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Laparoscopic Marsupialization of a Simple Renal Cyst
0022-5347/93/1505-1486$03.00/0 THE JOURNAL OF UROLOGY Copyright © 1993 by AMERICAN UROLOGICAL ASSOCIATION, INC.
Vol. 150, 1486-1488, November 1993 Printed in U. S.A.
Case Reports LAPAROSCOPIC MARSUPIALIZATION OF A SIMPLE RENAL CYST MARSHALL L. STOLLER,* PIERCE B . IRBY, III, MAMDOUH OSMAN AND PETER R. CARROLL From the Department of Urology, University of California School of Medicine, San Francisco, California
ABSTRACT
An 8 cm. symptomatic simple renal cyst, recurrent despite previous aspiration and injection of sclerosing agents, was marsupialized using laparoscopic techniques. No complications occurred and followup by ultrasonography confirmed resolution of the lesion. We suggest that laparoscopic management of symptomatic simple renal cysts may be an attractive alternative to open surgical techniques. KEY WORDS: kidney, cysts, peritoneoscopy
Most simple renal cysts are asymptomatic and are commonly discovered by ultrasonography or computerized tomography (CT) of the abdomen for other diagnostic purposes. Rarely, treatment may be necessary in the case associated with pain or secondary obstruction of the collecting system. 1 • 2 Treatment options for symptomatic simple renal cysts include open sur gery, 3 endoscopic marsupialization or excision, 2 • -5 and simple percutaneous needle aspiration of the cyst with or without injection of a sclerosing agent.7 A new approach for definitive surgical therapy of symptomatic large exophytic simple renal cysts using laparoscopic techniques is presented. 4
CASE REPORT
A 67-year-old Filipino man complained of left flank pain for several years with a documented large simple renal cyst in the left lower pole. The cyst was aspirated twice and cephalothin was injected as a sclerosing agent while the patient was in the Phillipines during the previous year. The second treatment followed the initial attempt by 7 months. The aspirated fluid was clear, yellow and sterile, and cytological examinations were negative. Although temporary relief of symptoms occurred after each aspiration, flank pain recurred on both occasions within 3 months with corresponding reaccumulation of cyst fluid. The patient presented to our university because of pain. A 10 mm. caliceal calculus was found in the left lower pole. The stone was thought to be the source of the pain and was treated with extracorporeal shock wave lithotripsy (ESWLt) but the pain persisted. Followup studies showed excellent radiographic evidence of fragmentation and the patient passed approxi mately 60% of the particles. An excretory urogram demon strated nondilated upper tracts with bilateral prompt excretion. Renal ultrasonography revealed an 8 cm. renal cyst in the left lower pole with adjacent stone debris and a 3 cm. left parapelvic cyst (fig. 1). CT of the abdomen confirmed the location of the large cyst at the lateral anterior inferior pole of the left kidney (fig. 2). Informed consent was obtained and laparoscopy was per formed. With the patient under general anesthesia, a ureteral occlusion balloon was passed endoscopically to the level of the left ureteropelvic junction to aid in identification of the ureter Accepted for publication April 2, 1993. * Requests for reprints: Department of Urology, U-518, University of California, San Francisco, California 94143-0738. t Dornier Medical Systems, Inc., Marietta, Georgia.
FIG. 1. Renal ultrasonography of left kidney shows large simple renal cyst (open arrow) at lower pole, 10 mm. calculus adjacent at superior margin of cyst (arrow) and 3 cm. parapelvic cyst (arrowhead).
during laparoscopy. The patient was then placed in the supine position with the left flank elevated 30 degrees by a vacuum positioning cushion. Pneumoperitoneum was introduced and laparoscopic ports were established. A 10 mm. sheath was positioned in the inferior crease of the umbilicus. A 12 mm. port was placed midway between the umbilicus and symphysis pubis, and 3 ports were positioned along the anterior axillary line (10 mm. upper, 5 mm. mid and 5 mm. lower). The mass effect of the cyst displacing the colon on the left side made the location of the lesion readily identifiable during laparoscopy. The colon on the left side was reflected medially by incising the peritoneal attachments laterally. The classic "blue dome" character of the cyst was then apparent. The cyst was punctured anteriorly and aspirated free of approximately 200 ml. of brown turbid fluid. Cytological examination of the fluid revealed no abnormalities. The exophytic wall of the cyst was excised down to normal renal parenchyma using scissors and electrocautery. The inner surface of the cyst was carefully inspected and found to be smooth. The epithelium was thoroughly cauterized with an argon beam coagulator. Blood loss was estimated at 30 ml. A No. 15F suction drain was introduced laterally through a 5
1486
LAPAROSCOPIC MARSUPIAL!ZATION OF S IMPLE RENAL CYST
FIG. 2. CT of abdomen shows large exophytic left simple renal cyst at anterior aspect of lower pole.
