暂无摘要。

To establish a new method for fast exposure of the internal maxillary artery (IMA) during extracranial-intracranial bypass surgery.
To explore the positional relationship between the IMA and the maxillary nerve and pterygomaxillary fissure, 11 formalin-fixed cadaveric specimens were dissected. Three bone windows of the middle fossa were created for further analysis. Then the IMA length that could be pulled up above the middle fossa was measured after different degrees of removal of bony structure. The IMA branches under each bone window were also explored in detail.
The top of the pterygomaxillary fissure was located 11.50 mm anterolateral to the foramen rotundum. The IMA could be identified just inferior to the infratemporal segment maxillary nerve in all specimens. After drilling of the first bone window, the IMA length that could be pulled above the middle fossa bone was 6.85 mm. After drilling of the second bone window and further mobilization, the IMA length that could be harvested was significantly longer (9.04 mm vs. 6.85 mm; P < 0.001). Removal of the third bone window did not significantly improve the IMA length that could be harvested.
The maxillary nerve could be used as a reliable landmark for the exposure of the IMA in the pterygopalatine fossa. With our technique, the IMA could be easily exposed and sufficiently dissected without zygomatic osteotomy and extensive middle fossa floor removal.

Internal maxillary artery (IMA) bypass has become popularized due to its medium-to-high blood flow, short graft length, and well-matched arterial caliber between donor and recipient vessels.
We described an open surgery of a NEW \"workhorse,\" the IMA bypass, to treat a giant, thrombosed cerebral aneurysm. The extracranial middle infratemporal fossa (EMITF) approach was used to unveil the pterygoid segment of the IMA for cerebral revascularization.
Although this technique is technically challenging, the variations in IMA can be effectively identified and sufficiently exposed in this technique to achieve favorable clinical outcomes with a high bypass patency rate.

BACKGROUND: Embolization of the middle meningeal artery (MMA) is a promising minimally invasive technique that is gaining traction in the treatment of chronic subdural hematoma. Unfortunately, the human meninges and associated arteries are significantly larger than those of conventional laboratory animals, making the development of a clinically relevant animal model for testing of embolization agents elusive.
OBJECTIVE: To introduce the posterior intercostal artery (PIA) model in swine and provide anatomical, angiographic, histological, and procedural data to validate its relevance in modeling the human MMA.
METHODS: In human cadaveric specimens, 3D angiograms of the internal maxillary arteries (n=6) were obtained and the dura with MMA were harvested and histologically processed. Angiographic and histologic data of the human MMA were compared with the swine PIA (three animals). Then, embolization of the PIA (n=48 arteries) was conducted with liquid embolization agent (Onyx, Medtronic), and angiographic and histological results were assessed acutely (four animals) and after 30 days (two animals).
RESULTS: The human MMA has equivalent diameter, length, branching pattern, 3D trajectory, and wall structure to those of swine PIAs. Each swine has 12 to 14 PIAs (6-7 per side) suitable for acute or chronic embolization, which can be performed with high fidelity using the same devices, agents, and techniques currently used to embolize the MMA. The arterial wall structure and the acute and chronic histological findings in PIAs after embolization are comparable to those of humans.
CONCLUSIONS: This PIA model in swine could be used for research and development; objective benchmarking of agents, devices, and techniques; and in the training of neurointerventionalists.

Cerebral revascularization strategies through extracranial to intracranial bypass have been adopted in the management of complex intracranial aneurysms. The internal maxillary artery used as a donor in a bypass is an effective method. At present, there are few quantitative analyses of cerebral blood flow perfusion. The main focus of this study was to evaluate the effectiveness of blood perfusion after bypass grafting.
From April 2015 to December 2017, 19 patients who underwent internal maxillary artery radial artery middle cerebral artery bypass surgery with unobstructed bypass vessels were selected. Cerebral blood flow perfusion before and after bypass surgery was quantitatively evaluated by computed tomography perfusion imaging. The cerebral blood perfusion in the region of interest was measured by computed tomography perfusion.
The aneurysms were excised after trapping in 2 cases with mass effects and neural compression. Proximal occlusion of the parent artery was performed in 9 cases of fusiform or giant dissecting aneurysms. Trapping was performed after bypass surgery in 8 cases. Within 3 months after surgery, 17 patients had good outcomes. After the hypothesis test, there was a significant difference between the preoperative △cerebral blood volume and postoperative △cerebral blood volume in the anterior area of the semioval center cross section (P = 0.001 < 0.05).
The internal maxillary artery as a bypass donor is an effective method that can provide sufficient intracranial blood perfusion, and there is usually no cerebral ischemia in the surrounding area.

