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Conservative management of paediatric renal abscess
Journal of Pediatric Urology (2013) 9, 1214e1217
Conservative management of paediatric renal abscess Evi Comploj a,*, Walburga Cassar b, Alessandra Farina c, Paolo Gasparella d, Emanuela Trenti a, Salvatore Palermo b, Christopher Burr Dechet a,e, Paolo Caione c, Armin Pycha a a
Department of Urology, Central Hospital of Bolzano, Bolzano (BZ), Italy Department of Pediatrics, Central Hospital of Bolzano, Bolzano, Italy c Division of Pediatric Urology, Department of Nephrology and Urology, Bambino Gesu` Children’s Hospital, IRCCS, Rome, Italy d Unit of Pediatric Surgery, Central Hospital of Bolzano, Bolzano, Italy e Division of Urology, University of Utah, Salt Lake City, UT, USA b
Received 7 March 2013; accepted 15 May 2013 Available online 20 June 2013
KEYWORDS Paediatric renal abscess; Kidney abscess; Conservative management
Abstract Objective: Renal abscesses in the paediatric patient population are a rare entity. Patients are usually treated with percutaneous surgical drainage of the renal abscess as conservative treatment with broad-spectrum antibiotics is not considered as effective. We describe the conservative management of renal abscesses without percutaneous drainage in 6 children. Materials and methods: Six patients with a median age of 31 months, admitted over a 6 year period at two medical centers, were retrospectively studied. All patients were treated conservatively. Results: In all patients, the abscesses were solitary, unilateral and located in the right kidney. The median abscess diameter was 38 mm. The diagnosis was made by ultrasonography. All 6 children were treated conservatively with a urinary catheter or suprapubic catheter and broad-spectrum antibiotics. None of the renal abscesses were surgically or percutaneously drained. Conclusions: A series of 6 paediatric renal abscesses, all successfully treated without surgical intervention, is presented. We believe that, in carefully selected cases, renal abscesses can be managed without percutaneous drainage. Furthermore, all children had complete resolution of the abscess. ª 2013 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.
* Corresponding author. Tel.: þ39 0471 908686; fax: þ39 0471 909738. E-mail addresses: [email protected], [email protected] (E. Comploj), [email protected] (W. Cassar), alessandra. [email protected] (A. Farina), [email protected] (P. Gasparella), [email protected] (E. Trenti), salvatore.palermo@asbz. it (S. Palermo), [email protected] (C.B. Dechet), [email protected] (P. Caione), [email protected] (A. Pycha). 1477-5131/$36 ª 2013 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.jpurol.2013.05.016
Conservative management of paediatric renal abscess
1215
Renal abscesses in the paediatric patient population are a rare entity. Generally they occur in the setting of an ascending infection with obstructed pyelonephritis or in the setting of bacteraemia with haematogenous seeding. Rarely a renal abscess can occur secondary to direct extension from an infected area adjacent to the kidney [1e5]. The differential diagnosis includes acute lobar nephronia, acute pyelonephritis complicated by papillary necrosis, emphysematous pyelonephritis, malacoplakia, tuberculosis or carcinomas. Although rare, renal cell carcinoma or Wilms’ tumour can have a similar presentation, and so an adequate diagnostic work-up is required [1,3,6]. Unfortunately there is often a delay in diagnosis because of the nonspecific clinical presentations. Patients can present with a wide spectrum of symptoms including fever, flank pain, abdominal discomfort, and/or sepsis [1]. Usually, patients are treated with percutaneous surgical drainage of the renal abscess, as conservative treatment with broad spectrum antibiotics is not considered as effective. We describe the conservative management without percutaneous drainage of 6 children who presented with a unilateral renal abscess.
