Urolithiasis lecture at Unimas 2016

Most Urinary stones can be treated with shockwave!

Plenary Lecture at 24 Malaysian Urological Conference, Johor Baru, 21 November 2015

The "Perfect" ESWL

by Dr Clarence C M Lei

Kidney & Urology Centre, Normah Hospital, Kuching, Malaysia

Introduction:

Urinary stone management comprises at least a third of urology practice. The classical presentation is a loin to groin acute colic in a young (30 to 60 years old) man.  Prevalence is about 5 to 15%. Microhaematuria is a useful clue to diagnosis.  Imaging to confirm the stone is often possible with clinic ultrasound and plain x-ray.  Nevertheless, the gold standard investigation is a non-contrast low dose CT urography.

Methods:

ESWL, extracorporeal shockwave lithotripsy is the greatest advance in modern urology. It was first reported by Chaussy C et al in the Journal of Urology, 1982; 127: 417.  The author has been using ESWL since  1989. His personal experience with lithotripters include Siemens (GHKL, 1991 – 1995), Edap (1996 – 1997) and the Dornier Compact (since 1998).  Early experience in GHKL recorded about 2000 cases of ESWL per annum.  In more recent years, the number of cases done is about 200 per annum.

Results:

Selection of the appropriate patient and stone is the most important factor for a successful ESWL.  If the patient  has an obvious urinary tract infection, this should be treated. Parenteral antibiotics should be given during ESWL in such cases.  More than 50% of the stones would be suitable for ESWL: more than 6 mm in size, but with a maximum diameter of < 20 mm.  Upper urinary tract stones (except for the lower pole) are ideally suitable, whereas lower urinary tract stones can be treated endoscopically with a success rate of almost 100%.  The few contraindications for ESWL include: pregnancy, gross obesity, uncorrected coagulopathy, nearby vascular calcifications and a non-functioning kidney. Informed consent is should be obtained. The patient should be  aware that the overall stone free rate is about 80%. I would also not persist if there is little fragmentation after 3 sessions, usually given every other day.  The alternative options with its complications and success rates should also be made known to the patient during the informed consent process.  The patient should also be informed of the complications of ESWL, viz bleeding (1 in 178 patients with significant perinephric haematoma in the author’s series), obstruction by the stone fragments, with up to 5% of patients requiring urgent ureteric stenting especially if there is fever.

The following technical points deserve attention during the ESWL: air pockets trapped in the coupling gel between the shockhead and the patient significantly reduced the delivery of shockwave energy. Delivery of the shockwave at 60/min versus 90/min results in a stone free rate at 3 months of 91 versus 80% respectively. There should be adequate analgesia: pre-medication with analgesics, anaesthetic cream and intravenous analgesia during ESWL. With sufficient analgesia, ESWL can be delivered with maximal power and number of shocks.  Accurate localisation of the stone with x-ray or ultrasound is important and this must be continuously monitored, say, every 200 shocks.  The patient should have follow-up documentation to show that the patient is stone free or has stable stone fragments.

ESWL treatment should be part of holistic management: e.g. co-existing diabetes, hypertension and chronic kidney disease.  All the lithotripsy medical staff should be credentialed in ESWL.  Stone Clinic staff should know about stone management, treatment of complications, other treatment options and the prevention of further stone episodes. The most important prevention is the adequate intake of fluid such that the patient produces 2 to 3 litres of urine per day. Serum calcium, uric acid and urine culture should be reviewed in all patients.

Conclusion:

ESWL remains a mainstay treatment for urinary stones.  The treatment of most upper urinary tract stones less than 20 mm is rewarding.  Selection of stone size, localisation, ESWL techniques, follow-up and stone prevention are important.  Stone treatment should be given as part of the holistic management of patient.

