Jakob Erdheim (1874-1937) was a Viennese pathologist who identified and defined a category of pituitary tumors known as craniopharyngiomas. He named these lesions “hypophyseal duct tumors” (Hypophysenganggeschwülste), a term denoting their presumed origin from cell remnants of the hypophyseal duct, the embryological structure through which Rathke’s pouch migrates to form part of the pituitary gland. He described the two histological varieties of these lesions as the adamantinomatous and the squamous-papillary types. He also classified the different topographies of craniopharyngiomas along the hypothalamus-pituitary axis. Finally, he provided the first substantial evidence for the functional role of the hypothalamus in the regulation of metabolism and sexual functions. Erdheim’s monograph on hypophyseal duct tumors elicited interest in the clinical effects and diagnosis of pituitary tumors. It certainly contributed to the development of pituitary surgery and neuroendocrinology. Erdheim’s work was greatly influenced by the philosophy and methods of research introduced to the Medical School of Vienna by the prominent pathologist Carl Rokitansky. Routine practice of autopsies in all patients dying at the Vienna Municipal Hospital (Allgemeines Krankenhaus), as well as the preservation of rare pathological specimens in a huge collection stored at the Pathological-Anatomical Museum, represented decisive policies for Erdheim’s definition of a new category of epithelial hypophyseal growths. Because of the generalized use of the term craniopharyngioma, which replaced Erdheim’s original denomination, his seminal work on hypophyseal duct tumors is only referenced in passing in most articles and monographs on this tumor.
Jakob Erdheim should be recognized as the true father of craniopharyngiomas 1).
Craniopharyngiomas frequently grow from remnants of the Rathke pouch, which is located on the cisternal surface of the hypothalamic region. These lesions can also extend elsewhere in the infundibulohypophyseal axis.
These tumors can also grow from the infundibulum or tuber cinereum on the floor of the third ventricle, developing exclusively into the third ventricle.
Genetic and immunological markers show variable expression in different subtypes of CP. Several current molecular treatments have shown some success in the management of this disease. Additional clinical trials and targeted therapies will be important to improve CP patient outcomes 2).
Compared with craniopharyngiomas, sellar gliomas presented with a significantly lower ratio of visual disturbances, growth hormone deficiencies, lesion cystic changes, and calcification. Sellar gliomas had significantly greater effects on the patients’ mentality and anatomical brain stem involvement 3).
Simultaneous sellar-suprasellar craniopharyngioma and intramural clival chordoma, successfully treated by a single staged, extended, fully endoscopic endonasal approach, which required no following adjuvant therapy is reported 4).
Pascual JM, Rosdolsky M, Prieto R, Strauβ S, Winter E, Ulrich W. Jakob Erdheim (1874-1937): father of hypophyseal-duct tumors (craniopharyngiomas). Virchows Arch. 2015 Jun 19. [Epub ahead of print] PubMed PMID: 26089144.
Reyes M, Taghvaei M, Yu S, Sathe A, Collopy S, Prashant GN, Evans JJ, Karsy M. Targeted Therapy in the Management of Modern Craniopharyngiomas. Front Biosci (Landmark Ed). 2022 Apr 20;27(4):136. doi: 10.31083/j.fbl2704136. PMID: 35468695.
Deng S, Li Y, Guan Y, Xu S, Chen J, Zhao G. Gliomas in the Sellar Turcica Region: A Retrospective Study Including Adult Cases and Comparison with Craniopharyngioma. Eur Neurol. 2014 Dec 18;73(3-4):135-143. [Epub ahead of print] PubMed PMID: 25531372.
Iacoangeli M, Rienzo AD, Colasanti R, Scarpelli M, Gladi M, Alvaro L, Nocchi N, Scerrati M. A rare case of chordoma and craniopharyngioma treated by an endoscopic endonasal, transtubercular transclival approach. Turk Neurosurg.2014;24(1):86-9. doi: 10.5137/1019-5149.JTN.7237-12.0. PubMed PMID: 24535799.
The resulting bone flap is centered over the depression of the sphenoid ridge. Approximately 33% of the craniotomy is anterior to the anterior margin of temporalis muscle insertion, ≈ 66% is posterior.
With the craniotome, starting at the frontal burr hole the craniotomy is taken anteriorly across the anterior margin of the superior temporal line, staying as low as possible on the orbit (to obviate having to rongeur bone, which is unsightly on the forehead). The distance “B” from the medial extent of the craniotomy to the frontal burr hole is 3 cm for anterior circulation aneurysms. For the approaches to skull base (e.g. Dolenc approach), distance “B” is larger and takes the opening to ≈ the mid orbit. Then from point “B,” a sharp superior turn is made and the opening is taken back to point “A.” The height (“H”) of the craniotomy needs to be only ≈ 3 cm for aneurysms of the Circle of Willis, and slightly larger (≈ 5 cm) for the middle cerebral artery aneurysms. Minimal exposure of the temporal cortex is necessary for aneurysms of the skull base region. For large flaps (e.g. for tumors), “H” is made larger to expose more temporal lobe.
Frontotemporal craniotomy, also known as “pterional craniotomy” (PC), provides an optimal microscopic exposure and a wide open working space for manipulation of intracranial structures, and it has been widely used in the field of neurosurgery for treatment of lesions in the anterior and posterior circulations 2).
The pterional craniotomy provides wide, multidirectional access to the anterior and middle cranial fossae as well as many structures of the interpeduncular fossae.
Other frontotemporal craniotomies derived from the pterional 3)4) and supraorbital 5) craniotomies, as are the combined epi- and subdural approach with anterior clinoid removal 6)7) and the orbitozygomatic extension of the pterional craniotomy 8)9).
The pterional craniotomy is well established for microsurgical clipping of most anterior circulation aneurysms. The incision and temporalis muscle dissection impacts postoperative recovery and cosmetic outcomes.
The minipterional (MPT) craniotomy offers similar microsurgical corridors, with a substantially shorter incision, less muscle dissection, and a smaller craniotomy flap.
Although pterional craniotomy and its variants are the most used approaches in neurosurgery, few studies have evaluated their precise indications.
da Silva et al., evaluated the pterional (PT), pretemporal (PreT), and orbitozygomatic (OZ) approaches through quantitative measurements of area, linear, and angular exposures of the major intracranial vascular structures.
Eight fresh, adult cadavers were operated with the PT, followed by the PreT, and ending with the OZ approach. The working area, angular exposure of vascular structures and linear exposure of the basilar artery were measured.
The OZ approach presented a wider area (1301.3 ± 215.9 mm2) with an increase of 456.7 mm2 compared with the PT and of 167.4 mm2 to the PreT (P = 0.011). The extension from PT to PreT and OZ increases linear exposure of the basilar artery. When comparing the PreT and OZ, they founded an increase in the horizontal and vertical angle to the bifurcation of the ipsilateral middle cerebral artery (P = 0.005 and P = 0.032, respectively), horizontal angle to the basilar artery tip (P = 0.02), and horizontal angle to the contralateral ICA bifurcation (P = 0.048).
The OZ approach offered notable surgical advantages compared with the traditional PT and PreT regarding to the area of exposure and linear exposure to basilar artery. Regarding angle of attack, the orbital rim and zygomatic arch removal provided quantitatively wider exposure and increased surgical freedom. A detailed anatomic study for each patient and surgeon experience must be considered for individualized surgical approach indication 10).
Bojaxhi E, Louie C, ReFaey K, Gruenbaum SE, Leone BJ, Bechtel P, Barbosa MP, Chaichana KL, Quinones-Hinojosa A. Reduced Pain and Opioid Use in the Early Postoperative Period in Patients Undergoing a Frontotemporal Craniotomy under Regional vs General Anesthesia. World Neurosurg. 2021 Jun;150:e31-e37. doi: 10.1016/j.wneu.2021.02.009. Epub 2021 Mar 5. Erratum in: World Neurosurg. 2022 Apr 19;163:2. PMID: 33684585.