showed a well vascularized peripheral ring (Fig. 1). Upon hospital admission, all 6 children were treated conservatively with a urinary catheter or suprapubic catheter and broad-spectrum antibiotics. Antibacterial therapy was initiated intravenously and continued for a period of 10e21 days. Surgical intervention and/or percutaneous drainage was not performed. Antimicrobial specific therapy was introduced when the cultures (urine or blood culture) were available. Cultures confirmed Escherichia coli in 4 cases, and Enterococcus faecalis or Enterobacter cloacae complex in the other 2 cases. The renal abscesses were monitored by ultrasonography. No computerized tomography (CT) scans were performed. The children defervesced and were asymptomatic within one week of antibiotic therapy. VCUGs performed following treatment of the abscesses revealed abnormal findings in 3 patients (50%): a urethral stenosis in a boy who had previously undergone hypospadias repair, and bilateral VUR (vesicoureteral reflux) detected in two children (one girl and one boy). Three patients had negative VCUGs. Follow-up was a median of 27 months (range 7 monthse7 years). Long-term follow-up has revealed complete resolution of abscess in all children. DMSA renal scan was performed in 4 cases between 2 and 4 months following hospital discharge. In 3 patients, renal scarring was observed, whereas 1 patient revealed no significant residual parenchymal damage.
Material and methods
Discussion
Between January 2006 and June 2012, six paediatric patients discharged from two medical centers with the final diagnosis of a renal abscess were identified. Age, sex, presenting symptoms, diagnostic work-up and treatment were recorded retrospectively. All patients underwent a renal ultrasound and voiding cystourethrogram (VCUG). A DMSA radionuclide renal scan was utilized in selected cases to evaluate renal parenchymal scarring. All the patients had a minimum of 6-months follow-up. B-Mode and PowerDoppler ultrasonography were performed at 1, 3 and 6 months and renal scintigraphy with DMSA scan was performed 3e6 months following abscess treatment.
Renal abscesses consist of purulent and necrotic material confined to the renal parenchyma. In the paediatric patient population, this is a rare and uncommon entity, and often may lead to an initial misdiagnosis with a subsequent delay in treatment. Renal abscesses are seen in all age groups, but the incidence is higher in the elderly adult population, presumed secondary to a higher incidence of skin infections and trauma [7]. They are three times more likely to occur in males than in females [8]. Since the introduction of broadspectrum antimicrobial agents in the 1940s, the percentage of abscesses caused by Staphylococci has decreased [9,10]. Gram-negative organisms, e.g. E. coli are now the most common cause [10,11] of renal abscesses, as seen in our series (4 out of 6 cases). The incidence of renal abscesses in children is unknown. Most abscesses are unilateral (77e97%) and occur more frequently in the right kidney (63%) [1,8]. In all 6 of our cases, a causative agent was identified in the urine and/or blood cultures. In three patients, urologic abnormalities (urethral stenosis, VUR) were identified (Table 1). Classically, abscess formation occurs in the setting of an ascending infection with obstructed pyelonephritis associated with VUR (2 out of 6 cases) or in the setting of a urinary tract obstruction (1 out of 6 cases). In the remaining 3 cases in our series, no urologic abnormalities were identified. Ultrasonography and CT scanning appear to be the most common diagnostic tools. In children, ultrasonography is the quickest method to recognize an abscess and avoids potential radiation exposure of the child. The abscess is often described as a hypoechoic lesion with surrounding hypervascularized parenchyma [12]. The appearance tends
Introduction
Results Six paediatric patients with a median age of 31 months (13e104 months) were retrospectively identified. All children were admitted for renal abscess treatment between January 2006 and April 2012. In all cases, the abscesses were solitary, unilateral, and located in the right kidney. The median abscess diameter was 38 mm (range 25e45 mm). All children presented with high fever, leucocytosis with a median of 16,200/ml (range 11,730e20,100/ml) and a Creactive protein (CRP) elevation with a median of 6.77 mg/ dl (range 1e44.02 mg/dl). The demographic data, clinical presentations, urine and blood cultures, and VCUG results are listed in Table 1. Ultrasonographic evaluation revealed a hypoechoic area within the renal parenchyma surrounded by a thin hyperechoic ring. Power-Doppler scans revealed no vascular signal within the internal, hypoechoic area but
1216
E. Comploj et al.
Table 1
Demographics and clinical characterization of 6 patients with renal abscess.
