ENDOSCOPIC TREATMENT OF FIBROEPITHELIAL POLYPS OF THE RENAL PELVIS AND URETER JOHN S. LAM, JONATHAN B. BINGHAM,
ABSTRACT Objectives. To report our experience on the endoscopic treatment of large fibroepithelial polyps of the renal pelvis and ureter. Fibroepithelial polyps of the upper urinary tract are rare benign tumors that have traditionally been treated by open exploration and resection. Methods. Five patients underwent either percutaneous or ureteroscopic treatment of a renal pelvic or ureteral fibroepithelial polyp by electroresection or holmium:yttrium-aluminum-garnet laser resection. Results. All 5 patients were without recurrence after endoscopic resection. The mean follow-up was 19.6 months (range 6 to 41). The average length of stay was 3 days (range 2 to 5) and 0.5 day (range 0 to 1) for those undergoing percutaneous and ureteroscopic treatment, respectively. No major complications resulted from either approach, and no ureteral strictures have developed. All patients treated remain recurrence free. Conclusions. Endoscopic management of large fibroepithelial polyps of the renal pelvis and ureter is an acceptable treatment modality with minimal morbidity and durable treatment results. The percutaneous approach offers the advantage of identifying the base of the polyp under direct visualization, allowing safe destruction of the stalk and efficient removal of the entire polyp. To our knowledge, this is the first reported series of percutaneous, antegrade excision of fibroepithelial polyps. UROLOGY 62: 810–813, 2003. © 2003 Elsevier Inc.
ibroepithelial polyps of the renal pelvis and ureter are rare benign mesodermal tumors. Approximately 175 cases have been documented in published reports.1– 4 Histologically, these polyps are composed of stroma derived from the mesoderm and covered by a layer of normal transitional epithelial cells.3 Fibroepithelial polyps typically present in young patients as a smooth, mobile, pedunculated mass in the upper urinary tract. The treatment of these benign polyps is dictated by the degree of obstruction, involvement of the urinary tract, and intraoperative impression of carcinoma. Fibroepithelial polyps have traditionally been treated by open exploration and resection. However, with the advent of smaller ureteroscopes and the holmium:yttrium-aluminum-garnet (YAG) laser, these patients may now be treated endoscopiFrom the Department of Urology, New York-Presbyterian Hospital, Columbia University College of Physicians and Surgeons, New York, New York Reprint requests: Mantu Gupta, M.D., Department of Urology, Columbia University College of Physicians and Surgeons, 161 Fort Washington Avenue, Irving Pavilion, 11th Floor, New York, NY 10032 Submitted: May 14, 2003, accepted (with revisions): June 20, 2003
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cally. We report our experience on percutaneous and ureteroscopic treatment of large fibroepithelial polyps of the renal pelvis and ureter. MATERIAL AND METHODS Between December 1999 and November 2002, we treated 5 patients with a fibroepithelial polyp of the upper urinary tract at our institution. Three patients presented with flank pain and two with gross hematuria. The evaluation initially included intravenous urography (IVU) or computed tomography (CT) in all patients. All patients had negative urinary cytology. The diagnosis was made by retrograde urography and ureteroscopy in all cases and confirmed histopathologically in all cases by biopsy of the lesion. The decision to use a percutaneous or ureteroscopic approach was primarily based on the size and location of the fibroepithelial polyp. If the polyp could not be resected ureteroscopically, the patient was fully counseled and brought back for a percutaneous approach. Percutaneous procedures were performed under general anesthesia, and ureteroscopic procedures were performed under either general or regional anesthesia. At the onset of the percutaneous procedure, cystoscopy and retrograde pyelography was performed to position a ureteral catheter in the collecting system. Patients were placed prone, and an upper or middle pole calix was chosen for percutaneous access. For the polyp located in the renal pelvis, dilation of the percutaneous tract was performed to 30F because the polyp filled the entire renal pelvis and was pedunculating down to the mid-ureter. Nephroscopy was performed to iden0090-4295/03/$30.00 doi:10.1016/S0090-4295(03)00691-5