Vietnam Urology

I was invited by Dr Vu Le Chuyen (Urology Chief, of General Plan Binh Dan Hospital, Ho Chi Minh City) of Vietnam Urology & Nephrology Association to lecture at their Annual Scientific Meeting held at the beach town of  Quang Binh on 8 August 2014.  There are no direct flights, even from Kuala Lumpur and the journey took a day!  The tour guide told us that “Vietnam is a poor country” but I am impressed by the country: friendly, metered taxis, clean toilets, clean environment and relatively cheap food. Vietnam has more urologists (~ 800 to population of 90 million)  compared to Malaysia (80 to 30 million). However, English is not widely spoken.  I had lunch and dinner with Dr Rainy Umbas (Director of Asian School of Urology) and about 10 Indonesian urologists: they speak good English and knows exactly about the urology practices in Malaysia!  Rightly, as we move into ASEAN free trade in 2015!!  I attach my edited lecture slides on pyeloplasty, group photo with some ASEAN urologists, dinner with Indonesian urologists

Urinary stones and kidney failure: treat both aggressively!

STONES IN AN ESTABLISHED CKD, DO WE PROCEED?

Dr Clarence Lei Chang Moh,

Consultant Urologist, Kidney & Stone Centre, Normah Hospital, Kuching.

CKD, chronic kidney disease, is diagnosed when there is kidney disease for more than 3 months, structural or biochemical.  There are 5 stages of CKD, with Stage 5 as creatinine clearance less than 15 mls/min. A patient is  likely to have CKD rather than acute kidney disease if he  has risk factors of diabetes, hypertension, increased age, low haemoglobin, low calcium, high phosphate, high PTH.  Ultrasound show echogenic and smaller kidneys unless the patient has diabetes or lymphoproliferative disease. 

Obstructive uropathy can be readily relieved by percutaneous nephrostomy or ureteric stenting, rather than dialysis.  Other indications for stone treatment in CKD include pain from obstruction and infection.  Even patients who need chronic dialysis should undergo stone treatment to maintain urine output such that the patient can enjoy fluid for some months.

Radiolucent uric acid stones can be treated by chemodissolution, once the obstruction has been relieved by ureteric stenting. The side with the “easier” stone can be treated first to allow some recovery of renal function.  Otherwise, the kidney with the better function (good renal size, cortex with less echogenicity) can then be operated.  Upper urinary tract stones less than 2 cm can be readily treated by ESWL, extracorporeal shockwave lithotripsy. 

Stone free rates after treatment are reduced in patients with CKD.  This may partly be related to the lower urine volume in patients with CKD.  In one study of ESWL for proximal ureteric stones, the stone free rate was 50% when the GFR was less than 60 as compared to 93% when the GFR was more than 60.  Therefore, the urologist must be inclined to do more axillary procedures when treating patients with CKD.

Patients who have nephrectomy for stones are more likely to develop CKD as compared to patients who had kidneys preserved.  In the Sarawak General Hospital, 36% of 71 nephrectomies over 32 months were done for stones with infection (reported in MUC 2012).   Uric acid and struvite stones have worse CKD compared to calcium stones (eGFR 55 vs 72).  Hence, stone analysis is important to stratify risk.  Urinary stones per se has a 2 times increased risk of CKD (1% vs 0.5%) even after adjustment for confounders (e.g. age, diabetes, hypertension), even after successful ESWL, and even after a single stone episode.  The basis may be genetic whereby a defect contributes to CKD and  stone formation.  Therefore, stone formers should only donate their kidneys after due consideration.

Managing patients with CKD is teamwork with the nephrologists, nurses, dietitians and the family.  Stones presenting with renal impairment may require urgent treatment e.g. haemodialysis for fluid overload, hyperkalaemia or restlessness due to severe uraemia. Management of stone & CKD includes management of underlying diabetes, hypertension, anaemia, gout and bone disease. According to the Malaysian National Renal Registry data (www.msn.org.my) 1-2 % (data 1993-2013) of renal failure in Malaysian is due to urinary stones whereas it is 0.2% in the US Renal Data System in 2011.

CONCLUSION: Every effort must be made to treat urinary stones especially in CKD. Axillary procedures e.g. ureteric stenting and aggressive medical measures should be implemented in treating stones with CKD.

Lecture given at Malaysian Urological Conference 2014