Kang HJ, Lee YS, Suh SJ, Lee JH, Ryu KY, Kang DG. Comparative analysis of the mini-pterional and supraorbital keyhole craniotomies for unruptured aneurysms with numeric measurements of their geometric configurations. J Cerebrovasc Endovasc Neurosurg. 2013 Mar;15(1):5–12.
Yasargil MG, Fox JL, Ray MW: The operative approach to aneurysms of the anterior communicating artery, in Krayenbül H (ed): Advances and Technical Standards in Neurosurgery. Wien: Springer-Verlag, 1975, Vol 2, pp 114–170
A video of Burkhardt et al. demonstrated the microsurgical resection of a de novo CM adjacent to a previously treated high-grade AVM and clipping of a middle cerebral artery (MCA) aneurysm. A 70-yr-old male with history of radiosurgery for AVM presented with aphasia and confusion. Preoperative angiography showed complete occlusion of the AVM. MRI showed multiple cystic lesions suspicious for radiation-induced necrosis and CM. IRB approval and patient consent was obtained. A pterional craniotomy was performed with transsylvian exposure of the insula. The radiated feeding arteries were followed to the occluded AVM nidus. A CM was noted deep to this candelabra of the MCA vessels, which were mobilized to access and resect the CM. A small incision was made in this insular cortex underneath the malformation circumferentially freeing it of adhesions. The sclerotic AVM nidus was circumferentially dissected and removed en bloc. Thorough exploration of the resection cavity revealed no residual CM or AVM nidus. Attention was then turned to the M2-MCA bifurcation aneurysm, which was occluded with a straight clip. Postoperative imaging confirmed complete CM resection. The patient recovered from his aphasia. This case demonstrates the management of a radiation-induced de novo CM following treatment of a high-grade AVM. Radiographic follow-up for radiosurgically treated AVM is needed to rule out long-term complications. Bleeding from a de novo CM mimics bleeding from residual AVM nidus, requiring careful angiographic evaluation 1).
A video of Norat et al. illustrated the use of a trans-Sylvian, trans-sulcal approach to resect a deep insular/basal ganglia cavernous malformation in a young patient. The use of the neuronavigation is essential for success in these types of operation as this tool limits the surgeon’s footprint in eloquent brain. Unlike superficial lesions where the removal of hemosiderin stained brain is possible and often safe, resection of deep-seated lesions requires the surgeon to distinguish between hemosiderin-stained brain and residual cavernous malformation. This task is not simple, and residual cavernous malformation is the most common reason for re-bleed in patients who have undergone surgery. Resection of symptomatic cavernous malformations in deep locations can be performed safely, but outcomes are heavily influenced by proper patient selection and surgeon experience. In patients with multiple cerebral cavernous malformations, such as the one in this case, genetic testing should be performed 2).
A video of Vigo et al. demonstrated the surgical management of a large left insular CM. A 29-year-old female with multiple CM and 7 years of partial seizures and recent onset of short memory loss. Neuroimaging showed a large left insular and planum polare CM with important mass effect and hemorrhage signs. The patient consented to surgery, and an awake pretemporal craniotomy was carried out with continuous motor evoked potential monitoring. No language function was localized in the superior temporal gyrus; therefore corticectomy of the middle portion was performed to expand the operative corridor. The vessel manipulation during wide opening of the sylvian fissure increased the risk of postoperative vasospasm and blood drain into the surgical field. The CM was exposed and completely removed without functional damage. The patient recovered from surgery without complications, and no seizures occurred at 2 months’ follow-up. Postoperative imaging showed complete removal of the CM 3).
A study included patients affected by iCMs and referred to the Senior Author (FA). All cases were divided in 2 groups, according to a mainly pial growth pattern (exophytic group) or a subcortical one (endophytic group). Endophytic iCM was further subdivided in 3 subgroups, based on the insular gyri involved. According to this classification, each patient underwent a specific additional neuroimaging investigation and surgical evaluation.
Results: A total of 24 patients were included. In the surgical group, trans-sylvian (TS) approach was used in 6 patients with exophytic or Zone I endophytic iCMs. The transcortical (TC) approach with awake monitoring was used in 6 cases of Zone II endophytic vascular lesions. Both TS and trans-intraparietal sulcal (TIS) approach were used for 3 cases of Zone III endophytic iCM. At follow-up, 3 patients were fully recovered from a transient speech impairment while a permanent morbidity was observed in one case.
Conclusions: ICMs represent a single entity with peculiar clinical and surgical aspects. The proposed iCM classification focuses on anatomical and functional concerns, aiming to suggest the best pre-operative work-up and the surgical evaluation 4).
A 25-yr-old female presented with an acute-onset right homonymous hemianopsia. Neuroimaging revealed a large left insular CM, adjacent to the posterior limb of IC. After obtaining IRB approval and patient consent, a left pterional craniotomy with a wide distal Sylvian fissure split was completed. Using neuronavigation, an insular entry point was chosen for corticectomy. The CM was opened with subsequent hematoma evacuation and intracapsular resection technique. Inspection of the cavity revealed remnants anteromedially near the IC, which were removed meticulously, mobilizing the CM away from the IC. Postoperative MRI demonstrated gross total resection of the CM. The patient was discharged home on postoperative day 5 with persistent homonymous hemianopia.This case describes the use of a transsylvian-transinsular approach to access deep lesions with the shortest surgical distance and minimal cortical transgression. A wide Sylvian fissure split exposes the M2 MCA and accesses a safe insular zone, keeping the most eloquent structures deep to the lesion in the surgical corridor. This approach can safely expose vascular pathologies in the insular region without the risk of injury to overlying eloquent frontal and temporal lobes, even in the dominant hemisphere 5).
Vigo V, Zanabria Ortiz R, Paganelli SL, da Costa MDS, Campos Filho JM, Chaddad-Neto F. Awake Craniotomy for Removal of Left Insular Cavernous Malformation. World Neurosurg. 2019 Feb;122:209. doi: 10.1016/j.wneu.2018.10.220. Epub 2018 Nov 9. PubMed PMID: 30415050.
Fioravanti A, Elia A, Morandini A, Valtulina C, Bertuccio A. Anatomo-functional evaluation for management and surgical treatment of insular cavernous malformation: a case series. Acta Neurochir (Wien). 2022 Jan 23. doi: 10.1007/s00701-021-05089-3. Epub ahead of print. PMID: 35066681.
Adjunctive devices are commonly employed in the treatment of wide necked cerebral aneurysms. Balloon remodeling and permanent stent implantation may lead to thromboembolic complications or the need for antiplatelet use. A temporary stent that does not lead to complete flow arrest may be beneficial 1).
Taqi et al. reported a early multi-institutional experience with the Comaneci device in the USA.
They reviewed all patients with WNAs that were treated using the Comaneci device for coil remodeling of ruptured and unruptured aneurysms at 4 institutions between July 2019 and May 2020. Clinical characteristics, angiographic variables, and endovascular results were assessed.
A total of 26 patients were included (18 women). The mean age was 62.7 years (range 44-81). Fifteen patients presented with ruptured aneurysms and 11 with unruptured aneurysms. The mean aneurysm neck width was 3.91 mm (range 1.9-6.5) with a mean dome-to-neck ratio of 1.57 (range 0.59-3.39). The mean maximum width was 5.80 mm (range 3.0-9.9) and the mean maximum height was 5.61 mm (range 2.0-11.8). Successful aneurysm occlusion was achieved in 25 of 26 patients. Complete occlusion was achieved in 16 patients, near-complete occlusion was observed in 9 patients, and 1 patient demonstrated residual filling. The mean time of device exposure was 24 min (range 8-76). No vasospasm was observed at the device location. Clot formation on the device was noted in 2 separate cases, but there were no clinical sequelae. There was 1 intraprocedural complication in a case that involved the simultaneous use of 2 Comaneci devices.
