Mario Teo

Clinical features and long-term outcomes of moyamoya disease: a single-center experience with 528 cases in China

OBJECTnThe aim of this study was to describe the baseline clinical features and long-term outcomes of patients with moyamoya disease (MMD) based on a 25-year period at a single center in China.nnnMETHODSnu2002Data obtained in 528 consecutive patients with MMD treated at the authors hospital from 1984 to 2010 were reviewed retrospectively. Events of transient ischemic attack, new infarction, and hemorrhage were included. The Kaplan-Meier risk of stroke was calculated.nnnRESULTSnu2002The mean (±SD) patient age was 26±13 years (range 2-67 years), and the female/male ratio was 0.9:1. There were 332 cases of ischemia and 196 hemorrhages. Adults had a higher rate of bleeding than children (50.7% vs 14.0%, respectively; p<0.001). One hundred twenty-two patients were treated conservatively, and 406 patients underwent revascularization procedures. Of 528 patients, 331 (62.7%) had at least 1 year of follow-up (median 39.5 months) and data from these patients were analyzed. Rebleeding and mortality rates in patients with hemorrhagic MMD (n=104) were higher than in those with ischemic MMD (n=227) (26.9% vs 2.2% [p<0.001] and 4.8% vs 0.4% [p<0.05], respectively). Twenty-five of 60 (41.7%) conservatively treated patients and 8 of 271 (2.9%) surgically treated patients experienced rebleeding events, a difference that was significant in the Kaplan-Meier curve of rebleeding (p<0.01). An improvement in perfusion was found in 164 of 224 (73.2%) surgically treated patients 1 month after discharge. However, there was no significant difference in the rate of ischemic events in the surgical and conservative groups (18.8% and 28.3%, respectively; p=0.09). Among the 104 hemorrhagic cases, rebleeding attacks were observed in 25 patients in the nonsurgical group (n=60) and 3 patients in the surgical group (n=44) (41.7% and 6.8%, respectively; OR 9.7 [95% CI 2.7-35.0]; p<0.01).nnnCONCLUSIONSnu2002There was no difference in the sex distribution of Chinese patients with MMD. Patients with hemorrhagic MMD had a much higher rate of rebleeding and poorer prognosis than those with the ischemic type. Surgical revascularization procedures can improve cerebral perfusion and have a positive impact in preventing rebleeding in patients with hemorrhagic MMD.

The effectiveness of percutaneous balloon compression in the treatment of trigeminal neuralgia in patients with multiple sclerosis

OBJECTnTrigeminal neuralgia (TN) is more common in multiple sclerosis (MS) patients than in the general population and among the former has an incidence of approximately 2%. The pathophysiology of TN in MS patients is believed to be caused by a demyelinating plaque at the root entry zone, and therefore procedures that cause direct nerve damage are thought to be the most effective surgical modality. The authors aimed to compare the efficacy of percutaneous balloon compression (PBC) in TN patients with and without MS.nnnMETHODSnRetrospectively collected clinical data on 80 consecutive patients who underwent 144 procedures and who received PBC for TN treatment between January 2000 and January 2010 were analyzed. The cohort included 17 MS and 63 non-MS patients.nnnRESULTSnThe mean age at first operation was significantly younger in the MS group compared with the non-MS group (59 years vs 72 years, respectively, p < 0.0001). After a mean follow-up of 43 months (MS group) and 25 months (non-MS group), the symptom recurrence rate following the first operation was higher in the MS group compared with that in the non-MS group (86% vs 47%, respectively, p < 0.01). During long-term follow-up, more than 70% of MS patients required multiple procedures compared with only 44% of non-MS patients. Excellent or satisfactory outcomes were not significantly different between the MS and non-MS cohorts, respectively, at 1 day postoperatively (82% vs 91%, p = 0.35), 3 months postoperatively (65% vs 81%, p = 0.16), and at last follow-up (65% vs 76%, p = 0.34). A similar incidence of postoperative complications was observed in the 2 groups.nnnCONCLUSIONSnPBC is effective in the treatment of trigeminal neuralgia in patients with MS, but, compared with that in non-MS patients, symptom recurrence is higher and requires multiple procedures.

