Effect of renal embolization with trisacryl and PAVc

OBJECTIVES: Evaluate the degree of vascular occlusion, vascular recanalization, and necrosis of the vascular wall caused by polyvinyl alcohol-covered polyvinyl acetate (PVAc) particles compared to trisacryl particles after renal embolization. METHODS: Seventy-nine female albino New Zealand rabbits underwent arterial catheterization of the right kidney. Thirty-three animals were embolized with trisacryl particles, thirty-one with PVAc particles, and fifteen were kept as controls. Four animals were excluded (three trisacryl and one PVAc) due to early death. Five subgroups of six animals were created. The animals in the different groups were sacrificed either 48 hours, 5 days, 10 days, 30 days, or 90 days after embolization. The control group was divided into subgroups of three animals each and kept for the same periods of time. The kidneys were dyed with hematoxylin-eosin and Masson's trichrome and then examined using optical microscopy. RESULTS: There were significant differences in the degree of vascular occlusion caused by the trisacryl and the PVAc particles between the five-day and the ten-day groups. Additional differences were noted between the five-day and 48-hour groups in regard to the amount of necrosis. For both findings, the PVAc group members showed adequate tissue reaction (ischemia and volumetric reduction) and less recanalization than those treated with trisacryl. CONCLUSION: The use of PVAc as an embolization material exhibited an adequate tissue reaction (ischemia and volumetric reduction), more expressive vascular occlusion and necrosis, and less recanalization than the trisacryl material.

Degradable Gelatin Microspheres as an Embolic Agent: an Experimental Study in a Rabbit Renal Model

OBJECTIVE: To investigate the basic characteristics of degradable gelatin microspheres (GMSs), including their embolic behavior and degradation periods when they are used as embolic materials in the renal arteries of rabbit models. MATERIALS AND METHODS: Based on the GMS particle size, 24 kidneys were divided into 3 groups of eight kidneys, and each group was embolized with a different GMS particle size (group 1: 35-100 micrometer, group 2: 100-200 micrometer, and group 3: 200-300 micrometer). From each group, two rabbits were sacrificed immediately after embolization (day 0), and a pair of rabbits from each group underwent an angiogram and were sacrificed on days 3, 7, and 14, respectively, after embolization. The level of arterial occlusion, the pathological changes in the renal parenchyma, and the degradation of the GMSs were evaluated angiographically and histologically. RESULTS: A follow-up angiogram on days 0, 3, 7, and 14 revealed the presence of wedge-shaped poorly-enhanced areas in the parenchymal phase as seen in all groups. The size of these areas tended to increase with the particle diameter, and persisted up to day 14. On days 3, 7, and 14, parenchymal infarctions were observed histologically in all cases, and this observation corresponded with the parenchyma being supplied by the embolized arteries. GMSs of group 1 mainly reached the interlobular arteries, while those of group 3 mainly reached the interlobar arteries. In all but two cases, the GMSs were identified histologically even on day 14, and sequential degradation was histologically identified in all GMS groups. CONCLUSION: GMSs can be used as degradable embolic materials which can control the level of embolization.

comparative study on the effect of lidocaine and furosemide on urinary output and graft function after renal transplantation

Renal transplantation is an ideal treatment for patients with chronic renal failure. It was demonstrated that despite the adhesion to surgical and anesthetic principles, urinary output is not satisfactory after transplantation. It seems that microvascular spasm of renal vasculature is responsible for this phenomenon. We designed a study to investigate whether lidocaine injection into renal artery can relieve vasospasm and subsequently improve output and graft function better than furosemide. In a randomized clinical trial, from July 2002 to November 2003, 100 consecutive patients who were referred to our center for kidney transplantation were recruited in this study. After obtaining written informed consent, they were divided blindly into two groups. In group 1, lidocaine was injected into renal artery, before arterial anastomosis, and group 2 received furosemide as the conventional intervention. Urine volume within 1, 4, and 24 postoperative hours and serum creatinine levels in the first three weeks were recorded and compared between the two groups. Urine volumes at 1, 4, and 24 hours after transplantation were higher significantly in lidocaine group [P<0.001]. Serum creatinine levels were lower significantly in the first postoperative day and also 21 days after transplantation in group 1 [P<0.001]. Comparing to furosemide, it seems that lidocaine can cause a more effective vasodilation in renal arteries of kidney allograft, resulting in a better diuresis. This may have a role in the betterment of graft function

Renal dose dopamine--it's myth and the truth.

Renal dose dopamine is prescribed worldwide for the prevention and treatment of acute renal failure. It's use is based on selective renal vasodilatation (induced at low doses) observed in animal studies and normal subjects. But most clinical studies have failed to demonstrate convincingly the benefit of low dose dopamine in acute renal failure. Moreover adverse effects of dopamine have been recognised warranting its use only in specific situations where benefit is proved. The available data on renal dose dopamine are either poor or statistically underpowered to draw conclusion. Therefore, a prospective, controlled trial with adequate patient number is required, to confirm the benefits.