Scandinavian Journal of Urology. 2014; 48: 538–543
ORIGINAL ARTICLE
Scandinavian Journal of Urology Downloaded from informahealthcare.com by University of Pennsylvania on 01/25/15 For personal use only.
Hand-assisted partial nephrectomy with early arterial clamp removal: Impact of the learning curve
NESSN H. AZAWI, THOMAS P. NORUS, HANS-ERIK WITTENDORFF & CLAUS DAHL Department of Urology, Roskilde Hospital, Roskilde, Denmark
Abstract Objective. The aims of this study were to present the results of hand-assisted laparoscopic partial nephrectomy according to the margin, ischaemia and complications system; to assess the role of the learning curve; and to compare this approach with other approaches. Material and methods. Data from 60 consecutive patients were obtained from a prospectively maintained database. The patients were divided into three cohorts (1, 2 and 3), with 20 patients each, according to their surgery dates. Results. The overall margin, ischaemia and complications rate was 90%. The warm ischaemia time was 9.5 min in cohort 1, decreasing to 5 min in cohort 3 (p < 0.0001). The Padua score (p = 0.0287) and tumour size (p = 0.0003) were significantly increased in cohort 3, but loss of kidney function decreased significantly to 3.5% in this cohort. Loss of kidney function of less than 5% was reported for eight (40%), nine (45%) and 14 (70%) patients in cohorts 1, 2 and 3, respectively (p = 0.0185). Conclusions. Handassisted laparoscopic partial nephrectomy with early removal of arterial clamps is safe and easy to learn. An expert laparoscopic surgeon can perform hand-assisted laparoscopic partial nephrectomy for complex tumours with a relatively high success rate according to the margin, ischaemia and complications system. Warm ischaemia time could be obtained within 5 min after 40 procedures.
Key Words: early arterial clamp removal, hospital stay, learning curve, partial nephrectomy, warm ischaemia time
Introduction Based on the available oncological and quality of life outcomes, current evidence suggests that localized renal cancers are best managed by nephron-sparing surgery (partial nephrectomy) rather than by radical nephrectomy, irrespective of the surgical approach [1]. Robot-assisted partial nephrectomy (RAPN) has emerged as a viable option for the surgical management of small renal masses [2–4]. This technology was initially only available at tertiary care centres. Open partial nephrectomy remains the gold standard procedure, even with its disadvantages regarding outcome [5]. Laparoscopic partial nephrectomy (LPN) is technically challenging and has a steeper learning curve because it requires not only precise tumour margin resection but
also complex and time-dependent renal haemostasis and reconstruction [6]. In the past few years, handassisted laparoscopic partial nephrectomy (HALPN) has been proposed as an alternative approach owing to the shorter warm ischaemia time (WIT), operative time and length of hospital stay (LOS) [7–9]. This study aimed to evaluate the results of HALPN and to compare them with the results of other approaches. Material and methods Between March 2011 and November 2012, 102 patients were diagnosed with renal masses of less than 8 cm. The data were extracted from a wellestablished database in the Department of Urology
Correspondence: N. H. Azawi, Department of Urology, Roskilde Hospital, Kogevej 7-13, DK-4000 Roskilde, Denmark. Tel: +45 26 39 30 34. E-mail: [email protected]
(Received 4 February 2014; revised 30 March 2014; accepted 6 May 2014) ISSN 2168-1805 print/ISSN 2168-1813 online 2014 Informa Healthcare DOI: 10.3109/21681805.2014.925499
Scandinavian Journal of Urology Downloaded from informahealthcare.com by University of Pennsylvania on 01/25/15 For personal use only.
