- Email: [email protected]
Robot Assisted Laparoscopic Partial Nephrectomy: Initial Experience
Oncology: Adrenal/Renal/Upper Tract/Bladder Robot Assisted Laparoscopic Partial Nephrectomy: Initial Experience Robert P. Caruso, Courtney K. Phillips, Eric Kau, Samir S. Taneja* and Michael D. Stifelman†,‡ From the Department of Urology, New York University School of Medicine, New York, New York
Purpose: Advances in laparoscopy have made laparoscopic partial nephrectomy a technically feasible procedure but it remains challenging to even experienced laparoscopists. We hypothesized that robotic assisted laparoscopic partial nephrectomy may make this procedure more efficacious than the standard laparoscopic approach. Materials and Methods: Ten patients with a mean age of 58 years and mean tumor size of 2.0 cm underwent robotic assisted laparoscopic partial nephrectomy and another 10 with a mean age of 61 years and mean tumor size of 2.18 cm underwent laparoscopic partial nephrectomy, as performed by a team of 2 surgeons (MS and ST) between May 2002 and January 2004. Demographic data, intraoperative parameters and postoperative data were compared between the 2 groups. Results: There were no significant differences in patient demographics between the 2 groups. Intraoperative data and postoperative outcomes were statistically similar. In the 10 patients who underwent robotic assisted laparoscopic partial nephrectomy there were 2 intraoperative complications. There was 1 conversion in the laparoscopic partial nephrectomy group. Conclusions: Robotic assisted laparoscopic partial nephrectomy is a safe and feasible procedure in patients with small exophytic masses. The robotic approach to laparoscopic partial nephrectomy does not offer any clinical advantage over conventional laparoscopic nephrectomy. Key Words: kidney, nephrectomy, laparoscopy, robotics
We have previously reported our technique and our RALPN series6 but had not yet examined whether this approach was superior to standard laparoscopy. Given these purported advantages, we hypothesized that this approach may facilitate excision, hemostasis and reconstruction, thereby decreasing operative time, blood loss and ischemic time. Before this study we performed more than 50 standard LPNs and multiple urological procedures with the da Vinci® system, including dismembered pyeloplasty, cyst marsupialization and radical nephrectomy.
dvances in laparoscopic surgery have made LPN a technically feasible procedure. Although patients with exophytic renal masses less than 4 cm are ideal candidates for LPN, select patients with larger, more endophytic tumors may be considered for LPN, especially in the setting of suboptimal renal function, a solitary kidney, bilateral tumors or a genetic predisposition to renal tumors.1,2 The largest obstacle to the widespread use of LPN is the technical difficulty involved. Tumor excision, hemostasis and reconstruction of collecting system defects involve a significant amount of intracorporeal suturing, which is timeconsuming for even experienced laparoscopists. In cases that require renal artery clamping ischemic time becomes an even more significant factor. The da Vinci® surgical system, which was Food and Drug Administration approved in 2000, has been used to perform radical prostatectomy, pyeloplasty, simple and donor nephrectomy, and recipient renal hilar anastomosis.3–5 Advantages of the robot are 3-dimensional stereoscopic optics, computer elimination of tremor, 6 degrees of instrument wrist motion and scaled down movement. Theoretically these differences allow more precision in a smaller operative field and they are particularly useful in procedures that involve extensive suturing.
A
MATERIALS AND METHODS Ten consecutive patients underwent RALPN from May 2002 to October 2003, as performed by the same team of 2 surgeons (MS and ST). Trocars were placed in a standard configuration with adjustments made for tumor location. The technique has been described previously.6 Briefly, standard laparoscopy was used to mobilize the kidney, isolate the hilum and expose the tumor capsule. The robot was then secured. The primary surgeon unscrubbed and sat at the robotic console, while the side surgeon performed the necessary tasks at the table. The finger of a cut glove was used to place and store fibrin soaked Gelfoam® and Surgicel® bolsters in the abdomen until they were needed after tumor excision. A laparoscopic ultrasound probe was used to define the deep and lateral tumor margins. The renal capsule was scored, leaving a 1 cm margin around the tumor. Mannitol (12.5 gm) was administered intravenously before clamping. No attempt was made to cool the kidney and the hilar vessels were occluded by the side surgeon with a laparoscopic bulldog clamp. The console surgeon then excised the tumor with the robotic endoscopic
Submitted for publication August 17, 2005. * Financial interest and/or other relationship with GTX, Bayer and AstraZeneca. † Correspondence: Department of Urology, New York University School of Medicine, 150 East 32nd St., Suite 2, New York, New York 10016 (telephone: 646-825-6325; FAX: 646-825-6397; e-mail: Michael. [email protected]). ‡ Financial interest and/or other relationship with Ethicon, Oncura, Cryolife and Intuitive.
