Percutaneous nephrostomy in infants

Pediatric urologic interventional radiology

Interventional radiologists are playing an increasingly important role in pediatric urologic intervention, working closely with the pediatric urologist. Interventional radiologists are frequently asked to establish percutaneous access to the renal collecting system prior to nephrolithotomy. Additionally, procedures such as percutaneous nephrostomy, ureteral stent placement and exchange, and renal parenchymal biopsy are frequently encountered requests. This article will review these common procedures and highlight techniques and pathology that are unique to the pediatric population.

Conventional versus modified technique for percutaneous nephrostomy in newborns and young infants

Percutaneous nephrostomy (PN) in newborns and young infants presents unique challenges. Twenty-six consecutive PN procedures in 18 patients were retrospectively reviewed. Fifteen procedures were performed with the conventional micropuncture technique. The modified technique describe herein was used in 11 procedures. Depending on whether there is obstruction and whether the obstruction is at the ureteropelvic junction level or distal to it, the technique selected will vary.

Blunt renal trauma in children with previously undiagnosed pre-existing renal lesions and guidelines for effective initial management of kidney injury

OBJECTIVES

To record pre-existing renal lesions (PERL) found incidentally during evaluation for blunt renal trauma in children, determine their importance, suggest guidelines for the effective initial management of children with significant renal trauma and to evaluate the role of temporary percutaneous nephrostomy tube drainage (TPND) in these patients.

PATIENTS AND METHODS

We reviewed 338 children who were hospitalized with blunt abdominal trauma between 1992 and 2000. Thirty-one patients had significant renal injury, 17 before 1997 (reviewed retrospectively) and the others reviewed and followed prospectively.

RESULTS

Eleven of the 31 children had a PERL, which had been undiagnosed before the injury. The mean (range) follow-up was 52 (15-104) months. There were 22 boys and nine girls (mean age 9.1 years, range 2-13). The mean age was lower in patients with a PERL than in children with isolated renal injury. The most common cause of blunt renal injuries was a fall (45%) followed by motor vehicle accidents. Renal stones were present in five children, pelvi-ureteric junction obstruction in four, megaureter in one and a renal cyst in one. The mean injury severity scores were 12 in the children with a PERL and 14 in patients without. TPND was used in seven (22%) children; four were associated with a PERL. The mean grade of injury score for the kidney was higher in patients with a PERL and in children who underwent TPND than in patients who previously had a normal kidney and in children who did not undergo TPND. Early surgical intervention was required in three children; all were associated with a PERL. Of the 13 children who underwent surgery 11 had previous disease.

CONCLUSIONS

The frequency of PERL is high (36%) in children with blunt renal trauma. PERL can predispose minor trauma to cause kidney injury even with no evidence of hydronephrosis. When a minor trauma results in renal injury, it is important to seek a PERL. In selected patients, TPND may decrease the length of hospital stay and improve the outcome of the injured kidney, thereby decreasing the need for further surgery in those with isolated renal injury; however, it appears not to decrease the need for later operations in children with a PERL.

Ultrasound-guided percutaneous drainage for treatment of pyonephrosis in two dogs

Pyonephrosis refers to suppurative destruction of the parenchyma of the kidney with complete or nearly complete loss of renal function. In dogs, nephrectomy is still the most common treatment for pyonephrosis; however, in the present report, a method for percutaneous ultrasound-guided drainage of the renal pelvis in dogs with pyonephrosis that does not require local or general anesthesia was described, and results of the procedure in 2 dogs were reported. Briefly, dogs were positioned in lateral recumbency with the affected side up, and skin overlying the affected kidney was aseptically prepared. The dilated renal pelvis was punctured percutaneously, under ultrasound guidance, with a 22-gauge needle, and a sample of material was obtained for analysis. The needle was then replaced with an IV catheter, and as much pus as possible was removed from the renal collecting system. A povidone iodine solution was then used to lavage the renal pelvis. Ultrasound-guided drainage and lavage of the renal pelvis was repeated daily until the renal pelvis was so small that it could no longer be punctured. Both dogs recovered and were reported by the owners to be healthy after the procedure.

