American urological association (AUA) has been the frontrunner in formulating guidelines for Urolithiasis since 1991. Since then, editions of guidelines have been published with the 2005guidelines on staghorn calculus being the latest (1) The European association of urology(EAU) haspublished similar guidelines since 2000. The latest updates have been published in 2010
The significant differences in the socioeconomic and disease pattern (mode of presentation, stone bulk, health care delivery facilities) for urolithiasis in India make it imperative to formulate our own guidelines.
Ministry of Health and Family Welfare, Government of India has issued the Standard Treatment Guidelines for Urolithiasis and ureteric colic. The recommendations drawn are largely based on the AUA/EAU guidelines with modifications recommended where appropriate. Indian references have been cited, particularly so, if they are prospective randomized studies and/or metanalysis. Recommendations have been given when adequate literature support is available. The referral criteria are noted when appropriate.
Following are the major recommendations :
The index patients are defined as follows:-
A non pregnant adult patient with unilateral ureteral calculi (no renal stones) and normal functioning contralateral kidney, the body habitus, anatomy and medical condition should not preclude the application of any of the available treatment options (2)
A staghorn calculi is defined as a stone with central body and at least one calyceal branch. A partial staghorn calculus fills part of the collecting system. A complete staghorn fills all the calyces and the renal pelvis.
Index patient (staghorn calculi):-
Adult with a staghorn stone (non Cystine, non uric acid) who has two functioning kidneys (functioning both kidneys) or a solitary kidney with normal function. The patients overall medical condition, body habitus and anatomy should permit any of the available intervention (1).
Non staghorn calculi Any pelvic and /or calyceal calculi which do not fit in the definition of staghorn calculi (2).
Incidence in our country
Although a few studies have been reported for a small group of subjects in screening camps.
The true incidence of urolithiasis in India is still not known. It is commonly seen in western states, hypothetically, attributable to high salinity of water .The presentation of a patient with urolithiasis differs in India. Large stone bulk on presentation is commonly seen in India.
What should be the optimal?
Imaging is absolutely imperative if, the patient has a solitary kidney or a history of fever. If the diagnosis of stone is in doubt then imaging is mandatory. (2) Execratory urography has been the gold standard in the work up for urolithiasis. Non contrast computerized tomography(NCCT) scan is quick and safe, contrast free alternative to excretory urography. Randomized studies have shown that non contrast helical CT has similar or superior results to excretory urography in acute flank pain(3) Contrast media should not be given or should be avoided when there is a elevated creatinine level, pregnancy or lactation(4)(5) Additional information can be gained by contrast enhanced CT scan(CTU), however at the moment there is no level 1 evidence to suggest that CTU is superior to IVU in the work up of urolithisis. .(6) . X-ray KUB and ultrasound is used by few clinicians as a measure of preoperative investigations, however this cannot be considered as a standard. These investigations help to plan access and predict the possible success rates. Recommendation:-Excretory urography is the gold standard in work up for urolithiasis and is mandatory in solitary kidney, history of fever and when the diagnosis is in doubt. NCCT is the investigation of choice in acute flank pain due to stone.
Analysis of stone composition
Stone analysis is desirable in recurrent stone formers. The preferred analytical procedures are:-
- X ray crystallography.
- Infrared spectroscopy.
The other methods of stone analysis are:-
- Radiographic characteristics of the stone.
- Microscopic examination of the urinary sediments to detect crystals.
- Urine Ph (alkaline in infection stones and acidic in uric acid stones.
- Urine culture.
Special investigations which are ordered on case to case merit are renal scintigraphy, antegrade, retrograde contrast study.
Indications for intervention
The indication for stone removal depends on the size, site and shape of the calculus. The likelihood of spontaneous passage, presence of obstruction should be assessed. The indications for intervention are:-
- When the stone diameter is more than 7 mm (because of low rate of spontaneous passage).
- When adequate pain relief is not achieved.
- When there is stone obstruction associated with infection.
- Obstruction in single kidney.
- Bilateral obstruction.
Recommendation:-For1, 2 stone removal with or without prior decompression(depending on the clinical situation) is recommended ,in situation ,3,4,5,6 emergency deobstruction of the collecting system is recommended.
