**5. Pathophysiology**

CVS can be either related or unrelated to current or previous catheters. Catheterassociated CVS are related to type of catheter, i.e., stiff non-tunneled or softer tunneled catheter, duration, number of catheters in the same site, vein site, and tip position are all related to CVS. The material of catheter can be responsible for platelet aggregation and thrombosis. This can lead to episodes of catheter-related bloodstream infections (CRBSI). Also, the blood turbulence produced due to tip design can be responsible for CVS. Traditionally, catheters inserted in SCVs are known to cause CVS, as the SCV is located between the clavicle and first rib. However, left IJV or EJV catheters passing through the left brachiocephalic veins are responsible for left BCV stenosis. In the left BCV, stenosis occurs at two points, at the junction of the

**173**

*Hemodialysis Vascular Access with Central Venous Disease*

left IJV to the left SCV and junction of the left BCV to the right BCV continuing as the SVC. So, the stenosis occurs at the contact points of catheters with vessel wall in this situation. Also, left BCV is situated between aorta and sternum and can contribute to stenosis. Right IJV catheters were not considered to cause CVS; however, prolong catheters in the right IJV, passing through the right BCV, can also cause right BCV CVS. Catheter tips in the SVC or SVC-right atrium junction are also known to cause thrombosis and/or CVS at the tip position site, (as illustrated in the clinical case above). Catheters on the ipsilateral side of cardiac rhythm device lines or ipsilateral AVF are also known to cause CVS. In the later situation, it is due to turbulent blood flow at high flow generated by AVF. This is more prominently seen in cephalic arch with proximal brachiocephalic AVF and rarely with distal radio-cephalic AVF.

Patients with prior history of central catheters or pacemaker leads may have CVS but are usually asymptomatic. The CVS comes to notice only when a VA is placed on ipsilateral side of CVS or a patient undergoes imaging for some other indications. Even in the presence of VA, asymptomatic CVS (<50%) are sometimes detected during other radiological procedures. These are usually found in cephalic arch or brachiocephalic veins. If these lesions are asymptomatic, one need not do intervention, even if stenosis is >50%. These require only observation for development of any symptoms or signs. This is because central veins are more elastic and prone to recoil after angioplasty. Also, the intimal damage to the veins caused by angioplasty balloon (cracking and fissuring of the vessel intima) may accelerate further stenosis, due to aggregation of thrombocytes and occurrence of thrombi leading to

intimal hyperplasia and fibrosis at the site of the original stenosis [5, 6].

older age (RR, 0.7 per decade; 95% CI, 0.6–0.8) [8].

**7. Diagnosis of CVS in symptomatic patients**

Prophylactic treatment of a stenosis that fulfills the anatomic criteria (>50% diameter reduction) but is not associated with a hemodynamic, functional, or clinical abnormality is not warranted and should not be performed. This is especially important for central venous lesions [7]. Two studies in one cohort were performed to address the issue of likelihood of developing CVS. Among 2811 patients, central venous stenosis was diagnosed in 120 (4.3%), at a median dialysis vintage of 2.9 (interquartile range, 1.8–4.6) years. Among a subset of 500 patients, all with a history of catheter use, 34 (6.8%) developed central venous stenosis, at a rate of 2.2 per 100 patient-years. The incidence of central venous stenosis was higher with a larger number of previous catheters [relative risk (RR), 2.2; 95% confidence interval (95% CI), 1.6–2.9]and pacemaker insertion (RR, 3.9; 95% CI, 1.7–8.9) and was lower with

The diagnosis of CVS is made from clinical and imaging findings. Most patients will have a history of previous central venous catheter placement and will present with ipsilateral arm, breast, face, or neck swelling. Many patients will have evidence of AV access dysfunction, with decreased access flows, increased venous pressures during dialysis, and a history of excessive bleeding from the puncture site after removal of needle. CVS leading to venous hypertension (VH) in the ipsilateral extremity and chest wall is a frequently encountered problem affecting 17 to 40% patients on HD. On physical examination, there may be numerous dilated collaterals in the neck or chest and arm edema or dilated tortuous draining veins of fistula on the side of the CVS. In the cases of bilateral innominate vein or SVC

