Sang Hyung Lee

Thromboembolic complications of elective coil embolization of unruptured aneurysms: the effect of oral antiplatelet preparation on periprocedural thromboembolic complication.

OBJECTIVEWe retrospectively evaluated whether antiplatelet preparation lowered the thromboembolic complication rate during the perioperative period. METHODSWe reviewed 328 elective coil embolization procedures in which only microcatheters were used for coiling. No antiplatelet medication was prescribed before the procedure in 95 cases (29%, group 1), whereas antiplatelet therapy was used in 233 cases (71%, group 2; 61 [18.6%] with a single agent [aspirin or clopidogrel] and 172 [52.4%] with both agents). Antiplatelet agents were not given after coiling unless atherosclerosis, severe coil protrusion, or a thromboembolic complication occurred during the procedure. A thromboembolic complication was defined as a procedural thromboembolic event or transient ischemic attack or stroke occurring within 2 days of embolization. RESULTSThromboembolic complications occurred in 11 cases (3.4%): 6 (6.3%) in group 1 and 5 (2.1%) in group 2 (P = .085). In 195 cases (59.5%) treated by the single microcatheter technique, the risk of thromboembolic complications was low and not affected by antiplatelet preparation (1.8% [no preparation] vs 2.2% [preparation]; P = 1.000). However, in 133 cases (40.5%) treated by the multiple microcatheter technique, antiplatelet preparation significantly reduced the thromboembolic complication risk by 85.2% (12.8% [no preparation] vs 2.1% [preparation]; odds ratio, 0.148; 95% confidence interval, 0.027–0.798; P = .023). The aneurysms treated by the multiple microcatheter technique had more complex configurations for coiling (P < .001). The risk of hemorrhage was not increased by antiplatelet preparation (P = .171). CONCLUSIONAntiplatelet preparation lowered the periprocedural thromboembolic complication rate in unruptured aneurysms treated by the multiple microcatheter technique and did not increase the risk of hemorrhage. Therefore, antiplatelet preparation can help to reduce complications in patients in whom technical difficulties are expected without the risk of hemorrhage.

Analysis of the factors influencing bone graft infection after cranioplasty.

BACKGROUND Delayed cranioplasty after decompressive craniectomy was performed using various reconstruction materials and methods. Bone graft infection is a major concern with cranioplasty. This study identified factors that are related to bone graft infection after cranioplasty. METHODS A total of 140 patients underwent reconstructive cranioplasty after decompressive craniectomy between 2000 and 2009. The sample population included 102 male patients and 39 female patients aged 6 years to 76 years, with a mean age of 47.5 years. Autografts were used for cranioplasty when available. Polymethylmethacrylate or customized linear high-density polyethylene was considered when autografts were unavailable. Bone graft infection was defined as the removal of the infected bone graft, and the related factors were evaluated retrospectively. RESULTS Bone graft infection occurred in 11 patients (7.86%). Bone graft infection after cranioplasty was significantly related to the number of operations (p = 0.002), operation time (p = 0.031), and diabetes (p = 0.004). An increased number of operations increased the infection rate from 4.3% to 33%. Infection rates increased rapidly after three times. The infection rate was less than 10% when cranioplasty was completed within 199 minutes. An infection rate greater than 20% was observed when cranioplasty required more than 200 minutes. Other factors, such as graft material, fixation devices, age, sex, the cause of the operation, the interval between craniectomy and cranioplasty, and underlying nondiabetic diseases, did not significantly alter the infection rate. CONCLUSION Short surgical times (<200 minutes) and a lower number of previous operations (less than three times) may decrease the risk of bone flap infection. Careful attention is required when performing cranioplasty, particularly in patients with diabetes. LEVEL OF EVIDENCE Prognostic/therapeutic study, level IV.

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.

The effect of brain atrophy on outcome after a large cerebral infarction

Purpose We retrospectively evaluated the effect of brain atrophy on the outcome of patients after a large cerebral infarct. Methods Between June 2003 and Oct 2008, 134 of 2975 patients with stroke were diagnosed as having a large cerebral infarct. The mean age of the patients was 70 (21–95) y. The mean infarct volume was 223.6±95.2 cm3 (46.0–491.0). The inter-caudate distance (ICD) was calculated as an indicator of brain atrophy by measuring the hemi-ICD of the intact side and then multiplying by two to account for brain swelling at the infarct site. The mean ICD was 18.0±4.8 mm (9.6–37.6). Results Forty-nine (36.6%) patients experienced a malignant clinical outcome (MCO) during management in the hospital. Thirty-one (23.1%) patients had a favourable functional outcome (FO) (modified Rankin scale (mRS) ≤3) and 49 (36.6%) had an acceptable functional outcome (AO) (mRS≤4) at 6 months after stroke onset. In the multivariate analysis, brain atrophy (ICD≥20 mm) had a significant and independent protective effect on MCO (p=0.003; OR=0.137; 95% CI 0.037 to 0.503). With respect to FO, the age and infarct volume reached statistical significance (p<0.001, OR=0.844, 95% CI 0.781 to 0.913; p=0.006, OR=0.987, 95% CI 0.977 to 0.996, respectively). Brain atrophy (ICD≥20 mm) was negatively associated only with AO (p=0.022; OR=0.164; 95% CI 0.035 to 0.767). Conclusions Brain atrophy may have an association with clinical outcome after a large stroke by a trend of saving patients from an MCO but also by interfering with their functional recovery.

