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Perioperative Comparison of Robotic Assisted Laparoendoscopic Single-Site (LESS) Pyeloplasty Versus Conventional LESS Pyeloplasty
EUROPEAN UROLOGY 61 (2012) 410–414
available at www.sciencedirect.com journal homepage: www.europeanurology.com
Endo-urology
Perioperative Comparison of Robotic Assisted Laparoendoscopic Single-Site (LESS) Pyeloplasty Versus Conventional LESS Pyeloplasty Ephrem O. Olweny, Samuel K. Park, Yung K. Tan, Cenk Gurbuz, Jeffrey A. Cadeddu *, Sara L. Best Department of Urology, University of Texas Southwestern Medical Center, Dallas, TX, USA
Article info
Abstract
Article history: Accepted October 14, 2011 Published online ahead of print on October 23, 2011
Background: Conventional laparoendoscopic single-site (C-LESS) pyeloplasty is technically challenging due to instrument clashing, loss of triangulation, and difficulty sewing. Application of the da Vinci S or Si robotic platforms could potentially overcome these challenges. Objective: Compare our initial experience with robotic assisted laparoendoscopic single-site (R-LESS) pyeloplasty to our latter experience with C-LESS pyeloplasty (ie, after the initial 15 patients). Design, setting, and participants: This single-institution retrospective observational cohort study involved consecutive patients who presented with symptomatic ureteropelvic junction obstruction and who were deemed suitable for single-incision pyeloplasty by the treating surgeon. Measurements: Demographic, clinical, perioperative, and early postoperative comparative outcomes. Results and limitations: Ten patients each underwent R-LESS or C-LESS pyeloplasty by a single surgeon between March 2009 and July 2011. For R-LESS and C-LESS groups, age, gender distribution, body mass index, proportion of patients with prior abdominal surgery, estimated blood loss, and hospital length of stay were statistically similar. Mean operative time was significantly longer for R-LESS (226 vs 188 min; p = 0.007). C-LESS pyeloplasty alone required an accessory port for the anastomosis in 10 of 10 cases. Two conversions to standard laparoscopy and two postoperative complications occurred in 3 of 10 patients in the C-LESS group, compared with no conversions and one postoperative complication in the R-LESS group ( p = 0.26). Study limitations are a retrospective design, a modest number of patients, and a lack of quantification of subjective outcomes such as instrument clashing and maneuverability. Conclusions: Adaptation of the da Vinci Si robotic surgical platform to laparoendoscopic single-site pyeloplasty appears to reduce the physical learning curve for this complex procedure. Future prospective, comprehensive evaluation of additional outcomes including subjective parameters, cosmesis, and longer term functional outcomes will help better define its role in minimally invasive dismembered pyeloplasty and better estimate its associated learning curve. # 2011 European Association of Urology. Published by Elsevier B.V. All rights reserved.
Keywords: Robotics Surgical procedures minimally invasive Pyeloplasty
* Corresponding author. Department of Urology, UT Southwestern Medical Center, 5323 Harry Hines Blvd, J8.106, Dallas, TX 75390-9110, USA. Tel. +1 214 648 6856; Fax: +1 214 648 8786. E-mail address: [email protected] (J.A. Cadeddu).
0302-2838/$ – see back matter # 2011 European Association of Urology. Published by Elsevier B.V. All rights reserved.
doi:10.1016/j.eururo.2011.10.024
EUROPEAN UROLOGY 61 (2012) 410–414
1.
Introduction
411
configuration. In 6 of 10 patients, the peritoneum was entered using a GelPOINT device inserted through a linear 2.5- to 3-cm fascial
Laparoendoscopic single-site (LESS) pyeloplasty was first performed in 2007 and represents one of the latest advances in the minimally invasive management of ureteropelvic junction (UPJ) obstruction [1–3]. It is technically very challenging, largely due to the difficulty associated with intracorporeal suturing through a single abdominal incision. This can be partially offset by inserting an accessory port, which, according to expert consensus, is still consistent with the nomenclature of LESS [4–7]. However, the associated learning curve remains steep, with a reported complication rate during early experience approaching 50% in one series [8]. Although application of the da Vinci S robotic surgical platform (Intuitive Surgical, Sunnyvale, CA, USA) has the potential to overcome some of these challenges, reports to date reveal only a marginal benefit with this approach, largely due to internal and external robotic arm clashing [9]. Accordingly, clinical experience with robotic assisted LESS (R-LESS) pyeloplasty has thus far been limited to small numbers of patients [1,3,10]. In 2010, Joseph and colleagues described the ‘‘chopstick’’ technique for R-LESS, a modification that enhanced the functionality of the robotic platform for LESS surgery [11]. We further modified this technique by (1) using a GelPOINT access device (Applied Medical, Rancho Santa Margarita, CA, USA); (2) using the robotic camera in a 308 upward configuration; and (3) using the da Vinci Si surgical robot, which has smaller profile robotic arms than the da Vinci S. We hypothesized that these modifications could further enhance the applicability of the robotic platform to LESS pyeloplasty and could reduce the learning curve associated with the technique.
incision. A triangular trocar configuration was used through the GelPOINT, using 5-mm trocars spaced by 3 cm. A 5-mm laparoscope was used through one port, and articulating graspers and shears (Real Hand, Novare Surgical Systems, Cupertino, CA, USA) were used for the dissection. The instruments were crisscrossed at the umbilicus to maximize triangulation. The UPJ was transected, the ureter and renal pelvis were spatulated, and a JJ ureteral stent was placed in antegrade fashion. A running anastomosis was completed over the stent using 3-0 polyglactin suture. During the anastomosis, a midaxillary 3- or 5-mm port, subsequently used for insertion of the surgical drain, was inserted to facilitate intracorporeal suturing. Conventional laparoscopic needle drivers were used in 9 of 10 patients, and an articulating Autosuture Endo Stitch device (Covidien, Mansfield, MA, USA) was used in 1 of 10. A 19F Blake drain was positioned adjacent to the anastomosis at the conclusion of the procedure.
