Trends in Incidence and Mortality by Hospital Teaching Status and Location in Aneurysmal Subarachnoid Hemorrhage

Comparative analysis of patient demographics, perioperative outcomes, and adverse events after lumbar spinal fusion between urban and rural hospitals: an analysis of the National Inpatient Sample (NIS) database

OBJECTIVE

Rural location of a patient's primary residence has been associated with worse clinical and surgical outcomes due to limited resource availability in these parts of the US. However, there is a paucity of literature investigating the effect that a rural hospital location may have on these outcomes specific to lumbar spine fusions.

METHODS

Using the National Inpatient Sample (NIS) database, we identified all patients who underwent primary lumbar spinal fusion in the years between 2009 and 2020. Patients were separated according to whether the operative hospital was considered rural or urban. Univariable and multivariable regression models were used for data analysis.

RESULTS

Of 2,863,816 patients identified, 120,298 (4.2 %) had their operation at a rural hospital, with the remaining in an urban hospital. Patients in the urban cohort were younger (P < .001), more likely to have private insurance (39.81 % vs 31.95 %, P < .001), and fewer of them were in the first (22.52 % vs 43.00 %, P < .001) and second (25.96 % vs 38.90 %, P < .001) quartiles of median household income compared to the rural cohort. The urban cohort had significantly increased rates of respiratory (4.49 % vs 3.37 %), urinary (5.25 % vs 4.15 %), infectious (0.49 % vs 0.32 %), venous thrombotic (0.57 % vs 0.24 %, P < .001), and neurological (0.79 % vs 0.36 %) (all P < .001) perioperative complications. On multivariable analysis, the urban cohort had significantly increased odds of the same perioperative complications: respiratory (odds ratio[OR] = 1.48; 95 % confidence interval [CI], 1.26-1.74), urinary (OR = 1.34; 95 %CI, 1.20-1.50), infection (OR = 1.63; 95 %CI, 1.23-2.17), venous thrombotic (OR = 1.79; 95 %CI, 1.32-2.41), neurological injury (OR = 1.92; 95 %CI, 1.46-2.53), and localized infection (OR = 1.65; 95 %CI, 1.25-2.17) (all P < .001).

CONCLUSIONS

Patients undergoing lumbar fusions experience significantly different outcomes based on the rural or urban location of the operative hospital.

Magnetic resonance analysis of deep cerebral venous vasospasm after subarachnoid hemorrhage in rabbits

Objective

Arterial spasm is proved to be an inducer of cerebral ischemia and cerebral infarction, while when a venous spasm occurs, cerebral edema is seen to be caused by a disturbance in cerebral blood flow. However, it is unclear and unproven whether venous spasm occurs after subarachnoid hemorrhage (SAH). To provide the theoretical basis for treating cerebral vasospasm after SAH, magnetic resonance imaging (MRI) was employed to observe the changes in the diameter of deep cerebral veins in rabbits after SAH.

Methods

Fourteen New Zealand rabbits were randomly divided into the SAH group (n = 10) and the normal saline group (NS group, n = 4). Specifically, the SAH models were established by the ultrasound-guided double injections of blood into cisterna magna. Moreover, the MRI was performed to observe the changes in the diameter of deep cerebral veins (internal cerebral vein, basilar vein, and great cerebral vein) and basilar artery before modeling (0 d) and 1, 3, 5, 7, 9, and 11 d after modeling.

Results

In the SAH group, the diameter of the basilar artery showed no evident change on the 1st d. However, it became narrower obviously on the 3rd d and 5th d, and the stenosis degree was more than 30%. The diameter gradually relieved from 7th to 9th d, and finally returned to normal on the 11th d. Moreover, the diameter of the internal cerebral vein significantly narrowed on the 1st d, the stenosis degree of which was 19%; the stenosis then relieved slightly on the 3rd d (13%), reached the peak (34%) on the 5th d, and gradually relieved from 7th d to 11th d. Moreover, the stenosis degree of the basilar vein was 18% on the 1st d, 24% on the 3rd d, and reached the peak (34%) on the 5th d.

Conclusion

After SAH in rabbits, the cerebral vasospasm was seen to occur in the basilar artery, and likewise, spasmodic changes took place in the deep cerebral vein. Furthermore, the time regularity of spasmodic changes between the cerebral vein and basilar artery was of significant difference, indicating that the venous vasospasm resulted in active contraction.

Short- and long-term mortality of subarachnoid hemorrhage according to hospital volume and severity using a nationwide multicenter registry study

Introduction

Recent improvements in treatment for subarachnoid hemorrhage (SAH) have decreased the mortality rates; however, the outcomes of SAH management are dependent on many other factors. In this study, we used nationwide, large-scale, observational data to investigate short- and long-term mortality rates after SAH treatment and the influence of patient severity and hospital volume.

Patients and methods

We selected patients with SAH treated with clipping and coiling from the South Korean Acute Stroke Assessment Registry. High- and low-volume hospitals performed ≥20 clipping and coiling procedures and <20 clipping and coiling procedures per year, respectively. Short- and long-term mortality were tracked using data from the Health Insurance Review and Assessment Service.