0022-5347/06/1761-0036/0 THE JOURNAL OF UROLOGY® Copyright © 2006 by AMERICAN UROLOGICAL ASSOCIATION
36
Vol. 176, 36-39, July 2006 Printed in U.S.A. DOI:10.1016/S0022-5347(06)00499-X
ROBOT ASSISTED LAPAROSCOPIC PARTIAL NEPHRECTOMY shears and a Maryland bipolar device, while the side surgeon provided exposure and suction. Excision depth depended on visual cues and frozen sections from the resection base. After excision the tumor was placed beside the kidney or on top of the liver for later retrieval. The right and left robotic arms were then exchanged for needle drivers. The side surgeon passed in 2-zero polyglactin sutures on CT-1 needles, which were used to ligate large perforating vessels and close collecting system defects. The base of the defect was cauterized with a TissueLink™ hook electrode and packed with a fibrin soaked Gelfoam® plug. The sterile side surgeon then activated the fibrin glue with thrombin injected percutaneously through a spinal needle. Surgicel® bolsters were placed in the defect and 2 or more 2-zero polyglactin mattress sutures on CT-1 needles were used to reapproximate the renal capsule. The kidney was placed back on stretch and the vascular bulldog clamp was removed. After hemostasis was confirmed the specimen was retrieved. A Jackson-Pratt drain was placed, all trocars were removed and the incisions were closed. In all patients demographic, historical, intraoperative, postoperative and pathological data were recorded. These data were compared to data on 10 consecutive patients who underwent standard LPN without the robot. These surgeries were also performed by the same team of 2 surgeons from March 2003 to January 2004 using the same steps outlined. The Mann-Whitney U test for numerical variables and the chi-square test for nominal variables were performed to determine whether there were any statistically significant differences between the 2 groups in the mentioned parameters. RESULTS Ten patients underwent RALPN and another 10 underwent LPN. The table lists preoperative characteristics in the 2 groups. There were no significant differences between the 2 groups in patient age, American Society of Anesthesiologists class, body mass index, mean lesion size, location, and preoperative hematocrit and creatinine. The table also lists intraoperative and postoperative data. There were no statistically significant differences in operative time, ischemic time, EBL, hospital stay, change in creatinine and change in hematocrit between the 2 groups.
Preoperative characteristics, intraoperative parameters and postoperative outcomes in patients with RALPN and LPN
No. pts Av age Av American Society of Anesthesiologists class Av body mass index Av lesion size (cm) No. tumor pole position: Lower Mid Upper Av preop creatinine (mg/dl) Av preop hematocrit (ml/dl) Av operative time (mins) Av ischemic time (mins) Av EBL (cc) Av discharge creatinine (mg/dl) Av discharge hematocrit (ml/dl) Av stay (days)
RALPN
LPN
10 58 2.1 28.1 1.95
10 61 2.6 28.5 2.18
4 5 3 1 3 4 0.97 1.07 43.2 41.0 279 253 26.4 29.3 240 200 1.05 1.06 36.3 34.2 2.60 2.65
p Value 0.84 0.19 0.95 0.46 0.46
0.54 0.12 0.11 0.24 0.90 0.90 0.16 0.89
37
There were no cases of postoperative renal insufficiency and no patients in either group required blood transfusion. There were 2 intraoperative complications in the RALPN group. In 1 case bleeding after removal of the vascular clamps necessitated conversion to a hand assisted approach. EBL was 300 cc and postoperative hematocrit was 31.7 ml/dl. In the other case back bleeding and poor visualization required conversion to an open procedure. EBL was 500 cc and postoperative hematocrit was 34 ml/dl. In the LPN group there was 1 conversion to open surgery for excessive back bleeding. Hospital stay in these 3 patients was not negatively impacted (2, 3 and 2 days, respectively). Only 1 patient in the entire series received blood transfusion. In this woman anemia did not result from LPN (EBL was 50 cc) but from transabdominal hysterectomy, which was performed after our procedure. Postoperative complications were urinary retention in 1 patient who underwent RALPN, prolonging hospital stay by 1 day, and colonic pseudo-obstruction in 1 patient with LPN who had a history of 3 idiopathic episodes of partial bowel obstruction. This patient required treatment with neostigmine, colonoscopy and a multi-agent bowel regimen, prolonging hospital stay to 6 days. Pathological examination of the excised lesions and frozen sections of the deep margins were performed in all cases. In the RALPN group 5 patients had clear cell RCC, 3 had chromophobe RCC, 1 had leiomyomatous angiomyolipoma and 1 had oncocytoma for an 80% malignancy rate. All margins were negative. In the LPN group 4 patients had clear cell RCC, 3 had oncocytoma, 2 had leiomyomatous angiomyolipoma, 1 had papillary RCC and 1 had inflammatory renal dysplasia for a 50% malignancy rate. Additionally, 1 oncocytoma in the LPN group had a negative margin intraoperatively but was found to have a positive margin on formal pathological review of the entire