Posterior Fossa Surgery Research Articles

The use of a reconstituted collagen foil dura mater substitute in paediatric neurosurgical procedures—Experience in 47 patients

Background. CSF leakage is a common complication of neurosurgical procedures, with defective dural suture thought to be the most frequent cause. We report our experience with a new collagen foil (TissuDura®, Baxter Healthcare SA, Switzerland) utilized as dural substitute in paediatric neurosurgical procedures.Methods. TissuDura® was used in children consecutively operated on at the department of paediatric neurosurgery, Catholic University, Rome, from March 2004 to August 2007. Children underwent surgical procedures in supratentorial, infratentorial and spinal compartments. In supratentorial and spinal procedures, the dural graft was used according to the overlay technique. In the posterior fossa procedures, the underlay technique was used.Results. Forty-seven patients received TissuDura® during surgery. Thirty-one patients underwent surgery for the removal of posterior fossa tumours, nine for supratentorial tumours and seven for spinal dysraphisms. No CSF leakage was observed following the use of TissuDura® in supratentorial procedures. Two post-operative CSF leaks occurred in patients who had undergone spinal surgery. No post-operative hydrocephalus was noted in these two surgery groups. Three cases of CSF leakage occurred in patients who had undergone posterior cranial fossa surgery. All 3 cases had an associated supratentorial ventricular dilation present prior to the removal of the tumour (one case) or occurring after the tumour excision (two cases). No clinically evident adverse reactions directly related to TissuDura® were observed.Conclusions. The main advantages of TissuDura® were its apparent ability to prevent CSF leakage when utilized in a specific subset of patients, and the absence of reactions or postoperative infections.

Postoperative Cervical Cord Compression Induced by Hydrogel (DuraSeal)

A retrospective case report. To raise the issue of DuraSeal for dural tear repair; to raise the issue of the potential for fatal consequences, if not considered to be an issue around and after surgery; and to illustrate this with a case. Cerebrospinal fluid leak is a potential complication of spinal, and posterior fossa surgery. Leakage may be caused by inadvertent dural tears during decompressive laminectomy or extradural spinal approaches, for spinal surgery. We present the case of a complication as a result of repair for dural tear with hydrogel. History, focused neurologic examination with pre- and postoperative magnetic resonance scan images. C5-C6 anterior cervical discectomy, and fusion with a standard commercial PEEK space cage. Intraoperatively there was a small cerebrospinal leak when excising the posterior longitudinal ligament. Surgicel and DuraSeal were used to seal this. The patient developed a quadriparesis after surgery which was a result of expansion of the hydrogel seen on MRI and at re-exploration. Hydrogel is now described for the second time to cause potentially fatal expansion.

Delayed Progressive Extradural Pneumatocele due to Incomplete Sealing of Opened Mastoid Air Cell after Micro-Vascular Decompression

A case of delayed progressive extradural pneumatocele after microvascular decompression (MVD) is presented. A 60-year-old male underwent MVD for hemifacial spasm; the mastoid air cell was opened and sealed with bone wax during surgery. One month after surgery, the patient complained of tinnitus, and progressive extradural pneumatoceles without cerebrospinal fluid (CSF) leakage was observed. Revision surgery was performed and the opened mastoid air cell was completely sealed with muscle patch and glue. The patient's symptoms were resolved, with no recurrence of pneumatoceles at 6 month follow up. Progressive extradural pneumatocele without CSF leakage after posterior fossa surgery is a very rare complication. Previous reports and surgical management of this rare complication are discussed.

Kinking of endotracheal tube during posterior fossa surgery

Kinking of endotracheal tube during posterior fossa surgery

Acute submandibular sialadenitis as a cause of unilateral neck swelling after posterior fossa surgery in sitting position

Acute submandibular sialadenitis as a cause of unilateral neck swelling after posterior fossa surgery in sitting position

Adhesion of rhomboid lip to lower cranial nerves as special consideration in microvascular decompression for hemifacial spasm: Report of two cases

