Acquired multicystic transformation of kidneys

Acquired multicystic renal transformation of diseased kidneys is a problem known since the early 19th century which has recently regained interest. Such cysts were known before dialysis was established, are seen prior to hemodialysis and in patients on peritoneal dialysis, and can therefore not be a consequence of hemodialysis. It is concluded that an increased incidence of renal cell carcinoma in such kidneys is not established, although, theoretically, several mechanisms might promote carcinogenesis in end-stage kidneys.

[Extrarenal dialysis in end-stage renal disease]

Renal replacement therapy (RRT) has reached its plain maturity. RRT is an unavoidable and banal tool in the armamentorium in the treatment of end stage renal failure (ESRD). It relies on several practical modalities (hemodialysis, peritoneal dialysis and their variants) that permit to satisfy various patient's needs and to ensure the continuity of life support system. Substitution of certain renal endocrine functions (human recombinant erythropoietin, active vitamin D) has brought a new dimension to the treatment of ESRD in improving substantially the quality of life of these patients. Now, if the long-term outcomes confirm the high efficiency of the renal replacement therapies they also draw their limits bounded by the occurrence of a specific pathology of the "long term dialysis" patient. Such dialysis-related pathology is clearly the new challenge for the nephrologist in the XXIst century that should lead to a deep revision of the RRT concept. Optimal treatment of ESRD patients rely clearly on several options that may be used sequentially to solve specific complications and should be part of a complete management program including renal transplantation in patient non contraindicated.

Daily subcutaneous administration of recombinant human erythropoietin (rhEPO) in peritoneal dialysis patients: a European dose-response study

In a prospective randomized open multicenter study, 107 anemic (Hct < = 28%) peritoneal dialysis (PD) patients were treated with s.c. rhEPO daily. The mean observation period was 299 days (range 14-479 days). Patients were randomly assigned to 3 groups with different initial doses: 5 U/kg (G5), 10 U/kg (G10), 20 U/kg (G20). Initial doses were maintained for at least 8 weeks unless the target Hct (30-35%) was achieved earlier. The weekly increase of Hct was significantly (p < 0.05) dose-dependent: 0.19% in G5, 0.5% in G10 and 0.94% in G20. In case of insufficient response (< 0.5% per week), the dose was doubled every 4 weeks. Final doses on achieving the target Hct ranged from 5 to 40 U/kg (median 20 U/kg). The dose was then reduced to 50% and adjusted individually. The median maintenance dose was 9.9 U/kg/day. No tendency towards higher blood pressure or intensification of antihypertensive treatment was observed. When rhEPO is administered daily, 10 U/kg/day (70 U/kg weekly) is the recommended starting dose. The need for higher doses used in unsatisfactory response, should lead to further examination to rule out iron deficiency and other reasons for non-response. The median maintenance dose reported here is the lowest published in the literature for PD patients and seems to be linked to the daily injections.

Staphylococcus aureus nasal carriage and infection in patients on continuous ambulatory peritoneal dialysis

We studied 140 consecutive patients beginning continuous ambulatory peritoneal dialysis (CAPD) at one of seven hospitals to assess the relation of the nasal carriage of Staphylococcus aureus to subsequent catheter-exit-site infection or peritonitis. Shortly before the implantation of the catheters, the patients' anterior nares were cultured for the presence of S. aureus. Antibiotics were not prescribed for the S. aureus carriers, but all the patients were monitored for signs of catheter infection (median follow-up, 10.4 months). At the initiation of CAPD, 63 patients (45 percent) carried S. aureus in the nares. Nasal carriage was more frequent among the 30 patients with diabetes (77 percent) than among the 110 without the disease (36 percent). The carriers of S. aureus had a significantly higher rate of exit-site infection than the noncarriers (0.40 vs. 0.10 episode per year; P = 0.012). Of these episodes, 24 of 34 were caused by S. aureus. The rates of peritonitis of all bacterial types did not differ significantly between the groups, but all 11 episodes of peritonitis caused by S. aureus occurred among the carriers. In 85 percent of the patients with clinical S. aureus infections, the strain from the nares and the strain causing the infection were similar in phage type and antibiotic profile. We conclude that in patients beginning ambulatory peritoneal dialysis, the nasal carriage of S. aureus is associated with an increased risk of catheter-exit-site infection and that the performance of nasal cultures before the implantation of the catheter can identify patients at high risk of subsequent morbidity.

