Paraclinoid aneurysms

How I do it-Dolenc approach for clipping of ventral wall paraclinoid ICA aneurysm

BACKGROUND

Ventral wall ICA aneurysms are a type of Paraclinoid aneurysms which arise from ventral surface of ICA opposite to the origin of the ophthalmic artery. These are technically challenging owing to its close proximity to the anterior clinoid process, difficulty in getting proximal control, difficulty in preserving ophthalmic artery and maintaining the patency of ICA.

METHOD

A 38 year old patient with a Ventral wall ICA aneurysm by Dolenc approach.

CONCLUSION

Tailored dural peeling and extradural anterior clinoidectomy exposes proximal part of Paraclinoid ICA allowing better proximal control and a wider exposure, which is crucial for clipping these aneurysms.

The avoidance of microsurgical complications in the extradural anterior clinoidectomy to paraclinoid aneurysms

OBJECTIVE

Paraclinoid segment internal carotid artery (ICA) aneurysms have historically been a technical challenge for neurovascular surgeons. The development of microsurgical approach, advances in surgical techniques, and endovascular procedures have improved the outcome for paraclinoid aneurysms. However, many authors have reported high complication rates from microsurgical treatments. Therefore, the present study reviews the microsurgical complications of the extradural anterior clinoidectomy for treating paraclinoid aneurysms and investigates the prevention and management of observed complications.

METHODS

Between January 2004 and April 2008, 22 patients with 24 paraclinoid aneurysms underwent microsurgical direct clipping by a cerebrovascular team at a regional neurosurgical center. Microsurgery was performed via an ipsilateral pterional approach with extradural anterior clinoidectomy. We retrospectively reviewed patients' medical charts, office records, radiographic studies, and operative records.

RESULTS

IN OUR SERIES, THE CLINICAL OUTCOMES AFTER AN IPSILATERAL PTERIONAL APPROACH WITH EXTRADURAL ANTERIOR CLINOIDECTOMY FOR PARACLINOID ANEURYSMS WERE EXCELLENT OR GOOD (GLASGOWS OUTCOME SCALE : GOS 5 or 4) in 87.5% of cases. The microsurgical complications related directly to the extradural anterior clinoidectomy included transient cranial nerve palsy (6), cerebrospinal fluid leak (1), worsened change in vision (1), unplanned ICA occlusion (1), and epidural hematoma (1). Only one of the complications resulted in permanent morbidity (4.2%), and none resulted in death.

CONCLUSION

Although surgical complications are still reported to occur more frequently for the treatment of paraclinoid aneurysms, the permanent morbidity and mortality resulting from a extradural anterior clinoidectomy in our series were lower than previously reported. Precise anatomical knowledge combined with several microsurgical tactics can help to achieve good outcomes with minimal complications.

Long-term surgical results with aneurysms involving the ophthalmic segment of the carotid artery

Object

Because of the anatomical complexity of the paraclinoid region, the surgical treatment of aneurysms arising in the C6 segment of the internal carotid artery is extremely challenging. The authors' aim in this study was to describe the extended clinical follow-up and assess the short-term and long-term effectiveness of surgical treatment for these aneurysms, focusing on the clinical outcome and degree of aneurysm occlusion and recurrence.

Methods

The authors retrospectively analyzed the clinical records for patients treated surgically between 1973 and 2004 at the University of Rome, “La Sapienza.” Aneurysms were classified into the following 3 groups according to the site where they arose: the anteromedial, anterior or anterolateral, and posteromedial wall of the C6 segment.

Results

Of the 108 aneurysms in 104 patients treated, 63 (58%) were large or giant. Eighty-eight aneurysms in 84 patients were clipped, 16 underwent a high-flow bypass, 2 were trapped, 1 was wrapped, and 1 was left untreated. The mean follow-up was 126 months; 47 patients had a follow-up of > 10 years. Of the 88 aneurysms that were clipped, 6 (6.8%) had an incomplete occlusion that required an immediate reoperation in 1 case and at 2 years in another. Overall 6 patients (5.8%) had surgery-related permanent complications.