2.3.
R-LESS pyeloplasty surgical technique
During R-LESS pyeloplasty, in all but one patient, initial cystoscopy with JJ stent insertion was performed, due to the fact that antegrade stent insertion in this case is limited by the physical separation of the surgeon from the patient’s bedside and to the anticipated need for temporary undocking of one or more robotic arms to make this feasible. In one right-sided case, we placed an antegrade stent through a 3-mm subxiphoid port (used for a liver-retracting instrument). The GelPOINT device was used for access in all cases. Two pediatric 5-mm robotic ports, a 12-mm standard laparoscopic camera port, and a 12-mm assistant trocar were placed through the GelPOINT in a diamond-shaped configuration (Fig. 1) with the camera port at the top. The ports were spaced by 3 cm. A 10-mm robotic camera lens was used in a 308 upward orientation, which diminished clashing between the robotic camera and instrument arms and preserved access to the assistant trocar. A left 5-mm robotic hook cautery (or scissors) and a right 5-mm tissue grasper were deployed in the respective robotic ports, crisscrossing at the umbilicus. The remote centers of motion of the robotic ports (black lines) were placed at the level of the anterior
2.
Materials and methods
2.1.
Patients
abdominal fascia. The robotic console was programmed such that the surgeon’s right hand controlled the left instrument and vice versa, resulting in intuitive manipulation of the instruments. Dismembered pyeloplasty was then performed in the standard
Consecutive patients presenting with symptomatic, primary UPJ obstruction were evaluated by a single surgeon, and suitability for
fashion, as described. During dissection and sewing, it was often necessary
[(Fig._1)TD$IG]
LESS pyeloplasty was determined based on clinical judgment and patient preference. The same surgeon performed all procedures. Symptoms included pain and/or pyelonephritis, with radiographic diagnosis of UPJ obstruction obtained by abdominal computed tomography and/or excretory urography, and diuretic renal scintigraphy in all cases. Eligible patients underwent C-LESS pyeloplasty between October 2007 and April 2010, after which we switched to R-LESS pyeloplasty. Each LESS patient was entered into a prospectively maintained institutional review board–approved database, which was analyzed retrospectively. The 10 most recent patients who underwent C-LESS pyeloplasty had surgery performed between March 2009 and April 2010, after 15 previous cases.
2.2.
C-LESS pyeloplasty surgical technique
Our surgical technique for C-LESS pyeloplasty has been described previously [2]. Briefly, a 2.5- to 3-cm curvilinear, periumbilical skin incision was made, and the anterior abdominal fascia was exposed. In 4 of 10 patients, intraperitoneal access was achieved through three 5-mm ports inserted through the same skin incision in a triangular
Fig. 1 – Port positions for robotic assisted laparoendoscopic single-site pyeloplasty.
412
EUROPEAN UROLOGY 61 (2012) 410–414
[(Fig._2)TD$IG]
Fig. 2 – Transposition of instruments during dissection and sewing.
to transpose the left- and right-handed instruments to maximize retraction or to optimize needle angles, respectively (Fig. 2a–2c). At the conclusion of the procedure, a 10F Blake drain was positioned, as described, and externalized through the umbilical incision. For all right-sided R-LESS and C-LESS procedures, a 3-mm liver retractor inserted through a separate stab incision or a 3-mm port was used (Fig. 1). JJ stents were left indwelling for 4 wk, and initial follow-up diuretic renography was performed at a minimum of 6 wk following stent removal.
2.4.
Statistical methods
Demographic, clinical, and perioperative outcomes including complications were compared for each group. Complications were classified according to the Clavien classification scheme [12]. Continuous variables were analyzed using the student t test, whereas categorical variables were analyzed using the chi-square test. A two-tailed significance level of 0.05 was used for each test. Stata v.10 statistical software (StataCorp LP, College Station, TX, USA) was used for statistical analyses.
3.
Results
Ten patients underwent R-LESS pyeloplasty between May 2010 and July 2011 (Group 1). Data for this group were compared with those for the 10 most recent patients, who underwent C-LESS pyeloplasty (Group 2). Patient demographics are listed in Table 1. The groups were similar with regard to baseline demographics and clinical features. With one exception in the C-LESS group, all patients had a body
Table 1 – Patient characteristics Description
No. or patients Age, yr, mean (SD) Gender, No. male/female BMI, kg/m2, mean (SD) Laterality, No. left.right Proportion with one prior abdominal procedure or more
mass index (BMI) <33 kg/m2, and, if present, history of prior abdominal surgery was limited to lower abdominal procedures. An accessory port was used for liver retraction in each right-sided R-LESS and C-LESS case; in contrast to C-LESS, all R-LESS pyeloplasty cases were completed without the need for an additional port to aid the anastomosis. The coaxial orientation of the robotic camera lens relative to the robotic instruments necessitated paying particular attention to scaling down the degree of excursion of the instruments relative to the camera with each move, thereby reducing the working envelope that is typically achievable with the robotic platform. Perioperative outcomes and complications are outlined in Tables 2 and 3, respectively. Mean operative time (including patient repositioning after cystoscopy) for R-LESS pyeloplasty (226 37 min) was significantly longer than for C-LESS pyeloplasty (188 12 min) ( p = 0.007). Two conversions to standard laparoscopy and two postoperative complications occurred in 3 of 10 patients in the C-LESS group, compared with no conversions and one postoperative complication in the R-LESS group ( p = 0.26). For the C-LESS group, one of the conversions was in a patient with a BMI of 44 in whom dissection was difficult due to obesity. After transection and spatulation of the ureter, a JJ stent could not be positioned through the umbilicus, necessitating insertion of additional ports. The second conversion in this group occurred in a patient with a BMI of 24 who had a paucity of intra-abdominal and
Table 2 – Perioperative outcomes
Group 1 (R-LESS)
Group 2 (C-LESS)
p value
10 40.3 (17.7) 3/7 21.8 (3.4) 3/7 4/10 (40%)
10 35.8 (13.7) 3/7 26.7 (7.3) 5/5 2/10 (20%)
– 0.53 1.00 0.07 0.36 0.33
R-LESS = robotic assisted laparoendoscopic single-site; C-LESS = conventional laparoendoscopic single-site; BMI = body mass index.
