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RETROPERITONEAL LAPAROSCOPY FOR RENAL BIOPSY IN CHILDREN
0022-5347/00/1643-1080/0 THE JOURNAL OF UROLOGY® Copyright © 2000 by AMERICAN UROLOGICAL ASSOCIATION, INC.®
Vol. 164, 1080 –1083, September 2000 Printed in U.S.A.
RETROPERITONEAL LAPAROSCOPY FOR RENAL BIOPSY IN CHILDREN PAOLO CAIONE, SALVATORE MICALI, STEFANO RINALDI, NICOLA CAPOZZA, ALBERTO LAIS, ENNIO MATARAZZO, GIOVANNI MATURO AND FRANCESCO MICALI From the Division of Pediatric Urology, Department of Surgery and Division of Nephrology and Urology “Bambino Gesu`” Children Hospital, and Department of Urology, “Tor Vergata” University, Rome, Italy
ABSTRACT
Purpose: We report our experience with the retroperitoneal laparoscopic approach for treating pediatric patients and when the percutaneous needle approach is not possible due to uncontrolled hypertension, bleeding disorders, anti-clotting medications and anatomical abnormalities. Materials and Methods: Retroperitoneal laparoscopic renal biopsy was performed in 20 patients 2 to 18 years old (mean age 9.7) during a 16-month period. At the same time 53 percutaneous needle biopsies and 1 open biopsy were performed. The child is in a flank position, and 2 trocars are used via a direct vision approach. The first trocar is 12 mm. in diameter and positioned on the posterior axillary line, and the second trocar is 5 mm. in diameter and is entered 4 cm. anteriorly. Gentle dissection is done to free the lower pole of the selected kidney, biopsy forceps are used to grasp the specimen under direct vision and the biopsy site is fulgurated using bipolar electrocautery. Results: Biopsy was performed successfully in all cases except 1, which was converted to an open procedure. Mean operative time was 40 minutes, blood loss was minimal and mean hospital stay was 1.2 days postoperatively. No pain medication was required postoperatively, and all patients returned to their usual activities within 3 to 5 days. A minor intraoperative complication, which was a peritoneal tear with no postoperative sequelae, occurred in 1 case. Conclusions: The retroperitoneal laparoscopic technique is simple and safe, and does not require extensive laparoscopic experience. We believe that this approach is reliable, and has less morbidity and several advantages compared to open surgery. It should be selected as the first choice for treating pediatric patients when percutaneous needle renal biopsy is contraindicated. KEY WORDS: laparoscopy, peritoneum, biopsy
Percutaneous renal biopsy has nephrological indications for the assessment of pediatric patients with renal failure, significant proteinuria, hematuria or the idiopathic nephrotic syndrome resistant to steroids.1 Throughout time the risks of percutaneous needle biopsy of the kidney have decreased with the use of reliable, minimally invasive imaging techniques and development of adequate protocols for the monitoring of patients postoperatively.2 The development of small caliber, biopsy needles has also contributed to the increased safety and comfort of this technique. With improvements in efficacy and reliability several conditions, including solitary kidney and obesity, that were assumed absolute are now considered relative contraindications of percutaneous biopsy.3 However, there are some patients in whom a percutaneous approach may be considered a major risk, including children less than 7 years old, and those with uncontrolled hypertension, bleeding disorders and anti-clotting medications.1–3 In these cases renal biopsy under direct vision is a reliable option. Renal biopsy under direct vision can be performed with an open incision or laparoscopically via a retroperitoneal approach.4 This method has been reported as advantageous in treating adults because the kidney is positively identified for a macroscopic diagnosis, and biopsy and hemostasis are better achieved under direct view.4 –7 We describe our personal technique and experience in a series of pediatric patients who underwent retroperitoneal laparoscopic renal biopsy. MATERIALS AND METHODS
biopsy under direct vision. After informed consent was obtained all patients underwent a nephrological and urological evaluation, including renal ultrasound, blood pressure and coagulation test and were believed to be unsuitable candidates for percutaneous needle renal biopsy (see table). Laparoscopic renal biopsy was performed in 11 boys and 9 girls. Mean age was 9.2 years (range 2 to 18). Preoperative diagnosis included the nephrotic syndrome in 7, acute renal failure in 2, macrohematuria and proteinuria in 5, the Henoch-Sho¨nlein syndrome in 3 and systemic lupus erythematosus in 3. Proteinuria was 0.58 to 7 gm. daily, body weight was 14 to 78 kg. (mean 40.0) and average serum creatinine was 0.97 mg. (range 0.5 to 2.24, normal 1 mg./100 ml.). The left kidney was chosen for biopsy in all patients. A nephrologist was present in the operating room during the procedures. During the same time period, the nephrological staff performed 53 percutaneous needle biopsies and we performed 1 open surgery biopsy due to a lack of parental consent to laparoscopic surgery. Thus, a total of 74 biopsies were performed. Overall mean patient age was 10.3 years. With the patient under general anesthesia a transurethral Foley catheter and nasogastric tube are positioned. The patient is then placed in the full flank position and secured to the operating table. A 2 port technique is used via a retroperitoneal route, which includes a 12 mm. laparoscopic port placed between the iliac crest and the 12th rib in the posterior axillary line, and a 5 mm. port inserted at the same level on the anterior axillary line (fig. 1). In all children the first trocar is positioned under direct vision using the Visiport*. This device allows the surgeon to incise and advance the
Between January 1998 and May 1999, 20 children were referred by the nephrological staff to our division for renal 1080
* Auto Suture, US Surgical Corp., Norwalk, Connecticut.
