Year : 2008 | Volume
: 19 | Issue : 6 | Page : 929--932
Patency rate and complications of vascular access grafts for hemodialysis in lower extremities
Department of Surgery, Sina Hospital, School of Medicine, Tehran University of Medical Sciences,Tehran, Iran
Associate Professor of Surgery, Sina Hospital, Hassan Abad Sq. 11364-Tehran
Placement of thigh grafts is an option in hemodialysis (HD) patients who have exhausted all upper extremity sites for permanent vascular access. To determine patency rate and complications of lower extremity grafts used for vascular access in patients on chronic HD in our center we studied prospectively the outcomes of 41 thigh grafts placed at a single institution during a 4-yr period (January 2000 and July 2003). Information was recorded on surgical complications and date of graft failure. The mean patient age was 55 ± 12 years and 54% of the patients were males. The primary patency rates were, 76%, 67%, and 60% at 3, 9, and 12 months, respectively. There were 10 (24.4%) patients with thrombosis and 2 (4.8%) patients with bleeding. Graft infection and pseudoaneurism were observed in 2 patients each. No significant differences in infection rate or graft patency rates were found by patient age and gender. In our experiences, lower extremity vascular access graft is not associated with higher morbidity. Lower extremity polytetrafluoroethylene vascular graft (ePTFE) seems to be an appropriate vascular access when arteriovenous fistulas and upper extremity grafts cannot be constructed.
|How to cite this article:|
Salimi J. Patency rate and complications of vascular access grafts for hemodialysis in lower extremities.Saudi J Kidney Dis Transpl 2008;19:929-932
|How to cite this URL:|
Salimi J. Patency rate and complications of vascular access grafts for hemodialysis in lower extremities. Saudi J Kidney Dis Transpl [serial online] 2008 [cited 2021 Dec 5 ];19:929-932
Available from: https://www.sjkdt.org/text.asp?2008/19/6/929/43467
Dialysis access procedures and complications are important causes of morbidity and hospitalization for chronic hemodialysis (HD) patients. The number of complicated subjects on dialysis is increasing, and creating a successful vascular access for these patients is a challenge. 
Because some individuals are not candidates for native fistula, synthetic grafts have been developed and shown to be suitable substitutes. ,, The National Kidney Foundation Clinical guidelines on vascular access recommend preferential placement of arteriovenous fistulas (A-VF) in hemodialysis patients, with A-V grafts reserved for patients whose vascular anatomy precludes fistula placement. The rationale for this recommendation is that fistulas require substantially fewer interventions than do grafts to maintain long-term patency for dialysis. ,
Surgeons are often tasked to provide dialysis access for patients with no sites available for access in the upper extremity, because of arterial steal syndrome or ischemic complications, severe axillary or subclavian arterial disease, and venous thrombosis. ,
Although some studies report a high rate of infection and limb amputation associated with prosthetic thigh AV access, others report favorable results, with patency and infection rates comparable to those achieved for prosthetic AV access in the upper extremity.  With the improvements in surgical techniques and advent of polytetrafluoroethylene (PTFE) for hemodialysis access, the groin has again received attention as a valuable hemodialysis access site. ,,,
We report in a prospective study, our experience with angioaccess grafts in the groin using the reporting standards for outcome developed by the Society for Vascular Surgery and the American Association for Vascular Surgery (SVS/AAVS) to assess the safety and durability, infection rate, and patient factors that influence outcome.
Patients and Methods
Patients and study design
The vascular surgeons at our institute create vascular access for approximately 500 hemodialysis patients yearly. The lower extremity is used only when no other permanent access site is available. We excluded in our study patients with arterial insufficiency and venous obstruction detected by physical examination and doppler study. We analyzed all prospectively stored data in a computerized file maintained by a general surgery resident regarding placement of new thigh grafts as vascular access and subsequent graft complications from January 2000 to July 2003. New grafts were placed for 41 patients by one of three vascular surgeons or by their two fellows.
A bolus of antibiotic (Vancomycin 1 g I.V.) was given before access surgery and 1 week later. Under spinal anesthesia, a 6- to 8-cm longitudinal incision, starting 2 cm below the crease of the inguinal ligament toward the knee was made. The saphenous vein and superficial femoral artery were exposed and proximal and distal control was performed.
In each instance, a looped bridged PTFE graft (8 mm) vascular access was created. The grafts were sutured end to side to the common or superficial femoral artery with 5-0 polypropylene sutures. The arterial inflow was the common femoral artery in 10 patients and the superficial femoral artery in 31 patients. The proximal saphenous vein was used as the outflow vessel. Dialysis through the grafts was initiated on 14-20 days postoperatively.