specimen. DISCUSSION In the last 20 years 2 techniques have revolutionized the treatment of renal masses, including laparoscopic radical nephrectomy and NSS. Laparoscopic radical nephrectomy was first described in 1991 by Clayman et al.7 Although this first procedure required almost 7 hours, significant improvements in experience, technique and instrumentation have dramatically decreased operative time. Even in its earliest incarnations laparoscopic nephrectomy resulted in significantly decreased hospital stay, recovery time and pain medicine requirements.8 These improved outcomes have remained durable.9 Today the surgery can be performed in 2 hours with as few as 3 port sites,9,10 markedly decreasing blood loss and complications rates. Laparoscopic radical nephrectomy is now the standard of care for all except a few advanced or extremely large renal masses. After the advent of laparoscopic radical nephrectomy the oncological efficacy of NSS was demonstrated.7 In 1890 NSS was first described11 but the morbidity of the procedure limited its practical application. Since then, advances in renal hypothermia, imaging and hemostasis have permitted its widespread application and several series have demonstrated disease specific survival and recurrence rates similar to those of radical nephrectomy.12,13 Most contemporary series have demonstrated disease specific survival rates of greater than 90% with recurrence rates of less than 5%.14 –17
38
ROBOT ASSISTED LAPAROSCOPIC PARTIAL NEPHRECTOMY
In 1993 Winfield et al first described combining the advantages of laparoscopy with NSS to perform LPN.18 Although it was originally used only for small exophytic tumors, advances in laparoscopic technique and technology have enabled urologists to treat larger, more centrally located tumors laparoscopically. However, LPN remains a technically difficult procedure due to the intracorporeal suturing and dissection involved. Adding to complexity is pressure to minimize ischemic time since many if not most lesions require hilar clamping. This has made LPN inaccessible to most urologists. The advantages of the da Vinci® surgical system are its ability to facilitate difficult laparoscopic techniques such as intracorporeal suturing. Six degrees of freedom at the distal end of instruments, 3-dimensional stereoscopic vision, movement scale down and decreased tremor allow sutures to be placed on perforating arteries using techniques more similar to those of open surgery than standard laparoscopy. During excision the Maryland bipolar device and endoscopic shears can be rotated with greater degrees of freedom, aiding in tumor dissection. Additionally, the system provides greater surgeon comfort, an often overlooked but critical component of LPN especially in the learning phase, when operative time can surpass 4 hours. Potential disadvantages of the da Vinci® system are cost, training, equipment malfunction and setup time. There is also a lack of tactile feedback or haptics in the current generation of robotic systems, making the surgeon reliant only on visual cues for haptic feedback. Additionally, while LPN can safely be performed with a primary surgeon and an assistant, RALPN is a procedure that must be done with 2 experienced surgeons. Although the surgeon at the robotic console is often considered the primary surgeon, the one who remains scrubbed at the table provides critical exposure, clamps the hilum, exchanges instruments and aids in hemostasis. Since the primary surgeon is away from the table, emergent conversions must be handled immediately by the side surgeon while the primary surgeon rescrubs. Although a formal cost analysis was not done, the robot and its instruments are overwhelmingly more expensive then standard laparoscopic instruments. Thus, without any evidence of shorter operative time or hospital stay we believe that it is safe to conclude that RALPN is more costly than LPN. When comparing our data to the only other RALPN series published to date,19 similar outcomes and observations were noted. Average operative time was around 4 hours. EBL and ischemic time were similar (240 vs 170 cc and 26 vs 22 minutes, respectively). The 2 series demonstrated a short mean hospital stay (2.6 and 4.3 days, respectively). In our series we noted 1 open conversion secondary to dislodgment of the vascular clamp, whereas no conversions were required in the series of Gettman et al.19 Those investigators used a different technique for hilar occlusion than ours in the majority of patients. They used an arterial occlusion balloon placed by interventional radiology before the procedure. The potential advantage of this technique is that it allows intraparenchymal cooling. Whether the added cost and potential morbidity of this technique are justified to achieve parenchymal cooling will only be answered by well controlled, prospective series evaluating renal function outcomes. The final observation made by the 2 teams is the need for an experienced laparoscopic side surgeon to provide technical assistance using conventional laparoscopic instruments.
