Seung Pil Ban

Long-Term Outcomes After Combined Revascularization Surgery in Adult Moyamoya Disease

Background and Purpose— The surgical outcomes of adult moyamoya disease are rarely reported. We aimed to evaluate the long-term outcomes of combined revascularization surgery in patients with adult moyamoya disease. Methods— Combined revascularization surgery consisting of superficial temporal artery–middle cerebral artery anastomosis with encephalodurogaleosynangiosis was performed on 77 hemispheres in 60 patients. Clinical, angiographic, and hemodynamic states were evaluated retrospectively using quantitative methods preoperatively and postoperatively in the short-term (≈6 months) and long-term (≈5 years) periods. The mean clinical follow-up duration was 71.0±10.1 months (range, 60–104 months). Results— Clinical status improved until 6 months after surgery and remained stable thereafter, as assessed by the Karnofsky Performance Scale and modified Rankin Scale. The revascularization area relative to supratentorial area significantly increased in the long-term period compared with that in the short-term period (54.8% versus 44.2%; P<0.001). Cerebral blood flow in the territory of the middle cerebral artery improved in the short-term period compared with that in the preoperative period (68.7 versus 59.1; considering blood flow of the pons as 50; P<0.001) and thereafter became stable (65.5 in the long term; P=0.219). The annual risks of symptomatic hemorrhage and infarction were 0.4% and 0.2%, respectively, in the operated hemispheres. Conclusions— Combined revascularization surgery resulted in satisfactory long-term improvement in clinical, angiographic, and hemodynamic states and prevention of recurrent stroke.

Analysis of Complications Following Decompressive Craniectomy for Traumatic Brain Injury

OBJECTIVE Adequate management of increased intracranial pressure (ICP) is critical in patients with traumatic brain injury (TBI), and decompressive craniectomy is widely used to treat refractory increased ICP. The authors reviewed and analyzed complications following decompressive craniectomy for the management of TBI. METHODS A total of 89 consecutive patients who underwent decompressive craniectomy for TBI between February 2004 and February 2009 were reviewed retrospectively. Incidence rates of complications secondary to decompressive craniectomy were determined, and analyses were performed to identify clinical factors associated with the development of complications and the poor outcome. RESULTS Complications secondary to decompressive craniectomy occurred in 48 of the 89 (53.9%) patients. Furthermore, these complications occurred in a sequential fashion at specific times after surgical intervention; cerebral contusion expansion (2.2 ± 1.2 days), newly appearing subdural or epidural hematoma contralateral to the craniectomy defect (1.5 ± 0.9 days), epilepsy (2.7 ± 1.5 days), cerebrospinal fluid leakage through the scalp incision (7.0 ± 4.2 days), and external cerebral herniation (5.5 ± 3.3 days). Subdural effusion (10.8 ± 5.2 days) and postoperative infection (9.8 ± 3.1 days) developed between one and four weeks postoperatively. Trephined and post-traumatic hydrocephalus syndromes developed after one month postoperatively (at 79.5 ± 23.6 and 49.2 ± 14.1 days, respectively). CONCLUSION A poor GCS score (≤ 8) and an age of ≥ 65 were found to be related to the occurrence of one of the above-mentioned complications. These results should help neurosurgeons anticipate these complications, to adopt management strategies that reduce the risks of complications, and to improve clinical outcomes.

Correlation of optic nerve sheath diameter with directly measured intracranial pressure in Korean adults using bedside ultrasonography