Comparative Outcomes of the Two Types of Sacral Extradural Spinal Meningeal Cysts Using Different Operation Methods: A Prospective Clinical Study

This prospective study compares different clinical characteristics and outcomes of patients with two types of sacral extradural spinal meningeal cysts (SESMC) undergoing different means of surgical excision. Using the relationship between the cysts and spinal nerve roots fibers (SNRF) as seen under microscope, SESMCs were divided into two types: cysts with SNRF known as Tarlov cysts and cysts without. The surgical methods were tailored to the different types of SESMCs. The improved Japanese Orthopedic Association (IJOA) scoring system was used to evaluate preoperative and postoperative neurological function of the patients. Preoperative IJOA scores were 18.5±1.73, and postoperative IJOA scores were 19.6±0.78. The difference between preoperative and postoperative IJOA scores was statistically significant (t = -4.52, p = 0.0001), with a significant improvement in neurological function after surgery. Among the improvements in neurological functions, the most significant was sensation (z=-2.74, p=0.006), followed by bowel/bladder function (z=-2.50, p=0.01). There was a statistically significant association between the types of SESMC and the number (F=12.57, p=0.001) and maximum diameter (F=8.08, p=0.006) of the cysts. SESMC with SNRF are often multiple and small, while cysts without SNRF tend to be solitary and large. We advocate early surgical intervention for symptomatic SESMCs in view of significant clinical improvement postoperatively.

Radiologic Surveillance of Untreated Unruptured Intracranial Aneurysms: A Single Surgeon's Experience

BACKGROUNDnThe management of untreated unruptured intracranial aneurysms remains controversial. The natural history is still not well understood and many patients are not routinely followed up. We present a single surgeons data on radiologic surveillance of these lesions.nnnMETHODSnA total of 94 patients with 152 unruptured intracranial aneurysms, with a mean follow-up time of 3.4 years from the time of diagnosis, underwent surveillance using computer tomogram angiography, magnetic resonance angiography, or digital subtraction angiography. Aneurysm growth was defined as an increase in ≥1 dimensions above the measurement error. Statistical analysis was performed.nnnRESULTSnOf 152 aneurysms, 126 (83%) were <7 mm, 25 (16%) were 7-12 mm, and 1 aneurysm was 13-24 mm. Eighteen of 152 (12%) cerebral aneurysms in 17 patients grew larger; 7% (9/126) of the aneurysms were <7 mm and 36% (9/25) of the aneurysms were 7-12 mm enlarged. Spontaneous aneurysmal rupture occurred in 4 of 152 aneurysms (2.6%) (i.e., 4/94 patients [4%]), with an average initial aneurysm size of 5.7 mm. The risk of aneurysm rupture per patient-year was 5% with growth, 0.2% without growth, and there was a 24-fold increase in aneurysmal rupture risk for growing aneurysm (Pxa0= 0.005). Of aneurysms in group 1 patients (no previous subarachnoid hemorrhage [SAH]) 15% (16/109) compared with 5% (2/43) of group 2 (previous SAH) aneurysms showed evidence of growth during the study period (Pxa0= 0.0424).nnnCONCLUSIONSnThese results support imaging follow-up of patients with untreated unruptured intracranial aneurysms, including those with aneurysms smaller than the current treatment threshold of 7 mm. Apart from the initial size, aneurysm growth is associated with an increased risk of SAH and therefore growing aneurysms warrant treatment. The data also demonstrated that incidental aneurysms, in patients without previous SAH, do not behave less aggressively, contrary to current opinion.

