Superciliary keyhole approach for unruptured anterior circulation aneurysms: surgical technique, indications, and contraindications

'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.

Effects of Scalp Nerve Block on the Quality of Recovery after Minicraniotomy for Clipping of Unruptured Intracranial Aneurysms : A Randomized Controlled Trial

OBJECTIVE

This study compared the quality of recovery (QoR) after minicraniotomy for clipping of unruptured intracranial aneurysms (UIAs) between patients with and without scalp nerve block (SNB).

METHODS

Patients were randomly assigned to the SNB (SNB using ropivacaine with epinephrine, n=27) and control (SNB using normal saline, n=25) groups. SNB was performed at the end of surgery. To assess postoperative QoR, the QoR-40, a patient-reported questionnaire, was used. The QoR-40 scores were measured preoperatively, 1-3 days postoperatively, at hospital discharge, and 1 month postoperatively. Pain and intravenous patient-controlled analgesia (IV-PCA) consumption were evaluated 3, 6, 9, and 12 hours and 1-3 days postoperatively.

RESULTS

All QoR-40 scores, including those measured 1 day postoperatively (primary outcome measure; 155.0 [141.0-176.0] vs. 161.0 [140.5-179.5], p=0.464), did not significantly differ between the SNB and control groups. The SNB group had significantly less severe pain 3 (numeric rating scale [NRS]; 3.0 [2.0-4.0] vs. 5.0 [3.5-5.5], p=0.029), 9 (NRS; 3.0 [2.0-4.0] vs. 4.0 [3.0-5.0], p=0.048), and 12 (NRS; 3.0 [2.0-4.0] vs. 4.0 [3.0-5.0], p=0.035) hours postoperatively. The total amount of IV-PCA consumed was significantly less 3 hours postoperatively in the SNB group (2.0 [1.0-4.0] vs. 4.0 [2.0-5.0] mL, p=0.044).

CONCLUSION

After minicraniotomy for clipping of UIAs, SNB reduced pain and IV-PCA consumption in the early postoperative period but did not improve the QoR-40 scores.

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.

The Keyhole Approach in Anterior Circulation Aneurysm - Current Indication and Limitation with Review of Literature

Introduction:

The keyhole approach has been an emerging technique for cerebral aneurysm surgery in the past two decades. The preoperative simulation and tailored-made approach for each patient make feasible to clip many cerebral aneurysms via keyhole approach. In our study, we reviewed the previous experiences of the keyhole approach, related specifically for anterior circulation aneurysm.

Material and Methods:

The comprehensive literature review was performed on PubMed, Google Scholar, ScienceDirect, and various neurosurgery and neurology journals. Then, each manuscript's reference list was reviewed for the potential relevant article. The data of total 17 articles, which met our inclusion criteria included for the final review.

Results:

It was found that the anterior communicating artery, middle cerebral artery, and internal carotid- posterior communicating aneurysms were the most common locations treated by keyhole approach. The size of an aneurysm was <10 mm in most of the studies. Many studies treated multiple aneurysms by single keyhole approach.

Conclusion:

The keyhole approach has shown benefit in term of satisfactory aneurysmal occlusion rate, short operative time, less blood loss, short hospital stay, and good overall surgical outcome.

Pterional versus superciliary keyhole approach: direct comparison of approach-related complaints and satisfaction in the same patient

