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Andrew L. Freeman, William J. Camisa, Glenn R. Buttermann and James R. Malcolm

OBJECT

This study was undertaken to quantify the in vitro range of motion (ROM) of oblique as compared with anterior lumbar interbody devices, pullout resistance, and subsidence in fatigue.

METHODS

Anterior and oblique cages with integrated plate fixation (IPF) were tested using lumbar motion segments. Flexibility tests were conducted on the intact segments, cage, cage + IPF, and cage + IPF + pedicle screws (6 anterior, 7 oblique). Pullout tests were then performed on the cage + IPF. Fatigue testing was conducted on the cage + IPF specimens for 30,000 cycles.

RESULTS

No ROM differences were observed in any test group between anterior and oblique cage constructs. The greatest reduction in ROM was with supplemental pedicle screw fixation. Peak pullout forces were 637 ± 192 N and 651 ± 127 N for the anterior and oblique implants, respectively. The median cage subsidence was 0.8 mm and 1.4 mm for the anterior and oblique cages, respectively.

CONCLUSIONS

Anterior and oblique cages similarly reduced ROM in flexibility testing, and the integrated fixation prevented device displacement. Subsidence was minimal during fatigue testing, most of which occurred in the first 2500 cycles.

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Andrew J. Molyneux, David W. Ellison, James Morris and James V. Byrne

✓ The authors report the pathological and histological findings in two patients with giant partially thrombosed aneurysms who were treated by means of Guglielmi detachable coils with subtotal occlusion of the aneurysms. Autopsies of these patients were performed 2 and 6 months after endovascular treatment. The histological findings revealed coils embedded in largely unorganized thrombus in the aneurysms; there was no clear reduction in size of the aneurysms over the period. There was no evidence of endothelialization of the aneurysm neck demonstrated in either case. The significance of these findings is discussed.

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James B. Campbell, C. Andrew L. Bassett, J. Martin Girado, R. James Seymour and Joseph P. Rossi

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Benjamin J. Shin, Andrew R. James, Innocent U. Njoku and Roger Härtl

Object

In this paper the authors' goal was to compare the accuracy of computer-navigated pedicle screw insertion with nonnavigated techniques in the published literature.

Methods

The authors performed a systematic literature review using the National Center for Biotechnology Information Database (PubMed/MEDLINE) using the Medical Subject Headings (MeSH) terms “Neuronavigation,” “Therapy, computer assisted,” and “Stereotaxic techniques,” and the text word “pedicle.” Included in the meta-analysis were randomized control trials or patient cohort series, all of which compared computer-navigated spine surgery (CNSS) and nonassisted pedicle screw insertions. The primary end point was pedicle perforation, while the secondary end points were operative time, blood loss, and complications.

Results

Twenty studies were included for analysis; of which there were 18 cohort studies and 2 randomized controlled trials published between 2000 and 2011. Foreign-language papers were translated. The total number of screws included was 8539 (4814 navigated and 3725 nonnavigated). The most common indications for surgery were degenerative disease, spinal deformity, myelopathy, tumor, and trauma. Navigational methods were primarily based on CT imaging. All regions of the spine were represented. The relative risk for pedicle screw perforation was determined to be 0.39 (p < 0.001), favoring navigation. The overall pedicle screw perforation risk for navigation was 6%, while the overall pedicle screw perforation risk was 15% for conventional insertion. No related neurological complications were reported with navigated insertion (4814 screws total); there were 3 neurological complications in the nonnavigated group (3725 screws total). Furthermore, the meta-analysis did not reveal a significant difference in total operative time and estimated blood loss when comparing the 2 modalities.

Conclusions

There is a significantly lower risk of pedicle perforation for navigated screw insertion compared with nonnavigated insertion for all spinal regions.

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Christoph P. Hofstetter, Andrew R. James and Roger Härtl

Object

Paracoccygeal transsacral fixation is a novel percutaneous technique for arthrodesis of L5–S1 and L4–5 (Axial Lumbar Interbody Fusion [AxiaLIF]). There are no reports on feasible revision strategies. The goal of this paper is to analyze the surgical details of failed AxiaLIF constructs and to describe revision strategies.

Methods

The medical charts, operative records, and imaging studies of 5 patients with failed multisegment instrumentation using the AxiaLIF device were reviewed.

Results

AxiaLIF constructs were revised in 5 patients with a mean age of 58.4 years. All AxiaLIF devices were part of multisegment fusion constructs for revision surgery and were revised an average of 15 months after implantation. Two AxiaLIF devices were percutaneously retrieved; one because of excessive bone resorption around the AxiaLIF screw, and the other because of chronic hardware infection. In these 2 patients, the anterior column was subsequently stabilized via anterior lumbar interbody fusion. In the other 3 patients, the AxiaLIF device was left in situ. In 2 of these patients the anterior column was stabilized with bilateral L5–S1 posterior lumbar interbody fusion, and in the remaining patient with L4–5 instability the posterior instrumentation only was revised. Revision surgeries were well tolerated. One patient suffered from a wound dehiscence of the back wound.

Conclusions

AxiaLIF devices are safely retrieved using percutaneous technique. Both anterior and posterior revision strategies may be used to achieve anterior column fixation.

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James V. Byrne, Min-Joo Sohn, Andrew J. Molyneux and B. Chir

Object

During a 5-year period 317 patients presenting with aneurysmal subarachnoid hemorrhage were successfully treated by coil embolization within 30 days of hemorrhage. The authors followed these cases to assess the stability of aneurysm occlusion and its longer-term efficacy in protecting patients against rebleeding.

