Treatment of Malpositioned Bare Metal Stent Due to Compression of Huge Thyroid Mass: A Case Report
Jin Ho Lee1, Joon Ho Song2, HeeYeoun Kim1, Dong Yeol Lee1, Joon Seok Oh1, Yong Hun Sin1, Joong Kyung Kim1, Seun Deuk Hwang2
1Department of Internal Medicine, Bong Seng Memorial Hospital, Busan, Korea
2Department of Internal Medicine, Inha University College of Medicine, Incheon, Korea
INTRODUCTION
Central venous stenosis (CVS) is a common complication of vascular access in hemodialysis patients, which increases hospitalization rate, morbidity, and mortality [1]. Significant CVS is defined as narrowing of the central vein by >50%.
The central vein includes the superior vena cava (SVC), brachiocephalic vein, and subclavian vein. The incidence of CVS is approximately 23%-41% in dialysis patients. Balloon angioplasty is the treatment of choice for CVS [2]. However, if the lesion recurs within 3 months or repeated stenosis occurs, stent deployment can be performed [3]. Recurrent stenosis is mostly caused by neointimal hyperplasia, extrinsic compression, mediastinitis, and postradiation therapy [1,4,5]. Space-occupying tumors occasionally cause stenosis by pressing the central vein between the arteries and bone and muscles, which also resists endovascular intervention. The alternative treatment is stent deployment in the lesion, and the stent placed on the stenosis may be malpositioned from the lesion by an external force [6].
Because the malpositioned stent cannot be removed outside, a new stent can be overlapped to prevent it from migrating into the heart [7]. We report a case of a patient with overlapping of another stent between previous migrated stent and recurrent CVS caused by a thyroid mass.
CASE
A 75-year-old woman was diagnosed with diabetic end stage renal disease (ESRD) and underwent hemodialysis. She implemented the Rt. brachiocephalic fistula operation in January 2016. One month after the operation, the fistula was fully matured and cannulation was performed. Before the puncture of the arteriovenous fistula, ultrasound-guided arteriovenous blood flow measurement or venography was not performed. She underwent hemodialysis three times a week at the local dialysis center. On the 60th day of the AVF creation, she was referred to our hospital as a major symptom with swollen dialysis arm and delayed hemostasis. During dialysis, the venous pressure rose to
Received: Aug 23, 2019, Revised: Sep 6, 2019, Accepted: Sep 27, 2019 Corresponding Author : Seun Deuk Hwang
Department of Internal Medicine, Inha University College of Medicine, 27 Inhang-ro, Jung-gu, Incheon 22332, Korea Tel: 82-32-890-2229, Fax: 82-32-890-2530, E-mail: lakisis79@hanmail.net
Central vein stenosis (CVS) is commonly associated with arteriovenous fistula for hemodialysis. CVS is associated with increased morbidity, prolonged hospitalization, and increased mortality. Endovascular intervention, such as balloon angioplasty and stent deployment, should be considered for the management of CVS. Particularly, stent insertion is the treatment of choice for refractory or recurrent CVS. However, the inserted stent may be malpositioned, wherein the second stent may overlap with the lesion and the first stent. This treatment will prevent the malpositioned stent from migrating into the heart and help with the treatment of existing lesions.
Key Words: Hemodialysis, Central vein stenosis, Stent 대 한 투 석 혈 관 학 회 지 : 제 2 권 제 2 호
Journal of Korean Dialysis Access 2019;2(2):47-49
Case Report
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Copyright © The Korean Society for Dialysis Access | eISSN: 2635-8603
대한투석혈관학회지 : 제 2 권 제 2 호 2019
48
250 mmHg and compared with the contralateral arm, fistula arm showed severe edema. On the physical exam, abnormal findings were observed in the arm elevation test in which the fistula was not collapsed. The patient was suspected of stenosis of the central vein and we decided to perform percutaneous transluminal angioplasty (PTA). On the fistulgraphy, 80% stenosis of Rt.
brachiocephalic vein and a large number of collateral veins were observed (Fig. 1A). We performed balloon dilatation on the lesion with a 12 mm diameter, 4 cm long Mustangballoon (Boston Scientific Inc., Watertown, Massachusetts, USA) (Fig.
1B). The lesion was enlarged sufficiently to raise the balloon to 14 atm without significant resistance. However, elastic recoil findings were shown on the angiography after removal of the balloon catheter (Fig. 1C). Despite of 12 mm balloon angioplasty, significant stenosis was remained. We performed enhance chest CT the next day in order to find the cause of elastic recoil. As a result of CT examination, the Rt. brachiocephalic vein was compressed between the 1st rib and the Rt. Internal carotid artery, which was laterally deviated by the thyroid mass (3.4×2.7 cm) (Fig. 1D). The patient's caregiver did not want to undergo
further testing or treatment for thyroid mass because the patient was in an elderly and debilitating condition. A week later, we conducted a second PTA. On the fistulographyusing the 7Fr sheath, 80% stenosis was observed in the Rt. brachiocephalic vein as in the previous lesion. Several collateral veins were also observed. We decided to position the 14 mm diameter, 40 mm length Wallstent (Boston Scientific Inc., Watertown, Massachusetts, USA) due to the high radial resistive strength (Fig. 2A). After the stent was inserted, the balloon catheter of the same diameter expanded the inside of the stent. The stenosis of the fistula disappeared and immediate technical success was achieved, and the patient's arm was immediately edited, the venous pressure decreased during the dialysis, and the hemostasis was successful after dialysis. However, the edema of the dialysis arm recurred 3 days after intervention.We decided on the second PTA. On central venography, the stent was migrated into the SVC, and stenotic lesions remained (Fig. 2B).
