Comparison of conservative management, microsurgery only, and microsurgery with preoperative embolization for unruptured arteriovenous malformations: A propensity score weighted prospective cohort study

AIMS

To compare the efficacy and deficiency of conservative management (CM), microsurgery (MS) only, and microsurgery with preoperative embolization (E + MS) for unruptured arteriovenous malformations (AVMs).

METHODS

We prospectively included unruptured AVMs undergoing CM, MS, and E + MS from our institution between August 2011 and August 2021. The primary outcomes were long-term neurofunctional outcomes and hemorrhagic stroke and death. In addition to the comparisons among CM, MS, and E + MS, E + MS was divided into single-staged hybrid and multi-staged E + MS for further analysis. Stabilized inverse probability of treatment weighting using propensity scores was applied to control for confounders by treatment indication across the three groups.

RESULTS

Of 3758 consecutive AVMs admitted, 718 patients were included finally (266 CM, 364 MS, and 88 E + MS). The median follow-up duration was 5.4 years. Compared with CM, interventions (MS and E + MS) were associated with neurological deterioration. MS could lower the risk of hemorrhagic stroke and death. Multi-staged E + MS was associated with neurological deterioration and higher hemorrhagic risks compared with MS, but the hybrid E + MS operation significantly reduced the hemorrhage risk.

CONCLUSION

In this study, unruptured AVMs receiving CM would expect better neurofunctional outcomes but bear higher risks of hemorrhage than MS or E + MS. The single-staged hybrid E + MS might be promising in reducing inter-procedural and subsequent hemorrhage.

Timing of microsurgical resection for ruptured brain arteriovenous malformations: a propensity score-matched analysis using prospective single-center registry data

OBJECTIVE

The optimal microsurgical timing in ruptured brain arteriovenous malformations (AVMs) is not well understood and is surrounded by controversy. This study aimed to elucidate the impacts of microsurgical resection timing on clinical outcomes.

METHODS

The authors retrieved and reviewed the records on all ruptured AVMs treated at their institution and registered in a nationwide multicenter prospective collaboration registry between August 2011 and August 2021. Patients were dichotomized into an early resection group (≤ 30 days from the last hemorrhagic stroke) and a delayed resection group (> 30 days after the last hemorrhagic stroke). Propensity score-matched analysis was used to compare long-term outcomes. The primary outcome was neurological status as assessed using the modified Rankin Scale (mRS). The secondary outcomes were complete obliteration rate, postoperative seizure, and postoperative hemorrhage.

RESULTS

Of the 3649 consecutive AVMs treated at the authors' institution, a total of 558 ruptured AVMs were microsurgically resected and had long-term follow-up. After propensity score matching, 390 ruptured AVMs (195 pairs) were included in the comparison of outcomes. The mean (± standard deviation) clinical follow-up duration was 4.93 ± 2.94 years in the early resection group and 5.61 ± 2.56 years in the delayed resection group. Finally, as regards the distribution of mRS scores, short-term neurological outcomes were better in the delayed resection group (risk difference [RD] 0.3%, 95% CI -0.1% to 0.6%, p = 0.010), whereas long-term neurological outcomes were similar between the two groups (RD 0.0%, 95% CI -0.2% to 0.2%, p = 0.906). Long-term favorable neurological outcomes (early vs delayed: 90.8% vs 90.3%, p > 0.999; RD 0.5%, 95% CI -5.8% to 6.9%; RR 1.01, 95% CI 0.94-1.07) and long-term disability (9.2% vs 9.7%, p > 0.999; RD -0.5%, 95% CI -6.9% to 5.8%; RR 0.95, 95% CI 0.51-1.75) were also similar between these groups. In terms of secondary outcomes, postoperative seizure (early vs delayed: 8.7% vs 5.6%, p = 0.239; RD 3.1%, 95% CI -2.6% to 8.8%; RR 1.55, 95% CI 0.74-3.22), postoperative hemorrhage (1.0% vs 1.0%, p > 0.999; RD 0.0%, 95% CI -3.1% to 3.1%; RR 1.00, 95% CI 0.14-7.04), and hospitalization time (16.4 ± 8.5 vs 19.1 ± 7.9 days, p = 0.793) were similar between the two groups, whereas early resection had a lower complete obliteration rate (91.3% vs 99.0%, p = 0.001; RD -7.7%, 95% CI -12.9% to 3.1%; RR 0.92, 95% CI 0.88-0.97).

CONCLUSIONS

Early and delayed resection of ruptured AVMs had similar long-term neurological outcomes. Delayed resection can lead to a higher complete obliteration rate, although the risk of rerupture during the resection waiting period should be vigilantly monitored.