Results of surgical clipping in a neurointerventional dominant department

Objectives. It has been 10 years since the publication of International Subarachnoid Aneurysm Trial (ISAT)1–3 and the first-line treatment for cerebral aneurysms in many UK neurosurgical centres is endovascular occlusion. Local audit has shown a significant reduction in surgical clipping cases since 2002, with a fall from over 150 cases per year pre ISAT, to approximately 25 cases per year currently. More so the cases referred for surgical occlusion represent more challenging lesions. With such a reduction in surgical numbers we felt it prudent to review our recent surgical outcomes. Design. Retrospective analysis of prospectively collected data. Subjects. 47 patients (32 females, 15 males), mean age: 53 (range, 29–74) years underwent surgical clipping of cerebral aneurysms from January 2012 to September 2013. Methods. Case notes, neuroradiology reports and cerebral angiograms were reviewed. Patient outcome was stratified according to Glasgow Outcome Score; 4–5 good outcome and 1–3 poor outcome. Results. Of the aneurysms clipped, 40 patients had suffered a subarachnoid haemorrhage and 7 were treated for unruptured aneurysms. The reasons for referral for surgical clipping were the presence of an aneurysmal clot 9 (19%), ‘failed coiling’ 16 (34%) and unsuitability for endovascular intervention due to anatomical considerations 22 (47%). A good outcome was recorded in 20/22 (91%) of patients who underwent clipping for anatomical reasons, 11/16 (69%) of patients who failed endovascular treatment and 5/9 (56%) of patients with an aneurysmal clot (p = 0.05). Of 31 aneurysms with post clipping angiographic studies, 28 (90%) had complete or satisfactory aneurysm obliteration. Conclusions. In the current era of neurointerventional dominance, the case mix undergoing microsurgical clipping is more challenging than the pre-ISAT cohort; however, post-procedural angiography has demonstrated a relatively high obliteration rate. It is reassuring that good neurological outcomes were observed in patients clipped for anatomical reasons.

The Outcome of Hypofractionated Stereotactic Radiosurgery for Large Vestibular Schwannomas

OBJECTIVESnStereotactic radiosurgery (SRS) for large vestibular schwannomas (VS) remains controversial. We studied the tumor local control and toxicity rates after hypofractionated SRS for VS > 3 cm.nnnMETHODSnA total of 587 patients with VS treated with SRS between 1998 and 2014 were reviewed retrospectively, and 30 Koos grade IV VSs were identified. There were 6 patients with neurofibromatosis 2 (NF2), 8 with cystic tumors, 22 with solid tumors, 19 who underwent primary CyberKnife (CK), and 11 with >3 cm after previous resection. Patients were treated by a median of 3 fractions at 18 Gy.nnnRESULTSnAfter a median 97 months, the 3- and 10-year Kaplan-Meier estimates of local control were 85% and 80%, respectively, with 20% requiring salvage treatment. For patients who had previous tumor resection rather than primary CK, the estimates were 46% and 5%, respectively, with progression, and 3-year control rates of 71% and 94% (Pxa0= 0.008). Tumor control was also lower among NF2 versus non-NF2 patients (40% vs. 95%; Pxa0= 0.0014). Among patients with good clinical baselines before CK, 88% were functionally independent (modified Rankin Scale score, 0-2), 88% had good facial function (House-Brackmann grade I-II), and 38% had serviceable hearing (Gardner-Robertson grade I-II) at last follow-up. Hearing worsening was more likely among patients treated with primary CK (33% vs. 90%; Pxa0= 0.04).nnnCONCLUSIONSnOverall, 80% of large VSs were adequately controlled by CK with 97 months of median follow-up. Patients with previous surgery and NF2 also appeared to have higher rates of tumor progression, and less favorable functional outcomes.

