Increasing arteriovenous fistulas in hemodialysis patients: problems and solutions

National guidelines promote increasing the prevalence of fistula use among hemodialysis patients. The prevalence of fistulas among hemodialysis patients reflects both national, regional, and local practice differences as well as patient-specific demographic and clinical factors. Increasing fistula prevalence requires increasing fistula placement, improving maturation of new fistulas, and enhancing long-term patency of mature fistulas for dialysis. Whether a patient receives a fistula depends on several factors: timing of referral for dialysis and vascular access, type of fistula placed, patient demographics, preference of the nephrologist, surgeon, and dialysis nurses, and vascular anatomy of the patient. Whether the placed fistula is useable for dialysis depends on additional factors, including adequacy of vessels, surgeon's experience, patient demographics, nursing skills, minimal acceptable dialysis blood flow, and attempts to revise immature fistulas. Whether a mature fistula achieves long-term patency depends on the ability to prevent and correct thrombosis. An optimal outcome is likely when there is (1) a multidisciplinary team approach to vascular access; (2) consensus about the goals among all interested parties (nephrologists, surgeons, radiologists, dialysis nurses, and patients); (3) early referral for placement of vascular access; (4) restriction of vascular access procedures to surgeons with demonstrable interest and experience; (5) routine, preoperative mapping of the patient's arteries and veins; (6) close, ongoing communication among the involved parties; and (7) prospective tracking of outcomes with continuous quality assessment. Implementing these measures is likely to increase the prevalence of fistulas in any given dialysis unit. However, differences among dialysis units are likely to persist because of differences in gender, race, and co-morbidity mix of the patient population.     

Increasing AV fistulas: revisiting a time-tested solution

Despite having the lowest complication rate of all hemodialysis accesses, the prevalence of autologous arteriovenous (AV) fistulas has declined to 28% in the United States. The reasons for this decline include high early AV fistula failure rates, long maturation times, the frequent need for emergent dialysis, unavailable or poor pre-ESRD programs and planning, patient resistance to the realities of impending ESRD, and financial disincentives to AV fistula placement. Despite these barriers, programs throughout the country have demonstrated the ability to increase AV fistula prevalence to more than 50%. The strategies employed have included increased reliance on upper arm brachiocephalic and transposed basilic vein fistulas, the use of preoperative imaging to identify the best sites for fistula creation, and aggressive attempts at salvage of nonmaturing fistulas. Other groups have systematically and successfully replaced failed grafts with upper arm brachiocephalic or bracheobasilic fistulas. These experiences clearly show that exceeding the National Kidney Foundation Dialysis Outcomes Quality Initiative (NKF-DOQI) goal of more than 50% fistula placement is achievable in the United States. Declining numbers of AV fistulas are the result of a combination of factors, including changes in our patient population and learned practice patterns coupled with a failure of our delivery system to provide education, timely referral, and incentives for fistula placement. Increasing AV fistula prevalence in the United States is achievable and will improve patient outcomes and decrease the costs of ESRD.     

A Challenge for Nephrologists—Increasing Fistula Maturation Rates, Reducing Fistula Maturation Time, and Decreasing Dialysis Catheter Prevalence in the United States

Tunneled dialysis catheters are simultaneously a benefit and burden for hemodialysis patients. The infectious and vascular complications of catheters are well documented. Despite this, prevalence of catheter use in the US hemodialysis population remains high and could be due in part to increased efforts to create arteriovenous (AV) fistulas in most new end-stage renal disease patients. The editorial argues that creating fistulas instead of prosthetic grafts is the correct approach and that inadequately diagnosed and treated primary fistula failure is a major cause of excessive and prolonged catheter dependency. An understanding of AV fistula physiology and the treatable causes of primary fistula failure are key to maximizing the percentage of created fistulas that are successfully used for dialysis. Diagnosis of fistula malfunction based on history, physical examination, and hemodynamic and angiographic evaluation is discussed, and treatment strategies presented. A major emphasis is placed on early primary fistula failure recognition and intervention. It is the author's contention if adequate vein and artery are selected for initial fistula construction nearly all fistulas should eventually function adequately to support dialysis and sooner than previously appreciated by utilizing an array of percutaneous and surgical therapies. Fistula malfunction is a unique problem within the spectrum of vascular disease and therefore demands that patients are treated by physicians with demonstrated expertise and experience.     

