Anterior vertebral artery decompression with an ultrasonic bone curette to treat bow hunter's syndrome

Ischemic Stroke Secondary to Dynamic Vertebral Artery Stenosis: Case Report and Review of the Literature

Ischemic stroke secondary to dynamic vertebral artery stenosis or occlusion, also known as “bow hunter's syndrome,” is a rare stroke mechanism. We report a case of a 24-year-old man with multiple hereditary exostosis (MHE) diagnosed at childhood. His first presentation to a neurologist was due to neck pain and clinical syndrome suggestive of ischemia in the vertebrobasilar territory. A therapeutic occlusion was done successfully without complication. The patient was discharged two days later on aspirin alone. In follow up one year later he continued to be symptom free. Moreover, this stroke mechanism has been reported extensively in the literature in isolation or secondary to many underlying diseases. In total, there are 168 cases reported in the published English literature, in either case reports or small series. In this review, we found that by far, vertebral artery occlusion at the atlanto-axial (C1-2) level dominated most reported cases. The most frequent presentation that led to further investigation was syncope or pre-syncope provoked by head rotation to one side. To our knowledge, there is no previous report of any stroke syndrome related to MHE before our case. In this paper, we report the first case secondary to MHE and review the literature up to date since the first reported case in 1952.

Removal of calcified lumbar disc herniation with endoscopic-matched ultrasonic osteotome - Our preliminary experience

Objective: To evaluate the clinical efficacy, practicability, and safety of an ultrasonic osteotome for percutaneous transforaminal endoscopic discectomy (PTED) in patients with calcified lumbar disc herniation (CLDH).Methods: A total of 25 CLDH patients who underwent PTED at our department between December 2017 and August 2018 were analyzed retrospectively. Post-operative lumbar spine CT was used to evaluate residual calcification. Efficacy was evaluated by pre- and post-operative with the pain visual analog scale (VAS), Oswestry disability index (ODI), and the Modified MacNab Scale; the incidence of intra- and postoperative complications was also analyzed.Results: All procedures were successfully completed and none of the patients was lost to follow-up. Postoperative CT verified the successful removal of calcified protrusions. VAS and ODI scores improved significantly after surgery. Based on the Modified MacNab scale, >90% patients achieved good or excellent outcomes. There were no complications such as dural tear and infection. Seven patients had varying degrees of postoperative dysesthesia. One patient experienced recurrence of herniation within 1 week after operation; successful recovery was achieved after repeat PTED.Conclusions: Use of this ultrasonic osteotome for PTED facilitated effective removal of calcified disc protrusion, relieved nerve compression, and protected the adjacent neurovascular tissues. The instrument may help expand the indications for endoscopic surgery and avoid open surgery for some CLDH patients.

Advances in the Pathogenesis, Diagnosis and Treatment of Bow Hunter's Syndrome: A Comprehensive Review of the Literature

Bow hunter's syndrome (BHS), also known as rotational vertebral artery (VA) occlusion syndrome, is a rare yet treatable type of symptomatic vertebrobasilar insufficiency resulting from mechanical occlusion or stenosis of the VA during head and neck rotation or extension. The symptoms of BHS range from transient vertigo to posterior circulation stroke. The underlying pathology is dynamic stenosis or compression of the VA by abnormal bony structures with neck rotation or extension in many cases, such as osteophyte, disc herniation, cervical spondylosis, tendinous bands or tumors. Imaging approaches, such as Doppler sonography, computed tomography and angiography, as well as magnetic resonance imaging and angiography, are widely used in the diagnosis and evaluation of this syndrome. Digital subtraction angiography with head rotation remains the gold standard diagnostic method. Conservative management, surgery and endovascular procedures are the three major treatment methods for BHS, whereas some symptomatic patients may need operative treatment including surgery and endovascular procedures when conservative management is not adequate.

