european urology 55 (2009)

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1 european urology 55 (2009) available at journal homepage: Endo-urology Single-Incision, Umbilical Laparoscopic versus Conventional Laparoscopic Nephrectomy: A Comparison of Perioperative Outcomes and Short-Term Measures of Convalescence Jay D. Raman, Aditya Bagrodia, Jeffrey A. Cadeddu * Department of Urology, University of Texas Southwestern Medical Center, Dallas, Texas, USA Article info Article history: Accepted August 5, 2008 Published online ahead of print on August 13, 2008 Keywords: Blood loss Complications Convalescence Cosmesis Kidney Laparoscopy Minimally invasive surgery Renal cell carcinoma (RCC) Scarless Abstract Background: Recent reports have suggested that single-port or single-incision laparoscopic surgery (SILS) is technically feasible. Objective: To present a comparison between SILS and conventional laparoscopic nephrectomy with respect to perioperative outcomes and short-term measures of convalescence. Design, setting, and participants: This was a case-control study comparing 11 SILS nephrectomies (cases) and 22 conventional laparoscopic nephrectomies (controls) performed from September 2004 to April The control group was matched in a 2:1 ratio to SILS cases with respect to patient age, surgical indication, and tumor size. Intervention: A single surgeon performed all SILS nephrectomy cases using three adjacent 5-mm trocars inserted through a single 2.5-cm periumbilical incision. Measurements: Demographics, operative time, blood loss, perioperative complications, transfusion requirement, decrease in serum hemoglobin, analgesic requirement, length of stay, and final pathology were compared. Results and limitations: Mean patient age was 53 yr for both groups, with more females in the SILS cohort (82% vs 41%). Nephrectomy was performed for benign disease in 45% of the cases. Median tumor size was 5.5 cm for both groups, and all but one suspected malignancy was renal cell carcinoma on final pathology. There was no difference between SILS and conventional laparoscopy cases in median operative time (122 min vs 125 min, p = 0.78), percent decrease from preoperative hemoglobin (14.1% vs 15.8%, p = 0.52), analgesic use (8 morphine equivalents vs 15 morphine equivalents, p = 0.69), length of stay (49 h vs. 53 h, p = 0.44), or complication rate (0% for both). The SILS group did have a lower recorded median estimated blood loss (20 ml vs 100 ml, p = 0.001). This study is retrospective and is susceptible to all limitations and biases inherent in such a design. Conclusions: SILS nephrectomy is feasible with perioperative outcomes and shortterm measures of convalescence comparable to conventional laparoscopic nephrectomy. Although SILS may offer a subjective cosmetic advantage, prospective comparison is needed to more clearly define its role. # 2008 European Association of Urology. Published by Elsevier B.V. All rights reserved. * Corresponding author. Department of Urology, 5323 Harry Hines Blvd., J8.106, MC 9110, Dallas, TX , USA. Tel ; Fax: address: jeffrey.cadeddu@utsouthwestern.edu (J.A. Cadeddu) /$ see back matter # 2008 European Association of Urology. Published by Elsevier B.V. All rights reserved. doi: /j.eururo

2 european urology 55 (2009) Introduction Although open approaches have historically been the gold-standard therapy for surgical diseases, considerable morbidity and delayed convalescence occurs following these procedures. Since the first laparoscopic nephrectomy by Clayman and colleagues in 1991, minimally invasive urologic surgery has gained significant momentum [1]. Presently, laparoscopic nephrectomy has assumed a central role in the management of benign and malignant kidney diseases. Although laparoscopy is less morbid than open surgery, it still requires several incisions, each at least 1 2 cm in length. Each incision carries potential morbidity risks of bleeding, pain, hernia, and/or internal organ damage and may incrementally decrease cosmesis [2,3]. Cosmesis is particularly important in procedures on pediatric patients and is also demanded by many adult patients [4]. A new alternative to conventional laparoscopy is single-port or single-incision laparoscopic surgery (SILS). SILS utilizes bent and articulating instrumentation introduced through either adjacent conventional trocars or a specialized multilumen port. This surgical innovation obviates the need to externally space trocars for triangulation, thus allowing for the creation of a small, solitary portal of entry into the abdomen. Early clinical series have demonstrated the feasibility as well as the safe and successful completion of SILS urologic procedures including nephrectomy, adrenalectomy, pyeloplasty, renal cryotherapy, varicocelectomy, and sacrocolpopexy [5 11]. In addition to potential benefits of cosmesis, other theoretical advantages of SILS compared to conventional laparoscopy include less postoperative pain, a faster recovery, and improvements in perioperative outcomes or other short-term measures of convalescence. Comparison of these variables has yet to be reported. In this paper, we attempt to better define potential benefits of SILS by reporting our comparative experience between SILS and conventional laparoscopic nephrectomy. 2. Methods 2.1. Patient selection Our institution s Institutional Review Board approved this study. This was a retrospective, case-control study comparing a single surgeon s experience with 11 SILS nephrectomies (cases) performed between August 2007 and March 2008 and 22 conventional laparoscopic nephrectomies Table 1 Preoperative surgical indications for 33 patients undergoing nephrectomy either by single-incision laparoscopic surgery (SILS) or by conventional laparoscopy Surgical Approach Number (%) Total 33 Nonfunctioning (benign) 15 (45) Enhancing renal mass 18 (55) SILS 11 (33) Nonfunctioning 5 Chronic pyelonephritis 3 28 prior UPJ obstruction 1 28 prior UVJ obstruction 1 Enhancing renal mass 6 <4 cm 1 4 cm 5 Conventional laparoscopy 22 (67) Nonfunctioning 10 Chronic pyelonephritis 5 28 prior UPJ obstruction 4 Duplicated system 1 Enhancing renal mass a 12 <4 cm 2 4 cm 10 UPJ, ureteropelvic junction; UVJ, ureterovesical junction. a One case of a 6-cm central renal mass was urothelial carcinoma on final pathology. performed from September 2004 to August 2007 (controls). For enhancing renal masses, radical nephrectomy was only performed for lesions not amenable to nephron-sparing surgery by either open or laparoscopic techniques. In cases of simple nephrectomy, a diuretic renogram confirmed <15% function in the kidney of interest with a normal contralateral renal moiety. Surgical indications are listed in Table 1. Prior to surgery, all patients undergoing the SILS nephrectomy were informed that the minimally invasive procedure would be attempted via a single umbilical incision. Patients were also counseled that additional incisions may be necessary as warranted during the surgical procedure. Furthermore, all SILS cases were consecutively performed except for one patient with a body mass index (BMI) >30 and a 7-cm enhancing renal mass who was preoperatively determined to be better suited for a conventional laparoscopic nephrectomy. The remaining patients reflect the initial series of SILS nephrectomies performed at our institution in continuum without selection bias. From September 2004 to August 2007, 122 conventional laparoscopic nephrectomies were performed at our institution. From this cohort, we selected 22 patients to serve as a control group for this study. These 22 patients were specifically matched in a 2:1 ratio to index SILS cases with respect to patient age, surgical indication (benign vs malignant), and tumor size. No consideration or analysis of operative parameters and outcomes was made until this group was definitively selected as the best comparison cohort based on preoperative variables only.

