Chemical ablation of the canine kidney using sodium tetradecyl sulfate (Sotradecol). A histopathologic study

We studied the histopathologic effect of intraarterial Sotradecol (Elkins-Sinn, Inc., Cherry Hill, NJ) on the kidney and examined the mechanism for destruction of renal parenchyma by Sotradecol. Sotradecol was injected into one renal artery distal to an occlusion balloon catheter in six dogs, and the kidneys were removed for histologic examination; four dogs within 20 minutes, and one each at 12 and 24 hours after embolization. The contralateral kidney of each dog underwent the same procedure but was injected with normal saline, and served as control. Histologic examination of the control kidneys was unremarkable. The embolized kidneys revealed extensive endothelial denudation and mural necrosis of the arteries and coagulation necrosis of the renal parenchyma. The changes were evident as early as 20 minutes after embolization, and necrosis became complete by 24 hours. The arteries were filled with red blood cell sludge. Sotradecol produces extensive tissue necrosis and complete renal parenchymal destruction through its direct cytotoxic action on the arterial wall, blood cell elements, and renal parenchyma.     

Instant selective arterial occlusion with isobutyl 2-cyanoacrylate.

Isobutyl 2-cyanoacrylate (IBC) delivered selectively in small doses produced immediate occlusion of the injected arteries in dogs without significant undesired sequelae. In one patient, pelvic hemorrhage was promptly stopped by a similar technique. In another patient, who was on chronic renal dialysis and judged too ill for nephrectomy, IBC occluded both renal arteries and terminated a life-threatening renal protein loss.     

Morphological characteristics of chronic total occlusion: predictors of different strategies for long-segment femoral arterial occlusions

Objectives

To investigate morphological characteristics used to predict recanalisation strategies in long-segment (>10 cm) femoral chronic total occlusion (LSF-CTO) angioplasty.

Methods

We retrospectively evaluated a range of morphological CTA and DSA features in patients who underwent recanalisation of LSF-CTO. The stage of CTO was classified into early (3–12 months) and late (>12 months) according to estimated duration. Characteristics including stump morphology, lesion length and calcification, proximal side branches, collaterals circulation, runoff vessels and concomitant arterial occlusion were used as predictors, and multivariate logistic regression analysis was performed to identify variables associated with late-stage CTO and retrograde technique.

Results

A total of 119 patients with 137 CTOs in 137 limbs were enrolled. Overall, successful recanalisation was achieved in 122 CTOs (89.1%). Flush occlusion [odds ratio (OR) 2.958; 95% confidence interval (CI) 1.172–7.465; p = 0.022], large collateral (OR 2.778; 95% CI 1.201–6.427; p = 0.017) and TransAtlantic Inter-Society Consensus II class D (TASC D) lesion (OR 1.743; 95% CI 1.019–2.981; p = 0.042) were predictors for late-stage CTO. Flush occlusion (OR 75.278; 95% CI 10.664–531.384; p < 0.001) and large collateral (OR 23.213; 95% CI 3.236–166.523; p = 0.002) were associated with high likelihood for retrograde approach.

Conclusions

Flush occlusion and large collateral were associated with a CTO at late-stage which may require retrograde recanalisation.

Key points

? CTO morphological characteristics help estimate lesion duration and optimise recanalisation strategies. ? Flush occlusion and large collateral is associated with late-stage CTO and retrograde recanalisation. ? Application of anterograde and retrograde recanalisation for long-segment femoral CTO is effective.

     

Intraarterial ethanol as a long-term occlusive agent in renal,hepatic, and gastrosplenic arteries of pigs

The renal, hepatic, or gastrosplenic arteries of eleven juvenile pigs were selectively injected intraarterially with 95% ethanol to evaluate its efficacy as an agent for use in permanent occlusion and infarction of the vascular bed supplied by the injected artery. A dose of 2.2 cc/5 kg (1 cc/5 lb) of 95% ethanol was injected over 30–45 sec. The animals were then killed at 1 to 91 days and all pigs demonstrated tissue infarction and vascular occlusion. Our results confirm that ethanol is an effective agent for the infarction of organs and that complications can result if catheter placement is not precise and normal tissue is inadvertently perfused.     

