Less invasive reconstruction of the temporalis muscle for pterional craniotomy: modified procedures

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.

Novel Hybrid Technique for Preservation of Frontal Branch of Facial Nerve: Subgaleal Preinterfascial Dissection

OBJECTIVE

The pterional approach is the workhorse of skull-base neurosurgery, which allows virtual access to any intracranial lesion around the circle of Willis. Preserving the frontotemporal branch of the facial nerve and conserving the temporal muscle's symmetry are fundamental objectives besides the access that can be obtained through this versatile neurosurgical technique. This manuscript proposes a subgaleal preinterfascial dissection, a novel hybrid technique that provides advantages of previously described temporal muscle dissection techniques while preserving the integrity of facial nerve branches and the unobstructed broad pterional region. We describe the subgaleal preinterfascial dissection as a safe and simple to technique to achieve preservation of the facial nerve frontal branches during anterolateral approaches.

METHODS

Two cadaveric heads were skillfully dissected and studied to perform a proper subgaleal preinterfascial dissection on both sides of each cadaver. Afterward, the same technique was employed in 108 patients during a pterional approach for different neurosurgical diseases, with a postoperative follow-up of 6 months.

RESULTS

None of the 108 patients presented postoperative frontotemporal branch palsy during postoperative follow-up. Likewise, no complications related to the proposed technique were present.

CONCLUSIONS

The subgaleal preinterfascial dissection is a reliable, safe technique that may be employed during a pterional approach with an unobstructed surgical view and excellent cosmetic and functional results, preserving the frontotemporal branch of the facial nerve.

Surgical technique of temporal muscle resuspension during cranioplasty for minimizing temporal hollowing: A case series

Background

Temporal hollowing is a common but often overlooked complication following cranioplasty. To minimize temporal hollowing caused by temporal muscle contraction, we present the novel technique for temporal muscle resuspension during cranioplasty.

Methods

This is a retrospective case series which were done by a single surgeon at our university tertiary-A hospital between January 2019 and February 2020. The surgical technique was performed according to the forms of temporal muscle based on preoperative 3-D reconstruction and intraoperative images. All patients were followed up and evaluated on esthetic and functional outcomes.

Results

17 patients with an average age of 39.35 years, frontotemporoparietal cranial defect size of 78.85 cm², and median follow-up of 7 months were included. The main cause of decompressive craniectomy was trauma (n = 15). Techniques of temporal muscle augmentative resuspension were performed. The follow-up esthetic and functional outcome evaluation showed that all patients had good postoperative results. No revision surgery was found among the patients.

Conclusions

This study proposes methods of temporal muscle augmentative resuspension based on forms of the muscle. We believe this might be of use in minimizing temporal hollowing after cranioplasty.

Antegrade Subperiosteal Temporalis Muscle Elevation and Posterior Retraction Technique Avoiding Muscle Incision for Pterional Craniotomy: A Technical Note

Background

The current technique of pterional craniotomy involves temporalis muscle incision followed by retrograde elevation. Feasibility of antegrade temporalis muscle elevation without any direct incision over its bulk is evaluated.

Objective

Incisionless "antegrade, subgaleal, subfascial, and subperiosteal elevation" of temporalis muscle preserves vascularity and muscle bulk. Posterior maneuvering of "bare" temporalis muscle bulk either above (out rolling) or under (in rolling) the scalp for pterional craniotomy is discussed.

Material and Methods

Technique of antegrade, subfascial, subperiosteal elevation, and posterior rotation of temporalis muscle without incising in its bulk by "out rolling" or "in rolling" along the posterior aspect of the scalp incision was carried out in 15 cadavers and later in 50 surgical cases undergoing pterional craniotomy. Postoperatively, patients were evaluated for subgaleal collection and periorbital edema. Operated side cosmesis and temporalis muscle bulk was compared with nonoperated temporalis muscle at 6 months interval.

Results

Antegrade subperiosteal dissection of temporalis muscle was possible in all cases. "In-rolling" or "out rolling" technique provided adequate surgical exposure during pterional craniotomy. Postoperative subgaleal collection and periorbital edema was prevented. Facial nerve paresis or temporalis muscle-related complications were avoided.