Editorial: Direct versus indirect bypass for moyamoya disease: ongoing controversy

In this issue of the Journal of Neurosurgery, Macyszyn and colleagues present a comparative analysis of direct, indirect, and combined revascularization techniques for moyamoya disease in adults and children based on data culled from the available English-language scientific literature.20 They conclude that outcomes after direct revascularization are significantly inferior compared with outcomes after the other two surgical approaches in both patient populations. The authors should be congratulated for attempting to address the controversy regarding the preferred revascularization procedure for moyamoya disease. In our own experience, direct revascularization for moyamoya disease is a very well-established technique, and a number of authors have described excellent results in both adult and pediatric populations.4,7–9,13,14 The main advantages of direct anastomosis over indirect procedures are the ability to augment flow immediately after surgery, a more consistent and higher extent of angiographic collateralization,2,3,5,10,12 and superiority in restoring post-bypass cerebrovascular reserve capacity.5 Direct anastomoses are also associated with excellent clinical outcomes, including a higher rate of symptomatic improvement, lower risk of recurrent ischemia, and increased stroke-free survival compared with indirect bypass.1,11,12 In their comparative analysis of adult patients, the authors included 6 adult series (one of which was our Stanford series), in which 762 cases had direct bypasses and 1524 had indirect bypasses. The perioperative risks of death, ischemic stroke, and intracranial hemorrhage were very similar between the two groups. However, the long-term risk of ischemic stroke in the indirect bypass group (10.5%) far exceeded that in the direct bypass group (1.4%). Interestingly, the authors stated that meta-regression analysis showed no significant increased rate of stroke or hemorrhage with length of follow-up but did not quantify further with regards to which intervention group they were addressing. Additionally, they stated that “indirect revascularization results in over one-half a QALY more than the direct option during the 4-year follow-up. This difference is highly statistically significant (p < 0.001).” However, in analyzing the authors’ Table 4, the expected QALYs in adults at the 4-year follow-up were 3.502 for the direct bypass group and 3.553 for the indirect bypass group; thus, a difference of a 0.05 QALY was obtained. Although this difference might be statistically significant, whether this translates into clinical significance is doubtful. Therefore, based on the data presented by the authors, we believe that direct bypass is still a better revascularization procedure in adults, especially in view of the lower long-term stroke risk. With regard to the comparative analysis in the pediatric cohort, 34 series, including 1900 cases, were included (1526 indirect bypasses, 258 combined procedures, and 116 direct bypasses). The authors then concluded that combined and indirect approaches are both superior to direct revascularization based on the analysis performed in the pediatric population. However, we would like to reiterate that in combined procedures, patients undergo a direct and an indirect component of the revascularization in the same setting. Therefore, the direct component would provide an immediate increase in cerebral perfusion, while the indirect collateralization would take months to form. This is also the case in most direct procedures, wherein after direct superficial temporal artery to middle cerebral artery bypass, the perivascular cuff forms indirect collateralization as seen on follow-up angiograms. Therefore, in our opinion, a more suitable analysis would have been to include the direct and combined groups as a single group to compare with the indirect group, as reported by other authors.12 While going through the case series selected to perform

Neck transfixion for sacral extradural spinal meningeal cysts without spinal nerve root fibers

PurposeThis prospective study analyzes clinical characteristics and outcomes of sacral extradural spinal meningeal cysts (SESMC) without spinal nerve root fibers (SNRF) undergoing neck transfixion.MethodsUsing the relationship between the cysts and SNRF, SESMCs were divided into two types: cysts with SNRF known as Tarlov cysts and cysts without. If the SESMCs were identified as those without SNRFs, the neck of the cyst was transfixed, ligated and the remaining cyst wall removed distal to the clip. The improved Japanese Orthopedic Association (IJOA) scoring system was used to evaluate preoperative and postoperative neurological functions of the patients.ResultsTwenty-seven patients were included in this study. The average age was 42.7xa0±xa011.93xa0years. The mean preoperative IJOA score was 17.5xa0±xa02.47, and postoperative IJOA score was 19.1xa0±xa01.41. The difference between preoperative and postoperative IJOA scores was statistically significant (txa0=xa0−3.75, Pxa0=xa00.001), with a significant improvement in neurological function after surgery. Among the improvements in neurological function, the most significant was bowel/bladder function (zxa0=xa0−2.33, Pxa0=xa00.02).ConclusionMost patients experienced significant improvement in their neurological function after surgery. The most significant area of neurological improvement was bowel/bladder dysfunction, however, preoperative stool or urine incontinence did not recover completely.

