Description and Validation of a Modular Training System for Laparoscopic Nephrectomy

Abstract

Background and Purpose:

Laparoscopic nephrectomy (LN) has largely replaced open nephrectomy. The aim of this study was to describe a validated modular system for training urologists in LN in the context of the shorter training times available in the current era.

Methods:

After attendance at dry and wet laboratory courses, three mentees (trainee, new consultant, and an experienced open surgeon) were mentored through a five-module LN training system in our center followed by the mentee's own hospital. A minimum of 25 independent procedures were then performed by mentees in their own hospital.

Results:

There were 17 to 32 mentored cases needed to become competent in LN, followed by up to 5 observed cases in the mentee's own center. Subsequently, data from the first 105 cases (80 LN and 25 laparoscopic nephroureterectomies [LNU]) performed by the three surgeons after the end of their training without observation by their mentor were retrospectively collected and analyzed. There were three conversions (2.9%). For LN and LNU, respectively: median operative time was 140 minutes (65–390 min) and 180 minutes (90–300 min); median estimated blood loss was 30 mL (0–2000 mL) and 50 mL (0–2000 mL); median postoperative stay was 4 days (2–45 days) and 6 days (3–27 days). Four (3.8%) patients needed a postoperative transfusion. There was no 30-day mortality.

Conclusion:

Mentees matched the median British Association for Urological Surgeons (BAUS) registry operative time (LN, 120–180 min, LNU, 180–240 min) and had lower conversion rates (2.9% vs 6.4% for BAUS). Mentees matched median BAUS database reported blood loss (LN and LNU <500 mL) and length of stay (LN–4 days, LNU–5 days). This modular training program allows urologists to become independent in LN after a short period of focused training in the training center followed by a short period of mentoring in the mentee's own center.

Introduction

L aparoscopic nephrectomy (LN) has largely replaced open nephrectomy for the extirpative treatment of the majority of patients with localized renal-cell cancers (RCCs) as well as most simple nephrectomies. Laparoscopic nephroureterectomy (LNU) has similarly replaced open nephroureterectomy in many specialist centers, although definitive long-term oncologic outcome data are still awaited.¹

LN has become an index procedure in urologic oncology practice, in view of the shift away from the open approach. As such, urology trainees who are planning a uro-oncology practice should develop the skills to enable them to perform LN during their training. There are a number of potential obstacles to urology trainees meeting this goal.

First, unlike laparoscopic cholecystectomy in general surgery, there are no common, simple laparoscopic urology procedures that allow trainees to obtain laparoscopic skills. Second, in some units consultant colleagues have been learning LN themselves, meaning the trainee cannot be taught the technique. Third, many patients with smaller RCCs, which have previously formed the majority of those undergoing straightforward LN, are now being offered nephron-sparing surgery,² leaving a smaller pool for suitable training cases. Finally, in the context of the European Working Time Regulation (EWTR),³ there is a concern about reduced training time available to trainees in which to obtain their surgical competencies.

There are, however, numerous ways that trainees can develop competence in LN, including surgical simulators, dry laboratory and wet laboratory courses.⁴ Furthermore, mentorship programs have been shown previously to improve safety in minimally invasive surgery.⁵ Unlike other laparoscopic procedures, such as endoscopic extraperitoneal radical prostatectomy, there is no published stepwise, modular approach to performing LN.^6,7

The aim of this study was to build on previous suggested mechanisms for mentoring surgeons in laparoscopic urological surgery^8,9 with a validated modular training system in LN that has been developed in our center.

Methods

A 23-step description of the transperitoneal approach to LN has been developed in Edinburgh since 1992 when the first LN was performed in the unit (Table 1). This 23-step approach to LN was developed by three surgeons (DAT, SAM, and ACPR), who sequentially mentored each other over a 19-year period. The individual steps of LN have been designated to five modules (Table 1) of increasing difficulty. The designation of these steps to particular modules was based on the opinion of the surgeons who developed the approach as well as external expert review.

Table 1.

