Safety and efficacy of laparoscopic three-dimensional printed extravascular stent placement for nutcracker syndrome

Abstract

Objective To assess the safety and effectiveness of laparoscopic implantation of three-dimensional (3D)-printed extravascular stent for treatment of nutcracker syndrome (NCS). Methods The clinical data of NCS in our hospital were prospectively collected from August 2015 to August 2016. Doppler ultrasound and CT examination were performed before the operation of all the patients who were in line with the diagnostic criteria of NCS. The 3D model of extravascular stents with especial device to prevent migration was designed and was made by 3D metal printer with titanium alloy. The left renal vein(LRV) was exposed completely up to the inferior vena cava, then the stent was placed around the compressed LRV. Results 10 patients were enrolled in the study, including 9 males and 1 females, age (21.5+ 4.6) years. Among these patients, there were 4 cases with severe hematuria, 1 case with proteinuria, 5 cases with left lumbago, and 5 cases with left severe varicocele. The preoperative doppler ultrasound examination showed the diameter of the the compressed LRV was (1.57±0.25)mm, and flow velocity was (164.40±55.27)cm/s; the diameter of the LRV at the renal hilum was (8.7±1.59)mm, and flow velocity was(10.70±2.21)cm/s. The average operation time was (75±11) min, and the average hospital stay after operation was 7 d. All symptoms were relieved at 3-7 d after operation. All patients were asymptomatic and all stents were stable after follow-up. At 12 months after surgery, the diameter of the LRV at the renal hilum was (8.23±1.90)mm on doppler ultrasound, and there was significant decrease (P<0.01); the flow velocity was (21.20±3.88)cm/s, and there was significant increase (P<0.01). Conclusions Laparoscopic three-dimensional printed extravascular stent placement is a safe, effective and minimally invasive technique for treatment of NCS. Key words: Nutcracker syndrome; 3D printing; Extravascular stent; Minimally invasive; Laparoscopy