In-depth characterization of the neuroinflammatory reaction induced by peripheral surgery in an animal model.

Delirium is a common complication seen after surgery and anesthesia, in particular in older patients. Although the etiology of postoperative delirium is only incompletely understood, various lines of evidence suggest that proinflammatory signaling from the peripheral site of inflammation to central nervous system results in a decrease of cerebral acetylcholine (ACh) levels thereby inducing neuroinflammation. To corroborate this theory, we applied an animal model for characterization of the neuroinflammatory response after partial hepatectomy (HPx). In this model, the surgery-induced decrease in cerebral ACh levels can be prevented by intraoperative application of physostigmine. Thus, ACh-associated changes in the expression and secretion of inflammation-related compounds can be assessed by comparing the results obtained after surgery, in physostigmine-treated and untreated controls. This way we were able to show that the decrease of cerebral ACh triggers increased secretion of IL-1ß, IL-6, TNFα, MIP-2 (CCL3), RANTES, MCP1, IFNgamma, and IP-10. A gene array covering the expression of 370 inflammation-related genes indicated 13 candidates that are induced upon cerebral ACh decrease after HPx. Quantification of the changes in the expression of these candidates by the comparative CT method revealed a significant increase (> 1.5-fold) in the expression of IL-1ß, IL-6, TNFα, MIP2, RANTES, MCP1, TLR2, TLR4, HMGB1, TNFSF6, TNFSF12, IL1R1 and ILR6. Thus, our results suggest that peripheral surgery induces a reduction of cerebral ACh levels which trigger a complex neuroinflammatory response. From a clinical point of view, manipulating cerebral ACh levels by procholinergic drugs such as physostigmine could become an option to therapeutically target this kind of neuroinflammation.

Cerebrospinal fluid leak during stapes surgery: Gushing leaks and oozing leaks, two different phenomena.

Cerebrospinal fluid (CSF) leak is an uncommon event that can occur during stapes surgery. Such leaks can be classified as gushing leaks (stapes gushers) and oozing leaks. A stapes gusher is a massive flow of CSF through the perforated footplate that fills the middle ear suddenly, while an oozing leak is a slower and less profuse flow. We conducted a retrospective, observational, multicenter study of 38 patients-23 men and 15 women, aged 23 to 71 years (mean: 47)-who had experienced a CSF leak during stapes surgery. Patients were divided into various groups according to the type of surgical procedure performed and the type of postoperative complications they experienced. Audiometric and clinical evaluations were carried out pre- and postoperatively. Correlations among surgical variations (total or partial stapedectomy, placement of a prosthesis), hearing outcomes, and the incidence of postoperative complications (postoperative CSF leak and vertigo) were studied. Our statistical analysis revealed that gushing leaks and oozing leaks result in different degrees of hearing impairment and different rates of complications. We recommend that an individual approach be used to manage these complications.

Combined minimally invasive techniques to cure accidental dural tears occurring during spine surgery: epidural blood patch associated with cerebrospinal fluid drainage and ventral bed rest.

We report the case of a 70-year-old man, with increased anesthetic risk, who beneficiated from a lumbar laminarthrectomy from lumbar vertebra 4 (L4) to sacral 1 (S1). A dural tear facing L5-S 1 levels occurred during surgery and was repaired intra-operatively. Postoperatively, back and radicular pain symptoms appeared along with a pseudo-meningocele. Successful treatment was only achieved after performing an epidural blood patch and closed subarachnoid drainage. This well-known but infrequent management was undertaken after a first epidural blood patch attempt, and after two unsuccessful surgical choking procedures. Management is here described, and discussed at the light of existing literature.

Intracranial hemorrhage after spine surgery.

OBJECT: The authors describe the largest case series of 8 patients with intracranial hemorrhage (ICH) after spinal surgery and identify associated pre-, intra-, and postoperative risk factors in relation to outcome. METHODS: The authors retrospectively reviewed the cases of 8 patients treated over 16 years at a single institution and also reviewed the existing literature and collected demographic, treatment, and outcome information from 33 unique cases of remote ICH after spinal surgery. RESULTS: The risk factors most correlated with ICH postoperatively were the presence of a CSF leak intraoperatively and the use of drains postoperatively with moderate hourly serosanguineous output in the early postoperative period. CONCLUSIONS: Intracranial hemorrhage is a rare complication of spinal surgery that is associated with CSF leakage and use of drains postoperatively, with moderate serosanguinous output. These associations do not justify a complete avoidance of drains in patients with CSF leakage but may guide the treating physician to keep in mind drain output and timing of drain removal, while noting any changes in neurological examination status in the meantime. Additionally, continued and worsening neurological symptoms after spinal surgery may warrant cranial imaging to rule out intracranial hemorrhage, usually within the first 24 hours after surgery. The presence of cerebellar hemorrhage and hydrocephalus indicated a trend toward worse outcome.

Cerebral epidural hematoma following cerebrospinal fluid drainage during thoracoabdominal aortic repair.

Cerebrospinal fluid (CSF) drainage is a common adjunct to thoracoabdominal aortic aneurysm (TAAA) repair. CSF drainage may improve perioperative spinal cord perfusion and thereby decrease the incidence of paraplegia or paraparesis. Complications of CSF drainage may arise. We present a case of cerebral epidural hematoma (EDH), possibly arising from excessive CSF drainage, during thoracoabdominal aortic repair.

Cerebrospinal fluid rhinorrhea following trans-sphenoidal pituitary macroadenoma surgery: experience from 592 patients.

OBJECTIVES: To determine the incidence, risk factors, diagnostic procedures, and management of cerebrospinal fluid (CSF) leaks following trans-sphenoidal pituitary macroadenoma surgery. METHODS: Retrospective analysis of 592 patients. RESULTS: Intra- and post-operative CSF leaks occurred in 14.2 and 4.4% of patients, respectively. Surgical revision, tumor consistency, and tumor margins were independently associated with intra-operative leaks, while the tumor size, consistency, and margins were risk factors of post-operative leaks. The intra-operative leak rate of ACTH adenomas was greater than all other types combined; the incidence of post-operative CSF leaks was highest for FSH adenomas. There were no significant differences among various techniques and we achieved an initial repair success rates of 83.3 and 92.9% for intra- and post-operative CSF leaks, respectively. Of the 26 patients with post-operative CSF leaks, five were complicated by meningitis and four by post-infectious hydrocephalus which required ventriculoperitoneal shunts. CONCLUSIONS: CSF leaks have a propensity to occur in cases with fibrous tumors or tumors with indistinct margin and may have some relationship with the tumor type. Endoscopic and microscopic repairs were shown to be effective techniques in managing these types of leaks. Post-infectious hydrocephalus may influence the outcome of the repair and ventriculoperitoneal shunts were necessary in some cases.