To our knowledge this is the first published series comparing LPN and RALPN performed by the same team of surgeons. Although the da Vinci® robot has been shown to be advantageous in many procedures, our small series of partial nephrectomy failed to show that this surgical system decreased blood loss, hospital stay, ischemic time, transfusion rates, operative time or complications rates. In fact, because the senior surgeon was seated away from the table at the console and was unscrubbed during RALPN, we found that the threshold for conversion was lower, especially when complications were noted during ischemic time. However, these results should be interpreted with some trepidation. Sample size was small and the 2 groups were not randomized. The decision to perform LPN or RALPN was made by the physician and patient without any differences in selection criteria between the 2 groups. Despite this there may be an element of selection bias. Additionally, temporally RALPN was as a whole performed earlier in our accrual period. A larger, randomized study would be needed to definitively conclude whether there was a significant difference between the 2 techniques. Finally, we did not examine whether RALPN or LPN skills were more easily acquired by novice laparoscopists. We suspect that the robot may make RALPN a more easily learned procedure than LPN and it may provide a more tangible benefit for complex lesions requiring more extensive reconstruction. CONCLUSIONS We report our RALPN series. RALPN is a safe and feasible procedure. Compared to LPN use of the da Vinci® robotic surgical system for partial nephrectomy did not result in significantly decreased ischemic time, operative time, blood loss or risk of conversion. Because of this, the robot is not routinely used for LPN at our institution. A larger, randomized series could help determine whether the robotic system results in other advantages that were not detected by this small series of small exophytic lesions.
Abbreviations and Acronyms EBL LPN NSS RALPN RCC
⫽ ⫽ ⫽ ⫽ ⫽
estimated blood loss laparoscopic partial nephrectomy nephron sparing surgery robot assisted LPN renal cell carcinoma
REFERENCES 1.
Clayman, R. V., Kavoussi, L. R., Soper, N. J., Dierks, S. M., Meretyk, S., Darcy, M. D. et al: Laparoscopic nephrectomy. New Engl J Med, 324: 1370, 1991 2. Fergany, A. F., Hafez, K. S. and Novick, A. C.: Long-term results of nephron sparing surgery for localized renal cell carcinoma: 10-year followup. J Urol, 163: 442, 2000 3. Abbou, C. C., Hoznek, A., Salomon, L., Olsson, L. E., Lobontiu, A., Saint, F. et al: Laparoscopic radical prostatectomy with a remote controlled robot. J Urol, 165: 1964, 2001 4. Sung, G. T., Gill, I. S. and Hsu, T. H.: Robotic-assisted laparoscopic pyeloplasty: a pilot study. Urology, 53: 1099, 1999 5. Guillonneau, B., Jayet, C., Tewari, A. and Vallancien, G.: Robot assisted laparoscopic nephrectomy. J Urol, 166: 200, 2001
ROBOT ASSISTED LAPAROSCOPIC PARTIAL NEPHRECTOMY 6.
7.
8.
9.
10.
11. 12. 13.
