Releasing of a Titanium Clamp (Craniofix®) Without Mechanical Defect After Craniotomy for Acute Subdural Hemorrhage / 대한신경손상학회지

After craniotomy, bone flap fixation can be performed using wires, sutures, microplates, and Craniofix®. Well-margined and fixed bone flaps are important not only for postoperative brain protection but also for esthetics. Herein, we report a case of cranioplasty due to bone flap dislocation by Craniofix® clamp loosening after craniotomy with acute subdural hemorrhage removal. Iatrogenic outward force during epidural drain removal adjacent to Craniofix®, insertion of the clamp around the circumference of the bone flap, increased intracranial pressure due to brain swelling and fluid collection, and external shock during postoperative patient management are thought to be the causes of bone flap dislocation. To our knowledge, this is the second reported case of craniotomy with a Craniofix® clamp release.

Iatrogenic Carotid-Cavernous Fistula after Stent Assisted Coil Embolization of Posterior Communicating Artery Aneurysm

Stent assisted coiling (SAC) is a useful technique for the treatment of wide necked complex aneurysm. As the frequency of SAC increases, stent-related complications such as thromboembolism, aneurysm rupture, and vessel rupture have been reported. However, to the best of our knowledge, carotid-cavernous fistula (CCF) after SAC has never been reported. The authors experienced a case of direct CCF after a SAC procedure for treatment of a complex posterior communicating artery (PCoA) aneurysm regrowth, which was treated by clip ligation 12 years before. The patient was managed conservatively and angiograms performed three months after the procedure showed the complete obliteration of the left PcoA aneurysm and the spontaneous disappearance of CCF. Navigation of Solitaire stent lumen with microcatheter can cause unexpected arterial injury, especially when the proximal tip is placed in the curved portion. It seems to be desirable to place the proximal tip of Solitaire stent in the straight portion whenever possible to reduce the risk of inadvertent arterial injury which might be caused by future navigation of stent lumen.

Thromboembolic Event Detected by Diffusion Weighted Magnetic Resonance Imaging After Coil Embolization of Cerebral Aneurysms

OBJECTIVE: The purpose of this study was to evaluate the occurrence rate of diffusion positive lesions (DPLs), and to assess the peri-procedural risk factors for the occurrence of DPLs in patients who underwent coil embolization of cerebral aneurysms. MATERIALS AND METHODS: A total of 304 saccular aneurysms were embolized during a seven-year period from Jan 2007 to Dec 2013. Of these, postoperative diffusion-weighted images were obtained in 186 procedures. There were 100 ruptured aneurysm and 86 unruptured aneurysms. The coiling procedures were as follows: simple coiling in 96, balloon assisted coiling (BAC) in 39, and stent assisted coiling (SAC) in 51 aneurysms. Clinical, angiographic and procedural factors were analyzed in relation to the occurrence of DPLs. RESULTS: Overall, DPLs were observed in 50.5%. In unruptured aneurysms, DPLs occurred in 23.5% of BAC, 41.9% of SAC and 57.7% of simple coiling (p = 0.08). Among ruptured aneurysms, DPLs occurred in 63.6% of BAC, 62.5% of SAC and 54.3% of simple coiling (p = 0.71). DPLs had a tendency to increase in ruptured aneurysms compared with unruptured aneurysms (57% vs. 43%, p = 0.077). Logistic regression analysis revealed that age > 55 years was the only independent risk factor for the occurrence of DPLs. CONCLUSION: DPLs occured more frequently in ruptured aneurysm and at an older age. Although most DPLs are asymptomatic, careful manipulation of cerebral or extracerebral arteries using various endovascular devices is important to reducing the occurrence of DPLs. BAC appeared to reduce occurrence of TE events in patient with unruptured aneurysm.

Analysis of Precedents Related to the Lumbar Disc Herniation / 대한신경손상학회지

OBJECTIVE: Herniated lumbar disc (HLD) is a relatively common disorder, while its causality is a matter of debate. Although there are a few rules in the Korean laws, they are usually nonspecific and comprehensive. By these rules, it is hard to solve the legal conflicts determining the work apportionment. The final judgments may be irrelevant by the inappropriate opinions of the doctors who are not concerned on the work apportionment. METHODS: We searched precedents related to the medical accidents of HLD in the Korean Supreme Court web site. There were 38 precedents related to the HLD from 1990 to 2011. We reviewed types of the court, types of the suits, legal judgments, the point of conflicts, and so on. We tried to find the problems and adequate solution. RESULTS: The Supreme Court made 20 in 38 precedents related to the HLD. The most common precedents were on the industrial insurance. Compensation suits for damages were the next. These two issues constituted about 70% of the precedents related to the HLD. There were other suits on the insurance money, accidental infliction of injury, and a man of national merit. The judgment on the work apportionment was independent to the year of suits, types of the court, and the types of the suits. CONCLUSION: By the precedents on the HLD, we could identify the importance of the doctors' opinion in various legal conflicts. Doctors should have concerns on the work apportionment of a certain trauma or a work objectively in HLDs.