BackgroundAlthough the rhomboid lip is a well-known structure constructing the foramen of Luschka, less attention has been directed to the structure for posterior fossa microsurgeries. The authors report two cases of the hemifacial spasm (HFS) with a large rhomboid lip, focusing on the importance of the structure during microvascular decompression.Case DescriptionA 59-year-old female presenting with left HFS was admitted to our hospital. A preoperative magnetic resonance image demonstrated an offending artery at the root exit zone of the VII nerve. The patient underwent microvascular decompression through the lateral suboccipital approach. The intraoperative findings showed that a large rhomboid lip adhered to the IX and X cranial nerves and prevented the exposure of the root exit zone of the VII cranial nerve. The rhomboid lip was meticulously separated from the cranial nerves so that the choroid plexus of the foramen of Luschka and the rhomboid lip could be safely lifted with a spatula, and the offending artery was successfully detached from the root exit zone. In another case of a 60-year-old male, the rhomboid lip was so large that it needed to be incised before separating it from the lower cranial nerves. In each case, the HFS was resolved following surgery without any new deficits.ConclusionThe large rhomboid lip adhering to the cranial nerves should be given more attention in the posterior fossa surgeries and should be managed based on the microsurgical anatomy for preventing unexpected lower cranial nerve deficit.

Reconstruction After Posterior Cranial Fossa Surgery—Case Report of Application of a Synthetic Tissue Sealant to Augment Dural Closure

Cerebrospinal fluid (CSF) leakage following cranial surgery is a well-described and potentially devastating complication, particularly in posteriorcranial fossa surgery. If untreated, a persistent CSF leak can evolve into wound breakdown, a surgical-site infection, and meningitis. Themorbidity of a complication following a cranial operation is harmful to the patient. Additionally, complications are a source of elevated medicalcosts. Numerous reconstruction strategies have been developed to thwart the ill effects of CSF leaks on patient outcomes and healthcarefinances. This case report illustrates the method employed at our institution to repair posterior fossa defects following surgery in thecerebellopontine angle.

Fixed dilatation of pupils at the end of posterior fossa surgery due to bupivacaine scalp infiltration

Fixed dilatation of pupils at the end of posterior fossa surgery due to bupivacaine scalp infiltration

Can bradycardia pose as a “red herring” in neurosurgery? Surgical stress exposes an asymptomatic sick sinus syndrome: Diagnostic and management dilemmas

Bradycardia in neurosurgery is almost always assumed to be secondary to intracranial conditions, specifically raised intracranial pressure causing Cushing’s reflex, the trigemino-cardiac reflex or brainstem lesions. We present a case of posterior fossa surgery in which persistent bradycardia developed in the postoperative period. A cardiac cause was initially overlooked since hydrocephalus was present preoperatively, which was initially assumed to be the cause of the bradycardia. The baseline pulse rate prior to surgery was 66 beats/minute. Only when repeated imaging revealed complete resolution of the hydrocephalus was a cardiology work up done and diagnosis of sick sinus syndrome established. The authors present an interesting case which demonstrates the need for a high degree of suspicion for such rare co-existing conditions. The diagnostic and management dilemmas are further discussed.

Extensive supratentorial hemorrhages following posterior fossa meningioma surgery

Remote supratentorial hematoma soon after posterior fossa surgery for the removal of a space-occupying lesion is a rare but dramatic and dreaded complication, carrying significant morbidity and mortality. A 47-year-old woman presented with headache of 1-year duration that worsened over last 2 months, progressive ataxia of 2 months’ duration, blurring and diminution of vision of 2 months’ duration and forgetfulness of 2 months’ duration. Fundus showed bilateral papille dema, and visual acuity was 6/9 in both eyes. She had left-sided cerebellar signs. There were no focal motor or sensory neurological deficits. MRI brain with contrast showed a large posterior fossa tumor with obstructive hydrocephalus. The patient underwent left paramedian suboccipital craniectomy in prone position with left side up. In the immediate postoperative period, the patient did no recover from anesthesia and was persistently drowsy. Immediate repeat CT scan showed diffuse subarachnoid hemorrhage spread all over the bilateral cerebral hemispheres with diffuse cerebral edema. The patient recovered with conservative management without deficits. This case stresses the importance of early postoperative CT scan and optimal management of the hemorrhage for good outcome.

