|Year : 2020 | Volume
| Issue : 4 | Page : 405-410
Outcomes of endovascular procedures in salvage of arteriovenous fistulas via the transradial route: A prospective study
Pranay Pawar1, MK Ayyappan2, Kapil Mathur2, Radhakrishnan Raju2
1 Department of Vascular Surgery, Christian Medical College and Hospital, Ludhiana, Punjab, India
2 Department of Vascular Surgery, Sri Ramachandra Medical College, Chennai, Tamil Nadu, India
|Date of Submission||03-Jun-2020|
|Date of Decision||25-Jun-2020|
|Date of Acceptance||04-Jul-2020|
|Date of Web Publication||24-Dec-2020|
Department of Vascular Surgery, Christian Medical College and Hospital, Ludhiana, Punjab
Source of Support: None, Conflict of Interest: None
Aim: To evaluate the primary patency and predictors of technical failure of arteriovenous fistulae (AVF) following transradial percutaneous transluminal angioplasty (PTA). Materials and Methods: This was a prospective study being conducted to evaluate the primary patency and predictors of technical failure of AVF following transradial PTA. This will help us identify high-risk patients and plan interventions in them at an earlier time to avoid access loss. The time period of the study was from October 2016 to October 2018 in the Department of Vascular and Endovascular Surgery at Sri Ramachandra Medical College, Chennai, Tamil Nadu. A total of 44 patients were included in this cohort and they were all followed up in the outpatient department and via telephonic contact for a period of 1 year. All the patients who underwent endovascular AVF salvage fitting the inclusion criteria were included in the study. The demographics of the patients were recorded at admission and patients were investigated for the cause of fistula dysfunction at the treating physicians discretion and an ultrasound Doppler was ordered for all patients to ascertain the cause of the stenosis. The statistical analysis was done by the ANOVA and t-test. Results: A total of 44 patients were included in this cohort and they were all followed up for a period of 1 year. The 30-day, 90-day, 6-month, and 12-month primary patencies were 84.1%, 81.8%, 63.63%, and 43.18%, respectively. Our technical success was 88.6%. In our study, we found that longer lesion lengths (>4 cm) were prone to early loss of primary patency and this was statistically significant. We found that patients above 60 years of age had lower primary patencies and the presence of diabetes mellitus also lowered the primary patency. Fistula maturation age did not show a correlation with patency in our cohort. Male patients had a higher patency rate and juxta-anastomotic stenoses postangioplasty had a higher primary patency due to the shorter lengths. Radiocephalic fistula angioplasties had a higher patency as compared to brachiocephalic angioplasty. Conclusion: Ours is the first study in India to proactively and preferably use the transradial approach over the transvenous approach, as it confers many benefits. The challenges of the transradial route are the smaller size of the radial artery in the Indian population as compared to the western population.
Keywords: Fistula salvage, percutaneous transluminal angioplasty, transradial approach
|How to cite this article:|
Pawar P, Ayyappan M K, Mathur K, Raju R. Outcomes of endovascular procedures in salvage of arteriovenous fistulas via the transradial route: A prospective study. Indian J Vasc Endovasc Surg 2020;7:405-10
|How to cite this URL:|
Pawar P, Ayyappan M K, Mathur K, Raju R. Outcomes of endovascular procedures in salvage of arteriovenous fistulas via the transradial route: A prospective study. Indian J Vasc Endovasc Surg [serial online] 2020 [cited 2021 Jan 28];7:405-10. Available from: https://www.indjvascsurg.org/text.asp?2020/7/4/405/304642
| Introduction|| |
In patients with end-stage renal failure, vascular access remains the Achilles' heel of maintenance hemodialysis. Successful hemodialysis requires repetitive access to large vessels that are capable of providing rapid extracorporeal blood flow. The primary arteriovenous fistula (AVF), created by an anastomosis of the radial artery with the cephalic vein, was first described by Brescia et al. in 1966. The cephalic vein becomes arterialized and will theoretically stay uncollapsed even when blood is drawn from it at high-flow rates. Throughout the past decades, this technique has remained the preferred mode of achieving vascular access during hemodialysis.,
Maintaining patent vascular access remains a major challenge, especially in an aging hemodialysis population. Cumulative data show that vascular access is lost predominantly from an inability to resolve a thrombotic episode. Over 85% of the documented episodes of thrombosis have an anatomical cause, the most common being stenotic lesions at the arteriovenous (AV) anastomosis or along the proximal venous limb. Prospective detection and preventive treatment of a high-grade venous stenosis are important, since they will improve the patency of vascular access and hence decrease the incidence of hemodialysis failure due to fistula loss. Percutaneous transluminal angioplasty (PTA) has been gaining favor in recent years as a means of correcting venous stenosis, thereby improving fistula function and prolonging fistula survival.
