Extracorporeal shock wave lithotripsy for struvite renal calculi: prospective study with extended followup

Follow-up of urolithiasis patients after treatment: an algorithm from the EAU Urolithiasis Panel

OBJECTIVE

To develop a follow-up algorithm for urinary stone patients after definitive treatment.

MATERIALS AND METHODS

The panel performed a systematic review on follow-up of urinary stone patients after treatment (PROSPERO: CRD42020205739). Given the lack of comparative studies we critically evaluated the literature and reached a consensus on the follow-up scheme.

RESULTS

A total of 76 studies were included in the analysis, including 17 RCTs. In the stone-free general population group, 71-100% of patients are stone-free at 12 months while 29-94% remain stone-free at 36 months. We propose counselling these patients on imaging versus discharge after the first year. The stone-free rate in high-risk patients not receiving targeted medical therapy is < 40% at 36 months, a fact that supports imaging, metabolic, and treatment monitoring follow-up once a year. Patients with residual fragments ≤ 4 mm have a spontaneous expulsion rate of 18-47% and a growth rate of 10-41% at 12 months, supporting annual imaging follow-up. Patients with residual fragments > 4 mm should be considered for surgical re-intervention based on the low spontaneous expulsion rate (13% at 1 year) and high risk of recurrence. Plain film KUB and/or kidney ultrasonography based on clinicians' preference and stone characteristics is the preferred imaging follow-up. Computed tomography should be considered if patient is symptomatic or intervention is planned.

CONCLUSIONS

Based on evidence from the systematic review we propose, for the first time, a follow-up algorithm for patients after surgical stone treatment balancing the risks of stone recurrence against the burden of radiation from imaging studies.

Duration of Follow-up and Timing of Discharge from Imaging Follow-up, in Adult Patients with Urolithiasis After Surgical or Medical Intervention: A Systematic Review and Meta-analysis from the European Association of Urology Guideline Panel on Urolithiasis

CONTEXT

No algorithm exists for structured follow-up of urolithiasis patients.

OBJECTIVE

To provide a discharge time point during follow-up of urolithiasis patients after treatment.

EVIDENCE ACQUISITION

We performed a systematic review of PubMed/Medline, EMBASE, Cochrane Library, clinicaltrials.gov, and reference lists according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement. Fifty studies were eligible.

EVIDENCE SYNTHESIS

From a pooled analysis of 5467 stone-free patients, we estimated that for a safety margin of 80% for remaining stone free, patients should be followed up using imaging, for at least 2 yr (radiopaque stones) or 3 yr (radiolucent stones) before being discharged. Patients should be discharged after 5 yr of no recurrence with a safety margin of 90%. Regarding residual disease, patients with fragments ≤4 mm could be offered surveillance up to 4 yr since intervention rates range between 17% and 29%, disease progression between 9% and 34%, and spontaneous passage between 21% and 34% at 49 mo. Patients with larger residual fragments should be offered further definitive intervention since intervention rates are high (24-100%). Insufficient data exist for high-risk patients, but the current literature dictates that patients who are adherent to targeted medical treatment seem to experience less stone growth or regrowth of residual fragments, and may be discharged after 36-48 mo of nonprogressive disease on imaging.

CONCLUSIONS

This systematic review and meta-analysis indicates that stone-free patients with radiopaque or radiolucent stones should be followed up to 2 or 3 yr, respectively. In patients with residual fragments ≤4 mm, surveillance or intervention can be advised according to patient preferences and characteristics, while for those with larger residual fragments, reintervention should be scheduled.

PATIENT SUMMARY

Here, we review the literature regarding follow-up of urolithiasis patients. Patients who have no stones after treatment should be seen up to 2-3 yr, those with large fragments should be reoperated, and those with small fragments could be offered surveillance with imaging.

