Paraclinoid aneurysms: Outcome analysis and technical remarks of a microsurgical series

Abstract Introduction A critical appraisal of the surgical results of paraclinoid aneurysms is essential in the flow diverters era. This study overviews the data of a three-decade surgical series of paraclinoid aneurysms while focusing on their technical remarks. Methods Overall data of a surgical consecutive series of paraclinoid aneurysms treated between 1993 and 2021 were retrospectively reviewed. Aneurysms were classified according to size and projection. Indications for surgery were different based on the availability of endovascular techniques, especially flow diverter, at the time of treatment. A statistical comparison between ruptured and unruptured aneurysms was accomplished. Results 58 patients were operated upon. Ophthalmic aneurysms were 68%, giant aneurysms 20%, and ruptured aneurysms 45%. Clipping and bypass were executed in 91% and 9% of cases, respectively. An mRS of 0–2 was achieved in 77% of patients, independently by the clinical onset. The mortality rate was 5%. Visual field was improved or unchanged in 71% of elective patients, whereas the incidence of de novo third and sixth cranial nerves deficit was 8% and 5%, respectively. On an average follow-up of 53.3 ± 38 months, a complete and durable aneurysm exclusion was achieved in 91.3% of patients with a single surgery. Conclusions Microneurosurgery is still a valuable treatment option for selected ruptured and unruptured paraclinoid aneurysms. In our experience, it has proven to be definitive and durable, with acceptable morbidity and mortality. Clipping is the treatment of choice in most surgical cases, achieving a good visual outcome in symptomatic patients

A Dedicated Tool for Presurgical Mapping of Brain Tumors and Mixed-Reality Navigation During Neurosurgery

Brain tumor surgery requires a delicate tradeoff between complete removal of neoplastic tissue while minimizing loss of brain function. Functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) have emerged as valuable tools for non-invasive assessment of human brain function and are now used to determine brain regions that should be spared to prevent functional impairment after surgery. However, image analysis requires different software packages, mainly developed for research purposes and often difficult to use in a clinical setting, preventing large-scale diffusion of presurgical mapping. We developed a specialized software able to implement an automatic analysis of multimodal MRI presurgical mapping in a single application and to transfer the results to the neuronavigator. Moreover, the imaging results are integrated in a commercially available wearable device using an optimized mixed-reality approach, automatically anchoring 3-dimensional holograms obtained from MRI with the physical head of the patient. This will allow the surgeon to virtually explore deeper tissue layers highlighting critical brain structures that need to be preserved, while retaining the natural oculo-manual coordination. The enhanced ergonomics of this procedure will significantly improve accuracy and safety of the surgery, with large expected benefits for health care systems and related industrial investors

Development of Dye-Perfused Human Placenta Model for Vascular Microsurgery Training: Preparation Protocol and Validation Testing in Hands-on Courses

Background Learning and straightening of surgical techniques requires continuous training that cannot overlook from lab activities. During microsurgery, specific bimanual abilities are necessary to perform perfect vessels dissection and anastomosis. In this scenario, the development of realistic training models is utmost important. Objective The aim of this research is to describe a detailed method of preparation of a dye-perfused human placenta training model and its application during microsurgical hands-on courses. An original description of training exercises has been reported. Moreover, a review of the literature on this topic has been performed. Methods Forty-five fresh human placentas were collected and prepared with a specific protocol. The model was used during four hands-on microsurgical training courses held in the Experimental Laboratory of Microsurgery “Botta 2” of the University of Pavia, Italy. The total number of participants was 40 divided into young specialists and residents of Neurosurgery, Otolaryngology and Maxillofacial surgeons. An on-line survey-based questionnaire, using the platform SurveyMonkey®, was administered to each participant to subjectively assess face and content validity of the proposed training model. Differences in categorical responses between groups were analyzed using chi-quadro (χ2) test for independence with STATA® 16 (StataCorp LLC) software. A comprehensive literature review of articles regarding the use of human placenta as a microsurgical training model was performed via multiple PubMed database searches. Results Forty-two of 45 placentas were considered appropriate for microsurgical model. In selected placentas, the arteries could be easily distinguished from the veins and all three vessels were cannulated and perfused with dyes. The model was used to perform vessels dissection and end-to-end, end-to-side and side-to-side anastomosis. Of the 40 course attendees, 33 completed the questionnaire, of which most indicated the placenta as a valuable, accurate, and reproducible model. No differences were observed among the groups. Conclusion The proposed model is an excellent tool for vascular microsurgical laboratory training. A standardized protocol makes its preparation easier and color perfusion enhances its reliability. The low-cost, accessibility, and the variety of size and number of placental vessels are the most important advantages of such polyhedral model, useful for several specialized surgical fields. Due to the possibility of choosing exercises with different degrees of difficulty, this model perfectly matches the philosophy of microsurgical practice. The application of rating scale that allow to verify the teaching efficacy of this training model represents the future step of this research