Modular Training Steps of Laparoscopic Nephrectomy

Operation side	Description of surgical step	Module
L+R	Patient positioning	1
L+R	Open (Hasson) placement of 12-mm camera port and insufflation	1
L+R	Open (Hasson) placement of 12-mm camera port and insufflation in obese patient	2
L+R	5-mm port placement (Maryland dissector)	1
L+R	12-mm port placement for working hand (harmonic scalpel, stapler, clip applicator, right angle dissector)	1
L+R	5-mm/12-mm port placement in patient with previous abdominal surgery	2
R	5-mm port placement for liver retraction with Endo Babcock	2
L+R	12-mm port placement for fan retractor to retract kidney	1
L+R	Division of congenital adhesions	2
L+R	Division of extensive adhesions in patient with history of abdominal surgery	3
L+R	Separation of colonic mesentery from Gerota fascia	2
R	Duodenal mobilization and exposure of vena cava demonstrating right gonadal vein entry/ureter	2
L+R	Mobilization of the lower pole	3
L+R	Identification and lateral retraction of the ureter (and left gonadal vein)	2
L+R	Identification of the renal hilum	3
L+R	Skeletonization of renal vein and artery	4
L+R	Clip ligation of renal artery	4
L+R	Division of renal vein with stapler or Hem-o-lok clips	4
L+R	Dissection of the upper pole and sparing of adrenal gland	2/3
L	Dissection of the upper pole and adrenalectomy	4
R	Dissection of the upper pole and adrenalectomy	5
L+R	Specimen entrapment and extraction	2
L+R	Closure of fascia and skin	1

Before commencing the modular training system in LN, individuals were expected to attend the British Association of Urological Surgeons (BAUS) laparoscopy dry laboratory course and subsequent to this, the BAUS laparoscopy wet laboratory course.⁴ After meeting with mentors (ACPR and SAM) and being accepted as mentees, the mentees were mentored through the various modular steps in the mentors center over ∼6 months. One mentee was taught in the department at any time, meaning two mentees/year could be taught. Appropriate training cases were scheduled by the mentor and were generally LN for cT_1–2 RCC, LNU for upper tract urothelial carcinoma, and simple nephrectomies for benign disease. The pace of the mentoring process was tailored to the individual mentee depending on the speed with which the mentee developed competencies.

When the mentor thought the mentee was competent in the complete procedure, the mentee was observed performing a minimum of five procedures in the mentee's own operating environment by the mentor, as suggested previously.⁸ The mentees were then deemed capable to perform LN independently if their performance was judged to be safe. The mentees were expected to submit the audit data of their patients to BAUS and to the mentor for continued review of performance.

To validate the modular system, the operative and postoperative outcomes of a minimum of the 25 initial independent cases (in their own centers, without the mentor present) of three mentees were compared with 25 contemporaneous cases performed by the mentors without a mentee or trainee participating. Operative approach, intraoperative details, postoperative stay, perioperative complications (Clavien-Dindo grade¹⁰), and kidney pathology were prospectively recorded by each mentee and mentors. Operative time and estimated blood loss were collected by the surgeon from the operation notes. For LNU cases, operative time included the endoscopic or open approach to the distal ureter.

Categorical variables were compared using the chi-square test, and continuous variables were compared using the analysis of variance test. All statistical analysis was performed using PASW version 18.0 (SPSS Inc, Chicago, IL); P<0.05 was taken to indicate significance.

Results

The three mentees included in this validation study were: An experienced urologic surgeon who had been a consultant for 15 years with a large experience of open kidney and pelvic surgery but no previous laparoscopic experience; a urologic surgeon within the first 5 years of appointment as a consultant who had previous general surgery laparoscopic experience (as a trainee and established consultant) and some open nephrectomy experience; and a specialist registrar in the final year of training. Two of these mentees were from out of the region in which mentorship occurred. Table 2 summarizes the previous experience of the three mentees.

Table 2.

