“SANDWICH” THERAPY FOR THE TREATMENT OF COMPLEX RENAL STONES
LEE E. PONSKY, STEVAN B. STREEM
Department of Urology, Cleveland Clinic Foundation, Cleveland, Ohio, USA
ABSTRACT
Purpose:
Shock wave lithotripsy (SWL) and percutaneous nephrolithotomy (PCNL) are
well accepted, minimally invasive modalities available for the treatment
of calculi. In this paper we review and discuss the technique of combination
“sandwich therapy” for the treatment of select patients with
large, extensively branched, or otherwise complex stones.
Materials and Methods: A review of the literature
on combined percutaneous nephrolithotomy and shock wave lithotripsy for
the management of “staghorn” calculi was performed and evaluated.
Results: Stone free rates after one month
of follow up approach 70%, while the remaining patients are left with
residual dust or gravel. Complications occur in less than 30% of patients,
and no nephrectomies or mortality have been reported with this approach.
The probability of new stone formation has been estimated to be 37% at
five years, and renal function has been shown to remain stable or improve
in 96% of patients.
Conclusion: The use of combination therapy
for the treatment staghorn calculi is safe and effective and can limit
much of the associated morbidity of SWL or PCNL monotherapy. We recommend
this combined “sandwich” approach as the treatment of choice
for select patients with large, extensively branched, or otherwise complex
staghorn calculi.
Key words:
kidney, calculi, shock wave lithotripsy, percutaneous nephrostolithotomy
Braz J Urol, 26: 18-23, 2000
INTRODUCTION
“Sandwich
therapy” provides a minimally invasive alternative endourologic approach
for the management of large, extensively branched or otherwise complex
calculi for patients with stones that might otherwise require operative
intervention, or who would not likely benefit from percutaneous nephrolithotomy
(PCNL) or shock wave lithotripsy (SWL) alone (1). In these patients, sandwich
therapy minimizes the risk of bleeding and sepsis associated with PCNL
monotherapy, and decreases the number of shock waves otherwise required
for SWL alone. Furthermore, prolonged nephrostomy drainage, which had
been a part of earlier approaches, can be avoided when utilizing this
combined management.
Sandwich therapy involves the use of primary
percutaneous debulking followed by SWL of residual “inaccessible”
infundibulocalyceal stone extensions or fragments. Following SWL, a secondary
percutaneous procedure is done through the mature tract to hasten clearance
of fragments from SWL. Additional percutaneous or SWL treatments can be
utilized as necessary to achieve a stone free state within a reasonable
time period.
Use of this approach limits the number of
punctures needed to manage large stones to one or two tracts. Limiting
the number of access tracts can help avoid the bleeding complications
that can be associated with the multiple percutaneous tracts that would
be required for percutaneous monotherapy. Furthermore, the use of upper
pole access is often not required, therefore avoiding the increased risk
of pleural complications.
Utilizing percutaneous debulking prior to
SWL also allows for a significantly reduced number of shock waves required
compared to SWL monotherapy, and this reduces the potential toxicity of
a large number of shock waves. Finally, having a large caliber nephrostomy
tube indwelling at the time of SWL decreases the risk of sepsis by providing
proximal diversion, especially in patients with infection-related (struvite)
calculi.
This combination therapeutic approach has
been proven to be safe and effective. It has also been demonstrated that
immediate and long term results are at least comparable to other forms
of management in this setting, specifically with respect to rates of recurrent
stones, infection, and maintenance of renal function (2-4).
PATIENT SELECTION
Even
patients with very large, extensively branched calculi can be managed
with this protocol. Currently, open operative intervention is reserved
only for patients in whom percutaneous techniques and SWL have failed
or are contraindicated or for patients with associated anatomic abnormalities
requiring open operative reconstruction. Occasionally, anatrophic nephrolithotomy
is utilized for a stone burden so large and complex that open operative
intervention more likely will render the patient stone free in a safer
manner than would the multiple percutaneous procedures and SWL that would
be otherwise be required.
In 1994 the AUA Nephrolithiasis Guidelines
Panel on staghorn stones recommended percutaneous stone removal as the
primary treatment modality, followed by shock wave lithotripsy and/or
repeat percutaneous procedures as warranted. SWL monotherapy and percutaneous
monotherapy were recommended as effective treatment choices only for small
volume struvite staghorn calculi in collecting systems that were anatomically
normal or nearly so (5).
POTENTIAL RISKS
The
potential risks are explained to the patient including the unlikely but
potential need for emergent open operative intervention, and the need
for secondary or even tertiary endourologic procedures that may be required
to achieve a stone free result. Bleeding requiring transfusion has been
reported in up to 14 % of patients, which compares favorably to percutaneous
monotherapy for staghorn calculi with a reported transfusion rate of up
to 53% (4,6), but this risk is also explained.
