Barbiturates for cerebral aneurysm surgery

Summary Ninety-two cerebral aneurysm cases treated by clipping under moderate hypothermia are reviewed. Twenty-three of these cases received pentobarbitone during surgery in doses sufficient to render the EEG flat. The overall combined mortality and morbidity (complication rate) among 69 non-barbiturate cases was 21.7%. There were significant differences in results between aneurysms in different anatomical locations. The complication rate among eight middle cerebral artery aneurysm cases was 62.5% and among ten internal carotid artery bifurcation cases 40%, while that among nineteen internal carotid artery cases was 16% and among 27 anterior communicating complex cases 7.4%. The overall complication rate among 23 pentobarbitone cases was 17%. There were no complications among eight middle cerebral artery cases; one of two internal carotid bifurcation cases became hemiplegic following occlusion of the middle cerebral artery at its origin. The complication rate among nine internal carotid cases was 22%. No difficulties were experienced regarding haemodynamic stability or cardiac rhythm while using pentobarbitone at normothermia or at 28 °C. It is suggested that cerebral aneurysms involving the middle cerebral artery which appear to be most at risk may have the most to gain by the prophylactic use of pentobarbitone during surgery.     

Problems of surgical treatment for multiple intracranial aneurysms]

A series of 105 patients presenting with multiple aneurysms and subarachnoid hemorrhage (SAH) were operated on for ruptured and unruptured aneurysms between 1976 and 1984. Clinical factors other than the severity of SAH affecting the outcomes included: 1) Misdiagnosis of the location of a ruptured aneurysm among multiple aneurysms resulted in poor outcomes because of multiple surgical approaches or rebleeding during the acute period. 2) Combinations of aneurysmal locations requiring multiple surgical approaches, such as interhemispheric and transsylvian, during the acute stage caused worse outcomes than with multi-stage surgeries. If an unruptured aneurysm could not be reached during the initial exposure, multi-stage surgery was safe if the ruptured aneurysm had been clipped during the acute period. 3) Complications occurring during unruptured aneurysm surgery. The patient's age, the location and size of the unruptured aneurysms were significant factors in the clinical prognosis. Surgery for unruptured aneurysm caused 1.8% morbidity in patients between 28 and 55 years, but 18.0% morbidity in patients over 56 years of age. Surgery for internal carotid artery aneurysms resulted in 14.8% overall morbidity. Surgery for middle cerebral and anterior cerebral artery aneurysms caused below 5% morbidity. Postoperative morbidity in patients with aneurysms less than 5 mm in diameter was 1.3%, and with aneurysms measuring 10 mm or more, 20%. The optimum treatment for multiple aneurysms with SAH should be based on all factors of the patient's condition, including the unruptured aneurysms.     

Intraoperative factors associated with surgical outcome in patients with unruptured cerebral aneurysms: the experience of a single surgeon

OBJECT: Some well-known predictors of clinical outcomes in patients with ruptured aneurysms are not useful for forecasting outcome in patients with unruptured aneurysms. The goal of this study was to analyze outcomes in patients harboring unruptured cerebral aneurysms in different locations and to create a predictive tool for assessing both favorable outcome and morbidity in a large series of unruptured aneurysms. METHODS: The authors analyzed data from 387 patients with nonruptured intracranial cerebral aneurysms who underwent surgery for clip placement. Intraoperative data were reviewed and seven factors that might influence outcomes were identified. These included the following: 1) aneurysm size larger than 10 mm; 2) presence of a broad aneurysm neck; 3) presence of plaque calcification near the aneurysm neck; 4) application of clips to more than one aneurysm during the same surgery; 5) temporary occlusion; 6) multiple clip applications and repositioning; and 7) use of multiple clips. The entire group of patients with unruptured aneurysms was divided into two subgroups on the basis of outcome. Each patient was subsequently assessed to formulate the factor accumulation index (FAI), the sum of different factors observed in a given patient. The subgroup of patients with expected outcomes was composed of 312 patients, whereas the subgroup of unexpected outcomes consisted of 31 patients. Depending on the anatomical locations of the aneurysms, the combined mortality-morbidity rate ranged from 5.7 to 25%, with the best results for patients harboring ophthalmic artery aneurysms and the worst results for those with vertebrobasilar system (VBS) aneurysms. The majority of patients with expected outcomes who harbored aneurysms of the middle cerebral artery, the internal carotid artery, and the VBS had a lower FAI, whereas the majority of patients with unexpected outcomes had a higher FAI. CONCLUSIONS: It is possible to predict outcomes in patients with unruptured cerebral artery aneurysms by calculating the FAI. The rate of postoperative morbidity increases with the FAI within the range of three to four factors.     

