Anterior paraclinoid aneurysms

OBJECT: The characteristics of a previously unclassified paraclinoid aneurysm arising from the anterolateral (dorsal) wall of the proximal internal carotid artery were retrospectively analyzed in seven patients (five women and two men) who were treated surgically for an aneurysm in this unusual location. METHODS: One patient presented with subarachnoid hemorrhage (SAH) caused by rupture of this aneurysm. The lesions were found incidentally (five cases) or during investigation of SAH due to another aneurysm (one case). There was a female predominance in this series; all female patients harbored multiple aneurysms. All patients underwent surgery. Removal of the anterior clinoid process was necessary because the proximal neck of the aneurysm was closely adjacent to the dural ring. CONCLUSIONS: This special group of aneurysms is very rare, is located exclusively in the intradural space, and carries the risk of SAH. The results of surgical treatment for this aneurysm are quite satisfactory.     

Ventral paraclinoid carotid aneurysms

A series of 15 patients with 17 ventral paraclinoid carotid artery aneurysms is presented. With this type of aneurysm the neck is at or just distal to the level of the ophthalmic artery and proximal to the posterior communicating artery on the ventral surface of the carotid artery. There is a high incidence of female patients and multiple aneurysms. At surgery, the aneurysms are hidden by the anterior clinoid process and often have an intracavernous component. The neck of the aneurysm is usually intradural and can be clipped.     

Endovascular treatment of paraclinoid aneurysms

BACKGROUND: Paraclinoid aneurysms include those that are distal to the cavernous segment of the internal carotid artery and proximal to the posterior communicating artery. The purpose of this study was to review our experience with the endovascular treatment of this group of aneurysms, which are difficult to treat surgically. METHODS: Between June 1994 and April 1999, 66 patients (56 female, 10 male) with a mean age of 50.1 years (range 13-75, median 51) underwent endovascular treatment for 71 paraclinoid aneurysms. The mean size of the dome was 8.9 mm (range 3-25 mm, median 7) and the of neck was 3.8 mm (range 1.4-8 mm, median 4). Thirteen patients presented with acute subarachnoid hemorrhage, and 4 with previous subarachnoid hemorrhage. Six aneurysms produced mass effect with visual symptoms, 4 presented with transient ischemic attacks, and 44 were incidental. Nine patients had had previous unsuccessful surgery. All procedures were performed under general anesthesia and with systemic heparinization. RESULTS: Ninety endovascular procedures were performed on 71 aneurysms: GDC coiling in 78 (including 45 with the remodeling technique), permanent balloon occlusion in 9, and 3 had both GDC coiling and permanent balloon occlusion. In ten aneurysms it was not possible to place coils in the lumen of the aneurysm with the available technology and balloon occlusion was not indicated. Five of these were treated surgically and 5 remain untreated. All patients had immediate post procedure angiography. Of the 61 aneurysms that were treated, 46 (75%) have angiographic follow-up of 6 months or more. Morphological outcome following endovascular therapy for 61 aneurysms at last available follow-up showed > 95% occlusion in 52/61 (85.2%) and <95% in 9/61 (14.8%). Eight patients required surgery, 2 for partial coiling, 2 for refilling of a neck remnant, 2 for persistent mass effect and 2 for coil protrusion. In the 90 procedures performed, 2 (2.2%) patients had major permanent deficits (1 monocular blindness, 1 hemiparesis), 1 (1.1%) had a minor visual field cut, and 2 (2.2%) patients died from major embolic events. CONCLUSION: Properly selected paraclinoid aneurysms can be successfully treated by endovascular technology. The morbidity and mortality rate of the endovascular approach in our experience is equal to or better than the published surgical series of similar aneurysms. We recommend that the endovascular approach be given primary consideration in the treatment of paraclinoid aneurysms.     

Ruptured anterior communicating artery aneurysms associated with fenestration of the anterior cerebral artery

Two patients with ruptured anterior communicating artery aneurysms associated with fenestration of the anterior cerebral artery are reported. In the literature, only 12 angiographic demonstrations of fenestration of the anterior cerebral artery have been reported. All fenestrations were limited to the distal half of the A1 portion, and seven of the 12 cases were associated with aneurysms. The high incidence of coexisting fenestration and aneurysm suggests that congenital factors may play a role in the pathogenesis of cerebral aneurysm.     

Surgical nuances of giant paraclinoid aneurysms

Paraclinoid aneurysms constitute formidable surgical challenge. The complex surgical anatomy and several factors such as size and projection of the lesion, choice of the surgical approach, relationships between the aneurysm and perforator vessels, site of proximal control, and potential improvement or worsening of visual symptoms account for these difficulties. In such complex cases, surgical nuances frequently determine the final outcome. In this paper, the authors present a comprehensive review of the tricky regional anatomy and describe the operative nuances one of the senior authors (E. dO.) has used to operate on these complex lesions.     

