Course of intracranial pressure after extirpation of posterior fossa tumours

Double seal technique to obliterate the eustachian tube orifice: a novel method for the treatment of recalcitrant cerebrospinal fluid leak

OBJECTIVE

To demonstrate a novel and effective surgical technique for the treatment of refractory cerebrospinal fluid rhinorrhoea after skull base surgery. The novel surgical technique is described and the findings of a review of relevant world English-language publications are reported.

CASE REPORT

A 44-year-old woman, otherwise fit and well, presented with more than a 2-year history of right-sided facial pain. A diagnosis of classical trigeminal neuralgia was made. Surgical treatment was undertaken with a retromastoid suboccipital craniotomy. Post-operatively, the patient showed signs of right-sided cerebrospinal fluid rhinorrhoea which was recalcitrant. In light of a continuous leak and several hospital admissions, a novel technique was performed whereby the eustachian tube orifice was obliterated using an endonasal endoscopic approach. The technique proved to be successful, with no further leakage.

CONCLUSION

Endoscopic obliteration of the eustachian tube using a double seal technique is a simple, safe and effective procedure in the treatment of a refractory cerebrospinal fluid leak.

Normal pressure hydrocephalus after gamma knife radiosurgery for cerebellopontine angle meningioma

There are no reports of hydrocephalus following radiosurgery for a meningioma. We report on a case where gamma knife therapy for a 4 cm diameter right cerebellopontine meningioma accelerated hydrocephalus three months post treatment. Examination of the cerebrospinal fluid (CSF) revealed a high protein level and thus, CSF malabsorption and CSF obstruction might have occurred after the radio surgery. It is important to consider this pathology, and the need for long term follow up.

Prevalence of hydrocephalus in 157 patients with vestibular schwannoma

The purpose of this study was to determine the prevalence of hydrocephalus in patients with vestibular schwannoma. A second objective was to investigate possible etiologies for hydrocephalus in this population by attempting to correlate the incidence and severity of hydrocephalus with tumor volume and extent of fourth ventricular compression. The MRI examinations of 157 adult patients with vestibular schwannoma were retrospectively reviewed. Tumor size was quantified, and the presence of accompanying hydrocephalus was assessed, categorized as communicating type or non-communicating type and then rated as mild, moderate or severe (grades 1-3). Next, the degree of fourth ventricular distortion caused by tumor mass effect was evaluated and categorized as mild, moderate or severe (grades 1-3). Spearman's rank correlation coefficient was used to test the relationships between tumor volume and (1) the extent of fourth ventricular effacement and (2) severity of hydrocephalus. Hydrocephalus was present in 28/157 (18%) cases and was categorized as mild in 11/28 (39%), moderate in 15/28 (54%) and severe in 2/28 (7%). Communicating-type hydrocephalus was present in 17/28 (61%) and non-communicating type in 11/28 (39%). There was a positive correlation between the grade of non-communicating hydrocephalus and tumor volume (r=0.38; P<0.001) and between the severity of fourth ventricular compression and extent of hydrocephalus in this group(r=0.43; P<0.001). In patients who were classified as having communicating hydrocephalus, the correlation between tumor volume and the severity of hydrocephalus was poor (r=0.19; P=0.02) as was the correlation between the extent of fourth ventricular distortion and the severity of hydrocephalus (r=0.21; P<0.01). There is a high prevalence of hydrocephalus in patients with vestibular schwannoma. In a minority of cases non-communicating type hydrocephalus is present and the severity of hydrocephalus can be attributed to the affect of tumor volume on fourth ventricular compression. More commonly, however, communicating-type hydrocephalus exists and the correlation between the severity of fourth ventricular compression and extent of hydrocephalus is poor. Therefore, other etiologies for hydrocephalus, such as tumor protein sloughing, are likely relevant.

Cerebrospinal fluid leak after acoustic neuroma surgery: a comparison of the translabyrinthine, middle fossa, and retrosigmoid approaches

OBJECTIVE

To determine whether the choice of surgical approach affects the rate of postoperative cerebrospinal fluid leakage in patients who have undergone surgical resection of acoustic neuroma.

STUDY DESIGN

Retrospective chart review.

SETTING

Tertiary referral center.

PATIENTS

Three hundred patients who underwent surgery for acoustic neuromas were selected by consecutive medical record number until 100 resections via each surgical approach (translabyrinthine, middle fossa, and retrosigmoid) had been gathered.

MAIN OUTCOME MEASURES

Surgical approach used, cerebrospinal fluid leak incidence, tumor size, patient age.

RESULTS

Postoperative cerebrospinal fluid leak of any severity was observed in 13% of translabyrinthine, 10% of middle fossa, and 10% of retrosigmoid patients. These difference in the rate of cerebrospinal fluid leakage were not statistically significant (p = 0.82). The majority of leaks were managed conservatively with fluid and activity restriction, often accompanied by a period of lumbar subarachnoid drainage. There was a need to return to the operating room for a definitive procedure in 4% of translabyrinthine, 2% of middle fossa, and 3% retrosigmoid patients; again not statistically different among the approaches (p = 0.43). Tumor size was not correlated with cerebrospinal fluid leak rate (p = 0.13). Patient age, for patients older than 50 years, was suggestive of increased odds of cerebrospinal fluid leak (p = 0.06).

CONCLUSION

Neither surgical approach nor tumor size affects the rate of postoperative cerebrospinal fluid leakage or the necessity of managing a leak with a return to the operating room. Cerebrospinal fluid leakage rates have remained stable in recent decades despite numerous innovative attempts to improve dural closure, seal transected air cell tracts, and occlude anatomic pathways. The finding that leak rates were similar among three dissimilar surgical techniques suggests that factors other than techniques of wound closure, such as transient postoperative rises in cerebrospinal fluid pressure, may be responsible for these recalcitrant cases.

Evolution of the management of hydrocephalus associated with acoustic neuroma

The management of hydrocephalus in association with a cerebellopontine angle tumor is controversial. There is a widely held belief that initial therapy should always be directed toward treatment of hydrocephalus before definitive surgery. The potential problems of cerebrospinal fluid (CSF) shunting and drainage have to led to an evolution in the management of hydrocephalus at St. Vincent's Hospital. There is growing evidence that complete removal of cerebellopontine angle tumors will result in resolution of hydrocephalus without requiring other methods of CSF decompression. The authors present their experience of 14 patients with hydrocephalus found in a recent series of 104 consecutive cases of acoustic neuroma. This study has detected a significant correlation between hydrocephalus and increasing tumor size (P = .0234). The mean tumor size in this series was 3.8 cm. The series has also demonstrated that successful. safe, and complete tumor removal can be achieved without CSF drainage before surgery.