Hand-assisted partial nephrectomy of Roskilde Hospital, and the database was approved by the Danish Data Protection Agency. All of the patients were evaluated by the same operating team, which consisted of three surgeons. The operations were performed by one surgeon or under his supervision. The inclusion criteria for the HALPN technique were the following: a World Health Organization (WHO) performance score of 0 or 1; a life expectancy of more than 10 years; a tumour size of less than 8 cm; and a distance of more than 1 cm between the tumour and renal hilum, as evaluated by computed tomographic urography. Exclusion criteria were: a tumour size more than 8 cm, tumour close to the renal hilum or multiple tumours on the ipsilateral kidney. In case of an absolute indication, all cases were included regardless of exclusion criteria. The locations of tumours were evaluated and listed according to the Preoperative Aspects and Dimensions Used for an Anatomical score (PADUA score) [10]. Patients with Padua scores of 7 or below, 8–9 and 10 or above were considered low-risk, intermediate-risk and high-risk patients, respectively. Operative time was defined as the exact surgical time, “skin to skin”. WIT was defined as the time from the placement to the removal of bulldog clamps. LOS was defined as the length of the primary postoperative stay, including transfers to other departments or hospitals and any readmissions within 30 days. The estimated glomerular filtration rate (eGFR) was calculated before surgery and a minimum of 12 months after surgery, according to the following formula: eGFR (ml/min/1.73 m2) = 175 (serum creatinine) – 1.154 (age) – 0.203 (0.742 if female) (1.212 if African American) (conventional units) [11]. Postoperative complications were classified according to the Clavien–Dindo classification of postoperative surgical complications [12]. The patient cohort was divided into three groups, consisting of 20 patients each, according to their surgery dates. Loss of kidney function was calculated as a percentage as follows: (LKF) = (eGFR before – eGFR after/eGFR before operation) 100. The surgical margin, ischaemia and complications rate (MIC) [13] was calculated to compare the outcomes of HALPN with those of other approaches. According to the MIC system, the goal of partial nephrectomy was attained when the surgical margins were negative, the WIT was less than 20 min, and no major complications (grade III–IV according to the Clavien classification) were observed. MedCalc for Windows, version 12.7.7 (MedCalc Software, Ostend, Belgium) was used to analyse the data. A paired t test was used to compare the distribution of eGFR before and after the operations. The Kruskal–Wallis test was used to compare the outcomes between the different cohorts. Multiple
539
regression analysis was performed and correlation coefficients were obtained to examine the relationships of MIC and LKF with various potential predictors. p < 0.05 was considered significant. Operative technique The patient was placed in the left or right lateral decubitus position. The table was flexed and the patient was safely supported on the table. Initial access to the peritoneal cavity was obtained via a subcostal incision on the left side and an inguinal incision on the right side, the length of which corresponded to the glove size of the primary surgeon minus 1 cm (7 cm for a size 8 surgical glove); a GelPort device (Applied Medical, Rancho Santa Margarita, CA, USA) was placed in this incision. A 12 mm trocar was inserted directly into the GelPort device and gas insufflations were started. Next, three accessory (12 mm) trocars were placed on the left side and one 5 mm and three 12 mm trocars were placed on the right side; the 5 mm trocar was used to support the liver. All trocars were inserted under visual control, and 10–15 ml marcain (2.5 mg/ml) was permeated to all trocar incisions. The colon and spleen were dissected from the left kidney, and the colon, duodenum and liver from the right kidney. If the tumour was located at the lower or middle pole, then the ureter was dissected and traced to the renal pelvis; otherwise, the dissection was continued against the renal fascia and a complete exploration of the kidney was achieved. The renal artery and vein were dissected carefully and an elastic tape was placed around each. The tumour was identified and the renal capsule was scored circumferentially by scissors with a 5 mm margin around the tumour. A vascular bulldog clamp was placed on the artery and a timer was started to monitor WIT. The tumour resection was performed using laparoscopic “cold” scissors (no cautery) to allow for clear visualization of normal parenchyma during excision. An assistant surgeon used a water irrigator for traction and to keep the field clear. The excised tumour mass was removed through Gelport incision; then the tumour resection bed was closed with uninterrupted 2-0 Vicryl sutures of 20 cm with Hem-o-lok clips at either end. The bulldog clamp was removed carefully and 3–4 interrupted 0 Vicryl was used to close the parenchymal defect with Hemo-lok clips at either end. All patients received 1– 2 TachoSil mesh on the parenchymal defect as well as a drain tube at the operation bed. No double-J catheter was placed. Fasciae related to the GelPort incision were closed using PDS-0 suture. Preoperative bowel cleansing was not performed. An intraoperative nasogastric tube was inserted as
