Intra-abdominal fat linked to partial nephroctomy complication risk
medwireNews: Intra-abdominal fat (IAF) measurement is a predictor for complication risk following minimally invasive partial nephrectomy (PN), report researchers.
"With further validation, this measurement may prove useful in the preoperative risk stratification of patients with small renal masses," say Michael Gorin (Johns Hopkins Medical Institutions, Baltimore, Maryland, USA) and colleagues.
Currently, body mass index (BMI) is most commonly used as a predictor for PN complication risk, but the relative distribution of body fat may be a more accurate measure, say the researchers.
Gorin and team evaluated BMI, outer-abdominal fat (OAF), and IAF using preoperative computed tomography and magnetic resonance imaging scans available for 195 individuals who underwent laparoscopic and robotic PN treatment for renal masses.
The patients had a mean OAF and IAF of 29.0 mm and 16.5 mm, respectively. Both OAF and IAF significantly correlated with BMI, with OAF showing the strongest correlation.
As reported in Urology, a total of 52 (26.7%) patients experienced a Clavien grade I-IV complication within 30 days of surgery, 16 (30.8%) of which were grade I-II complications (eg, urine leak or bleeding) and 18 (34.6%) were high grade (III-IV).
Multivariate analysis showed that only increasing IAF was significantly associated with grade I-IV complications, while both increasing IAF and intermediate and high tumor complexity (as measured by RENAL nephrometry score) were associated with high-grade complications.
On patient stratification by IAF tertile, 10.2% of those in the lowest quartile for IAF (≤8.05 mm) experienced a grade I-IV complication, compared with 42.9% of those in the highest quartile (≥22.6 mm). In addition, 2.0% of those in the lowest IAF quartile experienced a high-grade complication, compared with 16.3% in the highest quartile.
"One possible explanation for our findings may be that IAF is essentially a measurement of the perirenal fat that the urologist must tackle in order to resect a tumor," say Gorin and team. "This likely leads to poor surgical exposure during the crucial steps of hilar dissection, tumor excision, and renorrhaphy."
The researchers suggest that following further validation, IAF be considered as an additional measure to existing surgical risk predictors.
They add: "This metric may prove useful in counseling patients regarding their surgical risk."
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By Sally Robertson, By medwireNews Reporter