Robert H. Farnsworth

Evaluation of acute urinary tract infection in children by dimercaptosuccinic acid scintigraphy: a prospective study.

A prospective study examining the incidence of dimercaptosuccinic acid (DMSA) abnormalities in children at the time of acute urinary tract infection, the progression of these abnormalities following treatment and their correlation with the presence of vesicoureteral reflux is reported. DMSA scans performed within 72 hours of presentation in 65 previously healthy children with acute urinary tract infection were abnormal in 34 (52%). The scan appearances of 30 of 36 (83%) initially abnormal kidneys improved or became normal on the repeat DMSA study performed at 3 to 6 months after the acute urinary tract infection. A cystogram demonstrated significant vesicoureteral reflux in 11 of 45 cases (24%). Of these 11 cases 10 had abnormal DMSA studies and 1 had dilated upper tracts on ultrasound. Several conclusions may be drawn from our study. The incidence of DMSA abnormalities at the time of acute urinary tract infection is high but these abnormalities tend to resolve with time. An abnormal DMSA study at the time of urinary tract infection identifies most children with significant vesicoureteral reflux, and in our series a combination of ultrasound and DMSA identified all cases. This study may have major implications for the clinical investigation of children with urinary tract infection.

The Detection of Reflux Nephropathy in Infants by 99 mtechnetium Dimercaptosuccinic Acid Studies

Dimercaptosuccinic acid (DMSA) studies were performed in 113 infants less than 1 year old at risk of renal scarring. Of these patients 86 presented with urinary tract infection and 27 were asymptomatic. A voiding cystourethrogram was performed in all cases and excretory urography (IVP) was done in 99. More abnormalities were detected by DMSA study when compared to scars on IVP. When both studies were abnormal there was an excellent correlation on a site by site basis. Fever or systemic disorder was not a reliable sign to determine whether there was upper tract involvement with infection. The incidence of DMSA abnormalities in infants increased with high grade vesicoureteral reflux and decreased with low grade reflux. There was no significant difference in the incidence of abnormal kidneys between the infected and noninfected groups, suggesting that renal scarring may occur with sterile reflux.

Low incidence of new renal scars after ureteral reimplantation for vesicoureteral reflux in children: a prospective study.

PURPOSE The major aim of treating vesicoureteral reflux in children is the prevention of renal scars. Dimercapto-succinic acid (DMSA) is the modality of choice for detecting renal scars. We documented the incidence of new renal scarring and measured changes in differential renal function after ureteral reimplantation using DMSA studies. MATERIALS AND METHODS We evaluated 45 boys and 98 girls with a median age of 2 years who had vesicoureteral reflux and underwent ureteral reimplantation. DMSA scans were done preoperatively and at a median of 3.4 years postoperatively. Maximal reflux grade was III in 84 children (59%), IV in 27 (19%) and V in 6 (4%). RESULTS Preoperatively DMSA studies showed scarred or contracted kidneys in 106 of the 143 patients (74%). After reimplantation mean change in differential function was 2.5%. New scars developed in 3 children (2%). We noted greater than 6% decrease in relative differential function without new scarring in 7 cases (5%). CONCLUSIONS The incidence of new renal scars in our study using DMSA was lower than that in previous series using excretory urography and imaging. Surgical correction of vesicoureteral reflux may offer better protection of kidneys in childhood than previously believed.

Diuresis renography : the need for an additional view after gravity-assisted drainage

The role of diuresis renography (DR) in the evaluation of pelvi-ureteric junction obstruction is well established. However, problems may be encountered when applying this technique to patients after pyeloplasty because of the role of gravity-assisted drainage (GAD) in this post-operative group. Twenty-three radionuclide studies that were performed in 21 children were reviewed. All children underwent standard DR and all then had an additional view performed after GAD. In 12 children evaluated in a preoperative assessment for possible obstruction, 5 were obstructed on both DR and after GAD, 1 was equivocal on DR but drained after GAD, and 6 were not obstructed in either part of the study. In 11 children assessed after pyeloplasty, 5 were obstructed on DR but not obstructed on GAD, 3 were not obstructed in both studies, 1 was obstructed in both, and 2 were equivocal on DR but not obstructed after GAD. It can be concluded that when assessing patients, particularly those who have undergone pyeloplasty, DR should be supplemented with an additional view acquired after gravity-assisted drainage.

