Dialysis Access, or What You Need To Be On Hemodialysis

Kidney failure that is permanent is called chronic renal insufficiency.  There are 6 stages to kidney failure,.  When you get to stage 5, you are much closer to ending dialysis. Your kidney doctor (nephrologist) will decide with you when its time to start dialysis.  When to start dialysis really depends on a constellation of your symptoms (shortness of breath, nausea and loss of appetite, leg swelling) as well as the lab work.  In general, when you kidney function is heading down below 10-12%, you are getting close to needing dialysis.

There are two ways of dialyzing, namely hemodialysis (blood dialysis) and peritoneal dialysis (dialyzing with a catheter that is placed in your abdominal cavity).  We are going to deal with hemodialysis today.  In order to have hemodialysis, you have to have a way to take the “dirty” blood out, pass it through the kidney machine, and then put the “clean” blood back into your circulation.  This can be achieved by wants called an arteriovenous graft (AVG) or an arteriovenous fistula (AVF).  Simply defined, an AVG is where we put a prosthetic material to connect an artery to a vein, and an AVG is when we connect one of your veins directly to an artery.  Essentially, we are creating a high flow conduit that can accessed for pulling blood out of the circulation, and retiring it after putting the blood through the kidney machine.

An AVF is the best way of creating a dialysis access.  When we create an AVG, we don’t put any prosthetic material into your body.  We connect a vein in your arm to an artery, and create a low resistance pathway for blood to flow.  Remember arteries bring blood down to the hand and veins take blood back up.  When we sew a vein onto an artery, part of the blood flow that is going down the artery goes immediately back up the vein. In time, the vein gets bigger, and develops a stronger thrill (a “buzzing” feeling or vibration that you feel when you put your fingers over that area due to the rapid flow of blood in an elastic vessel).  Fistulas can be created in the forearm at the wrist or in the upper arm.  We always perform a preoperative ultrasound evaluation of the veins to assess the ideal site for creating the AVF, and I usually repeat the ultrasound at the time of surgery to conform the preoperative evaluation.  The surgery itself takes about an hour to perform as an outpatient, and is not particularly painful. Once you recover from the surgery discomfort, you can use your arm like normal, including weight lifting and exercising.  The advantage of the fistula is that is tends to last longer without clotting, and has a very low risk of getting an infection.  The downside of an AVF is that is takes 6-8 weeks to “mature” or get ready to use, and sometimes needs a revision because of narrowing in the fistula, or development of large side branches that steal blood from the main body of the fistula.

If your veins are small or scared up from previous blood draws or I.V’s we sometimes will use prosthetic material to create the connection between the artery and vein.  The most commonly used prosthetic material is polytetrafluoroethelene (PTFE).  In essence, we create a pathway for dialysis by tunneling the PTFE under the skin in a straight line o a loop to connect an artery that supplies blood to the vein that takes blood back.  The surgical site has to heal for 2-3 weeks before it can the used.  In this situation, blood is taken out of the PTFE on the “arterial side” and returned after passing through the dialysis machine on the “venous side”.  The advantage of an AVG is that is can be used within 2-3 weeks.  the disadvantage is that it tends to clot more often and may have to  be declotted, and it has a higher risk for infection.

The reason your nephrologist refers you to us as vascular surgeons before you might need to start dialysis is so that we can create an AVF or AVG well ahead of time. If you don’t have an AVF or AVG ready to use, and you need to start dialysis, we have to place tunneled catheters that hang out of your skin to use for dialysis immediately.  It has 2 openings or ports, one to pull blood out and put it into the kidney machine, and the other to return the cleaned blood back to the circulation.  Remember, there is nothing hanging out of you with an AVG or AVF.  Tunneled catheters are what we would like to avoid if at all possible.  First of all, its a nuisance having a piece of plastic tubing having out of your chest area.  you can’t shower properly, and it hangs up on your clothes, and can sometimes be accidentally pulled out.  But the bigger concern is that it is a piece of plastic tubing that is tunneled under your skin that ultimately ends up inside one of the main veins that drains towards the heart.  It is an invitation to getting an infection. If we place these tunneled catheters (sometimes called permacaths), we would like to remove them as soon as possible to avoid the potential complications.  That why it is far better to have an AVF created way ahead of time, even if you don’t need dialysis for 6 months, so that it will be ready for you when you need to start hemodialysis.

One final word on hemodialysis.  Typically, you need to go to the dialysis center 3 times a week for 4 hour sessions of dialysis.  However, more and more patients are able now to get dialysis machines at home, and so home hemodialysis is becoming a good option. I will discuss peritoneal dialysis at a later time.