The choice of decompression can be with ureteric stents, percutaneous nephrostomy depending on surgeon preference, expertise and the level of obstruction.
Treatment (including standard operating procedure)
I) Extracorporeal shock wave lithotripsy(ESWL)
The success of lithotripsy depends on the body habitus, location of the stone, efficacy of the lithotripter, stone bulk. The contraindications for ESWL for renal stones include pregnancy, bleeding disorders, uncontrolled urinary tract infections, morbid obesity, aortic aneurysms close to F1.
i) Role of stents
Routine use of stents is not recommended for ESWL for renal stones.
ii) Location of stones
The stone clearance is lower for stones in the lower calyx as compared to anywhere else in the kidney. Various studies have attempted to show the correlation of geometry of the lower calyx to predict the clearance of stone in this location. However the calyceal stone burden is the most important factor in predicting the clearance.
Although there is no critical size, 20 mm should be considered the upper limit for stones in the lower calyx to be recommended for ESWL. The EAU guidelines recommend ESWL as the treatment of choice for renal stones less than 20mm2(300mm2) (2). A multicentre trial has compared ESWL and Flexible ureteroscopy for lower calyceal stones. It failed to show any difference in the clearance rates.
iii) Total stone burden
It is recommended that stones smaller than 20mm2 to be treated with ESWL , while for larger stones more than 20mm2(300mm2), PCNL should be considered the treatment of choice.(2)
iv) Composition and hardness of stone
The composition of the stone is an important factor for predicting the success rates of renal calculi. Specific stone compositions have different clearance rates because of the varying fragility of stones. Cystine stones are harder to fragment, hence cystine stones larger than 15mm should not be treated with ESWL.PCNL would be a good option in these patients(2) The measurement of stone density with NCCT helps in predicting success rates of ESWL. Stones with greater than 1000 Hounsfield units (HU) show poor results with ESWL.
v) ESWL-procedural standard operating protocol
Simultaneous fluoroscopy and ultrasound monitoring is desirable.(2) The acoustic coupling between shock head and the skin should be optimal. Ultrasound gel is the best available gel. The ultrasound gel should be applied straight from the container rather than by hand.(15)(16). Level 4 evidence is available to suggest that proper analgesia results in limited movement and respiratory excursions. Better fragmentation can be achieved with starting the fragmentation at lower energy setting and then ramping up the power(17) . the manufacturers recommendation regarding the number of shocks and frequency should be followed.The optimal shock wave frequency is 1.0 Hz(18) It is important to limit the number of shocks and the power, due to concerns regarding damage to the kidney.
In case of infected stones, antibiotics should be given according to urine culture sensitivity, the same should be continued after surgery for 4 days (2) Clinical experience suggests that stones in the ureter rather than the kidney should be treated with shorter intervals between sessions.
The complications which are likely to be encountered and which should be counseled to the patient prior to surgery are:-
It is recommended that stones smaller than 20mm2 to be treated with ESWL. Routine use of stents is not recommended for ESWL for renal stones.The contraindications for ESWL for renal stones include pregnancy, bleeding disorders, uncontrolled urinary tract infections, morbid obesity, aortic aneurysms close to F1. Antibiotics should be given according to urine culture sensitivity, the same should be continued after surgery for 4 days. The physicians should refer to the manufacturer recommendation regarding the decision of number, frequency and power of shocks.
Technically most of the renal stones can be managed with a percutaneous nephrolithotomy. However the usual indications for PCNL are larger than 20mm2, staghorn, partial staghorn calculi and stones in patients with chronic kidney disease.
Standard operating protocol
General anaesthesia is preferable, although studies have demonstrated the utility of regional anaesthesia (19) PCNL has been performed traditionally in a prone position however it can technically also be performed in supine position, the advantage of this (supine position) approach is that the retrograde access is easier in supine position, anesthetist has a better control over the airway and simultaneous ureteric and renal stones can be managed without guided or fluoroscopy guided depending on the availability of instruments and expertise.
