Stent-Graft Length Is Associated with Decreased Patency in Treatment of Central Venous Stenosis in Hemodialysis Patients

Accepted Manuscript STENT GRAFT LENGTH IS ASSOCIATED WITH DECREASED PATENCY IN TREATMENT OF CENTRAL VENOUS STENOSIS IN HEMODIALYSIS PATIENTS Mina L. Boutrous, MD, Alejandro C. Alvarez, MD, Obi T. Okoye, MD, Jennifer C. Laws, MD, Donald L. Jacobs, MD, Matthew R. Smeds, MD PII:

S0890-5096(19)30258-4

DOI:

https://doi.org/10.1016/j.avsg.2019.01.024

Reference:

AVSG 4328

To appear in:

Annals of Vascular Surgery

Received Date: 7 November 2018 Revised Date:

28 December 2018

Accepted Date: 14 January 2019

Please cite this article as: Boutrous ML, Alvarez AC, Okoye OT, Laws JC, Jacobs DL, Smeds MR, STENT GRAFT LENGTH IS ASSOCIATED WITH DECREASED PATENCY IN TREATMENT OF CENTRAL VENOUS STENOSIS IN HEMODIALYSIS PATIENTS, Annals of Vascular Surgery (2019), doi: https://doi.org/10.1016/j.avsg.2019.01.024. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

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Original Scientific Article

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STENT GRAFT LENGTH IS ASSOCIATED WITH DECREASED

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PATENCY IN TREATMENT OF CENTRAL VENOUS STENOSIS IN

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HEMODIALYSIS PATIENTS

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Mina L. Boutrous, MD1, Alejandro C. Alvarez, MD2, Obi T. Okoye, MD1, Jennifer C. Laws, MD1,

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Donald L. Jacobs, MD1, Matthew R. Smeds, MD1

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Author Affiliations

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1. St. Louis University, Saint Louis, MO, USA 2. NHS Vascular LLC, SSM Health St. Mary’s Hospital, Saint Louis, MO, USA

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Correspondence to:

Matthew R. Smeds, MD, FACS Associate Professor of Surgery Division of Vascular Surgery Saint Louis University Hospital 3635 Vista Avenue St. Louis, MO 63110 E: [email protected]

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ABSTRACT: Objectives: Central venous occlusion may occur in hemodialysis patients resulting in arm or

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facial swelling and failure of dialysis access. Endovascular management with balloon

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angioplasty or stenting has been described, but there is minimal data on the use of covered stents

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in this pathology. We sought to review a single institution’s experience with the use of covered

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stents for central venous occlusive disease in hemodialysis patients.

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Methods: A retrospective review of all patients undergoing placement of covered stents between

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April 2014 and December 2016 for central venous occlusive disease to preserve a failing dialysis

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access was performed. Patients’ records were reviewed to identify demographics, medical co-

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morbidities, operative variables, primary patency rates and secondary interventions.

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Results: A total of 29 patients were included in the analysis. Viabahn (W.L. Gore and associates,

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Flagstaff, AZ) stent-grafts were exclusively used in all patients. Technical success rate was

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100%. The patients were predominantly female (65.5%), with a mean age of 67.9±12.1, and

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medical co-morbidities of hypertension (86%), diabetes (76%), and tobacco use (7%). The

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majority (86%) had prior angioplasty and 17/29 (59%) had previous central venous catheters.

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The right brachiocephalic vein was the most commonly stented vessel (28%). The median stent

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length and diameter utilized was 50 millimeters (range 25-100 millimeters) and 13 millimeters

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(range: 9-13 millimeters) respectively. The majority of patients (83%) received a single stent,

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with only two patients requiring more than one. Median follow up was 24 months (range: 6–41

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months). 4/29 (13.8%) patients developed symptomatic stent re-stenosis requiring secondary

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intervention, all of which occurred in patients with primary stenosis between 50 and 75%. When

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compared to the patients without re-stenosis, longer stents were found to be significantly

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associated with re-stenosis (62.5 centimeters [IQR: 0] vs 50 centimeter [IQR: 0], p=0.002).

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Primary patency rates were 92.9%, 91.7%, and 80.0% at 6, 12, and 24 months respectively.

