Last year we saw some notable changes to coding for diagnostic and therapeutic procedures performed in arteriovenous fistulas and grafts. Nine new procedure codes for percutaneous procedures performed in arteriovenous fistulas and grafts were created in 2017.
Before we look at the individual CPT codes and what procedure each one represents, it’s important to understand some key terms/definitions in the CPT manual that will help us understand the codes and apply them correctly:
- Arteriovenous fistula: An intentional connection between an artery and a vein that is surgically-created to allow a patient to receive dialysis. The point at which the artery and the vein connect is known as an anastomosis.
- Arteriovenous graft: Placement of a piece of vein from the patient’s own body or synthetic material (e.g., PTFE) to intentionally connect an artery and a vein to allow a patient to receive dialysis. With an arteriovenous graft, there are two anastomoses – one to the artery on one end of the graft and the other to the vein on the other end of the graft.
- Arterial anastomosis: In an arteriovenous fistula, this is the single anastomosis between the artery and the vein. In an arteriovenous graft, this is the anastomosis between the artery and the one end of the graft attached to the artery.
- Dialysis circuit: A term used in CPT interchangeably to refer to an arteriovenous fistula or an arteriovenous graft. The dialysis circuit begins with the arterial anastomosis and ends where the superior or inferior vena cava are connected to the right atrium of the heart.
- Peripheral segment: The part of the dialysis circuit that begins with the arterial anastomosis and continues through the entire axillary vein or cephalic vein for a dialysis circuit in the arm (whether the termination point of the peripheral segment is the end of the axillary vein or the cephalic vein will depend on the vein involved in the arteriovenous fistula or graft). For example, if the basilic vein is connected to an artery to form an arteriovenous fistula, the venous outflow will be the axillary artery. If you are a visual learner like me, check out this picture of the veins of the arm to help you visualize and understand all the anatomy of these vessels and how far the peripheral segment would extend: Picture of Arm Veins. In rare cases where the dialysis circuit is placed in the leg, the peripheral segment begins at the arterial anastomosis and continues through the entire common femoral vein: Picture of Leg Veins
- Central segment: The part of the dialysis circuit that begins with the central veins (the subclavian and the innominate veins) and continues through the superior vena cava to the right atrium of the heart for a dialysis circuit in the arm. In rare cases where the dialysis circuit is placed in the leg, the central segment begins with the iliac veins then continues through the inferior vena cava to the right atrium of the heart. Again if you are a visual learner, check out this link which shows the connection between the inferior and superior vena cavas and the right atrium of the heart to help you visualize how far the dialysis circuit continues (all the way into the chest until these major veins empty into the heart): Termination Point for Dialysis Circuits.
- “In/through the dialysis circuit”: The coding guidelines and examples you may see from coding consultants will often make reference to using the codes we will discuss today for a procedure performed “in” or “through” the dialysis circuit. A procedure performed “in/through” the dialysis circuit is any procedure (e.g., angioplasty, stent, etc.) performed by placing a needle(s) or catheter(s) into a structure that is part of the dialysis circuit. Again, the dialysis circuit runs from the arterial anastomosis to the juncture where the inferior or superior vena cava joins the right atrium of the heart so if a needle or catheter is inserted in any point along this track, the procedure is stated to be performed “in/through the dialysis circuit.”
- Peri-anastomotic region: The portion of the dialysis circuit that includes a small part of the native artery immediately adjacent to the arterial anastomosis where that artery is joined to a vein or the end of a graft to form a dialysis circuit; the anastomosis itself; and the part of the vein/graft immediately adjacent to the arterial anastomosis. Any interventions performed in this region even if they are in the small segment of the native artery adjacent to the arterial anastomosis are considered “in the dialysis circuit” and may not be reported separately.
Now that we have established some of these key terms, let’s take a look at the codes themselves to see what each one includes. These first six codes are progressive hierarchal codes (codes where each code in the series includes the work of the code(s) that preceded it). This concept is important to understanding how these codes are used when multiple procedures occur in the same dialysis circuit.