When To Consider An Aggressive Treatment for Venous Reflux and Varicose Veins

A young lady who saw my previous article of compression hose asked me to discuss the topic of when to treat vein issues more aggressively.  To recap, venous reflux that can lead to varicose veins, pain, swelling and and a generalized uncomfortable sensation in the legs, particularly in the calf area.  Sometimes, so called restless legs syndrome may be due to venous reflux.  The goal of management is to move the vein blood out of your legs.   Conservative management includes an exercising program, anything that uses the calf muscles like walking 20-30 minutes a day, which promotes movement of the vein blood back up the legs.  Remember, venous reflux leads to vein blood sitting in your legs veins, and there is no medications currently FDA approved to treat these symptoms except for pain medications (although there are some herbal and European products that have been reported as helping).  In addition, prop your legs up, be careful about your weight (the more weight you carry the harder your veins have to work), and wear compression hose.  If that does not help with your symptoms, then consider an aggressive approach to the problem

The vein system is made of the Deep Veins, and the Superficial Veins.  There are also connections between the two called Perforator Veins.  There are one way valves in both the deep and superficial venous systems, that normally allow blood to go up the vein. These valves snap shut and prevent the backward flow of vein blood, particularly when you sit or stand.  By the way, leg vein valve issues are completely unrelated to heart valve issues.  As gravity tries to pull the blood back down, if the valves are not competent, then blood tends to accumulate in the leg veins. In time, the veins tend to swell and lose their structural integrity.  Veins have an elastic component to them, and as they overstretch, the elastic component is damaged, and they act more like plastic bags, rather than elastic structures. This leads to varicose veins and many of the symptoms  associated with venous reflux.

A venous Doppler test is performed to make sure there are no issues with the deep vein valves or evidence for previous blood clots.  In addition, the superficial system is assessed to check the competency of the superficial valves, and to measure the size of the vein both when lying down and when standing.  Most people with varicose veins have problems with their superficial venous system, which includes the Greater Saphenous Vein (GSV) which runs from the groin down to the ankle on the inside part of the leg, and the Lesser Saphenous Vein (LSV) that runs from behind the knee to the outer ankle.

For patient who doe not get relief of their symptoms with conservative management, we will discuss a more aggressive approach with why we call ablation of the saphenous vein.  Essentially, the goal of the ablation procedure is to shut down the GSV or LSV.  People usually ask me at this point, “don’t I need this vein?”  The answer is yes, normally you do need that vein, but right now it is hurting you rather than helping you.  The blood in the faulty vein is flowing backwards down the leg rather than up towards the body, and thats why you get the symptoms of pain, swelling an varicose veins.  Their are essentially 2 technologies that are currently popular for ablating the GSV or LSV, but there are others being developed.  The first technology is radio frequency ablation (RF), and the second is laser ablation (EVLT).  I prefer the RF but they essentially both do the same thing, which is damage the inner lining of the vein and shut down the backward flow of vein blood.  The procedure takes about 30-45 minutes to do in the physicians office using local anesthesia, and either oral sedation or I.V. sedation. The inside of the vein has no sensation, its the outside surrounding tissue that has pain fibers.  We used whats called tumescence anesthesia where we infiltrate dilute numbing medication all around the vein under ultrasound guidance.  If this is done properly and with some patience, the procedure itself should not be painful.  If you have pain during the procedure, its because the numbing was not done completely.  Most people return to work within a could of days after the procedure, because the recovery is so much better than we used to see when we stripped veins.  There are other techniques that are being developed with injection of whats known as a sclerosing agent into the vein to close the fault vein down, but we can talk about that at another session if anyone is interested, because RF and EVLT dominate the current treatment market.

So the question becomes, do I need to have the aggressive approach with ablation of the vein done?  It really depends on the severity of your symptoms, and how much your veins and leg swelling are bothering you.  Its not like an artery problems like coronary artery disease where you might have a heart attack if you are not treated for chest pain.  Vein issues are more of a lifestyle problem.  “How much are my veins and swelling bothering me, and am I ready to have a more aggressive vein treatment?”  Some patients will have huge varicose veins, but they have mild symptoms and prefer to just leave the vein issues alone; that is a perfectly reasonable approach.  Other patients will have a lot of symptoms of pain and swelling, and will want to have the ablation procedure for relief of their symptoms.  In general, insurance companies will cover the ablation procedure if you have worn grade 20-30 mmHg compression hose for over 3 months, and have significant symptoms that limit your work or lifestyle such as performing your normal activities of daily living or exercising.  Some insurances (especially Cigna) can have a rider on your policy that does not allow ablation procedures no matter what.

