Interfascial approach for pterional craniotomy: technique and adjustments to prevent cosmetic complications

Virtual reality guided focused Sylvian approach for clipping unruptured middle cerebral artery aneurysms

Objective

The increasing prevalence of unruptured intracranial aneurysms, detected through advanced brain imaging, necessitates a cautious approach to surgical intervention, with a focus on minimizing associated risks. This retrospective study explores the safety and better aesthetic outcomes of a Virtual Reality (VR) guided Focused Sylvian Approach (FSA) in comparison to the standard Pterional Surgical Approach (SPA) for the clipping of unruptured small-medium-size (<10 mm) Middle Cerebral Artery (MCA) aneurysms.

Methods

23 patients with 23 unruptured MCA aneurysms underwent the VR-guided FSA from June 2020 to September 2023, while 22 patients with 23 unruptured MCA aneurysms who underwent SPA were retrospectively recruited from the medical records database from January 2017 to May 2020. The comparative analysis involved surgical duration, postoperative complications, hospital stay, and a three-month follow-up patient's sequela survey.

Results

All aneurysms were effectively treated. The FSA procedure demonstrated a shorter surgical duration compared to the SPA group (164 ± 48 min vs. 196 ± 133 min, P = 0.2974). Despite a slightly higher median age in the FSA group (59 vs. 56 years), the median hospital stay was shorter in the FSA group (6 days) compared to the SPA group (7 days). The SPA group exhibited a higher incidence of complications (17/23) including cephalalgia, scar irritation, scar numbness, and temporal muscle dysfunction, compared to the FSA group (1/23), with a statistical significance of P < 0.05. Although FSA cannot demonstrate significant surgical efficiency in surgical duration and hospitalization, its superior aesthetics and preservation of temporalis muscle function compared to the SPA group.

Conclusion

The VR-guided FSA offers improved aesthetics and preservation of muscle function compared to the SPA. Our retrospective study underscores the potential benefits of VR-guided, personalized, focused Sylvian approaches for managing unruptured small-medium-size MCA aneurysms.

Predictive factors of the postoperative proptosis recovery in surgery of spheno-orbital meningiomas

OBJECTIVE

This study aimed to identify factors affecting proptosis recovery in spheno-orbital meningioma (SOM) surgery and assess functional and oncological outcomes.

METHODS

Data from 32 consecutive SOM surgery cases (2002-2021) were analyzed. Clinical, radiological, operative, and oncological parameters were examined. Proptosis was assessed using the exophthalmos index (EI) on MRI or CT scans. Statistical analyses were performed to identify predictive factors for proptosis recovery.

RESULTS

Proptosis improved in 75% of patients post-surgery (EI decreased from 1.28 ± 0.16 to 1.20 ± 0.13, p = 0.048). Patients with stable or worsened EI had higher body mass index (28.5 ± 7.9 vs. 24.1 ± 4.7, p = 0.18), Simpson grade (IV 75% vs. 65%, p = 0.24), and middle sphenoid wing epicenter involvement (63% vs. 38%, p = 0.12), but no significant factors were associated with unfavorable exophthalmos outcomes. The improvement group had higher en plaque morphology, infratemporal fossa invasion, and radiation treatment for cavernous sinus residual tumor (88% vs. 75%, p = 0.25; 51% vs. 25%, p = 0.42; 41% vs. 25%, p = 0.42, respectively), but without statistical significance. Visual acuity remained stable in 78%, improved in 13%, and worsened in 9% during follow-up. Surgery had a positive impact on preoperative oculomotor nerve dysfunction in 3 of 4 patients (75%). Postoperative oculomotor nerve dysfunction was observed in 25%, of which 75% fully recovered. This occurrence was significantly associated with irradiation of an orbital tumor residue (p = 0.04). New postoperative trigeminal hypoesthesia was observed in 47%, of which 73% recovered. All SOMs were classified as WHO grade 1, and complementary treatments achieved oncological control, requiring gamma-knife radiosurgery in 53% and standard radiotherapy in 6%.

CONCLUSIONS

Surgery effectively improves proptosis in SOM, though complete resolution is rare. The absence of predictive factors suggests multifactorial causes, including body mass index and tumor resection grade. Postoperative oculomotor nerve dysfunction and trigeminal hypoesthesia are common but often recover. Gamma-knife radiosurgery maintains long-term oncological control for evolving tumor residue.