Percutaneous nephrostomy in children with ureteropelvic junction obstruction and poor renal function

OBJECTIVES

To evaluate the results of performing percutaneous nephrostomy (PCN) in all patients with kidneys with ureteropelvic junction obstruction (UPJO) and split renal function (SRF) of less than 10%, because the management of such cases is still under debate. If SRF improves, we perform pyeloplasty, otherwise nephrectomy is done.

METHODS

The records of all patients with UPJO (n = 20; 17 unilateral and 3 solitary kidney) with poor function who underwent PCN were analyzed. The PCN remained in situ for at least 4 weeks, during which patients received low-dose oral trimethoprim prophylaxis. Repeated renography was obtained after 4 weeks. If no improvement in the SRF had occurred, nephrectomy was performed, otherwise pyeloplasty was performed. The patients were followed up with renograms at 3 months, 1 year, 2 years, and 5 years.

RESULTS

Twelve of 17 kidneys with unilateral UPJO improved after PCN drainage and underwent pyeloplasty. The 5 kidneys that did not show improvement in the SRF underwent nephrectomy. In the patients with unilateral UPJO who improved after PCN drainage, the SRF increased to 29.2% +/- 12.6% and pyeloplasty was performed. At a mean follow-up of 2.3 years, none of these patients had developed hypertension, and the most recent SRF value was 31.4% +/- 12.8%.

CONCLUSIONS

Most of the poorly functioning UPJO kidneys show improvement in function and not all such kidneys should be removed without a trial of PCN.

Percutaneous nephrostomy in infants and children

RATIONALE AND OBJECTIVES

The purpose of this study was to review the authors' experience with percutaneous nephrostomy during an 11-year period, paying special attention to indications and outcomes.

MATERIAL AND METHODS

The records of 71 percutaneous nephrostomy procedures performed on 59 children at the authors' institution from January 1987 through December 1997 were retrospectively reviewed. In these children, ultrasonography was used for puncture and fluoroscopy for catheter insertion. Local anesthesia with sedation was used and later replaced by general anesthesia. Loop-end catheters were employed. The smallest patient weighed 1,200 g, and the mean patient age was 3.4 years.

RESULTS

The mean duration of drainage was 60 days, and the longest time was 11 months. Indications were mainly obstructions, with congenital obstruction (n = 28) and postoperative obstruction (n = 26) being the most common. Obstructive pyelitis, malignancy, stone, renal cystic disease, trauma, and neurogenic bladder disturbance were also indications. No complications such as loss of the kidney, serious infection, or hemorrhage of clinical importance were observed. Obstruction was successfully relieved in all patients, but 12 kidneys and five hemikidneys did not recover function and were eventually removed.

CONCLUSION

The percutaneous nephrostomy procedure is a safe technique that can be used successfully for short- and longterm drainage in all children, even in small infants and those with solitary kidneys, and is a valuable adjunct to surgery.

Correlation of ultrasound and renal scintigraphy in children with unilateral hydronephrosis in primary workup

Ultrasound accurately detects hydronephrosis in infants and children, while nuclear medicine techniques quantify relative renal function in addition to characterizing the urodynamic relevance of hydronephrosis. This prospective study was undertaken to examine the relationship between ultrasound morphological findings and relative renal function, quantified with dynamic 99mtechnetium mercaptotriacetylglycine imaging, in the initial diagnostic workup of children with unilateral hydronephrosis. The ultrasound grade of hydronephrosis and relative renal function ipsilateral to the hydronephrosis were inversely related, indicating that with more severe hydronephrosis ultrasound fails to estimate the potential reduction of relative kidney function. Because renal function is not necessarily affected by hydronephrosis, renal scintigraphy is indicated to assess the functional status of hydronephrotic kidneys.