Not Cast in Stone: Changes in Pediatric Nephrolithiasis

Transcription

1 Not Cast in Stone: Changes in Pediatric Nephrolithiasis Kristina D. Suson, MD January 23, 2015 Society of Women in Urology 4 th Annual Winter Meeting

2 Disclosures/Conflicts of Interest

3 Objectives To review the current status of pediatric nephrolithiasis Epidemiology Evaluation Management To contrast pediatric nephrolithiasis to adult stone disease To contextualize it in the AUA guidelines

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5 Incidence Dwyer et al, J Urol, 2012.

6 Incidence Also increase in South Carolina ERs from 1996 to 2007 Greatest increase among: Adolesents Pre-adolescents Caucasian children Amount of money charged for care increased >4x Sas et al, J Pediatr, 2010.

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8 Sex 1 st decade: > 2 nd decade: > Matalaga et al, Urol Res, 2010.

9 Sex Novak et al, Urology, 2009.

10 Obesity In 2008, nearly 1/3 children above the 85 th percentile Does elevated BMI contribute to increase in stones? Upper percentile body weight not associated with larger stones, earlier presentation, or more surgeries Lower percentile was associated with earlier symptomatic stone development Children with elevated BMI had lower urine oxalate excretion and higher supersaturation of calcium phosphate Ogden et al, JAMA, 2008; Kieran et al, J Urol, 2010; Eisner et al, J Urol, 2009.

11 Obesity Ayoob et al, Pediatr Nephrol, 2011.

12 Type of Stones Primary Stone Composition No.Total No. (%) Calcium Oxalate Monohydrate 26/65 (40) Calcium Oxalate Dihydrate 20/65 (31) Calcium Phoshate 16/65 (25) Struvite 2/65 (3) Urate 1/65 (2) Dwyer et al, J Urol, 2012.

13 Admissions Although incidence in increasing, fewer patients are admitted to the hospital More patients are managed in the ED Healthcare costs are shifting from inpatient to outpatient Average age of admitted patient decreased (12 vs 13, p <0.001), possibly reflecting ER management? Kusumi et al, Pediatr Nephrol, 2014 (online); unpublished research.

14 Co-Morbid Conditions HTN, DM among patients under 6 years of age HTN, obesity; less likely to have Type I DM 16% of infants < 1 have systemic disorder Conditions treated with topiramate Kusumi et al, Pediatr Nephrol, 2014 (online); Matalaga et al, Urol Res, 2010; Kokorowski et al, J Urol, 2012; Alpay et al, Pediatr Surg Int, 2013.

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16 Presentation Children Flank pain Abdominal pain Dysuria Incidental Infants UTI Incidental Restlessness Hematuria Vomiting Antenatal hydronephrosis Passing stones Voiding difficulty Sweating Anorexia Valentini and Lakshmanan, Adv Chronic Kidney Dis, 2011; Alpay et al, Pediatr Surg Int, 2013.

17 History As with adults Prior history Family history Previous CT scans (Fairly) unique to kids Anatomic anomalies Metabolic anomalies 50% or more may have predisposing cause

18 Work Up Renal bladder ultrasound, KUB If possible, avoid CT Of 42 patients, 21 had CT scans When compared to imagine, CT required for 12% Less than 20% of those getting scanned Of 50 patients getting both CT and US, 8 stones were missed Average size 2.3 mm Changed management in 4 pts US in all four demonstrated need for additional imaging Johnson et al, Urology, 2011, Passerotti et al, J Urol, 2009.

19 Work Up

20 Twinkle, twinkle little stone Twinkle increases detection of stones compared to grayscale 78% positive predictive value Fairly high false positive rate (51%) If negative, does not entirely preclude stone Dillman et al, Radiology, 2011.

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22 Diagnosis Increased use of CT scan 10% of imaged stones identified by CT from , vs 82% from (p<0.001) In PHIS, CT increased from 26% to 45% from and KUB use decreased from 59% to 38% (p<0.001) Use associated with: Older age Non-white race Public insurance Treating hospital most important factor Among commercially insured, those in Southeast and Midwest more likely to have initial CT, and New England less likely ED care pathways decrease usage Dwyer et al, J Urol, 2012, Routh et al, J Urol, 2010; Tasian et al, Pediatrics, 2014; Ziemba et al, J Urol, 2014 (online).

