Upper limb ischemia after vascular access surgery: differential diagnosis and management

Hand ischemia following placement of upper limb arteriovenous accesses for dialysis may result in debilitating complications and contribute to morbidity and mortality on dialysis. Two distinct clinical variants of hand ischemia are recognized: vascular steal syndrome, in which a spectrum of severity of ischemic changes affect all tissues of the hand; and ischemic monomelic neuropathy, where ischemia is confined to the nerves of the hand. Early diagnosis and treatment of these complications (often including closure of the access) is imperative to prevent hand paralysis, and digital or hand amputation.     

Upper extremity ischemia caused by small artery disease.

One hundred patients with ischemic finger ulceration had detailed prospective evaluation to determine the incidence of associated diseases, response to treatment, and natural history of the condition. A potentially serious associated disease was detected in each patient including autoimmune disease in 54%, Buerger's disease in 9%, arteriosclerosis obliterans in 9%, hypersensitivity angiitis in 22%, and miscellaneous diseases in 6%. Conservative treatment with soap and water scrubs, antibiotics, and local resection/debridement resulted in long-term healing without recurrence in 88% of patients. Most recurrences occurred in patients with autoimmune disease, usually scleroderma or CRST.     

Routine surveillance in vascular access for hemodialysis.

There is increasing evidence that surveillance of AV access for haemodialysis prevents access thrombosis and improves the quality of care. This article reviews the evidence for surveillance and the various strategies and techniques available for detection of the failing access.     

Prosthetic arteriovenous fistula for vascular access in hemodialysis.

Vascular access through subcutaneous prosthetic arteriovenous fistulas was studied in eighteen dogs. Dacron velour and woven Dacron grafts (6 mm diameter) were constructed across the lower abdomen between the common femoral artery and the opposite common femoral vein. In heparinized animals 197 percutaneous punctures were made with a "14 guage hemodialysis cannula at weekly intervals. Over a period of one and a half years there was no instance of infection. One of the fourteen Dacron velous and all four woven Dacron fistulas thrombosed. These data suggested the feasibility of achieving repetitive blood access through Dacron velour vascular prostheses. Nineteen Dacron velour fistula bypasses between the brachial artery and median basilic vein were performed in fifteen selected patients for a total dialysis period of ninety-six months. Failed standard subcutaneous fistulas or absence of suitable vessels in the upper extremity were indications for the primary procedure. Of three looped forearm fistulas, two thrombosed at twenty-two and two months. Complications among sixteen straight bypasses in the arm included two graft infections and one cannula tract infection. There were no instances of thrombosis in this group. The advantages of single needle dialysis in these high risk patients have been emphasized. Eleven grafts are presently functioning two to nine months postoperatively. Our preliminary results suggest that a Dacron velour fistula merits consideration as an alternative for vascular access in maintenance hemodialysis.     

Complications from permanent hemodialysis vascular access

From 1981 to 1986 a total of 499 operations were performed for permanent hemodialysis vascular access in 230 patients. At least 1 year's follow-up was achieved in all cases. This series is divided into 326 primary procedures and 173 secondary procedures. Of the primary procedures, there were 160 autogenous fistulas and 166 expanded polytetrafluoroethylene (PTFE) fistulas. The 156 secondary procedures consisted of 124 thrombectomies, 20 repairs of pseudoaneurysm, 12 fistula ligations, and 17 fistula excisions. The infectious complication rate (29/482) was 6%. Mean length of patency was 3.1 years for autogenous wrist fistula, 2.6 years for elbow fistula, 1.9 years for forearm loop PTFE, 2.1 years for straight forearm PTFE, 1.6 years for femoral popliteal PTFE, and 1.4 years for femoral arteriovenous loop PTFE. A vascular steal syndrome occurred in 8% of patients with autogenous elbow fistulas (4/48), compared with 1.7% (2/112) of patients with wrist fistulas and 1.8% (3/166) of those with PTFE fistulas. All infected fistulas required excision, and all fistulas associated with the steal syndrome required ligation. Use of PTFE to construct permanent hemodialysis vascular access has a significantly higher incidence of thrombosis, infection, pseudoaneurysm formation, and limb loss (p less than 0.01 for all complications) and a significantly lower mean length of patency (p less than 0.0001) when compared with autogenous fistulas. Age, sex, hypertension, diabetes mellitus, and the use of perioperative antibiotics were not found to be related significantly to access complications.     

