Original Paper
Urologia Internationalis
Received: May 23, 2013 Accepted: June 25, 2013 Published online: October 16, 2013
Urol Int 2014;92:392–395 DOI: 10.1159/000353973
Prospective Randomized Comparison of Retroperitoneoscopic Pyelolithotomy versus Percutaneous Nephrolithotomy for Solitary Large Pelvic Kidney Stones Vishwajeet Singh a Rahul Janak Sinha a Dheeraj Kumar Gupta a Mohit Pandey b Departments of a Urology and b Radiology, King George Medical University, Lucknow, India
Abstract Objectives: We performed a prospective randomized comparison of retroperitoneoscopic pyelolithotomy (RP) versus percutaneous nephrolithotomy (PNL) for solitary pelvic stones >3 cm and assessed the outcome results. Methods: From 2010 to 2012, 44 patients with a solitary pelvic stone >3 cm without any anatomical abnormality were randomized to either RP or PNL on a 1:1 ratio. Stone-free rate, number of procedures per patient and complications were recorded. Results: The stone-free rate on the first postoperative day was 95.5% in the RP group versus 72.7% in the PNL group (p = 0.04). The stone-free rates at 3 months were similar between the two groups. Blood loss, visual pain analog score and analgesic requirement on the first postoperative day were significantly higher in the PNL group whereas the mean operative time and overall complications were similar between the two groups. Conclusion: In patients with solitary large pelvic stones, RP is associated with lesser blood loss, postoperative pain and analgesia as well as with a higher stone-free rate in the immediate postoperative period in comparison to PNL. However, the stone clearance rate remains the same at 3 months in both groups. © 2013 S. Karger AG, Basel
© 2013 S. Karger AG, Basel 0042–1138/13/0924–0392$38.00/0 E-Mail [email protected] www.karger.com/uin
Introduction
Treatment modalities for large pelvic stones include percutaneous nephrolithotomy (PNL), shockwave lithotripsy (SWL), as well as a combination of PNL, SWL and open pyelolithotomy [1]. Alternative treatment modalities such as laparoscopic stone removal have been found feasible especially where PNL has failed with stones >3 cm, stones with concomitant ureteropelvic junction obstruction and in pelvic kidneys [2–4]. Laparoscopic pyelolithotomy, either transperitoneal or retroperitoneoscopic, as a primary procedure for large solitary renal stones has been limited to few case reports/case series [2–5]. Moreover, the outcomes of the procedure with respect to the stone-free rate, procedures per patient and complication rates have not been addressed. The present study was executed as a prospective randomized study comparing retroperitoneoscopic pyelolithotomy (RP) and PNL as the primary procedure for solitary pelvic kidney stones >3 cm and to assess the outcome results.
Material and Methods From 2010 to 2012, 44 patients with a solitary pelvic stone >3 cm were randomized into two arms on a 1:1 ratio. Group I included the RP approach and group II PNL. Apart from routine tests, an intravenous urogram was obtained to evaluate stone location, hydronephrosis and the status of the opposite kidney.
Prof. Vishwajeet Singh Department of Urology King George Medical University Lucknow 226003, Uttar Pradesh (India) E-Mail vishwajeeturo @ sify.com
Downloaded by: UCSF Library & CKM 169.230.243.252 - 3/5/2015 6:04:39 AM
Key Words Retroperitoneoscopic pyelolithotomy · Percutaneous nephrolithotomy · Solitary pelvic stones
Retroperitoneoscopic Pyelolithotomy Cystoscopy and ureteric catheterization were performed under fluoroscopic guidance. In case of failure to negotiate the ureteric catheter across the ureteropelvic junction due to impaction, it was placed just below the stone. In flank position, a 2.5-cm incision was made below and in front of the tip of 12th rib, the muscles were split and the dorsolumbar fascia incised to enter into the retroperitoneum. The retroperitoneal space was developed initially by blunt finger dissection and subsequently by the indigenous balloon method [4]. A Hasson’s trocar was inserted and used as camera port, and two more ports (5 and 12 mm) were inserted and the procedure accomplished. A longitudinal pyelotomy was made over the stone which was retrieved into a disposable pouch and taken out intact. The pyelotomy was closed using 3-0 Vicryl suture (intracorporeal) over a 6-Fr/26-cm double J stent. A plain X-ray kidney-ureter-bladder (KUB) and renal ultrasound were done on the first postoperative day. In one patient, a clinically significant residue of 7 mm was observed in postoperative X-ray KUB on day 1. In this patient, during stone extraction, the stone was broken in pieces and one fragment might have migrated intraoperatively into one of the calyces which was not realized intraoperatively. The patient was subjected postoperatively to SWL. Visual pain scoring was done on the first and second postoperative days by a person who was blind to the procedure. The stent was removed after 2 weeks.