3 1200 european urology 55 (2009) Fig. 1 (a) Schematic of conventional laparoscopy port placement for left nephrectomy; (b) schematic of port placement for single-incision laparoscopic surgery (SILS) for left nephrectomy; (c) actual SILS port placement for a right nephrectomy Trocar placement and surgical technique The operative techniques for conventional laparoscopic and SILS nephrectomy have previously been described [5,12]. For conventional laparoscopy, we utilize three ports: a 12-mm trocar near the midclavicular line 2 cm below the umbilicus, a 12-mm periumbilical trocar, and a 5-mm trocar near the midclavicular line 3 cm below the costal margin (Fig. 1a). For SILS nephrectomy, a 2.5-cm periumbilical skin incision was made, and three adjacent, reusable, 5-mm trocars were inserted through separate fascial sites within the same skin incision (Fig. 1b and c). For right nephrectomies, an additional 3-mm subxyphoid trocar was used for liver retraction with both techniques. SILS nephrectomy cases utilized articulating graspers and endoshears (Real Hand, Novare Surgical Systems, Cupertino, CA, USA) and a 458, 5-mm rigid laparoscope (Fig. 2a and b). The dissection proceeded until the renal hilum was encountered, at which time the central 5-mm trocar was exchanged for a 12- mm trocar to accommodate an endovascular stapler. The renal artery, renal vein, and ureter were sequentially divided using the laparoscopic stapler. The remaining attachments were divided, and specimens were placed in a laparoscopic sack. For both conventional and SILS nephrectomies, specimens were removed via the umbilical incision either intact (for kidneys with renal masses) or morcellated (for nonfunctional kidneys). Postoperatively, all patients received continuous intravenous ketorolac for 48 h as well as oral or intravenous narcotics as needed. Patients were discharged home when they were tolerating a diet and had stable hemoglobin Outcomes and statistical analysis Demographic information, operative time (OR time), estimated blood loss (EBL), perioperative complications, transfu-

4 european urology 55 (2009) Fig. 2 (a) Articulating grasper and Maryland dissector (Novare Surgical Systems, Cupertino, CA, USA); (b) 458, 5-mm laparoscope used for single-incision laparoscopic surgery (SILS) cases. sion requirement, decrease in serum hemoglobin, analgesic requirement (morphine equivalents), length of stay (LOS), and final pathology were recorded. Data were available for all variables listed, and the data collection was performed by a medical student who was not involved in any of the surgical procedures. Perioperative complications were defined as those occurring within the first month of the nephrectomy procedure. Groups were compared using x 2 and Mann-Whitney tests for categorical and continuous variables, respectively. Statistical significance was set at p < 0.05, and all reported p values are two-sided. Analyses were performed with SPSS v.13.0 (SPSS Inc, Chicago, IL, USA). 3. Results Results are summarized in Table 2. A total of 15 men and 18 women were included in this study, and the mean patient age for both groups was 53 yr (range: 19 83). Compared to the conventional laparoscopy group, there were more females in the SILS cohort (82% vs 41%, p = 0.03). Nephrectomy was performed for nonfunctional kidneys in 15 of 33 cases (45%), with final pathology in all cases consistent with chronic pyelonephritis and interstitial fibrosis without evidence of malignancy. Eighteen patients had a radical nephrectomy for enhancing renal masses with a median tumor size of 5.5 cm (range: 3 7 cm) for both groups. In the SILS cohort, all six cases were pathologically renal cell carcinoma (RCC; four clear cell, one papillary, one chromophobe) with a stage distribution of one T1a and five T1b tumors. In the conventional laparoscopy group, 11 of 12 cases were pathologically RCC (9 clear cell, 1 papillary, 1 chromophobe), with a stage distribution of two T1a and nine T1b tumors. One patient with a central renal mass and a negative urinary cytology had a frozen section suggestive of RCC, but final pathology revealed transitional cell carcinoma (TCC) of the renal pelvis. There were no positive surgical margins in any case. There was no difference in median OR time (122 min vs 125 min, p = 0.78), analgesic use (8 morphine equivalents vs 15 morphine equivalents, p = 0.69), LOS (49 h vs 53 h, p = 0.44), and minor or