Phillips, C. K., Taneja, S. S. and Stifelman, M. D.: Robotassisted laparoscopic partial nephrectomy: the NYU technique. J Endourol, 19: 441, 2005 Clayman, R. V., Kavoussi, L. R., Soper, N. J., Dierks, S. M., Meretyk, S., Darcy, M. D. et al: Laparoscopic nephrectomy: initial case report. J Urol, 146: 278, 1991 Kavoussi, L. R., Kerbl, K., Capelouto, C. C., McDougall, E. M. and Clayman, R. V.: Laparoscopic nephrectomy for renal neoplasms. Urology, 42: 603, 1993 Rozenberg, H., Bruyere, F., Abdelkader, T., Husset, A. and Hamoura, H.: Transperitoneal laparoscopic nephrectomy. Prog Urol, 9: 1034, 1999 Desgrandchamps, F., Gossot, D., Jabbour, M. E., Meria, P., Teillac, P. and Le Duc, A.: A 3 trocar technique for transperitoneal laparoscopic nephrectomy. J Urol, 161: 1530, 1999 Czerny, H. E.: Ueber nierenextirpation bietr. Klin Khir, 6: 485, 1890 Gohji, K., Kamidon, O. S. and Yamanaka, N.: Renal cell carcinoma in a solitary kidney. Br J Urol, 66: 248, 1990 Thrasher, J. B., Robertson, J. E. and Paulson, D. F.: Expanding indications for conservative renal surgery in renal cell carcinoma. Urology, 43: 160, 1994
14.
15.
16.
17.
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19.
39
Hafez, K. S., Fergany, A. F. and Novick, A. C.: Nephron sparing surgery for localized renal cell carcinoma: impact of tumor size on patient survival, tumor recurrence and TNM staging. J Urol, 162: 1930, 1999 Lee, C. T., Katz, J., Shi, W., Thaler, H. T., Reuter, V. E. and Russo, P.: Surgical management of renal tumors 4 cm or less in a contemporary cohort. J Urol, 163: 730, 2000 Barbalias, G. A., Liatsikos, E. N., Tsintavis, A. and Nikiforidis, G.: Adenocarcinoma of the kidney: nephron sparing surgical approach versus radical nephrectomy. J Surg Oncol, 72: 156, 1999 Belldegrun, A., Tsui, K. H., deKernion, J. B. and Smith, R. B.: Efficacy of nephron-sparing surgery for renal cell carcinoma: analysis based on the new 1997 tumor-node-metastasis staging system. J Clin Oncol, 17: 28, 1999 Winfield, H. N., Donovan, J. F., Godet, A. S. and Clayman, R. V.: Laparoscopic partial nephrectomy: initial case report for benign disease. J Endourol, 7: 521, 1993 Gettman, M. T., Blute, M. L., Chow, G. K., Neurer, R., Bartsch, G. and Peschel, R.: Robotic-assisted laparoscopic partial nephrectomy: technique and initial clinical experience with da Vinci Robotic System. Urology, 64: 914, 2004
Purpose: Advances in laparoscopy have made laparoscopic partial nephrectomy a technically feasible procedure but it remains challenging to even experienced laparoscopists. We hypothesized that robotic assisted laparoscopic partial nephrectomy may make this procedure more efficacious than the standard laparoscopic approach. Materials and Methods: Ten patients with a mean age of 58 years and mean tumor size of 2.0 cm underwent robotic assisted laparoscopic partial nephrectomy and another 10 with a mean age of 61 years and mean tumor size of 2.18 cm underwent laparoscopic partial nephrectomy, as performed by a team of 2 surgeons (MS and ST) between May 2002 and January 2004. Demographic data, intraoperative parameters and postoperative data were compared between the 2 groups. Results: There were no significant differences in patient demographics between the 2 groups. Intraoperative data and postoperative outcomes were statistically similar. In the 10 patients who underwent robotic assisted laparoscopic partial nephrectomy there were 2 intraoperative complications. There was 1 conversion in the laparoscopic partial nephrectomy group. Conclusions: Robotic assisted laparoscopic partial nephrectomy is a safe and feasible procedure in patients with small exophytic masses. The robotic approach to laparoscopic partial nephrectomy does not offer any clinical advantage over conventional laparoscopic nephrectomy. Key Words: kidney, nephrectomy, laparoscopy, robotics
We have previously reported our technique and our RALPN series6 but had not yet examined whether this approach was superior to standard laparoscopy. Given these purported advantages, we hypothesized that this approach may facilitate excision, hemostasis and reconstruction, thereby decreasing operative time, blood loss and ischemic time. Before this study we performed more than 50 standard LPNs and multiple urological procedures with the da Vinci® system, including dismembered pyeloplasty, cyst marsupialization and radical nephrectomy.
