EAU 2020 Urolithiasis Flashcards
Non-infection stones
Calcium oxalate
Calcium phosphate
Uric acid
Infection stones
MAP
Carbonate apatite
Ammonium urate
Stones from Genetic causes
Cystine
Xanthine
2,8-Dihydroxyadenine
MINERAL NAME
Calcium oxalate monohydrate
Whewellite
MINERAL NAME
Calcium oxalate dihydrate
Weddelite
MINERAL NAME
Basic calcium phosphate
Apatite
MINERAL NAME
Calcium hydroxyl phosphate
Carbonate apatite
MINERAL NAME
b-tricalcium phosphate
Whitlockite
MINERAL NAME
Carbonate apatite phosphate
Dahllite
MINERAL NAME
Calcium carbonate
Aragonite
MINERAL NAME
Uric acid/uric acid dihydrate
Uricite
MINERAL NAME
Magnesium ammonium phosphate
Struvite
MINERAL NAME
Magnesium acid phosphate trihydrate
Newberyite
MINERAL NAME
Magnesium ammonium phosphate monohydrate
Dittmarite
Radiopaque stones
Calcium oxalate dihydrate
Calcium oxalate monohydrate
Calcium phosphates
Poor radiopacity
Magnesium ammonium phosphate
Apatite
Cystine
Radiolucent stones
Uric acid Ammonium urate Xanthine 2,8-Dihydroxyadenine Drug-stones
Repeat stone analysis in patients presenting with:
Recurrent stones despite drug therapy
Early recurrence after complete stone clearance
Late recurrence after a long stone-free period because stone composition may change
Pregnant women: first and second line imaging
1st: Ultrasound
2nd: MRI
Last option: low-dose CT
Children: diagnosis recommendations in children
Complete metabolic evaluation based on stone alaysis
Collect stone material to classify stone type
First-line imaging: ultrasound (kidney, fluid-filled bladder, ureter)
KUB x-ray or low dose non-contrast CT if ultrasound will not provide information
Pain relief: first drug of choice
NSAIDs and paracetamol: ex. metamizoledipyrone.
Pain relief: second drug of choice
Opiates: hydromorphine, pentazocine, or tramadol (NOT pethidine)
Pain relief: when to offer renal decompression or URS stone removal
In case of analgesic refractory colic pain
Two options for urgent decompression of obstructed collecting systems:
Indwelling ureteral stent placement
Percutaneous nephrostomy tube placement
Obstructed collecting systems: definitive treatment of stones should be delayed until ______.
Sepsis resolves
After decompression of obstructed collecting system, collect _______ and start ________.
Urine for antibiogram
Antibiotics immediately + intensive care, if necessary.
Re-evaluate antibiotic regimen after antibiogram findings.
Medical expulsive therapy should only be used in _____________.
Informed patients if active stone removal is not indicated.
Patients treated with _____, ______, and ______ are more likely to pass stones with fewer colic episodes than those not receiving such therapy.
MET:
alpha-blockers (tamsulosin)
calcium-channel inhibitors (nifedipine)
PDE-5 inhibitors (tadalafil)
Offer alpha-blockers as MET for _________ stones.
Ureteral (distal) , > 5 mm
Irrigation chemolysis has been in limited clinical use to dissolve _____.
Struvite stones
Uric acid stones > 5 mm can be dissolved by oral alkalinisation of urine above pH ___.
7.0
Inform patient on how to monitor _________ by __________ to modify the dosage of alkalising medication.
urine pH, dipstick
Oral chemolitholysis is based on alkalinisation of urine using _____ or ______, and pH should be adjusted to _____.
Alkaline citrate
Sodium bicarbonate
pH 7.0-7.2
Carefully monitor patients during/after chemolysis of _________.
Uric acid stones
Combine oral chemolysis with _____ in larger ureeral stones if active intervention is not indicated.
Tamsulosin
ESWL: _________ prevents renal injury.
Stepwise power ramping
Optimal shock wave frequency is:
1.0 - 1.5 Hz
___________ between the cushion of the treatment head and the patient’s skin is important.
Proper acoustic coupling
Ensure correct use of _____________ monitoring during ESWL.