Patient
Sex
Age (months)
Symptoms at presentation
VCUG
Urine culture
Blood culture
1 2 3 4
Male Male Female Male
13 104 20 18
Negative Negative VUR bilateral Urethral stenosis
Male
48
6
Female
42
Escherichia coli Escherichia coli Escherichia coli Enterococcus faecalis Enterobacter cloacae complex Escherichia coli
Negative Negative Negative Negative
5
Fever UTI, fever and flank pain Pyelonephritis Fever with urinary retention Acute abdominal pain with dysuria, fever Fever, dysuria and abdominal pain
to be that of a well-defined mass, but internal purulent material can be observed (Fig. 1). The management approach of renal abscesses in children is a controversial issue. Classically, this includes antimicrobial therapy and percutaneous drainage of the abscess. Some authors now recommend drainage when there is no clinical response after 48e72 h of empiric
Mild VUR bilateral with right Hutch diverticulum Negative
Enterobacter cloacae complex Negative
antibiotic therapy or in immunocompromised patients [1]. Other authors recommend immediate percutaneous drainage [13] if renal abscesses measure 3e5 cm [8,14,15]. We treated all our patients, with renal abscesses between 2.5 and 4.5 cm, without the need for percutaneous drainage. All patients were managed with broad-spectrum intravenous antibiotic therapy and transient (2e6 days)
Figure 1 Ultrasonographic features of an abscess in the right kidney: a) a hypoechoic mass occupying the middle portion of the kidney. b) Power-Doppler reveals vascular ring surrounding the non-vascularized parenchymal abscess. c) and d) Progressive reduction of the lesion until almost complete resolution at 7 and 10 days.
Conservative management of paediatric renal abscess transurethral bladder catheterization. The use of ultrasonography avoided the possible harmful effects of CT scanning in this paediatric population. A high degree of peripheral vascularization within the renal parenchyma was seen in these paediatric renal abscesses. This may help explain the success of treating such patients with antibiotic therapy only and avoiding percutaneous/surgical drainage.
Conclusion A series of 6 paediatric cases with renal abscesses is presented. All patients were successfully treated without surgical intervention. We believe that in carefully selected cases, percutaneous drainage can be avoided and children can be managed conservatively. Careful ultrasonographic monitoring during treatment is recommended.
Conflict of interest statement There is any financial and personal relationships with other people or organizations.
Acknowledgement There are no financial or commercial interests. No funding source was involved with this work.
References [1] Chaudhry S, Bolt R. Bilateral renal abscess in a previously healthy 11-year-old girl. Eur J Pediatr 2010;169(11):1423e5.
1217 [2] Angel C, Shu T, Green J, Orihuela E, Rodriquez G, Hendrick E. Renal and peri-renal abscesses in children: proposed physiopathologic mechanisms and treatment algorithm. Pediatr Surg Int 2003;19:35e9. [3] Brook I. The role of anaerobic bacteria in perinephric and renal abscesses in children. Pediatrics 1994;93(2):261e4. [4] Cheng CH, Tsai MH, Su LH, Wang CR, Lo WC, Tsau YK, et al. Renal abscess in children: a 10-year clinical and radiologic experience in a tertiary medical center. Pediatr Infect Dis J 2008;27(11):1025e7. [5] Constantine S, Kaye J. Metastatic renal abscess mimicking Wilms’ tumour. Pediatr Radiol 2004;34(11):924e6. [6] http://www.uptodate.com/contents/renal-andperinephricabscess?. [7] Baradkar VP, Mathur M, Kumar S. Renal abscess due to Escherichia coli in a child. Saudi J Kidney Dis Transpl 2001;22: 1215e8. [8] Dembry LM, Andriole VT. Renal and perirenal abscesses. Infect Dis Clin North Am 1997;11(3):663e80. [9] Thorley JD, Jones SR, Sanford JP. Perinephric abscess. Medicine (Baltimore) 1974;53(6):441e51. [10] Rote AR, Bauer SB, Retik AB. Renal abscess in children. J Urol 1978;119(2):254e8. [11] Steele BT, Petrou C, de Maria J. Renal abscess in children. Urology 1990;36(4):325e8. [12] Fiegler W. Ultrasound in acute renal inflammatory lesions. Eur J Radiol 1983;3(4):354e7. [13] Pampinella D, Giordano S, Failla MC, Di Gangi M, Matina F, Nasta R, et al. Ascesso renale in eta ´ pediatrica: descrizione di un caso [Renal abscess in childhood: a case report]. Le infezioni in Medicina 2011;4:254e6. [14] Siegel JF, Smith A, Moldwin R. Minimally invasive treatment of renal abscess. J Urol 1996;155(1):52e5. [15] Lang EK. Renal, perirenal, and pararenal abscesses: percutaneous drainage. Radiology 1990;174(1):109e13.
