Clinically Insignificant Residual Fragments: Is It an Appropriate Term in Children?

Is percutaneous nephrolithotomy effective and safe in infants younger than 2 Years old? Comparison of mini standard percutaneous nephrolithotomy

BACKGROUND

In this study, we aimed to compare the operative outcomes, postoperative outcomes, stone-free status and complications of SPCNL and MPCNL in infants younger than two years of age.

METHODS

We retrospectively analyzed 163 patients younger than two years of age who underwent percutaneous nephrolithotomy (PCNL) in our institution between September 1999 and March 2022. The patients were divided into two groups depending on the tract size. The MPCNL group consisted of 73 patients with a tract of 22 Fr or less, and the SPCNL consisted of 90 patients with a tract greater than 22 Fr.

RESULTS

The median age of 163 patients included in the study was 17.3 (range 7-24) months. Although the median stone size was lower in the SPCNL group, no statistically significant difference was found between the two groups in terms of stone size (p = 0.073). The median operative time was 74.8 min in the MPCNL group and 62.8 min in the SPCNL group, with a statistically significant difference (p = 0.002). Stone free rates (SFR) were 89 % and 90.8 % in the MPCNL and SPCNL groups, and the clinically insignificant residual fragments (CIRF) rates were 11 % and 4.6 %, respectively (p = 0.064). The fluoroscopy time, nephrostomy withdrawal time, and hospitalization stay were similar in the two PCNL groups (p = 0.535, p = 0.253, and p = 0.143, respectively). Postoperative fever was similar in MPCNL and SPCNL groups (p = 0.504). Although bleeding (6.7%-2.7 %) and blood transfusion (3.3%-1.4 %) rates were higher in the SPCNL group, there was no statistically significant difference (p = 0.248 and p = 0.420, respectively). Prolonged urinary leakage occurred in 6 (8.2 %) patients in the MPCNL group and 1 (1.1 %) patient in the SPCNL group, with a statistically significant difference (p = 0.026).

CONCLUSIONS

With the development of MPCNL, the use of SPCNL in infants has decreased considerably. However, SPCNL continues to be an effective and reliable method when needed in suitable patients. Although PCNL in infants shows some differences from adults, it is an effective and safe method for suitable patients.

LEVEL OF EVIDENCE

Although we created our study by retrospectively examining the pediatric urology data that we created prospectively, our study is of a retrospective nature. Therefore the Level of Evidence is 3.

Is Triple D Score Effective to Predict the Stone-Free Rate After Shockwave Lithotripsy in Pediatric Population?

Introduction: Triple D score was developed using skin-to-stone distance (SSD), stone density (SD), and stone volume (SV) for prediction of extracorporeal shockwave lithotripsy (SWL) outcomes in adults. SWL is the first-line treatment method for kidney stones <2 cm in children, however, it was not validated in the pediatric population. This article aims to validate Triple D score in pediatric patients. Materials and Methods: Of the 269 children treated with SWL between 2007 and 2021, a total of 147 children who had adequate follow-up data and evaluated with noncontrast CT before SWL were included in the study. Parameters were calculated for each of the SV, SSD, and SD variables. Receiver operator characteristic analysis was used to set cutoff values. Triple D scores were calculated, and success rates were determined for each score. Stone-free status was determined as complete clearance after 3 months of final SWL. Results: The median age of the study group was 7 years (range 1-16). Ninety-three of the 147 (63%) children had stone-free status. Mean SV, SSD, and SD values were significantly higher in the SWL-failed group than in the stone-free group after detecting cutoff values of 155 mm³, 6.5 cm, and 550 HU, respectively. Stone-free rates were detected as 23.8%, 35.1%, 74.0%, and 92.0% with the Triple D scores of 0, 1, 2, and 3 points. Conclusions: Our study confirms that Triple D scores support the SWL outcomes in the pediatric population. We believe that our research on Triple D score validation in children is of great clinical importance although various factors may affect to predict the success of SWL. IRB Approval: 2021/514/194/14.

Ability of ESWL nomograms to predict stone-free rate in children

INTRODUCTION

We aimed to evaluate whether the pediatric extracorporeal shock wave lithotripsy (ESWL) nomograms can predict stone-free status in children effectively and whether they are applicable to our series. We hypothesize that two current nomograms predicting successful treatment with ESWL in pediatric patients are valid.

STUDY DESIGN

We evaluated 415 renal units (children <18 years) with eligible data who received ESWL treatment for upper urinary tract stones. Children's age, gender, stone size, stone surface area, stone location and history of previous intervention were recorded. Children with no residual fragments after ESWL treatment were designated as stone-free. The nomograms described by Dogan and Onal were implemented to our series for the prediction of stone-free status.