The initial experience shows that the Comaneci device is a promising and reliable tool that can safely support coil remodeling of WNAs 2).
Five patients underwent Comaneci-assisted wide-necked aneurysm coiling during the study period; 4 were treated via a radial artery approach, and 1 was treated via a femoral artery approach. Two patients presented with subarachnoid hemorrhage: 1 had a ruptured posterior inferior cerebellar artery aneurysm (Hunt-Hess 5, Fisher 4), and 1 had a ruptured middle cerebral artery aneurysm (Hunt-Hess 2, Fisher 1). Mean aneurysmal neck size was 4.4 ± 0.8mm; mean aspect ratio was 1.2 ± 0.3. Raymond-Roy 1 occlusion was achieved in all aneurysms except the posterior inferior cerebellar artery aneurysm. Systematic literature review identified 4 articles that found use of the Comaneci device to treat wide-necked aneurysms to be effective.
This device can be used with transfemoral and transradial approaches, allowing for continued flow through the parent vessel during the coiling procedure while providing a scaffold for dense coiling of the aneurysm and its neck 3).
Kara et al. from Bakirkoy, Istanbul, Turkey reported the experience of using single stent-assisted coiling combined with a Comaneci device in the treatment of unruptured WNBAs at 1-year angiographic follow-up, there was no filling in any aneurysm. There was no mortality or morbidity cases related to the procedure 4).
Molina-Nuevoet al. reported a retrospective single-center analysis taken from a prospective database of consecutive aneurysms of the anterior circulation treated using the Comaneci device in the period from March 2017 to March 2019.
Eighteen aneurysms were collected from 16 patients (9 women and 7 men) treated using the Comaneci device. The mean age was 48.4 years (range 36-81). Twelve patients had SAH, three were incidental aneurysms and one had compressive symptoms. A complete asymptomatic occlusion rate of 88.8% was obtained. The major complication rate was 5.55%.
The Comaneci embolization assist device is a safe, effective option for endovascular treatment of complex aneurysms with an unfavorable ratio 5).
29 ruptured intracranial aneurysms from different locations were included. Successful embolization was achieved in all lesions; complete post-procedure occlusion was seen in 25 (86%) cases. Insufficient embolization or neck remnant was observed in four cases (13.7%). Complications probably related, directly related, or indirectly related to the device occurred in 3.44% of patients (1/29 patients). At least one angiographic follow-up was performed in each of the 29 cases. The 12 month follow-up examination has yet to be done.
Conclusion: The Comaneci device offers a new promising and reliable technique that can safely support aneurysm coiling occlusion even in a rupture environment. However, long term monitoring of patients treated by this device is mandatory 6)
All intracranial aneurysms treated by coil occlusion with the Comaneci device between December 2014 and November 2015 were included. Angiographic and clinical results were retrospectively analysed, including follow-up examinations. All aneurysms were unruptured.
18 aneurysms of the internal carotid artery were included. Successful coil occlusion assisted by the Comaneci device as intended was possible in 14 cases (77.8%). Insufficient coverage of the aneurysmal neck was observed in four cases (22.2%), with modification of the treatment to stent-assisted coiling or remodeling. One clinically relevant complication occurred (5.6%).
The initial experience showed that use of the Comaneci device is straightforward for the treatment of selected wide-necked aneurysms. Further studies with long-term follow-up data are needed to identify the significance of the presented technique in the neurointerventional armamentarium 7).
Three patients were treated with the Comaneci device. Two patients had acute ruptured posterior communicating aneurysms and one patient was treated electively for a carotico-ophthalmic aneurysm. Excellent occlusion of all three aneurysms was obtained. One patient developed a distal middle cerebral artery clot, that was treated with intravenous aspirin, with minor neurological consequences. These early results show that the Comaneci device can be used to achieve good cerebral aneurysm occlusion. Vessel patency is maintained throughout the procedure with potential advantages over conventional balloon assisted coiling 8).
A 57-year-old female patient presented to our hospital with a 3-month history of frequent multiple sentinel severe headaches. At the time of hospitalization, the patient was neurologically intact with a Glasgow Coma Scale score of 15. There was no evidence of focal neurologic deficits or cranial nerve lesions, but there was discrete neck stiffness and a diagnosed saccular aneurysm associated with a fenestration of the basilar artery. After multidisciplinary discussion involving neurosurgeons and interventional neuroradiologists and taking into consideration the patient’s clinical presentation and previous history of subarachnoid hemorrhage, as well as the morphology of the posterior circulation aneurysm, endovascular treatment of the basilar fenestration aneurysm was deemed appropriate or simply use was chosen.
This case results are similar to previously published good results of endovascular coiling and add information regarding the relatively new Comaneci device, which helped to achieve considerable packing density of the aneurysmal sac. Using this device lowers the risk of peri- and postoperative complications. We believe that this technique is safer and better than the balloon-assisted and stent-assisted coiling in ruptured case scenarios of wide-neck aneurysms in the posterior circulation. 9)
Taqi MA, Raz E, Vechera A, Shapiro M, Gupta R, Haynes J, Taussky P, Grandhi R, Riina HA, Nelson PK, Nossek E. Early Experience with Comaneci, a Newly FDA-Approved Controllable Assist Device for Wide-Necked Intracranial Aneurysm Coiling. Cerebrovasc Dis. 2021 May 10:1-8. doi: 10.1159/000514371. Epub ahead of print. PMID: 33971661.
Lim J, Vakharia K, Waqas M, Affana C, Siddiqui AH, Davies JM, Levy EI. Comaneci Device for Temporary Coiling Assistance for Treatment of Wide-Necked Aneurysms: Initial Case Series and Systematic Literature Review. World Neurosurg. 2021 May;149:e85-e91. doi: 10.1016/j.wneu.2021.02.080. Epub 2021 Feb 25. PMID: 33640525.
Kara B, Selcuk H, Kilinc F, Cakir C, Zalov H. Combination of temporary bridging device (Comaneci) and permanent stenting in the treatment of unruptured wide neck bifurcation aneurysms. Neuroradiology. 2021 Mar 7. doi: 10.1007/s00234-021-02677-z. Epub ahead of print. PMID: 33677621.
Sirakov S, Sirakov A, Hristov H, Minkin K, Penkov M, Karakostov V. Early experience with a temporary bridging device (Comaneci) in the endovascular treatment of ruptured wide neck aneurysms. J Neurointerv Surg. 2018 Oct;10(10):978-982. doi: 10.1136/neurintsurg-2017-013641. Epub 2018 Feb 6. PMID: 29438035.
Lawson AL, Chandran A, Puthuran M, Goddard T, Nahser H, Patankar T. Initial experience of coiling cerebral aneurysms using the new Comaneci device. BMJ Case Rep. 2015 Jun 29;2015:bcr2015011726. doi: 10.1136/bcr-2015-011726. PMID: 26123460; PMCID: PMC4488707.
Sirakov S, Panayotova A, Sirakov A, Hristov H, Minkin K, Raychev R. Fenestration of the Basilar Artery associated with Aneurysm treated by support of temporary bridging device – Comaneci. A case report. World Neurosurg. 2018 Aug 18. pii: S1878-8750(18)31830-8. doi: 10.1016/j.wneu.2018.08.047. [Epub ahead of print] PubMed PMID: 30130570.
The PECD prototype is fluoroscopically guided percutaneous cervical disc decompression without endoscopic visualization, such as automated nucleotomy7)8).
