Page 23 - Read Online

Page 2 of 10 Mari et al. Mini-invasive Surg 2024;8:7 https://dx.doi.org/10.20517/2574-1225.2023.103

(ECOG) score ≥ 1 and American Society of Anesthesiologists physical status (ASA PS) score ≥ 3, respectively.
Surgical indications were elective in 90.5% of cases. The preoperative aspects and dimensions used for an
anatomical (PADUA) score median was 8.0 (interquartile range: 7.0-9.5). The predominant histotype was clear
cell RCC, accounting for 70.4% of the cohort. PSMs were detected in 6.7% of the patients. Multivariable logistic
regression showed surgical indications with an odds ratio (OR) of 6.06 (P < 0.001), surface, intermediate, base
(SIB) score > 1 with an OR of 2.37 (P = 0.001), and PADUA score with an OR of 1.10 (P = 0.006) were significant
predictors of PSMs.

Conclusion: Attaining negative margins remains the oncological cornerstone of partial nephrectomy. Our data
underscore that tumor-specific (PADUA score) and surgical parameters (imperative indication, SIB score > 1, off-
clamp approach) are the principal determinants for PSMs after RAPN.

Keywords: Partial nephrectomy, positive margin, predictors, renal cancer, robotics

INTRODUCTION
Partial nephrectomy (PN) has been widely accepted as the preferred treatment for patients with clinical T1
[1]
renal cell carcinoma (RCC) . This method not only offers the advantage of preserving renal function but
also has oncologic outcomes similar to radical nephrectomy . However, one challenge in PN is the
[2,3]
potential for positive surgical margins (PSMs). PSM rates after PN have been reported to range from 0% to
10% . This risk appears to be higher in surgeries involving smaller, high-grade tumors or those considered
[4]
[5,6]
imperative, regardless of the surgical approach used .
The implications of PSMs on cancer recurrence and patient survival are still debated among experts. While
some studies suggest that local tumor recurrence is more common in cases with PSMs, especially for
inherently aggressive tumors, others find minimal impact of PSMs on cancer-specific survival . Given the
[7,8]
lengthy progression of T1 RCC after surgery, the PSM could be used as a surrogate of oncologic outcome
after surgery, and, as such, it is an essential measure for evaluating outcomes after PN. Evidence suggests
that patients with PSMs might experience reduced overall survival; however, other factors related to patient
characteristics, such as age and comorbidities, and tumor characteristics, such as tumor fat invasion and
nucleolar grade, might play a role . In the current literature, there is a noticeable gap in models designed to
[9]
predict the likelihood of PSMs after PN.

The present study aims to fill this gap by identifying predictors of PSMs after PN based on data from a
prospectively maintained database of a tertiary referral center.

METHODS
Population data
After obtaining approval from the ethics committee, we accessed and examined our continuously updated
institutional RCC database, which was maintained prospectively. From this database, we specifically
analyzed 1611 patients who underwent robot-assisted PN (RAPN) between January 2017 and December
2022. Patient characteristics, such as age, gender, Body Mass Index (BMI), and comorbidity status, were
documented. This included the Charlson Comorbidity Index (CCI) assessment, among others.

The principles of SIB (Surface, Intermediate, Base) score assignment have been previously described [10,11] . In
summary, post-operative examination allowed the medical practitioner to demarcate the Circumferential
Surface, Intermediate, and Base meta-zones within the intrarenal section of the PN specimen. Subsequently,
the domain with the most minimal boundary (named score-specific area) within each meta-zone was