Table 1. Comparison of operative and postoperative parameters between RP and PNL
Parameters Primary procedure done alone Secondary procedure SWL Flexible nephroscopy Number of adjunctive procedures Number of procedures per patient Mean visual pain analog score on postoperative day 1 Mean tramadol requirement on day 1, mg Stone-free status in the immediate postoperative period (day 1)
RP (n = 22)
21 (95.5) 1 (4.5) 0 22 (100)
PNL (n = 22) p value
18 (81.8)
0.15 0.02
4 (18.18) 2 (9.09) 22 (100)
0.8
2.04
2.27
0.7
4.20±0.48
5.20±0.78
0.001
151.61±35.31 186.65±30.76 0.001
21 (95.5)
16 (72.7)
0.04*
Figures in parentheses are percentages. * p value 3 cm [1, 4, 6]. Laparoscopic pyelolithotomy is specifically indicated for concomitant pyelolithotomy and pyeloplasty, pelvic kidneys with large stone burden, stones in poorly functioning polar areas or with nonfunctioning kidneys as well as in failed cases after PNL/SWL [4]. The indications of a transperitoneal approach versus retroperitoneoscopy for pelvic stones are ill defined. Prospective randomized comparison on laparoscopic ureterolithotomy has been reported, but up to date, no prospective randomized comparison was performed on RP versus PNL [7]. In a series by Desai and Assimos [9], only 1.1% of patients required a laparoscopic approach for stone management. In the present study, we looked at a particular subgroup of patients with a solitary pelvic stone >3 cm without any renal abnormality and compared the outcome of RP against PNL. The interesting observation in terms of operative time was comparable between the two groups (table 1). Goel and Hemal [4], in a nonrandomized comparison between RP and PNL, reported a significantly longer mean operative time of 142.8 min for RP, considering it to be the effect of the learning curve. Al-Hunayan et al. [5], in a retrospective comparison of RP with transperitoneal pyelolithotomy, reported a mean operative time of 93.2 ± 25.4 min for RP. Another important observation of the present study was the difference in visual pain score on the first postoperative day, which was significantly higher in the PNL group. The greater pain led to a significantly higher analgesic requirement. Although there was only one percutaneous tract in the PNL group, it was interesting to see the visual pain scoring which was significantly higher in the PNL group (table 1). Pain in PNL is multifactorial. Trauma to the renal capsule and parenchyma with tract dilation and postoperative nephrostomy remains the major cause. Other causes are intraoperative perirenal fluid and blood extravasation [10]. In this study, the stone-free rate in the PNL group when assessed on the first postoperative day was 72.7%, which was significantly lower than in the RP group (95.5%). This was due to the migration of fragments into minor calyces, detected on the postoperative CT scan, requiring an ancillary procedure like SWL and flexible 394
Urol Int 2014;92:392–395 DOI: 10.1159/000353973
