Hemodialysis International 2014; 18:846–850
3 Stellato T, Cappelleri A, Farina M, et al. Severe reversible acute renal failure in idiopathic nephrotic syndrome. J Nephrol. 2010; 23:717–724. 4 Tavares MB, Chagas de Almeida Mda C, Martin RT, de Souza AC, Martinelli R, dos-Santos WL. Acute tubular necrosis and renal failure in patients with glomerular disease. Ren Fail. 2012; 34:1252–1257.
5 Mohamed N, Goldstein J, Schiff J, Rohan J. Collapsing glomerulopathy following anthracycline therapy. Am J Kidney Dis. 2013; 61:778–781. 6 Jhaveri KD, Shah HH, Calderon K, Campenot ES, Radhakrishnan J. Glomerular diseases seen with cancer and chemotherapy: A narrative review. Kidney Int. 2013; 84:34–44.
Balloon inflation time in angioplasty of dialysis access stenosis
To the Editor: In their recent observational study, Elramah et al. reported that a 30-second balloon inflation was associated with longer primary-assisted patency compared with a 60second inflation in angioplasty of dialysis access stenosis.1 Although the results are hypothesis generating, there are some important aspects of the study that warrant further discussion. Other potential confounding factors may have influenced the observed result. Longer lesion length and younger arteriovenous fistulas (AVFs) have been found to be associated with shorter primary patency after angioplasty in multiple studies.2 Elramah et al. did not adjust for lesion length in multivariate analysis and the hazards ratio for AVF age (i.e., dialysis vintage) is not presented. Post-intervention patency has also been shown to be shorter in upper arm compared with forearm access.3–5 These factors should be included in multivariate analysis. Patients were analyzed multiple times if they underwent several interventions because each new intervention was analyzed separately, potentially introducing additional biases in multivariate analysis. Because only two operators performed angioplasties, each with different inflation
Correspondence to: B. L. Neuen, MBBS (Hons I), Department of Renal Medicine, Cairns Hospital, 165 The Esplanade, Cairns, Qld 4870, Australia. E-mail: [email protected] Conflict of interest: None. Financial disclosures: None.
times, differences in patency may reflect other aspects of procedural technique that were not measured. Given that patients were not randomized, additional information on the characteristics of treated lesions would be informative. In the 60-second inflation group, was there more elastic recoil, longer lesions, or recurrent stenosis within a certain time period? If lesions less amenable to angioplasty were subjected to longer balloon inflation time, it may be a reflection of lesion characteristics rather than the intervention. We recently found that severity of pre-angioplasty stenosis was associated with shorter patency after angioplasty.3 Additional details on mean degree of stenosis prior to angioplasty, how lesion measurements were made, validated and defined would also provide meaningful information. Identifying optimal angioplasty technique will assist in the rational testing and use of new endovascular devices, such as drug eluting balloons,6 cutting balloons7 and covered stents,8 to treat dialysis access stenosis. Given the limitations of the current study, the findings of Elramah et al. should be further investigated in a prospective setting. Brendon L. NEUEN, Frank GRAINER, Murty L. MANTHA Department of Renal Medicine, Cairns Hospital 165 The Esplanade Cairns 4870 Queensland, Australia E-mail: [email protected]
Manuscript received July 2014.
© 2014 International Society for Hemodialysis DOI:10.1111/hdi.12208
847
Hemodialysis International 2014; 18:846–850
REFERENCES 1 Elramah M, Boujelbane L, Yevzlin AS, Wakeen M, Astor BC, Chan MR. Dialysis access venous stenosis: Treatment with balloon angioplasty 30-second vs. 1-minute inflation times. Hemodial Int. 2014; doi: 10.1111/hdi.12183; in press. 2 Neuen BL, Gunnarsson R, Webster AC, Baer RA, Golledge J, Mantha ML. Predictors of patency after balloon angioplasty in hemodialysis fistulas: A systematic review. J Vasc Interv Radiol. 2014; 25:917–924. 3 Neuen BL, Gunnarsson R, Baer RA, et al. Factors associated with patency following angioplasty of hemodialysis fistulae. J Vasc Interv Radiol. 2014; doi: 10.1016/ j.jvir.2014.05.020; in press. 4 Rajan DK, Bunston S, Misra S, Pinto R, Lok CE. Dysfunctional autogenous hemodialysis fistulas: Outcomes after angioplasty—Are there clinical predictors of patency? Radiology. 2004; 232:508–515.
