in the management of atrial fibrillation. Several technical advances allowed for better safety profiles and lower recurrence rates, leading to an increasing number of ablations worldwide. Despite that, major complications are still reported, and esophageal thermal injury remains a significant concern as atrioesophageal fistula (AEF) is often fatal. Recognition of the mechanisms involved in the process of esophageal lesion formation and the identification of the main determinants of risk have set the grounds for the development and improvement of different esophageal protective strategies. More sensitive esophageal temperature monitoring, safer ablation parameters and catheters, and different energy sources appear to collectively reduce the risk of esophageal thermal injury. Adjunctive measures such as the prophylactic use of proton-pump inhibitors, as well as esophageal cooling or deviation devices, have emerged as complementary methods with variable but promising results. Nevertheless, as a multifactorial problem, no single esophageal protective measure has proven to be sufficiently effective to eliminate the risk, and further investigation is still warranted. Early screening in the patients at risk and prompt intervention in the cases of AEF are important risk modifiers and yield better outcomes.

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.

[Clinical application of computed tomography angiography and three-dimensional reconstruction in repairing high-voltage electrical burn wounds in necks, shoulders, axillas, and upper arms with tissue flaps].

Objective: To explore the application value of computed tomography angiography (CTA) and three-dimensional reconstruction in repairing high-voltage electrical burn wounds in necks, shoulders, axillas, and upper arms with tissue flaps. Methods: From December 2014 to December 2018, 12 patients with high-voltage electrical burns in necks, shoulders, axillas, and upper arms were hospitalized. The size of wounds ranged from 13 cm×10 cm to 32 cm×15 cm after complete debridement. Before tissue flap repair, the subclavian artery-axillary artery-brachial artery and their branches were examined by CTA. The main target vessels and their branches were conducted by three-dimensional reconstruction, and the development of the axis vessels for the tissue flaps planning to dissect and their branches were observed. For wounds in upper arms, amputation stump bone exposed wounds, and wounds in axillas and the anterior, the latissimus dorsi myocutaneous flap is the first choice for repair, if the thoracodorsal artery and internal and external branches are well developed according to CTA examination. Latissimus dorsi myocutaneous flaps were used in 6 patients with the area of myocutaneous flap ranging from 16 cm×12 cm to 32 cm×17 cm. All the donor sites were covered by split-thickness skin graft of thighs. For large wounds in occiputs, necks, and scapulas, the contralateral lower trapezius myocutaneous flap is the first choice for repair, if the superficial descending branch and deep branch of the contralateral transverse cervical artery are well developed according to CTA examination. For small wounds in necks and scapulas, the ipsilateral lower trapezius myocutaneous flap can be used for repair, if the superficial descending branch of the ipsilateral transverse cervical artery is well developed according to CTA examination. Lower trapezius myocutaneous flaps were used in 4 patients with the area of myocutaneous flap ranging from 18 cm×12 cm to 25 cm×17 cm. The donor site of one patient was sutured directly and the donor site of the other 3 patients was covered by split-thickness skin graft of thighs. For wounds in the posteromedial side of upper arms and the anterior side of axillas, the lateral thoracic skin flaps can be used for repair, if the latissimus dorsi myocutaneous flap can not be utilized for reasons of back burn or no muscle is needed for dead space, when the blood supply of side chest skin is reliable according to CTA examination. Lateral thoracic skin flaps were used in 2 patients with the area of skin flap ranging from 16 cm×12 cm to 17 cm×14 cm. The donor site of one patient was sutured directly and the donor site of the other one patient was covered by split-thickness skin graft of thigh. Results: During the operation of tissue flap repair in 12 patients, the orientation and starting position of the axis vessels were consistent with those observed by CTA examination before operation. All the tissue flaps survived after operation. During follow-up of 1 to 24 months, the patients were satisfied with no serious scar contracture affecting the function nor secondary infection or chronic ulcer. Conclusions: CTA and its three-dimensional reconstruction technique can clearly reconstruct the subclavian artery-axillary artery-brachial artery and their branches before repair of high-voltage burn wounds in necks, shoulders, axillas, and upper arms. It can be used to observe whether the vessels are embolized or not and the starting position and orientation of blood vessels, which can provide an important reference for the selection of tissue flap transplantion.

[Effects of anteriolateral thigh perforator flap and fascia lata transplantation in combination with computed tomography angiography on repair of electrical burn wounds of head with skull exposure and necrosis].

