Minimally Invasive Treatment of Renal Abscess

Guidelines for the Prevention, Diagnosis, and Management of Urinary Tract Infections in Pediatrics and Adults: A WikiGuidelines Group Consensus Statement

Importance

Traditional approaches to practice guidelines frequently result in dissociation between strength of recommendation and quality of evidence.

Objective

To create a clinical guideline for the diagnosis and management of urinary tract infections that addresses the gap between the evidence and recommendation strength.

Evidence Review

This consensus statement and systematic review applied an approach previously established by the WikiGuidelines Group to construct collaborative clinical guidelines. In May 2023, new and existing members were solicited for questions on urinary tract infection prevention, diagnosis, and management. For each topic, literature searches were conducted up until early 2024 in any language. Evidence was reported according to the WikiGuidelines charter: clear recommendations were established only when reproducible, prospective, controlled studies provided hypothesis-confirming evidence. In the absence of such data, clinical reviews were developed discussing the available literature and associated risks and benefits of various approaches.

Findings

A total of 54 members representing 12 countries reviewed 914 articles and submitted information relevant to 5 sections: prophylaxis and prevention (7 questions), diagnosis and diagnostic stewardship (7 questions), empirical treatment (3 questions), definitive treatment and antimicrobial stewardship (10 questions), and special populations and genitourinary syndromes (10 questions). Of 37 unique questions, a clear recommendation could be provided for 6 questions. In 3 of the remaining questions, a clear recommendation could only be provided for certain aspects of the question. Clinical reviews were generated for the remaining questions and aspects of questions not meeting criteria for a clear recommendation.

Conclusions and Relevance

In this consensus statement that applied the WikiGuidelines method for clinical guideline development, the majority of topics relating to prevention, diagnosis, and treatment of urinary tract infections lack high-quality prospective data and clear recommendations could not be made. Randomized clinical trials are underway to address some of these gaps; however further research is of utmost importance to inform true evidence-based, rather than eminence-based practice.

Ultrasound-Mediated Antibiotic Delivery to In Vivo Biofilm Infections: A Review

Bacterial biofilms are a significant concern in various medical contexts due to their resilience to our immune system as well as antibiotic therapy. Biofilms often require surgical removal and frequently lead to recurrent or chronic infections. Therefore, there is an urgent need for improved strategies to treat biofilm infections. Ultrasound-mediated drug delivery is a technique that combines ultrasound application, often with the administration of acoustically-active agents, to enhance drug delivery to specific target tissues or cells within the body. This method involves using ultrasound waves to assist in the transportation or activation of medications, improving their penetration, distribution, and efficacy at the desired site. The advantages of ultrasound-mediated drug delivery include targeted and localized delivery, reduced systemic side effects, and improved efficacy of the drug at lower doses. This review scrutinizes recent advances in the application of ultrasound-mediated drug delivery for treating biofilm infections, focusing on in vivo studies. We examine the strengths and limitations of this technology in the context of wound infections, device-associated infections, lung infections and abscesses, and discuss current gaps in knowledge and clinical translation considerations.

Successful treatment of a renal allograft abscess with antimicrobial agents alone and appropriate follow-up imaging

A renal allograft abscess is a relatively rare condition. Appropriate antimicrobial therapy and drainage are recommended for treating renal abscesses. However, drainage can be challenging, depending on the location of the abscess. We present the case of a young female kidney transplant recipient who was successfully cured of a renal allograft abscess, using antimicrobial agents and appropriate follow-up imaging, without the need of any risky procedures.

Renal Abscess Drainage Using a Novel Transgastric Endoscopic Approach: A Case Report

Renal and perinephric abscesses are rare purulent infections within or around renal parenchyma, typically treated with antibiotics or various procedural approaches depending on abscess size. In this case report, we describe the novel use of a transgastric endoscopic ultrasound (EUS)-guided technique with placement of a stent for drainage between a renal abscess and the stomach in a patient who had failed attempted percutaneous drainage twice and where an open surgical approach was deemed inappropriate. The patient presented with a chief complaint of left flank pain, with CT revealing a ~4 x 4 cm renal abscess in the upper pole of the left kidney. Urology, Infectious Disease, and Interventional Radiology were consulted. Following two failed attempts at percutaneous drain placement, the patient elected for EUS-guided transgastric stent placement for drainage. The stent was removed by postoperative day two after significant decompression of the abscess. He was advised to follow up outpatient with Urology to confirm full renal abscess resolution.

A pictorial review of genitourinary infections and inflammations

Various infectious and inflammatory diseases affect the genitourinary system. This paper provides a review of multiple common and uncommon infectious and inflammatory conditions affecting the genitourinary system and some associated complications. These include acute infectious cystitis, emphysematous cystitis, acute pyelonephritis, emphysematous pyelonephritis, renal and perinephric abscesses, pyonephrosis, xanthogranulomatous pyelonephritis, epididymo-orchitis, vasitis, prostatitis, pelvic inflammatory disease, renal hydatid infection, renal tuberculosis, actinomycosis, Erdheim-Chester Disease, IgG4-Related Kidney Disease, urethritis and urethral strictures, ureteritis cystica, and genitourinary fistulas. Radiologists should be aware of these diseases' complications and management. Uncommon conditions must be considered when evaluating the genitourinary system.

Urinary tract infection in children: A narrative review of clinical practice guidelines

Background

Urinary tract infection (UTI) has been a major burden on the community and the health-care systems all over the globe. It is the most common cause of bacterial infection in the pediatric age group, with an annual incidence of 3%. The aim of this study is to review and summarize all available guidelines on the diagnosis and management of children with UTI.

Materials and Methods

This is a narrative review of the management of children with a UTI. All biomedical databases were searched, and any guidelines published from 2000 to 2022 were retrieved, reviewed, and evaluated to be included in the summary statements. The sections of the articles were formulated according to the availability of information in the included guidelines.

