Laparoscopic Pyeloplasty and Flexible Nephroscopy: Simultaneous Treatment of Ureteroplevic Junction Obstruction and Nephrolithiasis

Abstract

Background and Objective:

Ureteropelvic junction obstruction and concomitant calculus disease may coexist. Therapeutic controversy exists regarding their ideal management. We report our use of flexible nephroscopy during laparoscopic pyeloplasty for caliceal stone removal.

Methods:

From August 1998 through May 2002, 50 laparoscopic pyeloplasties were performed. Seven patients had documented ureteropelvic junction obstruction and ipsilateral nephrolithiasis. Preoperative stone burden and location were assessed. After pyelotomy, a 16 Fr flexible endoscope was passed through the uppermost trocar under direct laparoscopic guidance into the collecting system. Stone extraction was performed with a 2.4 Fr Nitinol basket. Postoperative imaging was assessed.

Results:

Complete stone-free status confirmed by postoperative imaging was achieved in 6 of 7 patients. The longest individual stone diameter ranged from 4 mm to 13 mm (mean, 10.3 mm), and an average of 2.5 stones per patient was removed (range, 1 to 4 stones). Neither intraoperative fluoroscopy nor lithotripsy was required. No intraoperative or delayed complications were noted during a mean follow-up of 8.5 months (range, 2 to 17 months).

Conclusions:

Laparoscopic pyeloplasty and concomitant flexible nephroscopy with basket extraction is a simple, attractive alternative for the simultaneous treatment of ureteropelvic junction obstruction presenting with coexisting nephrolithiasis. It appears more efficacious when the stone number is limited and diameters measure from 5 mm to 20 mm.

INTRODUCTION

The surgical treatment of ureteropelvic junction (UPJ) obstruction has evolved significantly over the past 2 decades. Open surgical resection and reanastomosis of the abnormal ureteral segment was described by Kuster¹ in 1892 and later popularized by Anderson and Hynes.² Reported success rates of over 90% made dismembered pyeloplasty the procedure of choice for UPJ obstruction.³ To circumvent the postoperative morbidity of open surgery in the adult population, several minimally invasive techniques have been developed to treat ureteropelvic junction obstruction. Initially reported in 1983, percutaneous endopyelotomy provided patients with an alternative to open surgery associated with less postoperative morbidity and success rates approaching 85%.^4–9 The Acucise cutting balloon (Applied Medical Resources, Rancho Santa Margarita, CA) was initially described for retrograde treatment of ureteropelvic junction obstruction in the early 1990s and provided reasonable success rates approaching 80%.^10,11 Similarly, use of the holmium:YAG laser to perform a ureteroscopic endopyelotomy has improved drainage in 83% of patients presenting with primary and secondary ureteropelvic junction obstruction.¹² Laparoscopic pyeloplasty was first described in 1993, and recent follow-up data have shown success rates of over 90% for both primary and secondary disease.^13–18 The presence of ureteropelvic junction obstruction associated with concomitant ipsilateral calculus disease presents a challenging situation for the urologist. We report our utilization of flexible nephroscopy during laparoscopic pyeloplasty for nephrolithiasis removal.

METHODS

All patients were referred to our university for evaluation of suspected unilateral, single-system ureteropelvic junction obstruction. All patients came with an intravenous urography (IVU). Computed tomography (CT) and mercaptoacetyltriglycine (MAG-3) nuclear renography were completed preoperatively by all patients to confirm the diagnosis and assess perinephric anatomy. Cumulative stone burden and location were determined by IVU and CT. All patients had an obstructive pattern with at least >20% differential renal function of that renal unit on diuretic nuclear scintigraphy. Informed surgical consent was obtained, including discussion of possible open conversion, blood transfusion, urinary tract infection, and any subsequent stone removal procedure. One patient with a partial staghorn calculus elected to undergo a Percutaneous Nephrolithotomy followed by laparoscopic pyeloplasty and was excluded from the study.