Delayed ischemic deterioration in patients with early aneurysm operation and intravenous nimodipine

A consecutive series of 100 individuals with aneurysmal subarachnoid hemorrhage were subjected to early aneurysm operation followed by subsequent intravenous administration of the calcium antagonist nimodipine during the critical period for symptomatic vasospasm. A total of 85 patients were in Hunt and Hess neurological Grades I through III, and 15 were in Grade IV or V before operation. In 39 individuals the aneurysm was located in the anterior cerebral artery complex (ACA), in 29 it originated from the internal carotid artery complex (ICA), and in 32 individuals the ruptured aneurysm arose from the middle cerebral artery (MCA). Of the patients, 71% made a good neurological recovery; the morbidity was 22%, and the mortality was 7%. Of the Grade I-III patients, 79% made a good neurological recovery, and the mortality was 6%. Delayed ischemic cerebral deterioration with permanent dysfunction occurred in five patients, all with ruptured ACA aneurysms. No single patient in the ICA or MCA populations developed delayed ischemic deterioration with fixed neurological deficit despite the presence of several potential risk factors, especially among the MCA aneurysm patients.     

Continuous monitoring of regional cerebral blood flow during temporary arterial occlusion in aneurysm surgery

OBJECT: Temporary arterial occlusion (TAO) during aneurysm surgery carries the risk of ischemic sequelae. Because monitoring of regional cerebral blood flow (rCBF) may limit neurological damage, the authors evaluated a novel thermal diffusion (TD) microprobe for use in the continuous and quantitative assessment of rCBF during TAO. METHODS: Following subcortical implantation of the device at a depth of 20 mm in the middle cerebral artery or anterior cerebral artery territory, rCBF was continuously monitored by TD microprobe (TD-rCBF) throughout surgery in 20 patients harboring anterior circulation aneurysms; 46 occlusive episodes were recorded. Postoperative radiographic evidence of new infarction was used as the threshold for failure of occlusion tolerance. The mean subcortical TD-rCBF decreased from 27.8+/-8.4 ml/100 g/min at baseline to 13.7+/-11.1 ml/100 g/min (p < 0.0001) during TAO. The TD microprobe showed an immediate exponential decline of TD-rCBF on clip placement. On average, 50% of the total decrease was reached after 12 seconds, thus rapidly indicating the severity of hypoperfusion. Following clip removal, TD-rCBF returned to baseline levels after an average interval of 32 seconds, and subsequently demonstrated a transient hyperperfusion to 41.4+/-18.3 ml/l 00 g/min (p < 0.001). The occurrence of postoperative infarction (15%) and the extent of postischemic hyperperfusion correlated with the depth of occlusion-induced ischemia. CONCLUSIONS: The new TD microprobe provides a sensitive, continuous, and real-time assessment of intraoperative rCBF during TAO. Occlusion-induced ischemia is reliably detected within the 1st minute after clip application. In the future, this may enable the surgeon to alter the surgical strategy early after TAO to prevent ischemic brain injury.     

Observation of de novo formation and growth of an intracranial aneurysm: a case report

We observed a de novo formation and growth of an aneurysm in a 43-year-old woman who was followed up after treatment of a subarachnoid hemorrhage (SAH). In 2002, the patient, whose mother had a history of SAH, presented with SAH at the age of 36. Three-dimensional computed tomography angiography (3D-CTA) and digital subtraction angiography showed an aneurysm in the right internal carotid-posterior communicating artery. The aneurysm was clipped and postoperative course was uneventful without neurological deficit. The patient was followed up by 3D-CTA and magnetic resonance angiography every 6 months, because of an untreated small aneurysm, 3 mm in diameter, in the left middle cerebral artery (MCA). The MCA aneurysm remained unchanged but a de novo aneurysm, 1.5 mm in diameter, developed in the right anterior cerebral artery (ACA) 6 years after the first surgery. The ACA aneurysm grew to 4 mm in diameter during the following 10 months but the MCA aneurysm remained unchanged. Both aneurysms were clipped in one session. The MCA aneurysm had a smooth wall but the ACA aneurysm had an irregular and thin wall. The postoperative course was uneventful. Young female patients who have developed SAH with familial history, like this case, should receive long-term follow up to check whether a de novo aneurysm has developed.     

