Neonatal renal candidiasis: sonographic diagnosis

Management of an Extremely Low Birth Weight Infant with Bilateral Renal Obstruction Caused by Candida albicans Fungus Balls

We report an extremely low birth weight infant with anuria caused by bilateral Candida albicans fungus balls it was treated with a combination of antifungal therapy, irrigation and pyelotomy. This lead to a recovery of renal function, after a follow-up of 77 month no more Candida was cultured from urine.

Neonatal Systemic Candidiasis Diagnosed by Ultrasound

The diagnosis of systemic candidiasis in ill high-risk neonates is often delayed as there are no specific clinical features and the significance of positive cultures for Candida species may be uncertain. Early diagnosis and treatment is essential to reduce mortality and may be aided by ultrasound examination of the commonly involved organs — The brain and kidneys. In this paper we describe 2 cases where the diagnosis was first raised following ultrasound examination, and review the spectrum of abnormalities seen on renal and cranial ultrasound examination. We emphasise the importance of using this imaging technique in the high-risk neonate in initiating earlier diagnosis and treatment, or in establishing the significance or otherwise of positive cultures.

Successful management of a renal fungal ball in a pretermature neonate: A case report and review of literature

Invasive fungal infection is common in the present day NICUs - generally manifesting as candiduria or candida sepsis. Fungal balls in the kidneys are very uncommon and most are amenable to higher antifungal agents. However, we had a child who did not respond to such measures and ultimately needed a surgical removal of the fungal ball in his kidney.

We report this case along with a review of literature to highlight about this uncommon, but an important cause of persistent sepsis in pre-term infants and to review the treatment options including a surgical removal.

Clinical practice: Obstructive renal candidiasis in infancy

Renal candidiasis is an increasingly common condition affecting predominantly premature infants receiving neonatal intensive care or term infants with urogenital tract anomalies. Multiple risk factors are usually present. Although rare, some infants develop an obstructive uropathy due to fungal balls, and this requires prompt detection and intervention to preserve kidney function. The management of obstructive renal bezoars is challenging and not well summarised in the past. This is mainly due to scarce literature confined to case reports or case series only. This review clarifies various definitions used in relation to renal candidiasis and identifies infants particularly at risk of obstruction. Clinical presentation, diagnosis and the role of imaging are discussed. A summary of the recent literature is provided to outline the range of existing treatment options available with published drug dosages and mode of delivery used. No single approach is successful in all cases and clinicians need to be aware of the different options available: apart from adequate urinary drainage and use of systemic +/- local antifungal agents, additional treatment with fibrinolytic agents and/or endoscopic or open surgical removal may be required. A new simplified algorithm for use in management is proposed. We hope this review will help clinicians in their management of patients presenting with this complex and challenging diagnosis.

Renal ultrasonography and detection of pseudomycelium in urine as means of diagnosis of renal fungus balls in neonates

OBJECTIVE

To present a series of neonates with renal fungus balls diagnosed by ultrasonography, urine culture and/or by the detection of Candida pseudomycelium in urine.

PATIENTS AND METHODS

We revised the clinical records of neonates for whom the diagnosis of renal fungus ball was established by ultrasound and laboratory studies; these patients had been hospitalized at the National Institute of Pediatrics in Mexico between January 1st, 1999 and December 31st, 2002.

RESULTS

During the study period, 9 neonates were diagnosed with renal fungus ball. In 7 cases, the ethiologic agent was Candida albicans; whereas it was C. tropicalis in one case and C. parapsilosisin the other. Urine culture was positive (> or =10,000 UFC/ml) in 8 cases, whereas the fungal density was only 2400 UFC/ml in the last sample. Pseudohyphae were present in all cases and ultrasonography showed fungus ball in every case. All patients received a single antifungal drug, either amphotericin B or fluconazole. All the patients recovered and none of them required surgical treatment. Control postreatment by ultrasound studies showed that the fungus balls had disappeared in every case.

CONCLUSION

The diagnosis of Candida renal fungus balls based on the ultrasound study and urine culture is also substantiated by the detection of pseudomycelium in the centrifugation pellet of urine samples, which is a fast diagnostic method. This approach permitted an early diagnosis and treatment of Candida renal fungus balls.

