Hemodialysis membranes act to remove accumulated uremic toxins, excess ions and water from the patient via the dialysate, and to supply from the dialysate those ions that are insufficient. In evaluating dialysis membranes, the most important factors are diffusive and hydraulic permeability. It is primarily through diffusion, resulting from the difference in concentration between the blood and the dialysate, that the toxins and ions pass through the dialysis membrane. Thus if diffusive and hydraulic permeability can be measured, it becomes possible to evaluate dialysis membranes.
Basically, the diffusive permeability can be found from data on differences in concentration and on the solute flux obtained when filtration flux is set to zero. Techniques for the measurement of the diffusive and hydraulic permeability of flat dialysis membranes are already well established and measurement is comparatively simple, but this is not the case for hollow-fiber dialysis membranes.
To find the hydraulic permeability of a dialysis membrane, the filtrate volume obtained at a certain trnsmembrane pressure is measured over a given period of time. If a dialyzer is used, the (static) pressure of the fluid along the length of the flow channel changes, so that it is technically difficult to determine transmembrane pressure accurately while the blood and dialyste are flowing. Thus in measuring the filtration coefficient available method include the dead-end or complete filtration method.
This paper describes dialysis membrane and dialyzer for blood purification, solute transport mechanism of membrane and technical evaluation of dialysis membrane. The next generation of artificial kidney is lastly viewed.

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Polymorphism in the gene for angiotensin converting enzyme (ACE), especially the D/D type, is associated with a risk of cardiovascular disease and progressive deterioration of renal function in previous reports. In this paper, ACE polymorphism was investigated in 120 patients on maintenance hemodialysis (HD) in comparison with normal controls. Uninterruptedly, the association of these polymorphisms with serological parameters in the hemodialytic period (less than 10 years/more than 10 years) were examined. In conclusion, D/D type in ACE polymorphism was significantly (p<0.001) higher in HD patients than in normal control (n=100), but the D/D type was not significantly higher in the longer HD periods. Patients receiving HD for more than 10 years were characterized as the high Kt/V and low I/I type. In conclusion, patients with D/D type in ACE polymorphism were introduced to hemodialysis relatively early, although this type was not associated with HD-period. The I/I type was strongly associated with the levels of Kt/V. Association of genetic factors and laboratory data in patients on maintenance HD were confirmed in this study.

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Atherosclerotic diseases are major influence on the mortality and morbidity in patients with chronic renal failure on maintenance dialysis. Epidemiologically, dietary fat intake has been demonstrated to be one of the main factors influencing the development of atherosclerosis. This study investigated whether the level of dietary fat intake was suitable for preventing atherosclerotic diseases in maintenance dialysis patients. Total amount of dietary fat intake, dietary intake of individual fatty acids and serum individual fatty acids concentrations were measured in 12 hemodialysis (HD) and 10 continuous ambulatory peritoneal dialysis (CAPD) patients.
The percentage of fat intake to total energy intake was 27.7±7.0% in HD patients and 26.6±7.3% in CAPD patients, and which were both more than the nationally recommended criteria for the general population. The ratio of the intake of saturated fatty acids, monounsaturated fatty acids and ployunsaturated fatty acids was 1.1:1.5:1.0 in HD patients and 1.2:1.5:1.0 in CAPD patients. Intake of polysaturated fatty acids was above the nationally recommended criteria for both patient groups. The ratio of n-6 to n-3 polysaturated fatty acids intake was 5.8:1 in HD patients and 3.4:1 in CAPD patients. There was a significant correlation between dietary intake and serum concentration in the ratio of n-6 to n-3 polysaturated fatty acids.
These data show that to prevent atherosclerotic diseases in maintenance dialysis patients, the percentage of fat intake to total energy intake should be lowered by encouraging the consumption of less saturated fatty acids, and n-6 polysaturated fatty acids intake should be decreased, while n-3 polysaturated fatty acids intake should be increased.

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The incidence of asymptomtic cerebrovascular lesions was examined in hemodialysis (HD) patients using magnetic resonance imaging. Lacunae (high intensity foci within 1cm on T2-weighted images) and PVH (periventricular hyperintensity on T2-weighted images) were evaluated in 37 HD patients with HD duration less than 1 year (group A), 33 patients on maintence HD for more than years (group B) and 82 control subjects. Lacunae were found in 56% of group A and in 73% of group B, and PVH were found in 44% and 39%, respectively. The incidences of both lacunae and PVH were more frequent in HD patients than in control subjects. The numbers of lacunae and the severity of PVH increased with age. Lacunae were more frequently observed among diabetics in group A and hypertensives in group B. Asymptomatic cerebrovascular lesions were more frequently found in HD patients than in normal controls, suggesting that chronic uremia, aging, hypertension and diabetes might be contributing factors.