nephroscopy. In the RP group, the entire stone was retrieved in toto in a single session in all patients except for one in whom the stone was broken during extraction and a fragment was detected postoperatively on renal ultrasound as CSR. Although both groups attained a similar stone-free status at the end of 3 months, the stone-free status was better in the RP group in the immediate postoperative period (day 1). Our experience shows that RP offers a rapid and higher stone-free rate of 95.5% in the immediate postoperative period in comparison to a metaanalysis undertaken by the American Urological Association for staghorn stones which documented a stone-free rate of 81.6% for open stone surgery, 80.8% for combined PNL and SWL, 73.3% for PNL alone and only 50% for shock wave monotherapy. The total number of procedures per patient in the present study was 2.04 and 2.27 in the RP and PNL group, respectively. This is higher as compared to the meta-analysis reported by the American Urological Association guideline which reports an average of 1.9 procedures per patient [1, 11]. The reason for the higher number of procedures is due to the inclusion of stent removal as an adjunctive procedure. In the present study, 6 patients (27.3%) in the PNL group incurred additional financial burden to treat the residual disease. Micali et al. [12], in a study on transperitoneal laparoscopic procedures, have used flexible cystoscopy to retrieve caliceal stones through a 10/12-mm port. The procedure is cumbersome and time consuming but has also been reported by others [13–15]. The major limitation of RP lies in the requirement of greater expertise with a steeper learning curve. A stone in the intrarenal pelvis is another hurdle for the selection of cases for RP. Laparoscopic pyelolithotomy has been reported in children [13, 16], in horseshoe kidneys [17] and in ectopic kidneys [14, 15, 18]. Transperitoneal laparoscopic assisted PNL was performed in above cases in which the bowel is reflected and fluoroscopy-guided puncture and dilatation are performed [9, 14, 15, 18]. The major limitation of this study was selection bias with a small sample size. However, the present study is the first prospective randomized comparison of RP versus PNL in the English literature.
Conclusion
RP is an effective treatment option for a large solitary renal stone. In comparison to PNL, RP has the advantage of stone removal in one attempt but requires a high level of laparoscopic technical expertise. Singh/Sinha/Gupta/Pandey
Downloaded by: UCSF Library & CKM 169.230.243.252 - 3/5/2015 6:04:39 AM
end of 3 months was 100% in both groups. Two patients in each group developed postoperative febrile urinary tract infection which was treated with antibiotics.
References
RP versus PNL for Solitary Large Pelvic Kidney Stones
6 Matlaga BR, Lingeman JE: Surgical management of upper urinary tract calculi; in Wein AJ, Kavoussi LR, Novick AC, Partin AW, Peters CA (eds): Campbell-Walsh Urology. Philadelphia, Saunders, 2012, vol 3, pp 1357–1410. 7 Mandal S, Goel A, Kathpalia R, Sankhwar S, Singh V, Sinha RJ, et al: Prospective evaluation of complications using the modified Clavien grading system, and of success rates of percutaneous nephrolithotomy using Guy’s stone score: a single-center experience. Indian J Urol 2012;28:392–398. 8 Singh V, Sinha RJ, Gupta DK, Kumar M, Akthar A: Transperitoneal versus retroperitoneal laparoscopic ureterolithotomy: a prospective randomized comparison study. J Urol 2013;189:940–945. 9 Desai RA, Assimos DG: Role of laparoscopic stone surgery. Urology 2008;71:578–580. 10 Dalela D, Goel A, Singh P, Sankhwar SN: Renal capsular block: a novel method for performing percutaneous nephrolithotomy under local anesthesia. J Endourol 2004;18:544–546. 11 Segura JW, Preminger GM, Assimos DG, Dretler SP, Kahn RI, Lingeman JE, et al: Nephrolithiasis Clinical Guidelines Panel summary report on the management of staghorn calculi. J Urol 1994;151:1648.