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Secondary patency rates were 96.4%, 95.8%, and 93.3% at 6 months, 12 months, and 24 months

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respectively. The overall primary patency rate was estimated at 86.2% using Kaplan-Meier

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analysis at 30.5 months (95% CI: 26.5 - 34.5 months).

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Conclusions: Covered stent-grafts have reasonable primary patency and excellent secondary

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patency when used for central venous stenosis in dialysis patients. Stent graft length is associated

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with poorer long-term patency rates.

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INTRODUCTION: Central Venous Stenosis (CVS) has long been described as a significant pathologic process affecting the hemodialysis patient population1–3. The onset and progression of the entity

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has been attributed to a number of different factors4; most notably the use of temporary dialysis

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catheters which are responsible for intimal trauma and subsequent injury 5,6. Given the

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widespread use of these catheters as well as their prolonged use and high infection rates, the

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incidence of CVS continues to rise making the need to deal with this problem an integral part of

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modern vascular surgery practices3,6.

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Historically, different modes of treatment have been proposed to deal with CVS7, with early trials of angioplasty and Palmaz stents showing promising initial results but hindered

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longevity8. This prompted exploration of different modalities of treatment in an attempt to

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provide a long-term solution for this problem, however a consensus has yet to be reached9.

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Multiple studies have previously shown that angioplasty and/or bare metal stents can be used as potential options for the treatment of CVS3,9,10. However, more recent studies have

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shown superiority with the use of covered stent grafts over both angioplasty and bare metal

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stents in terms of long term patency and rates of secondary interventions11,12.The feasibility of

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using covered stent grafts was tested in animal models that yielded acceptable results13. Several

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centers have opted using covered stent grafts to provide better outcomes for CVS, with the

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results being strongly favorable at least in the short term6,12,14,15. Our study’s aim was to examine

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our own institution’s experience and mid-term results with the use of covered stent grafts for the

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treatment of CVS and identify factors predictive of failure of this therapy.

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MATERIAL AND METHODS: All patients with end-stage renal disease on hemodialysis requiring endovascular stent placement for maintenance of patency between April 2014 and December 2016 were identified

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by querying a prospectively maintained institutional registry. These patients were from a

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system-based nephrology group/dialysis center, and thus access creation and maintenance, as

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well as follow-up was documented in the same electronic medical record. Patients were included

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in this analysis if they had follow up documentation for a minimum of 6 months from the initial

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stent placement. Access patency was determined from hemodialysis flow rates when available,

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and need for intervention. Primary patency (intervention-free stent graft patency) was defined as

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the interval from time of graft deployment to any intervention designed to maintain or reestablish

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patency. Secondary patency (access survival until abandonment) was defined as the interval from

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time of graft deployment to access abandonment or time of measurement of patency, including

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intervening manipulations (surgical or endovascular interventions) designed to reestablish the

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functionality of thrombosed access16. The study was approved by the Institutional Review Board

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of Saint Louis University. Informed consent was waived due to the retrospective nature of the

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data collection process.

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Patient demographics, co-morbidities, type of access were abstracted from the registry.

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Additional data on previous interventions were obtained from retrospective chart review.

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Descriptive statistics were reported as mean and standard deviations (M±SD) for normally

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distributed continuous data, while median and interquartile range (median [IQR]) were used to

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report non-normal continuous data. Categorical data were reported using proportions, and

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compared using Fisher’s exact test. The assumption of normality was evaluated using normal

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distribution plots, and confirmed using the Shapiro-Wilk test. Normally distributed continuous

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data were analyzed using the Student T-test, while non-normally distributed continuous variables

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were compared using the Mann-Whitney U Test. P-values ≤ 0.05 were considered statistically

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significant. Patency rates were estimated using Kaplan-Meier analyses. Data was analyzed using

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IBM SPSS Statistics for Mac, Version 20.0. Armonk, NY: IBM Corp.

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HYPOTHESIS:

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Our original hypothesis was that longer covered stent grafts provided a superior long

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term patency rate given that it achieves complete exclusion of the segment showing stenosis.

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RESULTS:

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A total of 29 patients were identified and included in the analysis (Table I). Overall, the population were predominantly female (65.5%), with a mean age of 67.9±12.1. Twenty-five

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patients (86%) had a history of hypertension, 22 (76%) were diabetic, 9 (31%) were obese (BMI

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> 30), while 2 (7%) were active tobacco users. The majority (86%) of patients had undergone

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prior angioplasty at least once, 10 (34%) of the patients have had more than one attempt of

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angioplasty, and 17 (59%) had a previous central venous catheter. With respect to type of access

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and laterality, 17 patients (59%) had AV fistulas, and 16 (55%) with right handed access.

