To the best of our knowledge, this is the first study with such a large cohort of octogenarians to examine the clinical course of surgical management for cervical SSEH. We assessed morbidity and mortality rates and determined potential risk factors for both loss of ambulation and occurrence of postoperative SSEH exclusively in octogenarians undergoing spinal decompression less than 24 h after the first signs of neurological deterioration. Octogenarians constitute a frail cohort with an age-adjusted CCI of 9.1, and almost 50% were receiving anticoagulant agents with an increased PTT of 46.5 s. The in-hospital mortality rate was 4.5%, while the 90-day mortality increased by 9.1%. During the follow-up period of more than 2 years (26.8 months), no deaths occurred. Interestingly, significant improvements in neurological deficits, as measured by MS, were seen at discharge, and 63.6% regained their ability to walk after surgery. The remaining patients recovered substantially and regained independence in their daily activities after rehabilitation. Notably, higher rates of comorbidities and higher grades of preoperative motor weakness were significant risk factors for loss of ambulation after surgery. Revision surgery due to postoperative SSEH required five patients to use anticoagulants in-house. Logistic regression analysis revealed that the use of anticoagulant agents and increased PTT were significantly associated with postoperative occurrence of SSEH.
Review of literature
Miscellaneous factors such as arterial hypertension, anticoagulant agents, lifting, and vascular anomalies have been hypothesized to predispose patients to SSEH [
2,
11,
34]. In the present study, despite the generally high rates of comorbidities, over 80% of patients presented with arterial hypertension and almost 50% were under anticoagulation due to a cardiovascular disease. Liao et al. (2009) conducted a retrospective study of 35 patients with a mean age of 42.6 years and reported that arterial hypertension was present in 34.3% of the cases, while only one patient received an anticoagulant [
20]. No significant association was found between hypertension or anticoagulant use and clinical outcomes. In contrast, Nitta et al. (2021) in their retrospective analysis of 30 patients with a mean age of 67 years (range 62–78 years) showed that both higher rates of underlying diseases, as determined by ASA, and preoperative consumption of anticoagulant agents were significant risk factors for worse outcomes [
25]. Groen and Ponssen (1990), in a review and meta-analysis of 199 cases, also expressed the notion that there might be a potential relationship between arterial hypertension, anticoagulant use, and the coexistence of SSEH [
12], a phenomenon most frequently observed in older patients because of their cardiovascular profile. In accordance with these findings, Shin et al. (2006) postulated that both arterial hypertension and anticoagulation might contribute to higher rates of bleeding, although a causative relationship could not be established [
27]. Some case reports also indicated that patients receiving oral anticoagulants, such as dabigatran or rivaroxaban, have a higher risk of the occurrence of SSEH ([
1,
16]. It should be noted that the aforementioned studies mainly examined younger patients, while patients aged ≥ 80 years were either marginalized or ignored. According to the findings of the present study dedicated to octogenarians, both arterial hypertension and anticoagulation might be two key factors contributing to the occurrence of SSEH; however, these results should be considered with caution owing to the small sample size. Undoubtedly, increased awareness is warranted among emergency physicians confronted with such cases. Unreassuringly, neither parameter significantly affected the clinical outcomes.
It is well known that octogenarians are impaired due to higher rates of comorbidities, which is why a surgical procedure for spinal pathology is currently viewed with reluctance due to potential postoperative complications that may also lead to death. However, in the presence of acute onset of neurological deficits, surgery is inevitable in such a debilitating cohort. According to the findings of the present study, each patient underwent surgical decompression of the cervical spinal canal via laminectomy and hematoma evacuation of at least two segments less than 24 h after the initial presentation of neurological decline. Most importantly, a significant improvement in motor deficits was observed at discharge. Unique risk factors for loss of ambulation were higher rates of comorbidities and higher degrees of neurological deficits on admission. After surgery, eight patients were unable to walk with an initially complete paraplegia, whereas a slight improvement was observed. Therefore, the patients were transferred to a rehabilitation clinic. At the latest follow-up, the patient had recovered fully. Consistent with these findings, Liao et al. (2009) highlighted the importance of swift surgical management after neurological deterioration. In particular, they showed that patients undergoing surgery within 48 h after the first neurological signs experienced significantly better neurological recovery compared to those treated after 48 h [
20]. Factors such as age, sex, location, and extent of surgery did not significantly affect the outcomes [
20]. Similarly, Zhong et al. (2011) concluded that early surgery after symptom onset might be a key factor for better recovery. Additionally, they stated that worse preoperative neurological status was correlated with less favorable outcomes, whereas these patients fully recovered at the latest follow-up, as also shown in the present study [
32]. In another study of 10 older patients with SSEH (range 72–84 years), emergent decompression and evacuation of the hematoma led to substantially good recovery rates [
10]. In line with the abovementioned studies, Yan et al. (2022) also found that preoperative severe neurological deficits and extended paraplegia time of more than 12 h were significantly correlated with a worse prognosis [
30]. Therefore, although a general consensus concerning the optimal management of such cases is still debatable, we feel that emergent decompression gray might be a critical pillar for the therapy of SSEH in such a frail cohort.
