成人シャント手術—腰部くも膜下腔腹腔シャント（L-P shunt）のTIPS

Lumbo-Peritoneal Shunt for Patients with Idiopathic Normal Pressure Hydrocephalus:Surgical Technique

Point

・脳への穿刺を必要としない腰部くも膜下腔腹腔シャント（L-P shunt）は低侵襲な手術として最近注目されてきている．

・高齢者が対象のため合併症の回避が重要である．L-P shuntは腹腔側チューブが逸脱しやすいので，腹直筋貫通法にZ縫合を加えるなどさまざまな手技の工夫を習得する．

・術後もシャントの効果が最大限に得られているか注視していく姿勢が大切である．

　The SINPHONI-2 study（a group of Japanese prospective multicenter cohort studies on the treatment of idiopathic normal pressure hydrocephalus［iNPH］）showed the safety and efficacy of lumboperitoneal（L-P）shunt surgery for iNPH. A total of 660 probable iNPH patients underwent L-P shunt surgery at our NPH center between April 2009 and March 2020（age: 77.3 ± 6.2 years）. Our surgical technique includes 1）general anesthesia, 2）use of the original drape, 3）upward insertion of the spinal tube through L2/3 via a paramedian puncture in patients with highly deformed lumbar spines, 4）posterior placement of a Codman Hakim programmable valve with Siphonguard^TM, 5）inclination of the table at a 35° angle without position change and re-sterilization, 6）laparotomy via rectal muscle splitting, and 7）oblique maneuvering the peritoneal tube from the upper lateral to the lower medial sector. During the first year after surgery, postoperative complications occurred in 14 of 172 patients （8.1%）, including four patients with chronic subdural hematoma requiring evacuation （2.3%）, three with spinal tube occlusion （1.7%）, three with migration of the spinal tube, two with lower-limb numbness （1.2%）, and two with abdominal tube occlusion. Our L-P shunt procedure seems to be generally acceptable considering the low number of complications.