Late recanalisation beyond 24 hours is associated with worse outcome: an observational study

Objectives

We evaluated the rate of late recanalisation beyond 24 h after intravenous thrombolysis (IVT) and its relationship with haemorrhagic transformation and outcome.

Methods

We reviewed prospectively collected clinical and imaging data from acute ischaemic stroke patients with distal internal carotid artery or proximal middle cerebral artery occlusion who underwent angiography on admission, 24 h and 1 week after IVT. Patients were trichotomised according to vascular status: timely recanalisation (<24 h), late recanalisation (24 h-7 days), and no recanalisation.

Results

Non-invasive angiography revealed timely recanalisation in 52 (50.0 %) patients, late recanalisation in 25 (24.0 %) patients, and no recanalisation in 27 (26.0 %) patients. Pre-existing atrial fibrillation was associated with the occurrence of late recanalisation (odds ratio 6.674; 95 % CI: 1.197 to 37.209; p?=?0.030). In patients without timely recanalisation, shift analysis indicated that late recanalisation led to a worse modified Rankin Scale score (odds ratio 6.787; 95 % CI: 2.094 to 21.978; p?=?0.001).

Conclusions

About half of all patients without recanalisation by 24 h after IVT may develop late recanalisation within 1 week, along with higher mRS scores by 3 months. Pre-existing atrial fibrillation is an independent predictor for late recanalisation.

Key Points

? About half of patients may develop late recanalisation within 1 week. ? Pre-existing atrial fibrillation was associated with the occurrence of late recanalisation. ? Late recanalisation led to a higher mRS score than no recanalisation.

     

In vitro experiment and initial clinical experience in angioplasty,in vascular occlusive disease with a new pulsed dye-laser system

The feasibility of using a pulsed dye-laser in angioplasty for detection and disintegration of calcified plaques was studied in vitro. The laser (495 nm wave-length; 2 s pulse duration) was used as the exciting source for laser-induced-fluorescence (LIF) signals. Spectral data in the 520 to 800 nm region of normal artery wall, calcified plaques, and fibro-fatty plaques were analysed with an optical multichannel analyser. Good signal-to-noise ratio and different spectra for different specimens were obtained within only 2 s. Fluorescence analysis can be performed in less than 300 ns and therefore the laser can be controlled before plasma threshold is reached. This can lead to a clinical by useful feedback system in an intelligent laser, which can selectively ablate atherosclerotic tissue. In a parallel step we investigated a pulsed dye-laser device (504 nm; 1.2 s) for in vivo recanalisation of arteries in ischaemic lower limbs. A specially designed 9F or 7F guide wire directed multifibre catheter was used for treatment of 17 patients. The recanalisation technical success was 8/8 (4 occlusions/5 stenoses) in the iliac arteries (IA) and 8/9 (8 occlusions/4 stenoses) in the superficial femoral (SFA) and popliteal arteries (PA). All occlusion lengths were below 10 cm. Three early re-occlusions occured, caused by very bad run-off. There was one clinically insignificant SFA perforation and one groin haematoma. Additional techniques (balloon dilatation, stenting, lysis) were considered necessary in 15/17 patients. Mean ankle-arm-index increased significantly in the 1 week examination in rest from 0.61 to 0.76 (P < 0.05) in IA and from 0.65 to 0.93 (P < 0.01) in SFA. Pulsed dye-laser angioplasty promises to be an effective method for plaque ablation/debulking. Correspondence to: M. Zwaan     

Renal Artery Embolization Using a New Liquid Embolic Material Obtained by Partial Hydrolysis of Polyvinyl Acetate (Embol): Initial Experience in Six Patients

Objective

To evaluate the therapeutic efficacy of a new liquid embolic material, Embol, in embolization of the renal artery.

Materials and Methods

Embol is a new embolic material obtained by partial hydrolysis of polyvinyl acetate mixed in absolute ethanol and Iopromide 370 and manufactured by Schering Korea, Kyonggido, Korea. Six patients who underwent embolization of the renal artery using Embol were evaluated. Four were male and two were female and their ages ranged from 11 to 70 (mean, 53) years. Clinical and radiologic diagnoses referred for renal artery embolization were renal cell carcinoma (n = 3), renal angiomyolipoma (n = 2) and pseudoaneurysm of the renal artery (n = 1). After selective renal angiography, Embol was injected through various catheters, either with or without a balloon occlusion catheter. Changes in symptoms and blood chemistry which may have been related to renal artery embolization with Embol were analyzed.