A challenge for nephrologists--increasing fistula maturation rates, reducing fistula maturation time, and decreasing dialysis catheter prevalence in the United States.

Tunneled dialysis catheters are simultaneously a benefit and burden for hemodialysis patients. The infectious and vascular complications of catheters are well documented. Despite this, prevalence of catheter use in the US hemodialysis population remains high and could be due in part to increased efforts to create arteriovenous (AV) fistulas in most new end-stage renal disease patients. The editorial argues that creating fistulas instead of prosthetic grafts is the correct approach and that inadequately diagnosed and treated primary fistula failure is a major cause of excessive and prolonged catheter dependency. An understanding of AV fistula physiology and the treatable causes of primary fistula failure are key to maximizing the percentage of created fistulas that are successfully used for dialysis. Diagnosis of fistula malfunction based on history, physical examination, and hemodynamic and angiographic evaluation is discussed, and treatment strategies presented. A major emphasis is placed on early primary fistula failure recognition and intervention. It is the author's contention if adequate vein and artery are selected for initial fistula construction nearly all fistulas should eventually function adequately to support dialysis and sooner than previously appreciated by utilizing an array of percutaneous and surgical therapies. Fistula malfunction is a unique problem within the spectrum of vascular disease and therefore demands that patients are treated by physicians with demonstrated expertise and experience.     

Arteriovenous access outcomes in haemodialysis patients with HIV infection.

BACKGROUND: Arteriovenous (AV) grafts in haemodialysis patients usually fail due to thrombosis or infection. There is limited information on whether graft outcomes in HIV-positive haemodialysis patients differ from those in HIV-negative controls. METHODS: Using a prospective, computerized vascular access database, we identified retrospectively 15 HIV-positive dialysis patients having a graft placed during a 6.5-year period (January 1999 to June 2005), and compared their graft outcomes to those observed in 30 age-, sex- and access date-matched HIV-negative control patients. In addition, the outcomes of AV fistulas in 23 HIV-positive patients were compared with those observed in 32 matched HIV-negative controls. RESULTS: Thrombosis-free graft survival was substantially worse among the HIV-positive patients than in the HIV-negative controls (1-year survival, 17% vs 62%). The hazard ratio for graft thrombosis in the HIV-positive patients was 3.22 (95% CI, 1.66-10.32, P = 0.002). Infection-free graft survival was also lower in HIV-positive patients (hazard ratio 3.51; 95% CI, 1.21-18.85, P = 0.025). Finally, cumulative graft survival (from creation until permanent failure) tended to be lower in HIV-positive patients (1 year survival, 41% vs 65%, P = 0.07). The primary failure rate of fistulas (those never usable for dialysis) was similar in HIV-positive patients and in their controls (44% vs 41%, P = 0.83). Cumulative fistula survival was similar for HIV-positive and negative patients (hazard ratio 1.32; 95% CI, 0.65-3.58, P = 0.33). CONCLUSION: AV grafts have inferior outcomes in HIV-positive patients as compared with HIV-negative patients, whereas fistulas have a similar survival in both groups.     

