George M. Nassar

Presence of a Failed Kidney Transplant in Patients Who Are on Hemodialysis Is Associated with Chronic Inflammatory State and Erythropoietin Resistance

Patients returning to hemodialysis (HD) after failure of their kidney transplant suffer from high morbidity and mortality rates. It is common practice to keep failed kidney transplants in place. It is not known if these failed kidney transplants induce an inflammatory state that contributes to morbidity and mortality. In a single facility, patients starting on HD with failed kidney transplant were identified (Group A) and screened for the presence of chronic inflammatory state. Those with clinical symptoms attributed to the failed allograft (Group A1) were not offered transplant nephrectomy unless deemed necessary during follow-up. Their clinical and laboratory data were followed up for 6 months. Similar data were obtained from a group of incident HD patients (Group B). Forty-three patients had a failed Kidney transplant (Group A). Of these, 29 comprised Group A1 and 14 Group A2. Group B comprised 121 patients. In comparison with Group B, Group A exhibited worse anemia and erythropoietin resistance index (ERI), had lower serum albumin and prealbumin, and higher CRP. Group A1 had lower Hb and higher ferritin, CRP, and ESR in comparison with Group A2. Following transplant nephrectomy, Group A1 had improvement in ERI, serum albumin, prealbumin, ferritin, fibrinogen, CRP, and ESR. At 6 months, Group A1 had higher Hb and serum albumin levels, and lower CRP and ERI in comparison with Group A2. Group B parameters showed no change during follow-up. Patients returning to HD following failure of their kidney transplant suffer from a chronic inflammatory state. Resection of failed transplants in symptomatic patients is associated with amelioration of markers of chronic inflammation. Transplant nephrectomy should be considered a treatment option for patients with failed kidney transplants, especially if they exhibit signs and symptoms of chronic inflammatory state.

Clotted arteriovenous grafts: a silent source of infection.

Infectious complications are frequent causes of morbidity and mortality among hemodialysis patients. Of particular concern to this population are infections related to the hemodialysis vascular access. The incidence of bacteremic and nonbacteremic infections is highest when the dialysis access is a central venous catheter and lowest when it is a native arteriovenous fistula (1, 2). Unfortunately the prosthetic arteriovenous graft (PAVG), which has become an acceptable alternative to the native dialysis fistula when the latter is not surgically feasible, is often plagued by infection (3, 4). The risk of PAVG infection starts at the time of surgical placement. Zibari et al. (5) reported a 30-day graft infection rate of 6% in 208 patients undergoing PAVG placement. While the incidence of postoperative PAVG infection can be reduced with prophylactic antimicrobial therapy, a persistent risk of PAVG infection is posed by the need for repetitive cannulation of the graft for dialytic purposes (6). Difficulty in cannulation of the PAVG, perigraft hematoma formation, and a break in the sterile technique further increase the likelihood of PAVG infection. The risk of PAVG infection does not end when the graft is no longer in use. Unused grafts are typically nonfunctioning with a thrombosed lumen. It is common practice to leave these clotted grafts in place, and thus many hemodialysis patients have one or more old clotted grafts in their extremities. Even though these old clotted grafts tend to be considered innocuous by most health care practitioners, it has recently been recognized that they may harbor occult bacterial infection that can lead to serious infectious complications (7). It is difficult to diagnose infection in old clotted grafts largely due to the fact that such infections tend to be silent. Clinical recognition of PAVG-related infection is easy when there is tenderness, erythema, warmth, induration, or local drainage around the graft. In patent grafts, these localizing signs of infection are typically noted at the sites of previous graft punctures or surgical manipulation. In old clotted grafts, these signs are frequently absent. Thus the diagnosis of clinically silent graft infection requires a high index of suspicion and is frequently missed (7, 8). To evaluate the prevalence and clinical relevance of silent infection in clotted grafts, we studied a series of 20 hemodialysis patients with old clotted PAVGs who presented with fever (15 patients) or fever and clinical signs of sepsis (5 patients) in whom the source of infection was not immediately localized to any organ system. Comparison was made with 21 asymptomatic hemodialysis patients with clotted PAVGs who served as control subj cts. Both febrile patients and control subjects were evaluated with indium scans and then subjected to surgical removal of the graft. Bacterial cultures of the recovered surgical material and blood were done simultaneously in all study participants. Blood cultures were positive for bacterial pathogens in 15 of the 20 febrile patients, indicating that serious illness was present. In contrast, all of the asymptomatic control subjects had negative blood cultures. Indium uptake in or around the clotted grafts was present on scanning in all 20 patients and in 15 of the control subjects. The importance of the indium scan findings was verified when purulent infected material was recovered from graft material in all 20 patients and in 13 of 15 indium scan-positive control subjects. The pathogens recovered from blood culture were identical to those cultured from the graft material in all patients, strongly indicating a causal relationship. By far the most frequent pathogen recovered from the graft material was Staphylococcus aureus; this was followed byS. epidermidisand less frequently, Escherichia coli, Serratia marcescens , and Streptococcus pneumonia . The finding of staphylococcal species as the most frequent pathogens in infected graft material is consistent with the high prevalence of staphylococcal bacteremia in emodialysis patients. Bacterial infections, particularly those caused by S. aureus , may result in life-threatening complications, especially in an immune-compromised host such as the chronic hemodialysis patient (9). Mortality from S. aureusbacteremia is about 20–25%. Late serious complications of S. aureusbacteremia may be as high as 43% and include recurrent bacteremia, endocarditis, purulent pericarditis, septic arthritis, epidural abscess, and osteomyelitis (10). These complications are more common with short (2 weeks or less) courses of antimicrobial therapy, and several authorities advocate at least 4 weeks of treatment. Such prolonged treatment will increase the cost and the likelihood of antimicrobialrelated side effects. Considering the high cost of treating bacteremic episodes and the serious complications of bacteremia, infected old clotted grafts should be recognized as a serious hazard. Indium scanning is a well-established and accepted method for localization of infection in general (11, 12). This technique requires administration of autologous indium-labeled leukocytes, and subsequent (24 h later) total body scanning with a gamma camera (7). It has been shown to be useful in vascular graft infection, with a satisfactory overall level of sensitivity and specificity (13, 14). A variety of lesions other than foci of Address correspondence to: Juan Carlos Ayus, MD, Baylor College of Medicine, 4 Brompton Ct., Houston, TX 77024. Seminars in Dialysis—Vol 13, No 1 (January–February) 2000 pp. 1–3