Conclusion

Antegrade, subgaleal, subfascial, and subperiosteal dissection techniques of temporalis muscle elevation without any direct incision in its bulk enables neurovascular and muscle volume preservation. Posterior maneuvering of elevated temporalis muscle with "out rolling" or "in-rolling" technique is easy, quick, and provides adequate exposure during pterional craniotomy. Opening and closing of scalp layers without violating subgaleal space prevent postoperative subgaleal hematoma and periorbital edema.

Mastication after craniotomy: pilot assessment of postoperative oral health-related quality of life

BACKGROUND

Neurosurgical approaches to the brain often require the mobilization of the temporal muscle. Many patients complain of postoperative pain, atrophy, reduced mouth opening, and masticatory problems. Although the pterional, frontolateral-extended-pterional, and temporal craniotomies are the most frequently used approaches in neurosurgery, a systematic assessment of the postoperative oral health-related quality of life has never been performed so far. This study evaluates the oral health-related quality of life of patients after pterional, frontolateral-extended-pterional, or temporal craniotomy using a validated and standardized dental questionnaire, compares the results with the normal values of the general population, and investigates whether this questionnaire is sensitive to changes caused by surgical manipulation of the temporal muscle.

METHODS

The "Oral Health Impact Profile" (OHIP14) is a validated questionnaire to assess the oral health-related quality of life. It asks the patients to assess their oral health situation within the past 7 days in 14 questions. Possible answers range from 0 (never) to 4 (very often). Sixty patients with benign intracranial processes operated through a lateral cranial approach were included. The questionnaire was answered before surgery (baseline) and 3 months and 15 months after surgery.

RESULTS

Overall, postoperative OHIP scores increase significantly after 3 months and decrease after 15 months, but not to preoperative values. No factors can be identified which show a considerable relationship with the postoperative OHIP score.

CONCLUSIONS

Postoperative impairment of mouth opening and pain during mastication can be observed 3 to 15 months after surgery and sometimes cause feedback from patients and their dentists. However, in line with existing literature, these complaints decrease with time. The study shows that the OHIP questionnaire is sensitive to changes caused by surgical manipulation of the temporal muscle and can therefore be used to investigate the influence of surgical techniques on postoperative complaints. Postoperatively, patients show worse OHIP scores than the general population, demonstrating that neurosurgical cranial approaches negatively influence the patient's oral health-related wellbeing. Larger studies using the OHIP questionnaire should evaluate if postoperative physical therapy, speech therapy, or specialized rehabilitation devices can improve the masticatory impairment after craniotomy.

TRIAL REGISTRATION

Clinical trial register: DRKS00011096.

Keyhole approach in anterior circulation aneurysm: Current indication, advantages, technical limitations, complications and their avoidance

Keyhole surgery recently evolved as a minimal invasive surgical approach for treatment of anterior circulation aneurysm. This review was done to evaluate the keyhole approach for anterior circulation aneurysms, their indications, advantages, technical limitations, complications and their avoidance. The literature review was performed with the phrase "keyhole approach for anterior circulation aneurysm" as a search term in PubMed central, Medline, Google scholar and Embase data base to identify all the articles published till December 2020. Out of 113 articles searched, 22 were included in this review after screening for eligibility. On analyzing these articles, there was total 2058 aneurysm in 1871 patients. Out of 2058 aneurysm, 988 were ruptured and 547 unruptured. In 5 studies, which include 344 aneurysms in 344 cases, aneurysm ruptured or unruptured status was not specified. The most frequent aneurysm site was anterior communicating artery (n=573). The size of the aneurysm mentioned in most of the study was <15 mm. The rate of complete occlusion was ranged from 93.6-100%. The range of intra operative rupture (IOR) was 0-28.6%. The mean operative time was ranged from 70 min-5.34 hours as reported in 13 studies. Good outcome [Glasgow outcome scale (GOS): 4-5] were seen in 75-100% cases. The frontalis muscle weakness has been reported in 3 studies and ranged from 0-1.99%. Keyhole surgery can be a safe and effective treatment modality for treatment of a selected anterior circulation aneurysm. In the experienced hand it has certain advantages over standard pterional craniotomy.

