[Diagnosis and therapy of the nutcracker phenomenon: long-term follow-up]

To study the diagnosis of adult nutcracker phenomenon (NCP) and assess the therapeutic value of endovascular stenting (ES) and superior mesentery artery transposition (SMAT) for the treatment of NCP in long-term follow-up.

Six patients (6 men) aged 16 and 34 years old (mean age, 22.7 +/- 18.0 years) were diagnosed as having NCP using the examination of the doppler ultrasound and/or magnetic resonance of artery/digital radiography (MRA/DSA). Three patients underwent ES and 3 patients received SMAT for the treatment of the NCP patients associated with recurrent gross hematuria and left flank pain. Doppler ultrasound and urine examination were used at pre- and post-operation.

In 3 patients who underwent SMAT, the postoperative complications comprised retroperitoneal hematoma necessitating surgical revision (n = 1). Functional disorder of intestine (n = 1) and paralytic ileus (n = 1) that were resolved by conservative management. In 3 patients who experienced ES, 1 patient received surgical revision because the position of stent was not suitable in left renal vein but no other complication took place. During the follow-up of 6 approximately 50 months (mean 24.7 +/- 18.0 months), except that 1 patient's hematuria disappears at rest and reappears after motion while the other 5 patients remain asymptomatic and free of hematuria. The dopplar ultrasound showed the left renal vein diameters of the angel segment between superior mesentery artery and aorta were (0.18 +/- 0.05) cm preoperation and (0.65 +/- 0.17) cm postoperation, P < 0.001; the left renal vein diameters of the portal segment were (0.89 +/- 0.22) cm preoperation and (0.79 +/- 0.20) cm postoperation, P = 0.003; the left renal vein diameter's ratio between portal and angel segment were (4.99 +/- 0.79) preoperation and (1.23 +/- 0.16) postoperation, P < 0.001.

Dopplar ultrasound plays a very important role in the diagnosis of adult NCP. SMAT is an efficient surgical approach to the treatment of the nutcracker phenomenon and is associated with an acceptable risk of complications. But ES is safer and more efficient than SMAT and may represent a valuable approach to lessening the morbidity of surgical procedures. ES is a new therapeutic method for adult NCP.