Pure ethiodized oil-based transcatheter ablative therapy in normal rabbit kidneys and kidneys inoculated with VX-2 carcinoma.

PURPOSE: To evaluate the efficacy of ablation with selective arterial injection of pure ethiodized oil followed by arterial occlusion with 9:1 ethanol-Ethiodol mixture (EEM) and coil placement in normal rabbit kidneys and kidneys inoculated with VX-2 carcinoma. MATERIALS AND METHODS: All experiments were conducted with Animal Care and Use Committee approval. In six rabbits (group 1), one kidney was embolized with pure Ethiodol until capillary stasis, followed by injection of 9:1 EEM until arterial stasis and then coil placement into the main renal artery. In 12 other rabbits, one kidney was inoculated with VX-2 tumor. Ethiodol and EEM embolization and coil placement followed 7 days later (group 2, n = 6) or 11-14 days later (group 3, n = 6). Kidneys were evaluated (angiography, computed tomography, macro- and microscopy) 7 days after treatment. RESULTS: Capillary stasis was achieved in groups 1, 2, and 3 with (mean ± standard deviation) 0.47 ± 0.03, 0.53 ± 0.02, and 0.56 ± 0.04 ml of pure Ethiodol, followed by 0.47 ± 0.05, 0.42 ± 0.03, and 0.38 ± 0.04 ml of EEM, respectively, which caused complete arterial occlusion in 17 of 18 kidneys. In group 1, all but one kidney showed at least 95% generalized coagulative necrosis. In group 2, all six kidneys exhibited 100% coagulative necrosis, with no viable tumor present. In group 3, 100% coagulative necrosis was present in all kidneys, with a small viable tumor in one. CONCLUSION: In the rabbit, selective arterial injection of pure Ethiodol can cause complete renal parenchyma and tumor ablation when it is followed by prompt, contiguous, and permanent occlusion of the arterial compartment.

Pure ethiodized oil as a capillary embolic agent with and without ethanol-ethiodol mixture in the rabbit kidney: embolic efficacy and temporal histopathologic findings.

PURPOSE: To determine the extent of ablation and the temporal histopathologic findings associated with selective arterial injection of pure Ethiodol in the normal rabbit kidney, with or without arterial occlusion of the main renal artery. MATERIALS AND METHODS: In 19 rabbits, 27 kidneys were embolized by injecting 0.6 mL of pure Ethiodol into the main renal artery to achieve capillary stasis. A 9:1 ethanol-ethiodized oil mixture was then injected into 17 of the 27 kidneys until complete arterial stasis was accomplished. Macro- and microscopic evaluation was performed 10 minutes to 6 weeks and 60 minutes to 1 week, respectively, for kidneys with and without arterial occlusion. RESULTS: Ethiodol followed by ethanol-Ethiodol mixture (mean +/- standard deviation, 0.37 mL +/- 0.03) caused complete and permanent arterial stasis in all 17 kidneys. Thrombosis of the large arteries occurred initially. Ischemic coagulative necrosis of renal tubules and damage to glomeruli were detected 2 hours after embolization. Within 24 hours, the glomeruli and most tubules of the cortex and medulla were necrotic. Without arterial occlusion, the arteriocapillary bed of the kidneys was completely patent, with normal contrast medium excretion. Ethiodol was observed in glomeruli and interstitial capillaries from 60 minutes to 1 week and caused mild acute glomerulitis from day 1. The lesions were confined to the glomeruli, and no significant parenchymal changes were observed. CONCLUSIONS: In the rabbit, selective arterial injection of pure Ethiodol produces complete renal ablation within 24 hours if prompt and permanent occlusion of the arterial compartment guarantees its permanent capillary retention.

Transcatheter arterial embolization of renal VX-2 carcinoma: ethiodol-ethanol capillary embolization combined with carboplatin.

