arpal tunnel syndrome (CTS) is currently the most common type of compression neuropathy, affecting C approximately 1% of the general population (2, 6). CTS results from compression of the median nerve at the level of the wrist. Diagnosis is determined on the basis of clinical symptoms, confirmed with electrophysiological studies. Phalen first introduced and popularized an open technique to cut the flexor retinaculum and decompress the carpal tunnel in 1950s (2). Excellent results from this procedure have made open carpal tunnel release (OCTR) the gold standard in the surgical treatment of this condition. In recent years, there has been a growing interest in minimally invasive procedure. In 1987, Okutsu first introduced the use of an endoscope to cut the transverse carpal ligament in patients with CTS (2). Since then, at least six types of procedures have been developed (1, 4), In the North America, two of the popular techniques are the Agee (single portal) and Chow (dual portal) systems (4, 6).