540
N. H. Azawi et al.
needed, and prophylactic antibiotic was planned preoperatively. A bladder drainage catheter was inserted for all patients and removed on the first postoperative day, and a drainage tube was planned to be removed when there was less than 150 ml accumulation within the first postoperative day.
Scandinavian Journal of Urology Downloaded from informahealthcare.com by University of Pennsylvania on 01/25/15 For personal use only.
Results Sixty patients (Table I) met the inclusion criteria for the HALPN procedure. In nine of the 60 patients, Table I. Preoperative demographic distribution. Age (years)
63 (40–78)
Gender: male
46 (76)
Medical comorbidities Hypertension
14 (23.3)
Diabetes mellitus
5 (8.3)
Coronary artery disease
6 (10)
eGFR before operation (ml/min/1.73 m2)
78 (23–97)
50
52 (87)
Padua score
7 (6–12)
Low (6–7)
33 (55)
Moderate (8–9)
22 (36.6)
High (10) Tumour size (cm) Estimated blood loss (ml)
5 (8.3) 3 (1.7–8) 100 (20–400)
0–50
18 (30)
51–100
13 (21.6)
>100
29 (48.3)
Clavien score £2 ‡3 WIT (min)
57 (9) 3 (5) 6.5 (4–30)
0.05).
Scandinavian Journal of Urology Downloaded from informahealthcare.com by University of Pennsylvania on 01/25/15 For personal use only.
Hand-assisted partial nephrectomy Increased intra-abdominal pressure during laparotomy also impaired renal function [19]. These issues could explain why a short operative time may be associated with decreased LKF. There is clearly a need for more studies to understand the pathophysiological changes that occur during partial nephrectomy, which requires maintaining the current focus on advancing the partial nephrectomy technique towards zero ischaemia time with short operative time and consequent favourable postoperative outcomes. Regarding the learning curve, there was no significant improvement in success rates in the different cohorts according to the MIC system. This finding may have been due to the high success rate obtained after HALPN across different periods, which indicates the efficiency of the HALPN approach compared with other techniques. However, there was a significant learning curve effect with regard to WIT and LKF (Figures 2 and 3), despite increasing tumour sizes and high Padua scores. The limitations of this study are that the sample size was small, the data were collected prospectively but analysed retrospectively, and the follow-up period may have been too short to clarify the impact of LKF on survival. HALPN with early removal of the arterial clamp is safe and easy to learn. The authors believe that an expert laparoscopic surgeon must perform 40 procedures to obtain a WIT of 5 min or less. The MIC system was easy to use, and it is a useful tool for reporting the results of different approaches for partial nephrectomy. WIT, operative time and hypertension contributed significantly to LKF. More studies are needed to improve our understanding of the pathophysiological changes that occur during partial nephrectomy. Declaration of interest: No conflicts of interest exist. There was no funding regarding this paper.
References [1] Ljungberg B, Cowan NC, Hanbury DC, Hora M, Kuczyk MA, Merseburger AS, et al. EAU guidelines on renal cell carcinoma: the 2010 update. Eur Urol 2010;58: 398–406. [2] Gettman MT, Blute ML, Chow GK, Neururer R, Bartsch G, Peschel R. Robotic-assisted laparoscopic partial nephrectomy: technique and initial clinical experience with DaVinci robotic system. Urology 2004;64:914–18. [3] Kaul S, Laungani R, Sarle R, Stricker H, Peabody J, Littleton R, et al. Da Vinci-assisted robotic partial nephrectomy: technique and results at a mean of 15 months of follow-up. Eur Urol 2007;51:186–91.