Unruptured paraclinoid aneurysms: a management strategy

OBJECT: To elucidate an optimal managenent strategy for unruptured paraclinoid aneurysms, the authors retrospectively reviewed their experience in the treatment of 100 patients who underwent 112 procedures for111 paraclinoid aneurysms performed using direct surgery and/or endovascular treatment. METHODS: Between 1997 and 2002, 111 unruptured paraclinoid aneurysms categorized according to a modified al-Rodhan classification (Group la, 30 anterior wall lesions; Group lb, 25 ventral paraclinoid lesions; Group IL 18 true ophthalmic artery lesions; Group III, 37 carotid cave lesions; and Group IV, one transitional lesion) were treated by direct surgery (35 lesions) and/or endovascular treatment (77 lesions) (one aneurysm was treated by both procedures). In lesions in Groups Ia, Ib, II, and III that were treated by endovascular treatment, complete aneurysm obliteration was achieved in 50, 65, 50, and 78%, respectively, and the combined transient and permanent morbidity rates due to cerebral embolic events were 20, 25, 20, and 13.9%, respectively. Overall, the transient morbidity rate after endovascular treatment was 14.3% and the permanent morbidity rate was 6.5%. Notably, permanent visual deficits caused by retinal embolism occurred after endovascular treatment in two patients with Group II aneurysms. Direct surgery was mainly performed in Groups Ia (20 lesions), Ib (five lesions), and II (eight lesions), with complete neck clip occlusion achieved in 80, 80, and 71.4%, respectively; the transient and permanent morbidity rates associated with aneurysms treated by surgery were 8.6 and 2.9%, respectively. CONCLUSIONS: Endovascular therapy for superiorly projecting paraclinoid aneurysms (Groups Ia and II) is associated with lower rates of complete obliteration than direct surgery, and with rates of cerebral embolic events comparable to those of endovascular treatment in the other groups. Furthermore, endovascular treatment for Group II aneurysms entails additional risks of retinal embolism. Therefore, direct surgery is recommended for the treatment of paraclinoid aneurysms projecting superiorly. For other groups, especially for Group III, endovascular treatment is the acceptable first line of therapy.     

Radiometric analysis of paraclinoid carotid artery aneurysms

OBJECT: Classification of paraclinoid carotid artery (CA) aneurysms based on their associated branching arteries has been confusing because superior hypophyseal arteries (SHAs) are too fine to appear opacified on cerebral angiograms. The authors performed a retrospective radiometric analysis of surgically treated paraclinoid aneurysms to elucidate their angiographic and anatomical characteristics. METHODS: A retrospective analysis was made of 85 intradural paraclinoid aneurysms in which the presence or absence of branching arteries had been determined at the time of surgical clipping. The lesions were classified as supraclinoid, clinoid, and infraclinoid aneurysms based on their relation to the anterior clinoid process on lateral angiograms of the CA. The direction of the aneurysms were measured according to angles formed between the medial portion of the horizontal line crossing the aneurysm sac and the center of the aneurysm neck on anteroposterior angiograms. Branching arteries were associated with 68 aneurysms, of which 28 were ophthalmic artery (OphA) lesions (32.9%) and 40 were SHA ones (47.1%); associated branching arteries were absent in 17 aneurysms (20%). Twenty-five aneurysms (29.4%) were located at the supraclinoidal level, 46 (54.1%) at the clinoidal, and 14 (16.5%) at the infraclinoidal. The majority of aneurysms identified at the supraclinoidal level were OphA lesions (44%) or those unassociated with branching arteries (48%), with mean directions of 57 degrees or 67 degrees, respectively. At the clinoidal level, the mean directions of aneurysms were 76 degrees in six lesions unassociated with branching arteries (13%), 43 degrees in 16 OphA lesions (35%), and -11 degrees in 24 SHA ones (52%). All aneurysms at the infraclinoidal level arose at the origin of the SHAs, with a mean direction of -29 degrees, and most of these were embedded in the carotid cave. CONCLUSIONS: Aneurysms arising from the SHA can be distinguished from those not located at an arterial division by cerebral angiography, because SHA lesions are usually located at the medial or inferomedial wall of the internal carotid artery at the clinoidal or infraclinoidal level. Their distribution correlates well with the reported distribution of SHA origins. The carotid cave aneurysm is a kind of SHA lesion that originates at the most proximal intradural CA.     

Ruptured abdominal aortic aneurysms

Eighty two aortic replacements of ruptured abdominal aortic aneurysms have been performed during the last 6 years. There were 72 male and 10 female patients, and the average age was 71.33 years. Hemorrhagic shock on the admission was observed in 45 patients, and 13 have been operated urgently without any diagnostic procedures. The transperitoneal approach have been used for the operation. Two aorto duodenal and one aorto caval fistulas, have been found. Only exploration (three patients died immediately after laparotomy and 6 after cross clamping) has been done in 9 cases, and the aortic replacement in 70 cases (27 with tubular, and 43 with bifurcated graft). In 3 cases and axillobifemoral bypass had to be done. During the operation eleven patients died, and 30 in postoperative period, during the period between one and 40 days. Total intrahospital mortality rate was 50%, compared with 3.5% for 250 electively operated patients with abdominal aortic aneurysms in same period. In postoperative period the most important cause of death was multiple organs failures. Statistically significant greater mortality rate (p > 0.01%) was found in cases of late operative treatment, hemorrhagic shock, intra-operational bleeding, ruptured front wall, suprarenal cross clamping and in patients older than 75 year. In complicated cases such as juxtarenal aneurysm, 3 sutures parachute technique for proximal anastomosis, a temporary transection of the left renal vein, and intraaortal balloon occlusive catheter for proximal bleeding control are recommended.     