PTA is an established treatment for stenosis in both native AVFs and prosthetic grafts, but patency after angioplasty is highly variable. Only 26%–58% of native AVFs remain functional without subsequent interventions at 12 months. Patency in native AVFs after angioplasty depends on a range of clinical, anatomic, and biochemical factors.
| Materials and Methods|| |
This was a prospective study being conducted to evaluate the primary patency and predictors of technical failure of AVF following transradial PTA. This will help us identify high-risk patients and plan interventions in them at an earlier time to avoid access loss. The time period of the study was from October 2016 to October 2018 in the Department of Vascular and Endovascular Surgery at Sri Ramachandra Medical College, Chennai, Tamil Nadu. A total of 44 patients were included in this cohort and they were all followed up in the outpatient department and via telephonic contact for a period of 1 year. All the patients who underwent endovascular AVF salvage fitting the inclusion criteria were included in the study. The demographics of the patients were recorded at admission and patients were investigated for the cause of fistula dysfunction at the treating physicians discretion, and an ultrasound Doppler was ordered for all patients to ascertain the cause of the stenosis. The statistical analysis was done by the ANOVA and t-test.
Failing or failed AV fistulas with reduced or absent thrill due to stenosis/thrombosis with ultrasonography (USG) Doppler as routine imaging.
Completely thrombosed fistula >14 days.
- Patient demographics
- AVF creation date
- AVF failure date
- Total fistula functioning time
- Failure cause
- USG Doppler report
- Procedure performed
- Intraoperative finding
- Lesion length and type
- Technical success
- Residual stenosis
- Patency at 1, 3, 6, 9, and 12 months.
Presence of thrill postoperatively and initiation of dialysis for at least 1 week.
After ascertaining the history and thorough clinical examination, the patient underwent an USG Doppler to find out the anatomical cause of the stenosis. Subsequently, the patient was planned either for a radiocephalic or brachiocephalic fistula angioplasty.
Position: Supine with arm abducted and in supination.
Anesthesia: local infiltration with 1% lignocaine.
Steps: After positioning the patient, a screening USG was done to confirm the findings. After local infiltration, a 5F or 6F micro-sheath was inserted in the radial artery and 2500 units of heparin were given. A fistulogram was taken and a 4F vertebral catheter and a 0.014/0.035 guidewire were used to cross the lesion. After crossing, the lesion was dilated with a 5–7 mm standard balloon for 1 min and was repeated up to three times if there was any residual lesion. The catheter and wire were removed and a final fistulogram was performed to check the postangioplasty status. The sheath was removed and manual compression was given on the radial artery insertion site. Postoperatively, these patients were kept on clopidogrel 75 mg for 30 days and were advised to undergo dialysis after 1 day. These patients underwent regular follow-up for 1 year [Figure 1] and [Figure 2].
| Results|| |
This study was done to ascertain the demographics and to analyze the results of transradial endovascular salvage of AVFs at a tertiary hospital in South India.