The advantage of ultrasound guided access is the potential to avoid major visceral injuries.(22) The access site should be the posterior calyx. The tract should be the shortest possible tract from the skin to the desired calyx traversing the papilla. Depending on the stone configuration a calyx should be selected (Supracostal, infracostal or subcostal) so that maximum stone bulk can be cleared minimum number of tracts. (23) Renal tract dilatation either balloon, amplatz or metallic dilators are a matter of surgeon preference and availability (2). In lower polar stones ESWL, PCNL and flexible ureterorenoscopy are competing procedures with different success rates and complications (12)(24).In complicated cases or when secondary intervention is required a nephrostomy tube which serves the dual purpose of tamponade and a conduit for second look is placed.
In uncomplicated cases, tubeless percutaneous nephrolithotomy with or without application of tissue sealants is a safe alternative (25) (26)
The patients should be counseled regarding the complications which are likely to be encountered such as life threatening bleeding with a possible need for angioembolisation or even nephrectomy. It may be associated with infective complications leading to urosepsis. The patients should be counseled regarding the possibility of residual calculi and the consequences thereof. The procedure becomes challenging in complex stones, although the complications are not specific to them. Such cases should be identified and managed by experienced surgeons.
Technically, most of the renal stones can be managed with a percutaneous nephrolithotomy. However the uasual indications for PCNL are larger than 20mm2 , staghorn, partial staghorn calculi and stones in patients with chronic kidney disease. The access to the collecting system can be gained either ultrasound guided or fluoroscopy guided depending on the availability of instruments and expertise. Renal tract dilatation either balloon, amplatz or metallic dilators are a matter of surgeon preference and availability. In complicated cases or when secondary intervention is required a nephrostomy tube which serves the dual purpose of tamponade and a conduit for second look is placed. In uncomplicated cases, tubeless percutaneous nephrolithotomy with or without application of tissue sealants is a safe alternative.
III) Flexible ureterorenoscopy
Flexible ureteroscopy offers a good treatment option for calculi less than 20mm in size. Due to improved technology and development in accessories and optics the role of flexible ureteroscopy is likely to be expanded in the future. The procedure wherein flexible ureteroscopy is used in the kidney is called as retrograde intrarenal surgery (RIRS). Flexible URS is not recommended as a first line of treatment for renal calculi. It has been demonstrated as a effective way of treating stones which are refractory to ESWL. It has also been seen useful when simultaneously used with PCNL, in this way it reduces the number of tracts during the procedure It is recommended that sterile urine should be documented prior to intervention.
Standard technique for flexible ureteroscopy
• Fluoroscopy equipment is advisable in all cases
• Preoperative imaging helps to determine the size and location of the stone.
• The use of safety wire is recommended (0.035 floppy tip) .
• The ureteroscope can be introduced over a guide wire (back loaded) or they may be
advanced through a ureteral access sheath.
• Stone extraction blindly without endoscopic vision should not be done
• Small stones can be extracted with baskets of forceps.
• Intracorporeal lithotripsy can be performed with holmium laser. The other alternatives
are ballistic, ultrasonic or electrohydraulic lithotripsy. (2). The holmium Yag laser is the
preferred modality for flexible ureteroscopy (29)
• The stenting after an uncomplicated flexible ureteroscopy is optional. The indications
for stenting after completion of URS are ureteral stricture, ureteral injury, solitary
kidney, renal insufficiency, large stone burden residual stones.
Accessories and instrumentation
A 365 micron laser fiber is suited for ureteral stones. The 200 micron fiber preserves tip deflection. Holmium laser is the preferred energy source for flexible ureteroscopy. Nitinol baskets preserve tip deflection, in addition the tipless design reduces the mucosal injury, hence they are more suited for flexible ureteroscopy.(30)
Access sheaths have been used by various workers. The size of the available access sheaths ranges from 9-16Fr, they have a hydrophilic coating. Generally they are introduced over a wire. The advantages of access sheath are reducing the operating time particularly in large stone burden. Another theoretical advantage is, it helps in maintaining a low pressure in the pelvicalyceal system.(31)
Flexible ureteroscopy offers a good treatment option for calculi less than 20mm in size. Flexible URS is not recommended as a first line of treatment for renal calculi. It has been demonstrated as a effective way of treating stones which are refractory to ESWL. Stenting after a uncomplicated ureteroscopy is optional.It is mandatory that sterile urine should be documented prior to intervention.