Fluoroscopic and/or ultrasonographic
Proper analgesia improves ESWL treatment results by:
Limiting pain-induced movements and excessive respiratory excursions
Prescribe antibiotics prior to ESWL in case of ________ or ________
Infected stones or bacteriuria
Stenting before ESWL does not improve ______ but may reduce ________
Does not improve SFRs
May reduce steinstrasse formation
ESWL complications related to stone fragments:
Steinstrasse
Regrowth of fragments
Renal colic
ESWL complications, infectious:
Bacteriuria in non-infection stones
Sepsis
ESWL complications, tissue effect:
Renal: hematoma symptomatic/asymptomatic
Cardiovascular: dysrhythmia, morbid cardiac events
GI: bowel perforation, liver, spleen hematoma
Antegrade URS is an option for:
Large, impacted, proximal ureteral calculi
The most effective lithotripsy system is the:
Holmium:yttrium-aluminium-garnet (Ho:YAG) laser, effective in all stone types.
Pneumatic and US systems: high disintegration efficacy URS, but stone migration is common problem
Is routine stenting necessary before URS?
No.
BUT: it improves URS management of stones, improves SFR, and reduces intraop complications.
“I hate stents! 😤 “ - JBM
Stents should be inserted in patients who are:
At increased risk of complications:
- Ureteral trauma
- Residual fragments
- Bleeding
- Perforation
- UTIs
- Pregnancy
- All doubtful cases
________ reduce the morbidity and increase the tolerability of ureteral stents.
Alpha-blockers
_________ accelerates the spontaneous passage of fragments and reduces episodes of colic/stent-related symptoms.
MET
Use _____ lithotripsy for flexible URS.
Ho:YAG laser
Perform stone extraction only under:
Direct endoscopic visualization of the stone.
DO NOT insert a stent in _______ URS cases.
Uncomplicated
“I hate stents! 😤 “ - JBM
When ESWL is not indicated or has failed, or when upper urinary tract is not amenable to retrograde URS, use _____ removal of ureteral stones.
Percutaneous antegrade removal
_________ therapy must be discontinued before PCNL.
Anti-coagulant therapy
Contraindications to PCNL:
Untreated UTI
Tumor in the access tract area
Potential malignant kidney tumor
Pregnancy
Safer PCNL position: chupine or prone?
Both are equally safe.
Prone: more options for puncture, preferred for upper pole or multi-access
Supine: allows simultaneous retrograde access to collecting system using fURS
Tubeless PCNL
PCNL without an NT.
Totally tubeless PCNL
PCNL without an NT and ureteral stent.
In uncomplicated cases, results in shorter hospital stay, with no disadvantages reported.
Intraop irrigation pressure ____ mmHg and unobstructed post-op urinary drainage may be important factors in preventing ____
< 30 mmHg
Post-op sepsis
Bleeding after PCNL may be treated by _______. For severe bleeding, ________ may be necessary.
Briefly clamping the NT.
Super-selective embolic occlusion of the arterial branch
PCNL with small instruments: lower _____ but longer ______.
Lower blood loss, longer duration.
Perform ______ when starting PCNL to assess stone comprehensiveness and anatomy of the collecting system to ensure safe access.
Pre-procedural imaging + contrast medium where possible or retrograde study
Perform a tubeless or totally tubeless PCNL in _______ cases.
Uncomplicated
Obtain ____ or ____ before treatment/ stone removal procedure is planned
Urine culture or urinary microscopy
Treat ______ prior to stone removal.
UTIs
Offer perioperative antibiotic prophylaxis to all patients undergoing ______.
Endourological treatment
Procedures with an elevated risk of hemoarrhage or perinephric hematoma if with uncorrected bleeding diathesis:
SWL PNL Percutaneous nephrostomy Laparoscopic surgery Open surgery
Low-risk bleeding procedures
Cystoscopy Flexible cystoscopy Ureteral catheterisation Extraction of ureteral stent URS
High-risk bleeding procecures
ESWL
PNT
PCNL
________ is the preferred intervention if stone removal is essential and anti-thrombotic therapy cannot be discontinued.
Retrograde flexible URS
Hard, SWL resistant stones
Brushite
Calcium oxalate monohydrate
Cystine
Homogenous stones with a high density on CT
Alternative treatment: RIRS or URS
URS, contraindications
None. 💪
Apart from general problems, for example with general anaesthesia or untreated UTIs, URS can be performed in all patients without any specific contraindications.
Indications for active removal of URETERAL stones:
Stones with low likelihood of spontaneous passage Persistent pain despite analgesic meds Persistent obstruction Renal insufficiency (RF, bilateral obstruction, or single kidneney)
Compared to ESWL, URS has a better chance of __________ with a single procedure.
Achieving stone-free status
URS has higher ______ compared to ESWL.
Complication rate
In cases of severe obesity, use _____ as first-line therapy for ureteral (and renal) stones.