Results

UTI diagnoses are based on positive urine culture from a specimen of urine obtained through catheterization or suprapubic aspiration, and diagnoses cannot be established on the bases of urine collected from a bag. The criteria for diagnosing UTI are based on the presence of at least 50,000 colony-forming units per milliliter of a uropathogen. Upon confirmation of UTI, the clinician should instruct parents to seek rapid medical assessment (ideally within 48 h) of future febrile disease to ensure that frequent infections can be detected and treated immediately. The choice of therapy depends on several factors, including the age of the child, underlying medical problems, the severity of the disease, the ability to tolerate oral medications, and most importantly local patterns of uropathogens resistance. Initial antibiotic choice of treatment should be according to the sensitivity results or known pathogens patterns with comparable efficacy of oral and parenteral route, for 7 days to 14 days duration. Renal and bladder ultrasonography is the investigation of choice for febrile UTI, and voiding cystourethrography should not be performed routinely unless indicated.

Conclusion

This review summarizes all the recommendations related to UTIs in the pediatric population. Due to the lack of appropriate data, further high-quality studies are required to improve the level and strength of recommendations in the future.

Large Renal Abscess in Pregnancy: Case Report of a Rare Finding

The incidence of renal abscesses during pregnancy has not been well-established. A renal abscess is usually secondary to the complications of acute pyelonephritis and can lead to severe consequences, including fetal and/or maternal death. Little is known about the incidence of renal abscesses in pregnant women; however, the literature consistently refers to it as an extremely rare occurrence. We report a case of a large renal abscess discovered in the early postpartum period following a recurrent urinary tract infection and flank pain during pregnancy. The patient was successfully managed with abscess drainage and prolonged antibiotics.

Renal abscess with Capnocytophaga canimorsus infection from a dog bite

We present a case of renal abscess caused by Capnocytophaga canimorsus infection in a previously healthy middle-aged man. He presented with sepsis and an acute kidney injury, and although not identified on his initial assessment, he had sustained a dog bite 5 days prior to hospital admission. The patient developed left loin pain and imaging investigation revealed a renal abscess. Gram stain showed a gram-negative bacillus and C. canimorsus was identified by 16S PCR from these samples along with aspirate from the abscess. The patient responded to treatment with carbapenems but required a prolonged course. His clinical condition was further complicated by a pleural effusion and the development of fatigue symptoms consistent with a post-infection chronic fatigue syndrome. We present this case which we believe to be the first documented case of C. canimorsus causing renal abscess. We discuss the challenges relating to investigation, management and the importance of detailed diagnostic exposure histories in sepsis of unknown origin.

Iliopsoas abscess in patients receiving hemodialysis: a case series and a literature survey

Background

Iliopsoas abscess is a relatively rare but serious infectious disease. Infectious disease is one of the major causes of death among patients receiving hemodialysis for end-stage renal disease (ESRD).

Case presentation

We experienced three cases of iliopsoas abscess in patients receiving hemodialysis. The infection route was distinct in each case. A 79-year-old woman with ESRD due to autosomal dominant polycystic kidney disease exhibited bilateral iliopsoas abscesses caused by bacterial contamination during a lumbar epidural block procedure. A 60-year-old woman with ESRD due to diabetic nephropathy was diagnosed as having an iliopsoas abscess, caused by the direct invasion of bacteria from a renal abscess. A 78-year-old woman who started hemodialysis because of nephrosclerosis developed an iliopsoas abscess caused by the hematogenous spread of bacteria from emphysematous cystitis. All three cases were treated with antibiotics and/or percutaneous drainage. A survey of published reports suggested that iliopsoas abscess can be caused by infection through a variety of routes in hemodialysis patients.

Conclusion

Because hemodialysis patients are at a high risk of infection because of their immunocompromised state, physicians should pay close attention to infection prevention. If iliopsoas abscess is suspected, examinations such as computed tomography, magnetic resonance imaging, and blood culture sampling should be conducted promptly, followed by appropriate treatment with antibiotics and/or drainage.

Renal abscesses in children: an 11-year retrospective study and review of the literature

BACKGROUND

There is limited literature on renal abscesses in children and therefore no consensus on management. The objectives of this study were to describe renal abscesses in a contemporary paediatric Australian population and present a 20 year review of the literature.

METHODS

An 11 year retrospective comparative study was conducted of paediatric patients with renal abscesses. A literature review of all eight original articles on paediatric renal abscesses from January 2001 to December 2021 was performed.

RESULTS

Fourteen children with a mean age of 11 years were diagnosed with a renal abscess on ultrasound and/or computed tomography. The most common presenting symptoms were fever (n = 13, 93%) and flank or abdominal pain (n = 12, 86%). The most common causative organisms were Staphylococcus aureus (n = 7, 50%) and Escherichia coli (n = 4, 29%). All renal abscesses less than 3 cm were managed with antibiotics alone. Five out of nine abscesses 3-5 cm were managed with percutaenous drainage (56%). Two multi-loculated abscesses greater than 5 cm required open drainage in theatre (100%).

CONCLUSIONS

The most common causative organism in the North Queensland population was S. aureus, with a higher incidence of MRSA. This should be taken into consideration when prescribing empirical antibiotics. Most renal abscesses in children that are less than 3 cm in size can be managed with antibiotic therapy only. The evidence for management of larger abscesses is less clear, but where clinically appropriate conservative management with antibiotic therapy should be considered in the first instance, with percutaneous drainage in cases of antibiotic failure.

A case of Citrobacter koseri renal abscess and review of the literature

Citrobacter species are anaerobic gram-negative bacteria that are known to cause infections in immunocompromised hosts, particularly in hospital settings. Their opportunistic nature and tendency to develop antibiotic resistance make Citrobacter species challenging to treat. Renal or perinephric abscess formation as a result of Citrobacter infection is uncommon, having only previously been reported in four cases. We present a case of a 70-year-old man with diabetes and prostate cancer who was diagnosed with an 18 cm perinephric and a 10 cm perihepatic abscess caused by Citrobacter koseri. The patient required drains and re-positioning of the drains multiple times in addition to a prolonged course of antibiotics to achieve complete radiographic resolution. This case highlights the challenges in treating renal and perinephric abscess, as it required drain re-placements two additional times after the initial placement and an additional 4 weeks of antibiotics. Successful treatment for larger abscesses usually requires a two-arm approach, with antibiotics in combination with either percutaneous or surgical abscess drainage.