Details of the Outcomes of Each Mentee's Initial Experience of Laparoscopic Nephrectomy Independent of the Mentor

	Mentee
Variable	1 (Senior consultant)	2 (Junior consultant)	3 (Trainee)	Mentor	BAUS ^*	P value ⁺
Previous experience
Surgical	No lap, open nephrectomy	General surgery lap, open nephrectomy	General surgery and urology lap		N/A
Dry laboratory	Yes	Yes	Yes	N/A	N/A
Wet laboratory	Yes	Yes	Yes	N/A	N/A
Open nephrectomy (cases as surgeon)	800	60	21	N/A	N/A
Training cases needed
Number of operations on each module before competent
Module 1	3	2	2	N/A	N/A
Module 2	4	6	10	N/A	N/A
Module 3	4	10	10	N/A	N/A
Module 4	11	25	15	N/A	N/A
Module 5	2	2	7	N/A	N/A
Total number of training cases	17	32	25	N/A	N/A
Operative details of independent cases
Number of patients	53	25	27	25	1496
Median (range):
Age, years	64.0 (17.0–85.0)	61.6 (16.9–79.1)	64.7 (19.4–84.7)	64.4 (39.7–89.2)	65.0 (16.0–19.0)	0.87 (ANOVA test)
Operation						0.028 (chi–square test)
Laparoscopic simple nephrectomy, n (%)	3 (5.7)	6 (24.0)	7 (25.9)	1 (4.0)	161 (10.8)
Laparoscopic radical nephrectomy, n (%)	38 (71.7)	12 (48.0)	14 (51.9)	21 (84.0)	923 (61.7)
Laparoscopic nephroureterectomy, n (%)	12 (22.6)	7 (28.0)	6 (22.2)	3 (12.0)	286 (19.1)
Intraoperative details
Median (range):
Operative time, min	125 (65–240)	140 (110–315)	180 (100–390)	108 (45–330)	∼120–180	<0.0005 (ANOVA test)
Estimated blood loss, mL	50 (0–2000)	0 (0–2000)	50 (10–2000)	20 (5–12000)	<500	0.076 (ANOVA test)
Transfusion rate (%)	1 (1.9)	3 (12.0)	0	1 (4.2)	59/1165 (5.1)	0.11 (chi–square test)
Conversions (%)	0	2 (8.0)^a	1 (4.2)^b	1 (3.7)^c	87/1439 (6.4)	0.28 (chi–square test)
Postoperative stay, days
Median (range):	5 (2–35)	4 (3–11)	4 (2–18)	5 (2–14)	4 (0–75)	0.29 (ANOVA test)
Perioperative complications, n (%)						0.011 (chi–square test)
No complications	39 (73.6)	22 (88.0)	24 (88.9)	14 (58.3)	NR
Clavien grade I	6 (11.3)	3 (12.0)	2 (7.4)	1 (4.2)	NR
Clavien grade II	7 (13.2)	0	0	8 (33.3)	NR
Clavien grade IIIa	2 (3.8)	0	0	0	NR
Clavien grade IIIb	0	0	1 (3.7)^d	0	NR
Clavien grade IVa	0	0	0	0	NR
Clavien grade IVb	0	0	0	0	NR
Clavien grade V (death)	0	0	0	1 (4.2)^e	NR
Histology, n (%)						0.1 (chi–square test)
RCC	39 (73.6)	11 (44.0)	10 (37.0)	20 (80.0)	840/1368 (61.4)
RCC pT₁ (% of all RCC)	27 (69.2)	6 (54.5)	9 (90.0)	8 (40.0)	NR
RCC pT₂ (% of all RCC)	11 (28.2)	3 (27.3)	1 (10.0)	2 (10.0)	NR
RCC pT₃ (% of all RCC)	1 (2.6)	2 (18.2)	0	10 (50.0)	NR
Oncocytoma	0	0	2 (7.4)	0	38/1368 (27.7)
AML	1 (1.9)	0	1 (3.7)	1 (4.0)	NR
TCC	8 (15.1)	5 (20.0)	7 (25.9)	3 (12.0)	258/1368 (18.9)
Nonfunctioning kidney	4 (7.5)	7 (28.0)	6 (22.2)	1 (4.0)	127/1368 (9.3)
Other	1 (1.9)^f	2 (8.0)^g	1 (3.1)^h	0	105/1368 (7.7)

Personal communication from Sarah Fowler (BAUS Cancer Registry and Audits Manager).