543
[4] Scoll BJ, Uzzo RG, Chen DY, Boorjian SA, Kutikov A, Manley BJ, et al. Robot-assisted partial nephrectomy: a large single-institutional experience. Urology 2010;75:1328–34. [5] Gill IS, Matin SF, Desai MM, Kaouk JH, Steinberg A, Mascha E, et al. Comparative analysis of laparoscopic versus open partial nephrectomy for renal tumors in 200 patients. J Urol 2003;170:64–8. [6] Aboumarzouk OM, Stein RJ, Eyraud R, Haber GP, Chlosta PL, Somani BK, et al. Robotic versus laparoscopic partial nephrectomy: a systematic review and meta-analysis. Eur Urol 2012;62:1023–33. [7] Azawi NH, Christensen T. Promising early results after hand-assisted laparoscopic partial nephrectomy in carefully selected patients. Dan Med J 2012;59:A4520. [8] Elsamra SE, Leone AR, Lasser MS, Thavaseelan S, Golijanin D, Haleblian GE, et al. Hand-assisted laparoscopic versus robot-assisted laparoscopic partial nephrectomy: comparison of short-term outcomes and cost. J Endourol 2013; 27:182–8. [9] Engel JD, Williams SB. Unclamped hand-assisted laparoscopic partial nephrectomy for predominantly endophytic renal tumors. Urol J 2013;10:767–73. [10] Ficarra V, Novara G, Secco S, Macchi V, Porzionato A, De Caro R, et al. Preoperative aspects and dimensions used for an anatomical (PADUA) classification of renal tumours in patients who are candidates for nephron-sparing surgery. Eur Urol 2009;56:786–93. [11] Levey AS, Coresh J, Greene T, Stevens LA, Zhang YL, Hendriksen S, et al. Using standardized serum creatinine values in the modification of diet in renal disease study equation for estimating glomerular filtration rate. Ann Intern Med 2006;145:247–54. [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] Buffi N, Lista G, Larcher A, Lughezzani G, Ficarra V, Cestari A, et al. Margin, ischemia, and complications (MIC) score in partial nephrectomy: a new system for evaluating achievement of optimal outcomes in nephron-sparing surgery. Eur Urol 2012;62:617–18. [14] Porpiglia F, Bertolo R, Amparore D, Fiori C. Margins, ischaemia and complications rate after laparoscopic partial nephrectomy: impact of learning curve and tumour anatomical characteristics. BJU Int 2013;112:1125–32. [15] Long JA, Yakoubi R, Lee B, Guillotreau J, Autorino R, Laydner H, et al. Robotic versus laparoscopic partial nephrectomy for complex tumors: comparison of perioperative outcomes. Eur Urol 2012;61:1257–62. [16] Weight CJ, Larson BT, Fergany AF, Gao T, Lane BR, Campbell SC, et al. Nephrectomy induced chronic renal insufficiency is associated with increased risk of cardiovascular death and death from any cause in patients with localized cT1b renal masses. J Urol 2010;183:1317–23. [17] Pouliot F, Pantuck A, Imbeault A, Shuch B, Calimlim B, Audet JF, et al. Multivariate analysis of the factors involved in loss of renal differential function after laparoscopic partial nephrectomy: a role for warm ischemia time. Can Urol Assoc J 2011;5:89–95. [18] Corcoran AC, Page IH. Effects of hypotension due to hemorrhage and of blood transfusion on renal function in dogs. J Exp Med 1943;78:205–24. [19] Sugrue M, Buist MD, Hourihan F, Deane S, Bauman A, Hillman K. Prospective study of intra-abdominal hypertension and renal function after laparotomy. Br J Surg 1995;82:235–8.
