Positive trends in paediatric renal biopsy service provision in the UK: a national survey and re-audit of paediatric renal biopsy practice

Optimization of Pediatric Kidney Biopsy: Impact of Needle Size and Passes

PURPOSE

This study evaluated the impact of needle size and the number of passes on complication rates and glomerular yield in pediatric native kidney biopsies performed under real-time ultrasound (US) guidance, aiming to determine the optimal biopsy approach.

MATERIALS AND METHODS

Pediatric native kidney biopsies performed between March 2019 and February 2022 at a single tertiary-care children's hospital were included. Biopsies were done with a semi-automated 16 G needle until December 2020, then with an 18 G needle, with varying numbers of passes. US examinations were conducted 24 h post-biopsy to assess complications. Patients were categorized into six subgroups using needle size and the number of passes and compared for complication rates, glomerular yield, and diagnostic adequacy.

RESULTS

A total of 145 pediatric patients (59.3% female, 40.7% male) with a mean age of 10.74 (±4.69) years were included. An 18 G needle was used in 76 (52.4%) cases and a 16 G needle in 69 (47.6%) cases. Minor complications occurred in 56 (38.6%) cases, with no major complications. Complication rates were not significantly different between 18 G and 16 G (p=0.088) but increased with the number of passes (p<0.001). Mean glomerular yield was higher with 16 G than 18 G (34.6 vs. 22.6, p<0.001), though not significantly affected by the number passes (p=0.123). The 18 G needle was associated with inadequate sampling (p=0.024). The optimal scenario was a 16 G needle with one or two passes.

CONCLUSION

Real-time US-guided pediatric kidney biopsy is safe. A 16 G needle with one or two passes optimizes glomerular yield without increasing complications. Three or more passes should be avoided.

Puncture approaches for ultrasound-guided kidney biopsy specimens: a pediatric model study using piglet kidneys

BACKGROUND

The optimal puncture approach for real-time ultrasound-guided native kidney needle biopsy in children remains undetermined due to insufficient evidence. This study evaluated various puncture approaches for glomeruli count and arterial injury in the small kidneys of piglets.

METHODS

A total of 144 kidneys sourced from a slaughterhouse were examined. On each kidney, three puncture approaches were performed on the lower pole using a 16-gauge needle: Caudocranial, Craniocaudal, and Vertical. Blinded pediatric nephrologists assessed core length, glomeruli count, and arterial injury.

RESULTS

The kidneys had a mean vertical length of 9.31 ± 0.59 cm. Of 432 punctures, no punctures traversed the kidney. The Vertical approach yielded a significantly shorter core length than other methods (P < 0.001), but the glomeruli count was consistent across approaches (P = 0.41). Over 60% of the biopsies resulted in arterial injury, with the Caudocranial approach showing significantly higher injury rates (P < 0.03).

CONCLUSIONS

This study focused on puncture techniques in a pediatric model, suggesting that the Craniocaudal and Vertical approaches are advantageous for selective glomerular sampling without increasing the arterial injury risk. Although further research on smaller kidneys is necessary, these findings offer valuable guidance for biopsy approaches to small kidneys, particularly in pediatric patients.

IMPACT

Kidney biopsy is essential for establishing diagnosis and determining treatment strategies; however, there is no consensus on the puncture approach in children who have the additional risk factor of small-sized kidneys. This study compared between biopsy specimens from piglet models of pediatric kidneys to clarify the best puncture approach based on pediatric characteristics. Although the same number of glomeruli were sampled using all approaches, the Caudocranial approach exhibited a significantly higher incidence of arterial injury. In kidney biopsy that considers the characteristics of children with small kidneys, the Craniocaudal or Vertical approaches may improve the safety and quality of biopsy specimens.

Is kidney biopsy necessary in children with idiopathic nephrotic syndrome?

AIM

To investigate the need, in the Northern European setting, to perform kidney biopsy in children with steroid-sensitive nephrotic syndrome.

METHODS

In this retrospective study 124 individuals aged 1-18 years with idiopathic nephrotic syndrome, followed in the paediatric hospitals in southern Sweden from 1999 to 2018, were included.

RESULTS

There was a median follow-up time of 6.5 (0.2-16.8) years. The majority (92%) of children were steroid-sensitive and of them, 60.5% were frequently relapsing or steroid-dependent. Microscopic haematuria was found at onset in 81.1% and hypertension in 8.7%. At least one kidney biopsy was performed in 93 (75%). The most common indication was a steroid-dependent or relapsing course (58.4%). One of 79 steroid-sensitive children had another histological diagnosis than minimal change nephropathy 1.3%, 95% confidence interval (0.002, 0.068). Bleeding occurred after eight biopsies (6.6%). Twenty individuals (30.7%) were transferred to adult units, 18 still on immunosuppression.

CONCLUSION

We have in our cohort of unselected children with idiopathic nephrotic syndrome confirmed that a kidney biopsy rarely gives important medical information in steroid-sensitive children without any other complicating factor and that the liberal policy of kidney biopsy in the Nordic countries safely can be changed.