Acute-on-Chronic Subdural Hematoma: Not Uncommon Events

OBJECTIVE: Patients with asymptomatic chronic subdural hematoma (SDH) are prone to fall or slip. Acute trauma on these patients may develop acute subdural bleeding over the chronic SDH. We recently experienced 9 patients with acute-on-chronic SDH. We report the clinical and radiological features of this lesion. METHODS: We retrospectively examined the computed tomographic (CT) scans of 107 consecutive patients who diagnosed as chronic SDH from January 2008 to December 2010. All cases of CSDH were diagnosed on CT with or without MRI scan. RESULTS: Acute-on-chronic SDH is not rare, being 8% of chronic SDH. The most common cause of trauma was a slip in drunken state. Alcoholism with multiple episodes of trauma was one of the prominent histories. Acute-on-chronic SDH appeared as a hyperdense layer of clot with irregular blurred margin or lumps in liquefied hematoma. Single or two burr holes was usually effective to remove the hematoma. CONCLUSION: Repeated trauma may cause acute bleeding over the chronic SDH. It will be helpful to understand the role of repeated trauma as a mechanism of hematoma enlargement.

Postoperative Course and Recurrence of Chronic Subdural Hematoma

OBJECTIVE: Chronic subdural hematoma (CSDH) is known to have a significant recurrence rate. There are different criteria defining the recurrence of CSDH. We evaluated the postoperative course of CSDH and tried to propose the reasonable criteria of recurrence. METHODS: We retrospectively examined the medical records and pre- and postoperative CT scans of 149 consecutive patients who underwent surgery from January 2005 to December 2009. Diagnosis was confirmed by CT scanning or MRI. The postoperative courses were either resolved or recurrent. The resolved CSDH was one of the three types; early resolution, delayed resolution, or late resolution. The recurrent CSDH was one of the four types; recurrence without resolution, early recurrence after resolution, late recurrence after resolution, or recurrent-and-resolved type. RESULTS: The CSDH was resolved within 30 days after surgery in 58 (39%) patients, between 1 to 3 months in 62 (42%), and after 3 months in 11 (7%) patients. The CSDH was recurred in 18 (12%) patients. Late resolution or recurrence was more common in the aged. The recurrent hematoma was seen on the same side in 11 patients, on the different side in 7 patients. Recurrence was significantly more common in the thick hematomas. CONCLUSION: For a working criteria of the recurrence of CSDH, we propose the early recurrence as return of symptoms or reaccumulation of the hematoma after a surgery within 3 months regardless of the location, amount or repeated operations. The late recurrence can be defined as reappearance or enlargement of a liquefied hematoma within the cranial cavity surrounded by the membranes or persistent CSDH beyond 3 months after surgery.

Morphological Characteristics of the Thalamoperforating Arteries

OBJECTIVE: The aim of this study was to investigate the morphological characteristics of the thalamoperforating arteries that arise from the P1 segment of the posterior cerebral artery. METHODS: Thalamoperforating arteries located in the interpeduncular fossa were dissected in 26 formalin-fixed human cadaver brains. We investigated the origin site of thalamoperforating arteries from the P1 segment, number and diameter, and variations in their origin. RESULTS: Thalamoperforating arteries arose from the superior, posterior or posterosuperior surfaces of the P1 segment at the mean 1.93 mm (range, 0.41-4.71 mm) distance from the basilar apex and entered the brain through the posterior perforated substance. The average number was 3.6 (range 1-8) and mean diameter was 0.70 mm (range 0.24-1.18 mm). Thalamoperforating arteries could be classified into five different types according to their origin at the P1 segment : Type I (bilateral multiple), 38.5%; Type II (unilateral single, unilateral multiple), 26.9%; Type III (bilateral single), 19.2%; Type IV (unilateral single), 11.5%; Type V (unilateral multiple), 3.8%. In 15.4% of all specimens, thalamoperforating arteries arose from the only one side of P1 segment and were not noted in the other side. In such cases, the branches arising from the one side of P1 segment supplied the opposite side. CONCLUSION: Variations in the origin of the thalamoperforating arteries should be keep in mind to perform the surgical clipping, endovascular treatment or operation involving the interpeduncular fossa. In particular, unilateral single branch seems to be very risky and significant for surgical technique or endovascular treatment.

