Aortic Injury during Transforaminal Lumbar Interbody Fusion

Iatrogenic Abdominal Aortic Rupture During Transpedicular Bone Grafting for Thoracolumbar Burst Fractures Successfully Treated by Endovascular Stent Implantation

PURPOSE

Vascular injury resulting from transpedicular bone grafting in the treatment of thoracolumbar burst fractures has not been reported but can be lethal. The management of patients with iatrogenic aortic injury remains a difficult clinical problem. This study describes a case of iatrogenic abdominal aortic rupture at the level of L2 during transpedicular bone grafting for the first time.

CASE REPORT

A 55 year-old male patient suffered from a T12 vertebral body mild compression fracture and an L2 vertebral body burst fracture due to falling. This patient was treated with posterior open reduction and pedicle screw fixation combined with transpedicular bone grafting in the L2 vertebrae using a paravertebral approach. Unfortunately, during transpedicular bone grafting, the abdominal aorta was punctured by the tip of the graft funnel. The use of endovascular stent implantation successfully averted a clinical catastrophe. The patient had a good clinical outcome, and no complications associated with vascular trauma were apparent at a 1-year follow-up examination.

CONCLUSION

For the repair of vascular injury caused by transpedicular bone grafting, endovascular techniques can provide a safe, minimally invasive, and effective treatment option.

CLINICAL IMPACT

Surgeons should carefully evaluate the specificity of the patient's anatomical structures preoperatively and be more cautious during transpedicular bone grafting in the treatment of thoracolumbar burst fractures.

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%.

Outpatient Minimally Invasive Lumbar Fusion Using Multimodal Analgesic Management in the Ambulatory Surgery Setting

BACKGROUND

The transition of minimally invasive (MIS) spine surgery from the inpatient to outpatient setting has been aided by advances in multimodal analgesic (MMA) protocols. This clinical case series of patients demonstrates the feasibility of ambulatory MIS transforaminal lumbar interbody fusion (TLIF) and lateral lumbar interbody fusion (LLIF) procedures while using an enhanced MMA protocol.

METHODS

Consecutive MIS TLIF or LLIF procedures with percutaneous pedicle screw fixation and direct decompression in the ambulatory setting were reviewed. The procedures were performed using an MMA protocol. The ambulatory surgery center (ASC) did not allow for observation of patients for periods of time greater than 23 hours. We recorded patient demographics, perioperative, and postoperative characteristics.

RESULTS

Fifty consecutive patients were identified from September 2016 to July 2019. Forty-one patients (82%) underwent MIS TLIF, and 9 patients underwent MIS LLIF (18.0%). All patients were discharged on the same day of surgery. The mean length of stay was 4.5 hours and 3.8 hours for the TLIF and LLIF cohorts, respectively. Our review of medical records revealed no postoperative complications following either the TLIF or the LLIF procedures.

CONCLUSIONS

The present study of 50 consecutive patients is the largest clinical series of ASC patients undergoing lumbar fusion procedures in a stand-alone facility with no extended postoperative observation capability. While using MMA protocol within the ASC, no postoperative complications were observed for either MIS TLIF or LLIF procedures. All patients were discharged from the ambulatory surgical center on the day of surgery with well-controlled postoperative pain.

LEVEL OF EVIDENCE

4.

CLINICAL RELEVANCE

The MMA protocol is an essential aspect in transitioning minimally invasive lumbar spine surgery to the ASC. Our findings indicate that MIS lumbar fusion spine surgery with an enhanced MMA protocol can lead to safe and timely ASC discharge while minimizing hospital admission.

Combined Method of Neuronal Cell-Inducible Vector and Valproic Acid for Enhanced Gene Expression under Hypoxic Conditions

BACKGROUND

Gene therapy shows the ability to restore neuronal dysfunction via therapeutic gene expression. The efficiency of gene expression and delivery to hypoxic injury sites is important for successful gene therapy. Therefore, we established a gene/stem cell therapy system using neuron-specific enolase promoter and induced neural stem cells in combination with valproic acid to increase therapeutic gene expression in hypoxic spinal cord injury.

METHODS

To examine the effect of combined method on enhancing gene expression, we compared neuronal cell-inducible luciferase levels under normoxia or hypoxia conditions in induced neural stem cells with valproic acid. Therapeutic gene, vascular endothelial growth factor, expression with combined method was investigated in hypoxic spinal cord injury model. We verified gene expression levels and the effect of different methods of valproic acid administration in vivo.

RESULTS

The results showed that neuron-specific enolase promoter enhanced gene expression levels in induced neural stem cells compared to Simian Virus 40 promoter under hypoxic conditions. Valproic acid treatment showed higher gene expression of neuron-specific enolase promoter than without treatment. In addition, gene expression levels and cell viability were different depending on the various concentration of valproic acid. The gene expression levels were increased significantly when valproic acid was directly injected with induced neural stem cells in vivo.

CONCLUSION

In this study, we demonstrated that the combination of neuron-specific enolase promoter and valproic acid induced gene overexpression in induced neural stem cells under hypoxic conditions and also in spinal cord injury depending on valproic acid administration in vivo. Combination of valproic acid and neuron-specific enolase promoter in induced neural stem cells could be an effective gene therapy system for hypoxic spinal cord injury.

Lumbar spinal fusion in the outpatient setting: an update on management, surgical approaches and planning

Outpatient lumbar spinal fusion surgery has the potential for improved patient satisfaction, speed of recovery, and economic advantages when compared to inpatient surgery. Despite the rise in the number of these procedures performed annually, the literature on this topic remains scarce. As such, there is a need for a comprehensive review of current concepts in indications and management. The current review will present the most recent literature regarding pre-operative, intra-operative, and post-operative considerations when performing outpatient lumbar spinal fusion surgery.

Complication avoidance in minimally invasive spinal surgery

Minimally invasive techniques in spinal surgery allow surgeons to perform operations with less of the approach-related morbidity inherent to traditional open procedures. Yet these muscle-sparing procedures come with a unique set of risks that stem from the novel approaches, limited exposure, and/or a restricted working corridor that they employ. The literature suggests that these operations can be performed without an increased rate of complication once the associated learning curve has been surmounted, suggesting that knowledge of and experience with the nuances of these procedures are essential for patient safety. The present article describes the complications specific to a variety of minimally invasive spinal surgeries and provides guidance on how to avoid them.

Aortic Rupture During Surgical Management of Tubercular Spondylodiscitis

Aortic rupture is a rare but possible complication during spine surgery. It may manifest as severe intraoperative hemorrhage or present in a delayed manner after the formation of an aneurysm or an arteriovenous fistula. Though it is commonly encountered during anterior surgeries involving the surgical field close to the thoracic or abdominal aorta, it can also occur during a posterior surgery. Aortic injury could be associated with surgeries ranging from the commonly performed pedicle screw instrumentation to a complex three-column osteotomy. It can also occur, as in the reported case, while performing complex procedures in the presence of a pre-existing aneurysm or aortic adhesions due to coexisting infectious or inflammatory pathologies. The treatment options for such aortic ruptures range from open repair to endovascular stenting techniques. We discuss a case of an aortic rupture that occurred during a posterior vertebral column resection (PVCR) procedure performed on a 58-year-old female with spastic paraparesis secondary to tuberculous spondylodiscitis and the lessons learnt.