Supraorbital minicraniotomy

'What's in a name', a systematic review of the pterional craniotomy for aneurysm surgery and its many modifications with a proposal for simplified nomenclature

BACKGROUND

The pterional or frontosphenotemporal craniotomy has stood the test of time and continues to be a commonly used method of managing a variety of neurosurgical pathology. Already described in the beginning of the twentieth century and perfected by Yasargil in the 1970s, it has seen many modifications. These modifications have been a normal evolution for most neurosurgeons, tailoring the craniotomy to the patients' specific anatomy and pathology. Nonetheless, an abundance of variations have appeared in the literature.

METHODS

A search strategy was devised according to the 2020 Preferred Reporting Items of Systematic Reviews and Meta-Analyses (PRISMA) statement. To identify articles investigating the variations in the pterional approach, the following search terms were applied: (pterional OR minipterional OR supraorbital) AND (approach OR craniotomy OR technique).

RESULTS

In total, 3552 articles were screened with 74 articles being read in full with 47 articles being included for review. Each article was examined according the name of the technique, temporalis dissection technique, craniotomy technique and approach.

CONCLUSION

This systematic review gives an overview of the different techniques and modifications to the pterional craniotomy since it was initially described. We advocate for the use of a more standardised nomenclature that focuses on the target zone to simplify the management approach to supratentorial aneurysms.

Cosmetic Outcomes of Supraorbital Keyhole Craniotomy Via Eyebrow Incision: A Systematic Review and Meta-Analysis

Background  Supraorbital eyebrow craniotomy is a minimally invasive alternative to a frontotemporal craniotomy and is often used for tumor and vascular pathologies. The purpose of this study was to investigate how patient cosmetic outcomes are affected by technique variations of this approach. Methods  PubMed, Embase, and Scopus databases were systematically searched, and results were reported according to PRISMA guidelines. For the meta-analysis portion, the DerSimonian-Laird random effects model was used, and the primary end points were patient satisfaction and percentage of permanent cosmetic complications. Results  A total of 2,629 manuscripts were identified. Of those, 124 studies (8,241 surgical cases) met the inclusion criteria. Overall, 93.04 ± 11.93% of patients reported favorable cosmetic outcome following supraorbital craniotomy, and mean number of cases with permanent cosmetic complications was 6.62 ± 12.53%. We found that vascular cases are associated with more favorable cosmetic outcomes than tumor cases ( p  = 0.0001). Addition of orbital osteotomy or use of a drain is associated with adverse cosmetic outcomes ( p  = 0.001 and p  = 0.0001, respectively). The location of incision, size of craniotomy, utilization of an endoscope, method of cranial reconstruction, skin closure, use of antibiotics, and addition of pressure dressing did not significantly impact cosmetic outcomes ( p  > 0.05 for all). Conclusions  Supraorbital craniotomy is a minimally invasive technique associated with generally high favorable cosmetic outcomes. While certain techniques used in supraorbital keyhole approach do not pose significant cosmetic risks, utilization of an orbital osteotomy and the addition of a drain correlate with unfavorable cosmetic outcomes.

Supraorbital Keyhole Craniotomy via Eyebrow Incision: A Systematic Review and Meta-Analysis

BACKGROUND

Supraorbital eyebrow keyhole craniotomy is a minimally invasive alternative to a frontotemporal craniotomy and is often used for tumor resection and aneurysm clipping. The purpose of this study is to provide a contemporary review on the outcomes related to this approach and to determine whether they vary with the type of pathology and the addition of an endoscope.

METHODS

PubMed, Embase, and Scopus databases were systematically searched, and results were reported according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. For the meta-analysis portion, the DerSimonian-Laird random effects model was used.

RESULTS

A total of 2629 manuscripts were identified. of those, 124 studies (8241 surgical cases) met the inclusion criteria. Mean total complication rate was 26.7 ± 25.7% and the mean approach-related mortality rate was 1.3 ± 2.8%. Technical success, defined as gross total tumor resection or complete aneurysm clipping, was achieved in 83.6 ± 21.5% of the cases. Vascular pathologies were associated with greater technical success, lower total complications, and longer length of hospital stay compared with tumor cases (P < 0.05 for all). For vascular cases, addition of the endoscope yielded lower technical success (P = 0.001) and lower complication rate (P = 0.041). The use of the endoscope for tumor pathologies did not affect technical success, complications, mortality, length of hospital stay, operative time, or reoperation rate (P > 0.05).

CONCLUSIONS

The supraorbital craniotomy via an eyebrow incision is a feasible minimally invasive approach with an overall high technical success rate for both vascular and tumor pathologies.

