Abducens nerve palsy as a postoperative complication of minimally invasive thoracic spine surgery: a case report

Acute Cranial Nerve VI Palsy Following Prolonged Prone Positioning in an Adolescent With Neurofibromatosis Type 1: A Rare Complication of Spinal Surgery in the Prone Position

The abducens or sixth cranial nerve provides motor innervation to the lateral rectus muscle, which abducts the ipsilateral eye with secondary innervation of the contralateral medial rectus muscle to allow for coordinated movement of both eyes. Various acute and chronic pathologic conditions, most importantly pontine infarctions and increased intracranial pressure, can result in acute sixth cranial nerve palsies. We report the uncommon occurrence of acute abducens nerve palsy following spinal fusion surgery in an 18-year-old male patient with a history of multiple neurological and orthopedic conditions. Postoperatively, the patient presented with symptoms that included left diplopia with restricted upward and downward gaze, indicative of abducens nerve palsy. The anatomy of the sixth cranial nerve is discussed, potential etiologies of sixth nerve palsy presented, and a proposed diagnostic workup reviewed. Our report emphasizes the need for comprehensive exploration of ocular symptoms following spinal surgery, given the various potential etiologies of sixth nerve palsy.

Clinical Consequences of Incidental Durotomy during Full-Endoscopic Lumbar Decompression Surgery in Relation to Intraoperative Epidural Pressure Measurements

Background: Seizures, neurological deficits, bradycardia, and, in the worst cases, cardiac arrest may occur following incidental durotomy during routine lumbar endoscopy. Therefore, we set out to measure the intraoperative epidural pressure during lumbar endoscopic decompression surgery. Methods: We conducted a retrospective observational cohort study to obtain intraoperative epidural measurements with an epidural catheter-pressure transducer assembly through the spinal endoscope on 15 patients who underwent lumbar endoscopic decompression of symptomatic lumbar herniated discs and spinal stenosis. The endoscopic interlaminar technique was employed. Results: There were six (40.0%) female and nine (60.0%) male patients aged 49.0667 ± 11.31034, ranging from 36 to 72 years, with an average follow-up of 35.15 ± 12.48 months. Three of the fifteen patients had seizures with durotomy and one of these three had intracranial air on their postoperative brain CT. Another patient developed spinal headaches and diplopia on postoperative day one when her deteriorating neurological function was investigated with a brain computed tomography (CT) scan, showing an intraventricular hemorrhage consistent with a Fisher Grade IV subarachnoid hemorrhage. A CT angiogram did not show any abnormalities. Pressure recordings in the epidural space in nine patients ranged from 20 to 29 mm Hg with a mean of 24.33 mm Hg. Conclusion: Most incidental durotomies encountered during lumbar interlaminar endoscopy can be managed without formal repair and supportive care measures. The intradural spread of irrigation fluid and intraoperatively used drugs and air entrapment through an unrecognized durotomy should be suspected if patients deteriorate in the recovery room. Ascending paralysis may cause nausea, vomiting, upper and lower motor neuron symptoms, cranial nerve palsies, hypotension, bradycardia, and respiratory and cardiac arrest. The recovery team should be prepared to manage these complications.

Transient internuclear ophthalmoplegia following anterior cervical discectomy and fusion

Background:

Internuclear ophthalmoplegia (INO), characterized by impaired horizontal eye movement, occurred following an anterior cervical discectomy/fusions (ACDF).

Case Description:

A 48-year-old female with recurrent C5-6 foraminal stenosis presented with right C6 radiculopathy. She underwent a C5-6 ACDF, but postoperatively, complained of diplopia. Her examination revealed left-eye INO. Notably, the brain magnetic resonance imaging showed no significant radiological findings. The patient’s diplopia and INO resolved spontaneously on postoperative day 2 and never recurred.

Conclusion:

Ocular complications following anterior cervical spine procedures are rare. Here, a 48-year-old female developed left eye INO following an ACDF that spontaneously resolved on postoperative day 2.

Systematic Review: Applications of Intraoperative Ultrasound in Spinal Surgery

BACKGROUND

Due to increased practicality and decreased costs and radiation, interest has risen for intraoperative ultrasound (iUS) in spinal surgery applications; however, few studies have provided a robust overview of its use in spinal surgery. We synthesize findings of existing literature on usage of iUS in navigation, pedicle screw placement, and identification of anatomy during spinal interventions.

METHODS

Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were utilized in this systematic review. Studies were identified through PubMed, Scopus, and Google Scholar databases using the search string. Abstracts mentioning iUS in spine applications were included. Upon full-text review, exclusion criteria were implemented, including outdated studies or those with weak topic relevance or statistical power. Upon elimination of duplicates, multi-reviewer screening for eligibility, and citation search, 44 manuscripts were analyzed.

RESULTS

Navigation using iUS is safe, effective, and economical. iUS registration accuracy and success is within clinically acceptable limits for image-guided navigation (Table 2). Pedicle screw instrumentation with iUS is precise with a favorable safety profile (Table 2). Anatomical landmarks are reliably identified with iUS, and surgeons are overwhelmingly successful in neural or vascular tissue identification with iUS modalities including standard B mode, doppler, and contrast-enhanced ultrasound (CE-US) (Table 3). iUS use in traumatic reduction of fractures properly identifies anatomical structures, intervertebral disc space, and vasculature (Table 3).

CONCLUSION

iUS eliminates radiation, decreases costs, and provides sufficient accuracy and reliability in identification of anatomical and neurovascular structures in various spinal surgery settings.

