Surgical management: contemporary and future perspective
Despite the future probably lies in developing new drugs to target the abovementioned molecular pathways, to prevent recurrent sinus surgery or even avoid it, nowadays steroid therapy and surgery still play a relevant role in the treatment strategy of CRS. Anti-inflammatory therapies are at the forefront in the treatment of eosinophilic CRSwNP (E-CRSwNP) and, above all, corticosteroids, both intranasal and systemic (they contrast type 2 inflammation thus controlling both local and associated systemic effects of the disease) [37]. However, chronic and/or recurrent use of both systemic corticosteroids (particularly frequent in patients with CRSwNP and concomitant severe asthma [38]) and topical corticosteroids is associated with a relevant increased risk to develop adverse events (i.e.: type-2 diabetes, hypertension, glaucoma, osteoporosis…) [37,39] that may have also a dramatic burden in terms of health-care costs [40].
Along with steroids, sinonasal surgery improves nasal symptoms in patients with CRSwNP. Especially in patients with aspirin intolerance, allergic fungal rhinosinusitis (AFRS) and asthma, nasal polyposis is histologically dominated by dense eosinophilic infiltration: in these cases, a more aggressive surgical approach is required and is often combined with extensive postoperative use of corticosteroids to preserve good surgical results and prevent polyps regrowth [41]. Different “versions” of endoscopic sinus surgery exist and technique has evolved over time. Since 1984, Functional Endoscopic Sinus Surgery (FESS) has become the world gold standard in the management of sinonasal inflammatory disease unresponsive to medical therapy [41]. FESS, as it was originally presented, currently leaves some interpretative doubts. Based on its original principles, the aim of FESS is the rehabilitation of a sinus ventilation by exposure of its natural ostium without altering its profile, minimizing mucosal stripping and preserving anatomical landmarks (such as the middle turbinate) [41]. This “limited” surgery is especially adequate for larger sinuses (frontal and maxillary),that rarely require extensive manipulation. It precisely means to clear ethmoidal clefts, reestablishing ventilation and drainage of diseased large sinuses via their physiological routes34: the frontal recess for frontal sinus ventilation and the lateral wall of the middle meatus for maxillary sinus ventilation. Little deviations from the FESS paradigm take place, for example, when the maxillary sinus ostium is enlarged anteriorly and/or posteriorly (to the nasal fontanelle areas), still resulting in a window in its physiologic place. Over time, the concept of FESS has developed further. According to EPOS 2020 steering group [1], “full FESS” indicates sinus opening that includes anterior and posterior ethmoidectomy, large middle meatal antrostomies, sphenoidotomy and frontal opening (e.g. a Draf IIa procedure), still without damaging important landmark as the middle turbinate and mucosa in general. This is particularly applicable to compartmental sinusitis and CRSsNP, and it can be applied to non-type 2 CRSwNP. The functionality criterion cannot be respected in severely extensive CSRwNP and in conditions characterized by type 2 inflammation, since limited surgery will not be effective in the long run. As disease becomes more severe, wider surgical resections turn out to be necessary: a large “ethmoidectomy box” with wide lateral fenestration to the maxillary sinus, extended upward to the frontal sinus and backward to the sphenoid. In many cases, the steadiness of the middle turbinate is compromised by both the destructive action of the disease and the extension of surgery. Being systematic in the endoscopic approach (ESS) implementation and in designing a targeted surgical treatment responds to the following needs: to create a surgical bed as wide as possible to help control recurrence with topical medications, to facilitate reintervention by simple polyps debridement, to minimize post-surgical restenosis.
In spite of great advancements in the biologics field for very severe and recurrent forms of polyposis, nowadays – and at least in the initial phase of a larger diffusion of these new drugs – few patients will have access to biological therapies. The first therapeutic attempt in complicated and relapsing CRSwNP will certainly be surgery. In 2018, a newly proposed approach (named “reboot approach” [42,43]) was introduced in the surgical scenario of severe recalcitrant CRSwNP, especially for cases who underwent multiple interventions. It aims to restore a non-inflammatory state of the epithelium by entirely removing the dysfunctional eosinophilic-infiltrated mucosa up to the periosteum of nasal and paranasal cavities, partially sparing the mucosa of the inferior conchas [42,43]. The procedure is accompanied by a Draf III or at least Draf IIb frontal drainage. The rationale is that removal of type 2 inflammatory environment might allow unaffected mucosa to grow and re-epithelize sinuses walls, markedly decreasing the risk of relapse.
An upcoming fascinating perspective could be represented by the combination of surgery and biological therapy for E-CRSwNP. In such manner, endoscopic surgery could be minimized to the true principles of FESS, supported by the effects of post-operative administration of targeted drugs.