Effects of Modified Osteoplastic Pterional Craniotomy on Temporal Muscle Volume and Frontal Muscle Nerve Function

Introduction  Pterional craniotomy is a surgical approach frequently used in aneurysm and skull base surgery. Pterional craniotomy may lead to cosmetic and functional problems, such as eyebrow drop due to facial nerve frontal branch damage, temporal muscle atrophy, and temporomandibular joint pain. The aim was to compare the postoperative effects of our modified osteoplastic craniotomy with classical pterional craniotomy in terms of any change in volume of temporal muscle and in the degree of frontal muscle nerve damage. Materials and Methods  Aneurysm cases were operated with either modified osteoplastic pterional craniotomy or free bone flap pterional craniotomy according to the surgeon's preference. Outcomes were compared in terms of temporal muscle volume and frontal muscle nerve function 6 months postoperatively. Results  Preoperative temporal muscle volume in the modified osteoplastic pterional and free bone flap pterional craniotomy groups were not different ( p  > 0.05). However, significantly less atrophy was observed in the postoperative temporal muscle volume of the osteoplastic group compared with the classical craniotomy group ( p  < 0.001). In addition, when comparing frontal muscle nerve function there was less nerve damage in the modified osteoplastic pterional craniotomy group compared with the classical craniotomy group, although this did not reach significance ( p  > 0.05). Conclusion  Modified osteoplastic pterional craniotomy significantly reduced atrophy of temporal muscle and caused proportionally less frontal muscle nerve damage compared with pterional craniotomy, although this latter outcome was not significant. These findings suggest that osteoplastic craniotomy may be a more advantageous intervention in cosmetic and functional terms compared with classical pterional craniotomy.

Cosmetic outcome after electrocautery versus non-electrocautery dissection of the temporalis muscle for pterional craniotomy

Objective

Despite the usefulness of pterional craniotomy (PC), its cosmetic outcome is questionable. Electrocautery (EC) causes injuries to adjacent structures, and it could be a factor that affects the cosmetic outcome. Evaluation of cosmetic outcome is difficult because it is often determined by patient’s subjective criteria. The objective of this study is to compare the cosmetic outcome after EC versus non-electrocautery (NEC) dissection of the temporalis muscle for PC by analyzing long-term follow-up data determined from both physician and patient’s aspects.

Methods

Patients at follow-ups between January 2014 and April 2021 after PCs were enrolled. The keyhole (KH) site, the inferior margin of the temporal line of the frontal bone (ITL), the mid-temporal (mid-T) area, and the posterior incision line (PIL) were inspected by a physician to check the presence of depressions. Patient’s cosmetic satisfaction was categorized into satisfactory, intermediate, or unsatisfactory by a survey. The presence of osteolysis was checked from the radiological images. Patients were classified into two groups; one with EC dissection and another with NEC retrograde dissection using a double-ended dissector.

Results

The incidences of depression at the mid-T area and osteolysis were higher in the EC group (p=0.001, p＜0.001). The percentage of satisfactory cosmetic outcome was lower in the EC group (p=0.002). The presences of depression at the mid-T area and osteolysis were related with lower rate of satisfactory outcomes (p＜0.001, p＜0.001).

Conclusions

NEC dissection causes less destruction to adjacent structures and brings better cosmetic outcome after PC.

Analysis of Factors Associated with Temporal Hollowing after Pterional Craniotomy

Background  Temporal hollowing is a common complication after pterional craniotomy. Etiologies of hollowing are still in debate and inconclusive. The objective of this study is to determine the etiology and predictive factors of temporal hollowing after pterional craniotomy.

Methods  A retrospective study of patients who underwent pterional craniotomy was conducted. Inclusion criteria included older than 18 years, having undergone unilateral pterional craniotomy, and with no craniofacial anomaly or temporal defect. Volumes of bone, temporalis muscle, and extratemporalis layer were calculated.

Results  A total of 51 patients were included. Bone volumes of surgical and nonsurgical sites were 219.12 + 23.02 cm ³ , and 228.39 + 22.76 cm ³ , respectively ( p = 0.04). Difference of bony volume was 9.10 cm ³ (3.99%). Volumes of temporalis muscle in surgical and nonsurgical sites were 12.86 + 3.95 cm ³ , and 18.10 + 6.08 cm ³ , respectively ( p < 0.005). Difference of muscle volume was 5.08 cm ³ (28.32%). Volume of extratemporalis soft tissue in surgical and nonsurgical sites were 11.99 + 5.70 cm ³ , and 17.31 + 7.76 cm ³ , respectively ( p < 0.005). Difference of soft tissue volume was 5.56 cm ³ (31.68%). No statistical significance of the difference of bony, muscle, and soft tissue volumes were found between causes of disease, operative time, and postoperative radiation.