23 CT Scan CT can help determine: Cause of symptoms Anatomy If ESWL appropriate As with adults, attenuation value <1000 Hounsfield units predicted successful treatment Possibly improved outcome with skin-to-stone distance greater than 6.5 cm McAdams et al, J Urol, 2010.

24 CT Scan Attempts at radiation reduction Original setting 250 ma 80 ma setting Mean dose reduction 67% No significant decrease in detection 40 ma setting Mean dose reduction 82% Decreased detection overall No decreased detection in children < 50 kg 250 ma 80 ma Karmazyn et al, AJR Am J Roentgenol, ma

25 Metabolic Evaluation In Olmsted county, 40% had no evaluation Of privately insured patients between , only 12% had 24-hour urine Younger patients Seen by urology (4x/likely) Seen by nephrology (7x/likely) Dwyer et al, J Urol, 2012; Ellison et al, Urology, 2014.

26 To whom are kids admitted? Early Compared children admitted to pediatric hospitals with stones between and Late Urology Pediatrics Nephrology Heme/Onc GPS GI Other Urology Pediatrics Nephrology Family GI Adolescent Other Unpublished research.

27 Metabolic Evaluation Of 52 patients undergoing evaluation, 63% had abnormality 79.5% of children <1 y Of 45 patients with 24-hour urine, 68.9% had abnormality Most common: Hypocitraturia (58.1%) Hypercalciuria (48.3%) Diet analysis revealed lower intact of Mg and K in hypocitraturia kids Dwyer et al, J Urol, 2012; Kovacevic et al, J Urol, 2012.

28 Metabolic Evaluation Standard serum studies: creatinine, bicarbonate, ph, calcium, albumin, phosphate, K, Mg, urate When appropriate, PTH Of 45 patients with 24-hour urine, no patient had abnormal serum chemistries Kokorowski et al, Indian J Urol, 2010; Kovacevic et al, J Urol, 2012.

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30 Medical Management Increase hydration (1.5x maintenance) Decrease sodium Hypercalciuria (>4mg/kg/24 h): thiazide diuretic if not hypercalcemic Hyperoxaluria Diet changes, avoid excess vitamin C Primary hyperoxaluria-1: pyridoxine Malabsorption: GI consult, Mg, pyrophosphate Uric acid stones: K Cit Cystine: K Cit to target ph 7-7.5, D-penicillamine, alpha-mercaptopropionylglycine Valentini and Lakshmanan, Adv Chronic Kidney Dis, 2011.

31 Medical Management AUA Guideline (2014) EXHAUSTIVE! Differences in Kids* - The actual numbers, i.e. liters, mg, etc. 5. Clinicians should perform additional metabolic testing in high-risk or interested first-time stone formers and recurrent stone formers. 16. Clinicians should offer allopurinol to patients with recurrent calcium oxalate stones who have hyperuricosuria and normal urinary calcium. 17. Clinicians should offer thiazide diuretics and/or potassium citrate to patients with recurrent calcium stones in whom other metabolic abnormalities are absent or have been appropriately addressed and stone formation persists. 21. Clinicians may offer acetohydroxamic acid (AHA) to patients with residual or recurrent struvite stones only after surgical options have been exhausted. * My Opinion

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33 Expulsive Therapy Multi-institution, retrospective, case-control study Tamsulosin* increased odds of spontaneous passage by 3.3x on multi-variate analysis Dosing Small children: half a capsule (0.2 mg) Older children: one capsule (0.4 mg) *OFF LABEL USE Tasian et al, J Urol, 2014.

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35 Surgical Options ESWL Ureteroscopy PCNL Traditional Mini Micro Lap/Robotic, or slightly less minimally invasive surgery

36 ESWL Like adults Effective Safe Slower rate = better clearance Unlike adults General anesthesia Ultrasound for localization Salem et al, J Urol, 2014.

37 ESWL Does It Work? Retrospective review of renal stones in 450 patients and ureteral stones in 50 patients 3,000 shocks at shocks/minute Renal stones 83.5% stone free 4% retreatment Ureteral stones 58.5% stone free 28% retreatment Complications 10% renal colic 5% vomiting Badawy et al, Int Urol Nephrol, 2012.

