Delayed Presentation of Thoracic Aortic Pseudoaneurysm Following Pedicle Screw Implantation: A Case Report

Management of intercostal artery pseudoaneurysm following posterior pedicle screw insertion: illustrative case

BACKGROUND

Pedicle screw insertion in posterior spinal surgery can cause vascular injuries, including rare intercostal artery pseudoaneurysms, which are typically discovered incidentally during reimaging. Onyx embolization is an effective treatment for small artery pseudoaneurysms.

OBSERVATIONS

A 36-year-old man who had initially presented with back pain that remained unresponsive to nonsteroidal anti-inflammatory drugs was diagnosed with a T7-8 sarcomatous lesion confirmed by magnetic resonance imaging and biopsy. He underwent a posterior resection and T5-10 stabilization with pedicle screws. After surgery, significant hemorrhage led to his transfer for digital subtraction angiography, which revealed a prominent vascular tumor blush and a pseudoaneurysm of the right T5 intercostal artery due to screw placement. The tumor and pseudoaneurysm were effectively embolized using superselective catheterization and Onyx.

LESSONS

This report highlights the dangers of intercostal artery damage from posterior spinal screws, emphasizing the need for meticulous postoperative imaging. Onyx embolization is an effective treatment for such complications. https://thejns.org/doi/10.3171/CASE24291.

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.

Assessment of the tolerance angle for pedicle screw insertion

Cannulation process intervenes before implantation of pedicle screw and depends on the surgeon's experience. A reliable experimental protocol has been developed for the characterization of the slipping behavior of the surgical tool on the cortical shell simulated by synthetic materials. Three types of synthetic foam samples with three different densities were tested using an MTS Acumen 3 A/T electrodynamic device with a tri-axis 3 kN Kistler load cell mounted on a surgical tool, moving at a constant rotational speed of 10° mm-1 and performing a three-step cannulation test. Cannulation angle varied between 10° and 30°. Synthetic samples were scanned after each tests, and cannulation coefficient associated to each perforation section was computed. Reproducibility tests resulted in an ICC for Sawbone samples of 0.979 (p < 0.001) and of 0.909 (p < 0.001) for Creaplast and Sawbone samples. Cannulation coefficient and maximum force in Z-axis are found the best descriptors of the perforation. Angular threshold for perforation prediction was found to be 17.5° with an area under the curve of the Receiver Operating Characteristic of 89.5%. This protocol characterizes the cannulation process before pedicle screw insertion and identifies the perforation tool angle until which the surgical tool slips on the cortical shell depending on bone quality.

Delayed open treatment of aortic penetration by a thoracic pedicle screw: illustrative case

BACKGROUND

Iatrogenic aortic injury from pedicle screw malpositioning or anterior prominence in posterior spinal fusion represents a rare but potentially devasting complication. While intraoperative aortic injury is associated with hemodynamic instability, delayed presentations of pedicle screw aortic impingement or violation often present insidiously with pseudoaneurysm or vascular remodeling in clinically asymptomatic patients. Currently, there is a lack of guidance in the field for the recommended surveillance, urgency of operative intervention, and optimal surgical management of delayed pedicle screw aortic injuries.

OBSERVATIONS

The following case study discusses the open treatment of delayed thoracic aortic penetration from an excessively long T12 pedicle screw in an asymptomatic adolescent patient with idiopathic scoliosis. The pedicle screw prominence anteriorly was corrected by burring the screw tip until it was flush with the vertebral body. The associated aortic injury was addressed with open vascular repair via primary anastomosis supplemented with a bovine pericardial patch.

LESSONS

Complete aortic wall penetration from an excessively long thoracic pedicle screw with otherwise stable screw positioning may be addressed most effectively with a single anterior surgical approach for open aortic repair and screw tip burring.