*DOI: http://dx.doi.org/10.5772/intechopen.93030*

**6. Asymptomatic CVS**

*Hemodialysis Vascular Access with Central Venous Disease DOI: http://dx.doi.org/10.5772/intechopen.93030*

left IJV to the left SCV and junction of the left BCV to the right BCV continuing as the SVC. So, the stenosis occurs at the contact points of catheters with vessel wall in this situation. Also, left BCV is situated between aorta and sternum and can contribute to stenosis. Right IJV catheters were not considered to cause CVS; however, prolong catheters in the right IJV, passing through the right BCV, can also cause right BCV CVS. Catheter tips in the SVC or SVC-right atrium junction are also known to cause thrombosis and/or CVS at the tip position site, (as illustrated in the clinical case above). Catheters on the ipsilateral side of cardiac rhythm device lines or ipsilateral AVF are also known to cause CVS. In the later situation, it is due to turbulent blood flow at high flow generated by AVF. This is more prominently seen in cephalic arch with proximal brachiocephalic AVF and rarely with distal radio-cephalic AVF.

### **6. Asymptomatic CVS**

*Cardiac Diseases - Novel Aspects of Cardiac Risk, Cardiorenal Pathology and Cardiac Interventions*

Since CVS precludes to a creation of successful VA for long-term HD, it is essential to spread the awareness about preservation of central veins. It is a common practice to preserve peripheral veins (especially in nondominant hand) in a patient with chronic kidney disease (CKD, G III or higher). This is known to residents, fellows, nursing staff, etc. However, the concept of preservation of central veins in CKD is not widespread. CKD patients do get repeated central catheters at pre-HD stage due to medical problems, or PICC line, or the cardiologists requiring to put cardiac rhythm devices. There needs to be a dialog with cardiology colleagues to try and avoid insertion of SCV leads in CKD patients who are going to need HD in future. They can be requested to go for epicardial lead pacemakers (**Figure 2**) (author's personal work). Also, stiff non-cuffed HD catheters should not be kept in situ in jugular veins for more than 15 days. Even if patient has acute kidney injury and likely to need prolonged HD beyond 15 days, it is essential to change them to TCC, which has lesser chances of CVS than non-cuffed catheters. SCV catheterization should not be performed in CKD patients, although it still occurs frequently. Many intensivists prefer SCVs for central line insertion, and they should be con-

CVS can be either related or unrelated to current or previous catheters. Catheter-

*(A) Pacemaker lead, with TCC. Pull back angiograph shows SVC occlusion and filling of azygous vein. (B)* 

*Pacemaker with epicardial leads in a patient with CKD GIIIb due to DKD.*

associated CVS are related to type of catheter, i.e., stiff non-tunneled or softer tunneled catheter, duration, number of catheters in the same site, vein site, and tip position are all related to CVS. The material of catheter can be responsible for platelet aggregation and thrombosis. This can lead to episodes of catheter-related bloodstream infections (CRBSI). Also, the blood turbulence produced due to tip design can be responsible for CVS. Traditionally, catheters inserted in SCVs are known to cause CVS, as the SCV is located between the clavicle and first rib. However, left IJV or EJV catheters passing through the left brachiocephalic veins are responsible for left BCV stenosis. In the left BCV, stenosis occurs at two points, at the junction of the

**4. Preservation of central veins**

vinced to avoid it in CKD patients.

**172**

**5. Pathophysiology**

**Figure 2.**

Patients with prior history of central catheters or pacemaker leads may have CVS but are usually asymptomatic. The CVS comes to notice only when a VA is placed on ipsilateral side of CVS or a patient undergoes imaging for some other indications. Even in the presence of VA, asymptomatic CVS (<50%) are sometimes detected during other radiological procedures. These are usually found in cephalic arch or brachiocephalic veins. If these lesions are asymptomatic, one need not do intervention, even if stenosis is >50%. These require only observation for development of any symptoms or signs. This is because central veins are more elastic and prone to recoil after angioplasty. Also, the intimal damage to the veins caused by angioplasty balloon (cracking and fissuring of the vessel intima) may accelerate further stenosis, due to aggregation of thrombocytes and occurrence of thrombi leading to intimal hyperplasia and fibrosis at the site of the original stenosis [5, 6].

Prophylactic treatment of a stenosis that fulfills the anatomic criteria (>50% diameter reduction) but is not associated with a hemodynamic, functional, or clinical abnormality is not warranted and should not be performed. This is especially important for central venous lesions [7]. Two studies in one cohort were performed to address the issue of likelihood of developing CVS. Among 2811 patients, central venous stenosis was diagnosed in 120 (4.3%), at a median dialysis vintage of 2.9 (interquartile range, 1.8–4.6) years. Among a subset of 500 patients, all with a history of catheter use, 34 (6.8%) developed central venous stenosis, at a rate of 2.2 per 100 patient-years. The incidence of central venous stenosis was higher with a larger number of previous catheters [relative risk (RR), 2.2; 95% confidence interval (95% CI), 1.6–2.9]and pacemaker insertion (RR, 3.9; 95% CI, 1.7–8.9) and was lower with older age (RR, 0.7 per decade; 95% CI, 0.6–0.8) [8].

