were reduced by the cost of probe. With a median follow-up of 20 months there was no difference in oncological outcome.

Laparoscopy and Robotic LAPAROSCOPIC PARTIAL NEPHRECTOMY VS LAPAROSCOPIC RADIOFREQUENCY ABLATION BENSALAH et al. Evaluation of costs and morbidity associated with laparoscopic radiofrequency ablation and laparoscopic partial nephrectomy for treating small renal tumours Karim Bensalah, Ilia Zeltser, Altug Tuncel, Jeffrey Cadeddu and Yair Lotan Department of Urology, University of Texas South-western Medical Center at Dallas, Dallas, Texas, USA Accepted for publication 6 July 2007 Study Type Economic (no sensitivity analysis) Level of Evidence 4 OBJECTIVE To compare the costs and morbidity of laparoscopic radiofrequency ablation (LRFA) and laparoscopic partial nephrectomy (LPN) for treating small localized renal tumours. PATIENTS AND METHODS We retrospectively analysed the outcomes of 88 patients treated at our institution for a renal tumour either by LPN (50) or LRFA (38) between March 2000 and May 2006. Patients with multiple tumours, combined LRFA and LPN, and those who had other simultaneous surgical procedures were excluded. Clinical variables and outcomes were analysed for each patient. Direct cost data were available for 40 patients treated with LPN and 14 with LRFA. Continuous and categorical variables were compared using an independent t-test and chi-square test, respectively. RESULTS The tumour size was comparable in each group; patients in the LRFA group had more comorbidities (P = 0.01) and a higher overall mortality rate (P = 0.01) but no patient died from cancer. Operative duration, estimated blood loss and length of stay were significantly shorter in the LRFA group but there was no difference in complication rate. LRFA was less costly than LPN ($6103 vs $6808, P = 0.3) but not statistically significantly. The cost savings from the shorter operative duration and length of stay were reduced by the cost of probe. With a median follow-up of 20 months there was no difference in oncological outcome. CONCLUSION Patients undergoing LRFA tend to be older and have more comorbidities than those treated with LPN. The cost is minimally lower for LRFA, secondary to the added cost of the probe. LRFA might be a good alternative treatment in patients at higher risk of surgical complications, but LPN provides good results when done by an experienced surgeon. KEYWORDS kidney cancer, laparoscopic partial nephrectomy, laparoscopic radiofrequency ablation, cost comparison INTRODUCTION The widespread use of cross-sectional imaging has lead to a significant increase in the incidence of RCC; most incidentally discovered RCC masses are small and amenable to nephron-sparing surgery (NSS) [1]. Although randomized trials comparing laparoscopic partial nephrectomy (LPN) to open PN are not available, the excellent 5- year oncological efficacy of LPN was recently reported [2]. However, wide acceptance of LPN outside high-volume centres has been difficult, mainly because of the technical challenges inherent in this technique. Thermoablative technologies were introduced to minimize the morbidity of NSS, particularly in infirm and elderly patients with multiple comorbidities. Cryoablation and radiofrequency ablation (RFA) are the two most commonly used energy sources that can be used percutaneously or laparoscopically. The main limitation of in-situ ablation is that the tumour is not excised and therefore pathological confirmation of complete tumour eradication is lacking. Instead, the adequacy of ablation is confirmed by the absence of enhancement on follow-up imaging. Despite this limitation, several studies have reported the mid-range oncological efficacy of both cryoablation and RFA [3 6]. While percutaneous approaches to RFA are less invasive than laparoscopy, they are not an option for masses adjacent to bowel or the ureter. A patient with a small anterior renal mass who wishes to have a minimally invasive approach to treatment has three options, i.e. observation, laparoscopic ablation and LPN. Despite there being several reports suggesting that observation is a reasonable alternative for those with small renal masses, many patients are unwilling to accept this alternative [7]. LPN and laparoscopic ablation have different risks, costs and potential oncological outcomes. Currently there are no studies comparing the costs and morbidity for laparoscopic RFA (LRFA) and LPN. Thus the aim of the present study was to compare patient variables, morbidities and costs associated with LRFA and LPN. PATIENTS AND METHODS This study was approved by the institutional review board of our institution. We analysed retrospectively 102 patients with small renal masses who were treated with either LPN (56) or LRFA (46) between March 2000 and May 2006 at one of our institution s hospitals. We excluded five patients who had multiple unilateral tumours, five who had LRFA and LPN in the same operation, and four who had 2007 BJU INTERNATIONAL 101, 467 471 doi:10.1111/j.1464-410x.2007.07276.x 467