RETROPERITONEAL LAPAROSCOPIC RENAL BIOPSY
1081
Indication for pursuing a laparoscopic approach and pathological diagnosis Pt. No. — Age (Yrs). 1 — 10 2—4 3—4 4—7 5—7 6—4 7 — 11 8 — 17 9 — 14 10 — 2 11 — 16 12 — 11 13 — 12 14 — 5 15 — 11 16 — 9 17 — 14 18 — 18 19 — 4 20 — 5
Contraindications for Percutaneous Biopsy Uncontrolled hypertension Uncontrolled hypertension, age Age Age, parents request Age Uncontrolled hypertension, age Uncontrolled hypertension Anti-clotting medications Uncontrolled hypertension Age Uncontrolled hypertension Medullary cystic disease Not cooperative patient Age Parents request Unsuccessful previous needle biopsy Uncontrolled hypertension Parents request Age Age
Pathological Diagnosis Proliferative glomerulonephritis, the Henoch-Sho¨nlein syndrome Proliferative glomerulonephritis Proliferative glomerulonephritis The Alport syndrome Proliferative glomerulonephritis Thrombotic microangiopathy Proliferative glomerulonephritis Proliferative lupus glomerulonephritis Proliferative lupus glomerulonephritis Proliferative glomerulonephritis, the Henoch-Sho¨nlein syndrome Proliferative glomerulonephritis Medullary cystic disease IgA nephropathy The Alport syndrome The Alport syndrome IgA nephropathy Mesangial proliferative glomerulonephritis IgA nephropathy Focal segmental glomerulonesclerosis The Henoch-Sho¨nlein syndrome
FIG. 2. Pediatric biopsy forceps and jaws FIG. 1. Patient position for retroperitoneal renal biopsy and trocar placement. O, 12 mm. port auto suture at posterior axillary line between 12th rib and iliac crest. X, 5 mm. port (5 to 8 cm. anterior to first port) at anterior axillary line.
RESULTS
ketorolac was administered to all patients postoperatively and none required additional analgesia. The nasogastric tube was removed from all patients immediately and the Foley catheter was removed 1 to 5 hours after laparoscopy. Mean hospital stay was 1.2 days (range 1 to 2) postoperatively and all patients returned to their usual activities within 3 to 5 days. An intraoperative complication occurred in 1 patient when the peritoneum was inadvertently entered. However, no further treatment was necessary, and convalescence was uneventful. There were no postoperative complications related to the biopsy. Open surgery was performed in a 17-year-old female who was taking anti-clotting medication and was obese (body weight 78 kg.). Procedure conversion was due to bleeding and poor visualization of the laparoscopic field. The 53 percutaneous needle biopsies were performed successfully in 46 patients, whereas an insufficient or inappropriate renal parenchymal specimen was obtained in 6 biopsies (11%). Gross hematuria was present in 3 patients (5.5%) and perirenal hematoma in 1. Mean hospital stay was 1.4 days, which was not statistically significant different from the laparoscopy group.
