A novel technique for tailoring frontal osteoplastic flaps using the ENT magnetic navigation system

The role of the osteoplastic flap in the endoscopic era: a retrospective multicentre experience on revision surgery

Objective

To retrospectively review the experience of five tertiary-care university hospitals on frontal sinus revision surgery with osteoplastic flap (OPF).

Methods

Descriptive analysis of patients who underwent frontal sinus surgery with OPF after one or more endoscopic procedures for benign and inflammatory pathologies from 2000 to 2022. Clinical charts were reviewed for demographics, indications, clinical presentation, previous frontal procedures, OPF technique and outcomes.

Results

Of the 124 patients who underwent an OPF procedure, 33 met inclusion criteria. With a mean of 2.1 previous endoscopic surgeries, Draf III was the most common former procedure. In 30 (91%) cases OPF was part of a combined procedure. The most common indications were inverted papilloma (61%), mucocele (9%) and chronic rhinosinusitis (6%). Frontal outflow stenosis (36%) and mucocele (9%) were the most frequent complications observed. Improvement of overall symptoms and patient satisfaction after the OPF procedure were recorded.

Conclusions

Even in the endoscopic era, OPF still represents a paramount procedure that should be included in the rhino-surgeon's armamentarium, in particular in patients with challenging pathologies and anatomy when previous endoscopic endonasal attempts have failed.

Comprehensive access strategies to the frontal sinus

PURPOSE OF REVIEW

Despite the impressive evolutions in endoscopic endonasal approaches and instrumentations, the frontal sinus remains a challenging area. Different surgical options have been described over the years, but the main criticism lies in choosing the most suitable approach for a given case, based on the anatomy of each patient and the disease to treat. The purpose of this study is to provide a comprehensive review of surgical access strategies currently available to address the frontal sinus, including both endonasal and traditional external procedures, analysing indications, contraindications, complications and outcomes.

RECENT FINDINGS

Frontal sinus surgery includes minimally invasive endonasal approaches (balloon dilatation, Draf type I); extended endonasal approaches (Draf type IIA-IIB-IIC, Draf type III and their modifications via orbital transposition and contralateral pyriform aperture resection); external procedures (superior eyelid incision, frontal osteoplastic flap, Riedel procedure, Riedel-Mosher operation); and combined approaches.

SUMMARY

Recent advances in endoscopic endonasal techniques have deeply reshaped the surgical options to manage frontal sinus diseases, in an attempt to minimize the invasiveness of the procedures and maximize their outcomes. Traditional external procedures should be used in selected cases nonamenable for endonasal surgery. The appropriate selection of cases appears to be of paramount importance to obtain successful outcomes.

Use of three-dimensional printing for the osteoplastic flap approach: A viable technique

The osteoplastic flap technique is the open and direct approach to the frontal sinus and is especially useful when disease extends laterally into the frontal sinus. One of the vital steps of surgery is delineation of the boundary of the frontal sinus. This can usually be performed either by using the classical 6-ft Caldwell view X-ray template or more recently by application of the image-guided navigation system. The present article describes an alternative technique of using 3D printing technology for preoperative creation of the onlay template to mark the limits of the frontal sinus during osteoplastic flap technique and its advantages.

Surgical management of inverted papilloma involving the frontal sinus: a practical algorithm for treatment planning

Inverted papilloma of the frontal sinus is a challenging disease. Given its rarity, only small case series are present in the literature. The objectives of the present study are to review our experience in the surgical management of inverted papillomas involving the frontal sinus and to propose a practical algorithm for selecting the most appropriate approach. Data on patients affected by inverted papilloma involving the frontal sinus and surgically treated between 2002 and 2016 were collected. The type of involvement of frontal sinus and extent of surgery performed (endoscopic endonasal, external or combined approaches) were analysed. A brief review of consistent literature was also carried out. Forty-seven consecutive patients were treated using an exclusive endoscopic endonasal approach (EEA) in 18 cases, while a combined endonasal with external osteoplastic approach was required in 29 cases. Most patients (29/47, 62%) had been treated previously, mainly by an endoscopic approach. A single intraoperative complication occurred (1/47, 2%), i.e. cerebrospinal fluid (CSF) leak, that was successfully repaired intraoperatively without any consequences. Recurrences were observed in only 2/47 cases (4%) after a mean follow-up of 43 months (range, 12-137). The management of inverted papilloma involving the frontal sinus requires great expertise and the surgical technique should be tailored to the site of attachment of the tumour, its extension and the anatomical conformation of each frontal sinus. The encouraging results obtained in this case series support the use of this practical treatment algorithm.

