Minimally Invasive Stent Screw-Assisted Internal Fixation Technique Corrects Kyphosis in Osteoporotic Vertebral Fractures with Severe Collapse: A Pilot "Vertebra Plana" Series.

BACKGROUND AND PURPOSE: Fractures with "vertebra plana" morphology are characterized by severe vertebral body collapse and segmental kyphosis; there is no established treatment standard for these fractures. Vertebroplasty and balloon kyphoplasty might represent an undertreatment, but surgical stabilization is challenging in an often elderly osteoporotic population. This study assessed the feasibility, clinical outcome, and radiologic outcome of the stent screw-assisted internal fixation technique using a percutaneous implant of vertebral body stents and cement-augmented pedicle screws in patients with non-neoplastic vertebra plana fractures. MATERIALS AND METHODS: Thirty-seven consecutive patients with vertebra plana fractures were treated with the stent screw-assisted internal fixation technique. Vertebral body height, local and vertebral kyphotic angles, outcome scales (numeric rating scale and the Patient's Global Impression of Change), and complications were assessed. Imaging and clinical follow-up were obtained at 1 and 6 months postprocedure. RESULTS: Median vertebral body height restoration was 7 mm (+74%), 9 mm (+150%), and 3 mm (+17%) at the anterior wall, middle body, and posterior wall, respectively. Median local and vertebral kyphotic angles correction was 8° and 10° and was maintained through the 6-month follow-up. The median numeric rating scale score improved from 8/10 preprocedure to 3/10 at 1 and 6 months (P < .001). No procedural complications occurred. CONCLUSIONS: The stent screw-assisted internal fixation technique was effective in obtaining height restoration, kyphosis correction, and pain relief in patients with severe vertebral collapse.

Armed Kyphoplasty: An Indirect Central Canal Decompression Technique in Burst Fractures.

BACKGROUND AND PURPOSE: Burst fractures are characterized by middle column disruption and may feature posterior wall retropulsion. Indications for treatment remain controversial. Recently introduced vertebral augmentation techniques using intravertebral distraction devices, such as vertebral body stents and SpineJack, could be effective in fracture reduction and fixation and might obtain central canal clearance through ligamentotaxis. This study assesses the results of armed kyphoplasty using vertebral body stents or SpineJack in traumatic, osteoporotic, and neoplastic burst fractures with respect to vertebral body height restoration and correction of posterior wall retropulsion. MATERIALS AND METHODS: This was a retrospective assessment of 53 burst fractures with posterior wall retropulsion and no neurologic deficit in 51 consecutive patients treated with armed kyphoplasty. Posterior wall retropulsion and vertebral body height were measured on pre- and postprocedural CT. Clinical and radiologic follow-up charts were reviewed. RESULTS: Armed kyphoplasty was performed as a stand-alone treatment in 43 patients, combined with posterior instrumentation in 8 and laminectomy in 4. Pre-armed kyphoplasty and post-armed kyphoplasty mean posterior wall retropulsion was 5.8 and 4.5 mm, respectively (P < .001), and mean vertebral body height was 10.8 and 16.7 mm, respectively (P < .001). No significant clinical complications occurred. Clinical and radiologic follow-up (1-36 months; mean, 8 months) was available in 39 patients. Three treated levels showed a new fracture during follow-up without neurologic deterioration, and no retreatment was deemed necessary. CONCLUSIONS: In the treatment of burst fractures with posterior wall retropulsion and no neurologic deficit, armed kyphoplasty yields fracture reduction, internal fixation, and indirect central canal decompression. In selected cases, it might represent a suitable minimally invasive treatment option, stand-alone or in combination with posterior stabilization.

Vertebral augmentation for neoplastic lesions with posterior wall erosion and epidural mass.

