Retroperitoneal vs transperitoneal laparoscopic lithotripsy of 20-40 mm renal stones within horseshoe kidneys

Figure 1 The trocar position during laparoscopic treatment. A: Transperitoneal procedure: Two 10-mm trocars were placed, one at the umbilicus and the other 2 cm below the umbilicus adjacent to the rectus sheath, respectively. The trocar at the umbilicus was the camera port. A 12-mm trocar was inserted 2 cm below the costal margin in the mid-clavicular line. The other two 5-mm trocars were placed 2 cm below the costal margin in the anterior axillary line and midaxillary line, respectively; B: Retroperitoneal procedure: One 10-mm trocar was located 1 cm above the level of the iliac crest in the midaxillary line as the camera port. One 12-mm trocar was placed 2 cm below the costal margin in the anterior axillary line. One 5-mm trocar was inserted 1 cm below the costal margin in the posterior axillary line.