Complications from kidney stents are usually rare, although some effects may occur. Stent malpositioning and ante grade dissection are the complications associated with renal stenting. However, these complications can be recognized and effectively managed. On rare occasions, a kidney stent may become dislodged from its location and move away from the kidney. If a stent in an artery moves into the opening of another artery, it can block blood flow, a condition known as occlusion, explains Radiology Info.
A stent is small tube made of a metal or fabric mesh that is inserted into the body to improve the flow of fluids, usually blood through a blood vessel. Doctors place kidney stents in the renal arteries, the blood vessels that carry blood to the kidneys, or in the ureters, small tubes that carry urine from the kidneys to the bladder. Stents are often used to treat blood vessels that have become too narrow, a condition known as stenosis. Kidney stents in the ureters can increase the risk of urinary tract infections, according to the Stillwater Medical Group. The presence of a foreign object in the ureter promotes the growth of bacteria, resulting in infection. In some cases, the stent may become encrusted with crystals made of minerals found in urine, which can cause severe pain when urinating, the Stillwater Medical Group reports.
Accurate placement of a stent at the renal artery ostium is a common challenge. Bad positioning may result in the stent advancing into the renal artery, leaving the ostiallesion inadequately treated or the stent projecting a significant distance into the aortic lumen with potential complications, including tilting or even complete dislodgement embolization of the stent. Techniques to avoid stent mal positioning include the use of multiple projections to accurately profile the renal artery ostium relative to the aortic wall and predilatation of the stenosis to avoid proximal or distal migration of the stent during balloon inflation.
Kidney damage is another possible complication of stent placement in the renal artery. Atherosclerotic renal artery (RA) stenosis contributes to hypertension, renal insufficiency and end stage renal disease, and is independently associated with adverse cardiovascular events. Percutaneous renal intervention is efficacious in treating renovascular hypertension and may be effective in stabilizing or improving renal function, thereby reducing cardiovascular risk. However, high rates of procedural complications have been reported.
Blood clots can occur related to the placement of kidney stents. Some people receiving stents develop a blood clot where the stent is inserted. If a blood clot breaks away from the blood vessel where it formed, it can travel to the heart, brain or lungs, causing a heart attack, stroke or pulmonary embolism. The risk of blood clot increases with the length of time the stent is in place, explains the National Heart Lung and Blood Institute. Doctors often prescribe blood thinners to reduce this risk in people receiving stents. Young patients with severe hypertension, typically women without cardiovascular risk factors, may have renal artery stenosis owing to FMD which is a rare disorder of unknown cause.