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Viabahn (W.L. Gore and associates, Flagstaff, AZ) stent-grafts were used exclusively in

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all patients, with technical success achieved in 100% of cases (Figure 1). The brachiocephalic

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vein (59%) was the most common site of intervention – 8 patients (28%) had stents placed on the

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right, 3 patients (10%) on the left, and an additional 6 patients (21%) had right brachiocephalic

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stents placed in conjunction with subclavian stents (Table II). The majority of patients (93%)

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received a single stent, with only two patients requiring more than one. The indication for stent

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placement was access dysfunction in 86% (25/29) of cases, while central venous occlusion

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(complete occlusion) was implicated in the remaining four cases. All 4 patients with central

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venous occlusion developed severe access dysfunction; however the access was salvaged

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following covered stent graft deployment. The degree of stenosis prior to initial stent placement

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was > 75% in 59% (17 patients) of cases. The median stent length was 50 mm (range 25 mm -

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100 mm), and the deployed stent diameter reported at 13 mm (range 9 – 13 mm) (Table III).

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The median follow up was 24 months (range: 6–41 months). All patients went on to have

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successful dialysis through their salvaged access. During this period, 4 patients (14%) developed

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symptomatic stent re-stenosis requiring a secondary intervention. These patients all had primary

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stenosis between 50% and 75% on initial angiography. It was noted that the type and laterality of

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the dialysis access of the study cohort were not indicators for the development of symptomatic

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stent stenosis nor was coverage of the internal jugular vein (Table IV). When compared to the

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patients without evidence of re-stenosis, longer stents were found to be significantly associated

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with re-stenosis – 62.5 cm [IQR: 43.8] vs 50 [IQR: 0], p=0.002.

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Primary patency rates were 92.9%, 91.7%, and 80.0% at 6, 12, and 24 months respectively. Patients with re-stenosis were treated with percutaneous transluminal angioplasty,

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and technical success reported in 100% of cases. Secondary patency rates were 96.4%, 95.8%,

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and 93.3% at 6 months, 12 months, and 24 months respectively (Table V). The overall primary

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patency rate was estimated at 81.2 % using Kaplan-Meier analysis at 30.5 months (95% CI: 26.5

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- 34.5 months) (Figure 2).

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DISCUSSION:

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CVS in the hemodialysis patient population has emerged as a common yet debilitating pathology resulting in arm and facial swelling as well as loss of dialysis access. CVS was

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initially managed with recurrent balloon angioplasty, however, preferred therapy has shifted to

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bare metal stents until most recently when studies have shown superiority of covered stent

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grafts14,17.

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Our single institution study has shown primary and secondary patency rates that were comparable to these contemporary studies while our study has had, to our knowledge, the longest

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median follow-up duration of 24 months in comparison to other studies. Laterality, type of

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access as well as site of prosthesis deployment had no effect on the outcome in terms of duration

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of patency. This is consistent with the study by Anaya-Ayala et al6. There is clearly some

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controversy in the use of covered stents within the thoracic outlet, given increased forces exerted

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on endoprosthesis delivered to this area. While it is not desirable, alternative options are not

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often available in this patient population, and our small series showed no difference in patency in

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those who received stent-grafts in this area as opposed to just in the brachiocephalic veins.

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One point of data that showed statistical significance in our study was the length of

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endoprosthesis used; in contrary to our original hypothesis, longer devices had lower patency

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rates which now makes our group a strong advocate of treating the shortest distance possible in

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the central veins without the need to “prophylactically over treat” an area that does not show at

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least 50% luminal reduction on radiographic imaging. This methodology has also been

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advocated by Ehrie et al18 which reported that intervening on a previously asymptomatic area of

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central venous stenosis would result in an “unmasking” of the asymptomatic nature of the lesion

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resulting in recurrent symptomatic stenosis; the only difference in the intervention on their study

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population was percutaneous transluminal angioplasty as opposed to stenting.