We performed a total of 44 cases of AVF angioplasties in the study period and they were followed up till a minimum of 12 months. There were 32 males and 12 females. The age group between 41 and 60 years had the most patients. Diabetic patients were 31 in number. All the interventions were by standard balloon angioplasties through the transradial route. No cutting or drug-coated balloons were used in this study.
27 radiocephalic angioplasties were done and 17 brachiocephalic angioplasties were done. Cephalic vein stenoses were the most common lesion and the lesion length between 2 and 4 cm occurred the most [Table 1] and [Table 2].
The 30-day, 90-day, 6-month, and 12-month primary patencies were 84.1%, 81.8%, 63.63%, and 43.18%, respectively. Our technical success was 88.6% [Figure 3].
Stenosis length more than 4 cm was found to have markedly reduced primary patency as compared to lesions of lesser length. This was statistically significant (P = 0.01).
Although the patency of the fistula decreased with increasing age, it was statistically insignificant (P = 0.536).
We analyzed the correlation between fistula maturation time and primary patency and fistulas that were more than 6 months old showed lesser patency than the fistulas which were <6 months old. This was statistically insignificant (P = 0.607).
Diabetic patients had reduced primary patency as compared to nondiabetics, but it was statistically insignificant (P = 0.707). Although males had higher patency rates than females, this was statistically insignificant (P = 0.259).
The juxta-anastomotic lesions were associated higher patencies as compared to the other types (P = 0.714). We analyzed the patency difference between radiocephalic and brachiocephalic fistulas. While radiocephalic fistula angioplasties had higher patency rates, the difference was insignificant (P = 0.487).
| Discussion|| |
The flow disturbances and hemodynamic changes associated with an AV access can initiate an intimal hyperplasia (IH) response. The IH occurs primarily at the outflow anastomosis of a prosthetic AV access and anywhere along the outflow vein in an autogenous AV access. It can also involve the distant, ipsilateral central veins, even in the absence of previous indwelling catheters.,
Venous stenosis in both AV grafts and fistulas is primarily due to venous neo IH. It is characterized by:
- The presence of alpha smooth muscle actin positive cells
- An abundance of extracellular matrix components
- Angiogenesis (neovascularization) within the neointima and adventitia
- A macrophage layer lining the perigraft region and
- An increased expression of mediators and cytokines such as transforming growth factor-β, platelet-derived growth factor, and endothelin within the media, neointima, and adventitia.
Quantitative measurements of blood flow have proven to be the most sensitive predictor method of surveillance for impeding thrombosis in AVF. The NFK-K/DOQI recommends that vascular access with blood flow <600 mL/min or <1000 mL/min that has decreased by more than 25% over 4 months should be referred for a fistulogram. Unfortunately, this report did not make a distinction between AV fistula and AV graft. It is well known that AV fistula can remain patent even with flows below 300 mL/min.,
KDOQI guidelines: Treatment of fistula complications
- Angioplasty should be performed if greater than 50% stenosis is present in either the arterial or venous limbs. Successfully treated lesions should have <30% residual stenosis
- Aneurysms should be managed by avoiding cannulation of the aneurysm and by treating the postaneurysmal stenosis that is causing the aneurysm
- If thrombosis is detected, thrombectomy should be performed as early as possible
- Findings of ischemia should prompt referral to Vascular Surgery
- Infections of surgically created vascular access should be treated as subacute bacterial endocarditis including 6 weeks of antibiotic treatment. Septic emboli warrant surgical excision of the vascular access.
Guidelines regarding clinical outcome goals
- An institution should aim to have >65% of its patients with a functioning fistula, and <10% of its patients using cuffed catheters for permanent dialysis access
- Grafts and fistulas treated with angioplasty should have a primary patency rate of 50% at 6 months
- The goal primary patency rate is 40% at 3 months after percutaneous thrombectomy of a graft.
The above recommendations reiterate the fact that a collaborative effort is required among all professionals involved in the care of these patients.