Urol Int 2014;92:392–395 DOI: 10.1159/000353973
12 Micali S, Moore RG, Averch TD, et al: The role of laparoscopy in the treatment of renal and ureteral calculi. J Urol 1997;157:463–466. 13 El-Ghoneimi A, Valla JS, Steyaert H, Aigrain Y: Laparoscopic renal surgery via a retroperitoneal approach in children. J Urol 1998;160: 1138–1141. 14 Chang TD, Dretler SP: Laparoscopic pyelolithotomy in an ectopic kidney. J Urol 1996; 156:1753. 15 Harmon WJ, Kleer E, Segura JW: Laparoscopic pyelolithotomy for calculus removal in a pelvic kidney. J Urol 1996;155:2019–2020. 16 Jordan GH, McCammon KA, Robey EL: Laparoscopic pyelolithotomy. Urology 1997; 49: 131–134. 17 Turk I, Deger S, Winkelmann B, et al: Laparoscopic bilateral pyelolithotomy in a horseshoe kidney. BJU Int 2001;88:442. 18 Hoenig DM, Shalhav AL, Elbahnasy AM, et al: Laparoscopic pyelolithotomy in a pelvic kidney: a case report and review of the literature. J Soc Laparoendosc Surg 1997;1:163–165.
395
Downloaded by: UCSF Library & CKM 169.230.243.252 - 3/5/2015 6:04:39 AM
1 Preminger GM, Assimos DG, Lingeman GE, Nakada SY, Pearle MS, Wolf JS: Chapter 1: AUA guideline on management of staghorn calculi: diagnosis and treatment recommendations. J Urol 2005; 173: 1991– 2000. 2 Gaur DD, Trivedi S, Prabhudesai MR, Gopichand M: Retroperitoneal laparoscopic pyelolithotomy for staghorn stones. J Laparoendosc Adv Surg Tech A 2002;12:299–303. 3 Ozawa H, Nagai A, Uematsu K, Ohmori H, Kumon H: Retroperitoneoscopic pyelolithotomy as initial treatment for upper urinary tract large stone. Acta Med Okayama 2005;59: 109–112. 4 Goel A, Hemaal AK: Evaluation of the role of retroperitoneoscopic pyelolithotomy and its comparison with percutaneous nephrolithotomy. Int Urol Nephrol 2003;35:73–76. 5 Al-Hunayan A, Abdulhalim H, El-Bakry E, Hassabo M, Kehinde EO: Laparoscopic pyelolithotomy: is the retroperitoneal route a better approach? Int J Urol 2009;16:181–186.
Urologia Internationalis
Received: May 23, 2013 Accepted: June 25, 2013 Published online: October 16, 2013
Urol Int 2014;92:392–395 DOI: 10.1159/000353973
Prospective Randomized Comparison of Retroperitoneoscopic Pyelolithotomy versus Percutaneous Nephrolithotomy for Solitary Large Pelvic Kidney Stones Vishwajeet Singh a Rahul Janak Sinha a Dheeraj Kumar Gupta a Mohit Pandey b Departments of a Urology and b Radiology, King George Medical University, Lucknow, India
Abstract Objectives: We performed a prospective randomized comparison of retroperitoneoscopic pyelolithotomy (RP) versus percutaneous nephrolithotomy (PNL) for solitary pelvic stones >3 cm and assessed the outcome results. Methods: From 2010 to 2012, 44 patients with a solitary pelvic stone >3 cm without any anatomical abnormality were randomized to either RP or PNL on a 1:1 ratio. Stone-free rate, number of procedures per patient and complications were recorded. Results: The stone-free rate on the first postoperative day was 95.5% in the RP group versus 72.7% in the PNL group (p = 0.04). The stone-free rates at 3 months were similar between the two groups. Blood loss, visual pain analog score and analgesic requirement on the first postoperative day were significantly higher in the PNL group whereas the mean operative time and overall complications were similar between the two groups. Conclusion: In patients with solitary large pelvic stones, RP is associated with lesser blood loss, postoperative pain and analgesia as well as with a higher stone-free rate in the immediate postoperative period in comparison to PNL. However, the stone clearance rate remains the same at 3 months in both groups. © 2013 S. Karger AG, Basel
© 2013 S. Karger AG, Basel 0042–1138/13/0924–0392$38.00/0 E-Mail [email protected] www.karger.com/uin
Introduction
Treatment modalities for large pelvic stones include percutaneous nephrolithotomy (PNL), shockwave lithotripsy (SWL), as well as a combination of PNL, SWL and open pyelolithotomy [1]. Alternative treatment modalities such as laparoscopic stone removal have been found feasible especially where PNL has failed with stones >3 cm, stones with concomitant ureteropelvic junction obstruction and in pelvic kidneys [2–4]. Laparoscopic pyelolithotomy, either transperitoneal or retroperitoneoscopic, as a primary procedure for large solitary renal stones has been limited to few case reports/case series [2–5]. Moreover, the outcomes of the procedure with respect to the stone-free rate, procedures per patient and complication rates have not been addressed. The present study was executed as a prospective randomized study comparing retroperitoneoscopic pyelolithotomy (RP) and PNL as the primary procedure for solitary pelvic kidney stones >3 cm and to assess the outcome results.
