Delayed Presentation of Aortic Injury by a Thoracic Pedicle Screw

Endovascular repair for thoracic aortic pseudoaneurysm induced by pedicle screw implantation: a case report with 8 years follow-up

BACKGROUND

Pedicle screw instrument surgeries can result in the development of aortic pseudoaneurysm, which is a rare yet potentially severe complication; therefore, the purpose of this work is to describe the case of pseudoaneurysm of the thoracic aorta caused by the severe migration of a pedicle screw after surgery.

CASE PRESENTATION

We herein report a patient who underwent endovascular repair for the pseudoaneurysm of the descending thoracic aorta following thoracic vertebral fixation surgery. A 28-80 mm covered stent was initially inserted through the right femoral artery, and intraoperative aortography revealed a minor extravasation of contrast material. Subsequently, an additional 28-140 mm covered stent was implanted. The patient recovered well during the 8-year follow-up period.

CONCLUSIONS

Vascular complications resulting from spinal surgery are severe and rare, necessitating early diagnosis and intervention.

Abdominal Arterial Translation in Lower Lumbar Spine Level Due to Positional Change: A Clinical Survey Using Intraoperative Computed Tomography

Background: Abdominal vascular injury, a fatal complication of lumbar disc surgery, should concern spine surgeons. This study aimed to compare the position of the abdominal arteries in the supine and prone positions and the factors involved. Thirty patients who underwent lumbar surgery by posterior approach were included. Methods: All patients underwent computed tomography (CT) preoperatively in the supine position and intraoperatively in the prone position. In the CT axial image, at the L4, L4/5 disc, L5, and L5/S1 disc level, we measured the shortest distance between the abdominal arteries and the vertebral body (SDA: shortest distance to the aorta), and the amount of abdominal arterial translation, defined as "SDA on intraoperative CT" minus "SDA on preoperative CT". Additionally, the preoperative CT axial images were evaluated for the presence of aortic calcification. Results: No significant difference in SDA values based on patients' positions was observed at each level. In males, the supine position brought the abdominal artery significantly closer to the spine at the left side of the L5/S level (p = 0.037), and, in cases of calcification of the abdominal artery, the abdominal artery was found to be closer to the spine at the left side of the L4/5 level (p = 0.026). Conclusions: It is important to confirm preoperative images correctly to prevent great vessel injuries in lumbar spine surgery using a posterior approach.

Delayed aortic injury after thoracic corrective osteotomy: a case report

PURPOSE

To present a case of delayed aortic perforation due to a nondisplaced fracture of the 9th rib after vertebral osteotomy for degenerative kyphoscoliosis in patients with osteoporosis.

METHODS

A 78-year-old female patient with osteoporosis had undergone T9-iliac correction surgery for degenerative kyphoscoliosis. After 2 years, the patient underwent T10 pedicle subtraction osteotomy for a T10 vertebral fracture and progression of kyphosis. Postoperatively, the patient had been doing well for 3 weeks; however, just before the day of discharge, she died following a cardiopulmonary arrest. An autopsy was performed with the consent of her family.

RESULTS

Autopsy revealed a large amount of blood and a clot in the left thoracic cavity. Aortic perforation was found just in front of a nondisplaced fracture of the left 9th rib.

CONCLUSION

This report describes a new critical complication after spinal correction surgery. Even without pedicle screw malposition, aortic injuries can happen to patients with osteoporosis after corrective osteotomy for degenerative kyphoscoliosis due to positional change of aorta and fragility of the ribs. The spine surgeon should be aware of this type of complication, and rib fractures around the aorta after vertebral osteotomy should not be neglected even when there is no displacement.

Does intraoperative CT navigation increase the accuracy of pedicle screw placement in pediatric spinal deformity surgery? A systematic review and meta-analysis

PURPOSE

Although pediatric spinal deformity correction using pedicle screws has a very low rate of complications, the long-term consequences of screw malposition is unknown. CT navigation has been proposed to improve screw accuracy. The aim of this study was to determine whether intraoperative navigation during pedicle screw placement in pediatric scoliosis makes screw placement more accurate. We also examined radiation exposure, operative time blood loss and complications with and without the use of CT navigation in pediatric spinal deformity surgery.

METHODS

A systematic review of the literature was conducted. After screening, 13 articles were qualitatively and quantitatively analyzed to be used for the review. A random effects meta-analysis using REML methodology was employed to compare outcomes of screw accuracy, estimated blood loss, radiation exposure, and surgical duration.

