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what happens when a left renal vein stent is dislodged
Posted: Thu Aug 22, 2013 7:57 pm
by Cece
http://www.semvascsurg.com/article/S089 ... 7/abstract
Endovenous removal of dislodged left renal vein stent in a patient with nutcracker syndrome
Muhammad A. Rana
, Gustavo S. Oderich
Corresponding Author Information
email address
, Haraldur Bjarnason
Abstract
Stent migration and dislodgment is a potential complication after endovenous stenting of the left renal vein (LRV) for nutcracker syndrome. Our purpose is to describe the technique for endovenous removal of such a dislodged stent that was used in a 36-year-old woman with nutcracker syndrome initially treated with renal vein transposition. Recurrent renal vein compression and symptoms developed and a 14 × 20-mm self-expanding stent was placed in the LRV and was noted to be dislodged into the inferior vena cava on the first post-procedure day. Through right internal jugular access, the stent was stabilized by cannulating a cell of the stent using a guide wire and an angled angiographic catheter. A 20Fr sheath was then placed via right femoral vein access into the inferior vena cava. The stent lumen was cannulated from femoral approach and the stent straightened with a stiff wire. An 18-mm angioplasty balloon was then used to capture the stent. The stent was then compressed with two 25-mm loop snares while simultaneously deflating the balloon as it was pulled into the 20Fr sheath and removed. The LRV was restented with an 18 × 40-mm self-expanding stent. Stenting of LRV for nutcracker syndrome can result in stent migration. Endovenous removal of such a dislodged self-expanding stent is feasible. Our technique emphasizes stent stabilization with cell cannulation and capture over a larger diameter balloon.
Some patients with CCSVI are also diagnosed with left renal vein compression, aka nutcracker syndrome, which redirects flow from the left renal vein into the cerebrospinal venous drainage veins. Treatment for this is a left renal vein stent. In this patient, who was not a CCSVI patient, the left renal vein stent came loose and ended up in the inferior vena cava. The doctor was able to go in through the right jugular vein and catch the stent and remove it. Amazing. The left renal vein was then restented with a larger stent. But this impressive technique is dependent on there being a follow-up examination the day after the procedure, or they might not have caught the stent migration. In CCSVI, there often isn't a follow-up exam. Also, I'd be adverse to having an IR go in through the right jugular vein, which would mean puncturing the jugular and risking a clot forming at the puncture site. Things to think about. If the stent size is determined by using IVUS to measure the vein, stent migration may be reduced as a risk.
Re: what happens when a left renal vein stent is dislodged
Posted: Fri Aug 23, 2013 7:04 am
by Cinna
The 14 x 20mm stent that was placed seems very small to me for a renal vein. I seem to recall that my renal stent is 20 x 60 mm, and IVUS was used. I remember asking Dr Sclafani at the time about the size and he said it that was normal for a renal vein. Perhaps he will weigh in on this discussion.
My renal stent was placed July, 2011. I had a further angioplasty in Dec. 2012 by Dr. S at which time both of my jugulars and azygous veins needed re-ballooning and my renal vein was checked and found to be patent (open and flowing). The stent had not moved and is doing its job. My health keeps getting better and better. I was diagnosed in 1991, SPMS by 1994 and am in my early 60s. I've just returned from a holiday in the Andes and hiked for a mile and a half at an altitude of 13,200' with energy left to take another walk that evening. Unlike most people in my group, I didn't take any diamox for altitude sickness. By contrast, I remember being at 8,500' about 6 years ago (pre CCSVI) and had the worst 4 day migraine that I've ever experienced, as well as chest pain, shortness of breath, and very weak legs. This is just my latest benefit from CCSVI treatment and I'm glad I have the renal stent.
Re: what happens when a left renal vein stent is dislodged
Posted: Fri Aug 23, 2013 7:45 am
by dlynn
I had LRV stents placed this past December, and X-rays this past Feb. showed they are still in place. I maintain
improvements unrelated (I guess) to MS/CCSVI, so I'm guessing my stented vein is patent. I don't recall the size of the stents. And like you Cinna I have chest pain, shortness of breath and weak legs, oh and also balance issues. These
were all alleviated by the procedure I had for CCSVI only, so I believe I need another (CCSVI) procedure.
Re: what happens when a left renal vein stent is dislodged
Posted: Fri Aug 23, 2013 8:27 am
by 1eye
This is just my latest benefit from CCSVI treatment and I'm glad I have the renal stent.
This gives
me hope, anyway, because you did quite a lot better than I have so far. I think we need to hear some success stories regularly because of the constant negativism coming from so-called skeptics.
You were in the ranks of the pw'SPMS' longer than I by about 10 years, diagnosed a longer time, close to me in age, and yet you have had this success. Great news. There's hope for me yet...
Re: what happens when a left renal vein stent is dislodged
Posted: Fri Aug 23, 2013 8:51 am
by Cinna
1eye, I wish you all the best, and don't give up hope.
dlynn, sorry if my post was confusing. The high altitude symptoms I mentioned only occurred some 6 years ago, prior to any treatment for CCSVI. This time at a much higher altitude, I didn't suffer serious ill effects, other than 4 manageable headaches over a week (no migraine). All the best to you too.
