ABSTRACT
OBJECTIVE@#To evaluate the effectiveness of super-selective renal artery embolization in treatment of post-percutaneous nephrolithotomy bleeding, and to analyse the causes of failure embolization.@*METHODS@#In the study, 65 post-percutaneous nephrolithotomy patients with severe renal bleeding and hemodynamic instability were treated by super-selective renal artery embolization. First of all, we performed selective renal arteriography. After clarifying the location of the bleeding, superselective intubation of the injured vessel with a microcatheter was carried out. Then the injured vessel was embolized with Tornado micro-coil. When complete embolization was not achieved with micro-coil, a small amount of gelatin sponge particles were added. If there was no positive finding of the beginning selective renal arteriography, the following measures could be taken to prevent missing lesions: (1) Abdominal aorta angiography was performed to determine whether there were anatomical variations, such as accessory renal arteries or multiple renal arteries; (2) Ultra-selective intubation angiography next to the nephrostomy tube path was performed; (3) Renal arteriography was repeated; (4) Renal arteriography after removing the nephrostomy tube while retaining the puncture channel. We evaluated the different angiographic findings and analysed the causes of embolization failure.@*RESULTS@#Bleeding was successfully controled in 60 patients (62 kidneys) whose renal arteriography was postive. Positive findings included: pseudoaneurysm formation, patchy contrast extravasation, pseudoaneurysm combined with arteriovenous fistula, contrast agent entering the collection system, extravascular perinephric leakage of contrast. After first embolization, bleeding was controled in 53 patients (55 kidneys). The success rate after the first and second embolization was 88.7% and 96.7% respectively. The second session was required because of failure to demonstrate bleeding arteries during the first session (4 patients, 57.1%) and recurrent hemorrhage of the embolized injured arteries (2 patients, 28.6%). In 5 patients with no positive findings, after conservative treatment, hematuria disappeared. All the patients were followed up for 3, 6, and 12 months after embolization, and no hematuria occurred again, and no sustained and serious renal insufficiency.@*CONCLUSION@#Super-selective renal artery embolization is an effective treatment for post percutaneous nephrolithotomy bleeding. The main cause of failure is omitting of injured arteries during renal arteriography. Renal artery branch injury has various manifestations. Attention should paid to the anatomical variation of the renal artery, and patient and meticulous superselective intubation angiography is the key to avoiding missing the lesion and improving the success rate of embolization.
Subject(s)
Humans , Embolization, Therapeutic , Hemorrhage/etiology , Nephrolithotomy, Percutaneous/adverse effects , Nephrostomy, Percutaneous , Renal Artery , Retrospective StudiesABSTRACT
<p><b>BACKGROUND</b>Intravoxel incoherent motion (IVIM) has the potential to provide both diffusion and perfusion information without an exogenous contrast agent, its application for the brain is promising, however, feasibility studies on this are relatively scarce. The aim of this study is to assess the feasibility of IVIM perfusion in patients with acute ischemic stroke (AIS).</p><p><b>METHODS</b>Patients with suspected AIS were examined by magnetic resonance imaging within 24 h of symptom onset. Fifteen patients (mean age was 68.7 ± 8.0 years) who underwent arterial spin labeling (ASL) and diffusion-weighted imaging (DWI) were identified as having AIS with ischemic penumbra were enrolled, where ischemic penumbra referred to the mismatch areas of ASL and DWI. Eleven different b-values were applied in the biexponential model. Regions of interest were selected in ischemic penumbras and contralateral normal brain regions. Fast apparent diffusion coefficients (ADCs) and ASL cerebral blood flow (CBF) were measured. The paired t- test was applied to compare ASL CBF, fast ADC, and slow ADC measurements between ischemic penumbras and contralateral normal brain regions. Linear regression and Pearson's correlation were used to evaluate the correlations among quantitative results.</p><p><b>RESULTS</b>The fast ADCs and ASL CBFs of ischemic penumbras were significantly lower than those of the contralateral normal brain regions (1.93 ± 0.78 αμm2/ms vs. 3.97 ± 2.49 αμm2/ms, P = 0.007; 13.5 ± 4.5 ml·100 g-1·min-1 vs. 29.1 ± 12.7 ml·100 g-1·min-1, P < 0.001, respectively). No significant difference was observed in slow ADCs between ischemic penumbras and contralateral normal brain regions (0.203 ± 0.090 αμm2/ms vs. 0.198 ± 0.100 αμm2/ms, P = 0.451). Compared with contralateral normal brain regions, both CBFs and fast ADCs decreased in ischemic penumbras while slow ADCs remained the same. A significant correlation was detected between fast ADCs and ASL CBFs (r = 0.416, P < 0.05). No statistically significant correlation was observed between ASL CBFs and slow ADCs, or between fast ADCs and slow ADCs (r = 0.111, P = 0.558; r = 0.200, P = 0.289, respectively).</p><p><b>CONCLUSIONS</b>The decrease in cerebral blood perfusion primarily results in the decrease in fast ADC in ischemic penumbras; therefore, fast ADC can reflect the perfusion situation in cerebral tissues.</p>