BACKGROUND AND PURPOSE: The presence of a cortical erosion of the posterior wall or an epidural mass is commonly considered a contraindication to performing a vertebral augmentation, considering the perceived increased risk of an epidural cement leak. Our aim was to assess technical and clinical complications of vertebral augmentation procedures performed for pain palliation and/or stabilization of neoplastic lytic vertebral body lesions, with cortical erosion of the posterior wall, often associated with a soft-tissue epidural mass. MATERIALS AND METHODS: In 48 patients, we performed retrospective vertebral augmentation assessment on 70 consecutive levels with cortical erosion of the posterior wall, as demonstrated by preprocedural CT/MR imaging. An epidural mass was present in 31/70 (44.3%) levels. Cavity creation was performed with Coblation Wands before cement injection in 59/70 levels. Injection of high-viscosity polymethylmethacrylate was performed under real-time continuous fluoroscopic control. Postprocedural CT of the treated levels was performed in all cases. Clinical follow-up was performed at 1 and 4 weeks postprocedurally. RESULTS: In 65/70 (92.8%) levels, the vertebral augmentation resulted in satisfactory polymethylmethacrylate filling of the lytic cavity and adjacent trabecular spaces in the anterior half of the vertebral body. An epidural leak of polymethylmethacrylate occurred in 10/70 (14.2%) levels, causing radicular pain in 3 patients, which spontaneously resolved within 1 week in 2 patients, while 1 patient with a T1-T2 foraminal leak developed severe weakness of the intrinsic hand muscles and a permanent motor deficit. CONCLUSIONS: In our series of vertebral augmentation of neoplastic lytic vertebral lesions performed for palliation of pain and/or stabilization, we observed a polymethylmethacrylate epidural leak in only 14.2% of levels, despite the presence of cortical erosion of the posterior wall and an epidural mass, with an extremely low rate of clinical complications. Our data seem to justify use of vertebral augmentation in patients with intractable pain or those at risk for vertebral collapse.

Minimally-invasive posterior lumbar stabilization for degenerative low back pain and sciatica. A review.

The most diffused surgical techniques for stabilization of the painful degenerated and instable lumbar spine, represented by transpedicular screws and rods instrumentation with or without interbody cages or disk replacements, require widely open and/or difficult and poorly anatomical accesses. However, such surgical techniques and approaches, although still considered "standard of care", are burdened by high costs, long recovery times and several potential complications. Hence the effort to open new minimally-invasive surgical approaches to eliminate painful abnormal motion. The surgical and radiological communities are exploring, since more than a decade, alternative, minimally-invasive or even percutaneous techniques to fuse and lock an instable lumbar segment. Another promising line of research is represented by the so-called dynamic stabilization (non-fusion or motion preservation back surgery), which aims to provide stabilization to the lumbar spinal units (SUs), while maintaining their mobility and function. Risk of potential complications of traditional fusion methods (infection, CSF leaks, harvest site pain, instrumentation failure) are reduced, particularly transitional disease (i.e., the biomechanical stresses imposed on the adjacent segments, resulting in delayed degenerative changes in adjacent facet joints and discs). Dynamic stabilization modifies the distribution of loads within the SU, moving them away from sensitive (painful) areas of the SU. Basic biomechanics of the SU will be discussed, to clarify the mode of action of the different posterior stabilization devices. Most devices are minimally invasive or percutaneous, thus accessible to radiologists' interventional practice. Devices will be described, together with indications for patient selection, surgical approaches and possible complications.

Posterior vertebral arch cement augmentation (spinoplasty) to prevent fracture of spinous processes after interspinous spacer implant.

BACKGROUND AND PURPOSE: Interspinous spacers are implanted to treat symptomatic lumbar stenosis. Posterior vertebral element fractures can occur during or after interspinous spacer implants, especially in patients with osteopenia. The purpose of our study was to assess the biomechanical rationale, safety, feasibility, and effectiveness of posterior vertebral arch cement augmentation (spinoplasty) in preventing delayed spinous process fractures after interspinous spacer implants in patients with risk factors for fragility fractures. MATERIALS AND METHODS: We performed a nonrandomized historically controlled clinical trial. From June 2007 to March 2010, we implanted interspinous spacers in 35 eligible patients with fragility-fracture risk factors. In 19/35 patients treated after April 2009, after we assessed the theoretic biomechanical effects of cement augmentation of the spinous process and laminae by FEM, a percutaneous spinoplasty was also performed. Clinical and radiologic follow-up ranged between 12 and 36 months after the intervention. RESULTS: No intraprocedural spinous process fractures were observed in either group, and no patients in the 24-hour postoperative period had complications that were procedure-related. Symptomatic delayed spinous process fractures were diagnosed in 4/16 patients who did not undergo spinoplasty (25.0%), while no fractures were diagnosed in the 19 treated patients (P = .035). CONCLUSIONS: Spinoplasty is feasible and safe. It has a biomechanical rationale, as demonstrated by an FEM. In our preliminary experience, it seems effective in preventing delayed fractures of the posterior arch post-interspinous spacer placement in patients at risk for fragility fractures. These patients have a significant risk of developing a symptomatic delayed spinous process fracture if not treated with spinoplasty.

Plasma radio-frequency-based diskectomy for treatment of cervical herniated nucleus pulposus: feasibility, safety, and preliminary clinical results.