Randomized controlled trials
Ahn et al. compared the surgical results of PECD and ACDF. Data from patients treated with single-level PECD (n = 51) or ACDF (n = 64) were analyzed. Patients were prospectively entered into the clinical database and their records were retrospectively reviewed. Perioperative data and clinical outcomes were evaluated using the visual analogue scale (VAS), Neck Disability Index (NDI), and modified Macnab criteria. VAS and NDI results significantly improved in both groups. The rates of excellent or good results were 88.24% and 90.63% in the PECD and ACDF group, respectively. The revision rates were 3.92% and 1.56% in the PECD and ACDF group, respectively. Operative time, hospital stay, and time to return to work were reduced in the PECD group compared to the ACDF group (p < 0.001). The five-year outcomes of PECD were comparable to those of conventional ACDF. PECD provided the typical benefits of minimally invasive surgery and may be an effective alternative for treating soft cervical disc herniation 9).
A total of 103 patients with ACDF or FACD were followed up for two years. In addition to general parameters specific measuring instruments were used. Postoperatively 85.9% of the patients no longer had arm pain, and 10.1% had occasional pain. There were no significant clinical differences between the decompression with or without fusion. The full-endoscopic technique afforded advantages in operation technique, rehabilitation and soft tissue injury. The recorded results show that FACD is a sufficient and safe alternative to conventional procedures when the indication criteria are fulfilled. At the same time, it offers the advantages of a minimally invasive intervention 10).
Ahn Y, Keum HJ, Shin SH. Percutaneous Endoscopic Cervical Discectomy Versus Anterior Cervical Discectomy and Fusion: A Comparative Cohort Study with a Five-Year Follow-Up. J Clin Med. 2020 Jan 29;9(2). pii: E371. doi: 10.3390/jcm9020371. PubMed PMID: 32013206.
Ruetten S, Komp M, Merk H, Godolias G. Full-endoscopic anterior decompression versus conventional anterior decompression and fusion in cervical disc herniations. Int Orthop. 2009 Dec;33(6):1677-82. doi: 10.1007/s00264-008-0684-y. Epub 2008 Nov 18. PubMed PMID: 19015851; PubMed Central PMCID: PMC2899164.
Unlike traditional textbooks that detail natural history, physiology, and morphology, Video Atlas of Neuroendovascular Procedures presents basic and complex neuroendovascular procedures and cases with concise text and videos. Renowned neuroendovascular surgeons Leonardo Rangel-Castilla, Adnan Siddiqui, Elad Levy, and an impressive group of contributors have compiled the quintessential neuroendovascular resource. Organized into eight major subtopic sections, this superb video atlas covers a full spectrum of endovascular approaches to diagnose and treat intra- and extracranial neurovascular disease.
The book starts with a section on vascular access and concludes with endovascular complications and management. Forty chapters includes succinct summaries, scientific procedural evidence, the rationale for endovascular intervention, anatomy, required medications, device selection, avoiding complications, and managing potential problems that can arise during procedures. The image-rich clinical cases feature insightful firsthand knowledge and pearls.
More than 1,000 relevant, high quality neuroimaging findings and artist illustrations enhance understanding of impacted anatomy and approaches Specific techniques and key steps are brought to life through more than 140 outstanding videos narrated by highly experienced endovascular neurosurgeons — conveniently accessible via smart phones or tablets using QR technology Essential diagnostic procedures such as cerebral and spinal angiography, cerebral venogram, and balloon test occlusion Complex neuroendovascular procedures including various angioplasty and stenting approaches for extracranial vessel disease, carotid and vertebral arteries, and venus sinus; thrombectomy procedures to treat acute ischemic stroke; and coiling, flow diversion, and embolization techniques for intracranial aneurysms, brain/spinal AVMs and fistulas, and select CNS and extracranial tumors The content-rich reference is a must-have for all resident and veteran neurosurgeons, interventional radiologists, and neurologists. Learn to safely perform a wide array of cutting-edge neuroendovascular procedures — from access to closure — and achieve improved outcomes for your patients.
They settle in an area of great hemodynamic stress. This characteristic, together with the fact that it affects young individuals, a tendency to growth and bleeding, a high rate of early bleeding and an unfavorable neck-bottom relationship, make these brain aneurysms good candidates for microsurgical treatment versus endovascular treatment. However, and even considering that the incidence of these aneurysms is relatively low, references in the literature on this subgroup of aneurysms are very scarce 1). 2)3)4)5)6)7)8).
Sakamoto et al. studied the location of the aneurysm sac and showed that they somewhat deviate towards the exit of the A1, where hemodynamic stress would be higher 9).
Some cases have been described associated with agenesis or internal carotid fenestration 10).
They are characterized clinically by their tendency to occur at a younger age.
The most frequent clinical presentation is subarachnoid hemorrhage, although in the Gonzalez-Darder et al. series most of the intervened cases were discovered by chance. In the literature, it is described that some patients present with the ophthalmologic clinic by compression of the optic belt. Since the aneurysm is buried in the sinus of the frontal lobe, the association of a frontal hematoma that rises towards the caudate is typical and can open to the lateral ventricle, often associating long-path deficits. As in the series described, most of our patients were female and many of them young. This last fact implies the need to study associated risk factors, especially vascular dysplasias, connective diseases, and polycystic kidney disease. At the time of diagnosis, aneurysms are usually medium or large in size, giant aneurysms being exceptional 15).
They frequently rupture at a younger age compared to other intracranial aneurysms 16).
Additionally, the increased hemodynamic stress at this level translates into a higher rate of recurrent aneurysm compared with aneurysms in other locations 17)18)
Treatment is recommended since they tend to bleed at a lower age than other aneurysms 19).
The presence of multiple perforators in this area along with the angle of origin often skewed toward the MCA or the anterior cerebral artery primarily can make treatment challenging 20).
They are surgically characterized by the technical difficulties posed by their domes being adherent to the frontal lobe, their location at the apex of the sylvian fissure, and their relation to myriad perforator complexes 21).
The surgical treatment of ICA bifurcation aneurysms is particularly challenging, due to their location at the highest point of the ICA and the presence of multiple perforators at this level that may be adherent to the back side of the aneurysm 22)
Endovascular treatment of ICA bifurcation aneurysms is feasible and effective and is associated with high immediate angiographic occlusion rates. However, retreatment rates and procedure-related morbidity and mortality are non-negligible 23).
Periprocedural complications following endovascular treatment of ICA terminus aneurysms are not negligible. Aneurysms at this location are at a high risk of ischemic stroke in the territory of the ipsilateral MCA (either from distal emboli during the procedure or clot formation at the level of the neck with impairment of distal MCA flow), a potential source of serious morbidity and mortality 24)25)26).
In the meta-analysis of Morales-Valero et al., perioperative morbidity rates were approximately 4% and mortality rates were 3%. Perioperative stroke was a major contributor to morbidity and mortality, occurring in approximately 3% of patients. Although good long-term neurologic outcome was achieved in 90% of patients regardless of aneurysm rupture status, the periprocedural complication rate reported is not trivial. Particularly worrisome is the procedure-related mortality of 4% for unruptured and 6% for ruptured ICA bifurcation aneurysms. These findings stress the importance of proper patient selection because these aneurysms are often adequately and effectively treatable with surgical clip ligation. The high retreatment rate observed in the meta-analysis and in the own series is similar to that reported for aneurysms located in other bifurcation points 27).
Fifty-one patients with ICAbifAs were treated in the study period out of which 40 patients underwent microsurgical clipping. The median age was 48 yr (range 14-68 yr). Nearly 95% of the patients presented in a good clinical grade (World Federation of Neurological Surgeons grade 1 and 2). At 6-mo follow-up, 36 patients (90%) had good clinical outcome (Glasgow Outcome Scale 4 and 5). According to their direction, ICAbifAs were grouped as anteriorly directed (10 cases), superiorly directed (23 cases), and posteriorly directed (7 cases). Operative techniques and nuances utilized depend on aneurysmal direction and are presented here.
An appropriate surgical strategy based on the direction of ICAbifAs as per the preoperative radiology, meticulous dissection of aneurysmal wall from adjacent perforators, and clip application with the aim of remodeling the ICA bifurcation are integral to achieving a good outcome 28).