Is the aspect ratio a reliable index for predicting the rupture of a saccular aneurysm?

OBJECTIVE: The present retrospective study was undertaken to prove the reliability of the aspect ratio (aneurysm depth to aneurysm neck width) for predicting an aneurysmal rupture. The aspect ratio is considered a better geometric index than aneurysm size for determining the intra-aneurysmal blood flow. METHODS: We measured the aspect ratios and the sizes of aneurysms, as determined by examining angiographic films magnified 1.4x, in 129 patients with ruptured aneurysms and in 72 patients with 78 unruptured aneurysms. After categorizing the aneurysms into four groups on the basis of their locations (aneurysms of the anterior communicating artery, middle cerebral artery, internal carotid artery-posterior communicating artery [ICA-PComA], and other aneurysms), a statistical analysis of ruptured and unruptured aneurysms was performed. RESULTS: The mean aneurysm size was found to be statistically significant in the aneurysms at the ICA-PComA and in locations excluding the anterior communicating artery, the middle cerebral artery, and the ICA-PComA. However, the mean aspect ratio was statistically significant at all four locations. In patients with ruptured aneurysms, no ruptured aneurysms with an aspect ratio of less than 1.0 were found. The distribution of the ruptured group versus the unruptured group with an aspect ratio of less than 1.6 at each location was 13 versus 79%, respectively, at the anterior communicating artery, 11 versus 58% at the middle cerebral artery, 11% versus 85% at the ICA-PComA, and 7 versus 81% at other locations. CONCLUSION: The aspect ratio between ruptured aneurysms and unruptured aneurysms was found to be statistically significant, and almost 80% of the ruptured aneurysms showed an aspect ratio of more than 1.6, whereas almost 90% of the unruptured aneurysms showed an aspect ratio of less than 1.6. This study therefore suggests that the aspect ratio may be useful in predicting imminent aneurysmal ruptures.     

A case of giant aneurysm associated with vertebral fenestration (author's transl)]

A case of giant aneurysm associated with vertebral fenestration was reported. A 18-year-old female had complained of visual disturbance of left eye for past 2 years without headache, nausea and vomiting. Neurological examinations revealed normal except for optic atrophy on the left side. Physiological examinations were normal. Skull plain films showed the small calcification at the left supraclinoid region. Left common carotid angiograms revealed a giant aneurysm at left internal carotid artery measuring 4 X 2 X 2 cm in size, and left middle cerebral artery was poorly visualized. Vertebral angiograms showed the fenestration at left craniospinal junction. Computerized tomograms showed a round, granular high density lesion, and this lesion was clearly homogenously enhanced by contrast medium. It was considered that the direct surgery to this aneurysm might be impossible, because the neck of the aneurysm was located at extradural portion. Ligation of her common carotid artery was performed with Selverstone clamp. Her postoperative course was uneventful, and the postoperative angiograms revealed the reduction of the size of aneurysm. The etiological hypotheses of these cerebral vascular anomalies were briefly discussed.     

Bypass-surgery and coil-embolisation in the treatment of cerebral giant aneurysms

OBJECTIVE: Operative clipping is the most effective method in the treatment of cerebral giant aneurysms. But about 50% of all giant aneurysms are treatable this way. We want to report about eight patients with giant cerebral aneurysms, which were in our opinion "unclippable" without causing ischaemia in depending brain areas. METHODS: We describe eight cases of giant aneurysms of the pericallosal artery (n = 1) the middle cerebral artery (n = 3), the basilar tip (n = 3) and of the upper part of the basilar artery (n = 1). One patient with an aneurysm of the pericallosal artery was treated with an extra-intracranial saphenous vein bypass saphenous bypass, in three cases of middle cerebral artery aneurysms an extra-intracranial bypass was also done combined with a resection of the aneurysm. The four patients suffering from an aneurysm of the basilar artery got an extra intracranial bypass too followed by an occlusion of the aneurysm with GD-Coils. RESULTS: There was no peri-operative mortality and no severe peri- or postoperative complication. The neurological symptoms of all patients were unchanged after the operation. An angiographic control showed a complete obliteration of the aneurysm and a free running bypass in all cases. CONCLUSION: Bypass surgery and combined bypass surgery and coil embolisation are effective methods in the treatment of giant cerebral aneurysms, which can not be treated by clipping alone.     