General endotracheal anesthesia was administered to all patients. No bowel prep was given. Nitrous oxide was avoided to prevent bowel distension. Once adequate anesthesia was obtained, the patient was placed in the dorsal lithotomy position on the operating room table. If a double-J ureteral stent was not present, then one was subsequently placed on the operative side in standard fashion under fluoroscopic guidance. If a double-J stent had been present for several months, then it was exchanged for a new one by using the established technique. The selected double-J stent size was 2 cm longer than usual, which helped to prevent inadvertent proximal migration out of the bladder with manipulation during the repair. A retrograde pyelogram was performed to define the UPJ obstruction and clear the distal ureter. A Foley catheter and a nasogastric tube were inserted after the cystoscopy. The Foley was subsequently clamped after establishment of pneumoperitoneum to allow distention of the renal pelvis to assist with dissection. The patient was then placed in a 45° lateral decubitus position, carefully padding all pressure points, and secured in position by a “beanbag” device.

A pneumoperitoneum was achieved with carbon dioxide by using either a Veress needle or the Hasson technique to achieve 15 mm Hg of intraabdominal pressure. A 12-mm port was positioned infraumbilically, followed by two 12-mm ports in the midclavicular line and, occasionally, a 5-mm port in the lateral position to complete a diamond arrangement (Figure 1). General inspection of the abdominal cavity was performed followed by reflection of the colon medially. The renal pelvis and UPJ were identified and dissected free, carefully preserving any crossing vessels if present. Once the anatomical configuration of the hilum was identified and the area of the ureteropelvic junction was examined, either a Foley Y-V (if no crossing vessels) or a dismembered pyeloplasty (if crossing vessel) was initiated (Figure 2). The ureter was partially incised, and the internal stent was removed from the renal pelvis, thus allowing access for nephroscopy and stone removal. The pyelotomy was made of appropriate length to achieve the pyeloplasty and was not elongated for the nephroscopy. A second pyelotomy for the sole purpose of nephroscopy was not necessary.

Figure 1.

Diagram of laparoscopic port placement.

Figure 2.

Mobilized collecting system (no crossing vessel present).

A second endoscopy tower with camera and light source was brought into the room as we continued our dissection. When ready, continuous irrigation was assembled and through the uppermost midclavicular port, a 16 Fr Storz flexible cystoscope (Karl Storz Endoscopy-America, Inc., Culver City, CA) was passed under laparoscopic vision directly into the previously made pyelotomy. Intermittent suction controlled the continuous irrigation of saline via the nephroscope (Figure 3). With preoperative knowledge of stone number and location, inspection of individual calices allowed identification of the calculi, which were then extracted by using a 2.4 Fr Nitinol “zero tipped” basket (Microvasive, Boston Scientific Inc., Watertown, MA) (Figure 4). Continuous irrigation via the cystoscope allowed for superb visualization. The irrigant was aspirated by placing the suction probe just below the pyelotomy through the accessory laparoscopic port. Neither lithotripsy nor fluoroscopy was required, rather endoscopy continued until all counted stones were removed. The ureter and renal pelvis were appropriately positioned, and completion of the anastomosis was performed by using interrupted 2-zero polyglycolic acid sutures tied intracorporeally to provide a tension-free, watertight closure over the internal stent. The two 12-mm ports were closed under direct vision with the Carter-Thomason port closure device (Inlet Medical, Edina, MN). A 19 Fr Blake drain was placed through the lateral 5-mm port; and finally, the infraumbilical port was closed.

Figure 3.

Flexible nephroscopy under direct laparoscopic visualization.

Figure 4.

Endoscopic basket retrieval of nephrolithiasis.

In the postoperative period, a plain abdominal film (KUB) was obtained to evaluate for residual calculi and to compare to the preoperative films. Stone analysis was performed on all retrieved calculi. The Foley catheter was removed in 48 hours, and the drain was removed in 72 hours to 96 hours if recorded output was minimal. The stent was removed at approximately 6 weeks, and a MAG-3 nuclear renal scan was performed at 8 weeks to 10 weeks after the corrective procedure.