Results

The six patients showed immediate total occlusion of their renal vascular lesions. One of the three in whom renal cell carcinoma was embolized with Embol underwent radical nephrectomy, and the specimen thus obtained revealed 40% tumor necrosis. In the two patients with angiomyolipomas, the tumors decreased in size and abdominal pain subsided. Bleeding from pseudoaneurysm of the renal artery was successfully controlled. Four patients showed symptoms of post-embolization syndrome, and one of these also showed increased levels of blood urea nitrogen and creatinine. One patient experienced transient hypertension.

Conclusion

Embol is easy to use, its radiopacity is adequate and it is a safe and effective embolic material which provides immediate and total occlusion of renal vascular lesions.     

Imaging Features of Gray-Scale and Contrast-Enhanced Color Doppler US for the Differentiation of Transient Renal Arterial Ischemia and Arterial Infarction

Objective

To characterize the imaging features on gray-scale and contrast-enhanced color Doppler US images which differentiate renal ischemia from renal infarction.

Materials and Methods

The segmental renal arteries of eight healthy rabbits were surgically ligated. In four of these rabbits, the ligated renal artery was released 60 minutes after arterial occlusion to cause transient ischemia. In the remaining four rabbits, the arterial ligation was retained to cause a permanent infarction. The gray-scale and contrast-enhanced color Doppler US imaging features of the involved renal parenchyma of both ischemia and infarction groups were compared with respect to the presence or absence of parenchymal swelling, echogenicity changes, tissue loss and perfusion defects.

Results

Parenchyma swelling, echogenic changes, tissue loss and perfusion defects were found to be more extensive in the infarction than the ischemia group. The hyperechoic areas reperfused with blood flow recovered normal echogenicity and perfusion, whereas the hyperechoic areas without reperfusion became renal infarcts.

Conclusion

Gray-scale and contrast-enhanced color Doppler US showed that the hyperechoic areas with reperfusion may reverse to normal parenchyma and allow the differentiation of renal ischemia from renal infarction.     

Time-course of ”redistribution” of thallium-201 administered during transient ischemia

The redistribution of Tl-201 administered as a single dose during treadmill exercise and monitored by external imaging may permit differentiation between transient ischemia and old myocardial infarction. The time course of this redistribution of Tl-201 was examined in 20 closed chest dogs instrumented with indwelling left atrial catheters and occlusive cuffs placed around the proximal left circumflex coronary artery. In 15 of the dogs Tl-201 and Sr-85 microspheres (15) were injected during transient coronary artery occlusion: Five of the dogs were sacrificed 2 min later without releasing the occlusion; five dogs were sacrificed after 30 min and five dogs after 4 h of reperfusion. Five dogs with permanent occlusion of the left circumflex coronary artery were studied 4 h after Tl-201 administration. Compared to normal myocardium Tl-201 activity in regions with>95% flow reductions was decreased by 93.3% in the five dogs sacrificed 2 min after administration. After 30 min of reperfusion this difference was 59.7% and was only 16.5% after 4 h of reperfusion. During the initial 30 min of reperfusion this change in regional distribution was due to a 22% fall in activity in normal myocardium and a 4.4 fold increase in the transiently ischemic myocardium. Activity in normal myocardium declined further by 63% from 30 to 240 min of reperfusion while activity in the transiently ischemic myocardium decreased by 15.5%, although this change was statistically not significant. Thus, early redistribution of Tl-201 reflects active uptake of Tl-201 by transiently ischemic tissue and decrease in Tl-201 activity in normal myocadium. During late reperfusion redistribution is primarily due to a more rapid loss of Tl-201 from normal myocardium. We conclude that transient ischemia is visualized best early after stress. Imaging begun late after exercise, e.g., after 30 min, may not permit differentiation between transient ischemia and old myocardial infarction.Dr. Schuler is a recipient of a Fulbright Travel Grant and a grant from the Heinrich-Hertz Foundation, Duesseldorf, GermanyThis project was supported by Specialized Center of Research on Ischemic Heart Disease, NIH Research Grant HL-17682 by the National Heart, Lung and Blood Institute     