URS
Treatment:
Proximal ureteral stone: > 10 mm
- URS
2. SWL
Treatment:
Proximal ureteral stone: < 10 mm
SWL or URS
Treatment:
Distal ureteral stone: > 10 mm
- URS
2. SWL
Treatment:
Distal ureteral stone: < 10 mm
SWL or URS
Dissolution of stones through pharmacological treatment is an option for _____ stones only.
Uric acid stones only
Indications for active removal or RENAL stones:
stone growth;
stones in high-risk patients for stone formation;
obstruction caused by stones;
infection;
symptomatic stones (e.g., pain or haematuria)
stones > 15 mm;
stones < 15 mm if observation is not the option of choice;
patient preference;
comorbidity;
social situation of the patient (e.g., profession or travelling);
choice of treatment.
The following can impair successful stone treatment:
Thanos FAQ
Steep infundibular-pelvic angle Long calyx Long skin-to-stone distance Narrow infundibulum SWL resistant stones (CaOxMono, brushite, cystine)
Stones with density _______ on NCCT are less likely to be disintegrated by ESWL.
> 1000 HU (and with high homogeneity)
First-line treatment for larger renal stones > 2cm
PCNL
Kidney stone, non-lower pole: > 20 mm
- PCNL
2. RIRS or SWL
Kidney stone, non-lower pole: 10 - 20 mm
SWL or Endourology
Kidney stone, non-lower pole: < 10 mm
- SWL or RIRS
2. PCNL
Lower pole kidney stone: > 20 mm
- PCNL
2. RIRS or SWL
Lower pole kidney stone: < 10 mm
- SWL or RIRS
2. PCNL
Lower pole kidney stone: 10 - 20 mm, unfavorable factors
- Endourology
2. SWL
Lower pole kidney stone: 10 - 20 mm, no unfavorable factors
SWL or endourology
Offer laparoscopic or open surgical stone removal in rare cases in which:
ESWL, URS, or PCNL fail or are unlikely to successful
Steinstrasse is:
An accumulation of stone fragments or stone gravel in the ureter, and may interfere with the passage of urine.
______ increases stone expulsion and reduces the need for endoscopic intervention for steinstrasse.
MET
Steinstrasse + UTI/fever should be treated preferably with:
PNT
Treat steinstrasse when:
Large stone fragments are present.
Options: SWL or URS (in absence of signs of UTI).
Perform imaging after ESWL or URS to determine ________.
Presence of residual fragments
Treat all uncomplicated cases of urolithiasis in pregnancy:
Conservatively (except when there are clinical indications for intervention)
Perform _____ to remove large renal stones in patients with urinary diversion
PCNL
Patients undergoing urinary diversion and/or suffering from neurogenic bladder are at risk of ______.
Recurrent stone formation
Common allergy in myelomeningocele patients.
Latex allergy
For patients with transplanted kidneys with stones, offer:
Any of the contemporary options: ESWL, fURS, PCNL
Special problems in stone removal:
Calyceal diverticulum
SWL, PCNL, or RIRS, and also laparoscopic retroperitoneal surgery
Special problems in stone removal:
Horseshoe kidney
SWL, PCNL, or RIRS
Passage after SWL might be poor
Special problems in stone removal:
Stones + UPJO
PCNL + percutaneous endopyelotomy or open reconstructive surgery
URS + endopyelotomy with Ho:YAG laser
Incision with Acucise balloon catheter
Open pyeloplasty + stone removal
Children: first-line for single ureteral stones < 10 mm
ESWL (if localisation is possible)
Children: second-line for single ureteral stones < 10 mm
URS
Children: renal stones with diameter up to 20 mm (~300 mm2)
SWL
Children: renal stones with diameter >20 mm (~300 mm2)
PCNL
Children: renal stones with diameter <20 mm (~300 mm2) in all locations, alternative
Retrograde renal surgery
General preventive measures: fluid intake/drinking advice
Fluid amount: 2.5-3.0 L/day Circadian drinking Neutral pH beverages Diuresis: 2.0-2.5 L/day Specific weight of urine: < 1010 g/day
General preventive measures: Nutritional advice for a balanced diet
Balanced diet Rich in vegetables and fibre Normal calcium content: 1-1.2 g/day Limited NaCl content: 4-5 g/day Limited animal protein content: 0.8-1.0 g/kg/day
General preventive measures: Lifestyle advice to normalise general risk factors
BMI: Retain a normal BMI level
Adequate physical activity
Balancing of excessive fluid loss
Vegetarian diet ______ urinary pH
Increases (alkaline content).
Calcium oxalate stone formers should ______ intake of Vitamin C.
Avoid!
Excessive consumption of animal protein can cause:
Hypocitraturia
Low urine pH
Hyperoxaluria
Hyperuricosuria
(Favoring stone formation)
Should calcium intake be restricted?