CPT 36901 is the first code in the series and is used to report a diagnostic fistulogram. This procedure involves introducing a needle or catheter into the fistula/graft, injecting dye, and then obtaining images of the dialysis circuit. Physicians may use the term “angiogram” to describe a fistulogram. An angiogram is an image of a blood vessel(s) taken after introduction of dye to allow the physician to view the blood vessel and when this procedure occurs in/through a dialysis circuit, the term angiogram and diagnostic fistulogram are synonyms. This procedure can be helpful to diagnose complications of the dialysis circuit such as clot, stenosis, or pseudoaneurysm. This code includes introducing one or more needles/catheters into the dialysis circuit, the injection of contrast, the work of obtaining images, and the physician’s interpretation. This code includes obtaining and interpreting images in the peripheral and central segments of the dialysis circuit as necessary (the exact images obtained and commented on by the physician will depend on the patient’s symptoms and the area of the dialysis circuit that is of concern).
CPT 36902 is the second code in the series and is used to report an angioplasty in the peripheral segment. An angioplasty involves inserting a small balloon which is inflated to open up an artery/vein so blood can flow through it freely. This code includes the work of introducing one or more needles/catheters into the dialysis circuit to perform the angioplasty procedure. If more than one angioplasty is needed in the peripheral segment, CPT 36902 is reported only once to capture all angioplasties in the peripheral segment. Also, because these first six codes are progressive hierarchal codes , if a diagnostic fistulogram is needed in addition to the angioplasty, the fistulogram is also included in this code. Coders should not report both 36902 and 36901 together when these procedures are performed in the same dialysis circuit.
CPT 36903 is the third code in the series and is used to report a stent placement in the peripheral segment. A stent is a tube-like device that can be inserted into an artery or vein and expanded to provide support for the walls of the artery or vein and keep them open so blood can flow through the vessel freely. This code includes the work of introducing one or more needles/catheters into the dialysis circuit to perform the stent procedure. If more than one stent is needed in the peripheral segment, CPT 36903 is reported only once to capture all stents in the peripheral segment. Also, because these codes are progressive hierarchal codes, if an angioplasty in the peripheral segment and/or a diagnostic fistulogram are also needed in addition to the stent, the angioplasty and/or fistulogram are also included in this code. Coders should not report CPT 36903 with 36902 and/or 36901 when these procedures are performed in the same dialysis circuit.
CPT 36904 is the fourth code in the series and is used to report percutaneous procedures to remove blood clots (aka thrombus) from the dialysis circuit. Unlike the codes we’ve talked about to point, this procedure code covers clot removal from the entire dialysis circuit (peripheral segment and/or central segment as needed). Methods for removing these blood clots can include mechanical thrombectomy which involves inserting a catheter with a device that breaks up clots and allows them to be removed. They may also include infusions like a TPA infusion to dissolve the clots. This code includes the work of introducing one or more needles/catheters into the dialysis circuit to perform the percutaneous clot removal procedure. Also, because these codes are progressive hierarchal codes, if a diagnostic fistulogram is needed in addition to the percutaneous clot removal procedure, the fistulogram is also included in this code. Coders should not report 36904 and 36901 together when these procedures are performed in the same dialysis circuit. If a percutaneous clot removal procedure occurs in addition to a peripheral segment angioplasty or stent, there are combination codes for that (see CPT 36905 and 36906 below). Do not report 36904 with 36902 and/or 36903 in the same dialysis circuit.
CPT 36905 is the fifth code in the series and is used to report percutaneous procedures to remove blood clots plus an angioplasty procedure in the peripheral segment of the dialysis circuit. This code includes the work of CPT codes 36902 and 36904 combined. Because these codes are progressive hierarchal codes, if a diagnostic fistulogram is needed in addition to the percutaneous clot removal and angioplasty procedures, the fistulogram is also included in this code. Coders should not report 36905 and 36901 together when these procedures are performed in the same dialysis circuit. Again coders also should not report 36904 and 36902 together when percutaneous clot removal and peripheral segment angioplasty are performed in the same dialysis circuit (this one combination code 36905 represents the work of those two codes together).
CPT 36906 is the sixth code in the series and is used to report percutaneous procedures to remove blood clots plus a stent placement in the peripheral segment of the dialysis circuit. This code includes the work of CPT codes 36903 and 36904 combined. Because these codes are progressive hierarchal codes, if a diagnostic fistulogram and/or an angioplasty in the peripheral segment are needed in addition to the percutaneous clot removal and stent procedures, the fistulogram and/or angioplasty are also included in this code. Coders should not report 36902, 36905, or 36901 with CPT 36906 when these procedures are performed in the same dialysis circuit or report those individual codes together. This one code includes all the work described by those codes combined.