Biomaterials for Regenerative Cranioplasty: Current State of Clinical Application and Future Challenges

Acquired cranial defects are a prevalent condition in neurosurgery and call for cranioplasty, where the missing or defective cranium is replaced by an implant. Nevertheless, the biomaterials in current clinical applications are hardly exempt from long-term safety and comfort concerns. An appealing solution is regenerative cranioplasty, where biomaterials with/without cells and bioactive molecules are applied to induce the regeneration of the cranium and ultimately repair the cranial defects. This review examines the current state of research, development, and translational application of regenerative cranioplasty biomaterials and discusses the efforts required in future research. The first section briefly introduced the regenerative capacity of the cranium, including the spontaneous bone regeneration bioactivities and the presence of pluripotent skeletal stem cells in the cranial suture. Then, three major types of biomaterials for regenerative cranioplasty, namely the calcium phosphate/titanium (CaP/Ti) composites, mineralised collagen, and 3D-printed polycaprolactone (PCL) composites, are reviewed for their composition, material properties, and findings from clinical trials. The third part discusses perspectives on future research and development of regenerative cranioplasty biomaterials, with a considerable portion based on issues identified in clinical trials. This review aims to facilitate the development of biomaterials that ultimately contribute to a safer and more effective healing of cranial defects.

A Prospective Comparison Between Soft Tissue Dissection Techniques in Pterional Craniotomy: Functional, Radiological, and Aesthetic Outcomes

BACKGROUND AND OBJECTIVES

Given the complex anatomy of the operative region and individual surgeon preferences, some techniques for soft tissue dissection before pterional craniotomy have gained more popularity than others. This prospective study used subjective and objective measurements to compare the functional, radiological, and aesthetic outcomes of 3 such dissection techniques.

METHODS

This multicenter prospective cohort study included all patients who underwent elective pterional craniotomy between 2018 and 2020 at 3 centers in Riyadh, Saudi Arabia. All patients underwent 1 of 3 soft tissue dissection techniques: myocutaneous flap, interfascial, and subfascial dissection techniques. Clinical and radiological assessments were performed upon discharge and at the 3- and 6-month follow-ups.

RESULTS

We included 78 patients, with a mean age of 44.9 ± 16.3 years. Myocutaneous flap, interfascial, and subfascial dissections were performed in 34 (43%), 24 (30%), and 20 patients (25%), respectively. The myocutaneous flap method had the shortest opening ( P = .001) and closure ( P = .005) times; tenderness was more evident in this group than in the others ( P = .05). The frontalis muscle was most affected in the interfascial dissection group ( P = .05). The frontalis nerve function was similar in all groups after 6 months ( P = .54). The incidence of temporomandibular joint dysfunction was highest in the myocutaneous flap group (29%). Decreased temporalis muscle thickness at the 6-month postoperative follow-up was most severe in the subfascial dissection group (12.6%), followed by the myocutaneous flap (11.9%) and interfascial dissection (9.9%) groups, with no significant difference ( P = .85). Temporal hollowing was more prominent in the myocutaneous flap group ( P = .03). Cosmetic satisfaction was highest in the interfascial dissection group, with no significant difference ( P = .4).

CONCLUSION

This study provides important information for neurosurgeons in weighing the benefits and risks of each technique for their patients.

Extradural disconnection of the cavernous sinus with preservation of the internal carotid artery: indication and technique

BACKGROUND

Extradural disconnection of the cavernous sinus (CS) with preservation of the internal carotid artery (ICA) is indicated for aggressive and recurrent tumors, in patients presenting loss of oculomotor function and non-functional circle of Willis.

METHOD

Extradural resection of the anterior clinoid process disconnects the CS anteriorly. The ICA is dissected in the foramen lacerum via extradural subtemporal approach. The intracavernous tumor is split and removed following the ICA. Bleeding control of the inferior and superior petrosal and intercavernous sinuses completes posterior CS disconnection.

CONCLUSION

This technique can be proposed for recurrent CS tumors and need of ICA preservation.

Surgical morbidity of the extradural anterior petrosal approach: the Lariboisière experience

OBJECTIVE

Concerns about the approach-related morbidity of the extradural anterior petrosal approach (EAPA) have been raised, especially regarding temporal lobe and venous injuries, hearing impairment, facial nerve palsy, cerebrospinal fluid fistula, and seizures. There is lack in the literature of studies with detailed analysis of surgical complications. The authors have presented a large series of patients who were treated with EAPA, focusing on complications and their avoidance.

METHODS

The authors carried out a retrospective review of patients who underwent EAPA at their institution between 2012 and 2021. They collected preoperative clinical characteristics, operative reports, operative videos, findings on neuroimaging, histological diagnosis, postoperative course, and clinical status at last follow-up. For pathologies without petrous bone invasion, the amount of petrous apex drilling was calculated and classified as low (< 70% of the volume) or high (≥ 70%). Complications were dichotomized as approach related and resection related.

