Bypass combined with embolization via a venous graft in a patient with a giant aneurysm in the posterior communicating artery and bilateral idiopathic occlusion of the internal carotid artery in the neck

Sacral Insufficiency Fracture Following Short-Segment Lumbosacral Fusion: Case Series and Review of the Literature

STUDY DESIGN

Retrospective case series.

OBJECTIVE

Sacral insufficiency fracture is a rare and serious complication following lumbar spine instrumented fusion. The purpose of this study was to describe the patient characteristics, presentation, evaluation, treatment options, and outcomes for patients with sacral insufficiency fracture after short-segment lumbosacral fusion.

METHODS

Six patients from our institutional database and 16 patients from literature review were identified with a sacral insufficiency fracture after short-segment (L4-S1 or L5-S1) lumbar fusion within 1 year of surgery.

RESULTS

Patients were 55% female with a mean age of 58 years and body mass index of 30 kg/m². Osteoporosis or osteopenia was the most common comorbidity (85%). Half of patients sustained a sacral fracture after surgery from a posterior approach, while the others had anterior or anterior-posterior surgery. Mean time to fracture was 42 days with patients clinically presenting with new sacral pain (86%), radiculopathy (60%), or neurologic deficit (5%). Ultimately, 73% of patients underwent operative fixation often involving extension of the construct (75%) and fusion to the pelvis (69%). Men (P = .02) and patients with new radicular pain or neurologic deficit (P = .01) were more likely to undergo revision surgical treatment while women over 50 years of age were more likely to be treated conservatively (P = .003).

CONCLUSIONS

Spine surgeons should monitor for sacral insufficiency fracture as a source of new-onset pain in the postoperative period in patients with a short segment fusion to the sacrum. The recognition of this complication should prompt an assessment of bone health and management of underlying bone fragility.

Endovascular stent-coiling of a giant basilar artery aneurysm through a previous radial artery bypass

Giant, partially-thrombosed basilar artery (BA) aneurysms are extraordinarily difficult to treat. Due to the high risk of rupture exclusion of these aneurysms from the circulation is imperative. In certain instances, direct clipping is unsuitable, and high-flow bypass and proximal parent vessel clip occlusion is required. We report a case of a recurrent partially-thrombosed giant BA apex aneurysm treated with endovascular stent-coiling through a previous radial artery bypass graft. Following the initial bypass and aneurysm trapping six years prior, the patient was neurologically stable until three months prior to admission when he developed new diplopia and left third nerve palsy. Imaging studies demonstrated interval enlargement of the thrombosed portion of the aneurysm and increased size in the filling portion of the aneurysm. In the present case, the existing radial artery bypass graft between left VA and left PCA permitted successful stent-assisted embolization of the recurrent BA aneurysm. To our knowledge, this is the first published case of endovascular stent-coiling of a BA aneurysm through a radial artery bypass graft. This novel technique can be a useful alternative for endovascular aneurysm treatment in these challenging lesions.

Coiling of a Ruptured Large Internal Carotid Artery Aneurysm via Extracranial-Intracranial Saphenous Vein Bypass Graft Just After Proximal Ligation of the Internal Carotid Artery

BACKGROUND

Combined direct and endovascular surgery has been performed to treat large to giant internal carotid artery (ICA) aneurysms. This report describes successful treatment of a large ICA aneurysm by coiling of the aneurysm via an extracranial-intracranial saphenous vein (SV) graft just after bypass and ICA proximal ligation.

CASE DESCRIPTION

A 66-year-old woman presented with a left ICA supraclinoid aneurysm with progressive visual field defect and impaired visual acuity in the left eye. While waiting for scheduled surgery, she experienced a subarachnoid hemorrhage. An extracranial-intracranial high-flow bypass using an SV graft and proximal ligation of the ICA were performed. Coiling of the aneurysm was immediately performed successfully via the SV bypass graft. The patient experienced no new neurologic deficit after this treatment. Follow-up radiologic evaluations using magnetic resonance imaging and magnetic resonance angiography revealed complete aneurysm occlusion.

