[Endovascular embolization as a stage of preoperative preparation for improving surgical treatment of patients with inverted papilloma - a retrospective case series analysis. A clinical example of simultaneous endovascular embolization using navigation under the control of flat-detector computed tomography on a robotic angiographic complex and removal of an inverted papilloma in a hybrid operating room].

Inverted papilloma (IP) is a sinonasal epithelial tumor that originates from Schneiderian membrane. A number of cellular factors associated with angiogenesis are involved in growth of IP, and causes an increased bleeding of the tumor. The main treatment is surgical removal of sinonasal papilloma. Preoperative endovascular embolization reduces intraoperative blood loss, increases the likelihood of successful and complete resection, and shortens the operation time. New robotic angiographic systems with a FDCT option provide a technical possibility of using 3D and 4D imaging to perform safer and more accurate interventional procedures.

Objective: To evaluate the features and the effectiveness of surgical removal of an inverted papilloma with preliminary endovascular embolization as a preparatory stage.

Material and methods: We conducted a retrospective analysis of the medical cards of 8 patients with a diagnosis of inverted papilloma of the nasal cavity and paranasal sinuses, who underwent elective surgical treatment with preliminary embolization of the vessels feeding the tumor in the ENT department of Botkin Moscow Multidisciplinary Scientific and Clinical Center from the beginning of 2020 to December 2024. The demographic and clinical data of patients, as well as the main aspects of endovascular interventions and characteristics of the surgical stage of sinonasal papilloma removal were analyzed. A clinical case of simultaneous embolization and removal of an inverted papilloma in a hybrid operating room using the Artis pheno (Siemens Healthineers) angiographic system is described.

Results: Males predominated among the studied patients, accounting for 75%. The age of the patients ranged from 37 to 82 years, with an average age of 70.5 [49; 74.5]. In the analyzed cases, inverted papilloma was at stage T3 (6 patients) and at stage T4 (2 patients) according to Krouse classification. 7 patients had concomitant chronic non-communicable diseases. In all cases, the first stage was performed by distal embolization of the branches of the maxillary artery. No post-embolization complications were registered in any of the cases. In the second stage, all the patients were operated on using an endoscopic or combined (endoscopic and external) approach, depending on the extention of the tumor, by the same surgeon. Four patients with stage T3 were undergone of the tumor removal through a prelacrimal approach. The volume of blood loss was 200 [137.5; 262.5] ml. The tumors were radically removed due to excellent visualization of the surgical field. The surgery time was 67.5 [62.5; 77.5] minutes.

Conclusions: After analyzing the presented series of clinical cases, we can conclude that endovascular embolization is safe and effective stage before surgical removal of an inverted papilloma of the nasal cavity and paranasal sinuses. As a minimally invasive stage of preoperative preparation, it can be used in somatically compromised burdened patients. The combination of high-quality visualization of blood flow features, including the use of flat-detector computed tomography, and a rational method of endovascular occlusion allows interventional radiologists to perform intravascular intervention with minimal risk of complications. As a result, improved intraoperative overview due to devascularization and the choice of optimal surgical access ensure radical removal of the tumor. The undoubted advantages make it possible to integrate this approach into clinical practice.