NO.
High intake of sodium affects urine composition:
Calcium excretion is increased by reduced tubular reabsorption;
Urinary citrate is reduced due to loss of bicarbonate;
Increased risk of sodium urate crystal formation.
Alkaline citrates
R:
Alkalinisation
Hypocitraturia
Inhibition of calcium oxalate crystallisation
D:
5-12 g/d (14-36 mmol/d)
Children: 0.1-0.15 g/kg/d
S/SE:
Daily dose for alkalinisation depends on urine pH
ST:
Calcium oxalate
Uric acid
Cystine
Allopurinol
R:
Hyperuricosuria
Hyperuricaemia
D:
100-300 mg/d
Children: 1-3 mg/kg/d
S/SE:
100 mg in isolated hyperuricosuria
Renal insufficiency demands dose correction
ST: Calcium oxalate Uric acid Ammonium urate 2,8-Dihydroxyadenine
Calcium
R:
Enteric hyperoxaluria
D:
1000 mg/d
S/SE:
Intake 30 min before meals
ST:
Calcium oxalate
Captopril
R:
Cystinuria
Active decrease of urinary cystine levels
D:
75-150 mg
S/SE:
Second-line option due to significant side effects
ST:
Cystine
Febuxostat
R:
Hyperuricosuria
Hyperuricaemia
D:
80-120 mg/d
S/SE:
Acute gout contraindicated, pregnancy, xanthine stone formation
ST:
Calcium oxalate
Uric acid
L-Methionine
R:
Acidification
D:
600-1500 mg/d
S/SE:
Hypercalciuria, bone demineralisation, systemic acidosis. No long-term therapy
ST:
Infection stones
Ammonium urate
Calcium phosphate
Magnesium
R:
Isolated hypomagnesiuria Enteric hyperoxaluria
D:
200-400 mg/d
Children: 6 mg/kg/d
S/SE:
Renal insufficiency demands dose correction. Diarrhoea, chronic alkali losses, hypocitraturia
ST:
Calcium oxalate
Sodium bicarbonate
R:
Alkalinisation
Hypocitraturia
D:
4.5 g/d
S/SE:
N/A
ST:
Calcium oxalate
Uric acid
Cystine
Pyridoxine
R:
Primary hyperoxaluria
D:
Initial dose
5 mg/kg/d
Max. 20 mg/kg/d
S/SE:
Polyneuropathia
ST:
Calcium oxalate
Thiazide (Hydrochlorothiazide)
R:
Hypercalciuria
D:
25-50 mg/d
Children: 0.5-1 mg/kg/d
S/SE:
Risk for agent- induced hypotonic blood pressure, diabetes, hyperuricaemia, hypokalaemia, followed by intracellular acidosis and hypocitraturia
ST:
Calcium oxalate
Calcium phosphate
Tiopronin
R:
Cystinuria
Active decrease of urinary cystine levels
D:
Initial dose
250 mg/d
Max. 2000 mg/d
S/SE:
Risk for tachyphylaxis and proteinuria
ST:
Cystine
High risk stone formers: general factors
Early onset of urolithiasis (especially children and teenagers)
Familial stone formation
Brushite-containing stones (CaHPO4.2H2O)
Uric acid and urate-containing stones
Infection stones
Solitary kidney (the kidney itself does not particularly increase the risk of stone formation, but prevention of stone recurrence is of more importance)
High risk stone formers: associated disease
Hyperparathyroidism Metabolic syndrome Nephrocalcinosis Polycystic kidney disease (PKD) Gastrointestinal diseases (i.e. jejuno-ileal bypass, intestinal resection, Crohn’s disease, malabsorptive conditions, enteric hyperoxaluria after urinary diversion) and bariatric surgery Increased levels of vitamin D Sarcoidosis Spinal cord injury, neurogenic bladder
High risk stone formers: Genetically determined stone formation
Cystinuria (type A, B and AB) Primary hyperoxaluria (PH) Renal tubular acidosis (RTA) type I 2,8-Dihydroxyadeninuria Xanthinuria Lesch-Nyhan syndrome Cystic fibrosis
High risk stone formers: Anatomical abnormalities associated with stone formation
Medullary sponge kidney (tubular ectasia) Ureteropelvic junction (UPJ) obstruction Calyceal diverticulum, calyceal cyst Ureteral stricture Vesico-uretero-renal reflux Horseshoe kidney Ureterocele
High risk stone formers: Environmental factors
High ambient temperatures
Chronic lead and cadmium exposure
Most common metabolic abnormalities associated with calcium stone formation:
Hypercalciuria Hyperoxaluria Hyperuricosuria Hypomagnesiuria Hypocitraturia
Elevated levels of ionised calcium in serum (or total calcium and albumin) require:
Assessment of intact PTH to confirm or exclude suspected hyperparathyroidism (HPT).