Characteristic sites of stenosis in arteriovenous fistulas
There are three main types of AVFs. The radiocephalic fistula is a forearm fistula created by anastomosing the side of a radial artery to the end of a cephalic vein. It is also referred to as the Brescia–Cimino fistula. The brachiocephalic fistula is an upper arm fistula created by connecting the side of a brachial artery to the end of a cephalic vein at or slightly central to the level of the elbow. Finally, the brachial artery-to-transposed basilic vein fistula is another upper arm fistula. This fistula is created by anastomosing the side of a brachial artery to the end of a basilic vein that has been transposed laterally and elevated superficially to make it amenable to dialysis cannulation. The sites of stenosis can be
- Draining vein
- Cephalic arch
Percutaneous transluminal angioplasty for arteriovenous fistula dysfunction
Angioplasty for stenosis of AVFs was, for the first time, reported in 1981. The technique was feasible in three of the five patients of the study and showed encouraging results. Since that time, there is much progress regarding PTA on AVFs and arteriovenous grafts (AVGs). The choice for PTA or surgery for the treatment of stenosis of AVFs depends on the experience of the vascular surgeon. In any case, the target of both techniques has to be 50% for primary patency during the first 6-month period. Venous stenoses have traditionally been corrected surgically, but this extends the fistula further up the involved extremity, thereby minimizing future vascular access sites. Transcatheter techniques have, in recent years, made it possible to treat these lesions percutaneously, and PTA is an excellent means of correcting venous stenosis in both native and synthetic fistulae. It has the advantages of being a shorter procedure than surgery, inciting less stress and discomfort to patients, obviating the need for prolonged hospitalization, having a lower chance of infection, sparing the patient's veins, and in selected cases, enabling immediate dialysis without the need for a temporary central venous catheter.
Factors influencing technical success and patency of percutaneous transluminal angioplasty in arteriovenous fistulas
There are several factors, be it clinical, anatomical, and biochemical factors that affect fistula patency. There are several studies and meta-analysis, which have contributed to our awareness of these factors.
In a meta-analysis by Neuen et al., they found out that fistulas which were <6 months of age, longer lesion lengths >4 cm, patients with diabetes mellitus, residual stenosis >50%, and patient age >75 years were all independently associated with shorter primary patency.
In a study by Malka et al., occluded fistulas as compared to stenosed fistulas, fistulas requiring pharmacomechanical thrombectomy, and fistulas needing a second reintervention were associated with poor patency rates. Given the number of interventions necessary to maintain some AVFs and AVGs, at some point, it may be prudent to abandon the failing access and to pursue a new hemodialysis access in some patients.
A study by Tessitore et al. showed that prophylactic PTA of stenosis in functioning forearm AVF improves access survival and decreases access-related morbidity, supporting the usefulness of preventive correction of stenosis before the development of access dysfunction. It also strongly supports surveillance program for early detection of stenosis.
A study by Aktas et al. showed that early dysfunction positively correlated with patient age and diabetes mellitus. These two factors also lowered the primary patency. The secondary patency was lowered in the presence of factors such as increased patient age, diabetes mellitus, longer lesion length, early recurrence, and residual stenosis.
Sugimoto et al. also showed that older age, presence of diabetes, longer lesions, and multiple lesions contributed to decrease in the primary patency.
All the above studies and analyses show that older age, occluded fistulas, younger fistulas, presence of diabetes and risk factors of atherosclerosis, and longer and multiple lesions lead to decrease the patencies to fistulas postangioplasty. Early recurrence and significant residual stenosis postangioplasty do not harbor well for the patency.
Our 30-day, 90-day, 6-month, and 12-month primary patencies were 84.1%, 81.8%, 63.63%, and 43.18%, respectively. Heye et al. reported a primary patency of 48.5% at 1 year, 31.4% at 2 years, and 22.5% at 3 years. Aktas et al. were able to report substantially higher primary patencies of 84.7%, 62.2%, and 23.7% at 1, 2, and 3 years, respectively.
