Mohamed Samy Elhammady

Minimally invasive anterolateral approaches for the treatment of back pain and adult degenerative deformity

MINIMALLY INVASIVE AND interbody and instrumented fusion techniques are increasingly being used for the treatment of adult degenerative disc disease, stenosis, and deformity of the lumbar spine. Advocates of minimal access spinal approaches list certain advantages over open procedures, including decreased postoperative pain and narcotic requirements, shorter hospital stays, less blood loss, and smaller incisions. The minimally invasive anterolateral approach allows access to the lumbar spine through the retroperitoneal space. We report on the short-term clinical and radiographic outcomes in four patients with mid to high lumbar coronal deformities treated at our institution with the anterolateral transpsoas minimally invasive approach. The primary presentation of these patients was back and leg pain. All patients showed improvement in their preoperative symptoms and solid arthrodesis at 6 months. Independent nonbiased patient pain analysis was also performed. Mean follow-up was 10 months (standard deviation, 1.4 mo), and mean hospital stay was 3.5 days (standard deviation, 1.9 d). One patient had additional posterior segmental instrumentation placed. Mean Cobb angles in the coronal plane were 28.5 degrees preoperatively and 18.3 degrees postoperatively (P < 0.05). We also present a historical perspective on retroperitoneal spine surgery, a regional anatomic description of the lumbosacral plexus and surrounding structures, and a description of the surgical technique as related to treatment of lumbar deformity.

Eagle syndrome as a cause of transient ischemic attacks

Eagle syndrome is an uncommon entity but is well known in the otorhinolaryngology and oral surgery literature. This syndrome results from the compression of cranial nerves in the neck by an elongated styloid process causing unilateral cervical and facial pain. The styloid process can also cause compression of the cervical carotid arteries leading to the so-called carotid artery syndrome together with carotidynia or neurological symptoms due to flow reduction in these arteries. The authors discuss the case of a 70-year-old man who suffered from transient ischemic attacks on turning his head to the left, with immediate remission of symptoms when his head returned to the neutral position. The patient was studied with dynamic angiography, which clearly showed focal flow restriction. Once a diagnosis was made, the styloid process was removed surgically and the patient completely recovered from his symptoms. A postoperative angiogram demonstrated complete resolution of the pathology. Neurosurgeons might encounter patients with Eagle syndrome and should be aware of the symptoms and signs. Once the diagnosis is made, the treatment is clear and very effective.

Onyx embolization of carotid-cavernous fistulas

OBJECT The authors conducted a study to determine the safety and efficacy of embolization of carotid-cavernous fistulas (CCFs) with the ethylene vinyl alcohol copolymer, Onyx. METHODS They prospectively collected data in all patients with CCFs who underwent Onyx-based embolization at their institution over a 3-year period. The type of fistula, route of embolization, viscosity of Onyx, additional use of coils, extent of embolization, procedural complications, and clinical follow-up were recorded. RESULTS A total of 12 patients (5 men and 7 women who were age 24-88 years) underwent embolization in which Onyx was used. There were 1 Barrow Type A, 1 Type B, 3 Type C, and 7 Type D fistulas. Embolization was performed via a transvenous route in 8 cases and a transarterial route in 4 cases. Onyx 34 was used in all but 2 cases: a direct Type A fistula embolized with Onyx 500 and an indirect Type C fistula embolized with Onyx 18. Adjuvant embolization with framing coils was performed in 7 cases. All procedures were completed in a single session. Immediate fistula obliteration was achieved in all cases. Clinical resolution of presenting symptoms occurred in 100% of the patients by 2 months. Neurological complications occurred in 3 patients. One patient developed a complete cranial nerve (CN) VII palsy that has not resolved. Two patients developed transient neuropathies--1 a Horner syndrome and partial CN VI palsy, and 1 a complete CN III and partial CN V palsy. Radiographic follow-up (mean 16 months, range 4-35 months) was available in 6 patients with complete resolution of the lesion in all. CONCLUSIONS Onyx is a liquid embolic agent that is effective in the treatment of CCFs but not without hazards. Postembolization cavernous sinus thrombosis and swelling may result in transient compressive cranial neuropathies. The inherent gradual polymerization properties of Onyx allow for casting of the cavernous sinus but may potentially result in deep penetration within arterial collaterals that can cause CN ischemia/infarction. Although not proven, the angiotoxic effects of dimethyl sulfoxide may also play a role in postembolization CN deficits.