Intraoperative liquid embolization of an arteriovenous malformation in the basal ganglia and thalamic region

Total three patients with arteriovenous malformation (AVM) in basal ganglia or thalamic region were treated by intraoperative liquid embolizations. These procedures were decided because of repeated hemorrhagic episodes. In the case with AVM in the head of the caudate nucleus which was fed by several anterior perforating arteries originated from anterior cerebral artery (A1 portion) and middle cerebral artery (M1 portion), frontotemporal craniotomy was performed. After the microsurgical dissection of these feeders, one of the feeders lenticulostriate artery, was cannulated with a small-caliber polyethylene catheter, 0.6 mm in outer diameter and 0.3 mm in inner diameter. A small amount of isobutyl 2-cyanoacrylate (IBCA) was injected through the catheter. Same procedure was carried out one month later. Postoperative angiograms revealed about 90% loss of AVM. In two cases with AVM which involved almost entire thalamus, subtemporal craniotomy was done. Feeding vessels which originated from posterior communicating artery and posterior cerebral artery (PCA) were carefully dissected under the operative microscope and one of them was prepared for cannulation with small catheter. When the small amount of IBCA was injected, proximal PCA and internal carotid artery were temporarily occluded. In both cases intraoperative embolization was carried out twice. Postoperative angiograms revealed that the size of AVM was decreased to 20% in one and 40% in the other. Although temporary postoperative deterioration of neurological deficits such as hemiparesis and visual disturbance was slightly noted in all cases, no hemorrhagic episode was experienced for 6 months, 1.5 and 2 years in each after embolization.     

A case of multiple anomalies of cerebral vessels--fenestration of the middle cerebral artery aneurysm of the anterior communicating artery and arteriovenous malformation on the frontopolar region (author's transl)

A case associated with multiple cerebral vascular anomalies, which consisted of fenestration of the middle cerebral artery, arteriovenous malformation and aneurysm of the anterior communicating artery, was reported. A 48 year-old male has been suffering from the left paralysis and mental disorder after the initial attack of subarachnoid hemorrhage, and the second attack resulted in the deterioration of the symptoms. He was admitted to our clinic on October 28, 1974. On neurological examination, mental disorders, such as disorientation, emotional incontinence, amnesia and acalculia, hemiplegia on the left and meningeal irritation signs were observed in admission period. Physical examination was negative. Cerebral angiographic findings were as follows: 1) Moderate vasospasm of the right internal carotid artery at the terminal segment, mild bowing of the anterior cerebral artery and stretching of the frontparietal opercular branches of the middle cerebral artery were observed. 2) Right frontpolar arteriovenous malformation fed by the frontobasal artery and the frontopolar artery, and drained via the aberrant cortical vein into the superior sagittal sinus. 3) Aneurysm of the anterior communicating artery was opacified by left carotid angiography. 4) An abnormal vessel derived from the terminal segment of the right internal carotid artery and terminated at the portion of the sphenoidal segment of the middle cerebral artery. Complete loop was formed between genuine middle cerebral artery and this abnormal artery. He was operated with dissecting microscope on November 11, 1974. The arteriovenous malformation at right frontopolar region was totally removed and aneurysm of the anterior communicating artery was clipped. According to the operative findings, the arachnoid membrane over the right frontopolar region was turbid and adhered to the adjacent tissues. On the contrary, no abnormal findings suggestive of previous subarachnoid hemorrhage were observed around the region of the anterior communicating artery aneurysm. These findings showed that subarachnoidal bleeding was caused by rupture of the arteriovenous malformation of right frontopolar region, but not by the aneurysm on the anterior communicating artery. The postoperative course was uneventful and during the hospitalization the patient starts on rehabilitation therapy. The authors discussed the genesis of fenestration of the middle cerebral artery and relation among these combined vascular anomalies. We inferred that fenestration of the middle cerebral artery arose from the in complete fusion of procursor vascular network in embryonic stage. Additionally, we emphasized that it was necessary to make a distinction between these two terms "fenestration" and "duplication".     

