OBJECTIVE: To validate the hemostatic properties of collagen sponge made in China. METHODS: The experimental model of superficial cut of liver was established in 20 Sprague-Dawley adult rats, which were divided into two groups randomly. Collagen sponge or gelatin sponge was used to cover the cut respectively. Hemostatic result was observed. Afterwards, standard liver trauma model by resection left front liver lobe was made, wound was treated with collagen sponge or gelatin sponge respectively. Hemostatic result was observed. Concurrent hemostatic time and bleeding amount were noted. At 7, 14 and 20 days after operation, intra-abdominal adhension, infection and healing state of liver were observed by exploratory laparotomy. The histological changes of regenerate liver tissue were observed by microscopy. RESULTS: Collagen sponge adhered to wound well. Concurrent hemostatic time and bleeding amount in collagen sponge group were superior to those of gelatin sponge (P lt; 0.05). The histological examination showed that collagen sponge was absorbed and degraded rapidly, regenerative hepatocytes could be induced. CONCLUSION: Collagen sponge has fine hemostatic properties and can induce regeneration of hepatocytes effectively. It is worth popularizing for its convenience in clinical application and its properties of rapid degradation and absorption.
OBJECTIVE To establish an artificial bladder reflex arc in canines to reinnervate the neuropathic bladder and restore bladder function after spinal cord injury. It involves a somatic reflex arc with a modified efferent branch which passes the somatic motor impulses to the bladder and initiates autonomic bladder detrusor contraction. METHODS Intradural microanastomosis of the right L5 ventral root to S2 ventral root was performed to maintain the right L5 dorsal root intact. After axonal regeneration, the new patellar ligament-spinal cord center-bladder artificial bladder reflex pathway was established, and micturition was induced by knocking the patellar ligament. The early and final function of the reflex arc was observed by electrophysiological examinations, bladder pressure tests and detrusor electromyograms(EMG) at 6 months and 18 months postoperatively. RESULTS Single stimuli (115 mV, 1.0 ms) of the right L5 dorsal root resulted in evoked potentials recorded from the right S2 ventral root distal to the anastomosis site before and after the spinal cord was transected horizontally at the T10 segment level in all 6 canines. Bladder contraction was very quickly initiated by trains of stimuli(1,000 mV, 10 Hz, 2 s) of the right L5 dorsal root and bladder pressures increased rapidly to 65% of normal, and bladder contraction induced by knocking the right patellar ligament was increased to 51% of normal through the new reflex arc in 4 canines after 6 months of operation. Bladder pressures were increased by the same stimuli to average 84% of normal and to 62% of normal by knocking the patellar ligament in 2 canines after 18 months of operation. Stimuli(3.8 mA, 1.0 Hz) of the right L5 dorsal root and femoral nerve resulted in EMG similar to normal EMG could be recorded from the detrusor in 2 canines after 18 months postoperatively. CONCLUSION The somatic motor axons can be regenerated into the parasympathetic endoneurial tubes of autonomic nerve. Using the survived somatic reflex under the horizon of spinal cord injury to reconstruct the bladder autonomic reflex arc by intradural microanastomosis of ventral root is practical in the canine model and may have a potential of clinical application.