FIG. 3. Followup ultrasonogram shows resolution of simple cyst in lower pole after laparoscopic marsupialization. Residual calculus frag ments after ESWL are apparent (arrow) and parapelvic cyst is still present (arrowhead) .
mm. port placed under laparoscopic guidance. The colon on the left side was replaced to its peritoneal reflection laterally with surgical clips. The total time in the operating room was 4 hours. The postoperative period was uneventful and drainage was minimaL The patient was discharged from the hospital and returned to work the following day. The final pathological report confirmed a benign cyst wall. Followup renal ultraso nography 4 months later showed resolution of the cyst (fig. 3). The patient was completely asymptomatic. DISCUS SION
The majority of simple renal cysts are asymptomatic and need no surgical intervention because modern imaging tech niques can usually exclude the presence of cancer with a high degree of accuracy. 8 • However, varying degrees of obstruction of the caliceal system or renal pelvis, segmental ischemia and hypertension have been reported in kidneys affected by a simple renal cyst. 1 0- 12 Despite these effects, therapy for a simple renal cyst is not generally accepted or pursued, except in clear cases of related symptoms or impaired renal function. 1 · 2 Exploration and nephrectomy, decortication or marsupiali zation once constituted the treatment of choice for sympto9
1487
matic renal cysts. 3 Because of the high morbidity of open surgery, these procedures have been replaced by other minimally invasive techniques. Percutaneous puncture and as piration of a simple renal cyst under ultrasonographic or CT guidance are usually performed initially. Reaccumulation of fluid after aspiration is common; however, in 1 series more than 50% of the patients had no change in the cyst or even had an increase in cyst size at followup examination. 13 Recurrence after aspiration was unrelated to cyst size or patient age. 13 Rates of major and minor complications of aspiration with sclerosis have been reported to occur in up to 1.4 % and 10% of the cases, respectively. 1 4 More recent studies of use of aspiration with sclerosis have reported more than 95% success with 95% ethanol. 1 5 Various other agents also have been instilled percu taneously in an attempt to sclerose renal cysts, including so dium morrhuate, lipidol, phenol, tetracycline and bismuth phosphate. Rates of cyst recurrence ranged between 17% and 44 % . 7 • 16- 18 Two cases of severe inflammatory reaction after lipidol injection have been reported that resulted in eventual nephrectomy. 18 Rarely, the technique of aspiration and sclerosis has been associated with significant complications such as ureteropelvic junction obstruction. 19 We are unaware of pre vious reports of the use of cephalothin as a sclerosing agent. Percutaneous cyst resection or marsupialization has been used with apparent success. 2· 4-6 Direct inspection of the cyst and availability of tissue for biopsy are advantages of percuta neous resection. Potential risks are similar to other percuta neous renal procedures, including hemorrhage, extravasation and technical errors. Furthermore, as the resection proceeds the cyst cavity collapses, often impairing visibility and increas ing the risk of complications. 6 Direct puncture into a cyst rather than using a transparenchymal route, as for stone disease, may reduce the chance of significant hemorrhage. Recently, the flexible ureteronephroscope has been used in marsupialization of peripelvic cysts. 