dvances in laparoscopic surgery have made LPN a technically feasible procedure. Although patients with exophytic renal masses less than 4 cm are ideal candidates for LPN, select patients with larger, more endophytic tumors may be considered for LPN, especially in the setting of suboptimal renal function, a solitary kidney, bilateral tumors or a genetic predisposition to renal tumors.1,2 The largest obstacle to the widespread use of LPN is the technical difficulty involved. Tumor excision, hemostasis and reconstruction of collecting system defects involve a significant amount of intracorporeal suturing, which is timeconsuming for even experienced laparoscopists. In cases that require renal artery clamping ischemic time becomes an even more significant factor. The da Vinci® surgical system, which was Food and Drug Administration approved in 2000, has been used to perform radical prostatectomy, pyeloplasty, simple and donor nephrectomy, and recipient renal hilar anastomosis.3–5 Advantages of the robot are 3-dimensional stereoscopic optics, computer elimination of tremor, 6 degrees of instrument wrist motion and scaled down movement. Theoretically these differences allow more precision in a smaller operative field and they are particularly useful in procedures that involve extensive suturing.
A
MATERIALS AND METHODS Ten consecutive patients underwent RALPN from May 2002 to October 2003, as performed by the same team of 2 surgeons (MS and ST). Trocars were placed in a standard configuration with adjustments made for tumor location. The technique has been described previously.6 Briefly, standard laparoscopy was used to mobilize the kidney, isolate the hilum and expose the tumor capsule. The robot was then secured. The primary surgeon unscrubbed and sat at the robotic console, while the side surgeon performed the necessary tasks at the table. The finger of a cut glove was used to place and store fibrin soaked Gelfoam® and Surgicel® bolsters in the abdomen until they were needed after tumor excision. A laparoscopic ultrasound probe was used to define the deep and lateral tumor margins. The renal capsule was scored, leaving a 1 cm margin around the tumor. Mannitol (12.5 gm) was administered intravenously before clamping. No attempt was made to cool the kidney and the hilar vessels were occluded by the side surgeon with a laparoscopic bulldog clamp. The console surgeon then excised the tumor with the robotic endoscopic
Submitted for publication August 17, 2005. * Financial interest and/or other relationship with GTX, Bayer and AstraZeneca. † Correspondence: Department of Urology, New York University School of Medicine, 150 East 32nd St., Suite 2, New York, New York 10016 (telephone: 646-825-6325; FAX: 646-825-6397; e-mail: Michael. [email protected]). ‡ Financial interest and/or other relationship with Ethicon, Oncura, Cryolife and Intuitive.
0022-5347/06/1761-0036/0 THE JOURNAL OF UROLOGY® Copyright © 2006 by AMERICAN UROLOGICAL ASSOCIATION
36
Vol. 176, 36-39, July 2006 Printed in U.S.A. DOI:10.1016/S0022-5347(06)00499-X
ROBOT ASSISTED LAPAROSCOPIC PARTIAL NEPHRECTOMY shears and a Maryland bipolar device, while the side surgeon provided exposure and suction. Excision depth depended on visual cues and frozen sections from the resection base. After excision the tumor was placed beside the kidney or on top of the liver for later retrieval. The right and left robotic arms were then exchanged for needle drivers. The side surgeon passed in 2-zero polyglactin sutures on CT-1 needles, which were used to ligate large perforating vessels and close collecting system defects. The base of the defect was cauterized with a TissueLink™ hook electrode and packed with a fibrin soaked Gelfoam® plug. The sterile side surgeon then activated the fibrin glue with thrombin injected percutaneously through a spinal needle. Surgicel® bolsters were placed in the defect and 2 or more 2-zero polyglactin mattress sutures on CT-1 needles were used to reapproximate the renal capsule. The kidney was placed back on stretch and the vascular bulldog clamp was removed. After hemostasis was confirmed the specimen was retrieved. A Jackson-Pratt drain was placed, all trocars were removed and the incisions were closed. In all patients demographic, historical, intraoperative, postoperative and pathological data were recorded. These data were compared to data on 10 consecutive patients who underwent standard LPN without the robot. These surgeries were also performed by the same team of 2 surgeons from March 2003 to January 2004 using the same steps outlined. The Mann-Whitney U test for numerical variables and the chi-square test for nominal variables were performed to determine whether there were any statistically significant differences between the 2 groups in the mentioned parameters. RESULTS Ten patients underwent RALPN and another 10 underwent LPN. The table lists preoperative characteristics in the 2 groups. There were no significant differences between the 2 groups in patient age, American Society of Anesthesiologists class, body mass index, mean lesion size, location, and preoperative hematocrit and creatinine. The table also lists intraoperative and postoperative data. There were no statistically significant differences in operative time, ischemic time, EBL, hospital stay, change in creatinine and change in hematocrit between the 2 groups.
