Elsevier

European Urology

Volume 62, Issue 2, August 2012, Pages 333-340
European Urology

Surgery in Motion
Neurovascular Structure-adjacent Frozen-section Examination (NeuroSAFE) Increases Nerve-sparing Frequency and Reduces Positive Surgical Margins in Open and Robot-assisted Laparoscopic Radical Prostatectomy: Experience After 11 069 Consecutive Patients

https://doi.org/10.1016/j.eururo.2012.04.057Get rights and content

Abstract

Background

Intraoperative frozen-section analysis allows real-time histologic assessment of surgical margins (SMs) and identification of candidates for nerve-sparing (NS) procedures.

Objective

To examine the efficacy and oncologic safety of a systematic neurovascular structure-adjacent frozen-section examination (NeuroSAFE) during NS radical prostatectomy (RP).

Design, setting, and participants

From January 2002 to June 2011, 11 069 consecutive RPs were performed at the University Medical Center Hamburg-Eppendorf. Of these, 5392 (49%) were conducted with NeuroSAFE.

Surgical procedure

Our NeuroSAFE approach included the whole laterorectal circumference of the prostate to determine the SM status of the complete neurovascular tissue-corresponding prostatic surface.

Outcome measurements and statistical analysis

The impact of NeuroSAFE on NS frequency, SM status, and biochemical recurrence (BCR) was analyzed by chi-square test, and by Kaplan-Meier analyses in propensity score–based matched cohorts.

Results and limitations

Positive SMs (PSMs) were detected in 1368 (25%) NeuroSAFE RPs, leading to a secondary resection of the ipsilateral neurovascular tissue. Secondary wide resection resulted in conversion to a definitive negative SM (NSM) status in 1180 (86%) patients. In NeuroSAFE RPs, frequency of NS was significantly higher (all stages: 97% vs 81%; pT2: 99% vs 92%; pT3a: 94% vs 72%; pT3b: 88% vs 40%; p < 0.0001) and PSM rates were significantly lower (all stages: 15% vs 22%; pT2: 7% vs 12%; pT3a: 21% vs 32%; p < 0.0001) than in the matched non-NeuroSAFE RPs. In propensity score–based comparisons, NeuroSAFE had no negative impact on BCR (pT2, p = 0.06; pT3a, p = 0.17, pT3b, p = 0.99), and BCR-free survival of patients with conversion to NSM did not differ significantly from patients with primarily NSM (pT2, p = 0.16; pT3, p = 0.26). The accuracy of our NeuroSAFE approach was 97% with a false-negative rate of 2.5%. The major limitations of this study are its retrospective nature and relatively short follow-up.

Conclusions

NeuroSAFE enables real-time histologic monitoring of the oncologic safety of a NS procedure. Systematic NeuroSAFE significantly increases NS frequencies and reduces PSMs. Patients with a NeuroSAFE-detected PSM could be converted to a prognostically more favorable NSM status by secondary wide resection.

Introduction

Due to considerably improved postoperative potency and measurable effects on continence [1], [2], radical prostatectomy (RP) should be performed using a nerve-sparing (NS) technique as long as the oncologic outcome is not compromised [3]. However, NS is always a balancing act between the ambition to preserve as much quality of life as possible and the risk of compromising cancer control by leaving residual tumor behind in the preserved neurovascular tissue.

Intraoperative frozen-section (IFS) analysis of the whole neurovascular tissue-adjacent circumference enables a rapid but comprehensive histologic surgical margin (SM) assessment, allowing the surgeon to intraoperatively demonstrate the oncologic safety of an NS procedure. The clinical impact of IFS-guided NS during RP is controversial. The main points of criticism are that IFS is time and resource consuming, has low sensitivity and specificity, and has potentially conflicting oncologic results [4], [5], [6]. In our study, we assessed the clinical value of a complete neurovascular structure-adjacent frozen-section examination (NeuroSAFE) approach in a consecutive cohort of 11 069 RP patients.

Section snippets

Patient population

Data from 11 231 consecutive patients who underwent RP in our institution between January 2002 and June 2011 were analyzed. All procedures were performed by 12 surgeons according to our institutional surgical standard. All data were collected prospectively into an institutional review board-approved database. One hundred sixty-two patients were excluded due to neoadjuvant hormonal treatment (n = 124) or prior radiation therapy (n = 38). RP was performed using an open retropubic approach (n = 10 427)

Description of patient population

Clinicopathologic data are detailed in Table 2. Overall, 5392 RPs (48.7%) were navigated by NeuroSAFE. The standard tumor parameters were significantly worse in the NeuroSAFE group compared to non-NeuroSAFE patients, revealing a considerable selection bias. Adjustment for those confounding biases by propensity score–based matching resulted in a cohort of 2567 matched pairs. Of these, 161 (3%) and 17 (0.2%) of the NeuroSAFE, and 239 (4.2%) and 41 (0.7%) of the non-NeuroSAFE patients received an

Discussion

NeuroSAFE enables real-time histologic monitoring of the oncologic safety of a NS procedure. Our study demonstrates that patients undergoing NeuroSAFE-guided RP can significantly benefit from increased NS frequencies and decreased PSM rates without compromising oncologic outcome.

A particular feature of prostate cancer surgery is that >50% of the prostate surface is closely surrounded by functional neurovascular tissue [16]. The area of NS is prone to PSMs, which can be induced by ECE or

Conclusions

NeuroSAFE is an oncologically safe concept allowing intraoperative monitoring of patients in whom NS can be appropriately performed. A systematic application of this approach results in a significant increase of NS and significant reduction of PSMs in RP. Moreover, patients with a PSM could be converted to a prognostically more favorable NSM state by secondary resection of the ipsilateral neurovascular tissue.

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These authors contributed equally to this work and therefore share first authorship.

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