The occipital artery: a meta-analysis of its anatomy with clinical correlations

Quantitative Analysis of Occipital Artery Bypass Donor Vessels by Ultrasonography and DSA

BACKGROUND

Occipital artery (OA) acts as a vital donor vessel in intra-cranialand extra-cranial bypass. Ultrasonography and digital subtracted angiography (DSA) are becoming increasingly important in the assessment of vascular morphology and hemodynamically; however, quantitative analysis of occipital artery bypass donor vessels by Ultrasonography and DSA are seldom discussed.

METHODS

A retrospective study involving 62 cases accepted occipital artery bypass to treat posterior circulation aneurysms or artery occlusion/stenosis. The characteristics of OA are collected and analyzed.

RESULTS

Occipital artery bypasses were performed to treat posterior circulation aneurysms in 34 patients and to treat posterior circulation artery occlusion or stenosis in 28 patients. Compared with the ultrasonography group, the DSA group had a greater diameter of OA, and Bland Altman analysis indicated that the discrepancy between the 2 groups was about 0.555 mm. Ultrasonography showed the characteristics of OA: the mean Peak Systolic Velocity (PSV) was 42.98 cm/s, the mean End Diastolic Velocity (EDV) was 8.811 cm/s, and the mean Resistance Index (RI) was 1.46. There were no statistical differences in the diameter of OA, PSV, EDV, and RI between the male group and female group, the elderly group and younger adult group or the left occipital artery group and right occipital artery group. However, compared with patients with posterior circulation aneurysms, patients with artery occlusion or stenosis were older and had higher PSV, RI, and greater diameter in occipital arteries. The mean diameter of occipital arteries was increased in the first postoperative years but reduced in 3 patients during 1 year follow-up.

CONCLUSIONS

Both ultrasonography and DSA were effective assessment methods of occipital artery bypasses, and the DSA group had a greater diameter of OA. Age, gender, and left or right sides had little effect on the diameter of OA, PSV, EDV, and RI. Posterior circulation occlusion or stenosis had higher PSV, RI, and greater diameter of the occipital artery when compared with posterior circulation aneurysms. Occipital artery bypasses could increase the diameter of OA in most cases.

First standardized assessment of perforators and perforasomes of the occipital artery - An anatomical study

BACKGROUND

Flaps have become an integral part of plastic and reconstructive surgery. The robust blood supply of such flaps is a prerequisite to reduce flap failure. Despite the reported versatility of the occipital flap, comprehensive anatomical studies on its perforators and perforasomes are lacking. Hence, we examined the perforators originating from the occipital artery and their associated perforasomes, aiming to fill this knowledge gap for reconstructive surgery techniques.

METHODS

39 of 40 occipital arteries of 20 fresh anatomical head specimens were dissected. Perforators with a least an outer diameter of 0.50 mm were identified and injected with dye to color their respective perforasomes. Location and size of the colored skin areas were determined as well as the location of their perforators were documented and analyzed.

RESULTS

In total, 183 perforators were found and described. The mean diameter of these vessels was 0.88 ± 0.27 mm (0.5-2.1 mm). The mean area of the perforasomes was 1288.26 ± 662.51 mm2 (144.60-3890.60 mm2). They were localized over the whole nuchal and occipital area. Lastly, perforator diameters were significantly associated with the size of their resulting perforasomes.

CONCLUSION

This study is the first comprehensive overview of perforators and associated perforasomes of the occipital artery on a respectable amount of specimen. The arterial supply of big portions of the occipital and nuchal area is provided solely by the perforators of the occipital artery. For flap surgery, perforator diameter is a crucial detail to be considered in the decision-making process.

In situ interposition bypass for complex intracranial aneurysms: A single-center experience and efficacy analysis

The purpose of this study was to investigate the application and efficacy analysis of in situ interposition bypass in complex intracranial aneurysms. This study retrospectively analyzed the clinical data of 21 patients with complex intracranial aneurysms treated with in situ interposition bypass grafting in the Department of Neurosurgery at Tianjin Huanhu Hospital from June 2015 to December 2022. The aneurysms were located in the middle cerebral artery in 16 cases, the anterior cerebral artery in 3 cases, the posterior cerebral artery in 1 case, and the posterior inferior cerebellar artery in 1 case. The interposition graft vessels were taken from the radial artery in 15 cases, the superficial temporal artery in 5 cases, and the occipital artery in 1 case. All patients underwent end-to-end anastomosis with in situ interposition bypass after aneurysm resection, including 13 cases of "I-shaped" type, 5 cases of "V-shaped" type, and 3 cases of "Y-shaped" type. Postoperative digital subtraction angiography (DSA) or computed tomography angiography (CTA) reviews were performed for all the patients, and modified Rankin Scale (mRS) score was used to assess patient prognosis. Three patients developed postoperative basal ganglia infarction and two of them recovered well. One case developed transient incomplete aphasia and one case developed mild hemiparesis, which recovered well after 3 months. The remaining 16 patients did not develop new neurological deficits. Postoperative DSA or CTA showed that the anastomosis of the bypass graft and the graft vessels were patent, and all aneurysms were completely eliminated. Regular postoperative follow-up ranged from 3 to 89 months, and no aneurysm recurred. The percentage of patients with mRS ≤ 2 at the final follow-up was 90.5%. Based on the experience of surgical treatment in our center, in situ interposition bypass technique is a safe and effective option for the treatment of some complex intracranial aneurysms.

