External iliac artery occlusion in posterior spinal surgery

Neurological deterioration as a result of improper neck position detected by intraoperative neurophysiological monitoring in a cervical stenosis patient: A case report

RATIONALE

Intraoperative neurophysiological monitoring (IONM) is widely used in spinal surgeries to prevent iatrogenic spinal cord injury (SCI). Most surgeons focus on avoiding neurological compromise intraoperatively, while ignoring the possibility of nerve damage preoperatively, such as neck positioning. Thus, this study aims to report a case with transient neurological deterioration due to improper neck position detected by IONM during cervical surgery.

PATIENT CONCERNS

A 63-year-old male patient had been suffering from hypoesthesia of the upper and lower extremities for three years.

DIAGNOSES

Severe cervical stenosis (C5-C7) and cervical ossification of a posterior longitudinal ligament.

INTERVENTIONS

The cervical stenosis patient underwent an anterior cervical corpectomy decompression and fusion (ACDF) surgery with the assistance of IONM. When the lesion segment was exposed, the SSEP and MEP suddenly elicited difficulty indicating that the patient may have developed SCI. All the technical causes of IONM events were eliminated, and the surgeon suspended operation immediately and suspected that the IONM alerts were caused by cervical SCI due to the improper position of the neck. Subsequently, the surgeon repositioned the neck of the patient by using a thinner shoulders pad.

OUTCOMES

At the end of the operation, the MEP and SSEP signals gradually returned to 75% and 80% of the baseline, respectively. Postoperatively, the muscle strength of bilateral biceps decreased from grade IV to grade III. Besides, the sensory disturbance of both upper extremities aggravated. However, the muscle power and hypoesthesia were significantly improved after three months of neurotrophic therapy and rehabilitation training, and no complications of nerve injury were found at the last follow-up visit.

LESSONS

IONM, consisting of SSEP and MEP, should be applied throughout ACDF surgery from the neck positioning to suture incisions. Besides, in the ward 1to 2 days before operation, it is necessary for conscious patients with severe cervical stenosis to simulate the intraoperative neck position. If the conscious patients present signs of nerve damage, they can adjust the neck position immediately until the neurological symptoms relieve. Therefore, intraoperatively, the unconscious patient can be placed in a neck position that was confirmed preoperatively to prevent SCI.

Transient Monoplegia as a Result of Unilateral Femoral Artery Ischemia Detected by Multimodal Intraoperative Neuromonitoring in Posterior Scoliosis Surgery: A Case Report

This is to report a case of 16-year-old girl with transient right lower limb monoplegia as a result of femoral artery ischemia detected by multimodal intraoperative spinal cord neuromonitoring (MISNM) during posterior correction surgery of adolescent idiopathic scoliosis.A patient with a marfanoid body habitus and LENKE IA type scoliosis with the right thoracic curve of 48° of Cobb angle was admitted for posterior spinal fusion from Th6 to L2. After selective pedicle screws instrumentation and corrective maneuvers motor evoked potentials (MEP) began to decrease with no concomitant changes in somato-sensory evoked potentials recordings.The instrumentation was released first partially than completely with rod removal but the patient demonstrated constantly increasing serious neurological motor deficit of the whole right lower limb. Every technical cause of the MEP changes was eliminated and during the wake-up test the right foot was found to be pale and cold with no popliteal and dorsalis pedis pulses palpable. The patient was repositioned and the pelvic pad was placed more cranially. Instantly, the pulse and color returned to the patient's foot. Following MEP recordings showed gradual return of motor function up to the baseline at the end of the surgery, whereas somato-sensory evoked potentials were within normal range through the whole procedure.This case emphasizes the importance of the proper pelvic pad positioning during the complex spine surgeries performed in prone position of the patient. A few cases of neurological complications have been described which were the result of vascular occlusion after prolonged pressure in the inguinal area during posterior scoliosis surgery when the patient was in prone position. If incorrectly interpreted, they would have a significant impact on the course of scoliosis surgery.