Conclusions

Mortality and morbidity rates depend mainly on the patient's preoperative Hunt and Hess grade subarachnoid hemorrhage, whereas surgical morbidity principally reflects excessive manipulation of the optic nerve or ischemic problems due to excessive temporary trapping undertaken without adequate neuroprotection. In expert hands, surgery (clipping and bypass procedures) is a definitive treatment for C6 aneurysms and has an acceptable complication rate.

Large ophthalmic segment aneurysms with anterior optic pathway compression: assessment of anatomical and visual outcomes after endosaccular coil therapy

Object

The optimal therapy for ophthalmic segment aneurysms with anterior optic pathway compression (AOPC) is undecided. Surgical results have been described, but the results of endovascular coil therapy have not been well documented.

Methods

The authors retrospectively reviewed data obtained in all patients who harbored unruptured ophthalmic segment aneurysms with AOPC who underwent endovascular coil therapy at their institution. They analyzed baseline and outcome visual function, aneurysm features, extent of aneurysm closure, internal carotid artery (ICA) occlusion, additional interventions, and neurological outcome.

In 17 patients (16 women), age 38 to 83 years, there were 28 affected eyes. All aneurysms were greater than 10 mm in diameter. In the initial procedures 16 of 17 patients received endosaccular coils and the ICA was preserved; in one patient the aneurysm was trapped and the ICA occluded. Patients then underwent follow up for a mean of 2.90 years (range 1 month–11.2 years) after the last procedure. One patient died of subarachnoid hemorrhage (SAH) 1 month postoperatively and thus no follow-up data were available for this case. Vision worsened in six patients, stabilized in four, and improved in six. Twelve patients underwent 13 subsequent procedures, including endovascular ICA occlusion in seven, repeated coil therapy in five, and optic nerve decompression in one; vision improved in 83% of these cases after ICA occlusion. A second patient died of SAH 5 months after repeated coil treatment. At the final follow up, vision had improved in eight patients (50%), stabilized in four (25%), and worsened in four (25%). In 16 patients with follow-up studies, aneurysm closure was complete in eight (50%) and incomplete in eight (50%).

Conclusions

The authors found that in patients with ophthalmic segment aneurysms causing chronic AOPC, endosaccular platinum coil therapy, with ICA preservation, may not benefit vision and that additional procedures may be needed. Evaluation of their results suggests that endovascular trapping of the aneurysm and sacrifice of the ICA appear to result in good visual, clinical, and anatomical outcomes.

Microneurosurgical management of carotid-ophthalmic aneurysms

OBJECTIVE

To evaluate the management of carotid-ophthalmic segment aneurysms (COA) with modern microneurosurgical techniques and instruments.

METHOD

Sixty patients with COA undergoing microsurgical clipping between March 1994 and June 2002 in the Department of Neurosurgery, Tiantan Hospital, Beijing, were analyzed retrospectively. Neuroimaging included digital subtraction angiography (DSA), MRI, CT, three-dimensional CT angiography and three-dimensional DSA. From 1998, intraoperative Doppler ultrasound monitoring and endoscope-assisted techniques were used.

RESULT

All aneurysms were completely obliterated without either recurrence or death. The morbidity rate of surgery prior to 1998 was 21.7%, which decreased to 13.7% after 1998 (mean 18.3% for the whole study period).

CONCLUSION

Preoperative planning based on neuroimaging is very valuable. Advances in neuroimaging, endoscope-assisted techniques and intraoperative Doppler ultrasound monitoring are useful to decrease postoperative complications. Microneurosurgical techniques are optimal for the management of COA with ever lessening morbidity.