BENSALAH ET AL. another surgical procedure (one cholecystectomy, one PUJ repair, one ureterolysis and one cyst decortication) during the same operation, giving 88 (50 LPN, 38 LRFA) for final analysis. All patients had contrast-enhanced CT or MRI before surgery. All LPN procedures were done by one surgeon (J.A.C.) and LRFA was done by two different surgeons (J.A.C. and Y.L.). The decision to use one procedure over the other varied; initially, the choice of LPN was primarily offered to patients with exophytic masses, but those with more complex masses were offered LPN as surgical experience accumulated. LRFA was reserved for patients who were deemed poor candidates for LPN, either secondary to comorbidities or tumour location. Lesions were primarily anterior and not amenable to percutaneous approaches. Patient preference also played a role, as we have an active surveillance programme and patients had a preference for one approach or the other. The technique of LRFA was described in detail previously [3,6,8]. Briefly, a transperitoneal approach was used in all cases. After locating the tumour with intraoperative ultrasonography (US), Gerota s fascia was opened and the perinephric fat was reflected off the renal surface to identify the tumour. The tumour was biopsied using toothed laparoscopic biopsy forceps. The location on the abdominal wall allowing the most perpendicular path of the probe to the tumour was then identified. The Starburst XL (RITA Medical Systems, Fremont, CA, USA) probe was inserted through the abdominal wall and the kidney was manipulated so that the probe entered the lesion at a right-angle to the most exophytic point of the tumour. The probe was inserted into the tumour and the tines were deployed to encompass a diameter extending 5 10 mm beyond the measured margin of the tumour. Tine placement was confirmed with laparoscopic US. Once the target temperature of 105 C was reached, tumours of <2 cm in diameter were treated for two cycles of 5 min each, those of 2 3 cm were treated for two cycles of 7 min each, and those >3 cm were treated for two cycles of 8 min each. Occasionally, small lesions ( 1 cm) were treated with a single 3 5 min cycle. For LPN, after inducing general anaesthesia, and using the transperitoneal approach, the renal pedicle was dissected. The tumour was located using laparoscopic US and freed from overlying perirenal fat. The renal pedicle was occluded en bloc with an endoscopic Satinsky clamp, allowing tumour excision under warm ischaemia. The cortical surface of the resection bed was cauterized using the argonbeam coagulator. Bleeding vessels were secured using 2/0 polyglactin sutures. The calyceal system defect was also closed with 2/0 polyglactin sutures; the defect was filled with oxidized cellulose bolsters and Floseal (Baxter Inc, Deerfield, IL, USA). Renorraphy was completed using 0 polyglactin sutures. The renal pedicle was then unclamped and the tumour bed carefully inspected for delayed bleeding. The perirenal fat was closed over a Jackson-Pratt drain. The follow-up of LPN patients included a physical examination, chest radiograph, abdominal CT, and liver function tests at 6 and 12 months and annually thereafter. LRFA patients had a physical examination, chest radiography, liver function tests, and contrast-enhanced CT at 6 weeks, 3 and 6 months, and every 6 months thereafter. Recurrence was defined as any new enhancement or tumour growth after initial imaging showed no lesion enhancement. Patients were deemed to have no evidence of disease if there was no clinical or radiological evidence of recurrence or distant metastasis. For the cost analysis, detailed cost information was available from the hospital billing department for 40 patients who had LPN and 14 treated by LRFA, and included: room and board, laboratory, pharmacy, radiology, operating room, surgical supplies, anaesthesia, and recovery room. We specifically obtained cost and not charge data. Surgical supplies vary with the type of surgery and equipment used. The main determinants included use of routine disposable laparoscopic equipment (e.g. trocars, endocatch bag, clip-appliers) and use of adjunct technologies for haemostasis. Operating room costs depend on procedure time and include hospital costs for anaesthesia equipment and operating room overhead. Radiology costs are based on the use of CT and plain radiographs. For LRFA the cost of the disposable 15 G probe was $1525. The means between groups were compared using an independent t-test and chi-square test for continuous and categorical variables, respectively, with a two-tailed P 0.05 indicating statistical significance. RESULTS The baseline characteristics of the patients are shown in Table 1; patients were older in the LRFA group, although this was not statistically significant (62 vs 56.5 years, P = 0.08) and had more comorbidities (53% had an American Society of Anesthesiology score of 3 in the LRFA group, vs 26% in the LPN group, P = 0.01). The mean tumour size was similar (2.6 vs 2.3 cm). The hospital stay was shorter in the LRFA group (1.5 vs 2.9 days). Histology was obtained in 50 patients in the LPN group and in 36 in the LRFA group. There was no difference in the frequency of malignant tumours (82% vs 80%, respectively), nor was there any statistical difference between the grade distribution