Contemporary Management of Struvite Stones Using Combined Endourologic and Medical Treatment: Predictors of Unfavorable Clinical Outcome

BACKGROUND AND PURPOSE

Struvite stones have been associated with significant morbidity and mortality, yet there has not been a report on the medical management of struvite stones in almost 20 years. We report on the contemporary outcomes of the surgical and medical management of struvite stones in a contemporary series.

PATIENTS AND METHODS

A retrospective review of patients who were treated with percutaneous nephrolithotomy (PCNL) for struvite stones at Duke University Medical Center between January 2005 and September 2012 identified a total of 75 patients. Of these, 43 patients had adequate follow-up and were included in this analysis. Stone activity, defined as either stone recurrence or stone-related events, and predictors of activity were evaluated after combined surgical and medical treatment.

RESULTS

The study included 43 patients with either pure (35%) or mixed (65%) struvite stones with a median age of 55±15 years (range 21-89 years). The stone-free rate after PCNL was 42%. Stone recurrence occurred in 23% of patients. Postoperatively, 30% of patients had a stone-related event, while 60% of residual stones remained stable with no growth after a median follow-up of 22 months (range 6-67 mos). Kidney function remained stable during follow-up. Independent predictors of stone activity included the presence of residual stones >0.4 cm(2), preoperative large stone burden (>10 cm(2)), and the presence of medical comorbidities (P<0.05).

CONCLUSIONS

Struvite stones can be managed safely with PCNL followed by medical therapy. The majority of patients with residual fragments demonstrated no evidence of stone growth on medical therapy. With careful follow-up and medical management, kidney function can be maintained and stone morbidity can be minimized. Initial large stone burden, residual stones after surgery, and associated medical comorbidities may have deleterious effect on stone recurrence or residual stone-related events.

The management of staghorn calculi in children

OBJECTIVES

To review reports focusing on the surgical treatment of staghorn stones in children, as despite all the improvements in the surgical treatment of paediatric urolithiasis the management of staghorn calculi still represents a challenging problem in urology practice.

METHODS

To evaluate current knowledge about treating staghorn calculi in children, we searched PubMed for relevant articles published between 1991 and 2011, using a combination of related keywords, i.e. staghorn stone, child, kidney calculi, surgical treatment, electrohydraulic shockwave therapy (ESWL), percutaneous nephrolithotomy (PCNL), and open surgery. Reports relating to the treatment of paediatric stone disease in general (open surgery, PCNL, ESWL) were also searched with the same method. Additional references were obtained from the reference list of full-text reports.

RESULTS

Although open surgery had been widely used in the past for treating such stones in children, currently it has only limited indications in highly selected patients. Current published data clearly indicate that, in experienced hands, both PCNL and ESWL are now effective methods for treating staghorn calculi in children.

CONCLUSIONS

Due to advanced techniques and instrumentation, it is now possible to successfully treat staghorn calculi in children, with very limited safety concerns. Currently, while PCNL is recommended as the first-line surgical treatment, ESWL, open surgery and/or combined methods are valuable but secondary options in the treatment of paediatric staghorn calculi.

Management of staghorn calculus: single puncture with judicious use of the flexible nephroscope

PURPOSE OF REVIEW

To focus on the technique and results of a single percutaneous puncture for the management of staghorn renal calculi.

RECENT FINDINGS

The success rate for treating staghorn calculi with a single percutaneous puncture is over 90%. Animal and clinical studies seem to suggest that a single percutaneous access may be associated with reduced morbidity when compared with multiple percutaneous access punctures.

SUMMARY

A single percutaneous access, whenever feasible, offers reduced morbidity without compromising excellent stone-free rates in the management of staghorn calculi.

Extracorporeal shock-wave lithotripsy monotherapy of partial staghorn calculi. Prognostic factors and long-term results

OBJECTIVE

To define factors affecting the success and long-term outcome of extracorporeal shock-wave lithotripsy (ESWL) monotherapy of partial staghorn calculi.