Renal abscess in children: Is size an important determinant in deciding treatment options?

Background:

Renal abscess (RA) is rarely seen in the paediatric age group. The proposed management protocols are mainly derived from the adult series which may not be appropriate in children.

Objective:

In this retrospective analysis of cases with renal and perinephric abscesses, the objective is to correlate the clinical presentation, radiological findings and treatment options and also to propose a paediatric-specific practical management algorithm.

Study design:

This is a retrospective study of cases with renal and perinephric abscesses admitted between March 2012 and February 2020. The patients were reviewed for demographics, presentation, predisposing factors, laboratory investigations, imaging, management and outcome.

Results:

Analysis of 12 paediatric patients (13 renal units) with RA (median age 4 years) was done. Organisms were isolated in 8 of 12 (66.6%) patients with Gram-negative organisms being the commonest. On admission, all patients were started on empirical broad-spectrum antibiotics. Except for two patients who were critically ill with frank sepsis and had a tender renal lump, the rest of them were initially offered conservative management with intravenous antibiotics, and the response was reviewed after 48–72 hours. Of five units with abscess size of ⩽3 cm, two units (40%) responded to conservative management, while three units (60%) required intervention, and of eight units of size >3 cm, three units (37.5%) responded to conservative management and five units (62.5%) required intervention. None of the abscesses with perinephric collection (30.7%) responded to antibiotics and required intervention.

Conclusion:

A protocol based on the size of RA as recommended in most of the adult series may not be appropriate in the paediatric age group because of the differences in clinical presentation, predisposing factors and immune response. The clinical condition on presentation, response to antibiotic therapy and the presence of perinephric collection should be considered as an important determinant in deciding the need for intervention.

Level of evidence:

4

A case of a renal abscess caused by Salmonella bareilly in a previously healthy boy

Background

Renal abscesses are relatively uncommon in children, and usually due to Gram-negative rods or Staphylococcus aureus, whereas abscesses caused by Salmonella are very rare.

Case presentation

We present the case of a previously healthy 10-year-old boy who had a renal abscess due to Salmonella bareilly. He responded well to treatment with antibiotics, and computed tomography (CT)-guided drainage of the abscess. His blood, urine and abscess aspirate cultures were sterile, but a broad-range 16S rDNA polymerase chain reaction (PCR) assay of the aspirate followed by analysis of four Salmonella genes (fliC, fliD, sopE2, and spaO) identified S. bareilly as the causative agent.

Conclusion

To the best of our knowledge, this is the first report of renal abscess caused by S. bareilly.

Bilateral renal abscess fusing with the psoas on the right: A case report

Renal abscess is a medical and surgical urological emergency whose diagnosis has been improved by modern imaging.

It often poses a problem of therapeutic management between antibiotic therapy or the association of a drainage. Most abscesses are unilateral, the bilateral nature of the abscessed lesions suggests a hematogenous diffusion.

We report a case of a bilateral renal abscess fusing to the psoas muscle on the right that progressed well with antibiotic treatment and percutaneous drainage.

Imaging-guided drainage of renal abscess: A case report and literature review

Renal and perinephric abscesses are rare but severe infections of urinary tract. It may have atypical causes and requires usually an emergency management. A young patient presented with right flank pain, fever and chills was diagnosed with a large renal abscess ruptured in perinephric space. He underwent successful percutaneous drainage guided by both ultrasound and computed tomography of the abdomen. The concept of percutaneous route and the role of imaging, particularly ultrasound, in managing such emergencies are discussed alongside with a review of current literature.

Section headings

Inflammation and Infection.

Renal abscess caused by Panton-Valentine leukocidin-producing Staphylococcus aureus: report of an unusual case and review of the literature

BACKGROUND

Renal abscesses are rare and mainly caused by an ascending infection due to Gram-negative microorganisms. We report the first case of a renal abscess caused by Panton-Valentine leukocidin-producing Staphylococcus aureus in an immunocompetent patient, and we present a comprehensive review of the literature.

CASE PRESENTATION

A 20-year-old immunocompetent woman had a 2-month history of left-sided back pain, fever and urinary symptoms. Urinalysis showed leukocyturia (19,000/mm³) without bacteriuria. Intravenous cefotaxime treatment was initiated. A computed tomographic scan showed a large abscess in the left kidney. Computed tomographic percutaneous drainage was done and cultures of abscess and blood grew methicillin-susceptible Panton-Valentine leukocidin-producing Staphylococcus aureus. Treatment was switched to cefazoline and then to clindamycin for 21 days. The patient quickly improved and the abscess was completely resolved 6 months after end of antibiotic treatment.

CONCLUSION

To our knowledge, this is the first report of a renal abscess caused by Panton-Valentine leukocidin-producing Staphylococcus aureus. Treatment with percutaneous drainage and an antibiotic with toxin inhibiting effect was successful.

Diagnosis and Treatment of Retroperitoneal Infection

Background: Retroperitoneal infection is a persistent and widespread infectious disease that is difficult to treat. It is usually caused by secondary complications such as inflammation, damage, or perforation of adjacent organs in the retroperitoneal space. Pathogenic bacteria invade the retroperitoneal space through retroperitoneal and interstitial organs, peripheral tissue, and the blood. As a result, infections mostly arise from severe acute pancreatitis, acute colonic diverticulitis, inflammatory bowel disease, kidney abscess, and biliary tract injury. Initially manifested by the presence of lumbago, this disease spreads easily, is persistent, and is often misdiagnosed. Methods: Review and synthesis of pertinent literature and guidelines pertaining to abdominal infection and retroperitoneal infection. Results: Recent data indicate that mortality rates associated with retroperitoneal infection have been increasing annually. Early diagnosis and treatment have been shown to improve the prognosis. In the early stage, infection is insidious and lacks typical symptoms, and is primarily diagnosed with computed tomography (CT). Strategies that control the source of infection, rational use of antibiotic agents, and nutritional interventions are the primary approaches to treat the infections. Emergence of minimally invasive drainage technologies, including the ultrasound/CT-guided puncture and drainage, percutaneous nephroscope puncture and drainage, and drainage using a catheter through an abdominal puncture device (trocar) have shortened the treatment cycle and disease burden. However, current diagnosis and treatment for retroperitoneal infection are not sufficiently effective because some patients do not show typical clinical manifestations. Moreover, sensitivity and specificity of available auxiliary examination methods are not supported by sufficient evidence-based medical research. Additionally, there are no uniform standards on the timing of surgical intervention and treatment options. Therefore, we summarized the progresses on current diagnosis and treatment approaches for retroperitoneal infection.

