[Values in preoperative assessment of occlusion and intra-operative guidance of 64 row spiral CT in percutaneous coronary intervention for chronic coronary occlusion].

OBJECTIVE: To instigate the values of 64 row spiral CT in pre-operative assessment of the occlusion and intra-operative guidance in percutaneous coronary intervention for chronic total occlusion (CTO) in coronary heart disease. METHODS: Fifteen coronary disease patients planned to receive percutaneous coronary intervention underwent 64-row spiral CT-coronary angiography and coronary angiography (CAG). The diagnostic effects of these 2 techniques were compared. RESULTS: Seventeen CTO lesions were confirmed. MSCT succeeded to show the lengths of the 17 CTO lesions with a calcification identification rate of 76.4%, significantly higher than that of the CAG (41.5%). By cross-section examination, MSCT succeeded to detect the occlusion degree of the calcified lesions, and showed that 3 CTO lesions were occluded at a rate < 50%, and 10 lesions at a rate > or = 50%. Twelve complete occlusion lesions in 11 patients underwent PCT, success was seen in 6 of which and failure in the other 6. Univariate analysis showed that the length of lesion, branching at the proximal site, formation of bridging lateral branch, form of occlusion end, and calcification were all not significantly related to the success or failure of intervention. The percentage of the calcification area > or = 50% in the intervention failure group was 83.3%, significantly higher than that in the intervention success group (16.7%, P = 0.05). 3-D images of coronary artery could be obtained by MSCT to show all the complete occlusive lesions. CONCLUSION: 64-MSCT demonstrates a remarkable ability to identify silicified lesions, can re-establish 3-D images of coronary artery, and effectively guide the intervention therapy.

Chemical renal artery denervation with appropriate phenol in spontaneously hypertensive rats.

OBJECTIVE: To explore the effectiveness of renal denervation (RDN) on blood pressure with the appropriate dosage of phenol/ethanol solution in spontaneously hypertensive rats (SHRs). METHODS: RDN was performed on the bilateral renal artery. Forty SHRs were divided into four groups according on the dosage of phenol (10% phenol in absolute ethanol): sham group, 0.5 mL phenol group, 1 mL phenol group and 1.5 mL phenol group (n = 10 in each group). Blood pressure was measured by tail-cuff plethysmography. Plasma creatinine was determined four weeks after the treatment. The kidneys and renal arteries were collected and processed for histological examination. RESULTS: A sustained decrease in systolic blood pressure (SBP) was only observed after the application of 1 mL phenol for four weeks, while SBP was lowered during the first week after RDN and increased in the following three weeks in the 0.5 mL and 1.5 mL phenol groups compared with the sham group. Renal norepinephrine (NE) was significantly decreased four weeks after RDN in the 1 mL and 1.5 mL phenol group compared with the sham group, but not in the 0.5 ml group. RDN with 1 mL phenol obviously reduced glomerular fibrosis. Histopathological analysis showed that tyrosine hydroxylase immunoreactivity was lower in the 1 mL and 1.5 mL phenol groups compared with the sham group. Moderate renal artery damage occurred in the 1.5 mL phenol group. CONCLUSION: Chemical denervation with 1 ml phenol (10% phenol in absolute ethanol) effectively and safely damaged peripheral renal sympathetic nerves and contributed to the sustained reduction of blood pressure in SHRs.

Efficacy and safety of a novel multi-electrode radiofrequency ablation catheter for renal sympathetic denervation in pigs.

OBJECTIVE: To investigate the safety and efficacy of a self-developed novel multi-electrode radiofrequency ablation catheter (Spark) for catheter-based renal denervation (RDN). METHODS: A total of 14 experimental miniature pigs were randomly divided into four groups (55°& 5-watt, 55°& 8-watt, 65°& 5-watt, and 65° & 8-watt groups). Spark was used for left and right renal artery radiofrequency ablation. Blood samples collected from renal arteries and veins as well as renal arteriography were performed on all animals before, immediately after, and three months after procedure to evaluate the effects of Spark on the levels of plasma renin, aldosterone, angiotensin I, and angiotensin II as well as the pathological changes of renal arteries. RESULTS: One pig died of an anesthetic accident, 13 pigs successfully underwent the bilateral renal artery ablation. Compared with basic measurements, pigs in all the four groups had significantly decreased mean arterial pressure after procedure. Histopathological analysis showed that this procedure could result in intimal hyperplasia, significant peripheral sympathetic nerve damage in the renal arteries such as inflammatory cell infiltration and fibrosis in perineurium, uneven distribution of nerve fibers, tissue necrosis, severe vacuolization, fragmented and unclear nucleoli myelin degeneration, sparse axons, and interruption of continuity. In addition, the renal artery radiofrequency ablation could significantly reduce the levels of plasma renin, aldosterone, angiotensin I, and angiotensin II in pigs. CONCLUSIONS: The results suggest that this type of multi-electrode catheter-based radiofrequency ablation could effectively remove peripheral renal sympathetic nerves and reduce the activity of systemic renin-angiotensin system in pigs, thus facilitating the control of systemic blood pressure in pigs.

Utility of 64-MSCT in assessing acute non-reperfused myocardial infarct size.

OBJECTIVE: To evaluate the utility of multi-slice computed tomography (MSCT) in assessing acute non-reperfused myocardial infarct size. METHODS: Seven domestic pigs (mean weight 17.3 ± 1.9 kg) underwent ligation of the distal left anterior descending artery to establish a model of acute myocardial infarction (MI). MSCT and triphenyltetrazolium chloride (TTC) staining were performed two hours later. The following data were acquired and analyzed: MI volume (%), CT values of the infarcted region, left ventricular cavity and normal cardiac tissue at various scanning time-points (1, 5, 10, 15, 20 min after contrast injection). RESULTS: Using MSCT, the overall MI volume showed a time-dependent decrease, with a reduction of 28.87% after 20 min. The greatest reduction occurred at the 5 min time-point. In TTC staining, MI volume was 9.87% ± 2.44%. When MI size, as determined by MSCT, was compared with that by TTC staining in Bland-Altman plots, there was a better agreement at 5, 10, and 15 min time-points at 1 and 20 min. CONCLUSIONS: The study indicates that double-phase scanning examination using MSCT is a useful tool to assess MI size, and the optimal late-phase scanning time-point set within 5-15 min of contrast injection.