Comparable outcome of acute unplanned peritoneal dialysis and haemodialysis.
Koch M, Kohnle M, Trapp R, Haastert B, Rump LC, Aker S.
Nephrol Dial Transplant. 2011 May 28. [Epub ahead of print]
BACKGROUND:
The impact of dialysis modality on outcome, especially on infection early in the course of dialysis, in unplanned acute dialysis initiation has not been well evaluated. The aim of the study was to compare the rates and causes of mortality and morbidity in incident dialysis patients started unplanned acute peritoneal dialysis (PD) or haemodialysis (HD). Patients and methods. In this observational cohort study, incident dialysis patients with initiation of unplanned and acute PD (n = 66) or HD (n = 57) at a single centre from March 2005 to June 2010 were included and followed up for 6 months (0-183 days, mean follow-up time 4.72 months). For PD, surgically placed Tenckhoff catheters were used. All HD patients were dialysed with a central venous catheter (non-tunnelled or tunnelled). There were no significant differences in terms of gender, age and prevalence of diabetes mellitus in either group. The prevalence of heart failure [New York Heart Association (NYHA) Stage III-IV] was significantly higher in the PD group (73 versus 46% in HD group, P < 0.01). The population was stratified to PD and HD comparing mortality, infection, bacteraemia and hospitalization.
RESULTS:
Of the 123 patients who commenced acute and unplanned dialysis, n = 44 (35.8%) died during the follow-up period of 0-183 days. There were no significant difference in half-year mortality in n = 20 PD patients (30.3%) versus n = 24 HD patients (42.1%) (P = 0.19). The cardiovascular mortality in PD and HD patients were 9.1 and 10.5%, respectively (P = 1.00). Overall mortality due to infection was higher in the HD (17.5%) versus in the PD group (9.1%), however, not significant (P = 0.19). HD patients had significantly higher probability of bacteraemia in the first 183 days compared to PD patients (21.1 versus 3.0%, P < 0.01). Group comparison by Poisson regression analyses showed that the relative risk of bacteraemia in the PD group versus HD group was 0.16 (95% confidence interval, 0.05-0.57, P = 0.005). The significant difference was not affected by the confounder's patient age at time of dialysis, male sex, heart failure (NYHA III-IV), diabetes, malignancy and peripheral arterial occlusive disease Stage IV. There were high proportions of hospitalization after the initiation of dialysis in both groups (PD 75.0% and HD 67.3%, P = 0.40). Univariate and multiple regression analyses revealed only age at initiation of dialysis to be significantly associated with overall mortality (P < 0.05).
CONCLUSIONS:
Dialysis modality (PD versus HD) in an acute unplanned dialysis setting showed, in our population, no significant influence on survival. HD patients had a significantly higher risk of bacteraemia, perhaps due to central venous dialysis catheter. PD seems to be a safe and efficient, at least comparable, alternative to HD in acute unplanned dialysis settings.
Kimball TA, Barz K, Dimond KR, Edwards JM, Nehler MR.
J Vasc Surg. 2011 Jun 22. [Epub ahead of print]
BACKGROUND:
The National Kidney Foundation-Kidney Diseases Outcomes Quality Initiative (KDOQI) for vascular access guidelines state that patients with late-stage chronic kidney disease (CKD) should undergo native arteriovenous fistula (AVF) creation at least 6 months before anticipated start of hemodialysis (HD) treatments to obviate the need for other vascular access types, such as grafts or central catheters.
OBJECTIVE:
The objective of this study was to determine the incidence of HD, the functional patency, and associated morbidity of AVFs in patients with late-stage CKD placed according to KDOQI.
METHODS:
Consecutive patients with late-stage CKD who underwent AVF creation using KDOQI guidelines for anatomy between January 2003 and December 2007 at two tertiary academic centers were retrospectively evaluated. Baseline demographics, AVF type, and clinical comorbidities were recorded. Patients were stratified into one of four groups (groups A-D) over the follow-up course based on two end points: patency of their AVF and whether or not they began HD. The ideal primary outcome was AVF maturation and use for HD (group A; cumulative functional patency). Other outcomes included AVF patency but no HD (group B), HD with AVF failure (group C), or no HD and AVF abandonment (ie, death, refused hemodialysis, kidney transplant, or fistula failure; group D). Secondary outcomes were time to first cannulation, complications, and secondary interventions.