The mechanisms underlying SSEH are not yet fully understood. To date, two mechanisms have been proposed for this phenomenon. Beatty and Winston (1984) advocated that the vertebral venous plexus (a valveless low-pressure system) is associated with the abdominal and venous systems; thus, an increase in intraabdominal or intrathoracic pressure can lead to an elevated intraspinal venous plexus [
3]. This may result in a rupture of the vessels of the epidural venous plexus, mainly those in the dorsal space where most SSEHs are found [
3]. However, considering that intrathecal pressure is higher than epidural venous pressure, an epidural arterial source is thought to be the inciting event, especially in the presence of arterial hypertension or coagulopathy [
12,
21]. In the present study, almost all individuals presented with arterial hypertension and half of them were under anticoagulant agents; therefore, these conditions might contribute to the rupture of an arterial epidural vessel, thus causing the hematoma. Nevertheless, all SSEHs were in the dorsal epidural space. Therefore, the venous vessel theory might be the impetus for SSEH. We feel that both mechanisms should be further pursued in future studies to shed light on this still poorly understood topic.
In a retrospective study of 30 patients with SSEH, Zhong et al. (2011) reported deaths (16.7%), of whom 4 had a cervicothoracic SSEH (2 underwent surgery and 2 underwent conservative management) and died due to respiratory failure and 1 due to gastrointestinal infection immediately after surgery [
32]. In contrast, Liao et al. (2009) found a lower mortality rate of 5.7%, which was not surgery-related [
20]. This discrepancy between the studies might be attributable to the fact that, in the series from Zhong et al. (2011), patients were treated conservatively and death was inevitable due to the rapid disease progression. As shown in previous studies, disease-related mortality ranges from 6 to 8% and is highly correlated with cervical or cervicothoracic hematomas [
12,
30], which is in line with the findings of the present study exclusively in octogenarians with cervical SSEH. In our series, one patient died due to acute heart failure, whereas two died within 90 days due to severe pneumonia. None of the patients died during the surgical procedure.
Although the use of anticoagulant agents significantly affected the clinical outcome, we showed that a coagulation disorder as measured by PTT due to the use of anticoagulant agents was significantly associated with re-bleeding immediately after surgery. There are still contradictory results concerning the causal relationship between anticoagulant use and re-bleeding after spinal surgery. In their retrospective study of 3729 patients undergoing spinal surgery, Yi et al. (2006) concluded that postoperative hematoma was significantly associated with anticoagulation therapy [
31]. Lawton et al. (1995), in a retrospective analysis of 30 patients with a mean age of 48 years, asserted that postoperative spinal hematoma is correlated with both previous spinal surgery and anticoagulation medication [
19]. In agreement with these findings, Kou et al. (2002) found that coagulopathy and increasing age constitute to higher risk of postoperative spinal hematoma [
18]. Herein, it should be emphasized that our patients received antidotes to eliminate the anticoagulation effects of the anticoagulant agents according to the German Guidelines [
29]. Therefore, it raises the question why the use of such medication poses a risk factor for the recurrence of the SSEH. One potential explanation may be that the geriatric population and especially octogenarians, due to their pure baseline history with multiple prolonged comorbidities, may require discontinuation intervals since their renal function is substantially impaired (creatinine clearance of less than 30 mL/min) [
24]. Previous studies have stated that impaired renal function is a significant risk factor and prolongs the effects of anticoagulant agents despite discontinuation before surgery or the use of antidotes to counter their effect [
4,
5]. Noteworthily, according to the findings of the present study, over 40% of the examined patients presented with a chronic renal failure, while all the 10 patients who received anticoagulant agents suffered from impaired renal function. Thus, we feel that these findings support the hypothesis, as it was also previously shown that impaired renal function serves as an important confounding factor for a prolonged effect of the anticoagulants even after the administration of antidotes. Further research is warranted since octogenarians are mostly precluded from such studies, presumably due to their multiple underlying diseases related with worse outcomes [
4]. Nevertheless, we believe that, especially in the case of octogenarians, a meticulous preoperative evaluation with a sufficient record of the underlying diseases should be conducted. Therefore, surgeons will be alerted in case of a secondary postoperative neurological deterioration, and an emergent surgery can be performed to prevent further worsening of the clinical outcome or even death, especially in cases with cervical hematoma.