Radiation-induced inhibition of compensatory renal growth in the weanling mouse kidney

Four-hour balloon occlusion of the cranial mesenteric artery in 13 dogs produced a spectrum of widespread ischemic injury to the small bowel ranging from superficial mucosal infarction to transmural infarction. Twenty-four hours after the beginning of balloon occlusion, 15 mCl of 99mTc-pyrophosphate was injected into the cranial mesenteric artery in 8 dogs and into a peripheral vein in 5. Gamma camera imaging of the abdomen followed three hours later. Four of 8 dogs injected intra-arterially showed positive images with full-thickness mucosal or transmural infarction. The 4 intravenously injected dogs with positive images had transmural infarction. Only minimal ischemic injury with superficial mucosal infarction was found in the 5 dogs with negative images. Tracer uptake per gram infarcted tissue was highest after intra-arterial injection. It was concluded that 99mTc-pyrophosphate allows external imaging of extensive intestinal infarctions after both intra-arterial and intravenous injection.     

Experimental study on the usefulness of the autoperfusion balloon catheter in maintaining the blood supply to the distal organs]

Autoperfusion Balloon Catheters (APBC) were inserted into the renal arteries of seven dogs for about two and a half hours. Abdominal aortography showed renal arterial flow of the kidney obstructed by APBC. Macroscopic and microscopic examination revealed no significant changes in the resected specimen. It is concluded that APBC is useful in cases of proximal arterial occlusion by maintaining the blood supply to the distal organs for relatively short periods and that it can be used for the treatment of rupture of arteries which feed critical organs.     

CT-Guided Superior Vena Cava Puncture: A Solution to Re-Establishing Access in Haemodialysis-Related Central Venous Occlusion Refractory to Conventional Endovascular Techniques

Purpose

The purpose of this technical note is to demonstrate the novel use of CT-guided superior vena cava (SVC) puncture and subsequent tunnelled haemodialysis (HD) line placement in end-stage renal failure (ESRF) patients with central venous obstruction refractory to conventional percutaneous venoplasty (PTV) and wire transgression, thereby allowing resumption of HD.

Methods

Three successive ESRF patients underwent CT-guided SVC puncture with subsequent tract recanalisation. Ultrasound-guided puncture of the right internal jugular vein was performed, the needle advanced to the patent SVC under CT guidance, with subsequent insertion of a stabilisation guidewire. Following appropriate tract angioplasty, twin-tunnelled HD catheters were inserted and HD resumed.

Results

No immediate complications were identified. There was resumption of HD in all three patients with a 100 % success rate. One patient’s HD catheter remained in use for 2 years post-procedure, and another remains functional 1 year to the present day. One patient died 2 weeks after the procedure due to pancreatitis-related abdominal sepsis unrelated to the Tesio lines.

Conclusion

CT-guided SVC puncture and tunnelled HD line insertion in HD-related central venous occlusion (CVO) refractory to conventional recanalisation options can be performed safely, requires no extra equipment and lies within the skill set and resources of most interventional radiology departments involved in the management of HD patients.

     

自制支气管封堵器介入性肺叶切除实验研究

目的:探讨运用自制支气管封堵器行介入性肺叶切除的可行性.方法::健康犬12只随机分成3组,每组4只,A、B 组行靶肺支气管肺泡灌注平阳霉素-碘化油乳剂,A组用支气管封堵器堵塞靶支气管,B组用骨水泥堵塞靶支气管,C组为空白对照组.分别于术后28d及56d取肺组织,测定肺纤维化的程度.结果:A、B组动物均示肺不张形成,组织病理学显示靶肺呈纤维化改变;A、B组非靶肺与C组双肺均未见明显纤维化.结论:通过支气管肺泡灌注平阳霉素-碘化油乳剂后堵塞靶支气管可达到介入性肺叶切除目的,其中使用国产支气管封堵器比骨水泥行介入性肺叶切除术更方便,是一种安全简便的方法.     