Methods

These cases were followed for 6 to 65 months (median 22.3 months) by clinical review, angiography performed at 6 months posttreatment, and annual postal questionnaires.

Conclusions

Stable angiographic occlusion was evident in 86.4% of small and 85.2% of large aneurysms with recurrent filling in 38 (14.7%) of 259 aneurysms. Rebleeding was caused by aneurysm recurrence in four patients (between 11 and 35 months posttreatment) and by rupture of a coincidental untreated aneurysm in one patient. Annual rebleeding rates were 0.8% in the 1st year, 0.6% in the 2nd year, and 2.4% in the 3rd year after aneurysm embolization, with no rebleeding in subsequent years. Rebleeding occurred in three (7.9%) of 38 recurrent aneurysms and in one (0.4%) of 221 aneurysms that appeared stable on angiography. Periodic follow-up angiography after coil embolization is recommended to identify aneurysm recurrence and those patients at a high risk of late rebleeding.

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James V. Byrne, Min-Joo Sohn and Andrew J. Molyneux

Object. During a 5-year period 317 patients presenting with aneurysmal subarachnoid hemorrhage were successfully treated by coil embolization within 30 days of hemorrhage. The authors followed patients to assess the stability of aneurysm occlusion and its longer-term efficacy in protecting patients against rebleeding.

Methods. Patients were followed for 6 to 65 months (median 22.3 months) by clinical review, angiography performed at 6 months posttreatment, and annual questionnaires. Stable angiographic occlusion was evident in 86.4% of small and 85.2% of large aneurysms with recurrent filling in 38 (14.7%) of 259 aneurysms. Rebleeding was caused by aneurysm recurrence in four patients (between 11 and 35 months posttreatment) and by rupture of a coincidental untreated aneurysm in one patient. Annual rebleeding rates were 0.8% in the 1st year, 0.6% in the 2nd year, and 2.4% in the 3rd year after aneurysm embolization, with no rebleeding in subsequent years. Rebleeding occurred in three (7.9%) of 38 recurrent aneurysms and in one (0.4%) of 221 aneurysms that appeared stable on angiography.

Conclusions. Periodic follow-up angiography after coil embolization is recommended to identify aneurysm recurrence and those patients at a high risk of late rebleeding.

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David B. Niemann, Andrew D. Wills, Nicholas F. Maartens, Richard S. C. Kerr, James V. Byrne and Andrew J. Molyneux

Object. The aim of this study was to evaluate the efficacy of a treatment combination of coil embolization and clot evacuation in patients presenting with an intracerebral hematoma (ICH) caused by the rupture of an aneurysm.

Methods. Twenty-seven patients were prospectively recruited in this study between 1996 and 2000. Endovascular treatment of the putative ruptured aneurysm was performed as soon as practical after diagnosis and before surgical evacuation of the ICH. The Glasgow Outcome Scale (GOS) was used during follow up.

Despite admission World Federation of Neurosurgical Societies grades of IV or V in 25 patients (92%), 13 (48%) recovered well with GOS scores of 1 or 2, whereas six patients (21%) died.

Conclusions. The combined result of a favorable outcome in 48% of the patients and a mortality rate of 21% indicates that this treatment may be a valuable alternative for this patient group and warrants further study.

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Andrew Jea, Merdas Al-Otibi, Arnaud Bonnard and James M. Drake

Object

The use of laparoscopy-assisted placement of the distal catheter of a ventriculoperitoneal (VP) shunt has been well described in the literature, and several advantages of laparoscopy over laparotomy have been documented.

Methods

The authors retrospectively reviewed the charts of 11 consecutive children with hydrocephalus of various origins who underwent surgery for initial VP shunt placement or for revision of an existing VP shunt system between July 1, 2006, and December 31, 2006. The peritoneal catheter in all of these cases was implanted using a laparoscopic procedure and with the aid of a pediatric general surgeon. Laparoscopy-assisted placement of the distal catheter was successful in all patients. There were no periprocedural complications. There was one complication, an incisional hernia, noted in the short-term follow-up period.

Conclusions

The authors illustrate that laparoscopy-assisted implantation of a peritoneal catheter is a safe, effective, minimally invasive, and technically easy approach for VP shunt placement or revision in children. It allows accurate placement of the distal catheter in the peritoneal cavity, enables retrieval of fractured catheter segments, and allows confirmation of the patency of the shunt system.

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Christopher B. Michael, Andrew G. Lee, James R. Patrinely, Samuel Stal and J. Bob Blacklock

✓ The authors present a case of visual loss associated with fibrous dysplasia of the anterior skull base and the surgical management of this case. Preoperative computerized tomography scanning in this patient demonstrated a patent optic foramen and a rapidly growing cystic mass within the orbit, which was responsible for the patient's visual loss. A literature review revealed that this case is typical, in that cystic mass lesions of various types are frequently responsible for visual loss associated with fibrous dysplasia. The authors did not find significant evidence in the literature to support the notion that visual loss associated with fibrous dysplasia is the result of progressive optic canal stenosis, thus raising questions about the value of prophylactic optic canal decompression. Instead, as demonstrated by this case and those uncovered in the literature review, most instances of visual loss result from the rapid growth of mass lesions of cystic fibrous dysplasia, mucoceles, or hemorrhage. Findings of the literature review and the present case of fibrous dysplasia of the anterior skull base support a role for extensive surgical resection in these cases and indicate a need for additional prospective analysis of a larger number of patients with this disease.