An innovative method for detecting surgical errors using indocyanine green angiography during carotid endarterectomy: a preliminary investigation

BackgroundCarotid endarterectomy (CEA) is the most effective treatment method of carotid stenosis or occlusion. Surgeons typically check the blood flow in each vessel using Duplex Doppler ultrasonography or radiocontrast angiography in order to prevent postoperative complications. Embolic cerebral infarction on the ipsilateral side has been reported in 4–7% of patients undergoing CEA despite a tolerable blood flow reported by Duplex ultrasonography. This study was designed to evaluate a new intraoperative method for detecting technical errors during CEA using indocyanine green (ICG) angiography.MethodsSix consecutive patients with severe carotid stenosis or occlusion underwent CEA. Both ICG angiography and Doppler ultrasonography were performed before the carotid arterial incision and after the carotid arterial suture. After injecting ICG dye via an intravenous route, the internal surface, atheroma, and flow defect were visualized with a microscope.ResultsIn ICG angiography, stenotic lesions could be identified as regions of relatively dark signal intensity. Magnified real-time images could be created using a microscope with an infrared filter, including three-dimensional images and detailed images of the inner lumen. These images could then be compared with the results of Doppler ultrasonography. In the six cases assessed by both ICG angiography and Doppler ultrasonography, all Doppler results were acceptable. However, one patient underwent revision surgery because a fluttering atheroma was detected by ICG angiography. ICG angiography could assume the extent of severe stenotic area. ICG angiography could also detect mobile lesions such as a fluttering atheroma.ConclusionsIntraoperative ICG angiography before arteriotomy is useful to determine the precise stenotic area and the shape of the associated plaque. ICG angiography after an arteriotomy site is sutured is also useful for detecting residual stenosis or fluttering atheroma. ICG angiography could be an alternative method to Doppler ultrasonography for ensuring a complete and successful operation and preventing complications.

A technical strategy for carotid artery stenting: suboptimal prestent balloon angioplasty without poststenting balloon dilatation.

BACKGROUND:Traditional carotid artery stenting (CAS) consists of predilatation, optional deployment of embolic protection devices, stenting, and poststent angioplasty. Each step carries a risk of thromboembolism. OBJECTIVE:To design a new and simplified procedural protocol, suboptimal balloon angioplasty without routine poststenting balloon dilatation, and to describe the efficacy this protocol in terms of procedural risks and angiographic and clinical outcomes. METHODS:Over a period of 6 years, 161 carotid artery stenoses in 156 consecutive patients were treated by CAS with embolic protection devices. Among them, 110 lesions in 107 patients (68.3%) were treated by our simplified method (symptomatic, > 50% stenosis; asymptomatic, > 70% stenosis). Overall, 98 lesions (88.3%) had severe stenosis (> 70%). RESULTS:The mean stenosis was reduced from 77% to 10% after CAS. A persistent neurological deficit developed in 2 patients from thromboembolism. Hemodynamic insufficiency developed in 14 lesions during CAS (12.7%). The ipsilateral stroke and mortality rate was 4.5% within 1 month after CAS (asymptomatic, 3.6%; symptomatic, 4.8%). Over a mean of 19 months of follow-up, additive angioplasty was performed in 2 patients as a result of progressive restenosis (≥ 50%). A comparison of the balloon sizes of the prestent angioplasty for group 1 (balloon, ≤ 4 mm) and group 2 (balloon, ≥ 5 mm) showed no difference in restenosis between the groups at 15 months of follow-up after CAS. CONCLUSION:Our CAS technique with suboptimal prestenting angioplasty without routine use of poststenting dilatation is safe, simple, and efficient with acceptable risks.

Epilepsy After Bypass Surgery in Adult Moyamoya Disease

BACKGROUND:Postoperative seizure, well-known in association with other pathologies, has been rarely discussed in adult moyamoya disease. OBJECTIVE:We evaluated postoperative seizures in adult patients with moyamoya undergoing revascularization surgery. METHODS:From 2001 to 2007, 43 adult patients with moyamoya disease underwent 53 revascularization surgeries, consisting of direct bypass with or without indirect bypass. Incidence and profile of postoperative seizures were investigated, with evaluation of influencing factors. Multivariable analysis using a generalized estimation equation was performed to determine which factors were related to postoperative seizure. RESULTS:Seizures developed in 10 sides (18.9%) after revascularization for moyamoya disease, including immediate (<24 hours, n = 0), early (1-7 days, n = 5), late (8-30 days, n = 0), and delayed seizures (≥1 month, n = 7). Early and subsequent delayed seizures developed in the same lesions in 2 patients. Seizures developed only in the patients with combined direct and indirect revascularization. Postoperative temporary neurological deficits with imaging abnormalities were significantly related to postoperative nondelayed seizures (P = .02). Delayed seizures were significantly different according to the location of the recipient artery (P = .03), especially with the frontal branches. By multivariable analysis, revascularization using frontal branches trended toward increased incidence of delayed postoperative seizure, with adjusted odds ratio of 13.78 (95% confidence interval, 1.7-114.1). CONCLUSION:In adult patients with moyamoya disease, the incidence of delayed postoperative seizure seems to be higher than that of other pathologies. The delayed, pronounced formation of synangiosis in moyamoya disease may be related to the development of such delayed postoperative seizures, especially when the location of the recipient artery is frontal.

