Morphometric Analysis of the Ureter with Respect to Lateral Lumbar Interbody Fusion Using Contrast-Enhanced Computed Tomography.

OBJECTIVE: To analyze the anatomical location of the ureter in relation to lateral lumbar interbody fusion and evaluate the potential risk of ureteral injury. METHODS: One hundred eight patients who performed contrast-enhanced computed tomographic scans were enrolled in this study. The location of the ureter from L2-L3 to L4-L5 was evaluated. The distances between the ureter and psoas muscle, intervertebral disc, and retroperitoneal vessels were also recorded bilaterally. RESULTS: Over 30% of the ureters were close to the working corridor of extreme lumbar interbody fusion at L2-L3. Most of the ureters were close to working corridor of oblique lumbar interbody fusion, especially at L4-L5. The distance from the ureter to the great vessels on the left side was significantly narrowing from L2-L3 to L4-L5 (28.8±9.5 mm, 22.0±8.0 mm, 15.5±8.4 mm), and it was significantly larger than that on the right side (12.3±6.1 mm, 7.4±5.7 mm, 5.4±4.4 mm). CONCLUSION: Our findings indicate that the location of the ureter varies widely among individuals. To avoid unexpected damage to the ureter, it is imperative to directly visualize it and verify the ureter is not in the surgical pathway during lateral lumbar interbody fusion.

Life-threatening intracardiac cement embolisms after percutaneous kyphoplasty: a case report and literature review.

BACKGROUND: Percutaneous kyphoplasty is a popular technique in the treatment of osteoporotic vertebral fractures, but intracardiac cement embolism can be a life-threatening complication.Case presentation: The authors present a case involving a patient who developed dyspnea and chest tightness after percutaneous kyphoplasty. Echocardiography and chest computed tomography confirmed several foreign bodies in the right atrium and pulmonary arteries causing cardiac perforation and pericardial tamponade. Conservative treatment was administered, and the patient died of respiratory and heart failure. CONCLUSIONS: The present case highlights that surgical removal may be the first-choice treatment for symptomatic intracardiac cement embolism.

Magnetic Resonance Imaging Study of Oblique Corridor and Trajectory to L1-L5 Intervertebral Disks in Lateral Position.

OBJECTIVE: This study investigated the retroperitoneal oblique corridor and trajectory of L1-L5 as the lateral surgical access to the intervertebral disks in the Chinese population and detected the potential relationship between the corridor or trajectory and vertebral parameters, including disk axis, psoas muscle, and retroperitoneal vessel. METHODS: Seventy magnetic resonance imaging studies performed from January 2017 to January 2019 were investigated. The oblique corridor was defined as the distance between the left lateral border of the retroperitoneal vessel and the anterior border of psoas. The trajectory was defined as the distance between the retroperitoneal vessel and lumbar plexus. RESULTS: The oblique corridor analysis to L1-L5 disks have the following mean distances: L1-2 13.36 mm, L2-3 13.36 mm, L3-4 12.37 mm, and L4-5 10.36 mm. There was no difference in the L1-L5 corridor between genders. And the position of retroperitoneal vessel was negatively correlated with the corridor width. The trajectory measurements to L1-L5 disks have the following mean distances: L1-2 27.44 mm, L2-3 30.86 mm, L3-4 30.73 mm, and L4-5 24.36 mm. Moreover, the vertebral parameters, including the disk axis and psoas muscle, were positively correlated with the trajectory width. Otherwise, the position of retroperitoneal vessel was negatively correlated with the trajectory width. CONCLUSIONS: Compared with previous studies, the safe surgical area of the Chinese is generally smaller than that of Caucasian. The position of the retroperitoneal vessel is the vital potential to limit the corridor and trajectory. Preoperative assessment of vertebral parameters, especially vascular structure, is essential for planning surgical process.

Does the Access Angle Change the Risk of Approach-Related Complications in Minimally Invasive Lateral Lumbar Interbody Fusion? An MRI Study.

OBJECTIVE: To investigate the potential risk of approach-related complications at different access angles in minimally invasive lateral lumbar interbody fusion. METHODS: Eighty-six axial magnetic resonance images were obtained to analyze the risk of approach-related complications. The access corridor were simulated at different access angles and the potential risk of neurovascular structure injury was evaluated when the access corridor touching or overlapping the corresponding structures at each angle. Furthermore, the safe corridor length was measured when the corridor width was 18 and 22 mm. RESULTS: When access angle was 0°, the potential risk of ipsilateral nerve roots injury was 54.7% at L4-L5. When access angle was 45°, the potential risk of abdominal aorta, contralateral nerve roots or central canal injury at L4-L5 was 79.1%, 74.4%, and 30.2%, respectively. The length of the 18mm-wide access corridor was largest at 0° and it could reach 44.5 mm at L3-L4 and 46.4 mm at L4-L5. While the length of the 22 mm-wide access corridor was 42.3 mm at L3-L4 and 44.1 mm at L4-L5 at 0°. CONCLUSION: Changes in the access angle would not only affect the ipsilateral neurovascular structures, but also might adversely influence the contralateral neural elements. It should be also noted to surgeons that alteration of the access angle changed the corridor length.