Vascular Access Choice in Incident Hemodialysis Patients: A Decision Analysis

Hemodialysis vascular access recommendations promote arteriovenous (AV) fistulas first; however, it may not be the best approach for all hemodialysis patients, because likelihood of successful fistula placement, procedure-related and subsequent costs, and patient survival modify the optimal access choice. We performed a decision analysis evaluating AV fistula, AV graft, and central venous catheter (CVC) strategies for patients initiating hemodialysis with a CVC, a scenario occurring in over 70% of United States dialysis patients. A decision tree model was constructed to reflect progression from hemodialysis initiation. Patients were classified into one of three vascular access choices: maintain CVC, attempt fistula, or attempt graft. We explicitly modeled probabilities of primary and secondary patency for each access type, with success modified by age, sex, and diabetes. Access-specific mortality was incorporated using preexisting cohort data, including terms for age, sex, and diabetes. Costs were ascertained from the 2010 USRDS report and Medicare for procedure costs. An AV fistula attempt strategy was found to be superior to AV grafts and CVCs in regard to mortality and cost for the majority of patient characteristic combinations, especially younger men without diabetes. Women with diabetes and elderly men with diabetes had similar outcomes, regardless of access type. Overall, the advantages of an AV fistula attempt strategy lessened considerably among older patients, particularly women with diabetes, reflecting the effect of lower AV fistula success rates and lower life expectancy. These results suggest that vascular access-related outcomes may be optimized by considering individual patient characteristics.     

Predictors of adequacy of arteriovenous fistulas in hemodialysis patients.

BACKGROUND: Dialysis access procedures and complications represent a major cause of morbidity, hospitalization, and cost for chronic dialysis patients. To improve the outcomes of hemodialysis access procedures, recent clinical guidelines have encouraged attempts to place an arteriovenous (A-V) fistula, rather than an A-V graft, whenever possible in hemodialysis patients. There is little information, however, about the success rate of following such an aggressive strategy in the prevalent dialysis population. METHODS: We evaluated the adequacy of all A-V fistulas placed in University of Alabama at Birmingham dialysis patients during a two-year period. A fistula was considered adequate if it supported a blood flow of >/=350 ml/min on at least six dialysis sessions in one month. Fistula adequacy was correlated with clinical and demographic factors. RESULTS: The adequacy could be determined for 101 fistulas; only 47 fistulas (46.5%) developed sufficiently to be used for dialysis. The adequacy rate was lower in older (age >/= 65) versus younger (age < 65) patients (30.0 vs. 53.5%, P = 0.03). It was also marginally lower in diabetics versus nondiabetics (35.0 vs. 54.1%, P = 0.061) and in overweight (BMI >/= 27 kg/m2) versus nonoverweight patients (34.5 vs. 55.2%, P = 0.07). The adequacy rate was not affected by patient race, smoking status, surgeon, serum albumin, or serum parathyroid hormone. The adequacy rate was substantially lower for forearm versus upper arm fistulas (34.0 vs. 58.9%, P = 0.012). The adequacy of forearm fistulas was particularly poor in women (7%), patients age 65 or older (12%), and diabetics (21%). In contrast, upper arm fistulas were adequate in 56% of women, 54% of older patients, and 48% of diabetics. CONCLUSIONS: An aggressive approach to the placement of fistulas in dialysis patients results in a less than 50% early adequacy rate, which is considerably lower than that reported in the past. Moreover, the success rate of fistulas is even lower for certain patient subsets. To achieve an optimal outcome with A-V fistulas, we recommend that they be constructed preferentially in the upper arm in female, diabetic, and older hemodialysis patients.     

Long-term survival of arteriovenous fistulas in home hemodialysis patients

BACKGROUND: We report the outcome of arteriovenous (AV) fistulas created and managed by a multidisciplinary team in patients on hemodialysis (HD) over 20 years. METHODS: We analyzed 432 AV fistulas in 301 home HD patients (12% diabetic; median age 47 years) followed for up to 161 months. Observed end points were spontaneous or surgical AV fistula closure, or construction of a new vascular anastomosis. Survival was analyzed for first and second AV fistulas and predictors of outcome for first AV fistulas. RESULTS: One vascular surgeon constructed 58% of AV fistulas. Three hundred sixty-seven AV fistulas were in the forearm, 64 at or above the elbow, and 1 in the thigh. Four hundred fourteen AV fistulas used in situ vessels, and 18 were autografts. Two hundred thirty-one anastomoses were side-to-side. Only five grafts were placed during this time. There were 131 second and subsequent AV fistulas in 76 patients, 79 (60%) of which required primary construction, and 52 used arterialized vessels from a previous AV fistula. The median time from formation to use for first and second AV fistula, respectively, was 2.39 (SE 0.35) and 3.2 (SE 1.9) months. Assisted survival from first use for first AV fistula was 90% at 1 year, 66% at 5 years, 84% at 1 year, and 72% at 2 years for second AV fistula. AV fistula survival from creation was superior for side-to-side anastomoses (P < 0.0001) and in men (P= 0.05). CONCLUSION: A multidisciplinary approach has been successful in providing durable AV fistulas for home HD for >95% of consecutive patients entering our program.     