Retroperitoneal biopsy was performed successfully in 19 cases and 1 was converted to open surgery. An adequate amount of renal tissue was obtained for pathological examination. Diagnoses based on light and electron microscopy and immunohistochemistry are listed in the table. No difficulty in achieving hemostasis was encountered and none of the patients had gross hematuria postoperatively. Mean operative time was 40 minutes (range 30 to 120) and the estimated blood loss was minimum. A single dose of
Histological evaluation of renal parenchyma is often necessary in cases of several renal diseases. Pathological diagnosis often provides useful information in determining the prognosis and guiding the treatment.1, 8, 9 Several methods to sample renal tissue are available, including blind and ultrasound image guided percutaneous needle biopsy and open or laparoscopic approaches. Percutaneous needle biopsy is the
cannula through each tissue layer under direct vision until the retroperitoneal space is entered. Insufflation with carbon dioxide at 15 mm. Hg is started, and the laparoscope is then used to dissect bluntly the retroperitoneal space and mobilize the lateral peritoneal sheath from the anterior abdominal wall. The 5 mm. port is also inserted under direct vision. Finally, the carbon dioxide insufflation pressure is lowered to a working pressure of 8 to 10 mm. Hg and minimal dissection is required to expose the lower pole of the kidney. Short, 5 mm. laparoscopic cut, biopsy forceps are used to grasp 2 cortical parenchymal specimens (fig. 2). The biopsy site is fulgurated with bipolar electrocautery and a sheath of oxidized cellulose is applied if necessary. The carbon dioxide is slowly evacuated while looking for any bleeding, the 2 trocars are removed under direct vision and the skin is closed with absorbable sutures.
DISCUSSION
1082
RETROPERITONEAL LAPAROSCOPIC RENAL BIOPSY
most common method of sampling renal parenchyma in adults and pediatric patients because it is minimally invasive, and can be performed with local anesthesia and low morbidity.3 Unfortunately as many as 5% to 20% of percutaneous needle biopsies yield an inadequate amount of renal tissue for diagnosis10 and significant complications, such as hemorrhage and even renal loss, have been reported.11–13 Moreover, in children who do not cooperate and are younger than 7 years the percutaneous approach is not possible even with local anesthesia and, thus, general anesthesia is required. In addition to the younger patient age, our experience indicates contraindications of percutaneous renal biopsy, such as uncontrolled hypertension, bleeding disorders, anatomical abnormalities, such as a horseshoe or solitary kidney, and anti-clotting medication.1, 11, 14 Renal biopsy under direct vision is preferred in these patients which the retroperitoneal laparoscopic approach provides. With advances in endoscopic instrumentation and the development of laparoscopic techniques used in pediatric patients the retroperitoneal laparoscopic renal biopsy now provides a minimally invasive alternative to open biopsy. General anesthesia is required as in the open technique but the kidney is better identified and its surface explored with the optic magnification of the laparoscope. This retroperitoneal procedure requires 2 ports. During the procedure a nephrologist is recommended to be present and a preliminary macroscopic examination of the kidney, including site, size, color and bleeding intensity, can be performed. Moreover, more than 1 bioptic specimen can be taken from select areas of the renal surface and hemostasis is achieved under direct vision in a controlled, minimally invasive fashion. Using the retroperitoneal approach as described by Chen et al6 we were able to obtain sufficient renal tissue for the histopathological diagnosis in 19 cases. No bleeding complications or hematuria occurred, and no patient required a blood transfusion. The high success rate and lack of bleeding complications are equal to those reported in a large, open renal biopsy series.10, 15, 16 In contrast, the incidence of bleeding complications was 5% in a recent percutaneous renal biopsy series.13 We believe that our technique potentially reduces the risk of hemorrhage, hematuria and development of secondary arteriovenous fistulas compared with the percutaneous needle approaches because hemostasis is achieved and confirmed under direct vision. Furthermore the cup biopsy forceps that we use take generous and superficial cortical specimens without injuring the deeper, underlying central vessels or collecting system. Squadrito and Coletta first reported laparoscopic renal biopsy in a patient via a transperitoneal approach.17 Gaur popularized the retroperitoneoscopic approach and reported the use of a balloon to develop a retroperitoneal space.18 Gaur et al first reported retroperitoneoscopic renal biopsy in 17 patients.4 The 2 complications in their series were hemostasis through an enlarged incision and postoperative gross hematuria that resolved spontaneously in 2 days. Chen et al also prefer the retroperitoneal over the transperitoneal approach for renal biopsy because of the lower risk of injuries of intraperitoneal or postoperative ileus.6 Based on these experiences, we have modified Gaur’s technique by entering the retroperitoneum using the auto suture device through a standard 1 cm. incision rather than performing a larger cutdown. The 12 mm. auto suture cannula is suitable for younger children but the 5 mm. device can also be used. We quickly develop the retroperitoneum space with blunt and delicate maneuvers, using the laparoscope rather than the balloon. The peritoneal sheath is thin in children and easy to tear