RESULTS

Mean age of children was 64.7 ± 57.2 months. Male to female ratio was 219:196.78.8% (327) of children had single stone. Mean stone size was 10.0 ± 3.7 mm and mean stone surface area was 380.0 ± 72.2 mm². Our stone-free rate after single ESWL session was 52.5% (218/415). Mean residual stone size and stone surface area after single session was 6.4 ± 3.3 mm and 36.0 ± 44.2 mm² respectively. There were no significant difference between stone-free children and children with residual fragments regarding gender, age and history of previous intervention. Mean stone size and stone surface area in stone-free children were lower and lower pole stones had the lowest stone-free rate (p < 0.05). Area under curve for Dogan and Onal nomogram were 0.628 and 0.580 respectively in ROC analysis (0.05). The agreement between Dogan and Onal score was moderate in our series. In multivariate analysis only stone surface area and Dogan score found to be independent predictors of stone-free status (p < 0.05).

DISCUSSION

Only one study has assessed both nomograms in the literature. Both nomograms are reported to be independent predictors of stone free status. ROC analysis in our study revealed fair accuracy for both nomograms with higher area under curve for Dogan nomogram. Higher accuracy for both nomograms were reported by other authors. These nomograms offer practical data but more effective tools are needed to be developed for the prediction of stone-free status in pediatric ESWL.

CONCLUSIONS

Stone size and stone surface area are associated with stone clearance. Dogan and Onal nomograms can be useful in prediction of stone-free status in children. Dogan nomogram is superior to Onal nomogram.

European Association of Urology and European Society for Paediatric Urology Guidelines on Paediatric Urinary Stone Disease

CONTEXT

Paediatric stone disease is an important clinically entity and management is often challenging. Although it is known that the condition is endemic in some geographic regions of the world, the global incidence is also increasing. Patient age and sex; the number, size, location, and composition of the stone; and the anatomy of the urinary tract are factors that need to be taken into consideration when choosing a treatment modality.

OBJECTIVE

To provide a general insight into the evaluation and management of urolithiasis in the paediatric population in the era of minimally invasive surgery.

EVIDENCE ACQUISITION

A nonsystematic review of the literature on management of paediatric urolithiasis was conducted with the aim of presenting the most suitable treatment modality for different scenarios.

EVIDENCE SYNTHESIS

Because of high recurrence rates, open surgical intervention is not the first option for paediatric stone disease, except for very young patients with very large stones in association with congenital abnormalities. Minimally invasive surgeries have become the first option with the availability of appropriately sized instruments and accumulating experience. Extracorporeal shockwave lithotripsy (SWL) is noninvasive and can be carried out as an outpatient procedure under sedation, and is the initial choice for management of smaller stones. However, for larger stones, SWL has lower stone-free rates and higher retreatment rates, so minimally invasive endourology procedures such as percutaneous nephrolithotomy and retrograde intrarenal surgery are preferred treatment options.

CONCLUSIONS

Contemporary surgical treatment for paediatric urolithiasis typically uses minimally invasive modalities. Open surgery is very rarely indicated.

PATIENT SUMMARY

Cases of urinary stones in children are increasing. Minimally invasive surgery can achieve high stone-free rates with low complication rates. After stone removal, metabolic evaluation is strongly recommended so that medical treatment for any underlying metabolic abnormality can be given. Regular follow-up with imaging such as ultrasound is required because of the high recurrence rates.

Definition, treatment and outcome of residual fragments in staghorn stones

Technological advances in minimally invasive treatment of stone disease and its integration with concomitant clinical practice are amongst the most important achievements in urology. Despite the wealth of information accumulated over the years and the richness of existing literature, the knowledge about the definition, treatment and outcomes of residual stone fragments after percutaneous nephrolithotomy (PNL) is still insufficient. Due to the high stone load a lot of patients with staghorn stones have residual fragments (RFs) after treatment with PNL, which depends on the size of tract, definition of stone free rate (SFR), timing of evaluation and the imaging used. No consensus exists on the imaging modality or their timing in the evaluation of possible RFs. The treatment of residual stones is apparently different depending on the facilities of the department and the preference of the surgeon, which includes active surveillance, shock wave lithotripsy (SWL), retrograde intrarenal surgery (RIRS) or a second look PNL.

Update on Surgical Management of Pediatric Urolithiasis

Urolithiasis has always been a fascinating disease, even more so in children. There are many intriguing facets to this pathology. This article is a nonsystematic review to provide an update on the surgical management of pediatric urolithiasis. It highlights the pros and cons of various minimally invasive surgical options such as extracorporeal shockwave lithotripsy (ESWL), retrograde intrarenal surgery (RIRS), percutaneous nephrolithotomy (PCNL), laparoscopy, and robotics. This article also describes the various intracorporeal disintegration technologies available to fragment the stone, including the newer advancements in laser technology. It also emphasizes the cost considerations especially with reference to the emerging economies. Thus, this manuscript guides how to select the least-invasive option for an individual patient, considering age and gender; stone size, location, and composition; and facilities and expertise available.