Ruptured abdominal aortic aneurysms

A series of 180 consecutive patients with ruptured aortic aneurysms has been studied to determine the causes of death. 18% died before operation could be carried out, 8% proved inoperable and a further 10.5% died before operation could be completed. Overall mortality was 75%. By multivariate analysis, the most significant preoperative features influencing survival were a systolic BP less than 80 mmHg on admission and a history of hypertension, angina or myocardial infarct. The mortality increased with increasing age. Administration of fresh frozen plasma preoperatively significantly increased survival. However, we could not identify a single group of patients for whom the outcome was inevitably fatal.     

Results of microsurgical treatment of paraclinoid carotid aneurysms

The term “paraclinoid aneurysms”, has been used for aneurysms of the internal carotid artery (ICA) between the cavernous sinus and the posterior communicating artery. Due to their complex anatomical relationship at the skull base and because they are frequently large/giant, their surgical treatment remains a challenge. Ninety-five patients harboring 106 paraclinoid aneurysms underwent surgery (1990–2010). Age, 11–72 years old. Sex, 74:21 female/male. Follow-up; 1–192 months (mean?=?51.7 months). Eighty-six patients had single and 9 had multiple paraclinoid aneurysms. Sixty-six were ophthalmic, 14 were in the ICA superior wall, 13 in the inferior, 10 in the medial, and 3 in the ICA lateral wall. Eleven were giant, 29 were large, and 66 were small. Sixty-three patients had ruptured and 32 had unruptured aneurysms. Two patients with bilateral aneurysms had bilateral approaches, totaling 97 procedures. A total of 98.2 % of aneurysms were clipped (complete exclusion in 93.8 %). ICA occlusion occurred in 10 (5.6 %). There was no patient rebleeding during the follow-up period. A good outcome was achieved in 76.8 %, with better results for unruptured aneurysms, worse results for patients with vasospasm, and with no difference according to size. Thirty-six (37.9 %) patients had transient/permanent postoperative neurological deficits (25.4 % ruptured vs. 62.5 % unruptured aneurysms). The most frequent deficits were visual impairment and third cranial nerve palsies. Operative mortality was 11.6 %, all in patients presenting with ruptured aneurysms. Despite relatively high morbidity/mortality, especially for patients with ruptured aneurysms, microsurgical treatment of paraclinoid aneurysm has high efficacy, with better outcome for unruptured aneurysms and worse outcome for patients with vasospasm.     

Microsurgical management of large and giant paraclinoid aneurysms

BackgroundBecause of the complex topographic anatomical relationship between vascular, dural and bone structures, paraclinoid aneurysms, especially those of larger size, remain a great challenge for vascular neurosurgeons. We present our microneurosurgical experience of 51 consecutive patients with large and giant paraclinoid aneurysms to scrutinize our personal strategies related to surgical treatment.MethodsFifty-one patients with large or giant paraclinoid underwent micorneurosurgical aneurysm treatment. Operative strategies were planned according to preoperative state-of-the-art imaging studies, and a pterional-transsylvian approach was routinely used. Proximal control of the internal carotid artery (ICA) was achieved by exposure of the cervical portion of the vessel. Intraoperative electroencephalogram and somatosensory evoked potential monitoring, indocyanine green (ICG) videoangiography and/or microvascular Doppler ultrasonography (MDU) were regularly used. A postoperative digital subtraction angiography or computed tomography angiography was performed to verify the efficacy of treatment.ResultsForty-three large and giant paraclinoid aneurysm necks (84%) were directly clipped, seven unclippable aneurysms (14%) were trapped with extra-intracranial high-flow revascularization, and one aneurysm (2%) was treated with only ICA proximal Hunterian ligation. Two patients (4%) died in the early postoperative period. In 84% of the patients, the Glasgow Outcome Scale score was 4 or 5 at discharge. At the 6-month follow-up examination, the Rankin Outcome Scale score was 0-2 in 90% of patients.ConclusionsTemporary parent vessel occlusion, retrograde suction decompression, endoaneurysmectomy, parent vessel clip reconstruction, and bypass vascular anastomosis are essential techniques to treat complex paraclinoid aneurysms. The combined use of electrophysiological monitoring, MDU, intraoperative ICG videoangiography, and endoscopy can substantially improve microsurgical outcome.