Preoperative Tract Dilatation for Percutaneous Nephrolithotomy

PURPOSE: The purpose of this study was to understand the principle of percutaneous nephrolithotomy(PNL), toincrease its success rate, and to base the radiologic approach on preoperative interventional tract dilatation. MATERIALS AND METHODS: Twenty-six patients(male, 19, female, 7) with staghorn or pelviocalyceal calculi who hadundergone PNL were included in this study. After percutaneous nephrostomy(PCN) was performed in each patient, thetract was dilated to 30F with Amplatz dilators using coaxial techniques or a 30F, 10cm high-pressure tractdilatation balloon. One day before the calculi were fragmented and removed by PNL, a 30F Amplatz sheath wasinserted under local anesthesia. The time required for tract dilatation, complications, and surgery was analyzed. RESULTS: Percutaneous tract dilatation were successful in all patients, and forceps, a nephrolithotome and anephroscope were successfully introduced into the pelvocalyceal system. The average procedure time was 19.5minutes ; a double J stent was replaced in the pelvocalyceal system of 13 of 26 patients (50%) ; because ofimproper catheter direction or/and bleeding, the Amplatz sheath was replaced in three. After PNL, complicationsinvolving renal hematoma occurred in one patient. This did not affect the patient's prognosis, however. CONCLUSION:Owing to its short procedure time and low complication rate, interventional preoperative tract dilatation forPNL is thought to be an effective technique for patients with staghorn or pelvocalceal calculi.

Saline-enhanced Radiofrequency Electrocoagulation in Bovine Liver

PURPOSE: To determine the effectiveness of saline-enhanced radiofrequency electrocoagulation in bovine liver tissue MATERIALS AND METHODS: Saline-enhanced radiofrequency electrocoagulation (group I), hot saline injection induced by radiofrequency electrocoagulation (group II), and radiofrequency electrocoagulation (group III) were performed in ex vivo bovine liver. Radiofrequency power was 100 and 200 watts, and current was applied for 10, 20, and 30 seconds. Tissue was histopathologically examined for thermal injury. RESULTS: The largest diameter of thermal injury was about 41.0 mm in group I, 12.3 mm in group II and 9.3 mm in group III. The mean diameter of the injury increased with higher wattage in group I and II and with longer procedure time in group I (p<0.05). At corresponding wattage and times, group I showed a larger diameter of thermal injury and more increase in than group II or III(p<0.05). The degree of carbonization was more severe in group III than in groups I and II. Grossly, thermal injury showed a well-defined, relatively spherical configuration without extension along parenchymal interstitium. CONCLUSION: In an animal model, saline-enhanced radiofrequency electrocoagulation may effectively induce thermal injury, and may thus be another effective tool for use in the treatment of hepatic tumors. Further clinical experience is needed.

Enhancing Pattern of Gastric Carcinoma at Dynamic Incremental CT: Correlation with Gross and Histologic Findings

PURPOSE: To evaluate the enhancing pattern of gastric carcinomas at dynamic incremental CT and to correlate it with pathologic findings. MATERIALS AND METHODS: We retrospectively evaluated the enhancement pattern of stomach cancer on dynamic incremental CT of the 78 patients. All the lesions had been pathologically proved aftersurgery. The enhancement pattern was categorized as good or poor in the early phase ; homogeneous, heterogeneous or ring enhancement ; the presence or absence of delayed enhancement. There were 16 cases of early gastriccancer(EGC), and 62 cases of advanced gastric cancer(AGC). The Borrmann type of AGC were 1(n=1), 2(n=20), 3(n=32),4(n=8) and 5(n=1). The histologic patterns of AGC were tubular(n=49), signet ring cell(n=10), and mucinous(n=3). The enhancing patterns were compared with gross and histologic findings and delayed enhancement was corrrelated with pathologic evidence of desmoplasia. RESULTS: Good enhancement of tumor was seen in 24/41cases (58.5%) with AGC Borrmann type 3-5, in 6/21(28.6%) with AGC Borrmann type 1-2, and in 3/16(18.8%) with EGC (P<.05). By histologic pattern, good enhancement of tumor was seen in 8/10(80%) with signet ring cell type, in 21/49(42.9%)with tubular type, and in 1/3(33.3%) with mucinous type(P<.05). EGC was homogeneously enhanced in 14/16cases(87.5%), but AGC was heterogeneously enhanced in 33/62(53.2%), respectively(P<.01). There was no significant correlation between delayed enhancement and the presence of desmoplasia. CONCLUSION: AGC Borrmann type 3-5 andsignet ring cell type have a tendency to show good enhancement and EGC is more homogeneously enhanced at dynamicincremental CT.