Assessment of Cognitive Function Before and After Surgery for Posterior Cranial Fossa Lesions Using Computerized and Conventional Tests

Cognitive function has not been well studied after neurosurgery for posterior fossa lesions despite its potential importance in determining surgical indications and approaches. The present study evaluated changes in cognitive functions after posterior fossa surgery to detect any differences between the middle cranial fossa and lateral suboccipital approaches in 50 patients with posterior fossa lesions such as tumors and vascular diseases. Twenty-five patients underwent surgery via the middle fossa and 25 via the lateral suboccipital approaches. Computerized test battery (CogState) and conventional neuropsychological tests (serial seven-word learning test and mini-mental state examination) were examined before, 1 month after, and 3 months after surgery. All scores of the neuropsychological tests remained within normal limits after surgery. However, the scores of one computerized test battery and serial seven-word learning tests decreased significantly 1 month after surgery and recovered within 3 months, indicating temporary deterioration of short-term memory in the middle fossa group. The computerized tests detected significantly larger numbers of patients with worsened results than the conventional tests. The middle fossa approach and operation time showed correlations with the postoperative neuropsychological declines. The computerized tests could be performed easily and were beneficial for detecting subtle changes of the cognitive function after surgery. Cognitive function, especially short-term memory, may decline temporarily with the middle fossa approach and long operation time.

Management of Cerebrospinal Fluid Leak following Retrosigmoid Posterior Cranial Fossa Surgery

Objective: To detail our experience in the management of cerebrospinal fluid (CSF) leak following posterior cranial fossa surgery by the retrosigmoid approach. Patients and Methods: 412 patients who underwent posterior cranial fossa surgery by the retrosigmoid approach for a variety of diseases were included in the study. Results: There were 32 CSF leaks (7.7%) in the 412 patients. Of these, 16 were leaks from the incision site (50%) and 16 (50%) were CSF rhinorrheas. The CSF leaks were documented in 22 of the vestibular schwannoma surgeries (68.7%) and 10 of the vestibular nerve sectioning surgeries (31.3%). No CSF leak was seen following microvascular decompression and auditory brain stem implantation surgeries. Ten patients could be treated conservatively. Twelve patients needed the placement of a lumbar drainage. Surgical reexploration was performed in 10 patients. Conclusions: Initially, a conservative treatment should be instituted in the case of a CSF leak. If the conservative treatment fails, the placement of a lumbar drainage should be considered. Patients that do not respond to lumbar drainage require surgical reexploration. The abovementioned algorithm represents the safest and best option in the presence of a CSF leak, as confirmed by the absence of recurrences or multiple revisions in this study.

Causes prevention and management of subcutaneous hydrops after craniotomy of posterior cranial fossa in children

Objective To analyze the causes of subcutaneous hydrops following operation on lesions in posterior cranial fossa and discuss how to prevent and cure it.Methods The clinical data of 34 children who underwent neurosurgical operation for posterior cranial fossa lesions between July 2003 and December 2008 were analyzed retrospectively.Results Out of 34 posterior cranial fossa operations, 8 subcutaneous hydrops were identified.Higher rates of subcutaneous hydrops were associated with incomplete dural closure (6/12 vs 2/22) and the development of postoperative hydrocephalus (4/6 vs 4/28). The differences were statistically significant( P＜0.05). There was also a trend towards higher occurrence in cases with skull defect (4/11 vs 4/23), although it didn't reach statistical significance(P＞0.05). The use of subdural drainage seemed to be not associated with subcutaneous hydrops (P＞0.05). Conclusion Incomplete dural closure and postoperative hydrocephalus are main reasons of subcutaneous hydrops following operation on lesions in posterior cranial fossa in children, which can be prevented by a watertight dural closure and treatment of postoperative hydrocephalus effectively. Key words: Children; Posterior cranial fossa; Subcutaneous hydrops; Complication