RESULTS:
AVFs were created (46% forearm and 54% upper arm) in 150 patients with CKD (85% men, median age 63 years old). At a median follow-up of 10 months, 74 patients (49%) were receiving HD and of these, 48 patients (65%) were using their AVF (group A), whereas 26 patients (35%) were not due to fistula failure (group C). Thirty-four patients (23%) never initiated HD treatments, but had a viable AVF (group B), and 42 patients (28%) never initiated HD and abandoned their AVF (group D). Overall, AVF abandonment was 51%. Mean maturation time of all AVFs successfully cannulated was 285 days (range, 30-1265 days). Complications encountered were maturation failure for cannulation (15%), focal stenosis requiring intervention (13%), inadequate flows on HD (9%), steal syndrome (9%), and thrombosis (8%). Cumulative functional patency for all AVFs was 19% and 27% at 6 and 12 months, respectively, with a mean number of two interventions per AVF (range, 1-10). Mortality during the study was 23%.
CONCLUSION:
Despite successful creation and maturation of a preemptive AVF in nearly two-thirds of patients who started HD during the follow-up and given the following observations: the high overall mortality of the population, the morbidity and costs in secondary procedures of AVF creation, and the high incidence of abandonment, it is unclear if this strategy would demonstrate a benefit in a randomized trial when compared to other access strategies.
Choosing peritoneal dialysis reduces the risk of invasive access interventions.
Oliver MJ, Verrelli M, Zacharias JM, Blake PG, Garg AX, Johnson JF, Pandeya S, Perl J, Kiss AJ, Quinn RR.
Nephrol Dial Transplant. 2011 Jun 21. [Epub ahead of print]
BACKGROUND: Patients choosing between hemodialysis (HD) and peritoneal dialysis (PD) should be well informed of the risks and benefits of each modality. Invasive access interventions are important outcomes because frequent interventions lower patient's quality of life and consume limited resources. The objective of this study was to compare the risk of access interventions between the two modalities.
METHODS: Three hundred and sixty-nine incident chronic dialysis patients were prospectively enrolled at four Canadian centers that were eligible for both modalities, received at least 4 months of pre-dialysis care and started dialysis electively as an outpatient. Two hundred and twenty-four (61%) chose PD and 145 (39%) chose HD. Patients were followed for an average of 1.3 years (range 0.07-3.6 years).
RESULTS: In the PD group, there were fewer access interventions (2.5 versus 3.1 interventions per patient, adjusted odds ratio of 0.79 for PD versus HD, P = 0.005) and a lower intervention rate (2.3 versus 1.9 per patient-year, adjusted rate ratio of 0.81 for PD versus HD, P = 0.04). PD catheters were less likely to experience primary failure (4.6 versus 32%, P < 0.0001), showed a trend toward lower intervention rates during use (0.8 versus 1.2 per patient-year, P = 0.06), and had equal patency compared to fistulae (1-year patency of 84 versus 88%, P = 0.48). Patients managed exclusively with HD catheters (28% of the HD group) required 1.7 interventions per patient and an intervention rate of 1.9 per patient-year.
CONCLUSION: Patients who choose PD require fewer access interventions to maintain dialysis access than patients choosing HD.
Efficacy of covered stent placement for central venous occlusive disease in hemodialysis patients.
Anaya-Ayala JE, Smolock CJ, Colvard BD, Naoum JJ, Bismuth J, Lumsden AB, Davies MG, Peden EK.
J Vasc Surg. 2011 Jun 8. [Epub ahead of print]
OBJECTIVES:Covered stents have been proposed as an endovascular option for recalcitrant cases of hemodialysis-related central venous occlusive disease (CVOD). This study evaluated the efficacy and durability of covered stents in treating CVOD to preserve a functional dialysis access circuit.
METHODS: A retrospective review was performed of all patients with clinically significant CVOD who were treated by placement of covered stents from April 2007 to September 2010. Demographics, lesion locations and anatomic characteristics, stent graft, and access patency rates were determined. Complications, reinterventions, and factors influencing their outcomes were examined.