5 Turmel-Rodrigues L, Pengloan J, Baudin S, et al. Treatment of stenosis and thrombosis in haemodialysis fistulas and grafts by interventional radiology. Nephrol Dial Transplant. 2000; 15:2029–2036. 6 Katsanos K, Karnabatidis D, Kitrou P, Spiliopoulos S, Christeas N, Siablis D. Paclitaxel-coated balloon angioplasty vs. plain balloon dilation for the treatment of failing dialysis access: 6-month interim results from a prospective randomized controlled trial. J Endovasc Ther. 2012; 19:263–272. 7 Saleh HM, Gabr AK, Tawfik MM, Abouellail H. Prospective, randomized study of cutting balloon angioplasty versus conventional balloon angioplasty for the treatment of hemodialysis access stenoses. J Vasc Surg. 2014; doi: 10.1016/j.jvs.2014.04.002; in press. 8 Haskal ZJ, Trerotola S, Dolmatch B, et al. Stent graft versus balloon angioplasty for failing dialysis-access grafts. N Engl J Med. 2010; 362:494–503.
Intracerebral hemorrhage was the highest cause of mortality among stroke subtypes in Japanese dialysis patients
To the Editor: We were greatly interested to read the article entitled “Association of blood pressure with all-cause mortality and stroke in Japanese hemodialysis patients: The Japan dialysis outcomes and practice pattern study” by Inaba et al.1 Using data from the Japan Dialysis Outcomes and Practice Patterns Study (J-DOPPS), the authors revealed that both systolic and diastolic blood pressures were positively and monotonically associated with stroke-related death, suggesting that, as shown in the general population, hypertension is a definite risk factor for strokeCorrespondence to: M. Wakasugi, MD, MPH, PhD, Center for Inter-organ Communication Research, Niigata University Graduate School of Medical and Dental Sciences, Asahimachi 1-757, Chuo-ku, Niigata 951-8510, Japan. Email: [email protected] Conflict of interest: None declared.
related death in hemodialysis patients. However, the DOPPS questionnaire did not distinguish between ischemic and hemorrhagic stroke. We would like to suggest that many of the stroke-related deaths are likely due to intracerebral hemorrhage. Because of the efforts of the DOPPS to obtain a representative, random sample of facilities and patients within each country, the results would likely represent those from our nationwide survey. Using data from the Japanese Society for Dialysis Therapy registry and a national Vital Statistics survey, we reported that the stroke mortality rate in Japanese dialysis patients is approximately three times higher than that in the general population.2 Using the same data, we found and reported that intracerebral hemorrhage had the highest mortality rate in Japanese dialysis patients among three stroke subtypes (i.e., intracerebral hemorrhage, cerebral infarction, and subarachnoid hemorrhage).3 This is inconsistent with results from the general Japanese population in which cerebral infarction had the highest mortality
© 2014 International Society for Hemodialysis DOI:10.1111/hdi.12212
848
3 Stellato T, Cappelleri A, Farina M, et al. Severe reversible acute renal failure in idiopathic nephrotic syndrome. J Nephrol. 2010; 23:717–724. 4 Tavares MB, Chagas de Almeida Mda C, Martin RT, de Souza AC, Martinelli R, dos-Santos WL. Acute tubular necrosis and renal failure in patients with glomerular disease. Ren Fail. 2012; 34:1252–1257.
5 Mohamed N, Goldstein J, Schiff J, Rohan J. Collapsing glomerulopathy following anthracycline therapy. Am J Kidney Dis. 2013; 61:778–781. 6 Jhaveri KD, Shah HH, Calderon K, Campenot ES, Radhakrishnan J. Glomerular diseases seen with cancer and chemotherapy: A narrative review. Kidney Int. 2013; 84:34–44.
Balloon inflation time in angioplasty of dialysis access stenosis
To the Editor: In their recent observational study, Elramah et al. reported that a 30-second balloon inflation was associated with longer primary-assisted patency compared with a 60second inflation in angioplasty of dialysis access stenosis.1 Although the results are hypothesis generating, there are some important aspects of the study that warrant further discussion. Other potential confounding factors may have influenced the observed result. Longer lesion length and younger arteriovenous fistulas (AVFs) have been found to be associated with shorter primary patency after angioplasty in multiple studies.2 Elramah et al. did not adjust for lesion length in multivariate analysis and the hazards ratio for AVF age (i.e., dialysis vintage) is not presented. Post-intervention patency has also been shown to be shorter in upper arm compared with forearm access.3–5 These factors should be included in multivariate analysis. Patients were analyzed multiple times if they underwent several interventions because each new intervention was analyzed separately, potentially introducing additional biases in multivariate analysis. Because only two operators performed angioplasties, each with different inflation
Correspondence to: B. L. Neuen, MBBS (Hons I), Department of Renal Medicine, Cairns Hospital, 165 The Esplanade, Cairns, Qld 4870, Australia. E-mail: [email protected] Conflict of interest: None. Financial disclosures: None.
