[Pediatric nephrology in developing countries]

Pediatric nephrology is not a priority medicine in developing countries, but it should improve along with the development of both preventive and curative simple measures since the mortality rate is still important. This can be applied to the management of urinary tract infection, acute nephritis and some other cases of acute renal failure. The identification and management of chronic kidney diseases is mainly based on blood pressure measurement, proteinuria screening and plasma creatinine assessment. However renal replacement therapy (i.e., dialysis and transplantation) is highly expensive and its access is therefore limited to selected growing countries. The improvement in the care of renal children therefore requires better medical knowledge, nurse training and population information.

Skeletal features of primary hyperoxaluria type 1, revisited

PURPOSE

The purpose of this study was to describe the skeletal manifestations of primary hyperoxaluria type 1 (PH1), the most common of the primary hyperoxalurias.

METHODS

We clinically and radiographically reviewed 12 consecutive patients diagnosed with PH1, aged between 2 and 17 years. All patients had evidence of some type of renal involvement, 4 of whom were at end-stage renal disease (ESRD) and were under dialysis.

RESULTS

The main symptom was skeletal pain and was present only in the 4 severely involved patients and appeared during the second year of dialysis. The 2 most severely involved patients had evidence of pathological fractures. Radiological signs were present in patients with or without symptoms. These radiological signs were of two distinct types: those almost specific of oxalosis, such as dense and radiolucent metaphyseal bands and vertebral osteocondensations, which are found mainly in the severely involved individuals, and those less specific, such as signs of renal osteodystrophy, which are also found in less severely involved patients. Interestingly, our study revealed the presence of spondylolysis in 25% of cases. This latter finding is unique and has not previously been reported in the literature.

CONCLUSIONS

The skeletal manifestations of PH1 include specific and less specific radiological signs, with some patients being asymptomatic, and others presenting with bone pain and pathological fractures, as well as spondylolysis.

An unusual case of bilateral primitive obstructed megaureters due to ureteral valves presenting with anuria at the age of 1 month

Ureteric valves represent a very rare etiology of ureteral obstruction. We experienced an unusual case of bilateral distal ureteric valves that presented as bilateral primitive obstructed megaureters with anuria at the age of 40 days. To our knowledge, this is the second case of bilateral involvement of distal ureteric valves reported in the literature. Bilateral ureteral valves should be included in the differential diagnosis of bladder outlet obstruction, as well as bilateral primitive obstructed megaureters in children. Excision and ureteral reimplantation is curative.

[Microcatheterization with gadolinium and glue embolization for post-biopsy arteriovenous fistula in a patient with renal failure]

Percutaneous renal biopsy is frequently used in diagnosis of renal dysfunction. Nevertheless, complications, mostly vascular, may occur. Treatment must be minimally invasive with nephron preservation, especially in kidney failure. We present an interesting therapeutic approach with highly selective catheterization under gadolinium and glue embolization, leading to total cure of iatrogenic fistula without renal deterioration.

[Ultrasonographic evaluation of the kidney, liver and spleen size in children]

BACKGROUND

The aim of our study was to establish a standard growth curve of renal, hepatic and splenic dimensions with respect to age, and to find if any relationship existed between these different curves.

PATIENTS AND METHODS

One hundred and fifty abdominal ultrasound studies were obtained on 62 male and 88 female normal children free of any chronic disease, whose ages ranged from 0 to 15 years. Hepatic, splenic and renal dimensions were obtained in a similar and reproducible fashion for all patients. A statistical study of the measurements obtained compared to the age was performed by dividing the subjects into five groups according to age, and after calculating the mean size and variance.

RESULTS

Standard growth curves for the liver, kidney and spleen were constructed. Compared to age, splenic size follows the same growth as that of the kidneys, with a constant ratio. The growth pattern of the liver parallel the renal curve with a mean difference of 2.72 cm.

CONCLUSION

A moderate enlargement of spleen and liver is difficult to evaluate only by clinical examination. Ultrasound may detect it by using the kidney size as a reference.

[Multicenter study of children with terminal renal failure in Lebanon]

A retrospective study was conducted in June 1997 concerning all Lebanese children with end stage renal failure. This study was able to recognize 20 children and infants (age less than 15) dialysed regularly in 8 hemodialysis centers. The other 23 centers are not following children. Thirteen children are dialysed on bicarbonate and seven on acetate. Children receive erythropoietin occasionally; 30% of them are polytransfused, 60% of them suffer from anemia. Four children have never received immunization against hepatitis B and three are seropositive for hepatitis C. None of these children has regular school attendance and psychological support for the child and his family do not exist. We conclude that the situation of children on hemodialysis in Lebanon is alarming. Solutions are possible and available; they need to be undertaken urgently.