from the posterior abdominal wall and anterior aspect of the kidney as the retroperitoneal space is smaller than that in adults. In small children we recommend the use of short pediatric instruments, such as dolphin forceps, scissors and biopsy forceps. Some additional modifications are useful when the technique is applied to children. As the auto suture device is introduced, the initial insufflation pressure is kept at 15 mm. Hg and is then turned down 8 to 10 mm. Hg. When the second trocar is introduced we realize that higher initial insufflation pressure is more effective for the blunt laparoscope dissection, and its insertion is easier and safer. However, high pressure can underestimate bleeding, and a lower pressure is recommended during the procedure to reduce the possible risk of hypercapnia. At the end of the procedure, the pressure is gradually lowered, and the biopsy site is carefully controlled for bleeding before removal of the operating trocar. In conclusion retroperitoneal laparoscopic renal biopsy is a safe, reliable and minimally invasive alternative to open renal biopsy when percutaneous needle biopsy is not indicated. Our experience confirms that with a systematic and anatomical approach retroperitoneoscopic renal biopsy can be efficiently performed in pediatric patients older than 1 year. REFERENCES
1. Gault, M. H. and Muehrcke, R. C.: Renal biopsy: current views and controversy. Nephron, 34: 1, 1983 2. Donovan, K. L., Thomas, D. M., Wheeler, D. C. et al: Experience with a new method for percutaneous renal biopsy. Nephrol Dial Transplant, 6: 731, 1991 3. Schow, D. A., Vinson, R. K. and Morrisean, P. M.: Percutaneous renal biopsy of the solitary kidney: a contraindication? J Urol, 147: 1235, 1992 4. Gaur, D. D., Agarwal, D. K., Khochikar, M. V. et al: Laparoscopic renal biopsy via retroperitoneal approach. J Urol, 151: 925, 1994 5. Keizur, J. J., Tashima, M. and Das, S.: Retroperitoneal laparoscopic renal biopsy. Surg Laparosc Endosc, 3: 60, 1993 6. Chen, R. N., Moore, R. G., Micali, S. et al: Retroperitoneoscopic renal biopsy in extremely obese patients. Urology, 50: 195, 1997 7. Gimenez, L. F., Micali, S., Chen, R. N. et al: Laparoscopic renal biopsy. Kidney Int, 54: 525, 1998 8. Morel-Maroger, L.: The value of renal biopsy. Am J Kidney Dis, 1: 244, 1982 9. Manoligod, J. R. and Pirani, C. L.: Renal biopsy in 1985. Semin Nephrol, 5: 237, 1985 10. Nomoto, Y., Tomino, Y., Endoh, M. et al: Modified open renal biopsy: results in 934 patients. Nephron, 45: 224, 1987 11. Diaz-Buxo, J. A. and Donadio, J. V., Jr.: Complications of percutaneous renal biopsy: an analysis of 1,000 consecutive cases. Clin Nephrol, 4: 223, 1975 12. Rosenbaum, R., Hoffsten, P. E., Stanley, R. J. et al: Use of computerized tomography to diagnose complications of percutaneous renal biopsy. Kidney Int, 14: 87, 1978 13. Wickre, C. G. and Golper, T. A.: Complications of percutaneous needle biopsy of the kidney. Am J Nephrol, 2: 173, 1982 14. Healey, D. E., Newman, R. C., Cohen, M. S. et al: Laparoscopically assisted percutaneous renal biopsy. J Urol, 150: 1218, 1993 15. Patil, J., Bailey, G. L. and Mahoney, E. F.: Open renal biopsy in uremic patients. Urology, 3: 293, 1974 16. Bolton, W. K. and Vaughan, E. D.: A comparative study of open surgical and percutaneous renal biopsies. J Urol, 117: 696, 1977 17. Squadrito, J. F., Jr. and Coletta, A. V.: Laparoscopic renal exploration and biopsy. J Laparoendosc Surg, 1: 235, 1991 18. Gaur, D. D.: Laparoscopic operative retroperitoneoscopy: use of a new device. J Urol, 148: 1137, 1992
RETROPERITONEAL LAPAROSCOPIC RENAL BIOPSY
1083
DISCUSSION
Dr. Alaa El-Ghoneimi. Why do you think that your maneuver is more accurate than a needle biopsy? Dr. Paolo Caione. We think that a biopsy or any other renal maneuver under direct view is safer than if you do the procedure percutaneously with no view. Dr. Ck Yeung. What if the lesion is deeper and is not visible from the kidney surface? Doctor Caione. We take a cortical specimen. If the pathologist asks us to obtain a deeper fragment such as medulla, we have to use a needle through the second port. Doctor Yeung. Then you will be in a bind because of the pneumoretroperitoneum. You cannot use ultrasound to find it and you cannot palpate the lesion either. So how are you going to be sure that you are going to biopsy the lesion? Doctor Caione. It is not very easy. We did it only once by just looking at how much you can see the needle inside the kidney.