ORIGINAL ARTICLE
Scandinavian Journal of Urology Downloaded from informahealthcare.com by University of Pennsylvania on 01/25/15 For personal use only.
Hand-assisted partial nephrectomy with early arterial clamp removal: Impact of the learning curve
NESSN H. AZAWI, THOMAS P. NORUS, HANS-ERIK WITTENDORFF & CLAUS DAHL Department of Urology, Roskilde Hospital, Roskilde, Denmark
Abstract Objective. The aims of this study were to present the results of hand-assisted laparoscopic partial nephrectomy according to the margin, ischaemia and complications system; to assess the role of the learning curve; and to compare this approach with other approaches. Material and methods. Data from 60 consecutive patients were obtained from a prospectively maintained database. The patients were divided into three cohorts (1, 2 and 3), with 20 patients each, according to their surgery dates. Results. The overall margin, ischaemia and complications rate was 90%. The warm ischaemia time was 9.5 min in cohort 1, decreasing to 5 min in cohort 3 (p < 0.0001). The Padua score (p = 0.0287) and tumour size (p = 0.0003) were significantly increased in cohort 3, but loss of kidney function decreased significantly to 3.5% in this cohort. Loss of kidney function of less than 5% was reported for eight (40%), nine (45%) and 14 (70%) patients in cohorts 1, 2 and 3, respectively (p = 0.0185). Conclusions. Handassisted laparoscopic partial nephrectomy with early removal of arterial clamps is safe and easy to learn. An expert laparoscopic surgeon can perform hand-assisted laparoscopic partial nephrectomy for complex tumours with a relatively high success rate according to the margin, ischaemia and complications system. Warm ischaemia time could be obtained within 5 min after 40 procedures.
Key Words: early arterial clamp removal, hospital stay, learning curve, partial nephrectomy, warm ischaemia time
Introduction Based on the available oncological and quality of life outcomes, current evidence suggests that localized renal cancers are best managed by nephron-sparing surgery (partial nephrectomy) rather than by radical nephrectomy, irrespective of the surgical approach [1]. Robot-assisted partial nephrectomy (RAPN) has emerged as a viable option for the surgical management of small renal masses [2–4]. This technology was initially only available at tertiary care centres. Open partial nephrectomy remains the gold standard procedure, even with its disadvantages regarding outcome [5]. Laparoscopic partial nephrectomy (LPN) is technically challenging and has a steeper learning curve because it requires not only precise tumour margin resection but
also complex and time-dependent renal haemostasis and reconstruction [6]. In the past few years, handassisted laparoscopic partial nephrectomy (HALPN) has been proposed as an alternative approach owing to the shorter warm ischaemia time (WIT), operative time and length of hospital stay (LOS) [7–9]. This study aimed to evaluate the results of HALPN and to compare them with the results of other approaches. Material and methods Between March 2011 and November 2012, 102 patients were diagnosed with renal masses of less than 8 cm. The data were extracted from a wellestablished database in the Department of Urology
Correspondence: N. H. Azawi, Department of Urology, Roskilde Hospital, Kogevej 7-13, DK-4000 Roskilde, Denmark. Tel: +45 26 39 30 34. E-mail: [email protected]
(Received 4 February 2014; revised 30 March 2014; accepted 6 May 2014) ISSN 2168-1805 print/ISSN 2168-1813 online 2014 Informa Healthcare DOI: 10.3109/21681805.2014.925499
Scandinavian Journal of Urology Downloaded from informahealthcare.com by University of Pennsylvania on 01/25/15 For personal use only.