OBJECTIVE The objective of this study was to evaluate and compare the level of patient satisfaction and approach-related patient complaints between a superciliary keyhole approach and a pterional approach. METHODS Patients who underwent an ipsilateral superciliary keyhole approach and a contralateral pterional approach for bilateral intracranial aneurysms during an 11-year period were contacted and asked to complete a patient satisfaction questionnaire. The questionnaire covered 5 complaint areas related to the surgical approaches: craniotomy-related pain, sensory symptoms in the head, cosmetic complaints, palpable cranial irregularities, and limited mouth opening. The patients were asked to rate the 5 complaint areas on a scale from 0 (asymptomatic or very pleasant) to 4 (severely symptomatic or very unpleasant). Finally, the patients were asked to rate the level of overall satisfaction related to each surgical procedure on a visual analog scale (VAS) from 0 (most unsatisfactory) to 100 (most satisfactory). RESULTS A total of 21 patients completed the patient satisfaction questionnaire during a follow-up clinic visit. For the superciliary procedures, no craniotomy-related pain, palpable irregularities, or limited mouth opening was reported, and only minor sensory symptoms (numbness in the forehead) and cosmetic complaints (short linear operative scar) were reported (score = 1) by 1 (4.8%) and 3 patients (14.3%), respectively. Compared with the pterional approach, the superciliary approach showed better outcomes regarding the incidence of craniotomy-related pain, cosmetic complaints, and palpable irregularities, with a significant between-approach difference (p < 0.05). Furthermore, the VAS score for patient satisfaction was significantly higher for the superciliary approach (mean 95.2 ± 6.0 [SD], range 80-100) than for the pterional approach (mean 71.4 ± 10.6, range 50-90). Moreover, for the pterional approach, a multiple linear regression analysis indicated that the crucial factors decreasing the level of patient satisfaction were cosmetic complaints, craniotomy-related pain, and sensory symptoms, in order of importance (p < 0.05). CONCLUSIONS In successful cases in which the primary surgical goal of complete aneurysm clipping without postoperative complications is achieved, a superciliary keyhole approach provides a much higher level of patient satisfaction than a pterional approach, despite a facial wound. For a pterional approach, the patient satisfaction level is affected by the cosmetic results, craniotomy-related pain, and numbness behind the hairline, in order of importance.

Supraorbital Keyhole Approach for Intracranial Aneurysms : Transitioning from Concerns to Confidence

For surgical minimalism to reduce iatrogenic traumatization, a supraorbital keyhole approach has already been successfully applied to treat many unruptured anterior circulation aneurysms. However, using this minimal approach also raises several technical concerns due to the small cranial opening and cosmetic impact of a facial incision. Yet, such technical limitations can be overcome by using favorable surgical indications, slender surgical instruments, and optimized surgical techniques, while excellent cosmetic outcomes can be achieved using a short skin incision located <1 cm from the supraorbital margin, reconstruction of any bone defects around the bone flap, and meticulous wound closure. Thus, given such reassuring surgical results, in terms of the clipping status, neurological effects, and cosmetic outcomes, any concerns can be transitioned into confidence.

[A comparative study of the efficacy and safety of the eyebrow supraorbital approach in cerebral aneurysm surgery]

OBJECTIVE

The study objective was to compare the efficacy and safety of supraorbital eyebrow (SEA) and pterional (PA) approaches in surgery of anterior circle of Willis (ACW) aneurysms and to determine the advantages and disadvantages of SEA in aneurysm clipping.

MATERIAL AND METHODS

The analysis included 166 patients with ACW aneurysms aged 18 to 70 years who were treated in the Neurosurgery Department of the Interregional Clinical Diagnostic Center (Kazan) in the period from 2013 to 2016. At the first stage of the study, factors affecting surgical outcomes were compared (by using the Glasgow outcome scale (GOS)) in subpopulations of patients operated on using SEA (n=49) and PA (n=117). At the second stage, we compared the efficacy and safety of approaches using a case-control subanalysis in appropriate subgroups of the SEA (n=37) and PA (n=37) groups. The subgroups were comparable in the following factors: gender, age, severity of subarachnoid hemorrhage (SAH) on (Fisher scale), severity of the patient's condition (Hunt-Hess scale), size and location of the aneurysm, surgery duration, intraoperative aneurysm rupture (IOAR), amount of blood loss, rate of frontal sinus surgery, rate of nasal CSF leak, rate of intraoperative and postoperative complications, hemorrhagic and ischemic complications according to postoperative CT, patient's satisfaction with the cosmetic result of surgery (visual analogue scale - VAS), and treatment outcomes (GOS). Treatment outcomes (GOS) and patient's satisfaction with the cosmetic result of surgery (VAS) were considered as the efficacy parameters. The safety parameters included the amount of blood loss, rate of frontal sinus surgery, rate of nasal CSF leak, and rate of intraoperative and postoperative (hemorrhagic and ischemic) complications.