Preoperative Onyx Embolization of Vascular Head and Neck Tumors by Direct Puncture

OBJECTIVE Preoperative embolization of hypervascular head and neck tumors is frequently performed to reduce operative times and blood loss. While traditional transarterial embolization is commonly used, direct tumoral puncture has also been advocated as an alternative. We report our series of head and neck tumors embolized with onyx via direct tumoral puncture to ascertain the safety and efficacy of embolization using this technique. METHODS We prospectively collected data on all head and neck tumors embolized with onyx at our institution during a 24-month period. RESULTS A total of 18 patients underwent preoperative embolization via direct tumoral puncture. Tumors included nine carotid body tumors, three glomus vagale tumors, five juvenile nasopharyngeal angiofibromas (JNAs), and one intracranial frontal parasagittal meningioma. All embolizations were completed in a single session. Mean fluoroscopy time was 40 minutes. The overall mean percent tumor devascularization was 87%. Inadvertent transtumoral migration of onyx into the superior sagittal sinus occurred during intraoperative embolization of the meningioma using single-plane fluoroscopy and resulted in a large postoperative hemorrhagic venous infarct. There were no other endovascular-related complications in the remaining patients embolized using biplanar fluoroscopy. CONCLUSION Embolization of hypervascular head and neck tumors with onyx via direct tumoral puncture can be performed safely and efficiently. Tumor embolization by direct puncture may theoretically lower the risk of inadvertent migration of onyx through nontarget arterial vessels, but may increase the risk of inadvertent transtumoral embolization of venous structures. Caution should be exercised when using this technique for intracranial pathologies, and the importance of biplanar fluoroscopy to allow better visualization of the onyx migration cannot be overemphasized.

Outcomes in pediatric patients with Chiari malformation Type I followed up without surgery: Clinical article

OBJECT The natural history of untreated Chiari malformation Type I (CM-I) is poorly defined. The object of this study was to investigate outcomes in pediatric patients with CM-I who were followed up without surgical intervention. METHODS The authors retrospectively reviewed 124 cases involving patients with CM-I who presented between July 1999 and July 2008 and were followed up without surgery. The patients ranged in age from 0.9 to 19.8 years (mean 7 years). The duration of follow-up ranged from 1.0 to 8.6 years (mean 2.83 years). Imaging findings, symptoms, and findings on neurological examinations were noted at presentation and for the duration of follow-up. RESULTS The mean extent of tonsillar herniation at presentation was 8.35 mm (range 5-22 mm). Seven patients had a syrinx at presentation. The syrinx size did not change in these patients on follow-up imaging studies. No new syrinxes developed in the remaining patients who underwent subsequent imaging. The total number of patients with presenting symptoms was 81. Of those 81 patients, 67 demonstrated symptoms that were not typical of CM-I. Of the 14 patients with symptoms attributed to CM-I, 9 had symptoms that were not severe or frequent enough to warrant surgery, and surgery was recommended in the remaining 5 patients. Chiari malformation Type I was also diagnosed in 43 asymptomatic patients who had imaging studies performed for various reasons. No new neurological deficits were noted in any patient for the duration of follow-up. CONCLUSIONS The majority of patients with CM-I who are followed up without surgery do not progress clinically or radiologically. Longer follow-up of this cohort will be required to determine if symptoms or new neurological findings develop over the course of many years.

Carotid artery sacrifice for unclippable and uncoilable aneurysms: endovascular occlusion vs common carotid artery ligation.

BACKGROUND:Optimal treatment of intracranial aneurysms involves complete occlusion of the aneurysm with preservation of the parent artery and all of its branches. Attempts to occlude the aneurysm and preserve the parent artery may be associated with a higher level of risk than parent vessel occlusion or trapping. OBJECTIVE:To evaluate our series of patients with large and giant aneurysms who underwent treatment via endovascular coiling with parent artery sacrifice or surgical ligation of the common carotid artery (CCA) and gain insight into the advantages and risks of each of these alternatives. METHODS:We retrospectively reviewed all patients with aneurysms who underwent carotid sacrifice via endovascular occlusion or surgical CCA ligation during an 8-year period at our institution. RESULTS:Twenty-seven patients with large and giant aneurysms of the internal carotid artery underwent carotid artery sacrifice via endovascular occlusion (n = 15) or CCA ligation (n = 12). Of the patients who underwent endovascular occlusion, 3 developed groin complications, 1 developed a new sixth nerve palsy, 1 died from vasospasm related to subarachnoid hemorrhage, and 1 died secondary to rupture of an associated 3-mm anterior communicating artery aneurysm 5 days postoperatively. Of the patients undergoing CCA ligation, 1 patient developed a partial hypoglossal palsy. Clinical improvement of presenting symptoms was observed in all surviving patients regardless of the method of treatment. Complete aneurysm obliteration was documented in all patients during the initial hospital stay. The mean radiographic long-term follow-up was 14.2 months, which was available in 20 of the 25 surviving patients (80%). Complete obliteration was confirmed at follow-up in all but 2 patients with large cavernous aneurysms; 1 was initially treated with endovascular occlusion and the other with carotid ligation. CONCLUSION:Parent artery sacrifice is still a viable treatment for some complex aneurysms of the internal carotid artery. CCA ligation is a reasonable alternative to endovascular arterial sacrifice.