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Given the progression of how the problem of CVS has been tackled over the years and the lack of consensus on treatment methodology, it was only expected that new treatment options

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would be explored including drug coated balloons19,20. In 2017, Kitrou et al21 published their

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experience with a prospectively randomized control study constituting of 40 patients. The

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patients randomized to the drug coated balloon arm showed a clear superiority as evidenced by a

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longer intervention free period. Longitudinal comparisons in the same patients that were treated

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with a drug coated balloon angioplasty after a remote history of a conventional balloon

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angioplasty also showed better patency rates.

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Most recently in 2018, the first report of a drug eluting stent used to treat CVS was published22. The device was used in a patient that exhausted a number of options in trying to

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control his CVS symptoms including recurrent transluminal angioplasties, bare metal stenting as

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well as recurrent angioplasties for in stent stenosis that developed later in his course. Further

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research is needed to assess the efficacy of both drug coated balloons and stents in dealing with

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the pathology of CVS as well radiofrequency wire canalizations which has also been proposed in

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recent literature23.

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LIMITATIONS

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We acknowledge that despite our study having comparable patency rates to other

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contemporary ones, there are limitations to be mentioned. The study’s relatively small patient

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populations, as well as being from a single institution are the clearest of those limitations.

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Additionally, while our patient population was from our hospital system of nephrologists and

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dialysis centers and all patients received a thorough history and physical at each visit, we cannot

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be certain they didn’t receive interventions at other facilities. Furthermore, the frequency and

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duration of hemodialysis sessions were not taken into account as well as the caliber and site of

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prior tunneled dialysis catheters which have been shown to significantly contribute to the

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pathology of CVS 24. Finally, there is no direct comparison between the covered stents and other

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treatment modalities such as balloon angioplasty or bare metal stents.

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CONCLUSIONS:

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In our current series, covered stent-grafts have reasonable primary patency and excellent

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secondary patency when used for central venous stenosis in dialysis patients. Stent graft length

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was found to be associated with poorer long-term patency rates. Further randomized control

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trials are needed to assess the efficacy of covered stent grafts versus newly used methodologies

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like drug coated balloons as well as drug eluting stents for the treatment of CVS.

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1. Schwab SJ, Quarles LD, Middleton JP, Cohan RH, Saeed M, Dennis VW. Hemodialysisassociated subclavian vein stenosis. Kidney Int. 1988;33(6):1156-1159. doi:10.1038/ki.1988.124

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2. Sidawy AN, Spergel LM, Besarab A, Allon M, Jennings WC, Padberg FT, Jr, et al. The Society for Vascular Surgery: Clinical practice guidelines for the surgical placement and maintenance of arteriovenous hemodialysis access. J Vasc Surg. 48(5):S2-S25. doi:10.1016/j.jvs.2008.08.042

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3. Lumsden A., MacDonald M., Isiklar H, Martin LG, Kikeri D, Harker LA, et al. Central venous stenosis in the hemodialysis patient: incidence and efficacy of endovascular treatment. Cardiovasc Surg. 1997;5(5):504-509. doi:10.1016/S0967-2109(97)00043-4

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4. Hernández D, Díaz F, Rufino M, Lorenzo V, Perez T, Rodriguez A, et al. Subclavian vascular access stenosis in dialysis patients: Natural history and risk factors. J Am Soc Nephrol. 1998;9(8):1507-1510.

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5. Trerotola SO, Kuhn-Fulton J, Johnson MS, Shah H, Ambrosius WT, Kneebone PH. Tunneled Infusion Catheters: Increased Incidence of Symptomatic Venous Thrombosis after Subclavian versus Internal Jugular Venous Access. Radiology. 2000;217(1):89-93. doi:10.1148/radiology.217.1.r00oc2789

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6. Anaya-Ayala JE, Smolock CJ, Colvard BD, Naoum JJ, Bismuth J, Lumsden AB, et al. Efficacy of covered stent placement for central venous occlusive disease in hemodialysis patients. J Vasc Surg. 2011;54(3):754-759. doi:10.1016/j.jvs.2011.03.260

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7. Trerotola SO, Lund GB, Samphilipo MA, Magee CA, Newman JS, Olson JL, et al. Palmaz stent in the treatment of central venous stenosis: safety and efficacy of redilation. Radiology. 1994;190(2):379-385. doi:10.1148/radiology.190.2.8284384