Long-term outcomes of microsurgery and stereotactic radiosurgery as the first-line treatment for arteriovenous malformations: a propensity score-matched analysis using nationwide multicenter prospective registry data

BACKGROUND

This study aimed to compare the risk and benefit profile of microsurgery (MS) and stereotactic radiosurgery (SRS) as the first-line treatment for unruptured and ruptured arteriovenous malformations (AVMs).

MATERIALS AND METHODS

The authors included AVMs underwent MS or SRS as the first-line treatment from a nationwide prospective multicenter registry in mainland China. The authors used propensity score-matched methods to balance baseline characteristics between the MS and SRS groups. The primary outcomes were long-term hemorrhagic stroke or death, and the secondary outcomes were long-term obliteration and neurological outcomes. Subgroup analyses and sensitivity analyses with different study designs were performed to confirm the stability of our findings.

RESULTS

Of the 4286 consecutive AVMs in the registry from August 2011 to December 2021; 1604 patients were eligible. After matching, 244 unruptured and 442 ruptured AVMs remained for the final analysis. The mean follow-up duration was 7.0 years in the unruptured group and 6.1 years in the ruptured group. In the comparison of primary outcomes, SRS was associated with a higher risk of hemorrhagic stroke or death both in the unruptured and ruptured AVMs (unruptured: hazard ratio 4.06, 95% CI: 1.15-14.41; ruptured: hazard ratio 4.19, 95% CI: 1.58-11.15). In terms of the secondary outcomes, SRS was also observed to have a significant disadvantage in long-term obliteration [unruptured: odds ratio (OR) 0.01, 95% CI: 0.00-0.04; ruptured: OR 0.09, 95% CI: 0.05-0.15]. However, it should be noted that SRS may have advantages in preventing neurofunctional decline (unruptured: OR 0.56, 95% CI: 0.27-1.14; ruptured: OR 0.41, 95% CI: 0.23-0.76). The results of subgroup analyses and sensitivity analyses were consistent in trend but with slightly varied powers.

CONCLUSIONS

This clinical practice-based real-world study comprehensively compared MS and SRS for AVMs with long-term outcomes. MS is more effective in preventing future hemorrhage or death and achieving obliteration, while the risk of neurofunctional decline should not be ignored.

Cerebral Microbleeds-Long-Term Outcome After Cerebrospinal Fluid Shunting in Idiopathic Normal Pressure Hydrocephalus

BACKGROUND

Cerebral microbleeds (CMBs) are common in idiopathic normal pressure hydrocephalus (INPH) and have been suggested as radiological markers of a brain prone to bleeding. The presence of CMBs might be relevant when selecting patients for shunt surgery.

OBJECTIVE

To evaluate whether CMBs increases long-term risk of hemorrhagic complications and mortality or affects outcomes after cerebrospinal fluid shunt surgery in a cohort of patients with INPH.

METHODS

One hundred and forty nine shunted patients with INPH (mean age, 73 years) were investigated with MRI (T2* or susceptibility-weighted imaging sequences) preoperatively. CMBs were scored with the Microbleed Anatomic Rating Scale. Patients were observed for a mean of 6.5 years (range 2 weeks to 13 years) after surgery. Hemorrhagic events and death were noted. Improvement in gait was evaluated 3 to 6 months after surgery.

RESULTS

At baseline, 74 patients (50%) had CMBs. During follow-up, 7 patients (5%) suffered a hemorrhagic stroke and 43 (29%) suffered a subdural hematoma/hygroma with a median time from surgery of 30.2 months (IQR 50). Overall, having CMBs was not associated with suffering a subdural hematoma/hygroma or hemorrhagic stroke during follow-up with 1 exception that an extensive degree of CMBs (≥50 CMB) was more common in patients suffering a hemorrhagic stroke ( P = .03). CMBs were associated with increased mortality ( P = .02, Kaplan-Meier, log-rank test). The presence of CMBs did not affect gait outcome ( P = .28).

CONCLUSION

CMBs were associated with hemorrhagic stroke and mortality. CMBs do not seem to reduce the possibility of gait improvement after shunt surgery or contribute to the risk of hemorrhagic complications regarding subdural hematoma or hygroma.

Changes in the prefronto-thalamic tract following cranioplasty: Case reports

RATIONALE

The prefrontothalamic tract (PTT) injury is associated with various neuropsychological impairments including cognitive impairment. We report on three women with hemorrhagic stroke who showed changes in the PTT following cranioplasty (C/P) using diffusion tensor tractography (DTT) images.