Spontaneous Intracranial Epidural Hematoma Originating from Dural Metastasis of Hepatocellular Carcinoma

Spontaneous intracranial epidural hematoma (EDH) due to dural metastasis of hepatocellular carcinoma is very rare. A 53-year-old male patient with hepatocellular carcinoma, who was admitted to the department of oncology, was referred to department of neurosurgery because of sudden mental deterioration to semicoma with papillary anisocoria and decerebrate rigidity after transarterial chemoembolization for hepatoma. Brain computed tomography (CT) revealed large amount of acute EDH with severe midline shifting. An emergent craniotomy and evacuation of EDH was performed. Active bleeding from middle cranial fossa floor was identified. There showed osteolytic change on the middle fossa floor with friable mass-like lesion spreading on the overlying dura suggesting metastasis. Pathological examination revealed anaplastic cells with sinusoidal arrangement which probably led to spontaneous hemorrhage and formation of EDH. As a rare cause of spontaneous EDH, dural metastasis from malignancy should be considered.

Clinical Significance of Intraventricular Hemorrhage in Patients with Ruptured Aneurysms / 대한뇌혈관외과학회지

OBJECTIVE: The purpose of this study was to determine the clinical significance of intraventricular hemorrhage (IVH) in patients with ruptured aneurysms. METHODS: Of 1034 patients who were admitted to our hospital with ruptured aneurysms between 1994 and 2007, 128 (12.4%) had IVHs. The clinical, radiologic characteristics, and surgical outcomes in the IVH group were compared with the no-IVH group. RESULTS: The IVH group had a shorter time interval to admission. The incidence of IVH was significantly higher in patients > 70 years of age (p=0.021), males (p=0.000), alcohol abusers (p=0.039), patients with a Glagow Coma Scale (GCS) 10 cc (p=0.006), rebleeding (p=0.010), and shunt-dependant hydrocephalus (p=0.000) was significantly higher in the IVH group than the no-IVH group. The mortality rate in the IVH group was significantly higher than the no-IVH group (48.4% versus 22.1%). The amount of IVH had an influence on the mortality; IVH involving all of the ventricles (59.7%) and IVH only involving some of the ventricles (33.9%) was associated with a 6.6- and 2.3-fold higher mortality than the no-IVH group, respectively. IVH was significantly associated with a poor surgical outcome; however, this association was not significant in patients with a GCS < or =8, or histories of rebleeding or seizures. CONCLUSIONS: In patients with ruptured aneurysms, IVH reflects the clinical severity of SAH. IVH has a negative influence on surgical outcome, except in patients with a poor clinical status pre-operatively.

Disability Evaluation of the Pain : The Present and Prospect in Korea

OBJECTIVE: Pain has long been regarded as a subjective symptom. Recently, however, some regard a type of intractable chronic pain as a disease. Furthermore, chronic persistent pain becomes a cause of permanent impairment (PI). In 6th edition, the American Medical Association (AMA) Guides has rated the pain as a PI. In Korea, pain has been already been rated as a PI. Here, we examined the present status and the prospect of disability evaluation for the pain in Korea. METHODS: Pain can be rated as a PI by the Workmen's Compensation Insurance Act (WCIA) and Patriots and Veterans Welfare Corporation Act (PVWCA) in Korea. We examined the definition, diagnostic criteria and grades of the pain related disability (PRD) in these two acts. We also examined legal judgments, which were made in 2005 for patients with severe pain. We also compared the acts and the judgments to the criteria of the 6th AMA Guides. RESULTS: The PRD can be rated as one of the 4 grades according to the WCIA. The provisions of the law do not limit the pain only for the complex regional pain syndrome (CRPS). The PRD can be rated as one of the 3 grades by the PVWCA. If there were objective signs such as osteoporosis, joint contracture and muscle atrophy corresponding to the CRPS, the grade is rated as 6. When the pain always interferes with one's job except easy work, the grade is rated as high as 5. In Korea, judicial precedents dealt the pain as a permanent disability in 2005. CONCLUSION: Although there were no objective criteria for evaluation of the PRD, pain has been already rated as a PI by the laws or judicial precedents, in Korea. Thus, we should regulate the Korean criteria of PRD like the AMA 6th edition. We also should develop the objective tools for evaluation of the PRD near in future.