A retrospective study with 200 patients has shown that renal deterioration occurs in 28% of patients with staghorn calculi treated conservatively. This emphasizes the fact that staghorn stones should be aggressively managed surgically(32) PCNL should be the recommended modality as clearance rates are greater than 3 times that of ESWL.(33)
The following are the treatment options in staghorn calculi:-
- Percutaneous nephrolithotomy should be the first treatment utilized for most patients. (level2)
- ESWL should not be used as the preferred treatment modality for staghorn stones.
- Open surgery should be recommended only if the stones are not expected to be removed in a reasonable number of stages.
- Nephrectomy should be considered in non functioning kidneys. (1)
PCNL is the first choice for staghorn calculi. Open surgery is desirable in the situation when expertise is not available wherein the stone can be cleared in reasonable number of stages and tracts. Nephrectomy should be considered for non functioning kidneys.
Management of ureteric calculi and ureteric colic
The most common cause for ureteric colic is ureteric calculus. The priority in these patients should be relief of pain. The subsequent management of patients with ureteric colic would be determined by the level of obstruction and the stone size.
Agents recommended for relieving pain
It is recommended that pain should be relieved with diclofenac whenever possible. A alternative drug might be used if pain persists. Further more it has been shown that the resistive index significantly reduces if diclofenac is administered.. Level 4 evidence suggests that hydromorphine might be helpful, however there is a significant risk of vomiting (34) (35) (36) Diclofenac can affect renal function in patients with already reduced function. There is however no effect if the kidneys are functioning normally.
Agents for preventing episodes of renal colic
Diclofenac sodium is recommended for the purpose. Studies indicate that the incidence of recurrent renal colic decreases with administration of diclofenac sodium. (38) When the pain is unremitting the treating urologist should think of alternative measures such as drainage by stenting or percutaneous nephrostomy or even removal of the stone.
Medical expulsive therapy (MET)
The beneficial effect of these drugs is attributed to ureteral smooth muscle relaxation mediated through inhibition of calcium channel pumps or alpha receptor blockade. The prerequisite for this approach is that the patient should be comfortable this approach. And there should not be any immediate indication for stone removal.. Studies indicate that alpha blockers facilitate ureteral passage ,while nifedipine provides marginal benefit. Alpha blockers are recommended for MET(2)
Guidelines for Index patients
• Patients with bacteriuria should be treated with appropriate antibiotics
• Blind basketing without visualization endoscopically should not be performed.
• Patients with newly diagnosed stones less than 6 mm and well controlled symptoms, should be advised MET
• Patients who opt for Medical expulsion therapy should have well controlled pain, no evidence of sepsis, and adequate functional reserve, such patients should be periodically observed for stone position and assessment of hydronephrosis.
• Stone removal is recommended in persistent obstruction, failure of stone progression. or increasing or unremitting colic.
• Patient should be informed about the available treatment options.
• Both ESWL/ flexible URS are the preferred treatment options for upper ureteric calculi less than 1cm in size. For larger stones Antegrade ESWL/PCNL/laproscopic removal are recommended depending on expertise and instruments available
• URS is the preferred modality for distal and midureteric calculus.
Alpha blockers are recommended for MET. It is recommended that pain should be relieved with diclofenac whenever possible. Patients with newly diagnosed stones less than 6 mm and well controlled symptoms, should be advised MET .Patients who opt for Medical expulsion therapy should have well controlled pain, no evidence of sepsis, and adequate functional reserve, such patients should be periodically observed for stone position and assessment of hydronephrosis. Both ESWL/ flexible URS are the preferred treatment options for upper ureteric calculi less than 1cm in size. For larger stones antegrade ESWL/PCNL/laproscopic removal are recommended depending on clinical situation expertise and instruments available. URS is the preferred modality for distal and midureteric calculus.
Treatment of calculi in special situations
Calyceal diverticular stones
Once symptomatic all these stones require treatment. ESWL, PCNL, laparoscopy and observation remain the treatment options which can be offered to the patient. As the drainage of the calyx in concern is at times questionable ESWL has rather poor results. Sometimes the combination this treatment modality is recommended.