Statistical comparisons are between mentees and mentor only, BAUS figures excluded.

Reason for conversion: ^a(1) splenic tear managed conservatively, (2) duodenal injury and hilar bleeding (infiltrated by tumour); ^bbleeding from angle of renal artery and aorta; ^cfailure to progress

Complications: ^dincarcerated umbilical hernia; ^epost–operative death due to multi–organ failure following large blood loss.

Other pathologies: ^fcystic kidney; ^g(1) sarcoma, (2) squamous cell cancer; ^hXGP

BAUS=British Association for Urological Surgeons; lap=laparoscopy; N/A=not applicable; ANOVA=analysis of variance; NR=not recorded; RCC=renal-cell cancer; AML=acute myelogenous leukemia; TCC=transitional-cell carcinoma.

The mentees needed exposure to a differing number of LN/LNU training cases (17–32 cases) and individual modules before being designated safe for independent practice. The senior consultant, with a vast open nephrectomy experience, needed almost half the number of training cases of some other mentees. The greatest numbers of training cases were needed for the mentees to become competent on module 4 (hilar skeletonization, renal vessel ligation and division). There were few module 5 cases needed to become competent.

Overall, the three mentees performed 105 independent cases between them, which comprised 80 laparoscopic nephrectomies (LN for RCC and benign disease) and 25 LNU. Of note, the first mentee was able to undertake 53 independent cases in the study period, whereas the mentees who were trained subsequently had only performed 25 and 27 cases by the date of analysis. Over this period, the mentor only performed 25 cases in which he was the main surgeon, not involved in any mentoring or teaching of more junior trainees. Overall, there were three (2.9%) conversions. For LN and LNU, respectively, median operative time was 140 minutes (65–390 min) and 180 minutes (90–300 min); median estimated blood loss was 30 mL (0–2000 mL) and 50 mL (0–2000 mL); median postoperative stay was 4 days (2–45 days) and 6 days (3–27 days). In total, four (3.8%) patients needed a postoperative transfusion.

Considering all mentees, there were two postoperative complications necessitating surgical intervention—a pseudo-obstruction and an incarcerated umbilical hernia (thought to have been precipitated by the insufflation pressure). There was no 30-day mortality in any of the 105 independently performed cases.

There was a significant difference in the specific operations performed independently by each surgeon (P=0.028 (chi-square test), Table 2). The senior consultant and mentor together performed a higher proportion of laparoscopic radical nephrectomies because they both had a large RCC practice. The junior consultant and trainee, however, performed a higher proportion of simple nephrectomies for benign disease. There were similar proportions of LNUs performed by each mentee.

In terms of intraoperative data, the only significant difference between the three mentees/mentor was in operative times. The trainee mentee had the longest median operative time (180 min), which was significantly longer than the mentor (P=0.004, independent t test) and senior consultant (P=0.0001, independent t test) but not junior consultant (P=0.1, independent t test).

There was a significant difference in the rate of perioperative complications with the mentor having a significantly higher rate of Clavien grade II complications (mainly chest infections, necessitating antibiotics). There was also one postoperative death in the mentor's series, secondary to multiorgan failure after a large blood loss.

There was a difference in final pathologies of the four surgeons (Table 2). The senior consultant mentee and the mentor both had a higher proportion of RCCs. In the mentor's series, 10 (50%) of the RCCs were pT₃.

Discussion

Our mentoring approach has developed from recommendations made in previous expert summaries,⁸ using a stepwise, modular approach to the transperitoneal LN operation. Our data suggest that this modular approach is valid as a safe technique with which to teach urologists of all grades and experience once they have acquired basic laparoscopic skills through dry and wet laboratory courses. The initial results of the independent cases performed by the mentees compared well with the outcomes of the mentor, suggesting competence has been achieved. In the context of the EWTR, this type of structured, concentrated mentoring approach taking place at the high volume mentor center is required to ensure trainees are safely and efficiently taught the index procedure of LN.