Re: what happens when a left renal vein stent is dislodged
Posted: Sun Aug 25, 2013 10:28 am
by drsclafani
Cinna wrote:The 14 x 20mm stent that was placed seems very small to me for a renal vein. I seem to recall that my renal stent is 20 x 60 mm, and IVUS was used. I remember asking Dr Sclafani at the time about the size and he said it that was normal for a renal vein. Perhaps he will weigh in on this discussion.
My renal stent was placed July, 2011. I had a further angioplasty in Dec. 2012 by Dr. S at which time both of my jugulars and azygous veins needed re-ballooning and my renal vein was checked and found to be patent (open and flowing). The stent had not moved and is doing its job. My health keeps getting better and better. I was diagnosed in 1991, SPMS by 1994 and am in my early 60s. I've just returned from a holiday in the Andes and hiked for a mile and a half at an altitude of 13,200' with energy left to take another walk that evening. Unlike most people in my group, I didn't take any diamox for altitude sickness. By contrast, I remember being at 8,500' about 6 years ago (pre CCSVI) and had the worst 4 day migraine that I've ever experienced, as well as chest pain, shortness of breath, and very weak legs. This is just my latest benefit from CCSVI treatment and I'm glad I have the renal stent.
That is pretty amazing outcome Cinna
but i am a bit skeptical of the 20x60 mm sizing of a renal stent. I reviewed all the stent data (still incomplete entry) and did not find any 20 mm diameter stents. Most renal stents are 12 to 14 mm in diameter. Lengths are 40-60 mm . I prefer 60 mm to get more contact between metal and intima, thereby reducing risk of migration, but sometimes the vein is too short for the 60 mm stents.
Re: what happens when a left renal vein stent is dislodged
Posted: Mon Aug 26, 2013 6:19 am
by dlynn
I just found my medical report.
"Based on intravascular ultrasound... Two 12mmx40mm Protégé stents were deployed, one within the other with an overlap allowing total length of 5cm."
Re: what happens when a left renal vein stent is dislodged
Posted: Mon Aug 26, 2013 10:43 am
by Cece
I would not be brave enough to hike at altitude after my own past experiences (pre CCSVI treatment) and it is thrilling, Cinna, that you are doing so well.
article linked in the first post wrote:Recurrent renal vein compression and symptoms developed and a 14 × 20-mm self-expanding stent was placed in the LRV and was noted to be dislodged into the inferior vena cava on the first post-procedure day.
Ok so the stent that migrated in the case study had an appropriately sized diameter at 14 mm but was too short at 20 mm in length, if we accept Dr. Sclafani's standard of a 60 mm long stent. Dlynn's stent at 12 mm diameter and essentially 75 mm length (because of the doubling) had three to four times as much contact between vein wall and stent as the one that migrated in the case study.
I know this is not fascinating to everyone but I really enjoy knowing as much as there is to know. I haven't heard of any renal stents migrating in CCSVI patients as of yet but not all IRs are even examining the left renal vein so I think the number of CCSVI patients being treated for left renal vein compression is low. I do wonder why the patient in the case study had imaging done the next day: was this standard or was there pain or some symptom of the stent having migrated that prompted the imaging.
Re: what happens when a left renal vein stent is dislodged
Posted: Mon Aug 26, 2013 12:02 pm
by dlynn
Cece,
Did the Dr. use IVUS, from what I've seen posted, it is best at determining stent size.
I tried the link but it did not work for me
Re: what happens when a left renal vein stent is dislodged
Posted: Mon Aug 26, 2013 1:13 pm
by Cinna
Sorry to have given the wrong width for my stent. I didn't mean to mislead anybody.
Re: what happens when a left renal vein stent is dislodged
Posted: Mon Aug 26, 2013 4:12 pm
by Cece
http://tinyurl.com/mz8qa8c
The original link needs to be copied and pasted to make it work but this one should work.
IVUS isn't mentioned so yeah probably wasn't used.
Cinna you were right about the 60 mm and about the stent being too small (at least lengthwise). That's the first thing I should have thought too and I didn't think it.
Here's a publication with some more left renal vein stenting cases:
http://www.sciencedirect.com/science/ar ... 1405005392
1 patient had a stent migration as it was being placed. The stent was 20mm x 60mm so it was a big one. 2 other patients had stent migrations at 3-4 months after the stents were placed.
In our own experience of venous stenting, two stents were left in a transversal position in the inferior vena cava after migration during stenting without adverse effect after 26 and 48 months.
The first patient received a 20-mm-diameter, 60-mm-long Wallstent that migrated into the retrohepatic inferior vena cava and was pulled down 5 cm with an Amplatz Goose Neck Snare Kit (ev3 Inc, Plymouth, Minn). However, it adopted a transversal position in the inferior vena cava just cephalad to the left renal vein and was left in place because further attempts failed.
For patients 1 and 2, we used 60-mm-long stents, and angiographic control showed they were slightly protruding into the inferior vena cava. For the two next patients, 40-mm-long stents were used, with an excellent completion angiography. Symptoms disappeared until the third and the fourth month, when both patients had secondary stent dislodgement. These complications proved the efficiency of the treatment but also showed that 40-mm-long stents are too short. Lin13 had the same complication using a 12-mm-diameter, 40-mm-long, Wallstent.
We now believe that the 16-mm-diameter, 60-mm-long Wallstent should be considered as the base of sizing for left renal vein stenting but should be fit to patient morphology and anatomic measurements taken during the procedure. As with all venous stenoses, stents need to be stabilized, so long stents that lean on both sides of the stenosis should be used