Impact of obesity on arteriovenous fistula outcomes in dialysis patients

Fistula use for dialysis is less frequent among obese than non-obese patients. This discrepancy may be due to a lower rate of fistula placement in obese patients, a higher primary failure rate (fistulas that are never usable for dialysis), or a higher secondary failure rate (fistulas that fail after being used successfully for dialysis). Using a prospective, computerized vascular access database, we identified all patients receiving a first fistula or graft at our institution during a 2-year period. The access outcomes were compared between obese (body mass index (BMI) >or=30 kg/m2) and non-obese (BMI<30 kg/m2) patients. Fistula placement was equally likely between obese and non-obese patients (47.4 vs 47.1%). The primary failure rate of fistulas was similar in both groups (46 vs 41%, P=0.45). Among those fistulas that were usable for dialysis, the secondary survival was worse in obese patients (hazard ratio 2.74; 95% confidence interval (CI), 1.48-7.90; P=0.004). Secondary fistula survival in obese vs non-obese patients was 68 vs 92% at 1 year, 59 vs 78% at 2 years, and 47 vs 70% at 3 years. On multiple variable survival analysis with age, sex, race, diabetes, coronary artery disease, peripheral vascular disease, fistula location, surgeon, and obesity in the model, obesity was the only significant factor predicting secondary fistula failure (hazards ratio 2.93; 95% CI, 1.44-5.93; P=0.004). In conclusion, long-term fistula survival is worse in obese than non-obese patients, owing to a higher secondary failure rate.     

Primary arteriovenous fistulas in the forearm for hemodialysis: effect of miscellaneous factors in fistula patency

BACKGROUND: The provision and maintenance of vascular access remains a major cost to end-stage renal failure programs. In addition, vascular access occlusion, results in significant morbidity in hemodialysis patients. Age, gender, diabetes mellitus, malignancy, smoking habits, administration of heparin per hemodialysis session, previous dialysis catheter insertion, number of hemodialysis sessions and location of the fistula may be associated with survival of the primary arteriovenous fistula. We examined the effects of various factors on fistulas in 412 chronic renal insufficiency patients. METHODS: From 1995 to 2004, 412 arteriovenous fistulas were created by the Department of Cardiovascular Surgery at the Medical Faculty of Atatürk University for hemodialysis. The mean age of the patients was 45 years (range 6 to 62 years). We evaluated the effects of various factors for patency rates in the patients who had primary arteriovenous fistulas. Primary patency was defined as the duration of fistula patency without revision. Twenty-eight patients (6.7%) with ischemic cardiac disease did not require surgical interference. Analyzed data were age, gender, smoking habits, diabetes mellitus, malignant neoplasm, previous dialysis catheter insertion, number of hemodialysis sessions, and fistula location. RESULTS: In 298 patients, where lower-arm radiocephalic fistulas were created, the fistula patency was 74.1%, 64.2%, 49.8%, 33.7%, and 4.1% after 1, 2, 3, 4, and 5 years, respectively, in the other 114 patients, where upper-arm fistulas were created, these rates were 84.0%, 72.2%, 53.3%, 39.8%, and 12.3%, respectively. There was no significantly difference between the upper-arm fistulas and the lower-arm fistulas statistically (p = 0.069). Factors affecting the primary patency of arteriovenous fistulas were diabetes mellitus (p = 0.0001), hemodialysis counts > or =3 per week (p < 0.0005), presence of malignancy (p < 0.0005), previous catheter insertion (p < 0.0007), and administration of heparin per hemodialysis session (p = 0.0008). CONCLUSION: While primary arteriovenous fistula patency was shortened in chronic renal insufficiency patients with diabetes mellitus, presence of malignancy, and previous catheter insertion, patency was longer in patients with heparin used for hemodialysis and hemodialysis count per week (> or =3).     