There are a number of strengths to the approach presented above. This is the first time the detailed steps involved in a modular program in LN have been described. The approach described matches that taught on the BAUS dry and wet laparoscopy courses. The validation process has included surgeons of various grades, levels of previous experience, and laparoscopic exposure. We recognize the limitations of this study, including: The small number of mentees included in the validation process; the variable nature of the validation cases, making accurate direct comparisons between mentees and mentor impossible; and the lack of fine detail of each of the operative steps, which precludes objective assessment. Furthermore, we recognize that the number of training cases needed was determined in a subjective fashion by the mentee. Finally, it has not been possible to determine the degree to which mentees were able to deal with relatively rare intraoperative problems such as vigorous hemorrhage.

The level of laparoscopic experience of the mentee urologist did not seem to relate to the number of cases needed to become competent in LN. Indeed, the senior consultant mentee who was very experienced in open nephrectomy, but without any previous laparoscopic experience, was the mentee who worked through the modules to competence most rapidly. The number of cases needed to develop enough skill for independent practice is not important because modern surgical training is competency based—eg, use of the Intercollegiate Surgical Curriculum Programme in the United Kingdom.

In terms of clinical indications for LN, the junior consultant and trainee performed ∼50% LN for RCC, 25% LNU for upper urinary tract urothelial carcinoma, and 25% cases were simple nephrectomies. The renal cancer practice of the senior consultant mentee, however, dictated that he performed a greater proportion of LN for RCC (∼75%), which was a similar level to the mentor (who also has a large renal cancer practice). Whereas the mentees performed LN predominantly for T₁ and T₂ RCC, 53% of the LN for RCC the mentor performed were for T₃ RCC. LN for T₃ RCC has been deemed feasible in selected patients by the European Association of Urology. Furthermore, we have recently described a large series of LN for T₃/T₄ RCC showing that this procedure is surgically safe and oncologically sound.¹¹

The intraoperative details from this validation cohort were comparable with both the mentor's and the BAUS Cancer Registry 2011 figures (personal communication from Sarah Fowler BAUS Cancer Registry and Audits manager). Mentees matched the median BAUS Cancer Registry operative time (120–180 min for LN, 180–240 min for LNU; only ranges for operative time and estimated blood loss are recorded on BAUS Cancer Registry) and had lower conversion rates (2.9% vs 6.4% for BAUS). Mentees matched median BAUS database reported blood loss of <500 mL for both LN and LNU as well as length of stay of 4 days for LN and 5 days for LNU.

The Clavien-Dindo complication classification for the mentees showed an acceptable level of complications with few complications necessitating intervention. Furthermore, the mentees compared favorably with the mentor who had a worse complication profile because of excess of grade II complications (mainly chest infections necessitating antibiotics). The reason for the higher level of complications in the mentor's practice may be because of deliberate selection of low-risk cases by the mentee; the mentor's cases presented here are those cases that were not suitable for the trainee laparoscopic surgeons to perform and so selection bias may have influenced the complication rate.

The acceptable results of the 105 independent LN and LNU performed by three mentees learning a modular approach to LN demonstrate that the procedure can be taught safely and effectively to those with differing laparoscopic and urologic experience over a reasonable period. The following aspects of this modular training system have been identified as key to this method of training: BAUS dry and wet laboratories, which prepare the mentee for the systematic approach to the procedure and the equipment to be used; observing and assisting with the operation with their mentor; developing skills in each sequential module before moving on to the next more technically challenging module; documentation of progress with each module to allow two different mentors using the same modular approach to work with the same mentee; if necessary, the mentees must ensure that their own department supports the introduction of LN as a new technique and that the appropriate equipment is available. A business case may be needed, with the mentor attending the mentee's base hospital to observe at least five cases once the mentee is deemed competent; this ensures the mentor is content that the mentee has translated the technique into the base hospital. The mentee keeps detailed outcome data for 25 cases that is presented to the mentor in 5 to 10 case batches.