BACKGROUND AND PURPOSE: Several techniques, including chymopapain, mechanical aspiration, laser-based disk decompression, and endoscopic keyhole surgery, have been proposed as minimally invasive alternatives to fusion for treating cervical disk herniation, though none has gained wide acceptance. The purpose of this study was to assess feasibility, safety, and preliminary clinical results of percutaneous plasma-mediated radio-frequency-based diskectomy for cervical disk herniation. METHODS: Patients (N = 55) with cervical soft disk protrusion were treated over a 29-month period. They had radicular pain; 3 patients also had moderate myelopathy. The procedure was performed with the Perc-DC SpineWand by using an anterior approach. Most cases were conducted with local anesthetic on an outpatient basis. Clinical outcomes were graded by using the Macnab criteria. RESULTS: At 2 months, outcomes were good or excellent in 44/55 (80%) patients; the success rate was similar at 6 months, when 44 (85%) patients (n = 52/55) had good or excellent results. One clinically relevant complication (infectious diskitis) occurred within the first month postprocedure and was successfully treated. One technical complication (in situ rupture of the device tip) was observed; however, the patient remained asymptomatic during the 2-year follow-up. The 3 patients with clinical myelopathy experienced regression of cord compression symptoms; MR imaging in 2 patients showed morphologic evidence of reduction of cord compression. CONCLUSIONS: Plasma radio-frequency-based diskectomy in the cervical spine appears to be a minimally invasive low-risk approach, which is easy to perform, associated with only minimal discomfort to the patient, and effective in the short term.

Angioplasty and stenting of the cervical carotid bifurcation under filter protection: a prospective study in a series of 53 patients.

The aim of this study is to assess safety, reliability, ease of use and usefulness of filter protection devices during angioplasty and stenting of stenotic lesions of the cervical carotid bifurcation. Over a period of 42 months, 53 patients harboring a cervical carotid bifurcation stenotic lesion were treated, by angioplasty and/or stenting using filter protection devices of different kinds. The stenosis was atherosclerotic in 48 cases, post-surgical in four and post-radiation in one case. In all cases, the treatment was successful, with good restoration of the luminal diameter. There were three major strokes (5.6%) and one minor stroke (1.9%). Two of these (one major, one minor) occurred a few hours after the stenting procedure and both seemed by all evidence due to a hemorrhagic hyperperfusion syndrome. One hemiparesis and dysphasia occurred two days after the procedure, secondary to subacute thrombosis with occlusion of the stent. One patient complained of three episodes of decrease in visual acuity of the eye ipsilateral to the stenting in the two weeks following treatment. In conclusion, in our experience, use of the devices adds only few minutes to the procedure time; direct lesions of the arterial wall, such as dissections or intraluminal thrombi, related to the use of filters were never observed, and spasm of the distal I.C.A. also proved rapidly regressive. The content of all filters, if any, was histologically examined, but plaque material was found only in one case, probably owing to our primary stenting technique without use of pre-dilation. The major technical drawback is in-filter coagulation, which occurred in 16 cases, occluding the membrane of the filter and thus slowing or blocking intracranial flow. Such an event can be counteracted by a more aggressive anti-coagulation protocol, which could, however, be responsible for the two complications with hemorrhagic brain infarction. Furthermore, we observed two other major neurological events, which bring the incidence of neurological complications in this series as high as 7.5%. Therefore, it is our opinion that safety of filters is not yet proven, and consequently great care must be taken in their use.

Spontaneous dissection of carotid and coronary arteries.

The authors report a case of spontaneous dissection of both carotid arteries, followed by spontaneous dissection of the left anterior descending coronary artery after a few days. No major abnormalities of collagen production were found. This case may be underlain by a dysplasia of common precursors of the carotid and coronary walls.

Automated percutaneous lumbar discectomy: technique, indications and clinical follow-up in over 1000 patients.

This paper summarises my experience, over 14 years, treating over 1350 patients suffering from lumbar disc pathology, using minimally invasive intradiscal decompressive percutaneous techniques. The vast majority underwent the method introduced by Onik in 1985, referred to as "automated" since it involves a mechanical probe, working by a "suction and cutting" action for removal of the nucleus pulposus. Postoperative follow-up of at least 6 months was available for 1047 patients aged 15-92 years, who underwent this procedure up to June 2002. Results, based on a patient satisfaction, have been good in 58% of patients at 2 months and in 67.5% at 6 months; they have been particularly favourable in some subgroups such as elderly people (79.5% of excellent or good results), patients previously operated upon (78%) and those with "discogenic" low back pain (79%). Complication rates have been extremely low (less than 1%) and all complications cleared up without sequelae. In comparison with other percutaneous disc treatments, Onik's achieves the best compromise between clinical efficacy, comfort for the patient and low invasiveness.

Angioplasty and stenting of the cervical carotid bifurcation: report of a 4-year series.