Objective: To explore the effects of anteriolateral thigh perforator flap and fascia lata transplantation in combination with computed tomography angiography (CTA) on repair of electrical burn wounds of head with skull exposure and necrosis. Methods: Seven patients with head electrical burns accompanied by skull exposure and necrosis were admitted to our burn center from March 2016 to December 2017. Head CTA was performed before the operation. The diameters of the facial artery and vein or the superficial temporal artery and vein were measured, and their locations were marked on the body surface. Preoperative CTA for flap donor sites in lower extremities were also performed to track the descending branch of the lateral circumflex femoral artery with the similar diameter as the recipient vessels on the head, and their locations were marked on the body surface. Routine wound debridement and skull drilling were performed successively. The size of the wounds after debridement ranged from 12 cm×8 cm to 20 cm×12 cm, and the areas of skull exposure ranged from 8 cm×6 cm to 15 cm×10 cm. Anteriolateral thigh perforator flaps with areas from 13 cm×9 cm to 21 cm×13 cm containing 5-10 cm long vascular pedicles were designed and dissected accordingly. The fascia lata under the flap with area from 5 cm×2 cm to 10 cm×3 cm was dissected according to the length of vascular pedicle. The fascia lata was transplanted to cover the exposed skull, and the anteriolateral thigh perforator flap was transplanted afterwards. The descending branch of the lateral circumflex femoral artery and its accompanying vein of the flap were anastomosed with superficial temporal artery and vein or facial artery and vein before the suture of flap. The flap donor sites were covered by intermediate split-thickness skin graft collected from contralateral thigh or abdomen. Results: The descending branch of the lateral circumflex femoral artery and its accompanying vein were anastomosed with superficial temporal artery and vein in six patients, while those with facial artery and vein in one patient. All the flaps survived after the operation, and no vascular crisis was observed. Wound healing was satisfactory. One patient was lost to follow up. Six patients were followed up for 6 to 10 months. The patients were bald in the head operation area with acceptable appearance. No psychiatric symptom such as headache or epileptic seizure was reported. The flap donor sites were normal in appearance. The muscle strength of the lower extremities all reached grade V. The sensation and movement of the lower extremities were normal. Conclusions: Anterolateral thigh perforator flap with fascia lata transplantation can effectively repair electrical burn wounds of head with skull exposure and necrosis. The fascia lata can be used to protect the vascular pedicle of flaps, which is beneficial to the survival of the flap. Preoperative head and lower extremities CTA can provide reference for intraoperative vascular exploration in donor site and recipient area, so as to shorten operation time.

[Clinical research of features of magnetic resonance imaging of high-voltage electrical burns in limbs at early stage].

