title: Endoscopically assisted piriformis-to-knee surgery of sciatic, peroneal, and tibial nerves: technical note.
abstract: BACKGROUND
  Proximal lesions of the sciatic nerve are often difficult to diagnose and to treat properly. In particular, if there are posttraumatic or postoperative alterations, imaging might not identify the level and location of lesion. Due to the sciatic nerve anatomy, the same is true for clinical and electrophysiological evaluation with a risk of delayed surgery and, thus, unsuccessful surgery. Therefore, in some unclear cases, surgical exploration of the whole sciatic nerve and its divisions could be the only means to determine the correct diagnosis and allow prompt treatment to produce the best clinical outcome.
  
  
  OBJECTIVE
  To describe a novel minimally invasive technique to explore and treat patients with proximal sciatic, peroneal, and tibial nerve lesions. Intraoperative findings, surgical considerations, and complications are presented.
  
  
  METHODS
  From January 2012 to November 2013, 9 consecutive patients with lesions of the sciatic, peroneal, and tibial nerves underwent endoscopy and were treated. The technical considerations of these cases are presented with regard to the retrospectively collected clinical and surgical data to evaluate the pros and cons of the technique.
  
  
  RESULTS
  A subgluteal incision, as the primary endoscopic port, was used in all 9 patients. An additional mid-thigh and fibular head incision was thought necessary in 3 patients. An extension of the approach by a secondary transgluteal incision was performed in 4 patients. In 2 of these sciatic lesions, autologous nerve grafts were placed. One perineurioma was detected and bioptically secured. There were no complications. Six patients experienced pain relief; in 6, we observed motor improvement. The mean follow-up was 9.5 months.
  
  
  CONCLUSIONS
  The endoscopically assisted single- to multiportal sciatic exploration technique provides excellent visualization that enables nerve inspection, lesion detection, and decompression, and obviates the need for more extensive approaches in cases of unclear sciatic nerve pathology. By adding several ports, whole-length exploration of the sciatic from the notch to fibular head level is feasible.
authors.affiliation: Department of Neurosurgery, University of Oldenburg, Oldenburg, Germany.
authors.forename: Christian Peter
authors.initials: CP
authors.lastname: Giuliano Heinen
authors.forename: Thomas
authors.initials: T
authors.lastname: Schmidt
authors.forename: Thomas
authors.initials: T
authors.lastname: Kretschmer
mesh_terms: D000328:Adult; D004724:Endoscopy / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020422:Mononeuropathies / Q000150:complications / Q000175:diagnosis* / Q000601:surgery*; D009437:Neuralgia / Q000175:diagnosis / Q000209:etiology / Q000601:surgery; D010543:Peroneal Nerve; D012189:Retrospective Studies; D012584:Sciatic Nerve; D013979:Tibial Nerve; D016896:Treatment Outcome