3D laparoscopic prostatectomy: A prospective single-surgeon learning curve in the first 200 cases with oncologic and functional results

Robot-assisted versus three-dimensional laparoscopic radical prostatectomy: 12-month outcomes of a randomised controlled trial

OBJECTIVES

To compare functional and oncological outcomes of robot-assisted laparoscopic prostatectomy (RALP) to three-dimensional laparoscopic radical prostatectomy (3D-LRP) at 12 months after surgery.

PATIENTS AND METHODS

Prospective randomised single-centre study of 145 consecutive men referred to radical prostatectomy in a tertiary referral centre in Finland. Patients were randomised 1:1 to the RALP (N = 75) and 3D-LRP (N = 70) groups. The primary outcome was urinary continence evaluated with the Expanded Prostate Cancer Index Composite 26-item version (EPIC-26) incontinence domain score at 12 months after surgery. Secondary outcomes included the use of protective pads at 12 months after surgery, EPIC-26 domain scores of irritative/obstructive, bowel, sexual and hormonal symptoms, positive surgical margin (PSM) rate, and biochemical recurrence (BCR). Complication frequency within the 3-month period after surgery was evaluated according to Clavien-Dindo classification. Statistical significance between groups was analysed using Mann-Whitney, chi-square and Fisher's exact tests. The trial was terminated after interim analysis based on no statistically significant difference in EPIC-26 urinary incontinence domain scores. Altogether 145 patients of the target accrual of 280 patients were recruited.

RESULTS

Postoperative continence at 12 months after surgery according to the EPIC-26 incontinence domain was 79.25 in both groups (P = 0.4). Between group difference was -5.8 (95% confidence interval -15.2 to 3.6). There was no statistically significant difference in the rates of PSM or BCR between the two surgical modality groups.

CONCLUSION

We were unable to demonstrate a difference between the RALP and 3D-LRP groups for functional and oncological outcomes at 12 months after surgery.

CUSUM learning curves: what they can and can't tell us

INTRODUCTION

There has been increased interest in assessing the surgeon learning curve for new skill acquisition. While there is no consensus around the best methodology, one of the most frequently used learning curve assessments in the surgical literature is the cumulative sum curve (CUSUM) of operative time. To demonstrate the limitations of this methodology, we assessed the CUSUM of console time across cohorts of surgeons with differing case acquisition rates while varying the total number of cases used to calculate the CUSUM.

METHODS

We compared the CUSUM curves of the average console times of surgeons who completed their first 20 robotic-assisted (RAS) cases in 13, 26, 39, and 52 weeks, respectively, for their first 50 and 100 cases, respectively. This analysis was performed for prostatectomy (1094 surgeons), malignant hysterectomy (737 surgeons), and inguinal hernia (1486 surgeons).

RESULTS

In all procedures, the CUSUM curve of the cohort of surgeons who completed their first 20 procedures in 13 weeks demonstrated a lower slope than cohorts of surgeons with slower case acquisition rates. The case number at which the peak of the CUSUM curve occurs uniformly increases when the total number of cases used in generation of the CUSUM chart changes from 50 to 100 cases.

CONCLUSION

The CUSUM analyses of these three procedures suggests that surgeons with fast initial case acquisition rates have less variability in their operative times over the course of their learning curve. The peak of the CUSUM curve, which is often used in surgical learning curve literature to denote "proficiency" is predictably influenced by the total number of procedures evaluated, suggesting that defining the peak as the point at which a surgeon has overcome the learning curve is subject to routine bias. The CUSUM peak, by itself, is an insufficient measure of "conquering the learning curve."