Central venous disease in hemodialysis patients: prevalence, etiology and treatment

Numerical modelling of the interaction between dialysis catheter, vascular vessel and blood considering elastic structural deformation

The dialysis catheter indwelling in human bodies has a high risk of inducing thrombus and stenosis. Biomechanical research showed that such physiological complications are triggered by the wall shear stress of the vascular vessel. This study aimed to assess the impact of CVC implantation on central venous haemodynamics and the potential alterations in the haemodynamic environment related to thrombus development. The SVC structure was built from the images from computed tomography. The blood flow was calculated using the Carreau model, and the fluid domain was determined by CFD. The vascular wall and the CVC were computed using FEA. The elastic interaction between the vessel wall and the flow field was considered using FSI simulation. With consideration of the effect of coupling, it was shown that the catheter vibrated in the vascular systems due to the periodic variation of blood pressure, with an amplitude of up to 10% of the vessel width. Spiral flow was observed along the catheter after CVC indwelling, and recirculation flow appeared near the catheter tip. High OSI and WSS regions occurred at the catheter tip and the vascular junction. The arterial lumen tip had a larger effect on the WSS and OSI values on the vascular wall. Considering FSI simulation, the movement of the catheter inside the blood flow was simulated in the deformable vessel. After CVC indwelling, spiral flow and recirculation flow were observed near the regions with high WSS and OSI values.

Y-shaped stenting of brachiocephalic vein in a symptomatic hemodialysis patient

Stenosis or obstruction of neck great veins represent a frequent and severe complication in hemodialysis patients. Endovascular treatment with percutaneous transluminal angioplasty and/or stenting of these veins is the gold standard to restore patency. However, the jugular vein is frequently overstented in these cases and this might lead to persistent symptomatology of those patients also losing an access for future catheter placement. Herein, we present the 6-months performance of a Y-shaped stenting of the brachiocephalic and internal jugular vein leading to complete resolution of the symptoms, and maintenance of the jugular vein access.

Diagnostic Value of Contrast-Enhanced Ultrasonography for Catheter-Related Right Brachiocephalic Vein and Superior Vena Cava Lesions in Patients Undergoing Hemodialysis-A Pilot Study

OBJECTIVES

To evaluate the diagnostic efficacy of contrast-enhanced ultrasonography (CEUS) for detecting catheter-related right brachiocephalic vein (RBV) and superior vena cava (SVC) obstructions in patients undergoing hemodialysis (HD).

METHODS

From June 1, 2021 to December 31, 2022, we enrolled 80 patients undergoing HD who had used or were using a central venous catheter as vascular access. We evaluated the diagnostic efficacy of conventional ultrasonography and CEUS for identifying RBV and SVC obstructions and compared them with that of digital subtraction angiography (DSA). In the stratified analysis, the SVC was divided into the upper and lower segments. In total, we analyzed 240 central venous segments, including the RBV.

RESULTS

Among the RBV and SVC visualized by DSA, conventional ultrasonography and CEUS could visualize 67.92 and 100% of the vein segments, respectively; however, the lengths and diameters of the RBV and SVC were smaller than those recorded with DSA (P < .001). The diagnostic efficacy of CEUS for detecting catheter-related central venous obstruction was better than that of conventional ultrasonography, with a higher sensitivity (83.95 vs 41.98%), specificity (89.94 vs 53.46%), accuracy (87.92 vs 49.58%), and F1 score (82.42 vs 49.64%). CEUS showed good agreement (κ = 0.732) with DSA. In the stratified analyses, CEUS also showed higher sensitivity (83.93, 83.33, and 84.62%, respectively) and better agreement with DSA (κ = 0.635, 0.655, and 0.673, respectively) than conventional ultrasonography for detecting the RBV and the upper and lower segments of the SVC.

CONCLUSIONS

CEUS had high sensitivity and specificity in diagnosing catheter-related RBV and SVC obstructions.

Implantation of an arteriovenous graft through the peripheral vascular access in the presence of superior vena cava stenosis but a patent azygos vein: A case report

Long-term indwelling central venous catheters (CVCs) may cause complications, such as central venous disease (CVD). CVD eliminates the possibility of establishing new arteriovenous access. We herein describe a case in which an arteriovenous graft (AVG) is implanted through the peripheral veins and blood flows back to the patent azygos vein, secondary to superior vena cava stenosis. This shows that if the CVD is correctable or the collateral circulation is an alternative vascular pathway that allows blood to return back to the right atrium, the internal fistula flow is well-balanced with the collateral circulation and there are no clinical symptoms of CVD, an arteriovenous access can be established for the operation. This provides a viable, long-term vascular access option for hemodialysis patients with central venous resource depletion.

The evolving panorama of vascular access in the 21st century

There are three major types of hemodialysis vascular access: hemodialysis catheters, arteriovenous grafts, and arteriovenous fistulas. Arteriovenous fistulas provide the best access due to their reliability and long-term patency. They are recommended by the current Kidney Disease Outcomes Quality Initiatives (K-DOQI) guidelines; however, not all patients benefit from arteriovenous fistulas due to poor maturation or a lack of adequate vasculature. Currently, hemodialysis is initiated via catheters in the majority of patients. Catheters are associated with high morbidity and mortality due to infection, lower quality of dialysis, and the development of central vein stenosis. The varied responses of patients to the different access types exemplify the need to choose the "right access for the right patient" based on scores that can predict death risk and progression of chronic kidney disease. Additionally, vascular access, often referred to as the "Achilles' heel" of hemodialysis patients, represents a significant percentage of the Medicare budget that continues to increase yearly. The purpose of this paper is to review the current literature on the management of vascular access complications and infection treatment and prevention. The paper also explores emerging research regarding the devices and methods to improve access outcomes such as early cannulation arteriovenous grafts, endovascular arteriovenous fistula creation, and regenerative grafts with resorbable scaffolds, among others. The data were collected through literature searches via PubMed, Athens and web search engines.

Trigeminal neuralgia due to intracranial venous reflux following central venous disease in a patient on hemodialysis: A case report

Background:

A wide variety of conditions can cause trigeminal neuralgia (TN).

