Nephro-Urolithiasis Flashcards
What is the prevalence of urinary system stones in the general population?
2-3%
What is the lifetime risk of urinary system stones in males?
1:8
What is the M:F ratio of incidence of urinary system stones?
M:F 3:1
What is the peak age of incidence of urinary system stones in males?
30 years
What is the peak age of incidence of urinary system stones in females?
Bimodal peak - 35 and 55 years
What is the risk of stone recurrence within 1 year?
10%
What is the risk of stone recurrence within 10 years?
50%
What is the most common cause of urological emergency admission?
Colic
What are the stone types?
Calcium oxalate - 45% Calcium oxalate + phosphate - 25% Triple phosphate (infective) - 20% Calcium phosphate - 3% Uric acid - 5% Cysteine - 3%
What are the symptoms and signs of urinary tract stones?
Renal pain - fixed in loin, or in flank if stones are lodged higher up Ureteric colic, may be radiating to groin Dysuria Haematuria Testicular or vulval pain Urinary infection Loin tenderness Pyrexia
What are the investigations for renal tract stones?
Blood tests - FBC, U&Es, creatinine Calcium, albumin, urate Parathormone Urine analysis and culture 24 hour urine collections Ultrasound IVU CT KUB Urogram reconstruction
What are the indications for surgical treatment of urinary tract stones?
Obstruction - if stones don't pass naturally Recurrent gross haematuria Recurrent pain and infection Progressive loss of kidney function Patient occupation
What are the surgical techniques for treatment of urinary tract stones?
Open surgery - rare
Endoscopic surgery more common
ESWL
PCLN
What are the advantages and disadvantages of open surgery?
Advantages
Single procedure with the least recurrence rate
Disadvantages Large scar Long hospital stay General wound complications Longer recovery
What are the indications for open surgery of urinary tract stones?
Non-functioning infected kidney with large stones necessitating nephrectomy
Cases which for technical reasons cannot be managed by PCNL or ESWL
When is a single partial or total nephrectomy indicated?
Non-functioning kidney with large stag horn stones or elderly frail patients with complex stones and a normal contralateral kidney
What is the percentage of contralateral stone formation after total nephrectomy?
Up to 30%
What are the indications for percutaneous nephrolithotomy (PCNL)?
Large stone burden (risk of stenosis) Associated PUJ stenosis Infundibular stricture Calyceal diverticulum Morbid obesity or skeletal deformity ESWL resistant stones e.g. cysteine Lack of availability of ESWL
How should percutaneous access be achieved?
Should be joint between urologist and interventional radiologist, intra-renal and adjacent viscera anatomy should be understood by both
Renal puncture - guided by ultrasound or x-ray
What are the contraindications for PCNL?
Uncorrected coagulopathy
Active UTI
Obesity or unusual body habitus unsuitable for x-ray tables
Relative contraindications include small kidneys and severe peri-renal fibrosis
What are the complications of PCNL?
3-8% have serious complications
Pseudoaneurysm or AV fistula 0.5-1% UT injury - pelvic tear 8-15%, ureteral tear 5%, stricture of PUJ 0.1-0.8% Bowel injury Pneumothorax Liver and spleen injury (very rare) Fever and sepsis MI
What is ESWL?
Extracorporeal Shock Wave Lithotripsy
When is ESWL commonly used as first-line treatment?
For renal and ureteric calculi
Generally done on a day case with simple analgesia
When is ESWL not the first line treatment?
For stones > 3cm
Also less effective for lower pole stones
When is ESWL no longer effective?
After 2 treatments
Often ineffective for treating cysteine stones
What are the indications for open ureterolithotomy?
Not suitable for laparoscopic approach
Failed ESWL or ureteroscopy
What are the indications for ureteroscopy?
Severe obstruction Uncontrollable pain Persistent haematuria Lack of progression Failed ESWL Patient occupation
What is the standard instrument for treating lower ureteric stones with ureteroscopy? What is the success rate?
Rigid ureteroscope
90-100% success rate
What is the success rate of ureteroscopy for proximal stones?
60-70%
What are the instrument options for surgery for ureteric/renal stones?
Flexible ureteroscope
Flexible lithoclast
Holmium laser
What are the potential complications of ureteroscopy?
Minor complications in 0-30%: Haematuria Fever Small ureteric perforation Minor vesico-ureteric reflux
Major complications:
Major ureteric perforation
Ureteric avulsion
Ureteral necrosis and stricture formation
What is the presentation of bladder stones?
Suprapubic/groin/penile pain Dysuria Frequency Haematuria UTI (persistent) Sudden interruption of urinary stream Usually secondary to outflow obstruction
What is the treatment of bladder stones?
Most treated endoscopically
Larger stones can be treated by open excision