Objectives The correlation of optic nerve sheath diameter (ONSD) as seen on ultrasonography (US) and directly measured intracranial pressure (ICP) has been well described. Nevertheless, differences in ethnicity and type of ICP monitor used are obstacles to the interpretation. Therefore, we investigated the direct correlation between ONSD and ventricular ICP and defined an optimal cut-off point for identifying increased ICP (IICP) in Korean adults with brain lesions. Methods This prospective study included patients who required an external ventricular drainage (EVD) catheter for ICP control. IICP was defined as an opening pressure over 20 mmHg. ONSD was measured using a 13 MHz US probe before the procedure. Linear regression analysis and receiver operator characteristic (ROC) curve were used to assess the association between ONSD and ICP. Optimal cut-off value for identifying IICP was defined. Results A total of 62 patients who underwent ONSD measurement with simultaneous EVD catheter placement were enrolled in this study. Thirty-two patients (51.6%) were found to have IICP. ONSD in patients with IICP (5.80 ± 0.45 mm) was significantly higher than in those without IICP (5.30 ± 0.61 mm) (P < 0.01). The IICP group showed more significant linear correlation with ONSD (r = 0.57, P < 0.01) compared to the non-IICP group (r = 0.42, P = 0.02). ONSD > 5.6 mm disclosed a sensitivity of 93.75% and a specificity of 86.67% for identifying IICP. Conclusion ONSD as seen on bedside US correlated well with directly measured ICP in Korean adults with brain lesions. The optimal cut-off point of ONSD for detecting IICP was 5.6 mm.

Congenital paraspinal Ewing sarcoma family of tumors with an epidural extension

Congenital Ewing sarcoma family of tumors (ESFT) is a rare disease, and only 12 patients have been reported. Among those patients, only two had paraspinal tumors with an epidural extension. A 3-week-old infant boy presented with a huge dorsal mass. Whole-spine MRI scans showed a paraspinal mass with an epidural extension from the T11 to L2 levels, causing severe spinal cord compression. An initial operation was performed to confirm the pathological diagnosis. Twenty days after the first operation, the patient showed left lower-extremity weakness. A second operation was performed with a laminectomy from the T11 to L2 levels, and the epidural mass was radically resected. Pathologically, the tumor was confirmed as an ESFT. The patient received adjuvant chemotherapy. His neurological deficit recovered after the second surgery, and there was no tumor recurrence during 17 months of follow-up.

P2Y12 Reaction Units Threshold for Implementing Modified Antiplatelet Preparation in Coil Embolization of Unruptured Aneurysms: A Prospective Validation Study

Purpose To identify and apply an optimized P2Y12 reaction units (PRU) threshold for implementing modified antiplatelet preparation to prevent thromboembolic events in patients nonresponsive to clopidogrel (clopidogrel nonresponders) undergoing coil embolization of unruptured aneurysms and to evaluate the clinical validity. Materials and Methods The optimal PRU threshold for prediction of thromboembolic events was determined with the Youden index in post hoc analysis of a previous, prospectively enrolled cohort of 165 patients in whom the antiplatelet regimen was not modified. This optimal PRU threshold was used to define clopidogrel nonresponders in a prospective validation study of 244 patients. Standard preparation (aspirin, clopidogrel) was maintained for 126 patients responsive to clopidogrel (clopidogrel responders, 51.6%), and modified preparation (aspirin, prasugrel) was prescribed prior to embolization for 118 clopidogrel nonresponders (48.4%). Fifty-seven clopidogrel nonresponders from the previous cohort who did not receive the modified preparation were included as a historical control group. Thromboembolic and bleeding events were compared among groups by using logistic regression analysis. Results Post hoc analysis from the previous cohort yielded PRU of at least 220 as the optimal threshold for modified preparation selection. The thromboembolic event rate of the clopidogrel responders (one of 126 [0.8%]) was lower than that of the historical control group that received standard preparation (seven of 57 patients [12.3%]; adjusted risk difference [RD], -10.1%; 95% confidence interval [CI]: -18.5, -1.7; P = .015) and was similar to that of clopidogrel nonresponders who received modified preparation (one of 118 [0.8%]; adjusted RD, -0.5%; 95% CI: -3.1, 2.1; P = .001 for noninferiority; P = .699 for superiority). Bleeding event rates did not differ among groups (four of 126 clopidogrel responders [3.2%] vs four of 57 clopidogrel nonresponders that received standard preparation [7.0%] [adjusted RD, -4.5%; 95% CI: -11.1, 3.4; P = .228] vs five of 118 clopidogrel nonresponders that received modified preparation [4.2%] [adjusted RD, -0.6%; 95% CI: -5.8, 4.2; P = .813]). Conclusion Patients undergoing coil embolization of unruptured aneurysms, regardless of clopidogrel responsiveness, had low thromboembolic risk when using PRU of at least 220 as the threshold for implementing modified antiplatelet preparation with prasugrel.