Hand-assisted partial nephrectomy of Roskilde Hospital, and the database was approved by the Danish Data Protection Agency. All of the patients were evaluated by the same operating team, which consisted of three surgeons. The operations were performed by one surgeon or under his supervision. The inclusion criteria for the HALPN technique were the following: a World Health Organization (WHO) performance score of 0 or 1; a life expectancy of more than 10 years; a tumour size of less than 8 cm; and a distance of more than 1 cm between the tumour and renal hilum, as evaluated by computed tomographic urography. Exclusion criteria were: a tumour size more than 8 cm, tumour close to the renal hilum or multiple tumours on the ipsilateral kidney. In case of an absolute indication, all cases were included regardless of exclusion criteria. The locations of tumours were evaluated and listed according to the Preoperative Aspects and Dimensions Used for an Anatomical score (PADUA score) [10]. Patients with Padua scores of 7 or below, 8–9 and 10 or above were considered low-risk, intermediate-risk and high-risk patients, respectively. Operative time was defined as the exact surgical time, “skin to skin”. WIT was defined as the time from the placement to the removal of bulldog clamps. LOS was defined as the length of the primary postoperative stay, including transfers to other departments or hospitals and any readmissions within 30 days. The estimated glomerular filtration rate (eGFR) was calculated before surgery and a minimum of 12 months after surgery, according to the following formula: eGFR (ml/min/1.73 m2) = 175 (serum creatinine) – 1.154 (age) – 0.203 (0.742 if female) (1.212 if African American) (conventional units) [11]. Postoperative complications were classified according to the Clavien–Dindo classification of postoperative surgical complications [12]. The patient cohort was divided into three groups, consisting of 20 patients each, according to their surgery dates. Loss of kidney function was calculated as a percentage as follows: (LKF) = (eGFR before – eGFR after/eGFR before operation) 100. The surgical margin, ischaemia and complications rate (MIC) [13] was calculated to compare the outcomes of HALPN with those of other approaches. According to the MIC system, the goal of partial nephrectomy was attained when the surgical margins were negative, the WIT was less than 20 min, and no major complications (grade III–IV according to the Clavien classification) were observed. MedCalc for Windows, version 12.7.7 (MedCalc Software, Ostend, Belgium) was used to analyse the data. A paired t test was used to compare the distribution of eGFR before and after the operations. The Kruskal–Wallis test was used to compare the outcomes between the different cohorts. Multiple
539
regression analysis was performed and correlation coefficients were obtained to examine the relationships of MIC and LKF with various potential predictors. p < 0.05 was considered significant. Operative technique The patient was placed in the left or right lateral decubitus position. The table was flexed and the patient was safely supported on the table. Initial access to the peritoneal cavity was obtained via a subcostal incision on the left side and an inguinal incision on the right side, the length of which corresponded to the glove size of the primary surgeon minus 1 cm (7 cm for a size 8 surgical glove); a GelPort device (Applied Medical, Rancho Santa Margarita, CA, USA) was placed in this incision. A 12 mm trocar was inserted directly into the GelPort device and gas insufflations were started. Next, three accessory (12 mm) trocars were placed on the left side and one 5 mm and three 12 mm trocars were placed on the right side; the 5 mm trocar was used to support the liver. All trocars were inserted under visual control, and 10–15 ml marcain (2.5 mg/ml) was permeated to all trocar incisions. The colon and spleen were dissected from the left kidney, and the colon, duodenum and liver from the right kidney. If the tumour was located at the lower or middle pole, then the ureter was dissected and traced to the renal pelvis; otherwise, the dissection was continued against the renal fascia and a complete exploration of the kidney was achieved. The renal artery and vein were dissected carefully and an elastic tape was placed around each. The tumour was identified and the renal capsule was scored circumferentially by scissors with a 5 mm margin around the tumour. A vascular bulldog clamp was placed on the artery and a timer was started to monitor WIT. The tumour resection was performed using laparoscopic “cold” scissors (no cautery) to allow for clear visualization of normal parenchyma during excision. An assistant surgeon used a water irrigator for traction and to keep the field clear. The excised tumour mass was removed through Gelport incision; then the tumour resection bed was closed with uninterrupted 2-0 Vicryl sutures of 20 cm with Hem-o-lok clips at either end. The bulldog clamp was removed carefully and 3–4 interrupted 0 Vicryl was used to close the parenchymal defect with Hemo-lok clips at either end. All patients received 1– 2 TachoSil mesh on the parenchymal defect as well as a drain tube at the operation bed. No double-J catheter was placed. Fasciae related to the GelPort incision were closed using PDS-0 suture. Preoperative bowel cleansing was not performed. An intraoperative nasogastric tube was inserted as