血余炭栓塞狗肾动脉病理改变的初步研究

目的：观察中药血余炭栓塞狗肾动脉的病理改变，为临床提供实验依据。方法：将中药血余炭磨制成200-500μm大小的颗粒，超选栓塞部分末梢动脉血管。栓塞术后第7、14和56天分别处死1、2和3号犬，取出双肾固定，制作病理标本。结果：栓塞术后第7天，肉眼见栓塞部分肾脏缩小，切面末梢血管内有栓塞剂；镜下见血余炭栓塞剂附着于血管壁伴血栓形成。栓塞术后第14天，炎性反应明显，并有少量出血，血管壁炎性坏死，血栓逐渐机化。栓塞术后第56天见栓塞部分肾脏明显缩小，有大面积的缺血性梗死；镜下见血栓完全机化，栓塞组织呈缺血性梗死，栓塞血管有少量再通。结论：血余炭栓塞的病理过程为：血余炭附着血管壁，诱发血栓形成，血栓机化，血管壁炎性坏死，管腔闭塞，栓塞组织缺血性梗死，栓塞血管少量可再通。     

Placement of Endovascular Stent across the Branching Arteries: Long-term Serial Evaluation of Stent-tissue Responses Overlying the Arterial Orifices in an Experimental Study

Purpose

This study was designed to investigate the effects of stenting across the branching arteries on the patency and stent-tissue responses over the branching arterial orifices.

Methods

Thirteen dogs were observed after placing aortic stents across the celiac arteries (CA), superior mesenteric arteries (SMA), and renal arteries (RA). The animals were grouped according to stent types: large-cell group (n?=?6) and small-cell group (n?=?7). Angiography was performed to evaluate the branching artery patency at 2, 6, and 12?months after stent insertion, and the stent-tissue responses covering the orifices were evaluated on histopathologic examination.

Results

All branching arteries were patent on follow-up angiography; however, three patterns of stent-tissue responses over the orifices were observed: neointimal layering, bridging septa, and papillary hyperplasia. Although neointimal layering and bridging septa were evenly observed, severe papillary hyperplasia was more frequent at SMA and CA than RA. Four RA showed less than 50% ostial patency, and localized infarct was observed in six kidneys (24%). The ostial patency tended to decrease with small-cell stent during the follow-up period.

Conclusions

Various stent-tissue responses over the branching artery orifices are induced by the aortic stent covering the branching arteries and may not be easily detected by conventional angiography. Subclinical renal infarct also may occur despite patent renal angiography.     

Renal artery embolization with diluted hot contrast medium: an experimental study.

PURPOSE: To evaluate the safety and efficacy of diluted hot contrast medium to embolize the renal arteries in a canine model. MATERIALS AND METHODS: Transcatheter embolization was performed in 15 dogs (five dogs in each phase: I, II, and control). The diluted hot contrast medium was heated to 90 degrees C--100 degrees C and 30--60 mL were injected into a renal artery of each dog in phase I (optimization studies) and II (efficacy studies). In the control group, balloon inflation was performed without injection of diluted hot contrast medium. The temperature measurement was performed on one dog in phase I by temperature probe. Follow-up angiography was performed immediately (n = 15), at 1 week (n = 9), at 1 month (n = 9), and after 3 months (n = 5). All dogs were killed and kidneys were removed for histologic examination. RESULTS: The procedure was performed successfully in all dogs. Follow-up angiography showed complete obstruction of the injected renal arteries in phases I and II. The microscopic findings showed acute full-thickness necrosis of the renal cortex and renal artery in phase I, and complete coagulative necrosis of the cortex, medulla, and intrarenal blood vessels in phase II. There were no histologic changes of renal veins, inferior vena cava (IVC), and aorta. There were nonspecific findings in the control group. CONCLUSION: This preliminary experimental study suggests that diluted hot contrast medium may be a safe agent for renal ablation without thrombus formation in the renal vein or IVC.     

Transarterial ethanol ablation for sporadic and non-hemorrhaging angiomyolipoma in the kidney

Purpose

We evaluated the efficacy and side effects of transarterial ethanol ablation in sporadic and non-hemorrhaging angiomyolipomas (AMLs) in the kidney.

