What are the advantages of laparoscopic radical prostatectomy (LRP)? In a recent review [2], we were not able to identify a single prospective randomised trial (phase 3 study) comparing both approaches. As we have learnt mainly from pharmacologic studies, only such results may yield an evidence level of IA/B. However, comparison of drugs differs entirely from the comparison of surgical techniques. There exists no “placebo double-blinded surgery” and the outcome of any surgical techniques depends on multiple factors:

• the expertise and experience of the surgeon (ie, surgeon's preference)
• the complexitiy of the procedure (ie, learning curve)
• the patient selection (ie, comorbidities)
• the assessment of the outcome (ie, methodology)

1. Surgeon's preference and learning curve

Of course, an experienced surgeon who has passed the “learning curve” of a procedure (RRP, LRP) may be able to perform both techniques in a randomised, prospective trial. However, in most cases this surgeon has his own preference regarding both techniques. This might be reflected by the last cases he did before starting the study and by his individual learning curve.

Theoretically, a comparison of surgical technques should be biased by the learning curve; however, this is a very difficult task. Various authors tried to define the learning curve of LRP [3–6], but there is a consensus only regarding the transferability of the technique and not about the number of procedures required. Some authors state that 20–50 cases might be sufficient to pass the learning curve of LRP, and others argue that RRP can be trained very easily (ie, see one, do one, teach one). My personal experience with both approaches [7] is entirely different: I strongly believe that radical prostatectomy—open or laparoscopic—represents a technique that underwent a continuous process of improvement concerning all relevant factors such as operating time, transfusion rate, complication rate, preservation of neurovascular bundle, and modifications of dissection for early continence. As a result, just recently a very experienced center [8] published, in this journal, their actual technique of nerve-sparing RRP.

Consecutively, there is a double bias in this study. On one hand, the surgeon has a 15-yr experience with RRP (>1000 cases) versus only 150 cases of LRP, whereas the latter represents his preferred and recently more frequently applied operative technique. However, it has to be stressed that the format of this study reaches the lowest bias level concerning the expertise and learning curve of the surgeon.

2. Patient selection and assessment of the outcome

The type of randomisation (computer-generated randomisation table) remains one of the weak points of the study. Why were 120 consecutive patients age-matched? What about the preferences of the patients to be operated by one of the two techniques? However, at least all analysed patient parameters were comparable in both arms.

The results of the study were in accordance with our recent meta-analysis [2] of comparative studies:

• LRP requires a longer operative time.
• LRP is associated with less blood loss.
• LRP requires fewer analgesics.
• LRP enables earlier mobilisation.
• LRP leads to a high rate of early catheter removal.
• LRP shows the same rates of positive margins.

The postoperative pain score did not differ significantly in between groups; however, if one takes the cumulative data (relative risk to postoperative day 3), the differences become significant as well as the cumulated requirement of analgesics. It has been already shown by Fornara and Zacharis [9] that the objective parameters evaluating the acute-phase reaction following RRP and LRP do not differ when comparing laparoscopic versus open radical prostatectomy. Nevertheless, this phase 3 study confirms the advantages of LRP as a less invasive technique.

3. Perspectives

Can we expect more? Of course, there might be further advantages concerning the convalescence period of both groups, which was not analysed by the authors. Advocates of RRP still ask for more. Theoretically, the better vision should result in a better dissection technique and thus higher rates of early continence and potency. Indeed, improvement areas in radical prostatectomy include:

• the rate of positive margins in case of pT2 tumours (which should be ideally 0%)
• the rate of early catheter removal (which should be ideally 100% after 5–7 d)
• the rate of early continence (which should be ideally 100% after 3 months)
• the rate of potency (which should be at least 70–90% in well-selected patients)

Based on the technical improvement by the use of video-endoscopic surgery in well-trained hands, some steps seem to be achievable. This study already shows the superior quality of the anastomosis, if performed laparoscopically. It is mainly related to the fact that the endoscopic technique allows the completion of the anastomosis under vision in contrast to the open technique [8].

On the other hand, LRP does not allow palpation and, therefore, other senses have to be developed, such as the interpretation of the magnified anatomy (ie, from 2.5-fold to 10-fold). One of the main advantages is that these details are present for everyone in the operating room and the entire case can be recorded. Based on this, the critical steps of the procedure (ie, apical dissection) can be reiterated and discussed with the pathologist to identify the source of positive margins [10].

It has to mentioned that after only 7 years LRP has become an established surgical technique for the management of localised prostate cancer, meeting the end points of RRP (positive margins and oncologic and functional outcome). Further emphasis will be on improving the outcome beyond the simple adavantages of the minimally invasive approach proven by this study with an evidence level IB. For this purpose further studies are necessary.

I am quite sure that not many similar studies will be presented in the future because there will not be many surgeons with comparable expertise in both techniques. Therefore, a follow-up study of the two groups is of utmost importance, including a cost analysis as well as mid- and long-term follow-up.

References

1. Guazzoni G, Cestari A, Naspro R, et al.. Intra- and perioperative outcomes comparing radical retropubic and laparoscopic radical prostatectomy: results from a prospective, randomised, single surgeon study. Eur Urol. 2006;50:98–104.
2. Rassweiler J, Hruza M, Teber D, Su LM. Laparoscopic and robotic assisted radical prostatectomy—critical analysis of the results. Eur Urol. 2006;49:612–624.
3. Poulakis V, Dillenburg W, Moeckel M, et al.. Laparoscopic radical prostatectomy: prospective evaluation of the learning curve. Eur Urol. 2005;47:167–175.
4. Frede T, Erdogru T, Zukosky D, Gulkesen H, Teber D, Rassweiler J. Comparison of training modalities for performing laparoscopic radical prostatectomy: experience with 1,000 patients. J Urol. 2005;174:673–678.
5. Bollens R, Sandhu S, Roumeguere T, Quackels T, Schulman C. Laparoscopic radical prostatectomy: the learning curve. Curr Opin Urol. 2005;15:1–4.
6. Stolzenburg JU, Rabenalt R, Do M, Horn LC, Liatsikos EN. Modular training for residents with no prior experience with open pelvic surgery in endoscopic extraperitoneal radical prostatectomy. Eur Urol. 2006;49:491–498.
7. Rassweiler J, Seemann O, Schulze M, Teber D, Hatzinger M, Frede T. Laparoscopic versus open radical prostatectomy: a comparative study at a single institution. J Urol. 2003;169:1689–1693.
8. Graefen M, Walz J, Huland H. Open retropubic nerve-sparing radical prostatectomy. Eur Urol. 2006;49:38–48.
9. Fornara P, Zacharias M. Minimal invasiveness of laparoscopic radical prostatectomy: reality or dream?. Aktuelle Urol. 2004;35:395–405.
10. Touijer K, Kuroiwa K, Saranchuk JW, et al.. Quality improvement in laparoscopic radical prostatectomy for pT2 prostate cancer: impact of video documentation review on positive surgical margin. J Urol. 2005;173:765–768.

Jens Rassweiler,
Department of Urology, SLK Kliniken Heilbronn, Germany

published online 27 March 2006.

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