BACKGROUND: The internal maxillary artery and extracranial middle meningeal artery are vitally important. Anatomical studies of the relationship of between them using computed tomography angiography are rare.
METHODS: This study assessed 75 cases involving 150 sides. And the vascular diameters and lengths of the internal maxillary artery and middle meningeal artery were measured using a GE workstation. The distance between the zygomatic arch midpoint and the internal maxillary artery, the angle between the internal maxillary artery and middle meningeal artery were measured, and the middle meningeal artery branch and internal maxillary artery aneurysm were recorded. The internal maxillary artery course classifications were recorded. All of these parameters were statistically analysed.
RESULTS: Ages ranged from 18 to 72 (average 40.2) years, and there were 30 women (40%, 30/75) and 45 men (60%, 45/75). Internal maxillary artery length from its origin to middle meningeal artery origin was 1.37 ± 0.59 cm. The extracranial middle meningeal artery length was 1.79 ± 0.48 cm. The vessel diameters of internal maxillary artery origin, middle meningeal artery origin, and middle meningeal artery at the skull base were 2.93 ± 0.52 mm, 1.58 ± 0.43 mm, and 1.33 ± 0.43 mm, respectively. Among the 150 sides of internal maxillary artery course type, there were 138 superficial (92%, 138/150) and 12 (8%, 12/150) deep course cases. The angle between the internal maxillary artery and middle meningeal artery was 116.2 ± 35.76°.
CONCLUSIONS: The findings of this study elucidate the imaging features of the internal maxillary artery and extracranial middle meningeal artery and their relationships, which are helpful for the extracranial-intracranial bypass and endovascular treatment via the internal maxillary artery and middle meningeal artery.

The internal maxillary artery (IMAX) is currently considered one of the main donor vessels in extracranial-to-intracranial bypass surgeries. Four main techniques for harvesting the IMAX have been described: via the anterior medial infratemporal fossa (AMITF), the middle infratemporal fossa (MITF), the anterior lateral middle fossa (ALMF), and the lateral middle fossa (LMF). The advantages and limitations of these techniques have not yet been systematically evaluated and compared.
Twenty-five cadaver specimens were used to evaluate the harvesting technique. The length and the caliber of the targeted IMAX segments, as well as the depth from the operating plane to the IMAX, surgical time, and surgical area of exposure, were analyzed.
The MITF technique provided the greatest operating area of exposure (mean, 3.88 ± 0.97 cm2). The LMF and MITF techniques provided the largest IMAX caliber (mean, 3.1 ± 0.4 mm and 3.0 ± 0.3 mm, respectively). The ALMF technique provided the shallowest operative depth as well as the least time of exposure (21.8 minutes). The MITF technique exposed the longest IMAX segment (mean, 18.8 ± 3.5 mm).
Advantages of the AMITF and MITF techniques include anatomic simplicity, absence of skull base drilling, and greater discretion in muscle dissection. These properties can simplify the anastomosis procedure compared with the ALMF and LMF techniques. Identification of the IMAX pattern is important before selecting the approach for this bypass operation.

暂无摘要。

OBJECTIVE: To investigate the anatomy of the infratemporal fossa (ITF) and to discuss the practicality of endoscopic transvestibular surgery for an ITF tumor.
METHODS: Five fresh cadaveric specimens (10 sides) with vascular silicone injection were prepared for endoscopic anatomy. A transvestibular vertical incision was made along the ramus of the mandible, and pivotal nerves, arteries, and muscles were exposed to sculpt the anatomic landmarks of the ITF.
RESULTS: The endoscopic transvestibular approach exposed the detailed structure of the ITF. The buccinator muscle and the adjoining superior pharyngeal constrictor muscle shaped the paramedian border of the ITF, while the medial pterygoid muscle (MPM) and the lateral pterygoid muscle formed the lateral border. The ITF was delimited by the skull base in the upper margin, and it was proximal to the parapharyngeal space in the inferior part. The inferior alveolar nerve was the first reference point, and the maxillary artery and the lateral pterygoid muscle were also the landmarks of the ITF. The lingual nerve, the eustachian tube (ET), and the middle meningeal artery were also located in the posterior part of the ITF.
CONCLUSIONS: The endoscopic transvestibular approach provides a feasible and facile corridor to the ITF. With accurate hemostasis, this approach may provide another option for accessing the ITF for removal of tumors.

Serpentine aneurysms of the posterior cerebral artery (PCA) treated by the internal maxillary artery (IMA) bypass are rare. Here, the authors report the case of a 34-year-old male patient who presented with a half-year history of gradual severe headache and right-sided limb monoparesis and paresthesia lasting for 1 week. Preoperative angiograms showed a serpentine aneurysm in the left distal PCA, which was treated with internal maxillary artery-radial artery-posterior cerebral artery (IMA-RA-PCA) bypass followed by parent artery occlusion (PAO). The postoperative course was uneventful; radiological images revealed that the aneurysm disappeared, and there was good graft patency and excellent perfusion of the distal PCA territories. To the authors\' knowledge, this is the first and only case of distal PCA serpentine aneurysm to be treated by IMA-RA-PCA bypass followed by proximal PAO. These findings suggest that IMA bypass surgery is a good and feasible treatment option for serpentine aneurysms of the PCA that can preserve the parent artery. Moreover, the anatomic segments of the PCA and different treatment options available for PCA serpentine aneurysms are also discussed in this study.