Experience with long-term peritoneal insulin infusion from external pumps

The long-term acceptability and feasibility of continuous peritoneal insulin infusion (CPII) from external pumps was evaluated in 40 insulin-dependent diabetic patients continuously treated for 1-27 months (mean 12 months). Blood glucose control was satisfactory and did not deteriorate with time (glycosylated haemoglobin 8.1 +/- 1.1%, mean +/- S.D., normal range 5.5-7.5%). Major problems included 1 episode of local peritonitis, 12 hypoglycaemic comas, 7 severe hyperglycaemic episodes, all cured without sequelae. Minor problems were frequent, mostly pump and catheter-related. Pump and catheter survival rates were 46% and 70% at one year, respectively. No peritoneal reaction was noted apart from occasional tissue growth around the catheter. This method of insulin treatment was judged satisfactory and acceptable by most of the subjects. Only one patient dropped out, after 1.5 years. These results were achieved through stringent selection of patients, intensive education with strict instructions, careful medical care, and possibly through the inherent physiological advantages of intraperitoneal insulin infusion.

Continuous peritoneal insulin infusion with portable pumps: factors affecting the operating life of the chronic catheter

Fifty-nine chronic peritoneal catheters made of polyethylene covered with silastic were used to treat 43 IDDM patients peritoneally for 3-34 mo (mean 14 mo) with portable peristaltic pumps and U40 acidic insulin. The operative life of the catheters was determined by actuarial analysis. The mechanisms of catheter failure were determined by preremoval x-ray opacification, removal under laparoscopic examination, and electron microscopic analysis of the catheter. Factors such as age, sex, duration of diabetes, implantation and tunnelization procedures, length of the catheter, and rate of infusion were analyzed. The 50% survival rate of the catheters was 16 mo. Six catheters were irreversibly obstructed by intraluminal fibrin formation and/or extraluminal adhesions, although insulin precipitation was never encountered. Seven catheters had to be removed because of a persisting local infection. Other causes were negligible (misinsertion, irreparable break). The only factor significantly related to incidence of catheter failure was gender with respect to obstruction (1 obstruction among 24 women versus 5 among 19 men, P less than 0.03).

Optimal routes for chronic insulin infusion with portable and implantable devices

The optimal route for chronic insulin infusion via portable or implantable pumps is still a subject of controversy. Through the literature reports and personal experience (representing 70 patient-years of continuous treatment), the authors have found that the subcutaneous route is the ideal route in terms of comfort, safety, and cost. However, owing to sluggish and unpredictable insulin resorption, it appears that subcutaneous infusion is often not more effective than intensive conventional insulin therapy. The intravenous route gives the best diabetic control, but with a high risk of infection and obstruction. The intramuscular route, although more efficient than the subcutaneous, can be envisaged for only short periods because of its poor tolerance. The portal route is still at an experimental stage. The authors chose the intraperitoneal route because of the following advantages: near physiological insulin resorption kinetics; better diabetes control than subcutaneous infusion although comparable to intravenous; a 30% reduction of insulin requirements; and satisfactory local tolerance and acceptability with respect to severe asepsy precautions, patient selection, intensive education, and careful medical follow-up. The intraperitoneal route is feasible for portable insulin pumps, but basically more adaptable to implantable devices.

Long-term ambulatory peritoneal insulin infusion of brittle diabetes with portable pumps: comparison with intravenous and subcutaneous routes