Fifty-nine patients with 61 unruptured ICAbifAs were included. Seven aneurysms were treated surgically (11.5 %), 22 underwent endovascular treatment (36 %), and 32 were managed conservatively (52.5 %). In the surgical group, short- and long-term complete aneurysm occlusion rates were 100 % with no cases of perioperative or long-term permanent morbidity or treatment-related mortality. In the endovascular group, two patients (11.7 %) with giant aneurysms had perioperative thromboembolic events with transient morbidity. There was one case of aneurysm rupture at follow-up in a giant aneurysm treated with partial coil embolization. Complete/near-complete occlusion rates were 63 %. There was one case of aneurysm rupture after 114 aneurysm-years of follow-up in the conservative management group (0.89 %/year), but no ruptures were observed in small aneurysms selected for conservative management.
Unruptured small ICAbifAs have a benign natural history. In patients selected for treatment, excellent results can be achieved in the vast majority of patients with judicious use of endovascular and surgical therapy 29).
A total of 58 patients with ICA bifurcation aneurysms were treated. By interdisciplinary consensus, 30 aneurysms were assigned for coiling and 28 for clipping. Patients who underwent surgical clipping were younger and had larger aneurysms. More patients were assigned to coiling if their aneurysms originated only from the ICA bifurcation or projected superiorly. For the combined angiographic endpoint, complete and nearly complete occlusion (Raymond-Roy I + II), similar rates of 96% (coiling) or 100% (clipping) could be achieved. Raymond-Roy I occlusion occurred more often after clipping (79% vs 41% coiling). Follow-up of the endovascular group showed minor recanalization of the aneurysm neck (Raymond-Roy II) in 42%. One patient (4%) showed a major recanalization (Raymond-Roy III) and needed re-treatment. For incidental findings, no bleeding complications or new persistent neurological deficits occurred during follow-up.
Treatment of ICA bifurcation aneurysms after interdisciplinary assignment to clipping or coiling is effective and safe. Despite significantly more minor recanalizations after coiling, the re-treatment rate was very low, and no bleeding was observed during follow-up. Multivariate analysis revealed that origin only from the ICA bifurcation was an independent predictor of aneurysm recanalization after endovascular treatment 30).
The records of 65 patients with 66 ICA BA were retrieved from data prospectively accrued between September 1999 and July 2013. Clinical and morphological outcomes of the aneurysms were assessed, including technical aspects of treatment.
The aneurysms under study were directed either superiorly (41/66, 62.1%), anteriorly (24/66, 36.4%), or posteriorly (1/66, 1.5%), and all were devoid of perforators. Aneurysmal necks were situated symmetrically at the terminal ICA (37/66, 56.1%) or slightly deviated to the proximal A1 segment (29/66, 43.9%). The steam-shaped S microcatheter (73.8%) was most commonly used to select the aneurysms, and the single microcatheter technique was most commonly applied (56.1%) to perform coil embolization, followed by balloon remodelling (21.2%), multiple microcatheter (15.1%), and stent-protection (7.6%). Successful aneurysmal occlusion was achieved in 100% of cases, with no procedure-related morbidity or mortality. Imaging performed in the course of follow-up (mean duration 27.3 months) confirmed stable occlusion of most lesions (47/53, 88.7%).
Through tailored technical strategies, ICA BA are amenable to safe and effective endovascular coil embolization, with a tendency for stable occlusion long-term 31).
Morales-Valero et al. performed a comprehensive literature search for reports on contemporary endovascular treatment of ICA bifurcation aneurysms from 2000 to 2013, and we reviewed our experience. We extracted information regarding periprocedural complications, procedure-related morbidity and mortality, immediate angiographic outcome, long-term clinical and angiographic outcome, and retreatment rate. Event rates were pooled across studies by using random-effects meta-analysis.
Including our series of 37 patients, 6 studies with 158 patients were analyzed. Approximately 60% of the aneurysms presented as unruptured; 88.0% (95% CI, 68.0%-96.0%) of aneurysms showed complete or near-complete occlusion at immediate postoperative angiography compared with 82.0% (95% CI, 73.0%-88.0%) at last follow-up. The procedure-related morbidity and mortality were 3.0% (95% CI, 1.0%-7.0%) and 3.0% (95% CI, 1.0%-8.0%), respectively. The retreatment rate was 14.0% (95% CI, 8.0%-25.0%). Good neurologic outcome was achieved in 93.0% (95% CI, 86.0%-97.0%) of patients.
Endovascular treatment of ICA bifurcation aneurysms is feasible and effective and is associated with high immediate angiographic occlusion rates. However, retreatment rates and procedure-related morbidity and mortality are non-negligible 32).
Internal carotid artery (ICA) bifurcation aneurysms are relatively uncommon and frequently rupture at a younger age compared to other intracranial aneurysms.
Gupta et al treated a total of 999 patients for intracranial aneurysms, of whom 89 (8.9%) had ICA bifurcation aneurysms, and 42 of the 89 patients were 30 years of age or younger. The study analyzed the clinical records of 70 patients with ICA bifurcation aneurysms treated from mid 1997 to mid 2003. Multiple aneurysms were present in 15 patients. Digital subtraction angiography films were studied in 55 patients to identify vasospasm and aneurysm projection. The aneurysm projected superiorly in most of these patients (37/55, 67.3%).
They preferred to minimize frontal lobe retraction, so widely opened the sylvian fissure to approach the ICA bifurcation and aneurysm neck. Elective temporary clipping was employed before the final dissection and permanent clip application. Vasospasm was present in 24 (43.6%) of 55 patients. Forty-eight (68.6%) of the 70 patients had good outcome, 14 (20%) had poor outcome, and eight (11.4%) died. Patients with ICA bifurcation aneurysms tend to bleed at a much younger age compared to those with other intracranial aneurysms. Wide opening of the sylvian fissure and elective temporary clipping of the ICA reduces the risk of intraoperative rupture and perforator injury. Mortality was mainly due to poor clinical grade and intraoperative premature aneurysm rupture 33).
A series of 25 patients treated by clipping under the operating microscope are analyzed and compared with previous cases. Twenty-five patients, 11 men and 14 women (mean age 51 years), were treated by the same neurosurgeon. Seventeen patients presented with subarachnoid hemorrhage (Hunt & Kosnik Grade I in three, II in five, III in two, IV in seven), five with unruptured ICA bifurcation aneurysms, and three with unruptured ICA bifurcation aneurysms but another ruptured aneurysm. There were 23 small, one large, and one giant ICA bifurcation aneurysms. The projection was superior in 12, anterior in seven, and posterior in six cases. Pterional approach was employed for all cases. Outcomes were evaluated at discharge with the Glasgow Outcome Scale. Favorable outcomes (good recovery (GR) and moderate disability (MD)) were obtained in ten of 17 patients with ruptured ICA bifurcation aneurysm. Favorable outcomes were significantly greater in Grades I and II (three in I, four in II) than in Grades III and IV (one in III, two in IV; P=0.0498). Seven of eight patients with unruptured ICA bifurcation aneurysm had favorable outcomes. Temporary clipping and projection of the aneurysm did not affect the outcome. Causative factors of unfavorable outcomes were primary brain damage in cases of small and large aneurysms and perforator damage in the case of giant aneurysm. Poor clinical grade and vasospasm are the causative factors of poor outcome in patients with ruptured ICA bifurcation aneurysm. Preservation of perforators is crucial in cases of giant aneurysm. Clipping of unruptured ICA bifurcation aneurysms is recommended since they tend to bleed at a lower age than other aneurysms 34).
Mahajan et al. reported a unique case of recanalized left internal carotid artery aneurysm with thrombus adherent to the aneurysm neck and M1 origin diagnosed on 2-dimensional angiography causing embolic stroke in a 66-year-old female who was successfully treated with stent-assisted coiling. This is important to recognize as a cause of embolic stroke 35).
