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SIMULTANEOUS BILATERAL PERCUTANEOUS NEPHROLITHOTOMY
0022-5347/97/1586-2065$03.00/0 THE JOURNAL OF UROLOGY Copyright 0 1997 by AMERICAN U R O ~ I C A ASSOCIATION, L INC.
Vol. 158,2065-2068. December 1997 Printed in U S A
SIMULTANEOUS BILATERAL PERCUTANEOUS NEPHROLITHOTOMY JOHN W. DUSHINSKI*
AND
JAMES E. LINGEMAN
From the Methodist Hospital Institute for Kidney Stom Disease, Indianapolis, Indiana
ABSTRACT
Purpose: We evaluate t h e results of simultaneous bilateral percutaneous nephrolithotomy. Materials and Methods: The charts of 52 patients scheduled for simultaneous bilateral percutaneous nephrolithotomy at the Methodist Hospital of Indiana were retrospectively reviewed. The results of the 48 patients who underwent the procedure were tabulated and analyzed. Results: Mean operative time was 269 minutes and mean hospital stay was 5.6 days. Of t h e patients 45 were rendered stone-free (96.9%of 96 renal units) and 3 had insignificant debris (fragments less than 4 mm.) unilaterally. Complications were infrequent and included hydrothorax in 5 cases, ureteral obstruction by fragment migration in 2, hematuria causing clot retention in 2, blood transfusion in 2 and ureteral perforation with a guide wire in 1. Conclusions: Simultaneous bilateral percutaneous nephrolithotomy is a well tolerated, safe, cost-effective and expeditious approach to patients with bilateral renal calculi requiring percutaneous nephrolithotomy. KEYWORDS:nephrostomy, percutaneous; urinary calculi Fernstrom and Johannson fist described percutaneous nephrolithotomy in 1976.' Subsequent reports on percutaneous nephrolithotomy from the Mayo Clinic2 and the University of Minnesota3 in the United States, and Alken et a14 in Germany confirmed its advantages and refined the technique. Further advances in technique and equipment have allowed urologists to perform percutaneous stone removal with increasing efficacy and decreasing complications. Because the percutaneous approach allows stone removal with less morbidity, shorter convalescence and reduced cost compared to open techniques,6 percutaneous nephrolithotomy has now replaced open surgical procedures for removal of large or complex renal calculi a t most institutions. Patients with large stone burdens bilaterally present a particular challenge to the urologist. These patients formerly had been subjected to separate procedures and multiple anesthetics to clear stone burden. In July 1990, as an alternative, we began offering simultaneous bilateral percutaneous nephrolithotomy to patients requiring percutaneous nephrolithotomy for significant stone burden bilaterally. Although simultaneous bilateral percutaneous nephrolithotomy has been performed regularly at our institution for more than 6 Years, there are few reports describing the procedure in the bterature6-8 with a total of only 21 patients. We describe our operative technique, and discuss the results and complications in the 52 patients offered the procedure. MATERIALS AND METHODS
Between July 1990 and November 1996,52 patients were Offered,consented to and were brought to the operating room for simultaneous bilateral percutaneous nephrolithotomy. The charts of these 52 patients were reviewed and data were tabulated. Patient characteristics are listed in table 1. All Patients received intravenous antibiotics before the procedure and were given a general anesthetic. Occlusion balloon catheters are placed over guide wires and inflated at each ureteropelvic junction to facilitate percutaneous needle puncture and to prevent stone migration mto the ureter during fragmentation of large stones. The Patient is then placed in the modified prone position (initial Accepted for publication May 29, 1997. *Current address: Rockyview General Hospital, 7007 14th St. S.W., Calgary, Alberta,Canada.
