Expression of inducible nitric oxide synthase in muscle flaps treated with ischemic postconditioning.

BACKGROUND/OBJECTIVE: Preconditioning has been considered promising for the treatment of ischemic flaps. In this study, the therapeutic effect of postconditioning was compared with that of preconditioning during ischemia/reperfusion (I/R) injury, and a role of inducible nitric oxide synthase (iNOS) in postconditioning treatment was also explored. METHODS: Sixty rats were randomly divided into four groups with 15 rats in each group. Ischemic injury was induced in a rat's gracilis muscle flap model. Preconditioning and postconditioning were performed respectively on the flaps in the pre-con group and the post-con group. No treatment was given to the flaps in the control group, and flaps without I/R injury were used as a sham control. Muscle viability ratio, histology, and gene expression of iNOS were examined at different time intervals (3, 12, and 18 h). RESULTS: A significantly higher survival ratio was observed in both the pre-con group (78.98 ± 3.39, 62.74 ± 3.7, and 54.42 ± 4.45 %) and the post-con group (77.42 ± 4.14, 59.74 ± 6.67, and 49.52 ± 4.13 %) than the control group (45.22 ± 3.69, 42.44 ± 3.76, and 33.2 ± 3.29 %) at 3, 12, and 18 h postoperatively (P < 0.05). There was no statistical difference between the pre-con group and the post-con group (P > 0.05). Histological examination showed delayed and attenuated tissue damage in both the pre-con group and the post-con group when compared to that of the control group. A higher expression of iNOS was observed in both the pre-con group and the post-con group than the control group and the sham group (P < 0.05). CONCLUSIONS: Significant improvement of flap survival could be achieved by both preconditioning and postconditioning treatments; however, better protection could be provided by preconditioning. The higher expression of iNOS may play an important role in the therapeutic effect of postconditioning during I/R injury.

"The chisel test"--a useful operative, technique for determining adequate, compression during arthrodesis.

Healing of an arthrodesis occurs optimally when the prepared joint surfaces are held rigidly under compression [1]. We routinely use the "Chisel test" intra-operatively to determine whether we have achieved adequate compression and rigidity after fixation of our foot and ankle fusions. This previously un-reported technique uses tools already on hand when performing an arthrodesis and takes seconds to perform.

The use of Integra with a sensate fasciocutaneous pedicled flap for the salvage reconstruction of a below knee amputation after pedestrian vs train multi-planar degloving injury.

Degloving injuries occur when there is sufficient tangential force to a body surface to disrupt the structures connecting skin and subcutaneous tissues to the superficial fascia. There may also be associated injuries to the underlying soft tissues, bone, nerves and vessels. The injury may be so severe that the limb is non-viable and requires amputation. Our patient sustained a severe lower limb degloving injury after an accident where the leg was caught and dragged along the platform by a train. There was insufficient skin to cover a below knee amputation stump. So, the dermal regeneration template Integra(r) was used in association with a sensate neurovascular fasciocutaneous pedicled flap salvaged from the non-viable lower leg to reconstruct the defect and avoid the need for an above knee amputation.

Cobb procedure and Rose calcaneal osteotomy for the treatment of tibialis posterior tendon dysfunction.

Forty-three patients with stage 2 posterior tibialis tendon dysfunction underwent surgical reconstruction in the form of a Cobb procedure and Rose calcaneal osteotomy between 1997 and 2003, and were evaluated pre- and postoperatively. The average age was 57 years, and the mean followup time was 51 months (range 10-83). The average AOFAS score preoperatively was 58 and improved to 85 postoperatively (p < 0.0001). Sixty-six per cent of patients achieved a single heel raise. Eighty-four per cent expressed a subjective satisfaction rate, whilst 16% reported no improvement. Seventy-eight per cent of the patients were able to use normal shoes and 65% no longer required the use of any orthotics. The minor complication rate was 16% with no major complications. All osteotomies united uneventfully. Two patients have subsequently developed subtalar osteoarthritis, and six calcaneal screws had to be removed for prominence and tenderness. Our results compare very favourably with other less anatomical reconstructions, any donor site morbidity has been avoided and there have been very low complication rates.

Ocular microtremor during general anesthesia: results of a multicenter trial using automated signal analysis.

Ocular microtremor (OMT) is a fine physiologic tremor of the eye related to neuronal activity in the reticular formation of the brainstem. The frequency of OMT is suppressed by propofol and sevoflurane and predicts the response to command at emergence from anesthesia. Previous studies have relied on post hoc computer analysis of OMT wave forms or on real-time measurements confirmed visually on an oscilloscope. Our overall aim was to evaluate an automated system of OMT signal analysis in a diverse patient population undergoing general anesthesia. In a multicenter trial involving four centers in three countries, we examined the accuracy of OMT to identify the unconscious state and to predict movement in response to airway instrumentation and surgical stimulation. We also tested the effects of neuromuscular blockade and patient position on OMT. We measured OMT continuously by using the closed-eye piezoelectric technique in 214 patients undergoing extracranial surgery with general anesthesia using a variety of anesthetics. OMT decreased at induction in all patients, increased transiently in response to surgical incision or airway instrumentation, and increased at emergence. The frequency of OMT predicted movement in response to laryngeal mask airway insertion and response to command at emergence. Neuromuscular blockade did not affect the frequency of OMT but decreased its amplitude. OMT frequency was unaffected by changes in patient position. We conclude that OMT, measured by an automated signal analysis module, accurately determines the anesthetic state in surgical patients, even during profound neuromuscular blockade and after changes in patient position.