A 70-year-old man with progressive visual disturbances, left superior quadrantanopsia, and right-sided papilledema underwent imaging that demonstrated a right internal carotid artery (ICA) terminus aneurysm with third-ventricle mass effect and ipsilateral optic nerve and chiasm compression. We performed a right modified orbitozygomatic craniotomy, with proximal control and dissection of the aneurysm and small perforator arteries. Temporary ICA and anterior cerebral artery (ACA) clips allowed placement of a large curved permanent clip, reconstructing the ICA bifurcation and maintaining adequate patency of the ACA and middle cerebral artery. Complete aneurysm obliteration was confirmed by intraoperative indocyanine green angiography and postoperative CT angiography. The video can be found here: http://youtu.be/5WEEgmA-g2A36).
A 64-year-old woman, with visual deficit, harboring a large wide-necked aneurysm located at the junction between left internal carotid artery and left A1 segment of anterior cerebral artery, was submitted to endovascular treatment. As she had pre-existing occlusion of left internal carotid, approach from the contralateral internal carotid was used to advance the pipeline embolization device through the anterior communicating artery and place the flow diverter horizontally across the neck (from M1 to A1). Coil embolization was also performed through a microcatheter navigated via posterior communicating artery. The intervention was uneventful, with total aneurysm occlusion. Patient presented with visual improvement on follow-up.
Horizontal deployment of pipeline embolization device appears to be an acceptable and feasible alternative to treat internal carotid bifurcation aneurysms. Long-term follow-up and a greater number of cases are mandatory to establish the safety of this strategy 37).
In a video presentation, a 68-year-old male with a large ruptured right ICA bifurcation aneurysm is presented. The patient’s neurological exam was rapidly deteriorating, therefore the patient was transferred to the operating theater after initial evaluation by CT and CT angiogram. A pterional craniotomy was performed, the frontal hematoma was partially removed and the aneurysm was clipped. Residual hematoma was removed after securing the aneurysm and the aneurysm dome was punctured(detail of surgical clipping in the video). Patient made a good recovery at 2 weeks post-op with complete recovery of left sided weakness, and some remaining cognitive deficit. The video can be found: http://youtu.be/dKFWptdgC4M38).
Cikla et al. presented a 66-year-old man with seizures, aphasia, and hemiparesis. Work-up revealed a giant partially thrombosed aneurysm of the internal carotid artery bifurcation with surrounding vasogenic edema. He underwent clip reconstruction of the aneurysm via a cranio-orbital approach. Although they prepared for bypass with the radial artery and/or the superficial temporal artery, they were able to clip-reconstruct the aneurysm without bypass. The patient improved upon his pre-morbid state after surgery and made an excellent recovery. The video can be found in http://youtu.be/P_10hRQFuPo39).
A report of Zhang et al. documented the treatment of a giant aneurysm of the internal carotid artery bifurcation with a fistula to the cavernous sinus, which appeared following closed head trauma. A 39-year-old man suffered from blunt head trauma in an automobile accident. Two weeks after the trauma, progressive chemosis of the left eye was presented. Four months after the trauma, digital subtraction angiography showed an internal carotid artery bifurcation aneurysm, with drainage into the cavernous sinus. The lesion was successfully obliterated with preservation of the parent artery by using coils in conjunction with Onyx. Follow-up angiography obtained 3 months postoperatively revealed persistent obliteration of the aneurysm and fistula as well as patency of the parent artery. Endovascular treatment involving the use of coils combined with Onyx appears to be a feasible and effective option for treatment of this hard-to-treat lesion 40).
A 55-year-old man presented with intracerebral hemorrhage (ICH) without subarachnoid hemorrhage (SAH) manifesting as acute onset of consciousness disturbance and right hemiparesis. Computed tomography showed ICH mainly localized in the left putamen, but no evidence of SAH. Magnetic resonance angiography demonstrated a cerebral aneurysm originating from the bifurcation of the left internal carotid artery, which was considered to be responsible for the ICH. The patient underwent emergent intravascular surgery for coil embolization of the aneurysm, and his neurological symptoms gradually recovered with rehabilitation after surgery. Although ICH without SAH is a rare presentation of a cerebral aneurysm, ruptured cerebral aneurysm should be considered as a potential cause of ICH. The localization and extent of ICH may be suggestive of a latent cerebral aneurysm in such cases 41).
A surgical case of an eleven year old boy with excellent outcome is reported, with a subsequent review on the subject. Patients may present with classical subarachnoidal hemorrhage, but also with compressive signs with bigger and unruptured lesions. Initial management of these cases is basically the same of older patients, considering their age, weight and special intensive care for infants 42).
A 58-year-old hypertensive woman presenting with mild headaches underwent computed tomography, which showed a nonruptured aneurysm of the left internal carotid artery. She subsequently underwent cerebral angiography, confirming that the aneurysm was located at the left terminal carotid segment with a wide neck. INTERVENTION: Using a cross-over approach from the contralateral internal carotid artery, a new self-expandable stent was advanced through the anterior communicating artery and placed horizontally across the aneurysm neck. Aneurysm occlusion was performed by subsequent trans-stent catheterization of the aneurysm and coil packing.
Successful stent placement allowed subtotal coil occlusion of the aneurysm with a good anatomic and clinical result. No complications were encountered. The new self-expandable stent is a highly flexible, low-profile device that can be safely navigated through tortuous intracranial vessels even in a crossover technique. Its radial force and closed cell design is suitable for stent-assisted coiling and may be superior to stents with an open cell design 43).
Spontaneous pure acute subdural haematoma (ASDH) without intraparenchymal or subarachnoid haemorrhage caused by a ruptured cerebral aneurysm is extremely rare. The present case is the first report of an internal carotid artery bifurcation aneurysm presenting as pure ASDH. Suitable diagnostic investigations and therapeutic strategies are discussed. Arterial origin of bleeding should be considered in all cases of non-traumatic ASDH and a vascular anomaly has to be excluded. The neurological status on admission dictates the appropriate timing and methodology of the neuroradiological investigations 44).
Geyik, S., Yavuz, K., Cekirge, S., Saatci, I.: Endovascular treatment of basilar and ICA termination aneurysms: effects of the use of hydroCoils on treatment stability in a subgroup of patients prone to a higher recurrence rate. Neuroradiology 2007; 49: 1015-21.
Miyazawa N, Nukui H, Horikoshi T, Yagishita T, Sugita M, Kanemaru K. Surgical management of aneurysms of the bifurcation of the internal carotid artery. Clin Neurol Neurosurg. 2002 May;104(2):103-14. PubMed PMID: 11932039.
Morales-Valero SF, Brinjikji W, Murad MH, Wald JT, Lanzino G. Endovascular treatment of internal carotid artery bifurcation aneurysms: a single-center experience and a systematic review and meta-analysis. AJNR Am J Neuroradiol. 2014 Oct;35(10):1948-53. doi: 10.3174/ajnr.A3992. Epub 2014 Jun 5. Review. PubMed PMID: 24904050.
La Pira B, Brinjikji W, Burrows AM, Cloft HJ, Vine RL, Lanzino G. Unruptured internal carotid artery bifurcation aneurysms: general features and overall results after modern treatment. Acta Neurochir (Wien). 2016 Nov;158(11):2053-2059. PubMed PMID: 27644699.
Konczalla J, Platz J, Brawanski N, Güresir E, Lescher S, Senft C, du Mesnil de Rochemont R, Berkefeld J, Seifert V. Endovascular and surgical treatment of internal carotid bifurcation aneurysms: comparison of results, outcome, and mid-term follow-up. Neurosurgery. 2015 May;76(5):540-50; discussion 550-1. doi: 10.1227/NEU.0000000000000672. PubMed PMID: 25635884.