2 · 20 Although this procedure is minimally invasive and requires only a short hospital stay, its application is limited principally to intrarenal peripelvic rather than exophytic cysts. Long-term followup is not yet available to compare the results of endoscopic with those of open marsupialization. Laparoscopic surgery has been limited mainly to gynecolog ical practice until the last few years. With the recent advent of laparoscopic cholecystectomy, this technique has become well accepted in general surgical practice. In urology laparoscopy has been used in evaluating cryptorchid testes, renal explora tion and biopsy, varicocele ligation and pelvic lymphadenec tomy. 21 -23 Clayman et al reported the first case of laparoscopic nephrectorny using a device for morcellation to evacuate 190 gm. of renal tissue via an 11 mm. port. 24 More recently, the same authors reported laparoscopic ureterolysis and intraperi tonealization of the ureter in a patient with retroperitoneal fibrosis. 25 Further applications of urological laparoscopy are inevitable. The compelling advantages of laparoscopic procedures in clude minimal postoperative pain and scarring, decreased blood loss due to excellent visualization of vessels during dissection and meticulous hemostasis, short hospital stay and more rapid patient recovery compared with open surgical alternatives.25 In addition, it enables biopsy of the base of the cyst to rule out a malignancy. However, laparoscopic surgery requires longer op erating time than open procedures. Furthermore, as a new surgical technique, long-term results and complication rates have not been documented. Based on our case, we suggest that laparoscopic marsupialization of a renal cyst is an effective method that is associated with minimal blood loss and rapid patient recovery. Additional experience with this technique seems warranted because it may be an attractive alternative to open surgical techniques for the management of recurrent symptomatic simple renal cysts that are recalcitrant to aspira tion and sclerosis.
1488
LAPAROSCOPIC MARSUPIALIZATION OF SIMPLE RENAL CYST REFERENCES
1. Richter, S., Karbel, G., Bechar, L. and Pikielny, S.: Should a benign renal cyst be treated? Brit. J. Urol., 5 5 : 457, 1983. 2. Kavoussi, L. R., Clayman, R. V., Mikkelsen, D. J. and Meretyk, S.: Ureteronephroscopic marsupialization of obstructing peripelvic renal cyst. J. Urol., 1 4 6 : 411, 1991. 3. Amar, A. D. and Das, S.: Surgical management of benign renal cysts causing obstruction of renal pelvis. Urology, 1 4 : 429, 1984. 4. Hulbert, J. C., Hunter, D., Young, A. T. and Castaneda-Zuniga, W.: Percutaneous intrarenal marsupialization of a perirenal cys tic collection-endocystolysis. J. Urol., 1 3 9 : 1039, 1988. 5. Martinez-Sagarra Ocej a , J.: Serous renal cysts: translumbar per cutaneous resection. Arch. Esp. Urol., 44: 523, 1991. 6. Hubner, W., Pfab, R., Porpaczy, P. and Hartung, R.: Renal cysts: percutaneous resection with standard urologic instruments. J. Endourol., 4: 61, 1990. 7. Holmberg, G. and Hietala, S. 0.: Treatment of simple renal cysts by percutaneous puncture and instillation of bismuth-phosphate. Scand. J. Urol. Nephrol., 2 3 : 207, 1989. 8. Bosniak, M. A.: The current radiological approach to renal cysts. Radiology, 1 5 8 : 1, 1986. 9. Aronson, S., Frazier, H. A., Baluch, J. D., Hartman, D. S. and Christenson, P. J.: Cystic renal masses: usefulness of the Bosniak classification. Urol. Rad., 1 3 : 83, 1991. 10. Barloon, T. J. and Vince, S. W.: Caliceal obstruction owing to a large parapelvic cyst: excretory urography, ultrasound and com puterized tomography findings. J. Urol., 1 3 7 : 270, 1987. 11. Evans, A. T. and Coughlin, J. P.: Urinary obstruction due to renal cysts. J. Urol., 1 0 3 : 2 77, 1970. 12. Rockson, S. G., Stone, R. A. and Gunnells, J. C., Jr.: Solitary renal cyst with segmental ischemia and hypertension. J. Urol., 1 12 : 550, 1974. 13. Wahlqvist, L. and Grumstedt, B.: Therapeutic effect of percuta-
14. 15. 16. 17. 18. 19.
20. 21. 22. 23. 24.