TABLE1. Patient characteristics Mean (ranee) 49.9 Yrs. (6-89) 5' 7" (4' W-6' 3") Ht. Wt. 190 lbs. (50-368) 29.9 kgJm.2 (14.1-57.3) Body mass index* 929 111111.' (265,478) Stone surface area renal unit * Calculated as weight in kilograms divided by the square of the height in meters. Patients with a body mass index greater than 30 kgJm? are considered morbidly obese. Age
side elevated approximately 30 degrees). The side that is more symptomatic is approached first; in the absence of a predominance of symptoms on 1side the more difficult side is treated initially. A retrograde pyelogram is performed and percutaneous access into the desired calk is established using an 18 gauge needle and biplanar C-arm fluoroscopy.9 Once access is confirmed, an angiographic catheter is used to advance a hydrophilic guide wire down the ureter and the wire is then exchanged for a super stiff wire. A second safety wire is used in all instances. The tract is balloon dilated and an Amplatz working sheath is placed into the collecting system. Rigid nephroscopy is performed initially, with the ultrasonic lithotripsy device being used to evacuate clot and as much stone as possible. Fragments are also retrieved with stone grasping forceps for stone analysis and culture. Occasionally, a pneumatic lithotripsy device is used, particularly for harder stones. Flexible nephroscopy with pressurized irrigant is used at the time of every primary procedure and each calk is examined for residual fragments. Larger caliceal stones are fragmented with the electrohydraulic device or, more recently, with the holmium laser. The rigid nephroscope and ultrasonic device are used to evacuate fragments from the renal pelvis once all calices have been examined. Additional tracts are established when indicated using the same access technique. When the kidney appears stone-free fluoroscopically and nephroscopically, a Malacot re-entry nephrostomy tube is placed over the stiff wire and is sutured to the skin. At this point a decision is made regarding the procedure on the contralateral side. If the decision is made to proceed with the second side, the patient is repositioned with the second side
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SIMULTANEOUS BILATERAL PERCUTANEOUS NEPHROLITHOTOMY
elevated 30 degrees, re-prepared and re-draped. The surgical technique on the second side is identical to that on the initial side. Prior to leaving the operating room suite we routinely fluoroscope over the chest to rule out hydrothorax in all patients with supracostal punctures. Hydrothorax is drained by needle aspiration before transferring the patient to the recovery room. Chest tubes have not been required. Most of our simultaneous bilateral percutaneous nephrolithotomy patients also receive an intrathecal morphine injection before leaving the operating room. Several patients required additional procedures, which were performed under the same anesthetic as the primary simultaneous bilateral percutaneous nephrolithotomy. Three patients required llguration of a caliceal diverticulum, 2 unilateral retrograde ureteroscopy , 1 bilateral retrograde ureteroscopy, 1 an endopyelotomy, and 1 fulguration of a caliceal diverticulum and unilateral retrograde ureteroscopy. Fulguration of caliceal diverticula and the endopyelotomy were performed during the percutaneous portion of the procedure in an antegrade fashion, while retrograde ureteroscopy was performed with the patient in the lithotomy position, before insertion of the ureteral balloon occlusion catheters. Nephrostograms and nephrotomograms are performed 24 to 48 hours post-operatively to assess for residual fragments, antegrade flow and the integrity of the collecting system. Noncontrast computerized tomography is performed on patients with radiolucent stones and those whose body habitus precludes adequate imaging on plain films. Patients with residual fragments and all patients with staghorn or struvite stones undergo bilateral secondary nephroscopy 48 to 72 hours post-operatively. Most of these procedures are performed under intravenous sedation, and the patient is discharged from the hospital that day. If no additional tracts are required, then the nephrostomy tubes are removed and collection bags are placed on the flank over the tube sites. RESULTS
Ofthe 52 patients with bilateral calculi treated percutaneously 28 men and 20 women underwent simultaneous bilateral percutaneous nephlithotomy. Three patients had prolonged complicated procedures on the initial side necessitating postponement of the second side. One patient was discovered to have pyonephrosi with the initial needle puncture on 1side. In thispatient a nephrostomytube was inserted and the procedure on that side was deferred. In all 4 patients the postponed second side p d u r e was performed later during the same hospital stay. Of the 48 patients (96 renal units) who underwent simultaneous bilateral percutaneous nephrolithotomy 14 (17 renal units)required additional dilated access while 5 (6 renal units) required nondilated punctures. Therefore, multiple access of some type was used in 24% of cases. Mean length of the initial operative procedure was 269 minutes (range 40 to 435). T w o patients received shock wave lithotripsy postoperatively as part of a sandwich therapy (both early in our experience), 37 underwent a secondary percutaneous nephrolithotomy and 11did not require shock wave lithotripsy or secondary percutaneous nephrolithotomy. Mean hospitalization was 5.6 days (range 2 to 16). At hospital discharge 45 patients were stone-free bilaterally and 3 had insignificant fragments (less than 4 mm.) unilaterally, giving a stone-free rate per renal unit of 96.9%. Complications were infrequent and included ureteral perforation in 1 case (2.1%), obstruction by fragment migration in 2 (4.2%),hydrothorax in 5 (10.4%),hematuria causing clot retention in 2 (4.2%)and hemorrhage requiring transfusion in 2 (4.2%).Of the 5 cases of hydrothorax 4 were drained in the operating room at the end of the procedure and 1 was drained in the recovery room. One of 2 patients requiring