5 1202 european urology 55 (2009) Table 2 Comparison of demographic parameters, perioperative variables, and short-term measures of convalescence for 33 patients undergoing nephrectomy either by single-incision laparoscopic surgery (SILS) or by conventional laparoscopy All patients Laparoscopic approach Number of patients SILS Conventional p value Age (years) Median (range) 54 (19 83) 55 (19 83) 53 (21 82) 0.99 y Gender Males (%) 15 (45) 2 (18) 13 (59) Females (%) 18 (55) 9 (82) 9 (41) 0.03 * Tumor size (cm) n =18 n =6 n =12 Median (range) 5.5 (3 7) 5.5 (3 7) 5.5 (3 7) 1.00 y Operative time (minutes) Median (range) 125 (90 240) 122 (90 210) 125 (90 240) 0.78 y Estimated blood loss (ml) Median (range) 100 (10 600) 20 (10 600) 100 (20 520) y Morphine equivalents (mg) Median (range) 13 (0 54) 8 (1 54) 15 (0 49) 0.6 y Change in hemoglobin (%) Median (range) 15.5 (0 24) 15.4 (5 23) 16.0 (0 24) 0.52 y Length of stay (hours) Median (range) 52 (29 106) 49 (30 74) 53 (29 106) 0.44 y * x 2 test. y Mann-Whitney test. major perioperative complications (0% for both) between the SILS index cases and conventional laparoscopy controls. Furthermore, no patients in either cohort demonstrated a delay in initiating oral intake or a regular diet. Operative records for the SILS group did note a lower recorded median EBL (20 ml vs 100 ml, p = 0.001). There was no difference, however, between the SILS and conventional laparoscopy cohorts with respect to the absolute decrease (1.8 mg/dl vs 2.3 mg/dl, p = 0.20) or percent decrease (14.1% vs 15.8%, p = 0.52) from preoperative hemoglobin to postoperative day 1 measurements. No patient from either cohort required a blood transfusion. 4. Discussion The introduction of laparoscopy in the early 1990s ushered in a new era in the surgical treatment of human diseases. Evolution of minimally invasive techniques has furthered an impetus in the surgical community to reduce the invasiveness of laparoscopic surgery. To achieve this goal, surgeons have proposed limiting the number of abdominal incisions (as in SILS) or eliminating them completely (as in natural orifice translumenal endoscopic surgery [NOTES]) [13]. Although preclinical animal models have demonstrated the potential applications of NOTES [14], human experience with this technique (particularly for urologic surgery) is still largely limited. Conversely, laboratory and clinical work with SILS procedures has shown a remarkable explosion over the past year. SILS has actually been reported in the literature for appendectomy [15] and cholecystectomy [16] since 1998, although the approach failed to gain momentum for years due to technical limitations with conventional instrumentation. Innovations such as articulating instrumentation and novel multilumen ports have ushered in a renaissance for single-port laparoscopy or SILS, with several series citing successful completion of a range of urologic procedures [5 11]. To date, however, experience with SILS is still in its infancy, with fewer than 75 published cases reported for all indications and fewer than 20 nephrectomy cases. As clinical experience with SILS increases, it is imperative that we critically evaluate two important questions: First, does SILS compromise on current standards of surgical care? Second, are the true benefits of SILS restricted to only improved cosmesis, or are there benefits with respect to convalescence and postoperative recovery? In this study, we performed a case-control comparison of SILS and conventional laparoscopic

6 european urology 55 (2009) nephrectomies performed by a single surgeon. In controlling for surgeon, patient age, organ of interest (kidney), surgical indication (benign vs malignant), and tumor size, we hoped to minimize the potential for selection bias between surgical modalities. We noted no differences in OR time, hospital LOS, narcotic analgesic use, complication rate, transfusion requirement, or surgical margin status between SILS and conventional laparoscopic nephrectomies. We did observe that operative records for the SILS group noted a lower recorded median EBL (20 ml vs 100 ml) compared to conventional laparoscopy. Similar decreases from preoperative hemoglobin in both surgical groups as well as the large standard deviation in calculated results from small samples sizes suggests that this may be an artifact of inaccuracies in surgeon-reported EBL. Our findings underscore that in the hands of an experienced laparoscopic surgeon, SILS nephrectomy is equally efficacious to conventional laparoscopic nephrectomy without compromising on surgical or postoperative outcomes. Interestingly, despite this series representing our initial SILS experience, we noted no differences in any operative variables compared to conventional laparoscopy. This is likely attributable to all cases being performed by an experienced surgeon who had previously completed multiple SILS nephrectomy