Management strategy for infectious cerebral aneurysms: report of four cases

The surgical and/or endovascular treatment of four patients with infectious cerebral aneurysm associated with infective endocarditis was reported. Two patients presented with intracerebral hemorrhage. One of them, with large hematoma, was treated surgically and the other, with small hematoma, was treated by endovascular surgery. The third patient, with unruptured aneurysm of the distal anterior cerebral artery, was treated by endovascular parent-artery occlusion without neurological deterioration. The fourth patient, with unruptured aneurysm of the distal middle cerebral artery, was initially treated with antibiotics, resulting in stabilization of the aneurysm. However, three weeks after open heart surgery, the aneurysm ruptured, causing a large cerebral hematoma. Despite prompt evacuation of the hematoma and surgical resection of the aneurysm, this patient remained in a vegetative state. Management strategy of intracranial infective aneurysms is discussed.     

Intraoperative angiography during aneurysm surgery: a prospective evaluation of efficacy

OBJECT: Indications for intraoperative angiography during aneurysm surgery remain unclear. To define its use, the authors report the results of a prospective study in which this modality was used in all patients undergoing surgery for intracranial aneurysms. METHODS: Intraoperative angiography was performed prospectively in the surgical treatment of 517 consecutive aneurysms regardless of the lesion's location, size, or complexity. In 64 (12.4%) of 517 aneurysms intraoperative angiography findings prompted a change in surgical treatment. Residual aneurysm (47%) was the most frequent finding leading to clip revision. In 44% of cases, intraoperative angiography revealed vessel compromise. Surgery for aneurysms of the proximal internal carotid artery (ICA) was the most frequently altered, with lesions located at the superior hypophyseal artery (SHA) and clinoidal region having the highest revision rates, eight (40%) of 20 and eight (44%) of 18, respectively. Aneurysm size predicted the need for revision; giant aneurysms (> 24 mm) underwent revision in nine (29%) of 31 cases, whereas large aneurysms (15-24 mm) were revised in 12 (22%) of 54 cases. In a multivariate logistic regression model, factors related to increased revision rates included the SHA and clinoidal locations, as well as giant and large size. Ninety-five patients underwent both intraoperative and postoperative angiography. Five discrepancies were noted (95% accuracy); four were flow-related and one involved a previously unrecognized residual aneurysm. Complications attributable to intraoperative angiography occurred in 0.4% of cases. CONCLUSIONS: Proximal ICA location and large aneurysm size significantly predicted revision of surgery following intraoperative angiography. Unexpected findings, even in less complex locations, are frequently identified on intraoperative angiography. Low complication rates, high accuracy, and the unexpected need for clip readjustments favor a more widespread use of intraoperative angiography.     

Intracranial hematomas following aneurysmal rupture: experience with 309 cases

Three hundred and nine consecutive cases of intracranial hematomas due to aneurysmal rupture--representing 34% of the total number of patients with aneurysms observed in a 12-year period--were evaluated; of these, 211 were submitted to computed tomography scan. Hematomas were present on admission in 71% of patients and occurred at rebleeding in 29%. Ruptured middle cerebral artery aneurysms caused an intracranial hematoma more frequently than aneurysms in other locations. Ventricular hematomas were frequently observed--especially at rebleeding--in cases with anterior communicating artery aneurysms. Basal ganglia hematomas were detected in eight cases with internal carotid bifurcation aneurysms and in three with middle cerebral artery aneurysms. Subdural hematomas were observed in 32 cases, mainly due to ruptured middle-cerebral-artery and internal-carotid-artery aneurysms. As for clinical evolution, a rapid deterioration was observed in 39% of cases and a chronic course in 46%; a subacute deterioration was far less frequent. Delayed deterioration from vasospasm was observed in 8% of cases, and appeared to be related to the amount of subarachnoid bleeding associated with the hematoma. One hundred and forty-two patients were submitted to surgical treatment (evacuation of hematoma together with exclusion of aneurysm); deep coma, poor medical condition, stabilized neurological disability, or combinations of these factors accounted for the high number of patients not operated upon. Regardless of treatment, 24% of patients showed good results and 58% died. Presence of a large hematoma, ventricular hemorrhage, and shift of the ventricles represented significant risk factors, associated with a poor prognosis. A comparison between two groups of patients admitted within 3 days of hemorrhage--47 operated on early, and 149 with delayed treatment--showed that better results were achieved by early operations, especially for cases in Hunt's grades IV and V.     