Unlike the codes we’ve talked about to point, the next two codes represent procedures performed in the central segment of the dialysis graft:
CPT 36907 is the seventh code in the series and is used to report an angioplasty in the central segment. Just like CPT 36902, this procedure involves inserting a small balloon which is inflated to open up a vein so blood can flow through it freely. The only difference between these two codes is that CPT 36902 represents this work in the peripheral segment while CPT 36907 represents this work in the central segment. Because CPT 36907 represents work in a different segment of the dialysis circuit, this code may be reported in additon to CPT codes 36901-36906. In fact, CPT 36907 is an add on code which means it may never be reported by itself. You must first report a code from CPT range 36818-36833 or a code from CPT range 36901-36906.
CPT 36908 is the eighth code in the series and is used to report a stent placement in the central segment. Just like CPT 36903, this procedure involves inserting a tube-like device into a vein which is expanded to provide support for the walls of the artery or vein and keep them open so blood can flow through the vessel freely. The only difference between these two codes is that CPT 36903 represents this work in the peripheral segment while CPT 36908 represents this work in the central segment. Because CPT 36908 represents work in a different segment of the dialysis circuit, this code may be reported in addition to CPT codes 36901-36906. In fact, CPT 36908 is an add on code which means it may never be reported by itself. You must first report a code from CPT range 36818-36833 or a code from CPT range 36901-36906.
The ninth and final code in the series represents work that may occur in one or both segments of the dialysis circuit or in accessory veins connected to and accessed through the dialysis circuit.
CPT 36909 is reported for vascular embolization or occlusion that occurs in the main dialysis circuit itself or in the accessory veins (small veins connected to the dialysis circuit that can cause lower blood flow in the dialysis circuit). A vascular embolization or occlusion involves placing devices such as coils, beads, or other vessel blocking devices to completely occlude an accessory vein and/or to partially occlude a vein and improve flow in the dialysis circuit. This code includes the work of placing one or more needles and/or catheters into the dialysis circuit and introducing one or more of these vessel occluding devices into the circuit itself or into the accessory veins. This code is reported only once per dialysis circuit regardless of how many vessel occluding devices are placed. CPT 36909 is an add on code and can never be reported by itself. We must first report a code from CPT range 36901-36906 in order to report this code.
Okay time to put these codes and definitions into action with some examples.
Example 1: A 76 year old patient presents with a non-functioning arteriovenous fistula. A fistulogram with possible intervention is recommended. The right arm was prepped and draped, and a 21 gauge needle was introduced into the cephalic vein just beyond the arterial anastomosis. An angiogram was performed showing a widely patent fistula throughout the peripheral segment. In the innominate vein, a high-grade stenosis was observed. Therefore, a 6 french sheath was threaded from the cephalic vein to the level of the observed stenosis, and angioplasty was performed. A completion angiogram revealed improved flow and no further stenosis in the innominate vein. The sheath was withdrawn and pressure applied to ensure control of bleeding. The patient was transferred to recovery in stable condition.
Answer Example 1: In this example, we see the physician start off by introducing a needle into the dialysis circuit (he’s in the cephalic vein just beyond the arterial anastomosis in the peripheral segment). He then performs a diagnostic fistulogram (he uses the word “angiogram” but remember an angiogram is just a picture of a blood vessel taken after dye is injected so the physician can see the blood vessel and when this procedure occurs in a dialysis circuit, it’s known more specifically as a diagnostic fistulogram). He then provides us with his interpretation of that diagnostic fistulogram. The peripheral segment is patent – all blood vessels are open with normal flow. The innominate vein which is in the central segment has a high-grade stenosis – a significant area of narrowing in the blood vessel. He then introduces a sheath (aka a catheter) and threads that to the level of the observed stenosis (in the innominate vein) and performs an angioplasty. This angioplasty in the innominate vein is in the central segment. Our code for the angioplasty is CPT 36907 since the angioplasty occurs in the central segment. Because CPT 36907 is an add on code, we will report the work that occurred during the diagnostic fistulogram first with CPT 36901 so we have our primary CPT code and then report the add on code 36907 for the central segment angioplasty.
