Syuji Shimazaki

Surgical stabilization of internal pneumatic stabilization? A prospective randomized study of management of severe flail chest patients.

BACKGROUND We compared the clinical efficacy of surgical stabilization and internal pneumatic stabilization in severe flail chest patients who required prolonged ventilatory support. METHODS Thirty-seven consecutive severe flail chest patients who required mechanical ventilation were enrolled in this study. All the patients received identical respiratory management, including end-tracheal intubation, mechanical ventilation, continuous epidural anesthesia, analgesia, bronchoscopic aspiration, postural drainage, and pulmonary hygiene. At 5 days after injury, surgical stabilization with Judet struts (S group, n = 18) or internal pneumatic stabilization (I group, n = 19) was randomly assigned. Most respiratory management was identical between the two groups except the surgical procedure. Statistical analysis using two-way analysis of variance and Tukeys test was used to compare the groups. RESULTS Age, sex, Injury Severity Score, chest Abbreviated Injury Score, number of rib fractures, severity of lung contusion, and Pao2/Fio2 ratio at admission were all equivalent in the two groups. The S group showed a shorter ventilatory period (10.8 +/- 3.4 days) than the I group (18.3 +/- 7.4 days) (p < 0.05), shorter intensive care unit stay (S group, 16.5 +/- 7.4 days; I group, 26.8 +/- 13.2 days; p < 0.05), and lower incidence of pneumonia (S group, 24%; I group, 77%; p < 0.05). Percent forced vital capacity was higher in the S group at 1 month and thereafter (p < 0.05). The percentage of patients who had returned to full-time employment at 6 months was significantly higher in the S group (11 of 18) than in the I group (1 of 19). CONCLUSION This study proved that in severe flail chest patients, surgical stabilization using Judet struts has beneficial effects with respect to less ventilatory support, lower incidence of pneumonia, shorter trauma intensive care unit stay, and reduced medical cost than internal fixation. Moreover, surgical stabilization with Judet struts improved percent forced vital capacity from the early phase after surgical fixation. Also, patients with surgical stabilization could return to their previous employment quicker than those with internal pneumatic stabilization, even in those with the same severity of flail chest. We therefore concluded that surgical stabilization with Judet struts may be preferably applied to patients with severe flail chest who need ventilator support.

High-dose vitamin C therapy for extensive deep dermal burns

We studied the haemodynamic effects of antioxidant therapy with high-dose vitamin C administration (170 mg/kg/24 h) in guinea-pigs with 70 per cent body surface area deep dermal burns. The animals were divided into three groups of six animals each. Group 1 was resuscitated with Ringers lactate solution according to the Parkland formula; group 2 with 25 per cent of the Parkland formula with vitamin C; and group 3 with 25 per cent of the Parkland formula without vitamin C. There were no significant differences in heart rates or in blood pressures between the groups throughout the 24-h study period. Group 3 showed significantly higher haematocrit values at 3 h postburn and thereafter as compared with those of group 2. The cardiac output values of group 2 were significantly higher than those of group 3, but equivalent to those of group 1. The water content of the burned skin in group 2 was significantly lower than that in the other groups, indicating that increased postburn capillary permeability was minimized by the administration of vitamin C. With adjuvant high-dose vitamin C administration, we were able to reduce the 24-h resuscitation fluid volume from 4 ml/kg/per cent burn to 1 ml/kg/per cent burn, while maintaining adequate cardiac output.

Bone marrow-derived myofibroblasts recruited to the upper dermis appear beneath regenerating epidermis after deep dermal burn injury.