Unilateral Multicystic Dysplastic Kidney With Progressive Infundibular Stenosis in the Contralateral Kidney: Experience at 1 Center and Review of Literature

PURPOSE We analyzed the association between unilateral multicystic dysplastic kidney and subsequent contralateral infundibular stenosis, which can result in progressive calyceal dilatation, and has been linked to global hyperfiltration injury and renal impairment. MATERIALS AND METHODS During the last 10 years 200 children presented with unilateral multicystic dysplastic kidney. Of these children 5 subsequently exhibited contralateral infundibular stenosis. We reviewed the published data on multicystic dysplastic kidney as well as infundibular stenosis to examine this association further. RESULTS Three patients underwent open surgical exploration since rapid progression with associated parenchymal thinning was detected. Literature review failed to identify any discussion of infundibular stenosis in studies focusing on long-term followup of children with a unilateral multicystic dysplastic kidney. Several case reports and case series discuss this condition in association with other collecting system anomalies. However, these anomalies are hypothesized to be part of a disease spectrum resulting from aberrant formation of the collecting system. Bilateral involvement has been reported in fewer than 10 cases. CONCLUSIONS Our cases represent a part of the spectrum of pyelocalyceal dysgenesis that can have bilateral involvement of varying degrees. Of particular concern was the delayed presentation in some of our patients and the progressive nature of the lesions. Although exceedingly rare, we wish to highlight the association of multicystic dysplastic kidney and progressive infundibular stenosis of the contralateral kidney and renal impairment.

DMSA studies in infants under one year of age

In this paper, we report the results of dimercaptosuccinic acid studies performed in infants under 1 year of age at risk of renal scarring

Congenital unilateral renal tubular dysgenesis and severe neonatal hypertension

Severe arterial hypertension rarely occurs in the neonatal period but may have life-threatening consequences. It is most often caused by renal parenchymal or vascular abnormality, which, to be accurately diagnosed, may require a combination of imaging modalities. We report on a case of neonatal hypertension presenting as cardiac failure. Initial imaging suggested unilateral renal artery stenosis, but this was not corroborated by magnetic resonance angiography. Surgical nephrectomy was curative for the hypertension and also allowed diagnosis of renal tubular dysgenesis. Unilateral congenital tubular dysgenesis without renal infarction has not been previously reported. We speculate that the condition was secondary to a period of localised hypoperfusion during early foetal life.

The disappearance of one half of a horseshoe kidney.

An infant girl was seen 3 weeks after birth to evaluate her kidneys because of an antenatal ultrasound diagnosis of right hydronephrosis. A postnatal Tc-99m MAG 3 study revealed a horseshoe kidney with the right component being smaller than the left. The girl was seen again at 4.5 years with urinary incontinence that involved a constant drip of urine that left her never completely dry. Cystoscopic examination revealed a deficient bladder neck. The left ureteric orifice was located intravesically but the right ureteric orifice ended ectopically at the urethral-vaginal septum. It was unclear whether the childs incontinence resulted from the incompetent bladder neck or from urine draining from the ectopic right ureter, which opened distal to the urethral sphincter. A Tc-99m DMSA study revealed that there was no residual function in the right component of the horseshoe kidney, with only a normal left kidney now seen. The sequence of studies indicated an unusual regression of a hemicomponent of a horseshoe kidney.