Case Description:

We describe a rare case of a 77-year-old female patient on hemodialysis presenting with severe TN on the right side of the face for several weeks. She underwent multiple revisions using catheter for brachiocephalic venous stenosis over 6 years after a therapeutic arteriovenous fistula (AVF) was created in the left forearm. Her facial pain was consistent with Type 1 TN and remained intractable even after carbamazepine treatment. The initial magnetic resonance imaging did not demonstrate arterial compression on the right trigeminal nerve; instead, the vein adjacent to the right trigeminal nerve showed a hyperintense signal. In addition, the contralateral cortical veins and transverse sigmoid sinus were dilated. Angiography from the left brachial artery revealed intracranial venous reflux (IVR) through the left jugular vein due to an occluded brachiocephalic vein. Her pain was relieved immediately after her left upper arm was compressed with a sphygmomanometer to decrease the shunt. Surgical elimination of the AVF on the left forearm resulted in complete resolution of TN. Postoperative radiological examination revealed the resolution of IVR, and her TN has not recurred by her 6-month follow-up.

Conclusion:

The radiological diagnosis of IVR might be complicated because the true causative lesion for focal neurological symptoms might be remotely located. IVR following central venous disease should be a differential when patients on hemodialysis present neurological symptoms.

Central venous catheters are associated with thrombosis among adult inpatients undergoing therapeutic plasma exchange

BACKGROUND

For inpatients undergoing therapeutic plasma exchange (TPE) in the United States, the primary mode of venous access is the central venous catheter (CVC). To evaluate the impact of CVC on thrombosis outcomes of patients undergoing TPE, we analyzed the National Inpatient Sample (NIS) database.

STUDY DESIGN AND METHODS

In a cross-sectional analysis of the NIS, we identified hospital discharges of adult patients treated with TPE. Cases were classified into two groups based on CVC status. The primary outcome was thrombosis. Secondary outcomes were major bleeding, packed red blood cell (PRBC) transfusion, in-hospital mortality, hospital length of stay (LOS), and charges.

RESULTS

Among 9863 TPE-treated discharges, CVC was used in 5988 (60%). These numbers correspond to weighted national estimates of 49 315 and 29 940, respectively. There was a positive and significant association between CVC and thrombosis (OR = 1.23, 95% 1.04-1.46, P = 0.0174), PRBC transfusion (OR = 1.15, 95% 1.03-1.29, P = 0.0121), in-hospital mortality (OR = 1.36, 95% 1.10-1.68, P = 0.0043), hospital LOS (15.63 vs 12.45 days, P < 0.0001) and hospital charges ($166 387 vs. $132 655, P < 0.0001).

CONCLUSION

In hospitalized patients undergoing TPE, CVC use is associated with increased rates of thrombosis. Future studies are needed to investigate strategies to decrease CVC use and/or prevent CVC-associated complications in TPE-treated inpatients.

Brachio-azygos transthoracic arteriovenous grafts for hemodialysis patients with bilateral central venous obstruction: A small case series

BACKGROUND

It is difficult to find a reliable outflow vein for vascular access in hemodialysis patients with bilateral central venous obstruction. The lower extremity veins are currently used as the most common alternative veins to make a new vascular access. However, in patients not amenable to make lower extremity access, intrathoracic vein should be considered as an outflow vein, but there are limitations in its use due to postoperative complications.

METHODS

We introduce a series of cases that underwent arteriovenous graft operation using an intrathoracic vein, the azygos arch, as an outflow vein. Brachio-azygos transthoracic arteriovenous graft is a surgical procedure that anastomoses the azygos arch and the brachial artery with 7 mm ringed polytetrafluoroethylene graft via lateral thoracotomy without median sternotomy.

RESULTS

The chest tubes of the patients were removed on the third postoperative day and they discharged within a week. About 1 month later, hemodialysis was initiated through the BATAVG, and it has been used without access dysfunction.

CONCLUSION

Brachio-azygos transthoracic arteriovenous grafts were performed using the azygos arches without major complications. The azygos arch can be a good alternative outflow vein to make a new vascular access for hemodialysis patients with bilateral central venous obstruction.

Effectiveness of sharp recanalization of superior vena cava-right atrium junction occlusion

BACKGROUND

Conventional recanalization techniques may fail in patients with completely occluded superior vena cava (SVC).

AIM

To analyze the effectiveness and complications of sharp recanalization for completely occluded SVC.

METHODS

This was a retrospective study of patients that underwent puncture and recanalization of the SVC between January 2016 and December 2017 at our hospital. Sharp recanalization was performed using the RUPS-100 system. The patients were followed for 12 mo. The main outcomes were the patency rate of SVC and arteriovenous fistula flow during dialysis.

RESULTS

The procedure was successful in all 14 patients (100%). Blood pressure in the distal SVC decreased in all 14 cases (100%) from 26.4 ± 2.7 cmH₂O to 14.7 ± 1.3 cmH₂O (P < 0.05). The first patency rates of the SVC at 24 h and at 3, 6, 9 and 12 mo after sharp recanalization were 100%, 92.9%, 85.7%, 78.6% and 71.4%, respectively. There were two (14.3%) severe, one (7.1%) moderate and one (7.1%) minor complication. The severe complications included one case of pericardial tamponade and one case of hemothorax.

CONCLUSION

The results suggest that sharp recanalization can be an additional tool to extend or renew the use of an occluded upper extremity access for hemodialysis. This could be of use in patients with long-term maintenance hemodialysis in whom the maintenance of central venous access is often a challenge.

Hybrid angioplasty-catheter placement procedure performed in a hemodialysis patient with central venous obstruction disease. Presentation of a case

Obstruction or occlusion of the central veins (Central venous disease, CVD) represents a major complication in hemodialysis patients (HD) limiting central venous access available for a central venous catheter placement. Endovascular treatment with percutaneous transluminal angioplasty (PTA) is the first therapeutic option to restore patency and gain access. This case presents our initial experience of a HD patient with CVD treated with a combination therapy of a balloon PTA to the left brachiocephalic trunk, through the right hepatic vein and standard catheter placement technique to the previously occluded junction of the left internal jugular vein to the left subclavian vein.

Results of Stenting for Central Venous Occlusions and Stenoses in the Hemodialysis Patients

Objectives: We aim to investigate the results of stenting for central venous occlusions and stenoses in the hemodialysis patients.

Methods: Twenty-nine cases treated with endovascular recanalization with deployment of bare metal stent (BMS) for central venous occlusions (24 cases) and recurrent stenoses (5 cases) between 2014 and 2018 were retrospectively analyzed. Results of these procedures including success rate, operative time, estimated blood loss, morbidity, primary patency, assisted primary patency and freedom from target-lesion revascularization (TLR) were evaluated.