CONCLUSIONS

Aneurysm coiling via an extracranial-intracranial SV bypass graft could offer an alternative when an antegrade access route to the ICA is not used because of prior parent artery ligation.

Successful flow reduction surgery for a ruptured true posterior communicating artery aneurysm caused by the common carotid artery ligation for epistaxis

Background:

Carotid artery occlusion can lead to the development of rare true posterior communicating artery (PCoA) aneurysms because of hemodynamic stress on the PCoA. Surgical treatment of these lesions is challenging.

Case Description:

The authors report a case of a true PCoA aneurysm that developed and ruptured 37 years after ligation of the ipsilateral common carotid artery for epistaxis. The lesion was successfully treated with clipping of the distal M1 segment of the middle cerebral artery (MCA) after the occipital artery-radial artery free graft-MCA bypass, which led to extreme reduction in collateral flow through the PCoA. A cortical branch, located just proximal to the obliteration site, functioned as a sufficient flow outlet. The aneurysm shrank, and the patient has been doing well without any symptoms for 5 years after surgery.

Conclusions:

M1 obliteration combined with high-flow extra-intracranial bypass might be a promising option for a true PCoA aneurysm, and therapeutic design that leaves a sufficient flow outlet on the M1 is mandatory to avoid unexpected occlusion of the M1 and its perforators.

Risk of intracerebral aneurysm rupture during carotid revascularization

OBJECTIVE

Robust guidelines exist for the treatment of carotid stenosis and intracranial aneurysms independently, however, the management of tandem carotid stenosis and intracranial aneurysms remains uncertain. Although the prevalence of tandem pathologies is small (1.9%-3.2%), treating carotid stenosis can alter intracranial hemodynamics potentially predisposing to aneurysm rupture. In this review, our aim was to assess the safety of intervention in this cohort, by analyzing outcomes from the published literature.

METHODS

The preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines were used to conduct the review. Articles from 1947 to 2012 were searched using EMBASE Classic and EMBASE (November, 1947 -March, 2012) and Ovid MEDLINE(R) In-Process and other NonIndexed Citations and Ovid MEDLINE(R) on Ovid SP, http://ClinicalTrials.gov, http://controlled-trials.com and the Cochrane review database using a predefined search strategy.

RESULTS

One hundred forty-one patients from 27 articles were included. Interventions ranged from single (n=104, 74%), staged (n=26, 18%) to simultaneous procedures (n=11, 8%). The largest cohort of patients was treated by carotid endarterectomy alone (n=92, 66%). The majority of patients presented with a symptomatic carotid stenosis and an asymptomatic ipsilateral intracranial aneurysm (n=70, 50%). Five subarachnoid hemorrhages occurred (4% [5/140], three within 30 days of the procedure and two thereafter) of which two were fatal. All five occurred in patients who underwent carotid endarterectomy as a single procedure (5%). Two of the five patients presented with ruptured posterior communicating artery aneurysms.

CONCLUSIONS

Published reports of perioperative aneurysm rupture are rare in individuals with tandem carotid stenosis and intracranial aneurysms. This is the first analysis of all published cases. However, it is limited by the small number of studies and the possible underreporting due to publication bias and underdiagnosis where angiography was not performed. Although we report a low incidence of subarachnoid hemorrhage, analysis of registry data with a larger cohort is warranted to confirm these findings.

Sacral fractures after lumbosacral fusion: a characteristic fracture pattern

OBJECTIVE

The purpose of this study was to describe the radiologic pattern of sacral fractures after lumbosacral fusion and to identify clinical characteristics relevant to the radiologic diagnosis.

MATERIALS AND METHODS

A search of CT, nuclear medicine, and MRI radiology reports over a 5-year period at our institution revealed a total of 23 patients with sacral fractures after lumbosacral fusion. Two radiologists reviewed all of the images to determine the sacral fracture pattern. The clinical records of these patients were reviewed for interval after surgery, fusion length, hardware, approach, preoperative diagnosis, symptoms, treatment, and risk factors.