So, we placed a second stent that overlaps the SVC lesion with a portion of the misplaced stent. 14 mm×4 cm EPICstent (Boston Scientific Inc., Watertown, Massachusetts, USA) was overlapped
A B C D
A
Fig. 1. (A) Central vein stenosis (CVS). (B) 12-mm balloon. (C) Elastic recoil. (D) Chest CT: CVS due to thyroid mass.
A B C
Fig. 2. (A) Wallstent deployment. (B) Stent migration into the superior vena cava (SVC). (C) Overlapping of the stent between central vein stenosis (CVS) and migrated stent.
Jin Ho Lee, et al. : Treatment of Malpositioned Bare Metal Stent Due to Compression of Huge Thyroid Mass: A Case Report 49
between CVS lesion and migrated stent (Fig. 2C). Arm swelling was disappeared. The edema of fistula arm disappeared the day after the procedure. There is no central vein stenosis for 6 months after the second PTA, and both stents are fixed in place without displacement and no abnormal findings were observed.
DISCUSSION
CVS is a common complication of vascular access, most commonly seen in patients with brachiocephalic AVF. CVS has various symptoms. In the early days, the venous pressure increases during hemodialysis, and edema of the dialysis arm is observed. Thereafter, the collateral vein is visible in the upper arm, or the hemostasis time is prolonged after dialysis [1,2,4].
On physical examination, thill decreases, pressure increases, and abnormal findings are observed during arm elevation test. In addition, if the central vein is maintained, blood flow decreases, dialysis efficiency decreases, and patient morbidity and mortality increase. The most common cause of CVS is neointimal hyperplasia and stenosis of other vascular access.
However, it sometimes occurs because of compression due to external tissue, mediastinitis, and complication after radiation therapy [1,4,5]. Another problem of central venous stenosis is the treatment failure or recurrence after conventional balloon dilatation. Particularly, compression due to external tissue may cause elastic recoil even after balloon dilatation, and maintaining the patency and repeating the procedure may be difficult [8]. In these cases, external tissue removal is the primary treatment, but stenting is the next treatment option if the patient cannot tolerate the procedure. When the stent is inserted into the lesion, the blood vessel diameter is maintained, and resistance to external pressure is generated; hence, blood flow for hemodialysis is sufficient. Because the stent cannot be removed once it has been placed in a vein, it must be carefully determined and inserted during the procedure. The stent may not be properly inserted or may migrate after successfulinsertion, allowing it to enter the heart or into the pulmonary artery [9]. In these patients, open- heart surgery is required, resulting in additional risks and costs for the patient. If the migrated stent is not distant from the lesion, an additional stent may be inserted to hold and secure the stent that has been displaced. Wall stent endoprosthesis has a braided construction and closed-cell design, thus providing compression resistance. In addition, bare metal stents composed of nitinol are common, but recent studies have shown that stentgrafts are more helpful in maintaining patency [10]. The
treatment for CVS includes various endovascular interventions, such as conventional balloon dilatation, drug-eluting balloon, bare metal stent insertion, and stent graft insertion. The primary treatment for CVS is external tissue removal. However, endovascular intervention is an alternative treatment. Initially, balloon dilatation is the primary treatment, but if maintaining patency for more than 3 months is difficult, or if elastic recoil is present, stenting is indicated. If the location of the stent is moved after insertion, additional stents may be used to overlap CVS and the migrated stent.
CONFLICT OF INTEREST
The authors declare that they have no conflict of interest.
REFERENCES
1. Agarwal AK, Patel BM, Haddad NJ. Central vein stenosis: a nephrologist's perspective. Semin Dial. 2007; 20(1): 53-62.
2. Kim YC, Won JY, Choi SY, et al. Percutaneous treatment of central venous stenosis in hemodialysis patients: long-term outcomes. Cardiovasc Intervent Radiol. 2009; 32(2): 271-8.
3. Bakken AM, Protack CD, Saad WE, et al. Long-term outcomes of primary angioplasty and primary stenting of central venous stenosis in hemodialysis patients. J Vasc Surg.
2007; 45(4): 776-83.
4. Agarwal AK. Central vein stenosis: current concepts. Adv Chronic Kidney Dis. 2009; 16(5): 360-70.
5. Kotoda A, Akimoto T, Kato M, et al. Central venous stenosis among hemodialysis patients is often not associated with previous central venous catheters. Asaio j. 2011; 57(5): 439- 43.
6. Shi Y, Cheng J, Song Y, et al. Anatomical factors associated with left innominate vein stenosis in hemodialysis patients.
Hemodial Int. 2014; 18(4): 793-8.
7. Baron TH. Minimizing endoscopic complications:
endoluminal stents. Gastrointest Endosc Clin N Am. 2007;
17(1): 83-104, vii.
8. Maya ID, Saddekni S, Allon M. Treatment of refractory central vein stenosis in hemodialysis patients with stents.
Semin Dial. 2007; 20(1): 78-82.
9. Taylor JD, Lehmann ED, Belli AM, et al. Strategies for the management of SVC stent migration into the right atrium.
Cardiovasc Intervent Radiol. 2007; 30(5): 1003-9.
10. Jones RG, Willis AP, Jones C, et al. 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): 1240-5.