Conservative management of paediatric renal abscess Evi Comploj a,*, Walburga Cassar b, Alessandra Farina c, Paolo Gasparella d, Emanuela Trenti a, Salvatore Palermo b, Christopher Burr Dechet a,e, Paolo Caione c, Armin Pycha a a
Department of Urology, Central Hospital of Bolzano, Bolzano (BZ), Italy Department of Pediatrics, Central Hospital of Bolzano, Bolzano, Italy c Division of Pediatric Urology, Department of Nephrology and Urology, Bambino Gesu` Children’s Hospital, IRCCS, Rome, Italy d Unit of Pediatric Surgery, Central Hospital of Bolzano, Bolzano, Italy e Division of Urology, University of Utah, Salt Lake City, UT, USA b
Received 7 March 2013; accepted 15 May 2013 Available online 20 June 2013
KEYWORDS Paediatric renal abscess; Kidney abscess; Conservative management
Abstract Objective: Renal abscesses in the paediatric patient population are a rare entity. Patients are usually treated with percutaneous surgical drainage of the renal abscess as conservative treatment with broad-spectrum antibiotics is not considered as effective. We describe the conservative management of renal abscesses without percutaneous drainage in 6 children. Materials and methods: Six patients with a median age of 31 months, admitted over a 6 year period at two medical centers, were retrospectively studied. All patients were treated conservatively. Results: In all patients, the abscesses were solitary, unilateral and located in the right kidney. The median abscess diameter was 38 mm. The diagnosis was made by ultrasonography. All 6 children were treated conservatively with a urinary catheter or suprapubic catheter and broad-spectrum antibiotics. None of the renal abscesses were surgically or percutaneously drained. Conclusions: A series of 6 paediatric renal abscesses, all successfully treated without surgical intervention, is presented. We believe that, in carefully selected cases, renal abscesses can be managed without percutaneous drainage. Furthermore, all children had complete resolution of the abscess. ª 2013 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.
* Corresponding author. Tel.: þ39 0471 908686; fax: þ39 0471 909738. E-mail addresses: [email protected], [email protected] (E. Comploj), [email protected] (W. Cassar), alessandra. [email protected] (A. Farina), [email protected] (P. Gasparella), [email protected] (E. Trenti), salvatore.palermo@asbz. it (S. Palermo), [email protected] (C.B. Dechet), [email protected] (P. Caione), [email protected] (A. Pycha). 1477-5131/$36 ª 2013 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.jpurol.2013.05.016
Conservative management of paediatric renal abscess
1215
Renal abscesses in the paediatric patient population are a rare entity. Generally they occur in the setting of an ascending infection with obstructed pyelonephritis or in the setting of bacteraemia with haematogenous seeding. Rarely a renal abscess can occur secondary to direct extension from an infected area adjacent to the kidney [1e5]. The differential diagnosis includes acute lobar nephronia, acute pyelonephritis complicated by papillary necrosis, emphysematous pyelonephritis, malacoplakia, tuberculosis or carcinomas. Although rare, renal cell carcinoma or Wilms’ tumour can have a similar presentation, and so an adequate diagnostic work-up is required [1,3,6]. Unfortunately there is often a delay in diagnosis because of the nonspecific clinical presentations. Patients can present with a wide spectrum of symptoms including fever, flank pain, abdominal discomfort, and/or sepsis [1]. Usually, patients are treated with percutaneous surgical drainage of the renal abscess, as conservative treatment with broad spectrum antibiotics is not considered as effective. We describe the conservative management without percutaneous drainage of 6 children who presented with a unilateral renal abscess.
showed a well vascularized peripheral ring (Fig. 1). Upon hospital admission, all 6 children were treated conservatively with a urinary catheter or suprapubic catheter and broad-spectrum antibiotics. Antibacterial therapy was initiated intravenously and continued for a period of 10e21 days. Surgical intervention and/or percutaneous drainage was not performed. Antimicrobial specific therapy was introduced when the cultures (urine or blood culture) were available. Cultures confirmed Escherichia coli in 4 cases, and Enterococcus faecalis or Enterobacter cloacae complex in the other 2 cases. The renal abscesses were monitored by ultrasonography. No computerized tomography (CT) scans were performed. The children defervesced and were asymptomatic within one week of antibiotic therapy. VCUGs performed following treatment of the abscesses revealed abnormal findings in 3 patients (50%): a urethral stenosis in a boy who had previously undergone hypospadias repair, and bilateral VUR (vesicoureteral reflux) detected in two children (one girl and one boy). Three patients had negative VCUGs. Follow-up was a median of 27 months (range 7 monthse7 years). Long-term follow-up has revealed complete resolution of abscess in all children. DMSA renal scan was performed in 4 cases between 2 and 4 months following hospital discharge. In 3 patients, renal scarring was observed, whereas 1 patient revealed no significant residual parenchymal damage.