Description
No. of patients Procedure time, min, mean (SD) EBL, ml, mean (SD) Conversion to laparoscopy Morphine equivalents, mean (SD) LOS, d, mean (SD) No. of complications
Group 1 (R-LESS)
Group 2 (C-LESS)
10 226 (36.7) 56 (21) 0/10 (0%) 30.3 (22.3) 2.6 (1.0) 1/10 (10%)
10 188 (12.4) 42 (35) 2/10 (20%) 49.6 (31.5) 2.6 (1.3) 2/10 (20%)
p value
– 0.007 0.38 0.14 0.13 0.99 0.53
R-LESS = robotic assisted laparoendoscopic single-site; C-LESS = conventional laparoendoscopic single-site; EBL = estimated blood loss; LOS = length of stay.
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EUROPEAN UROLOGY 61 (2012) 410–414
Table 3 – Postoperative complications Group 1 (R-LESS)
Group 2 (C-LESS)
No. of patients No. of complications
10 1/10 (10%)
10 2/10 (20%)
Clavien grade 3a 3b
1 urine leak requiring NT (suspected stent obstruction) 0
1 urine leak requiring NT (suspected stent obstruction) 1 obstruction after stent removal, requiring urgent restenting, subsequent NT insertion, and eventual diagnostic URS
R-LESS = robotic assisted laparoendoscopic single-site; C-LESS = conventional laparoendoscopic single-site; NT = nephrostomy tube; URS = ureteroscopy.
retroperitoneal fat. The renal pelvis and ureter were accessed through a transmesenteric incision, but the tight working space necessitated insertion of additional ports. Early clinical and radiographic follow-up was available for 8 of 10 patients in each group at a median of 12 wk (range: 10–15) for R-LESS and 40 wk (range: 9–51) for C-LESS. Clinical outcomes were favorable for both groups. In the C-LESS group, seven of eight are asymptomatic, and the most recent renal scan showed significantly improved drainage when compared to the preoperative study; t1/2 postlasix was 20 min in each case. One of eight developed recurrent flank pain, with the t1/2 at 13 wk and 38 wk increasing from 11 min to 17 min, respectively. Slowly developing reobstruction is suspected in this patient, who is currently being observed. In the R-LESS group, eight of eight are asymptomatic, and all patients have improved drainage postoperatively, with t1/2 postlasix 11 min in each case. 4.
Discussion
Minimally invasive dismembered pyeloplasty is an acceptable alternative to open pyeloplasty, given similar intermediate-term functional outcomes and lower morbidity [13–15]. LESS is the latest evolution of minimally invasive surgery and to date has been performed for >1000 urologic cases worldwide, <100 of these being pyeloplasties [16]. LESS pyeloplasty has been reported to yield shortterm clinical outcomes similar to conventional laparoscopic pyeloplasty [2] and could potentially achieve superior cosmesis [17]. However, it is technically very challenging and is associated with a steep learning curve [8]. Similarly, the learning curve for other LESS upper urinary tract procedures is significant, with one multiinstitutional study demonstrating only a moderate, insignificant decline in associated complication rates over a 3-yr period [18]. In the present series, we compared our initial experience with R-LESS pyeloplasty to our latter experience with C-LESS pyeloplasty, that is, after the expected learning curve (10 patients [8]) had been overcome. We believe that the application of the da Vinci Si robotic platform with technique modifications, as described, dramatically improved the ease of performing LESS pyeloplasty. This was primarily due to (1) the enhanced visibility afforded by the wider field of view of the three-dimensional high-definition robotic camera lens system; (2) the greater maneuverability afforded by the EndoWrist robotic instruments; and (3) reduced internal and external clashing of the robotic arms
and instruments, respectively, which was afforded by the 308 upward camera configuration, the use of pediatric robotic instruments, and the crisscrossing of the instruments at the abdominal wall to maximize separation of both the robotic arms and the instrument tips. The ability for intuitive control of the crisscrossed robotic instruments during R-LESS was also a distinct advantage over the counterintuitive handedness that is characteristic of C-LESS. Although not standardized, common surrogates for estimating the learning curve for surgical procedures include operative time, conversion rates, and complication rates [19]. We believe that the longer operative time for R-LESS pyeloplasty in our series was due to the extra time needed for cystoscopy and stent insertion rather an effect of the learning curve. Stent insertion times are incorporated in the recorded operative time for each technique but were not separately recorded. Accordingly, reanalysis of our data excluding the estimated time required for cystoscopy and stent placement during R-LESS pyeloplasty would introduce added bias when comparing with operative times for C-LESS pyeloplasty. In this series, the need for additional ports besides the one needed for liver retraction in right-sided cases was eliminated with R-LESS. Although no conversions occurred in the R-LESS cohort, we believe that the conversions in the C-LESS group were primarily due to confounding factors, namely, morbid obesity in one patient and variation in surgical technique in the other. Perioperative complication rates were statistically similar for both groups. However, in comparison to our first 10 C-LESS pyeloplasty cases [8], fewer complications were observed during our initial phase of R-LESS pyeloplasty. These findings suggest that use of the da Vinci Si platform with the technique modifications described may potentially reduce the learning curve associated with single-incision pyeloplasty. Early functional outcomes were similar and encouraging for both groups, although follow-up for R-LESS is considerably shorter than for C-LESS. Longer term follow-up is pending. A few limitations of this study warrant discussion. First, the number of subjects is small, given that the series describes our initial 10 R-LESS pyeloplasty patients. Nevertheless, publishing this first series is important. Future evaluation in a larger cohort will further inform on the relative merits of the technique. Second, the retrospective design introduces the potential for selection and other biases in some of the outcomes analyzed. Third, operative time and conversion rates as measures of the learning curve could not be evaluated reliably in this series
414
EUROPEAN UROLOGY 61 (2012) 410–414
for the reasons discussed. A future prospective randomized study in which time for specific surgical steps is recorded for each approach would help overcome some of these limitations. Finally, important subjective outcomes such as visibility and maneuverability were not quantified, and although our overall impression is that these were significantly improved during R-LESS, a more objective assessment would be beneficial.