RESULTS

Out of 50 patients who underwent laparoscopic pyeloplasty from August 1998 to May 2002, we identified 8 patients who presented with unilateral, single-system ureteropelvic junction obstruction, and concurrent ipsilateral nephrolithiasis. One patient with a partial staghorn calculus elected to have a percutaneous stone extraction prior to the laparoscopic pyeloplasty, and therefore was excluded from analysis. Seven patients were available for review (Table 1). One patient had a prior attempted open corrective procedure for UPJ obstruction. All patients had an obstructed pattern (T1/2 >15 minutes) by MAG-3 renography with at least >20% confirmed differential renal function of the involved kidney. All calculi were located in the caliceal system. Cumulative stone burden ranged from 1.0 cm to 4.0 cm. The longest individual stone diameters ranged from 4 mm to 13 mm (mean, 10.3 mm), and an average of 2.5 stones was removed from each patient (range, 1 to 4 stones). No major intraoperative or delayed complications occurred, and no blood transfusion was required. Crossing vessels were identified in 4 of the 7 patients. MAG-3 renography performed 8 weeks postoperatively confirmed the absence of obstruction in all patients. Current mean follow-up from time of the last visit was 8.5 months (range, 2 to 17 months). Table 2 details the postoperative findings. The postoperative abdominal film confirmed a stone-free status in 6 of the 7 patients. One patient with approximately 2 dozen stones each measuring <3 mm in diameter had several suspected residual lower calyx calculi in association with a thick proteinaceous material, and this patient remains asymptomatic without progression of stone disease. In four of the 7 patients who had stone analysis performed calcium oxalate was revealed as the major component (>75%).

Table 1.

Patient Characteristics, Preoperative Imaging Findings, and Surgical Procedure

Patient	Age (Years)	Sex	Stone Size (mm)	Stone Location	Procedure	Stent Duration (Weeks)
1	66	F	5 (1-2 stones)	Lower pole	Right Y-V plasty	6
2	59	F	5	Lower pole	Left Dismembered Pyeloplasty*	5.5
3	30	M	10	Lower pole	Left Dismembered Pyeloplasty*	7.5
4	57	M	10 (2 stones) 15 (2 stones)	Mid and Lower pole	Left Y-V plasty	5.5
5	66	M	<10	Lower pole	Right Dismembered Pyeloplasty*	5.5
6	20	M	<10 (4 stones)	Lower pole	Right Dismembered Pyeloplasty*	5
7	18	F	<15 (3 stones)	Lower pole	Right Y-V plasty	5

^*Anterior crossing vessel was present.

Table 2.

Calculi Characteristics

Patient	Diagnosis (Postoperative)	Plain Film (Postoperative)	Stone Analysis*	Total Weight (g)
1	<3 mm Proteinaceous Mass of 2 Dozen Stones	6 mm Radiolucent	98% COM	0.358
2	8 mm Stone	No Stones Seen	NA	NA
3	10 mm Stone	No Stones Seen	60% COM	0.124
			30% COD
			10% CA
4	10-13 mm (4 Stones)	No Stones Seen	80% UAD	1.497
			20% COM
5	4 mm Stone	No Stones Seen	86% COM	NA
	5 mm Stone		12% COD
6	9-13 mm (4 Stones)	No Stones Seen	100% CHPD	0.149
7	11-13 mm (3 Stones)	No Stones Seen	50% COM	1.641
			25% COD
			25% CA

*COM = calcium oxalate monohydrate, COD = calcium oxalate dihydrate, CA = carbonate apatite, UAD = uric acid dihydrate, CHPD = calcium hydrogen phosphate dihydrate.

