CSF rhinorrhoea after endonasal intervention to the anterior skull base (CRANIAL): proposal for a prospective multicentre observational cohort study.

BACKGROUND: The endonasal transsphenoidal approach (TSA) has emerged as the preferred approach in order to treat pituitary adenoma and related sellar pathologies. The recently adopted expanded endonasal approach (EEA) has improved access to the ventral skull base whilst retaining the principles of minimally invasive surgery. Despite the advantages these approaches offer, cerebrospinal fluid (CSF) rhinorrhoea remains a common complication. There is currently a lack of comparative evidence to guide the best choice of skull base reconstruction, resulting in considerable heterogeneity of current practice. This study aims to determine: (1) the scope of the methods of skull base repair; and (2) the corresponding rates of postoperative CSF rhinorrhoea in contemporary neurosurgical practice in the UK and Ireland. METHODS: We will adopt a multicentre, prospective, observational cohort design. All neurosurgical units in the UK and Ireland performing the relevant surgeries (TSA and EEA) will be eligible to participate. Eligible cases will be prospectively recruited over 6 months with 6 months of postoperative follow-up. Data points collected will include: demographics, tumour characteristics, operative data), and postoperative outcomes. Primary outcomes include skull base repair technique and CSF rhinorrhoea (biochemically confirmed and/or requiring intervention) rates. Pooled data will be analysed using descriptive statistics. All skull base repair methods used and CSF leak rates for TSA and EEA will be compared against rates listed in the literature. ETHICS AND DISSEMINATION: Formal institutional ethical board review was not required owing to the nature of the study - this was confirmed with the Health Research Authority, UK. CONCLUSIONS: The need for this multicentre, prospective, observational study is highlighted by the relative paucity of literature and the resultant lack of consensus on the topic. It is hoped that the results will give insight into contemporary practice in the UK and Ireland and will inform future studies.

Transsphenoidal pituitary surgery in the elderly is safe and effective.

OBJECT: With an increasingly ageing population, the number of elderly people diagnosed with pituitary tumours continues to rise. There is a concern that with increasing age and comorbidities, there is higher anaesthetic risk, as well as peri-operative morbidity and mortality from pituitary surgery. This study aimed to audit the benefits and complications of transsphenoidal surgery performed in a large pituitary centre in elderly patients. METHODS: Data on all elderly patients (age: ≥ 70 years) undergoing transsphenoidal surgery at a large tertiary referral centre between November 2003 and August 2012 were collected retrospectively. RESULTS: A total of 104 operations were performed on 102 patients during 106 months. Median age was 75.2 years (range: 70-94) and 63 (61%) of the patients were male. Median follow-up was 15.2 months (range: 2.3-84.4). The majority presented with either peripheral visual field defects (26.4%) or pituitary hormone deficits (17.9%). A significant number (21.7%) of tumours were incidental radiological findings while investigating other diagnoses like stroke and dementia. 48.1% of operations were undertaken microscopically and the remaining 51.9% were endoscopic. Median hospital stay was 4 days (range: 3-18). Intra-operative complications included hypotension (1.9%) and blood loss requiring transfusion (2.9%). The 30-day complications included transient diabetes insipidus (9.6%), syndrome of inappropriate anti-diuretic hormone secretion (8.7%), delayed cerebrospinal fluid leak requiring lumbar drainage (0.9%) with no patient requiring formal repair. There were no peri-operative deaths. Long-term assessment suggested 79% had improved or stable endocrine function with 7% achieving biochemical cure and 91% showed improved or stable visual fields. CONCLUSIONS: Pituitary surgery in the elderly, whether microscopic or endoscopic, has low morbidity and mortality and is a safe and effective intervention for both symptom control and functional outcomes.

Terson's syndrome diagnosed by CT.

We report a case of Terson's syndrome diagnosed by a CT head scan. The presence of vitreous haemorrhage may not be appreciated clinically in unwell patients with a subarachnoid haemorrhage. Therefore features of vitreous haemorrhage should be sought on CT head imaging in patients presenting with a subarachnoid haemorrhage.