[3] White WM, Haber GP, Goel RK, Crouzet S, Stein RJ, Kaouk JH. Singleport urological surgery: single-center experience with the first 100 cases. Urology 2009;74:801–4. [4] Aron M, Canes D, Desai MM, Haber GP, Kaouk JH, Gill IS. Transumbilical single-port laparoscopic partial nephrectomy. BJU Int 2009; 103:516–21. [5] Autorino R, Cadeddu JA, Desai MM, et al. Laparoendoscopic singlesite and natural orifice transluminal endoscopic surgery in urology: a critical analysis of the literature. Eur Urol 2011;59:26–45. [6] Box G, Averch T, Cadeddu J, et al. Nomenclature of natural orifice
5.
Conclusions
translumenal endoscopic surgery (NOTES) and laparoendoscopic single-site surgery (LESS) procedures in urology. J Endourol 2008;
Adaptation of the da Vinci Si robotic surgical platform to LESS pyeloplasty appears to reduce the physical learning curve for this complex procedure. Future prospective, comprehensive evaluation of additional outcomes including subjective parameters, cosmesis, and longer term functional outcomes will help better define its role in minimally invasive dismembered pyeloplasty and better estimate its associated learning curve.
22:2575–81. [7] Gill IS, Advincula AP, Aron M, et al. Consensus statement of the consortium for laparoendoscopic single-site surgery. Surg Endosc 2010;24:762–8. [8] Best SL, Donnally C, Mir SA, Tracy CR, Raman JD, Cadeddu JA. Complications during the initial experience with laparoendoscopic single-site pyeloplasty. BJU Int 2011;108:1326–9. [9] Kaouk JH, Goel RK, Haber GP, Crouzet S, Stein RJ. Robotic single-port transumbilical surgery in humans: initial report. BJU Int 2009; 103:366–9.
Author contributions: Jeffrey A. Cadeddu had full access to all the data in
[10] Stein RJ, White WM, Goel RK, Irwin BH, Haber GP, Kaouk JH. Robotic
the study and takes responsibility for the integrity of the data and the
laparoendoscopic single-site surgery using GelPort as the access
accuracy of the data analysis. Study concept and design: Cadeddu, Olweny, Best. Acquisition of data: Park, Tan, Gurbuz. Analysis and interpretation of data: Olweny, Best. Drafting of the manuscript: Olweny. Critical revision of the manuscript for important intellectual content: Cadeddu, Olweny, Best. Statistical analysis: Olweny. Obtaining funding: None. Administrative, technical, or material support: Cadeddu, Gurbuz. Supervision: Cadeddu, Best. Other (specify): None. Financial disclosures: I certify that all conflicts of interest, including specific financial interests and relationships and affiliations relevant to the
platform. Eur Urol 2010;57:132–7. [11] Joseph RA, Goh AC, Cuevas SP, et al. ‘‘Chopstick’’ surgery: a novel technique improves surgeon performance and eliminates arm collision in robotic single-incision laparoscopic surgery. Surg Endosc 2010;24:1331–5. [12] Dindo D, Demartines N, Clavien PA. Classification of surgical complications: a new proposal with evaluation in a cohort of 6336 patients and results of a survey. Ann Surg 2004;240:205–13. [13] Chen RN, Moore RG, Kavoussi LR. Laparoscopic pyeloplasty. Indications, technique, and long-term outcome. Urol Clin North Am 1998;25:323–30. [14] Jarrett TW, Chan DY, Charambura TC, Fugita O, Kavoussi LR. Laparoscopic pyeloplasty: the first 100 cases. J Urol 2002;167: 1253–6. [15] Etafy M, Pick D, Said S, et al. Robotic pyeloplasty: the University of California-Irvine experience. J Urol 2011;185:2196–200.
subject matter or materials discussed in the manuscript (eg, employment/
[16] Kaouk JH, Autorino R, Kim FJ, et al. Laparoendoscopic single-site
affiliation, grants or funding, consultancies, honoraria, stock ownership or
surgery in urology: worldwide multi-institutional analysis of 1076
options, expert testimony, royalties, or patents filed, received, or pending), are the following: None.
cases. Eur Urol 2011;60:998–1005. [17] Park SK, Olweny EO, Best SL, Tracy CR, Mir SA, Cadeddu JA. Patientreported body image and cosmesis outcomes following kidney
Funding/Support and role of the sponsor: None.
surgery: comparison of laparoendoscopic single-site, laparoscopic, and open surgery. Eur Urol 2011;60:1097–104.
References [1] Desai MM, Berger AK, Brandina R, et al. Laparoendoscopic singlesite surgery: initial hundred patients. Urology 2009;74:805–12.
[18] Greco F, Cindolo L, Autorino R, et al. Laparoendoscopic single-site upper urinary tract surgery: assessment of postoperative complications and analysis of risk factors. Eur Urol. In press. doi:10.1016/ j.eururo.2011.08.032.