Long-Term Performance of the Hemodialysis Reliable Outflow (HeRO) Device: The 56-Month Follow-Up of the First Clinical Trial Patient

The Hemodialysis Reliable Outflow (HeRO®) Vascular Access Device is a novel long‐term subcutaneous dialysis graft, ideally suited for catheter‐dependent patients and patients dialyzing with failing fistulas or grafts due to venous outflow stenosis. This case presentation depicts the clinical course of the first patient to enter a Food and Drug Administration approved clinical trial and receive the HeRO device. The course of this patient over 56 months of follow‐up provides the longest experience with the HeRO device to‐date. In this patient, the HeRO device provided long‐term dialysis access patency in conjunction with adequate dialysis and a low intervention rate.

Salvage of a severely dysfunctional arteriovenous fistula with a strictured and occluded outflow tract.

Arteriovenous fistulas (AVFs) created for the purpose of hemodialysis are frequently lost due to various vascular lesions. Endovascular therapies with percutaneous transluminal balloon angioplasty have become very valuable in treating AVF dysfunction due to vascular stenosis. Experience with these therapies is relatively limited. In this case report, we present a patient with a severely dysfunctional AVF. The vascular lesions affecting his AVF were numerous and severe. We show how the application of aggressive endovascular treatment succeeded in restoring use of his AVF. Throughout the discussion we share observations and personal experiences that may be useful for interventionalists and health care practitioners involved with the maintenance, use, and treatment of dialysis vascular accesses.

ASDIN Original Investigations: Salvage of a Severely Dysfunctional Arteriovenous Fistula with a Strictured and Occluded Outflow Tract

Arteriovenous fistulas (AVFs) created for the purpose of hemodialysis are frequently lost due to various vascular lesions. Endovascular therapies with percutaneous transluminal balloon angioplasty have become very valuable in treating AVF dysfunction due to vascular stenosis. Experience with these therapies is relatively limited. In this case report, we present a patient with a severely dysfunctional AVF. The vascular lesions affecting his AVF were numerous and severe. We show how the application of aggressive endovascular treatment succeeded in restoring use of his AVF. Throughout the discussion we share observations and personal experiences that may be useful for interventionalists and health care practitioners involved with the maintenance, use, and treatment of dialysis vascular accesses.

ASDIN Original Investigations: Salvage of a Severely Dysfunctional Arteriovenous Fistula with a Strictured and Occluded Outflow Tract: SALVAGE OF A SEVERELY DYSFUNCTIONAL AVF

Arteriovenous fistulas (AVFs) created for the purpose of hemodialysis are frequently lost due to various vascular lesions. Endovascular therapies with percutaneous transluminal balloon angioplasty have become very valuable in treating AVF dysfunction due to vascular stenosis. Experience with these therapies is relatively limited. In this case report, we present a patient with a severely dysfunctional AVF. The vascular lesions affecting his AVF were numerous and severe. We show how the application of aggressive endovascular treatment succeeded in restoring use of his AVF. Throughout the discussion we share observations and personal experiences that may be useful for interventionalists and health care practitioners involved with the maintenance, use, and treatment of dialysis vascular accesses.