PATIENT CONCERNS

The 3 women with hemorrhagic stroke showed reductions of cognitive impairment following C/P. Mini-Mental State Examination scores (MMSE) were increased by 7-, 8-, and 5-point in patient 1, 2, and 3, respectively, after C/P compared with the patients' pre-C/P MMSE scores.

DIAGNOSIS

Three patients were diagnosed with spontaneous intracerebral hemorrhage. Three patients underwent C/P using auto-bone at 7 (patient 1 and 3) and 13 (patient 2) weeks after onset.

INTERVENTIONS

Diffusion tensor imaging data were acquired within 3 days before and 21 days after C/P.

OUTCOMES

The pre-C/P DTT results showed non-reconstruction of the dorsolateral prefrontal cortex (DLPFC; patient 2 and 3) on the contralateral operation (contra-OP) side and orbitofrontal cortex (OFC; patient 3) on both sides, but those were reconstructed on post-C/P DTT. Except for the contra-OP side OFC of patient 2, all fractional anisotropy values decreased on post-C/P DTT compared with pre-C/P DTT. The mean diffusivity values of the VLPFC and OFC were higher on post-C/P DTT except for the contra-OP side VLPFC of patient 1 and contra-OP side OFC of patient 2. The voxel numbers also increased except for the contra-OP side VLPFC of patient 1.

LESSONS

We demonstrated structural changes in the PTT along with concomitant reductions of cognitive impairments following C/P in 3 women with hemorrhagic stroke using DTT. The DTT changes suggest that C/P can affect the state of the PTT on both the OP and contra-OP sides. However, the limitation that DTT analysis may underestimate or overestimate fiber tract status due to regions of fiber complexity and crossing fiber should be considered.

COVID-19 and Changes in Neurosurgical Workload in the United Kingdom

BACKGROUND

Cessation of elective procedures and lower bed capacity during the COVID-19 pandemic have led to a rise in the waiting lists for surgery, but it is unclear if workload has recovered sufficiently to account for this backlog. We describe the change in neurosurgical workload at a tertiary neurosciences center in the United Kingdom after the first pandemic wave in comparison with the months before and during the first wave.

METHODS

A retrospective review of theatre records and electronic referrals-between December 1, 2019, and August 31, 2020-was performed. The months of December 2019-February 2020 were designated as pre-COVID months and March-May 2020 were designated as COVID months. The time period from June to August 2020 was designated as post-wave months. Statistical analyses were performed on SPSS v22 (IBM).

RESULTS

Referrals declined from 572 in January to a nadir of 352 in April before a steady rise to August. Referral volumes for degenerative spinal disease and traumatic brain injuries showed a statistically significant change during the year. On average, 212 procedures per month were performed in the pre-COVID months, 167 procedures per month during COVID months, and 232 procedures per month in the post-wave months. The number of patients on the waiting list for scheduled operations rose from March (785 patients) onward to a peak of 997 patients in July.

CONCLUSIONS

In the aftermath of COVID-19, higher referral volumes and operative procedures were apparent in the post-wave months as services returned to normal. With the expectation of a second wave of infections, it is unclear whether this will be sustainable.

Neurosurgical Services in the Northern Zone of Sarawak in Malaysia: The Way Forward Amid the COVID-19 Pandemic

Background

The novel coronavirus disease 2019 (COVID-19) pandemic has set a huge challenge to the delivery of neurosurgical services, including the transfer of patients. We aimed to share our strategy in handling neurosurgical emergencies at a remote center in Borneo island. Our objectives included discussing the logistic and geographic challenges faced during the COVID-19 pandemic.

Methods

Miri General Hospital is a remote center in Sarawak, Malaysia, serving a population with difficult access to neurosurgical services. Two neurosurgeons were stationed here on a rotational basis every fortnight during the pandemic to handle neurosurgical cases. Patients were triaged depending on their urgent needs for surgery or transfer to a neurosurgical center and managed accordingly. All patients were screened for potential risk of contracting COVID-19 prior to the surgery. Based on this, the level of personal protective equipment required for the health care workers involved was determined.

Results

During the initial 6 weeks of the Movement Control Order in Malaysia, there were 50 urgent neurosurgical consultations. Twenty patients (40%) required emergency surgery or intervention. There were 9 vascular (45%), 5 trauma (25%), 4 tumor (20%), and 2 hydrocephalus cases (10%). Eighteen patients were operated at Miri General Hospital, among whom 17 (94.4%) survived. Ninety percent of anticipated transfers were avoided. None of the medical staff acquired COVID-19.

Conclusions

This framework allowed timely intervention for neurosurgical emergencies (within a safe limit), minimized transfer, and enabled uninterrupted neurosurgical services at a remote center with difficult access to neurosurgical care during a pandemic.