MRI location of the distal dural ring plane: anatomoradiological study and application to paraclinoid carotid artery aneurysms

The distal dural ring plane (DDRP) separates the intradural from the extradural paraclinoid internal carotid artery. The purpose of this study was to evaluate its position with MR imaging. The protocol used a T2-weighted sequence in two orthogonal planes: diaphragmatic (DIA-P) and carotid (CAR-P). The DDRP passes through four anatomoradiological reference points (RefP). We developed on a cadaveric model a correlation method supported by correlation lines and angles (CA) projecting the RefP toward the DDRP. RefP were correlated to the DDRP in 65-84% of cases in the DIA-P and 60-76% of cases in the CAR-P. CA were identified and correlated to the DDRP, respectively, in 87% and 60% of cases in the DIA-P, and 60% and 51% of cases in the CAR-P (failure often related to a lack of visibility of just one RefP). A higher tissular contrast in living subjects allowed the identification of CA in 90% and 80% of cases, respectively, in the DIA-P and the CAR-P. We propose that CA, when identified, should be considered as an approximation of the inferior radiological limit of the DDRP curve. In difficult angiographical cases, this MRI protocol could help to locate paraclinoid aneurysms on both sides of the cavernous sinus roof.

Temporary Aneurysm Orifice Balloon Occlusion as an Alternative to Retrograde Suction Decompression for Giant Paraclinoid Internal Carotid Artery Aneurysms: Technical Note

OBJECTIVE:

Giant paraclinoid carotid artery aneurysms frequently require the temporary interruption of local circulation to facilitate safe clip occlusion. Owing to the brisk retrograde blood flow through the ophthalmic artery and cavernous branches, the simple trapping of the aneurysm by cervical internal carotid artery clamping and intracranial distal clipping may not adequately soften the lesion. Retrograde suction decompression aspiration of this collateral supply by a catheter introduced into the cervical internal carotid artery is a popular method to achieve aneurysm deflation. With a large collateral supply, the method is not effective enough. The advent of relatively long and maneuverable soft balloons allows temporary occlusion of the aneurysm orifice.

METHODS:

We applied this method in two instances of giant carotid ophthalmic aneurysms. In both instances, a 15- to 20-mm-long and 4-mm-wide occlusion balloon was inserted in the internal carotid artery at the level of the aneurysm before craniotomy. After craniotomy and dissection of the aneurysm neck, the balloon was inflated under intraoperative angiographic control.

RESULTS:

The aneurysm became soft enough in both cases without tapping and aspiration to allow safe clip occlusion. In the first case, the postoperative course was uneventful and visual acuity improved. A known additional infraclinoid part of the aneurysm was eliminated endovascularly 5 months later using balloon-protected injection of vinyl alcohol copolymer (Onyx; Micro Therapeutics, Inc., Irvine, CA). In the second case, a postoperative symptomatic vasospasm developed 15 hours after surgery. Hypertensive therapy resulted in the disappearance of symptoms and an otherwise uneventful course with improvement of vision.

CONCLUSION:

This preliminary experience suggests that this new method is a feasible alternative to retrograde suction decompression.

Aneurisma paraclinóideo: técnica cirúrgica e resultados em 51 pacientes

Analisam-se 51 pacientes portadores de 55 aneurismas paraclinóideos (APC) submetidos a tratamento cirúrgico. Em decorrência de tratar-se de procedimento de alta complexidade, descrevemos em pormenor os seus aspectos técnicos. O processo clinóideo anterior foi removido por via extradural após secção da duplicação dural da tenda da fissura orbitária superior e/ou por via intradural. Conseguiu-se exclusão do APC nos 51 pacientes. Em dois casos a clipagem foi parcial e, em três, ocorreu oclusão da ACI. Em 42 (82%) pacientes ocorreu bom resultado; em 5 (10%), incapacidade moderada; em 1 (2%), incapacidade grave e três (6%) faleceram por infarto cerebral. Sete (13,7%) pacientes tiveram lesão adicional do nervo óptico, sendo parcial em 4 (7,7%) e total em 3 (6%).