Multicystic dysplastic kidney and calyceal diverticulum - more of an association than a coincidence?: Letters to the editor

Presacral lesions occupy the presacral space, a potential space bounded by rectum and sacrum. Masses here enlarge into the pelvis or abdominal cavity without causing early compressive symptoms, and often present late because of non-specific symptoms and imaging findings. An unusual case is presented that highlights this diagnostic difficulty. A 46-year-old female was referred following the incidental discovery of a mass during laparoscopic right oophorectomy, which was adherent to the left ovary and rectum (see Fig. 1). There were no remarkable features on examination and tumour markers were normal. Computed tomography (CT) imaging demonstrated a 4-cm presacral mass that did not appear to arise from colon, with softtissue radiographic density. A laparotomy, performed for both diagnosis and treatment, revealed a firm retroperitoneal mass, involving rectum and left ovary. Frozen sections were inconclusive and an anterior resection with en bloc resection was undertaken. Histology demonstrated a mesenteric plexiform neurofibroma. The patient had no other identifiers of neurofibromatosis, was referred to a neurologist and ultimately had an uneventful recovery. This case highlights the diagnostic issues involved in managing presacral masses. Minimal symptoms and inconclusive imaging findings led to a tissue diagnosis at laparotomy being required. There is a broad differential diagnosis, with the most common lesions congenital, comprising teratomas in children and chordomas in adults. Other causes include tailgut cysts, rectal duplication cysts, cystic teratomas and dermoid/epidermoid cysts. Segmental neurofibromatosis presenting as presacral mass has not been widely described. While neurofibromatosis is relatively common, (1 in 3000), segmental neurofibromatosis is much less so (1 in 36,000). Plexiform neurofibromas are pathognomonic for NF1, and represent diffuse neural enlargement. Imaging may be useful to aid management. While plain radiography and ultrasound are non-specific, magnetic resonance and CT show improved diagnostic benefit. These modalities may demonstrate a cystic component, the presence of fat or calcification and relationships to abdominal viscera. Unfortunately, there is a broad spectrum of imaging findings attributable to neurofibromas, and contribute to the low specificity of these scans. This unusual case of a plexiform neurofibroma presenting as a presacral mass demonstrates the difficulties in the investigation and diagnosis of presacral masses. With imaging findings often nonspecific, histological diagnosis and surgical excision may ultimately be required.

Multicystic dysplastic kidney and calyceal diverticulum – more of an association than a coincidence?

Presacral lesions occupy the presacral space, a potential space bounded by rectum and sacrum. Masses here enlarge into the pelvis or abdominal cavity without causing early compressive symptoms, and often present late because of non-specific symptoms and imaging findings. An unusual case is presented that highlights this diagnostic difficulty. A 46-year-old female was referred following the incidental discovery of a mass during laparoscopic right oophorectomy, which was adherent to the left ovary and rectum (see Fig. 1). There were no remarkable features on examination and tumour markers were normal. Computed tomography (CT) imaging demonstrated a 4-cm presacral mass that did not appear to arise from colon, with softtissue radiographic density. A laparotomy, performed for both diagnosis and treatment, revealed a firm retroperitoneal mass, involving rectum and left ovary. Frozen sections were inconclusive and an anterior resection with en bloc resection was undertaken. Histology demonstrated a mesenteric plexiform neurofibroma. The patient had no other identifiers of neurofibromatosis, was referred to a neurologist and ultimately had an uneventful recovery. This case highlights the diagnostic issues involved in managing presacral masses. Minimal symptoms and inconclusive imaging findings led to a tissue diagnosis at laparotomy being required. There is a broad differential diagnosis, with the most common lesions congenital, comprising teratomas in children and chordomas in adults. Other causes include tailgut cysts, rectal duplication cysts, cystic teratomas and dermoid/epidermoid cysts. Segmental neurofibromatosis presenting as presacral mass has not been widely described. While neurofibromatosis is relatively common, (1 in 3000), segmental neurofibromatosis is much less so (1 in 36,000). Plexiform neurofibromas are pathognomonic for NF1, and represent diffuse neural enlargement. Imaging may be useful to aid management. While plain radiography and ultrasound are non-specific, magnetic resonance and CT show improved diagnostic benefit. These modalities may demonstrate a cystic component, the presence of fat or calcification and relationships to abdominal viscera. Unfortunately, there is a broad spectrum of imaging findings attributable to neurofibromas, and contribute to the low specificity of these scans. This unusual case of a plexiform neurofibroma presenting as a presacral mass demonstrates the difficulties in the investigation and diagnosis of presacral masses. With imaging findings often nonspecific, histological diagnosis and surgical excision may ultimately be required.