Two-year follow-up of contrast stasis within the sac in unruptured aneurysm coil embolization: progressive thrombosis or enlargement?

BACKGROUND AND PURPOSE: The fate of contrast stasis within an aneurysmal sac after coiling has not been established. We followed and evaluated the potential risks of recanalization of unruptured aneurysms embolized with BPCs for 2 years. MATERIALS AND METHODS: A total of 301 unruptured aneurysms in 252 patients were treated with BPCs. Contrast stasis was observed on initial postembolization angiograms in 104 (34.6%) of these aneurysms. For follow-up, skull images by an angiographic unit (at 3, 9, 15, and 21 months), CE-MRA including TOF source images (at 6, 12, and 18 months), and DSA (at 24 months) were used. RESULTS: In 89 (85.6%) of the 104 aneurysms with contrast stasis, the stasis disappeared on 6-month MRAs and occlusions remained unchanged without recanalization for 2 years. In the remaining 15 (14.4%), recanalization occurred during follow-up. The presence of contrast stasis was not found to be associated with the obliteration rate (P = .641) or packing attenuation (aneurysms without contrast stasis 30.7% ± 11.18 versus aneurysms with contrast stasis 33.0% ± 12.11, P = .113). Contrast stasis was not found to be a risk factor for recanalization (15/104 [14.4%] versus 29/197 [14.7%], P = 1.000). CONCLUSIONS: Contrast stasis is a benign angiographic finding that can disappear within 6 months on follow-up MRA. In addition, contrast stasis was not found to be associated with a low obliteration rate or packing attenuation or to be a risk factor for recanalization. The present study shows that aneurysms with contrast stasis on initial postembolization angiograms are no more likely to recanalize than aneurysms without contrast stasis.

Pressure Measurement in Carpal Tunnel Syndrome : Correlation with Electrodiagnostic and Ultrasonographic Findings

OBJECTIVE This study was done to evaluate the correlation between carpal tunnel pressure (CTP), electrodiagnostic and ultrasonographic findings in patients with carpal tunnel syndrome (CTS). METHODS CTP was measured during endoscopic carpal tunnel release (ECTR) for CTS using Spiegelberg ICP monitoring device with parenchymal type catheter. Neurophysiologic severity and nerve cross sectional area were evaluated using nerve conductive study and ultrasonography (USG) before ECTR in all patients. RESULTS Tests were performed in a total of 48 wrists in 39 patients (9 cases bilateral). Maximum CTP was 56.7 +/- 19.3 mmHg (Mean +/- SD) and 7.4 +/- 3.3 mmHg before and after ECTR, respectively. No correlation was found between maximum CTP and either neurophysiologic severity or nerve cross sectional area, whereas we found a significant correlation between the latter two parameters. CONCLUSION CTP was not correlated with neurophysiologic severity and nerve cross sectional area. Dynamic, rather than static, pressure in carpal tunnel might account for the basic pathophysiology of CTS better.

Medial Loop of V2 Segment of Vertebral Artery Causing Compression of Proximal Cervical Root

Objective It is rare that the medial loop in the V2 segment of the vertebral artery (VA) causes compression of the proximal cervical root of the spinal cord without leading to bony erosion and an enlarged foramen. We evaluated the clinical significance and incidence of the medial loop in the V2 segment of the VA. Methods We reviewed the records from 1000 consecutive patients who had undergone magnetic resonance imaging evaluation of the cervical spine between January 2005 and January 2008. The inclusion criteria were that over a third of the axial aspect of the VA located in the intervertebral foramen was inside the line between the most ventral points of the bilateral lateral mass, and that the ipsilateral proximal root deviated dorsally because of the medial loop of the VA. We excluded cases of bone erosion, a widened foramen at the medial loop of the VA, any bony abnormalities, tumors displacing VA, or vertebral fractures. The medical records were reviewed retrospectively to search for factors of clinical significance. Results In six patients (0.6%), the VA formed a medial loop that caused compression of the proximal cervical root. One of these patients had the cervical radiculopathy that developed after minor trauma but the others did not present with cervical radiculopathy related to the medial loop of the VA. Conclusion The medial loop of the VA might have a direct effect on cervical radiculopathy. Therefore, this feature should be of critical consideration in preoperative planning and during surgery.