Conclusions  Hollowing after pterional craniotomy is an unavoidable result. Bone, temporalis muscle, and soft tissues are combined etiologies. No predictive factors including age, sex, causes, operative time, radiation, and surgical technique are demonstrated. Volume of temporal area reduction was 19.74 cm ³ . Immediate reconstruction is recommended and volume of reconstruction is calculated from preoperative imaging.

The minipterional approach for ruptured and unruptured anterior circulation aneurysms: Our initial experience

Objective:

To report our experience with the minipterional (MPT) craniotomy approach for anterior circulation aneurysms and to discuss the clinical outcomes as well as to evaluate the advantages of this unique approach.

Materials and Methods:

Single-center retrospective review of 57 cases involving anterior circulation aneurysms both ruptured and unruptured aneurysms treated with the MPT. We analyzed the clinical and patient demographic data, aneurysm characteristics, surgical outcomes, and complications in these individuals.

Results:

Between July 2008 and March 2014, of the 57 patients reviewed: 45 had middle cerebral artery (MCA), 6 had internal carotid artery terminus, and 7 had posterior communicating artery aneurysms. 20 of the 57 patients presented with a ruptured aneurysm. The average aneurysm size was 5.8 mm. The length of hospitalization for unruptured aneurysm cases ranged between 3 and 5 days. The average follow-up for all cases was 21.5 months. Successful clipping of the aneurysms was obtained in all patients. None of the cases required additional skin incisions or craniotomy extensions. The overall surgical outcomes were favorable. There was no postoperative facial nerve damage, temporalis muscle wasting, or symptoms of paresthesias around the incision line. Two patients developed a postoperative stroke manifested as symptoms of unilateral arm and facial weakness, receptive aphasia, and dysarthria.

Conclusion:

The MPT provides a reliable and less invasive alternative to the standard pterional craniotomy. Furthermore, ruptured and unruptured anterior circulation aneurysms can safely and effectively be treated with limited bone removal which provides better cosmetic outcomes and excellent postoperative temporalis muscle function.

Superficial Temporal Artery-Sparing Mini-Pterional Approach for Cerebral Aneurysm Surgery

OBJECTIVE

The purposes of this study were to introduce a superficial temporal artery (STA)-sparing mini-pterional approach for the treatment of cerebral aneurysms and review the surgical results of this approach.

METHODS

Between June 2010 and December 2015, we performed the STA-sparing mini-pterional approach for 117 patients with 141 unruptured intracranial aneurysms. We analyzed demographic, radiologic, and clinical variables including age, sex, craniotomy size, aneurysm location, height of STA bifurcation, and postoperative complications.

RESULTS

The mean age of patients was 58.4 years. The height of STA bifurcation from the superior border of the zygomatic arch was 20.5 mm±10.0 (standard deviation [SD]). The craniotomy size was 1051.6 mm²±206.5 (SD). Aneurysm neck clipping was possible in all cases. Intradural anterior clinoidectomy was performed in four cases. Contralateral approaches to aneurysms were adopted for four cases. Surgery-related complications occurred in two cases. Permanent morbidity occurred in one case.

CONCLUSION

Our STA-sparing mini-pterional approach for surgical treatment of cerebral aneurysms is easy to learn and has the advantages of small incision, STA sparing, and a relatively wide surgical field. It may be a good alternative to the conventional pterional approach for treating cerebral aneurysms.

Postoperative temporal hollowing: Is there a surgical approach that prevents this complication? A systematic review and anatomic illustration

BACKGROUND

Temporal hollowing is a common complication following surgical dissection in the temporal region. Our objectives were to: (1) review and clarify the temporal soft tissue relationships - supplemented by cadaveric dissection - to better understand surgical approach variations and elucidate potential etiologies of postoperative hollowing; (2) identify if there is any evidence to support a surgical approach that prevents hollowing through a systematic review.

METHODS

Cadaveric dissection was performed on six hemi-heads. A systematic review of the literature was undertaken to identify surgical approaches with a decreased risk of postoperative hollowing.

RESULTS

A total of 1212 articles were reviewed; 19 of these met final inclusion criteria. Level I and II evidence supports against the use of a dissection plane beneath the superficial layer of the deep temporal fascia or through the intermediate temporal fat pad. Level II evidence supports preservation of the temporalis muscle origin - no evidence is available to support other temporalis resuspension techniques. For intracranial exposure, refraining from temporal fat pad dissection (Level I Evidence) and use of decreased access approaches such as the minipterional craniotomy (Level I Evidence) appear to minimize temporal soft tissue atrophy.

