title: Transient hyperemia immediately after rapid decompression of chronic subdural hematoma.
abstract: OBJECTIVE
  Intracerebral hemorrhage occurring after removal of a chronic subdural hematoma (CSH) is a rare but usually devastating postoperative complication. In patients with CSH, we determined cerebral blood flow immediately after surgical decompression to clarify the pathogenic mechanism of this complication.
  
  
  METHODS
  In 22 patients with unilateral CSH, a catheter was inserted into the hematoma cavity through a single burr hole without leakage of the contents. Cerebral blood flow was measured using single-photon emission computed tomography 1 day before surgery, immediately after rapid decompression by opening the catheter, and 3 days after surgery.
  
  
  RESULTS
  Single-photon emission computed tomography imaging immediately after decompression demonstrated areas of hyperemia in nine patients (41%). In all nine patients, hyperemia was observed in the cortex beneath the CSH, and it disappeared on the 3rd postoperative day. The patients with hyperemia were significantly older than those without hyperemia. Other variables, including preoperative cerebral blood flow, intrahematoma pressure before decompression, and mean arterial blood pressure during decompression had no significant effect on the occurrence of hyperemia.
  
  
  CONCLUSIONS
  In elderly patients, rapid decompression of CSH frequently results in transient hyperemia in the cerebral cortex beneath the hematoma.
authors.affiliation: Department of Neurosurgery, Iwate Medical University, Morioka, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Ogasawara
authors.forename: K
authors.initials: K
authors.lastname: Koshu
authors.forename: T
authors.initials: T
authors.lastname: Yoshimoto
authors.forename: A
authors.initials: A
authors.lastname: Ogawa
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000098:blood supply / Q000000981:diagnostic imaging*; D002543:Cerebral Hemorrhage / Q000000981:diagnostic imaging / Q000209:etiology*; D002560:Cerebrovascular Circulation; D003545:Cysteine / Q000031:analogs & derivatives; D019299:Decompression, Surgical; D005260:Female; D006408:Hematoma, Subdural / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D006940:Hyperemia / Q000000981:diagnostic imaging / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D015609:Organotechnetium Compounds; D011183:Postoperative Complications; D019275:Radiopharmaceuticals; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; C059659:technetium Tc 99m bicisate; D003545:Cysteine