MATERIAL AND METHODS

We retrospectively reviewed 92 patients with partial staghorn calculi who were treated with ESWL monotherapy. The outcome of the treatment was evaluated after 3 months. Long-term follow-up data (>24 months) were available for 49 patients. These data were further analyzed to determine long-term outcome.

RESULTS

At 3 months, the overall stone-free rate was 59.8%. Multiple ESWL sessions were required in 85.8% of patients. Stone surface area>500 mm2 was the only factor that significantly decreased the stone-free rate. Post-ESWL complications occurred in 12 patients (13%), among whom renal obstruction was observed in 10.8%. Secondary procedures were needed in 17 cases (18.4%). After a mean follow-up period of 7.5 years, the stone-free rate was 59.2% (29/49) and one-third of patients developed recurrence. In the long term, clinically insignificant residual fragments (CIRFs) passed spontaneously in 23% of patients, remained stable in 38.5% and became bigger in 38.5%. Regrowth of CIRFs was related to a history of stone recurrence. No patients showed deterioration of kidney function on the treated side and an improvement in pre-ESWL hydronephrosis was observed in 73.3% of patients.

CONCLUSIONS

ESWL is suitable for staghorn stones<or=500 mm2. In the long term, CIRFs became bigger and required secondary intervention in one-third of patients. A history of stone recurrence is a significant predictor of regrowth of CIRFs. ESWL provides long-term preservation of function of the treated kidneys; however, one-third of patients develop recurrence.

[Infective lithiasis]

"Infection Lithiasis" refers to calculi that occur with persistent urinary tract infection. Stones composed of magnesium ammonium phosphate (struvite) and carbonate apatite, called "triple phosphate" stones, are the more common type of infection lithiasis. These stones are also called "staghorn" calculi because they may grow rapidly and fill the entire collecting system. They form during urinary infection with urea-splitting micro-organism. They may originate de novo or complicate a lithiasis when pre-existing stones are colonized with urea-splitting bacteria. They represent about 2-3% of stones referred for laboratory analysis. This article reviews the epidemiology, pathogenesis, clinical features, and management of struvite stones. A singular pathologic entity recently described, called "encrusted cystitis or encrusted pyelitis", mainly caused by Corynebacterium urealyticum is also review. Infection lithiases caused by non-urease-producing bacteria may also occur and are examined in this article. Finally, the controversial role of nanobacteria in nephrolithiasis is discussed.

Urinary Tract Infections after Extracorporeal Shock Wave Lithotripsy

Extracorporeal shock wave lithotripsy (ESWL) has been using since a long time in the treatment of urolithiasis; until now it is not universally stated if such a procedure represents a risk factor for the development of complications (such as pyelonephritis) and if the same procedure needs an antimicrobial prophylaxis. We began a prospective study in order to evaluate the clinical and microbiological follow-up of all the patients undergoing ESWL at the Centre of urologic lithotripsy of the University of Pisa into a two months period.

Methods

Fifty-four consecutive patients were enrolled (38 males and 16 females). All the patients were studied, examining their urine samples before ESWL and after one week and evaluating their risk factors for urinary tract infections.

Results

12 (22.2 %) out of 54 patients had a significant bacteriuria (≥ 104 CFU/mL) before undergoing ESWL; such bacteriuria persisted in eight of the twelve patients even though they received an appropriate antimicrobial therapy. 41 (75.9%) patients without a significant bacteriuria at the enrollment remained asymptomatic –with sterile urine- after ESWL and they did not receive therapy. One patient with multiple stones, who had a clinical history of previous urinary infections, developed an acute pyelonephritis after ESWL when she stopped the antibiotic terapy.

Conclusions

Such preliminary data seem to show that the risk of developing urinary infections after ESWL is represented primarily by a history of previous urinary infections and by the presence of an asymptomatic urinary tract infection before ESWL. The decision about the need of an antimicrobial prophylaxis should be taken in every single case basing on the peculiar clinic history of the patient.

