AUA Annual Meet ingMay 16-21, 2014

ORLANDO, FL, USA

Determination of the learning curve of robotic flexible ureterorenoscopy

Zafer Tokatli*1, Ahmet Yaser Muslumanoglu2, Evren Suer3, Mehmet Ilker Gokce 3, AbdulkadirTepeler4, Okan Bas5, Emrah Yuruk2, Omer Onur Cakir2, Gokhan Atis6, Gurdal Inal 1, Remzi Saglam1

1Department of Urology, Medicana International Hospital, Ankara; 2Department of Urology, Bagcilar Training Hospital, Istanbul, Turkey;

3Department of Urology, Ankara University Medical School Hospital, Ankara, Turkey; 4Department of Urology, Bezm-i Alem University Hospital, Istanbul, Turkey; 5Oncology Training Hospital, Ankara, Turkey. 6Department of Urology, Göztepe Training Hospital, Istanbul, Turkey;

ObjectivesRetrograde intrarenal surgery (RIRS) is rapidly evolving in the last decade based on significant improvements of the armamentarium especially Flexible ureterorenoscopy (FURS). Our study consisted of three steps. Our objective in the first step was to compare the performance of FURS experts and trainees on robotic FURS performed with RoboflexTM Avicenna device (ELMED, Turkey). In the second step to follow the increase of the robotic performance of them, from beginning to the maximum performance.and to search how many cases do we need to reach the manual performance of the experienced user. Third step is developed to overcome the short-comings of second step and to maintain standardized evaluation of learning curves of both experts and trainees who have used the RoboflexTM device.

MethodsA total of 7 experts (Group 1) and 7 trainees (Group2) of fURS were included to the study group. All the participants used Storz flexX2 for manual fURS and Robotic FURS. Participants who had performed > 50 FURS were accepted as experts and lower than 10 case as trainees. After watching a video showing all functions of RoboflexAvicena all of the participant request-ed to drive into the Minnesota University Kid-ney Model from the ureter to the upper calices, middle calix and lover calices and came back to the ureter. They did same manually. All of the participants performed both flexible and robotic fURS twice. During all procedures a record was kept of the duration and the mean time values of the groups were compared.

MethodsFor the second step: we started a prospective multicentric, randomised clinical trial to compare manual vs robotic fURS and determine the learning curve. The trial is based on the CT calculated volume of the stone and progress of the fragmented stone volume/minute and the progress with the experience.

STEP 1

STEP 2

STEP 3

Results Mean age of the study group was 39 years old and both of the groups mean age values were similar. Mean time to evaluation of calicial system for the two groups is summarized in table 1

Results Second step was terminated as the study protocol was found to be inappropriate to reach the objectives. The results were effected from a number of parameters, such as caliceal anatomy, type of the device and laser device, surgeons experience etc.

MethodsA unique kidney model (figure 1) was developed and standard stones volume of 5 mm3 were fragmented by a group of experts (> 50 FURS) and trainees. Each participant performed both manual and robotic FURS and time to completion of fragmentation (all fragments <2 mm) was recorded. Holes of 2 mm diameter were located atthe bottom of the calyx of the model and fragments <2mm dropped down so completion of fragmentation was observed objectively. However some fragments <2 mm did not drop down so the participants were allowed to end the session when they felt all the residual fragments were <2 mm in size. Size of the biggest fragment was measured with a sensitive ruler to decide appropriate fragmentation. All sessions were performed with the same ureterorenoscope (FlexXC, ureteroscope, Storz, Germany) and laser device (Auriga XL).

ResultsTo date, 5 experts and 5 trainees were involved in the study. The trial is still going on and 15 participant for each group (experts & trainees) is planned to be involved. Time to fragmentation of each participant is given in table 2.

ConclusionsRobotic-assisted flexible ureterorenoscopy using the Avicenna RoboflexTM provides a suitable and safe platform for FURS with significant improvement of ergonomics. However Learning curves of the surgeons for performing RoboflexTM is an important subject to investigate. This ongoing trial on a kidney model with standard calyceal anatomy, laser type and energy level will maintain relevant data on learnig curves of both experts and trainees and the time of fragmentation seems to decrease even after the second procedure. Additionally the time of the fragmentation seems to be shorter than manual by roboflex in the trainees group, and they can reach the level of experts in the 4 th trial.

Group 1 Group 2 P value

Manual 1(mean) 69 110 < 0,05

Manual 2 (mean) 58 91 < 0,05

Robotic 1 171 180 > 0,05

Robotic 2 126 128 > 0,05

Table 1Table 2. Time to fragmentation of experts and trainees groups

Experts Group Trainees Group

Expe

rt 1

Expe

rt 2

Expe

rt 3

Expe

rt 4

Expe

rt 5

Avar

age

Trai

nees

1

Trai

nees

2

Trai

nees

3

Trai

nees

4

Trai

nees

5

Avar

age

Manuel 1 24 18 23 25 30 24 40 58 45 35 40 43.6Manuel 2 18 17 25 23 28 22.2 35 36 39 32 38 35Manuel 3 23 19 24 20 25 22.2 38 34 39 30 35 35.2Manuel 4 22 17 22 22 26 21 32 35 35 28 36 33.2Manuel 5 20 18 20 22 24 20.8 30 33 30 31 34 31.6Robotic 1 32 31 39 31 40 34.6 39 44 36 34 32 37Robotic 2 31 30 26 29 34 30 32 30 34 28 30 30.8Robotic 2 27 28 27 25 28 27 28 29 32 27 29 29Robotic 4 27 25 28 26 26 26.4 26 28 28 27 26 27Robotic 5 27 26 27 25 26 26.2 25 27 26 24 25 25.4

Acrylic Kidney ModelRoboticfragmentation in the Acrylic Kidney Model

Manual fragmentation of artifical stone in the Acrylic Kidney Model