Detection of acute femoral artery ischemia during neuroembolization by somatosensory and motor evoked potential monitoring

Neuromonitoring can be used to map out particular neuroanatomical tracts, define physiologic deficits secondary to specific pathology or intervention, or predict postoperative outcome and proves essential in the detection of central and peripheral ischemic events during neurosurgical intervention. Herein, we describe an instance of elective balloon-assisted coiling of a recurrent basilar tip aneurysm in a 61-year-old woman, where intraoperative somatosensory evoked potentials (SSEPs) and transcranial motor evoked potentials (TcMEPs) were lost in the right lower extremity intraoperatively. We aim to highlight that targeted use of monitoring proves advantageous in both the open surgical and endovascular setting, even in the avoidance of potential iatrogenic peripheral nerve damage and limb ischemia as documented herein. Consideration of the increased risk for peripheral ischemia in the neurointerventional setting is especially imperative in particular populations where blood vessels might be of diminished size, such as in infants, young children, and severely deconditioned adults.

Somatosensory-evoked potential monitoring detects iliac artery occlusion during posterior spinal fusion

STUDY DESIGN

Report of a rare case of iliac artery occlusion occurring during posterior spinal surgery.

OBJECTIVE

To clarify causes of an acute occlusion of iliac vessels during posterior spinal surgery.

SUMMARY OF BACKGROUND DATA

Acute embolic occlusion of the iliac artery is a medical and surgical emergency. Iatrogenic occlusion of major vessels to the lower extremities during posterior lumbar spine operation is a rare entity.

METHODS

We report this complication occurring during decompression and fusion in a 55-year-old female with history of diabetes, hyperlipidemia, and multivessels vascular disease. The application of somatosensory evoked potentials during this case detected an asymmetry of cortical responses due to low blood flow to the affected limb.

RESULTS

This patient underwent endovascular intervention and placement of stents to restore the flow to the limbs.

CONCLUSION

It is feasible to assume that continuous and direct pressure on the inguinal region during surgery on Jackson table was the primary cause of the iliac artery occlusion, particularly in these patients with known peripheral vascular disease. Early recognition and prompt vascular intervention can prevent serious sequelae.

Bilateral femoral artery ischemia detected by multimodality neuromonitoring during posterior scoliosis surgery: a case report

STUDY DESIGN

Case report.

OBJECTIVE

To report a case of a bilateral femoral artery ischemia detected by neuromonitoring during posterior scoliosis surgery and to review relevant literature regarding this rare complication.

SUMMARY OF BACKGROUND DATA

Lower extremity ischemia is a potentially devastating risk of posterior spinal surgery. Ischemia can be a result of thrombotic occlusion or vascular compression during patient positioning. Multimodality neuromonitoring, increasingly used to prevent neurologic injury, can also detect hypoperfusion to the extremities. To date, there have been no reports of bilateral lower extremity ischemia detected by multimodality neuromonitoring during posterior spine surgery.

METHODS

A 15-year-old boy with adolescent idiopathic scoliosis underwent posterior spinal fusion with instrumentation. Intraoperative changes in somatosensory-evoked potentials and motor-evoked potentials were noted 1 hour into the case, before instrumentation or the reduction maneuver. After trouble shooting methods did not localize a technical cause for the changes, the patient's lower extremities were noted to be hypoperfused and pulseless.

RESULTS

The patients was repositioned and lower extremity perfused improved. Palpable distal pulses were detected. Neuromonitoring signals returned to baseline and the surgery completed. The patient had no postoperative neurologic or vascular deficits.

CONCLUSION

Lower extremity ischemia secondary to prone positioning is a rare risk of posterior spinal surgery. This is the first case report of this potentially devastating, but preventable complication detected by multimodality neuromonitoring.