RESULTS

This study included 49 patients: 26 with meningiomas, 10 brainstem cavernomas, 4 chondrosarcomas, 4 chordomas, 2 schwannomas, 1 epidermoid cyst, 1 cholesterol granuloma, and 1 osteoblastoma. The most common approach-related complications were temporal lobe injury (6.1% of patients), seizures (6.1%), pseudomeningocele (6.1%), hearing impairment (4.1%), and dry eye (4.1%). Approach-related complications occurred most commonly in patients with a meningioma (p = 0.02) and Meckel's cave invasion (p = 0.02). Gross-total or near-total resection was correlated with a higher rate of tumor resection-related complications (p = 0.02) but not approach-related complications (p = 0.76). Inferior, lateral, and superior tumoral extension were not correlated with a higher rate of tumor resection-related complications. No correlation was found between high amount of petrous bone drilling and approach- or resection-related complications.

CONCLUSIONS

EAPA is a challenging approach that deals with critical neurovascular structures and demands specific skills to be safely performed. Contrary to general belief, its approach-related morbidity seems to be acceptable at dedicated skull base centers. Morbidity can be lowered with careful examination of the preoperative neuroradiological workup, appropriate patient selection, and attention to technical details.

Implantation of Acellular Dermal Matrix to Prevent Frontotemporal Depression Following Minipterional Craniotomy for the Surgical Clipping of Unruptured Intracranial Aneurysms

OBJECTIVE

The objective of the study was to assess the esthetic efficacy of acellular dermal matrix (ADM) implantation to prevent frontotemporal depression (FTD) following minipterional craniotomy (MPT) to clip unruptured intracranial aneurysms.

METHODS

We retrospectively compared the incidence of FTD in 100 patients treated without ADM from March to July 2019 and 100 patients treated with ADM from August to December 2019. ADM was implanted in the interfascial layer to cover the temporalis muscle. The specific location and degree of FTD were analyzed by measuring the thickness and area of multiple points (P1-P12) and regions (S1-S3) through brain computed tomography preoperatively and 1 year postoperatively.

RESULTS

In the non-ADM group, the thickness at P1, P2, P5, P6, and P9 was reduced and the area of S1 and S2 was smaller after surgery than before surgery (P < 0.05), similar to the incision and suture site of the temporalis muscle. However, in the ADM group, the preoperative and postoperative measurements were not different. FTD recognition was significantly lower in the ADM group (6.0%) than that in the non-ADM group (17.0%) (P = 0.015) and occurred in the retroorbital region through P1, P2, P5, and P6, with the area under the receiver operating characteristic curves of 0.840, 0.766, 0.811, and 0.751, respectively. ADM implantation was the only significant predictive factor for FTD recognition in multivariate logistic regression analysis (odds ratio = 0.30; 95% confidence interval: 0.11-0.79; P = 0.015).

CONCLUSIONS

Even MPT cannot completely prevent FTD in the retroorbital region. ADM implantation in MPT can help to improve esthetic satisfaction.

Mini-temporal approach as an alternative to the classical pterional approach for resective temporal region surgeries

Background

Classical pterional appoach for temporal surgeries may cause atrophy and dysfunction of temporalis, injury to the facial nerve, and unnecessary cortical exposure. As an alternative to the classical pterional approach for such surgeries, we hereby describe an mini-temporal approach which reduces these risks and proven to be practical in neurological surgeries.

Material and methods

In the mini-temporal incision design, the frontal end of the incision never surpassed the hairline at the level of temporal line, and a one-layer skin-galea-muscle flap was detached from the cranium, effectively avoiding the injuries of facial nerve. The surgical bone window was completely located underneath the temporalis muscle, allowing it to be completely repositioned postoperatively.

Results

We demonstrated the application of mini-temporal approach in a variety of temporal region tumors, which can be applied to complete successful resective surgeries while effectively reducing injuries to extra-temporal cortex, temporalis, and facial nerve. There were no postoperative complications related to extra-temporal cortical damage, atrophy of temporalis, or injury to the facial nerve.

Conclusion

The mini-temporal approach can effectively shorten the time of craniotomy and closure, decrease the size of bony removal, increase the restoration of temporalis during closure, and lower the chance of facial nerve injury. Therefore, it improves cosmetic outcomes and reduces the risk of unintentional extra-temporal cortical injury, which fully embodies the minimally invasive principle in neurosurgery.

