Prospective assessment and histological analysis of adherent perinephric fat in partial nephrectomies.
The complexity of partial nephrectomy (PN) is partly anticipated by morphometric tumor-based scores that do not consider patient-related issues such as adherent perinephric fat (APF). Also, the objective is to prospectively assess the predictive factors of APF during PN, its effect on complications, and to correlate it to the histological reality.



A total of 125 consecutive patients undergoing robotic or open PN were prospectively included. The Mayo adhesive probability score (MAP score) was compared to the peroperative presence of APF defined by a score≥2. Adipose tissue was analyzed histologically for fibrosis and inflammatory infiltrate of CD68+macrophages. Univariate and multivariate logistic regression analyses were performed to evaluate predictive factors of APF, and outcomes were compared using chi-square and Kruskal-Wallis tests.



APF was present in 51 patients (40.8%) and associated with slight longer operating time and increased blood loss. Warm ischemia time, margins, transfusion, and the Clavien-Dindo score were not different. In multivariate analysis, only male sex, age, waist circumference, fat density on computed tomography, and MAP score were significant predictors of APF. A radioclinical score was more predictive of APF than MAP score alone. Histologically, there was no macrophage infiltration but larger adipocytes in APF without significant differences in fibrosis.



APF can be accurately predicted using radioclinical data as the MAP score, combined with sex, age, and waist circumference. APF is associated with increased operative time and blood loss without postoperative complications. Histological analysis finds larger adipocytes in APF without inflammatory infiltrate, and no difference in fibrosis.
Department of Urology, Hôpital européen Georges-Pompidou (HEGP), Assistance Publique-Hôpitaux de Paris (APHP), Paris, France; Paris-Descartes University, Paris, France.
Charles
C
Dariane
Department of Urology, Hôpital européen Georges-Pompidou (HEGP), Assistance Publique-Hôpitaux de Paris (APHP), Paris, France; Paris-Descartes University, Paris, France.
Thomas
T
Le Guilchet
Department of Urology, Hôpital européen Georges-Pompidou (HEGP), Assistance Publique-Hôpitaux de Paris (APHP), Paris, France; Paris-Descartes University, Paris, France.
Sophie
S
Hurel
Department of Urology, Hôpital européen Georges-Pompidou (HEGP), Assistance Publique-Hôpitaux de Paris (APHP), Paris, France; Paris-Descartes University, Paris, France.
François
F
Audenet
Department of Urology, Hôpital européen Georges-Pompidou (HEGP), Assistance Publique-Hôpitaux de Paris (APHP), Paris, France; Paris-Descartes University, Paris, France.
Aurélien
A
Beaugerie
Paris-Descartes University, Paris, France; Department of Pathology, HEGP, APHP, Paris, France.
Cécile
C
Badoual
Nutrition Department, Institute of Cardiometabolism and Nutrition (ICAN), APHP, Pitié-Salpêtrière Hospital, Paris, France; Sorbonne Universités, UPMC University Paris 06, INSERM, UMR_S 1166, NutriOMique, Paris, France.
Joan
J
Tordjman
Nutrition Department, Institute of Cardiometabolism and Nutrition (ICAN), APHP, Pitié-Salpêtrière Hospital, Paris, France; Sorbonne Universités, UPMC University Paris 06, INSERM, UMR_S 1166, NutriOMique, Paris, France.
Karine
K
Clément
Clinical Research Unity, Tarnier Hospital, APHP, Paris, France.
Saïk
S
Urien
Department of Urology, Hôpital européen Georges-Pompidou (HEGP), Assistance Publique-Hôpitaux de Paris (APHP), Paris, France.
Michel
M
Pietak
Department of Urology, Hôpital européen Georges-Pompidou (HEGP), Assistance Publique-Hôpitaux de Paris (APHP), Paris, France.
Eric
E
Fontaine
Department of Urology, Hôpital européen Georges-Pompidou (HEGP), Assistance Publique-Hôpitaux de Paris (APHP), Paris, France; Paris-Descartes University, Paris, France.
Arnaud
A
Méjean
Department of Urology, Hôpital européen Georges-Pompidou (HEGP), Assistance Publique-Hôpitaux de Paris (APHP), Paris, France; Paris-Descartes University, Paris, France. Electronic address: marc-olivier.timsit@aphp.fr.
Marc-Olivier
MO
Timsit
D000273:Adipose Tissue / Q000473:pathology*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016063:Blood Loss, Surgical; D006801:Humans; D007668:Kidney / Q000473:pathology* / Q000601:surgery*; D016015:Logistic Models; D008875:Middle Aged; D015999:Multivariate Analysis; D009392:Nephrectomy / Q000379:methods*; D061646:Operative Time; D011446:Prospective Studies; D055105:Waist Circumference; D055815:Young Adult
Adherent perinephric fat; Fibrosis; Partial nephrectomy; Perirenal fat; Renal cell carcinoma