;ransfusion received 2 units of autologous blood (donated areoperatively because the patient had idiopathic thrombo:ytopenic purpura), and the other was anemic on hospital admission (hemoglobin 10.1 gmJdl., normal 12 to 16 for women and 14 to 18 for men) and required 2 units of donor blood postoperatively. The mean decrease in hemoglobin in the 48 patients undergoing simultaneous bilateral percutaneous nephrolithotomy was 2.6 gmJdl. (range 1.2 to 6.6) with a trend to a larger decrease with increasing numbers of dilated tracts (table 2). Stones were classified into 1 of 6 groups based on the chemical analysis (see table 5). Calcium oxalatelcalcium phosphate stones were found in 26 patients (54.2%), struvite/ carbonate apatite in 11 (22.9%), cystine in 5 (10.4%), mixed calcium oxalate and uric acid in 3 (6.3%),pure uric acid in 2 (4.2%)and a combination of calcium oxalate and struvite in 1 (2.1%). DISCUSSION
Technique and instrumentation for percutaneous nephrolithotomy have advanced considerably in the last 2 decades. This minimally invasive approach has been shown to decrease patient morbidity and cost, and shorten convalescence compared to open surgical techniques.5 The improved outcomes have prompted the exploration of simultaneous bilateral percutaneous nephrolithotomy as a surgical option for patients with large stone burdens bilaterally. Simultaneous percutaneous extraction of renal calculi has been previously reported. Colon-Perez e t a1 reported in 1987 on 3 patients treated with simultaneous bilateral percutaneous nephrolithotomy for renal calculi 0.8 to 3.8 cm.6 They noted that blood loss and post-operative pain were not significantly greater than in patients undergoing unilateral percutaneous nephrolithotomy. Regan et a1 also reported on 3 patients treated with simultaneous bilateral percutaneous nephrolithotomy, and concluded that it was a well tolerated, safe, expeditious and cost-effective approach for patients with bilateral calculi requiring percutaneous management.? Ahlawat et a1 more recently reported on 16 patients undergoing simultaneous bilateral percutaneous nephrolithotomy.8 They reported decreased operative time (83 minutes) in comparison to the prior studies, and concluded that simultaneous bilateral percutaneous nephrolithotomy was a suitable treatment for patients with bilateral stones. However, the stone size was not mentioned by Ahlawat et a1 and the stonefree rate per renal unit was low (81.3%), while the transfusion rate was unacceptably high (25%). In our study we present data from the 48 patients undergoing simultaneous bilateral percutaneous nephrolithotomy. About half of the stones were staghorn stones. Mean stone surface area was a substantial 929 mm.' (range 26 to 5,478). Stone surface area has been demonstrated to be an accurate method of comparing renal calculi, particularly staghorns.'" The figure shows the preoperative film of the kidneys, ureters and bladder from 1of the simultaneous bilateral percutaneous nephrolithotomy patients with stones slightly larger than the mean. Of the 52 patients brought to the operating room for simultaneous bilateral percutaneous nephrolithotomy, 48 (92.3%) underwent the procedure. In 3 patients the second side waa
TABLE2. Hemoglobin decrease in relation to total number dilated tracts reouired ~
No.Tracts (No.pts.)
5 (1)
~~~~
Mean Gm./Dl. Hemoglobin Decrease (ranee)
2.3(-1.2-6.1) 2.7 (0.6-6.6) 3.8 (3.34.4) 4.1
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additional procedures performed, injection of subarachnoid morphine and resident participation in every case. Of the patients in this study 11required multiple dilated tracts on 1side and 3 required multiple dilated tracts on both sides. There was a tendency towards a greater decrease in hemoglobin when more dilated tracts were placed (table 2). However, this was not associated with the need for transfusion if other risk factors were not present. Both of the patients reauirine transfusion were anemic on hosDital admission (hemoglobyinlevels 10.1 and 11.0 gmldl.). 1; addition, 1 of these patients suffered from idiopathic thrombocytopenic purpura and received only the 2 units of autologous blood that she had donated preoperatively. Hemoglobin decrease in our 2 transfusion patients was only 2.9 and 4.4 gmldl. and, therefore, neither patient would likely have been transfused had preoperative hemoglobin levels been in the normal range. No other complications were associated with increased numbers of tracts. Factors thought to contribute to the low transfusion rate include balloon tract dilation, upper pole access when indicated and the use of flexible nephroscopy during the primary procedure. The use of flexible nephroscopy with intracorporeal lithotripsy devices eliminates excessive torquing of the rigid scope, thereby minimizing renal parenchymal tears. Postoperative fever was common in the simultaneous bilateral percutaneous nephrolithotomy patients but all responded to general measures, and no patient became frankly septic or required intensive care unit admission. Other complications were infrequent. No patient required a chest tube. Preoperative film of kidneys, ureters and bladder shows stone Two patients had persistent urine drainage from the flank sizes of 1,570 (right) and 1,321 (left) m.'