Prognostic Value of Serum S100 Protein by Elecsys S100 Immunoassay in Patients with Spontaneous Subarachnoid and Intracerebral Hemorrhages

OBJECTIVE: The serum S100 protein has been known to reflect the severity of neuronal damage. The purpose of this study was to assess the prognostic value of the serum S100 protein by Elecsys S100 immunoassay in patients with subarachnoid hemorrhage (SAH) and intracerebral hemorrhage (ICH) and to establish reference value for this new method. METHODS: Serum S100 protein value was measured at admission, day 3 and 7 after bleeding in 42 consecutive patients (SAH : 20, ICH : 22) and 74 healthy controls, prospectively. Admission Glasgow coma scale (GCS) score, Hunt & Hess grade and Fisher grade for SAH, presence of intraventricular hemorrhage, ICH volume, and outcome at discharge were evaluated. Degrees of serum S100 elevation and their effect on outcomes were compared between two groups. RESULTS: Median S100 levels in SAH and ICH groups were elevated at admission (0.092 versus 0.283 microgram/L) and at day 3 (0.110 versus 0.099 microgram/L) compared to healthy controls (0.05 microgram/L; p<0001). At day 7, however, these levels were normalized in both groups. Time course of S100 level in SAH patient was relatively steady at least during the first 3 days, whereas in ICH patient it showed abrupt S100 surge on admission and then decreased rapidly during the next 7 days, suggesting severe brain damage at the time of bleeding. In ICH patient, S100 level on admission correlated well with GCS score (r=-0.859; p=0.0001) and ICH volume (r=0.663; p=0.001). A baseline S100 level more than 0.199 microgram/L predicted poor outcome with 92% sensitivity and 90% specificity. Logistic regression analyses showed Ln (S100) on admission as the only independent predictor of poor outcome (odd ratio 36.1; 95% CI, 1.98 to 656.3). CONCLUSION: Brain damage in ICH patient seems to develop immediately after bleeding, whereas in SAH patients it seems to be sustained for few days. Degree of brain damage is more severe in ICH compared to SAH group based on the S100 level. S100 level is considered an independent predictor of poor outcome in patient with spontaneous ICH, but not in SAH. Further study with large population is required to confirm this result.

Open Surgical Evacuation of Spontaneous Putaminal Hematomas: Prognostic Factors and Comparison of Outcomes between Transsylvian and Transcortical Approaches

OBJECTIVE: The purpose of this study was to investigate the factors affecting the surgical outcome and to compare the surgical results between transsylvian and transcortical approaches in patients with putaminal hematomas. METHODS: Retrospective review of charts and CT scan images was conducted in 45 patients (20 transsylvian and 25 transcortical approaches) who underwent open surgical evacuation of putaminal hematomas. Mean Glasgow coma scale (GCS) score and hematoma volume were 7.5+/-3.2 and 78.1+/-29.3 cc, respectively. The factors affecting the functional mortality were investigated using a multivariate logistic regression analysis. In addition, surgical results between transsylvian and transcortical approaches were compared. RESULTS: None of the patients had a good recovery after the surgery. Overall functional survival rate and mortality were 37.7% and 31%, respectively. The only risk factor for functional mortality was GCS motor score after controlling age, history of hypertension, side of hematoma, hematoma amount, midline shift, presence of intraventricular hemorrhage and surgical approach (p=0.005). Even though a transcortical approach was shorter in operative time (4.4 versus 5.1 hour) and showed a higher mortality rate (40% versus 20%) and lower functional survival (45% versus 35%) compared to the transsylvian approach, the differences were not statistically significant between the two groups. CONCLUSION: In patients who have large amounts of hematoma and require open surgical evacuation, the only significant risk factor for functional survival is the preoperative GCS score. Cortical incision methods such as transsylvian and transcortical approaches have no influence on the surgical outcome. To decompress the swollen brain rapidly, transcortical approach seems to be more suitable than transsylvian approach.

Neuropathic Back Pain : Are There Any Practical Diagnostic Criteria?