Safety of Endoscopic Transsphenoidal Pituitary Surgery during the COVID-19 Pandemic and Comparison to the Pre-Pandemic Era.

Objective The COVID-19 pandemic has caused significant disruption to the surgical care of patients with pituitary tumors. Guidance issued early during the pandemic suggested avoiding transnasal approaches to minimize risks of transmitting COVID-19 to health care professionals involved in these procedures. Methods This observational, single-center study compares results of endoscopic transsphenoidal approach (TSA) for pituitary tumors since the start of the pandemic to a pre-pandemic period. Anesthetic time, surgical time, and complication rates were compared. Newly acquired COVID-19 infections and transmission rates to patients and staff were reviewed. Data were analyzed by using the independent t -test, Mann-Whitney U test, and Pearson Chi-square test, significance set at p <0.05. Results Over a 12-month period, a total of 50 and 69 patients underwent endoscopic TSA for pituitary tumor during and before the pandemic, respectively. All patients tested negative for COVID-19 preoperatively. Median duration of anesthesia was 35 minutes (interquartile range [IQR]: 22) during the pandemic and 25 minutes (IQR: 8, p = 0.0002) pre-pandemic. Median duration of surgery was 70 minutes (IQR: 28) during the pandemic and 79 minutes (IQR: 33.75, p = 0.126) pre-pandemic. There were no statistically significant differences between intraoperative CSF leaks and complication rates. No staff members tested positive for COVID-19. Three patients tested positive for COVID-19 postdischarge, but the infections were community acquired. Conclusion In contrast to published guidelines, adequate preoperative testing, a multidisciplinary approach and the implementation of standardized protocols and vaccination against COVID-19 allow for endoscopic transsphenoidal surgery to be performed safely in patients with pituitary pathology during the pandemic.

Disseminated intravascular coagulation after isolated mild head injury.

A rare case is described of acute disseminated intravascular coagulation (DIC) following isolated mild head injury with acute subdural haematoma, coagulopathy onset preceding craniotomy. Surgical treatment of the cause followed by swift diagnosis and treatment soon after surgery enabled a good outcome. Post-operative recollection of subdural and extadural blood was treated by further surgery. DIC following isolated mild head injury without axonal damage is rare, but fatal if missed. Thrombocytopaenia in head injured patients should be investigated expediently. Post-operative interim imaging (if not standard practice) should also be considered to exclude haemorrhagic recollection requiring further surgery.

Cerebrospinal fluid leaks after transsphenoidal surgery - Effect of a polyethylene glycol hydrogel dural sealant.

To investigate cerebrospinal fluid (CSF) leak rates after mainly endoscopic endonasal transsphenoidal surgery with and without polyethylene glycol hydrogel dural sealant (DuraSeal®), we prospectively collected data from a single-centre consecutive case series over four years from January 2007 to December 2010 inclusive. 250 patients were identified (135 male, 115 female; median age 52years, range 14-83). 180 patients received DuraSeal® (72%). 85 (34%) had intra-operative dural breach and 13 (5.2%) developed post-operative CSF leaks (3 without intra-operative dural breach) requiring lumbar drainage or formal repair. Of this group 5/251 (2.0%) patients required a formal repair. Post-operative CSF leak was seen in 5/189 (2.7%) of patients with pituitary adenoma, of which 2/5 (40%) were in cases undergoing revision surgery. 5/13 (38.4%) patients who developed a CSF leak presented with either Rathke's cleft cyst or craniopharyngioma. 3/71 patients not receiving DuraSeal® leaked (4.2%) and 10/180 patients receiving DuraSeal® leaked (5.6%). 11/234 patients without Tisseel (4.7%) and 2/16 receiving Tisseel (12.5%) leaked. 54 patients (22%) received intra-operative lumbar drains, one of whom developed subsequent CSF leak (1.9%), in contrast to 12/197 (6.1%) of patients without intra-operative lumbar drains who later developed CSF leak. The rate of post-operative CSF leak requiring re-exploration and nasoseptal flap repair was low (2.0%) in this mainly endoscopic case series without statistically significant benefit from either DuraSeal® or Tisseel. Intra-operative and post-operative lumbar drainage appears beneficial in patients at higher risk of post-operative CSF leak.