#### **7. Diagnosis of CVS in symptomatic patients**

The diagnosis of CVS is made from clinical and imaging findings. Most patients will have a history of previous central venous catheter placement and will present with ipsilateral arm, breast, face, or neck swelling. Many patients will have evidence of AV access dysfunction, with decreased access flows, increased venous pressures during dialysis, and a history of excessive bleeding from the puncture site after removal of needle. CVS leading to venous hypertension (VH) in the ipsilateral extremity and chest wall is a frequently encountered problem affecting 17 to 40% patients on HD. On physical examination, there may be numerous dilated collaterals in the neck or chest and arm edema or dilated tortuous draining veins of fistula on the side of the CVS. In the cases of bilateral innominate vein or SVC

stenosis or occlusion, patients may present with SVC syndrome. CVS can often be diagnosed by duplex ultrasound, with an absence of normal respiratory variation in the diameter of central veins and polyphasic atrial waves. It is difficult to visualize the central veins with duplex ultrasound in obese and muscular patients [9]. The author has seen patients with severe CVS presenting with not only ipsilateral limb edema but hemifacial swelling, diminished vision, and hearing loss on the right side and throbbing headache. We have also encountered a patient in whom there was no prior history of any catheters or lines but had narrowed fibrosed right IJV. This was detected at the time of insertion of TCC for initiation of chronic dialysis. In this particular patient, right EJV was patent (indirect evidence that the right IJV was blocked for a long time, but patient was asymptomatic). We had a patient with right upper limb oedema and history of multiple right IJV non-cuffed catheters for dialysis but never had any SCV catheters. During angiography, right SCV was found to be thrombosed. As per the European Best Practice Guidelines on VA [10], if symptomatic CVS is suspected, digital subtraction angiography (DSA) of the access and the complete venous outflow tract should be performed. In certain cases, ultrasonography with Doppler, computerized tomography (CT) of central veins or magnetic resonance imaging (MRI) plain study with time of flight (TOF) technique (**Figure 3**) may be deployed prior to DSA for venous mapping.

The main regions of central vein which are affected are the right BCV or SCV, right IJV, left BCV or SCV, and left IJV or SVC. The problem of cephalic arch stenosis in proximal brachiocephalic AVF (prevalence ~30%) or sometimes due to radio-cephalic AVF should also be kept in mind. Percutaneous transluminal angioplasty (PTA) with balloon dilatation is the primary basis for endovascular therapy. However, balloon dilation should be performed only if there is a clinical indication such as arm or face swelling. Several studies have reported that balloon dilation for a narrowed lesion found incidentally on angiogram and without symptoms accelerates lesion growth [11–13].

#### **Figure 3.**

*MRI using TOF protocol, without contrast, to have venous mapping prior to intervention, in a patient who was grossly edematous and had no veins available to perform CT venography. It showed multiple levels of CVS, including bilateral IJVs, EJVs, and bilateral BCVs.*

**175**

systemic fibrosis.

*Hemodialysis Vascular Access with Central Venous Disease*

response to angioplasty, elastic and inelastic [14].

A major problem with lesions in the central veins is that many are elastic. It has been postulated that there are actually two types of lesions based upon their

It is reasonable to perform PTA for central venous lesion if this intervention is required to maintain stable dialysis therapy. However, the presence of large fresh thrombus at the lesion site represents a contraindication to PTA unless the thrombus can first be removed by thrombectomy or another method. The left brachiocephalic lesions can be due to not only compressive stenosis but also organic stenosis. In particular, the left brachiocephalic vein may be compressed between the sternum

The lesions can be partial but significant (>60% stenosis, for intervention purpose, however, venography demonstrating more than 50% stenosis of the subclavian, brachiocephalic vein, and superior vena cava in the upper extremity or the iliac vein or inferior vena cava in the lower extremity is considered central venous occlusion) or complete thrombotic occlusion [or chronic total occlusion (CTO)]. In addition, patients with TCC present with catheter malfunction and may have catheter-related sheath (CRS) (old term: fibrin sheath), with or without clot at the

They can change to peritoneal dialysis if feasible. One can plan for thigh AVF or graft. But if both these are not the options, one is left with exploring central venous access with angioplasty and insertion of HD catheters, with TCC or Hemodialysis Reliable Outflow (HeRO®) device. For the purpose of this chapter, we would focus on upper limb CVS. Not to forget the fact that in the presence of SVC stenosis, no AVF or upper limb grafts will be feasible if the SVC stenosis is tight and has a chance for recurrence in spite of SVC angioplasty with or without stent. With improved dialysis survival, there are increasing numbers of patients who have exhausted definitive access options due to central venous stenosis and are maintaining dialysis on a central venous catheter. The HeRO allows an alternative by providing a defini-

catheter tip (called catheter-related atrial thrombus, CRAT).