Preoperative characteristics, intraoperative parameters and postoperative outcomes in patients with RALPN and LPN
No. pts Av age Av American Society of Anesthesiologists class Av body mass index Av lesion size (cm) No. tumor pole position: Lower Mid Upper Av preop creatinine (mg/dl) Av preop hematocrit (ml/dl) Av operative time (mins) Av ischemic time (mins) Av EBL (cc) Av discharge creatinine (mg/dl) Av discharge hematocrit (ml/dl) Av stay (days)
RALPN
LPN
10 58 2.1 28.1 1.95
10 61 2.6 28.5 2.18
4 5 3 1 3 4 0.97 1.07 43.2 41.0 279 253 26.4 29.3 240 200 1.05 1.06 36.3 34.2 2.60 2.65
p Value 0.84 0.19 0.95 0.46 0.46
0.54 0.12 0.11 0.24 0.90 0.90 0.16 0.89
37
There were no cases of postoperative renal insufficiency and no patients in either group required blood transfusion. There were 2 intraoperative complications in the RALPN group. In 1 case bleeding after removal of the vascular clamps necessitated conversion to a hand assisted approach. EBL was 300 cc and postoperative hematocrit was 31.7 ml/dl. In the other case back bleeding and poor visualization required conversion to an open procedure. EBL was 500 cc and postoperative hematocrit was 34 ml/dl. In the LPN group there was 1 conversion to open surgery for excessive back bleeding. Hospital stay in these 3 patients was not negatively impacted (2, 3 and 2 days, respectively). Only 1 patient in the entire series received blood transfusion. In this woman anemia did not result from LPN (EBL was 50 cc) but from transabdominal hysterectomy, which was performed after our procedure. Postoperative complications were urinary retention in 1 patient who underwent RALPN, prolonging hospital stay by 1 day, and colonic pseudo-obstruction in 1 patient with LPN who had a history of 3 idiopathic episodes of partial bowel obstruction. This patient required treatment with neostigmine, colonoscopy and a multi-agent bowel regimen, prolonging hospital stay to 6 days. Pathological examination of the excised lesions and frozen sections of the deep margins were performed in all cases. In the RALPN group 5 patients had clear cell RCC, 3 had chromophobe RCC, 1 had leiomyomatous angiomyolipoma and 1 had oncocytoma for an 80% malignancy rate. All margins were negative. In the LPN group 4 patients had clear cell RCC, 3 had oncocytoma, 2 had leiomyomatous angiomyolipoma, 1 had papillary RCC and 1 had inflammatory renal dysplasia for a 50% malignancy rate. Additionally, 1 oncocytoma in the LPN group had a negative margin intraoperatively but was found to have a positive margin on formal pathological review of the entire specimen. DISCUSSION In the last 20 years 2 techniques have revolutionized the treatment of renal masses, including laparoscopic radical nephrectomy and NSS. Laparoscopic radical nephrectomy was first described in 1991 by Clayman et al.7 Although this first procedure required almost 7 hours, significant improvements in experience, technique and instrumentation have dramatically decreased operative time. Even in its earliest incarnations laparoscopic nephrectomy resulted in significantly decreased hospital stay, recovery time and pain medicine requirements.8 These improved outcomes have remained durable.9 Today the surgery can be performed in 2 hours with as few as 3 port sites,9,10 markedly decreasing blood loss and complications rates. Laparoscopic radical nephrectomy is now the standard of care for all except a few advanced or extremely large renal masses. After the advent of laparoscopic radical nephrectomy the oncological efficacy of NSS was demonstrated.7 In 1890 NSS was first described11 but the morbidity of the procedure limited its practical application. Since then, advances in renal hypothermia, imaging and hemostasis have permitted its widespread application and several series have demonstrated disease specific survival and recurrence rates similar to those of radical nephrectomy.12,13 Most contemporary series have demonstrated disease specific survival rates of greater than 90% with recurrence rates of less than 5%.14 –17
38
ROBOT ASSISTED LAPAROSCOPIC PARTIAL NEPHRECTOMY
In 1993 Winfield et al first described combining the advantages of laparoscopy with NSS to perform LPN.18 Although it was originally used only for small exophytic tumors, advances in laparoscopic technique and technology have enabled urologists to treat larger, more centrally located tumors laparoscopically. However, LPN remains a technically difficult procedure due to the intracorporeal suturing and dissection involved. Adding to complexity is pressure to minimize ischemic time since many if not most lesions require hilar clamping. This has made LPN inaccessible to most urologists. The advantages of the da Vinci® surgical system are its ability to facilitate difficult laparoscopic techniques such as intracorporeal suturing. Six degrees of freedom at the distal end of instruments, 3-dimensional stereoscopic vision, movement scale down and decreased