Cervicogenic vertigo treated by c1 transverse foramen decompression : a case report

Cervicogenic vertigo was known as Bow hunter's syndrome. Occlusion of vertebral artery causes vertebrobasilar insufficiency and we reported cervicogenic vertigo case which was treated by simple decompression of transverse foramen of C1. The patient was 48 years old female who had left side dominant vertebral artery and vertigo was provoked when she rotated her head to right side. Angiography showed complete obliteration of blood flow of left vertebral artery when her head was rotated to right side. The operation was decompression of left vertebral artery at C1 level. Posterior wall of transverse foramen was resected and vertebral artery was exposed and decompressed. After surgery, vertigo of the patient was disappeared, and angiography showed patent left vertebral artery when her head was rotated to right side. Vertigo caused by compression of cervical vertebral artery could be treated by decompression without fusion or instrumentation, especially in C1 transverse foramen.

Application of ultrasonic bone curette in endoscopic endonasal skull base surgery: technical note

Background Endoscopic endonasal surgery (EES) of the skull base often requires extensive bone work in proximity to critical neurovascular structures. Objective To demonstrate the application of an ultrasonic bone curette during EES. Methods Ten patients with skull base lesions underwent EES from September 2011 to April 2012 at the University of Pittsburgh Medical Center. Most of the bone work was done with high-speed drill and rongeurs. The ultrasonic curette was used to remove specific structures. Results All the patients were submitted to fully endoscopic endonasal procedures and had critical bony structures removed with the ultrasonic bone curette. Two patients with degenerative spine diseases underwent odontoid process removal. Five patients with clival and petroclival tumors underwent posterior clinoid removal. Two patients with anterior fossa tumors underwent crista galli removal. One patient underwent unilateral optic nerve decompression. No mechanical or heat injury resulted from the ultrasonic curette. The surrounding neurovascular structures and soft tissue were preserved in all cases. Conclusion In selected EES, the ultrasonic bone curette was successfully used to remove loose pieces of bone in narrow corridors, adjacent to neurovascular structures, and it has advantages to high-speed drills in these specific situations.

Simultaneous bilateral stenosis of the vertebral arteries treated by unilateral decompression: a case report

A 56-year-old man presented with a 3-month history of progressive dizziness. His dizziness was aggravated when his head was rotated to the right side. Diagnostic angiography showed that a normal right-sided vertebral artery in the neutral position became an abnormal vertebral artery with two stenotic lesions at the C3-4 and C5-6 levels when the patient's head was turned to the right. A normal left-sided vertebral artery also showed a stenotic lesion at the C2 level when the patient's head was turned right. The axial dimensions of the bilateral vertebral arteries were similar. The patient was successfully treated with decompression of only one level (C5-6). We conclude that if a bilateral stenosis is found upon one directional head rotation and the bilateral vertebral arteries are similarly sized, a one-sided treatment may suffice.

Bow hunter's syndrome causing vertebrobasilar insufficiency in a young man with neck muscle hypertrophy

Vertebrobasilar insufficiency is characterized by impaired blood flow within the posterior circulation, producing symptoms of vertigo, nausea, vomiting, visual disturbances, and syncope. Given these nonspecific symptoms, the diagnosis of vertebrobasilar ischemia may be difficult to distinguish from more benign conditions. A healthy 37-year-old man presented to our clinic with near syncope upon turning his head to the left. Dynamic angiography revealed occlusion of the left vertebral artery at C7 with 90° head rotation to the left, consistent with bow hunter's syndrome. No obvious bony abnormalities were identified on computed tomography or magnetic resonance imaging scans. Transient rotational vertebral artery syndrome, a rare cause of vertebrobasilar insufficiency, has most often been reported at the C1-2 level, and the majority of cases occur in patients >50 years of age because of degenerative osteophytes and contralateral atherosclerosis. We present the unusual case of a young man with symptoms of vertebrobasilar insufficiency and discuss the potential effects of weightlifting and neck muscle hypertrophy on vertebral artery flow dynamics.

