The impact of laparoscopic adrenalectomy on renal function. Results of a prospective randomised clinical trial

Laparoscopic adrenalectomy is the gold standard management of benign adrenal masses and isolated metastases to adrenal glands. Two techniques of endoscopic adrenalectomy: lateral transperitoneal approach (LTA) and posterior retroperitoneal approach (PRA) seem to be equally safe and effective. Recent studies suggest advantages of PRA over LTA in terms of lower intensity of postoperative pain, shorter hospital stay, faster recovery, and lower early morbidity. However, PRA involves high insufflation pressure of CO₂ within a limited retroperitoneal space. The aim of our study was to prospectively assess the effect of LTA versus PRA laparoscopic adrenalectomies on renal function.

We randomly assigned patients referred for unilateral adrenalectomy to either LTA (n = 33) or PRA (n = 44). The inclusion criteria were: hormonal activity and/or tumour diameter > 4 cm and/or suspicion of metastasis to adrenal gland. The exclusion criteria comprised: tumours > 8 cm, results of imaging studies suggesting primary invasive malignancy, and refusal to undergo randomisation. The patients were prospectively followed for a minimum of six months. Serum creatinine, cystatin C, and urinary neutrophil gelatinase-associated lipocalin (NGAL) were measured preoperatively and at postoperative days: 1, 7, and 30.

We found increased concentrations of urinary NGAL at day 1 following laparoscopic adrenalectomy using PRA, as compared to LTA. Patients undergoing right-sided PRA had increased creatinine concentrations, as compared to left-sided PRA. Patients with aldosterone-producing adenoma had decreased preoperative eGFR as compared to subjects with non-functioning incidentaloma. NGAL increased significantly in this group postoperatively. All the disturbances normalised within one month postoperatively.

Renal function impairment after PRA may result from compression of inferior vena cava by high retroperitoneal pressure during right-sided adrenalectomy. Despite the transient character of the observed abnormalities, we suggest that patients with high risk of acute kidney injury may benefit from an alternative technique of adrenalectomy using LTA.