tify the stalk of the fibroepithelial polyp, and a resectoscope with a thin wire loop was used to excise the stalk completely off the renal pelvic sidewall. Biopsy forceps were then used to extract the mass in a piecemeal fashion until it had been removed in its entirety. For polyps located in the ureter, a guidewire was placed down the ureter, dilation of the percutaneous tract was performed to 14F, and a 12/14F ureteral access sheath was placed down the ureter. A flexible 7F ureteroscope was used to identify the stalk of the polyp. A holmium:YAG laser (Trimedyne, Irvine, Calif) was used to resect ureteral polyps. It operated at a wavelength of 2100 nm, and the frequency was usually set between 5 to 10 Hz and a power of 10 to 15 W. A 200-m quartz fiber was used to resect the entire base of the tumor stalk off of the wall of the ureter. A large Segura basket was then passed through the flexible ureteroscope, and the entire specimen was put in the basket and removed in its entirety. At the end of the procedure, a 6F multilength double-pigtail ureteral stent was placed followed by placement of a separate nephrostomy tube. Ureteroscopic procedures were initiated with cystoscopy and retrograde pyelography. Ureteroscopy was performed in combination with holmium:YAG laser resection of the polyp using a small caliber (7.5F) semirigid or flexible ureteroscope. Our standard technique for ureteroscopic treatment of fibroepithelial polyps includes placement of a 0.038-in. floppytipped guidewire past the polyp (glidewire when necessary) to maintain access, placement of a safety wire for flexible ureteroscopy, and ureteroscopy with direct visual holmium:YAG laser resection. Continuous irrigation and/or intermittent manual pumping of irrigant to obtain a clear ureteroscopic view were used as appropriate. Basket retrieval of polypoid fragments was used when necessary. A 6F, multilength, double-pigtail ureteral stent was placed at the end of the procedure. Ureteral stents were left indwelling for 6 weeks postoperatively. Results were based on IVU findings performed 3 months after the procedure. Thereafter, all patients underwent yearly CT or IVU as radiographic follow-up after endoscopic treatment of fibroepithelial polyps. The duration of the hospital stay was noted, as well as all complications.
RESULTS All patients had a radiolucent filling defect demonstrated with IVU or contrast-enhanced CT on the initial evaluation (Fig. 1A). All patients underwent diagnostic ureteroscopy and had a confirmed histopathologic diagnosis of a fibroepithelial polyp. The average patient age was 40 years (range 22 to 59). Four patients were men and one was a woman. The mean operative time was 92 minutes (range 69 to 115) and 43 minutes (range 39 to 47) for those undergoing percutaneous and ureteroscopic resection of fibroepithelial polyps, respectively. One fibroepithelial polyp was located in the renal pelvis and four were located in the proximal to middle ureter. The polyp in the renal pelvis was on the left side. The polyps in the ureter were on the right side in 1 patient and the left side in 3 patients. The fibroepithelial polyps were treated percutaneously if they were in the renal pelvis or if the base of the stalk could not be reached ureteroscopically. Resection of the fibroepithelial polyps was performed percutaneously in 3 patients and ureteroscopically in 2 patients. The lengths of the UROLOGY 62 (5), 2003
FIGURE 1. (A) IVU revealing left mid-ureteral filling defect. (B) Postoperative IVU 3 months after percutaneous removal of polyp.