DURAL AUGMENTATION

Primary closure of the dura remains difficult in many neurosurgical cases. One option for dural grafting is the collagen sponge, which is available in multiple forms, namely, monolayer collagen and bilayer collagen. Our primary goal was to assess differences in the incidence of postoperative cerebrospinal fluid (CSF) leak, including fistula and pseudomeningocele, and postoperative infection between monolayer collagen and bilayer collagen grafts. A single-center retrospective analysis of 475 consecutive neurosurgical procedures was performed. Primary endpoints were CSF leak and infection, adjusting for the impact of additional nonautologous materials. Multivariate regression analysis was used to identify predictors of postoperative CSF leak and infection. The overall frequency of postoperative CSF leak was 6.7%. There was no significant difference in the incidence of CSF leak based on the type of collagen sponge (monolayer versus bilayer) used (5.5% versus 7.5%, respectively; P = 0.38). The overall frequency of postoperative infection was 4.2%. There was no significant difference in the incidence of infection between groups (4.9% versus 3.8%; P = 0.54). Bilayer sponges were associated with a significantly lower incidence of CSF leak than monolayer sponges (odds ratio, 0.09; 95% confidence interval, 0.01-0.73). Bilayer collagen sponges are associated with a reduction in postoperative CSF leak, notably in posterior fossa surgery. The need for additional non-native materials is predictive of postoperative CSF leak, along with location and type of procedure. Intrinsic patient characteristics (e.g., age, diabetes, smoking) do not seem to affect the efficacy of collagen sponge dural grafts.

Assessment of Cognitive Function Before and After Surgery for Posterior Cranial Fossa Lesions

Background: Cognitive function after neurosurgery for posterior fossa lesions has not been well studied despite its potential importance in determining surgical indications and approaches. The aim of this study is to evaluate changes in cognitive functions after posterior fossa surgery and to detect any differences between the middle cranial fossa (MF) and lateral suboccipital (SO) approaches. Method: Fifty patients with posterior fossa lesions such as tumors and vascular diseases were included in this study. Twenty-five patients underwent surgery via the MF and 25 via the SO approach. Computerized test battery (CogState) and conventional neuropsychological tests (serial seven-word learning test and Mini Mental State Examination) were examined before and at 1 and 3 months after surgery. Findings: After the surgery, all the scores of the neuropsychological tests remained within normal limits. In the MF group, however, the scores of one patient's results from the computerized test battery and serial seven-word learning tests decreased significantly 1 month after surgery and recovered within 3 months, indicating temporary deterioration of short-term memory. The computerized tests detected significantly larger numbers of patients with worsened results than the conventional tests. The MF approach and operative time showed correlations with the postoperative neuropsychological declines. Conclusions: The computerized tests could be performed easily and were beneficial for detecting subtle changes of the cognitive function after surgery. After posterior fossa neurosurgery, cognitive function, especially short-term memory, may decline temporarily with the MF approach and long operative time.

Face-Related Ictal Hallucinations and Illusions and Reflex-Type Phenomena

Face-Related Ictal Hallucinations and Illusions and Reflex-Type Phenomena

Brain stem tension pneumocephalus leading to respiratory distress after subdural haematoma evacuation

Brain stem tension pneumocephalus leading to respiratory distress after subdural haematoma evacuation

Collagen matrix duraplasty for posterior fossa surgery: evaluation of surgical technique in 52 adult patients

Complete dural closure is not always possible following posterior fossa surgery, often requiring a graft to secure complete closure. The authors report their experience of using a collagen matrix as an onlay dural graft for repair of a posterior fossa dural defect. A retrospective analysis was performed in 52 adult patients who had undergone collagen matrix duraplasty for the posterior fossa. Complications directly related to the dural graft, the presence or absence of hydrocephalus, and the role of closed suction wound drainage in relation to postsurgical pseudomeningoceles were analyzed. The indication for posterior fossa surgery was tumors in 32 patients, vascular abnormalities in 9 patients, and spontaneous cerebellar hemorrhage in 11 patients. Closed suction wound drainage was used in 23 patients (44.2%). Forty-eight (92.3%) of 52 patients had a dural defect > 2 cm. Nine (81.8%) of 11 patients with hydrocephalus required ventriculoperitoneal shunts. Complications of the surgery included pseudomeningoceles in 2 patients (3.8%; no closed suction wound drainage); superficial wound infections in 1 patient (1.9%; with closed suction wound drainage); and unexplained eosinophilia in 1 patient. Duraplasty using a collagen matrix is safe and effective in the posterior fossa, and is easy to use and time efficient. Meticulous layered wound closure, the detection and effective control of hydrocephalus, and the use of closed suction wound drainage reduces complications related to collagen matrix duraplasty for the posterior fossa.

