The effect of the da Vinci® Vessel Sealer on robot-assisted laparoscopic prostatectomy complications.

The da Vinci® Vessel Sealer is a major contributor to the total cost of robot-assisted laparoscopic prostatectomy (RALP). We aimed to assess whether the use of the Vessel Sealer is associated with better surgical outcomes in a population of patients that underwent RALP with lymphadenectomy. We tested whether the use of the Vessel Sealer is associated with the development of lymphocele and/or other surgical outcomes. Most surgeons used the Vessel Sealer in almost all or almost no patients. Thus, to avoid the potential confounding variable of surgeon skill, we performed the initial analyses using data from a single surgeon who changed practice over time, and then using the entire population. Overall, the Vessel Sealer was used in 500 (36%) RALPs. Surgeon 1 performed 492 surgeries, and used the Vessel Sealer in 191 (39%). The Vessel Sealer was not associated with better surgical outcomes in patients operated on by Surgeon 1. The odds ratio for development of lymphocele was 1.95 (95% confidence interval [CI] 0.57-6.75). In the entire population, use of the sealer was significantly associated with a very small reduction of blood loss (22 cc, CI 13-30) but with a 32-min increase in the operating room time (CI 26-37). Use of the Vessel Sealer will have, at best, a very small effect on RALP outcomes that is of highly questionable relevance given its cost. In light of these results, the Vessel Sealer will only be used at our institution in the context of clinical trials.

Prostate-specific Antigen Density Cutoff of 0.15 ng/ml/cc to Propose Prostate Biopsies to Patients with Negative Magnetic Resonance Imaging: Efficient Threshold or Legacy of the Past?

BACKGROUND: A prostate-specific antigen density (PSAd) cutoff of 0.15 ng/ml/cc is a commonly recommended threshold to identify patients with negative prostate magnetic resonance imaging (MRI) who should proceed to a prostate biopsy. We were unable to find any study that explicitly examined the properties of this threshold compared with others. OBJECTIVE: To investigate whether the 0.15 cutoff is justified for selecting patients at risk of harboring high-grade cancer (Gleason score ≥3 + 4) despite negative MRI. DESIGN, SETTING, AND PARTICIPANTS: A cohort of 8974 prostate biopsies provided by the Prostate Biopsy Collaborative Group (PBCG) was included in the study. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Locally weighted scatterplot smoothing was used to investigate whether there was a change in the risk of high-grade cancer around this value. We examined whether the use of this cutoff in patients with negative MRI corresponds to a reasonable threshold probability for a biopsy (defined as a 10% risk of high-grade disease). To do so, we applied the negative likelihood ratio of MRI, calculated from eight studies on prostate MRI, to the risk curve derived from the PBCG. RESULTS AND LIMITATIONS: There was no discontinuity in the risk of high-grade prostate cancer at a PSAd cutoff of 0.15. This cutoff corresponded to a probability of high-grade disease ranging from 2.6% to 10%, depending on MRI accuracy. Using 10% as threshold probability, the corresponding PSAd cutoff varied between 0.15 and 0.38, with the threshold increasing for greater MRI accuracy. Possible limitations include difference between studies on MRI and the use of ultrasound to measure prostate volume. CONCLUSIONS: The 0.15 cutoff to recommend prostate biopsies in patients with negative MRI is justified only under an extreme scenario of poor MRI properties. We recommend a value of at least ≥0.20. Our results suggest the need for future studies to look at how to best identify patients who need prostate biopsies despite negative MRI, likely by using individualized risk prediction. PATIENT SUMMARY: In this study, we investigated whether the commonly used prostate-specific antigen density cutoff of 0.15 is justified to identify patients with negative magnetic resonance imaging (MRI) who should proceed to a prostate biopsy. We found that this cutoff is appropriate only in case of very poor MRI quality, and a higher cutoff (≥0.20) should be used for the average MRI.