Bypass – Surgery and Coil – Embolisation in the Treatment of Cerebral Giant Aneurysms

Summary  Objective. Operative clipping is the most effective method in the treatment of cerebral giant aneurysms. But about 50% of all giant aneurysms are treatable this way. We want to report about eight patients with giant cerebral aneurysms, which were in our opinion “unclippable” without causing ischaemia in depending brain areas.  Methods. We describe eight cases of giant aneurysms of the pericallosal artery (n=1), the middle cerebral artery (n=3), the basilar tip (n=3) and of the upper part of the basilar artery (n=1). One patient with an aneurysm of the pericallosal artery was treated with an extra-intracranial saphenous vein bypass saphenous bypass, in three cases of middle cerebral artery aneurysms an extra-intracranial bypass was also done combined with a resection of the aneurysm. The four patients suffering from an aneurysm of the basilar artery got an extra intracranial bypass too followed by an occlusion of the aneurysm with GD-Coils.  Results. There was no peri-operative mortality and no severe peri- or postoperative complication. The neurological symptoms of all patients were unchanged after the operation. An angiographic controll showed a complete obliteration of the aneurysm and a free running bypass in all cases.  Conclusion. Bypass surgery and combined bypass surgery and coil embolisation are effective methods in the treatment of giant cerebral aneurysms, which can not be treated by clipping alone.     

Multiple intracranial aneurysms: determining the site of rupture

A retrospective hospital chart and radiograph review was performed of all patients with multiple intracranial aneurysms seen over a 52-month period. Sixty-nine patients with a total of 205 aneurysms were studied. Among the patients with aneurysms, the incidence of multiple aneurysms was 33.5%. Multiple aneurysms were much more common in women, with a female to male ratio of 5:1 for all patients and 11:1 for patients with three or more aneurysms. Common locations for multiple aneurysms were the posterior communicating artery (22%), middle cerebral artery (21.5%), anterior communicating artery (12%), and ophthalmic artery (11%). However, locations with the highest probability of rupture were the anterior communicating artery (62%), posterior inferior cerebellar artery (50%), and basilar artery summit (50%). The middle cerebral artery was the least likely site for rupture. In contrast to previous studies, in this series irregularity of contour was more important than size in identifying the site of rupture. Using a simple algorithm outlined in the text, it was possible to identify the site of aneurysm rupture in 97.5% of cases.     

Treatment for traumatic aneurysm of the cerebral artery--identification between deteriorating type and spontaneously disappearing type (author's transl)]

Thirty five cases of traumatic aneurysm of the cortical cerebral artery were reviewed in the literatures cited in the references. Five cases of them healed spontaneously without operative treatment (disappearing type), the other cases underwent direct operation of aneurysm, in spite of high operative moltality or mobility (deteriorating type). Recently four cases of traumatic aneurysm of the cortical cerebral artery were treated in our clinic. Three cases which had the aneurysm in the pericallosal artery (1 case) and middle cerebral artery (2 cases) respectively underwent radical operation for treatment as progressively deteriorating type and fourth case which had the aneurysm in the peripheral part of the frontopolar artery was treated by medication as the spontaneously disappearing type until the aneurysm disappeared on the angiogram. According to the review of literatures, it is the most important for the treatment of tramatic aneurysm to know whether disappearing type or deteriorating type, because deteriorating type had bad prognosis without radical operation and the prognosis of disappearing type was excellent without operation. Analysing the clinical signs and angiographical findings of the all cases, the authors found out some specific characteristics of the spontaneously disappearing type. are (1) The aneurysm is found in the relativery late post traumatic stage except for cases caused by penetrating wound, (2) The irregular shape, uneven opacity of the aneurysm without clear neck connecting with pearent artery on angiography, (3) Shape and size of the aneurysm in follow up angiogram (two weeks or more) became smaller, (4) Around of aneurysm, there are not any kind of intracranical hemetoma. According to these results, differential diagnosis between spontaneously disappearing type and deteriorating type was done in the author's four cases and the three cases of deteriorating type were relieved by radical operation without any postoperative disability and one case of spontaneously disappearing type was treated by medical treatment until disappear of aneurysm. It is concluded that traumatic aneurysm of the cortical cerebral artery is relative rare and it is important to know whether deteriorating type or spontaneously disappearing type in order to get excellent results.     