[2] Tracy CR, Raman JD, Bagrodia A, Cadeddu JA. Perioperative outcomes
[19] Calvert RC, Morsy MM, Zelhof B, Rhodes M, Burgess NA. Comparison
in patients undergoing conventional laparoscopic versus laparoen-
of laparoscopic and open pyeloplasty in 100 patients with pelvi-
doscopic single-site pyeloplasty. Urology 2009;74:1029–34.
ureteric junction obstruction. Surg Endosc 2008;22:411–4.
available at www.sciencedirect.com journal homepage: www.europeanurology.com
Endo-urology
Perioperative Comparison of Robotic Assisted Laparoendoscopic Single-Site (LESS) Pyeloplasty Versus Conventional LESS Pyeloplasty Ephrem O. Olweny, Samuel K. Park, Yung K. Tan, Cenk Gurbuz, Jeffrey A. Cadeddu *, Sara L. Best Department of Urology, University of Texas Southwestern Medical Center, Dallas, TX, USA
Article info
Abstract
Article history: Accepted October 14, 2011 Published online ahead of print on October 23, 2011
Background: Conventional laparoendoscopic single-site (C-LESS) pyeloplasty is technically challenging due to instrument clashing, loss of triangulation, and difficulty sewing. Application of the da Vinci S or Si robotic platforms could potentially overcome these challenges. Objective: Compare our initial experience with robotic assisted laparoendoscopic single-site (R-LESS) pyeloplasty to our latter experience with C-LESS pyeloplasty (ie, after the initial 15 patients). Design, setting, and participants: This single-institution retrospective observational cohort study involved consecutive patients who presented with symptomatic ureteropelvic junction obstruction and who were deemed suitable for single-incision pyeloplasty by the treating surgeon. Measurements: Demographic, clinical, perioperative, and early postoperative comparative outcomes. Results and limitations: Ten patients each underwent R-LESS or C-LESS pyeloplasty by a single surgeon between March 2009 and July 2011. For R-LESS and C-LESS groups, age, gender distribution, body mass index, proportion of patients with prior abdominal surgery, estimated blood loss, and hospital length of stay were statistically similar. Mean operative time was significantly longer for R-LESS (226 vs 188 min; p = 0.007). C-LESS pyeloplasty alone required an accessory port for the anastomosis in 10 of 10 cases. Two conversions to standard laparoscopy and two postoperative complications occurred in 3 of 10 patients in the C-LESS group, compared with no conversions and one postoperative complication in the R-LESS group ( p = 0.26). Study limitations are a retrospective design, a modest number of patients, and a lack of quantification of subjective outcomes such as instrument clashing and maneuverability. Conclusions: Adaptation of the da Vinci Si robotic surgical platform to laparoendoscopic single-site pyeloplasty appears to reduce the physical learning curve for this complex procedure. Future prospective, comprehensive evaluation of additional outcomes including subjective parameters, cosmesis, and longer term functional outcomes will help better define its role in minimally invasive dismembered pyeloplasty and better estimate its associated learning curve. # 2011 European Association of Urology. Published by Elsevier B.V. All rights reserved.
Keywords: Robotics Surgical procedures minimally invasive Pyeloplasty
* Corresponding author. Department of Urology, UT Southwestern Medical Center, 5323 Harry Hines Blvd, J8.106, Dallas, TX 75390-9110, USA. Tel. +1 214 648 6856; Fax: +1 214 648 8786. E-mail address: [email protected] (J.A. Cadeddu).
0302-2838/$ – see back matter # 2011 European Association of Urology. Published by Elsevier B.V. All rights reserved.
doi:10.1016/j.eururo.2011.10.024
EUROPEAN UROLOGY 61 (2012) 410–414
1.
Introduction
411
configuration. In 6 of 10 patients, the peritoneum was entered using a GelPOINT device inserted through a linear 2.5- to 3-cm fascial
Laparoendoscopic single-site (LESS) pyeloplasty was first performed in 2007 and represents one of the latest advances in the minimally invasive management of ureteropelvic junction (UPJ) obstruction [1–3]. It is technically very challenging, largely due to the difficulty associated with intracorporeal suturing through a single abdominal incision. This can be partially offset by inserting an accessory port, which, according to expert consensus, is still consistent with the nomenclature of LESS [4–7]. However, the associated learning curve remains steep, with a reported complication rate during early experience approaching 50% in one series [8]. Although application of the da Vinci S robotic surgical platform (Intuitive Surgical, Sunnyvale, CA, USA) has the potential to overcome some of these challenges, reports to date reveal only a marginal benefit with this approach, largely due to internal and external robotic arm clashing [9]. Accordingly, clinical experience with robotic assisted LESS (R-LESS) pyeloplasty has thus far been limited to small numbers of patients [1,3,10]. In 2010, Joseph and colleagues described the ‘‘chopstick’’ technique for R-LESS, a modification that enhanced the functionality of the robotic platform for LESS surgery [11]. We further modified this technique by (1) using a GelPOINT access device (Applied Medical, Rancho Santa Margarita, CA, USA); (2) using the robotic camera in a 308 upward configuration; and (3) using the da Vinci Si surgical robot, which has smaller profile robotic arms than the da Vinci S. We hypothesized that these modifications could further enhance the applicability of the robotic platform to LESS pyeloplasty and could reduce the learning curve associated with the technique.
incision. A triangular trocar configuration was used through the GelPOINT, using 5-mm trocars spaced by 3 cm. A 5-mm laparoscope was used through one port, and articulating graspers and shears (Real Hand, Novare Surgical Systems, Cupertino, CA, USA) were used for the dissection. The instruments were crisscrossed at the umbilicus to maximize triangulation. The UPJ was transected, the ureter and renal pelvis were spatulated, and a JJ ureteral stent was placed in antegrade fashion. A running anastomosis was completed over the stent using 3-0 polyglactin suture. During the anastomosis, a midaxillary 3- or 5-mm port, subsequently used for insertion of the surgical drain, was inserted to facilitate intracorporeal suturing. Conventional laparoscopic needle drivers were used in 9 of 10 patients, and an articulating Autosuture Endo Stitch device (Covidien, Mansfield, MA, USA) was used in 1 of 10. A 19F Blake drain was positioned adjacent to the anastomosis at the conclusion of the procedure.