Vol. 164, 1080 –1083, September 2000 Printed in U.S.A.
RETROPERITONEAL LAPAROSCOPY FOR RENAL BIOPSY IN CHILDREN PAOLO CAIONE, SALVATORE MICALI, STEFANO RINALDI, NICOLA CAPOZZA, ALBERTO LAIS, ENNIO MATARAZZO, GIOVANNI MATURO AND FRANCESCO MICALI From the Division of Pediatric Urology, Department of Surgery and Division of Nephrology and Urology “Bambino Gesu`” Children Hospital, and Department of Urology, “Tor Vergata” University, Rome, Italy
ABSTRACT
Purpose: We report our experience with the retroperitoneal laparoscopic approach for treating pediatric patients and when the percutaneous needle approach is not possible due to uncontrolled hypertension, bleeding disorders, anti-clotting medications and anatomical abnormalities. Materials and Methods: Retroperitoneal laparoscopic renal biopsy was performed in 20 patients 2 to 18 years old (mean age 9.7) during a 16-month period. At the same time 53 percutaneous needle biopsies and 1 open biopsy were performed. The child is in a flank position, and 2 trocars are used via a direct vision approach. The first trocar is 12 mm. in diameter and positioned on the posterior axillary line, and the second trocar is 5 mm. in diameter and is entered 4 cm. anteriorly. Gentle dissection is done to free the lower pole of the selected kidney, biopsy forceps are used to grasp the specimen under direct vision and the biopsy site is fulgurated using bipolar electrocautery. Results: Biopsy was performed successfully in all cases except 1, which was converted to an open procedure. Mean operative time was 40 minutes, blood loss was minimal and mean hospital stay was 1.2 days postoperatively. No pain medication was required postoperatively, and all patients returned to their usual activities within 3 to 5 days. A minor intraoperative complication, which was a peritoneal tear with no postoperative sequelae, occurred in 1 case. Conclusions: The retroperitoneal laparoscopic technique is simple and safe, and does not require extensive laparoscopic experience. We believe that this approach is reliable, and has less morbidity and several advantages compared to open surgery. It should be selected as the first choice for treating pediatric patients when percutaneous needle renal biopsy is contraindicated. KEY WORDS: laparoscopy, peritoneum, biopsy
Percutaneous renal biopsy has nephrological indications for the assessment of pediatric patients with renal failure, significant proteinuria, hematuria or the idiopathic nephrotic syndrome resistant to steroids.1 Throughout time the risks of percutaneous needle biopsy of the kidney have decreased with the use of reliable, minimally invasive imaging techniques and development of adequate protocols for the monitoring of patients postoperatively.2 The development of small caliber, biopsy needles has also contributed to the increased safety and comfort of this technique. With improvements in efficacy and reliability several conditions, including solitary kidney and obesity, that were assumed absolute are now considered relative contraindications of percutaneous biopsy.3 However, there are some patients in whom a percutaneous approach may be considered a major risk, including children less than 7 years old, and those with uncontrolled hypertension, bleeding disorders and anti-clotting medications.1–3 In these cases renal biopsy under direct vision is a reliable option. Renal biopsy under direct vision can be performed with an open incision or laparoscopically via a retroperitoneal approach.4 This method has been reported as advantageous in treating adults because the kidney is positively identified for a macroscopic diagnosis, and biopsy and hemostasis are better achieved under direct view.4 –7 We describe our personal technique and experience in a series of pediatric patients who underwent retroperitoneal laparoscopic renal biopsy. MATERIALS AND METHODS
biopsy under direct vision. After informed consent was obtained all patients underwent a nephrological and urological evaluation, including renal ultrasound, blood pressure and coagulation test and were believed to be unsuitable candidates for percutaneous needle renal biopsy (see table). Laparoscopic renal biopsy was performed in 11 boys and 9 girls. Mean age was 9.2 years (range 2 to 18). Preoperative diagnosis included the nephrotic syndrome in 7, acute renal failure in 2, macrohematuria and proteinuria in 5, the Henoch-Sho¨nlein syndrome in 3 and systemic lupus erythematosus in 3. Proteinuria was 0.58 to 7 gm. daily, body weight was 14 to 78 kg. (mean 40.0) and average serum creatinine was 0.97 mg. (range 0.5 to 2.24, normal 1 mg./100 ml.). The left kidney was chosen for biopsy in all patients. A nephrologist was present in the operating room during the procedures. During the same time period, the nephrological staff performed 53 percutaneous needle biopsies and we performed 1 open surgery biopsy due to a lack of parental consent to laparoscopic surgery. Thus, a total of 74 biopsies were performed. Overall mean patient age was 10.3 years. With the patient under general anesthesia a transurethral Foley catheter and nasogastric tube are positioned. The patient is then placed in the full flank position and secured to the operating table. A 2 port technique is used via a retroperitoneal route, which includes a 12 mm. laparoscopic port placed between the iliac crest and the 12th rib in the posterior axillary line, and a 5 mm. port inserted at the same level on the anterior axillary line (fig. 1). In all children the first trocar is positioned under direct vision using the Visiport*. This device allows the surgeon to incise and advance the
Between January 1998 and May 1999, 20 children were referred by the nephrological staff to our division for renal 1080
* Auto Suture, US Surgical Corp., Norwalk, Connecticut.