RESULTS

Screws placed with CT navigation surgery were three times as likely to be deemed "acceptable" compared with screws placed with freehand and 2D fluoroscopy assistance, twice as likely to be "perfect", and only 1/3 as likely to be potentially unsafe (all p value < 0.01). EBL was not significantly different between groups; however, operative time was roughly thirty minutes longer on average. Random effects analysis showed no significant difference in effective dose radiation while using CT navigation (p = 0.06).

CONCLUSION

This systematic review of the literature demonstrates that intraoperative navigation results in more accurate pedicle screw placement compared to non-navigated techniques. We found that blood loss was similar in navigated and non-navigated surgery. Operative time was found to be approximately a half hour longer on average in navigated compared to non-navigated surgery. Effective radiation dose trended higher in navigated cases compared to non-navigated cases but did not reach statistical significance.

Rating the incidence of iatrogenic vascular injuries in thoracic and lumbar spine surgery as regards the approach: A PRISMA-based literature review

PURPOSE

To assess the rate, timing of diagnosis, and repairing strategies of vascular injuries in thoracic and lumbar spine surgery as their relationship to the approach.

METHODS

PubMed, Medline, and Embase databases were utilized for a comprehensive literature search based on keywords and mesh terms to find articles reporting iatrogenic vascular injury during thoracic and lumbar spine surgery. English articles published in the last ten years were selected. The search was refined based on best match and relevance.

RESULTS

Fifty-six articles were eligible, for a cumulative volume of 261 lesions. Vascular injuries occurred in 82% of instrumented procedures and in 59% during anterior approaches. The common iliac vein (CIV) was the most involved vessel, injured in 49% of anterior lumbar approaches. Common iliac artery, CIV, and aorta were affected in 40%, 28%, and 28% of posterior approaches, respectively. Segmental arteries were injured in 68% of lateral approaches. Direct vessel laceration occurred in 81% of cases and recognized intraoperatively in 39% of cases.

CONCLUSIONS

Incidence of iatrogenic vascular injuries during thoracic and lumbar spine surgery is low but associated with an overall mortality rate up to 65%, of which less than 1% for anterior approaches and more than 50% for posterior ones. Anterior approaches for instrumented procedures are at risk of direct avulsion of CIV. Posterior instrumented fusions are at risk for injuries of iliac vessels and aorta. Lateral routes are frequently associated with lesions of segmental vessels. Suture repair and endovascular techniques are useful in the management of these severe complications.

Screw Malposition: Are There Long-term Repercussions to Malposition of Pedicle Screws?

BACKGROUND/INTRODUCTION

Pedicle screws have long been part of the continued advancements in spine surgery. Despite the many techniques that have been devised for their safe placement, malposition of screws continues to occur. Studies have evaluated the possible safe limits of screw malposition, and have given some insight on anatomic variation in spinal deformity. Review of the literature reveals several cases of deleterious long-term sequelae of malpositioned screws.

DISCUSSION

With the current experience, proposed recommendations are provided to detect and avoid the potential long-term sequelae. Though the literature has helped to define possible concerning screws, there are no good studies predicting long-term risk.

CONCLUSION

Improvements in technology and techniques, advancements in intraoperative confirmation and postoperative surveillance, studies that assist risk stratification, and expert consensus evaluations will help guide surgeons in their decision for addressing misplaced screws.

Aortic injury in spine surgery……What a spine surgeon needs to know

Aortic injury is a rare, yet underreported and underestimated complication of spine surgery. Anatomical relation between the aorta and the spine changes under physiological (positional) as well as pathological (deformity) conditions, which puts the aorta at risk of injury during spine surgery. Clinical presentation of aortic injury ranges from asymptomatic perforation of the aorta to acute fatal bleeding. Although several diagnostic methods have been reported, CT-angiography remains an important diagnostic study. Several advancements in the open and the endovascular surgical management have been reported to be successfully used in the management of aortic injury following spine surgery. Management approach of malpositioned screws abutting the aorta is still controversial. Anatomical knowledge and understanding of the previously reported mechanisms of aortic injury are important to be integrated in the preoperative planning process. If the complication occurs, time-to- recognition and to-appropriate-management are important factors for predicting mortality. If unrecognized and untreated in the acutely injured patients, mortality can approach 100%.