2.3.
R-LESS pyeloplasty surgical technique
During R-LESS pyeloplasty, in all but one patient, initial cystoscopy with JJ stent insertion was performed, due to the fact that antegrade stent insertion in this case is limited by the physical separation of the surgeon from the patient’s bedside and to the anticipated need for temporary undocking of one or more robotic arms to make this feasible. In one right-sided case, we placed an antegrade stent through a 3-mm subxiphoid port (used for a liver-retracting instrument). The GelPOINT device was used for access in all cases. Two pediatric 5-mm robotic ports, a 12-mm standard laparoscopic camera port, and a 12-mm assistant trocar were placed through the GelPOINT in a diamond-shaped configuration (Fig. 1) with the camera port at the top. The ports were spaced by 3 cm. A 10-mm robotic camera lens was used in a 308 upward orientation, which diminished clashing between the robotic camera and instrument arms and preserved access to the assistant trocar. A left 5-mm robotic hook cautery (or scissors) and a right 5-mm tissue grasper were deployed in the respective robotic ports, crisscrossing at the umbilicus. The remote centers of motion of the robotic ports (black lines) were placed at the level of the anterior
2.
Materials and methods
2.1.
Patients
abdominal fascia. The robotic console was programmed such that the surgeon’s right hand controlled the left instrument and vice versa, resulting in intuitive manipulation of the instruments. Dismembered pyeloplasty was then performed in the standard
Consecutive patients presenting with symptomatic, primary UPJ obstruction were evaluated by a single surgeon, and suitability for
fashion, as described. During dissection and sewing, it was often necessary
[(Fig._1)TD$IG]
LESS pyeloplasty was determined based on clinical judgment and patient preference. The same surgeon performed all procedures. Symptoms included pain and/or pyelonephritis, with radiographic diagnosis of UPJ obstruction obtained by abdominal computed tomography and/or excretory urography, and diuretic renal scintigraphy in all cases. Eligible patients underwent C-LESS pyeloplasty between October 2007 and April 2010, after which we switched to R-LESS pyeloplasty. Each LESS patient was entered into a prospectively maintained institutional review board–approved database, which was analyzed retrospectively. The 10 most recent patients who underwent C-LESS pyeloplasty had surgery performed between March 2009 and April 2010, after 15 previous cases.
2.2.
C-LESS pyeloplasty surgical technique
Our surgical technique for C-LESS pyeloplasty has been described previously [2]. Briefly, a 2.5- to 3-cm curvilinear, periumbilical skin incision was made, and the anterior abdominal fascia was exposed. In 4 of 10 patients, intraperitoneal access was achieved through three 5-mm ports inserted through the same skin incision in a triangular
Fig. 1 – Port positions for robotic assisted laparoendoscopic single-site pyeloplasty.
412
EUROPEAN UROLOGY 61 (2012) 410–414
[(Fig._2)TD$IG]
Fig. 2 – Transposition of instruments during dissection and sewing.
to transpose the left- and right-handed instruments to maximize retraction or to optimize needle angles, respectively (Fig. 2a–2c). At the conclusion of the procedure, a 10F Blake drain was positioned, as described, and externalized through the umbilical incision. For all right-sided R-LESS and C-LESS procedures, a 3-mm liver retractor inserted through a separate stab incision or a 3-mm port was used (Fig. 1). JJ stents were left indwelling for 4 wk, and initial follow-up diuretic renography was performed at a minimum of 6 wk following stent removal.
2.4.
Statistical methods
Demographic, clinical, and perioperative outcomes including complications were compared for each group. Complications were classified according to the Clavien classification scheme [12]. Continuous variables were analyzed using the student t test, whereas categorical variables were analyzed using the chi-square test. A two-tailed significance level of 0.05 was used for each test. Stata v.10 statistical software (StataCorp LP, College Station, TX, USA) was used for statistical analyses.
3.
Results
Ten patients underwent R-LESS pyeloplasty between May 2010 and July 2011 (Group 1). Data for this group were compared with those for the 10 most recent patients, who underwent C-LESS pyeloplasty (Group 2). Patient demographics are listed in Table 1. The groups were similar with regard to baseline demographics and clinical features. With one exception in the C-LESS group, all patients had a body
Table 1 – Patient characteristics Description
No. or patients Age, yr, mean (SD) Gender, No. male/female BMI, kg/m2, mean (SD) Laterality, No. left.right Proportion with one prior abdominal procedure or more
mass index (BMI) <33 kg/m2, and, if present, history of prior abdominal surgery was limited to lower abdominal procedures. An accessory port was used for liver retraction in each right-sided R-LESS and C-LESS case; in contrast to C-LESS, all R-LESS pyeloplasty cases were completed without the need for an additional port to aid the anastomosis. The coaxial orientation of the robotic camera lens relative to the robotic instruments necessitated paying particular attention to scaling down the degree of excursion of the instruments relative to the camera with each move, thereby reducing the working envelope that is typically achievable with the robotic platform. Perioperative outcomes and complications are outlined in Tables 2 and 3, respectively. Mean operative time (including patient repositioning after cystoscopy) for R-LESS pyeloplasty (226 37 min) was significantly longer than for C-LESS pyeloplasty (188 12 min) ( p = 0.007). Two conversions to standard laparoscopy and two postoperative complications occurred in 3 of 10 patients in the C-LESS group, compared with no conversions and one postoperative complication in the R-LESS group ( p = 0.26). For the C-LESS group, one of the conversions was in a patient with a BMI of 44 in whom dissection was difficult due to obesity. After transection and spatulation of the ureter, a JJ stent could not be positioned through the umbilicus, necessitating insertion of additional ports. The second conversion in this group occurred in a patient with a BMI of 24 who had a paucity of intra-abdominal and
Table 2 – Perioperative outcomes
Group 1 (R-LESS)
Group 2 (C-LESS)
p value
10 40.3 (17.7) 3/7 21.8 (3.4) 3/7 4/10 (40%)
10 35.8 (13.7) 3/7 26.7 (7.3) 5/5 2/10 (20%)
– 0.53 1.00 0.07 0.36 0.33
R-LESS = robotic assisted laparoendoscopic single-site; C-LESS = conventional laparoendoscopic single-site; BMI = body mass index.