**10. The procedure: approaching and crossing stenosis**

The approach to central vein could be from femoral veins, internal jugular veins, and brachial or cephalic veins. One needs to have thorough history, clinical examination, and Doppler study to arrive at a conclusion about suspected site of CVS. When these are unable to point the site of likely lesion, one may perform contrast-enhanced computer tomography (CT) venogram. The problem with CT venography is the need to inject iodinated contrast. This can be a problem in HD patients at times, who have no peripheral access to inject contrast. In such cases, magnetic resonance (MR) venography without gadolinium, using time-of-flight protocol, may yield equally good results and help plan the procedure. Gadolinium should be avoided in patients with eGFR of <30 ml/min due to risk of nephrogenic

**9. Options for patients with CVS needing VA**

*DOI: http://dx.doi.org/10.5772/intechopen.93030*

and the right brachiocephalic artery [15].

**8. CVD and similar conditions**

tive access solution [16].

*Cardiac Diseases - Novel Aspects of Cardiac Risk, Cardiorenal Pathology and Cardiac Interventions*

stenosis or occlusion, patients may present with SVC syndrome. CVS can often be diagnosed by duplex ultrasound, with an absence of normal respiratory variation in the diameter of central veins and polyphasic atrial waves. It is difficult to visualize the central veins with duplex ultrasound in obese and muscular patients [9]. The author has seen patients with severe CVS presenting with not only ipsilateral limb edema but hemifacial swelling, diminished vision, and hearing loss on the right side and throbbing headache. We have also encountered a patient in whom there was no prior history of any catheters or lines but had narrowed fibrosed right IJV. This was detected at the time of insertion of TCC for initiation of chronic dialysis. In this particular patient, right EJV was patent (indirect evidence that the right IJV was blocked for a long time, but patient was asymptomatic). We had a patient with right upper limb oedema and history of multiple right IJV non-cuffed catheters for dialysis but never had any SCV catheters. During angiography, right SCV was found to be thrombosed. As per the European Best Practice Guidelines on VA [10], if symptomatic CVS is suspected, digital subtraction angiography (DSA) of the access and the complete venous outflow tract should be performed. In certain cases, ultrasonography with Doppler, computerized tomography (CT) of central veins or magnetic resonance imaging (MRI) plain study with time of flight (TOF) technique

(**Figure 3**) may be deployed prior to DSA for venous mapping.

ates lesion growth [11–13].

The main regions of central vein which are affected are the right BCV or SCV,

right IJV, left BCV or SCV, and left IJV or SVC. The problem of cephalic arch stenosis in proximal brachiocephalic AVF (prevalence ~30%) or sometimes due to radio-cephalic AVF should also be kept in mind. Percutaneous transluminal angioplasty (PTA) with balloon dilatation is the primary basis for endovascular therapy. However, balloon dilation should be performed only if there is a clinical indication such as arm or face swelling. Several studies have reported that balloon dilation for a narrowed lesion found incidentally on angiogram and without symptoms acceler-

*MRI using TOF protocol, without contrast, to have venous mapping prior to intervention, in a patient who was grossly edematous and had no veins available to perform CT venography. It showed multiple levels of CVS,* 

**174**

**Figure 3.**

*including bilateral IJVs, EJVs, and bilateral BCVs.*

A major problem with lesions in the central veins is that many are elastic. It has been postulated that there are actually two types of lesions based upon their response to angioplasty, elastic and inelastic [14].

It is reasonable to perform PTA for central venous lesion if this intervention is required to maintain stable dialysis therapy. However, the presence of large fresh thrombus at the lesion site represents a contraindication to PTA unless the thrombus can first be removed by thrombectomy or another method. The left brachiocephalic lesions can be due to not only compressive stenosis but also organic stenosis. In particular, the left brachiocephalic vein may be compressed between the sternum and the right brachiocephalic artery [15].
