O.A. Ivanchenko, N.G. Chuchueva, A.S. Lopatin, City Polyclinic No. 9, South-Eastern Administrative District, Moscow, Central Clinical Hospital, Administrative Department of the President of the Russian Federation. Puncture of the maxillary sinus (MS) through the inferior nasal passage remains one of the most, if not the most, common diagnostic and therapeutic procedures in otolaryngology. It is regularly performed in the treatment of acute and chronic sinusitis, as well as for the diagnosis of any diseases of the MS. The diagnostic algorithm remains virtually routine: sinusitis symptoms, sinus radiography, and, if pneumatization of the MS decreases, a puncture. Incidentally, although inflammation of the frontal and sphenoid sinuses is no less severe and carries at least an equal risk of complications, when pneumatization of these sinuses is first detected, the physician's approach is much more cautious, usually limiting the procedure to a course of antibiotics. It is believed that such a widespread love for maxillary sinus puncture is not due to any clearly justified indications, but simply to the fact that this procedure is easy to perform and is familiar to every ENT physician. At the same time, the effectiveness of this puncture treatment method has not yet been proven in controlled comparative studies (in fact, there are studies confirming the opposite), and medications for sinusitis are administered to the sinus contrary to officially registered indications. In order to reassess the efficacy and safety of maxillary sinus puncture, as well as the appropriateness of this treatment method, from a modern perspective, we conducted a series of anatomical and clinical studies. In the first, we performed an endoscopic assessment of the severity of traumatic sequelae on the lateral wall of the inferior nasal meatus at a typical needle insertion site, and in two other studies, we sought to determine whether the effectiveness of treatment for acute maxillary sinusitis is enhanced by repeated maxillary sinus punctures in addition to traditional antibiotic therapy. An endoscopic study of the consequences of maxillary sinus puncture was performed on 27 cadavers of both sexes who died from intercurrent illnesses. For this study, the inferior nasal meatus and the sinus itself (through the middle meatus) were examined with a 30° rigid endoscope after puncture with a Kulikovsky needle. The study showed that in half of the cases, maxillary sinus puncture is accompanied by injury to the nasolacrimal duct opening, which can subsequently lead to tear drainage obstruction, the development of chronic dacryocystitis, and other complications. Endoscopic monitoring of needle position revealed that injury is avoided precisely when the puncture hole in the sinus wall is located behind the canal opening. An examination of the middle nasal meatus demonstrated that pathological changes in the ostiomeatal complex are present in approximately 30% of cases. In 20% of cases, the natural opening was nonfunctional, and in 12.2%, an additional opening was present in the posterior fontanella. In a number of cases, during forced sinus irrigation with a needle, a rupture of the medial wall of the maxillary sinus occurred in the area of ??the posterior fontanella. To evaluate the efficacy of the puncture method, 80 adult patients with acute purulent uncomplicated sinusitis were included in two studies. Both open-label, controlled, randomized trials had a similar design. In the first, 20 patients received puncture-free treatment with amoxicillin clavulanate (Augmentin) at a dose of 625 mg 3 times a day for 7 days; the remaining 20 patients also underwent maxillary sinus punctures with the administration of dioxidine. In the second study, 40 patients received orally moxifloxacin (Avelox) at a dose of 400 mg once a day for 5 days as background therapy; 20 of them received gentamicin solution during sinus punctures. The severity of disease symptoms (nasal congestion, nasal discharge, headache and facial pain, and olfactory impairment) was assessed dynamically using the modified Kennedy-Lund visual scale (1995). Radiography (in the first study) or CT scan (in the second) of the paranasal sinuses with quantitative assessment of the detected changes were performed at the start of treatment and after 10 days. When comparing the rate of regression of maxillary sinusitis symptoms, no statistically significant differences were found between the groups receiving treatment with puncture-based and non-puncture methods. Rhinoscopic appearance, radiographic and CT changes also did not differ significantly between the groups, and studies with both antibiotics yielded almost identical results. The obtained data certainly do not negate the role of maxillary sinus puncture as a method for diagnosing and treating purulent sinusitis. However, in light of the results obtained, it is necessary to more strictly evaluate the indications for this procedure, which is far from 100% safe, not to use it for the treatment of mild catarrhal forms, and to make wider use of the possibilities of modern antibiotic therapy in the treatment of sinusitis.