polyps treated percutaneously were 20, 3, and 1.5 cm. The lengths of the polyps treated ureteroscopically were both 1 cm. Endoscopic resection was successful in all patients at a mean follow-up of 19.6 months (range 6 to 41). All fibroepithelial polyps in the ureter were 811
treated with the holmium:YAG laser. The fibroepithelial polyp in the renal pelvis was treated with electroresection owing to its large size (20 cm), which filled the entire renal pelvis and was pedunculating down to the mid-ureter. In addition, sufficient space was available to use a resectoscope safely in the renal pelvis. The other two percutaneous cases each involved a large polyp in the proximal to middle ureter. These could not be treated ureteroscopically, because the base of the polyp could not be well visualized to allow for safe destruction of the stalk. This was due to the body of the fibroepithelial polyp pedunculating down the ureter, taking up the entire lumen and obstructing the base of the stalk. No major intraoperative or perioperative complications developed, and no blood transfusions were required. The average length of stay was 3 days (range 2 to 5) and 0.5 day (range 0 to 1) for those undergoing a percutaneous and ureteroscopic approach, respectively. One patient who underwent a percutaneous approach stayed 5 days owing to stent migration, which required repositioning before discharge. Postoperatively, pain was minimal and controlled with oral analgesics after discharge home. IVU performed 3 months after fibroepithelial polyp resection showed a disappearance of the filling defect (Fig. 1B). Thereafter, all patients underwent annual radiographic follow-up with IVU and/or contrast-enhanced CT scan. To date, no patients have developed a ureteral stricture or experienced a recurrence. COMMENT Fibroepithelial polyps of the renal pelvis and ureter are rare benign mesodermal tumors; however, they represent the most common benign lesions that affect the upper urinary tract of adults and children.1– 4 They are most often smoothly marginated and cylindrical, sessile, or even frondlike. These polyps are thought to be either congenital slow-growing lesions or lesions that develop as a result of chronic urothelial irritants, such as infection, inflammation, or obstruction. Other benign lesions of the upper urinary tract include endometriomas, fibromas, leiomyomas, granulomas, neurofibromas, hemangiomas, and lymphangiomas.4,5 Renal pelvic tumors account for approximately 10% of all renal tumors and 5% of all urothelial tumors.5 Ureteral tumors occur with one quarter the incidence of renal pelvic tumors.5 These tumors can be classified as epithelial or mesenchymal. Primary epithelial tumors of the upper urinary tract are more common and are usually malignant, and mesodermal tumors of the upper urinary tract are rare lesions that are almost always 812
benign. Fibroepithelial polyps are classified as benign hamartomas because of their histologic organization; however, malignant degeneration has been reported.6 It is important to distinguish fibroepithelial polyps from upper urinary tract carcinoma, because the management and prognosis can be significantly different. All patients should have biopsy proven histologic confirmation before beginning definitive therapy. Fibroepithelial polyps can occur in newborns and adults older than 70 years but commonly present in the third to fourth decades of adults, with a male/female ratio of 3:2. Most fibroepithelial polyps occur in the ureter, 15% occur in the renal pelvis, and a small number develop in the posterior urethra or bladder.3 Renal pelvic polyps have a female preponderance (79%) and more commonly occur on the right side (79%).1 The more common ureteral polyp occurs more often in men, with a predilection for the proximal ureter on the left side (70%).3 Approximately 62% of ureteral fibroepithelial polyps occur at the ureteropelvic junction or upper ureter.3 Fibroepithelial polyps of the lower urinary tract occur most commonly in the posterior urethra and more often in children. Most polyps are smaller than 5 cm; however, larger polyps have been reported, including the one in our series. Ureteral polyps usually appear as solitary tumors; however, rare cases of multiple and bilateral appearance have been reported.4 The most common presenting signs and symptoms are hematuria and/or flank or abdominal pain. Urinary frequency, dysuria, and pyuria are less common findings. In children, fibroepithelial polyps have also been described as an uncommon cause of obstruction of the ureteropelvic junction.7 A fibroepithelial polyp should be suspected when IVU or retrograde pyelography demonstrates a radiolucent filling defect originating from the proximal ureter and negative cytology. Confusion may result when the polyp is particularly long and protrudes into the bladder or is associated with a calculus.8 Hydronephrosis may or may not be present. CT can be used to evaluate other radiolucent filling defects of the collecting system, such as sloughed papillae, radiolucent stones, fungi, or blood clots. Cystoscopy is essential after an episode of gross hematuria to evaluate the bladder for urothelial tumors. Grossly, most fibroepithelial polyps are long slender projections with a smooth surface presenting as single or multiple fronds arising from a common base. Microscopically, these lesions are made up of a cone of fibrovascular stroma emerging from the submucosa and covered by a normal transitional epithelium without papillary formation.2 Despite a preoperative diagnosis of a benign, largely intraluminal lesion, most case reports of UROLOGY 62 (5), 2003