Successful medical management of perinephric abscess and urosepsis following urethral obstruction in a cat

OBJECTIVE

To describe the clinical presentation and medical management of a cat with perinephric abscessation and urosepsis following urethral obstruction and catheterization.

CASE SUMMARY

A 2-year-old intact male domestic shorthaired cat presented to an emergency and referral center for lethargy, vomiting, and hematuria. Severe azotemia and hyperkalemia were observed on a serum biochemistry panel. The patient was diagnosed with urethral obstruction and was treated with urethral catheterization, calcium gluconate, IV fluid therapy, buprenorphine, and prazosin. The patient's azotemia improved, and the hyperkalemia resolved. Urinary catheterization was discontinued. The patient developed pyrexia, worsening azotemia, hypoalbuminemia, hyperbilirubinemia, and dysuria. Urethral catheterization was repeated. Abdominal radiographs showed left renomegaly, and abdominal ultrasound revealed left perinephric fluid. Ultrasound-guided centesis of the perinephric fluid revealed septic inflammation, and the sample was consistent with urine based upon sample creatinine. Fluid from the perinephric abscess and urine from the bladder both grew Pasturella spp. The patient was treated with perinephric catheterization, saline lavage, and a continuous infusion of cefotaxime for 72 h. The patient's azotemia quickly resolved, and the patient was discharged after 6 days of hospitalization. The patient was reported to have made a full recovery.

NEW OR UNIQUE INFORMATION PROVIDED

This is the first described case of perinephric abscess and urosepsis following urethral obstruction in a cat and its successful medical management. Perinephric abscess not associated with intrarenal abscess has not previously been identified. Additionally, continuous antimicrobial infusion to treat overwhelming infection and the use of the RapidBac Vet immunoassay for point-of-care detection of urinary tract infection has not been described in cats.

Asymptomatic Bacteriuria in Pregnancy Complicated by Pyelonephritis Requiring Nephrectomy

Routine prenatal care in the United States includes screening for asymptomatic bacteriuria (ASB), which occurs in 2 to 7 percent of pregnant women and can cause urinary tract infection and pyelonephritis. We present the case of a pregnant woman affected by multidrug resistant Klebsiella induced ASB during her prenatal screen, which was untreated due to a repeat urine culture showing mixed flora; subsequently, the patient's postpartum course was complicated by pyelonephritis and perinephric abscess, concluding in a radical nephrectomy. Current recommendations are to treat ASB after two consecutive voided urine cultures showing the same bacterial strain in quantitative counts of =/> 10(5) colony forming units (cfu)/mL or a single-catheterized specimen with quantitative count of =/> 10(2) cfu/mL. For women with ASB in their prenatal screen or other high risk factors, consideration should be given to testing urine cultures every trimester until the completion of pregnancy to prevent the complications of persistent bacteriuria.

Invasive Group B streptococcus: multiloculated perinephric abscesses treated with percutaneous drainage

Group B streptococcus infections (GBSI) are commonly associated with neonates and pregnant women, but may also affect nonpregnant adults. Among its spectrum of manifestations, perinephric abscess (PA) is exceedingly rare. Comorbid conditions such as diabetes mellitus (DM) and immunosuppression increase the risk of GBSI. We describe a 61-year-old Vietnamese man with compensated alcoholic cirrhosis, who presented with acute encephalopathy following subacute, progressive abdominal pain. He was afebrile and hemodynamically stable. Laboratory data were remarkable for leukocytosis, thrombocytopenia, azotemia, and pyuria. He was found to have two right-sided PA measuring 15 × 10 × 11 cm and 4.6 × 2.7 × 7.8 cm, requiring interval placement of multiple percutaneous drains. Culture from abscesses revealed beta-hemolytic Group B streptococcus (GBS). His course was complicated by contiguous spread to abdominal wall and paraspinal musculature, as well as a new diagnosis of type 2 DM. Along with drainage, a prolonged course of intravenous antimicrobial treatment led to abscess resolution. Given the rising number of unusual clinical presentations of GBSI, this bacteria should be considered as a part of the microbiological differential diagnosis of PA, especially in conditions leading to immunosuppression.

Renal abscesses in cats: six cases

Case series summary Six cats were diagnosed with renal abscesses. Common clinical findings were lethargy, dehydration, abdominal pain and nephromegaly. Fever was noted in half of the cases. Diagnosis was established by ultrasonography, cytological examination and bacterial culture of abscess aspirates. At least one possible contributing factor could be identified in all cases. Antibiotics were consistently used and in two cats the abscess was surgically drained. The short-term outcome was fair but the long-term outcome was dependent on the underlying condition. Relevance and novel information The results of this small case series suggest that renal abscess should be considered when nephromegaly and/or abdominal discomfort are noted. Diagnosis of renal abscess is straightforward when ultrasonography and fine-needle aspirate analysis can be performed. Medical treatment is assumed to be preferable but surgical treatment may be warranted on a case-by-case basis. Given that almost every affected cat was diagnosed with at least one comorbidity, a thorough evaluation is recommended for all cats with renal abscesses.

Clinical assessment of children with renal abscesses presenting to the pediatric emergency department

Background

Renal abscesses are relatively uncommon in children but may result in prolonged hospital stays and life-threatening events. We undertook this study to analyze the clinical spectrum of renal abscesses in children admitted to the pediatric emergency department (ED) and to find helpful clinical characteristics that can potentially aid emergency physicians for detecting renal abscesses in children earlier.

