Nobuyoshi Ohtori

Healing Process of Sinus Mucosa after Endoscopic Sinus Surgery

In the treatment of chronic sinusitis, the mucosa should be preserved, or, when severely damaged, only the mucosal surface removed with cutting forceps. It is especially important not to expose the surface of the bone by complete removal of the mucosa. When the mucosa is conserved, or excision is limited to only the mucosal surface, ciliated cells regenerate within 6 months. However, where the mucosa was completely removed during surgery and the bone was exposed, the area was covered with nonciliated cells, and only scattered cilia were present.

Endoscopic Endonasal Treatment of Ostium of the Frontal Sinus and the Results of Endoscopic Surgery

We discuss a procedure for opening the nasofrontal duct and the postoperative findings in endoscopic endonasal surgery. The route of the anterior ethmoidal artery was also studied. The subjects of this study were 57 patients (105 sides) who had frontal sinus disease. The patients all underwent surgery for chronic sinusitis between 1990 and 1992. Patients undergoing revision surgery were excluded. All patients were operated on by the same surgeon. In each patient, following anterior and posterior ethmoidectomy, the frontal sinus ostial region was opened using a 70 endoscope, while carefully monitoring the anterior ethmoidal artery. The agger nasi was left intact. The cells around the ostium were opened using a curved suction tip and upward bent forceps, and the lamellae were removed to achieve the greatest possible communication with the frontal sinus. In 77 sides (73.4%), the communication between the frontal and ethmoidal sinuses was well maintained. The ostium was patent with edematous mucosa in 18 sides (17.1%). The opened ostium could not be confirmed due to presence of polyp, etc., in 10 sides (9.5%). During surgery, the route of the anterior ethmoidal artery was confirmed in 70.8%; and of these cases, it was located anterior to the third ground lamella in about 50%.

Comparative analysis of surgical processes for image-guided endoscopic sinus surgery

AbstractPurposeThis study proposes a method to analyze surgical performance by modeling, aligning, and comparing surgical processes. This method is intended to serve as a means to support the enhancement of surgical skills for endoscopic sinus surgeries (ESSs). We focus on surgical navigation systems used in image-guided ESSs and aim to construct a comparative analysis method for surgical processes based on the information about the surgical instruments motion obtained from the navigation system. MethodsThe proposed method consists of the following three parts: quantification of surgical features, modeling of surgical processes, and alignment and comparison of surgical process models (SPMs). First, we defined time-series parameters using the navigation-based surgical data. Second, we created SPMs by applying the defined parameters and the relative positional information of the instruments to the patient’s anatomy. Third, we constructed a method to align and compare SPMs based on dynamic time warping with barycenter averaging.ResultsThe proposed method was validated on a dataset containing surgical data obtained by an optical tracking system from 14 clinical ESS cases. We evaluated the validity of the comparative analysis by aligning and comparing SPMs between experts and residents. The validation results suggested that the proposed method could achieve proper alignment of the SPMs and clarify the differences in surgical processes between experts and residents.ConclusionWe developed a method to enable a time-series comparative analysis of surgical processes based on the surgical data from the navigation system. This method can allow surgeons to identify differences between their procedures and reference procedures such as experts’ procedures.