This work compares different routes of insulin infusion via portable pumps with chronically implanted catheters and evaluates the long-term feasibility of the technique. Six severely unstable (i.e., uncontrolled by optimized intensive insulin therapy) diabetic individuals (age range: 35 +/- 4 yr; duration: 11 +/- 2 yr) were selected. Promedos pumps (Siemens A. G., Erlangen, West Germany) were exclusively used because of their portability and long-life insulin reservoir (1-mo duration with U40 acidic Hoechst insulin). Each patient underwent three randomized 1-mo periods of insulin infusion: subcutaneous (s.c.), intravenous (i.v.), and intraperitoneal (i.p.) before the catheter was left indefinitely in one of these sites. Diabetic control was improved and insulin doses reduced whatever the route of infusion, although the s.c. route gave slightly higher values. These results did not deteriorate with time: mean blood glucose was 126 +/- 3 mg/dl and HbA1 was 8.3 +/- 0.6% after 10-18 mo of constant infusion versus 237 +/- 35 mg/dl and 10.0 +/- 0.8%, respectively, under conventional therapy. From a practical point of view, the i.p. route seems preferable since all s.c. catheters provoked local reactions after less than 1 mo and the two chronic i.v. catheters obstructed after 8 and 9 mo. All other incidents were minor and curable without removal of the catheters. All patients argued improvement of both diabetes and quality of life and no one has resigned so far. Thus, the i.p. infusion technique seems beneficial to unstable diabetic individuals and adaptable to long-term therapy, although intensive education and careful follow-up are necessary.

Permanent loss of ultrafiltration capacity of the peritoneum in long-term peritoneal dialysis: an epidemiological study

Permanent loss of the ultrafiltration (UF) capacity of the peritoneum has been observed with an increasing frequency among our patients treated by long-term intermittent (IPD) and/or continuous ambulatory peritoneal dialysis (CAPD). The analysis of various characteristics of our PD population (patients age, dialysis techniques, peritoneal infection rate and treatment duration) indicates that the incidence of this complication increases exponentially with the duration of PD, the loss of UF capacity being observed after a shorter period in CAPD than in IPD. These observations suggest that long-term irrigation of the peritoneal cavity leads to a progressive deterioration of the peritoneum resulting in its altered permeability with loss of the ability to ultrafiltrate; the cause of this abnormality is as yet unknown.

Clinical experience in human diabetics with portable and implantable insulin minipumps

We report our personal experience of chronic ambulatory insulin therapy via portable and implantable pumps in insulin-dependent diabetics. Fifteen patients, poorly controlled on conventional insulin injections, were equipped with portable Siemens pumps. These pumps offer compactness, safety means, portability, one-month insulin reservoir and variable insulin rates. The pump catheter was chronically inserted in the peritoneal space using a non-surgical personal technique. Our present experience, representing six patient-years of treatment (range 1 to 16 months), shows excellent steady blood glucose control (mean blood glucose is 115 +/- 5 mg/dl v. 187 +/- 21 mg/dl with conventional therapy). All incidents were minor and most were catheter related. However, there was no catheter removal or discontinuation of pump treatment. All patients declared that there was a marked improvement in their quality of life. One of the pump-treated patients agreed to be transferred to a totally implantable Siemens prototype. The pump was inserted in the muscular wall of abdomen, and the delivery catheter terminated in the peritoneal space. Refills are made percutaneously approximately every 20 days. Rates and functions of the pump are remotely controlled. Five months after implantation, results, compared with those of a portable pump, show similar excellent blood glucose control and pump precision with a further improvement in the patient's quality of life. Thus, although further miniaturization and longer autonomy are expected in the forthcoming devices, our present experience shows that, with careful patient instruction and follow up, insulin pumps could represent in the next years an alternative to conventional insulin therapy for poorly controlled diabetics.

Total implantation of a remotely controlled insulin minipump in a human insulin-dependent diabetic

This study reports our first total implantation of an insulin minipump in a severely unstable 23-year-old female insulin-dependent diabetic. The implantable unit includes a stepping motor, a percutaneously refillable insulin reservoir (10 ml, U 100 special insulin), a battery with a life span of one year, and a method for prevention of overdosage. Variable continuous basal and superimposed 1-hour high rates are programmed and checked via an external remote controller. The pump was inserted in the lateral muscles of the abdomen and the insulin delivery catheter terminated in the peritoneal cavity. Excellent glycemic control was reached rapidly and has continued seven months after implantation (mean blood glucose is 123 +/- 62 mg/dl; glycosylated hemoglobin is 7.0 +/- 1.2%), with the unit providing the only source of insulin. The only negative aspects were a chronic lymphorrhea in the first two months, and a need for frequent and laborious insulin refills (every 20 days). Only slight local discomfort was experienced. Thus, although further miniaturization and autonomy are expected, these preliminary results show that with careful instruction and followup, implanted pumps could represent a reliable and safe alternative to conventional insulin therapy for selected diabetics.