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Between January 1996 and arch 1997, 49 HDS^® grafts were implanted in 47 patients (male/female; 25/24, average age of 59 years old) who were diagnosed that autologous fistula construction was impossible to create.
The causes of renal failure were diabetes mellitus in 21 and chronic lomeruloephritis in 11. The mean duration of hemodialysis at the time of implantation was 3.7 years, and the mean number of previous vascular access procedures was 2.4. Forty-two grafts were implanted in the proximal upper arm, 3 in the forearm, 3 in the distal upper arm, and 1 between the brachial artery and the axillry vein. The mean interval between surgery and the first use was 8.5 days and 39 of 43 grafts (90%) were cannulated within 14 days. The hemostasis after cessation of cannulation was able to be done within 15 minutes in all cases. Thirteen complications occurred in 12 grafts. Thrombosis was the most common complication (9), and 4 thrombosed grafts were salvaged. Other complications included infection (2), seroma (1), raft exposure (1).
Five patients died during the course of the study, but none of the deaths were related to the graft. The overall primary, i. e., without any treatments, and secondary, i. e., necessary for treatments patency rates were 85%, 87% at 6 months, and 77%, 83% at 12 months, respectively. The patency rate of HDS^® graft is superior to that of conventional ePTFE graft.
We conclude that the HDS^® graft is well to tolerable for an earlier use after creation and the long-term patency rate is superior to that with conventional ePTFE graft.

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Using an ultrasound duplex system composed of doppler flowmeter and B-mode colour scanner, we evaluated arteriovenous fistula dysfunctions, such as impaired shunt flow or high venous pressure, in 14 patients requiring chronic hemodialysis. Insufficient venous dilatation and venous thrombosis were demonstrated as the etiologies of arteriovenous fistula dysfunction. Dissection of the venous wall, venous valve and deep accessory vein were also clearly recognized on colour doppler imaging. The percent of stenosis in arteriovenous fistulas could be calculated by measuring the areas or flow rates in the stenotic portion compared to that distal or proximal to the stenotic sites.
It was concluded that the ultrasound duplex system was useful for diagnosing arteriovenous fistula dysfunction because it can demonstrate a three-dimensional view showing the intravascular structure and deep accessory vein and can calculate the percent area stenosis.

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We report hemodialysis patient treated by arterial administration of SMANCS. A 71-year-old male was referred to our hospital for dialysis therapy. A mosaic-patterned mass with halo (5cm in diameter) was discovered on screening ultrasonography. CT scan of the abdomen revealed tumor in the S8 segment of the liver. Hepatic functions were well preserved. After obtaining informed consent, the first arterial administration of SMANCS (4mg) with lipiodol was performed in July 1996. The second arterial administration of SMANCS (6mg) with lipiodol was performed along with emboliztion in April 1997. There were no serious complications, while undergoing hemodiafiltrtion or hemodialysis three times per week. It was suggested that arterial administration therapy with SMANCS can be performed safely in patient undergoing chronic hemodialysis.

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A 59-year-old female patient underwent total gastrectomy for early gastric cancer. On the 11th postoperative day, renal function rapidly declined and the patient demonstrated oliuria and hyperkalemia. The serum creatinine level was elevated to 8mg/dl, then hemodialysis was initiated. Urinary Bence-Jones protein and monoclonal IgA were detected by immunoelectrophoreis. On the 88th postoperative day, renal biopsy was performed, and the specimen showed eosinophilic casts in the renal tubules. Thus, a diagnosis of multiple myeloma and associated acute renal failure was made. Urinary volume gradually increased after an oliguric phase lasting for one month. However, her general condition deteriorated because of infection and the patient died.
In this case, the preoperative urine and blood examination did not show any abnormalities suggestive of multiple myeloma. However, the patient developed acute renal failure postoertively. We conclude that postoperative pyrexia and dehydration contributed to the rise of urinary Bence-Jones protein, which led to the development of acute renal failure.

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Sclerosing encapsulating peritonitis (SEP) is one of the most serious complications of CAPD. To revise the definition, diagnosis and therapeutic strategy for sclerosing encapsulating peritonitis (SEP) in patients on CAPD proposed over the last 3 years, a consensus meeting on SEP was held on November 29, 1997 in Tokyo. We confirmed that SEP is defined as clinical entity demonstrating persistent, intermittent and/or recurrent clinical symptoms due to adhesive bowel obstruction in patients receiving peritoneal dialysis. This year, we made minor changes concerning the recommended treatment of SEP. The basic strategy for the treating SEP is sustained bowel rest. Long-term total parental nutrition (TPN) therapy is effective for treating SEP patients. It was reported that steroid pulse therapy was effective in 6 of 8 and corticosteroid administration was effective in 15 of 23 patients treated at 26 hospitals, although there were some reports of fatal outcomes. This therapeutic intervention as well as an immunosuppressive regimen should be evaluated in a large patient population.
We also proposed criteria for discontinuing CAPD to prevent the development of SEP in adult and pediatric patients. However, SEP showed heterogeneity among individual patients. Therefore, we proposed only a basic strategy for treating SEP in this revised version. Further study is needed in this area.

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