times, differences in patency may reflect other aspects of procedural technique that were not measured. Given that patients were not randomized, additional information on the characteristics of treated lesions would be informative. In the 60-second inflation group, was there more elastic recoil, longer lesions, or recurrent stenosis within a certain time period? If lesions less amenable to angioplasty were subjected to longer balloon inflation time, it may be a reflection of lesion characteristics rather than the intervention. We recently found that severity of pre-angioplasty stenosis was associated with shorter patency after angioplasty.3 Additional details on mean degree of stenosis prior to angioplasty, how lesion measurements were made, validated and defined would also provide meaningful information. Identifying optimal angioplasty technique will assist in the rational testing and use of new endovascular devices, such as drug eluting balloons,6 cutting balloons7 and covered stents,8 to treat dialysis access stenosis. Given the limitations of the current study, the findings of Elramah et al. should be further investigated in a prospective setting. Brendon L. NEUEN, Frank GRAINER, Murty L. MANTHA Department of Renal Medicine, Cairns Hospital 165 The Esplanade Cairns 4870 Queensland, Australia E-mail: [email protected]
Manuscript received July 2014.
© 2014 International Society for Hemodialysis DOI:10.1111/hdi.12208
847
Hemodialysis International 2014; 18:846–850
REFERENCES 1 Elramah M, Boujelbane L, Yevzlin AS, Wakeen M, Astor BC, Chan MR. Dialysis access venous stenosis: Treatment with balloon angioplasty 30-second vs. 1-minute inflation times. Hemodial Int. 2014; doi: 10.1111/hdi.12183; in press. 2 Neuen BL, Gunnarsson R, Webster AC, Baer RA, Golledge J, Mantha ML. Predictors of patency after balloon angioplasty in hemodialysis fistulas: A systematic review. J Vasc Interv Radiol. 2014; 25:917–924. 3 Neuen BL, Gunnarsson R, Baer RA, et al. Factors associated with patency following angioplasty of hemodialysis fistulae. J Vasc Interv Radiol. 2014; doi: 10.1016/ j.jvir.2014.05.020; in press. 4 Rajan DK, Bunston S, Misra S, Pinto R, Lok CE. Dysfunctional autogenous hemodialysis fistulas: Outcomes after angioplasty—Are there clinical predictors of patency? Radiology. 2004; 232:508–515.
5 Turmel-Rodrigues L, Pengloan J, Baudin S, et al. Treatment of stenosis and thrombosis in haemodialysis fistulas and grafts by interventional radiology. Nephrol Dial Transplant. 2000; 15:2029–2036. 6 Katsanos K, Karnabatidis D, Kitrou P, Spiliopoulos S, Christeas N, Siablis D. Paclitaxel-coated balloon angioplasty vs. plain balloon dilation for the treatment of failing dialysis access: 6-month interim results from a prospective randomized controlled trial. J Endovasc Ther. 2012; 19:263–272. 7 Saleh HM, Gabr AK, Tawfik MM, Abouellail H. Prospective, randomized study of cutting balloon angioplasty versus conventional balloon angioplasty for the treatment of hemodialysis access stenoses. J Vasc Surg. 2014; doi: 10.1016/j.jvs.2014.04.002; in press. 8 Haskal ZJ, Trerotola S, Dolmatch B, et al. Stent graft versus balloon angioplasty for failing dialysis-access grafts. N Engl J Med. 2010; 362:494–503.
Intracerebral hemorrhage was the highest cause of mortality among stroke subtypes in Japanese dialysis patients
To the Editor: We were greatly interested to read the article entitled “Association of blood pressure with all-cause mortality and stroke in Japanese hemodialysis patients: The Japan dialysis outcomes and practice pattern study” by Inaba et al.1 Using data from the Japan Dialysis Outcomes and Practice Patterns Study (J-DOPPS), the authors revealed that both systolic and diastolic blood pressures were positively and monotonically associated with stroke-related death, suggesting that, as shown in the general population, hypertension is a definite risk factor for strokeCorrespondence to: M. Wakasugi, MD, MPH, PhD, Center for Inter-organ Communication Research, Niigata University Graduate School of Medical and Dental Sciences, Asahimachi 1-757, Chuo-ku, Niigata 951-8510, Japan. Email: [email protected] Conflict of interest: None declared.
related death in hemodialysis patients. However, the DOPPS questionnaire did not distinguish between ischemic and hemorrhagic stroke. We would like to suggest that many of the stroke-related deaths are likely due to intracerebral hemorrhage. Because of the efforts of the DOPPS to obtain a representative, random sample of facilities and patients within each country, the results would likely represent those from our nationwide survey. Using data from the Japanese Society for Dialysis Therapy registry and a national Vital Statistics survey, we reported that the stroke mortality rate in Japanese dialysis patients is approximately three times higher than that in the general population.2 Using the same data, we found and reported that intracerebral hemorrhage had the highest mortality rate in Japanese dialysis patients among three stroke subtypes (i.e., intracerebral hemorrhage, cerebral infarction, and subarachnoid hemorrhage).3 This is inconsistent with results from the general Japanese population in which cerebral infarction had the highest mortality
© 2014 International Society for Hemodialysis DOI:10.1111/hdi.12212
848