Homocysteine and vascular access thrombosis in hemodialysis patients

BACKGROUND: Vascular access remains the Achilles' heel of successful hemodialysis, and thrombosis is the leading cause of vascular access failure. Hyperhomocystinemia is common in hemodialysis patients and is associated with venous and arterial thrombosis in patients without end-stage renal disease. SUBJECTS AND METHODS: In the study, 65 hemodialysis patients with native arteriovenous fistula were included. Two groups of patients were defined: group A including 45 patients with their vascular access either never or only once thrombosed, and group B including 20 patients with two or more thromboses of their vascular access. We determined serum concentrations of total homocysteine (immunoassay, Abbott) in our patients. RESULTS: In 63 (96.9%) patients, hyperhomocystinemia was presented. There was no statistically significant difference between group A and B regarding age, gender and duration of hemodialysis treatment. Total homocysteine concentrations were higher in group A (42.1 +/- 18.6 micromol/l) than in group B (36.1 +/- 18.1 micromol/l) patients but the difference was small and not statistically significant. CONCLUSION: We found no significant differences in total homocysteine concentrations between group A (thrombosis non-prone) and group B (thrombosis prone) patients. Our results suggest that thrombosis of native arteriovenous fistulas may not be caused by hyperhomocystinemia in these patients.     

血液透析血管通路的研究进展

血管通路是建立体外血液循环,进行血液透析治疗的前提.血流量充足、能够长期使用且并发症少的血管通路对于达到充分透析、改善血透患者生活质量以及生存率具有重要意义.随着老年、并发糖尿病等血管条件差的患者在血透患者中占比例增高,血管通路日益成为持续改进透析质量的瓶颈.本文综合国内外最新文献,对目前临床应用的自体动静脉内瘘、PTFE移植血管内瘘冲心静脉导管等各种血管通路的成功建立及影响因素、适应证以及对这些通路的评价等问题进行讨论.     

Barriers to optimal vascular access for hemodialysis

Vascular access is the Achilles heel for hemodialysis (HD). An arteriovenous fistula (AVF), considered the optimal access for HD, rather than a graft or central venous catheter (CVC) caused the “Fistula First” initiative to dominate quality assessment. However, this initiative had the unintended consequence of increasing the proportion of less desirable catheters, leading to “Fistula First, Catheter Last”. But as the end-stage kidney disease (ESKD) population expanded with aging, sicker patients, individual assessment of the appropriate access changed the paradigm to KDOQI’s “Patient First: ESKD Life-Plan” to attain the “right access, in the right patient, at the right time, for the right reasons”. However, such a goal has proved elusive because the optimal vascular access does not currently exist. Thus, ESKD care providers attempting to offer the “right access” must weigh the barriers to achieving the most optimal access to suit each of their HD patients. The barriers are based on shortcomings related specifically to each of the three vascular accesses and to characteristics of each ESKD patient's demographics, physical factors, quality of life, and cost considerations. This article will describe these barriers so that clinicians caring for ESKD patients initiating or receiving HD provide the most optimal vascular access for that specific patient.     

Massive upper extremity edema following vascular access surgery

We recently treated three patients with chronic renal failure who required subclavian vein cannulation with Uldall catheters following thrombosis of their arteriovenous fistulae. New arteriovenous fistulae were created in each patient following removal of the Uldall catheters. The patients were seen subsequently with massive, painful edema in the ipsilateral upper extremities from one to 10 weeks following creation of the arteriovenous fistulae. Radiographic studies documented stenosis or occlusion of the ipsilateral proximal subclavian vein. The arteriovenous fistula was ultimately ligated in each patient, which promptly resolved the pain and edema. Because subclavian vein thrombosis following temporary hemodialysis through an indwelling catheter is frequently asymptomatic until an arteriovenous fistula is constructed, venography should be considered in patients requiring upper extremity vascular access procedures. Demonstration of subclavian vein stenosis or occlusion would either preclude use of the upper extremity for an arteriovenous fistula or would require a concomitant procedure to relieve the venous obstruction.     