25.
neous puncture of simple renal cyst. Follow-up investigation of 50 patients. Acta Chir. Scand., 1 32 : 340, 1966. Lang, E. K.: Renal cyst puncture and aspiration: a survey of complications. AJR, 1 2 8 : 723, 1977. Bean, W. J.: Renal cysts: treatment with alcohol. Radiology, 1 3 8 : 329, 1981. Hobarth, K. and Kratzik, C.: Percutaneous sclerosing of kidney cysts with alcohol. Urologe A, 3 0 : 189, 1991. Zou, S. Z., Fan, W. N. and He, X. H.: Percutaneous ultrasound guided injection of sodium morrhuate in the treatment of cystic renal masses. Brit. J. Urol. , 6 8 : 441, 1991. Beyer, D. and Fiedler, V.: Is renal cyst puncture an available diagnostic procedure for differentiation of avascular, space-oc cupying renal lesions? Urologe A, 16: 339, 1977. Camacho, M. F., Bondhus, M . J., Carrion, H. M., Lockhart, J. L. and Politano, V. A.: Ureteropelvic junction obstruction resulting from percutaneous cyst puncture and intracystic isophendylate injection: an unusual complication. J. Urol., 124: 713, 1980. Kavoussi, L., Clayman, R. V. and Basler, J.: Flexible, actively deflectable fiberoptic ureteronephroscopy. J. Urol., 1 4 2 : 949, 1989. Manson, A. L., Terhune, D., Jordan, G., Auman, J. R., Peterson, N. and MacDonald, G.: Preoperative laparoscopic localization of the nonpalpable testis. J. Urol., 1 34: 919, 1985. Squadrito, J. F., Jr. and Coletta, A. V.: Laparoscopic renal explo ration and biopsy. J. Laparoendosc. Surg., 1: 235, 199 1 . Griffith, D. P., Schuessler, W. W. and Vanacaille, T. H.: Laparos copic lymphadenectomy: a low morbidity alternative for staging pelvic malignancies. J. Endourol., suppl., 4: S84, 1990. Clayman, R. V., Kavoussi, L. R., Soper, N. J., Dierks, S. M., Meretyk, S., Darcy, M. D., Roemer, F. D., Pingleton, E. D., Thomson, P. G. and Long, S. R.: Laparoscopic nephrectomy: initial case report. J. Urol., 1 46 : 278, 1991. Kavoussi, L. R., Clayman, R. V., Brunt, L. M. and Soper, N. J.: Laparoscopic ureterolysis. J. Urol. , 147: 426, 1992.
Vol. 150, 1486-1488, November 1993 Printed in U. S.A.
Case Reports LAPAROSCOPIC MARSUPIALIZATION OF A SIMPLE RENAL CYST MARSHALL L. STOLLER,* PIERCE B . IRBY, III, MAMDOUH OSMAN AND PETER R. CARROLL From the Department of Urology, University of California School of Medicine, San Francisco, California
ABSTRACT
An 8 cm. symptomatic simple renal cyst, recurrent despite previous aspiration and injection of sclerosing agents, was marsupialized using laparoscopic techniques. No complications occurred and followup by ultrasonography confirmed resolution of the lesion. We suggest that laparoscopic management of symptomatic simple renal cysts may be an attractive alternative to open surgical techniques. KEY WORDS: kidney, cysts, peritoneoscopy
Most simple renal cysts are asymptomatic and are commonly discovered by ultrasonography or computerized tomography (CT) of the abdomen for other diagnostic purposes. Rarely, treatment may be necessary in the case associated with pain or secondary obstruction of the collecting system. 1 • 2 Treatment options for symptomatic simple renal cysts include open sur gery, 3 endoscopic marsupialization or excision, 2 • -5 and simple percutaneous needle aspiration of the cyst with or without injection of a sclerosing agent.7 A new approach for definitive surgical therapy of symptomatic large exophytic simple renal cysts using laparoscopic techniques is presented. 4
CASE REPORT
A 67-year-old Filipino man complained of left flank pain for several years with a documented large simple renal cyst in the left lower pole. The cyst was aspirated twice and cephalothin was injected as a sclerosing agent while the patient was in the Phillipines during the previous year. The second treatment followed the initial attempt by 7 months. The aspirated fluid was clear, yellow and sterile, and cytological examinations were negative. Although temporary relief of symptoms occurred after each aspiration, flank pain recurred on both occasions within 3 months with corresponding reaccumulation of cyst fluid. The patient presented to our university because of pain. A 10 mm. caliceal calculus was found in the left lower pole. The stone was thought to be the source of the pain and was treated with extracorporeal shock wave lithotripsy (ESWLt) but the pain persisted. Followup studies showed excellent radiographic evidence of fragmentation and the patient passed approxi mately 60% of the particles. An excretory urogram demon strated nondilated upper tracts with bilateral prompt excretion. Renal ultrasonography revealed an 8 cm. renal cyst in the left lower pole with adjacent stone debris and a 3 cm. left parapelvic cyst (fig. 1). CT of the abdomen confirmed the location of the large cyst at the lateral anterior inferior pole of the left kidney (fig. 2). Informed consent was obtained and laparoscopy was per formed. With the patient under general anesthesia, a ureteral occlusion balloon was passed endoscopically to the level of the left ureteropelvic junction to aid in identification of the ureter Accepted for publication April 2, 1993. * Requests for reprints: Department of Urology, U-518, University of California, San Francisco, California 94143-0738. t Dornier Medical Systems, Inc., Marietta, Georgia.