Dilemma of oxalosis in end stage renal failure: isolated kidney allograft or hemodialysis

We report the case of a 10-year-old girl who received a cadaveric kidney transplant for oxalosis after a period of 12 months on hemodialysis. The donor was a 6-year-old child. Cold ischemia was four hours. Diuresis occurred immediately in the operating room. Mean daily diuresis was maintained at 8 liters: first by i.v. perfusion, then by nocturnal continuous nasogastric hydration. In addition to the usual immunosuppressive drugs, she received pyridoxine, sodium citrate, phosphate, hydrochlorothiazide and magnesium. Daily hemodialysis was performed from Day 1 to Day 9 and four additional sessions every other day. The postoperative course was satisfactory. Oxaluria was elevated initially at 1074 mg/24 h (normal < 50 mg/24 h). One year later, mean daily diuresis is still 8 liters, renal function is normal and oxaluria is at 296 mg/24 h. Repeated graft sonography showed no nephrocalcinosis, but mild oxalate deposits are noted on renal biopsy. Isolated renal transplantation was successful in our patient. It allowed us to stop hemodialysis and to avoid extra-renal accumulation of oxalate. Despite this success, we are convinced that long term prognosis is uncertain and liver transplantation should be realized to correct definitely the biochemical defect.

[Early hypomagnesemia, hypercalciuria and nephrocalcinosis: two cases in a family]

BACKGROUND

Hypomagnesemia-hypercalciuria and nephrocalcinosis is a rare inherited syndrome which is characterized by persistent hypomagnesemia despite supplementation, hypercalciuria, nephrocalcinosis and progressive renal failure.

OBSERVATIONS

Case 1. A girl was referred at the age of 18 months because of polyuria, polydipsia and vitamin-resistant rickets. There was hypomagnesemia, hypercalciuria and mild renal insufficiency; ultrasonography showed nephrocalcinosis. For two years, she received hydrochlorothiazide and the course of the disease was marked by a significant reduction of urine output and hypercalciuria, recurrent urinary tract infections and a progression toward chronic renal failure. Case 2. The brother of this child was investigated at the age of nine months because of polyuria and polydipsia. He also had hypomagnesemia, hypercalciuria and nephrocalcinosis. Renal function was initially normal. After two years on continuous treatment with hydrochlorothiazide, hypercalciuria decreased without deterioration of renal function. No signs of rickets were noted and nephrocalcinosis remained stable.

CONCLUSION

To our knowledge, these two patients are the youngest reported in the literature. The long-term deterioration of renal function is hazardous but rickets may be avoided by early administration of hydrochlorothiazide.

[Kidney transplantation in the child. Experiences of l'Hôtel-Dieu de France]

A retrospective study was conducted on all kidney transplantations performed between January 1993 and June 1996 in our multidisciplinary pediatric department. Thirteen children with a mean age of 6 years (3.5-12) were transplanted during the study period after an average waiting time of 2 years on dialysis for cadaveric transplants and 3.5 months for living related ones. No urologic complication was noted; however, intra-abdominal approach was decided to be performed only in children less than 9 kg. This decision was taken after the occurrence of one intestinal intussusception and two ileal obstructions. During these 3.5 years, five rejection episodes were treated: three were steroid responsive, two were resistant but responded respectively to plasmapheresis and to OKT3. The actuarial survival of the grafts and recipients were 100% for an average mean time of follow-up of 18 months. The latest serum creatinine and creatinine clearance averages were respectively 66 mumol/l and 105 ml/min/1.73 m2. In seven transplanted children for more than 18 months growth was satisfactory. Eleven children returned to school. Kidney transplantation is the optimal treatment for children and infants with chronic renal failure; however, this technique needs a highly experienced team and a permanent close follow-up. Some children with end stage renal disease can directly have preemptive transplantation which is becoming our recent choice to avoid the hemodialysis strain.

Renal biopsy in children in a developing country in 61 consecutive cases

Percutaneous renal biopsy in children is a safe procedure. It is used for definitive diagnosis, prognosis and evaluation of the response to therapy. Repeated percutaneous biopsies are currently performed especially in allograft kidneys and in native kidneys as well. No major complications were noted in our series. The use of the new automated technique with small disposable needles in a well sedated child and experienced operator minimizes the complication rate. The important clinical benefit of the percutaneous renal biopsy overcomes the minimal risk of the procedure. Mesangiocapillary glomerulonephritis and focal segmental glomerulosclerosis are the predominant histological findings in our series. More data from other centers are necessary to evaluate the real incidence of the different entities of renal diseases in our country.

Reversible severe vascular rejection after plasmapheresis

Vascular rejection in a transplanted child is frequently associated with bad prognosis on the short and long term. All therapeutic modalities available nowadays as monoclonal antibodies, intravenous cyclosporine or plasma exchange have given conflicting results. We report the case of a boy who was transplanted from his mother at the age of three. His primary disease was a cortico-resistant rapidly progressive glomerulonephritis; the immediate postoperative period was satisfactory but he developed a severe vascular rejection on day 5 post-transplantation, while on triple immunosuppression therapy associating antithymocyte globuline, prednisolone and azathioprine. Acute vascular rejection was corticoresistant but responded well to plasma exchange. In our patient, we believe that plasmapheresis was efficaceous on the reversibility of vascular rejection and moreover that he had not responded to corticotherapy even a week post methylprednisolone in the absence of any change in immunosuppression during plasmapheresis. No randomized study was realized until now to prove the efficacy of plasmapheresis in children with vascular rejection. The sporadic cases reported on the reversibility of such rejection after plasmapheresis, the innocuity of this therapy, if well performed in children, encourage us to consider this treatment modality in resistant vascular rejection.