Complications of posterior cranial fossa surgery—an institutional experience of 500 patients

Background The complication of the posterior fossa surgery is seldom described in the literature. The purposes of this retrospective study are to draw attention to the potential complications associated with posterior fossa surgery and to critically review the predisposing factors that might influence the complication rate. Methods We undertook a 10-year (1992-2002) retrospective study of all posterior fossa surgery performed at LSUHSC. A total of 500 patients were obtained from the operation database, and they were categorized into 5 groups based on the surgical approaches: (1) cerebellopontine angle lesion, (2) microvascular decompression for facial pain and spasm, (3) cerebellar lesions, (4) Chiari I decompression, and (5) petroclival lesions. Data collected for analysis included patient demographics, pathological characteristics of the lesions, and the postoperative complications that occurred as unexpected and undesirable events that prolonged hospital stay and may require surgical/medical intervention. Results Of the 500 patients reviewed, 220 (44%) patients had tumor resections at the cerebellopontine angle; 110 (22%) patients had microvascular decompression for trigeminal neuralgia and hemifacial spasm; 86 (17.2%) patients had cerebellar lesions; 60 (12%) patients had Chiari I decompression; and 24 (4.8%) patients required transpetrosal approaches for petroclival lesions. The overall complication rate in our study was 31.8%, affecting 159 patients. Cerebrospinal fluid leaks were the most frequently encountered, presenting in 65 (13%) patients followed by meningitis in 46 (9.2%) patients, wound infection in 35 (7%) patients, and CN palsies in 24 (4.8%) patients. Other complications that were observed to develop almost exclusively in patients undergoing cerebellar parenchymal tumor resection included cerebellar edema in 25 (5%) patients, hydrocephalus in 23 (4.6%) patients, cerebellar hematoma in 15 (3%) patients, and cerebellar mutism in 6 (1.2%) patients. The overall mortality rate related to surgery was 2.6% occurring in 13 patients. Conclusion Posterior fossa surgery involves greater morbidity and mortality and has a wider variety of complications than surgery in the supratentorial compartment. These complications may be avoided by careful perioperative planning, strict adherence to aseptic technique, meticulous microsurgical dissection, proper wound closure, and the judicious use of prophylactic agent. A thorough understanding of the patient's history, neurological findings, imaging studies, operative anatomy, as well as all potential adverse events associated with the procedure is also essential to minimize complications.

Children's vomiting following posterior fossa surgery: A retrospective study

BackgroundNausea and vomiting is a problem for children after neurosurgery and those requiring posterior fossa procedures appear to have a high incidence. This clinical observation has not been quantified nor have risk factors unique to this group of children been elucidated.MethodsA six year retrospective chart audit at two Canadian children's hospitals was conducted. The incidence of nausea and vomiting was extracted. Hierarchical multivariable logistic regression was used to quantify risk and protective factors at 120 hours after surgery and early vs. late vomiting.ResultsThe incidence of vomiting over a ten day postoperative period was 76.7%. Documented vomiting ranged from single events to greater than 20 over the same period. In the final multivariable model: adolescents (age 12 to <17) were less likely to vomit by 120 hours after surgery than other age groups; those who received desflurane, when compared to all other volatile anesthetics, were more likely to vomit, yet the use of ondansetron with desflurane decre kelihood. Children who had intraoperative ondansetron were more likely to vomit in the final multivariable model (perhaps because of its use, in the clinical judgment of the anesthesiologist, for children considered at risk). Children who started vomiting in the first 24 hours were more likely to be school age (groups 4 to <7 and 7 to <12) and receive desflurane. Nausea was not well documented and was therefore not analyzed.ConclusionThe incidence of vomiting in children after posterior fossa surgery is sufficient to consider all children requiring these procedures to be at high risk for POV. Nausea requires better assessment and documentation.