Material and Methods

A total of 10 patients with solitary and sporadic AMLs underwent selective transarterial absolute ethanol ablation for prophylaxis against hemorrhage. We confirmed the ratio areas of tumor vessel on angiogram, those of infraction on post-ablation computed tomography (CT) and those of tumor reduction in a 3-, 6- and 12-month follow-up CT.

Results

Once or twice a single infusion of 1 or 2 ml absolute ethanol achieved in a total occlusion of 22 feeding arteries which consisted of 7 proximal interlobar arteries, 12 distal interlobar arteries and 3 renal capsular arteries. Nontarget occlusion did not occur by ethanol reflux in any cases but occurred causing spasms provoked by repeated inflation and deflation of the balloon in one case. Total occlusion of tumor vessels was observed in 7 patients and 92-95% occlusion in 3. Ethanol ablation produced 1.8-22.5% (mean 8.4 ± 6.8%) areas of infarctions but the outcome was not serious in all cases. Mean percentage areas of tumor reduction were 29.4 ± 10.6% in a 3-month follow-up, 45.7 ± 11.9% in a 6-month and 59.3 ± 11.5% in a 12-month follow-up.

Conclusions

Absolute ethanol ablation for sporadic and non-hemorrhaging AML is safe and effective in reducing majority of tumor area in a 1-year follow-up.     

Local intra-arterial fibrinolysis in thromboembolic “T” occlusions of the internal carotid artery

Local intra-arterial fibrinolysis (LIF) is considered to support spontaneous recanalisation, which does not usually occur fast enough to prevent an infarct. Therefore, LIF may, at least theoretically, be especially useful in occlusions with large thromboembolic masses. We report our experience of LIF with urokinase in 12 patients with combined occlusions of the distal internal carotid, anterior and middle cerebral arteries (carotid “T” occlusions). There were 4 patients who survived with minor neurological deficits (Barthel index > 90), 4 with major deficits (Barthel index 40–55) and 4 patients died: in one of the last group a haematoma developed in a middle cerebral artery infarct. Recanalisation and clinical outcome were parallel in 10 of 12 patients. A patient with excellent leptomeningeal collaterals had a good clinical outcome despite only moderate recanalisation, and the patient with the parenchymal haematoma had good recanalisation. Recanalisation with urokinase in carotid “T” occlusions is often poor, but outcome can be good if treatment starts early, recanalisation succeeds and leptomeningeal collateral supply is good. Our results therefore encourage us, unlike previously reported series, to perform LIF in this type of occlusion. Received: 29 March 1996 Accepted: 4 June 1996     

Retrograde pancreatic venography after reduction of the arterial visceral flow: an experimental study

To evaluate techniques for retrograde pancreatic venography similar to epinephrine renal venography, 35 dogs had transjugular portography before and after the infusion of various doses of vasopressin systemically or selectively into the superior mesenteric and celiac arteries, or after occlusion of the distal thoracic aorta. Increased filling of the peripheral portal branches resulted, but none of the techniques provided diagnostically useful enhanced pancreatic visualization.     

Organ ablation by fluid emboli. An experimental study comparing two solidifying liquids

Embolization for ablation of organs and tumor infarction requires uniform permanent occlusion of the distal vasculature. This is best accomplished through the use of solidifying liquids. The study on 15 dogs reported here compares the degree of peripheral vascular embolization and its relation to tissue infarction both acutely and chronically following embolization of the renal arteries with two solidifying liquids, a low viscosity silicone and the occlusion gel Ethibloc. Silicone produced quite uniform distal distribution including 50 to 80% (mean 66%) of renal glomeruli, whereas Ethibloc occluded more proximally and reached only 10 to 50% (mean 22%) of all glomeruli. After three months complete cortical infarction of all nine kidneys embolized with silicone was found, whereas two of the three kidneys embolized with Ethibloc retained nests of viable glomeruli. Balloon occlusion of the entire renal artery inflow during embolization prevented distal venous emboli whereas partial inflow occlusion allowed systemic venous embolization. It is concluded that due to its more uniform distal penetration low viscosity silicone is a more suitable embolization agent than Ethibloc for organ ablation. Total arterial inflow occlusion during embolization effectively prevents systemic venous embolization.