|Year : 2020 | Volume
| Issue : 3 | Page : 222-224
Arteriovenous graft patency outcomes and prognostic factors: A single-center study
Rajendra Prasad Basavanthappa, Ranjith Kumar Anandasu, Ashwini Naveen Gangadharan, Luv Luthra, J P Vivek Vardhan, Chandrashekar Anagavalli Ramswamy, Sanjay C Desai, Adharsh Kumar Maruthu Pandian
Department of Vascular and Endovascular Surgery, MS Ramaiah Medical College and Hospital, Bengaluru, Karnataka, India
|Date of Submission||15-Sep-2019|
|Date of Acceptance||21-Oct-2019|
|Date of Web Publication||12-Sep-2020|
Ranjith Kumar Anandasu
Department of Vascular and Endovascular Surgery, MS Ramaiah Medical College and Hospital, Bengaluru, Karnataka
Source of Support: None, Conflict of Interest: None
Aim/Purpose: Functional, long-lasting vascular access is essential for maintaining effective long-term hemodialysis. Various factors including demographics and comorbid conditions have influenced the patency rates. As per the KDOQI reports, vascular access-related complications account for 15%–20% of hospitalizations in end-stage renal disease (ESRD) cases. This study aims to analyze various factors and to study the patency rates and complications of brachioaxillary arteriovenous (AV) prosthetic grafts for dialysis access at a single center. Materials and Methods: This was a single-center prospective study, which was conducted in Ramaiah Medical College Hospital, Bengaluru. All patients who underwent brachioaxillary AV prosthetic graft surgery for dialysis access over a period of 5 years from July 2012 to June 2017 were included. Follow-up of cases was done up to 2 years, and any complications encountered during the study period were recorded. Results: A total of 408 patients were included, in which 77% were male, with a mean age of 60.1 years. The most common comorbidity associated was hypertension (68%) followed by diabetes (36%), and the mean axillary vein diameter was 5.2 mm. The primary patency rates at the end of 1 and 2 years were 61.5% and 49%, respectively, and the secondary patency rates at the end of 1 and 2 years were 70% and 59%, respectively. Conclusions: In ESRD patients, in whom an autogenous fistula is not possible, prosthetic AV grafts are a suitable choice for vascular access and provide satisfactory patency rates for hemodialysis access. Thrombosis, secondary to venous intimal hyperplasia, is the most common complication and generally occurs by the 3rd month. Interventions will improve long-term patency rates and should consist of thrombectomy and thrombolysis in addition to balloon angioplasty. However, complications will still be encountered and their early recognition with aggressive surveillance and appropriate management is necessary to prolong overall graft survival.
Keywords: Arteriovenous fistula, arteriovenous graft, end-stage renal disease, ePTFE (polytetrafluoroethylene)
|How to cite this article:|
Basavanthappa RP, Anandasu RK, Gangadharan AN, Luthra L, Vardhan J P, Ramswamy CA, Desai SC, Maruthu Pandian AK. Arteriovenous graft patency outcomes and prognostic factors: A single-center study. Indian J Vasc Endovasc Surg 2020;7:222-4
|How to cite this URL:|
Basavanthappa RP, Anandasu RK, Gangadharan AN, Luthra L, Vardhan J P, Ramswamy CA, Desai SC, Maruthu Pandian AK. Arteriovenous graft patency outcomes and prognostic factors: A single-center study. Indian J Vasc Endovasc Surg [serial online] 2020 [cited 2020 Sep 28];7:222-4. Available from: http://www.indjvascsurg.org/text.asp?2020/7/3/222/294911
| Introduction|| |
Arteriovenous graft (AVG) is an option for hemodialysis (HD) only after arteriovenous fistula (AVF). Rise in chronic kidney disease patients and exhaustion of access sites and small-caliber veins unsuitable for AVF creation are few reasons for increased AVG creation. Herein, a prosthetic graft made of ePTFE (polytetrafluoroethylene) is used to connect brachial artery and axillary vein. Fistula first initiative is recommended as per revised KDOQI guidelines. Upper limb AVG creation is preferred in patients with failed AVF and exhausted autogenous venous conduits. The AVG is a major financial burden on health-care systems and it is associated with high morbidity and mortality. However, AVG creation has more complication than AVF. This study aims to analyze various factors and to study the patency rates and complications of brachioaxillary AV prosthetic grafts for dialysis access at a single center.
| Materials and Methods|| |
This was a single-center prospective study, which was conducted in Ramaiah Medical College Hospital, Bengaluru. Four hundred and eight patients with end-stage renal disease (ESRD) who underwent brachioaxillary AV prosthetic graft surgery for dialysis access over a period of 5 years from July 2012 to June 2017 were included. Follow-up of cases was done up to 2 years, and any complications encountered during the study period were recorded. All patients below 18 years and other than brachioaxillary AV prosthetic graft were excluded. We reviewed outpatient clinic and electronic medical follow-up records for graft event information and complications associated with it.