Bridging to a high flow upper arm native fistula for hemodialysis with the LifeSite Hemodialysis Access System

Permanent vascular access for chronic hemodialysis requires a reliable structure with adequate blood flow. Endogenous arteriovenous (AV) fistulas offer the best outcomes, but standard radiocephalic fistulas are not always feasible. A reliable alternative is a transposed basilic vein-brachial artery AV fistula, which offers a number of advantages over synthetic AV grafts. The transposed basilic vein fistula provides high flow rates along with low rates of infection, thrombosis, and other complications; however, longer maturation times may be nec-essary. This longer maturation time may necessitate the use of a "bridge device" for access. The new, fully subcutaneous vascular access device - the LifeSite(R) hemodialysis Access System - offers several significant advantages over a standard dialysis catheter as a bridge device: higher flow rates without recirculation, as well as lower rates of infection, thrombosis, and hospitalization. This article describes the surgical procedure for the creation of the transposed basilic vein fistula and the implantation procedure for the LifeSite System. We report on the use of this combined sequential approach to vascular access in 14 patients with excellent results. All 14 patients initially implanted with the LifeSite System were successfully bridged to a functional transposed basilic vein fistula. The mean flow rate with the LifeSite System was 450 ml/min; only one device had to be removed due to infection in an HIV-positive patient, and no other complications were observed. The mean time to maturation of the transposed basilic vein fistula was 6 months; the upper arm fistulas delivered a mean flow rate of 1100 ml/min with a 100% patency rate at 6 months. The sequential use of the LifeSite System and a transposed basilic vein fistula represents a valuable approach to increasing the usage of a high flow native AV fistula.     

Gender differences in outcomes of arteriovenous fistulas in hemodialysis patients

BACKGROUND: The prevalence of arteriovenous (A-V) fistula use is lower among female than male hemodialysis patients. This difference may be due, in part, to smaller vessel diameter in women. However, even when routine preoperative vascular mapping is used to select vessels with suitable diameters, fistulas are still less likely to mature in women than in men. METHODS: To explore the reasons for this gender discrepancy, we evaluated the outcomes of 230 A-V fistulas placed at our institution after preoperative mapping. Vessel diameters, radiologic and surgical interventions, and fistula adequacy for dialysis were assessed. RESULTS: Fistula adequacy for dialysis was lower in women than men (31 vs. 51%, P = 0.001). The inferior outcome of fistulas in women was observed for both forearm fistulas (18 vs. 43%, P = 0.02) and upper arm fistulas (39 vs. 60%, P = 0.04). Differences in vessel diameter did not explain the lower patency rate of fistulas among women. Among fistulas not lost due to technical failure or early thrombosis, 31% underwent one or more interventions (salvage procedures) due to failure to mature. These interventions included angioplasty, ligation of tributaries, superficialization, and surgical revision of the anastomosis. A salvage procedure was more likely in women than in men (42 vs. 23%, P = 0.04). The likelihood of fistula maturation after an intervention was similar among women and men (50 vs. 37%, P = 0.40). Salvage procedures increased the proportion of adequate fistulas to a greater degree in women than in men (relative increases of 68 and 15%, respectively). CONCLUSIONS: These data suggest that fistulas are less likely to be useable for dialysis in women than in men, despite routine preoperative mapping and frequent interventions undertaken to salvage immature fistulas.     

Effect of preoperative sonographic mapping on vascular access outcomes in hemodialysis patients.

