Modified orbitozygomatic craniotomy with a single burr hole in the alternative sphenoid ridge keyhole

BACKGROUND

One-piece modified orbitozygomatic approach (OZA) is an extended version of the pterional approach that also includes orbital walls and frontal process of the zygomatic bone. For this craniotomy one burr hole must be placed in MacCarty keyhole and another - in the temporal region.

OBJECTIVE

To develop a technique of the one-piece modified OZA with single a burr hole in the alternative sphenoid ridge keyhole that allows access to orbit, anterior cranial fossa and middle cranial fossa and apply it intraoperatively.

METHODS

A single human head specimen was used. The dissection was performed using standard surgical instruments high-speed Stryker drill. Every stage of the approach was photographed. We also report a surgical case of a patient with orbital cavernous hemangioma that was resected using the described technique.

RESULTS

The technique of the one-piece modified OZA with a single burr hole in the alternative sphenoid ridge keyhole is described, and its advantages and limitations are analyzed. The technique is used to totally resect an orbital cavernous hemangioma with good functional and cosmetic result.

CONCLUSION

Modified OZA with a single burr hole in the sphenoid ridge keyhole is possible and may be an alternative to the classic technique. The advantages of this variation are the placement of just one burr hole and the preservation of a larger portion of the orbital roof. The latter facilitates better bone reconstruction and better cosmetic outcome. Disadvantages are the difficulty of identifying the location of the sphenoid ridge keyhole and risk of damaging the dura.

Assessing the reliability of zygomatic bone landmarks as guides to reach the inferior orbital fissure in orbitozygomatic osteotomy: anatomical study of 83 human skulls

To perform an adequate orbitozygomatic craniotomy, it is very important that the bone cut which passes through the body of the zygoma reaches the inferior orbital fissure (IOF). To reach the IOF, two surface landmarks on the body of the zygoma are described: a point located directly superior to the malar eminence and the zygomaticofacial foramen. The article explores the reliability of these landmarks and three other alternative points to reach the IOF. Eighty-three adult skulls were used in this study. The IOF dimensions and the relationship with the malar eminence, the point superior to the malar eminence, the zygomaticofacial foramen, and 3 alternative points (E, C, F) were analyzed. The malar eminence was unacceptable for use as a guide to the IOF. The point superior to the malar eminence was also unacceptable as a guide as only 9.4% and 10.9% were in the projection of the IOF on the right and left, respectively. 59.7% of the total zygomaticofacial foramina fell in the IOF projection. The point F fell in the projection of the IOF in 98.8% and 100.0% on the right and left, respectively. The use of the malar eminence as a guide to reach the IOF is unreliable in one third of cases as it is not easily identified intraoperatively in these cases. The zygomaticofacial foramen cannot be considered a reliable surgical landmark to reach the IOF. The authors recommend using a novel landmark which may be identified as a midpoint between intersections of the anterior and posterior margins of the zygomatic frontal process on a line extending from the inferior margin of the zygomatic arc. This point is reliable in 98.8-100% of cases.

[Dissection of brachiocephalic arteries as a complication of open neurosurgery: case report and literature review]

BACKGROUND

Abnormal styloid processes cause dissection of supra-aortic arteries in some cases. In total, about 33 cases have been described in the world and national literature. However, there were no dissections associated with neurosurgery. At the same time, anomalies of styloid process may be an unidentified cause of many spontaneous dissections of brachiocephalic arteries.

OBJECTIVE

To analyze modern data on dissection of brachiocephalic arteries associated with anomalies of styloid process and describe dissection in a 44-year-old patient with deviated styloid processes after posterior cranial fossa surgery.

MATERIAL AND METHODS

Searching for literature data was performed using the keywords "dissection of the cervicocerebral arteries", "dissection of the brachiocephalic arteries", "stylocarotid syndrome" and "Eagle syndrome" in the PubMed and Medscape databases. We also describe a patient hospitalized for microsurgical resection of cystic-solid hemangioblastoma of medulla oblongata who developed postoperative dissection of both internal carotid and vertebral arteries.

RESULTS

We found 1777 papers between 01/01/1900 and 01/18/2021. In most cases, ICA dissection was not a result of stylocarotid syndrome. There were 121 full-text Russian- or English-language articles. We selected 46 most relevant publications. Analyzing these papers, we found that small distance between the tops of styloid processes and internal carotid arteries can be a risk factor of dissection of brachiocephalic arteries in addition to styloid process elongation. Our patient was diagnosed with just such an anomaly.

CONCLUSION

Anomalies of styloid processes can cause dangerous vascular complications. Therefore, the length and abnormal deviation of styloid process should be considered when planning intraoperative position of a patient associated with prolonged neck flexion.

[The orbitozygomatic approach. History, technique, and modifications]

The orbitozygomatic approach (OZA) has been used in neurosurgical practice since the 1980s. Many approach modifications have been proposed; anatomical and clinical developments have been conducted in many clinics. However, there is no algorithm for choosing an approach option, depending on the type and topographo-anatomical features of pathology.

MATERIAL AND METHODS

We searched for publications in the PubMed and Medscape databases using the keywords 'orbitozygomatic'.

RESULTS

A total of 447 publications matching the search terms were found. In most of them, the approach was either not actually orbitozygomatic or was mentioned in the description of a clinical case. One hundred and nineteen full text Russian or English papers were available for detailed analysis. Of these, we selected 72 most relevant publications.

DISCUSSION

There were no studies demonstrating disadvantages of the OZA compared to traditional craniotomies. Orbitozygomatic approaches are widely used in routine neurosurgical practice. Existing approaches are not without disadvantages. The publications are based on small material. The recommendations on choosing the optimal OZA option are based on the authors' opinion, i.e. they satisfy the minimum level of evidence. There are no studies comparing the efficacy of OZA options in different types and topographo-anatomical variants of neurosurgical pathology of the anterior and middle skull base.

CONCLUSION

The reasonability of using the orbitozygomatic approach in neurosurgical practice is obvious. There are a large number of orbitozygomatic approaches and their modifications. The modern literature lacks an algorithm for choosing the optimal OZA option for specific types and topographo-anatomical variants of the pathological process.