The investigator conduct a randomized clinical trial for the needlescopic and conventional laparoscopic adrenalectomy to assess whether mini laparoscopic adrenalectomy is better than conventional laparoscopic adrenalectomy in terms of pain, complication rate , and wound cosmetics

If the participant with unilateral PA tumor less than 4cm is willing to enter the clinical trial, he/she will be randomly assigned to two groups (conventional vs needlescopic laparoscopic adrenalectomy) in a 1:1 ratio, followed by preoperative assessement. All procedures were performed by experienced laparoscopic urologists (number of complex laparoscopic procedures > 50 cases/yr for 10 yrs). The participant were blinded to the type of surgical procedure underwent until the pain assessment was completed in the morning of the second days after surgery

Inclusion Criteria:

1. Over the age of 20 years old.
2. Primary aldosteronism with unilateral adrenal lesions smaller than 4 cm
3. Indications for laparoscopic surgery.
4. Informed consent

Exclusion Criteria:

1. Over 80 years old
2. Suspected adrenal malignancy or pheochromocytoma
3. Other concurrent surgery
4. Patients who underwent bilateral adrenal tumor resection at the same time
5. History of peritonitis or having undergoing major ipsilateral abdominal surgery.
6. American Society of Anesthesiologists (ASA) Class III or IV (with severe cardiovascular disease, uncontrolled hypertension, diabetes, chronic pulmonary obstructive pulmonary disease, morbid obesity (BMI > 40), dialysis patients, myocardial infarction, stroke, coronary artery disease, liver or coagulation dysfunction, etc.)
7. Opioid addiction
8. Patient have side effects from taking of acetaminophen, celecoxib or opioids
9. Acute intoxication of alcohol, sleep aids, anesthetics, centrally acting analgesics, opium or psychotropic drugs has occurred.
10. Patients using monoamine oxidase inhibitors (MAOIs) concurrently or within the past 14 days.
11. Patients with chronic pain or respiratory depression (such as chronic obstructive pulmonary disease)
12. Pregnancy