Supraorbital vs Endo-Orbital Routes to the Lateral Skull Base: A Quantitative and Qualitative Anatomic Study

BACKGROUND

Various extensions of the supraorbital approach reach the lateral and parasellar middle cranial fossa regions by removing the orbital rim and greater/lesser sphenoid wings. Recent proposals of a purely endoscopic ventral transorbital pathway to these regions heighten the need to compare these surgical windows.

OBJECTIVE

To detail the lateral and parasellar middle cranial fossa regions and quantify exposures by 2 surgical windows (transcranial and transorbital) through anatomic study.

METHODS

In 5 cadaveric specimens (10 sides), dissections consisted of 3 stages: stage 1 began with the supraorbital approach via the eyebrow; stage 2, endo-orbital approach via the superior eyelid, continued with removal of lesser and greater sphenoid wings; and stage 3, extended supraorbital, re-evaluated the gains of stage 2 from the perspective of stage 1. Operative working areas were quantified in Sylvian, anterolateral temporal, and parasellar regions; bone removal volumes were measured at each stage (nonpaired Student t-test).

RESULTS

Visualization into the anterolateral temporal and Sylvian areas, though varied in perspective, were comparable with either eyelid or transcranial routes. Compared with transcranial views through a supraorbital window, the eyelid approach significantly increased exposure in the parasellar region with wider angle of attack (P &lt; .01) and achieved comparable bone removal volumes.

CONCLUSION

Stage 2’s unique anatomic view of the lateral and parasellar middle cranial fossa regions paves the way for possible surgical application to select pathologies typically treated via transcranial approaches. Disadvantages may be the surgeon's unfamiliarity with the anatomy of this purely endoscopic, ventral route and difficulties of dural and orbital repair.

Interfascial Dissection for Protection of the Nerve Branches to the Frontalis Muscles during Supraorbital Trans-Eyebrow Approach: An Anatomical Study and Technical Note

Introduction Preservation of the temporal branches of the facial nerve during anterolateral craniotomies is important. Damaging it can inflict undesirable cosmetic defects to the patient. The supraorbital trans-eyebrow approach (SOTE) is a versatile keyhole craniotomy but still has a high rate of frontalis muscle (FM) palsy. Objective Anatomical study to implement the interfascial dissection during the SOTE to preserve the nerves to the FM. Methods Slight modification of the standard technique of the SOTE was performed in 6 cadaveric specimens (12 sides). Results Distal rami to the FM were exposed. The standard "u-shape" incision of the FM can cross over the nerves. Alternatively, an "l-shape" incision was performed until the superior temporal line (STL). An interfascial dissection was performed near to the STL and the interfascial fat pad was used as a protective layer for the nerves. Conclusion Various pathologies can be addressed with the SOTE. In the majority of the cases the cosmetic results are good, but FM palsy remains a drawback of this approach. The interfascial dissection may be used in an attempt to prevent frontalis rami palsy.

The extended transorbital craniotomy: an anatomic study

BACKGROUND

Supra-/transorbital approaches are mostly limited to suprasellar and anterior fossa pathologies, whereas lateral supraorbital approaches provide less retrosellar exposure and less overall operative volume, especially in the temporal region.

OBJECTIVE

Our cadaveric study proposes removal of the lesser and greater wings of the sphenoid bone to increase both the lateral angle typically achieved with pterional approaches and exposure to the temporal lobe and perisellar region.

METHODS

In 5 cadaveric specimens, our 3 steps to expand transorbital exposures included the following: step 1, standard transorbital craniotomy via a 3-cm supra-eyebrow incision; step 2, removal of the lesser sphenoid wing completed extradurally; and step 3, partial removal of the greater sphenoid wing. Operative extension in sylvian, parasellar, and anterolateral temporal exposures were quantified for each step (t test).

RESULTS

Step 2 provided the greatest increased exposure in the sylvian and parasellar regions compared with step 3, whereas step 3 provided a significant proportion of the exposure in the lateral temporal region. Finally, the lateral view progressively increased with each subsequent step.

CONCLUSION

Our 3-step removal of the lesser and greater wings of the sphenoid bone quantified increased sylvian, anterior temporal, and parasellar exposures for this minimally invasive approach with excellent cosmesis. Its increases the anterolateral view (similar to a subfrontal pterional approach) and offers potential applications to vascular and neoplastic (ie, sphenoid meningiomas) pathologies classically treated via a pterional or frontotemporal orbitozygomatic approach.