What is the fate of insignificant residual fragment following percutaneous nephrolithotomy in pediatric patients with anomalous kidney? A comparison with normal kidney

Pediatric population has increasing incidence of renal calculus and it is estimated to be around 50/10,000 population. The treatment of choice for large and complex stone in anomalous kidney is percutaneous nephrolithotomy (PCNL). The fate of insignificant residual fragment after PCNL in pediatric patients is not well documented. Here, we are reporting our long-term experience and follow-up of insignificant residual fragment in pediatric patients with anomalous kidney in comparison to normal kidney. Intuitional ethical approval was taken. A retrospective analysis of PCNL in pediatric (<18 years) anomalous kidney was performed from 2001 to 2013. The data of 52 pediatric patients with anomalous kidney (group B) have been compared to 251 normal kidneys (group A). The mean age of the patients was 7.83 + 3.45 (range 3-18) in group A and 8.21 ± 3.25 (range 5-18) in group B. The mean size of the insignificant residual fragment was 2.2 + 0.5 mm (1-4) in group A and 2.1 + 0.6 mm (range 1-4) in group B. Most of these residual fragments were single in number (72.55 vs. 67.30%, respectively). 54.98% children in group A and 67.30% in group B were symptomatic in the follow-up. Stone size was increased, stable and spontaneously passed in 49.8 vs. 71.15, 22.7 vs. 19.23 and 27.49 vs. 9.61% (p < 0.03), respectively, over mean follow-up of 50.34 months. Insignificant residual fragments in children are notorious for regrowth (49.8% in normal and 71.15% in anomalous kidney) in future. Most of the children will require symptomatic treatment (55.37 vs. 82.69%) or reintervention (39 vs. 46%) for insignificant residual fragment.

Residual stones after percutaneous nephrolithotomy: comparison of intraoperative assessment and postoperative non-contrast computerized tomography

OBJECTIVES

To compare the intraoperative surgeon perspective for detection of residual fragments (RFs) after percutaneous nephrolithotomy (PNL) with postoperative NCCT.

METHODS

A prospective study of adult patients who underwent PNL between March and September 2014 was conducted. Stone complexity was evaluated using the Guy's stone score (GSS). All patients were evaluated by pre- and postoperative NCCT. After the procedure, the surgeon had been asked whether there were residual stones or not. The sensitivity, specificity and predictive values were tested against postoperative NCCT. Predictors of accurate intraoperative assessment were determined using univariate and multivariate statistical analyses.

RESULTS

The study included 306 consecutive patients. The surgeons reported no residual stones in 236 procedures; of whom 170 (72%) were reported stone-free by NCCT. On the other hand, 65 out of 70 procedures (93%) reported with residual stones by the surgeons were true by NCCT. The sensitivity was 50% and the NPV was 72%, while the specificity was 97% and the PPV was 93%. On multivariate analysis, only lower GSS (p < 0.001) was independently associated with true negative surgeon opinion.

CONCLUSIONS

Although there was a high surgeon ability to detect post-PNL residual stones, postoperative imaging is mandatory because of the high false negative rates and low NPV. The surgeon opinions can be judged only in stones with lower GSS. The NPV could be enhanced if a consistent definition of clinically significant RFs is introduced.

Postural therapy for renal stones in children: A Rolling Stones procedure

INTRODUCTION

Despite many advances, the management of renal stones - especially lower caliceal stones (LCS) - remains a challenge. The gravity-dependent location of the lower calices hinders the spontaneous clearance of fragments, which can be a nidus for future growth and symptomatic recurrence. Currently, there is no standard adjunctive therapy to facilitate fragment passage.

OBJECTIVES

To report the safety and effectiveness of mechanical percussion diuresis and inversion (PDI) therapy for eliminating renal stones in children.

PATIENTS AND METHODS

Since November 2013, children with residual fragments (after shock wave lithotripsy or flexible ureteroscopy) or native symptomatic renal stones were prospectively included in a protocol of four PDI sessions. After giving written consent, the children drank 10 ml/kg of water 30 min before therapy. They then laid in a prone Trendelenburg position on a couch angled at 45° and received continuous 10-min mechanical percussion applied over the affected flank by a physiotherapist (Figure summary). Tolerance stone burden reduction and stone clearance were documented with ultrasound 4 weeks after the last session.

RESULTS

Seventeen participants, with a median age of 10.8 years (range 18 months to 18 years), received 82 PDI sessions performed over 22 months. The median stone diameter was 5 mm (range 3-9). All children tolerated the PDI therapy well. Over a median follow-up of 11 months (range 3-18), no significant adverse effects were noted. The overall stone-free rate was 65%. Four of the six patients with residual fragment passed their fragments. The patients who did not become stone free by PDI experienced a decrease in fragment size of 57% (range 34-71). The observance rate was 100%.

DISCUSSION

Many studies have demonstrated that the gravity-dependent position of the lower calyces appears to be an important factor limiting the clearance of LCS. Positioning patients with a degree of inversion in order to put the collecting system beyond the horizontal plane affected the LCS through gravitational force. Complications were rare. PDI appeared to save costs and have similar success rates as shock wave lithotripsy for native small renal stones in children.

CONCLUSION

PDI is safe and effective for facilitating gravity-dependent drainage of renal stones and provides an opportunity to treat children in a quick, non-invasive, economic, painless, non-radiative and diverting fashion. This therapy is a valuable alternative in the pattern of stone management. In case of persistent fragments, it is recommend that the number of sessions be increased to six.