fibroepithelial polyps describe open or, occasionally, laparoscopic management. With the advent of small-caliber ureteroscopes, endoscopic biopsy and resection of these tumors is becoming more popular. However, ureteroscopic resection can be difficult in patients with a long, polypoid lesion. This difficulty is often due to inability to access the base of the stalk because of hindrance from the pedunculated body of the lesion, which often can hang inferiorly for several centimeters and take up the entire lumen of the ureter. Visualization may also be poor and little working space is available, making it difficult to differentiate the ureteral wall from the polyp itself. It can be quite dangerous to start cutting in this setting, especially if the polyp cannot be retracted away from the ureter. To achieve complete removal of the lesion, it must be severed at its base and the base generously fulgurated to prevent recurrence. Percutaneous, antegrade excision of large fibroepithelial polyps offers a minimally invasive approach in which direct visualization of the base of the polyp is achieved and allows for easy removal of the polyp once the stalk is excised. This can be done with minimal morbidity by dilation to only 16F and placement of a ureteral access sheath, allowing for placement of a flexible ureteroscope down the ureter. However, percutaneous access into the renal pelvis can be technically difficult if hydronephrosis is absent and calices and pelvis are fine and delicate. The degree of obstruction and hydronephrosis sometimes encountered in these patients is significantly less than one would expect given the size of the lesion, possibly because of the slow-growing, nonmalignant nature of these lesions. If percutaneous access or resection is not possible, a laparoscopic or open approach may be used. Urologists are familiar with the laser because of its widespread use and availability for the management of ureteral calculi. The holmium:YAG laser is an ideal modality for the endoscopic management of renal pelvic and ureteral fibroepithelial polyps. The fiber size facilitates use in small-caliber ureteroscopes necessary for use in children or when the ureteral lumen is compromised because of an intraluminal mass. The fibrous stalk attachment can be thick and difficult to resect using grasping or biopsy forceps, increasing the potential for ureteral perforation. The depth of penetration of the holmium:YAG laser is desirable to avoid inadver-
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tent thermal injury to the ureteral wall during coagulation of the resection site. However, caution must exercised because the holmium:YAG laser is still capable of causing ureteral wall injury if not properly controlled. Holmium:YAG laser resection may be the preferred mode of conservative management of fibroepithelial polyps in the new millennium. When malignancy is suspected or when an endoscopic approach is not practical, however, segmental resection of the ureter, dismembered pyeloplasty, or nephroureterectomy may be needed. CONCLUSIONS Most fibroepithelial polyps of the renal pelvis and ureter can now be managed less invasively with endoscopic surgery and judicious use of the holmium:YAG laser. This can be performed either percutaneously or ureteroscopically with minimal morbidity and early convalescence without evidence of stricture formation or recurrence. The percutaneous approach offers the advantage of identifying the base of the polyp under direct visualization, which allows for safe destruction of the stalk and easy removal of the entire polyp. To our knowledge, this is the first reported series of percutaneous, antegrade excision of fibroepithelial polyps. REFERENCES 1. Brady JD, Korman HJ, Civantos F, et al: Fibroepithelial polyp of the renal pelvis: nephron-sparing surgery after falsepositive biopsy for transitional cell carcinoma. Urology 49: 460 –464, 1997. 2. Bolton D, Stoller ML, and Irby P III: Fibroepithelial ureteral polyps and urolithiasis. Urology 44: 582–587, 1994. 3. Williams TR, Wagner BJ, Corse WR, et al: Fibroepithelial polyps of the urinary tract. Abdom Imaging 27: 217–221, 2002. 4. Kiel H, Ullrich T, Roessler W, et al: Benign ureteral tumors: four case reports and a review of the literature. Urol Int 63: 201–205, 1999. 5. Messing EM: Urothelial tumors of the urinary tract, in Walsh PC, Retik AB, Vaughan ED Jr, et al (Eds): Campbell’s Urology, 8th ed. Philadelphia, WB Saunders, 2002, vol 3, pp 2765–2773. 6. Davides KC, and King LM: Fibrous polyps of the ureter. J Urol 115: 651–653, 1976. 7. Macksood MJ, Roth DR, Chang CH, et al: Benign fibroepithelial polyps as a cause of intermittent ureteropelvic junction obstruction in a child: a case report and review of the literature. J Urol 134: 951–952, 1985. 8. Yeh CC, Lin HC, Chen CC, et al: Ureteral fibroepithelial polyp prolapsed into the bladder cavity suspending a bladder stone. J Urol 165: 1627–1628, 2001.