Fibroblasts and myofibroblasts migrating to sites of tissue repair after injury may not only be locally recruited but could also be recruited from the bone marrow. However, the characteristics and functional roles, if any, of these cells in wound healing are poorly understood. Here, we show unequivocally that bone marrow‐derived fibroblasts do contribute to deep dermal burn wound healing. Bone‐marrow stromal cells were collected from femurs of male Lewis rats, cultured for a week, and then the adherent cells were labeled with the fluorescent marker PKH‐26. These cells stained positive for α‐smooth muscle actin and prolyl 4‐hydroxylase, but did not express RM‐4 (a macrophage marker), CD34, or cytokeratin, characteristic of myofibroblastic differentiation. When injected intravenously into Lewis rats, they homed to the bone marrow. Five days after transplantation, a deep dermal burn was made on the back of the rat, and biopsies were taken 7, 10, and 14 days later. PKH‐positive cells were not found at day 7, but by day 10, they were easily detected mainly in the upper dermis close beneath the regenerating epidermis. These PKH‐positive cells still stained for α‐SMA and prolyl 4‐hydroxylase, but not RM4. Thus, it is suggested that myofibroblasts originating in the bone marrow contribute not only to promotion of granulation but also enhancement of dermal–epidermal interaction after thermal injury.

Mild hypotension and body burns synergistically increase bacterial translocation in rats consistent with a two-hit phenomenon

Wistar rats were burned over 15% of their total body surface area and suffered hemorrhagic hypotension (mean blood pressure 80 mm Hg) 72 hours after the thermal injury (burn + hypotension group). Rats in other groups were treated in the same way except sham hypotension in burn group, sham burn in hypotension group, and sham hypotension and sham burn in control group. At the end of the study period, the mesenteric lymph nodes (MLN), liver, and spleen were cultured for translocated bacteria. The cecal bacterial burden was not affected by the insults. The number of bacteria translocated to the MLN after the thermal injury was much greater in the burn + hypotension group (156.19 +/- 42.29 colony-forming units [CFUs]/gm tissue) rather than in the other groups (5.24 +/- 8.34, 9.86 +/- 16.56, 40.21 +/- 45.8 in the control, hypotension, and burn groups, respectively). This indicates that bacterial translocation (BT) is the result of a two-hit phenomenon. The gut-MLN BT ratio, obtained by dividing the bacterial CFUs in the MLN by those in the cecum, was higher in the burn + hypotension group than in the other groups (p < 0.01). This ratio allows standardized measurements of BT to the MLN despite differences in the absolute bacterial load in the gut, and the elevated gut mesenteric lymph nodes BT ratio of the burn + hypotension group suggests that the two-hit phenomenon of BT may be the result of alterations in the gut mucosal barrier function.

Delayed hemorrhage following transcatheter arterial embolization for blunt hepatic injury

This is the first report of delayed hemorrhage (21 days after the injury) following transcatheter arterial embolization (TAE) for severe hepatic injury. The first TAE was performed about 2 h after admission on a 21-year-old man with severe blunt hepatic injury. Three bilomas were detected by cholescintigraphy 19 days later. The patients status had been eventless until the occurrence of a delayed hemorrhage with hypotension. Angiography was repeated and three pseudoaneurysms were detected TAE, pseudoaneourysms disappeared and hemorrhage could be controlled. Intrahepatic biloma may be related to pseudoaneurysms and delayed hemorrhage in severe hepatic injury.

Enzyme-free method for cultured skin grafting.

Cultured skin autografting has promise to improve the prognosis of severe burn injury. Established methods for cultured epithelial cell autografting need enzymatic proteolytic reaction that have potential risks of losing cell surface structures and causing allergic reactions in the recipients. Therefore, we have developed an enzyme-free method of cultured skin autografting. Donor skin was obtained in 0.2-0.3 mm thickness during an operation of debriding burned eschar. The skin was cut into pieces and spread on removable soft culture surface membrane in culture plates. Modified MCDB 153 medium with 10 microg/L epidermal growth factor and 150 mg/L bovine pituitary extract was used. The tissues were incubated at 37 degrees C in a water-saturated atmosphere of 5% CO2 in air. After 3 weeks, the cultured tissue on the membrane was removed mechanically from the bottom of the plates and implanted on granulated recipient sites in upside down manner. The cultured auto-skin grafting was successfully performed in two patients with severe burn. The recipient sites were partially epithelized in 2 weeks and maintained thereafter. Our method is performed easily using partial thickness donor skin without enzymatic processes.