Type of vascular access and mortality in U.S. hemodialysis patients

BACKGROUND: Vascular access (VA) complications account for 16 to 25% of hospital admissions. This study tested the hypothesis that the type of VA in use is correlated with overall mortality and cause-specific mortality. METHODS: Data were analyzed from the U.S. Renal Data System Dialysis Morbidity and Mortality Study Wave 1, a random sample of 5507 patients, prevalent on hemodialysis as of December 31, 1993. The relative mortality risk during a two-year observation was analyzed by Cox-regression methods with adjustments for demographic and comorbid conditions. Using similar methods, cause-specific analyses also were performed for death caused by infection and cardiac causes. RESULTS: In diabetic mellitus (DM) patients with end-stage renal disease, the associated relative mortality risk was higher for those with arteriovenous graft (AVG; RR = 1.41, P < 0.003) and central venous catheter (CVC; RR = 1.54, P < 0.002) as compared with arteriovenous fistula (AVF). In non-DM patients, those with CVC had a higher associated mortality (RR = 1.70, P < 0.001), as did to a lesser degree those with AVG (RR = 1.08, P = 0.35) when compared with AVF. Cause-specific analyses found higher infection-related deaths for CVC (RR = 2.30, P < 0.06) and AVG (RR = 2.47, P < 0.02) compared with AVF in DM; in non-DM, risk was higher also for CVC (RR = 1.83, P < 0.04) and AVG (RR = 1.27, P < 0.33). In contrast to our hypothesis that AV shunting increases cardiac risk, deaths caused by cardiac causes were higher in CVC than AVF for both DM (RR = 1.47, P < 0.05) and non-DM (RR = 1.34, P < 0.05) patients. CONCLUSION: This case-mix adjusted analysis suggests that CVC and AVG are correlated with increased mortality risk when compared with AVF, both overall and by major causes of death.     

Upper extremity entrapment neuropathy and tourniquet use in patients undergoing hemodialysis

Patients with end-stage renal disease, undergoing hemodialysis, have been shown to have an increased prevalence of carpal tunnel syndrome. From mid-1981 through 1986, 21 patients undergoing hemodialysis were operated on for 33 cases of clinically diagnosed entrapment of the median and/or ulnar nerves, including 14 extremities with functioning vascular access. All patients report improvement in symptoms and function in the affected extremity. Preoperative tourniquet use did not have a permanent adverse effect on any access site. Electrophysiologic studies were not reliable predictors of clinically resolvable nerve entrapment.     

Thrombophilia and the risk for hemodialysis vascular access thrombosis

Vascular access thrombosis is the most common and costly complication in hemodialysis patients. The role of thrombophilia in access thrombosis is not established. A case-control study was conducted of 419 hemodialysis patients to determine whether thrombophilia was associated with arteriovenous fistula or graft thrombosis. Participants were enrolled from three in-center and five satellite dialysis units associated with a Canadian academic health science center that provides dialysis services in a catchment area of one million. Patients were tested for factor V Leiden, prothrombin gene mutation, factor XIII genotype, methylenetetrahydrofolate reductase genotype, lupus anticoagulant, anticardiolipin antibody, factor VIII, homocysteine, and lipoprotein (a) concentrations. Overall, 59 (55%) patients with access thrombosis had at least one thrombophilia compared with 122 (39%) patients without access thrombosis (unadjusted odds ratio [OR], 1.91; 95% confidence interval [CI], 1.23 to 2.98). After controlling for important risk factors, the association between any thrombophilia and access thrombosis remained (adjusted OR, 2.42; 95% CI, 1.47 to 3.99). For each additional thrombophilic disorder, the odds of access thrombosis increased significantly (adjusted OR, 1.87; 95% CI, 1.34 to 2.61). This study suggests that thrombophilia is associated with access thrombosis in dialysis patients. Large, multicenter, prospective cohort studies are needed to confirm the observations from this case-control study.     

The modified bovine heterograft in vascular access for chronic hemodialysis.