OBJECTIVE: We wanted to determine whether transcatheter Ethiodol-based capillary embolization in combination with carboplatin could improve the efficiency of a 1:1 Ethiodol-ethanol mixture (EEM) to ablate kidneys that been inoculated with VX-2 carcinoma. MATERIALS AND METHODS: The right kidney in 34 New Zealand white rabbits were inoculated with fresh VX-2 tumor fragments. One week later, the kidneys were subjected to transarterial treatment (4-5 rabbits/group): Saline infusion (Group 1); carboplatin infusion (5 or 10 mg, Groups 2A and 2B); carboplatin-Ethiodol (CE) alone (Group 3) and followed by main renal artery occlusion with ethanol (RAO) (Group 4); carboplatin-EEM (C-EEM) followed by RAO (Group 5); carboplatin infusion followed by EEM plus RAO (Group 6); and EEM followed by RAO (Group 7). The animals were followed for up to 3-weeks. The treated kidneys were evaluated angiographically and macroscopically. The kidneys that showed successful embolization macroscopically were entirely cut into serial sections, and these were examined microscopically. Histologically, the kidneys were evaluated on the basis of the residual tumor found in the serial sections. RESULTS: The results obtained with carboplatin infusion alone (Groups 2A and 2B) and CE without RAO (Group 3) were similar to those of the control animals (Group 1). Kidneys from Groups 4-7 demonstrated macroscopically successful embolization with histologically proven complete renal parenchyma infarction; however, some residual tumor was evident in all but one animal. CONCLUSION: None of the Ethiodol-based modalities combined with locoregional carboplatin were more efficacious for tumor ablation than EEM alone.

Comparison of two foreign body retrieval devices with adjustable loops in a swine model.

The purpose of the study was to compare two similar foreign body retrieval devices, the Texan (TX) and the Texan LONGhorn (TX-LG), in a swine model. Both devices feature a < or = 30-mm adjustable loop. Capture times and total procedure times for retrieving foreign bodies from the infrarenal aorta, inferior vena cava, and stomach were compared. All attempts with both devices (TX, n = 15; TX-LG, n = 14) were successful. Foreign bodies in the vasculature were captured quickly using both devices (mean +/- SD, 88 +/- 106 sec for TX vs 67 +/- 42 sec for TX-LG) with no significant difference between them. The TX-LG, however, allowed significantly better capture times than the TX in the stomach (p = 0.022), Overall, capture times for the TX-LG were significantly better than for the TX (p = 0.029). There was no significant difference between the total procedure times in any anatomic region. TX-LG performed significantly better than the TX in the stomach and therefore overall. The better torque control and maneuverability of TX-LG resulted in better performance in large anatomic spaces.

Comparison of the Texan foreign body retrieval device and the Amplatz goose neck snare in vivo and in vitro.

PURPOSE: To compare the capturing ability of the Texan foreign body retrieval device with that of the Amplatz gooseneck snare in a swine model and to analyze their capturing mechanisms. MATERIALS AND METHODS: The Texan device with a < or = 30-mm adjustable loop was compared with the 5-mm, 15-mm, and 35-mm Amplatz snares for retrieval of foreign bodies from the iliac vein, infrarenal aorta, inferior vena cava, and stomach. Capture times by two investigators were compared. RESULTS: All 24 attempts with the Texan device were successful, as were 21 of 23 attempts with the Amplatz snare; two attempts with the 5-mm Amplatz snare were abandoned, and the failures were attributed to the suboptimal size of the snare. Other than the two abandoned attempts, there was no difference between the capturing performances of the Texan device and the 5-mm, 15-mm, and 35-mm Amplatz snares when they were compared side by side. In all vascular interventions, however, the Texan device performed significantly better in capture times than did the 5-mm and 15-mm Amplatz snare (P = .015). In all interventions, the Texan device performed significantly better in capture times than did all three sizes of the Amplatz snare (P= .012). CONCLUSION: The overall performance of the Texan device based on its capturing ability was significantly better than that of the Amplatz snares. The adjustability of the loop and the more versatile capturing technique made capture and retrieval of foreign bodies easier.

Vascular injury caused by mechanical thrombectomy in porcine arteries: AKónya eliminator device versus Arrow-Trerotola percutaneous thrombolytic device.

