Patient Characteristics
Altogether, 23 patients, including 10 male and 13 female patients met the inclusion and exclusion criteria and were thus enrolled, whose baseline characteristics were summarized in Table 1. The median age, BMI and preoperative eGFR were 49.0 years (range, 22-67), 23.8 kg/m2 (interquartile range (IQR), 20.8-27.0) and 94.0 ml/min/1.73m2 (IQR, 82.4-105.7), respectively. Six (26.1%) patients had a history of abdominal surgery. Nine (39.1%) patients had hormone-active tumor, including five (21.7%) aldosterone-producing adenoma (APA), two (8.7%) cortisol-producing adenoma (CPA) and two (8.7%) pheochromocytoma (PHEO). The median long diameter of tumors was 2.8 cm (IQR, 1.5-3.5).
Perioperative and Pathology Outcomes
All patients received partial adrenalectomy via the retroperitoneal approach. The median OT was 86.5 minutes (IQR, 60-112.5), of which the median preparation time, docking time and console time were 15.3 (IQR, 10.0-17.3), 4.3 (IQR, 3.4-5.6), 46.5 (IQR, 35.1-59.0) minutes, respectively. The median EBL was 50 mL (range, 20-400). No case was converted to open or received intraoperative transfusion. Two (8.7%) patients with PHEO were routinely transferred to ICU for one day.
Altogether, three (13.0%) patients developed postoperative complications, including one (4.3%) grade II complication of one patient requiring antibiotic treatment due to postoperative fever. 17 (73.9%) patients underwent incisional pain, and two (8.7%) of them received weak opioids for analgesia. During hospitalization, the median time to first flatus and stool dropping were 2 days (range, 1-3) and 3 days (range, 2-4). The median time of urinary catheter placement and perirenal drainage was 1 day (range, 1-3) and 3 days (range, 2-4). The overall perirenal drainage volume was 90.0 ml (IQR, 65.0-131.0), which declined from 50.0 ml (IQR, 30.0-95.0) on postoperative day 1 to 25.0 ml (IQR, 15.0-50.0) on postoperative day 2. The median LOS and postoperative LOS were 10.0 days (IQR, 8.0-12.0) and 4.0 days (IQR, 3.0-5.0), respectively. No patient was readmitted within 30 days.
According to the pathology findings, all surgical margins are negative. The removed masses, including 19 (82.6%) adenoma, two (8.7%) pheochromocytoma and two (8.7%) adrenocortical nodular hyperplasia pathologically.
Follow-up for Hormone-active Patients
The short-term postoperative follow-up for hormone-active patients was performed at a median of 3.3 months (2.4-3.9) after discharge (Table 3). The follow-up was available in seven (77.8%) patients and two were unable to come for their visit due to personal reasons.
In the five APA patients, the postoperative SBP (175 mmHg (IQR, 180-190) vs 135 mmHg (IQR, 133-143), P=0.042) and DBP (100 mmHg (IQR, 100-120) vs 85 mmHg (IQR, 78-90), P=0.042) decreased significantly compared to baseline. One patient stopped taking antihypertensive drug, and the remaining four patients underwent reductions in number or dose of antihypertensive drugs to varying degrees. Serum potassium elevated from 2.6 mmol/L (IQR, 2.1-2.9) to 4.0 mmol/L (IQR, 3.6-4.4) (P=0.042). One patient still received potassium supplementation discontinuously. For the three APA patients who came for follow-up, the aldosterone-renin ratio (ARR) declined from 1714 to 59, 617 to 29 and 2132 to 277, respectively.
In the two CPA patients, the postoperative blood pressure decreased from 130/85 to 120/70 mmHg and 145/85 to 135/70 mmHg, respectively. The cortisol (8 am) level decreased from 20.7 to 14.6 μg/ml and 26.1 to 21.9 μg/ml, respectively. The urinary cortisol level decreased from 374.4 to 81.9 μg/24h and 641.5 to 152.7 μg/24h, respectively. The adreno-cortico-tropic-hormone (ACTH) level increased accordingly.
In the two PHEO patients, the postoperative blood pressure (SBP/DBP) decreased from 170/105 to 120/80 mmHg and 160/100 to 120/70 mmHg, respectively. One patient still takes antihypertensive drug. Relevant endocrine measures declined to the normal range.