Objective: To analyze the features of magnetic resonance imaging (MRI) of patients with high-voltage electrical burns in limbs at early stage. Methods: Thirty-eight patients with high-voltage electrical burns, conforming to the study criteria, were hospitalized in our unit from March 2013 to August 2016. T(1) weighted imaging (T(1)WI), T(2)WI, fat-suppression T(2)WI plain scan, and fat-suppression T(1)WI enhanced scan of MRI were performed in 78 limbs, including 56 upper limbs and 22 lower limbs at post injury hour 72. The MRI signal characteristics of electrical burns in skin and subcutaneous tissue, skeletal muscle, tendon, joint ligament, and skeleton of limbs were analyzed. " Sandwich-like" necrosis and injury in skeletal muscle, injuries of tendon, joint ligament, and skeleton were observed. MRI signal characteristics of amputated upper limbs and salvaged limbs were also analyzed. All patients underwent surgery within 24 h after MRI examination, and the muscle vitality was judged during operation. Muscle tissue without reaction to electrical stimulation which was completely necrotic as shown by MRI, muscle tissue with weak reaction to electrical stimulation which was injured with blood supply as shown by MRI, and muscle tissue with edema as shown by MRI were collected, and then the pathological characteristics of muscle tissue were observed with HE staining. Results: (1) The defect area of patients at entrance of current was bigger than that at exit. The skin and subcutaneous tissue extensively unevenly thickened. T(2)WI manifested hyperintensity, and T(1)WI manifested isointensity, while fat-suppression enhanced T(1)WI manifested uneven enhancement. Zonal effusion was seen in the region of serious subcutaneous edema. (2) For complete necrosis of skeletal muscle, T(2)WI manifested hypointense, isointensity, or slight hyperintensity, and T(1)WI manifested isointensity, slight hyperintensity, or mixed signal of isointensity and slight hyperintensity, while fat-suppression enhanced T(1)WI manifested most no enhancement area with clear boundary. The MRI signals of injured skeletal muscle could be divided into two types. Type Ⅰ signal was for partial necrotic muscle adjacent to the completely necrotic zone. T(2)WI manifested uneven hyperintensity or slight hyperintensity, with unclear boundary. T(1)WI manifested isointensity or slight hyperintensity. Fat-suppression enhanced T(1)WI manifested significant banding or laciness enhancement. Type Ⅱ signal was for deep muscle tissue far from the complete necrotic zone. T(2)WI manifested hyperintensity, and T(1)WI manifested isointensity or main isointensity mixed with hyperintensity, while fat-suppression enhanced T(1)WI manifested uneven moderate or slight enhancement. Normal muscle signal, type Ⅰ signal, and type Ⅱ signal were all mixed with necrotic signal, showing " sandwich-like" change. For skeletal muscle edema, T(2)WI manifested slight hyperintensity and unclear boundary, and T(1)WI manifested hypointense, while fat-suppression enhanced T(1)WI manifested no obvious enhancement. (3) For complete necrosis of tendon, T(2)WI manifested isointensity or slight hyperintensity, and T(1)WI manifested isointensity, while fat-suppression enhanced T(1)WI manifested no enhancement. For tendon injury, T(2)WI manifested isointensity, and T(1)WI manifested isointensity or hypointense, while fat-suppression enhanced T(1)WI manifested slight enhancement. (4) Severe injury of wrist joint were manifested as complete necrosis of soft tissue around joint. T(2)WI manifested slight hyperintensity or isointensity, and T(1)WI manifested isointensity, while fat-suppression enhanced T(1)WI manifested no enhancement or slightly uneven enhancement. For completely destroyed wrist joints, the structures were not clear from outside to inside. T(2)WI manifested slight hyperintensity or isointensity, and T(1)WI manifested hypointense or isointensity, while fat-suppression enhanced T(1)WI manifested no enhancement. For elbow injury, T(2)WI manifested hyperintensity, and T(1)WI manifested isointensity or hypointense, while fat-suppression enhanced T(1)WI manifested uneven enhancement. For knee injury, T(2)WI manifested hyperintensity, and T(1)WI manifested hypointense, while fat-suppression enhanced T(1)WI manifested slight enhancement. (5) For bone edema, T(2)WI manifested isointensity, while fat-suppression T(2)WI manifested slight hyperintensity. T(1)WI manifested isointensity, and fat-suppression enhanced T(1)WI manifested patchy enhancement. (6) MRI of amputated upper limbs showed necrosis signals, type Ⅰ signals, type Ⅱ signals, and mixed signals of type Ⅰ and type Ⅱ in skeletal muscle. The necrosis signal and type Ⅰ signal area of the distal end were more than 50% greater than those of the lesion. The scope of the ecological tissue was large and the boundary was not clear. There were diffuse injuries in both anterior and posterior muscles, and the ulnar and radial artery pulsation disappeared in the upper limbs. The MRI of salvaged limbs were type Ⅰ signal, type Ⅱ signal, mixed signals of type Ⅰ and type Ⅱ, and local necrosis signals of skeletal muscle. The type Ⅰ signal was the main type, and the distal end showed type Ⅱ signal. (7) For completely necrotic skeletal muscle as shown by MRI, surgical exploration showed loss of muscle viability, and pathological examination showed complete necrosis of striated muscle tissue. For injury area of skeletal muscle as shown by MRI, surgical exploration showed interecological muscle with activity worse than mormal muscle, and pathological examination showed normal muscle cells and muscle fiber mixed with necrotic striated muscle cells having karyopyknosis, with different degree of injury. For edema area of skeletal muscle as shown by MRI, surgical exploration showed swelling skeletal muscle and normal muscle vitality, and pathological examination showed striated muscle interstitial edema with a large number of inflammatory cells infiltration. The manifestions of MRI were consistent with the results of surgical exploration and pathological examination. Conclusions: Skeletal muscle complete necrosis, injury, and edema could be preferably differentiated by MRI, and the definite scope and depth of electrical injury, the injury of skin, tendon, joint ligament, and bone could also be displayed well on MRI. It can provide objective imaging basis for the diagnosis of high-voltage electrical burns in limbs at early stage, the establishment of clinical operation plan, and the judgment of intraoperative tissue vitality.