RESULTS: In 25 patients (56% men; mean age, 57 ± 29 years) with CVOD, covered stents were used in 20 to treat symptomatic venous hypertension or in 5 at the time of access creation to enable functionality. The target lesion was accessed via the dialysis access site or the common femoral vein. The Viabahn endoprosthesis (W. L. Gore and Associates, Flagstaff, Ariz) was used in 24 patients (average size and length, 11 mm × 5 cm) and a 13-mm × 5-cm Fluency covered stent (Bard Peripheral Vascular, Tempe, Ariz) was implanted in 1 patient. Technical success was 100%, and resolution of arm edema occurred after covered stent deployment in symptomatic patients. Two postprocedural cases (8%) of thrombosis occurred, one within 30 days and another at 3 months. Both required percutaneous thrombectomy and percutaneous transluminal angioplasty (PTA). Three additional patients (12%) required PTA due to restenosis in one of the ends of the device. Covered stent primary patency (PP), assisted primary patency (APP), and secondary patency (SP) were 56%, 86%, and 100% at 12 months, respectively. Access patency rates at 12 months were 29%, 85%, and 94% for PP, APP, and SP, respectively, in patients that received a covered stent for access salvage; patency rates were 74%, 85%, and 94% for PP, APP, and SP, respectively, in patients in whom the access was created after the venous outflow restoration.
CONCLUSIONS: Placement of covered stents for hemodialysis-related CVOD is safe, effective in relieving symptoms, and enabled functionality of new dialysis access circuits. Further prospective and randomized studies are necessary to determine whether covered stents provide superior long-term results to those achieved with PTA and bare metal stents.
Stent graft treatment for hemodialysis access aneurysms.
Shemesh D, Goldin I, Zaghal I, Berelowitz D, Verstandig AG, Olsha O.
J Vasc Surg. 2011 Jun 7. [Epub ahead of print]
BACKGROUND: Aneurysms that develop in arteriovenous accesses as a result of repeated punctures are sometimes complicated by infection or ischemia causing sloughing of the overlying skin, which may endanger the access and risk major bleeding and other complications. Surgical revision may necessitate the temporary use of a central venous catheter until dialysis can be resumed via the access. We used stent grafts in selected patients for the exclusion of access aneurysms.
METHODS: Twenty of 63 patients requiring access revision for complication of an aneurysm from February 2005 to December 2009 underwent ambulatory endovascular stent graft deployment. Indications included signs of impending rupture, questionable viability of overlying skin, pain, infection, and limitation of cannulation sites by the size or number of the aneurysms. Endovascular treatment always included angioplasty of associated outflow or central vein stenoses at the same ambulatory session.
RESULTS: Twenty patients with complicated access aneurysms were treated by endovascular stent graft exclusion at an average of 4.8 ± 4.3 years (range, 0.2 to 16.1 years) after access construction: nine graft pseudoaneurysms, nine native vein aneurysms, and two acute iatrogenic pseudoaneurysms. Six patients had skin erosion over the aneurysm, and 12 had painful aneurysms and clinical signs of compromised blood supply to the skin. Another two patients with an acute giant false aneurysm occurring during endovascular procedures were treated in the same interventional session by the stenting technique to control bleeding. All the aneurysms underwent endovascular exclusion without complications. Only one infected puncture site failed to heal within 2 months of stenting and was closed surgically 10 months later due to persistent localized graft infection, but with no further bleeding episodes. Only one aneurysm did not reabsorb within 3 months. Patients with painful skin ischemia had immediate pain relief. All patients also had stenosis in the draining veins necessitating additional percutaneous transluminal angioplasty. Only one patient required hospitalization (for intravenous antibiotic treatment of staphylococcal sepsis). No patients required a central catheter for hemodialysis. One access occluded due to cephalic arch stenosis in a noncompliant patient. Functional patency was 87% at 12 months, with a median follow-up of 15 months (range, 6.3 to 55.5 months).
CONCLUSION: Endovascular treatment with stent grafts in complicated access aneurysms is a simple, safe and rapid ambulatory procedure that enables treatment of both the aneurysm and its accompanying draining vein stenosis. It enables continued cannulation of the existing access and avoids the use of central catheters.
Estimated radiation exposure from medical imaging in hemodialysis patients.
De Mauri A, Brambilla M, Chiarinotti D, Matheoud R, Carriero A, De Leo M.
J Am Soc Nephrol. 2011 Mar;22(3):571-8. Epub 2011 Feb 25.
