in 2,015 endoscopic endonasal skull base cases over a 13-year period (only 1 case occurred in managing 256 cases of sinonasal malignancies); the mortality rate was about 17% with a mean blood loss of 1,600 mL (range 400–4,200). The authors proposed strategies to prevent injury and, in case of ICA damage, to deal with it: anatomical knowledge, preemptive vascular control via a neck incision, careful preoperative assessment of imaging and planning, early endovascular assessment with angiography, surface with mucoperiosteal flaps or grafts of the exposed ICA. In our experience, in agreement with that of other authors [23], and in addition to meticulous preoperative radiological evaluation (angio-TC and occlusion test), we consider the magnetic neuronavigation system and the Doppler-ultrasound instrumentations to be indispensable intraoperative aids.
5Skull base reconstruction failure. From the data available in the literature it emerges that the most common major complication of skull base reconstruction is cerebrospinal fluid leak (CSF-L) in the postoperative period, with a prevalence of 3–4.3% [22–24]. A recent report published by an Italian center has shown a CSF-L rate after anterior skull base reconstruction of about 5.8% [27]. Another series from an Italian center analyzed 62 patients who underwent endoscopic tumor removal: the authors found that the risk of CSF-L is related to the learning curve of the surgeon and refinement of the surgical technique [16]. Even other reports published in the literature, such as that from the University of Pittsburgh Medical Center, have shown that the surgical experience plays a strategic role in the success of anterior skull base reconstruction after tumor removal with a CSF-L rate as high as 20–30% in the case of early reconstructive experience [24, 25]. As a last remark, the risk of brain herniation, a rare and life-threatening complication, may occur more easily in cases of intracranial hypertension (high BMI, OSAS), and in concomitant neck dissection with the injury or postoperative thrombosis of a dominant internal jugular vein [20].
Conclusions
EER, when properly planned and performed by experienced surgeons, is the ideal treatment for a large number of skull base malignancies, in association with appropriate adjuvant/neoadjuvant therapies, with long-term outcomes comparable to those achieved with traditional external approaches [21]. EER should be performed only in high-specialized centers and by surgeons with extensive endoscopic experience. Long and dedicated training in the treatment of inflammatory and benign endonasal lesions is required, with accurate and precise knowledge of sinonasal and skull base anatomy.
Lastly, multidisciplinary team-work is of utmost importance, with the cooperation of several specialists, including otolaryngologists, neurosurgeons, ophthalmologists, radiation oncologists, medical oncologists, occupational physicians, and pathologists [2–5]. To date, due to the rarity of sinonasal and skull base tumors, further studies with longer pathology-specific follow-up are needed to validate and confirm these statements and to refine the role of endoscopic endonasal surgery in the setting of multidisciplinary care.
Disclosure Statement
All authors have no conflict of interest to declare.
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