38 ESWL Does It Work? Complication No. Pts (%) Pain > 24 hrs 2 (0.9) Fever > 38 C, no UTI 1 (0.5) Ureteral obstruction 1 (0.5) Laryngospasm 1 (0.5) UTI 1 (0.5) TOTAL 6 (2.8) Retrospective review of prospective database, with 157 renal calculi and 59 ureteral calculi Mean age 6.6 years Renal: 42% were tubed 80% stone-free at 3 months 19.7% additional procedure Ureteral: 69% were stented 78% stone-free at 3 months 22% additional procedure Landau et al, J Urol, 2009.

39 ESWL Predicting Success! Based on MVA, ESWL successful for Renal pelvis stones to 24 mm Upper/interpolar calyceal stones to 15 mm Lower pole stones to 11 mm Hounsfield units Obesity not a hindrance Increasing hydronephrosis may decrease effectiveness Not effective Cystine stones Prior urologic surgery/anatomic anomaly El-Nahas et al, Int J Urol, 2013; El-Assmy et al, Urology, 2013; Akça et al, Int Urol Nephrol, 2013; Turunc et al, J Endourol, 2013; Landau et al, J Urol, 2009; Nelson et al, J Urol, 2008.

40 ESWL Large Stones 24 patients, mean stone size 31 mm (25 35 mm) Stone-free: 20 pts (83.3%) Clinically insignificant fragments : 4 pts Clinical Concerns - General anesthetic - Long term impact of ESWL Number of sessions N (%) 1 4 (16.7%) 2 12 (50%) 3 7 (29.1%) 4 1 (4.2%) Complication N(%) Renal colic 2 (8.3%) Steinstrasse 4 (16.7%) Spontaneous passage 3 (75%; 12.5%) Ureteroscopy 1 (75%, 4.2%) Total 6 (25%) - Clinically insignificant Shouman et al, Urology, 2009.

41 ESWL Large Stones Per AUA guideline: Average treatment 2.7 sessions Complications minor and rare

42 ESWL Long Term Effects Review including 151 papers No long term impact on renal function Contradictory evidence on renal growth No long term renal scars No conclusion DM No conclusion HTN Akin and Yucel, Res Rep Urol, 2014.

43 ESWL Long Term Effects Finding N (%) Normal function pre- and post- ESWL Decreased function preand no change post- ESWL Transient decreased function post-eswl Permanent decreased function post-eswl Improved function post- ESWL 66 (70) 18 (19) 2 (2) 1 (1) 7 (7) Griffin et al, J Urol, 2010.

44 Ureteroscopy Increased popularity with improved technology First line therapy for distal or mid-ureteral stones Equivalent outcomes for renal stones as ESWL* Passive vs active dilation User DEPENDENT variable Thomas, Urol Res, 2010.

45 Ureteroscopy - Technology Semi-rigid ureteroscopes 4.5Fr needle scope, 2.4 Fr working channel 6/7.5Fr self-dilating Flexible ureteroscopes (6.9Fr) Ureteral access sheaths (smallest internal lumen 9.5Fr, starting at 13 cm) 8/10 dilator Balloon dilation Zhu et al, Indian J Urol, 2010.

46 Ureteroscopy Gaining Access Retrospectively reviewed charts to identify predictors of needing preureteroscopic stent Were unable to identify any Conclude it is worth a shot to attempt ureteroscopy Hung up equally among the usual suspects Corcoran et al, J Urol, 2008; Netter Collection of Medical Illustrations: The Urinary System, Section 6 Urinary Tract Obstructions, 2012.

47 Ureteroscopy Gaining Access Hydrodilation of the ureteral orifice Used hand pump designed for arthroscopic surgery Used technique in 26 patients without significant complication Unclear how many were spared a pre-op stent Soygur et al, J Urol, 2006.

48 Ureteroscopy Retrospective review of 100 consecutive patients undergoing ureteroscopic stone surgery (57 ureteral, 43 renal) PCNL and ESWL remained stable, while ureteroscopy increased 7x Smaldone et al, J Urol, 2007.