CONCLUSIONS

This study highlights the significance of preservation of the temporal soft tissue components to prevent hollowing. Preserving the temporalis origin and avoiding dissection between the leaflets of the deep temporal fascia or through the intermediate temporal fat pad appear to minimize this complication.

Effectiveness of Temporal Augmentation Using a Calvarial Onlay Graft during Pterional Craniotomy

Temporal hollowing occurs to varying degrees after pterional craniotomy. The most common cause of temporal hollowing is a bony defect of the pterional and temporal regions due to the resection of the sphenoid ridge and temporal squama for adequate exposure without overhang. The augmentation of such bony defects is important in preventing craniofacial deformities and postoperative hollowness. Temporal cranioplasty has been performed using a range of materials, such as acrylics, porous polyethylene, bone cement, titanium, muscle flaps, and prosthetic dermis. These methods are limited by the risk of damage to adjacent tissue and infection, a prolonged preparation phase, the possibility of reabsorption, and cost inefficiency. We have developed a method of temporal augmentation using a calvarial onlay graft as a single-stage neurosurgical reconstructive operation in patients requiring craniotomy. In this report, we describe the surgical details and review our institutional outcomes. The patients were divided into pterional craniotomy and onlay graft groups. Clinical temporal hollowing was assessed using a visual analog scale (VAS). Temporal soft tissue thickness was measured on preoperative and postoperative computed tomography (CT) studies. Both the VAS and CT-based assessments were compared between the groups. Our review indicated that the use of an onlay graft was associated with a lower VAS score and left-right discrepancy in the temporal contour than were observed in patients undergoing pterional craniotomy without an onlay graft.

A Simple Method for Reconstruction of the Temporalis Muscle Using Contourable Strut Plate after Pterional Craniotomy: Introduction of the Surgical Techniques and Analysis of Its Efficacy

Objective

Pterional craniotomy (PC) using myocutaneous (MC) flap is a simple and efficient technique; however, due to subsequent inferior displacement (ID) of the temporalis muscle, it can cause postoperative deformities of the muscle such as depression along the inferior margin of the temporal line of the frontal bone (DTL) and muscular protrusion at the inferior portion of the temporal fossa (PITF). Herein, we introduce a simple method for reconstruction of the temporalis muscle using a contourable strut plate (CSP) and evaluate its efficacy.

Materials and Methods

Patients at follow-ups between January 2014 and October 2014 after PCs were enrolled in this study. Their postoperative deformities of the temporalis muscle including ID, DTL, and PITF were evaluated. These PC cases using MC flap were classified according to two groups; one with conventional technique without CSP (MC Only) and another with reconstruction of the temporalis muscle using CSP (MC + CSP). Statistical analyses were performed for comparison between the two groups.

Results

Lower incidences of ID of the muscle (p < 0.001), DTL (p < 0.001), and PITF (p = 0.001) were observed in the MC + CSP than in the MC Only group. The incidence of acceptable outcome was markedly higher in the MC + CSP group (p < 0.001). ID was regarded as a causative factor for DTL and PITF (p < 0.001 in both).

Conclusion

Reconstruction of the temporalis muscle using CSP after MC flap is a simple and efficient technique, which provides an outstanding outcome in terms of anatomical restoration of the temporalis muscle.

Prospective randomized study comparing clinical, functional, and aesthetic results of minipterional and classic pterional craniotomies