BACKGROUND: Current DOQI guidelines encourage placing arteriovenous (AV) fistulas in more hemodialysis patients. However, many new fistulas fail to mature sufficiently to be usable for hemodialysis. Preoperative vascular mapping to identify suitable vessels may improve vascular access outcomes. The present study prospectively evaluated the effect of routine preoperative vascular mapping on the type of vascular accesses placed and their outcomes. METHODS: During a 17-month period, preoperative sonographic evaluation of the upper extremity arteries and veins was obtained routinely. The surgeons used the information obtained to plan the vascular access procedure. The types of access placed, their initial adequacy for dialysis, and their long-term outcomes were compared to institutional historical controls placed on the basis of physical examination alone. RESULTS: The proportion of fistulas placed increased from 34% during the historical control period to 64% with preoperative vascular mapping (P < 0.001). When all fistulas were assessed, the initial adequacy rate for dialysis increased mildly from 46 to 54% (P = 0.34). For the subset of forearm fistulas, the initial adequacy increased substantially from 34 to 54% (P = 0.06); the greatest improvement occurred among women (from 7 to 36%, P = 0.06) and diabetic patients (from 21 to 50%, P = 0.055). In contrast, the initial adequacy rate of upper arm fistulas was not improved by preoperative vascular mapping (59 vs. 56%, P = 0.75). Primary access failure was higher for fistulas than grafts (46.4 vs. 20.6%, P = 0.001), but the subsequent long-term failure rate was higher for grafts than fistulas (P < 0.05). Moreover, grafts required a threefold higher intervention rate (1.67 vs. 0.57 per year, P < 0.001) to maintain their patency. The overall effect of this strategy was to double the proportion of patients dialyzing with a fistula in our population from 16 to 34% (P < 0.001). CONCLUSIONS: Routine preoperative vascular mapping results in a marked increase in placement of AV fistulas, as well as an improvement in the adequacy of forearm fistulas for dialysis. This approach resulted in a substantial increase in the proportion of patients dialyzing with a fistula in our patient population. Fistulas have a higher primary failure rate than grafts, but have a lower subsequent failure rate and require fewer procedures to maintain their long-term patency.     

Where Are All the AV Fistulas?

Increasing the prevalence of arteriovenous (AV) fistulas is crucial to decreasing the incidence and costs of dialysis access failure. Despite almost uniform agreement in the dialysis community of the need to increase AV fistulas, U.S. fistula prevalence has only increased modestly since the publication of the Dialysis Outcomes Quality Initiative (DOQI) clinical practice guidelines in 1997. Fistula rates of 28% in incident patients and 27% in prevalent patients [Health Care Finance Administration (HCFA) clinical performance measures project data for 1999] do not approach the fistula rates achieved by various focused U.S. programs, nor those routinely observed in Europe. Systemic barriers that limit the availability and funding of both pre-end-stage renal disease (ESRD) care and preoperative imaging, coupled with financial disincentives, lack of accountability, and educational deficiencies, impede progress toward increased fistula placement. Improvements in AV fistula prevalence require a realistic appraisal and correction of the system problems hindering achievement of this goal. The DOQI and Kidney Disease Outcomes and quality Initiative (K/DOQI) were excellent first steps; however, implementation will require modification of other structures that impact on patient care delivery.     

Primary Arteriovenous Fistulas in the Forearm for Hemodialysis: Effect of Miscellaneous Factors in Fistula Patency