Massive Hemoptysis Caused by an Aortobronchial Fistula Related to Pedicle Screw Impingement

We report a case of a 50-year-old man with a 10-year history of pedicle screw internal fixation in the thoracic spine and heroin abuse, who presented with sudden-onset massive hemoptysis with hemorrhagic shock and asphyxia. Urgent contrast-enhanced chest computed tomography (CT) characteristically showed thoracic aortic perforation, a paravertebral pseudoaneurysm, and an intrapulmonary hematoma. Emergency percutaneous thoracic endovascular aortic repair (pTEVAR) with the preclose technique using a vascular closure device under local anesthesia achieved success without any complications. The current case highlights the importance of understanding massive hemoptysis caused by an aortobronchial fistula related to pedicle screw impingement in clinical practice and the value of pTEVAR with the preclose technique under local anesthesia in the emergency setting.

Delayed Penetration of the Thoracic Aorta by Pedicle Screws: A Case Report of Screws Left As-Is

STUDY DESIGN

A case report.

OBJECTIVE

Presentation of a patient diagnosed with perforation of the aorta by pedicle screws at levels T6 and T9 2 years after spinal fusion, who was advised no intervention. Review of other reported cases that did not undergo excision of the penetrating screws.

SUMMARY OF BACKGROUND DATA

More than 30 cases of aortic penetration by pedicle screws were described. Gradual penetration of the screws into the aorta rarely causes symptoms other than backache. However, only two cases were treated conservatively.

METHODS

A 65-year-old female patient underwent spinal decompression and T5-T10 posterior fusion following a spinal abscess. Two years and 8 months postoperatively, she underwent a computed tomography scan for suspicion of spinal hardware infection, which showed T6 and T10 screws penetrating the thoracic aorta.

RESULTS

Due to high morbidity, the patient was not offered an operation for screw excision.

CONCLUSION

This case report adds to the only two previous reports of patients who did not undergo revision of pedicle screws penetrating thoracic aorta.

LEVEL OF EVIDENCE

5.

Aortic Injury by Thoracic Pedicle Screw. When Is Aortic Repair Required? Literature Review and Three New Cases

PURPOSE

Aortic injury by pedicle screw is rare but can cause serious complications. It has not been clearly determined when aortic repair is necessary in cases of screw impingement without perforation of the aortic wall. In this article, we review the treatment and clinical course of pedicle screw aortic impingement and attempt to clarify this issue.

METHODS

Cases of aortic injury during thoracic screw procedures were found using a MEDLINE search and analyzed together with 3 new cases that we present.

RESULTS

Nineteen cases collected from the literature and 3 new cases were included in the study. In 7 of the cases, aortic impingement by the pedicle screw was detected during postoperative follow-up (day 1) radiologic examinations. In the other cases, time to presentation of aortic impingement ranged between 2 weeks and 60 months after fixation. The main indications for thoracic spinal fixation were post-traumatic vertebral fracture and kyphoscoliosis/scoliosis. Repair of the aortic damage ranged from primary repair to stent and tube graft placement by the thoracic endovascular aortic repair method.

CONCLUSIONS

In cases in which the screw impinges less than 5 mm into the aortic wall, hardware revision without aortic repair may be sufficient if recognized early and there are no sign of aortic leakage in vascular imaging. However, cases with more than 5 mm of screw impingement should undergo aortic repair first, even in the absence of aortic leakage, following by screw revision.

The effect of patient positioning on the relative position of the aorta to the thoracic spine

PURPOSE

Detailed knowledge of the anatomy of the thoracic aorta is crucial for thoracolumbar spinal surgery. The purpose of the present study is to describe the relative displacement of the aorta to the spine in supine, prone and prone position with padding. Improved understanding of the magnitude and direction of this often-overlooked change could benefit preoperative planning and decision-making.

METHODS

A total of 200 patients underwent CT scan of the thoracic spine in the standard supine, prone and prone position with padding. Axial CT images from T4 to T12, in all three different positions, were selected and the following parameters were measured: (a) distance B connecting left pedicle entry point to the edge of the aortic wall and (b) projections Bx and By, representing the minimum AP depth and horizontal displacement of the aortic wall relative to the left pedicle entry point O.

RESULTS

There was a significant difference in the distance B between the three different positions across all thoracic vertebrae levels, confirming that positioning significantly affects aorta's relative position. Moreover, in the prone position with padding at the level of T6, the aortic wall lies at a minimum distance from the left pedicular axis and thus from the typical screw trajectory.

CONCLUSION

The results of this study show that prone positioning for posterior thoracolumbar approach affects significantly the anatomic relationship of the aorta to the spine. Surgeons should be aware that standard supine CT evaluation represents a static technique, which can differ considerably from surgical reality. These slides can be retrieved from electronic supplementary material.