“Acidic arrest” (urine pH constantly < 5.8) may promote:
Co-crystallisation of uric acid and calcium oxalate
Urine pH levels constantly > 5.8 in the day profile indicate:
RTA, provided UTI has been excluded. An ammonium chloride loading test confirms RTA and identifies RTA subtype
Hypercalciuria may be associated with ______ or _______.
Normocalcemia (idiopathic hypercalciuria, or granulomatous diseases) or hypercalcaemia (hyperparathyroidism, granulomatous diseases, vitamin D excess, or
malignancy).
Hypocitraturia (male < 1.7 mmol/d, female < 1.9 mmol/d) may be ______ or secondary to _______.
Idiopathic or secondary to metabolic
acidosis or hypokalaemia.
Types of hyperoxaluria:
Primary hyperoxaluria (oxalate excretion mostly > 1 mmol/day), appears in three genetically determined forms;
Secondary hyperoxaluria (oxalate excretion > 0.5 mmol/day, usually < 1 mmol/day), occurs due to intestinal hyperabsorption of oxalate or extreme dietary oxalate intake
Mild hyperoxaluria (oxalate excretion 0.45-0.85 mmol/day), commonly found in idiopathic calcium oxalate stone formers.
Hypomagnesiuria (< 3.0 mmol/day) may be related to:
Poor dietary intake or to reduced intestinal absorption (chronic diarrhoea).
Prescribe ____ in case of hypercalcuria.
Thiazide + alkaline citrates
Offer ____ and _____ in enteric hyperoxaluria.
Alkaline citrates
Calcium supplement
Advise diet with ______ and ______ in enteric hyperoxaluria.
Reduced dietary fat and oxalate
Prescribe ________ and ______ in case of hypocitraturia.
Alkaline citrates and sodium bicarbonate
Prescribe ______ in case of hyperuricosuria.
Allopurinol
Offer _____ as second-line treatment of hypericosuria.
Febuxostat
Avoid excessive intake of _______ in hypericosuria.
Animal protein
Prescribe ______ for primary hyperoxaluria.
Pyridoxine
Struvite/infection stones: Prescribe ____ OR ____ to ensure urinary acidification.
Ammonium chloride, 1 g, two or three times daily OR methionine, 200-500 mg, one to three times daily, as an alternative
Factors predisposing to struvite stone formation:
- Neurogenic bladder
- Spinal cord injury/paralysis
- Continent urinary diversion
- Ileal conduit
- Foreign body
- Stone disease
- Indwelling urinary catheter
- Urethral stricture
- Benign prostatic hyperplasia
- Bladder diverticulum
- Cystocele
- Calyceal diverticulum
- UPJ obstruction
Obligate urease-producing bacteria (consider urease inhibition with AHA 15 mg/kg/day)
- Proteus spp.
- Providencia rettgeri
- Morganella morganii
- Corynebacterium urealyticum
- Ureaplasma urealyticum
Facultative urease-producing bacteria (consider urease inhibition with AHA 15 mg/kg/day)
- Enterobacter gergoviae
- Klebsiella spp.
- Providencia stuartii
- Serratia marcescens
- Staphylococcus spp.
Cystine stones: urine dilution
Advise patients to increase their fluid intake so that 24-hour urine volume exceeds 3 L.
Cystine stones: alkalinisation
Prescribe potassium citrate 3-10 mmol two or three times daily, to achieve pH > 7.5 for patients with cystine excretion < 3 mmol/day.
Cystine stones: complex formation with cystine
For patients with cystine excretion, > 3 mmol/day, or when other measures are insufficient: prescribe in addition to other measures tiopronin, 250-2,000 mg/day.
Active compounds crystallising in urine
- Allopurinol/oxypurinol
- Amoxicillin/ampicillin
- Ceftriaxone
- Quinolones
- Ephedrine
- Indinavir
- Magnesium trisilicate
- Sulphonamides
- Triamterene
- Zonisamide
Substances impairing urine composition
- Acetazolamide
- Allopurinol
- Aluminium magnesium hydroxide
- Ascorbic acid
- Calcium
- Furosemide
- Laxatives
- Methoxyflurane
- Vitamin D
- Topiramate
Matrix stones: main risk factors
Recurrent UTIs, especially due to P. mirabilis or E. coli
Previous surgery for stone disease
Chronic renal failure and haemodialysis