Results: Nine lesions were in brachiocephalic vein (Occlusion/Stenosis: 8/1) and 20 lesions were in subclavian vein (Occlusion/Stenosis: 16/4). Procedural success was 94% (29/31 cases) and operation time/estimated blood loss was 68±39 min/28±54 g. Symptom were relieved or disappeared in all successful cases. Morbidity (extravasation of contrast medium) was 3% (1/29). During the period of observation, 1 stent fracture with occlusion and 1 stent migration to periphery were recognized. 1-year primary patency, freedom from TLR, and assisted primary patency were 40% (median patent time: 256 days), 67% (median patent time: 524 days), and 77%, respectively.

Conclusion: Stenting for central venous occlusions and stenoses in the hemodialysis patients is safe and durable treatment option. However, considering its off-label use and potential hazard including vessel rupture, stent migration, and stent fracture, the indication for BMS deployment should be conservative, and interventionist should be well acquainted with prevention and measures to these complications. (This is a translation of Jpn J Vasc Surg 2019; 28: 193–198.)

The diagnostic value of multi-detector CT angiography for catheter-related central venous stenosis in hemodialysis patients

The objective is to compare Multi-detector CT angiography (MDCTA) and digital subtraction angiography (DSA) in diagnosing hemodialysis catheter related-central venous stenosis (CVS). During a period of 6 years, hemodialysis patients with suspected catheter related-CVS who received both MDCTA and DSA were retrospectively enrolled. We analyzed the sensitivity, specificity, accuracy, Cohen's kappa coefficient (κ) and other diagnostic parameters for MDCTA compared to DSA. A total of 1533 vascular segments in 219 patients were analyzed. Among the 280 lesions identified by DSA, 156 were correctly identified by MDCTA. There were 124 false negative and 41 false positive diagnoses. MDCTA had a high specificity (96.73%) but a low sensitivity (55.71%), with a moderate inter-test agreement (κ = 0.5930). In stratified analyses of vascular segments, the specificities of MDCTA were 89.93% (superior vena cava), 98.95% (left brachiocephalic vein), 95.33% (right brachiocephalic vein), 99.53% (left subclavian vein), 97.61% (right subclavian vein), 97.13% (left internal jugular vein), and 95.86% (right internal jugular vein), while the sensitivities were 90.00%, 65.52%, 66.67%, 87.50%, 40.00%, 20.00% and 8.11%, respectively. Good to excellent inter-test agreement was observed for the superior vena cava (κ = 0.7870), left brachiocephalic vein (κ = 0.7300), right brachiocephalic vein (κ = 0.6610), and left subclavian vein (κ = 0.8700) compared with poor to low agreement for the right subclavian vein (κ = 0.3950), left internal jugular vein (κ = 0.1890), and right internal jugular vein (κ = 0.0500). MDCTA had a high specificity in diagnosing hemodialysis catheter related-CVS. Its sensitivity varied by central venous segments, with better performance in superior vena cava and brachiocephalic veins.

Evaluating a Novel Telescoping Catheter Set for Treatment of Central Venous Occlusions

BACKGROUND

Central venous occlusive disease (CVOD) is a prevalent problem in patients with end-stage renal disease (ESRD) and can lead to access malfunction or ligation for symptomatic relief. The purpose of this study is to evaluate the efficacy of the TriForce® Peripheral Crossing Set (Cook Medical), a novel reinforced telescoping catheter set designed to provide additional support for crossing difficult central venous occlusions.

METHODS

This is a single-center retrospective study from a quaternary referral center. We identified 37 patients over a 17-month period who underwent 56 attempts at endovascular recanalization for the treatment of central venous occlusion. Technical success rates, procedural data, and outcomes were compared between those undergoing recanalization using traditional wire/catheter sets versus the TriForce catheter set.

RESULTS

Average age was 48 ± 2 years. Comorbidities were similar between the two cohorts and included ESRD (61%), deep venous thrombosis (30%), and May-Thurner syndrome (7%). Forty attempts were made with traditional wire/catheter sets and 16 attempts with the TriForce catheter set to treat 2.1 ± 0.2 and 1.9 ± 0.3 occluded venous segments, respectively (P = 0.74). Technical success rates were significantly higher for the group undergoing recanalization using the TriForce catheter (69% versus 38%, P = 0.04) and 4 patients were successfully recanalized using the TriForce catheter set after a failed attempt with traditional wire/catheter sets. Mean fluoroscopy time and radiation dose were 13 ± 3 min and 14,623 ± 2,775 μGy∗m² for traditional techniques versus 30 ± 6 min and 30,408 ± 10,433 μGy∗m² for the novel telescoping catheter set (P = 0.01 and 0.09, respectively). Freedom from reintervention at 1 year was 60% for the TriForce cohort versus 44% for the traditional wire/catheter cohort (P = 0.25).

CONCLUSIONS

The novel TriForce reinforced telescoping catheter set is a useful adjunct that may improve recanalization rates of CVOD compared with traditional wire/catheter sets.

Anticoagulant strategies for the patient with chronic kidney disease

Chronic kidney disease (CKD) is a global health problem affecting up to 14% of the adult population in developed countries. On the basis of current guidelines, patients with CKD will often fulfil criteria for both short-term and long-term anticoagulation. Paradoxically, patients with CKD are not only at a higher risk of thrombosis, they are also at increased risk of bleeding. Furthermore, the pharmacokinetics and pharmacodynamics of many anticoagulant therapies are significantly affected by renal dysfunction. In addition, patients with advanced CKD are often systematically excluded from major clinical trials. As such, the decision on whether to anticoagulate or not, and if so with what agent, poses significant challenges. A solid understanding of the condition in question and the available treatments is required to make an informed judgement call. An in-depth appreciation of the advantages and disadvantages of the currently available anticoagulants is a key element in the decision-making process.

[Thoracic Central Venous Occlusive Disease and Haemodialysis Access]

Benign central venous thoracic occlusion is a frequent issue in haemodialysis patients. Symptomatic stenosis affects quality of life and can cause dysfunction of arteriovenous access or make it impossible to implant a haemodialysis catheter. Common risk factors for the development of the occlusions are central venous catheters and cardiac rhythm devices. The gold standard for diagnosis is venous angiography. Treatment of asymptomatic lesions can lead to clinical deterioration and should be avoided. The primary method of treatment for symptomatic patients is endovascular therapy. Repeat balloon angioplasty is a standard therapy. In case of elastic recoiling or early recurrence, placement of bare metal stent or stent graft could be considered. Surgical options should be preserved only for refractory cases. Further randomised trials are needed to prove the efficacy of new devices, such as dedicated venous stents and drug coated balloons.

Analysis of the positional relationship between the left brachiocephalic vein and its surrounding vessels via computed tomography scan: A retrospective study

OBJECTIVES

This study aimed to clarify the positional relationship between the left brachiocephalic vein and its surrounding vessels and to analyse the association between this positional relationship and ageing.