The Preoperative Functional Downgrading of Brain AVMs

The actual role of preoperative embolization of brain arteriovenous malformations (AVMs) is undervalued.The present study aims to describe the effectiveness, safety, technics, and results of the endovascular-based functional downgrading of brain AVMs.Data regarding 31 Spetzler-Martin (SM) grade III AVMs that consecutively underwent a combined endovascular-surgical treatment were reviewed. Clinical and radiological outcomes were evaluated according to modified Ranking Scale score (mRS) and postoperative angiography, respectively.Low-density Onyx was used in all cases, and the timeframe between the embolizations was 10-15 days. Procedures were 1.6 (±0.6) on average. Superselective nidal catheterization was essential to reach the deepest parts of the AVMs, which were the targets. Onyx made the nidus compact and easier to dissect. The Average obliteration rate was 29.6%, with negligible morbidity. Surgery was performed after 3.7 days on average and the AVM exclusion was complete in 83.4% of cases. An mRS score between 0 and 2 was reported in 77.5% of patients, while the best outcome was achieved in small and medium-deep malformations.An effective and safe functional downgrading of brain AVMs must be based upon specific technical key aspects, which make surgery easier and, ultimately, allow for the achievement of the best outcome

Microneurosurgery for Paraclinoid Aneurysms in the Context of Flow Diverters

The advent of flow diverter (FD) stents has apparently reduced the role of microneurosurgery for paraclinoid aneurysms despite sparse high-quality evidence about their long-term effects.The present study critically reviews the overall results of a microneurosurgical series of 57 paraclinoid aneurysms.Of these aneurysms, 47.4% were regular in size while 19.3 were giant. Barami type I was predominant. In 21 aneurysms a hemorrhagic onset occurred. Pterional approach with intradural anterior clinoidectomy was preferred by far. Clipping was possible in 91.2% of aneurysms and a high-flow bypass was the choice in five cases. An mRS of 0-2 was achieved in 77.3% of patients, typically <50 years old.Visual field appeared improved or unchanged in 36.3% and 63.6% of the symptomatic patients, respectively. In 76.1% of incidental aneurysms, campimetry was unaffected by surgery.A complete aneurysm exclusion was achieved in 93% of cases using a single procedure. No recurrences were documented on an average follow-up of 54.1 ± 34 months.Microneurosurgery is still a valuable, definitive, and durable option for Barami type Ia, Ib, or II paraclinoid aneurysm, especially in patients <50 years old and visually symptomatic. Conditions other than these are ideal candidates for FD stents

Microneurosurgical Management of Posterior Inferior Cerebellar Artery Aneurysms: Results of a Consecutive Series

none3Aneurysms of the posterior inferior cerebellar artery (PICA) are uncommon. The complex anatomy of PICA and its intimate relationships with medulla, lower cranial nerves, and jugular tubercle makes the surgical treatment of these aneurysms fascinating. The reported is study aimed at a critical review of the overall results of a personal series of PICA aneurysms, treated by the senior author, R. Galzio. Demographics, charts, videos, outcome, and follow-up of a cohort of PICA aneurysms managed in the last 10 years were retrospectively analyzed, focusing only upon those treated with microneurosurgery. Twenty-five patients, harboring a single aneurysm, were operated on. Fifteen aneurysms were ruptured. Nineteen were proximal, all of these being been treated through a far-lateral approach. Trans-condylar or trans-tubercular variants were rarely necessary and however reserved to peculiar cases. Twenty-three aneurysms underwent direct treatment consisting of clip ligation. At 6-month follow-up, 60% of patients had a modified Rankin Score (mRS) of 0-2. Given the high anatomical variability of both PICA and patients' bony anatomy, a case-by-case meticulous preoperative imaging evaluation is mandatory for the choice of the most suitable and tailored surgical corridor which, in turn, is pivotal to achieve the best outcome.noneDel Maestro, Mattia; Luzzi, Sabino; Galzio, RenatoDel Maestro, Mattia; Luzzi, Sabino; Galzio, Renat