Material and methods
Discussion
Between January 2006 and June 2012, six paediatric patients discharged from two medical centers with the final diagnosis of a renal abscess were identified. Age, sex, presenting symptoms, diagnostic work-up and treatment were recorded retrospectively. All patients underwent a renal ultrasound and voiding cystourethrogram (VCUG). A DMSA radionuclide renal scan was utilized in selected cases to evaluate renal parenchymal scarring. All the patients had a minimum of 6-months follow-up. B-Mode and PowerDoppler ultrasonography were performed at 1, 3 and 6 months and renal scintigraphy with DMSA scan was performed 3e6 months following abscess treatment.
Renal abscesses consist of purulent and necrotic material confined to the renal parenchyma. In the paediatric patient population, this is a rare and uncommon entity, and often may lead to an initial misdiagnosis with a subsequent delay in treatment. Renal abscesses are seen in all age groups, but the incidence is higher in the elderly adult population, presumed secondary to a higher incidence of skin infections and trauma [7]. They are three times more likely to occur in males than in females [8]. Since the introduction of broadspectrum antimicrobial agents in the 1940s, the percentage of abscesses caused by Staphylococci has decreased [9,10]. Gram-negative organisms, e.g. E. coli are now the most common cause [10,11] of renal abscesses, as seen in our series (4 out of 6 cases). The incidence of renal abscesses in children is unknown. Most abscesses are unilateral (77e97%) and occur more frequently in the right kidney (63%) [1,8]. In all 6 of our cases, a causative agent was identified in the urine and/or blood cultures. In three patients, urologic abnormalities (urethral stenosis, VUR) were identified (Table 1). Classically, abscess formation occurs in the setting of an ascending infection with obstructed pyelonephritis associated with VUR (2 out of 6 cases) or in the setting of a urinary tract obstruction (1 out of 6 cases). In the remaining 3 cases in our series, no urologic abnormalities were identified. Ultrasonography and CT scanning appear to be the most common diagnostic tools. In children, ultrasonography is the quickest method to recognize an abscess and avoids potential radiation exposure of the child. The abscess is often described as a hypoechoic lesion with surrounding hypervascularized parenchyma [12]. The appearance tends
Introduction
Results Six paediatric patients with a median age of 31 months (13e104 months) were retrospectively identified. All children were admitted for renal abscess treatment between January 2006 and April 2012. In all cases, the abscesses were solitary, unilateral, and located in the right kidney. The median abscess diameter was 38 mm (range 25e45 mm). All children presented with high fever, leucocytosis with a median of 16,200/ml (range 11,730e20,100/ml) and a Creactive protein (CRP) elevation with a median of 6.77 mg/ dl (range 1e44.02 mg/dl). The demographic data, clinical presentations, urine and blood cultures, and VCUG results are listed in Table 1. Ultrasonographic evaluation revealed a hypoechoic area within the renal parenchyma surrounded by a thin hyperechoic ring. Power-Doppler scans revealed no vascular signal within the internal, hypoechoic area but
1216
E. Comploj et al.
Table 1
Demographics and clinical characterization of 6 patients with renal abscess.