540
N. H. Azawi et al.
needed, and prophylactic antibiotic was planned preoperatively. A bladder drainage catheter was inserted for all patients and removed on the first postoperative day, and a drainage tube was planned to be removed when there was less than 150 ml accumulation within the first postoperative day.
Scandinavian Journal of Urology Downloaded from informahealthcare.com by University of Pennsylvania on 01/25/15 For personal use only.
Results Sixty patients (Table I) met the inclusion criteria for the HALPN procedure. In nine of the 60 patients, Table I. Preoperative demographic distribution. Age (years)
63 (40–78)
Gender: male
46 (76)
Medical comorbidities Hypertension
14 (23.3)
Diabetes mellitus
5 (8.3)
Coronary artery disease
6 (10)
eGFR before operation (ml/min/1.73 m2)
78 (23–97)
50
52 (87)
Padua score
7 (6–12)
Low (6–7)
33 (55)
Moderate (8–9)
22 (36.6)
High (10) Tumour size (cm) Estimated blood loss (ml)
5 (8.3) 3 (1.7–8) 100 (20–400)
0–50
18 (30)
51–100
13 (21.6)
>100
29 (48.3)
Clavien score £2 ‡3 WIT (min)
57 (9) 3 (5) 6.5 (4–30)
0.05).
Scandinavian Journal of Urology Downloaded from informahealthcare.com by University of Pennsylvania on 01/25/15 For personal use only.
Hand-assisted partial nephrectomy Increased intra-abdominal pressure during laparotomy also impaired renal function [19]. These issues could explain why a short operative time may be associated with decreased LKF. There is clearly a need for more studies to understand the pathophysiological changes that occur during partial nephrectomy, which requires maintaining the current focus on advancing the partial nephrectomy technique towards zero ischaemia time with short operative time and consequent favourable postoperative outcomes. Regarding the learning curve, there was no significant improvement in success rates in the different cohorts according to the MIC system. This finding may have been due to the high success rate obtained after HALPN across different periods, which indicates the efficiency of the HALPN approach compared with other techniques. However, there was a significant learning curve effect with regard to WIT and LKF (Figures 2 and 3), despite increasing tumour sizes and high Padua scores. The limitations of this study are that the sample size was small, the data were collected prospectively but analysed retrospectively, and the follow-up period may have been too short to clarify the impact of LKF on survival. HALPN with early removal of the arterial clamp is safe and easy to learn. The authors believe that an expert laparoscopic surgeon must perform 40 procedures to obtain a WIT of 5 min or less. The MIC system was easy to use, and it is a useful tool for reporting the results of different approaches for partial nephrectomy. WIT, operative time and hypertension contributed significantly to LKF. More studies are needed to improve our understanding of the pathophysiological changes that occur during partial nephrectomy. Declaration of interest: No conflicts of interest exist. There was no funding regarding this paper.
References [1] Ljungberg B, Cowan NC, Hanbury DC, Hora M, Kuczyk MA, Merseburger AS, et al. EAU guidelines on renal cell carcinoma: the 2010 update. Eur Urol 2010;58: 398–406. [2] Gettman MT, Blute ML, Chow GK, Neururer R, Bartsch G, Peschel R. Robotic-assisted laparoscopic partial nephrectomy: technique and initial clinical experience with DaVinci robotic system. Urology 2004;64:914–18. [3] Kaul S, Laungani R, Sarle R, Stricker H, Peabody J, Littleton R, et al. Da Vinci-assisted robotic partial nephrectomy: technique and results at a mean of 15 months of follow-up. Eur Urol 2007;51:186–91.
