Laparoscopic placement of the Tenckhoff catheter for peritoneal dialysis.

Continuous ambulatory peritoneal dialysis catheters can be inserted by open laparotomy as well as by laparoscopy. A prospective randomized study was scheduled to investigate the results of the laparoscopic versus open laparotomy technique for placement of continuous ambulatory peritoneal dialysis catheters. Fifty patients were enrolled and randomly allocated into two groups of 25 patients each. Group A underwent continuous ambulatory peritoneal dialysis catheter placement via the open laparotomy technique. In 22 patients, catheters were inserted via midline incision, and in 3 patients with histories of previous catheterization, a paramedian incision was used. Continuous ambulatory peritoneal dialysis was started 24 to 48 hours later. Group B underwent laparoscopic placement of the catheter with fixation into the pelvis and suture closure of the port wounds. In 21 patients, this catheter placement was the first such placement, and in 4 patients, a previous catheter had been inserted by the open technique and removed for dysfunction. Continuous ambulatory peritoneal dialysis was started at the end of the procedure. The mean operative time was 22 minutes in group A and 29 minutes in group B (P < 0.001). Fluid leakage was observed in eight patients in group A, but in no patients in group B (P < 0.005). Peritonitis occurred in five patients in group A and in three patients in group B (P > 0.1). Tip migration occurred in five patients in group A and no patients in group B (P < 0.005). In group B, two patients underwent a simultaneous cholecystectomy and one underwent incisional hernia repair. Laparoscopic placement of a Tenckhoff catheter leads to better function than does the open procedure; it allows immediate start of dialysis without fluid leakage and permits simultaneous performance of other laparoscopic procedures.

Effect of L-carnitine supplementation on lipid parameters in hemodialysis patients.

It has been reported that cumulative carnitine losses through dialysis membranes may worsen hyperlipidemia during long-term hemodialysis. However, carnitine supplementation has not shown a consistent beneficial response. We undertook the present study to determine if there is any hypolipidemic effect of L-carnitine on Greek dialysis patients in concert with the dialysate buffer composition (acetate or bicarbonate). A total of 28 patients (16 male, 12 female), mean age 43 years (range 21-61), with end-stage renal disease on maintenance hemodialysis for a mean period of 25 months (range 7-84) were studied. The dialysis schedule was 4 h, 3 times/week using cuprophane hollow-fiber dialyzers and acetate (n = 14) or bicarbonate (n = 14) dialysate. In all patients L-carnitine (5 mg/kg body weight) was infused intravenously 3 times/week at the end of each hemodialysis session. Blood samples for carnitine and lipid determinations were obtained before treatment, and 3 and 6 months following treatment. Even though L-carnitine did not modify most of the serum lipid levels, a significant decrease in serum triglycerides was evident in the whole group of patients (from 225 +/- 76 to 201 +/- 75 mg/dl, p = 0.03). Furthermore, L-carnitine could decrease serum triglycerides only in hypertriglyceridemic patients (from 260 +/- 64 to 226 +/- 82 mg/dl, p < 0.05). L-Carnitine resulted in a reduction of serum triglycerides in both patients on bicarbonate and on acetate dialysis, while there were no significant differences in the changes of lipid parameters after L-carnitine between the two groups of hemodialysis patients. We conclude that relatively low doses of L-carnitine supplementation could contribute to the management of some hypertriglyceridemic hemodialysis patients.

Absence of HCV viraemia in anti-HCV-negative haemodialysis patients.

BACKGROUND: Immunologic alterations have been reported in chronic haemodialysis (HD) patients. Some HD patients may have, therefore, an inability to produce detectable amounts of serum antibodies to hepatitis C virus (anti-HCV). Previous studies have shown the presence of HCV viraemia in anti-HCV-negative HD patients (ranging from 1 to 15%). However, the universal epidemiologic impact of these cases remains uncertain since there are conflicting results. In this context, we conducted a study in an attempt to investigate the presence of HCV viraemia among anti-HCV-negative HD patients in a well-defined geographic area of the northwestern part of Greece. METHODS: During a 6 month period, 81 anti-HCV-negative HD patients were tested twice for the presence of HCV RNA, using the reverse transcriptase polymerase chain reaction (RT-PCR) combined with a DNA enzyme immunoassay (DEIA). At the same time, periodic testing for anti-HCV by two commercially available third generation assays was done. In addition, 15 anti-HCV-positive HD patients and 20 non-HD patients with well established chronic HCV infection used as internal controls were tested for the presence of HCV RNA and anti-HCV. RESULTS: None of the anti-HCV-negative HD patients were shown to be viraemic by the combined RT-PCR and DEIA method. During the same time period, all remained anti-HCV negative by the third generation assays. By contrast, all the patients with known HCV-infection were positive by the two enzyme immunoassays, whereas 13 anti-HCV-positive HD patients (86.7%) and 18 non-HD patients (90%) were viraemic by RT-PCR. CONCLUSIONS: This study demonstrated that routine HCV RNA testing in anti-HCV-negative HD patients appears not to be necessary particularly when third generation assays are used for the detection of anti-HCV.

