Stephen Honeybul

Long-Term Complications of Decompressive Craniectomy for Head Injury

There is currently much interest in the use of decompressive craniectomy for intracranial hypertension. Though technically straightforward, the procedure is not without significant complications. A retrospective analysis was undertaken of 164 patients who had had a decompressive craniectomy for severe head injury in the years 2004 to 2009 at the two major hospitals in Western Australia. Eighty-six patients had a bifrontal decompression and seventy-eight had a unilateral decompression. Two patients died due to post-operative care issues. Complications attributable to the decompressive surgery were: herniation of the cortex through the bone defect (42 patients, 25.6%), subdural effusion (81 patients, 49.4%), seizures (36 patients, 22%), hydrocephalus (23 patients, 14%), and syndrome of the trephined (2 patients, 1.2%). Complications attributable to the subsequent cranioplasty included: sudden death due to massive cerebral swelling in 3 patients (2.2%), infection requiring removal of the bone flap in 16 patients (11.6%), and bone flap resorption requiring augmentation in 10 patients (7.2%). After excluding simple complications such as subdural effusion and brain herniation through the skull defect and some patients who died as a direct consequence of traumatic brain or extracranial injury, 81 patients (55.5%) had at least one complication after decompressive craniectomy. The occurrence of at least one complication after decompressive craniectomy was significantly associated with an increased risk of prolonged stay in the hospital or rehabilitation facility (odds ratio 2.54, 95%confidence interval 1.22,5.24, p=0.013), after adjusting for predicted risk of unfavorable outcome.

Complications of decompressive craniectomy for head injury.

There is much interest in the use of decompressive craniectomy for intracranial hypertension. Whilst technically straightforward, the procedure is not without significant complications. A retrospective analysis was undertaken of 41 patients who had had a decompressive craniectomy for severe head injury in the years 2006 and 2007 at the two major hospitals in Western Australia, Sir Charles Gairdner Hospital and Royal Perth Hospital. Complications attributable to the decompressive surgery were: herniation of the cortex through the bone defect, 18 patients (51%); subdural effusion, 22 patients (62%); seizures, five patients (14%) and hydrocephalus, four patients (11%). Complications attributable to the subsequent cranioplasty were: infection, four patients (11%) and bone flap resorption, six patients (17%). Syndrome of the trephined occurred in three (7%) of those patients whose bone flap had significantly resorbed. Two deaths (5.5%) occurred as a direct complication of the craniectomy or cranioplasty procedure. I attempted to define what may be regarded as a complication of the decompressive procedure rather than what may be a consequence of the primary pathological process of traumatic brain injury.

Observed versus Predicted Outcome for Decompressive Craniectomy: A Population-Based Study

A number of studies have shown that decompressive craniectomy can reduce intracranial pressure and may improve outcome for patients with severe head injury. This cohort study assessed the long-term outcome of neurotrauma patients who had a decompressive craniectomy for severe head injury in Western Australia between 2004 and 2008. The web-based outcome prediction model developed by the CRASH trial collaborators was applied to the cohort. Predicted outcome and observed outcome were compared. Characteristics of outcome between those who had had a unilateral and those who had had a bilateral decompressive procedure were compared. All complications were recorded. Among a total of 1,786 adult neurotrauma patients admitted during the study period, 147 patients (8.2%) had a decompressive craniectomy. A significant proportion of patients who required unilateral (37.3%) and bilateral (46.5%) craniectomy were able to return to work or study at 18 months after the injury. The patients who required bilateral craniectomy more likely to be associated with an unfavorable outcome (Glasgow Outcome Scale score >or=3) than those who had unilateral craniectomy (odds ratio 4.42; 95% confidence interval 1.16,16.81; p = 0.029), after adjusting for the timing of surgery, mechanism of injury, and the predicted risk of unfavorable outcome. The functional outcome after either unilateral or bilateral decompressive craniectomy was significantly better than that predicted by the CRASH head injury prediction model when the predicted risk was less than 80%. This study has demonstrated that in Western Australia decompressive craniectomy is a relatively common surgical procedure for the management of neurotrauma. A significant proportion of patients had a better-than-predicted long-term functional outcome.