There are certain circumstances I do recommend strongly that patients have an ablation procedure performed.  If you have a venous stasis ulcer, either healed or open, then an ablation procedure really works well to close the ulcer.  You can look up venous stasis ulcers on the internet, but these are painful sores that form on the inside or outside ankle and take a long time to heal.  The ablation  procedure performed properly and for the right reason not only helps to close the ulcer, but also reduces the risk for recurrent ulcers.  Once you have a venous stasis ulcer, the risk for recurrent ulcers is about 50%.  If you have the ablation procedure performed, the risk for recurrent ulcers falls to 9%.  I had a patient with a 20 year history of a venous stasis ulcer on his right ankle who healed his wound within 4 weeks after the ablation. Interesting side note, he had Cigna insurance, and despite the fact that we had pre-approval for the procedure, after the ablation Cigna refused to pay because they said it was not in his policy or some other BS like that, so I ate the cost of the RF ablation kit which is about $625.  Oh well, at least his wound finally healed up.

Other situation where I recommend strongly that you have an ablation procedure is if you have had bleeding from varicose veins.  If anyone has experience this event, it is very scary for patients.  It looks like you cut an artery because blood comes out at high pressure due to the venous reflux.  It is a painless event, and usually leads to a picture of blood all over the place (hog slaughter is how one patient described it…well we live in Texas).  Its actually simple to control if this ever happens to you.  Just wrap the bleeding area with compressive dressings snugly, get your butt on the ground and your feet propped up on the wall, and don’t unwrap anything for 30 minutes.  When you get your legs up straight, the vein blood drains back into the body and reduces the vein pressure in the bleeding vein.  Ablation needs to be performed for bleeding veins to prevent further bleeding.  What we usually do it inject the offending vein with clerking agent to scar it up and clot it, and then set the patient up for the ablation procedure as soon as possible.

Other situations when I recommend ablation is for patients who have a lot of venous stasis changes (brown discoloration of the skin), or repeated bouts of cellulitis.  Essentially, the reason some patients get this problem is that with venous reflux, the skin becomes permanently damaged due to the chronic high vein pressures.  This can lead to a permanent staining of the skin (venous stasis discoloration) as well as possibly recurrent skin infections (cellulitis).  I think I will address this issues at a later session.  Time to go to work

The Importance of Compression Hose for Prevention of Leg Swelling and Varicose Veins

I wear compression hose to work every day.  After 25 years of vascular surgery practice, my leg veins have taken a beating.  If I don’t wear compression hose, my legs ache, swell, and I tend to not sleep well because my legs trash around at night.  About 30% of the so called “restless legs syndrome” is  actually related to vein issues rather than some type of neurologic problem.  Before you try medications such as Requip for restless legs syndrome, wear good medical grade compression hose daily for a week and see how your legs feel.

There are numerous risk factors for vein problems or Chronic Venous Insufficiency (CVI).  Women tend to get the problem more than men.  Family history of varicose veins is a big risk factor, as well an occupation where you sit or stand all day.  Cosmetologists,  nurses, physicians, hair dressers, truck drivers, teachers especially come to mind when thinking of occupations that predispose to vein problems.   I also see plenty of secretaries and airplane stewardesses and other people who tend to be on their feet or sitting for prolonged periods of time.  The typical signs and symptoms of CVI are swelling, particularly at the ankle and calf, varicose veins, a dull aching and discomfort in the legs below the knees.  There can be a brown skin discoloration.  Sometimes when the legs swell and contract, you can get a red rash like skin changes, that eventually turn brown.  The latter stages (what we class class V or VI) venous stasis disease is when one develops ulcers, typically over the inner or sometimes over the outer ankle, although it can also form at other sites.  I have been doing this so many years, I can spot it a mile away.  CVI is so under diagnosed quite frankly because the primary care physician has so many other things to take care of that they dont’ have a chance to really look at the legs.  Vein problems are actually far more prevalent that arterial problems but far less diagnosed.  If you have unexplained leg swelling, its a good bet that is is either from vein problems, or medications, and less likely a del vein thrombosis.  Other contributors to swelling include congestive heart failure, liver and kidney disease, and lymphatic issues.

The treatment of CVI is usually conservative.  I recommend 30 minutes a day of walking at a steady pace.  Its not good enough to be walking all day short distances as most patients tell me they do.  Its the continuous long distance walking that helps.  When you walk, the calf muscles have a pump mechanism that helps to push the vein flow up.  CVI and varicose veins occur because the one way valves are not working well (more at a later date).    There is no god medication for CVI, so the whole goal is to get the vein blood out of the legs.  Weight control is also important.  The more weight you carry, the harder the veins have to work, just simple hemodynamics.  Elevate your legs as much as possible when you are not walking.  The analogy I use is when I drop my hands, my veins really pop out.  When I lift them up, they collapse.  So you want the vein blood to get out of your legs by elevating them.  Lastly, I wear compression hose every day.  I use 20-30 mmHg compression hose.  I put them on in the morning after I shower, and take them off when I work out.  You will notice that some long distance runners wear compression hose when they are running.  I don’ find it necessary to wear them when I am working out, but if it makes your legs feel better, there is no harm done.  You certainly don’t need to wear compression hose when you go to bed because your legs are already elevated.