cases in a porcine model [5]. This prior experience in the animal laboratory likely shortened the learning curve with this newer technique. Of note, almost 50% of our initial SILS nephrectomy series was composed of surgery for nonfunctional (chronic pyelonephritis) kidneys. Anecdotally, we observed no increased difficulty in these cases compared to radical nephrectomy, although we presume that there may be future cases in which dense retroperitoneal inflammatory reaction may prove a challenging obstacle. For minimally invasive nephrectomies, our data do raise the question of what the true benefit of SILS may be. Although the retrospective design is imperfect, this case-matched study suggests that all measurable perioperative outcomes and shortterm measures of convalescence are equivalent with no obvious advantage for SILS nephrectomy. One potential explanation is that for kidneys with renal masses, specimens were not morcellated and were removed by extending the umbilical incision up to 4 6 cm depending on tumor size. Extending this incision may have blunted any demonstrable differences in postoperative analgesic requirement between the two cohorts. Of note, however, is that subgroup analysis demonstrated that even for the 15 cases with morcellated specimens, there was no difference in any outcome measures, including analgesic consumption (median: 12 morphine equivalents vs 13 morphine equivalents) and hospital LOS (median: 49 h vs 53 h), between SILS and conventional laparoscopy. We acknowledge that this is a pilot study; larger studies with a minimum of 100 to 200 patients would be necessary to detect a 10% difference in outcome variables between the two approaches. In addition, as operative experience with SILS increases, we may be able to better evaluate variables beyond the initial theoretical learning-curve period. Collectively, these data imply that although SILS nephrectomy is feasible and efficacious, the only objective benefit may be for those patients who are most concerned with cosmesis. Interestingly, in our series, 80% of SILS nephrectomies were performed in women, suggesting some degree of patient selection. This potential cosmetic benefit does warrant a more thorough evaluation in the form of validated patient-reported-outcome instruments, as has been well studied in the cosmetic and reconstructive surgical literature [17,18]. This study has several limitations. First, the study is retrospective and is susceptible to all limitations and biases inherent in a retrospective design. Though prospective randomization is ideal, we are unaware of any work currently published using this methodology; we are planning work with a prospective study design to better address this issue. Second, we used morphine equivalents as a surrogate for measuring postoperative pain. The optimal means of assessing postoperative pain would involve using a visual analog scale as well as measuring analgesic requirement until the patient is completely free of pain (pain score 1). Over the past 3 yr, however, we have not routinely used a visual analog scale to assess pain following conventional laparoscopic nephrectomy and we do not monitor exact narcotic use once the patient has been discharged from the hospital, which makes such a retrospective comparison impossible. Third, there were more females in the SILS group, and this gender difference may contribute to differential analgesic consumption and pain perception. Future work with larger patient numbers may enable us to better elucidate whether there is a gender-related difference. Fourth, this study only looks at SILS nephrectomy using one particular SILS approach. Nonextirpative surgery such as pyeloplasty, renal cryotherapy, and varicocelectomy may show benefits with respect to postoperative analgesic requirement because lengthening an incision for specimen extraction is unnecessary. Future prospective studies may better define whether an advantage exists

7 1204 european urology 55 (2009) for SILS for nonextirpative surgery. Finally, our results reflect the experience of a high-volume laparoscopic surgeon who has been able to transition to SILS. These findings may be less generalizable to surgeons with less experience in minimally invasive surgery. 