Background. The provision and maintenance of vascular access remains a major cost to end-stage renal failure programs. In addition, vascular access occlusion, results in significant morbidity in hemodialysis patients. Age, gender, diabetes mellitus, malignancy, smoking habits, administration of heparin per hemodialysis session, previous dialysis catheter insertion, number of hemodialysis sessions and location of the fistula may be associated with survival of the primary arteriovenous fistula. We examined the effects of various factors on fistulas in 412 chronic renal insufficiency patients. Methods. From 1995 to 2004, 412 arteriovenous fistulas were created by the Department of Cardiovascular Surgery at the Medical Faculty of Atatürk University for hemodialysis. The mean age of the patients was 45 years (range 6 to 62 years). We evaluated the effects of various factors for patency rates in the patients who had primary arteriovenous fistulas. Primary patency was defined as the duration of fistula patency without revision. Twenty-eight patients (6.7%) with ischemic cardiac disease did not require surgical interference. Analyzed data were age, gender, smoking habits, diabetes mellitus, malignant neoplasm, previous dialysis catheter insertion, number of hemodialysis sessions, and fistula location. Results. In 298 patients, where lower-arm radiocephalic fistulas were created, the fistula patency was 74.1%, 64.2%, 49.8%, 33.7%, and 4.1% after 1, 2, 3, 4, and 5 years, respectively, in the other 114 patients, where upper-arm fistulas were created, these rates were 84.0%, 72.2%, 53.3%, 39.8%, and 12.3%, respectively. There was no significantly difference between the upper-arm fistulas and the lower-arm fistulas statistically (p = 0.069). Factors affecting the primary patency of arteriovenous fistulas were diabetes mellitus (p = 0.0001), hemodialysis counts ≥3 per week (p < 0.0005), presence of malignancy (p < 0.0005), previous catheter insertion (p < 0.0007), and administration of heparin per hemodialysis session (p = 0.0008). Conclusion. While primary arteriovenous fistula patency was shortened in chronic renal insufficiency patients with diabetes mellitus, presence of malignancy, and previous catheter insertion, patency was longer in patients with heparin used for hemodialysis and hemodialysis count per week (≥3).     

Vascular access and increased risk of death among hemodialysis patients

BACKGROUND: Hemodialysis with a venous catheter increases the risk of infection. The extent to which venous catheters are associated with an increased risk of death among hemodialysis patients has not been extensively studied. METHODS: We conducted a retrospective cohort study of 7497 prevalent hemodialysis patients to assess the association between dialysis with a venous catheter and risk of death due to all causes and to infection. RESULTS: A tunneled cuffed catheter was used for access in 12% of the patients and non-cuffed, not tunneled catheter in 2%. Younger age (P = 0.0005), black race (P = 0.0022), female gender (P = 0.0004), short duration since starting dialysis (P = 0.0003) and impaired functional status (P = 0.0001) were independently associated with increased use of catheter access. The proportion of patients who died was higher among those who were dialyzed with a non-cuffed (16.8%) or cuffed (15.2%) catheter compared to those dialyzed with either a graft (9.1%) or a fistula (7.3%; P < 0.001). The proportion of deaths due to infection was higher among patients dialyzed with a catheter (3.4%) compared to those dialyzed with either a graft (1.2%) or a fistula (0.8%; P < 0.001). The adjusted odds ratio (95% CI) for all-cause and infection-related death among patients dialyzed with a catheter was 1.4 (1.1, 1.9) and 3.0 (1.4, 6.6), respectively, compared to those with an arteriovenous (AV) fistula. CONCLUSION: Venous catheters are associated with an increased risk of all-cause and infection-related mortality among hemodialysis patients.     

Late creation of vascular access for hemodialysis and increased risk of sepsis

The creation of fistulas or grafts before starting dialysis is recommended, but whether it reduces major adverse events is largely unknown. The objective of this study was to determine if early access creation was associated with a reduced risk of hospitalization from sepsis and mortality. Fistulas or grafts created at least 4 mo before starting hemodialysis were defined as Early creations (n = 1240), and accesses created between 4 mo and 1 mo before starting hemodialysis were defined as Just Prior creations (n = 997). Accesses created within 1 mo of starting dialysis or after were defined as Late creations (reference group, n = 3687). Hemodialysis catheter use was defined as insertion, removal, or manipulation of a catheter before the occurrence of sepsis. Eighty percent of accesses were fistulas. Early access creation was associated with a relative risk (RR) of sepsis of 0.57 (95% CI, 0.41 to 0.79) compared with Late access creation. Catheter use increased the risk of sepsis by 1.41 (95% CI, 1.14 to 1.81). The risk of sepsis with Early creation decreased to 0.48 (95% CI, 0.35 to 0.65) if catheter use was not adjusted. Early access creation was associated with lower mortality (RR 0.76; 95% CI 0.58 to 1.00), but this association became nonsignificant if catheter use and sepsis were adjusted. Catheter use and sepsis independently increased mortality. This study demonstrates that fistula creation at least 4 mo before starting chronic hemodialysis is associated the lowest risk of sepsis and death, primarily by reducing the use of hemodialysis catheters.     