. after hospital discharge. These 2 patients were found to have distal ureteral stones that were removed as an outpatient via retrograde ureteroscopy. The 2 patients who had hematuria and clot retention required only conservative management (bladder irrigation). One patient suffered a ureteral perforadeferred due to the length and complexityof the procedure on tion when a guide wire was advanced through the wall of the the initial side. One of these patients was a 63-year-old ureter into the retroperitoneum. A DoubleJ* stent was left woman with chronic anemia secondary to a myelodysplastic indwelling for 2 weeks and the patient has had no further v d r o m e . She also had a history of angina and required complications. The addition of an intrathecal morphine injection at the periodic transfusions to maintain the hemoglobin level. The stone burden on the initial side was 4,856 mm.2 and the end of the simultaneous bilateral percutaneous nephrolithoprimary procedure was 225 minutes long. The second patient tomy procedure has subjectively decreased patient discomwas a 22-year-old myelomeningocelepatient with severe ky- fort postoperatively. In the first few patients it was found phoscoliosis and a colon conduit urinary diversion. She re- that the postoperative discomfort associated with simultaquired 2 difficult dilated tracts in a primary procedure that neous bilateral percutaneous nephrolithotomy was sign& lasted 230 minutes. The third patient was a 43-year-old cantly greater than with unilateral percutaneous nephrowoman with an initial side stone burden of 2,066 mm.' re- lithotomy. The intrathecal morphine injections are quiring 2 dilated tracts. The initial side procedure lasted 195 performed by the anesthesiologist at the end of the case if the minutes and the patient bled more than usual. Preoperative patient has consented to the injection before the procedure. hemoglobin was 11.3 gmldl. and she eventually required 4 The decreased postoperative discomfort has resulted in a decreased need for intramuscular narcotics postoperatively units of transfused blood. The fourth patient who had the second side deferred was and is in part responsible for shortened hospital stays later in discovered to have pyonephrosis on 1 side with the initial the study. Only 2 of the last 12 patients undergoing simulneedle puncture, contraindicating definitive management on taneous bilateral percutaneous nephrolithotomy stayed in that side. All patients are informed preoperatively that the the hospital longer than 4 days (mean hospital stay for these Procedure on the second side will be performed only if all goes 12 patients was 3.9 days). Two patients underwent shock wave lithotripsy subsewell with the first side. The mean operative time of 269 minutes is admittedly quent to the primary percutaneous nephrolithotomy procelong. This reflects, in part, our preference to remove as much dure as part of sandwich therapy. Both of these patients were stone as possible during the primary procedure. The treat- treated early in the series and would likely not undergo ment strategy also includes establishing additional dilated sandwich therapy today. The use of flexible nephroscopy and and nondilated tracts when necessary, the use of rigid and intramrporeal lithotripsy during primary and secondary perflexible instruments during the primary procedurel and a cutaneous nephrolithotomy procedures has greatly improved meticulous technique. Extreme care is necessary d m g per- our ability to render the patient stone-free, while at the same mtaneous nephrolithotomy procedures to minimize compli- time keeping costs to a minimum. The majority (35 of 48) of our simultaneous bilateral percations, and also to maximize stone removal, since even a S ~ a l amount l of bleeding can obscure stone fragments. The cutaneous nephrolithotomy patients undergo secondary flexBtrategy does prolong the procedure but we believe the ben- ible nephroscopy 48 to 72 hours after the primary procedure. efits of a high stone-free rate and low complication rate more We have a low threshold for performing secondary nephros&an outweigh the longer operating room time. Other factors * Medical Engineering Corp., New York, New York that contributed to the length of the operation were the
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SIMULTANEOUS BILATERAL PERCUTANEOUS NEPHROLITHOTOMY
copy since up to 30% of patients with negative radiographic studies following percutaneous nephrolithotomy are found to have significant residual fragments at the time of secondary nephroscopy." All of our infection stone patients undergo secondary procedures to make absolutely sure that no fragments remain. At 48 hours flexible nephroscopy can be performed without the aid of a working sheath, in a nearly bloodless field, under intravenous sedation. A cost comparison with nonsimultaneous bilateral percutaneous nephrolithotomy patients was not performed because a suitable group for comparison is not available. In an earlier study on staghorn stones from this institution the mean operative time for unilateral percutaneous nephrolithotomy was 202 minutes,'* although recent operative times would be shorter. In a more recent study on the costeffectiveness of treatment options for staghorn stones the mean hospital stay for unilateral cases was 5.3 days.13 Although comparing these data with the simultaneous bilateral percutaneous nephrolithotomy data (mean operating room time 269 minutes, mean hospital stay 5.6 days) is not statistically precise, we believe the savings in medication costs, anesthesia, radiological studies, other investigations and hospital stay associated with simultaneous bilateral percutaneous nephrolithotomy would be readily apparent when compared to 2 separate procedures and 2 hospital stays. CONCLUSIONS
At our institution the simultaneous bilateral approach is a well tolerated, safe, expeditious and cost-effective approach for management of patients with bilateral renal calculi requiring percutaneous nephrolithotomy. At centers with advanced expertise in unilateral percutaneous nephrolithotomy, simultaneous bilateral percutaneous nephrolithotomy should be offered to all patients requiring bilateral treatment. Patients should be informed that the procedure on the second side will be deferred to a later date if the procedure on the first side is overly prolonged or complex.