Results

Among 2,634 patients treated using clipping and coiling, 1,544 (58.6%) and 1,090 (41.4%) were hospitalized in high- and low-volume hospitals, respectively, and 910 (34.5%) and 1,724 (65.5%) were treated with clipping and coiling, respectively. Mortality rates were 13.5, 14.4, 15.2, and 16.1% at 3 months, 1, 2, and 4 years, respectively. High-volume hospitals had a significantly lower 3-month mortality rate. Patients with mild clinical status had a significantly lower 3-month mortality rate in high-volume hospitals than in low-volume hospitals. Patients with severe clinical status had significantly lower 1- and 2-year mortality rates in high-volume hospitals than in low-volume hospitals.

Conclusion

Short- and long-term mortality in patients with SAH differed according to hospital volume. In the modern endovascular era, clipping and coiling can lead to better outcomes in facilities with high stroke-care capabilities.

Meta-analysis of associations of genetic polymorphisms with cerebral vasospasm and delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage

INTRODUCTION

Cerebral vasospasm (CV) and delayed cerebral ischemia (DCI) are among the most hazardous complications of aneurysmal subarachnoid hemorrhage (aSAH). Genetic factors are thought to play a significant role in the development of both complications.

AIM

To perform a comprehensive meta-analysis of studies that study the association between different genetic polymorphisms and development of DCI and/or CV.

METHODS

We searched MEDLINE and Science Direct databases on May 29, 2021, using iterations of the keywords "subarachnoid hemorrhage", "vasospasm", "delayed cerebral ischemia", and "gene". After duplicates were removed, the two reviewers screened the titles of the articles and abstracts independently. A random-effect model was used to calculate the relative risk with 95% CI; a fixed-effect model was additionally explored.

RESULTS

We pooled data from 16 articles that reported an association between eNOS, apolipoprotein E4 (ApoE4), haptoglobin (Hp), or ryanodine-1 (RYR-1) and CV, DCI, or both. Presence of Hp 2-2 was associated both with CV (RR 2.10, 95% CI 1.33-3.31, p = 0.0014) and DCI (RR 1.57, 95%CI 1.06-2.34, p = 0.026). ApoE4 allele had a borderline association with CV (RR 1.48, 95%CI 0.99-2.21, p = 0.054).

CONCLUSION

Our meta-analysis supports the association between the presence of the Hp2-2 allele and the occurrence of CV and DCI after aSAH. Further studies investigating this association are needed to reinforce this finding.

Short and Long-term Outcomes of Subarachnoid Hemorrhage Treatment according to Hospital Volume in Korea: a Nationwide Multicenter Registry

BACKGROUND

Subarachnoid hemorrhage is a potentially devastating cerebrovascular attack with a high proportion of poor outcomes and mortality. Recent studies have reported decreased mortality with the improvement in devices and techniques for treating ruptured aneurysms and neurocritical care. This study investigated the relationship between hospital volume and short- and long-term mortality in patients treated with subarachnoid hemorrhage.

METHODS

We selected subarachnoid hemorrhage patients treated with clipping and coiling from March-May 2013 to June-August 2014 using data from Acute Stroke Registry, and the selected subarachnoid hemorrhage (SAH) patients were tracked in connection with data of Health Insurance Review and Assessment Service to evaluate the short-term and long-term mortality.

RESULTS

A total of 625 subarachnoid hemorrhage patients were admitted to high-volume hospitals (n = 355, 57%) and low-volume hospitals (n = 270, 43%) for six months. The mortality of SAH patients treated with clipping and coiling was 12.3%, 20.2%, 21.4%, and 24.3% at 14 days, three months, one year, and five years, respectively. The short-term and long-term mortality in high-volume hospitals was significantly lower than that in low-volume hospitals. On Cox regression analysis of death in patients with severe clinical status, low-volume hospitals had significantly higher mortality than high-volume hospitals during short-term follow-up. On Cox regression analysis in the mild clinical status group, there was no statistical difference between high-volume hospitals and low-volume hospitals.

CONCLUSION

In subarachnoid hemorrhage patients treated with clipping and coiling, low-volume hospitals had higher short-term mortality than high-volume hospitals. These results from a nationwide database imply that acute SAH should be treated by a skilled neurosurgeon with adequate facilities in a high-volume hospital.

Aneurysmal Subarachnoid Hemorrhage: the Last Decade

Aneurysmal subarachnoid hemorrhage (SAH) affects six to nine people per 100,000 per year, has a 35% mortality, and leaves many with lasting disabilities, often related to cognitive dysfunction. Clinical decision rules and more sensitive computed tomography (CT) have made the diagnosis of SAH easier, but physicians must maintain a high index of suspicion. The management of these patients is based on a limited number of randomized clinical trials (RCTs). Early repair of the ruptured aneurysm by endovascular coiling or neurosurgical clipping is essential, and coiling is superior to clipping in cases amenable to both treatments. Aneurysm repair prevents rebleeding, leaving the most important prognostic factors for outcome early brain injury from the hemorrhage, which is reflected in the neurologic condition of the patient, and delayed cerebral ischemia (DCI). Observational studies suggest outcomes are better when patients are managed in specialized neurologic intensive care units with inter- or multidisciplinary clinical groups. Medical management aims to minimize early brain injury, cerebral edema, hydrocephalus, increased intracranial pressure (ICP), and medical complications. Management then focuses on preventing, detecting, and treating DCI. Nimodipine is the only pharmacologic treatment that is approved for SAH in most countries, as no other intervention has demonstrated efficacy. In fact, much of SAH management is derived from studies in other patient populations. Therefore, further study of complications, including DCI and other medical complications, is needed to optimize outcomes for this fragile patient population.