Methods

From 2004 to 2011, we retrospectively analyzed 17 patients, aged 18 years or younger, with a definite diagnosis of renal abscess admitted to the ED. The following clinical information was studied: demographics, clinical presentation, laboratory testing, microbiology, imaging studies, treatment modalities, complications, and long-term outcomes. We analyzed these variables among other potential predisposing factors.

Results

During the 8-year study period, 17 patients (7 males and 10 females; mean age, 6.1 ± 4.5 years) were diagnosed with renal abscesses on the basis of ultrasonography and computed tomography findings. The 2 most common presenting symptoms were fever and flank pain (100% and 70.6%, respectively). All of the patients presented with leukocytosis and elevated C-reactive protein (CRP) levels. Organisms cultured from urine or from the abscess were identified in 11 (64.7%) patients, and Escherichia coli was the most common organism cultured. All patients were treated with broad-spectrum intravenous antibiotics with the exception of 4 children who also required additional percutaneous drainage of the abscess.

Conclusions

Renal abscesses are relatively rare in children. We suggest that primary care physicians should keep this disease in mind especially when children present with triad symptoms (fever, nausea/vomiting, and flank pain), pyuria, significant leukocytosis, and elevated CRP levels. However, aggressive percutaneous drainage may not need to be routinely performed in children with renal abscesses.

Clinical assessment of children with renal abscesses presenting to the pediatric emergency department

BACKGROUND

Renal abscesses are relatively uncommon in children but may result in prolonged hospital stays and life-threatening events. We undertook this study to analyze the clinical spectrum of renal abscesses in children admitted to the pediatric emergency department (ED) and to find helpful clinical characteristics that can potentially aid emergency physicians for detecting renal abscesses in children earlier.

METHODS

From 2004 to 2011, we retrospectively analyzed 17 patients, aged 18 years or younger, with a definite diagnosis of renal abscess admitted to the ED. The following clinical information was studied: demographics, clinical presentation, laboratory testing, microbiology, imaging studies, treatment modalities, complications, and long-term outcomes. We analyzed these variables among other potential predisposing factors.

RESULTS

During the 8-year study period, 17 patients (7 males and 10 females; mean age, 6.1 ± 4.5 years) were diagnosed with renal abscesses on the basis of ultrasonography and computed tomography findings. The 2 most common presenting symptoms were fever and flank pain (100% and 70.6%, respectively). All of the patients presented with leukocytosis and elevated C-reactive protein (CRP) levels. Organisms cultured from urine or from the abscess were identified in 11 (64.7%) patients, and Escherichia coli was the most common organism cultured. All patients were treated with broad-spectrum intravenous antibiotics with the exception of 4 children who also required additional percutaneous drainage of the abscess.

CONCLUSIONS

Renal abscesses are relatively rare in children. We suggest that primary care physicians should keep this disease in mind especially when children present with triad symptoms (fever, nausea/vomiting, and flank pain), pyuria, significant leukocytosis, and elevated CRP levels. However, aggressive percutaneous drainage may not need to be routinely performed in children with renal abscesses.

Pediatric renal abscesses: A contemporary series

INTRODUCTION

Pediatric renal abscesses are an uncommon diagnosis, with a paucity of data comparing treatment modalities. Patient presentation ranges from persistent dull flank/abdominal pain with or without fevers, to those who are overtly ill, presenting with hemodynamic instability and bacteremia. Management for pediatric renal abscesses is typically based on results extrapolated from small series in adult cohorts, with conservative measures recommended when the lesion is <3 cm.

OBJECTIVE

This study evaluated the presentation, management and outcomes of a contemporary cohort of pediatric patients with renal abscesses.

STUDY DESIGN

A total of 16 consecutive pediatric patients with radiologically diagnosed intra-renal or peri-nephric abscesses from 1990 to 2012 were identified. Patients were identified by querying institutional records via ICD-9 and CPT codes referencing renal abscess. Charts were retrospectively reviewed to evaluate multiple clinical variables, including: presenting symptoms, size of abscess, management strategy and clinical outcomes. Clinical resolution was confirmed via repeat ultrasound or computed tomography.

RESULTS

The median age at presentation was 13 years (range 1 month-18 years) and 13/16 patients (81%) were female. Abscess formation was secondary to: urinary tract infection in 13 (81%); hematogenous seeding from a skin infection in one (6%); and an unknown etiology in two (12%) patients. The most common organism identified on urine culture was Escherichia coli (10, 77%). Hematogenous seeding was confirmed in only one case, with Staphylococcus aureus growing on culture from both a cutaneous lesion and percutaneous drainage of the renal lesion. Overall, abscesses were a median of 2.2 cm (IQR 2, 3.7), with 13 (81%) successfully managed with conservative therapy, including intravenous antibiotics, with resolution on repeat imaging at a median of 21 days (range 6-55). For patients presenting with abscesses ≤3 cm, conservative measures were employed in 10/11 cases, with 100% success rate. Three patients had larger abscesses (3.8, 4, and 10 cm), which resolved after treatment with percutaneous drainage. A voiding cystourethrogram was performed in 10 patients, with two (20%) detecting an abnormality (low-grade vesicoureteral reflux, which required no further intervention).

CONCLUSIONS

Pediatric renal abscesses were most commonly small and secondary to an E. coli UTI. Most small (≤3 cm) renal abscesses resolved with conservative management. Percutaneous drainage should be considered for lesions >3 cm and in patients who remain persistently febrile, despite culture-specific antibiotics, are immunocompromised or critically ill.