En bloc resection of a multilevel high-cervical chordoma involving C-2: new operative modalities

En bloc resection of cervical chordomas has led to longer survival rates but has resulted in significant morbidities from the procedure, especially when the tumor is multilevel and located in the high-cervical (C1–3) region. To date, there have been only 5 reported cases of multilevel en bloc resection of chordomas in the high-cervical spine. In this technical report the authors describe a sixth case. A complete spondylectomy was performed at C-2 and C-3 with spinal reconstruction and stabilization, using several new modalities that were not used in the previous cases. The use of 1) preoperative endovascular sacrificing of the vertebral artery, 2) CT image-guidance, 3) an ultrasonic aspirator for skeletonizing the vertebral artery, and 4) the custom design of an anterior cage all contributed to absence of intraoperative or long-term (20 months) hardware failure and pseudarthrosis.

Cervical anterior fusion with the Williams-Isu method: clinical review

Anterior decompression and fusion of the cervical spine is a widely accepted treatment for cervical canal disease. The Williams-Isu method involves cervical anterior fusion with autologous bone grafts from cervical vertebral bodies. Its advantages are a wide operative field, excellent graft fusion, the absence of problems related to the iliac donor site, and direct visualization of the nerve root. For detailed decompression of the cervical root, an ultrasonic bone curette (SONOPET, Stryker Japan K.K., Tokyo) may be useful. To prevent graft extrusion, bioabsorbable screws featuring a head are placed in 4 corners of the bone graft and are fixed with a tap on a part of the graft. The screws are visualized on postoperative X-ray, computed tomography, and magnetic resonance imaging studies. In 69 patients reported elsewhere there were no complications attributable to screw insertion, screw or graft extrusion, or surgery-related infections. When adequate bone cannot be harvested, a piece of ceramic hydroxyapatite is placed between the bone grafts. This sandwich method reinforces the graft, and radiological evidence suggests that it yields better results with respect to the angle and height of the fused segment. For the surgical treatment of cervical ossification of the posterior longitudinal ligament, a large vertebral bone window and a large bone graft are needed; this may result in postoperative radiological worsening. Radiological studies have shown that cervical ossification of the posterior longitudinal ligament can, as can cervical spondylosis, be addressed with the Williams-Isu method. Detailed radiological studies in patients treated with the Williams-Isu method have demonstrated that the range of motion and the disc height of the fused segment must be considered to prevent worsening in that segment after anterior fusion. The Williams-Isu method cannot completely correct cervical alignment, and great caution must be exercised in patients with preoperative malalignment. To reduce the levels to be fused in patients with multilevel lesions due to cervical disease, the Williams-Isu method can be combined with the transvertebral approach. The transvertebral approach facilitated by the wide Williams-Isu window allows the root bifurcation area to be confirmed during the early stage of surgery and possible decompression along the root. Radiological examination has shown that the combination of the Williams-Isu method and transvertebral approach does not affect the fusion level compared with the Williams-Isu method alone and produces better results than does the transvertebral approach alone.

Safety of spinal decompression using an ultrasonic bone curette compared with a high-speed drill: outcomes in 337 patients

Object

Unintended durotomies are a common complication of spine surgery and are often correlated with increased postoperative morbidity. Recently, ultrasonic bone curettes have been introduced in spine surgery as a possible alternative to the conventional high-speed drill, offering the potential for greater bone-cutting precision and less damage to surrounding soft tissues. To date, however, few studies have investigated the safety and efficacy of the ultrasonic bone curette in reducing the rates of incidental durotomy compared with the high-speed drill.

Methods

The authors retrospectively reviewed the records of 337 consecutive patients who underwent posterior cervical or thoracic decompression at a single institution between January 2009 and September 2011. Preoperative pathologies, the location and extent of spinal decompression, and the use of an ultrasonic bone curette versus the high-speed drill were noted. The rates of incidental durotomy, as well as hospital length of stay (LOS) and perioperative outcomes, were compared between patients who were treated using the ultrasonic bone curette and those treated using a high-speed drill.