DISCUSSION

The incidence of concurrent renal calculi and ureteropelvic junction obstruction is 20%, and this scenario presents some controversy in regards to cause and treatment alternatives.¹⁹ A possible cause of the obstruction may be stenosis of the ureteropelvic junction, a result of an obstructing stone, or both. One hypothesis is that renal obstruction secondary to the stenotic ureteral segment results in urinary stasis, promotion of nucleation and stone formation, and that correction of this obstruction results in a decreased incidence of recurrent calculi.¹⁹ In contrast, others profess the importance of a metabolic evaluation because patients who present with both ureteropelvic junction obstruction and calculi may have a fundamental underlying metabolic abnormality, as most patients with ureteropelvic junction obstruction do not have stones.²⁰ Thorough evaluation of a patient's symptoms, renal function, anatomy, and previous attempts at correction will help direct the physician in selecting the most appropriate surgical intervention. Percutaneous nephrolithotomy followed by simultaneous or subsequent antegrade endopyelotomy is an option often presented to patients in this situation.^{19, 21, 22} The overall success rate of endopyelotomy decreased to 39% when a crossing vessel and a large redundant renal pelvis were present.⁸ Primary percutaneous stone removal followed by retrograde endopyelotomy using the Acucise device or the holmium laser is an additional proposed option.²² Traditional open pyeloplasty may be accompanied by pyelolithotomy for concurrent stone removal.²³ Likewise, performance of laparoscopic pyeloplasty and subsequent stone removal is a therapeutic alternative.^{15, 16} Performance of concomitant stone removal allows for a minimally invasive one-stage therapeutic option.

The technique of using a flexible nephroscope for removal of renal calculi during a laparoscopic procedure has been described by a group from Johns Hopkins University.^{15, 16} The authors initially presented successful laparoscopic stone removal in 15 of 17 patients, of whom 9 went on to have laparoscopic pyeloplasty repair. Key points to their described technique included (1) the importance of not transecting the ureter before stone removal, (2) the use of the 2-camera system to pass the cystoscope under laparoscopic guidance, (3) the placement of the laparoscopic suction device below the renal pelvis to provide a clear operative field, (4) the intraoperative use of fluoroscopy as a crucial tool in locating and confirming complete stone removal, and (5) the maneuver of pulling the proximal end of the stent through the pyelotomy incision to allow maximal cystoscope mobility. At median follow-up of 13.7 months, all patients were asymptomatic, stone free, and without obstruction based on postoperative intravenous pyelography. Subsequently, an updated series was recently reported, involving 19 patients with a mean follow-up of 12 months and a long-term stone-free rate of 80%.²⁴ The authors report the use of the holmium laser to perform lithotripsy as an adjunct measure for stone removal.

Our technique shares several similarities and differences with the one previously described. The use of the 2-camera system allows superb visualization and laparoscopic guidance of the flexible endoscope. Overflow of saline irrigation is easily managed by intermittent suction, which will maintain the established pneumoperitoneum. Thorough preoperative review of each patient's radiological studies allowed us to adequately assess complete stone burden and location, and therefore we found intraoperative use of fluoroscopy not to be essential. Not bringing a portable “c-arm” into the operating room provided additional working space in an often times crowded suite, and operative time was not spent positioning the fluoroscopic unit. Our 1 patient with residual calculi was noted to have nearly 2 dozen small (<3 mm) stones interlaced with a thick proteinaceous material that likely would have been missed even if intraoperative fluoroscopy had been utilized. Preoperatively, it was believed this area was 1 or 2 small lower pole stones. This patient has subsequently passed small stones after the Foley Y-V plasty. No intraoperative lithotripsy was performed. Our 1 patient who elected percutaneous nephrolithotripsy prior to undergoing laparoscopic repair underwent the procedure of choice for her stone burden. Treatment of calculi >20 mm or branched staghorn calculi are most likely amenable to such an approach. All additional stones in the 6 remaining patients were accounted for at the end of the procedure and, subsequently confirmed to be stone free with postoperative imaging.

CONCLUSION

We have presented herein a series of patients who underwent successful laparoscopic pyeloplasty with concurrent nephrolithiasis removal via flexible pyeloscopy. This is a simple, attractive alternative for the simultaneous treatment of UPJ obstruction with coexisting nephrolithiasis and should be offered preoperatively to the patient if laparoscopic repair is considered. It appears to be more efficacious when a limited number of radiographically identified stones are present and individual calculi range in diameter size from 5 mm to 20 mm. Intraoperative fluoroscopy and lithotripsy are not felt to be mandatory.