PURPOSE: To compare vascular injuries induced by a nonrotational thrombectomy device equipped with an adjustable basket (the AKónya Eliminator [AKE] device) and the Arrow-Trerotola percutaneous thrombolytic device (PTD) in porcine external iliac arteries (EIAs). MATERIALS AND METHODS: The EIAs of nine domestic pigs underwent simulated thrombectomy with the AKE after the diameter of the basket had been adjusted to the vessel's diameter and with the PTD after motor activation. Three animals were euthanized immediately after treatment (group 1, acute), three after 1 week (group 2, subchronic), and three after 6 weeks (group 3, chronic). Vessel diameters were measured angiographically at four anatomic locations at the three time points. A histologic grading system was established to quantify the degree of vascular injury and lumen compromise. Four other EIAs were treated with an "oversized" AKE basket and followed for 6 weeks. RESULTS: Histologically, the acute lesions in the AKE-treated vessels were more superficial than those in the PTD-treated vessels. In group 2, two of three PTD-treated arteries occluded, and their subchronic injuries were more serious than those in the AKE-treated arteries. In group 3, all AKE-treated arteries remained patent, but one of the PTD-treated vessels occluded, and the lumen sizes of the PTD- and AKE-treated arteries differed significantly. After 6 weeks, there was no significant difference between arteries treated with the PTD and those treated with the oversized AKE in terms of diameter or histologic grading. CONCLUSIONS: The adjustable basket and hand-controlled operation of the AKE were significantly less injurious to the arterial wall than the constant-size PTD basket operated at 3,000 rpm. Damage produced by the oversized AKE basket was similar to that produced by the PTD.

Ethiodized oil-ethanol capillary embolization in rabbit kidneys: temporal histopathologic findings.

PURPOSE: To determine the temporal histopathologic findings associated with selective arterial injection of a 1:1 ethiodized oil-ethanol mixture (EEM) in normal rabbit kidney followed by administration of pure ethanol into the main renal artery. MATERIALS AND METHODS: In five rabbits, the EEM was injected sequentially into each segmental renal artery of the right kidney until capillary stasis occurred. Pure ethanol was then injected into the main renal artery to achieve complete arterial stasis. Before sacrifice, the left kidney in each animal was acutely (ie, with a short follow-up period) embolized by using the same technique. The 10 kidneys of the five rabbits were evaluated microscopically at 1 (n = 3), 1(1/2) (n = 1), and 3 hours (n = 1) and 1 (n = 1), 3 (n = 1), 5 (n = 1), 7 (n = 1), and 14 days (n = 1) after embolization. RESULTS: Injection of the EEM (mean volume, 0.46 mL +/- 0.14 [SD]) followed by ethanol alone (mean volume, 0.25 mL +/- 0.09) led to complete stasis in all kidneys. There was no recanalization in the chronically (ie, with a longer follow-up period) embolized kidneys. Microscopically, uniform distribution of the EEM was evident in all slices at all time points. From 1 to 3 hours, sloughing of endothelium, formation of thrombi, and deposition of eosinophilic material along the renal, interlobar, and arcuate arteries were observed, without evidence of parenchymal damage. Within 24 hours, complete coagulative necrosis of the entire kidney occurred as a result of an occluding thrombus in the main renal artery. Analysis at subsequent time points revealed liquefaction of necrotic tissue and replacement with granulation tissue. CONCLUSION: In the rabbit, selective renal arterial injection of EEM followed by administration of ethanol produces vascular endothelial damage initiating thrombosis that results in renal infarction and ablation within 24 hours.

Capillary embolization using ethiodol-ethanol for complete renal ablation in Swine.

RATIONALE AND OBJECTIVES: To evaluate the effect of capillary embolization with superselectively administered 1:1 Ethiodol-ethanol mixture (EEM) for complete nephrectomy in normal porcine kidneys. MATERIALS AND METHODS: One kidney in each animal was completely embolized by sequential segmental arterial injections of the EEM via a microcatheter until complete capillary stasis occurred. Group 1 (n = 5): Initial embolization did not occlude the arterial compartment. Group 2 (n = 7): The capillary embolization was performed in conjunction with absolute ethanol injection and coil placement during balloon catheter occlusion. RESULTS: Group 1: Complete recanalization occurred following the EEM embolization (1-week). After the repeat embolization (EEM + pure ethanol without balloon occlusion), three of five kidneys showed partial recanalization (2-weeks). Following a third embolization (EEM + coil) in two pigs, one kidney showed partial recanalization (12-weeks). Group 2: Complete renal artery occlusion was achieved in all kidneys with no recanalization. Histologically, four kidneys exhibited total ablation whereas three showed minimal preexisting parenchyma (8-weeks). CONCLUSIONS: Permanent arterial occlusion with histologically complete renal ablation was achieved using a two-phase technique of homogeneous capillary embolization with 1:1 EEM and ethanol and coil occlusion performed during temporary balloon occlusion. Sequential segmental EEM injections alone did not produce permanent capillary embolization.