Results

Among 88 patients who were treated using an ultrasonic bone curette and 249 who were treated using a high-speed drill, 5 (5.7%) and 9 (3.6%) patients had an unintentional durotomy, respectively. This finding was not statistically significant (p = 0.40). No patients in either cohort experienced statistically higher rates of perioperative complications, although patients treated using an ultrasonic bone curette tended to have a longer hospital LOS. This difference may be attributed to the fact that this series contained a statistically higher number of metastatic tumor cases (p < 0.0001) in the ultrasonic bone curette cohort, likely increasing the LOS for that patient population. In 13 patients, the dural defect was repaired intraoperatively. No patients who experienced an incidental durotomy had new-onset or permanent neurological deficits postoperatively.

Conclusions

The safety and efficacy of ultrasonic bone curettes in spine surgery has not been well established. This study shows that the ultrasonic bone curette has a similar safety profile compared with the high-speed drill, although both are capable of causing iatrogenic dural tears during spine surgery.

Rare case of bilateral vertebral artery stenosis caused by C4-5 spondylotic changes manifesting with bilateral bow hunter's syndrome

BACKGROUND

Rotational vertebral artery occlusion syndrome refers to vertebrobasilar insufficiency as a result of mechanical occlusion or stenosis of the vertebral artery by head rotation. In most cases, symptoms are produced on extension or rotation to one side. No case of bow hunter's syndrome with bilateral presentation at the C4 level has yet been reported.

CASE DESCRIPTION

A 54-year-old man presented with symptomatic bilateral bow hunter's syndrome induced by head rotation. The patient complained of intermittent dizziness, episodes of double vision, nonpulsatile tinnitus, and headaches indicative of vertebral artery insufficiency with exacerbation of symptoms on rotation of his head to either side. Computed tomography angiography showed bilateral vertebral artery stenosis, and dynamic cerebral angiography revealed bilateral rotational vertebral artery occlusion, with compression of the ipsilateral vertebral artery on head rotation to either side. Bilateral surgical decompression at C4-5 with anterior cervical diskectomy and fusion with a plate was performed.

CONCLUSIONS

Bony obstruction of the vertebral artery on head rotation tends to occur at levels C4 and below, affecting the ipsilateral side. In this rare case, symptomatic bilateral vertebral artery stenosis occurred as a result of bony compression and was symptomatic on head rotation both to the right and to the left. This stenosis was improved with anterior decompression bilaterally, and no further events occurred postoperatively.

Bone removal with a new ultrasonic bone curette during endoscopic endonasal approach to the sellar-suprasellar area: technical note

BACKGROUND

Accessing intradural lesions via an extended endoscopic endonasal approach requires a relatively large bony removal over the skull base.

OBJECTIVE

We describe the Sonopet ultrasonic bone curette with a new dedicated endonasal hand-piece.

MATERIALS AND METHODS

We used this ancillary device in 27 nonconsecutive endonasal procedures for different skull base lesions (18 standard pituitary operations and 9 extended approaches for either meningiomas or craniopharyngiomas).

RESULTS

The ultrasonic bone curette with endonasal hand-piece was easy to use and effective during the removal of the bone covering or when close to the carotid and optic prominences, as well as in preserving the integrity of the superior intercavernous sinus. In only 1 case was small tearing of the dura mater observed during the bony removal. No cases of injury to the major neurovascular structures occurred.

CONCLUSION

The Sonopet ultrasonic bone curette is a useful tool during endoscopic endonasal skull base surgery.

Multiple symptomatic vertebral artery loops treated with posterior cervical fusion

Multiple symptomatic vertebral artery (VA) loops are rare and their management is challenging. A 55-year-old man presented with a 5-year history of frequent episodes of presyncope and mild left C5 radiculopathy that was exacerbated by flexion or extension of his neck. Examination revealed complex left VA loops at C2/3 and C4. The patient underwent posterior cervical fusion which resolved his presyncope and improved his radiculopathy. Posterior cervical fusion is an option for management of patients suffering from symptoms secondary to multiple VA loops.