Sugimoto et al. reported 1-year primary patency of 47.3% of successful procedures. Asif et al. reported 6-month patency of 75% and 12 month patency of 51%.,,,
Our patencies compare favorably with Western and Eastern literature and that is in spite of our interventions being done in fistulas which are occluded rather stenosed and having a fairly late referral.,,,
Tessitore et al. have lent support to the fact that PTA is useful for the preventive treatment of stenosis, before the onset of significant access dysfunction. PTA was associated with a fourfold increase in median functional failure-free survival and a 2.87-fold reduction of AVF relative risk of failure.
This point cannot be overemphasized that proper surveillance and robust teamwork between the nephrologist, dialysis technician, and the vascular surgeon is required in order to recognize early fistula dysfunction and initiate timely and appropriate treatment to maximize the fistula life.
In our study, we found that longer lesion lengths (>4 cm) were prone to early loss of primary patency and this was statistically significant. We also found that patients above 60 years of age had lower primary patencies and the presence of diabetes mellitus also lowered the primary patency. Fistula maturation age did not show a correlation with patency in our cohort. Male patients had a higher patency rate and juxta-anastomotic stenoses postangioplasty had a higher primary patency due to the shorter lengths. Radiocephalic fistula angioplasties had a higher patency as compared to brachiocephalic angioplasty. Ours is one of the first studies to proactively use the transradial approach over the transvenous approach. Although technically difficult, it does have several advantages.
- The whole fistula system can be accessed, imaged, and intervened from one port
- It is in a straight line with no angulations
- Hemostasis easier to secure with no pressure on the draining vein
- Less radiation to the operator and the platform for the future.
Heye et al. found that primary patencies were influenced by initial stenosis grade and fistula type, with radiocephalic fistula angioplasties having better outcome. Contrary to our study, Heye et al. suggested that fistulas which were functioning for more than 6 months were associated with increased primary patency. Older patients and patients with diabetes had lower patency rates.
Neuen et al. conducted a meta-analysis and suggested that fistula characteristics such as newer fistulas and longer lesion lengths have greater primary patency loss. A study, which they included, found that a composite of diabetes, coronary artery disease, and peripheral vascular disease was associated with shorter primary patency than if more than one comorbidity was present. They also did not find any correlation between lesion site and patency.
In a study by Aktas et al., the age of the patient and the presence of diabetes had a significant effect on primary patency. As the age of the patient increased, the duration of primary patency became shorter (P < 0.001). While the mean primary patency duration was 25 months in patients with diabetes, it was 34.2 months in patients without diabetes. Age, presence of diabetes, length of stenosis, early recurrence development, and presence of residual stenosis were found to be significantly associated with secondary patency.
Malka et al. in their study showed that the second percutaneous intervention on failing dialysis access was associated with excellent technical success but poor rates of primary patency. The need for pharmacomechanical thrombectomy at the second percutaneous intervention was the only predictor of loss of primary patency, whereas the presence of an AVG rather than an AVF predicted the loss of secondary Patency.
The limitation of our study is the small sample size, which limits our ability to get statistical significance. In spite of this, our primary patencies compare well with Western literature. Another point is that all our accesses were transradial, while most of the studies used the transvenous route. Western studies have a more stringent surveillance protocol in place and hence they are able to report better primary and secondary patencies.
| Conclusion|| |
This study serves to highlight the fact that the native fistula should be salvaged as long as its meaningful, as non-functioning accesses contribute negatively to survival in patients with chronic kidney disease. Teamwork between all the specialties involved in the care of these patients is of utmost importance. Early and timely intervention will help in maximizing patencies and technical successes.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Brescia MJ, Cimino JE, Appel K, Hurwich BJ. Chronic hemodialysis using venipuncture and a surgically created arteriovenous fistula. New England J Med 1966;275:1089-92.
