Association of Mayo Adhesive Probability Score With Perioperative Outcomes and Histological Characteristics of Adherent Perinephric Fat in Laparoscopic Adrenalectomy

Background/aim: To evaluate the difficulty of laparoscopic adrenalectomy by investigating the usefulness of the Mayo Adhesive Probability (MAP) score for assessing adherent perinephric fat and its correlation with histological reality.

Patients and methods: We retrospectively evaluated 103 patients who underwent laparoscopic adrenalectomies. Based on preoperative computed tomography images, the patients were categorized into two groups: high (3-5 points) and low MAP (0-2 points). Clinical characteristics and perioperative data were compared between the two groups. Additionally, we analyzed the pathological tissue of the tumor and surrounding fat using hematoxylin-eosin-saffron staining.

Results: Compared with the low MAP group, the high MAP group had younger patients (59 vs. 62 years, p=0.097), more male patients (93.3% vs. 44.3%, p<0.001), and higher body mass indices (26.4 vs. 23.8, kg/m², p=0.029). The MAP group experienced a significantly higher estimated blood loss compared to the low MAP group (10 vs. 52.3, ml, p=0.047). Tumor and adhering perirenal fat tissues of pheochromocytoma, adrenal carcinoma, and metastatic adrenal tumors exhibited significantly higher expression of vascular endothelial growth factor and cluster of differentiation 204 compared to the low MAP group (p<0.001). Additionally, both proteins were highly expressed in the adhering perirenal fat in the high MAP group (p=0.020, p=0.015).

Conclusion: Patients with a preoperative MAP score ≥3, pheochromocytoma, or malignant tumor had a high risk of increased intraoperative blood loss. Strict perioperative management should be performed in such cases.