title: Postoperative retroperitoneal hematoma following transforaminal percutaneous endoscopic lumbar discectomy.
abstract: OBJECTIVE
  The purpose of this study was to demonstrate the clinical characteristics of postoperative retroperitoneal hematoma (RPH) following transforaminal percutaneous endoscopic lumbar discectomy (PELD) and to discuss how to prevent the complication of unintended hemorrhage.
  
  
  METHODS
  The medical records of 412 consecutive patients treated with transforaminal PELD between January 2005 and May 2007 were reviewed. A total of 4 patients (0.97%) experienced symptomatic postoperative RPH. The clinical outcomes were evaluated using the visual analog scale and the Oswestry Disability Index.
  
  
  RESULTS
  The common symptom in all patients with a hematoma was inguinal pain. The mean hematoma volume was 527.9 ml (range 53.3-1274.1 ml). Two patients with massive diffuse-type RPHs compressing the intraabdominal structures required open hematoma evacuation performed by general surgeons, and the other 2 patients with small, localized RPHs of < 100 ml were treated conservatively. The mean follow-up period was 21.3 months (range 13-29 months). The mean visual analog scale score for radicular leg pain improved from 7.6 to 1.8 and that for back pain improved from 4.3 to 2. The mean Oswestry Disability Index improved from 58.8 to 9.1%. The preoperative symptoms improved after the second treatment without significant neurological sequelae in all patients.
  
  
  CONCLUSIONS
  Although transforaminal PELD is a minimally invasive and safe procedure, the possibility of RPH should be kept in mind. Adequate technical and anatomical considerations are important to avoid this unusual hemorrhagic complication, especially in the patient with underlying medical problems or previous operative scarring. A high index of suspicion and early detection is also important to avoid the progression of the hematoma.
authors: Department of Neurosurgery, Wooridul Spine Hospital, Seoul, Korea. ns-ay@hanmail.net
authors: Yong
authors: Y
authors: Ahn
authors: Jin Uk
authors: JU
authors: Kim
authors: Byung Hoi
authors: BH
authors: Lee
authors: Sang-Ho
authors: SH
authors: Lee
authors: Jong Dae
authors: JD
authors: Park
authors: Dong Hyun
authors: DH
authors: Hong
authors: June Ho
authors: JH
authors: Lee
mesh_terms: D000328:Adult; D017587:Diskectomy, Percutaneous / Q000009:adverse effects*; D004724:Endoscopy / Q000009:adverse effects*; D005260:Female; D006406:Hematoma / Q000473:pathology*; D006801:Humans; D007405:Intervertebral Disc Displacement / Q000601:surgery*; D008159:Lumbar Vertebrae / Q000098:blood supply / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000209:etiology / Q000473:pathology* / Q000517:prevention & control; D012187:Retroperitoneal Space / Q000473:pathology