Cranioplasty with custom-made titanium plates-14 years experience

BACKGROUND There is no consensus on which material is best suited for repair of cranial defects. OBJECTIVE To investigate the outcomes following custom-made titanium cranioplasty. METHODS The medical records for all patients who had titanium cranioplasty at 2 major neurosurgical centers in Western Australia were retrieved and analyzed for this retrospective cohort study. RESULTS Altogether, 127 custom-made titanium cranioplasties on 113 patients were included. Two patients had 3 titanium cranioplasties and 10 patients had 2. Infected bone flap (n = 61, 54%), either from previous craniotomy or autologous cranioplasty, and contaminated bone flap (n = 16, 14%) from the initial injury were the main reasons for requiring titanium cranioplasty. Complications attributed to titanium cranioplasty were common (n = 33, 29%), with infection being the most frequent complication (n = 18 patients, 16%). Complications were, on average, associated with an extra 7 days of hospital stay (interquartile range 2-17). The use of titanium as the material for the initial cranioplasty (P = .58), the presence of skull fracture(s) (P > .99) or scalp laceration(s) (P = .32) at the original surgery, and proven local infection before titanium cranioplasty (P = .78) were not significantly associated with an increased risk of infection. Infection was significantly more common after titanium cranioplasty for large defects (hemicraniectomy [39%] and bifrontal craniectomy [28%]) than after cranioplasty for small defects (P = .04). CONCLUSION Complications after using titanium plate for primary or secondary cranioplasty were common (29%) and associated with an increased length of hospital stay. Infection was a major complication (16%), and this suggested that more vigorous perioperative infection prophylaxis is needed for titanium plate cranioplasty.

The Retrospective Application of a Prediction Model to Patients Who Have Had a Decompressive Craniectomy for Trauma

There is currently a resurgence of interest in the use of decompressive craniectomy. As the procedure is used more frequently, there may be an increasing number of patients surviving a severe traumatic brain injury with severe neurological impairment. The aim of this study was to determine if we could predict those cases that fall into this category. We used the web-based prediction model prepared by the CRASH collaborators and applied it to a cohort of patients who had a decompressive craniectomy in 2006 and 2007 at the two major trauma hospitals in Western Australia. All clinical and radiological data were reviewed and entered into the model, and predicted outcome and actual outcome were compared. Our analysis indicated that a significant cut-off point appeared at which the model predicted a 75% risk of an unfavorable outcome at 6 months; 19 of 27 patients with CRASH scores <75% returned to work, whereas none of the 14 patients with higher scores achieved this degree of rehabilitation at 18 months. Statistical analysis of the outcomes in our cohort confirmed that the CRASH model reliably predicted unfavorable outcome. This study demonstrated that our ability to predict poor outcome has improved.

The impact of cranioplasty on neurological function

Abstract Objectives. To assess changes in neurological function after cranioplasty. Methods. Functional and neurocognitive assessments including activities of daily living assessment, functional independence measure (FIM) and the Cognitive assessment report (COGNISTAT) were conducted on all patients within 72 h before and 7 days after cranioplasty. A change in the total FIM score of 2 points was taken to be clinically significant. Results. Assessments were performed on 25 patients. The functional status was unchanged in eighteen patients (72%), four patients (16%) demonstrated a significant improvement and three patients (12%) deteriorated significantly. Those with deterioration after cranioplasty had some forms of complications including pneumocephalus or seizure. After excluding the three patients who had immediate medical or surgical complications after surgery, there was a mild overall improvement in the mean FIM score (2.1, 95% confidence interval 0.1–4.3, p = 0.049), mainly due to an improvement in their motor function. Conclusions. A small but significant number of patients appear to improve clinically following cranioplasty. The so-called syndrome of the trephined may be more common than had been previously appreciated.

Incidence and Risk Factors for Post-Traumatic Hydrocephalus following Decompressive Craniectomy for Intractable Intracranial Hypertension and Evacuation of Mass Lesions