FIG. 1. Renal ultrasonography of left kidney shows large simple renal cyst (open arrow) at lower pole, 10 mm. calculus adjacent at superior margin of cyst (arrow) and 3 cm. parapelvic cyst (arrowhead).
during laparoscopy. The patient was then placed in the supine position with the left flank elevated 30 degrees by a vacuum positioning cushion. Pneumoperitoneum was introduced and laparoscopic ports were established. A 10 mm. sheath was positioned in the inferior crease of the umbilicus. A 12 mm. port was placed midway between the umbilicus and symphysis pubis, and 3 ports were positioned along the anterior axillary line (10 mm. upper, 5 mm. mid and 5 mm. lower). The mass effect of the cyst displacing the colon on the left side made the location of the lesion readily identifiable during laparoscopy. The colon on the left side was reflected medially by incising the peritoneal attachments laterally. The classic "blue dome" character of the cyst was then apparent. The cyst was punctured anteriorly and aspirated free of approximately 200 ml. of brown turbid fluid. Cytological examination of the fluid revealed no abnormalities. The exophytic wall of the cyst was excised down to normal renal parenchyma using scissors and electrocautery. The inner surface of the cyst was carefully inspected and found to be smooth. The epithelium was thoroughly cauterized with an argon beam coagulator. Blood loss was estimated at 30 ml. A No. 15F suction drain was introduced laterally through a 5
1486
LAPAROSCOPIC MARSUPIAL!ZATION OF S IMPLE RENAL CYST
FIG. 2. CT of abdomen shows large exophytic left simple renal cyst at anterior aspect of lower pole.
FIG. 3. Followup ultrasonogram shows resolution of simple cyst in lower pole after laparoscopic marsupialization. Residual calculus frag ments after ESWL are apparent (arrow) and parapelvic cyst is still present (arrowhead) .
mm. port placed under laparoscopic guidance. The colon on the left side was replaced to its peritoneal reflection laterally with surgical clips. The total time in the operating room was 4 hours. The postoperative period was uneventful and drainage was minimaL The patient was discharged from the hospital and returned to work the following day. The final pathological report confirmed a benign cyst wall. Followup renal ultraso nography 4 months later showed resolution of the cyst (fig. 3). The patient was completely asymptomatic. DISCUS SION
The majority of simple renal cysts are asymptomatic and need no surgical intervention because modern imaging tech niques can usually exclude the presence of cancer with a high degree of accuracy. 8 • However, varying degrees of obstruction of the caliceal system or renal pelvis, segmental ischemia and hypertension have been reported in kidneys affected by a simple renal cyst. 1 0- 12 Despite these effects, therapy for a simple renal cyst is not generally accepted or pursued, except in clear cases of related symptoms or impaired renal function. 1 · 2 Exploration and nephrectomy, decortication or marsupiali zation once constituted the treatment of choice for sympto9
1487
