Renal Vein Thrombosis in the Neonate: DISCUSSION

renal vein thrombosis

RVT is a clotting process that originates in the venous radicles and progresses into the main renal vein and vena cava. In Germany, the minimum incidence of symptomatic neonatal RVT between 1992 and 1994 was 2.2 per 100,000 live births. Zigman et al reported an incidence of 2.3 cases/year in Canada. Review of the literature in PubMed, African Journal online and Embasse showed no reports from Africa and Japan.

The clinical symptoms are dependent on the location and the degree of the thrombotic changes in the renal vein system. Occasionally, symptoms of an obliteration of the vena cava can appear, and in the complex disease a consumption coagulopathy can occur. The diagnosis requires a high index of clinical suspicion. It can be made on the basis of hematuria and renal mass­es in the presence of predisposing factors, although hematuria and enlarged kidneys can be seen in 60% and 50% of cases, respectively. The “diagnostic triad” of flank mass, gross hematuria and thrombocytopenia was present in 13% of RVT reported by Zigman et al. Similarly, Ortiz et al. reported the classic triad of abdominal mass, hematuria and uremia in less than 20% of RVT. Our patient had thrombocytopenia but no hematuria. buy cialis soft tabs

RVT is mediated by endothelial cell injury in conjunction with diminished vascular blood flow in an infant with hypoxia, dehydration, birth asphyxia, shock and sepsis. Other predisposing factors include the presence of indwelling umbilical venous catheters and polycythemia. The pathogenesis of RVT in infants of diabetic mothers is not well established, although polycythemia in the latter may predispose to thrombosis. Our patient was macrosomic with a birthweight of 4.6 kg, but the mother was not diabetic. The child had features similar to that of an infant of diabetic or gestational diabetic mother, such as jaundice, jitteriness and hypoglycemia, within 24 hours of life. However, he was not polycythemic (PCV 43%). Lack of proper technique of breastfeeding as well as separation of mother and child may have resulted in failure to initiate breastfeeding by the mother. This is because separation of a baby from the mother soon after delivery alters the mouthing and rooting mechanisms necessary for effective suckling. Unfortunately, artificial milk was not given to the child because its use is prohibited in our hospital, which has been declared “a baby-friendly hospital,” implying that only breast milk is allowed in the first six months of life in the hospital. Hypovolemia resulting from such prolonged delay in commencing oral feeds may have predisposed the child to RVT, worsened by exposure to phototherapy. The child had risk for sepsis, with neutrophilia and elevated ESR, but no organism was isolated. He received adequate antibiotic therapy.

The diagnosis of RVT was highly favored in this patient with renal ultrasound findings. In the first week of RVT, the affected kidney swells and becomes echogenic with prominent echopoor medullary pyramid as seen in the present case. According to our research findings, earlier diagnosis of RVT was by intravenous pyelography, which was 79% accurate. Ricci et al. noted that renal ultrasonography confirmed the diagnosis with 92% accuracy. More recently, Hibbert et al. reported that ultrasound provides an accessible and reliable tool in the assessment of suspected neonatal RVT. The use of Doppler sonography (Duplex, Color and Power Doppler) demonstrate the renal flow patterns, the extent of vascular flow and facilitates the follow-up of thrombosis during therapy. However, infe­rior vena cava and renal venography or selective renal arteriography remains the gold standard for diagnosis in occult cases. canadian pharmacy support net

RVT may be unilateral, with bilateral commonly leading to acute and chronic renal failure. Sixteen of the 21 cases reviewed by Ortiz et al. were bilateral. All the cases showed electrolyte imbalance and severe metabolic acidosis. Rasoulpour and McLean noted reduced glomerular filtration (two of four cases) on follow-up only in infants with bilateral abnormalities. Our patient had bilateral renal involvement, which has a poor prognostic outcome. Nephrectomy was once considered standard therapy for bilateral renal venous thrombosis, but recently nonoperative therapy with thrombolytics and heparin have been found successful. Of 17 patients treated nonop-eratively at the Children’s Hospital of Pittsburgh (PA), 14 (82%) survived, including five with bilateral disease. Similarly, long-term renal function impairment was found in 33% and 100% of patients who did and did not receive heparin respectively in Montreal, Canada. In contrast, Weinschenk et al. did not demonstrate any success with combination thrombolytic and anticoagulant in their study. Supportive therapy is necessary in all cases to correct dehydration and sepsis. Surgical intervention is not indicated in the acute phase except in the rare instance of bilateral disease. Nephrectomy is required in those with nonvisualization of affected renal units upon initial urographic examination, which mostly shows an atrophic, functionless kidney later with risk of hypertension, persistent infection and scarring. Our patient is currently being offered supportive therapy without anticoagulant and will be dialyzed if the azotemia worsens.

In conclusion, we have reported a case of RVT and discussed possible etiologic factors. There was an association between delayed breastfeeding and RVT in the patient, although the causal role is pure speculation. However, breastfeeding counselors must support mothers in order to establish lactation soon after delivery especially in hospitals where artificial milk is not allowed. We recommend measures aimed at anticipation and prevention of RVT because of its poor outcome, which is heightened by lack of facilities for renal replacement therapy (RRT) in most hospitals in Nigeria.

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