Bladder debris on ultrasound as a predictor for positive urine culture in a pediatric population

Pre-operative factors associated with the development of distal ureteral stump syndrome after upper pole heminephrectomy

INTRODUCTION

For children with duplex systems and severe hydroureteronephrosis of the upper pole, heminephrectomy is one of many suitable treatments, particularly if there is no associated lower pole reflux. Distal ureteral stump syndrome (DSS) is a very difficult complication and manifests as stump empyema, urinary tract infection and/or vulvar discharge and can occur months to years later in 10-20 percent of patients. Secondary distal ureterectomy is an extremely difficult surgery due to inflammation and adhesions. To avoid DSS, distal ureterectomy at the time of heminephrectomy can be performed concurrently but carries a risk of lower pole ureter devascularization and injury. Current literature on DSS has shown associations with subtotal ureterectomy or long ureteral stumps. We hypothesized that there may be preoperative variables prior to heminephrectomy that are associated with the development of DSS.

OBJECTIVE

Identify pre-operative risk factors for the development of DSS in pediatric patients who underwent upper pole heminephrectomy for duplex kidneys.

STUDY METHODS

Retrospective analysis of pediatric patients who underwent upper pole heminephrectomy at single, academic institution from 1999 to 2021. Pre-operative patient age, gender, history, imaging, and lab results were extracted from patient charts to assess for factors that may predict the development of DSS. Patient groups with and without DSS were compared using Fischer's Exact Test.

RESULTS

Five (14%) of 36 patients developed DSS and required secondary distal ureterectomy at a median time of 22 months (IQR 6-27) after heminephrectomy. The presence of ureteral debris (80% of DSS) on preoperative ultrasound (p < 0.001), reflux into the upper pole (p = 0.005), and mucus discharge (100% of DSS) (p < 0.001) prior to surgery were found to be significantly associated with those who developed DSS, compared to those who did not. These three pre-operative factors had high specificity (97-100%) and negative predictive value (94-97%).

DISCUSSION

Substantial experience has shown that less than 20% of patients benefit from distal ureterectomy during upper heminephrectomy. Whether using an open or laparoscopic approach, selection of at-risk patients should lower operative time and avoid injury and devascularization of the lower pole ureter for most patients.

CONCLUSION

The presence or absence of ureteral debris, mucus discharge and/or upper pole reflux prior to heminephrectomy may be useful guides in selecting which patients would benefit from concurrent distal ureterectomy and conversely which patients may safely avoid the additional dissection.

Rapid and Efficient Computation of Cell Paths During Ultrasonic Focusing

This biophysical analysis explores the first-principles physics of movement of white blood cell sized particles, suspended in an aqueous fluid and experiencing progressive or standing waves of acoustic pressure. In many current applications the cells are gradually nudged or herded toward the nodes of the standing wave, providing a degree of acoustic focusing and concentration of the cells in layers perpendicular to the direction of sound propagation. Here the underlying biomechanics of this phenomenon are analyzed specifically for the viscous regime of water and for small diameter microscopic spheroids such as living cells. The resulting mathematical model leads to a single algebraic expression for the creep or drift velocity as a function of sound frequency, amplitude, wavelength, fluid viscosity, boundary dimensions, and boundary reflectivity. This expression can be integrated numerically by a simple and fast computer algorithm to demonstrate net movement of particles as a function of time, providing a guide to optimization in a variety of emerging applications of ultrasonic cell focusing.

Significance of sonographically detected bladder debris in children less than 2 years old with febrile urinary tract infection

PURPOSE

To investigate the relationship between bladder debris found on renal and bladder ultrasonography (RBUS) and the first febrile urinary tract infection (UTI) episode in children under 2 years old.

METHODS

We retrospectively reviewed the data of children aged <2 years with the first febrile UTI. We recorded bladder debris on RBUS and other findings (blood test, urinalysis, and urine culture). Other RBUS findings (renal pelvis debris, renal parenchymal change, wall thickening, and renal collecting system [RCS] dilatation) were recorded. Patients were divided into the debris (D) and non-D groups.

RESULTS

Of 128 patients (boys: girls = 81:47, mean age = 5.6 ± 4.2 months), 24 (18.8%) had bladder debris. The mean C-reactive protein (CRP) levels were higher in the D group (6.1 ± 4.0 vs 4.3 ± 3.5, P = .03). Twenty-one patients in the D group (87.5%) had hematuria (odds ratio = 3.706, 95% confidence interval = 1.035-13.267, P = .04). No significant differences were seen in the urine culture results between both groups. Significant associations were seen between bladder debris and other RBUS findings such as debris in renal pelvis, renal parenchymal change, and RCS wall thickening.

CONCLUSION

Bladder debris on RBUS is a common finding in children aged <2 years during the first febrile UTI. Bladder debris was related to higher CRP levels, hematuria and sonographic findings, but not to urine culture results.

The role of bladder function in the pathogenesis and treatment of urinary tract infections in toilet-trained children

Urinary tract infections (UTIs) are a common reason for referral to pediatric specialists and the risk profile of these children is influenced by age, sex, and underlying urinary tract abnormalities. UTIs in toilet-trained children represent a different entity than confirmed, febrile UTIs that occur in infants, impacted by suboptimal bladder habits, bladder dysfunction, constipation, or a combination of these factors. A comprehensive literature search was conducted using PubMed and MEDLINE and search terms included recurrent UTI, VUR, bladder and bowel dysfunction (BBD), constipation, lower urinary tract symptoms, and voiding dysfunction. Common presenting symptoms of UTI in children include fever (> 38 °C) with or without "traditional" lower urinary tract symptoms (LUTS) such as dysuria, malodorous urine, frequency, urgency, and incontinence. However, many infections in older children are afebrile episodes-consisting primarily of LUTS-which may or may not be confirmed with biochemical and/or microbiological evidence. Therefore, when evaluating toilet-trained children with recurrent UTIs, it is paramount to consider dysfunctional elimination as an underlying cause, diagnose, and treat it prior to indicating surgical options, even in the presence of VUR or other anatomical abnormalities. Although the impact of bladder function on the risk of infections is important, so is the accurate diagnosis and initial evaluation. This review article will focus on an often overlooked yet critical factor: the impact of bladder function, particularly for toilet-trained children, as well as the importance of implementing bladder training strategies, aggressive management of constipation, and pharmacological management as necessary.

General Pediatric Clinical Applications of POCUS: Part 1

The use of point-of-care ultrasound (POCUS) performed by non-radiologists has become more widespread and is entering new arenas of clinical care. Children in particular are prime candidates for ultrasound, as they are both usually thinner than adults and are particularly at risk from the harmful effects of ionizing radiation. In this two-part article, we propose 10 uses of POCUS that pediatricians can apply to their practice in both inpatient and outpatient settings. [Pediatr Ann. 2020;49(3):e147-e152.].