OBJECT The object of this study was to compare the clinical, functional, and aesthetic results of 2 surgical techniques, pterional (PT) and minipterional (MPT) craniotomies, for microsurgical clipping of anterior circulation aneurysms. METHODS Fifty-eight patients with ruptured and unruptured anterior circulation aneurysms were enrolled into a prospective randomized study. The first group included 28 patients who underwent the MPT technique, and the second group comprised 30 patients who underwent the classic PT craniotomy. To evaluate the aesthetic effects, patients were asked to grade on a rule from 0 to 100 the best and the worst aesthetic result. Photographs were also taken, assessed by 2 independent observers, and classified as showing excellent, good, regular, or poor aesthetic results. Furthermore, quantitative radiological assessment (percentage reduction in thickness and volumetric analysis) of the temporal muscle, subcutaneous tissue, and skin was performed. Functional outcomes were compared using the modified Rankin Scale (mRS). Frontal facial palsy, postoperative hemorrhage, cerebrospinal fistula, hydrocephalus, and mortality were also analyzed. RESULTS Demographic and preoperative characteristics were similar in both groups. Satisfaction in terms of aesthetic result was observed in 19 patients (79%) in the MPT group and 13 (52%) in the PT group (p = 0.07). The mean score on the aesthetic rule was 27 in the MPT group and 45.8 in the PT group (p = 0.03). Two independent observers analyzed the patient photos, and the kappa coefficient for the aesthetic results was 0.73. According to these observers, excellent and good results were seen in 21 patients (87%) in the MPT and 12 (48%) in the PT groups. The degree of temporal muscle, subcutaneous tissue, and skin atrophy was 14.9% in the MPT group and 24.3% in the PT group (p = 0.01). Measurements of the temporal muscle revealed 12.7% atrophy in the MPT group and 22% atrophy in the PT group (p = 0.005). The volumetric reduction was 14.6% in the MPT and 24.5% in the PT groups (p = 0.012). Mortality and mRS score were similar in both groups at the 6-month evaluation (p = 0.99). CONCLUSIONS Minipterional craniotomy provides clinical results similar to those of the PT technique. Moreover, it provides better cosmetic results. It can be used safely and effectively to surgically treat aneurysms of the anterior circulation instead of the PT approach.

Lateral supraorbital approach vs pterional approach: an anatomic qualitative and quantitative evaluation

BACKGROUND

Several minimally invasive modifications of the standard pterional approach have been proposed recently. The lateral supraorbital approach is one of these modifications.

OBJECTIVE

To provide a qualitative and quantitative anatomic comparison of the surgical exposure and the operability afforded by the standard pterional approach and the lateral supraorbital approach.

METHODS

Eight pterional approaches and 8 lateral supraorbital approaches were used in 8 fresh human cadaver heads. One qualitative and 2 quantitative tools were used to assess the surgical exposure.

RESULTS

Qualitatively, the lateral supraorbital approach has the advantages of reduced trauma to the temporalis muscle and exposure that is comparable to that provided by the standard pterional approach to the sellar and suprasellar regions. This approach offers limited exposure of the interpeduncular fossa compared with the pterional one. Quantitatively, the pterional approach provides a greater surgical volume than the lateral supraorbital approach (32.90 mL vs 23.60 mL with P < .05). Also, the pterional approach provides a greater associated surgical operability than the lateral supraorbital approach (exposure score of 66 and 53, respectively). However, the lateral supraorbital approach offers an equivalent access to the anterior communicating artery complex, optic nerve, optic chiasm, and sellar area (the exposure scores were 19 for both approaches).

CONCLUSION

From an anatomic point of view, both approaches provide similar exposure to the sellar, suprasellar, and anterior communicating artery areas. The pterional approach provides better exposure of the retrosellar area. The ability to operate in the retrosellar area, as judged by our model, was higher with the pterional than with the lateral supraorbital approach.

The frontotemporal-orbitozygomatic approach: reconstructive technique and outcome

BACKGROUND

The frontotemporal-orbitozygomatic (FTOZ) approach, also known as "the workhorse of skull base surgery," has captured the interest of many researchers throughout the years. Most of the studies published have focused on the surgical technique and the gained exposure. However, few studies have described reconstructive techniques or functional and cosmetic outcomes. The goal of this study was to describe the surgical reconstruction after the FTOZ approach and analyze the functional and cosmetic outcomes.

METHODS

Seventy-five consecutive patients who had undergone FTOZ craniotomy for different reasons were selected. The same surgical (one-piece FTOZ) and reconstructive techniques were applied in all patients. The functional outcome was measured by complications related to the surgical approach: retro-orbital pain, exophthalmos, enophthalmos, ocular movement restriction, cranial nerve injuries, pseudomeningocele (PMC) and secondary surgeries required to attain a reconstructive closure. The cosmetic outcome was evaluated by analyzing the satisfaction of the patients and their families. Questionnaires were conducted later in the postoperative period. A statistical analysis of the data obtained from the charts and questions was performed.