METHOD

Chest contrast-enhanced computed tomography was performed for 100 adults. The contact number between left brachiocephalic vein and surrounding vessels (aorta, brachiocephalic artery, left common carotid artery and left subclavian artery) was determined. The correlations of ageing with the cross-sectional areas of left brachiocephalic vein crossing brachiocephalic artery and left common carotid artery and peripheral end of left brachiocephalic vein were analysed.

RESULTS

LBV was in contact with aorta in 19, brachiocephalic artery in 97, left common carotid artery in 90 and left subclavian artery in 21 patients. There were significant negative correlations of ageing with the cross-sectional areas of left brachiocephalic vein crossing brachiocephalic artery and left common carotid artery and peripheral end of left brachiocephalic vein.

CONCLUSIONS

Brachiocephalic artery and left common carotid artery have easy contact with left brachiocephalic vein. There was a negative relationship between the cross-sectional area of left brachiocephalic vein and age.

Efficacy and safety of a mother-child technique for recanalization of chronic central venous occlusive disease in hemodialysis patients

OBJECTIVE

There is no optimal treatment for central vein occlusive disease that remains a major contributor to vascular access impairment. This study aimed to review the outcomes of percutaneous treatment with a mother-child technique in the treatment of symptomatic central venous stenosis (CVS) and central venous occlusion (CVO) in patients on hemodialysis.

METHODS

Data were collected retrospectively and included all consecutive patients with CVS or CVO who were treated with percutaneous angioplasty and stenting. The occlusive lesions were crossed using the mother-child technique with an angiographic catheter-in-guiding catheter system.

RESULTS

A total of 36 patients with symptomatic CVS and 45 patients with total CVO were included. The average age and gender composition were similar between the two groups. Patients with CVO had higher prevalence of diabetic nephropathy than CVS (24.4% vs 5.6%; P < .05). Lesion success, device success, and procedural success were achieved in 36 (100%), 1 (100%), and 36 (100%) patients in the CVS group and in 43 (95.6%), 11 (100%), and 43 (95.6%) patients in the CVO group, respectively. There were no severe complications or procedure-related deaths in either group. During follow-up (median, 6 months), the primary patency rates were 89.7% (CVS) and 81.0% (CVO) at 6 months and were 54.2% (CVS) and 47.1% (CVO) at 12 months. The assisted primary patency rates were 100% (CVS) and 91.2% (CVO) at 6 and 12 months.

CONCLUSIONS

With extra backup support of the mother-child technique, percutaneous treatment provides an effective and safe method for recanalization of chronic venous occlusion in patients on hemodialysis.

Central venous disease in hemodialysis patients

Central venous disease (CVD) is difficult to treat and often resistant to treatment. In CVD, hemodialysis vascular access should sometimes be abandoned, or in serious cases, the patient's life may be threatened. Therefore, prevention is ideal. However, as the prevalence of chronic kidney disease (CKD) has increased steadily with population aging, CKD patients with a peripherally inserted central catheter (PICC) are encountered frequently. PICCs can cause CVD, and the basilic vein, which is regarded as the important last option for native arteriovenous fistula (AVF) creation in end-stage renal disease (ESRD) patients, is destroyed frequently after its use as the entry site of PICC. The most well-established risk factors for CVD are a history of central venous catheter (CVC) insertion and its duration of use. Therefore, to reduce the incidence of CVD, catheterization in the central vein (CV) should be minimized, along with its duration of use. In this review, we will first explain the basic territories of the CV and introduce its pathophysiology, clinical features, and advanced treatment options. Finally, we will emphasize prevention of CVD.

Inter-observer agreement of color duplex ultrasound of central vein stenosis in hemodialysis patients

Purpose

To assess the inter-observer agreement of color duplex ultrasound of central vein stenosis in hemodialysis patients.

Patients and methods

This prospective study was conducted on 35 hemodialysis patients with suspected central vein stenosis. All patients underwent color flow duplex examination of the subclavian, internal jugular and brachiocephalic veins in hemodialysis patients. Image analysis was performed by two reviewers for diameter reduction, peak venous velocity ratio, post-stenotic turbulent flow, waveform changes, and thrombus formation.

Results

There was no significant difference between both observers for diameter reduction ( p = 0.105) and for the mean peak systolic velocity ratio ( p = 0.515). The overall inter-observer agreement of color duplex ultrasound of central vein stenosis was excellent ( k = 0.84, percent agreement = 89.7%, P = 0.001). There was excellent inter-observer agreement of both reviewers for diameter reduction ( k = 0.928, percent agreement = 97.14%), peak venous velocity ratio ( k = 0.7, percent agreement = 85.7%), waveform changes ( k = 0.62, percent agreement = 77.14%), post-stenotic turbulent flow ( k = 0.866, percent agreement = 88.6%), thrombus formation ( k = 1, percent agreement = 100%).

Conclusion

We concluded that color duplex ultrasound is a reliable and reproducible method for diagnosis of central vein stenosis in hemodialysis patients.

Prevalence of Central Vein Stenosis in Patients Referred for Vein Mapping

BACKGROUND AND OBJECTIVES

Central vein stenosis is considered to be common in patients on hemodialysis but its exact prevalence is not known. In this study, we report the prevalence of central vein stenosis in patients with CKD referred for vein mapping.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We conducted a retrospective study of adult patients who had bilateral upper extremity venographic vein mapping from September 1, 2011 to December 31, 2015. Patients with and without stenosis were compared for differences in clinical or demographic characteristics. Multiple logistic regression was used to identify independent associations between patient characteristics and central vein stenosis.

RESULTS

There were 525 patients who underwent venographic vein mapping during the study period, 27% of whom were referred before initiation of hemodialysis. The mean age (±SD) and body mass index were 59 (±15) years and 28 (±7), respectively. Women accounted for 45% of patients; 82% were black. The prevalence of central vein stenosis was 10% (95% confidence interval [95% CI], 8% to 13%) for the whole group, and 13% (95% CI, 10% to 17%) among patients with tunneled central venous dialysis catheters. Current use of tunneled hemodialysis catheters (odds ratio [OR], 14.5; 95% CI, 3.25 to 65.1), presence of cardiac rhythm devices (OR, 5.07; 95% CI, 1.82 to 14.11), previous history of fistula or graft (OR, 3.28; 95% CI, 1.58 to 6.7), and history of previous kidney transplant (OR, 18; 95% CI, 4.7 to 68.8) were independently associated with central vein stenosis.