Strategies for and Outcome of Repeat Revascularization Surgery for Moyamoya Disease: An American Institutional Series.

BACKGROUND: Revascularization for moyamoya disease (MMD) effectively prevents future ischemic events. However, small subsets of patients with persistent or new symptoms due to inadequate collateralization require repeat revascularizations. OBJECTIVE: To investigate the clinical and radiological outcome of repeat revascularization in MMD patients with previous indirect or direct bypasses. METHODS: Single institution, retrospective analysis of a prospective MMD database. RESULTS: From 1991 to 2014, this institution performed 1244 revascularization bypasses (1107 direct, 137 indirect) in 765 patients, of whom 57 were repeat revascularizations (38 indirect, 19 direct bypass). When initially performed at the institution, the repeat revascularization rate was 4% for indirect and 1% for direct bypasses (P = .03). Cohorts with previous indirect vs direct bypass were slightly younger (mean age 23 vs 30 yr), with fewer females (61% vs 84%, P = .08), and a similar mean duration between initial bypass and repeat revascularization (49 vs 47 mo). Both groups had similar repeat revascularization due to transient ischemic attacks (66% vs 63%). One acute graft occlusion in the previous direct bypass group was revised within 1 wk postoperatively. Over 50% of the repeat revascularizations in both groups were direct bypasses; the major difference being that the repeat bypass in the direct group was to augment another vascular territory. At nearly 5 yr mean follow‐up, over 80% of patients in both groups are well, free from stroke/transient ischemic attack symptoms, with excellent radiological results. CONCLUSION: Repeat revascularization can safely and effectively prevent future ischemic events. Indirect bypass has a higher rate of repeat revascularization than direct bypass.

Surgical outcomes of Majewski osteodysplastic primordial dwarfism Type II with intracranial vascular anomalies

OBJECTIVE Majewski osteodysplastic primordial dwarfism Type II (MOPD II) is a rare genetic disorder. Features of it include extremely small stature, severe microcephaly, and normal or near-normal intelligence. Previous studies have found that more than 50% of patients with MOPD II have intracranial vascular anomalies, but few successful surgical revascularization or aneurysm-clipping cases have been reported because of the diminutive arteries and narrow surgical corridors in these patients. Here, the authors report on a large series of patients with MOPD II who underwent surgery for an intracranial vascular anomaly. METHODS In conjunction with an approved prospective registry of patients with MOPD II, a prospectively collected institutional surgical database of children with MOPD II and intracranial vascular anomalies who underwent surgery was analyzed retrospectively to establish long-term outcomes. RESULTS Ten patients with MOPD II underwent surgery between 2005 and 2012; 5 patients had moyamoya disease (MMD), 2 had intracranial aneurysms, and 3 had both MMD and aneurysms. Patients presented with transient ischemic attack (TIA) (n = 2), ischemic stroke (n = 2), intraparenchymal hemorrhage from MMD (n = 1), and aneurysmal subarachnoid hemorrhage (n = 1), and 4 were diagnosed on screening. The mean age of the 8 patients with MMD, all of whom underwent extracranial-intracranial revascularization (14 indirect, 1 direct) was 9 years (range 1-17 years). The mean age of the 5 patients with aneurysms was 15.5 years (range 9-18 years). Two patients experienced postoperative complications (1 transient weakness after clipping, 1 femoral thrombosis that required surgical repair). During a mean follow-up of 5.9 years (range 3-10 years), 3 patients died (1 of subarachnoid hemorrhage, 1 of myocardial infarct, and 1 of respiratory failure), and 1 patient had continued TIAs. All of the surviving patients recovered to their neurological baseline. CONCLUSIONS Patients with MMD presented at a younger age than those in whom aneurysms were more prevalent. Microneurosurgery with either intracranial bypass or aneurysm clipping is extremely challenging but feasible at expert centers in patients with MOPD II, and good long-term outcomes are possible.