RESULTS

Of the 75 patients studied, 59 had no complications whatsoever. Ocular movement restriction was found in two patients (2.4 %). Cranial nerve injury was documented in seven patients (8.5 %). One patient (1.2 %) underwent surgical repair of a cerebrospinal fluid (CSF) leak from the initial surgery. Two patients (2.4 %) developed delayed postoperative pseudomenigocele. One patient (1.2 %) developed intraparenchymal hemorrhage (IPH). Full responses to the questionnaires were collected from 28 patients giving an overall response rate of 34 %. Overall, 22 patients (78.5 %) were satisfied with the cosmetic outcome of surgery.

CONCLUSION

The reconstruction after FTOZ approach is as important as the performance of the surgical technique. Attention to anatomical details and the stepwise reconstruction are a prerequisite to the successful preservation of function and cosmesis. In our series, the orbitozygomatic osteotomy did not increase surgical complications or alter cosmetic outcomes.

The minipterional craniotomy: technical description and anatomic assessment

OBJECTIVE

To describe a modification of the pterional approach (PT), the minipterional craniotomy (MPT), and compare the anatomic exposure provided by these two approaches.

METHODS

The anatomic exposure offered by the MPT and PT were compared in eight sides of cadaver heads using a computerized tracking system, a robotic microscope, and an image-guidance system. The area of surgical exposure, angular exposure, and anatomic limits of each craniotomy were evaluated. Three recently operated clinical cases (EGF) are also reported.

RESULTS

There were no statistical differences in the total area of surgical exposure between the two craniotomies (PT, 1524.7 +/- 305 mm; MPT, 1469.7 +/- 380.3 mm; P > 0.05) or among the ipsilateral, middle, and contralateral components of the area (P > 0.05). There were no differences in angular exposure along the longitudinal and transverse axis angles for the three selected targets, the bifurcations of internal carotid and middle cerebral arteries, and the anterior communicating artery (P > 0.05). Except for the distal portion of the operculoinsular compartment of the sylvian fissure, no significant differences in the limits of the surgical exposure through the PT and MPT were apparent on the image-guidance system.

CONCLUSION

The MPT craniotomy provides comparable surgical exposure to that offered by the PT. The advantages of the MPT include reduction of tissue trauma and bony removal, a decrease in surgical time, and improved cosmetic outcomes.

Iatrogenic traumatic brain injury: penetration of Kirschner's knitting needle into the middle cranial cavity

Traumatic penetrations of foreign objects into the craniocerebral cavity are often encountered in the department of emergency and traumatology. A 5-year-old child was brought to the department of pediatric neurosurgery with a severe headache and fatigue. On admission, the patient had initial neurologic examinations and radiologic scans. The consciousness assessment by Glasgow Coma Scale was 13. Neuroradiologic studies revealed a long hyperdense object extending from the extracranial cavity into the middle cranial fossa. A thorough history was obtained with attention to how and when the injury was sustained. Two weeks before the incident, the child had a blunt trauma of mandibular fractures with dislocation of the temporomandibular joint. Maxillomandibular surgery was performed with a Kirschner's knitting needle to fixate the temporomandibular articulation and simple interdental ligatures for mandibular fracture stabilization. The present radiologic film suggested that the mandibular fracture was not properly fixated allowing the mobilization of Kirschner's needle moving either externally or internally. A standard pterional access with frontotemporosphenoidal approach was performed according to the method of Yasargil and Oikawa-Miyazawa followed by an extradural approach method of Dolenc to the middle cranial structure at the skull base. Several stages of hemostasis were carried out with electrohemocoagulation on the penetrated Kirschner's needle during the needle extracting process at the extradural space of the middle cranial fossa. Two weeks postoperatively, computed tomography scan revealed the supratentorial and middle craniocerebral structures were in symmetric localization. The patient was free of neurologic deficits with no signs of excessive cerebrospinal fluid volume formation. In conclusion, the method of fixation requires appropriate application techniques to ensure adequate fracture fixation during the healing cascade. The neurosurgical approach also requires a specific measure on its management and rehabilitation for the maintenance of such a patient.

Modified osteoplastic orbitozygomatic craniotomy

✓ The authors report on a surgical technique involving a one-piece osteoplastic bone flap, which incorporates the frontal, temporal, and lateral portions of the orbital rim as a technically simpler alternative to the standard orbitozygomatic (OZ) craniotomy. The orbital rim component extends just laterally from the supraorbital foramen/notch to the frontozygomatic suture. This craniotomy obviates the need for removing the zygoma and has evolved from the authors' experience in more than 200 patients with a variety of pathological lesions, both vascular and tumorous.