Example 2: A 54 year old patient presents with a non-maturing fistula. Her nephrologist is concerned she may have large accessory veins causing poor flow in her fistula. The patient is brought in for a fistulogram to better assess the anatomy and determine next steps. After sterile prep and drap, a 21 gauge needle is used to enter the basilic vein in the left arm. Dye is introduced and images obtained. Fistulogram reveals the presence of multiple large collateral veins causing abnormally low flow in the dialysis circuit throughout the peripheral segment. A 5 French sheath is introduced, and one at a time, each of these large collateral veins were selectively engaged and embolization coils placed. A completion fistulogram shows improved flow in the circuit and the decision was made to terminate the procedure. The patient was wheeled to recovery in stable condition.
Answer Example 2: In this example, we see the physician start off by introducing a needle into the dialysis circuit (he’s in the basilic vein in the peripheral segment of the dialysis circuit). He then performs a fistulogram (this time he actually uses the term fistulogram but angiogram would have been an acceptable synonym here as well). He introduces dye and obtains images of the dialysis circuit (here is describing the steps of performing the fistulogram). He then provides an interpretation that there are multiple large collateral veins causing poor flow in the fistula. Note that “collateral veins” is a synonym for “accessory veins.” Once he’s identified these collateral veins as the cause of the problem in the fistula, he threads a catheter into each collateral vein and places “embolization coils” (which are a type of vessel occluding device). He then notes improved flow in the fistula. We will report CPT 36909 for the placement of the embolization coils. Even though he places more than one coil, we report CPT 36909 only once for all vessel occlusion devices placed in the same dialysis circuit/accessory veins of that dialysis circuit. Because CPT 36909 is an add on code and may not be reported by itself, we will also report CPT 36901 for the diagnostic fistulogram at the start of the case which gives us a valid primary code for our add on code 36909.
Example 3: A 61 year old patient presents with complaints of poor flow in her AV graft during recent dialysis. A diagnostic fistulogram was performed in radiology yesterday revealing a high grade stenosis in the graft body as well as in the axillary vein. The patient also has thrombus at the arterial anastomosis. The decision was made to bring her to the OR today for thrombectomy and stent placement.
After sterile prep and drape, a small puncture was made overlying the graft just distal to the arterial anastomosis. A catheter was introduced and mechanical thrombectomy was performed disrupting the known clot at the arterial anastomosis. The catheter was then threaded towards the venous side of the graft in the area of the previously identified stenosis. Balloon angioplasty was performed followed by placement of a Viabahn stent. Finally, the catheter was threaded up the venous outflow the area of previously identified stenosis in the axillary vein. A balloon angioplasty was performed to open up the venous outflow. A completion angiogram was obtained showing no evidence of further clot or stenosis. This concluded the procedure, and the patient was transferred to recovery in stable condition.
Answer Example 3: In this case, the physician starts off by giving us the results of a recent fistulogram performed by the interventional radiologist so he is not personally performing the fistulogram. Based on those results, he’s already decided to perform a thrombus removal and stent placement. He starts off by introducing a catheter into the dialysis circuit in the graft body itself (which means the puncture and subsequent catheter placement was directly into the piece of graft connecting the artery and the vein over in the peripheral segment). He then begins with a mechanical thrombectomy at the arterial anastomosis to break up the clot. After completing the mechanical thrombectomy, he moves further into the graft closer to where it connects to the vein and finds the area of stenosis where he performs a balloon angioplasty followed by placement of a stent. Finally, he moves further up the venous outflow of the dialysis circuit into the axillary vein where he does one final balloon angioplasty of an area of stenosis. Note that he is still in the peripheral segment with this last procedure since he is in the axillary vein. So all of the procedures in this case are in the peripheral segment and they include mechanical thrombectomy plus a stent placement plus two balloon angioplasties. This documentation supports CPT 36906. This one combination code includes a thrombus removal plus a stent placement in the peripheral segment. Also because these codes are progressive hierarchal codes the angioplasties which both occur in the peripheral segment are included and may not be reported separately.
These cases illustrate some common percutaneous procedures you may encounter in AV dialysis circuits. Be sure to check back for our next article as well where we will discuss some challenges of coding AV dialysis circuit procedures when some procedures are performed through a percutaneous approach (the procedure codes we have discussed here) and some are performed through an open incision overlying the dialysis circuit. We will also talk about how to code cases where percutaneous procedures occur in the dialysis circuit but the approach to the procedure is through puncture of a blood vessel outside of the dialysis circuit which changes your CPT codes.