RETROPERITONEAL LAPAROSCOPIC RENAL BIOPSY
1081
Indication for pursuing a laparoscopic approach and pathological diagnosis Pt. No. — Age (Yrs). 1 — 10 2—4 3—4 4—7 5—7 6—4 7 — 11 8 — 17 9 — 14 10 — 2 11 — 16 12 — 11 13 — 12 14 — 5 15 — 11 16 — 9 17 — 14 18 — 18 19 — 4 20 — 5
Contraindications for Percutaneous Biopsy Uncontrolled hypertension Uncontrolled hypertension, age Age Age, parents request Age Uncontrolled hypertension, age Uncontrolled hypertension Anti-clotting medications Uncontrolled hypertension Age Uncontrolled hypertension Medullary cystic disease Not cooperative patient Age Parents request Unsuccessful previous needle biopsy Uncontrolled hypertension Parents request Age Age
Pathological Diagnosis Proliferative glomerulonephritis, the Henoch-Sho¨nlein syndrome Proliferative glomerulonephritis Proliferative glomerulonephritis The Alport syndrome Proliferative glomerulonephritis Thrombotic microangiopathy Proliferative glomerulonephritis Proliferative lupus glomerulonephritis Proliferative lupus glomerulonephritis Proliferative glomerulonephritis, the Henoch-Sho¨nlein syndrome Proliferative glomerulonephritis Medullary cystic disease IgA nephropathy The Alport syndrome The Alport syndrome IgA nephropathy Mesangial proliferative glomerulonephritis IgA nephropathy Focal segmental glomerulonesclerosis The Henoch-Sho¨nlein syndrome
FIG. 2. Pediatric biopsy forceps and jaws FIG. 1. Patient position for retroperitoneal renal biopsy and trocar placement. O, 12 mm. port auto suture at posterior axillary line between 12th rib and iliac crest. X, 5 mm. port (5 to 8 cm. anterior to first port) at anterior axillary line.
RESULTS
ketorolac was administered to all patients postoperatively and none required additional analgesia. The nasogastric tube was removed from all patients immediately and the Foley catheter was removed 1 to 5 hours after laparoscopy. Mean hospital stay was 1.2 days (range 1 to 2) postoperatively and all patients returned to their usual activities within 3 to 5 days. An intraoperative complication occurred in 1 patient when the peritoneum was inadvertently entered. However, no further treatment was necessary, and convalescence was uneventful. There were no postoperative complications related to the biopsy. Open surgery was performed in a 17-year-old female who was taking anti-clotting medication and was obese (body weight 78 kg.). Procedure conversion was due to bleeding and poor visualization of the laparoscopic field. The 53 percutaneous needle biopsies were performed successfully in 46 patients, whereas an insufficient or inappropriate renal parenchymal specimen was obtained in 6 biopsies (11%). Gross hematuria was present in 3 patients (5.5%) and perirenal hematoma in 1. Mean hospital stay was 1.4 days, which was not statistically significant different from the laparoscopy group.