Endoscopic Fenestration of Middle Fossa Arachnoid Cysts: A Technical Description and Case Series

Background: Arachnoid cysts are intra-arachnoidal cerebrospinal fluid collections most frequently seen in the middle cranial fossa. The optimal method of treatment for symptomatic arachnoid cysts remains controversial and includes cyst shunting, open craniotomy and endoscopic fenestration. All these techniques, however, have been associated with the development of postoperative subdural fluid collections. We describe a new endoscopic transcortical technique that attempts to avoid this complication. Methods: Six patients with middle cranial fossa arachnoid cysts were treated with endoscopic fenestration at our institution between January 2002 and December 2005. Three cases were approached directly through the cyst, while the other 3 were approached by passing the endoscope through the rim of adjacent cortex. Results: All six endoscopic fenestrations were successful in treating the arachnoid cysts. Among the 3 patients treated via a direct cyst entry, 2 cases developed significant subdural hygromas, 1 of which required aspiration. On the other hand, 1 of the 3 cases treated using a transcortical technique developed an insignificant postoperative extra-axial collection that resolved at 3 months without intervention. Conclusion: Endoscopic fenestration is an effective treatment for symptomatic arachnoid cysts. Endoscopic fenestration via a transcortical approach attempts to minimize cerebrospinal fluid drainage into the subdural space, avoiding the development of significant postoperative extra-axial collections, while promoting flow into the basal cisterns.

Onyx embolization of a carotid cavernous fistula via direct transorbital puncture

The treatment of indirect carotid cavernous fistulas (CCFs) is challenging and primarily accomplished by endovascular means utilizing a variety of embolic agents. Transvenous access to the cavernous sinus is the preferred method of embolizaiton of indirect CCFs as they are frequently associated with numerous small-caliber meningeal branches. Although the inferior petrosal sinus is the simplest, shortest, and most commonly used venous route to the cavernous sinus, the superior ophthalmic vein, superior petrosal sinus, basilar plexus, and pterygoid plexus present other endovenous options. Occasionally, however, use of these venous routes may not be possible due to vessel tortuosity or sinus thrombosis and occlusion. The authors report a case of an indirect CCF that could not be treated endovascularly due to inability to access the cavernous sinus via a transfemoral transvenous approach. Angiography revealed a small, deeply located superior ophthalmic vein that was thought to be suboptimal for a direct cutdown. The cavernous sinus was cannulated directly via a transorbital approach using fluoroscopic guidance with a 3D skull reconstruction overlay. The fistula was subsequently obliterated using ethylene vinyl alcohol copolymer (Onyx). The technique and advantages of both 3D osseous reconstruction as well as Onyx embolization are discussed.

Direct percutaneous embolization of a carotid body tumor with Onyx

Carotid body tumors (CBTs) are rare highly vascular lesions that frequently require preoperative embolization to minimize surgical morbidity secondary to blood loss. Embolization has typically been performed via a transarterial route. However, this frequently results in incomplete devascularization of the tumor due to the complex angioarchitecture of the feeding arteries. Direct intralesional embolization has been used to gain easier accesses to the tumor vasculature and thus increase the likelihood of complete embolization. Cyanoacrylate glue has been the most commonly used embolic agent. The authors present a case of CBT that underwent direct intralesional embolization using Onyx (ev3; ethylene vinyl alcohol copolymer). To their knowledge, there have been no previous reports of direct percutaneous embolization of a CBT with this agent.

Preoperative Embolization of Juvenile Nasopharyngeal Angiofibromas: Transarterial Versus Direct Tumoral Puncture

OBJECTIVE Preoperative embolization of juvenile nasopharyngeal angiofibromas (JNA) has been shown to reduce operative times and blood loss. Although traditional transarterial (TA) embolization is commonly used, direct tumoral puncture (DTP) has also been advocated as an alternative. We report our series of JNAs embolized with Onyx and compare the two embolization techniques. METHODS We retrospectively reviewed all JNAs embolized with Onyx at our institution during a 20-month period. The fluoroscopy time, percent of tumor devascularization, periprocedural complications, and intraoperative blood loss were compared between the two groups. RESULTS A total of 10 patients with JNA underwent preoperative embolization by a TA route (n = 5) or DTP (n = 5). Mean fluoroscopy time was 50 and 39 minutes in the TA and DTP groups, respectively. The mean percent tumor devascularization in the TA group was 77% compared with 93% in the DTP group. Intraoperative estimated blood loss in tumors embolized transarterially was higher than those embolized by DTP (862 mL vs. 412 mL); however, this difference did not reach statistical significance. There were no neurological complications related to the embolization procedures in either group. CONCLUSIONS Embolization of JNAs with Onyx can be performed safely by either method. Direct puncture is associated with shorter embolization procedure times and results in a greater degree of tumor devascularization. Although there was a trend toward lesser blood loss in patients embolized by DTP, it did not reach statistical significance in this small series. Larger series are needed to determine whether the improved tumor penetration achieved with DTP translates into clinical benefit.