OBJECTIVE: A new point of view on the chronic back pain proposed which is, named neuropathic back pain(NBP). Some proposed a certain pain scale as an useful diagnostic tool. Before scientific verification, some doctors prescribed a new anticonvulsant for the NBP. We investigated diagnostic tools for NBP by a review of the literature. METHODS: A comprehensive computer search of the English literature concerning neuropathic low back pain was performed using the key words such as neuropathic back pain and diagnosis in the PubMed. RESULTS: In 1998, the term NBP was first used in a patient with lung cancer. In the English literature, there were two diagnostic methods for the NBP, Neuropathic pain scale(NPS) and a pharmacological test. NPS is a pain questionnaire, which depends on the patients'subjective reports on the given questions, such as 'how hot is your pain feel'. By the pharmacological test, NBP was defined as 50% or more decrease of pain on intravenous lidocaine and on local anesthetic epidurally. It also depends on the patients'subjective response to the therapy. CONCLUSION: There were still no reliable objective diagnostic criteria for the NBP. It seems to be better to reserve the new anticonvulsants for the NBP till scientific approval.

Outcomes in the Management of Spontaneous Cerebellar Hemorrhage

OBJECTIVE: The operative indications on cerebellar hemorrhage have been controversial especially when the patient condition is grave. Therefore we investigated whether it can be justifiable if we perform the surgery in poor clinical grade. METHODS: Clinical records and computerized tomography(CT) films of the 89 patients, who were undergone hospital treatment due to spontaneous cerebellar hemorrhage between May 1997 and May 2004, were retrospectively researched. RESULTS: The study population consisted of 36 males and 53 female patients. The mean age was 65years (range 23~89). As a result of treatment, the patients, whose Glasgow coma scale(GCS) score were higher, showed better outcomes (p=0.001). 13 patients (14.6%) were below 5 in GCS score and 10 patients of these were operated. Among 10 patients, 4 patients (40%) showed good outcome and 5 patients (50%) had been dead. 3 patients (60%) of these dead patients had the findings of intraventricular hemorrhage, fourth ventricular obliteration and hydrocephalus in CT scan. CONCLUSION: This study suggests that operation may be justifiable in clinically poor grade patient with spontaneous intra cerebellar hemorrhage.

Arteriovenous Malformation of the Scalp: Efficacy of Computed Tomography Angiography

We report a rare case of scalp arteriovenous malformation(AVM). A 55-year-old woman presented with a pulsatile palpable mass on her left temporo-parietal scalp. She complained of insomnia because of bruit, which was audible when she lay on her left side. Computed tomography angiography(CTA) for the scalp vessel showed AVM on the left temporo-parietal region. Multiple enlarged arteries, such as the superficial temporal artery, posterior auricular artery, and occipital artery, were directly connected to the elongated dilated superficial temporal vein. Digital subtraction angiography also showed similar results. Fistulous portions were clearly delineated on both modalities. Surgical excision of the malformations, including feeding arteries and the draining vein, resulted in immediate relief of the symptoms. Usefulness of CTA in the diagnosis of vascular lesions on the scalp was emphasized.

Endodermal Cyst of the Posterior Fossa

We report a case of endodermal cyst of the posterior fossa. A 44-year-old man presented with headache for three months. Computed tomography and magnetic resonance imaging revealed a 6x2.5x2cm sized extra-axial non-enhancing cystic lesion on the ventral aspect to brain stem. To avoid retraction injury to brain stem, far lateral transcondylar approach was selected. Right suboccipital craniotomy and partial removal of occipital condyle with resection of C-1 and C-2 hemilaminae exposed the extra-axial cyst well. The cyst has a whitish thick membrane. It was not adherent to brain stem and lower cranial nerves. Total removal of the cyst was done without difficulty. Histological analysis disclosed a layer of pseudostratified columnar epithelium with basement membrane. The result of immunohistochemical study was consistent with endodermal cyst.

Significance of an Early Clinical Course during the External Ventricular Drainage in Thalamic Hemorrhage

OBJECTIVE: The purpose of this study is to investigate the significance of an early clinical course during the external ventricular drainage(EVD) in patients with thal amic hemorrhage. METHODS: During the last 11 years(1990-2000), a hundred patients with thalamic hemorrhage who underwent EVD were studied. Thirty-four patients underwent temporary closing of EVD at the mean interval of 4.5 days after EVD. The clinical course was divided into 3 groups according to change of Glasgow Coma Scale(GCS) scores of 2 or more within 3 days after EVD compared with those just before EVD: deteriorated, unchanged, and improved. RESULTS: The factors affecting mortality were unchanged(odds ratio [OR] 0.05, 95% confidence interval [CI]0.01-0.38, p=0.0028) and deteriorated clinical course(OR 0.06, 95% CI 0.01-0.38, p=0.0033), GCS scores at the time of admission(OR 1.3, 95% CI 1.02-1.66, p=0.0346), amount of hematoma(OR 0.91, 95% CI 0.83-1.00, p=0.0461) and hematoma enlargement(OR 0.06, 95% CI 0.01-0.65, p=0.0198). The factor affecting the early clinical deterioration was the hematoma enlargement(OR 0.11, 95% CI 0.03-0.38, p=0.0005). The shunt operation was predicted in patients who showed the clinical improvement after EVD followed by the clinical deterioration within 48 hours after temporary closing of EVD. CONCLUSION: It is suggested that an early clinical course during the maintenance of EVD is important to predict mortality and necessity of shunt operation.