in the malignant subsets. With a mean follow-up of 15 months in the LPN and 25 months in the LRFA group, there were no recurrences in the LPN and one recurrence in the LRFA group. The patients with the recurrence died from congestive heart failure 3 months after the recurrence was identified on CT. Six patients died in the LRFA group from causes unrelated to RCC (four from congestive heart failure, one from end-stage cirrhosis and one from unknown causes but with no evidence of disease at the last follow-up) and one died in the LPN group (heart failure). The difference in follow-up between LPN and LRFA patients was mainly because we have a very strict programme for the prospective evaluation of RFA, whereas LPN patients return to the care of their primary urologist if they are doing well. Overall there were five complications in the LPN group and three in the LRFA group. In the LPN group, two patients had a urinary leak requiring stenting, one had a perirenal haematoma not requiring a transfusion, one had delayed bleeding requiring bladder clot evacuation and stenting, and one had acute urinary retention that resolved spontaneously. In the LRFA group, the complications included one ureteric stricture requiring a nephrectomy for a nonfunctioning kidney at 1 year, an isolated hydrocalyx and persistent pain at the puncture site. The overall cost and cost components are also shown in Table 1; LRFA was less costly than LPN ($6103 vs $6808, P = 0.3) but this was not statistically significant. The cost savings from shorter surgery and hospital stay were reduced by the extra cost of the probe. Costs 468 2007 BJU INTERNATIONAL

LAPAROSCOPIC PARTIAL NEPHRECTOMY VS LAPAROSCOPIC RADIOFREQUENCY ABLATION Variable LPN LRFA P No. of patients 50 38 Gender, n (%) 0.757 male 31 (62) 22 (58) female 19 (38) 16 (42) Mean (SD): age, years 56.5 (11.7) 62 (17.5 0.080 BMI, kg/m 2 31.1 (8.0) 29.6 (4.8) 0.340 tumour size, cm 2.6 (0.9) 2.3 (0.7) 0.170 ASA score, n (%) 0.010 1 2 37 (74) 18 (47) 3 4 13 (26) 20 (53) Mean (SD) operative times, min* 282 (55) 132 (30) <0.001 EBL, ml 217 (178) 24 (24) <0.001 Malignant tumour, n (%) 41/50 (82) 29/36 (80) 0.700 Tumour grade, n (%) 0.500 1 2 37 (90) 20 (95) 3 4 4 (10) 1 (5) Mean (SD) length of stay, days 2.9 (1.6) 1.5 (0.7) <0.001 follow-up, months 15.0 (18.1) 25.2 (19.8) 0.020 Complications, n (%) 5 (10) 3 (8) 0.700 Recurrence, n 0 1 0.200 Death, n (%) 1 (2) 6 (16) 0.010 Costs, mean (SD) USA$ No of patients 40 14 Direct cost 6808 (2324) 6103 (1698) 0.300 Anaesthesia 290 (94) 226 (69) 0.020 Laboratory 793 (330) 504 (278) 0.005 Operating room 1599 (501) 1297 (409) 0.040 Radiology 107 (201) 111 (207) 0.900 Room and board 1629 (1097) 699 (493) 0.005 Pharmacy 617 (292) 419 (292) 0.030 Surgical supplies 1827 (728) 2647 (976) 0.002 related to anaesthesia, surgical supplies, laboratory and radiology were all significantly lower for the LRFA group. The LRFA group had much lower room and board costs than for LPN (almost a third), and indeed the most expensive item for LRFA was the disposable RFA probe. DISCUSSION Open PN is the reference standard for NSS because the long-term oncological outcomes are excellent [9]. LPN has recently emerged as an alternative option, with excellent mid-term oncological and functional results, comparable to those of open NSS [2,10]. Nevertheless, LPN is technically demanding and is associated with longer renal ischaemia time and higher urological complication rates, even in the most experienced hands [10]. The TABLE 1 The characteristics of the patients and the cost comparison between LPN and LRFA Available for *19 LPN and 33 LRFA, 24 LPN and 38 LRFA; Malignant or benign type determined on biopsy in 36 patients; Determined in 21/29 patients with malignant tumour for LRFA patients; includes the cost of the RFA probe ($1525). ASA, American Society of Anesthesiology; EBL, estimated blood loss. need to decrease the morbidity of LPN, particularly in older patients with multiple comorbidities, has led to the development of ablative technologies. Encouraging short and mid-term data are now available for both cryotherapy [4] and RFA [6,8,11]. We began offering RFA to our patients in May 2001, using both percutaneous and laparoscopic approaches, and recently reviewed our experience, showing a 96.8% recurrence-free rate at a mean follow-up of 25 months [6]. Several reports compared laparoscopic cryoablation to LPN [12,13] but there are very few reports on the surgical and oncological outcomes of LRFA specifically [14]. In the present study we focused on patients who had had LRFA and compared their surgical outcome with a group treated by LPN. With a median follow-up of 2 years there was only one recurrence in the 38 patients treated with LRFA and none died from RCC (97% recurrence-free survival, 100% cancerspecific survival). There was no statistically significant difference in cancer-specific survival between the LRFA and LPN groups. More patients died in the LRFA group (six vs one, P = 0.02) reflecting the higher comorbidity of the patients treated with LRFA. Our results are comparable to the intermediate-term outcomes reported with open and LPN. Patard et al. [15] reported a 100% cancer-specific