CONCLUSIONS

In this population, the prevalence of central vein stenosis was 10% and was clustered among those with tunneled hemodialysis catheters, cardiac rhythm device, and previous history of dialysis access or transplant.

Percutaneous intervention for symptomatic central vein stenosis in patients with upper limb arteriovenous dialysis access

Central venous stenosis is an important hindrance to long-term maintenance of arteriovenous access in the upper extremities in dialysis patients.

Aim

The present study was done to determine feasibility and clinical success of endovascular approach for the treatment of symptomatic central venous stenosis associated with significant ipsilateral limb edema in dialysis patients with vascular access in the upper limb.

Methods

A database of hemodialysis patients who underwent endovascular treatment for central venous stenosis from January 2014 to January 2017 at our institute was retrospectively reviewed. Follow-up was variable.

Results

The study included ten patients (6 men and 4 women) with a mean age of 45.2 years, who underwent thirteen interventions during a period of 3 years. The technical success rate for endovascular treatment was 100%. One patient underwent primary PTA (percutaneous transluminal angioplasty). Seven patients underwent primary PTA and stenting. Three patients underwent secondary PTA. One among these patients underwent secondary PTA twice along with fistuloplasty. One patient underwent secondary PTA with stenting. No immediate complications were encountered during the procedure. Our study shows a primary patency rate of 67% and 33% at 6 months and 12 months for PTA with stenting. Our study also shows secondary or assisted primary patency of 75% at 6 months of follow-up.

Conclusions

Endovascular therapy (PTA) with or without stenting for central venous stenosis is safe, with low rates of technical failure. Multiple additional interventions are the rule and long-term patency rate is not very good.

Preoperative management of arteriovenous fistula (AVF) for hemodialysis

Native arteriovenous fistula (AVF) is the favorite access for hemodialysis (HD). The National Kidney Foundation's Kidney Disease Outcomes Quality Initiative (KDOQI) recommends its creation in most patients with renal failure. Unfortunately, intensive efforts to promote native AVF in patients with marginal vessels have increased the rate of primary fistula failure. A non-functioning fistula prompts the use of central venous catheter (CVC) that, unlike AVF, has been associated with an increased risk of morbidity and mortality among patients receiving HD. We believe that successful and timely AVF placement relies on the development of a multidisciplinary integrated preoperative program divided into five stages: (i) management of patients with advanced chronic kidney disease (CKD), (ii) management of preoperative risk factors for AVF failure, (iii) planning of native AVF, (iv) assessment of patient eligibility and (v) preoperative vascular mapping. Focusing specifically on native AVF, we review scientific evidence regarding preoperative management of this vascular access in order to favor construction of long-term functioning fistula minimizing development of severe complications.

Ultrasound-guided costoclavicular approach infraclavicular brachial plexus block for vascular access surgery

INTRODUCTION

We report the use of a newly described regional technique, ultrasound-guided costoclavicular approach infraclavicular brachial plexus block for surgical anesthesia in two high-risk patients undergoing 2nd stage transposition of basilic vein fistula.

METHODS

Both patients had features of difficult airway, American Society of Anesthesiologists (ASA) physical status class III and central venous occlusive disease. The common approach, i.e., ultrasound-guided supraclavicular brachial plexus block was technically difficult with inherent risk of vascular puncture due to dilated venous collaterals at the supraclavicular area possibly compromising block quality. The risk of general anesthesia (GA) was significant as patients were morbidly obese with possible risk of obstructive sleep apnea postoperatively. As an alternative, we performed the ultrasound-guided costoclavicular approach infraclavicular brachial plexus block with 20 mL local anesthetic (LA) ropivacaine 0.5% delivered at the identified costoclavicular space using in-plane needling technique. Another 10 mL of LA was infiltrated along the subcutaneous fascia of the proximal medial aspect of arm.

RESULTS

Both surgeries of >2 hours' duration were successful, without the need of further local infiltration at surgical site or conversion to GA.

CONCLUSIONS

Ultrasound-guided costoclavicular approach can be an alternative way of providing effective analgesia and safe anesthesia for vascular access surgery of the upper limb.

Placement of Upper Extremity Arteriovenous Access in Patients with Central Venous Occlusions: A Novel Technique

BACKGROUND

Central venous occlusion is a common occurrence in patients with end-stage renal disease. Placement of upper extremity arteriovenous access in patients with occlusion of the brachiocephalic veins is often not an option. Avoidance of lower extremity vascular access can decrease morbidity and infection.

METHODS

The central venous lesions were crossed centrally via femoral access. The wire was retrieved in the neck extravascularly. A Hemodialysis Reliable Outflow catheter was then placed in the right atrium and completed with an arterial anastomosis.

RESULTS

We describe a novel technique for placing upper extremity arteriovenous access in patients with occlusion of the brachiocephalic veins. This technique was utilized in 3 patients. The technical success was 100%.

CONCLUSIONS

The placement of upper extremity arteriovenous access in patients with central venous occlusions is technically feasible.

Hemodialysis Tunneled Catheter Noninfectious Complications

Noninfectious hemodialysis catheter complications include catheter dysfunction, catheter-related thrombus, and central vein stenosis. The definitions, causes, and treatment strategies for catheter dysfunction are reviewed below. Catheter-related thrombus is a less common but serious complication of catheters, requiring catheter removal and systemic anticoagulation. In addition, the risk factors, clinical manifestation, and treatment options for central vein stenosis are outlined.

Hemodialysis Tunneled Catheter Noninfectious Complications

Noninfectious hemodialysis catheter complications include catheter dysfunction, catheter-related thrombus, and central vein stenosis. The definitions, causes, and treatment strategies for catheter dysfunction are reviewed below. Catheter-related thrombus is a less common but serious complication of catheters, requiring catheter removal and systemic anticoagulation. In addition, the risk factors, clinical manifestation, and treatment options for central vein stenosis are outlined.

Complications of Permanent Hemodialysis Catheter Placement; Need for Better Pre-Implantation Algorithm?