Retroperitoneal biopsy was performed successfully in 19 cases and 1 was converted to open surgery. An adequate amount of renal tissue was obtained for pathological examination. Diagnoses based on light and electron microscopy and immunohistochemistry are listed in the table. No difficulty in achieving hemostasis was encountered and none of the patients had gross hematuria postoperatively. Mean operative time was 40 minutes (range 30 to 120) and the estimated blood loss was minimum. A single dose of
Histological evaluation of renal parenchyma is often necessary in cases of several renal diseases. Pathological diagnosis often provides useful information in determining the prognosis and guiding the treatment.1, 8, 9 Several methods to sample renal tissue are available, including blind and ultrasound image guided percutaneous needle biopsy and open or laparoscopic approaches. Percutaneous needle biopsy is the
cannula through each tissue layer under direct vision until the retroperitoneal space is entered. Insufflation with carbon dioxide at 15 mm. Hg is started, and the laparoscope is then used to dissect bluntly the retroperitoneal space and mobilize the lateral peritoneal sheath from the anterior abdominal wall. The 5 mm. port is also inserted under direct vision. Finally, the carbon dioxide insufflation pressure is lowered to a working pressure of 8 to 10 mm. Hg and minimal dissection is required to expose the lower pole of the kidney. Short, 5 mm. laparoscopic cut, biopsy forceps are used to grasp 2 cortical parenchymal specimens (fig. 2). The biopsy site is fulgurated with bipolar electrocautery and a sheath of oxidized cellulose is applied if necessary. The carbon dioxide is slowly evacuated while looking for any bleeding, the 2 trocars are removed under direct vision and the skin is closed with absorbable sutures.
DISCUSSION
1082
RETROPERITONEAL LAPAROSCOPIC RENAL BIOPSY
most common method of sampling renal parenchyma in adults and pediatric patients because it is minimally invasive, and can be performed with local anesthesia and low morbidity.3 Unfortunately as many as 5% to 20% of percutaneous needle biopsies yield an inadequate amount of renal tissue for diagnosis10 and significant complications, such as hemorrhage and even renal loss, have been reported.11–13 Moreover, in children who do not cooperate and are younger than 7 years the percutaneous approach is not possible even with local anesthesia and, thus, general anesthesia is required. In addition to the younger patient age, our experience indicates contraindications of percutaneous renal biopsy, such as uncontrolled hypertension, bleeding disorders, anatomical abnormalities, such as a horseshoe or solitary kidney, and anti-clotting medication.1, 11, 14 Renal biopsy under direct vision is preferred in these patients which the retroperitoneal laparoscopic approach provides. With advances in endoscopic instrumentation and the development of laparoscopic techniques used in pediatric patients the retroperitoneal laparoscopic renal biopsy now provides a minimally invasive alternative to open biopsy. General anesthesia is required as in the open technique but the kidney is better identified and its surface explored with the optic magnification of the laparoscope. This retroperitoneal procedure requires 2 ports. During the procedure a nephrologist is recommended to be present and a preliminary macroscopic examination of the kidney, including site, size, color and bleeding intensity, can be performed. Moreover, more than 1 bioptic specimen can be taken from select areas of the renal surface and hemostasis is achieved under direct vision in a controlled, minimally invasive fashion. Using the retroperitoneal approach as described by Chen et al6 we were able to obtain sufficient renal tissue for the histopathological diagnosis in 19 cases. No bleeding complications or hematuria occurred, and no patient required a blood transfusion. The high success rate and lack of bleeding complications are equal to those reported in a large, open renal biopsy series.10, 15, 16 In contrast, the incidence of bleeding complications was 5% in a recent percutaneous renal biopsy series.13 We believe that our technique potentially reduces the risk of hemorrhage, hematuria and development of secondary arteriovenous fistulas compared with the percutaneous needle approaches because hemostasis is achieved and confirmed under direct vision. Furthermore the cup biopsy forceps that we use take generous and superficial cortical specimens without injuring the deeper, underlying central vessels or collecting system. Squadrito and Coletta first reported laparoscopic renal biopsy in a patient via a transperitoneal approach.17 Gaur popularized the retroperitoneoscopic approach and reported the use of a balloon to develop a retroperitoneal space.18 Gaur et al first reported retroperitoneoscopic renal biopsy in 17 patients.4 The 2 complications in their series were hemostasis through an enlarged incision and postoperative gross hematuria that resolved spontaneously in 2 days. Chen et al also prefer the retroperitoneal over the transperitoneal approach for renal biopsy because of the lower risk of injuries of intraperitoneal or postoperative ileus.6 Based on these experiences, we have modified Gaur’s technique by entering the retroperitoneum using the auto suture device through a standard 1 cm. incision rather than performing a larger cutdown. The 12 mm. auto suture cannula is suitable for younger children but the 5 mm. device can also be used. We quickly develop the retroperitoneum space with blunt and delicate maneuvers, using the laparoscope rather than the balloon. The peritoneal sheath is thin in children and easy to tear