Radiation exposure accompanying medical imaging associates with cancer risk. Patients with recurrent or chronic diseases may be especially at risk, because they may undergo more of these procedures. The aim of this study was to assess the individual cumulative effective doses (CEDs), which quantify radiation from medical imaging procedures, in a cohort of 106 hemodialysis patients during a median follow-up of 3 years. We retrospectively calculated individual radiation exposures by collecting the number and type of radiologic procedures from hospital records. We also estimated organ doses for computed tomography procedures. The mean and median annual CEDs were 21.9 and 11.7 mSv per patient-year, respectively. The mean and median total CEDs per patient during the study period were 57.7 and 27.3 mSv, respectively. By radiation dose group, we classified 22 patients as low (<3 mSv/yr), 51 as moderate (3 to <20 mSv/yr), 22 as high (20 to <50 mSv/yr), and 11 as very high (≥50 mSv/yr). Seventeen patients had a total CED >100 mSv, a value associated with a substantial increase in risk for cancer-related mortality. Of the total CED,s 76% was a result of CT scanning. The annual CED significantly associated with age and transplant waitlist status. In summary, this study shows that a significant fraction of surviving hemodialysis patients during a 3-year period receives estimated radiation doses that may put them at an increased risk for cancer.
The role of the nephrologist in the management of vascular access
Carlo Lomonte and Carlo Basile
Nephrology and Dialysis Unit, Miulli General Hospital, Acquaviva delle Fonti, Italy
Nephrol Dial Transplant (2011) 26: 1461–1463
Advance Access publication 7 March 2011
Introduction
The Dialysis Outcomes and Practice Patterns Study (DOPPS) associated the preferred application of autogenous arteriovenous fistulas (AVFs), as currently applied in Europe and Japan, with a decrease in therapeutic costs [1]. The 1-year probability of failure for a prosthetic vascular access (VA) is almost twice that of autogenous AVFs [1]. Reduced primary patency increases hospitalizations, use of central vein catheters (CVCs), invasive and surgical procedures and thus costs. Preparation and maintenance costs are greater for grafts and CVCs [2]. The worldwide increase in dialysis patients with multiple comorbidities enhances the need for VA, but efficient application is hampered as the system mostly relies on isolated professionals with often limited experience, instead of experts working in teams. Centres cannot match the demand and/or do not comply with the guidelines [3]. As a consequence, many patients start dialysis on a CVC [4], while many AVFs (30–60%) fail or do not mature [5], suggesting an incorrect selection of patients [6], resulting from failures in management and training.
Medial Fibrosis, Vascular Calcification, Intimal Hyperplasia, and Arteriovenous Fistula Maturation
Michael Allon, MD,1 Silvio Litovsky, MD,2 Carlton J. Young, MD,3
Mark H. Deierhoi, MD,3 Jeremy Goodman, MD,3 Michael Hanaway, MD,3
Mark E. Lockhart, MD, MPH,4 and Michelle L. Robbin, MD4
Am J Kidney Dis. xx(x):xxx
Background: Arteriovenous fistulas (AVFs) for hemodialysis frequently fail to mature because of inadequate dilation or early stenosis. The pathogenesis of AVF nonmaturation may be related to pre-existing vascular pathologic states: medial fibrosis or microcalcification may limit arterial dilation, and intimal hyperplasia may cause stenosis.
Study Design: Observational study.
Setting & Participants: Patients with chronic kidney disease (N _ 50) undergoing AVF placement.
Predictors: Medial fibrosis, microcalcification, and intimal hyperplasia in arteries and veins obtained during AVF creation.
Outcome & Measurements: AVF nonmaturation.
Results: AVF nonmaturation occurred in 38% of patients despite attempted salvage procedures. Preoperative arterial diameter was associated with upper-arm AVF maturation (P _ 0.007). Medial fibrosis was similar in patients with nonmaturing and mature AVFs 60% _ 14% vs 66% _ 13%; P _ 0.2). AVF nonmaturation was not associated with patient age or diabetes, although both variables were associated significantly with severe medial fibrosis. Conversely, AVF nonmaturation was higher in women than men despite similar medial fibrosis in both sexes. Arterial microcalcification (assessed semiquantitatively) tended to be associated with AVF nonmaturation (1.3 _ 0.8 vs 0.9 _ 0.8; P _ 0.08). None of the arteries or veins obtained at AVF creation had intimal hyperplasia. However, repeated venous samples obtained in 6 patients during surgical revision of an immature AVF showed venous neointimal hyperplasia.
Limitations: Single-center study.
Conclusion: Medial fibrosis and microcalcification are frequent in arteries used to create AVFs, but do not explain AVF nonmaturation. Unlike previous studies, intimal hyperplasia was not present at baseline, but developed de novo in nonmaturing AVFs.