Comparison of outcomes of an 18-gauge vs 16-gauge ultrasound-guided percutaneous renal biopsy: a systematic review and meta-analysis

Background: The needle size used in ultrasound-guided percutaneous renal biopsy significantly influences the efficacy and safety of the procedure. The aim of this study is to perform a comparative analysis of 16-gauge and 18-gauge needles for ultrasound-guided percutaneous renal biopsy.Methods: This systematic review and meta-analysis included randomized controlled trials and observational studies that compared the outcomes of using 18-gauge and 16-gauge needles for ultrasound-guided percutaneous renal biopsy. The efficacy parameters included a mean number of glomeruli obtained and the number of passes, while the safety parameters focused on the rate of complications. We searched multiple databases, assessed the risk of bias, and conducted statistical analyses using appropriate models.Results: Fifteen studies were included. Compared to the 18-gauge needle, the use of 16-gauge needle for the biopsy was associated with the significantly higher mean number of glomeruli obtained (pooled SMD 0.61, 95%CI: 0.32 to 0.89; p < 0.001) and fewer required passes (pooled SMD -0.57, 95%CI: -0.97 to -0.18; p = 0.004). No significant difference was observed in the individual safety parameters, including pain, hematuria, need for blood transfusion, major, and minor complications. However, the use of 16-gauge needle was associated with higher odds of total complications (pooled OR 1.57, 95%CI: 1.16 to 2.13; p = 0.004).Conclusion: While the 16-gauge needle for ultrasound-guided percutaneous renal biopsy offers improved efficacy in terms of a higher mean number of glomeruli and fewer required passes, it is associated with higher total complications. A judicious needle size selection that would consider patient-specific factors and risk-benefit ratio, is crucial for optimizing patient outcomes.

Renal Biopsy in Children-Effect on Treatment Decisions: A Single-Center Experience

Renal biopsy is an important diagnostic tool, though invasive and carries risks involved with sedation. The authors wanted to compare suspect histopathological diagnosis with final diagnosis and find out impact of biopsy findings on treatment. They retrospectively analyzed 108 patients. Details of patients, diagnosis, treatment and complications due to kidney biopsy were documented. Statistical analysis was done using SPSS version 20.0 (IBM, NY). Indications of 108 children (69 boys, 39 girls) undergoing renal biopsy were steroid-resistant nephrotic syndrome (35.1%), steroid-dependent nephrotic syndrome requiring calcineurin inhibitors (CNI) (12%), nephrotic range proteinuria with atypical features (16.7%), lupus nephritis (13%), and acute kidney injury (AKI) stage 3 (17.6%). Suspect and histopathological diagnoses were similar in 53% cases with agreement factor of 0.462. Treatment changed in 28.7%. Renal biopsy made substantial impact in patients with nephrotic range proteinuria with atypical features (55.6%) and AKI stage 3 (52.6%). One (0.9%) had developed gross hematuria, which resolved spontaneously.

Pediatric interventional radiology - does it add value?

Although attempts have been made to show that pediatric interventional radiology adds value in children's hospitals, none has been particularly persuasive. An analysis of individual procedures would seem to be the most scientific approach, but there are numerous problems, including the effects that different health care systems have on clinical practice and the difficulty of generalizing the results of a single-center study to other hospitals, even within the same type of health care system. It is unsurprising that there are no published randomized controlled trials comparing both the costs and outcomes of specific pediatric interventional radiology procedures with surgical alternatives, and in fact these may not be feasible. There is only anecdotal evidence of the value of pediatric interventional radiology in multidisciplinary teams in children's hospitals. Currently, the best justification may be the counterfactual: demonstrating what can go wrong if pediatric interventional radiology expertise is not available.

Safety and utility of surveillance biopsies in pediatric kidney transplant patients

There is currently no way to diagnose a rejection before a change in serum creatinine. This had led some to start doing SB, but little data exist on the utility and safety of SB in pediatric patients. There is also little known on practice patterns of pediatric nephrologists. A retrospective review of pediatric kidney transplant SB between January 2013 and January 2017 at a single center was performed. A survey went to the PedNeph email list. There were 47 SB; 15 at 6 months, 12 at 1 year, 13 at 2 years, and 7 at 3 years. There were 3 minor (1 gross hematuria and 2 hematomas) and no major complications. On 6-month SB, 1 had SC 1A ACR (6.7%) with no BR ACR. On the 12-month SB, there were 5 with SCBR ACR (41.7%) and 1 with SC AMR (8.3%). On the 2-year SB, there were 4 that had SCBR ACR (30.8%), and 1 with SC AMR (7.7%). On the 3-year SB, 1 had chronic transplant glomerulitis (14.3%). The survey showed that 34.3% of pediatric nephrologists perform SB. SB can be performed safely. By early identification of histological lesions, SB gives us an opportunity for individualized immunosuppressive regimens that may prevent chronic allograft dysfunction and improve long-term graft outcome.