Our approach can be compared and contrasted with alternative training programs in urologic laparoscopy. Five-day minifellowship/miniresidency courses have been proven to provide urologic surgeons with an effective introduction and uptake of laparoscopic urology.¹² The Japanese Society of Endourology and ESWL have established the Endoscopic Surgical Skill Qualification System in urologic laparoscopy.¹³ In the Japanese model, the mentees must have completed 2 years of laparoscopic training, performed 20 laparoscopic procedures, and are then independently assessed by two expert referees who view unedited videotapes showing the entire laparoscopic procedure. In the modular training system we have outlined, video recording of challenging steps of the operation (ie, the hilar dissection) for unsupervised cases in the mentee's own center may help the mentor assess final competence in these procedures. Furthermore, the training phase of the modular training system could be enhanced by the use of assessment tools such as Objective Structured Assessment of Technical Skills, Global Operative Assessment of Laparoscopic Skills, or Global Rating Index for Technical Skills.¹⁴

Conclusion

This modular training system in LN has been proven to be useful in training trainee and consultants in LN because it provides a safe system for rapid competence in LN. These modules are currently being used to train selected trainees in our regional training program who wish to pursue a career in laparoscopic urology. Looking to the future, after a successful (or rarely unsuccessful) mentorship process, the mentee may be given a formal outcome and perhaps certification of their newly gained competence in LN.⁹

Footnotes

Acknowledgments

We are grateful to Sarah Fowler (BAUS Cancer Registry and Audits manager) for providing the most recent BAUS outcome data.

Disclosure Statement

No competing financial interests exist.

Abbreviations Used

References

Stewart

, Humphries

, Cutress

et al. Long-term comparative outcomes of open versus laparoscopic nephroureterectomy for upper urinary tract urothelial-cell carcinoma after a median follow-up of 13 years. J Endourol, 2011; 25:1329–1335.

Ljungberg

, Cowan

, Hanbury

et al. EAU guidelines on renal cell carcinoma: The 2010 update. Eur Urol, 2010; 58:398–406.

Directive 2003/88/EC of The European Parliament and of The Council of 4 November 2003. http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2003:299:0009:0019:en:PDF Official Journal of the European Union, 2003 2012 September 21.

Laird

, Stewart

, Hou

et al. A novel bovine model for training urological surgeons in laparoscopic radical nephrectomy. J Endourol, 2011; 25:1377–1383.

Birch

, Asiri

, de Gara

. The impact of a formal mentoring program for minimally invasive surgery on surgeon practice and patient outcomes. Am J Surg, 2007; 193:589–592.

Stolzenburg

, Schwaibold

, Bhanot

et al. Modular surgical training for endoscopic extraperitoneal radical prostatectomy. BJU Int, 2005; 96:1022–1027.

Ganzer

, Rabenalt

, Truss

et al. Evaluation of complications in endoscopic extraperitoneal radical prostatectomy in a modular training programme: A multicentre experience. World J Urol, 2008; 26:587–593.

Keeley

Jr , Timoney

, Rané

, Tolley

. Mentorship in urological laparoscopic surgery: Lessons learned. BJU Int, 2009; 103:1111–1113.

Abboudi

, Ahmed

, Kirby

et al. Mentorship programmes for laparoscopic and robotic urology. BJU Int, 2011; 107:1869–1871.

10.

Clavien

, Barkun

, de Oliveira

et al. The Clavien-Dindo classification of surgical complications: Five-year experience. Ann Surg, 2009; 250:187–196.

11.

Stewart

, Ang

, Laird

et al. The operative safety and oncological outcomes of laparoscopic nephrectomy for T3 renal cell cancer. BJU Int, 2012; 110:884–890.

12.

Kolla

, Gamboa

, Li

et al. Impact of a laparoscopic renal surgery mini-fellowship program on postgraduate urologist practice patterns at 3-year followup. J Urol, 2010; 184:2089–2093.

13.

Matsuda

, Ono

, Terachi

et al. The endoscopic surgical skill qualification system in urological laparoscopy: A novel system in Japan. J Urol, 2006; 176:2168–2172.

14.

Doyle

, Webber

, Sidhu

. A universal global rating scale for the evaluation of technical skills in the operating room. Am J Surg, 2007; 193:551–555.