1/6. Influence of low frequency electric fields on anti- and pro-coagulability of the vascular endothelium: new insights into high-voltage electrical injury.After high-voltage electric injury, patients often show tissue necrosis and thrombosis of blood vessels even remote from entry and exit site of electrical current. In this study, plasma levels of TAT, F(1 2), PAI-1, and t-PA were determined in vivo in three patients with high-voltage injury for 96 hours after trauma. In order to analyse a possible effect on haemostasis related to endothelial cell damage, protein s, TF, ET-1, PGI(2), NO, t-PA, and PAI-1 were determined for 72 hours in vitro in cell culture supernatant of HUVECs that had been exposed to 1, 10, 30, and 50 electric field periods of 50 Hz with field strength of 60 V/cm and duration of 20 ms. Furthermore, expression of thrombomodulin was immunohistochemically analysed. Clotting activation could be observed in our patients by increased levels of F(1 2) and TAT between 12 and 72 hours after injury, whereas fibrinolysis was disturbed due to high PAI-1. One patient presented thrombosis of vessels by day 3. in vitro, PAI-1 increased significantly (p<0.05) in medium of cells with an application of 30 and 50 periods between 2 and 48 hours. Between 4 and 72 hours, the concentration of t-PA was significantly lower (p<0.05) in the medium of HUVECs exposed to 10, 30, and 50 periods, whereas there was a significant increase (p<0.05) in the concentration of TF in the cell groups with an application of 30 and 50 periods. 24, 48, and 72 hours after injury, there was just weak or no staining for thrombomodulin in HUVECs with an application of 30 and 50 periods. The disturbed balance between clotting system and fibrinolysis seen in vitro after electric injury might explain the clinical observation of a progressive thrombosis of blood vessels after electric injury leading to tissue loss.- - - - - - - - - - ranking = 1keywords = vessel (Clic here for more details about this article) |
2/6. Is 'virtual histology' the next step after the 'virtual autopsy'? Magnetic resonance microscopy in forensic medicine.AIM: The study aimed to validate magnetic resonance microscopy (MRM) studies of forensic tissue specimens (skin samples with electric injury patterns) against the results from routine histology. methods AND RESULTS: Computed tomography and magnetic resonance imaging are fast becoming important tools in clinical and forensic pathology. This study is the first forensic application of MRM to the analysis of electric injury patterns in human skin. Three-dimensional high-resolution MRM images of fixed skin specimens provided a complete 3D view of the damaged tissues at the site of an electric injury as well as in neighboring tissues, consistent with histologic findings. The image intensity of the dermal layer in T2-weighted MRM images was reduced in the central zone due to carbonization or coagulation necrosis and increased in the intermediate zone because of dermal edema. A subjacent blood vessel with an intravascular occlusion supports the hypothesis that current traveled through the vascular system before arcing to ground. CONCLUSION: High-resolution imaging offers a noninvasive alternative to conventional histology in forensic wound analysis and can be used to perform 3D virtual histology.- - - - - - - - - - ranking = 0.33333333333333keywords = vessel (Clic here for more details about this article) |
3/6. High-voltage electrical injury: electron microscopic findings of injured vessel, nerve, and muscle.Bilateral legs damaged by high-voltage electrical injury were treated by amputation and a free thin rectus abdominis myocutaneous flap with reduced muscle. Damaged arteries at 2 months after injury showed disappearance of endothelium, and a decreased number and morphological changes in smooth-muscle cells. Injured nerves and muscles showed early regenerating processes after total degeneration, and no progressive muscular necrosis. These results suggest that severe degeneration of the neurovascular bundle and muscle is unavoidable in high-voltage electrical injuries of the extremities. Therefore, early amputation, sequential debridement, late coverage by a flap, and prolonged rehabilitation are required in this injury.- - - - - - - - - - ranking = 1.3333333333333keywords = vessel (Clic here for more details about this article) |