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8. Landwehr P, Lackner K, Götz R. Dilatation und ballonexpandierbare Stents zur Therapie zentralvenöser Stenosen bei Dialysepatienten. Fortschr Röntgenstr. 2008;153(09):239-245. doi:10.1055/s-2008-1033372

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9. Sprouse LR II, Lesar CJ, Meier GH III, Parent FN, Demasi RJ, Gayle RG, et al. Percutaneous treatment of symptomatic central venous stenosis angioplasty. J Vasc Surg. 39(3):578-582. doi:10.1016/j.jvs.2003.09.034

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10. Bakken AM, Protack CD, Saad WE, Lee DE, Waldman DL, Davies MG. Long-term outcomes of primary angioplasty and primary stenting of central venous stenosis in hemodialysis patients. J Vasc Surg. 2007;45(4):776-783. doi:10.1016/j.jvs.2006.12.046

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11. Modabber M, Kundu S. Central Venous Disease in Hemodialysis Patients: An Update. Cardiovasc Intervent Radiol. 2013;36(4):898-903. doi:10.1007/s00270-012-0498-6

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12. Carmona J, Rits Y, Jones B, Dowers L, Bednarski D, Rubin JR. Patency of the Viabahn stent graft for the treatment of outflow stenosis in hemodialysis grafts. Am J Surg. 2016;211(3):551-554. doi:10.1016/j.amjsurg.2015.12.006

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13. Byung Seok Shin, Mi-hyun Park, Gyeong Sik Jeon, Byung Mo Lee, Kichang Lee, DaeYoung Kang, et al. Use of Covered Stents in the Central Vein: A Feasibility Study in a Canine Model. J Endovasc Ther. 2011;18(6):802-810. doi:10.1583/11-3566.1

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14. Jones RG, Willis AP, Jones C, McCafferty IJ, Riley PL. Long-term Results of Stent-graft Placement to Treat Central Venous Stenosis and Occlusion in Hemodialysis Patients with Arteriovenous Fistulas. J Vasc Interv Radiol. 2011;22(9):1240-1245. doi:10.1016/j.jvir.2011.06.002

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15. Verstandig AG, Berelowitz D, Zaghal I, Goldin I, Olsha O, Shamieh B, et al. Stent Grafts for Central Venous Occlusive Disease in Patients with Ipsilateral Hemodialysis Access. Spec Focus Venous Access. 2013;24(9):1280-1287. doi:10.1016/j.jvir.2013.04.016

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16. Sidawy AN, Gray R, Besarab A, Henry M, Ascher E, Silva MJ, et al. Recommended standards for reports dealing with arteriovenous hemodialysis accesses. J Vasc Surg. 35(3):603-610. doi:10.1067/mva.2002.122025

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17. Jesus G. Ulloa, Vincent E. Kirkpatrick, Samuel E. Wilson, Russell A. Williams. Stent Salvage of Arteriovenous Fistulas and Grafts. Vasc Endovascular Surg. 2014;48(3):234-238. doi:10.1177/1538574413518609

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18. Ehrie JE, Sammarco TE, Chittams JL, Trerotola SO. Unmasking of Previously Asymptomatic Central Venous Stenosis following Percutaneous Transluminal Angioplasty of Hemodialysis Access. J Vasc Interv Radiol. 2017;28(10):1409-1414. doi:10.1016/j.jvir.2017.07.006

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19. Horikawa M, Quencer KB. Central Venous Interventions. SI Dial Access. 2017;20(1):48-57. doi:10.1053/j.tvir.2016.11.006

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20. Massmann A, Fries P, Obst-Gleditsch K, Minko P, Shayesteh-Kheslat R, Buecker A. Paclitaxel-Coated Balloon Angioplasty for Symptomatic Central Vein Restenosis in Patients With Hemodialysis Fistulas. J Endovasc Ther. 2015;22(1):74-79. doi:10.1177/1526602814566907

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21. Kitrou PM, Papadimatos P, Spiliopoulos S, Katsanos K, Christeas N, Brountzos E, et al. Paclitaxel-Coated Balloons for the Treatment of Symptomatic Central Venous Stenosis in Dialysis Access: Results from a Randomized Controlled Trial. J Vasc Interv Radiol. 2017;28(6):811-817. doi:10.1016/j.jvir.2017.03.007