Lee WJ, Cho YD, Kang HS, Kim JE, Cho WS, Kim KM, Han MH. Endovascular coil embolization in internal carotid artery bifurcation aneurysms. Clin Radiol. 2014 Jun;69(6):e273-9. doi: 10.1016/j.crad.2014.01.017. Epub 2014 Mar 11. PubMed PMID: 24625690.
Mahajan A, Goel G, Das B, Narang KS. Recanalized Left Internal Carotid Artery Bifurcation Aneurysm with Adherent Thrombus at Aneurysm Neck and M1 Origin Diagnosed on 2-Dimensional Angiography-Cause of Embolic Stroke. World Neurosurg. 2018 May;113:296-297. doi: 10.1016/j.wneu.2018.02.163. Epub 2018 Mar 7. PubMed PMID: 29524698.
Zhang ZH, Yang XJ, Wu ZX, Li YX, Jiang P. Endovascular treatment of a giant internal carotid artery bifurcation aneurysm with drainage into cavernous sinus. Chin Med J (Engl). 2012 Feb;125(3):539-42. PubMed PMID: 22490418.
Yamamoto N, Terakawa Y, Okada Y, Mitsuhashi Y, Nishio A, Shimotake K, Murata T. Ruptured internal carotid artery bifurcation aneurysm presenting with only intracerebral hemorrhage without subarachnoid hemorrhage–case report. Neurol Med Chir (Tokyo). 2011;51(2):117-9. PubMed PMID: 21358153.
Meireles Borba A, Santana Pereira RS, Godinho A, Casulari LA. Internal carotid bifurcation aneurysm in childhood: a case report and literature review. J Neurosurg Sci. 2009 Sep;53(3):131-6. Review. PubMed PMID: 20075826.
Benndorf G, Klucznik RP, Meyer D, Strother CM, Mawad ME. “Cross-over” technique for horizontal stenting of an internal carotid bifurcation aneurysm using a new self-expandable stent: technical case report. Neurosurgery. 2006 Feb;58(1 Suppl):ONS-E172; discussion ONS-E172. PubMed PMID: 16462622.
Koerbel A, Ernemann U, Freudenstein D. Acute subdural haematoma without subarachnoid haemorrhage caused by rupture of an internal carotid artery bifurcation aneurysm: case report and review of literature. Br J Radiol. 2005 Jul;78(931):646-50. Review. PubMed PMID: 15961850.
The patient is positioned in the supine position with the head attached to the table with a Mayfield skull clamp. The head is elevated and left parallel to the ground plane.
The incision starts at the level of the lower edge of the zygomatic arch, slightly anterior to the tragus, and extends behind the hairline towards the contralateral pupillary line. In patients with thick subcutaneous tissue, a preauricular incision can be extended downwards quite safely, up to 25 mm below the superior edge of the zygomatic arch.
The anteroposterior position of the incision will depend upon the type and location of the lesion to be treated.
Dissection of the soft tissues
The dissection of soft tissues starts with subgaleal disection until the fatty tissue over the temporal aponeurosis is recognized. This sector roughly corresponds to the anterior fourth of the temporal muscle and is located immediately posterior to the frontal branch of the superficial temporal artery. From there, an incision is made on the external layer of the temporal fascia which, together with the interfascial fat, is dissected anteriorly in that plane to protect the frontal branch of the facial nerve. In this inter- fascial space runs a small vein, perpendicular to the incision, which must be coagulated and cut. Afterwards, the orbital rim is exposed at the top of the field, with the zygomatic arch lying below.
Sectioning of the zygomatic arch
The zygomatic arch is sectioned with two vertical cuts: a posterior cut immediately before the temporo–mandibular joint; and an anterior cut just behind the union of the zygomatic arch and zygomatic bone. Thus, the zygomatic arch is moved downwards, together with the masseter muscle.
The temporal muscle is separated from the skull via retrograde dissection, so as to avoid post-operative muscular atrophy.
A small cuff of muscle and fascia, at the level of the superior temporal line, is kept in place for reinsertion of this muscle at the end of surgery. Thus, the muscle is taken downwards, through the space left by the sectioned zygomatic arch. This procedure allows for complete exposure of the floor of the middle fossa.
A pterional approach (fronto–temporo–sphenoidal craniotomy) is performed in the usual way 2)3).
The quantity of frontal and temporal bone to be removed depends upon the type and location of the lesion to be resected. The greater wing of the sphenoid bone and the squamous portion of the temporal bone are drilled out until complete exposure of the lateral aspect of the temporal dura is achieved.
Two burr holes are made in the pterion above and below the lower wing of the sphenoid bone and the bone between them is flattened with a burr. A frontotemporal bone flap is cut with a vertical saw that includes the temporal muscle cuff. An additional hole below the upper temporal line may be helpful for this purpose. A free bone flap is lifted elevating and breaking down the bone. In the event of tumors that infiltrate the pterional bone or the external third of the sphenoid wing, it may be necessary to make the craniotomy around the involved bone, which is then removed by drilling or with a bone gouge. This is a pathological bone with reactive hyperostosis and/or tumor infiltration that must be removed, sometimes with profuse vascularization.
The transzygomatic approach offers excellent exposure to the floor of the middle fossa and the lateral wall of the cavernous sinus (both intradurally and extradurally). Also, combined with a pretemporal approach, it affords a good view of the interpeduncular cistern; and using a transtemporal approach, it provides good access to the insular region.
Once the craniotomy has been performed, the anatomical possibilities are numerous:
1.- intradural access to the middle fossa
2.- intradural pretemporal access to the basal cisterns
3.- intradural transtemporal access to the insular region
José M González-Darder in 2019 presented a prospective series of 26 cases with SWMs larger than 3 cm in one of its main diameter. All patients were studied following the same clinical and imaging procedures. The surgical approach was through a pterional transzygomatic craniotomy. The surgical procedure has the following steps: 1. Extradural tumor devascularization and resection of the hyperostotic and/or infiltrated bone and then intradurally; 2. Intradural tumor debunking; 3. Microdissection of vascular branches and perforators from the capsule; 4. Identification of the optic and oculomotor nerves and internal carotid artery; 5. Tumor capsule dissection and resection; 6. Dural resection or cauterization; 7. Dural and bone reconstruction and closing. Results All lesions were completely removed. Most complications were transient. The most relevant complication was a large middle cerebral artery infarct with permanent hemiplegia despite a decompressive craniotomy. Conclusion Large SWMs can be considered as a single pathology regarding the surgical approach and intraoperative microsurgical procedure strategies. The pterional transzygomatic approach allows an extradural devascularization of the tumor and an extensive bone resection that facilitates the intradural stage of tumor resection. The proposed approach allows a wide and radical resection of the duramater and bone that increases the Simpson grade. However, surgery does not control other biological or molecular prognostic factors involved in tumor recurrence 5).
A retrospective study of pathological findings, surgical outcomes and complications in a series of 31 cases operated on between 2009 and 2011 using a transzygomatic pterional approach.
The lesions involved the sphenoid wing (25.9%), several regions due to invasive growth pattern (19.5%), the temporal lobe (16.1%) and cavernous sinus (12.9%). The others were located in the floor of the middle fossa, Meckel’s cave, incisural space, cisterns, and infratemporal region. The pathological nature of the lesions was: benign meningioma (42%), temporal lobe tumour (19.5%), vascular disease (12.9%), inflammatory lesions (6.4%), atypical meningioma (6.4%), epidermoid cyst (6.4%), neurinoma (3.2%) and poorly differentiated infratemporal carcinoma (3.2%). The approach was usually combined extra-intradural (58.1%) and, less frequently, just extradural (16.1%) or intradural (25.8%). Approach-related complications were minor: haematomas in the wound not requiring treatment (67.8%), superior transient facial paresis (9.7%), transient temporomandibular joint dysfunction (12.9%) and atrophy of the temporal muscle (16.2%). There were no hardware-related complications or cosmetic issues related to the osteotomy and posterior osteosynthesis of the zygomatic arch.