Percutaneous chemolysis--an important tool in the treatment of urolithiasis

Persistent residual calculi after therapy, i.e. extracorporeal shock wave lithotripsy (ESWL), percutaneous nephrolitholapaxy (PNL), as well as pyelo- and nephrolithotomy are big problems in the treatment of urolithiasis. Furthermore, the therapy of stones is problematic in patients with inadequate drainage, impaired kidney function, or with high risks against anaesthetics. Between 1991 and 1997 percutaneous antegrade chemolysis was carried out in eleven patients. In nine of them complete dissolution of stones was achieved. In two further cases, in which calcium oxalate was the main component of the stones, chemolysis was unsuccessful. Through our own cases and under consideration of the literature, we will show that percutaneous chemolysis in these cases is useful and effective in the treatment of urolithiasis.

Minor residual fragments after extracorporeal shockwave lithotripsy: spontaneous clearance or risk factor for recurrent stone formation?

The aim of this study was to follow the fate of residual stone fragments (RF) < 5 mm after extracorporeal shockwave lithotripsy (SWL) over a sufficiently long period to determine how many are spontaneously cleared and after what time interval. A further aim was to clarify their role in clinical outcome and stone recurrence and regrowth. The clinical and radiologic data of 266 patients were analyzed. The patients were followed up for a mean of 387 days. After SWL, 55 patients (21%) had residual fragments < 5 mm in diameter. There were no significant differences between the stone-free patients and those with RF with regard to age, sex, relevant medical history, or SWL treatment. After a mean follow-up of 2.5 years, 12.7% of the residual fragments had not passed spontaneously, but all of them were clinically silent and located exclusively in the lower calices and the proximal ureter. Only 2% of the patients with RF showed stone regrowth, and no stone recurrences were observed within the follow-up period. In conclusion, although a minor pathophysiological role of RF < or = 5 mm cannot be discounted in recurrence and regrowth of kidney stones after SWL, more invasive attempts to clear all minor fragments do not seem warranted.

The management of upper urinary tract calculi by piezoelectric extracorporeal shock wave lithotripsy in spinal cord injury patients

From May 1988 to September 1994, 15 spinal cord injury patients were treated by piezoelectric extracorporeal shock wave lithotripsy. Aged from 23 to 71 years (mean = 39), they presented with a total of 23 stones, of which 18 were located in the calyces, three in the renal pelvis and two in the proximal ureter. The maximum dimensions of calculi varied from 5 to 35 mm (mean = 11). Patients were placed in a dorsal decubitus position during the sessions, three being sedated with diazepam, while the other 12 remained unsedated. All were treated routinely with systemic antibiotics. Auxiliary procedures consisted of two pyelocalyceal flushings, three double J ureteral stenting and three ureteroscopies with fragment removal with a Dormia basket. No episode of autonomic dysreflexia was observed. Short term side effects were limited to a few cases of gross haematuria which regressed spontaneously. Overall, eight successes (53%), and seven failures (47%), were registered. Of the failures, one was the result of a partial fragmentation, while six were related to intrarenal retention of residual fragments resulting in four cases in rapid recurrences. Extracorporeal shock wave lithotripsy can be easily applied to spinal cord injury patients. Its usefulness and limitations need to be well understood and a global consideration must be applied to the prevention and early detection of the upper urinary calculi in this exposed population of patients.

Nephrolithiasis Clinical Guidelines Panel summary report on the management of staghorn calculi. The American Urological Association Nephrolithiasis Clinical Guidelines Panel

The American Urological Association Nephrolithiasis Clinical Guidelines Panel recommendations for managing struvite staghorn calculi are based on a comprehensive review of the treatment literature and meta-analysis of outcome data from the 110 pertinent articles containing viable, unduplicated data. The panel concluded that the 3 most significant outcome probabilities are those of being stone-free, undergoing secondary unplanned procedures and having associated complications. Panel guideline recommendations for most standard patients are that neither shock wave lithotripsy monotherapy nor open surgery should be a first-line treatment choice but that a combination of percutaneous stone removal and shock wave lithotripsy should be used.