Primary patency was defined as normal function from the time of placement until graft failure or development of any malfunction requiring surgical correction such as thrombosis, infection, and aneurysm formation. Graft adequacy was defined prospectively as the ability to use it for hemodialysis with two needles and a blood flow of at least 350 mL/min in at least six dialysis sessions in 1 month. Early access failure was defined as access abandonment less than 30 days after placement. Late access failure, defined as access abandonment more than 30 days after placement.
Survival distributions were plotted using the Kaplan-Meier method for graft survival (primary patency). Log rank tests were used to evaluate for statistical differences in survival distribution among different groups.
Grafts that were functioning on last follow-up examination but were discontinued for reasons other than failure (such as transplantation or death) were censored in the life-table analysis.
The 41 thigh AV accesses graft accounted for approximately 15% of all grafts placed during the study period. Postoperative follow-up from time of creation access graft to at least 12 months was available for each of the 41 grafts in the study.
[Table 1] shows the demographics of our patients. The mean patients' age was 55 ± 12 years; 6.2% of the patients were age 65 or older. Fifty four percent of the patients were males, and the leading causes of end stage renal disease (ESRD) were hypertension in 17 (41.5%) cases and diabetes in 5 (12%). There were no operative (30 day) deaths in the series; however, 12 patients died from systemic complications of their renal disease during the follow-up period for a late mortality of 30 percent. None of these deaths were directly graft-related.
[Figure 1] shows the primary patency rates were, 76%, 70%, 67% and 60% at 3, 6, 9 and 12 months, respectively. There was no early access failure in our study. Late access failure occurred in 14 (34%) patients, and the most common event causing graft failure, and thus loss of patency was thrombosis in 10 (24.4%) patients. Two (4.8%) grafts developed frank infection, and they required surgical exploration. Other causes of graft failure included bleeding form graft aneurysmal degeneration (n = 2). However, there were no episodes of limb ischemia in any of the study patients. There were no significant differences in the incidence of thrombosis and infection between male and female patients by using Log Rank test.
Advances in HD technology have allowed application of this treatment modality to an ever-increasing number of ESRD patients. Maintaining patients on dialysis for more than a decade is not unusual and the treatment of such patients may be limited primarily by the availability of vascular access. , Access to the circulation has remained the Achilles heel of most HD patients, and it is the responsibility of surgeons to create a strategy of dialysis access that maximizes the use of potential access sites.
Ideally, any HD patient should receive an autogenous fistula that could be accessed throughout the patient's life. An end-to-side vein-artery anastomosis of the cephalic vein and radial artery distally in the non-dominant upper extremity is widely regarded as the favorite vascular access procedure. Successful native arteriovenous fistulas can also be performed more proximally in the upper extremity- in the elbow region or in the upper arm. Unfortunately, autogenous access is often impossible because of the obliteration of important superficial veins by prior medical intervention.
After exhausting the above-mentioned possibilities in the two upper extremities, we use synthetic graft in upper extremity. In patients with primarily unsuitable or secondarily surgically exhausted arm sites, a thigh fistula, either native with saphenous vein or as a bridge graft, can be performed. We have used as an alternative PTFE AV access graft placed in the thigh between the femoral artery and saphenous vein.
Several recently published studies report the outcome of prosthetic thigh AV access. The conclusions of these studies differ dramatically. Some suggest that thigh AV access is safe, with excellent long-term patency, while others consider it a procedure of last resort, because of the high rate of complications such as infection and arterial steal. ,,,,
Khadra et al, and Tashjian et al reported the only two large series of groin grafts with which this series can be compared. ,, Khadra, Dwyer, and Thompson reviewed 74 PTFE loop grafts placed in 61 patients between 1985 and 1991. Twelve of 74 (16%) grafts had complications involving graft infection, with a graft salvage rate of more than 50% and no major limb ischemia.  Tashjian, Lipkowitz and Madden reported one year primary patency rate of 71% for 73 prosthetic thigh AV access placed between 1990-1998.The incidence of infection in their series was 22%.  The incidence rate of infection for our grafts was 4.8%, which is lower than 16% and 22% reported by Khadra and Tashjian, respectively. Furthermore, this is also lower than reports of upper extremity PTFE access infection rates that ranged from 12% to 25%.
With regards to graft thrombosis, our one year primary patency rate of 67% compared favorably with a 1-year patency rate of 50% and 71% shown by Khadra and Thompson, respectively. , These rates are similar to the 62% to 68% range reported for upper extremity graft primary patency. 
In conclusion, thigh AV access graft is a viable option that can provide prolonged and reliable dialysis access for patients who have few sites for access placement. The incidence rate of infection and thrombosis is comparable with upper extremity angioaccess.
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