Fever and/or sepsis has been reported in
20% of patients undergoing sandwich therapy, and up to 27% being treated
with percutaneous monotherapy (4,6). Many patients undergoing sandwich
therapy have magnesium-ammonium-calcium phosphate stones associated with
chronic bacterial infection. For these patients, sensitivity-specific
oral antibiotic therapy is administered for at least 1 to 2 weeks prior
to intervention, and broad-spectrum antibiotic therapy is given intravenously
just prior to instrumentation.
TECHNIQUE
The technique is illustrated in the Figures. The site for the initial percutaneous puncture is chosen with the intention of providing access to the greatest stone burden. This usually allows for removal of the lower infundibulocalyceal and renal pelvic portions of the stone (Figures-1 and 2). Rarely, two or more tracts may be required to access particularly heavily involved collecting systems, especially those that are somewhat bifid. General anesthesia is used routinely. A Foley catheter is placed at the beginning of the procedure, and the patient is then positioned prone. Care is taken to ensure proper padding of the face, legs and arms, and two chest rolls are placed longitudinally under the chest.
Stone debulking then proceeds as a standard
percutaneous nephrolithotomy. This initial percutaneous debulking is performed
using a rigid 24.5 or 26F nephroscope and an ultrasonic lithotrite. For
some especially hard non-struvite stones, electrohydraulic or Holmium
laser lithotripsy is utilized as an adjunct. At this point, no attempt
is made to reach calyceal extensions of the calculus that are located
at acute angle to the existing tract and are therefore inaccessible to
the rigid nephroscope. After extracting the entire accessible stone burden
with this initial percutaneous debulking, a 24F nephrostomy tube is left
indwelling to gravity. The Foley catheter is removed within the next 12-24
hours, and ambulation is begun.
A nephrostogram, which includes oblique
views before and after contrast is administered, is obtained 48 hours
after the initial procedure. The nephrostogram is used to evaluate the
extent and location of residual stones, and also to assess for urinary
extravasation, as this would result in postponement of the subsequent
SWL.
If the urine is relatively clear and there
is no evidence of extravasation on the nephrostogram, SWL is performed
for the “inaccessible” stones the following day. One to 2 days
following the SWL, the previously “inaccessible” stones have
migrated to an accessible location in the renal pelvis or lower calyces
(Figure-3), and secondary rigid and/or flexible nephroscopy is then performed
via the mature tract or tracts. If the entire stone burden has been cleared,
the nephrostomy tube can be removed with the next 12-24 hours. However,
for those patients with persistent calculi, additional treatment including
secondary SWL or tertiary percutaneous extraction may be required.
One month following the final interventional
procedure, a plain radiograph and renal ultrasound or alternatively an
intravenous pyelogram is obtained (Figure-4). For those patients with
infection related stones, chronic antibiotic prophylaxis is prescribed
for the first 6-12 months of follow up. A metabolic evaluation can be
completed at this time, and any associated problems also addressed.
RESULTS
We
recently reviewed our results with 100 patients who underwent sandwich
therapy for renal calculi. Magnesium-ammonium-calcium phosphate was the
major component of the stone in 40.2% of patients. Calcium oxalate/phosphate
was the major component in 37.1%, and uric acid combined with calcium
oxalate/phosphate was the major component in 10.3%. Approximately 12%
were primarily uric acid, cystine, or ammonium acid urate. The mean number
of percutaneous procedures was just over 1.06 per patient, and fewer than
10% of patients required multiple access tracts, despite a mean stone
burden of 20.8 cm2. The mean number of shock waves to the involved renal
unit was 3,100, divided over a mean 1.4 SWL treatments/patient (4).
Significant complications, which included
bleeding requiring transfusion or fever delaying any planned treatment
or hospital discharge, affected less than 30% of patients. No patients
required a nephrectomy and there was no mortality. Early in our experience
the average hospital stay approached 15 days. Over the past 10 years,
the total length of hospitalization has decreased significantly and now
averages less than 6 days. The stone free rate has also improved with
experience. Of the first 25 patients in our series, 52% were stone free
at one month follow up, while in comparison, 70% of the last 25 patients
were rendered completely stone free, while the remainder had only residual
calyceal dust or gravel.
There was a significantly higher rate of
transfusion (20.5%) and fever or sepsis (33.3%) in patients with struvite
stones. Of those patients with non-infection related stones, the rates
of transfusion or fever/sepsis were significantly less at 10.3% and 12.1%
respectively (4).