Material and Methods From 2010 to 2012, 44 patients with a solitary pelvic stone >3 cm were randomized into two arms on a 1:1 ratio. Group I included the RP approach and group II PNL. Apart from routine tests, an intravenous urogram was obtained to evaluate stone location, hydronephrosis and the status of the opposite kidney.
Prof. Vishwajeet Singh Department of Urology King George Medical University Lucknow 226003, Uttar Pradesh (India) E-Mail vishwajeeturo @ sify.com
Downloaded by: UCSF Library & CKM 169.230.243.252 - 3/5/2015 6:04:39 AM
Key Words Retroperitoneoscopic pyelolithotomy · Percutaneous nephrolithotomy · Solitary pelvic stones
Retroperitoneoscopic Pyelolithotomy Cystoscopy and ureteric catheterization were performed under fluoroscopic guidance. In case of failure to negotiate the ureteric catheter across the ureteropelvic junction due to impaction, it was placed just below the stone. In flank position, a 2.5-cm incision was made below and in front of the tip of 12th rib, the muscles were split and the dorsolumbar fascia incised to enter into the retroperitoneum. The retroperitoneal space was developed initially by blunt finger dissection and subsequently by the indigenous balloon method [4]. A Hasson’s trocar was inserted and used as camera port, and two more ports (5 and 12 mm) were inserted and the procedure accomplished. A longitudinal pyelotomy was made over the stone which was retrieved into a disposable pouch and taken out intact. The pyelotomy was closed using 3-0 Vicryl suture (intracorporeal) over a 6-Fr/26-cm double J stent. A plain X-ray kidney-ureter-bladder (KUB) and renal ultrasound were done on the first postoperative day. In one patient, a clinically significant residue of 7 mm was observed in postoperative X-ray KUB on day 1. In this patient, during stone extraction, the stone was broken in pieces and one fragment might have migrated intraoperatively into one of the calyces which was not realized intraoperatively. The patient was subjected postoperatively to SWL. Visual pain scoring was done on the first and second postoperative days by a person who was blind to the procedure. The stent was removed after 2 weeks.
Table 1. Comparison of operative and postoperative parameters between RP and PNL
Parameters Primary procedure done alone Secondary procedure SWL Flexible nephroscopy Number of adjunctive procedures Number of procedures per patient Mean visual pain analog score on postoperative day 1 Mean tramadol requirement on day 1, mg Stone-free status in the immediate postoperative period (day 1)
RP (n = 22)
21 (95.5) 1 (4.5) 0 22 (100)
PNL (n = 22) p value
18 (81.8)
0.15 0.02
4 (18.18) 2 (9.09) 22 (100)
0.8
2.04
2.27
0.7
4.20±0.48
5.20±0.78
0.001
151.61±35.31 186.65±30.76 0.001
21 (95.5)
16 (72.7)
0.04*
Figures in parentheses are percentages. * p value 3 cm [1, 4, 6]. Laparoscopic pyelolithotomy is specifically indicated for concomitant pyelolithotomy and pyeloplasty, pelvic kidneys with large stone burden, stones in poorly functioning polar areas or with nonfunctioning kidneys as well as in failed cases after PNL/SWL [4]. The indications of a transperitoneal approach versus retroperitoneoscopy for pelvic stones are ill defined. Prospective randomized comparison on laparoscopic ureterolithotomy has been reported, but up to date, no prospective randomized comparison was performed on RP versus PNL [7]. In a series by Desai and Assimos [9], only 1.1% of patients required a laparoscopic approach for stone management. In the present study, we looked at a particular subgroup of patients with a solitary pelvic stone >3 cm without any renal abnormality and compared the outcome of RP against PNL. The interesting observation in terms of operative time was comparable between the two groups (table 1). Goel and Hemal [4], in a nonrandomized comparison between RP and PNL, reported a significantly longer mean operative time of 142.8 min for RP, considering it to be the