There continues to be a considerable interest in decompressive craniectomy in the management of severe traumatic brain injury (TBI). Though technically straightforward, the procedure is not without significant complications. In this study we assessed the incidence and risk factors for the development of subdural hygroma and hydrocephalus after decompressive craniectomy. A total of 195 patients who had had a decompressive craniectomy for severe TBI between 2004 and 2010 at the two major trauma centers in Western Australia were considered. Of the 166 patients who survived after the acute hospital stay, 93 (56%; 95% confidence interval [CI] 48,63%) developed subdural hygroma; 45 patients (48%) had unilateral and 48 patients (52%) had bilateral subdural hygromas. Of the 159 patients who survived more than 6 months after surgery, 72 (45%; 95% CI 38,53%) developed radiological evidence of ventriculomegaly, and 26 of these 72 patients (36%; 95% CI 26,48%) developed clinical evidence of hydrocephalus and required a ventriculoperitoneal (VP) shunt. Maximum intracranial pressure prior to decompression (p=0.005), subdural hygroma (p=0.012), and a lower admission Glasgow Coma Scale score (p=0.009), were significant risk factors for hydrocephalus after decompressive craniectomy. Hydrocephalus requiring a VP shunt was associated with a higher risk of unfavorable neurological outcomes at 18 months (odds ratio 7.46; 95%CI 1.17,47.4; p=0.033), after adjusting for other factors. Our results showed a clear association between injury severity, subdural hygroma, and hydrocephalus, suggesting that damage to the cerebrospinal fluid drainage pathways contributes to the primary brain injury rather than the margin of the craniectomy as the factor responsible for these complications.

What can be learned from the DECRA study

BACKGROUND There has been a resurgence of interest in the use of decompressive craniectomy for severe traumatic brain injury (TBI). Numerous studies have shown that the procedure can consistently reduce intracranial pressure (ICP), and a significant number of patients achieve a good long-term functional recovery. However, there has been debate regarding clinical indications and patient selection. METHODS The DECRA (Decompressive Craniectomy in Patients with Severe Traumatic Brain Injury) study compared patients who underwent early decompressive craniectomy for diffuse TBI with patients who received standard medical therapy. Of patients, 70% in the craniectomy group had an unfavourable outcome versus 51% in the standard care group (odds ratio 2.21 [95% confidence interval 1.14-4.26]; P=0.02). Based on these results, the authors concluded that decompressive craniectomy was associated with more unfavorable outcomes and that by adopting standard medical therapy rather than surgical decompression the health care system would save millions of dollars. These conclusions are not really supported by closer examination of the basic data. There were problems with randomization such that the patients in the surgical arm appeared to have sustained a more severe primary TBI, the ICP threshold of >20 mm Hg for >15 minutes did not reflect clinical practice, and there was a high crossover rate from the standard care arm to the surgical arm. Because of these problems, the DECRA trial has received a great deal of criticism, and some authorities have claimed that the results should have no influence on clinical practice. This claim is perhaps unfair, and an alternative interpretation is offered. RESULTS Overall, the results of the DECRA study showed that a relatively transient and mild increase in ICP (>20 mm Hg for 15 minutes as recruitment criterion) does not imply that there is significant ongoing secondary brain injury, and any potential improvement obtained by surgical decompression may well be offset by surgical morbidity. CONCLUSIONS The role of decompressive craniectomy when ICP continues to increase ≥20 mm Hg remains to be established. The ongoing RESCUEicp (Randomised Evaluation of Surgery with Craniectomy for Uncontrollable Elevation of Intra-Cranial Pressure) study hopes to address this issue.

The current role of decompressive craniectomy in the management of neurological emergencies

Abstract Decompressive craniectomy has been used as a lifesaving procedure for many neurological emergencies, including traumatic brain injury, ischaemic stroke, subarachnoid haemorrhage, cerebrovenous thrombosis, severe intracranial infection, inflammatory demyelination and encephalopathy. The evidence to support using decompressive craniectomy in these situations is, however, limited. Decompressive craniectomy has only been evaluated by randomized controlled trials in traumatic brain injury and ischaemic stroke and, even so, its benefits and risks in these situations remain elusive. If one considers a modified Rankin Scale of 4 or 5 or dependency in daily activity as an unfavourable outcome, decompressive craniectomy is associated with an increased risk of survivors with unfavourable outcome (relative risk [RR] = 2.9, 95% confidence interval [CI] = 1.5–5.8, p = 0.002, I2 = 0%; number needed to operate to increase an unfavourable outcome = 3.5, 95% CI = 2.4–7.4), but not the number of survivors with a favourable outcome (RR = 1.5, 95% CI = 0.9–2.6, p = 0.13, I2 = 0%).

Sudden death following cranioplasty: a complication of decompressive craniectomy for head injury

This report details three cases of massive post-operative cerebral swelling following autologous cranioplasty. All three patients had a bifrontal decompressive craniectomy for intractably raised intracranial pressure following severe neurotrauma, developed hydrocephalus necessitating shunt insertion and were making a poor neurological recovery.