Anaesthesia in the prone position

Prone positioning of patients during anaesthesia is required to provide operative access for a wide variety of surgical procedures. It is associated with predictable changes in physiology but also with a number of complications, and safe use of the prone position requires an understanding of both issues. We have reviewed the development of the prone position and its variants and the physiological changes which occur on prone positioning. The complications associated with this position and the published techniques for various practical procedures in this position will be discussed. The aim of this review is to identify the risks associated with prone positioning and how these risks may be anticipated and minimized.

Deep venous thrombosis after lumbar disc surgery due to compression of the vena cava caused by a retroperitoneal haematoma

The case of a 46-year-old Arabian male complaining of low back pain due to congenital lumbar spinal canal stenosis with additional disc herniation is presented. Following CT scan and MRI, bilateral enlarged partial hemilaminectomy was performed in L5/S1 with removal of herniated disc material. Intraoperatively, no complication was encountered. In the postoperative course, the patient had persistent low back pain and developed deep venous thrombosis in the left leg. Phlebography revealed thrombosis in the deep veins of the left leg extending into the pelvic region. The source of this high obstruction of the venous outflow was a retroperitoneal haematoma, visible on CT scan, compressing the vena cava at the level of L5/S1, the most probable cause of which was accidental perforation of the anterior spinal ligament. This case demonstrates that injury to the retroperitoneal vessels during lumbar disc surgery can also present as deep venous thrombosis due to obstruction of venous outflow.

Vascular injury and complication in neurosurgical spine surgery

Vascular injury is an uncommon, but not rare complication of spine surgery. The consequence of vascular injury may be quite devastating, but its incidence can be reduced by understanding the mechanisms of injury. Properly managing vascular injury can reduce mortality and morbidity of patients. A review of the literature was conducted to provide an update on the etiology and management of vascular injury and complication in neurosurgical spine surgery. The vascular injuries were categorized according to each surgical procedure responsible for the injury, i.e., anterior screw fixation of the odontoid fracture, anterior cervical spine surgery, posterior C1-2 arthrodesis, posterior cervical spine surgery, anterolateral approach for thoracolumbar spine fracture, posterior thoracic spine surgery, scoliosis surgery, anterior lumbar interbody fusion (ALIF), lumbar disc arthroplasty, lumbar discectomy, and posterior lumbar spine surgery. The incidence, mechanisms of injury, and reparative measures were discussed for each surgical procedure. Detailed coverage was especially given to vascular injury associated with ALIF, which may have been underestimated. The accumulation of anatomical knowledge and advanced imaging studies has made complex spine surgery safer and more reliable. It is not clear, however, whether the incidence of vascular injury has been reduced significantly in all procedures of spine surgery. Emerging new techniques, such as microendoscopic discectomy and lumbar disc arthroplasty, seem to be promising, but we need to keep in mind their safety issues, including vascular injury and complication.

Avascular necrosis of the femoral head after surgery for lumbar spinal stenosis

STUDY DESIGN

Case report.

OBJECTIVE

To report a previously undescribed complication of lumbar spinal surgery under prolonged hypotensive anesthesia.

BACKGROUND DATA

Avascular necrosis of bone most commonly affects the femoral head. The etiology of the condition is understood in only 75% of cases. There have been no prior reports of this condition following lumbar spine surgery carried out under hypotensive anesthetic.

METHODS

Notes review, clinical examination, plain radiographs, and magnetic resonance imaging diagnosed three patients who developed avascular necrosis of the femoral heads (five joints in total) after surgery for lumbar spinal stenosis. All three were treated with total hip replacement (five joints), and the diagnosis of avascular necrosis was confirmed in two by histopathological examination.

RESULTS

All three patients have recovered full mobility following hip replacement surgery. None had any residual symptoms of lumbar spinal stenosis or hip disease, and none of them had shown any clinical evidence of avascular necrosis in any other bone.

CONCLUSIONS

The development of avascular necrosis of the femoral heads following surgery for spinal stenosis may be due to hypotensive anesthesia, prone positioning on a Montreal mattress, or a combination of the two. Careful intraoperative positioning may reduce the risk of this occurring after spinal surgery. However, close postoperative surveillance and a high index of suspicion of worsening hip pathology in patients who appear to mobilize poorly after lumbar spinal surgery may be the only method of early detection and treatment for this condition.