5. Conclusions For urologists with experience in minimally invasive surgery, SILS nephrectomy is equally efficacious to conventional laparoscopic nephrectomy without compromising surgical standards of care; however, we noted no differences in perioperative outcomes or short-term measures of convalescence. Although SILS nephrectomy may offer a subjective cosmetic advantage, validated patient-outcome questionnaires are necessary to more objectively address this end point. Prospective comparison between SILS and conventional laparoscopic nephrectomy is needed to more clearly define its role. Author contributions: Jeffrey A. Cadeddu had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. Study concept and design: Raman, Bagrodia, Cadeddu. Acquisition of data: Bagrodia. Analysis and interpretation of data: Raman, Bagrodia, Cadeddu. Drafting of the manuscript: Raman. Critical revision of the manuscript for important intellectual content: Raman, Bagrodia, Cadeddu. Statistical analysis: Bagrodia. Obtaining funding: None. Administrative, technical, or material support: Raman, Cadeddu. Supervision: Raman, Cadeddu. Other (specify): None. Financial disclosures: I certify that all conflicts of interest, including specific financial interests and relationships and affiliations relevant to the subject matter or materials discussed in the manuscript (eg, employment/ affiliation, grants or funding, consultancies, honoraria, stock ownership or options, expert testimony, royalties, or patents filed, received, or pending), are the following: None. Funding/Support and role of the sponsor: None. References [1] Clayman RV, Kavoussi LR, Soper NJ, et al. Laparoscopic nephrectomy: initial case report. J Urol 1991;146: [2] Lowry PS, Moon TD, D Alessandro A, Nakada SY. Symptomatic port-site hernia associated with a non-bladed trocar after laparoscopic live-donor nephrectomy. J Endourol 2003;17: [3] Marcovici I. Significant abdominal wall hematoma from an umbilical port insertion. JSLS 2001;5: [4] Dunker MS, Stiggelbout AM, van Hogezand RA, et al. Cosmesis and body image after laparoscopic-assisted and open ileocolic resection for Crohn s disease. Surg Endosc 1998;12: [5] Raman JD, Bensalah K, Bagrodia A, Stern JM, Cadeddu JA. Laboratory and clinical development of single keyhole umbilical nephrectomy. Urology 2007;70: [6] Rane A, Rao P, Bonadio F, Rao P. Single port laparoscopic nephrectomy using a novel laparoscopic port (R-port) and evolution of single laparoscopic port procedure (SLIPP). J Endourol 2007;21:A287. [7] Ponsky LE, Cherullo EE, Sawyer M, Hartke D. Single access site laparoscopic radical nephrectomy: initial clinical experience. J Endourol 2008;22: [8] Desai MM, Rao PP, Aron M, et al. Scarless single port transumbilical nephrectomy and pyeloplasty: first clinical report. BJU Int 2008;101:83 8. [9] Goel RK, Kaouk JH. Single port access renal cryoablation (SPARC): a new approach. Eur Urol 2008;53: [10] Kaouk JH, Haber GP, Goel RK, et al. Single-port laparoscopic surgery in urology: initial experience. Urology 2008;71:3 6. [11] Kaouk JH, Palmer JS. Single-port laparoscopic surgery: initial experience in children for varicocelectomy. BJU Int 2008;102:97 9. [12] Kavoussi LR, Kerbl K, Capelouto CC, McDougall EM, Clayman RV. Laparoscopic nephrectomy for renal neoplasms. Urology 1993;42: [13] Raman JD, Cadeddu JA, Rao P, Rane A. Single-incision laparoscopic surgery: initial urological experience and comparison with natural-orifice transluminal endoscopic surgery. BJU Int 2008;101: [14] Wagh MS, Thompson CC. Surgery insight: natural orifice transluminal endoscopic surgery[em]an analysis of work to date. Nat Clin Pract Gastroenterol Hepatol 2007;4: [15] Esposito C. One-trocar appendectomy in pediatric surgery. Surg Endosc 1998;12: [16] Piskun G, Rajpal S. Transumbilical laparoscopic cholecystectomy utilizes no incisions outside the umbilicus. J Laparoendosc Adv Surg Tech A 1999;9: [17] Ching S, Thoma A, McCabe RE, Antony MM. Measuring outcomes in aesthetic surgery: a comprehensive review of the literature. Plast Reconstr Surg 2003;111:469 80, discussion [18] Pusic AL, Chen CM, Cano S, et al. Measuring quality of life in cosmetic and reconstructive breast surgery: a systematic review of patient-reported outcomes instruments. Plast Reconstr Surg 2007;120:823 37, discussion

8 european urology 55 (2009) Editorial Comment on: Single-Incision, Umbilical Laparoscopic versus Conventional Laparoscopic Nephrectomy: A Comparison of Perioperative Outcomes and Short-Term Measures of Convalescence Jens Rassweiler Department of Urology, SLK Kliniken Heilbronn, D Heilbronn, Germany jens.rassweiler@slk-kliniken.de Raman and colleagues present a retrospective matched-pair study comparing the short-term morbidity of umbilical single-incision laparascopic surgery (SILS) versus conventional laparoscopic nephrectomy [1]. As they mention, this is basically an old technique already pioneered by gynecologists in the 1960s using an operative laparoscope with an offset eyepiece, comparable to the rigid nephroscopes used during percutaneous renal surgery [2]. An