Pregnancy after kidney transplantation: two transplantation centers--Vicenza-Udine experience.

BACKGROUND: Pregnancy after kidney transplant has become possible thanks to the recent surgical and pharmacological breakthrough. MATERIALS AND METHODS: We performed a retrospective study including all childbearing women transplanted in our centers after 1997. The following variables were analyzed: type of nephropathy, patient age when dialysis started, age at transplantation, time between dialysis and transplantation and between transplantation and baby birth. We also considered immunosuppressive therapy, type of delivery, baby weight, Apgar score, and mother and baby follow-up. RESULTS: We followed up 13 pregnancies in 12 patients who were diagnosed with chronic pyelonephritis (n = 4), postpartum cortical necrosis (n = 1), immunoglobulin A GN (n = 4), diabetic nephropathy (n = 1), unknown nephropathy (n = 2). All patients received a cadaveric donor kidney. They were treated with calcium antagonists and alfamethyldopa for their high blood pressure. We observed 9 mother complications: nonnephrotic proteinuria (n = 1), urinary tract Infection (n = 1), pre-eclampsia (n = 4), internal placenta detachment (n = 1) and spontaneous abortions (n = 2); 4 fetal complications: IUGR (n = 2), acute distress respiratory syndrome (n = 1), Klinefelter syndrome (n = 1) and preterm births (n = 4). In 2 cases the child weight was lower when compared to the gestational age, and 5 babies were admitted to the neonatal intensive care unit. The mother's follow-up showed no acute rejection episodes. Breastfeeding was discouraged due to the transmission of immunosuppressive medications into breast milk. We did not observe significant disease upon child follow-up. CONCLUSION: Our data were in agreement with the literature confirming that pregnancy after kidney transplant though possible carries elevated risks. Patients therefore are referred to highly specialized centers where obstetricians, nephrologists, intensivists, and neonatologists provide surveillance and treatment.

The ''Ronco'' catheter for continuous flow peritoneal dialysis.

To perform CFPD, a two way access must be available in order to allow continuous inflow and outflow of the solution. This is most likely achieved with a double lumen peritoneal catheter. To design a double lumen catheter does not necessarily mean to increase the size of the tube or to increase the discomfort of the patient. However, the real challenge is to find a design in which minimal re-circulation is experienced. The two tips of the catheter must be positioned such that a maximal exposure of the peritoneal surface to the fluid is guaranteed during one single passage of the fluid from one lumen to another. Double lumen catheters with one short branch and another long of straight and of spiral shape were originally designed. Ash and coworkers have designed a catheter with a t-shape configuration in order to distantiate to the maximum the tips of the two lumens. Recently we have designed a novel catheter for CFPD equipped with a thin walled silicone diffuser used to gently diffuse the inflow dialysate into the peritoneum. The holes on the round tapered diffuser are positioned to allow dialysate to perpendicularly exit 360 degrees from the diffuser. The diffuser design and hole locations disperse the high-flow dialysate fluid at 360 degrees, reducing trauma to the peritoneal walls and allowing the dialysate to mix into the peritoneum. The dispersed fluid infused into the peritoneal cavity is then drained through the second lumen whose tip is placed into the lower Douglas cavity. The new catheter with diffuser is also equipped with a special removable hub that allows for easy creation of the subcutaneous tunnel without increasing the size of the skin exit site. The results so far achieved seems to offer advantages in terms of high flows, minimal pressure regimes and negligible recirculation.

The Vicenza ''Short'' peritoneal catheter: a twenty year experience.

Dislocation of peritoneal dialysis catheters is one of the major causes of technique failure. We evaluated 701 Vicenza catheters, implanted since 1985 in 365 males, mean age 53 +/- 16 yrs, range 24 - 87, and 336 females, mean age 51 +/- 17 yrs, range 21 - 82. The Vicenza catheter is defined "short" since it consists of a classic straight double cuff PD catheter having however an inner segment (the portion located in the peritoneal cavity) much shorter than any other type of catheter. It is implanted in the lower abdomen, just a few centimeters above the pubis. The analysis of our results obtained in a large PD population displayed good device survival at 2 and 5 years (94.3% and 91.5% respectively), a low dislocation rate (4%) and an exit-site infection rate similar to other double cuffed catheters. There was no selection of patients receiving this catheter since from 1985 we have used this catheter in every incident patient. Due to its lower implantation site this catheter demonstrates excellent wearability and good body image acceptance.

[Pregnancy after kidney transplantation. Case load of the Transplantation Center of Vicenza]. / Gravidanza dopo trapianto di rene: casistica del Centro Trapianti dell'Azienda Ospedaliera di Vicenza.