Surgical manipulation of primate cerebral arteries in established vasospasm

It is generally believed that surgery in the face of angiographic vasospasm is dangerous due to an increased incidence of postoperative cerebral ischemia. One theory is that arterial narrowing is exacerbated by surgical manipulation of vasospastic vessels during aneurysm dissection and clipping. This theory was tested in a primate model of cerebral vasospasm and the results reported. Six monkeys underwent baseline cerebral angiography, followed by induction of subarachnoid hemorrhage (SAH) on both sides of the circle of Willis. An equal amount of fresh autologous blood clot was placed around each internal carotid, anterior cerebral, and middle cerebral artery. Six days later, angiography was repeated and the right craniectomy was reopened for clot evacuation and surgical manipulation of the right cerebral arteries, including placement of a temporary aneurysm clip on the right middle cerebral artery. The left cerebral arteries were not exposed or manipulated, and served as controls. Twenty-four hours later angiography was repeated, then the animals were killed. Equal and significant vasospasm (greater than 40% reduction in vessel caliber compared to baseline, p less than 0.05) was seen in the middle cerebral arteries on both sides of the circle of Willis in all animals 6 and 7 days after SAH. There was no significant change in the severity of vasospasm on Day 7 compared with Day 6 in the right cerebral arteries. Increased risk of postoperative cerebral ischemia for surgery in the peak vasospasm period may be due to mechanisms other than increased arterial narrowing precipitated by surgical manipulation.     

Temporary clipping in aneurysm surgery: technique and results

The use of temporary clipping has become an established tool in the armamentarium of the aneurysm surgeon. Our experience with 62 consecutive patients is presented, detailing operative protocols and results. Twenty-two had unruptured aneurysms (35%), 15 were grade I (24%), 16 grade II (25%), five grade III (8%), and four grade IV (7%). The aneurysms were mainly located in the middle cerebral artery (29 patients) and the anterior communicating artery (13 patients). Eleven of our 62 patients (17%) developed a new, persistent postoperative deficit. However, in only one case (2%) was temporary clipping felt to be implicated in the development of the deficit. In three other patients (5%), the effect of temporary clipping, although unlikely, could not be excluded. Overall, 92% of our patients with temporary clipping had good to excellent outcome, with 3% mortality and 5% morbidity. We believe that temporary clipping is a safe procedure that contributes significantly to a better outcome.     

Confirmation of blood flow in perforating arteries using fluorescein cerebral angiography during aneurysm surgery

OBJECT: The authors performed fluorescein cerebral angiography in patients after aneurysm clip placement to confirm the patency of the parent artery, perforating artery, and other arteries around the aneurysm. METHODS: Twenty-three patients who underwent aneurysm surgery were studied. Aneurysms were located in the internal carotid artery in 12 patients, middle cerebral artery in six, anterior cerebral artery in three, basilar artery bifurcation in one, and junction of the vertebral artery (VA) and posterior inferior cerebellar artery in one. After aneurysm clip placement, the target arteries were illuminated using a beam from a blue light-emitting diode atop a 7-mm diameter pencil-type probe. In all patients, after intravenous administration of 5 ml of 10% fluorescein sodium, fluorescence in the vessels was clearly observed through a microscope and recorded on videotape. RESULTS: The excellent image quality and spatial resolution of the fluorescein angiography procedure facilitated intraoperative real-time assessment of the patency of the perforating arteries and branches near the aneurysm, including: 12 posterior communicating arteries; 12 anterior choroidal arteries; four lenticulostriate arteries; three recurrent arteries of Heubner; three hypothalamic arteries; one ophthalmic artery; one perforating artery arising from the VA; and one posterior thalamoperforating artery. All 23 patients experienced an uneventful postoperative course without clinical symptoms of perforating artery occlusion. CONCLUSIONS: Because the fluorescein angiography procedure described here allows intraoperative confirmation of the patency of perforating arteries located deep inside the surgical field, it can be practically used for preventing unexpected cerebral infarction during aneurysm surgery.