543
[4] Scoll BJ, Uzzo RG, Chen DY, Boorjian SA, Kutikov A, Manley BJ, et al. Robot-assisted partial nephrectomy: a large single-institutional experience. Urology 2010;75:1328–34. [5] Gill IS, Matin SF, Desai MM, Kaouk JH, Steinberg A, Mascha E, et al. Comparative analysis of laparoscopic versus open partial nephrectomy for renal tumors in 200 patients. J Urol 2003;170:64–8. [6] Aboumarzouk OM, Stein RJ, Eyraud R, Haber GP, Chlosta PL, Somani BK, et al. Robotic versus laparoscopic partial nephrectomy: a systematic review and meta-analysis. Eur Urol 2012;62:1023–33. [7] Azawi NH, Christensen T. Promising early results after hand-assisted laparoscopic partial nephrectomy in carefully selected patients. Dan Med J 2012;59:A4520. [8] Elsamra SE, Leone AR, Lasser MS, Thavaseelan S, Golijanin D, Haleblian GE, et al. Hand-assisted laparoscopic versus robot-assisted laparoscopic partial nephrectomy: comparison of short-term outcomes and cost. J Endourol 2013; 27:182–8. [9] Engel JD, Williams SB. Unclamped hand-assisted laparoscopic partial nephrectomy for predominantly endophytic renal tumors. Urol J 2013;10:767–73. [10] Ficarra V, Novara G, Secco S, Macchi V, Porzionato A, De Caro R, et al. Preoperative aspects and dimensions used for an anatomical (PADUA) classification of renal tumours in patients who are candidates for nephron-sparing surgery. Eur Urol 2009;56:786–93. [11] Levey AS, Coresh J, Greene T, Stevens LA, Zhang YL, Hendriksen S, et al. Using standardized serum creatinine values in the modification of diet in renal disease study equation for estimating glomerular filtration rate. Ann Intern Med 2006;145:247–54. [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] Buffi N, Lista G, Larcher A, Lughezzani G, Ficarra V, Cestari A, et al. Margin, ischemia, and complications (MIC) score in partial nephrectomy: a new system for evaluating achievement of optimal outcomes in nephron-sparing surgery. Eur Urol 2012;62:617–18. [14] Porpiglia F, Bertolo R, Amparore D, Fiori C. Margins, ischaemia and complications rate after laparoscopic partial nephrectomy: impact of learning curve and tumour anatomical characteristics. BJU Int 2013;112:1125–32. [15] Long JA, Yakoubi R, Lee B, Guillotreau J, Autorino R, Laydner H, et al. Robotic versus laparoscopic partial nephrectomy for complex tumors: comparison of perioperative outcomes. Eur Urol 2012;61:1257–62. [16] Weight CJ, Larson BT, Fergany AF, Gao T, Lane BR, Campbell SC, et al. Nephrectomy induced chronic renal insufficiency is associated with increased risk of cardiovascular death and death from any cause in patients with localized cT1b renal masses. J Urol 2010;183:1317–23. [17] Pouliot F, Pantuck A, Imbeault A, Shuch B, Calimlim B, Audet JF, et al. Multivariate analysis of the factors involved in loss of renal differential function after laparoscopic partial nephrectomy: a role for warm ischemia time. Can Urol Assoc J 2011;5:89–95. [18] Corcoran AC, Page IH. Effects of hypotension due to hemorrhage and of blood transfusion on renal function in dogs. J Exp Med 1943;78:205–24. [19] Sugrue M, Buist MD, Hourihan F, Deane S, Bauman A, Hillman K. Prospective study of intra-abdominal hypertension and renal function after laparotomy. Br J Surg 1995;82:235–8.