REFERENCES
1. Fernstriim, I. and Johannson, B.: Percutaneous pyelolithotomy. A new extraction technique. S a n d . J. Urol. Nephrol., 10: 257, 1976. 2. Segura, J.W.,Patterson, D. E., LeRoy, A. J., McGough, P. F. and Barrett, D. M.: Percutaneous stone removal of kidney stones: preliminary report. Mayo Clin. Proc., 87: 615,1982. 3. Clayman, R. V., Surya, V., Miller, R. P., Cwtaneda-Zuniga, W. R.,Smith, A. D., Hunter, D. H.,Amplatz, K. and Lange, P. H.: Percutaneous nephrolithotomy extraction of renal and ureteral calculi from 100 patients. J. Urol., 131: 868, 1984. 4. m e n , P., Hutschenreiter, G., Giinther, R. and Marberger, M.: Percutaneous stone manipulation. J. Urol., 128: 463,1981. 5. Brannen, G.E., Bush, W. H., Correa, R.J., Gibbons, R. P. and Elder, J. S.: Kidney stone removal: percutaneous versus surgical lithotomy. J. Urol., 133:6,1985. 6. Colon-Perez, B., Canto, R. J. and Ramose, M. E.: Simultaneous bilateral nephrostolithotomies: immediate results in three cases. J. Endourol., 1: 209, 1987. 7. Regan, J. S., Lam, H. S. and Lingeman, J. E.: Simultaneous bilateral percutaneous nephrolithotomy. J. Endourol., 6: 245, 1992. 8. Ahlawat, R.,Banejee, G. K and Dalela, D.: Bilateral simultaneous percutaneous nephrolithotomy. A prospective feasibility study. Eur. Urol., 28: 116,1995. 9. Lam, H. S.,Lingeman, J. E., Mosbaugh, P. M., Steele, R. E., Knapp, P. M., Scott, J. W. and Newman, D. M.: Evolution of the technique of combination therapy for staghorn calculi: a decreasing role for extracorporeal shock wave lithotripsy. J. Urol., part 2,148: 1058,1992. 10. Lam,H. S.,Lingeman, J. E., Russo, R. and Chua, G. T.: Stone surface area determination techniques: a unifying concept of staghorn stone burden assessment. J. Urol., 148. 1026, 1992. 11. Denstedt, J. D., Clayman, R.V. and Picus, D. D.: Comparison of endoscopic and radiological residual fragment rate following percutaneous nephrolithotripsy. J. Urol., 145:703,1991. 12. Kahnoski, R.J., Lingeman, J. E., Coury, T. A,, Steele, R. E. and Mosbaugh, P. G.: Combined percutaneous and extracorporeal shock wave lithotripsy for staghorn calculi: an alternative to anatrophic nephrolithotomy. J. Urol., 135: 679,1986. 13. Chandhoke, P. S.: Cost-effectiveness of different treatment options for staghorn calculi. J. Urol., 156 1567,1996.
Vol. 158,2065-2068. December 1997 Printed in U S A
SIMULTANEOUS BILATERAL PERCUTANEOUS NEPHROLITHOTOMY JOHN W. DUSHINSKI*
AND
JAMES E. LINGEMAN
From the Methodist Hospital Institute for Kidney Stom Disease, Indianapolis, Indiana
ABSTRACT
Purpose: We evaluate t h e results of simultaneous bilateral percutaneous nephrolithotomy. Materials and Methods: The charts of 52 patients scheduled for simultaneous bilateral percutaneous nephrolithotomy at the Methodist Hospital of Indiana were retrospectively reviewed. The results of the 48 patients who underwent the procedure were tabulated and analyzed. Results: Mean operative time was 269 minutes and mean hospital stay was 5.6 days. Of t h e patients 45 were rendered stone-free (96.9%of 96 renal units) and 3 had insignificant debris (fragments less than 4 mm.) unilaterally. Complications were infrequent and included hydrothorax in 5 cases, ureteral obstruction by fragment migration in 2, hematuria causing clot retention in 2, blood transfusion in 2 and ureteral perforation with a guide wire in 1. Conclusions: Simultaneous bilateral percutaneous nephrolithotomy is a well tolerated, safe, cost-effective and expeditious approach to patients with bilateral renal calculi requiring percutaneous nephrolithotomy. KEYWORDS:nephrostomy, percutaneous; urinary calculi Fernstrom and Johannson fist described percutaneous nephrolithotomy in 1976.' Subsequent reports on percutaneous nephrolithotomy from the Mayo Clinic2 and the University of Minnesota3 in the United States, and Alken et a14 in Germany confirmed its advantages and refined the technique. Further advances in technique and equipment have allowed urologists to perform percutaneous stone removal with increasing efficacy and decreasing complications. Because the percutaneous approach allows stone removal with less morbidity, shorter convalescence and reduced cost compared to open techniques,6 percutaneous nephrolithotomy has now replaced open surgical procedures for removal of large or complex renal calculi a t most institutions. Patients with large stone burdens bilaterally present a particular challenge to the urologist. These patients formerly had been subjected to separate procedures and multiple anesthetics to clear stone burden. In July 1990, as an alternative, we began offering simultaneous bilateral percutaneous nephrolithotomy to patients requiring percutaneous nephrolithotomy for significant stone burden bilaterally. Although simultaneous bilateral percutaneous nephrolithotomy has been performed regularly at our institution for more than 6 Years, there are few reports describing the procedure in the bterature6-8 with a total of only 21 patients. We describe our operative technique, and discuss the results and complications in the 52 patients offered the procedure. MATERIALS AND METHODS
Between July 1990 and November 1996,52 patients were Offered,consented to and were brought to the operating room for simultaneous bilateral percutaneous nephrolithotomy. The charts of these 52 patients were reviewed and data were tabulated. Patient characteristics are listed in table 1. All Patients received intravenous antibiotics before the procedure and were given a general anesthetic. Occlusion balloon catheters are placed over guide wires and inflated at each ureteropelvic junction to facilitate percutaneous needle puncture and to prevent stone migration mto the ureter during fragmentation of large stones. The Patient is then placed in the modified prone position (initial Accepted for publication May 29, 1997. *Current address: Rockyview General Hospital, 7007 14th St. S.W., Calgary, Alberta,Canada.