Patient
Sex
Age (months)
Symptoms at presentation
VCUG
Urine culture
Blood culture
1 2 3 4
Male Male Female Male
13 104 20 18
Negative Negative VUR bilateral Urethral stenosis
Male
48
6
Female
42
Escherichia coli Escherichia coli Escherichia coli Enterococcus faecalis Enterobacter cloacae complex Escherichia coli
Negative Negative Negative Negative
5
Fever UTI, fever and flank pain Pyelonephritis Fever with urinary retention Acute abdominal pain with dysuria, fever Fever, dysuria and abdominal pain
to be that of a well-defined mass, but internal purulent material can be observed (Fig. 1). The management approach of renal abscesses in children is a controversial issue. Classically, this includes antimicrobial therapy and percutaneous drainage of the abscess. Some authors now recommend drainage when there is no clinical response after 48e72 h of empiric
Mild VUR bilateral with right Hutch diverticulum Negative
Enterobacter cloacae complex Negative
antibiotic therapy or in immunocompromised patients [1]. Other authors recommend immediate percutaneous drainage [13] if renal abscesses measure 3e5 cm [8,14,15]. We treated all our patients, with renal abscesses between 2.5 and 4.5 cm, without the need for percutaneous drainage. All patients were managed with broad-spectrum intravenous antibiotic therapy and transient (2e6 days)
Figure 1 Ultrasonographic features of an abscess in the right kidney: a) a hypoechoic mass occupying the middle portion of the kidney. b) Power-Doppler reveals vascular ring surrounding the non-vascularized parenchymal abscess. c) and d) Progressive reduction of the lesion until almost complete resolution at 7 and 10 days.
Conservative management of paediatric renal abscess transurethral bladder catheterization. The use of ultrasonography avoided the possible harmful effects of CT scanning in this paediatric population. A high degree of peripheral vascularization within the renal parenchyma was seen in these paediatric renal abscesses. This may help explain the success of treating such patients with antibiotic therapy only and avoiding percutaneous/surgical drainage.
Conclusion A series of 6 paediatric cases with renal abscesses is presented. All patients were successfully treated without surgical intervention. We believe that in carefully selected cases, percutaneous drainage can be avoided and children can be managed conservatively. Careful ultrasonographic monitoring during treatment is recommended.
Conflict of interest statement There is any financial and personal relationships with other people or organizations.
Acknowledgement There are no financial or commercial interests. No funding source was involved with this work.
References [1] Chaudhry S, Bolt R. Bilateral renal abscess in a previously healthy 11-year-old girl. Eur J Pediatr 2010;169(11):1423e5.
1217 [2] Angel C, Shu T, Green J, Orihuela E, Rodriquez G, Hendrick E. Renal and peri-renal abscesses in children: proposed physiopathologic mechanisms and treatment algorithm. Pediatr Surg Int 2003;19:35e9. [3] Brook I. The role of anaerobic bacteria in perinephric and renal abscesses in children. Pediatrics 1994;93(2):261e4. [4] Cheng CH, Tsai MH, Su LH, Wang CR, Lo WC, Tsau YK, et al. Renal abscess in children: a 10-year clinical and radiologic experience in a tertiary medical center. Pediatr Infect Dis J 2008;27(11):1025e7. [5] Constantine S, Kaye J. Metastatic renal abscess mimicking Wilms’ tumour. Pediatr Radiol 2004;34(11):924e6. [6] http://www.uptodate.com/contents/renal-andperinephricabscess?. [7] Baradkar VP, Mathur M, Kumar S. Renal abscess due to Escherichia coli in a child. Saudi J Kidney Dis Transpl 2001;22: 1215e8. [8] Dembry LM, Andriole VT. Renal and perirenal abscesses. Infect Dis Clin North Am 1997;11(3):663e80. [9] Thorley JD, Jones SR, Sanford JP. Perinephric abscess. Medicine (Baltimore) 1974;53(6):441e51. [10] Rote AR, Bauer SB, Retik AB. Renal abscess in children. J Urol 1978;119(2):254e8. [11] Steele BT, Petrou C, de Maria J. Renal abscess in children. Urology 1990;36(4):325e8. [12] Fiegler W. Ultrasound in acute renal inflammatory lesions. Eur J Radiol 1983;3(4):354e7. [13] Pampinella D, Giordano S, Failla MC, Di Gangi M, Matina F, Nasta R, et al. Ascesso renale in eta ´ pediatrica: descrizione di un caso [Renal abscess in childhood: a case report]. Le infezioni in Medicina 2011;4:254e6. [14] Siegel JF, Smith A, Moldwin R. Minimally invasive treatment of renal abscess. J Urol 1996;155(1):52e5. [15] Lang EK. Renal, perirenal, and pararenal abscesses: percutaneous drainage. Radiology 1990;174(1):109e13.