Complications of hemodialysis access in HIV-positive patients

As long-term arteriovenous (AV) access for hemodialysis becomes more prevalent in human immunodeficiency virus (HIV)-positive patients it is important to evaluate the complications associated with each surgical technique. The records of 37 consecutive HIV-positive patients undergoing surgery for AV hemodialysis access were reviewed. Cases were analyzed for age, gender, presence of acquired immunodeficiency syndrome (AIDS), surgical procedure, and complications. AV fistulas were performed primarily in 23 patients, and prosthetic grafts were used in 14. There was no difference between these two groups in regard to age (P = 0.510), gender (P = 0.620), or presence of AIDS (P = 0.97). Complications requiring one or more reoperations occurred in four patients (17%) after AV fistulas and in seven patients (50%) after AV grafts (P = 0.035). When reoperations were accounted for a total of 28 AV fistulas and 20 AV grafts were performed with an overall complication rate of 21 and 70 per cent respectively (P = 0.001). Complications after AV grafts included thrombosis (40%), infection (25%), and aneurysm (5%). Thrombosis was the only complication observed after AV fistula (21%). The complication rate after AV access in HIV-positive patients was significantly greater after AV graft insertion than after AV fistulas, which resulted in a higher rate of reoperation. AV fistula when feasible should be considered the procedure of choice in this group of patients.     

Cardiac diseases in maintenance hemodialysis patients: results of the HEMO Study

BACKGROUND: Cardiac disease is a common cause of death in chronic hemodialysis patients. A subanalysis of the data on cardiac diseases in the Hemodialysis (HEMO) Study was performed. The specific objectives were: (1) to analyze the prevalence of cardiac disease at baseline; (2) to characterize the incidence of various types of cardiac events during follow-up; (3) to examine the association of cardiac events during follow-up with baseline cardiac diseases; and (4) to examine the effect of dose and flux interventions on various types of cardiac events. METHODS: The HEMO Study is a randomized multi-center trial on 1846 chronic hemodialysis patients at 15 clinical centers comprising 72 dialysis units. The scheduled maximum follow-up duration was 0.9 to 6.6 years, with the mean actual follow-up of 2.84 years. The interventions were standard-dose versus high-dose and low-flux versus high-flux hemodialysis in a 2 x 2 factorial design. RESULTS: At baseline, 80% of patients had cardiac diseases, including ischemic heart disease (IHD) (39%), congestive heart failure (40%), arrhythmia (31%), and other heart diseases (63%). There were a total of 1685 cardiac hospitalizations, with angina and acute myocardial infarction accounting for 42.7% of these hospitalizations. There were 343 cardiac deaths during follow-up, accounting for 39.4% of all deaths. IHD was implicated in 61.5% of the cardiac deaths. Any cardiac disease at baseline was highly predictive of cardiac death during follow-up [relative risk (RR) 2.57; 95% CI 1.73-3.83]. There were no significant effects of dose or flux assignments on the primary outcome of all-cause mortality or the main secondary cardiac composite outcome of first cardiac hospitalization or all-cause mortality. Assignment to high-flux dialysis was, however, associated with decreased cardiac mortality and the composite outcome of first cardiac hospitalization or death from cardiac causes. CONCLUSION: The HEMO Study identified IHD to be a major cause of cardiac hospitalizations and cardiac deaths. Future strategies for the prevention of cardiac diseases in the maintenance hemodialysis population should focus on this entity. Although high-flux dialysis did not reduce all-cause mortality, it might improve cardiac outcomes. This hypothesis needs to be further examined.