Delayed Vertebral Artery Dissection after Posterior Cervical Fusion with Traumatic Cervical Instability: A Case Report

Iatrogenic Vascular Injury Associated with Cervical Spine Surgery: A Systematic Literature Review

BACKGROUND

Iatrogenic vascular injury is an uncommon complication of anterior and/or posterior surgical approaches to the cervical spine. Although the results of this injury may be life-threatening, mortality/morbidity can be reduced by an understanding of its mechanism and proper management.

METHODS

We conducted a literature review to provide an update of this devastating complication in spine surgery. A total of 72 articles including 194 cases of vascular lesions following cervical spine surgery between 1962 and 2021 were analyzed.

RESULTS

There were 53 female and 41 male cases (in addition to 100 cases with unreported sex) with ages ranging from 3 to 86 years. The vascular injuries were classified according to the spinal procedures, such as anterior or posterior cervical spine surgery. The interval between the symptom of the vascular injury and the surgical procedure ranged from 0 to 10 years. Only two-thirds of patients underwent intra- or postoperative imaging and the most frequently injured vessel was the vertebral artery (86.60%). Laceration was the most common lesion (41.24%), followed by pseudoaneurysm (16.49%) and dissection (5.67%). Vascular repair was performed in 114 patients. The mortality rate was 7.22%, and 18.04% of patients had 1 or more other complications. Most presumed causes of vascular lesions were by instrumentation/screw placement (31.44%) or drilling (20.61%). Sixteen patients had an anomalous artery. Direct microsurgical repair was achieved in only 15 cases.

CONCLUSIONS

Despite increased anatomical knowledge and advanced imaging techniques, we need to consider the risk of vascular injury as a surgical complication in patients with cervical spine pathologies.

The assessment of the frequency and arrangement of the subsegmental branches of V3 using computed tomography angiography

Background

The frequency and arrangement of the subsegmental branches of the third portion of the vertebral artery (V3) have been assessed in small samples by autopsy, but they have not been assessed by computed tomography angiography (CTA). To determine the frequency and arrangement of subsegmental branches of V3 by CTA and to analyze the interrelationships among frequency, arrangement, sex, and side-to-side.

Methods

First, the radiology records of 668 consecutive patients who underwent cervical or craniocervical CTA scans from October 1, 2017 to October 31, 2019 were retrospectively retrieved. Second, the four demarcation points were ascertained to define the three subsegments by reviewing the resource images, namely, the vertical portion of V3(V3v), horizontal portion of V3(V3h), and extradural portion of V3(V3e). Then, the numerical value and the location of the bifurcating branch in each subsegment of V3 were recorded. Third, the frequency and arrangement of the branches was assessed, and the relationships between sex, laterality and frequency and arrangement were analyzed as well as the interobserver performance.

Results

On the left, 25%, 20.21%, and 6.59% were the frequencies of one branch in the V3v, V3h, and V3e, and 1.05%, 0.00%, and 0.45% were the frequencies of two branches, respectively. On the right, 25.04%, 17.07%, and 6.44% were the frequencies of one branch in the V3v, V3h, and V3e, and 1.04%, 0.3%, and 0.15% were the frequencies of two branches, respectively. There were no differences between the side-to-side and numerical values of the branches according to the t-test (P=0.4341, P=0.7968), and there were no differences between the side-to-side variable, sex variable and number of branches according to the t-test (P=0.4474, P=0.3593). There were no differences between the side-to-side and eight arrangements (permutation of 000; 100; 110; 111; 010; 011; 001; 101) by using the two-sample KS test (P=0.942), and there were no differences between sex and the eight arrangements according to the two-sample KS test (P=0.9973, P=0.8519). The interobserver reliability was excellent (Spearman's ranked correlation: 0.9927).

Conclusions

The frequency and arrangement of V3 subsegmental branches could be displayed by source imaging with CTA, and there were no significant differences according to the sex or side of the individual. It was imperative to acquaint the subsegmental branches before the operation involving V3 in the craniocervical junction to determine the surgical approach and reduce bleeding during the surgical procedures.

Efficacy of Endovascular Proximal Occlusion before Direct Reposition Surgery of Blunt Cervical Fracture with Unilateral Vertebral Injury

Cerebral infarction related to traumatic vertebral artery (VA) injuries is not common. However, if VA injuries cause ischemic and/or hemorrhage stroke, these subsequent problems can result in severe residual impairment and mortality. Herein, we present five patients with cervical vertebra fractures due to blunt cervical trauma who underwent preoperative endovascular therapy. Between June 2010 and April 2018 in our hospital, five patients with traumatic occlusion of a unilateral VA underwent coil embolization to prevent post-surgical stroke due to reperfusion in the VA. Because of cervical instability or subluxation, all of the patients received endovascular therapy before surgery for their cervical fracture. None of the patients presented with stroke after presurgical embolization and direct surgery. When stagnated blood, including thrombi, in the occluded VA is released during cervical surgery, brain embolism may occur. Therefore, early cerebrovascular vessel assessment and presurgical endovascular treatment must be considered to prevent stroke after direct surgery.

Impact of Perioperative Neurologic Deficits on Clinical Outcomes After Posterior Cervical Fusion

BACKGROUND

In the United States, the number of posterior cervical fusions has increased substantially. Perioperative neurologic complications associated with this procedure, such as spinal cord and peripheral nerve injuries, can have significant effects on patient health. We examined the impact of perioperative neurologic deficits on mortality in patients undergoing posterior cervical fusion. The secondary aim was to understand the risk factors for perioperative neurologic complications.

METHODS

Data were collected from the National Inpatient Sample (NIS) Health Cost Utilization Project (HCUP) between 1999 and 2011. Patients younger than 18 years and older than 80 years were excluded, as were patients who underwent posterior cervical fusion caused by trauma. Patient demographics and comorbidities were compiled as well as variables that have been associated with increased risk of perioperative neurologic deficits. We used the van Walraven score, a weighted numeric surrogate for the Elixhauser comorbidity index, as a covariate to assess comorbidities that have been associated with in-hospital mortality and morbidity after posterior cervical fusion. In addition, we performed univariate comparisons between covariates and surgical outcomes. We conducted a multivariable logistic regression, adjusting for many of the covariates, as well as trend analyses.

RESULTS

An analysis of 33,644 patients yielded an overall rate of perioperative neurologic deficits, morbidity, and mortality of 1.08%, 40.44%, and 1.00%, respectively. Perioperative neurologic deficits were independent risk factors predictors of in-hospital mortality (odds ratio, 5.270; P < 0.0001) and morbidity (odds ratio, 2.579; P < 0.0001). Other statistically significant predictors of mortality included increasing van Walraven score, myocardial infarction, metastatic cancer, and weight loss. These were also independent predictors of morbidity along with but not limited to age, device complications, congestive heart failure, paralysis, diabetes with chronic complications, deficiency anemias, device complications, and intraspinal abscess.

CONCLUSIONS

Perioperative neurologic deficits are serious complications of posterior cervical fusion and can independently predict in-hospital mortality and morbidity. As this procedure continues to be used increasingly, attention should be directed toward preventing these complications and intervening earlier in patients who have a neurologic deficit. Future efforts should be geared toward screening for at-risk patients with the initiation of surgical prehabilitation.