ideal indication was ligation of the tubes. A further step of single-port surgery represented the operative resectoscope developed by Buess in the 1980s for transanal endoscopic microsurgery [3]. This device consists of a rectoscope 40 mm in diameter with up to five ports for insertion of the telescope and curved instruments. This device has been modified for transumbilical laparoscopy, with three ports for insertion of a rigid or flexible telescope and flexible or bent instruments. The authors have to be congratulated for their results: Despite the ergonomically poorer design of SILS with problems concerning triangulation, retraction, instrument crowding, and in-line vision, the outcomes including operative times were identical. This success was based on the expertise of the surgeon with laparoscopy and the training on the animal model. The authors, however, were not able to show any clinically significant advantage of single-port surgery. Even the postulated potential cosmetic benefit remains doubtful. The questions is, why should we promote this technical modification of laparoscopy? Is it worthwhile to quit the proven principle of triangulation based on optimized trocar placement (ie, by preoperative planning) [4]? Is it justified to take the risk of a suboptimal angle of the endoscopic stapler for vascular control? Of course, flexible instruments may be able to compensate for some of these disadvantages, but the peritoneal cavity is different from the narrow intraluminal space of the rectum, colon, or renal collecting system. Consequently, I am not convinced about the future of SILS as a new procedure. Nevertheless, endoscopic surgery may benefit from the technological input (ie, flexible instruments, staplers) for such new old techniques. References [1] Raman JD, Bagrodia A, Cadeddu JA. Single-incision umbilical laparoscopic versus conventional laparoscopic nephrectomy: a comparison of perioperative outcomes and short-term measures of convalescence. Eur Urol 2009;55: [2] Wheeless CR. A rapid, inexpensive and effective method of surgical sterilization by laparoscopy. J Reprod Med 1969;5: [3] Buess G, Kipfmüller K, Hack D, Grüssner R, Heintz A, Junginger T. Technique of transanal endoscopic microsurgery. Surg Endosc 1988;2:71 5. [4] Baumhauer M, Feuerstein M, Meinzer H-P, Rassweiler J. Navigation in endsocopic soft tissue surgery: perspectives and limitations. J Endourol 2008;22: DOI: /j.eururo DOI of original article: /j.eururo Editorial Comment on: Single-Incision, Umbilical Laparoscopic versus Conventional Laparoscopic Nephrectomy: A Comparison of Perioperative Outcomes and Short-Term Measures of Convalescence Richard Naspro Urology Department, Humanitas Gavazzeni, Bergamo, Italy nasprorichard@yahoo.com The authors present a study reporting a retrospective, nonrandomised, and comparative (casematched) experience comparing single-port or single-incision laparoscopic surgery (SILS) with standard laparoscopic nephrectomy in a single centre (single surgeon) [1]. As a feasibility study describing an exciting new surgical approach, its results are of potential interest and add evidence to the growing literature for different treatment options [2 4].

9 1206 european urology 55 (2009) Although the design of the study makes it difficult to draw sound conclusions, this paper [1] does raise interesting considerations regarding the rationale and potential limitations of SILS. To date, the lack of prospective comparative data in the literature inhibits a solid understanding of the real benefits of such a minimally invasive approach. The authors are well aware of this problem and elegantly address these issues in the discussion section. It is currently difficult to consider that the step from standard laparoscopy to SILS will produce the same impact and excitement as when passing from open surgery to laparoscopy. At the moment, the biggest advantage of SILS seems to be for those cases in which the extraction of a big specimen is not contemplated. Future studies should surely be focused in this area. References [1] Raman JD, Bagrodia A, Cadeddu JA. Single incision umbilical laparoscopic versus conventional laparoscopic nephrectomy: a comparison of perioperative outcomes and short-term measures of convalescence. Eur Urol 2009;55: [2] Goel RK, Kaouk JH. Single-port access renal cryoablation (SPARC): a new approach. Eur Urol 2008;53: [3] Canes D, Desai MM, Aron M, et al. Transumbilical singleport surgery: evolution and current status. Eur Urol 2008;54: [4] Gill IS, Canes D, Aron M, et al. Single port transumbilical (E-NOTES) donor nephrectomy. J Urol 2008;180: DOI: /j.eururo DOI of original article: /j.eururo