Diplopia developed by cervical traction after cervical spine surgery

Diplopia is a rare complication of spine surgery. The abducens nerve is one of the cranial nerves most commonly related to diplopia caused by traction injury. We report a case of a 71-year-old woman who presented with diplopia developing from abducens nerve palsy after C1–C2 fixation and fusion due to atlantoaxial subluxation with cord compression. As soon as we discovered the symptoms, we suspected excessive traction by the instrument and subsequently performed reoperation. Subsequently, the patient’s symptoms improved. In other reported cases we reviewed, most were transient. However, we thought that our rapid response also helped the patient’s fast recovery in this case. The mechanisms by which postoperative diplopia develops vary and, thus, remain unclear. We should pay attention to the fact that the condition is sometimes an indicator of an underlying, life-threatening condition. Therefore, all patients with postoperative diplopia should undergo thorough ophthalmological and neurological evaluations as well as careful observation by a multidisciplinary team.

Surgical treatment of thoracic disc herniation: an overview

BACKGROUND

Surgical treatment of thoracic disc herniation (TDH) is technically demanding due to its proximity to the spinal cord.

METHODS

Literature review.

RESULTS

Symptomatic TDH is a rare condition predominantly localized between T8 and L1. Surgical indications include intractable back or radicular pain, neurological deficits, and myelopathy signs. Giant calcified TDH (> 40% spinal canal occupation) are frequently associated with myelopathy, intradural extension, and post-operative complications. Careful pre-operative planning helps reduce the risk of complications. Pre-operative CT and MRI identify the hernia's location and size, calcifications, and intradural extension. The approach must provide adequate dural sac visualization with minimal manipulation of the cord. Non-anterior approaches are favoured if they provide at least equal exposure than anterior approach owing to higher risk of pulmonary morbidity associated with anterior approach. A transthoracic approach is recommended for central calcified herniated discs. A posterolateral approach is often suitable for non-calcified lateralized TDH. Thoracoscopic approaches are less invasive but have a substantial learning curve. Retropleural mini-thoracotomy is an acceptable alternative. Pre-operative identification of the pathological level is confirmed by intra-operative level check. Intra-operative cord monitoring is preferable but warrant further studies. Magnification and adequate lightening of the surgical field are paramount (microscope, thoracoscopy). Intra-operative CT scan with navigation is becoming increasingly popular since it provides real-time control on the decompression. Indications of fusion consist of pre-operative back pain, Scheuermann's disease, multilevel resection, wide vertebral body resection (> 50%), and herniation at thoracolumbar junction. Neurological deterioration, dural tear, and subarachnoid-pleural fistula are the most severe complications.

CONCLUSION

Further improvements are still warranted in thoracic spine surgery despite the advent of minimally invasive techniques. Intra-operative CT scan will probably enhance the safety of the TDH surgery.

Non-neurological outcomes of anterior and posterolateral approaches in the surgical treatment of thoracic disc disease: a retrospective study

Background

Symptomatic thoracic disc herniation (TDH) is rare, and for those patients that fail conservative treatment, two main categories of surgical approaches exist-anterior and posterolateral. In many cases either approach would be considered equally appropriate. Recommendations in support of either anterior or posterolateral approaches are currently based on case series and expert opinion. Here, we utilize National Surgical Quality Improvement Program (NSQIP) database to determine and compare the rates of complication associated with anterior or posterolateral approaches in the treatment of TDH.

Methods

An analysis of NSQIP data from 2005 to 2014 was conducted. Patients were included based on a combination of a postoperative diagnosis of TDH. Patients were then grouped according to anterior or posterior approaches on the basis of Current Procedural Terminology (CPT) codes. Propensity score matching was performed to account for baseline demographics [sex, race, age, obesity, diabetes, smoking, history of chronic obstructive pulmonary disease (COPD), history of CHF, and American Society of Anesthesiologists (ASA) class]. The 30-day outcome measures of these patients were analyzed.

Results

A total of 432 patients were identified, 80.3% underwent posterolateral and 19.7% anterior interventions. There were no significant differences in 30-day outcome measures between the anterior or posterior intervention groups. Within the matched group of 170 patients, the anterior group had significantly longer lengths of stay (5.49±3.96 vs. 4.01±4.81, P<0.0001), but there were no observed significant differences in the rate of occurrences of UTIs, pneumonias, sepsis, bleeding, intubation, or death.

Conclusions

Posterolateral and anterior approaches carry an equal non-neurological perioperative complication profile. Posterolateral approaches may carry shorter hospital stays compared to anterior interventions.

Thoracic disc herniation: Surgical treatment

Thoracic disc herniation is rare and mainly occurs between T8 and L1. The herniation is calcified in 40% of cases and is labeled as giant when it occupies more than 40% of the spinal canal. A surgical procedure is indicated when the patient has severe back pain, stubborn intercostal neuralgia or neurological deficits. Selection of the surgical approach is essential. Mid-line calcified hernias are approached from a transthoracic incision, while lateralized soft hernias can be approached from a posterolateral incision. The complication rate for transthoracic approaches is higher than that of posterolateral approaches; however, the former are performed in more complex herniation cases. The thoracoscopic approach is less invasive but has a lengthy learning curve. Retropleural mini-thoracotomy is a potential compromise solution. Fusion is recommended in cases of multilevel herniation, herniation in the context of Scheuermann's disease, when more than 50% bone is resected from the vertebral body, in patients with preoperative back pain or herniation at the thoracolumbar junction. Along with complications specific to the surgical approach, the surgical risks are neurological worsening, dural breach and subarachnoid-pleural fistulas. Giant calcified herniated discs are the largest contributor to myelopathy, intradural extension and postoperative complications. Some of the technical means that can be used to prevent complications are explored, along with how to address these complications.