effect of the learning curve. Al-Hunayan et al. [5], in a retrospective comparison of RP with transperitoneal pyelolithotomy, reported a mean operative time of 93.2 ± 25.4 min for RP. Another important observation of the present study was the difference in visual pain score on the first postoperative day, which was significantly higher in the PNL group. The greater pain led to a significantly higher analgesic requirement. Although there was only one percutaneous tract in the PNL group, it was interesting to see the visual pain scoring which was significantly higher in the PNL group (table 1). Pain in PNL is multifactorial. Trauma to the renal capsule and parenchyma with tract dilation and postoperative nephrostomy remains the major cause. Other causes are intraoperative perirenal fluid and blood extravasation [10]. In this study, the stone-free rate in the PNL group when assessed on the first postoperative day was 72.7%, which was significantly lower than in the RP group (95.5%). This was due to the migration of fragments into minor calyces, detected on the postoperative CT scan, requiring an ancillary procedure like SWL and flexible 394
Urol Int 2014;92:392–395 DOI: 10.1159/000353973
nephroscopy. In the RP group, the entire stone was retrieved in toto in a single session in all patients except for one in whom the stone was broken during extraction and a fragment was detected postoperatively on renal ultrasound as CSR. Although both groups attained a similar stone-free status at the end of 3 months, the stone-free status was better in the RP group in the immediate postoperative period (day 1). Our experience shows that RP offers a rapid and higher stone-free rate of 95.5% in the immediate postoperative period in comparison to a metaanalysis undertaken by the American Urological Association for staghorn stones which documented a stone-free rate of 81.6% for open stone surgery, 80.8% for combined PNL and SWL, 73.3% for PNL alone and only 50% for shock wave monotherapy. The total number of procedures per patient in the present study was 2.04 and 2.27 in the RP and PNL group, respectively. This is higher as compared to the meta-analysis reported by the American Urological Association guideline which reports an average of 1.9 procedures per patient [1, 11]. The reason for the higher number of procedures is due to the inclusion of stent removal as an adjunctive procedure. In the present study, 6 patients (27.3%) in the PNL group incurred additional financial burden to treat the residual disease. Micali et al. [12], in a study on transperitoneal laparoscopic procedures, have used flexible cystoscopy to retrieve caliceal stones through a 10/12-mm port. The procedure is cumbersome and time consuming but has also been reported by others [13–15]. The major limitation of RP lies in the requirement of greater expertise with a steeper learning curve. A stone in the intrarenal pelvis is another hurdle for the selection of cases for RP. Laparoscopic pyelolithotomy has been reported in children [13, 16], in horseshoe kidneys [17] and in ectopic kidneys [14, 15, 18]. Transperitoneal laparoscopic assisted PNL was performed in above cases in which the bowel is reflected and fluoroscopy-guided puncture and dilatation are performed [9, 14, 15, 18]. The major limitation of this study was selection bias with a small sample size. However, the present study is the first prospective randomized comparison of RP versus PNL in the English literature.
Conclusion
RP is an effective treatment option for a large solitary renal stone. In comparison to PNL, RP has the advantage of stone removal in one attempt but requires a high level of laparoscopic technical expertise. Singh/Sinha/Gupta/Pandey
Downloaded by: UCSF Library & CKM 169.230.243.252 - 3/5/2015 6:04:39 AM
end of 3 months was 100% in both groups. Two patients in each group developed postoperative febrile urinary tract infection which was treated with antibiotics.