There is a correlation between central venous cannulation and the development of central venous stenosis. Minor retrosternal vein lesions can be easily missed. Computerized tomographic (CT) venography is the diagnostic procedure of choice. The aim of this study was to examine the complications after catheter implantation in patients with prior permanent catheter placement and to evaluate present diagnostic procedures performed prior to choosing permanent access site in order to reduce possible complications after catheter placement. Complications of permanent CVC insertion in our department were analyzed between October 2011 and February 2015. We have implanted the Tesio twin catheter system and the Hickman Bard dual lumen catheter. All patients with prior permanent dialysis catheter were evaluated with color doppler, while patients with suspected central venous stenosis (CVS) or thrombosis were evaluated with phlebography or CT venography prior to catheter placement. One hundred and ninety-eight permanent dialysis catheters were placed (173 Tesio [87.4%] and 25 Hickman [12.6%]) in 163 patients. There were 125 patients (76.7%) with prior temporary catheter and 61 (48.8%) of them had more than one prior permanent catheter (1.92 catheter per person).There were 4/61 (6.5%) patients with catheter-related complications without prior phlebography and CT venography. Phlebography and CT venography were performed in 30 (24.0%) patients with suspected CVS/thrombosis and with dialysis vintage of 76.23 months (52.78-98.28). Phlebography and CT venography were more sensitive than color doppler in the detection of CVS/thrombosis in patients with prior permanent catheter placements (P < 0.001). Since this diagnostic algorithm was introduced prior to catheter placement there were no catheter insertion-related complications or dysfunctions (P < 0.001). All our procedures on patients with prior permanent catheters followed preliminary color doppler diagnostics. Nevertheless, in four cases, the vessel obstruction and abnormality led to catheter insertion-related complications. When phlebography and CT venography was performed before the procedure in patients with prior permanent catheters and one or more CVS or thrombosis, early and late catheter-related complications were avoided by careful selection of the least injured vein and planning of procedure. When planning a permanent dialysis catheter placement in patients with prior multiple CVC, phlebography and CT venography may be diagnostic procedures of choice for avoidance of early catheter dysfunction and CVC placement complications.

Epidemiology of haemodialysis catheter complications: a survey of 865 dialysis patients from 14 haemodialysis centres in Henan province in China

OBJECTIVES

To investigate the incidence rates and risk factors for catheter-related complications in different districts and populations in Henan Province in China.

DESIGN

Cross-sectional.

SETTING

Fourteen hospitals in Henan Province.

PARTICIPANTS

865 patients with renal dysfunction undergoing dialysis using catheters between October 2013 and October 2014.

MAIN OUTCOME MEASURES

The main outcome measures were complications, risk factors and patient characteristics. Catheter-related complications included catheter-related infection (catheter exit-site infection, catheter tunnel infection and catheter-related bloodstream infection), catheter dysfunction (thrombosis, catheter malposition or kinking, and fibrin shell formation) and central vein stenosis.

RESULTS

The overall incidence rate was 7.74/1000 catheter-days, affecting 38.61% of all patients, for catheter infections, 10.58/1000 catheter-days, affecting 56.65% of all patients, for catheter dysfunction, and 0.68/1000 catheter-days, affecting 8.79% of all patients, for central vein stenosis. Multivariate analysis showed that increased age, diabetes, primary educational level or below, rural residence, lack of a nephropathy visit before dialysis and pre-established permanent vascular access, not taking oral drugs to prevent catheter thrombus, lower serum albumin levels and higher ferritin levels were independently associated with catheter infections. Rural residence, not taking oral drugs to prevent thrombus, lack of an imaging examination after catheter insertion, non-tunnel catheter type, lack of medical insurance, lack of nephropathy visit before dialysis and pre-established permanent vascular access, left-sided catheter position, access via the femoral vein and lower haemoglobin level were independently associated with catheter dysfunction. Diabetes, lack of nephropathy visit before dialysis and pre-established permanent vascular access, lack of oral drugs to prevent catheter thrombus, left-sided catheter location and higher number of catheter insertions, were independently associated with central vein stenosis.

CONCLUSIONS

The rate of catheter-related complications was high in patients with end-stage renal disease in Henan Province. Our finding suggest that strategies should be implemented to decrease complication rates.

Avoiding the use of a femoral bridging catheter using a two-stage Hemodialysis Reliable Outflow (HeRO) graft implantation technique

PURPOSE

To evaluate a two-stage Hemodialysis Reliable Outflow (HeRO) implantation technique that avoids the use of a femoral bridging catheter versus the conventional one-stage technique requiring a bridging catheter in selected patients.

METHODS

A retrospective review was performed on 20 end-stage renal disease patients with an internal jugular vein (IJV) catheter selected for two-stage HeRO implantation at our institution between January 2010 and March 2013. The arterial graft component (AGC) was implanted without anastomosing it to the target artery (first stage). After AGC incorporation, the venous outflow component was inserted (second stage). The preexisting IJV catheter was maintained for hemodialysis access during the interstage period. Patient characteristics, patency using Kaplan-Meier method and infection rates were analyzed.

RESULTS

A total of 17 patients with a mean age of 59 years (70.6% women) completed the two-stage procedure. During the interstage period (mean 12 weeks, range 4-22 weeks), no graft- or surgery-related infection occurred. The need of a femoral bridging catheter was avoided by utilizing the preexisting IJV dialysis catheter. The accumulated HeRO days were 3,916 days with a mean follow-up of 7.7 months (range 1-22.6 months). The HeRO-related infection rate was 0.3/1,000 days. The primary assisted and secondary patency rates at 6 months were 69% and 82%, respectively, which were similar to those of arteriovenous grafts. Staging conferred immediate vascular accessibility.

CONCLUSIONS

Avoiding the use of a femoral bridging catheter using the two-stage technique may lower infection rate, with comparable primary assisted and secondary patency to arteriovenous grafts and added benefit of immediate cannulatability in this subset of patients.

Percutaneous Transluminal Angioplasty for Central Venous Disease in Dialysis Patients: Influence on Cardiac Function

Purpose

Increased vascular access flow after percutaneous transluminal angioplasty (PTA) for central venous stenosis and occlusion (central venous disease, CVD) can affect cardiac function in hemodialysis (HD) patients. We evaluated the cardiac function, etiology, and treatment in HD patients with CVD.

Methods

HD patients with CVD treated by PTA between June 2006 and February 2013 were studied.

Results

Of the 26 patients, 22 had left arteriovenous fistulas (AVFs), 1 left arteriovenous graft (AVG), 2 right AVFs, and 1 right AVG. CVD sites were the left brachiocephalic vein (LBCV; n=13), left subclavian vein (LSCV; n=7), both LBCV and LSCV (n=3), right BCV (n=2), and right SCV (n=1). Computed tomography findings indicated a high extrinsic compression rate for the LBCV (91%) and LSCV (50%). The success rate of PTA was 96%. The primary patency rates at 3, 6, 9, and 12 months were 81%, 73%, 65%, and 57%, respectively. The post-PTA brachial artery flow volume was significantly increased compared with the pre-PTA volume (1306 vs. 957 ml/min; p=0.005). The post-PTA left ventricular ejection fraction and expiration inferior vena cava diameter were the same as the pre-PTA values (57% versus 60%, p=0.2 and 17 versus 17 mm, p=0.9, respectively).