RESULTS

All 23 sacral fractures were horizontal through the sacral body, involved the screw holes, and exited through the posterosuperior sacral alae. The fractures occurred within 3 months of fusion in 19 of 23 patients. All 23 patients had symptoms at the time of fracture. Seventeen of 23 fusions were long (more than four vertebrae). Four of 23 patients had osteoporosis. Eleven of 23 fractures healed without surgery, and 12 were managed with transiliac fixation.

CONCLUSION

Sacral fractures after lumbosacral fusion have a characteristic transverse pattern through the sacral screw holes that differs from the configuration of more common sacral insufficiency fractures. Most of these fractures occur within 3 months after surgery, and many of the patients need additional surgical fixation. Because few of the patients had osteoporosis and most underwent long fusion, the fractures might have been caused by hardware-related stress raisers in the sacrum.

Surgical Treatment of Giant Intracranial Aneurysms: Current Viewpoint

Objective:

Despite new endovascular techniques and technological advances in microsurgery, the treatment of giant intracranial aneurysms is still a daunting neurosurgical task. Many of these aneurysms have a large, calcified neck, directly involve parent and collateral branches, and are partly thrombosed. In this retrospective review, we focused our analysis on the indications for high-flow, extracranial-intracranial (EC-IC) bypass surgery using a saphenous vein graft.

Methods:

A series of 130 patients were treated between 1990 and 2004; 31 patients were managed endovascularly, and 99 patients were treated microsurgically (surgical clipping in 58 patients and high-flow EC-IC bypass followed by aneurysm trapping in 41 patients). We examined the patients’ clinical records and pre- and postoperative case notes for cerebral angiographic examinations. Graft patency was verified with cerebral angiography, computed tomographic angiography, Doppler ultrasound, or graft palpation.

Results:

The high-flow EC-IC bypass was used for all surgically treated prepetrous aneurysms (3 patients), intracavernous aneurysms (1 patient), intracavernous aneurysms with subarachnoid extension (23 patients), as well as for some supraclinoid aneurysms (12 of the 32 patients). It was also used for 1 of the 9 aneurysms located in the carotid bifurcation and 2 of 5 vertebrobasilar circulation aneurysms. Of the 58 patients managed by surgical clipping, 4 (6.9%) died, and 51 (94.4%) improved. Of the 41 patients managed with high-flow EC-IC bypass, 4 (9.8%) died and 34 (91.9%) improved. Graft patency at the follow-up examination was 92.7%.

Conclusion:

The “gold standard” for the treatment of giant aneurysms remains surgical clipping. When direct surgical clipping or endovascular repair is contraindicated, the high-flow EC-IC bypass is a viable surgical option.

Sacral fractures complicating thoracolumbar fusion to the sacrum

STUDY DESIGN

Case series.

OBJECTIVE

To report on the rare complication of sacral fractures after long instrumented thoracolumbar fusions to the sacrum.

SUMMARY OF BACKGROUND DATA

Rigid spinal fusion with instrumentation results in redistribution of forces in the spine that can cause the adjacent segments to degenerate and fail. Rarely in long thoraco-lumbosacral fusion, these forces may lead to sacral fractures; only 4 cases are reported in the literature.

METHODS

Five patients with sacral fractures are presented; one had the fusion performed at a different institution. Patients' characteristics, radiographic findings, and final operative treatment are discussed.

RESULTS

Sagittal imbalance after the index operation (thoraco-lumbosacral fusion), osteoporosis, and obesity were potentially associated factors. Initial nonoperative treatment failed to improve patients' symptoms. Surgery was performed at an average of 3.25 months (range, 2-8 months) in 4 patients, and soon after presentation in the patient operated elsewhere (presented 18 months after the sacral fracture). The signs of failed L5-S1 fusion, present in 3 patients, were considered to be additional surgical indication. At surgery the posterior instrumentation was extended to the pelvis. Both the fracture and the failed anterior interbody fusion were addressed through an anterior approach in 4 cases and in one case with a posterior ascending titanium cage spanning from S2 to L5. Sagittal balance was restored only in the last patient, where at the time of the revision operation a pedicle subtraction osteotomy was performed. Pain resolved in all patients after surgery and to the latest follow-up (range, 6-36 months).