from the posterior abdominal wall and anterior aspect of the kidney as the retroperitoneal space is smaller than that in adults. In small children we recommend the use of short pediatric instruments, such as dolphin forceps, scissors and biopsy forceps. Some additional modifications are useful when the technique is applied to children. As the auto suture device is introduced, the initial insufflation pressure is kept at 15 mm. Hg and is then turned down 8 to 10 mm. Hg. When the second trocar is introduced we realize that higher initial insufflation pressure is more effective for the blunt laparoscope dissection, and its insertion is easier and safer. However, high pressure can underestimate bleeding, and a lower pressure is recommended during the procedure to reduce the possible risk of hypercapnia. At the end of the procedure, the pressure is gradually lowered, and the biopsy site is carefully controlled for bleeding before removal of the operating trocar. In conclusion retroperitoneal laparoscopic renal biopsy is a safe, reliable and minimally invasive alternative to open renal biopsy when percutaneous needle biopsy is not indicated. Our experience confirms that with a systematic and anatomical approach retroperitoneoscopic renal biopsy can be efficiently performed in pediatric patients older than 1 year. REFERENCES
1. Gault, M. H. and Muehrcke, R. C.: Renal biopsy: current views and controversy. Nephron, 34: 1, 1983 2. Donovan, K. L., Thomas, D. M., Wheeler, D. C. et al: Experience with a new method for percutaneous renal biopsy. Nephrol Dial Transplant, 6: 731, 1991 3. Schow, D. A., Vinson, R. K. and Morrisean, P. M.: Percutaneous renal biopsy of the solitary kidney: a contraindication? J Urol, 147: 1235, 1992 4. Gaur, D. D., Agarwal, D. K., Khochikar, M. V. et al: Laparoscopic renal biopsy via retroperitoneal approach. J Urol, 151: 925, 1994 5. Keizur, J. J., Tashima, M. and Das, S.: Retroperitoneal laparoscopic renal biopsy. Surg Laparosc Endosc, 3: 60, 1993 6. Chen, R. N., Moore, R. G., Micali, S. et al: Retroperitoneoscopic renal biopsy in extremely obese patients. Urology, 50: 195, 1997 7. Gimenez, L. F., Micali, S., Chen, R. N. et al: Laparoscopic renal biopsy. Kidney Int, 54: 525, 1998 8. Morel-Maroger, L.: The value of renal biopsy. Am J Kidney Dis, 1: 244, 1982 9. Manoligod, J. R. and Pirani, C. L.: Renal biopsy in 1985. Semin Nephrol, 5: 237, 1985 10. Nomoto, Y., Tomino, Y., Endoh, M. et al: Modified open renal biopsy: results in 934 patients. Nephron, 45: 224, 1987 11. Diaz-Buxo, J. A. and Donadio, J. V., Jr.: Complications of percutaneous renal biopsy: an analysis of 1,000 consecutive cases. Clin Nephrol, 4: 223, 1975 12. Rosenbaum, R., Hoffsten, P. E., Stanley, R. J. et al: Use of computerized tomography to diagnose complications of percutaneous renal biopsy. Kidney Int, 14: 87, 1978 13. Wickre, C. G. and Golper, T. A.: Complications of percutaneous needle biopsy of the kidney. Am J Nephrol, 2: 173, 1982 14. Healey, D. E., Newman, R. C., Cohen, M. S. et al: Laparoscopically assisted percutaneous renal biopsy. J Urol, 150: 1218, 1993 15. Patil, J., Bailey, G. L. and Mahoney, E. F.: Open renal biopsy in uremic patients. Urology, 3: 293, 1974 16. Bolton, W. K. and Vaughan, E. D.: A comparative study of open surgical and percutaneous renal biopsies. J Urol, 117: 696, 1977 17. Squadrito, J. F., Jr. and Coletta, A. V.: Laparoscopic renal exploration and biopsy. J Laparoendosc Surg, 1: 235, 1991 18. Gaur, D. D.: Laparoscopic operative retroperitoneoscopy: use of a new device. J Urol, 148: 1137, 1992
RETROPERITONEAL LAPAROSCOPIC RENAL BIOPSY
1083
DISCUSSION
Dr. Alaa El-Ghoneimi. Why do you think that your maneuver is more accurate than a needle biopsy? Dr. Paolo Caione. We think that a biopsy or any other renal maneuver under direct view is safer than if you do the procedure percutaneously with no view. Dr. Ck Yeung. What if the lesion is deeper and is not visible from the kidney surface? Doctor Caione. We take a cortical specimen. If the pathologist asks us to obtain a deeper fragment such as medulla, we have to use a needle through the second port. Doctor Yeung. Then you will be in a bind because of the pneumoretroperitoneum. You cannot use ultrasound to find it and you cannot palpate the lesion either. So how are you going to be sure that you are going to biopsy the lesion? Doctor Caione. It is not very easy. We did it only once by just looking at how much you can see the needle inside the kidney.