Endovascular Treatment for Acute Ischemic Stroke Patients over 80 Years of Age.

Objective We evaluated the effect of endovascular treatment (EVT) for acute ischemic stroke in patients over 80 years of age. Materials and Methods The records of 156 acute stroke patients aged over 80 years who were considered as candidates for EVT were analyzed. Fifty-six patients (35.9%, EVT group) underwent EVT and 100 patients (64.1%, non-EVT group) did not. Outcomes, in terms of functional outcomes and rates of symptomatic hemorrhage, in-hospital morbidity and mortality, were compared between groups. Each comparison was adjusted for age, time from onset, initial National Institute of Health Stroke Scale, and pre-stroke modified Rankin Scale (mRS). Results More patients in the EVT group achieved good outcomes (mRS score of 0-2) at 3 months (35.7% vs. 11.0%, adjusted odds ratio [OR] 4.779 [95% confidence interval 1.972-11.579], p = 0.001) and 12 months (35.7% vs. 14.0%, adjusted OR 3.705 [1.574-8.722], p = 0.003) after stroke. During admission, rates of hospital-acquired infection including pneumonia (12.5% vs. 29.0%, adjusted OR 0.262 [0.098-0.703], p = 0.008) and urinary tract infection (16.0% vs. 34.0%, adjusted OR 0.256 [0.099-0.657], p = 0.005) were significantly lower in the EVT group. More symptomatic hemorrhages (10.7% vs. 2.0%, adjusted OR 6.859 [1.139-41.317], p = 0.036) occurred in the EVT group, but no significant difference was observed in in-hospital mortality rate (12.5% vs. 8.0%, adjusted OR 1.380 [0.408-4.664], p = 0.604). Conclusion EVT improved functional outcome and reduced the risk of hospital-acquired infections in acute stroke patients over 80 years of age without increasing the risk of in-hospital mortality, although symptomatic hemorrhage occurred more frequently after EVT.

Bypass Surgery for Complex Intracranial Aneurysms: 15 Years of Experience at a Single Institution and Review of Pertinent Literature.

BACKGROUND Bypass surgery is a treatment option for complex intracranial aneurysms. OBJECTIVE To determine the utility of bypass surgery for the treatment of complex intracranial aneurysms and to review the literature on this topic. METHODS Sixty-two patients were included in this retrospective study. Unruptured aneurysms were dominant (80.6%), and the internal carotid artery was the most common location of the aneurysm (56.4%), followed by the middle cerebral artery (21.0%). The mean maximal diameter of the aneurysms was 20.5 ± 11.4 mm. The clinical and angiographic states were evaluated preoperatively, immediately after surgery (within 3 days) and at the last follow-up. The mean angiographic and clinical follow-up duration was 34.2 ± 38.9 and 46.5 ± 42.5 months, respectively. RESULTS Sixty-one patients (98.3%) underwent extracranial-intracranial bypass, and 1 underwent intracranial-intracranial bypass. At the last follow-up angiography, 58 aneurysms (93.5%) were completely obliterated and 4 were incompletely obliterated, with a graft patency of 90.3%. Surgical mortality was 0 and permanent morbidity was 8.1%. A good clinical outcome (Karnofsky Performance Scale ≥ 70 and modified Rankin Scale score ≤ 2) was achieved in 91.9% of patients (n = 57). CONCLUSION With a proper selection of bypass type, bypass-associated treatment can be a good alternative for patients with complex intracranial aneurysms when conventional microsurgical clipping or endovascular intervention is not feasible.