Description
No. of patients Procedure time, min, mean (SD) EBL, ml, mean (SD) Conversion to laparoscopy Morphine equivalents, mean (SD) LOS, d, mean (SD) No. of complications
Group 1 (R-LESS)
Group 2 (C-LESS)
10 226 (36.7) 56 (21) 0/10 (0%) 30.3 (22.3) 2.6 (1.0) 1/10 (10%)
10 188 (12.4) 42 (35) 2/10 (20%) 49.6 (31.5) 2.6 (1.3) 2/10 (20%)
p value
– 0.007 0.38 0.14 0.13 0.99 0.53
R-LESS = robotic assisted laparoendoscopic single-site; C-LESS = conventional laparoendoscopic single-site; EBL = estimated blood loss; LOS = length of stay.
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Table 3 – Postoperative complications Group 1 (R-LESS)
Group 2 (C-LESS)
No. of patients No. of complications
10 1/10 (10%)
10 2/10 (20%)
Clavien grade 3a 3b
1 urine leak requiring NT (suspected stent obstruction) 0
1 urine leak requiring NT (suspected stent obstruction) 1 obstruction after stent removal, requiring urgent restenting, subsequent NT insertion, and eventual diagnostic URS
R-LESS = robotic assisted laparoendoscopic single-site; C-LESS = conventional laparoendoscopic single-site; NT = nephrostomy tube; URS = ureteroscopy.
retroperitoneal fat. The renal pelvis and ureter were accessed through a transmesenteric incision, but the tight working space necessitated insertion of additional ports. Early clinical and radiographic follow-up was available for 8 of 10 patients in each group at a median of 12 wk (range: 10–15) for R-LESS and 40 wk (range: 9–51) for C-LESS. Clinical outcomes were favorable for both groups. In the C-LESS group, seven of eight are asymptomatic, and the most recent renal scan showed significantly improved drainage when compared to the preoperative study; t1/2 postlasix was 20 min in each case. One of eight developed recurrent flank pain, with the t1/2 at 13 wk and 38 wk increasing from 11 min to 17 min, respectively. Slowly developing reobstruction is suspected in this patient, who is currently being observed. In the R-LESS group, eight of eight are asymptomatic, and all patients have improved drainage postoperatively, with t1/2 postlasix 11 min in each case. 4.
Discussion
Minimally invasive dismembered pyeloplasty is an acceptable alternative to open pyeloplasty, given similar intermediate-term functional outcomes and lower morbidity [13–15]. LESS is the latest evolution of minimally invasive surgery and to date has been performed for >1000 urologic cases worldwide, <100 of these being pyeloplasties [16]. LESS pyeloplasty has been reported to yield shortterm clinical outcomes similar to conventional laparoscopic pyeloplasty [2] and could potentially achieve superior cosmesis [17]. However, it is technically very challenging and is associated with a steep learning curve [8]. Similarly, the learning curve for other LESS upper urinary tract procedures is significant, with one multiinstitutional study demonstrating only a moderate, insignificant decline in associated complication rates over a 3-yr period [18]. In the present series, we compared our initial experience with R-LESS pyeloplasty to our latter experience with C-LESS pyeloplasty, that is, after the expected learning curve (10 patients [8]) had been overcome. We believe that the application of the da Vinci Si robotic platform with technique modifications, as described, dramatically improved the ease of performing LESS pyeloplasty. This was primarily due to (1) the enhanced visibility afforded by the wider field of view of the three-dimensional high-definition robotic camera lens system; (2) the greater maneuverability afforded by the EndoWrist robotic instruments; and (3) reduced internal and external clashing of the robotic arms
and instruments, respectively, which was afforded by the 308 upward camera configuration, the use of pediatric robotic instruments, and the crisscrossing of the instruments at the abdominal wall to maximize separation of both the robotic arms and the instrument tips. The ability for intuitive control of the crisscrossed robotic instruments during R-LESS was also a distinct advantage over the counterintuitive handedness that is characteristic of C-LESS. Although not standardized, common surrogates for estimating the learning curve for surgical procedures include operative time, conversion rates, and complication rates [19]. We believe that the longer operative time for R-LESS pyeloplasty in our series was due to the extra time needed for cystoscopy and stent insertion rather an effect of the learning curve. Stent insertion times are incorporated in the recorded operative time for each technique but were not separately recorded. Accordingly, reanalysis of our data excluding the estimated time required for cystoscopy and stent placement during R-LESS pyeloplasty would introduce added bias when comparing with operative times for C-LESS pyeloplasty. In this series, the need for additional ports besides the one needed for liver retraction in right-sided cases was eliminated with R-LESS. Although no conversions occurred in the R-LESS cohort, we believe that the conversions in the C-LESS group were primarily due to confounding factors, namely, morbid obesity in one patient and variation in surgical technique in the other. Perioperative complication rates were statistically similar for both groups. However, in comparison to our first 10 C-LESS pyeloplasty cases [8], fewer complications were observed during our initial phase of R-LESS pyeloplasty. These findings suggest that use of the da Vinci Si platform with the technique modifications described may potentially reduce the learning curve associated with single-incision pyeloplasty. Early functional outcomes were similar and encouraging for both groups, although follow-up for R-LESS is considerably shorter than for C-LESS. Longer term follow-up is pending. A few limitations of this study warrant discussion. First, the number of subjects is small, given that the series describes our initial 10 R-LESS pyeloplasty patients. Nevertheless, publishing this first series is important. Future evaluation in a larger cohort will further inform on the relative merits of the technique. Second, the retrospective design introduces the potential for selection and other biases in some of the outcomes analyzed. Third, operative time and conversion rates as measures of the learning curve could not be evaluated reliably in this series
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for the reasons discussed. A future prospective randomized study in which time for specific surgical steps is recorded for each approach would help overcome some of these limitations. Finally, important subjective outcomes such as visibility and maneuverability were not quantified, and although our overall impression is that these were significantly improved during R-LESS, a more objective assessment would be beneficial.