Clinical manifestation of a calyceal diverticular abscess in a pregnant woman

Calyceal diverticula are congenital, nonsecretory abnormalities in which the transitional cell-lined cavity communicates with the renal collecting system. Here we present the case of a calyceal diverticular abscess during pregnancy. A 40-year-old primiparous woman developed the abscess at 23 weeks of gestation, with right flank pain and a 37.8°C fever. A transabdominal ultrasound revealed a 12 × 10 cm cystic mass in the right kidney. She was initially diagnosed with a simple renal cyst infection, and intravenous antibiotics were initiated. Percutaneous drainage was started at 26 weeks of gestation. When urine excretion from the cyst was confirmed by dye test using indigotindisulfonate sodium, the patient was diagnosed with a calyceal diverticular abscess. She gave birth to a 2,870 g healthy male at 38 weeks of gestation. Percutaneous drainage with low-dose antimicrobial therapy could thus allow for the continued pregnancy of women with a calyceal diverticular abscess until full term.

Perinephric abscesses in the pediatric population: case presentation and review of the literature

BACKGROUND

Perinephric abscesses in children are rare. Infection can come from various areas, and clinical signs overlap with more common etiologies, such as pyelonephritis. Imaging modalities and laboratory investigations help lead to a definitive diagnosis.

CASE-DIAGNOSIS/TREATMENT

We present a case of a 5-month-old infant presenting with a febrile illness and eventual diagnosis of a perinephric abscess causing abdominal compartment syndrome. The infant had no known risk factors, i.e., congenital genitourinal abnormalities or immunosuppression, and was treated successfully following initial resuscitation, appropriate antibiotics, and open surgical drainage. Cultures obtained from the abscess and peritoneal fluid were positive for S. aureus, while blood and urine cultures were negative.

CONCLUSIONS

A literature review found 13 studies looking at diagnosis and/or treatment of idiopathic perinephric abscess. With non-specific clinical signs and symptoms, diagnosis can be delayed and rests heavily on clinical suspicion and appropriate imaging. Treatment includes antibiotics alone, or in conjunction with percutaneous or open surgical drainage. In summarizing these studies, a suggestion for diagnosis and basic treatment approach is outlined.

Pediatric renal abscess: a 10-year single-center retrospective analysis

OBJECTIVE

The objective of this retrospective series is to describe the demographics and treatment of patients with renal abscesses and to determine if abscess size influences management.

METHODS

We reviewed all pediatric cases of renal abscesses treated over a 10-year period in our medical center. Clinical, laboratory, imaging data, and treatment modalities were analyzed.

RESULTS

Thirty-six patients were evaluated, with renal abscesses found in all age groups. The median age was 9.3 years, and 64% of patients affected were female. Fever and abdominal pain were the most common clinical symptoms. A premorbid genitourinary condition was present in 310/a of patients. Previous urinary tract infection was documented in 31% of the cases. Initial elevation of C-reactive protein or erythrocyte sedimentation rate, when obtained, was observed in >80% of cases. Abnormal urinalysis was recognized in two-thirds of encounters. Escherichia coli, the most common microorganism isolated, was found in half the cases. Staphylococcus aureus was isolated in 11%. Ultrasound and computed tomography were the most used diagnostic imaging modalities. Eighty-nine percent of the patients who received intravenous antibiotics alone as an initial treatment regimen did not require percutaneous drainage or surgery.

CONCLUSIONS

Ten of the 14 patients with an abscess size > or =3 cm had an invasive intervention, but only 1 of these 10 had an initial 48-hour trial of antibiotics alone. In contrast, only 2 of the 22 patients who had an abscess size <3 cm received an invasive intervention (Fisher P= .0002). We conclude that conservative treatment with intravenous antibiotics may be a reasonable initial approach.

A better way to manage perinephric abscesses: percutaneous ultrasonography-guided endoscopic lavage

PURPOSE

To report the efficacy and safety of percutaneous ultrasonography-guided endoscopic lavage in the management of perinephric abscesses.

PATIENTS AND METHODS

This is a retrospective review of patients in a single center who had perinephric abscesses and were treated by percutaneous ultrasonography-guided endoscopic lavage during the period of March 2001 to March 2013. Information including the demographics, comorbid medical conditions, presenting symptoms, size of abscesses, operation information, and postoperative information were retrieved for review.

RESULTS

There were 37 patients (40 operations) identified during the study period. The mean age was 56.8 years (21-91 years). Eighteen (48.9%) patients presented with loin pain (48.6%) and/or fever (18, 48.6%), and the mean diameter of the abscesses was 10.8 cm (5-22 cm). Thirty-one (77.5%) procedures were performed under general anesthesia. The mean operative time was 49.4 minutes (15-140 min). Thirty-one (77.5%) patients had their percutaneous track dilated to 32F. Only two of 37 (5.4%) patients needed repeated drainage. The average postoperative drainage time was 8.35 days (3-21 days). The median postoperative hospital stay for our patients was 10 days (4-101 days). There was no mortality related to the abscess in this cohort.

CONCLUSION

Percutaneous Ultrasonography-guided endoscopic lavage was shown to be an effective and safe approach for patients with perinephric abscesses.

Conservative management of paediatric renal abscess

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.

Current clinical management of renal and perinephric abscesses: a literature review

Renal and perinephric abscesses are rare but very severe conditions resulting from infections in or surrounding the kidneys. Symptoms and imaging techniques, such as computed tomography (CT), magnetic resonance imaging (MRI) and renal ultrasound (US) of higher quality have led to an early diagnosis that is very important for patients' prognosis. The best clinical approach to manage this disease is still debated. Antibiotic therapy represents the usual treatment of small renal abscesses. This management can be insufficient in case of larger renal abscesses requiring percutaneous or surgical drainage. Perinephric abscesses most commonly need invasive maneuvers. We conducted a literature review to clearly define the most recommended clinical managements for all cases of renal and perinephric abscesses.

Effect of diabetes on mortality and length of hospital stay in patients with renal or perinephric abscess

OBJECTIVES

We compared the risk of in-hospital mortality and the length of hospital stay between diabetic and non-diabetic patients hospitalized for renal or perinephric abscess.

METHOD

The data analyzed in this study were retrieved from Taiwan's National Health Insurance claims. The risk of in-hospital mortality and the length of hospital stay were compared between 1,715 diabetic patients, hospitalized because of renal or perinephric abscess in Taiwan between 1997 and 2007, and a random sample of 477 non-diabetes patients with renal or perinephric abscess.