Relevance of Antiplatelet Therapy Duration After Stent-Assisted Coil Embolization for Unruptured Intracranial Aneurysms

BACKGROUND The optimal duration of dual-antiplatelet therapy (DAPT) for preventing delayed thromboembolic events (DTEs) remains unclear. We aimed to determine whether longer DAPT provides improved protection against delayed DTEs. METHODS This retrospective cohort study included 507 stent-assisted coil embolization procedures using a single stent for unruptured intracranial aneurysms. We performed coarsened exact matching according to the duration of maintenance DAPT. DTEs were defined as any neurologic symptoms concerning the stented vascular territory and occurring at 1 month or later after the procedure. After stratification according to DAPT duration (short-term, <9 months; long-term, ≥9 months), the log-rank test and Z-analysis were performed to evaluate the efficacy of long-term DAPT for preventing DTEs. RESULTS Of 507 treated patients (median follow-up, 44 months), 25 (4.9%) experienced DTEs at 1 month after the procedure. Among all DTEs, 9 (1.8%) were infarctions confirmed on magnetic resonance imaging. Permanent neurologic deficit (modified Rankin Scale score ≥2) occurred in 2 (0.4%) patients. On procedure-to-event analysis, long-term DAPT was not superior for preventing DTEs. Most events occurred within 1 month of switching from DAPT to single-antiplatelet therapy, regardless of DAPT duration. The longest time from the procedure to DTE occurrence was 22 months. Age older than 54.5 years was identified as independent risk factor for DTE-stroke. CONCLUSIONS Compared with short-term DAPT, long-term DAPT delays the occurrence of DTEs but does not lower their incidence. Longer-term DAPT (>9 months) should be considered after stent-assisted coil embolization for unruptured intracranial aneurysms, although its efficacy remains to be clarified.

Long-term outcomes of treatment for unruptured intracranial aneurysms in South Korea: clipping versus coiling

Background The long-term outcomes of endovascular coiling and surgical clipping for the treatment of unruptured intracranial aneurysms are unclear. Methods We performed a nationwide retrospective cohort study using claims data from the Korean Health Insurance Review and Assessment Service on patients undergoing surgical clipping or endovascular coiling from 2008 to 2014. Inverse probability treatment weighting for average treatment effect on the treated and the multiple imputation method were used to balance covariates and handle missing values. The primary outcome was all-cause mortality at 7 years. Results We identified 26 411 patients of whom 11 777 underwent surgical clipping and 14 634 underwent endovascular coiling. After adjustment with the use of inverse probability treatment weighting for average treatment effect on the treated, all-cause mortality rates at 7 years were 3.8% in the endovascular coiling group and 3.6% in the surgical clipping group (HR 1.05; 95% CI 0.86 to 1.28; P=0.60, log-rank test). The adjusted probabilities of aneurysm rupture at 7 years were 0.9% after endovascular coiling and 0.7% after surgical clipping (HR 0.9; 95% CI 0.61 to 1.34; P=0.63, log-rank test). The probabilities of retreatment at 7 years after adjustment were 4.9% in the endovascular coiling group and 3.2% in the surgical clipping group (HR 1.52; 95% CI 1.28 to 1.81; P<0.001, log-rank test). Conclusions All-cause mortality at 7 years was similar between the elective surgical clipping and endovascular coiling groups in patients with unruptured aneurysms who had no history of subarachnoid hemorrhage due to aneurysm rupture.

Nationwide Mortality Data after Flow-Diverting Stent Implantation in Korea

Objective To investigate nationwide statistics on flow-diverting stent usage for cerebral aneurysm treatment and related mortality data. Methods We requested data extraction from the National Health Insurance Service claims database using electronic data interchange codes (J3207064, J3207073). Patient and hospital information as well as death statistics were collected from the database. Results A total of 169 procedures were performed using flow-diverting stents for cerebral aneurysm treatment from November 2014 to December 2016 in Korea. The majority of primary diagnosis was unruptured intracranial aneurysm. During the study period, nine subjects died, including one patient initially diagnosed with subarachnoid hemorrhage. The crude mortality rate was 5.3%. Five patients died within one month after the procedure; therefore, the estimated periprocedural mortality rate was 3.0±1.3%. The mortality rate as of the last day of 2016 was 6.3±2.1%. Conclusion In a 171 person-year follow-up in a Korean series, nine deaths occurred after flow-diverting stent treatment. The crude mortality rate in Korea (5.3%) was higher than that reported in a previous meta-analysis (3.8%).