Case report: intraoperative left common iliac occlusion in a scheduled 360-degree spinal fusion

STUDY DESIGN

This is a case report of a left common iliac artery occlusion identified as an intraoperative complication during a planned (combined anterior interbody and posterior fusion) 360 degrees spinal fusion.

OBJECTIVE

The purpose of this report was to document the occurrence of this rare complication during a planned 360 degrees fusion and to increase the awareness of this potential intraoperative vascular complication.

SUMMARY OF BACKGROUND DATA

Several cases of left iliac artery occlusion after anterior spinal surgery have been reported, but there has been no reported case of intraoperative iliac artery occlusion identified during a planned 360 degrees spinal fusion.

METHODS

The patient was a 46-year-old woman with chronic low and mid back pain and left leg pain for several years. She was a 2-pack-a-day cigarette smoker for 30 years. She was diagnosed with internal disc disruption at L3-L4 and L4-L5, unresponsive to nonoperative treatment, and was scheduled for a 360 degrees spinal fusion. During the anterior procedure, the left iliac vessels were retracted with a Wiley retractor during the discectomy and fusion. It was noted that there was no pulse in the left common iliac artery as the anterior procedure neared completion. Intraoperative Doppler showed the left iliac artery was occluded, and a left iliac endarterectomy and thrombectomy were performed immediately.

RESULTS

A significant occlusive plaque was separated distally and transected in a smooth fashion, and fresh thrombus was also removed. The procedure was successfully accomplished without any further complication with excellent restoration of arterial blood flow to the left lower extremity. Doppler study showed good triphasic flow in the iliac artery and all its branches. Because of the arterial repair, the posterior portion of the surgery was not undertaken at that time and was performed 2 weeks later.

CONCLUSIONS

Early recognition and appropriate treatment can prevent serious sequelae. Great care and observation should be given to the patients before surgery, intraoperatively, as well as after surgery.

Femoral artery ischemia during spinal scoliosis surgery detected by posterior tibial nerve somatosensory-evoked potential monitoring

STUDY DESIGN

A case report of unilateral leg ischemia caused by femoral artery compression detected using posterior tibial nerve somatosensory-evoked potentials during spinal scoliosis instrumentation surgery.

OBJECTIVES

To report a rare cause of intraoperative unilateral loss of all posterior tibial nerve somatosensory-evoked potential waveforms.

SUMMARY OF BACKGROUND DATA

Failure to obtain adequate popliteal fossa, spinal, subcortical, and cortical potentials during posterior tibial nerve somatosensory-evoked potential spinal cord monitoring usually results from technical factors or chronic conditions affecting the peripheral nerve.

METHODS

A 16-year-old boy with thoracic scoliosis had normal posterior tibial nerve somatosensory-evoked potentials both before surgery and in the operating room immediately after anesthesia induction and prone positioning on a four-post spinal frame.

RESULTS

One hour after the start of surgery, a minimal amplitude reduction of the right popliteal fossa potentials appeared. Fifteen minutes later, the amplitudes of the popliteal fossa, subcortical, and cortical potentials evoked by right posterior tibial nerve stimulation became substantially reduced. Subsequently, all waveforms were lost. Malfunction of the right posterior tibial nerve stimulator was initially suspected, but when proper function was verified, a search for other causes of this loss led to discovery of leg ischemia. The patient was repositioned on the spinal frame, and all posterior tibial nerve somatosensory-evoked potentials waveforms began to reappear 7 minutes later. There was no postoperative clinically detectable complication.

CONCLUSIONS

Although technical malfunction should always be suspected when all intraoperative somatosensory-evoked potential waveforms are initially seen and subsequently lost, one should also consider the possibility that intraoperative ischemia due to limb positioning could be the etiology.