The results of 100 modified bovine heterografts constructed in 93 patients for subcutaneous arteriovenous fistulas for chronic hemodialysis have been reviewed. Fifty-seven patients had the bovine heterograft inserted as the primary method of vascular access. Twenty-eight patients had complications consisting of graft thrombosis and stenosis, graft infection, and hemorrhage that required additional surgical procedures. Three patients with diabetes mellitus developed ischemia of the hand. Fourteen patients have died but none of the deaths could be attributable to the use of the bovine heterograft. In our experience the modified bovine heterograft has enjoyed a higher patient acceptance as compared to other methods of vascular access for hemodialysis. The chief advantage of the bovine graft has been the ability to use the graft in any patient as a means of immediate dialysis.     

Ultrafiltration method for measuring vascular access flow rates during hemodialysis.

BACKGROUND: The vascular access blood flow rate (QA) has been shown to be an important predictor of vascular access failure; therefore, the routine measurement of QA may prove to be a useful clinical method of vascular access assessment. METHODS: We have developed a new ultrafiltration (UF) method for determining QA during HD from changes in arterial hematocrit (H) after abrupt changes in the UF rate with the dialysis blood lines in the normal (DeltaHn) and reverse (DeltaHr) configurations. This method accounts for cardiopulmonary recirculation and requires neither intravenous saline injections nor accurate knowledge of the dialyzer blood flow rate. Clinical studies were conducted in 65 chronic HD patients from three different dialysis programs to compare QA determined by the UF method with that determined by saline dilution using an ultrasound flow sensor. RESULTS: Arterial H increased (P<0.0001) after abrupt increases in the UF rate when the lines were in the normal and reverse configurations. An increase in the UF rate from the minimum setting to 1.8 liter/hr resulted in a DeltaHn of 0.3+/-0.2 (mean +/- SD) H units and a DeltaHr of 1.6+/-1.0 H units. Q(A) values determined by the UF method (1050+/-460 ml/min) were 16+/-25% higher (P<0.001) than those determined by saline dilution (950+/-440 ml/min); the calculated QA values by the UF and saline dilution methods correlated highly with each other (R = 0.92, P<0.0001). The average coefficient of variation for duplicate measurements of QA determined by the UF method in a subset of these patients (N = 21) was approximately 10% when assessed in either the same dialysis session or consecutive sessions. CONCLUSIONS: The results from this study show that changes in arterial H after abrupt changes in the UF rate can be used to assess Q(A).     

Improvement in hemodialysis vascular access outcomes in a dedicated access center

There are more than 300,000 end-stage renal disease (ESRD) patients in the United States, with those on hemodialysis requiring vascular access for dialysis treatment. According to the 1999 annual report of the U.S. Renal Data System (USRDS), the leading cause of morbidity in this patient population is related to vascular access placement and the resultant complications. Vascular access procedures account for more than 10% of the annual ESRD budget and are conservatively estimated at $1 billion annually. The impact of dysfunctional vascular access on physician time, health care resources, and patient quality of life is profound. In 1997 I opened a freestanding, dedicated access center for the diagnosis and treatment of access-related disorders. This article summarizes the experience of this center. In our free-standing dialysis access center, a large referral base has been established consisting of 30 dialysis centers with approximately 2000 patients. During the 27 months from October 1997 to December 1999, 1087 patients were treated. These patients received 2862 access procedures (2.6 procedures/patient). Annualized, this gives a dysfunction rate of 1.15 episodes/patient/year at risk. Endovascular declotting procedures were performed 1282 times (45%) with a success rate (defined as one uneventful hemodialysis following the procedure) of 93% (1187/1282). Prospective angiography followed by percutaneous transluminal angioplasty was performed 703 times (24%). This procedure was successful 695 times for a success rate of 99%. There were 644 (23%) catheter procedures performed consisting of catheter placements, catheter exchanges through new or old tracts, and catheter removals. The success rate for catheter procedures was 99.1%. Complication rates were extremely low, both for major and minor complications, exceeding all published standards. Hemodialysis vascular access can be optimized in a freestanding, focused, outcomes-driven outpatient access center. Outcomes can meet or exceed the National Kidney Foundation Dialysis Outcomes Quality Initiative (NKF-DOQI) guidelines for vascular access while at the same time providing the patient with an outpatient procedure and the referring dialysis unit and nephrologist with an efficient, effective mode of patient care.