Candidal renal and urinary tract infection in neonates

Candida species are a common cause of urinary tract infection in newborns requiring intensive care. Renal candidiasis is frequently associated with these urinary tract infections and is manifest by "fungus balls" or renal parenchymal infiltration. Candidal urinary tract infections in high-risk newborns are often associated with candidemia, thereby warranting systemic antifungal therapy. Sonography is useful in diagnosing renal candidiasis, obstruction from "fungus balls," and abscesses. The sonographic appearance of "fungus balls" may persist long after clinical resolution of Candida infection in neonates and should not affect duration of antifungal therapy. Amphotericin B is currently the drug of choice for neonates with renal candidiasis and candidal urinary tract infection. Surgical management should be reserved for decompression of obstructive candidiasis and drainage of abscesses.

US of renal insufficiency in neonates

Congenital and acquired renal diseases that can produce renal insufficiency during the neonatal period may be classified according to their ultrasonographic (US) characteristics: increased parenchymal echogenicity (renal parenchymal diseases, angiotensin-converting enzyme inhibitor fetopathy, cortical necrosis), cystic disease (glomerulocystic kidney disease, autosomal recessive polycystic renal disease, multicystic dysplastic kidney, cystic renal dysplasia), obstructive uropathies (ureteropelvic junction obstruction, posterior urethral valves), infections (candidal infections and bezoars), and renal agenesis. High-resolution sector and linear-array transducers allow characterization of the underlying pathologic conditions in many cases. Findings of renal parenchymal disease will vary at Doppler US and, during the acute phase, diastolic flow can be decreased, absent, or reversed. In patients with glomerulocystic kidney disease, US shows bilaterally enlarged kidneys with diffusely increased echogenicity and retention of a reniform contour, loss of corticomedullary differentiation, and cortical cysts. Obstruction of the ureteropelvic junction, the most common cause of hydronephrosis in neonates, can be seen at US as a dilated renal pelvis with dilated and communicating calices, lack of dilatation in the distal portion of the ureter, changes of renal dysplasia with increased echogenicity of the renal parenchyma, and parenchymal cysts, depending on the severity and duration of the obstruction. High-resolution US provides improved characterization of the renal parenchyma and more precise description of renal architecture.

Imaging guided interventional procedures in paediatric uroradiology--a case based overview

OBJECTIVE

To describe the potential and application of interventional image guided procedures in the paediatric urinary tract.

PATIENTS AND METHODS

The different techniques are illustrated using case reports. The examples comprise established indications such as percutaneous nephrostomy for compromised kidneys in obstructive uropathy and infection, sonographic guided renal biopsy including monitoring or treatment of complications after biopsy, and evaluation and balloon dilatation of childhood renal artery stenosis. There are new applications such as treatment of stenosis in cutaneous ureterostomy or sonographically guided catheterism for deployment of therapeutic agents.

RESULTS

Generally, the procedures are safe and successful. However, complications may occur, and peri-/post-interventional monitoring is mandatory to insure early detection and adequate management. Sometimes additional treatment such as percutaneous embolisation of a symptomatic post biopsy arterio-venous fistula, or a second biopsy for recurrent disease may become necessary.

CONCLUSION

Imaging guided interventional procedures are performed successfully in a variety of diseases of the paediatric urinary tract. They can be considered a valuable additional modality throughout infancy and childhood.

Work-up of urinary tract infection in infants and children

Urinary tract infection (UTI) in infants and children demands rapid differentiation between upper UTI (pyelonephritis) and lower UTI (cystitis) for prompt treatment to be initiated so that renal damage is minimized. This pictorial review presents a wide gamut of structural and functional abnormalities of the urinary tract that may predispose infants and children to UTI, including vesicoureteral reflux, upper urinary tract obstruction (ureteropelvic junction obstruction), lower urinary tract obstruction (primary megaureter, ureterovesical junction obstruction, posterior urethral valve, ectopic ureterocele with or without associated duplex collecting system), neurogenic problems (dysfunctional voiding), calculi, and parenchymal scars. Sonography (ultrasound [US]) is the imaging modality of choice for assessment of renal size, growth (serial sonograms), texture, and blood flow. Other modalities used to work-up UTI in the pediatric patient include fluoroscopic voiding cystourethrogram, nuclear voiding cystourethrogram, and nuclear renal scintigraphy (NRS). Excretory urography is no longer recommended in the routine evaluation of childhood UTI because information regarding anatomy and function (qualitative and quantitative) can be better assessed with US and NRS, respectively. Computed tomography and magnetic resonance imaging are primarily reserved for complex cases in which a definitive diagnosis cannot be made with routine imaging. Algorithms for work-up of UTI in various pediatric age groups are presented.