There are more aggressive approaches to vein problems, but I will get into vein issues in depth at a later stage.  I would recommend to people that they stay away from the vein centers that are popping up all over the place.  I hate to make sweeping statements, but I would suggest to you that if your only tool is a hammer, the whole world looks like a nail.  Vein centers support themselves by doing procedures.  Get another opinion from a physician who tries conservative management first before recommending vein surgeries.

One last note on prevention.  I recommend that all women who learn that they are pregnant wear at least knee high 20-30 mmHg compression hose throughout their pregnancy.  The blood volume and hormonal changes of pregnancy can cause irreversible changes to veins that show up at a later date.  I also recommend if you have a strong family history of vein problems, or are in an occupation where you sit or stand a lot, you wear compression hose.  I will really get into leg vein issues and work-up of swelling of the legs at a later post.  It is a long and complicated discussion, but I see at least 5 new patients a week for work-up of leg swelling.  It is a poorly understood issues, and again most primary care doctors just have too much on their plate with documentation and requirements etc to really spend time on working this problem up.

Varicose and Spider Veins

Venous insufficiency and varicose veins are not well understood by most physicians.  The etiology is varicose veins is usually linked to an underlying valve problem, whether its in the deep or superficial venous system.  Essentially all vein blood in the legs is supposed to move up towards the body.  Unfortunately, since we stand or sit most of the day, gravity is always fighting us and trying to pull vein blood back down towards the ankles.  There are one way valves in the deep and superficial veins that normally close and prevent the backward flow of vein blood.  When those valves are not working well, blood tends to back up the veins and cause dilatation of the veins.  Over time, this leads to permanent damage to the vein wall, due to loss of elasticity.  As a result, varicose veins develop.  Typically, the valve problem is in the superficial venous system.  Symptoms of venous insufficiency include varicose veins, swelling, pain and a dull heaviness of the legs, skin discoloration, and in severe cases ulceration of the legs, typically at the ankles

Venous insufficiency and leg swelling

Perhaps one of the least understood problems we as vascular surgeons face is venous insufficiency.  Venous insufficiency affects approximately 200 million Americans, and is far more prevalent that peripheral vascular disease (PAD).  The reason why it is so under diagnosed is that it can take many different forms and symptoms, raging from leg swelling, to spider and varicose veins, to skin discoloration, to frank ulceration of the skin with non-healing wounds (see picture).  I will post another time about varicose veins and venous insufficiency. In this post, we will deal with leg swelling.  In my opinion, venous insufficiency is either the most or second most likely cause for leg swelling.  Typically, the swelling occurs below the knee, is relieved by elevation, and lead to minor discomfort, to severe pain.  The diagnosis is made by history and physical examination, followed by a venous Doppler.  The venous Doppler is best done by a vascular lab that is sensitive to studying vein valve function.  As obvious as this sounds, it is not often studies as a routine in most vascular labs.  Next time I will go into the work up and management of venous reflux and leg swelling

venous ulcer

Why do people get leg swelling?

Of all the patients I see in my clinic, leg swelling has to be the most prevalent cause for people to seek our help.  There is definitely an epidemic of people with leg swelling. I am just going to deal with the most common causes.  There are

  1. Medications side effects
  2. Venous insufficiency
  3. Deep venous thrombosis
  4. Lymphatic or venous obstruction

Of these, the most common causes are medication and venous insufficiency.  Lets deal with medication in this post.  The most common cause by far of leg swelling is blood pressure medication.  Specifically amlodipine (Norvasc) which is a very popular and effective medication for the management of high blood pressure.  a 5 mg dose of amlodipine is less likely to cause swelling as compared to a 10 mg dose.  The second most common drug that causes leg swelling is gabapentin (Neurontin).  So if you have new onset of leg swelling, make sure to check your medication side-effects.

Getting started

So I have been thinking about putting down all this stuff I have learned though 4 years of college, 4 years of medical school, 5 years of general surgery training, 2 years of lab research, 1 year of vascular surgery fellowship, and 23 years of vascular surgery practice!  I have forgotten more than I remembered, but there are definitely some things that are so repetitive in vascular surgery that I need to put them down in writing.  What we work up and take care of in vascular surgery is so alien to other physicians that it needs to be explored.  One of the first posts that I am going to cover is leg swelling issues, and work up and treatment options.  I see approximately 30-50 new patients a month, of whom at least 20 will be for evaluation of leg swelling