RESULTS

The in-hospital mortality rates from renal or perinephric abscess for the diabetic patients and the non-diabetic patients were not different, at 2.3% and 3.4%, respectively. However, diabetes was significantly associated with a longer length of hospital stay among patients with renal abscess, by 3.38 days (95% confidence interval [CI]: 1.59-5.17).

CONCLUSIONS

Diabetes does not increase the risk of in-hospital mortality from renal or perinephric abscess. Nevertheless, appropriate management of patients with diabetes and concurrent renal or perinephric abscess is essential to reduce the length of hospital stay.

Acute pyelonephritis in adults: a case series of 223 patients

BACKGROUND

Acute pyelonephritis (APN) is a common disease which rarely evolves into abscesses.

METHODS

We prospectively collected clinical, biochemical and radiological data of patients hospitalized with a diagnosis of APN from 2000 to 2008.

RESULTS

Urinary culture was positive in 64/208 patients (30.7%) and blood cultures in 39/182 cases (21.4%). Two hundred and thirteen patients were submitted to computed tomography (CT) or nuclear magnetic resonance (NMR): confirmation of APN was obtained in 196 patients (92%). Among these, 46 (23.5%) had positive urine culture, 31 (15.8%) had positive blood culture and 15 (7.6%) had positive cultures of both urine and blood. In 98 patients, either urine or blood cultures were negative, but CT/NMR were positive for APN. Fifty of the 213 patients submitted to CT/NMR (23.5%) had intrarenal abscesses: only 2 were evidenced by ultrasound examination. No differences were found between patients with positive or negative CT with regards to fever, leucocytosis, C-reactive protein, pyuria, urine cultures and duration of symptoms before hospitalization. No differences were found between patients with or without abscesses with regards to these parameters and risk factors. Patients with abscesses had a longer duration of treatment and hospitalization.

CONCLUSIONS

Our data suggest that in APN it is not always possible to routinely document urinary infection in a clinical setting. This finding could be explained by previous antibiotic treatment, low bacterial growth or atypical pathogens. Systematic CT or NMR is necessary to exclude evolution into abscesses, which cannot be suspected on clinical grounds or by ultrasound examination and may also develop in the absence of risk factors.

Scoring system development and validation for initial treatment failure in suppurative kidney infections

BACKGROUND

Suppurative kidney infections (SKIs) have potentially lethal implications and a high incidence of treatment-related morbidity and death. Until this point, there has been no study that has derived a prognostic model for adverse early outcomes in SKI. Therefore, our aim was to derive and validate a simple scoring system of early treatment failure in SKI.

METHODS

Logistic regression and bootstrap methods were used to create an integer score for estimating the risk of early treatment failure using patient characteristics, severity of disease, bacterial etiology, type of pathology, initial antibiotic therapy, and early urologic procedures.

RESULTS

This study included 92 adult patients with 104 SKIs. Early treatment failure was observed in 57 patients (54.8%). The length of the hospital stay and the treatment complications were significantly longer and more common, respectively, in patients with early treatment failure. The factors associated most strongly with early treatment outcome were whether there had been an early complete urologic procedure, the adequacy of early antibiotic therapy, and the presence or absence of sepsis syndrome. The total possible score ranged from 0 to 22 points, with a cut-off value of 5 points. A score of ≤ 5 points identified early success correctly in 85.3% of patients, whereas a score > 5 points correctly identified early failure in 93.2%. The scoring system retained its predictive ability on the validation set.

CONCLUSION

A scoring system was created to predict early treatment failure for a given patient with SKI. Although the system has good performance characteristics and provides a possible intervention measure, further studies should be performed before widespread implementation.

What is the best drainage method for a perinephric abscess?

PURPOSE

To compare the results of percutaneous and open drainage for perinephric abscess.

MATERIALS AND METHODS

The files of 86 patients who underwent drainage for perinephric abscesses from April 2001 through March 2008 were evaluated. The method of drainage for each patient was performed according to the clinical decision of the treating physician. Percutaneous tube drain (PCD) was used for drainage of the abscess in 43 patients (group 1), while the other 43 patients were managed with open drainage (group 2). Cure was defined as complete obliteration of the abscess cavity. The cure rates, complications, and hospital stay were compared between both groups.

RESULTS

The study included 50 males and 36 females with mean age 44.2 + or - 17.3. The most common predisposing factors were diabetes mellitus and/or stones. Open drainage of perinephric abscesses resulted in a statistically significant higher cure rate (98% versus 69%, p < 0.001) and shorter hospital stay than PCD (3.6 versus 6 days, p < 0.001). Failure of complete drainage of multilocular abscess was observed in 8 of 13 cases (61.5%) in group 1 and one of 38 cases (2.6%) in group 2 (P < 0.001). Complications were observed in 7% of group 1 and 11.5% in group 2 (P = 0.45). After mean follow-up of 19 months, 9 of 46 patients (19.6%) had recurrence; 7 of them were in group 1.

CONCLUSION

Percutaneous drainage of perinephric abscess is an effective minimally invasive treatment. However, PCD is not the optimal method for drainage of multilocular abscess because open surgical drainage provided higher cure rates and shorter hospitalization than PCD.

Renal abscesses measuring 5 cm or less: outcome of medical treatment without therapeutic drainage

PURPOSE

Diagnosis and proper treatment of renal abscesses remains a challenge for physicians. We investigated the characteristics and comorbidity factors of renal abscesses measuring 5 cm or less and critically examined the effectiveness of conservative treatment.

MATERIALS AND METHODS

Between February 2001 and March 2009 the records of 63 patients initially diagnosed at our hospital with renal or perirenal abscesses were retrospectively reviewed. In 63 patients with renal and perirenal abscesses, 51 abscesses measured 5 cm or less, and 49 abscesses were treated with intravenous antibiotics alone.

