Infundibulopelvic stenosis in children

Congenital infundibulopelvic stenosis: Indications for intervention, surgical technique, and review of literature

INTRODUCTION

Congenital infundibulopelvic stenosis (IFPS) is a rare renal dysmorphism marked by dilated calyces proximal to diminutive infundibulum and renal pelvises. The entity is theorized to exist on the spectrum of congenital obstructive renal diseases between ureteropelvic junction obstruction and multicystic dysplasia.

OBJECTIVE

This case series sought to review and present the surgical management of three cases of IFPS with progressive renal insufficiency.

MATERIALS AND METHODS

After Institute Review Board approval, we reviewed three cases of IFPS treated by a single surgeon over a 20-year period. All cases displayed evidence of progressive renal decline. The first case of a 16-year-old female had IFPS in a solitary kidney, with previous contralateral nephrectomy of a multicystic dysplastic kidney. The second case, a 17-year-old male, presented after blunt trauma to the ipsilateral flank. The third case of a 10-year-old female presented with microhematuria, mild azotemia and bilateral IFPS.

RESULTS

Our current surgical management has evolved from renal sinus exposure and multiple infundibuloplasties in the first case to preoperative three-dimensional mapping of the dilated calyceal system with intraoperative ultrasonography for selective calicocalicostomies draining to a lower pole ureterocalicostomy in the third case. Our first case, treated with multiple infundibuloplasties experienced slow renal decline into her 20s, and the later cases, treated with calicocalicostomies, have experienced stable to mild loss of renal function with ongoing nephrological follow-up.

DISCUSSION

IFPS is a complex pediatric urology problem without a clear treatment algorithm. The goal of surgical intervention is to offer an opportunity to halt or reduce progressive renal insufficiency. Our current surgical approach utilizes preoperative three-dimensional modeling via magnetic resonance urography to guide placement of multiple calicocalicostomies draining to a lower pole ureterocalicostomy.

CONCLUSIONS

Not all cases of IFPS require surgical intervention. We have intervened in cases of IFPS with progressive hydronephrosis or worsening renal insufficiency with acceptable results.

Pyocalycosis: a report of two cases of complicated hydrocalycosis

Hydrocalycosis is defined as cystic dilatation of a major calyx with a demonstrable connection to the renal pelvis and an epithelial lining of the cyst wall. Although this condition has long been known, there are no sufficient data concerning this pathology in the literature. In this study, we present two complicated hydrocalycosis--'pyocalycosis'--and discussed the therapeutic approaches.

Childhood infundibular stenosis

Infundibular stenosis is a rare condition marked by dilation of one or more calices proximal to a stenotic infundibulum. Contrary to older reports, more recent information suggests that progressive renal dysfunction occurs in a significant number of these patients. We present a case of incidentally discovered infundibular stenosis. On the basis of the existing published reports, we make several recommendations. Close monitoring for a decline in renal function secondary to hyperfiltration injury is essential, and a worsening should prompt referral to a pediatric nephrologist. Progressive hydronephrosis should be corrected surgically, although proof of effect on the disease process is lacking in the evidence-based reports.

Severe intrarenal fibrosis, infundibular stenosis, renal cysts, and persistent perilobar nephrogenic rests in a patient with Beckwith-Wiedemann syndrome 27 years after diffuse nephroblastomatosis and Wilms tumor: natural progression or a consequence of treatment?

A27-year-old woman presented with back and abdominal pain. She was diagnosed in infancy with Beckwith-Wiedemann syndrome and bilateral multifocal perilobar nephrogenic rests that progressed to diffuse nephroblastomatosis with neoplastic nephroblastomatous rests at 14 months of age and subsequently to a right Wilms tumor at 5 years of age. Computed tomography of the abdomen during the current admission showed multiple obstructed calices. Ureteroscopic inspection of the left kidney revealed severe intrarenal scarring with multiple infundibular stenosis, hydrocalices, and nephrocalcinosis. Renal biopsy showed sclerotic glomeruli with calcification and scarring and persistent subcapsular nodular renal blastema. Electrocautery incision and balloon dilatation provided temporary pain relief. After discharge, the patient has had two or three episodes of recurrent pain associated with new areas of infundibular stenoses and renal cysts. Bilateral nephrectomy and renal transplantation is being considered for management of progressive disease and relief of intractable pain. The potential causes of progressive and severe intrarenal fibrosis, infundibular stenosis and nephrocalcinosis, and renal cysts in this patient may include abnormal renal development secondary to Beckwith-Wiedemann syndrome itself, radiation or chemotherapy damage, or a combination.

Infundibulopelvic stenosis: a long-term followup

We followed 21 patients with congenital infundibulopelvic stenosis, a rare obstructive disorder of the intrarenal collecting system, for a median of 11 years (range 2 to 28 years). Of these patients 19 (90%) had evidence of bilateral renal disease. In particular, 10 patients had bilateral infundibular pelvic stenosis, 6 a contralateral cystic dysplastic kidney and 3 a congenitally absent kidney. Extended observations of the patients with this disorder revealed that end stage renal disease or renal insufficiency developed in 8 patients (37%), all with bilateral renal anomalies. Renal biopsies in patients with end stage renal failure revealed widespread areas of renal dysplasia proximal to the stenotic infundibulum with focal or global glomerulosclerosis of the glomeruli, which was not involved in the dysplastic process. These pathological findings are consistent with the presence of a renal hyperfiltration injury. Our data suggest that the prognosis of infundibulopelvic stenosis is dependent upon the extent of total renal mass involved with the disease process and the duration of followup.