Use of Proximal Suboccipital Segment of Occipital Artery as Donor for Posterior Circulation Revascularization Surgery: Technical Note

BACKGROUND

The distal suboccipital segment of the occipital artery is commonly used as a donor vessel for aneurysms of the posterior circulation requiring revascularization techniques. Isolating this segment of vessel can be challenging due to its course in and out of the various layers of the suboccipital musculature.

METHODS

We describe the use of the proximal suboccipital segment of the occipital artery within the occipital groove at the lateral skull base as a donor segment for an interposition graft in revascularization surgery. We present a case detailing the use of this technique for treatment of a dissecting PICA aneurysm and photographs from cadaveric dissections demonstrating relevant anatomy.

RESULTS

Our patient is a 62-year-old man who presented with a high-grade subarachnoid hemorrhage from a proximal dissecting-type aneurysm of the posterior inferior cerebellar artery (PICA). Endovascular options were limited to coil sacrifice of the parent vessel, and thus the patient was taken for a far lateral craniotomy, trapping of the aneurysm, and revascularization of the PICA territory via a saphenous vein interposition graft sewn proximally and distally to the occipital artery within the occipital groove and a cortical segment of the affected PICA, respectively. Postoperative imaging demonstrated filling of the PICA territory via the graft, and the patient ultimately recovered from his subarachnoid hemorrhage.

CONCLUSIONS

The use of the proximal suboccipital segment of the occipital artery is a viable option for a donor in posterior fossa revascularization surgery.

Occipital artery: Anatomical variations and neurosurgical applications

Background

The occipital artery (OA) is a branch of the external carotid artery. It gives rise to several cutaneous, muscular, and meningeal branches to supply different anatomical areas. The implication of OA in the neurosurgical field is well-established in the literature. Our aim in this study is to draw a complete picture of the anatomical variations and neurosurgical applications of the OA.

Methods

A literature review was conducted in Google Scholar and PubMed to review the studies discussing OA, its anatomical variation, and neurosurgical applications.

Results

We identified 29 articles that discuss the anatomical variations and neurosurgical applications of the OA. Certain variables are used to describe the surgical anatomy of OA. We also discussed certain applications of OA and its importance in neurosurgical bypass, embolization, and aneurysms.

Conclusion

Comprehending the anatomy of the OA is crucial for neurosurgeons to safely and effectively perform procedures such as bypass and embolization. In addition, knowledge of the anatomical variations of the OA can help surgeons anticipate potential challenges and tailor their approach accordingly.

Vertical Levels of the Occipital Artery Origin

Background and Objectives. The occipital artery (OA) is a posterior branch of the external carotid artery (ECA). The origin of the OA is commonly referred to a single landmark. We hypothesized that the origin of the OA could be variable as referred to the hyoid bone and the gonial angle. We thus aimed at patterning the vertical topographic possibilities of the OA origin. Materials and Methods. One hundred archived computed tomography angiograms were randomly selected, inclusion and exclusion criteria were applied, and 90 files were kept (53 males, 37 females). The cases were documented bilaterally for different levels of origin of the OA origin: type 1-infrahyoid; type 2-hyoid; 3-infragonial; 4-gonial; 5-supragonial; 6-origin from the internal carotid artery (ICA). Results. The incidence of unilateral types in the 180 OAs was: type 1-1.11%, type 2-5.56%, type 3-40.56%, type 4-28.33%, type 5-23.33% and type 6, ICA origin of the OA-1.11%. There was found a significant association between the location of the left and right origins of the OAs (Pearson Chi2 = 59.18, p < 0.001), which suggests the presence of a strong symmetry of the origins. Bilateral symmetry of the vertical types of the OA origin was observed in 56.67% of cases; in 43.33% there was bilateral asymmetry. Conclusions. The ICA origin of the OA is an extremely rare variant. For surgical planning or prior to endovascular approaches the topography of the OA origin should be carefully documented, as it may be located from an infrahyoid to a supragonial level.