Supraorbital eyebrow craniotomy for removal of intraaxial frontal brain tumors: a technical note

OBJECTIVE

To present the utility and selection criteria for the supraorbital (SO) craniotomy, an approach commonly used to remove extraaxial tumors such as meningiomas and craniopharyngiomas, to resect intraaxial frontal brain lesions.

METHODS

All consecutive patients who underwent a SO craniotomy for an intraaxial lesion were retrospectively analyzed for lesion location, pathology, extent of resection, operative times, length of stay, and complications.

RESULTS

During 28 months, 10 patients (mean age, 67.6 years; 7 women) underwent 11 SO procedures to resect intraaxial brain lesions. Pathologies included metastatic carcinoma (n = 7), glioma (n = 2), and radiation necrosis (n = 1). The mean distance of the shortest trajectory to the lesion was 2.4 mm. Gross total or near-total removal was achieved in 80% of the cases. Median length of hospital stay was 3 days (range, 2-6 days); it was 2 days for patients admitted electively for SO craniotomy. There were no new neurologic deficits, postoperative hematomas, or cerebrospinal fluid leaks.

CONCLUSIONS

The SO "eyebrow" craniotomy is a safe and effective keyhole method to remove intraaxial frontal lobe lesions, particularly lesions of the frontal pole and orbitofrontal region, allowing for minimal disruption of normal brain parenchyma and promoting a rapid recovery and short hospital stay. Metastatic tumors and select gliomas in this area are most amenable to this approach. Deeper intraaxial tumors can also be effectively accessed via this route with excellent clinical outcomes.

Transpalpebral orbitofrontal craniotomy: a minimally invasive approach to anterior cranial vault lesions

To describe a minimally invasive approach to anterior cranial vault pathology using a transpalpebral exposure with a miniorbitofrontal craniotomy.

DESIGN

Case series.

SETTING

Tertiary referral hospital with multidisciplinary skull base program. Participants include patients with intra-axial and extra-axial anterior skull base lesions who underwent the transpalpebral minicraniotomy approach.

MAIN OUTCOME MEASURES

Feasibility of the approach to permit adequate exposure of targeted lesion. We applied this approach in seven patients for the repair of persistent cerebrospinal fluid leaks, pneumocephalus, and the biopsy or resection of midline brain tumors along the anterior cranial base. The approach allowed bimanual instrumentation working with either endoscopic or microscopic visualization for tumor resection and repair of dural and cranial base defects. We measured an average working distance of 4 cm to the sella. The transpalpebral miniorbitofrontal craniotomy approach to the anterior cranial base is quick, adequate, and safe and should be considered as an alternative to extended bifrontal approaches and/or pterional craniotomies for select anterior cranial vault pathology.

Quantitative anatomic study of the transciliary supraorbital approach: benefits of additional orbital osteotomy?

BACKGROUND

The transciliary supraorbital approach (TCSO) provides an anterior view for visualizing sellar, parasellar, and suprasellar structures. Whether an orbital osteotomy adds to this exposure has not been quantified.

OBJECTIVE

We quantitatively evaluated the TCSO and benefits of an additional orbital osteotomy for exposing common sites of anterior circulation aneurysms.

METHODS

Under image guidance, TCSO and orbital osteotomy were performed on 10 sides of 5 cadaver heads to quantify exposures of 4 surgical targets: (1) the junction of the anterior cerebral and anterior communicating arteries (ACoA); (2) the internal carotid artery (ICA) at the level of the posterior communicating artery (PCoA); (3) the bifurcation of the ICA; and (4) the middle cerebral artery (MCA) bifurcation. Horizontal and vertical angles of attack and surgical freedom for instrument manipulation were measured before and after the orbital rim and roof were removed.

RESULTS

An orbital osteotomy significantly increased surgical freedom to the ACoA (from 471.15 +/- 182.14 mm2 to 683.35 +/- 283.78 mm2, P = .021); PCoA (from 746.58 +/- 242.78 mm2 to 966.23 +/- 360.22 mm2, P = .007); ICA bifurcation (from 616.08 +/- 310.95 mm2 to 922.38 +/- 374.88 mm2, P = .002); and MCA bifurcation (from 1160.77 +/- 412.03 mm2 to 1597.71 +/- 733.18 mm2, P = .004). There were no significant differences in horizontal angles of attack. The vertical angles of attack were significantly greater after orbital osteotomy, principally with the ACoA and ICA bifurcation as targets.

CONCLUSION

TCSO combined with orbital osteotomy improves exposure. Removing the orbital rim and roof increases the area for instrument use and improves the vertical angle of attack to common sites in the anterior circulation involving aneurysms.