Conclusions

Our findings suggest that increased vascular access flow after PTA for CVD has no relation to cardiac function.

Early Cannulation Prosthetic Graft (Acuseal™) for Arteriovenous Access: A useful option to provide a Personal Vascular access Solution

Purpose

Early cannulation arteriovenous grafts (ecAVGs), such as the GORE® Acuseal™, have “low bleed” properties permitting cannulation within 24 hours of insertion. They may provide an alternative to tunneled central venous catheters (and associated line complications) in patients requiring urgent vascular access.

Methods

We present our early experience of 37 patients treated with the GORE® Acuseal™ ecAVG.

Results

A total of 11 upper limb, 24 lower limb and 2 complex graft procedures were performed. Indications for ecAVG were as follows: bridge to transplantation (21.6%); bridge to arteriovenous fistula (AVF) maturation (8.1%); AVF salvage (8.1%); no native options (67.6%, including 17 patients with bilateral central vein stenosis); 36 AVGs (97.3%) were successfully cannulated. Mean time to first cannulation: 30.4±23.4 hours (range: 2–192). Primary and secondary patency rates at 3, 6 and 12 months were 64.9%, 48.6%, 32.4% and 70.2%, 59.4%, 40.5% respectively. The systemic bacteremia rate was 0.2 per 1,000 access days. There was one perioperative death. Other complications included hematoma at cannulation sites (n=9), pseudoaneurysm (n=3) and local infection at graft site (n=6). A total of 26 of 37 patients (70.6%) achieved a “personal vascular access solution”: bridge to transplantation (n=8), bridge to functioning AVF/interposition AVG (n=5), maintenance hemodialysis via ecAVG (n=13); death with functioning AVG (n=1).

Conclusions

Early experience with the GORE® Acuseal™ is encouraging. Patency and bacteremia rates are at least comparable to standard polytetrafluoroethylene grafts. ecAVGs have permitted cannulation within 24 hours of insertion and line avoidance in the majority of patients. Nearly three-quarters of patients achieved a definitive “personal vascular access solution” from their ecAVG.

Long Segment Recanalization and Dedicated Central venous Stenting in an Ultimate Attempt to Restore Vascular access Central Vein Outflow

Purpose

Maintaining vascular access in patients undergoing chronic hemodialysis is a challenging process, especially in patients enduring multiple central line placements and in whom peripheral options have been exhausted.

Case

We present a case of a 60-year-old male without options for peripheral vascular access due to multiple failed arteriovenous fistulas for hemodialysis. Furthermore, bilateral subclavian, brachiocephalic veins and iliac veins were occluded or significantly obstructed. After long segment central vein recanalization, an upper arm loop arteriovenous graft was implanted. The recanalized segment was stented with a 12-mm dedicated venous nitinol stent.

Conclusion

Chronic central vein obstructions demand stents with both high radial force and flexibility. We recommend dedicated venous stents to improve technical success and reduce stent-related complications like early re-occlusion due to fracturing, kinking or straightening.

The permanent catheter

An elderly woman receiving hemodialysis via a right brachiocephalic arteriovenous fistula presented to the clinic for elective removal of a tunneled hemodialysis catheter inserted 5 years ago. The catheter had not been removed earlier at the patient's request. Removal was now unsuccessful in the clinic. Exploration in the operating room revealed the innominate vein had fibrosed around the length of the catheter. The procedure was abandoned, catheter cut short and the remnant left in situ. This case serves as a reminder to exercise caution if there is difficulty in removing the catheter even after the cuff is dissected free, and to remove them once a working fistula or graft is available. Failing which, the patient bears an unnecessary risk of line infection, or as in this case, the catheter may unintentionally end up what its common misnomer "perm-cath" alludes to--becoming truly "permanent."

Fibrin sheath angioplasty: a technique to prevent superior vena cava stenosis secondary to dialysis catheters

Fibrin sheaths are a heterogeneous matrix of cells and debris that form around catheters and are a known cause of central venous stenosis and catheter failure. A total of 50 cases of central venous catheter fibrin sheath angioplasty (FSA) after catheter removal or exchange are presented. A retrospective review of an outpatient office database identified 70 eligible patients over a 19-month period. After informed consent was obtained, the dialysis catheter exiting the skin was clamped, amputated, and a wire was inserted. The catheter was then removed and a 9-French sheath was inserted into the superior vena cava, a venogram was performed. If a fibrin sheath was present, angioplasty was performed using an 8 × 4 or 10 × 4 balloon along the entire length of the fibrin sheath. A completion venogram was performed to document obliteration of the sheath. During the study, 50 patients were diagnosed with a fibrin sheath, and 43 had no pre-existing central venous stenosis. After FSA, 39 of the 43 patient's (91%) central systems remained patent without the need for subsequent interventions; 3 patients (7%) developed subclavian stenoses requiring repeat angioplasty and stenting; 1 patent (2.3%) developed an occlusion requiring a reintervention. Seven patients with prior central stenosis required multiple angioplasties; five required stenting of their central lesions. Every patient had follow-up fistulograms to document long-term patency. We propose that FSA is a prudent and safe procedure that may help reduce the risk of central venous stenosis from fibrin sheaths due to central venous catheters.

Report on the Hemodialysis Reliable Outflow (HeRO) experience in dialysis patients with central venous occlusions

OBJECTIVE

The Hemodialysis Reliable Outflow (HeRO) graft (Hemosphere/CryoLife Inc, Eden Prairie, Minn) has provided an innovative means to obtain hemodialysis access for patients with severe central venous occlusive disease. The outcomes of this novel treatment modality in a difficult population have yet to be clearly established.

METHODS

A retrospective review of HeRO graft placement from June 2010 to January 2012 was performed. Patient hemodialysis access history, clinical complexity, complications, and outcomes were analyzed. Categoric data were described with counts and proportions, and continuous data with means, ranges and, when appropriate, standard deviations. Patency rates were analyzed using life-table analysis, and patency rate comparisons were made with a two-group proportion comparison calculator.