These group of patients include those patients with stones in ectopic, horseshoe or kidneys with fusion anomalies. The approach to managing these stones should be individualized. The factors to be taken into consideration are the stone bulk, the location of the stone, the vascular and the anatomy of the pelvicalyceal system. Ultrasound helps in gaining access in ectopic kidney apart from being a diagnostic tool. CT is pivotal in deciding the management and choosing the method of treatment in anomalous kidney..
CT will also give the attenuation values and be a deciding factor in deciding ESWL or flexible ureteroscopy. Flexible ureteroscopy will be useful tool in stones small burden stones in size with the availability of smaller flexible ureteroscopes, and access sheaths. However the surgeon should consider complete “on table” clearance in these patients as the drainage is likely to be impaired. USG guided approach for ectopic kidneys should be done by surgeons well versed with it. Laparoscopic assisted PCNL has shown good clearance rates with minimal morbidity and less likely hood of ancillary procedures. Although adequate fragmentation can be achieved with ESWL, the drainage of fragments might be impaired due to the anatomical abnormalities. The choice of ESWL as a treatment option should be done prudently.(40)
Although the treatment modalities used are same in children as in adults. Specific points should be noted in children. The indications for ESWL are similar to those in adults. Stones in Children with a diameter of less than 20mm are ideal cases. The success rates decreases as stone burden increases. Larger stones should be treated with PCNL (2)
They are as follows:-
1) Children have a tendency to pass larger fragments.
2) Ultrasound should be the modality for localization of stone when ESWL is the
3) Smaller instruments should be used for endourologic manipulations(2)
Role of open surgery in the current era
In a developing country such as India, the cost factor plays a major role, which is mostly borne by the patient or a health care delivery mechanism, A study from India by Sinha et al , which although is a retrospective data and has a small sample size suggests that PCNL is less costly and as effective as open surgery. However randomized level 1 evidence by Al Kohlany et al comparing open surgery with PCNL suggests that PCNL offers equivalent clearance as open pyelolithotomy, with less morbidity, short hospital stay.and less renal damage. The trade off in a Indian clinical scenario will be to offer the best cost effective alternative available.
Nephrolithiassis –metabolic work up
See recommendation in section on- Nephrolithiassis –metabolic work up .
Who does what/ and timeline
The treating doctor ideally should be an Urologist or a surgeon trained in Urology. He is responsible for the initial workup of the patient and subsequent management of the patient. He is responsible for counseling the patient regarding the success rates, complications and possible outcome of any given procedure. All possible treatment options in a given clinical situation should be discussed with the patient. The patient on discharge should be given instructions for follow up and measures (dietary and pharmacologic) to prevent stone recurrence. Nursing and technical staff:-The nursing staff should be trained in the aspect of maintenance and use of endourologic equipment, considering the fragility and cost of these equipments. The responsibility of sterilization of these equipment lies with these personnel .The technical/nursing staff prepares the trolley and assists the surgeon during the procedure.
The criterion for referral remains, lack of appropriate infrastructure and expertise at primary level.
The indications for referral to tertiary care centre in managing stones disease are:- 1)Complex calculi ( multiple stones , staghorn calculi, stones with CKD, stones with obstructive uropathy) where in the opinion of the treating physician , the patient needs nephrolurological care and advanced surgical and medical care from a infrastructure standpoint
2) Special situations such as pediatric urolithiasis, stones in ectopic kidney.
Indications and selection of modality for treating calculi in a index patient
It depends on the stone size location, stone composition and BMI of the patient The following are the guidelines to be followed
1) Stone less than 1cm in the kidney -ESWL
2) Stone more than 1cm and less than 2cm in the kidney , -Flexi URS/ESWL/PCNL
3) Any stone more than 2cm in the kidney-PCNL
4) All staghorn and partial staghorn-PCNL
5Non progressive more than 6mm stone in the mid and lower ureter-semirigid URS.
6) Stones less than 1cm in upper ureter-ESWL
7) stones larger than 1cm in upper ureter-PCNL/ESWL/Flexi URS
Guidelines by The Ministry of Health and Family Welfare
Prof. Rajesh Ahlawat
Department of Urology & Kidney Transplant,
Dr Anup Kumar Gupta
Head of Department
Department of Urology
VMMC and Safdarjang Hospital,