TABLE1. Patient characteristics Mean (ranee) 49.9 Yrs. (6-89) 5' 7" (4' W-6' 3") Ht. Wt. 190 lbs. (50-368) 29.9 kgJm.2 (14.1-57.3) Body mass index* 929 111111.' (265,478) Stone surface area renal unit * Calculated as weight in kilograms divided by the square of the height in meters. Patients with a body mass index greater than 30 kgJm? are considered morbidly obese. Age
side elevated approximately 30 degrees). The side that is more symptomatic is approached first; in the absence of a predominance of symptoms on 1side the more difficult side is treated initially. A retrograde pyelogram is performed and percutaneous access into the desired calk is established using an 18 gauge needle and biplanar C-arm fluoroscopy.9 Once access is confirmed, an angiographic catheter is used to advance a hydrophilic guide wire down the ureter and the wire is then exchanged for a super stiff wire. A second safety wire is used in all instances. The tract is balloon dilated and an Amplatz working sheath is placed into the collecting system. Rigid nephroscopy is performed initially, with the ultrasonic lithotripsy device being used to evacuate clot and as much stone as possible. Fragments are also retrieved with stone grasping forceps for stone analysis and culture. Occasionally, a pneumatic lithotripsy device is used, particularly for harder stones. Flexible nephroscopy with pressurized irrigant is used at the time of every primary procedure and each calk is examined for residual fragments. Larger caliceal stones are fragmented with the electrohydraulic device or, more recently, with the holmium laser. The rigid nephroscope and ultrasonic device are used to evacuate fragments from the renal pelvis once all calices have been examined. Additional tracts are established when indicated using the same access technique. When the kidney appears stone-free fluoroscopically and nephroscopically, a Malacot re-entry nephrostomy tube is placed over the stiff wire and is sutured to the skin. At this point a decision is made regarding the procedure on the contralateral side. If the decision is made to proceed with the second side, the patient is repositioned with the second side
2065
2066
SIMULTANEOUS BILATERAL PERCUTANEOUS NEPHROLITHOTOMY
elevated 30 degrees, re-prepared and re-draped. The surgical technique on the second side is identical to that on the initial side. Prior to leaving the operating room suite we routinely fluoroscope over the chest to rule out hydrothorax in all patients with supracostal punctures. Hydrothorax is drained by needle aspiration before transferring the patient to the recovery room. Chest tubes have not been required. Most of our simultaneous bilateral percutaneous nephrolithotomy patients also receive an intrathecal morphine injection before leaving the operating room. Several patients required additional procedures, which were performed under the same anesthetic as the primary simultaneous bilateral percutaneous nephrolithotomy. Three patients required llguration of a caliceal diverticulum, 2 unilateral retrograde ureteroscopy , 1 bilateral retrograde ureteroscopy, 1 an endopyelotomy, and 1 fulguration of a caliceal diverticulum and unilateral retrograde ureteroscopy. Fulguration of caliceal diverticula and the endopyelotomy were performed during the percutaneous portion of the procedure in an antegrade fashion, while retrograde ureteroscopy was performed with the patient in the lithotomy position, before insertion of the ureteral balloon occlusion catheters. Nephrostograms and nephrotomograms are performed 24 to 48 hours post-operatively to assess for residual fragments, antegrade flow and the integrity of the collecting system. Noncontrast computerized tomography is performed on patients with radiolucent stones and those whose body habitus precludes adequate imaging on plain films. Patients with residual fragments and all patients with staghorn or struvite stones undergo bilateral secondary nephroscopy 48 to 72 hours post-operatively. Most of these procedures are performed under intravenous sedation, and the patient is discharged from the hospital that day. If no additional tracts are required, then the nephrostomy tubes are removed and collection bags are placed on the flank over the tube sites. RESULTS
Ofthe 52 patients with bilateral calculi treated percutaneously 28 men and 20 women underwent simultaneous bilateral percutaneous nephlithotomy. Three patients had prolonged complicated procedures on the initial side necessitating postponement of the second side. One patient was discovered to have pyonephrosi with the initial needle puncture on 1side. In thispatient a nephrostomytube was inserted and the procedure on that side was deferred. In all 4 patients the postponed second side p d u r e was performed later during the same hospital stay. Of the 48 patients (96 renal units) who underwent simultaneous bilateral percutaneous nephrolithotomy 14 (17 renal units)required additional dilated access while 5 (6 renal units) required nondilated punctures. Therefore, multiple access of some type was used in 24% of cases. Mean length of the initial operative procedure was 269 minutes (range 40 to 435). T w o patients received shock wave lithotripsy postoperatively as part of a sandwich therapy (both early in our experience), 37 underwent a secondary percutaneous nephrolithotomy and 11did not require shock wave lithotripsy or secondary percutaneous nephrolithotomy. Mean hospitalization was 5.6 days (range 2 to 16). At hospital discharge 45 patients were stone-free bilaterally and 3 had insignificant fragments (less than 4 mm.) unilaterally, giving a stone-free rate per renal unit of 96.9%. Complications were infrequent and included ureteral perforation in 1 case (2.1%), obstruction by fragment migration in 2 (4.2%),hydrothorax in 5 (10.4%),hematuria causing clot retention in 2 (4.2%)and hemorrhage requiring transfusion in 2 (4.2%).Of the 5 cases of hydrothorax 4 were drained in the operating room at the end of the procedure and 1 was drained in the recovery room. One of 2 patients requiring