Acute-Onset Quadriplegia With Recovery After High-Voltage Electrical Injury.

Although uncommon, electrical injuries are associated with significant morbidity and mortality. There have been several reports of neurological sequelae secondary to electrical injury; however, the neurophysiology is still not completely understood. These neurological complications pose the greatest risk for permanent disability. We present a case of acute-onset quadriplegia after high-voltage electrical injury without radiographic evidence. Two months after the injury, the patient went on to regain partial sensorimotor function. Only a few case reports in the literature exist describing neurological recovery after electrical burn-induced quadriplegia. These cases are reviewed.

Identification of Skin Electrical Injury Using Infrared Imaging: A Possible Complementary Tool for Histological Examination.

In forensic practice, determination of electrocution as a cause of death usually depends on the conventional histological examination of electrical mark in the body skin, but the limitation of this method includes subjective bias by different forensic pathologists, especially for identifying suspicious electrical mark. The aim of our work is to introduce Fourier transform infrared (FTIR) spectroscopy in combination with chemometrics as a complementary tool for providing an relatively objective diagnosis. The results of principle component analysis (PCA) showed that there were significant differences of protein structural profile between electrical mark and normal skin in terms of α-helix, antiparallel ß-sheet and ß-sheet content. Then a partial least square (PLS) model was established based on this spectral dataset and used to discriminate electrical mark from normal skin areas in independent tissue sections as revealed by color-coded digital maps, making the visualization of electrical injury more intuitively. Our pilot study demonstrates the potential of FTIR spectroscopy as a complementary tool for diagnosis of electrical mark.

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.

Radiofrequency ablation in the treatment of osteoid osteoma: results and complications.

BACKGROUND: Percutaneous radiofrequency ablation (RFA) for treatment of osteoid osteoma is effective and avoids the potential complications of open surgical resection. This study evaluates the efficacy of RFA at a single tertiary-care pediatric hospital and highlights an important complication. MATERIALS AND METHODS: The medical records of 21 cases of RFA in 21 children between 2004 and 2010 were reviewed retrospectively for demographic data, lesion site, access point and technique for ablation, clinical outcome and complications. RESULTS: Clinical follow-up was available for 17/21 children (81%) at an average of 17.0 months (range 0.5-86.1 months). No persistence or recurrence of pre-procedural pain was noted. Two children (9.5%) had a complication, including a burn to the local skin and muscle requiring local wound care, and a late subtrochanteric femur fracture treated successfully with open reduction internal fixation. CONCLUSION: RFA is a safe and effective alternative to surgical resection of the osteoid osteoma nidus. When accessing the proximal femur, the risk of late post-procedural fracture must be considered and discussed with the family. An understanding of biomechanical principles in the proximal femur might provide an effective strategy for limiting this risk.

Sonographically guided radiofrequency ablation with and without a superficial saline injection to prevent skin burns in a rabbit model.

OBJECTIVES: Our aim was to determine whether sonographically guided radiofrequency ablation with superficial saline injection can minimize thermal injury of the skin without an influence on therapeutic efficacy. METHODS: Institutional Animal Care Committee approval was obtained. Twelve percutaneous radiofrequency ablation procedures were performed in the thighs of 6 rabbits (control, n = 6, right thigh; experimental, n = 6, left thigh). The ablation with local anesthesia was performed in the most superficial area of the thigh muscle. In the experimental group, 1 mL of saline was injected before the ablation at the tissue layer between the skin and ablated muscle. The duration and energy of the ablation were the same in the control and experimental groups. Rabbits were compared for their gross skin state and histopathologic findings after the ablation. RESULTS: The degree of thermal coagulation of the muscle was similar in both groups at pathologic examination. Grossly, skin redness was mild in the experimental group but moderate in the control group. Of the 6 rabbits, 5 tended to show more frequent histopathologic changes, including an inflammatory reaction, interruption of collagen fibers, injury of the skin adnexa, and fibrosis, in the control group when compared with the experimental group. However, there was no statistically significant difference (all P> .05). One rabbit that underwent ablation at higher energy had a partially dissected epidermis in the control group only. CONCLUSIONS: Sonographically guided radiofrequency ablation with a saline injection superficial to a tumor might prevent skin burns and provide equivalent therapeutic efficacy for ablating superficial lesions.