Over a period of 46 months, 71 cervical carotid bifurcation stenotic lesions were treated by angioplasty and/or stenting. The stenosis was atherosclerotic in 61 cases, post-surgical or post-radiation in ten cases. The initial technical choice was that of primary stenting without cerebral protection; this attitude has been modified in recent cases by use of a protection balloon or filter. A technical success rate of 98% was achieved (71 cases treated out of 73 attempted). From the angiographic point of view, in all cases good restoration of the luminal diameter was obtained. There were three completely regressive minor strokes (4.2%), and one major stroke (1.4%). A follow-up of at least 1 year is available for 50 patients; a restenosis of less than 50% occurred in four (8%). In conclusion, angioplasty and stenting of the cervical carotid bifurcation is feasible in relatively safe conditions. However, analysis of the case complicated by a major stroke and the evolution of protection devices in recent years suggest the use of such devices for brain protection. The most suitable condition for endovascular treatment is considered to be an intermediate stenosis, i.e. with a residual lumen for safe passage of the devices used, without need for dangerous friction on plaque surfaces. The most dangerous phase of the treatment is dilation of the plaque by the balloon; deployment of an oversized stent without dilation is desirable whenever possible.

Brain protection with intracarotid filter in angioplasty and stenting of the cervical carotid bifurcation. Preliminary experience in five cases.

SUMMARY: We report our preliminary experience in five cases of carotid stenting and angioplasty performed under cerebral protection with new filter devices allowing carotid flow maintenance during the procedure. In four out of five cases solid material was found inside the filters after balloon inflation for angioplasty. The technical aspects are discussed with correlation to carotid plaque embolic behavior and to functional factors.

Carotid stents are not a source of microemboli late after deployment.

OBJECTIVES: To evaluate the presence of microembolic signals (MES) in the middle cerebral artery distal to a stented carotid artery late after stent deployment. MES may be a signal of thrombus formation at the stent level. PATIENTS AND METHODS: Two patient groups were studied with transcranial Doppler at different intervals after deployment of Palmaz stents or Wallstents for stenosis of the internal or common carotid artery. Group 1: from 6 to 12 months after stent deployment; Group 2: > 12 months after stenting. RESULTS: One out of 19 patients in Group 1 showed MES (5.0%); however, this patient also had two mechanical heart valves. None out of 17 patients in Group 2 had MES. CONCLUSIONS: Carotid stents seem to have a very low emboligenic potential after the early post-deployment period. This is a reassuring message for present and future patients harboring such stents.

Percutaneous cervical diskectomy: preliminary experience.

We assessed the feasibility of percutaneous treatment of a cervical herniated disc. In the lumbar region, the surgical instrument for percutaneous diskectomy passes only through the paravertebral muscles, while in the cervical region there is considerable risk of nervous, parenchymal and vascular lesions. Moreover, open surgery for cervical herniated nucleus pulposus is a well-established, low-risk procedure, with little risk of epidural fibrosis, the main complication of lumbar open surgery; a percutaneous procedure should therefore have a low morbidity rate. A safe percutaneous approach to cervical discs could be useful for biopsy and for treatment of high-risk patients for general anaesthesia. We treated 15 patients with cervical herniated nucleus pulposus; all gave informed consent and refused or were not eligible for open surgery. We used the Nucleotome described for treatment of lumbar herniated discs; except for the first three cases, we used colour Doppler sonography to detect hazardous structures in the path of the probe. We had one complication, a cervical haematoma due to damage to the inferior thyroid artery, prior to the use of ultrasound.

Percutaneous discectomy using Onik's method: 3 years' experience.

A total of 234 patients treated by percutaneous discectomy at 237 levels and followed-up between 11 months and 3 years 4 months showed an overall success rate of about 75%. In a subgroup of 112 of these patients rechecked for a second time, the clinical results remain consistently good even 24 months after surgery. In a special group of 28 patients who complained only of low back pain, percutaneous discectomy achieved a success rate of 85.7%. Complications consisted of one disc infection which cleared without clinical or radiological sequelae (0.26%).

Iopamidol and metrizamide in cervical myelography: side effects, EEG, and CSF changes.

Two nonionic contrast media, iopamidol and metrizamide (Amipaque), were used for cervical myelography (C1-C2 puncture) in 95 consecutive patients. Both contrast media gave excellent radiographic results. Headache and vagal symptoms were similar in both groups, whereas metrizamide produced more electroencephalographic changes and epileptic seizures. Meningeal irritation occurred in both groups and was severe in three cases. Cerebrospinal fluid showed protein and cellular changes of inflammatory type in both groups. Iopamidol is considered to be the more suitable contrast medium for cervical myelography despite its slight neurotoxicity.