The osteoplastic aspect of this technique was initially evaluated in 14 cadaveric sites in seven heads dissected prior to implementing this procedure clinically. The osteoplastic bone flap minimally obstructs the surgical view and provides all the advantages of a standard OZ craniotomy. Temporalis muscle atrophy leading to temporal hollowing is avoided, a bone union to the calvaria is improved, and the possibility of bone infection is decreased. The osteoplastic component of the technique adds to the improved long-term cosmesis and warrants active consideration in the art of neurosurgery.

Cortical osteotomy technique for mobilizing the temporal muscle in pterional craniotomies. Technical note

Although many procedures have already been performed to mobilize and reconstruct the temporal muscle for pterional craniotomies, the authors described a novel cortical osteotomy technique for creating and mobilizing a cortical bone slat along the superior temporal line with the temporal muscle attached to it. Screw fixation of the cortical bone slat then provides secured temporal muscle reconstruction. As such, this new technique minimized damage to the temporal muscle and prevented the formation of an anterior temporal hollow. In addition, key hole and parietal burr hole defects were covered by the cortical bone slat.

Biomechanical properties of high-density polyethylene for pterional prosthesis

The pterional approach is the most popular surgical technique in aneurysm and skull base tumor removal. Reconstruction of the temporal contour deformity due to craniotomy requires graft implantation. Porous high-density polyethylene (PHDPE) as a craniofacial and pterional implant material recently became available. However, material properties of the pterional implant are not yet known. In order to measure the biomechanical properties of PHDPE, we implemented the tensile test, the three-point bending test and the water displacement method for density measurement. Elastic modulus varies from 227 to 307MPa. Density range is 0.68 and 0.7 depending on the size of pores. The data can be used to study the character of the porous high-density polyethylene implant, how it resists stress or fatigue in combination with conventional plating systems.

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.

Cosmetic and functional reconstruction achieved using a split myofascial bone flap for pterional craniotomy. Technical note

Cosmetic deformities that appear following pterional craniotomy are usually caused by temporal muscle atrophy, injury to the frontotemporal branch of the facial nerve, or bone pits in the craniotomy line. To resolve these problems during pterional craniotomy, an alternative method was developed in which a split myofascial bone flap and a free bone flap are used. The authors have used this method in the treatment of 40 patients over the last 3 years. Excellent cosmetic and functional results have been obtained. This method can provide wide exposure similar to that achieved using Yaşargil's interfascial pterional craniotomy, without limiting the operative field with a bulky temporal muscle flap.

A newly designed key-hole button

Patients who have undergone frontotemporal craniotomy occasionally complain of scalp deformity in the anterior temporal area. This occurs as a result of inappropriate reconstruction of the temporal muscle and repair of the bone defect at the key hole and surrounding skull. Although several methods have been developed to prevent skin indentation on burr holes located over the convexity, satisfactory cosmetic repair of the key hole remains difficult because of its complicated bone curvature. To prevent such postoperative deformity, the authors designed a button made of hydroxyapatite ceramics to fit the key hole easily. This new, biocompatible "key-hole button" is shaped to alleviate the deformity of the temple by filling the bone defect in a more natural way. The specifications of this device and its clinical application are described.

Reconstruction of the temporalis muscle for pterional and cranio-orbital craniotomies

BACKGROUND

Atrophy of the temporalis muscle can result after dissection and reattachment with pterional and cranio-orbital craniotomies. To prevent this sequel, a number of surgical modifications have been used to preserve the deep temporal nerve and artery, and also to allow for reconstruction of the temporalis muscle with minimal damage. In this report another surgical modification for reconstruction of the temporalis muscle is described that can be used in both pterional and cranio-orbital craniotomies.

METHODS

The subperiosteum of the temporalis muscle is dissected sharply away from the temporal fossa preserving the deep temporal arteries and nerves. After the intracranial procedure, the bone flap is resecured and attached to the bone, and then several small holes are made along the superior temporal line, to which the temporalis muscle is directly reattached with sutures.

RESULTS

We have used the technique described in over 100 cases without related cosmetic or temporalis atrophy. With this technique, muscle tension has been maintained with good stabilization and cosmetic appearance.

CONCLUSION

In our technique, the temporalis muscle is anatomically reconstructed to the bone with easy attachment to the superior temporal line. The muscle tension is maintained with good stabilization and cosmetic appearance.