Correction of temporal hollowing after pterional craniotomy by autologous fat grafting. A single-center experience

OBJECTIVE

Aesthetic complications following neurosurgical procedures impact patient quality of life and self-perception. Postoperative temporal hollowing is frequently seen after temporal craniotomy, resulting mainly from atrophy of the temporal muscle. Autologous fat grafting is a tailorable method to correct such approach-related sequelae. We herein present our clinical patient series and discuss pearls and pitfalls of this method.

METHODS

In this retrospective single-center study, correction of postoperative temporal hollowing using autologous fat grafting was performed in 16 patients. Temporal tissue thickness ratio was measured using magnetic resonance tomography images to visualize the graft. Patients, plastic surgeons and neurosurgeons evaluated the results independently using the herein presented scale.

RESULTS

The mean interval between the neurosurgical procedure and fat grafting was 62 months. A mean volume of 11.5 ml autologous fat was injected in an average of 2.5 sessions after initial rigotomy. Temporal tissue thickness was significantly augmented at a mean of 2.2 years after the operation (mean 0.71 ± 0.25, range 0.43-1.1; p=0.0214) as compared to the preoperative finding (mean 0.48 ± 0.1, range 0.32-0.6). Patients were more satisfied with the results than were surgeons, reflecting the significant impact of the deformity on patient self-esteem.

CONCLUSIONS

Autologous fat grafting is a valuable method for correcting postoperative temporal hollowing that provides stable results, high patient and surgeon satisfaction and can be tailored to the patient's individual needs. It should not be considered a merely aesthetic operation, but an important rehabilitation step towards restoring the patient's quality of life.

Suprafascial dissection for pterional craniotomy to preserve the frontotemporal branch of the facial nerve with less temporal hollowing

Background:

To protect the frontotemporal branch of the facial nerve (FTFN) when performing pterional craniotomy, several reports suggest the subfascial or interfascial dissection technique. However, the reports of postoperative frontalis paralysis and temporal hollowing, which are common complications, were relatively limited. This study reports the incidence of postoperative frontalis paralysis and temporal hollowing after pterional craniotomy using the suprafascial and interfascial techniques.

Methods:

Patients who underwent pterional craniotomy, using the suprafascial technique (leaving the muscle cuff and not leaving the muscle cuff) and the interfascial technique, between November 2015 and September 2018 were retrospectively evaluated for postoperative frontalis paralysis and temporal hollowing using Chi-squared/ Fisher exact test.

Results:

Seventy-two patients underwent pterional craniotomy, using the suprafascial technique in 54 patients (leaving the muscle cuff in 21 patients and not leaving the muscle cuff in 33 patients) and the interfascial technique in 18 patients. Eleven patients (20.4%) in the suprafascial group and 1 patient (5.6%) in the interfascial group developed transient frontalis paralysis (P = 0.272). No permanent frontalis paralysis was observed. Obvious temporal hollowing occurred in 18.2% of patients in the suprafascial group without the muscle cuff, in 64.3% of patients in the suprafascial group with the muscle cuff, and in 72.7% of patients in the interfascial group (P = 0.003).

Conclusion:

The suprafascial dissection technique does not cause permanent injury of the FTFN, and this approach results in a significantly lower incidence of postoperative temporal hollowing than interfascial dissection, especially without leaving a temporalis muscle cuff.

Comparison of postoperative temporalis muscle atrophy between the muscle-preserving pterional approach and the mini-pterional approach in the treatment of unruptured intracranial aneurysms

This study aimed to compare the muscle-preserving pterional approach (modified classic pterional approach, mCP) and the mini-pterional approach (mPA) with respect to postoperative temporalis muscle atrophy.From November 2013 to April 2020, 78 patients with unruptured intracranial aneurysm of the anterior circulation underwent surgery using mCP or mPA in our institution. Patients' background characteristics, postoperative complications, and temporalis muscle volume (MV) rates (operative side/healthy side) were retrospectively investigated. In 64 patients (n = 31, mCP group; n = 33, mPA group), excluding 14 patients with missing imaging data from 6 to 24 months after surgery, associations between the MV rate and clinical variables were assessed. A multiple regression model was used to examine the association between the MV rate and the surgical method, which is a predictor of postoperative atrophy.The mCP group had a significantly higher mean MV rate than the mPA group (0.955 ± 0.040 and 0.915 ± 0.070, respectively; p = 0.008). Based on the results of the univariate analysis, a multiple regression model was established using sex, age, follow-up period, and the presence of diabetes in addition to the surgical method. Patients who underwent mCP had a higher MV rate than those who underwent mPA (t value = 2.33, p = 0.023).The present result suggested that mCP has a preventive effect on postoperative temporalis muscle atrophy. However, further studies are needed in order to prove that mCP is also effective in terms of postoperative aesthetic and functional outcomes.