Tang S, Lo CY, Tso WK, Lo WK, Li FK, Chan TM. Percutaneous transluminal angioplasty for stenosis of arteriovenous fistulae: A review of local experience. Hong Kong Med J 1998;4:36-41.
Roy-Chaudhury P, Kelly BS, Narayana A, Desai P, Melhem M, Munda R, et al
. Hemodialysis vascular access dysfunction from basic biology to clinical intervention. Adv Ren Replace Ther 2002;9:74-84.
Roy-Chaudhury P, Kelly BS, Miller MA, Reaves A, Armstrong J, Nanayakkara N, et al
. Venous neointimal hyperplasia in polytetrafluoroethylene dialysis grafts. Kidney Int 2001;59:2325-34.
Wang Y, Krishnamoorthy M, Banerjee R, Zhang J, Rudich S, Holland C, et al
. Venous stenosis in a pig arteriovenous fistula model–anatomy, mechanisms and cellular phenotypes. Nephrol Dial Transplant 2008;23:525-33.
Schwarz C, Mitterbauer C, Boczula M, Maca T, Funovics M, Heinze G, et al
. Flow monitoring: Performance characteristics of ultrasound dilution versus color Doppler ultrasound compared with fistulography. Am J Kidney Dis 2003;42:539-45.
Navuluri R, Regalado S. The KDOQI 2006 vascular access update and fistula first program synopsis. Semin Intervent Radiol 2009;26:122-4.
Quencer KB, Arici M. Arteriovenous fistulas and their characteristic sites of stenosis. AJR Am J Roentgenol 2015;205:726-34.
Lawrence PF, Miller FJ Jr, Mineaud E. Balloon catheter dilatation in patients with failing arteriovenous fistulas. Surgery 1981;89:439-42.
Beathard GA. Percutaneous transvenous angioplasty in the treatment of vascular access stenosis. Kidney Int 1992;42:1390-7.
Neuen BL, Gunnarsson R, Webster AC, Baer RA, Golledge J, Mantha ML. Predictors of patency after balloon angioplasty in hemodialysis fistulas: A systematic review. J Vasc Interv Radiol 2014;25:917-24.
Malka KT, Flahive J, Csizinscky A, Aiello F, Simons JP, Schanzer A, et al
. Results of repeated percutaneous interventions on failing arteriovenous fistulas and grafts and factors affecting outcomes. J Vasc Surg 2016;63:772-7.
Tessitore N, Mansueto G, Bedogna V, Lipari G, Poli A, Gammaro L, et al
. A prospective controlled trial on effect of percutaneous transluminal angioplasty on functioning arteriovenous fistulae survival. J Am Soc Nephrol 2003;14:1623-7.
Aktas A, Bozkurt A, Aktas B, Kirbas I. Percutaneous transluminal balloon angioplasty in stenosis of native hemodialysis arteriovenous fistulas: Technical success and analysis of factors affecting postprocedural fistula patency. Diagn Interv Radiol 2015;21:160-6.
Sugimoto K, Higashino T, Kuwata Y, Imanaka K, Hirota S, Sugimura K. Percutaneous transluminal angioplasty of malfunctioning Brescia-Cimino arteriovenous fistula: Analysis of factors adversely affecting long-term patency. Eur Radiol 2003;13:1615-9.
Asif A, Lenz O, Merrill D, Cherla G, Cipleu CD, Ellis R, et al
. Percutaneous management of perianastomotic stenosis in arteriovenous fistulae: Results of a prospective study. Kidney Int 2006;69:1904-9.
Heye S, Maleux G, Vaninbroukx J, Claes K, Kuypers D, Oyen R. Factors influencing technical success and outcome of percutaneous balloon angioplasty in de novo
native hemodialysis arteriovenous fistulas. Eur J Radiol 2012;81:2298-303.
[Figure 1], [Figure 2], [Figure 3]
[Table 1], [Table 2]