Outcome of Percutaneous Vertebroplasty Assessed by Ambulatory Scale in Patients with Osteoporotic Vertebral Compression Fractures

OBJECTIVE: The purpose of this study is to evaluate the outcome of percutaneous vertebroplasty based on the ambulatory scale, classified at our institution, and to determine the factors influencing on prognosis of vertebroplasty. METHODS: We retrospectively reviewed a consecutive patients undergoing percutaneous vertebroplasty between June 1999 and December 2001. A total of 151 patients underwent percutaneous vertebroplasty. We investigated the effects of clinical and radiological variables on ambulatory outcome of percutaneous vertebroplasty. RESULTS: Ambulatory status was improved in 94.7% and 88.7% of the patients at postoperative 1 day and last follow-up, respectively. Symptom duration, the remain of vertebral body height, the level and numbers of procedure, the amount of PMMA and presence of PMMA leakage did not influence on the ambulatory outcome of vertebroplasty(p>0.05). A stepwise logistic regression analysis demonstrated that preoperative ambulatory score and the severity of osteoporosis were important prognostic factors at postoperative 1 day, while only the patients' age was a significant prognostic factor at last follow-up, in patients with osteoporotic compression fractures. CONCLUSION: Percutaneous vertebroplasty can be an effective treatment modality for improvement in ambulatory status in patients with osteoporotic vertebral compression fractures, especially when the osteoporosis is severe and preoperative ambulatory score is low. At long term follow-up, only patients' age has an important prognostic value.

Transient Paraparesis After Laminectomy in a Patient with Multi-Level Ossification of the Spinal Ligament

Acute neurologic deterioration is not a rare event in the surgical decompression for thoracic spinal stenosis. We report a case of transient paraparesis after decompressive laminectomy in a 50-yr-old male patient with multi-level thoracic ossification of the ligamentum flavum and cervical ossification of the posterior longitudinal ligament. Decompressive laminectomy from T9 to T11 was performed without gross neurological improvement. Two weeks after the first operation, laminoplasty from C4 to C6 and additional decompressive laminectomies of T3, T4, T6, and T8 were performed. Paraparesis developed 3 hr after the second operation, which recovered spontaneously 5 hr thereafter. CT and MRI were immediately performed, but there were no corresponding lesions. Vascular compromise of the borderlines of the arterial supply by microthrombi might be responsible for the paraparesis.

Clinical Significance of Routine Cerebral Angiography after Cerebral Aneurysm Surgery

OBJECTIVE: To identify the clinical significance of routine postoperative angiography, the incidence of residual aneurysms after clipping and the risk factors related to the occurrence of residual aneurysm are investigated. METHODS: Of 255 patients who underwent aneurysm clipping between 1999 and 2002, ninety one patients underwent routine angiography after aneurysm clipping by one surgeon. There were 104 aneurysms in these 91 patients. Postoperative angiography were reviewed. RESULTS: Of the 104 aneurysms, 9 (8.7%) had aneurysmal remnant on postoperative angiography. Incomplete clipping was intentionally performed in 4 aneurysms more than 10mm in size and in one basilar tip aneurysm. The remaining 4 aneurysms had unexpected remnant of sac, which was anterior choroidal artery aneurysm in 1 and anterior communicating artery aneurysms projecting superiorly or posterior-superiorly in 3. Thus, the true incidence of residual aneurysm was 3.8% (4/104 aneurysms). Logistic regression analysis showed the size of aneurysm as the only risk factor of residual aneurysm. Occlusion or narrowing of major artery was noted in 4.8%. Even though we had re-adjusted the clip in two cases because of parent arterial narrowing on postoperative angiography, two patients died due to cerebral infarction. CONCLUSION: Routine postoperative angiography has little clinical significance in view of the incidence and management of the residual aneurysm or major arterial narrowing/occlusion. Postoperative angiography seems to be necessary in limited patients after aneurysm surgery.