RESULTS

HeRO graft placement was attempted 21 times in 19 patients (52% women), with 18 of 21 (86%) placed successfully. All but one was placed in the upper extremity. Mean follow-up after successful placement has been 7 months (range, 0-23 months). The primary indication for all HeRO graft placements except one was central vein occlusion(s) and need for arteriovenous access. Patients averaged 2.0 previous (failed) accesses and multiple catheters. Four HeRO grafts (24%), all in women, required ligation and removal for severe steal symptoms in the immediate postoperative period (P < .01 vs men). Three HeROs were placed above fistulas for rescue. All thrombosed <4 months, although the fistulas remained open. An infection rate of 0.5 bacteremic events per 1000 HeRO-days was observed. At a mean follow-up of 7 months, primary patency was 28% and secondary patency was 44%. The observed 12-month primary and secondary patency rates were 11% and 32%, respectively. Secondary patency was maintained in four patients for a mean duration of 10 months (range, 6-18 months), with an average of 4.0 ± 2.2 thrombectomies per catheter.

CONCLUSIONS

HeRO graft placement, when used as a last-resort measure, has been able to provide upper extremity access in patients who otherwise would not have this option. There is a high complication rate, however, including a very high incidence of steal in women. HeRO grafts should continue to be used as a last resort.

Is there a link between the structural impact of thoracic outlet and the development of central venous stenosis?

Central venous stenosis (CVS) is a serious complication for chronic hemodialysis (HD) patients. Previous reports of CVS have focused on prior central venous catheterization, because of the higher prevalence and potential for prevention of such an event. However, recent studies have demonstrated that CVS may also develop without a history of central venous catheterization. Although information about the etiological backgrounds regarding the development of CVS without previous central venous catheterization have gradually accumulated, the clinical impact of the chronic compression of the central venous system by the surrounding structures, which may likely determine the central venous susceptibility to CVS, remains poorly understood. This study proposes the hypothesis that the combination of chronic venous compression at the level of thoracic outlet characterized by the natural physique and elevated venous flow induced by the creation of vascular access should be evaluated as a potential factor for the development of CVS, since they may accelerate the development of venous stenosis, presumably through the stimulation of intimal hyperplasia, and thereby the subclavian venous susceptibility to CVS should be determined.

Utilização da técnica do varal para angioplastia de estenose de veia central com stent-graft

A estenose de veia central é uma das situações mais frequentes em pacientes com insuficiência renal crônica em hemodiálise. A angioplastia com o uso de stent-graft tem obtido bons resultados nestes casos. O sistema de liberação dos stents é de calibre maior, podendo dificultar sua navegabilidade em áreas de estenose ou tortuosidade acentuadas. A técnica do varal é comumente utilizada para o tratamento endovascular do aneurisma de aorta, permitindo atingir bom mecanismo de estiramento e facilitando a navegação do sistema de entrega da endoprótese. Descrevemos o caso de uma angioplastia de veia central com stent-graft na qual foi utilizada a técnica do varal para permitir a transposição da área de estenose.

Central venous thrombosis and perioperative vascular access in adult intestinal transplantation

BACKGROUND

Venous access is crucial in intestinal transplantation, but a thrombosed venous system may prevent the use of central veins of the upper body. The incidence of venous thrombosis and the necessity to perform alternative vascular access (AVA) in intestinal transplant recipients have not been fully investigated.

METHODS

Records of adult patients who underwent intestinal transplantation between January 1, 2001, and December 31, 2009, were reviewed. Contrast venography was performed as pre-transplantation screening. Vascular accesses at the transplantation were categorized as I (percutaneous line via the upper body veins), II (percutaneous line via the lower body veins), and III (vascular accesses secured surgically, with interventional radiology, or using non-venous sites). Categories II and III were defined as AVA. Risk factors for central venous thrombosis and those for requiring AVA were analysed, respectively.

RESULTS

Among 173 patients, central venous obstruction or stenosis (<50% of normal diameter) was found in 82% (141 patients). AVA was required in 4.6% (eight patients: four in each category II and III). Large-bore infusion lines were placed via the femoral arteries in all category III patients without complications. Existing inferior vena cava filter and hypercoagulable states were identified as the risk factors for the use of AVA, but not for central venous thrombosis. Outcomes of patients who underwent AVA were similar to those of patients without AVA.

CONCLUSIONS

The majority of adult patients undergoing intestinal transplantation had at least one central venous stenosis or obstruction. The recipient outcomes were comparable when either standard vascular access or AVA was used for transplantation.

Three-dimensional gadolinium-enhanced MR venography to evaluate central venous steno-occlusive disease in hemodialysis patients

AIM

To determine the agreement and diagnostic accuracy of three-dimensional gadolinium-enhanced magnetic resonance venography (3D-Gd-MRV) in central venous steno-occlusive disease (CVSD) in haemodialysis patients.

MATERIALS AND METHODS

Fourteen consecutive haemodialysis patients underwent interventional procedures to evaluate or treat CVSD. 3D-Gd-MRV was performed before the procedures and the results were compared with digital subtraction angiography (DSA).

RESULTS

DSA showed >50% stenosis in all 14 patients, 13 of whom were diagnosed correctly using 3D-Gd-MRV. Moderate stenosis was missed at 3D-Gd-MRV in one case whereby the indwelling dialysis central venous catheter may have caused an artefact on the images and hindered the accuracy of the result. The sensitivity of 3D-Gd-MRV in revealing stenosis was 93% (13/14). No complications caused by contrast agent toxicity occurred in any patient.

CONCLUSION

3D-Gd-MRV employing a non-breath-hold technique is highly sensitive in the diagnosis of CVSD and may be an alternative technique to DSA for the visualization of central veins.

Atypical Placement of Hemodialysis Catheters in Patients with Complete and Irreversible Obstruction of Central Venous Vessels

Purpose

This article describes the approach to atypical placement of central venous catheters (CVC) in dialysis patients with complete untreatable obstruction of central venous vessels.

Methods

Five patients with complete obstruction of central venous vessels underwent CT venography and digital venous angiography. After ultrasound-guided and radioscopic-assisted cannulation of the internal jugular vein, permanent CVCs were placed in atypical locations: in two patients a preliminary venous angioplasty was performed to facilitate the catheter positioning in a mediastinal enlarged collateral vein and in a persistent left superior vena cava; in three patients the CVC was placed in the azygos vein, enlarged because of the obstruction of the superior vena cava.

Results

In all cases, we achieved satisfactory morphological and functional immediate results. Hemodialysis (HD) was carried out long term in all patients except one who presented a non-functioning CVC after 4 months. In one case the catheter, still functioning well after 9 months, was removed due to kidney transplantation. The CVC in the left superior vena cava was replaced with a longer one after 12 months, and it is still functioning well 3 months after replacement. The patency of the other two catheters has to date been kept for 9 and 18 months.

Conclusions

The placement of CVC for HD in atypical sites can be considered a viable option in extreme cases; adequate imaging support is paramount in order to facilitate the procedure and to avoid complications.