survival at 1 and 2 years, and 99.7% at 3 years, after PN, with 99% of those with T1a tumours free of recurrence after a 42-month follow-up. Moinzadeh et al. [16] reported the 3-year outcome of 100 patients who had had LPN; none had any evidence of local or distant recurrence, the overall survival was 86%, and the cancer-specific survival 100%. In another series of 48 patients treated by LPN, Allaf et al. [17] found a 95.8% recurrence-free rate at a median follow-up of 37.7 months. In the present study, the overall morbidity was low in both groups, probably because all LPNs were by one experienced laparoscopic surgeon. The complication rate was similar in each group; there was one major complication in the LRFA group (one delayed stricture requiring a nephrectomy for a nonfunctioning kidney). Three complications in the LPN group required an immediate second procedure (three stent placements and one clot evacuation), prolonging the hospital stay and increasing hospital costs. The operative duration, estimated blood loss and length of stay were both lower in the LRFA than the LPN group. The median operative duration for LPN (282 min) was similar to those reported previously (163 274 min [18 21]) and longer than the mean time for LRFA (132 min). There was no statistically significant difference in direct costs between the procedures ($6808 vs $6103, P = 0.3). As emphasized in the cost analyses of laparoscopic cryoablation [22], the main cost component of ablative technologies is the probe, which at our hospital costs $1525. All other related costs (anaesthesia, laboratory, operating room, room and board, pharmacy) except radiology were less for LRFA, particularly the room and board cost, which was almost three times higher for the LPN group ($1629 vs $699). While this study focused on direct costs at the time of the 2007 BJU INTERNATIONAL 469

BENSALAH ET AL. procedure, indirect costs should also be considered, which are higher with ablative techniques because of the close surveillance required relative to patients who have LPN. The cost of CT of the abdomen and pelvis with contrast medium at our institution is $190, and this is done at 6 weeks, 3 and 6 months after the LRFA. This additional cost reduces or eliminates the cost benefits of LRFA within the first year. While cost is not the primary endpoint for managing patients with cancer, it is important when considering the impact of healthcare costs on society, especially in settings with fixed healthcare budgets. The management of small renal masses is important, given the increasing incidence. The role of observation of small masses is still to be defined, and many patients seek treatment as much for psychological reasons as the potential for cure. Also, as the incidence of kidney cancer increases with age, there is a growing effect of age and medical comorbidities on decisions made by the physician. The goal of optimizing cancer care and minimizing patient morbidity has led to a greater use of both laparoscopic approaches and ablative technologies. The present study shows that in experienced hands, there are very good outcomes for LPN, and with few complications. Not surprisingly, patients undergoing LRFA were older and had more comorbidities. Our study cannot address whether the avoidance of warm ischaemia had any benefit to patients in this group. As long-term data matures, it is possible that LRFA will become the optimum therapy for patients at higher risk of operative complications and who are not amenable to percutaneous approaches. We found this approach to have low morbidity and promising oncological outcomes. LRFA could also potentially be a good alternative treatment in centres with no experienced laparoscopists, where patients are not good candidates for open PN but renal-sparing approaches are desired. The limitations to the present study include the inevitable selection bias inherent in a retrospective evaluation. We also did not include indirect costs, such as the radiographic follow-up required for LRFA, or the financial effects on the loss of work. In conclusion, our results show that treatment outcome, mid-term oncological efficacy and costs are similar for LPN and LRFA. The operative duration, blood loss and length of stay clearly favour LRFA, and could therefore decrease the complication rate, particularly in centres where LPN is not a routine procedure. CONFLICT OF INTEREST None declared. REFERENCES 1 Chow WH, Devesa SS, Warren JL, Fraumeni JF Jr. Rising incidence of renal cell cancer in the United States. 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LAPAROSCOPIC PARTIAL NEPHRECTOMY VS LAPAROSCOPIC RADIOFREQUENCY ABLATION Jarrett TW, Solomon SB, Kavoussi LR. Cost analysis of open, laparoscopic, and percutaneous treatment options for nephron-sparing surgery. J Endourol/ Endourol Soc 2006; 20: 782 9 Correspondence: Yair Lotan, Department of Urology, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390 9110, USA. e-mail: Yair.Lotan@UTSouthwestern.edu Abbreviations: NSS, nephron-sparing surgery; (L)PN, (laparoscopic) partial nephrectomy; (L)RFA, (laparoscopic) radiofrequency ablation; US, ultrasonography. 2007 BJU INTERNATIONAL 471