49 Ureteroscopy Does It Work? Retrospective review of prospective database, from 2004 to 2007 Total of 170 flexible ureteroscopies No active dilation 57% required stent for 1 to 2 weeks 52% of pre-stented had 2 anesthethetics, vs 47% of unstented group (NS) No intraop or postop complications Stone clearance 10 mm = 100% > 10 mm = 97% Intraoperative Complications Ureteral ischemia Perforation Avulsion Significant contract extravasation Post-Operative Complications Worsening hydroureteronephrosis Ureteral stricture Need for further surgery Kim et al, J Urol, 2008.

50 Ureteroscopy Lower Pole Stones Retrospective review of 13 girls and 8 boys Stenting Pre-op = 38% Post-op = 71% Ureteral access sheath 43% Success rate < 15 mm 93% 15 mm 33% (p=0.01) Cannon et al, J Endourol, 2007.

51 Ureteroscopy Factors for Success Stone doesn t migrate Adequate ureter diameter Balloon dilation Pre-ureteroscopic stenting Age > 1 year Yucel et al, World J Urol, 2011

52 Ureteroscopy Improving Rads Kokorowski et al, J Urol, 2013.

53 ESWL vs Ureteroscopy for Ureteral Stones

54 Guideline Comparison Guideline for Index Patient S = Standard O = Option * = MY OPINION Peds* All Index < 10 mm stone Need Surgery S - Patients with bacteriuria should be treated with appropriate antibiotics. S - Stone extraction with a basket without endoscopic visualization of the stone (blind basketing) should not be performed. O - In a patient who has a newly diagnosed ureteral stone <10 mm and whose symptoms are controlled, observation with periodic evaluation is an option for initial treatment. Such patients may be offered an appropriate medical therapy to facilitate stone passage during the observation period. S - Patients should be counseled on the attendant risks of MET including associated drug side effects and should be informed that it is administered for an "off label" use. S - Patients who elect for an attempt at spontaneous passage or MET should have well-controlled pain, no clinical evidence of sepsis, and adequate renal functional reserve. S - Patients should be followed with periodic imaging studies to monitor stone position and to assess for hydronephrosis. S - Stone removal is indicated in the presence of persistent obstruction, failure of stone progression, or in the presence of increasing or unremitting colic. S - A patient must be informed about the existing active treatment modalities, including the relative benefits and risks associated with each modality. S - For patients requiring stone removal, both SWL and URS are acceptable first-line treatments. S - Routine stenting is not recommended as part of SWL. O - Stenting following uncomplicated URS is optional. O - Percutaneous antegrade ureteroscopy is an acceptable first-line treatment in select cases. O - Laparoscopic or open surgical stone removal may be considered in rare cases where SWL, URS, and percutaneous URS fail or are unlikely to be successful.

55 PCNL Can be performed with equal safety and efficiency in older and younger children Adult equipment offers quicker OR time and optimal fragment clearance Peds can use some specialized equipment Dogan et al, World J Urol, 2011, Kumar et al, J Pediatr Urol, 2011; Penbegul et al, Urology, 2012.

56 Miniature PCNL Similar to standard PCNL, in that you gain access in separate step Smaller nephroscopes Smaller sheaths MINI PCNL Choose the right size equipment for the patient Unsal et al, Urology, 2010; Wah et al, Cardiovasc Intervent Radiol, 2013.

57 Microperc Desai et al, J Urol, 2011.

58 Other MIS Options Laparoscopy Robot-assisted laparoscopic surgery Nephrolithotomy, pyelolithotomy, ureterolithotomy Both are best reserved for patients with an anatomic anomaly or how have failed endourologic management Agrawal et al, J Pediatr Urol, 2013; Ghani et al, Int Braz J Urol, 2014.

59 Treatment Success Definition of success? Stone-free after surgery? 1 surgery? X surgeries? Recurrence of stones? Compliance with medical management? Need for future surgery? What is stone free? Clinically insignificant fragments? Negative US? KUB? CT?

60 Treatment Success Dincel et al, J Pediatr Surg, 2013.

61 Conclusions Incidence of pediatric nephrolithiasis is rising, mostly among adolescents Hospital admissions are decreasing US is imaging modality of choice Every child deserves a metabolic work-up Medical expulsive therapy is used ESWL and ureteroscopy are both effective and safe PCNL and variations are also options

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