Quantitative computed tomography for spinal bone mineral measurements in chronic renal failure.

The aim of this study was to assess non-invasively the status of spinal trabecular bone in patients with chronic renal failure and the influence of the disease stage. Single energy quantitative computed tomography (CT) was used in 89 patients with chronic renal failure to measure spinal trabecular bone equivalent density. 23 patients were independent of dialysis and 66 were receiving long-term haemodialysis. Spinal trabecular bone density of the patients was compared with locally determined normal ranges. Although trabecular bone mineral density (BMD) was lower (9% on average) in the patients who were not dependent on dialysis compared with the predicted mean normal values (BMDp) for age- and sex-matched normal subjects, the difference was not statistically significant. A statistically significant reduction was found in patients on dialysis (BMD/BMDp 0.75 +/- 0.16, Z-score -1.3). Osteosclerosis was found in 11 patients and they were excluded from the study. Longitudinal measurements in 42 patients on dialysis without osteosclerosis showed a 2.9% mean reduction in BMD/BMDp over a period of 8 months. All but one of the 16 haemodialysis patients with osteopenic spinal fractures had trabecular BMD values lower than the fracture threshold determined by our technique. In conclusion, end-stage chronic renal failure was associated with reduction in the spinal trabecular bone density.

Lipid parameters including lipoprotein (a) in patients undergoing CAPD and hemodialysis.

OBJECTIVE: Dyslipidemia possibly contributes to the vascular complications commonly afflicting uremic patients. Lipoprotein (a) [Lp(a)] has been identified as an independent risk factor for atherosclerotic vascular disease. The aim of our study was to compare lipidparameters, including Lp(a), between hemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD) patients. DESIGN: A cross-sectional study. SETTING: University Medical Center. PARTICIPANTS: Forty CAPD and 40 HD patients carefully matched for age, sex, body mass index (BMI), smoking habits, and duration of dialysis were studied. A group of 40 healthy individuals matched for age, sex, BMI, and smoking habits was used as control. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Serum lipid parameters and atherogenic risk ratios were the main outcome measures. RESULTS: Both groups of dialysis patients had increased serum triglycerides and decreased levels of ApoA1 and HDL cholesterol compared to controls. Moreover, the risk ratios total cholesterol/HDL cholesterol and LDL cholesterol/HDL cholesterol were significantly higher, and the ratio ApoA1/ApoB was significantly lower in both groups of patients in comparison to the normal subjects. Both groups of dialysis patients exhibited decreased ratios of LDL cholesterol/ApoB and HDL cholesterol/ApoA1, suggesting the presence of compositional lipoprotein changes. CAPD patients had a more atherogenic lipid profile compared to HD patients, since they exhibited higher levels of total and LDL cholesterol, of ApoB as well as of the ratios total cholesterol/HDL cholesterol and LDL cholesterol/HDL cholesterol, and lower levels of the ratio ApoA1/ApoB compared to HD patients. Both groups of dialysis patients had increased serum Lp(a) levels. Even though CAPD patients had higher serum Lp(a) levels than HD patients, the differences between these two groups were only marginally statistically significant (p = 0.056 by Mann-Whitney U-test). Uremic dyslipidemia was positively correlated with serum albumin levels in both groups of patients. CONCLUSION: CAPD patients exhibit a more atherogenic lipid profile than that of HD patients. The marked disturbances in Lp(a) levels may further increase the vascular risk in both groups of patients.

Bone mineral status after renal transplantation. Assessment by noninvasive techniques.