RESULTS

At the first stage of the study, we found that the amount of intraoperative blood loss in the subpopulation of patients with ACW aneurysms who were operated on using SEA was statistically significantly less than that in the PA group (p=0.0000002). In the postoperative period, patients who underwent surgery using SEA less frequently experienced neurological deficit (p=0.003), less frequently developed first epileptic seizures (p=0.035), and had a lower rate of hemorrhagic complications (p=0.003) and better treatment outcomes (GOS) (p=0.01). Comparison of appropriate subgroups in the SEA and PA groups, which were selected according to the case-control methodology and were comparable in the main factors affecting treatment outcomes, confirmed statistically significantly lower blood loss for SEA (p=0.0000002) than for PA. Compared to the SEA group, the PA group was characterized by more frequent, but not statistically significantly different, IOAR (p=1), postoperative worsening of neurological deficit (p=0.115), newly developed epileptic seizures (p=0.493), and hemorrhagic complications (p=0.0557). There were no deaths in both groups. In the SEA group, the treatment outcome was scored 4 and 5 (GOS, favorable outcome); in the PA group, the treatment outcome was scored 3 (GOS) in 2 (5.4%) patients and 4 or 5 in 35 (94.6%) patients (p=0.063). The mean subjective score of satisfaction with the treatment result (VAS) in the SEA group was significantly higher (9.4±1) than in the PA group (8.8±1; p=0.01).

CONCLUSION

SEA is an adequate approach for clipping ACW aneurysms, in particular ACA-AComA and MCA aneurysms, which is as effective and safe as the pterional approach.

Intraoperative Mannitol Administration Increases the Risk of Postoperative Chronic Subdural Hemorrhage After Unruptured Aneurysm Surgery

OBJECTIVE

Although mannitol is used widely to facilitate brain retraction in cases of ruptured aneurysms, there is no consensus about the intraoperative administration of mannitol in the case of unruptured aneurysms. Accordingly, this study was conducted to identify an intraoperative mannitol administration strategy.

METHODS

Mannitol was administered routinely to patients (n = 90) from January 2015 to April 2016 and not administered to patients (n = 97) from May 2016 to June 2017. The patient groups with and without mannitol administration were then compared based on the patient medical records, radiologic data, and digital recordings from an intraoperative microscope.

RESULTS

The patient groups with and without mannitol administration were comparable regarding patient age, number of elderly patients, sex, and aneurysm locations. No between-group difference was identified in terms of the intradural procedural time, retraction-induced cortical injury, postoperative electrolyte imbalance, symptomatic infarction, and postoperative epidural hematomas. However, the patient group without mannitol administration showed a significantly lower incidence of chronic subdural hematomas (CSDHs) >50 mL (13.3% vs. 3.1%, P = 0.010). Moreover, a multivariate analysis revealed that an advanced age (P = 0.019), male sex (P <0.001), and mannitol administration (P = 0.040) were all statistically significant risk factors for a postoperative CSDH >50 mL following unruptured aneurysm surgery.

CONCLUSIONS

Withholding the administration of mannitol during a pterional or modified procedure for unruptured aneurysms was found to reduce the postoperative occurrence of a CSDH without increasing the operative difficulties or other postoperative complications.

Minipterional and Supraorbital Keyhole Craniotomies for Ruptured Anterior Circulation Aneurysms: Experience at Single Center

BACKGROUND

Keyhole craniotomy is a type of pterional craniotomy that involves a minimally invasive approach for the treatment of cerebral aneurysms. Currently, the minipterional keyhole craniotomy and supraorbital keyhole craniotomy procedures are frequently performed.