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22. Sadanori Shintaku, Tomoyasu Sato, Hideki Kawanishi, Misaki Moriishi, Shinichiro Tsuchiya. The efficacy of drug-eluting stent for recurrent central venous restenosis in a patient undergoing hemodialysis. J Vasc Access. March 2018:1129729818763473. doi:10.1177/1129729818763473

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23. Gajan Sivananthan, Daniel H. MacArthur, Kevin P. Daly, David W. Allen, Salar Hakham, Neil J. Halin. Safety and Efficacy of Radiofrequency Wire Recanalization of Chronic Central Venous Occlusions. J Vasc Access. 2015;16(4):309-314. doi:10.5301/jva.5000360

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24. Kundu S. Review of Central Venous Disease in Hemodialysis Patients. J Vasc Interv Radiol. 2010;21(7):963-968. doi:10.1016/j.jvir.2010.01.044

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Occlusion/Thrombosis (N= 4) 61±8.8

Patent (N=25) 69±12.3

0.225

72.3 (8.8)

81.2 (28.6)

0.338

1.71±0.08 28.3±6.2

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Table I Patient demographics

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2 (50%) 2 (50%) 0 (0%) 3 (75%) 4 (100%) 1 (25%) 3 (75%) 0 (0%) 0 (0%) 2 (50%) 4 (100%)

9 (36%) 14 (56%) 2 (8%) 19 (76%) 15 (60%) 4 (16%) 22 (88%) 3 (12%) 4 (16%) 15 (60%) 21 (84%)

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1.70±0.14 24.9±2.4

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Demographics (N = 29) Age, (mean±SD) 67.9 ± 12.1 Weight, [range 79.4 (23.4) (IQR)] Height, (mean±SD) 1.71 ± 0.9 BMI, (mean±SD) 27.9 ± 5.9 Smoking status Never 11 (37.9%) Former 16 (55.2%) Current 2 (6.9%) Diabetes 22 Gender (male) 19 (34.5%) COPD 5 (17.2%) Hypertension 25 (86.2%) Pacemaker 3 (10.3%) CAD 4 (13.8%) Prior central catheter 17 (58.6%) Previous angioplasty 25 (86.2%)

1.000 1.000 0.268 0.553 0.467 1.000 1.000 1.000 1.000

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N=29 2 (6.9%) 6 (20.7%) 8 (27.6%) 6 (20.7%) 2 (6.9%) 3 (10.3%) 1 (3.4%) 1 (3.4%)

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Site of Stents Right Subclavian vein Right Subclavian & R Brachiocephalic vein Right Brachiocephalic vein Left Subclavian vein Left Subclavian & Left Brachiocephalic vein Left Brachiocephalic vein Left Cephalic & Left Subclavian vein Left cephalic arch

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Table II Site of covered stent graft deployment

Stent length mm (N) 25 (2) 50 (24) 60 (1) 75 (1) 100 (1)

Percentage occlusion 0% (0/2) 8.3% (2/24) 0% (1/1) 100% (1/1) 100% (1/1)

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Table III Relationship between stent length and episodes of primary occlusion

Type of access (N=29)

Patent (N=25)

0 (0%) 1 (25%) 0 (0%) 0 (0%)

5 (17.2%) 3 (10.3%) 5 (17.2%) 3 (10.3%)

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5 (20%) 2 (8%) 5 (20%) 3 (12%)

6 (20.7%) 4 (13.8%) 1 (3.4%) 2 (6.9%)

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0.445

1 (25%) 1 (25%) 0 (0%) 1 (25%)

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Right R arm fistula R arm graft R forearm fistula R forearm graft Left L arm fistula L arm graft L forearm fistula L forearm graft

Occlusion/Thrombosis (N= 4)

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Table IV Type and laterality of access

5 (20%) 3 (12%) 1 (4%) 1 (4%)

Primary patency rate Secondary patency

12 months

92.9%

91.7%

96.4%

95.8%

24 months 80.0% 93.3%

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6 months

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Table V Primary and secondary patency rates of deployed stent grafts

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Fig 1. Preoperative and postoperative images for stent deployment. A, Pre-deployment image showing wire across target venous lesion B, Post stent deployment completion angiogram

Median patency rate 35 months (Std error: 2.1)

AC C

EP

TE D

M AN U

SC

RI PT

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Fig 2: Kaplan Meier analysis curve showing median patency rate