BACKGROUND: Pregnancy after kidney transplant has become possible thanks to recent surgical and pharmacological breakthroughs. MATERIALS AND METHODS: We performed a retrospective study including all pregnant women transplanted in our center after 1997. The following variables were analyzed. The type of nephropathy, patient age when dialysis began, patient age at trans-plantation, the time between dialysis and transplantation and the time between transplantation and childbirth. Immunosuppressive therapy, type of delivery, baby's weight and Apgar score were also considered. RESULTS: We followed four pregnancies in three patients who were, respectively, diagnosed with chronic pyelonephritis, post-partum cortical necrosis and immunoglobulin A (IgA) glomerulonephritis (GN). We observed complications in three cases and two pre-term births. In one case, the baby's weight at birth was lower when compared to the gestation age. We did not observe any significant disease in the baby's follow-up. CONCLUSIONS: We concluded that our data were in agreement with those in the literature confirming that pregnancy after kidney transplant, although possible, carries an elevated risk; and therefore, patients have to be referred to highly specialized centers.

Persistent secondary hyperparathyroidism after renal transplantation.

BACKGROUND: The persistence of secondary hyperparathyroidism after renal transplantation is frequent and often complicated by overt hypercalcemia. Recent investigations have shown an effect of the different vitamin D receptor (VDR) genotypes on parathyroid hormone (PTH) secretion in both primary and secondary hyperparathyroidism. The aims of this study were (i) to assess whether persistent secondary hyperparathyroidism after renal transplantation is characterized by any change in calcium-controlled PTH secretion, and (ii) whether different VDR allelic distributions might play any role on this setting. METHODS: Eighty-one cadaveric renal transplantation recipients, followed-up for at least 12 months, were checked for PTH, other primary metabolic and clinical variables, and VDR B/b alleles (BsmI). In 22 of these the following parameters were evaluated: (a) kinetics parameters of the Ca-PTH relation curve; (b) vertebral mineral density; (c) calcitriol serum levels; (d) PTH-related peptide serum levels; and (e) urinary hydroxyproline. RESULTS: According to the stabilised PTH levels (reached by the third month), the patients were divided in two groups: group A (N = 40, PTH < 80 pg/ml) and group B (N = 41, PTH > 80 pg/ml). Group B differed from group A in that patients had higher PTH levels at the time of transplantation, were older in age, and spent more time on dialysis. Group B had increased maximal and minimal PTH levels, and higher set-point levels than Group A. The patients with the BB pattern of VDR genotype were characterized by the lowest PTH levels both at time of transplantation and after stabilization, and lower set point values than patients with Bb and bb patterns. CONCLUSIONS: Our study suggests that (i) the severity of pre-existing secondary hyperparathyroidism is the main factor determining its persistence after renal transplantation, (ii) persistent secondary hyperparathyroidism is characterized by an autonomous pattern of PTH secretion, (iii) the VDR BB genotype seems to be related to lower PTH levels.

In vivo and in vitro neurotoxic action of plasma ultrafiltrate from uraemic patients.

BACKGROUND: In order to investigate the aetiology of uraemic neuropathy, we evaluated the neurotoxic activity of plasma from uraemic patients. To this end we prepared a concentrate (1:1000) of 2-60 kDa MW compounds from paired filtration dialysis ultrafiltrate and evaluated its activity on peripheral nerve conduction in vivo and in vitro. METHODS: The in vivo neurotoxicity was tested on rat sciatic nerve by intraneural injection of the uraemic concentrate, followed, 1 to 6 days later, by electrophysiological assessment of motor response and maximum conduction velocity. In vitro experiments were performed on isolated frog sciatic nerve in the presence of uraemic concentrate, and the neurotoxicity was evaluated from the rate of the decrease in the amplitude of the evoked maximal action potential. RESULTS: In the in vivo experiments, the sciatic nerves injected with the uraemic concentrate showed a decrease in maximum conduction velocity and a progressive impairment in evoked motor response. In the in vitro experiments uraemic concentrate induced a dose-dependent neurotoxic effect. CONCLUSIONS: Our study demonstrates the presence in plasma of uraemic patients of a compound of 2-60 kDa MW with neurotoxic activity.

Fetal activity acceleration determination for the evaluation of fetal reserve.

Fetal activity acceleration determination (FAD) was performed 462 times on a total of 410 patients for the evaluation of fetal reserve. Simultaneous oxytocin challenge test (OCT) was performed 324 times to evaluate the correlation between the two tests. In 308 instances, FAD was positive and OCT was either negative or probably negative. In 2 cases with inadequate FAD results the simultaneous OCT was suspicious and positive. In four instances of negative FAD the simultaneous OCT was positive. The correlation between the two tests was excellent. The outcome of all cases with positive FAD was also excellent. The result of the present study strongly suggests that the positive FAD indeed provides reassurance of fetal well-being. Only the inadequate or negative FAD requires the performance of an OCT for further evaluation of the fetal condition.

A study of fetal heart rate acceleration patterns.

Fetal heart rate (FHR) accelerations have never been fully investigated. These accelerations are responses of the healthy fetus to various stimuli and stresses. Observations and proper evaluation of FHR acceleration patterns will give reassurance of fetal well-being. The fetal activity acceleration acceleration determination (FAD) is a method of antepartum evaluation of fetal well-being. The FAD can be used where the oxytocin challenge test is contraindicated. The physiologic bases of FHR accelerations are discussed. An attempt has been made to classify the FHR acceleration patterns.