METHODS

We evaluated the feasibility and safety of supraorbital keyhole craniotomies and minipterional keyhole craniotomy for the clipping of ruptured intracranial aneurysms in the anterior cerebral circulation as an alternative to the pterional approach in a consecutive series of 25 patients.

RESULTS

The rate of intraoperative aneurysmal rupture was 8% (2/25), and all ruptures were safely controlled.

CONCLUSION

The success solely depends on careful selection of patients and the experience of the surgical team.

[Supraorbital keyhole craniotomy in surgery of anterior circle of willis aneurysms]

The progress in surgical treatment of intracranial aneurysms is based on the introduction of modern minimally invasive techniques. Among the variety of keyhole approaches, supraorbital craniotomy is most often used in surgical treatment of anterior circle of willis aneurysms. The authors present the preliminary results of application of supraorbital keyhole craniotomy for anterior circle of willis aneurysms in 27 patients. Most of the patients had unruptured aneurysms (18 patients). Nine patients had SAH, and 4 of them were operated on in the acute period. The patients' condition was assessed as a grade 1-2 (Hunt-Hess scale) and grade 1-3 (Fisher scale). There were no intraoperative aneurysm ruptures, other serious complications, and deaths. Postoperative complications were assessed at 2 weeks and 6 months. The postoperative cosmetic outcome was assessed by patients as excellent.

Intradural Procedural Time to Assess Technical Difficulty of Superciliary Keyhole and Pterional Approaches for Unruptured Middle Cerebral Artery Aneurysms

Objective

This study used the intradural procedural time to assess the overall technical difficulty involved in surgically clipping an unruptured middle cerebral artery (MCA) aneurysm via a pterional or superciliary approach. The clinical and radiological variables affecting the intradural procedural time were investigated, and the intradural procedural time compared between a superciliary keyhole approach and a pterional approach.

Methods

During a 5.5-year period, patients with a single MCA aneurysm were enrolled in this retrospective study. The selection criteria for a superciliary keyhole approach included : 1) maximum diameter of the unruptured MCA aneurysm <15 mm, 2) neck diameter of the MCA aneurysm <10 mm, and 3) aneurysm location involving the sphenoidal or horizontal segment of MCA (M1) segment and MCA bifurcation, excluding aneurysms distal to the MCA genu. Meanwhile, the control comparison group included patients with the same selection criteria as for a superciliary approach, yet who preferred a pterional approach to avoid a postoperative facial wound or due to preoperative skin trouble in the supraorbital area. To determine the variables affecting the intradural procedural time, a multiple regression analysis was performed using such data as the patient age and gender, maximum aneurysm diameter, aneurysm neck diameter, and length of the pre-aneurysm M1 segment. In addition, the intradural procedural times were compared between the superciliary and pterional patient groups, along with the other variables.

Results

A total of 160 patients underwent a superciliary (n=124) or pterional (n=36) approach for an unruptured MCA aneurysm. In the multiple regression analysis, an increase in the diameter of the aneurysm neck (p<0.001) was identified as a statistically significant factor increasing the intradural procedural time. A Pearson correlation analysis also showed a positive correlation (r=0.340) between the neck diameter and the intradural procedural time. When comparing the superciliary and pterional groups, no statistically significant between-group difference was found in terms of the intradural procedural time reflecting the technical difficulty (mean±standard deviation : 29.8±13.0 min versus 27.7±9.6 min).

Conclusion

A superciliary keyhole approach can be a useful alternative to a pterional approach for an unruptured MCA aneurysm with a maximum diameter <15 mm and neck diameter <10 mm, representing no more of a technical challenge. For both surgical approaches, the technical difficulty increases along with the neck diameter of the MCA aneurysm.