Data collection and follow-up
During the initial assessment for surgery, all patients' demographic data and comorbid conditions were evaluated and recorded. Preoperative duplex imaging of the upper limb veins and artery was done, and the suitable upper limb with good caliber artery and vein was taken for surgery. All patients preoperatively underwent cardiac evaluation with ECG and two-dimensional echo. Baseline blood investigations and preoperative heparin-free HD were done. This was followed by complete blood count, electrolytes, prothrombin time, activated partial thromboplastin time, international normalized ratio 4 hours post-HD. We proceeded with surgery under regional anesthesia after obtaining a pre-anesthetic evaluation and explaining the complications including steal phenomenon.
All details of surgery were recorded and stored. This included the size of vein and artery, back bleed and forward bleed from the artery; type of suture material, hypotension during surgery. All procedures were done as elective cases and none as emergency. All patients received anticoagulation in the form of low molecular weight heparin (LMWH) postsurgery for at least 3 days with intravenous antibiotics. Postoperative antiplatelets for a minimum of 3 months.
Follow-up was done initially after 2 weeks of surgery during which suture removal was done and the patients were allowed to undergo dialysis through AVG after 3 weeks from the time of surgery. Primary patency at the end of 1 year and 2 years and secondary patency at the end of 1 year and 2 years were primary outcomes. Complications were recorded and noted during the follow-up.
Vast majority of access failure is caused by thrombosis, secondary to intimal hyperplasia at venous outflow end. The mechanism of which is incompletely understood. However, possible factors include flow turbulence, vascular inflammation and prothrombotic milieu resulting in endothelial damage leading to stenotic lesions.
Primary patency is defined as per previous literature as continuously patent without any actions to maintain graft patency which reflects durability. Secondary patency is defined as the interval from time of access placement to access abandonment including intrervening interventions (surgical or endovascular interventions).
For descriptive analyses, continuous variables were summarized as median and interquartile range. Statistical analysis was performed using SPSS software (version 18.0; SPSS Inc., Chicago, Illinois, USA).
| Results|| |
Four hundred and eight patients with ESRD who underwent brachioaxillary AV prosthetic graft surgery for dialysis access over a period of 5 years from July 2012 to June 2017 were included. Baseline characteristics are shown in [Table 1]. In this study, 77% were male with a mean age of 60.1 years. Patient comorbidities included hypertension (68%) and diabetes mellitus (36%) depicted in [Figure 1]. The mean follow-up is for 2 years postsurgery.
Patency rates and prognostic factors
During the follow-up period, 136 patients required interventions. Of which, 98 patients underwent graft thrombectomy + access angioplasty, 34 underwent graft explantation, two patients underwent patch plasty at venous anastomotic end, and the remaining two underwent interposition graft placement. Complication rates observed in this study are depicted in [Table 2] and [Figure 2]. The primary graft patency rates at the end of 1 year and 2 years were 61.5 and 49%, respectively. The secondary patency rates at 1 year and 2 years were 70% and 59%, respectively, depicted in [Figure 3].
| Discussion|| |
Even though the guidelines suggest that AVF is the first choice for HD access in ESRD patients, in patients with multiple AV access failure and poor caliber veins unsuitable for AVF, another option for HD is AVG.
In a study conducted by Hurlbert et al., the primary and secondary patency rates were 47% and 87%, respectively. In a study conducted by Cinat et al., the primary and secondary patency rates were 43% and 66%, respectively. In a study conducted by Park et al., the primary and secondary patency rates were 42% and 85%, respectively, and our study has better primary patency than other studies and comparable secondary patency rates.
Primary patency was markedly affected by surgical factors and elective creations than emergent. Hence, timely referral is critical. Adjuvant medications such as LMWH in the immediate postoperative period and antiplatelets provide sufficient evidence on better graft patency, but did not prevent recurrent thrombosis and need for surgical thrombectomy.
| Conclusions and Future Perspective|| |
Vascular access is essential for any ESRD patients on HD, AVF or AVG. Still research is going on in identifying the pathophysiology of neointimal hyperplasia and its progression to result in loss of vascular access. Timely follow-up and assessment with flow rates, duration of dialysis, bleeding after dialysis is stopped should be assessed and recorded. Guidelines for graft surveillance and patient compliance will improve the patency rates. Novel treatment in arresting the neointimal hyperplasia by understanding molecular biology and genetics is on its way. Still, further studies are required and newer agents which can aid in arresting the neointimal hyperplasia and promote access patency.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3]
[Table 1], [Table 2]