matic renal cysts. 3 Because of the high morbidity of open surgery, these procedures have been replaced by other minimally invasive techniques. Percutaneous puncture and as piration of a simple renal cyst under ultrasonographic or CT guidance are usually performed initially. Reaccumulation of fluid after aspiration is common; however, in 1 series more than 50% of the patients had no change in the cyst or even had an increase in cyst size at followup examination. 13 Recurrence after aspiration was unrelated to cyst size or patient age. 13 Rates of major and minor complications of aspiration with sclerosis have been reported to occur in up to 1.4 % and 10% of the cases, respectively. 1 4 More recent studies of use of aspiration with sclerosis have reported more than 95% success with 95% ethanol. 1 5 Various other agents also have been instilled percu taneously in an attempt to sclerose renal cysts, including so dium morrhuate, lipidol, phenol, tetracycline and bismuth phosphate. Rates of cyst recurrence ranged between 17% and 44 % . 7 • 16- 18 Two cases of severe inflammatory reaction after lipidol injection have been reported that resulted in eventual nephrectomy. 18 Rarely, the technique of aspiration and sclerosis has been associated with significant complications such as ureteropelvic junction obstruction. 19 We are unaware of pre vious reports of the use of cephalothin as a sclerosing agent. Percutaneous cyst resection or marsupialization has been used with apparent success. 2· 4-6 Direct inspection of the cyst and availability of tissue for biopsy are advantages of percuta neous resection. Potential risks are similar to other percuta neous renal procedures, including hemorrhage, extravasation and technical errors. Furthermore, as the resection proceeds the cyst cavity collapses, often impairing visibility and increas ing the risk of complications. 6 Direct puncture into a cyst rather than using a transparenchymal route, as for stone disease, may reduce the chance of significant hemorrhage. Recently, the flexible ureteronephroscope has been used in marsupialization of peripelvic cysts. 2 · 20 Although this procedure is minimally invasive and requires only a short hospital stay, its application is limited principally to intrarenal peripelvic rather than exophytic cysts. Long-term followup is not yet available to compare the results of endoscopic with those of open marsupialization. Laparoscopic surgery has been limited mainly to gynecolog ical practice until the last few years. With the recent advent of laparoscopic cholecystectomy, this technique has become well accepted in general surgical practice. In urology laparoscopy has been used in evaluating cryptorchid testes, renal explora tion and biopsy, varicocele ligation and pelvic lymphadenec tomy. 21 -23 Clayman et al reported the first case of laparoscopic nephrectorny using a device for morcellation to evacuate 190 gm. of renal tissue via an 11 mm. port. 24 More recently, the same authors reported laparoscopic ureterolysis and intraperi tonealization of the ureter in a patient with retroperitoneal fibrosis. 25 Further applications of urological laparoscopy are inevitable. The compelling advantages of laparoscopic procedures in clude minimal postoperative pain and scarring, decreased blood loss due to excellent visualization of vessels during dissection and meticulous hemostasis, short hospital stay and more rapid patient recovery compared with open surgical alternatives.25 In addition, it enables biopsy of the base of the cyst to rule out a malignancy. However, laparoscopic surgery requires longer op erating time than open procedures. Furthermore, as a new surgical technique, long-term results and complication rates have not been documented. Based on our case, we suggest that laparoscopic marsupialization of a renal cyst is an effective method that is associated with minimal blood loss and rapid patient recovery. Additional experience with this technique seems warranted because it may be an attractive alternative to open surgical techniques for the management of recurrent symptomatic simple renal cysts that are recalcitrant to aspira tion and sclerosis.