Retro-cardiac esophageal mobility and deflection to prevent thermal injury during atrial fibrillation ablation: an anatomic feasibility study.

BACKGROUND: Atrial fibrillation (AF) ablation often causes minor esophageal (ESO) injury, and sometimes lethal posterior left atria (PLA)-ESO fistula. Avoidance techniques (energy reduction and/or complete target avoidance) provide questionable ESO protective value, and are likely associated with increased AF recurrence. METHODS AND RESULTS: Potential independent mobility, deflectability and age-related anatomic factors, assessed by multi-position, and age-progressive thoracic computed tomography scans, show (1) mobility of the retro-cardiac ESO-PLA juxtaposition, (2) age-related increased thermal ablation vulnerability; and also, age-increased potential for retro-cardiac ESO mobility and deflectability to avoid collateral injury; and that (3) the retro-cardiac vertebral bodies and the descending aorta create a patient-specific esophageal corridor which defines the resting supine esophageal position and the subsequent PLA-ESO crossing points. CONCLUSION: A small, 1-3 mm, increase in separation of the ESO relative to the PLA occurs when moving the patient from supine to lateral and from supine to prone position. Because of the concave spine; the PLA-ESO area of apposition increases. Patient rotation of 90° and 180° does not create enough passive PLA-ESO separation to avoid collateral ESO thermal energy; but, active repositioning lateral and out of ESO corridor appears feasible.

A series of models of non-thermal high voltage electrical injuries.

Although many models of electrical injury have been established, none of them are completely typical of the clinical features of electrical injury. As a result, research based on these models were incapable of explaining many clinical phenomena such as continuous tissue necrosis and also were unable to cope with high ratio of amputation of extremities. In order to investigate the mechanism of electrical injuries and better model the condition with similar clinical characteristics we developed a new model. Seventy-five New Zealand rabbits were employed in this study, of them 45 were used in a preliminary experiment including the selection of the size of electrode plate area, damaged extent, time length of electrical injury and interval length between two injuries and so on. Another 30 rabbits were equally divided into five groups with electrical injury times of 6, 12, 18, 24 and 30 cycles, respectively. Observations were made using clinical anatomical exploration, with quantification using an IDBI scale on the 2nd, 8th, 24th, 48th hours and 5th, 15th days, and TC-99m-DMP isotope scanning and gamma photography at 2nd hour and 5th day in post-injury, respectively. The results showed the effective electric field strength was 17,000 V/m, mean current intensity was 554 mA, average current density was 137 mA/cm(2) beneath the small electrode plate with 21 mA/cm(2) beneath big one, and average increase of tissue temperature was 1.73 degrees C during injury process which excluded the possibility of thermal injury. One single wound injury beneath the small plate of the experimental rabbits with loss of injured extremities from 5th to 15th post-injury days in groups 3-5 and obviously progressive tissue necrosis in and outside the wounds were obtained. A series of electrical injured models from mild, moderate, severe, extra severe, and destructive which was exactly similar to the clinical features of electrical injury cases was established.

A comparative study on the predictive value of digital subtraction angiography and B-mode ultrasonography in evaluating arterial injury in high-voltage electrical burn of the forearm.

To compare the predictive value of digital subtraction angiography (DSA) with B-mode ultrasonography in evaluating the arterial injury in high-voltage electrical burn of the forearm, 19 forearms sustaining high-voltage electric burn were examined with DSA and B-mode ultrasonography. During surgery, the involved arteries were examined closely to compare their gross pathology with the results of DSA and B-mode ultrasonography. The thrombotic or necrotic arteries found during surgery were excised and examined pathologically. Among 19 ulnar and radial arteries examined by DSA and B-mode ultrasonography, the abnormal signs were found in 14 ulnar and 11 radial arteries in DSA, including narrowing of lumen, beading of the wall, thrombosis, and slowing of blood flow, whereas abnormal signs were shown by B-mode ultrasonography in 19 ulnar and 16 radial arteries, including roughening, edema or exfoliation of the endothelium, thickening of vessel wall, narrowing of lumen, beading of the wall, and decrease in the blood flow. The vessels with severe injuries showed thrombosis or necrosis of the vessel wall. The aforementioned changes were confirmed during surgery and pathologic examination. B-mode ultrasonography is a more efficient tool than DSA in evaluating vascular injuries of the forearm sustaining high-voltage electrical burn.