tremor allow sutures to be placed on perforating arteries using techniques more similar to those of open surgery than standard laparoscopy. During excision the Maryland bipolar device and endoscopic shears can be rotated with greater degrees of freedom, aiding in tumor dissection. Additionally, the system provides greater surgeon comfort, an often overlooked but critical component of LPN especially in the learning phase, when operative time can surpass 4 hours. Potential disadvantages of the da Vinci® system are cost, training, equipment malfunction and setup time. There is also a lack of tactile feedback or haptics in the current generation of robotic systems, making the surgeon reliant only on visual cues for haptic feedback. Additionally, while LPN can safely be performed with a primary surgeon and an assistant, RALPN is a procedure that must be done with 2 experienced surgeons. Although the surgeon at the robotic console is often considered the primary surgeon, the one who remains scrubbed at the table provides critical exposure, clamps the hilum, exchanges instruments and aids in hemostasis. Since the primary surgeon is away from the table, emergent conversions must be handled immediately by the side surgeon while the primary surgeon rescrubs. Although a formal cost analysis was not done, the robot and its instruments are overwhelmingly more expensive then standard laparoscopic instruments. Thus, without any evidence of shorter operative time or hospital stay we believe that it is safe to conclude that RALPN is more costly than LPN. When comparing our data to the only other RALPN series published to date,19 similar outcomes and observations were noted. Average operative time was around 4 hours. EBL and ischemic time were similar (240 vs 170 cc and 26 vs 22 minutes, respectively). The 2 series demonstrated a short mean hospital stay (2.6 and 4.3 days, respectively). In our series we noted 1 open conversion secondary to dislodgment of the vascular clamp, whereas no conversions were required in the series of Gettman et al.19 Those investigators used a different technique for hilar occlusion than ours in the majority of patients. They used an arterial occlusion balloon placed by interventional radiology before the procedure. The potential advantage of this technique is that it allows intraparenchymal cooling. Whether the added cost and potential morbidity of this technique are justified to achieve parenchymal cooling will only be answered by well controlled, prospective series evaluating renal function outcomes. The final observation made by the 2 teams is the need for an experienced laparoscopic side surgeon to provide technical assistance using conventional laparoscopic instruments.
To our knowledge this is the first published series comparing LPN and RALPN performed by the same team of surgeons. Although the da Vinci® robot has been shown to be advantageous in many procedures, our small series of partial nephrectomy failed to show that this surgical system decreased blood loss, hospital stay, ischemic time, transfusion rates, operative time or complications rates. In fact, because the senior surgeon was seated away from the table at the console and was unscrubbed during RALPN, we found that the threshold for conversion was lower, especially when complications were noted during ischemic time. However, these results should be interpreted with some trepidation. Sample size was small and the 2 groups were not randomized. The decision to perform LPN or RALPN was made by the physician and patient without any differences in selection criteria between the 2 groups. Despite this there may be an element of selection bias. Additionally, temporally RALPN was as a whole performed earlier in our accrual period. A larger, randomized study would be needed to definitively conclude whether there was a significant difference between the 2 techniques. Finally, we did not examine whether RALPN or LPN skills were more easily acquired by novice laparoscopists. We suspect that the robot may make RALPN a more easily learned procedure than LPN and it may provide a more tangible benefit for complex lesions requiring more extensive reconstruction. CONCLUSIONS We report our RALPN series. RALPN is a safe and feasible procedure. Compared to LPN use of the da Vinci® robotic surgical system for partial nephrectomy did not result in significantly decreased ischemic time, operative time, blood loss or risk of conversion. Because of this, the robot is not routinely used for LPN at our institution. A larger, randomized series could help determine whether the robotic system results in other advantages that were not detected by this small series of small exophytic lesions.
Abbreviations and Acronyms EBL LPN NSS RALPN RCC
⫽ ⫽ ⫽ ⫽ ⫽
estimated blood loss laparoscopic partial nephrectomy nephron sparing surgery robot assisted LPN renal cell carcinoma
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