RESULTS

Most patients were women (91.8%), and their mean age was 42.3 years. The mean size of renal abscesses was 3.6 cm. The most common predisposing condition was diabetes mellitus (DM) (46.9%). Common clinical features were fever (83.7%) and flank pain (53.1%). On urinalysis, 31 (64.6%) cases had positive bacterial cultures with Escherichia coli (50.0%) being the most common pathogen. All 49 patients were treated with broad-spectrum intravenous antibiotics alone. All patients showed complete clinical regression and resolution of the renal lesions shown by CT between 3 and 14 weeks. The average hospital stay was 15.3 days (range, 5-31 days). Significant predictors of a long hospital stay were age, abscess size, and DM.

CONCLUSION

Medium-sized as well as small-sized renal abscesses were treated successfully with intravenous antibiotics alone. DM was a significant predictor of prolonged hospital stay. If therapeutic drainage is believed to involve considerable risk, then intravenous antimicrobial therapy may be a good alternative treatment.

Recent clinical overview of renal and perirenal abscesses in 56 consecutive cases

BACKGROUND/AIMS

The aim of this study was to examine the recent clinical trends and antibiotic susceptibilities of the causative microorganisms in renal and perirenal abscesses, and to elucidate the factors associated with treatment strategies.

METHODS

We retrospectively analyzed 56 patients who were diagnosed with renal and perirenal abscesses at our hospital from January 2000 to September 2007.

RESULTS

The mean age of the patients was 53.5 years, and a female predominance of patients (75%) was observed. Diabetes mellitus (44.6%) was the most common predisposing condition. The mean duration of symptoms before diagnosis was 11.6 days, and fever (75%) was the most common symptom. Escherichia coli (44%) and Klebsiella pneumoniae (28%) were common pathogens, and the rates of susceptibility of E. coli isolates to ampicillin, cephalothin, cefotaxime, trimethoprim-sulfamethoxazole, ciprofloxacin, gentamicin, and imipenem were 18.2%, 27.3%, 72.7%, 72.7%, 63.6%, 63.6%, and 100%, respectively. Abscesses were classified according to the location as follows: renal abscess (n=31, 55.4%) and perirenal abscess +/- renal abscess (n=25, 44.6%). In the renal abscess group, the infection rate of gram-negative organisms was higher than in the perirenal abscess group. Patients were also divided according to the treatment modality: antibiotics only (n=20, 35.7%) and percutaneous intervention or surgery (n=36, 64.3%). Patients who had a perirenal abscess or a large renal abscess required more invasive treatment.

CONCLUSIONS

This study revealed somewhat different results from those of previous studies. Clinical and microbial differences were observed between the renal and perirenal abscess groups. Abscess location and the size of the renal abscess were the factors associated with treatment strategies.

Risk factors for treatment failure in renal suppurative infections

There are conflicting results of published studies about prognostic value of various factors in purulent renal infections. The purpose of this study was to identify and quantify potential risk factors for early and late treatment failure in such infections. A retrospective review of 75 renal suppurative infections, at three tertiary Serbian Clinics of Urology, was conducted. We considered numerous potential risk factors in a multivariate analysis. This series was comprised of 49 women and 26 men, with mean age of 56.7 years. There were 38 and 37 patients who experienced successful and unfavorable early treatment outcome, respectively. Overall mortality rate was 9.3%. Comorbidity [odds ratio (OR) = 1.6], complex suppurative pathological findings (OR = 3.6), presence of Pseudomonas spp. (OR = 6.7), multiple bacterial strains (OR = 2.7), and positive culture itself (OR = 3.6) were the predictors of poor early prognosis. A urological intervention and presence of pyonephrosis significantly increased the chance for good initial outcome (OR = 0.32 and 0.37, respectively). In the late treatment failure analysis presence of comorbidities (OR = 5.8) and treatment complications (OR = 7.5) significantly increased chance for fatal outcome. Patients' baseline health status and complexity of suppuration itself were the most important predictors of clinical outcomes. Surgical drainage dominated over antimicrobial therapy.

Pheochromocytoma with abscess

We report a case of a 34-year-old man who suffered from pheochromocytoma with an abscess in the right adrenal. He presented with a high fever and back pain. He also had some episodes of headache and palpitation. Serum and urine catecholamine levels were elevated. From computed tomography and (123)I-meta-iodobenzylguanidine scans, his condition was diagnosed as pheochromocytoma with an abscess. Two pairs of blood cultures yielded Streptococcus agalactiae, which was believed to be derived from dental caries. He was successfully treated with antibiotics for his abscess and right adrenalectomy for his pheochromocytoma.

Renal and perinephric abscesses: analysis of 65 consecutive cases

OBJECTIVE

The objective was to describe the last 10 years' experience of the diagnosis and treatment of renal, perinephric, and mixed abscesses in an academic reference center.

PATIENTS AND METHODS

The medical records of 65 patients with renal, perinephric, and mixed abscesses treated at our hospital from January 1992 to December 2002 were reviewed. The data collected included predisposing factors, symptoms, physical examination, initial diagnosis, laboratory and radiologic evaluation, treatment, and clinical outcome.

RESULTS

Perinephric abscesses were found in 33 (50.8%) patients, renal abscesses were found in 16 (24.6%), and 16 (24.6%) had mixed abscesses. Urolithiasis (28%) and diabetes mellitus (28%) were the most common predisposing conditions. The duration of symptoms before hospital admission ranged from 2 to 180 days (mean 20 days). Urine culture was positive in 43% of patients and blood culture was positive in 40% of patients. Most of the perinephric abscesses received an interventional treatment: surgical drainage (24%), percutaneous drainage (42%) or nephrectomy (24%). Most patients were cured (73.3%) on discharge from hospital. Mixed (renal and perinephric) abscess treatment was similar: percutaneous drainage (37.5%), surgical drainage (18.75%) or nephrectomy (37.5%). Most patients were cured (60%) on discharge from hospital. Renal abscesses, however, were treated medically in 69% of patients and 73% were cured on discharge from hospital.

CONCLUSIONS

Perinephric and mixed abscesses are successfully managed by interventional treatment. Renal abscesses can be managed by medical treatment only, reserving interventional treatment for large collections or patients with clinical impairment. Early diagnosis is an important factor in the outcome of renal and perinephric abscesses.