;ransfusion received 2 units of autologous blood (donated areoperatively because the patient had idiopathic thrombo:ytopenic purpura), and the other was anemic on hospital admission (hemoglobin 10.1 gmJdl., normal 12 to 16 for women and 14 to 18 for men) and required 2 units of donor blood postoperatively. The mean decrease in hemoglobin in the 48 patients undergoing simultaneous bilateral percutaneous nephrolithotomy was 2.6 gmJdl. (range 1.2 to 6.6) with a trend to a larger decrease with increasing numbers of dilated tracts (table 2). Stones were classified into 1 of 6 groups based on the chemical analysis (see table 5). Calcium oxalatelcalcium phosphate stones were found in 26 patients (54.2%), struvite/ carbonate apatite in 11 (22.9%), cystine in 5 (10.4%), mixed calcium oxalate and uric acid in 3 (6.3%),pure uric acid in 2 (4.2%)and a combination of calcium oxalate and struvite in 1 (2.1%). DISCUSSION
Technique and instrumentation for percutaneous nephrolithotomy have advanced considerably in the last 2 decades. This minimally invasive approach has been shown to decrease patient morbidity and cost, and shorten convalescence compared to open surgical techniques.5 The improved outcomes have prompted the exploration of simultaneous bilateral percutaneous nephrolithotomy as a surgical option for patients with large stone burdens bilaterally. Simultaneous percutaneous extraction of renal calculi has been previously reported. Colon-Perez e t a1 reported in 1987 on 3 patients treated with simultaneous bilateral percutaneous nephrolithotomy for renal calculi 0.8 to 3.8 cm.6 They noted that blood loss and post-operative pain were not significantly greater than in patients undergoing unilateral percutaneous nephrolithotomy. Regan et a1 also reported on 3 patients treated with simultaneous bilateral percutaneous nephrolithotomy, and concluded that it was a well tolerated, safe, expeditious and cost-effective approach for patients with bilateral calculi requiring percutaneous management.? Ahlawat et a1 more recently reported on 16 patients undergoing simultaneous bilateral percutaneous nephrolithotomy.8 They reported decreased operative time (83 minutes) in comparison to the prior studies, and concluded that simultaneous bilateral percutaneous nephrolithotomy was a suitable treatment for patients with bilateral stones. However, the stone size was not mentioned by Ahlawat et a1 and the stonefree rate per renal unit was low (81.3%), while the transfusion rate was unacceptably high (25%). In our study we present data from the 48 patients undergoing simultaneous bilateral percutaneous nephrolithotomy. About half of the stones were staghorn stones. Mean stone surface area was a substantial 929 mm.' (range 26 to 5,478). Stone surface area has been demonstrated to be an accurate method of comparing renal calculi, particularly staghorns.'" The figure shows the preoperative film of the kidneys, ureters and bladder from 1of the simultaneous bilateral percutaneous nephrolithotomy patients with stones slightly larger than the mean. Of the 52 patients brought to the operating room for simultaneous bilateral percutaneous nephrolithotomy, 48 (92.3%) underwent the procedure. In 3 patients the second side waa
TABLE2. Hemoglobin decrease in relation to total number dilated tracts reouired ~
No.Tracts (No.pts.)
5 (1)
~~~~
Mean Gm./Dl. Hemoglobin Decrease (ranee)
2.3(-1.2-6.1) 2.7 (0.6-6.6) 3.8 (3.34.4) 4.1
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additional procedures performed, injection of subarachnoid morphine and resident participation in every case. Of the patients in this study 11required multiple dilated tracts on 1side and 3 required multiple dilated tracts on both sides. There was a tendency towards a greater decrease in hemoglobin when more dilated tracts were placed (table 2). However, this was not associated with the need for transfusion if other risk factors were not present. Both of the patients reauirine transfusion were anemic on hosDital admission (hemoglobyinlevels 10.1 and 11.0 gmldl.). 1; addition, 1 of these patients suffered from idiopathic thrombocytopenic purpura and received only the 2 units of autologous blood that she had donated preoperatively. Hemoglobin decrease in our 2 transfusion patients was only 2.9 and 4.4 gmldl. and, therefore, neither patient would likely have been transfused had preoperative hemoglobin levels been in the normal range. No other complications were associated with increased numbers of tracts. Factors thought to contribute to the low transfusion rate include balloon tract dilation, upper pole access when indicated and the use of flexible nephroscopy during the primary procedure. The use of flexible nephroscopy with intracorporeal lithotripsy devices eliminates excessive torquing of the rigid scope, thereby minimizing renal parenchymal tears. Postoperative fever was common in the simultaneous bilateral percutaneous nephrolithotomy patients but all responded to general measures, and no patient became frankly septic or required intensive care unit admission. Other complications were infrequent. No patient required a chest tube. Preoperative film of kidneys, ureters and bladder shows stone Two patients had persistent urine drainage from the flank sizes of 1,570 (right) and 1,321 (left) m.'