Effect of Radiofrequency Lesioning on Peripheral Nerve Conductivity in Relation to Distance between Lesioning Electrode and Target Tissue in Rats

OBJECTIVE: To investigate neurophysiologic changes of peripheral nerves, which were injured by radiofrequency thermocoagulation and evaluate an effective distance between the lesioning electrode and target nerve tissue. METHOD: Thirty Sprague-Dawley rats were used and divided into three groups by the distance between the lesioning electrode and the sciatic nerve: 2 mm, 4 mm, 6 mm for each group (10 rats for each group). Radiofrequency lesioning was performed with 1.5 Volt, 1 MHz-frequency and 1 ms duration current for 90 sec. On the first and the fifth day after radiofrequency lesioning, latencies and amplitudes of compound muscle action potential were compared with the baseline values. RESULTS: No statistically significant latency change was observed on the first and the fifth day after lesioning. The amplitude was significantly reduced in group I and II on the first and the fifth day after lesioning, in contrast that, there was no significant change in the group III. CONCLUSION: There was significant decrement in the amplitude after effective radiofrequency lesioning to the sciatic nerve with the distance of 4 mm or less. However, changes of the latencies was not significant. It was suggested that effective distance between raidiofrequency lesioning electrode and target peripheral nerve was 4 mm or less.

Extraperitoneal Bladder Rupture during the Bladder Distension Therapy: A case report

A 75-year-old woman presented a cauda equina syndrome with epiconus involvement from the compression fractures of T12, L1, and L3 vertebrae as a result of fall accident. Cystometrogram performed at three months after the injury showed a small bladder capacity and low compliance. Anticholinergic medications including intravesical instillation of oxybutynin solution failed to increase the bladder capacity or lower the intravesical pressure. Bladder distension therapy using normal saline infusion with a volume surpassing the previous measured maximal bladder capacity was performed. The procedures were repeated four times per day. At the fifth day of the distension therapy, the patient complained of acute low abdominal pain and gross hematuria. The cystogram revealed the extraperitoneal bladder rupture. The patient was treated successfully with antibiotics and continuous urinary drainage through the Foley catheter for 14 days. We report a case of extraperitoneal bladder rupture during the bladder distension therapy.

Correlation between Doppler Ultrasonography and Impedance Plethysmography in Lower Extremity Varicose Vein

OBJECTIVE: To investigate the diagnostic validity of doppler ultrasonography (US) and impedance plethysmography (IPG) using photoplethysmography for evaluation of varicose vein of the lower extremities. METHOD: One hundred sixty-six limbs in 83 consecutive patients with varicose vein were included. Venous reflux and deep venous lesions were assessed by doppler US. Venous filling time was evaluated using IPG. Diagnostic capabilities of two methods were analyzed using Receiver Operating Characteristic (ROC) curve. RESULTS: Doppler US identified superficial venous reflux in sixty-nine of 119 limbs with varicose vein and no abnor malities in 34 of 47 normal limbs (sensitivity, 58%; specifi-city, 75%). IPG demonstrated superficial venous insufficiency in 75 of the affected limbs and normal refill time in 38 of the normal limbs (sensitivity, 63%; specificity, 81%). Sensitivity was increased to 82% when both tests were used together. Area under the ROC curve was 0.66 in doppler US, 0.72 in IPG, and 0.76 in both tests. Deep venous lesion was found in 31 limbs using the both tests; 15 limbs with doppler US and 18 limbs with IPG. CONCLUSION: IPG was more superior to doppler US in diagnosing venous insufficiency. The combination of both tests provided more accurate diagnostic information in assessing venous valvular function