The pterional approach combined with osteotomy of the zygomatic arch allows mobilising the temporalis muscle away from the temporal fossa, consequently exposing its entire surface to complete the temporal craniotomy up to the middle fossa; it helps to access and treat pathology in this region or it can be used as a corridor to approach surrounding areas 6).
Chotai S, Kshettry VR, Petrak A, Ammirati M. Lateral transzygomatic middle fossa approach and its extensions: Surgical technique and 3D anatomy. Clin Neurol Neurosurg. 2014 Dec 29;130C:33-41. doi: 10.1016/j.clineuro.2014.12.014. [Epub ahead of print] PubMed PMID: 25576883.
González-Darder JM, Quilis-Quesada V, Botella-Maciá L. [Transzygomatic pterional approach. Part 2: Surgical experience in the management of skull base pathology]. Neurocirugia (Astur) 2012; 23(03):96–103
Campero A, Campero AA, Socolovsky M, Martins C, Yasuda A, Basso A, Rhoton A. The transzygomatic approach. J Clin Neurosci. 2010 Nov;17(11):1428-33. doi: 10.1016/j.jocn.2010.03.023. Epub 2010 Aug 6. Review. PubMed PMID: 20692168.
González-Darder JM. Combined Extradural and Intradural Pterional Transzygomatic Approach to Large Sphenoid Wing Meningiomas. Operative Technique and Surgical Results. J Neurol Surg B Skull Base. 2019 Jun;80(3):244-251. doi: 10.1055/s-0038-1668538. Epub 2018 Aug 21. PubMed PMID: 31143566; PubMed Central PMCID: PMC6534744.
González-Darder JM, Quilis-Quesada V, Botella-Maciá L. [Transzygomatic pterional approach. Part 2: Surgical experience in the management of skull base pathology]. Neurocirugia (Astur). 2012 May;23(3):96-103. doi: 10.1016/j.neucir.2012.04.005. Epub 2012 May 19. Spanish. PubMed PMID: 22613467.
The following time-stamps will guide you to certain key points & examples during this webinar:
At 1:30: “Moving from a pure optical platform to a digital platform is something that we are going to see increasingly in our operating rooms”
At 3:10: “As a tumor surgeon, we have multiple information chains, we have the structural MRI, functional MRI, tractography, MR spectroscopy, MAG imaging, fluorescence-guided surgery, intraoperative navigation and all of these things have to be integrated in our brains and extrapolated through our actions with the tumor. I think what this platform (ZEISS KINEVO 900) is enabling us to do, is give us the ability to integrate a lot of this in real-time so that we do not have to do this ourselves and we do not have to be swiveling our heads to look at this scan or that scan as we are operating.”
At 6:01: “Now, the PointLock concept is really one where you want to specifically focus on a particular target in three-dimensional space. But you want to be able to pivot around it without having to find it again. We all do that in the OR and while it may take only few seconds, those are precious seconds where you lose your chain of thoughts. [..] Achieving this at a functional level… and by that I mean the ability where the robot does it for you and you do not have to adjust at all in terms of fine tuning the focus or fine tuning the special referencing [..] I have used it in the OR, really without any training on it and it is something very intuitive.”
At 7:17: “Many of us use MRI spectroscopy (for example) to identify hotspots where we will perform biopsy. For example, in a low grade tumor we want to decrease the chance of missing a focus of transformation. By bookmarking those sites on the microscope, we can make sure that we can go directly to that spot without worrying about aligning the navigation and all of the other anatomical information around it.”
At 9:06: “In brain tumor operations there are many dimensions of the tumor that we need to work along and we often operate – move the microscope – operate. This platform enables you to continuously operate as you are moving. And, if you are using it as an exoscope function (particularly), you, yourself don’t have to move at all. Effectively, the microscope moves and you stay still. [..] it is an important distinction when you are doing a multi-hour operation and you are able to stay in a position of comfort and stability [..] instead of moving around your torso to accommodate the dimension.”
At 11:03: “The next generation of microscope will be something that is not so much part of you but is working in parallel with you. [..] For example, in a far-lateral type approach for lower cranial schwannoma, there are issues in positioning and the angle of view. But here we can operate in a relatively neutral position using 3D 4K visualization.“
At 13:13: Case explanation for Retrosigmoid Crainiotomy for Petrous Face Meningioma using the combination of exoscopic visualization and robotics.
At 13:54: “This is at the point where one can transition to the exoscope. Because the angles of approach that you want as you are trying to pull this tumor away from the brain tumor margins, really can be quite extreme. You can see in the inset where the angle of the microscope head is relative to my head. If I had to stretch to get to that angle I’m going to be relatively uncomfortable and less stable ergonomically with my hands and torso.”
At 15:12: “I would also add that the learning curve for this is not very steep. It is a relatively simple device to adopt into your workflow because many of us have already gotten used to using the foot pedal for basic robotic movements of the microscope head. What this does is: add these additional dimensions of moving in an angle and pivoting around a point. So, it is really like a real-time surveillance image happening as you operate.
At 16.31: “The digital integration of real-time functional imaging, real-time tractography, real-time stimulation mapping data into the cortex will basically make it seamless.”
Twenty adult cadaveric brains and four adult cadaveric heads were studied, using a magnification ranging from 3 times to 40 times, after perfusion of the arteries and veins with colored latex.
The choroidal fissure is a natural cleft between the thalamus and the fornix, and it is identified by following the choroid plexus in the lateral ventricle. The choroid plexus in the body of the lateral ventricle originates from the tela choroidea of the roof of the third ventricle and is apparently attached to the fornix by the taenia fornicis and to the thalamus by the taenia choroidea. The taenia is actually the ependyma that covers the internal wall of the ventricular cavity and the choroid plexus.
An understanding of the choroidal fissure is fundamental for use of the transchoroidal approach. Unlike transforaminal, subchoroidal, subforniceal, and interforniceal approaches to the third ventricle, which sacrifice some neural or vascular structures, the transchoroidal approach follows a natural route, and certainly it is one of the options to be considered when entry into the third ventricle is required 2).
Ito et al demonstrate an interhemispheric transchoroidal approach for third ventricular teratoma resection. Interhemispheric dissection exposed the corpus callosum at a length of about 2 cm. A callosotomy was made to enter into the right lateral ventricle. After septal vein ligation, dissection was made of the space between the right fornix and right internal cerebral vein (ICV); thus bilateral fornix and left ICV would be retracted to the left; right choroid plexus, right ICV to the right. By this transchoroidal approach, the foramen of Monro was extended posteriorly, providing enough of a surgical corridor to resect a posteriorly located third ventricular tumor. The video can be found here: https://youtu.be/gIzPiH3zx_o3).
Interhemispheric transcallosal route for resection of anterior third ventricular lesions
Peker HO, Aydin I, Dinc C, Baskaya MK. Microsurgical Resection of Thalamic Astrocytomas Via Anterior Interhemispheric Transcallosal Transchoroidal Approach: Demonstrating of Technique: 3-Dimensional Operative Video. Oper Neurosurg (Hagerstown). 2018 May 1;14(5):595. doi: 10.1093/ons/opx196. PubMed PMID: 28961966.
Wen HT, Rhoton AL Jr, de Oliveira E. Transchoroidal approach to the third ventricle: an anatomic study of the choroidal fissure and its clinical application. Neurosurgery. 1998 Jun;42(6):1205-17; discussion 1217-9. PubMed PMID: 9632178.
Ito Y, Inoue T, Tamura A, Tsutsumi K. Interhemispheric transchoroidal approach to resect third ventricular teratoma. Neurosurg Focus. 2016 Jan;40 Video Suppl 1:2016.1.FocusVid.15401. doi: 10.3171/2016.1.FocusVid.15401. PubMed PMID: 26722682.