. after hospital discharge. These 2 patients were found to have distal ureteral stones that were removed as an outpatient via retrograde ureteroscopy. The 2 patients who had hematuria and clot retention required only conservative management (bladder irrigation). One patient suffered a ureteral perforadeferred due to the length and complexityof the procedure on tion when a guide wire was advanced through the wall of the the initial side. One of these patients was a 63-year-old ureter into the retroperitoneum. A DoubleJ* stent was left woman with chronic anemia secondary to a myelodysplastic indwelling for 2 weeks and the patient has had no further v d r o m e . She also had a history of angina and required complications. The addition of an intrathecal morphine injection at the periodic transfusions to maintain the hemoglobin level. The stone burden on the initial side was 4,856 mm.2 and the end of the simultaneous bilateral percutaneous nephrolithoprimary procedure was 225 minutes long. The second patient tomy procedure has subjectively decreased patient discomwas a 22-year-old myelomeningocelepatient with severe ky- fort postoperatively. In the first few patients it was found phoscoliosis and a colon conduit urinary diversion. She re- that the postoperative discomfort associated with simultaquired 2 difficult dilated tracts in a primary procedure that neous bilateral percutaneous nephrolithotomy was sign& lasted 230 minutes. The third patient was a 43-year-old cantly greater than with unilateral percutaneous nephrowoman with an initial side stone burden of 2,066 mm.' re- lithotomy. The intrathecal morphine injections are quiring 2 dilated tracts. The initial side procedure lasted 195 performed by the anesthesiologist at the end of the case if the minutes and the patient bled more than usual. Preoperative patient has consented to the injection before the procedure. hemoglobin was 11.3 gmldl. and she eventually required 4 The decreased postoperative discomfort has resulted in a decreased need for intramuscular narcotics postoperatively units of transfused blood. The fourth patient who had the second side deferred was and is in part responsible for shortened hospital stays later in discovered to have pyonephrosis on 1 side with the initial the study. Only 2 of the last 12 patients undergoing simulneedle puncture, contraindicating definitive management on taneous bilateral percutaneous nephrolithotomy stayed in that side. All patients are informed preoperatively that the the hospital longer than 4 days (mean hospital stay for these Procedure on the second side will be performed only if all goes 12 patients was 3.9 days). Two patients underwent shock wave lithotripsy subsewell with the first side. The mean operative time of 269 minutes is admittedly quent to the primary percutaneous nephrolithotomy procelong. This reflects, in part, our preference to remove as much dure as part of sandwich therapy. Both of these patients were stone as possible during the primary procedure. The treat- treated early in the series and would likely not undergo ment strategy also includes establishing additional dilated sandwich therapy today. The use of flexible nephroscopy and and nondilated tracts when necessary, the use of rigid and intramrporeal lithotripsy during primary and secondary perflexible instruments during the primary procedurel and a cutaneous nephrolithotomy procedures has greatly improved meticulous technique. Extreme care is necessary d m g per- our ability to render the patient stone-free, while at the same mtaneous nephrolithotomy procedures to minimize compli- time keeping costs to a minimum. The majority (35 of 48) of our simultaneous bilateral percations, and also to maximize stone removal, since even a S ~ a l amount l of bleeding can obscure stone fragments. The cutaneous nephrolithotomy patients undergo secondary flexBtrategy does prolong the procedure but we believe the ben- ible nephroscopy 48 to 72 hours after the primary procedure. efits of a high stone-free rate and low complication rate more We have a low threshold for performing secondary nephros&an outweigh the longer operating room time. Other factors * Medical Engineering Corp., New York, New York that contributed to the length of the operation were the
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SIMULTANEOUS BILATERAL PERCUTANEOUS NEPHROLITHOTOMY
copy since up to 30% of patients with negative radiographic studies following percutaneous nephrolithotomy are found to have significant residual fragments at the time of secondary nephroscopy." All of our infection stone patients undergo secondary procedures to make absolutely sure that no fragments remain. At 48 hours flexible nephroscopy can be performed without the aid of a working sheath, in a nearly bloodless field, under intravenous sedation. A cost comparison with nonsimultaneous bilateral percutaneous nephrolithotomy patients was not performed because a suitable group for comparison is not available. In an earlier study on staghorn stones from this institution the mean operative time for unilateral percutaneous nephrolithotomy was 202 minutes,'* although recent operative times would be shorter. In a more recent study on the costeffectiveness of treatment options for staghorn stones the mean hospital stay for unilateral cases was 5.3 days.13 Although comparing these data with the simultaneous bilateral percutaneous nephrolithotomy data (mean operating room time 269 minutes, mean hospital stay 5.6 days) is not statistically precise, we believe the savings in medication costs, anesthesia, radiological studies, other investigations and hospital stay associated with simultaneous bilateral percutaneous nephrolithotomy would be readily apparent when compared to 2 separate procedures and 2 hospital stays. CONCLUSIONS
At our institution the simultaneous bilateral approach is a well tolerated, safe, expeditious and cost-effective approach for management of patients with bilateral renal calculi requiring percutaneous nephrolithotomy. At centers with advanced expertise in unilateral percutaneous nephrolithotomy, simultaneous bilateral percutaneous nephrolithotomy should be offered to all patients requiring bilateral treatment. Patients should be informed that the procedure on the second side will be deferred to a later date if the procedure on the first side is overly prolonged or complex.
REFERENCES
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