Associated Professor in Urology Haseki Training & Research Hospital, Istanbul – Turkey

muratbinbay@yahoo.com

Definition: �  Staghorn calculi are branched stones

that occupy a large portion of the collecting system

�  The term "partial staghorn" calculus designates a branched stone that occupies part but not all of the collecting system

�  “Complete staghorn" calculus refers to a stone that occupies virtually the entire collecting system

There is no consensus regarding the precise definition of staghorn calculus

Ø  number of involved calices Ø  specific volume criteria

Stone volume

Staghorn Calculi Mostly

�  Magnesium ammonium phosphate (struvite) and/or calcium carbonate apatite

Can also

�  Cystine or uric acid (either in pure form or mixed with other components)

Rarely

�  Calcium oxalate or phosphate stones

Preminger, 2005

Struvite/ calcium carbonate apatite stones also are referred to as "infection stones"

Ø 88% were found to have a UTI at the time of diagnosis Ø 82% were infected with urease-producing organisms

Emori, 1993

Ø  most often Proteus, Pseudomonas, Klebsiella, and form at relatively high pH (typically >7)

Eisner, 2013

Once an "infection stone" is present, infections tend to recur

�  52 kidneys with complete staghorn calculi

�  Metabolic stones 29 (56%) included Ø  55% calcium phosphate Ø  21% uric acid Ø  14% calcium oxalate Ø  10% cystine

�  Calcium oxalate or calcium phosphate was observed in 17% of the infection stones

Treatment

Until the early 1970s some physicians believed that patients harboring

staghorn calculi should not be treated

Untreated Staghorn Calculus

� Recurrent urinary tract infection �  Struvite stones must be removed completely to

minimize the risk of continued ureasplitting bacteriuria

� Destroy the kidney �  Renal deterioration occurred in 28% of patients who

were treated conservatively

� Cause life treatening sepsis

� Mortality

Teichman et al “Long term renal fate and prognosis after staghorn calculus management “J Urol, 1995

A newly diagnosed patient should be actively treated

Therapeutic Goal

� Complete removal of the stone � Eradicate any causative organisms

� Relieve obstruction � Prevent further stone growth and any

associated infection � Preserve kidney function

Treatment Options �  PNL monotherapy �  Combinations of PNL and SWL �  SWL monotherapy

�  Open surgery �  Typically anatrophic nephrolithotomy

�  Chemolysis, ureteroscopy, laparoscopic stone removal and other combination modalities are not considered standart treatment

Management Strategy �  Stone burden �  Stone location & distribution �  Anatomy of collecting system

�  Status of renal function �  Degree of hydronephrosis �  Presence of infection

�  Patient compliance

� Pelvicaliceal system area is the only anatomical factor that affects the success of PCNL

AUA Guidelines (1994è2004è2009)

Standards o  A newly diagnosed patient should be

actively treated.

o  The patient must be informed about the relative benefits and risks associated with the active treatment modalities.

Recommendations o  Percutaneous nephrolithotomy should

be the first treatment utilized for most patients.

o  If combination therapy is undertaken, percutaneous nephroscopy should be the last procedure for most patients.

o  Shock-wave lithotripsy monotherapy should not be used for most patients; however, if it is undertaken adequate drainage of the treated renal unit should be established before treatment.

o  Open surgery (nephrolithotomy by any method) should not be used for most patients.

Options o  Shock-wave lithotripsy monotherapy may

be considered in patients with small-volume staghorn calculi with normal collecting-system anatomy.

o  Open surgery can be considered for patients in whom the stone is not expected to be removed by a reasonable number of less invasive procedures.

AUA Guidelines

�  Success for combination therapy is substantially lower �  1994 ………PNL was the terminal procedure

�  2004……….SWL was the last procedure

Pediatric Patients �  Staghorn calculi are rare �  SWL offers better results compared to adults

�  Advances in technology and increased experience è safe & efficient PNL

�  PNL stone free rate %60-100

�  PNL is standart treatment

Why PNL Monotheraphy?

� The trend toward PNL monotherapy has been driven �  The expanded role of flexible nephroscopy �  Better grasping devices and baskets �  The holmium laser for intracorporeal

lithotripsy �  The use of multiple percutaneous access

tracts

�  Second look PNL

Our Strategy �  In pediatric patients with smaller

stone burden and small body volume, consider SWL

�  In patients with renal insufficiency and obstruction, insert preop percutaneus nephrostomy

�  In case of bilateral stones, consider split renal function, symptom of the patient and technical ease of surgical side

�  Obtain preop renal scan

�  If stone bulk is complex & peripheral, consider open / laparoscopic surgery

Technical Aspects of PNL �  Prophylactic antibiotics �  Prone position

�  Floroscopy guided access �  Optimal port of entry

�  Prefer upper caliceal access

�  Multiple tracts if necessary

�  Flexible nephroscopy ± Ho:YAG laser

� Combination lithotripters are preferred

�  Large nephrostomy tube �  Consider second look PNL

�  National prevalence, patient characteristics, access method, puncture frequency and outcomes (including bleeding rates, operative type and duration of hospital stay) were compared between patients with staghorn or nonstaghorn stones in 96 centers worldwide over a 1-year period

�  puncture→purely fluoroscopic Advantages:

�  Easier anesthesia management �  Simultaneous anterograde and retrograde access to the urinary tract

sPCNL is a safe and reproducible method

A systematic review: (9 studies of supine and 25 for prone PNL)

for staghorn calculi, prone PNL was associated with

ü  decreased operative time ü  similar rate of hemorrhage ü  better stone-free rate

de la Rosette et al, 2008

�  45 renal units

�  Single upper-pole percutaneous access �  Rigid nephroscopy+intracorporeal lithotripsy

followed by

flexible nephroscopy+holmium laser lithotripsy

�  Stone-free state was 95% �  Mean 1.6 procedures per

patient

Ø  Spared the morbidity of multiple nephrostomy tube placements

Ø  Minimizing the need for sandwich therapy

Wong, 2002

�  119 patients; - 16 (13.4%) had upper pole access - 70 (58.8%) lower or middle calix access - 33 (27.7%) multiple renal access

�  The stone-free rate;

�  The overall complication rate;

Upper pole access group

Lower/Middle access group

Multipl Access group

87.5% 80% 84.8%

Upper pole access group

Lower/Middle access group

Multipl Access group

25% 21.4% 45.4%

Ø  The success of treatment is highly related to optimal kidney access

Ø  The multiple access approaches can be used, with a slight increase in the incidence

of acceptable complications Netto, 2005

�  Success rate after one session of PCNL Ø 70.1% in single access Ø 81.1% for multiple accesses

�  The mean changes in creatinine values were not statistically significant

PCNL with multiple accesses is a highly successful

alternative with considerable complication rates

The use of flexible nephroscopes, or combination of retrograde flexible ureteroscopy with standard nephroscopy, reduces the need for multiple-access procedures

EAU Guidelines, 2012

�  Success rates are similar among all pelvicaliceal system types

�  Sampaio type B1 pelvicaliceal systems require increased number of access for achieving stone clearance

Lithotripsy Combined pneumatic and ultrasonic lithotripsy is

more costly Clearance rates are similar for both the combined

and the standard ultrasonic device

�  Respect to stone composition; Ø Combined pneumatic and ultrasonic lithotripsy is more

efficient for harder stones Ø Standard ultrasonic lithotripsy is more efficient for softer

stones Lehman, 2008 (Prospective randomized)

Shock-wave lithotripsy

§  SWL monotherapy may be considered in patients with

Ø  small-volume staghorn calculi Ø  normal collecting-system anatomy

§  SWL monotherapy should not be used for patients with

Ø  cystine stones

Open surgery Ø Extremely large staghorn calculi

Ø Unfavorable collecting-system anatomy

Ø Abnormalities of the body habitus (extreme morbid obesity or skeletal abnormalities)

Ø Multiple, endourological approaches have been performed unsuccessfully

Open surgery �  Anatrophic nephrolithotomy is usually the preferred

operation

�  Nephrectomy should be considered when the involved kidney has negligible function

�  Only 2% of patients were treated with open surgery Kerbl, 2002

�  Tertiary medical centers used in <1% of patients undergoing open stone removal

Matlaga, 2002

Open surgery: 26/5532 (0.47%)

The skills of open stone-removing procedures do not fall completely into oblivion

• radial nephrotomies • extended pyelolithotomy • lower pole resection • partial nephrectomy

Murat BINBAY, Istanbul Multi session PNL

Andreas SKOLARIKOS, Athens Open Surgery

GFR: 70.3 ml/min Left: 21.8 (31%)

Right: 48.5 (69%)

M.C, 45y.o, male

After 1st session PNL

After 2nd session PNL

After 3rd session PNL

A. Skolarikos Greece

Successful laparoscopic neprolithotomy

has been performed in a porcine model and also in humans but not in patients

with complex staghorn calculi Kaouk, 2003

�  Mean warm ischemia time: 20.8 (13-30) minutes

�  Stone size and collecting system anatomy have less impact on the outcomes during anatrophic nephrolithotomy

�  Excellent stone-free rates �  6.6% decrease in GFR

(PCNL=8%)

Laparoscopic surgery is feasible when anatrophic nephrolithotomy is indicated

Alternative Treatments

Ø  Chemolysis

Ø  Ureteroscopy Ø  Other combination modalities

�  Chemolysis currently is not commonly utilized as it prolongs hospitalization

�  There is no sufficient evidence in the literature to support the routine use of Renacidin irrigations to eradicate residual struvite fragments

AUA Guideline, 2005

�  Combined treatment with SWL and chemolysis is a minimal invasive option for patients with infection staghorn stones who are not suitable for PNL

�  Stone fragmentation leads to increased stone surface area and improved efficacy of chemolitholysis

Stone composition: Struvite

Irrigation solution: 10% hemiacidrin

Combination with SWL for staghorn stones

EAU Guidelines, 2012

Ureteroscopy monotherapy for low-volume staghorn stones

Ø  multiple procedures are required Ø  stone-free rates are lower than PNL-

based therapy Grasso, 1998, El-Anany, 2001

The utilization of both PNL and ureteroscopy in patients with staghorn stones

has been reported to be successful Landman, 2003

Surveillance and Medical Management

�  The management of patients with staghorn calculi continues after stone removal as these patients are at risk for stone recurrence �  Stone analysis �  24 hour urine testing

�  Medical therapy

�  Prophylactic or supressive antibiotic therapy �  Utilization of the urease inhibitor

acetohydroxamic acid

�  Pharmacologic prevention focused on Ø urease inhibitors (acetohydroxamic acid, Hydroxyurea)

Ø chronic suppressive antibiotics

�  Urease inhibitors have been shown in RCTs to decrease struvite stone formation but side effects are common

Urologic surgical intervention is critical for struvite stones

whenever feasible

Treatment Algorithm For The Evaluation And Medical Management

Conclusion

� The current recommendations suggest that percutaneous-based therapy should remain the mainstay for management of staghorn calculi

� Further advances in the PNL technique will not only increase stone-free outcomes and reduce post-operative complications, but also significantly reduce peri-operative patient morbidity