Magnetic resonance neurography of peripheral nerve following experimental crush injury, and correlation with functional deficit.

OBJECT: In a number of clinical studies magnetic resonance (MR) neurography has been used to examine patients with peripheral nerve damage, but little is understood about the sequence of imaging changes following nerve injuries, and how they correlate with functional deficit. The goal of this study was to further understanding of these changes and their implications. METHODS: Using the rat sciatic nerve crush model, the sciatic nerve was imaged at intervals over 70 days in 12 rats. Sham-operated contralateral nerves served as controls. A 4.7-tesla MR imager with a custom-made surface coil was used. The T2 maps were calculated from images obtained at four echo times and from regions of interest designated on the nerve at three sites. Walking-track analysis was performed at the same intervals as imaging. Magnetic resonance neurography revealed a mean T2 of normal sciatic nerve of 36 msec (standard deviation [SD] 1.2 msec). Crushed nerves demonstrated a sequence of changes in signal intensity that were maximal at 14 days, with a mean T2 of 64 msec (SD 5.2 msec), then falling to a T2 of 53 msec (SD 3.7 msec). Sham-operated nerves had a short and nonsustained rise in signal at 7 days. Walking-track analysis revealed maximum deficit immediately postinjury, with an improvement in function approaching that of control nerves at 30 days. CONCLUSIONS: In this study the authors demonstrate that quantitative assessment of nerve signals with MR neurography allows the sequence of events following nerve crush injury to be followed in vivo, and that a return toward a normal signal correlates with functional improvement. Assessment of peripheral nerve injury in patients by using MR neurography has the potential to confirm acute nerve injury as well as to monitor the recovery process.

Magnetic resonance neurography studies of the median nerve before and after carpal tunnel decompression.

OBJECT: Recently developed novel MR protocols called MR neurography, which feature conspicuity for nerve, have been shown to demonstrate signal change and altered median nerve configuration in patients with median nerve compression. The postoperative course following median nerve decompression can be problematic, with persistent symptoms and abnormal results on electrophysiological studies for some months, despite successful surgical decompression. The authors undertook a prospective study in patients with carpal tunnel syndrome, correlating the clinical, electrophysiological, and MR neurography findings before and 3 months after surgery. METHODS: Thirty patients and eight control volunteers were recruited to the study. The MR neurography consisted of axial and sagittal images (TR = 2000 msec, TE = 60 msec) obtained using a temporomandibular surface coil, fat saturation, and flow suppression. Maximum intensity projection images were used to follow the median nerve through the carpal tunnel in the sagittal plane. Magnetic resonance neurography in patients with carpal tunnel syndrome demonstrated proximal swelling (p < 0.001) and high signal change in the nerve, together with increased flattening ratios (p < 0.001) and loss of nerve signal in the distal carpal tunnel (p < 0.05). Sagittal images were very effective in precisely demonstrating the site and severity of nerve compression. After surgery, division of the flexor retinaculum could be demonstrated in all cases. Changes in nerve configuration, including increased cross-sectional area, and reduced flattening ratios (p < 0.001) were seen in all patients. In many cases restoration of the T. signal intensity toward that of controls was seen in the median nerve in the distal carpal tunnel. Sagittal images were excellent in demonstrating expansion of the nerve at the site of surgical decompression. CONCLUSIONS: In this study the authors suggest that MR neurography is an effective means of both confirming compression of the median nerve and its successful surgical decompression in patients with carpal tunnel syndrome. This modality may prove useful in the assessment of unconfirmed or complex cases of carpal tunnel syndrome both before and after surgery.