Image-guided anatomical and morphometric study of supraorbital and transorbital minicraniotomies to the sellar and perisellar regions: comparison with standard techniques

OBJECT

Minimally invasive approaches have been proposed for the treatment of anterior cranial base pathology. Whereas earlier studies have quantified surgical exposure by referring to the opening on the surface, this cadaveric morphometric study redefines the concept of working area by examining the deep exposures afforded by several different approaches. Specifically, the authors systematically quantify and compare the operative exposure afforded by the pterional, supraorbital, and transorbital keyhole approaches to the sellar, suprasellar, and perisellar regions, including the anterior communicating artery complex.

METHODS

Pterional, supraorbital, and transorbital approaches were sequentially performed in 5 embalmed cadaveric heads on both sides. Preoperative and postoperative CT scans were obtained for frameless stereotactic navigation and measurements. Using reproducible anatomical landmarks, 6 triangles were defined to systematically measure the working area, depth of the surgical window, and angle of observation for each approach. Areas of the triangles were calculated using the Heron mathematical formula based on stereotactic navigation measurements. Ten sets of data were analyzed.

RESULTS

The pterional, supraorbital, and transorbital keyhole approaches provided progressively increasing working areas. The transorbital approach was associated with significantly increased exposure when compared with the pterional approach (p < 0.01). The transorbital approach was associated with a shallower depth of the surgical window when compared with either the supraorbital (p < 0.05) or pterional (p < 0.01) approach. The angle of basal view increased 56.6% with the transorbital approach (p < 0.001) when compared with the supraorbital approach. The transorbital route provided greater exposure on deeply located midline and contralateral structures.

CONCLUSIONS

In refining the concept of working area as deep rather than superficial in the surgical field, the authors quantified the 6 triangles whose boundaries were relative to the target structures to be exposed in the approach. The authors' morphometric findings support the use of the supraorbital and transorbital approaches as a valid alternative to the pterional approach for the treatment of sellar and perisellar pathology. The transorbital approach combines the advantages of minimal invasiveness with those of cranial base techniques.

Eyelid approach to the anterior cranial base

Skull base approaches play a fundamental role in modern neurosurgery by reducing surgical morbidity. Increasing experience has allowed surgeons to perform minimally invasive approaches without straying from the premises of skull base surgery. The eyelid approach has evolved from the orbitopterional osteotomy into a more effective and targeted approach to disease of the anterior cranial fossa. In this technique, after an incision is made on the supratarsal fold, the orbicularis oculi muscle is incised, and a myocutaneous flap composed of the elements of the anterior lamella is elevated. Subperiosteal dissection is used to expose the superior and lateral walls of the orbit, the superior and lateral orbital rim, and the frontosphenoidal suture. A MacCarty bur hole is drilled, and a frontal osteotomy is fashioned medial to the supraorbital notch and extending through the orbital roof back toward the orbital half of the MacCarty bur hole, exposing the frontobasal brain. A conventional microsurgical technique is used to treat tumors and aneurysms of the anterior cranial fossa under the operative microscope.

Five patients were treated for unruptured aneurysms of the anterior circulation (3 anterior communicating artery aneurysms, 1 ophthalmic artery aneurysm, and 1 posterior communicating artery aneurysm) using the eyelid approach. The mean aneurysm size was 5 mm, and all aneurysms were approached from the right side. Three tumors in the anterior fossa (2 suprasellar pituitary adenomas and 1 craniopharyngioma) were also excised using this approach. There was no surgical morbidity. Three months after surgery all patients presented excellent cosmetic results. The eyelid approach may be considered as an effective, cosmetically beneficial, and minimally invasive skull base approach to selected aneurysms and tumors of the anterior circulation.

Minicraniotomia supraorbital para abordagem da região selar e parasselar

Relatamos nossa experiência com a minicraniotomia supraorbital em uma série de 36 pacientes operados, com resultados satisfatórios. Foram operados 31 aneurismas 4 adenomas hipofisários, um astrocitoma anaplásico e um cisto aracnóide. Houve um óbito na série. A técnica foi descrita em detalhes. Concluimos que a minicraniotomia é um método seguro para o tratamento de várias patologias parasselares, devendo ser avaliada a sua eficácia em estudos comparativos com as técnicas tradicionais.

Supraorbital eyebrow approach to skull base lesions

We report our experience with a supraorbital eyebrow minicraniotomy. This technique is suitable to lesions situated in the region of the anterior fossa, suprasellar cisterns, parasellar region and Sylvian fissure. A 50 mm incision in the eyebrow and a supraorbital minicraniotomy is performed. Sixteem patients harboring different lesions were operated on with good postoperative and cosmetic results. We conclude that this approach is safe and useful in selected cases.