1488
LAPAROSCOPIC MARSUPIALIZATION OF SIMPLE RENAL CYST REFERENCES
1. Richter, S., Karbel, G., Bechar, L. and Pikielny, S.: Should a benign renal cyst be treated? Brit. J. Urol., 5 5 : 457, 1983. 2. Kavoussi, L. R., Clayman, R. V., Mikkelsen, D. J. and Meretyk, S.: Ureteronephroscopic marsupialization of obstructing peripelvic renal cyst. J. Urol., 1 4 6 : 411, 1991. 3. Amar, A. D. and Das, S.: Surgical management of benign renal cysts causing obstruction of renal pelvis. Urology, 1 4 : 429, 1984. 4. Hulbert, J. C., Hunter, D., Young, A. T. and Castaneda-Zuniga, W.: Percutaneous intrarenal marsupialization of a perirenal cys tic collection-endocystolysis. J. Urol., 1 3 9 : 1039, 1988. 5. Martinez-Sagarra Ocej a , J.: Serous renal cysts: translumbar per cutaneous resection. Arch. Esp. Urol., 44: 523, 1991. 6. Hubner, W., Pfab, R., Porpaczy, P. and Hartung, R.: Renal cysts: percutaneous resection with standard urologic instruments. J. Endourol., 4: 61, 1990. 7. Holmberg, G. and Hietala, S. 0.: Treatment of simple renal cysts by percutaneous puncture and instillation of bismuth-phosphate. Scand. J. Urol. Nephrol., 2 3 : 207, 1989. 8. Bosniak, M. A.: The current radiological approach to renal cysts. Radiology, 1 5 8 : 1, 1986. 9. Aronson, S., Frazier, H. A., Baluch, J. D., Hartman, D. S. and Christenson, P. J.: Cystic renal masses: usefulness of the Bosniak classification. Urol. Rad., 1 3 : 83, 1991. 10. Barloon, T. J. and Vince, S. W.: Caliceal obstruction owing to a large parapelvic cyst: excretory urography, ultrasound and com puterized tomography findings. J. Urol., 1 3 7 : 270, 1987. 11. Evans, A. T. and Coughlin, J. P.: Urinary obstruction due to renal cysts. J. Urol., 1 0 3 : 2 77, 1970. 12. Rockson, S. G., Stone, R. A. and Gunnells, J. C., Jr.: Solitary renal cyst with segmental ischemia and hypertension. J. Urol., 1 12 : 550, 1974. 13. Wahlqvist, L. and Grumstedt, B.: Therapeutic effect of percuta-
14. 15. 16. 17. 18. 19.
20. 21. 22. 23. 24.
25.
neous puncture of simple renal cyst. Follow-up investigation of 50 patients. Acta Chir. Scand., 1 32 : 340, 1966. Lang, E. K.: Renal cyst puncture and aspiration: a survey of complications. AJR, 1 2 8 : 723, 1977. Bean, W. J.: Renal cysts: treatment with alcohol. Radiology, 1 3 8 : 329, 1981. Hobarth, K. and Kratzik, C.: Percutaneous sclerosing of kidney cysts with alcohol. Urologe A, 3 0 : 189, 1991. Zou, S. Z., Fan, W. N. and He, X. H.: Percutaneous ultrasound guided injection of sodium morrhuate in the treatment of cystic renal masses. Brit. J. Urol. , 6 8 : 441, 1991. Beyer, D. and Fiedler, V.: Is renal cyst puncture an available diagnostic procedure for differentiation of avascular, space-oc cupying renal lesions? Urologe A, 16: 339, 1977. Camacho, M. F., Bondhus, M . J., Carrion, H. M., Lockhart, J. L. and Politano, V. A.: Ureteropelvic junction obstruction resulting from percutaneous cyst puncture and intracystic isophendylate injection: an unusual complication. J. Urol., 124: 713, 1980. Kavoussi, L., Clayman, R. V. and Basler, J.: Flexible, actively deflectable fiberoptic ureteronephroscopy. J. Urol., 1 4 2 : 949, 1989. Manson, A. L., Terhune, D., Jordan, G., Auman, J. R., Peterson, N. and MacDonald, G.: Preoperative laparoscopic localization of the nonpalpable testis. J. Urol., 1 34: 919, 1985. Squadrito, J. F., Jr. and Coletta, A. V.: Laparoscopic renal explo ration and biopsy. J. Laparoendosc. Surg., 1: 235, 199 1 . Griffith, D. P., Schuessler, W. W. and Vanacaille, T. H.: Laparos copic lymphadenectomy: a low morbidity alternative for staging pelvic malignancies. J. Endourol., suppl., 4: S84, 1990. Clayman, R. V., Kavoussi, L. R., Soper, N. J., Dierks, S. M., Meretyk, S., Darcy, M. D., Roemer, F. D., Pingleton, E. D., Thomson, P. G. and Long, S. R.: Laparoscopic nephrectomy: initial case report. J. Urol., 1 46 : 278, 1991. Kavoussi, L. R., Clayman, R. V., Brunt, L. M. and Soper, N. J.: Laparoscopic ureterolysis. J. Urol. , 147: 426, 1992.