CONCLUSION

Relapse of low back or buttock pain and leg pain after thoracolumbar fusion to the sacrum may be related to a sacral fracture, difficult to diagnose in conventional radiographs. Surgery should be considered in the presence of a concomitant L5-S1 pseudarthrosis and when symptoms do not improve with the nonoperative treatment.

Sacral insufficiency fractures caudal to instrumented posterior lumbosacral arthrodesis

STUDY DESIGN

Retrospective review of sacral insufficiency fractures.

OBJECTIVE

Determine incidence of sacral insufficiency fractures after posterior lumbosacral fusion. Review the pertinent literature. Describe the ability of lumbopelvic fixation to restore the alignment of these fractures.

SUMMARY OF BACKGROUND DATA

Fractures of the sacrum are rare injuries that have been described at the caudal end of lumbopelvic constructs. Without a high index of suspicion, this entity can be overlooked, causing a diagnostic delay.

METHODS

Review of patients treated at our institution from 2002 to 2005.

RESULTS

Nine patients meet our inclusion criteria. Sacral insufficiency fractures were recognized on an average of 5 weeks in the 6 patients with the index procedure performed at our institution (Incidence of fracture with short segment instrumentation is 1.3%, whereas long segment fixation has an incidence of 3.1%). The other 3 referred patients had an average delay in diagnosis of 8 months. Two patients underwent immediate fracture stabilization and fusion. The remaining 7 patients were initially treated nonoperatively. Four patients abandoned bracing an average of 3.3 months after initiation of treatment. For all of the surgical candidates, preoperative kyphosis measured 9.7 degrees and anterolisthesis averaged 10 mm. Postoperative measurement improved to a mean kyphosis of 2.3 degrees and mean displacement of 1.2 mm. All operatively treated fractures healed and the patients regained their ambulatory capacity.

CONCLUSION

Sacral insufficiency fractures are an uncommon complication of segmental posterior lumbosacral fixation in osteoporotic patients. They are potentially unstable fractures and kyphosis and displacement may contribute to persistent problems of pain and postural malalignment. The diagnosis may be difficult and should be considered in the differential diagnosis in patients who do not improve during the postoperative course. Lumbopelvic fixation is a useful salvage treatment modality for patients who fail nonoperative treatment.

A novel approach to sagittal balance restoration following iatrogenic sacral fracture and resulting sacral kyphotic deformity

✓The authors describe the use of sacral pedicle subtraction osteotomy (PSO) with multiple sacral alar osteotomies for the correction of sacral kyphosis and pelvic incidence and for achieving sagittal balance correction in cases of fixed sagittal deformity after a sacral fracture.

In this paper, the authors report on a novel technique using a series of sacral osteotomies and a sacral PSO to correct a fixed sagittal deformity in a patient with a sacral fracture that had healed in a kyphotic position. The patient sustained this fracture after a previous surgery for multilevel instrumented fusion. Preoperative and postoperative radiographic studies are reviewed and the clinical course and outcome are presented.

Experts agree that the pelvic incidence is a fixed parameter that dictates the morphological characteristics of the pelvis and affects spinopelvic orientation and sagittal spinal alignment. An increased pelvic incidence is associated with a higher degree of spondylolisthesis in the lumbosacral junction, and increased shear forces across this junction. The authors demonstrate that the pelvic incidence can be altered and corrected with a series of sacral osteotomies to improve sacral kyphosis, compensatory lumbar hyperlordosis, and sagittal balance.