References
RP versus PNL for Solitary Large Pelvic Kidney Stones
6 Matlaga BR, Lingeman JE: Surgical management of upper urinary tract calculi; in Wein AJ, Kavoussi LR, Novick AC, Partin AW, Peters CA (eds): Campbell-Walsh Urology. Philadelphia, Saunders, 2012, vol 3, pp 1357–1410. 7 Mandal S, Goel A, Kathpalia R, Sankhwar S, Singh V, Sinha RJ, et al: Prospective evaluation of complications using the modified Clavien grading system, and of success rates of percutaneous nephrolithotomy using Guy’s stone score: a single-center experience. Indian J Urol 2012;28:392–398. 8 Singh V, Sinha RJ, Gupta DK, Kumar M, Akthar A: Transperitoneal versus retroperitoneal laparoscopic ureterolithotomy: a prospective randomized comparison study. J Urol 2013;189:940–945. 9 Desai RA, Assimos DG: Role of laparoscopic stone surgery. Urology 2008;71:578–580. 10 Dalela D, Goel A, Singh P, Sankhwar SN: Renal capsular block: a novel method for performing percutaneous nephrolithotomy under local anesthesia. J Endourol 2004;18:544–546. 11 Segura JW, Preminger GM, Assimos DG, Dretler SP, Kahn RI, Lingeman JE, et al: Nephrolithiasis Clinical Guidelines Panel summary report on the management of staghorn calculi. J Urol 1994;151:1648.
Urol Int 2014;92:392–395 DOI: 10.1159/000353973
12 Micali S, Moore RG, Averch TD, et al: The role of laparoscopy in the treatment of renal and ureteral calculi. J Urol 1997;157:463–466. 13 El-Ghoneimi A, Valla JS, Steyaert H, Aigrain Y: Laparoscopic renal surgery via a retroperitoneal approach in children. J Urol 1998;160: 1138–1141. 14 Chang TD, Dretler SP: Laparoscopic pyelolithotomy in an ectopic kidney. J Urol 1996; 156:1753. 15 Harmon WJ, Kleer E, Segura JW: Laparoscopic pyelolithotomy for calculus removal in a pelvic kidney. J Urol 1996;155:2019–2020. 16 Jordan GH, McCammon KA, Robey EL: Laparoscopic pyelolithotomy. Urology 1997; 49: 131–134. 17 Turk I, Deger S, Winkelmann B, et al: Laparoscopic bilateral pyelolithotomy in a horseshoe kidney. BJU Int 2001;88:442. 18 Hoenig DM, Shalhav AL, Elbahnasy AM, et al: Laparoscopic pyelolithotomy in a pelvic kidney: a case report and review of the literature. J Soc Laparoendosc Surg 1997;1:163–165.
395
Downloaded by: UCSF Library & CKM 169.230.243.252 - 3/5/2015 6:04:39 AM
1 Preminger GM, Assimos DG, Lingeman GE, Nakada SY, Pearle MS, Wolf JS: Chapter 1: AUA guideline on management of staghorn calculi: diagnosis and treatment recommendations. J Urol 2005; 173: 1991– 2000. 2 Gaur DD, Trivedi S, Prabhudesai MR, Gopichand M: Retroperitoneal laparoscopic pyelolithotomy for staghorn stones. J Laparoendosc Adv Surg Tech A 2002;12:299–303. 3 Ozawa H, Nagai A, Uematsu K, Ohmori H, Kumon H: Retroperitoneoscopic pyelolithotomy as initial treatment for upper urinary tract large stone. Acta Med Okayama 2005;59: 109–112. 4 Goel A, Hemaal AK: Evaluation of the role of retroperitoneoscopic pyelolithotomy and its comparison with percutaneous nephrolithotomy. Int Urol Nephrol 2003;35:73–76. 5 Al-Hunayan A, Abdulhalim H, El-Bakry E, Hassabo M, Kehinde EO: Laparoscopic pyelolithotomy: is the retroperitoneal route a better approach? Int J Urol 2009;16:181–186.