4/6. Delayed arterial thrombosis following an apparently trivial low-voltage electric injury.Vascular damage is a frequent and serious complication following high voltage injuries (greater than 1000 V), but does not seem to have been described with low-voltage current. We report an unusual case with delayed thromboses in the hand arteries of a young, healthy 24 yo man, after a 220 V electric shock. Two weeks after the accident he developed a successively increasing hand ischemia with Raynaud phenomenon, and finally fingertip necroses. angiography revealed multiple small vessel occlusion. Although systemic fibrinolysis with streptokinase was not initiated until eight weeks after the accident, a partial restitution of the markedly reduced macro- and microcirculation in the fingers was possible. The blood pressure of the ischemic fingers increased from 0 to 40 mmHg, with total relief of symptoms. Concomitantly, a marked improvement of the skin microcirculation could be objectively demonstrated by laser Doppler fluxmetry and dynamic capillaroscopy. Three conclusions can be made 1) low-voltage electric shock can initiate late vascular thromboses, 2) thrombolysis can be effective also weeks after the thromboses have been established, and 3) the improvement of the nutritional circulation in the ischemic areas can be nicely and objectively documented by the two methods described.- - - - - - - - - - ranking = 0.33333333333333keywords = vessel (Clic here for more details about this article) |
5/6. Management of severe forearm injuries.A review of principles and an operative guideline for repair of severely mutilating injuries to the forearm have been set forth. These concepts and their application have been illustrated in a series of clinical cases. The following key concepts have developed from these clinical experiences: 1. The surgeon must evaluate each case based upon the potential for return of sensation and function. One cannot justify the statement that a replanted arm is always superior to a prosthesis, even if its only purpose is cosmetic. 2. Care must be taken in the emergency room to evaluate the entire patient, and not to ignore other injuries while concentrating on a mangled extremity. 3. The crush-avulsion nature of injuries seen in a large referral center necessitates aggressive debridement of damaged soft tissue and bone. Wounds that have avulsion of skin, muscle, and nerve throughout the length of the arm do not lend themselves to repair. Destruction of an elbow joint generally precludes repair. 4. A well stabilized skeleton is essential before definitive soft tissue repairs can be performed. 5. Vascular repairs are meticulously performed using magnification. All vessels are reconstructed in an effort to recreate the original anatomy. 6. Wide destruction of muscle and tendon is frequent necessitating ingenuity in connecting proximal motor units to distal tendon. After repair, early active motion of the extremity is emphasized. 7. Perhaps the strongest contraindication to reconstruction of a severely damaged upper limb is avulsion of the nerves throughout the length of the forearm. Sharply divided nerves can be repaired by group fascicular suture. Crushed, divided nerves do well with accurate epineural approximation. Crushed nerves with epineural continuity ar best treated by observation and secondary grafting as required. 8. Primary coverage of areas denuded of skin is by split graft of local transposition flaps. More sophisticated techniques may be used at a later time (myocutaneous flaps or free flaps) if further reconstruction is contemplated. 9. Dressing must be carefully applied without constricting the extremity. A protective plaster is applied beginning from above the elbow and ending in a bonnet over the hand; this allows the recovery room nurse to monitor the vascular status of the repair. 10. The physiotherapist and occupational therapist are integrated into the perioperative care. Active range of motion exercises are begun as soon as the third day after the operation. Lightweight static and dynamic splints help to restore mobility.- - - - - - - - - - ranking = 0.33333333333333keywords = vessel (Clic here for more details about this article) |
6/6. Serratus anterior intercostal nerve graft: a new vascularized nerve graft.We present our investigative and clinical experience with a new vascularized nerve graft: the serratus anterior intercostal nerve graft. The serratus branch of the thoracodorsal arterial system was injected with silicone rubber injection compound in seven fresh cadavers (N = 11 injected specimens) after the composite serratus-intercostal structures were harvested. microdissection of selected vascular territories was then performed. Our findings reconfirmed the previously described vascular connections between the thoracodorsal system and the intercostal vessels via periosteal vessels. We also newly discovered vascular anastomoses between the serratus anterior muscle and the intercostal artery running within a mesentery. This mesentery is lateral to and distinct from the serratus-periosteal-intercostal network. The nerve graft was applied clinically in the reconstruction of a complex soft-tissue, 13-cm ulnar nerve defect of the volar forearm after an electrical injury. The clinical application was successful with limb salvage and return of protective sensation at 4 months. Our clinical and investigative results support the feasibility of the serratus anterior intercostal nerve graft, a unique and versatile new vascularized nerve graft.- - - - - - - - - - ranking = 0.66666666666667keywords = vessel (Clic here for more details about this article) |