RATIONALE AND OBJECTIVES: Bone mineral status in recipients of renal grafts is related to preexisting renal osteodystrophy and immunosuppressive treatment. The authors assessed bone mineral status after renal transplantation. METHODS: Bone mineral status of 20 male graft recipients was evaluated using the following noninvasive techniques: 1) neutron activation analysis, to measure hand bone phosphorus (HBP); 2) single photon absorptiometry, to measure forearm bone mineral content (BMC); and 3) single energy spectrum quantitative computed tomography, to measure spinal trabecular bone equivalent density (TBED). RESULTS: The mean (+/- SD, P) HBP, BMC, and TBED were found to be respectively, 4.8% (+/- 8.3%, P = .02), 6.6% (+/- 14.6%, P = .07) and 52% (+/- 8.5%, P < .001) lower than that measured in matched normal controls. Renal graft recipients demonstrated mean HBP and BMC decrements that were similar to those observed in matched patients on extrarenal dialysis, although the decrement in TBED was significantly greater in the graft recipients (P < .001). Repeated measurements performed during a 3-year period showed no statistically significant changes. CONCLUSIONS: Renal transplantation was associated with minor degree of osteopenia in the primarily cortical bone tissue. We speculate that the remarkably low TBED values in graft recipients does not reflect a mean 52% decrement of spinal bone minerals, but rather may be attributed in part to the deposition of adipose tissue in the spine as a result of corticosteroid treatment.

Effects of isradipine on hypertension and renal hemodynamics.

The safety and efficacy of isradipine as well as its long-term effects on renal hemodynamics were evaluated in a study of 17 patients with mild-to-moderate essential hypertension and normal or slightly impaired renal function. After a 4-week placebo period, isradipine was administered according to a schedule of increasing dosages ranging from 1.25 to 5 mg twice daily. During treatment and at the latest follow-up (at 6 months), isradipine was found to lower blood pressure (diastolic and systolic) significantly. There were no significant side effects or changes in blood chemistry during treatment. Plasma renin activity and serum aldosterone were slightly raised whereas the glomerular filtration rate, renal plasma flow, and filtration fraction were significantly raised at the latest follow-up compared with the pretreatment levels.

Pituitary adrenal responsiveness to corticotropin-releasing hormone in chronic uremic patients.

We investigated the effect of exogenous ovine corticotropin-releasing hormone (oCRH) on plasma levels of adrenocorticotropic hormone (ACTH) and cortisol in 24 chronic renal failure patients: 8 nondialysis (NDCRF), 8 on hemodialysis (HD), and 8 on continuous ambulatory peritoneal dialysis (CAPD). In all groups the acute administration of oCRH caused a further increase (less pronounced in NDCRF patients) in the already elevated levels of cortisol. Following oCRH administration, plasma ACTH rose significantly in CAPD patients, but there was a blunted response of the hormone in the NDCRF and HD groups. The patterns of the ACTH and cortisol response in the last two groups, resemble those observed in chronic stress. We conclude that the hypothalamic-pituitary-adrenal axis in chronic uremic patients, retains the ability to respond to exogenous oCRH. Patients on CAPD, however, display a better, identical to normal response, which can be due to less chronic stress and/or to the more effective clearance of uremic toxins.

Ovine corticotropin-releasing hormone stimulation test in patients with chronic renal failure: pharmacokinetic properties, and plasma adrenocorticotropic hormone and serum cortisol responses.

The data on the status of the hypothalamic-pituitary-adrenal (HPA) axis in haemodialysis (HD) patients are conflicting. Moreover, a state reminiscent of Cushing's syndrome has been reported in this group of patients. Corticotropin-releasing hormone (CRH), that is produced by the hypothalamus and modulates the secretion of adrenocorticotropic hormone (ACTH), has been shown to be useful as a provocative test of the HPA axis. We investigated the effect of exogenous ovine CRH (oCRH) on plasma levels of ACTH and cortisol in 13 chronic HD patients. The plasma concentrations of immunoreactive CRH following oCRH administration were similar in patients and controls. In all patients, oCRH given intravenously as bolus injection caused a further increase in the already elevated levels of cortisol. The mean basal plasma levels of ACTH were within the normal range. There was, however, a blunted ACTH response to oCRH. We conclude that the HPA axis in chronic HD patients retains the ability to respond to exogenous oCRH. The patterns of the ACTH and cortisol response to this peptide resemble those observed in chronic stress (depression, anorexia nervosa). Besides, the kinetics of disappearance of oCRH indicate that the kidney may not be the major organ that metabolizes oCRH.