Rewritten from a professional paper published by the authors: “Treatment of anterior communicating artery aneurysm by microsurgery through the brow-lock foramen”: Chinese Journal of Surgery, Vol. 50, No. 5, 2012 p477-p478, originally published by Wang Hui, Li Wensheng, Cai Meiqin, et al.
Anterior communicating artery aneurysms are highly prevalent, and craniotomy microclamping is an exact and reliable treatment. With the further development of microsurgery, the advanced, feasibility and minimally invasive nature of microsurgery using the “locking hole” approach to treat intracranial aneurysms has been proved by clinical practice. The anterior communicating artery aneurysm treated by transbrow locking foramen in our department has good results, which are summarized as follows.
Information and methods
1.General information
From October 2009 to August 2011, 16 cases of anterior communicating aneurysm treated by transbrow-lock foramen were collected, including 6 male and 10 female cases, aged 30-76 years old, with an average of 43.1 years old. All of them had a history of subarachnoid hemorrhage, including 2 cases with 2 hemorrhages. There were 16 anterior communicating artery aneurysms, with aneurysm diameters of 2,4~11 mm, and the dominant blood flow was right-sided in 9 cases and left-sided in 7 cases, including 6 cases with anterior cerebral artery defect on the opposite side.
2.Surgical method
The incision started from the lateral aspect of the supraorbital foramen and was about 5 cm long (Figure 1). The size of the bone flap was about 2,5×2 cm (Figure 2). The dura was cut to reveal the aneurysm-carrying artery and the aneurysm. A suitable aneurysm clip was selected to accurately clip the aneurysm neck. The dura was tightly sutured before closing the skull, the bone flap was retracted without drainage, the muscle was sutured in layers, and the skin was sutured intradermally with 4-0 cosmetic thread (Figure 3).
Figure 1 Surgical incision Figure 2 Bone window size Figure 3 Surgical scar (7 days after surgery)
Results
All 16 cases of aneurysm were successfully clamped in one operation. One of them was temporarily blocked the aneurysm-carrying artery for 9 min, and the aneurysm was separated and the neck was accurately clamped. The aneurysm was separated and the neck of the aneurysm was accurately clamped. There was no permanent limb paralysis after the operation. There was no cerebral infarction in this group, and all 15 cases returned to normal work and life after 3-24 months of follow-up, and one patient in preoperative coma survived vegetatively.
Figure 4 Preoperative CTA showing anterior communicating artery aneurysm (arrow) Figure 5 Postoperative CTA showing aneurysm clamped and no stenosis in the remaining artery
Discussion
1. Exposure of the anterior communicating artery complex through the brow-lock foramen
Reisch et al. have made a detailed study of the extent of exposure through the transbrow-lock foramen, through which the arterial ring at the base of the skull can be seen. Our intraoperative findings confirm the previous report. For anterior communicating artery aneurysms, this approach is fully adequate.
The locked foramen is more beneficial to the protection of brain tissue than the conventional bone window opening, and the rest of the brain tissue is under the protection of the skull when the brain is retracted 2-3 cm with an automatic retractor. All cases in this group obtained sufficient space after releasing cerebrospinal fluid. Therefore, for anterior communicating artery aneurysms, the transbrow-lock foramen approach can be used except for those with large hematomas that require decompression by debridement after bleeding.
2. Control of intraoperative aneurysm rupture bleeding by transobturator approach
Intraoperative aneurysm rupture is the most dangerous situation in aneurysm surgery, so a detailed preoperative surgical plan is especially important.
A careful reading of the pointing of the aneurysm can determine the ease of intraoperative aneurysm management and the chance of rupture. Anterior communicating aneurysms that point inferiorly and anteriorly have a greater chance of intraoperative rupture. However, satisfactory closure can be obtained by blocking the aneurysm-carrying artery, gentle microdissection, and selection of an appropriate aneurysm clip.
The choice of the side from which the brow clothoid is entered is also critical for possible rupture bleeding. In general, it is preferable to choose the side with the dominant blood flow to facilitate the fastest access to the aneurysm neck and gain initiative.
If the aneurysm ruptures intraoperatively, there is no need to panic, as the operator’s composure is crucial to the patient’s prognosis at this time. It is advisable to immediately clean the operative field with a double suction device, temporarily block the A1 bilaterally, quickly separate the aneurysm neck, and clamp it closed. In our group, one case showed intraoperative rupture, which took 9 minutes to handle. The patient recovered well after surgery and the clamping was satisfactory on CTA review. Our experience is that the transbrow-locked foramen approach is adequate for emergency situations of anterior communicating aneurysms.
3. The transbrow-locked approach has its corresponding indications
The transbrow-lock foramen has obvious advantages compared with other surgical approaches: (1) it reduces or even avoids brain traction through the natural gap, which reduces complications. ②Short operation time, fast postoperative recovery, short hospital stay and lower cost. ③No damage to the frontal branch of facial nerve, which eliminates facial paralysis. ④No skin preparation (hair shaving and eyebrow scraping) and absorbable thread suture without stitch removal, which is in line with people’s aesthetics.
There are many difficulties that may be encountered in transbrow locking hole surgery. Therefore, we believe that the transbrowlaparoscopic approach is suitable for aneurysms in and around the anterior communicating artery complex, and it is not advisable to generalize its application from the point to the surface, otherwise it will be counterproductive and contrary to the original purpose of minimally invasive surgery.