The management of fungal obstructive uropathy in neonates and infants

Obstructive uropathy caused by upper urinary tract fungal ball formation is an uncommon but well recognized clinical entity. The clinical course and management of an infant with unilateral fungal ball obstruction is described. Ultrasound and Tc-diaminotetraethylpentacetic acid (DTPA) renal scan contributed significantly to the diagnosis and management of this patient. Complete resolution of the obstruction was achieved by treatment with intravenous amphotericin B and oral 5-fluorocytosine. The clinical course and management of 35 patients described in the literature indicate that prematurity, use of broad spectrum antibiotics, prolonged hospital stay and the use of intravascular catheters are predisposing factors. The mortality rate is 34%. Young age, small size, the presence of candidaemia and withholding antifungal therapy are poor prognostic factors. A rational plan of treatment, extrapolated from the literature, is presented which may help to reduce the mortality rate in this condition.

Percutaneous nephrostomy drainage in the management of neonatal anuria secondary to renal candidiasis

We report a case of anuria in a premature neonate secondary to bilateral ureteropelvic junction obstructions related to Candida bezoars. Percutaneous decompression and drainage of both kidneys contributed significantly to the successful management of renal candidiasis in this patient. A review of the literature is presented.

Increased renal echogenicity in the neonate

We report data on newborn infants with increased renal echogenicity observed at the Division of Neonatal Intensive Care of Pavia during a five-year period. Review of 1600 abdominal ultrasonic evaluations revealed 103 newborn infants (56 females and 47 males, with birth weight from 560 to 3700 g and gestational age from 25 to 42 weeks) whose kidneys showed increased echogenicity. Three patients with infantile polycystic kidney disease, two with renal candidiasis, three with dysplastic kidney and two with renal vein thrombosis showed diffuse hyperechogenicity. Three patients with hemolytic-uremic syndrome showed cortical hyperechogenicity. Increased medullary echogenicity was observed in 90 infants with renal disease secondary to perinatal asphyxia. In 76 of these patients the evaluation of renal echogenicity and the renal function improved, while in the remaining 14 newborns the renal alteration persisted until death.

Renal stone formation following medical treatment of renal candidiasis

Two very low birth weight infants who developed renal candidiasis with pelvicalyceal fungal concretions were treated medically with Amphotericin B and 5 Fluorocytosine. Two months following cessation of therapy, the fungal concretions decreased in size, became sterile and developed calcification in residual debris. The calcifications was still present at demise in one patient and at 18 months follow up in the other. These calcifications occurred in the absence of simultaneous furosemide therapy.

An assessment of sonography in the diagnosis and management of neonatal renal candidiasis

The renal sonographic findings in six cases of neonatal candidiasis and 13 cases previously reported in the literature are reviewed. Focal and diffuse parenchymal changes and obstruction due to mycetoma formation were frequent features. In the current series the sonographic changes were found to bear an inconstant relationship to the probable time of onset of the infection. In addition, apparent sonographic deterioration occurred in neonates well after adequate antifungal treatment was initiated. In view of the potential toxicity of systemic antifungal therapy, sonographic renal parenchymal changes are not considered an adequate indication for either its initiation or its continuation.

Candida: an increasingly important pathogen in the nursery

Advances in neonatal care now permit the survival of very immature infants. Although candidiasis is not a new disease, the spectrum of clinical disease has greatly widened and the rate of invasive disease has increased significantly. This article reviews the history, microbiology, and epidemiology of candidal infections, both superficial and invasive. Particular attention is paid to the pathogenesis of and risk factors associated with the development of invasive disease, as well as its clinical manifestations, diagnosis, and treatment.