The long-term results of this sandwich approach
have been evaluated, specifically for patients with infection related
stones (3). With a mean follow up of 31 months, and as long as 5 years,
the rate of new stone formation or stone growth has been 22%, while recurrent
infection has developed in 30% of patients. In a more recent study using
Kaplan-Meier estimates, the risk of new stone formation was estimated
to be 36.8% over 5 years following combination therapy (7). Risk factors
for recurrence have been evaluated and demonstrate that rates of recurrent
stones are equivalent between patients undergoing percutaneous nephrolithotomy
alone or percutaneous nephrolithotomy and SWL combined in a sandwich protocol.
Finally, renal function has been shown to remain stable or improve in
96% of patients undergoing combination therapy (3), and this approach
has also been shown to maintain or improve renal function even in patients
with a solitary kidney (2).
CONCLUSIONS
The
need for early and aggressive intervention for the treatment of staghorn
calculi has been accepted practice for over 25 years (8). The goals of
treatment of patients with complex stone disease include achieving a stone
free renal unit, prevention of recurrent stones and infection, and preservation
of renal function. Traditionally, the best therapeutic option for the
treatment of staghorn calculi had been open operative intervention, as
“medical” management of these complex stones has been shown
to have a much higher renal related morbidity and mortality than operative
stone extirpation (9,10).
Though some smaller staghorn calculi may
be treated successfully with SWL or PCNL alone, there is a relatively
high incidence of complications associated with either one of these treatment
modalities as monotherapy for extensively branched or otherwise complex
stones, and there are now several studies that have demonstrated that
patients with this problem will benefit from a combined approach (4,11-13).
For the most difficult patients, the immediate and long term results have
been shown to be at least comparable to any other form of management currently
available, and for almost 15 years, we have found this approach applicable
to virtually any patient with large, extensively branched or otherwise
complex renal calculi.
REFERENCES
- Streem SB, Geisinger MA, Risius B: Endourologic “sandwich” therapy for extensive staghorn calculi. J Endourol, 1: 253, 1987.
- Streem SB, Geisinger MA: Combination therapy for staghorn calculi in solitary kidneys: Functional results with long-term follow-up. J Urol, 149: 449, 1993.
- Streem SB, Lammert G: Long-term efficacy of combination therapy for struvite staghorn calculi. J Urol, 147: 563, 1992.
- Streem SB, Yost A, Dolmatch B: Combination “sandwich” therapy for extensive renal calculi in 100 consecutive patients: immediate, long-term and stratified results from a 10-year experience. J Urol, 158: 342, 1997.
- Segura JW, Preminger GM, Assimos DG, Dretler SP, Kahn RI, Lingeman JE, Macaluso JN, Jr, and McCullough DL: Nephrolithiasis clinical guidelines panel summary report on the management of staghorn calculi. J Urol, 151: 1648, 1994.
- Winfield, HN, Clayman RV, Chaussy CG, Weyman PJ, Fuchs GJ, Lupu AN: Monotherapy of staghorn renal calculi: a comparative study between percutaneous nephrolithotomy and extracorporeal shock wave lithotripsy. J Urol, 139: 895, 1988.
- Streem SB: Long-term incidence and risk factors for recurrent stones following percutaneous nephrolithotomy or percutaneous nephrolithotomy/ESWL for infection-related calculi. J Urol, 153: 584, 1995.
- Blandy JP, Singh M: The case for a more aggressive approach to staghorn stones. J Urol, 115: 505, 1976.
- Teichman JMH, Long RD, Hulbert JC: Long-term renal fate and prognosis after staghorn calculus management. J Urol, 153: 1403, 1995.
- Koga S, Arakaki Y, Matsuoka M, Ohyama C: Staghorn calculi—long-term results and management. Brit J Urol, 68: 122, 1991.
- Rassweiler J, Gumpinger R, Miller K, Holzermann F, Eisenberger F: Multimodal treatment (extracorporeal shock wave lithotripsy and endourology) of complicated renal stone disease. Eur Urol, 12: 294, 1986.
- Fuchs G, Chaussy C: Extracorporeal shock wave lithotripsy for staghorn stones: reassessment of our treatment strategy. World J Urol, 5: 237, 1987.
- Segura JW, Patterson DE, LeRoy AJ: Combined percutaneous ultrasonic lithotripsy and extracorporeal shock wave lithotripsy for struvite staghorn calculi. World J Urol, 5: 245, 1987
________________________
Received: October 30, 1999
Accepted: November 5, 1999
_______________________
Correspondence address:
Stevan B. Streem, M.D.
Head, Section of Stone Disease & Endourology
Department of Urology, Cleveland Clinic
9500 Euclid Avenue
Cleveland, Ohio, 44195, USA
Fax: (0021) 1 216 445-7031
E-mail: streems@ccf.org