[3] White WM, Haber GP, Goel RK, Crouzet S, Stein RJ, Kaouk JH. Singleport urological surgery: single-center experience with the first 100 cases. Urology 2009;74:801–4. [4] Aron M, Canes D, Desai MM, Haber GP, Kaouk JH, Gill IS. Transumbilical single-port laparoscopic partial nephrectomy. BJU Int 2009; 103:516–21. [5] Autorino R, Cadeddu JA, Desai MM, et al. Laparoendoscopic singlesite and natural orifice transluminal endoscopic surgery in urology: a critical analysis of the literature. Eur Urol 2011;59:26–45. [6] Box G, Averch T, Cadeddu J, et al. Nomenclature of natural orifice
5.
Conclusions
translumenal endoscopic surgery (NOTES) and laparoendoscopic single-site surgery (LESS) procedures in urology. J Endourol 2008;
Adaptation of the da Vinci Si robotic surgical platform to LESS pyeloplasty appears to reduce the physical learning curve for this complex procedure. Future prospective, comprehensive evaluation of additional outcomes including subjective parameters, cosmesis, and longer term functional outcomes will help better define its role in minimally invasive dismembered pyeloplasty and better estimate its associated learning curve.
22:2575–81. [7] Gill IS, Advincula AP, Aron M, et al. Consensus statement of the consortium for laparoendoscopic single-site surgery. Surg Endosc 2010;24:762–8. [8] Best SL, Donnally C, Mir SA, Tracy CR, Raman JD, Cadeddu JA. Complications during the initial experience with laparoendoscopic single-site pyeloplasty. BJU Int 2011;108:1326–9. [9] Kaouk JH, Goel RK, Haber GP, Crouzet S, Stein RJ. Robotic single-port transumbilical surgery in humans: initial report. BJU Int 2009; 103:366–9.
Author contributions: Jeffrey A. Cadeddu had full access to all the data in
[10] Stein RJ, White WM, Goel RK, Irwin BH, Haber GP, Kaouk JH. Robotic
the study and takes responsibility for the integrity of the data and the
laparoendoscopic single-site surgery using GelPort as the access
accuracy of the data analysis. Study concept and design: Cadeddu, Olweny, Best. Acquisition of data: Park, Tan, Gurbuz. Analysis and interpretation of data: Olweny, Best. Drafting of the manuscript: Olweny. Critical revision of the manuscript for important intellectual content: Cadeddu, Olweny, Best. Statistical analysis: Olweny. Obtaining funding: None. Administrative, technical, or material support: Cadeddu, Gurbuz. Supervision: Cadeddu, Best. Other (specify): None. Financial disclosures: I certify that all conflicts of interest, including specific financial interests and relationships and affiliations relevant to the
platform. Eur Urol 2010;57:132–7. [11] Joseph RA, Goh AC, Cuevas SP, et al. ‘‘Chopstick’’ surgery: a novel technique improves surgeon performance and eliminates arm collision in robotic single-incision laparoscopic surgery. Surg Endosc 2010;24:1331–5. [12] Dindo D, Demartines N, Clavien PA. Classification of surgical complications: a new proposal with evaluation in a cohort of 6336 patients and results of a survey. Ann Surg 2004;240:205–13. [13] Chen RN, Moore RG, Kavoussi LR. Laparoscopic pyeloplasty. Indications, technique, and long-term outcome. Urol Clin North Am 1998;25:323–30. [14] Jarrett TW, Chan DY, Charambura TC, Fugita O, Kavoussi LR. Laparoscopic pyeloplasty: the first 100 cases. J Urol 2002;167: 1253–6. [15] Etafy M, Pick D, Said S, et al. Robotic pyeloplasty: the University of California-Irvine experience. J Urol 2011;185:2196–200.
subject matter or materials discussed in the manuscript (eg, employment/
[16] Kaouk JH, Autorino R, Kim FJ, et al. Laparoendoscopic single-site
affiliation, grants or funding, consultancies, honoraria, stock ownership or
surgery in urology: worldwide multi-institutional analysis of 1076
options, expert testimony, royalties, or patents filed, received, or pending), are the following: None.
cases. Eur Urol 2011;60:998–1005. [17] Park SK, Olweny EO, Best SL, Tracy CR, Mir SA, Cadeddu JA. Patientreported body image and cosmesis outcomes following kidney
Funding/Support and role of the sponsor: None.
surgery: comparison of laparoendoscopic single-site, laparoscopic, and open surgery. Eur Urol 2011;60:1097–104.
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[18] Greco F, Cindolo L, Autorino R, et al. Laparoendoscopic single-site upper urinary tract surgery: assessment of postoperative complications and analysis of risk factors. Eur Urol. In press. doi:10.1016/ j.eururo.2011.08.032.
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[19] Calvert RC, Morsy MM, Zelhof B, Rhodes M, Burgess NA. Comparison
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