Challenges in the Endovascular Treatment of Giant Intracranial Aneurysms

OBJECTIVE:

Giant intracranial aneurysms present unique therapeutic intricacies. The purpose of this study was to evaluate the anatomic and hemodynamic characteristics of these lesions and the current endovascular and combined surgical and endovascular techniques available for their treatment.

METHODS:

A review of the literature and the personal experiences of the authors with endovascular treatment of giant aneurysms are presented. This review included anatomic and hemodynamic features and analysis of the diverse endovascular techniques that have been reported for the management of these aneurysms.

RESULTS:

Anatomic features that create particular challenges in the therapeutic approach of giant aneurysms include size, shape (saccular, fusiform, serpentine), neck dimensions, branch involvement, intraluminal thrombosis, and location. Hemodynamic characteristics that affect endovascular treatment are lateral or terminal aneurysm type of flow and embolic material placement (inflow versus outflow aneurysmal region). The current endovascular therapeutic approaches include parent artery occlusion, trapping, endosaccular embolization with or without adjunctive techniques such as balloon-assisted or stent placement, and combined surgical and endovascular approaches, mainly with surgical revascularization and endovascular occlusion.

CONCLUSION:

Although there are a wide variety of endovascular therapeutic options for the treatment of giant intracranial aneurysms, none of the current techniques is completely successful and free of complications in the management of these complex lesions. A detailed and individualized analysis of each case in conjunction with sufficient understanding of the anatomy and hemodynamics of a particular aneurysm should guide the therapeutic decision. Further research advances will assist in elucidating the factors predisposing to genesis, progression, and aggressive clinical manifestations of these giant lesions.

Anterolateral approach to the craniocervical junction

OBJECT

The authors present the surgical results obtained using the anterolateral approach to the craniocervical junction (CCJ) to resect a lesion with an extradural component located anterolateral to the foramen magnum and upper cervical spine.

METHODS

The anterolateral approach, which is a presternomastoid retrojugular route to the CCJ, was performed in 14 patients. The skin incision follows the anterior edge of the sternomastoid muscle. The vertebral artery (VA) was exposed at C-1. This approach was extended either down to the cervical spine or anteriorly to the jugular foramen, according to specific requirements. Two patients had previously undergone other surgical procedures. The follow-up period ranged from 4 months to 6.2 years. The tumor resection was complete in 11 cases and subtotal in two. In a case of vertebral coiling, a vein graft was interposed between the V1 and the V3 segments of the VA, and the bypass was still patent at the 2-year follow-up examination. In two cases involving a glomus tumor, there was a transitory postoperative seventh cranial nerve deficit.

CONCLUSIONS

The aforementioned technique allows for sufficient access to lesions located anterolateral to the CCJ. It is indicated in cases in which lesions exhibit a significant extradural component, and it provides good control of the VA, the cervical portion of the internal carotid artery, sigmoid-jugular complex, and lower cranial nerves. This approach can easily be combined with a posterolateral approach and can be extended anteriorly toward the jugular foramen and inferiorly toward the lower cervical spine.

Revascularization with saphenous vein bypasses for complex intracranial aneurysms

Most intracranial aneurysms can be managed with either microsurgical clipping or endovascular coiling. A subset of complex aneurysms with aberrant anatomy or fusiform/dolichoectatic morphology may require revascularization as part of a strategy that occludes the aneurysm or parent artery or both. Bypass techniques have been invented to revascularize nearly every intracranial artery. An aneurysm that will require a saphenous vein bypass is one that cannot be treated with conventional microsurgical clipping or endovascular coiling and also requires deliberate sacrifice of a major intracranial artery as part of the alternative treatment strategy. In the past 7 years the senior author (MTL) has performed a total of 110 bypasses, of which 46 were for aneurysms. Twenty-two of these patients received high-flow extracranial-to-intracranial bypasses using saphenous vein grafts, of which 16 had aneurysms that were giant in size. We review the indications for saphenous vein bypasses for complex intracranial aneurysms, surgical techniques, and clinical management strategies.