A novel approach to skull-base and orbital osteotomies through virtual planning and navigation

OBJECTIVE

Computer-assisted planning of osteotomy lines, coupled with navigation-guided performance of planned osteotomies, is a highly innovative approach to skull-base and orbital surgery. The aim of this pilot study is to provide an assessment of the accuracy of this novel approach in guiding the correct positioning of osteotomy lines in frontal, temporal, and orbital regions, defining the agreement between the spatial position of the planned and performed osteotomies.

METHODS

Fifteen patients with orbital, frontal sinus, and lateral skull-base diseases underwent virtual surgical planning. Osteotomies to access the orbit, frontal sinus, and lateral skull base were planned on computer tomography-based three-dimensional models. The planned osteotomies were reproduced on the operating field using a navigation system. The positions of the performed and planned osteotomies were compared. The results were described as the mean positional difference between planned and performed osteotomies and as Lin's concordance coefficient, and Bland-Altman limits of agreement were also defined.

RESULTS

The overall mean difference was 0.719 mm (95% confidence interval [CI]: 0.472 to 0.965 mm). Overall, Lin's concordance coefficient was 0.997 (95% CI: 0.996 to 0.998), and overall Bland-Altman limits of agreement ranged from -1.407 to 2.844 mm. The smallest mean difference (0.587 mm, 95% CI: 0.244 to 0.931 mm) was calculated in the orbit group, whereas the highest mean difference (0.904 mm, 95% CI: 0.428 to 1.379 mm) was described in the lateral skull-base group.

CONCLUSION

This study's results support the use of this novel planning and navigation protocol for guiding osteotomy in anterior and lateral skull-base surgery, providing a clinical validation of this technique.

LEVEL OF EVIDENCE

4 Laryngoscope, 00:1-9, 2018 Laryngoscope, 129:823-831, 2019.

Endoscopic endonasal orbital transposition to expand the frontal sinus approaches

BACKGROUND

The management of frontal sinus disease still remains a challenging issue for rhinologists. Although endoscopic frontal sinus surgery has significantly advanced over the past years, there are some conditions in which the external approaches are still necessary. Recently, the increasing experience in endoscopic sinus surgery together with important technologic advancements have allowed expansion of the indications for selected lesions localized more and more lateral into the frontal sinus.

OBJECTIVE

The aim of this study was to describe the endoscopic endonasal approach to the far lateral portion of the frontal sinus and to evaluate the outcomes of this technique.

METHODS

A retrospective evaluation was carried out with patients at a single institution, who, from 2004 to 2012, underwent an exclusive endoscopic transnasal approach to the far lateral portion of the frontal sinus at a single institution. The surgical technique included the Draf IIb procedure, a modified Lothrop procedure (Draf III), and endoscopic lateralization of the orbit, differently associated according to the needs of each case.

RESULTS

Twenty-four patients were eligible for the present study. The lesions included were mucoceles in 9 cases, fibro-osseous lesions in 10 cases, and inverted papillomas in 5 cases. The overall follow-up ranged from 12 to 120 months (mean, 40.6 months). At the time of the last follow-up, no recurrence of disease was observed in the patients treated; in one case of osteoma, a small and stable in size (1 mm) persistent lesion was observed in an asymptomatic patient. One scheduled and one accidental cerebrospinal fluid leak with immediate skull base reconstruction occurred. No intraoperative or postoperative early or late orbital complication was observed in any case.

CONCLUSION

The endoscopic endonasal orbital transposition seems to facilitate the endoscopic management of selected far-lateral frontal sinus lesions. However, it is a demanding procedure that requires experience and skill to avoid intraoperative skull base and orbital complications.

Role of endoscopic surgery in the management of sinonasal and skull base schwannomas

BACKGROUND

The purpose of this study was to report our experience with the endoscopic management of sinonasal schwannomas, analyzing the advantages, limitations, and outcomes of the technique.

METHODS

A retrospective analysis was carried out on 11 patients treated endoscopically between 2000 and 2014 at a single institution.

RESULTS

Eight patients underwent an exclusive endoscopic endonasal approach, whereas, in 3 patients, an osteoplastic flap was combined because of massive or lateral frontal sinus involvement. The tumor extended into the orbit in 5 cases, and involved the skull base in 5 patients who required a concomitant endoscopic duraplasty. No evidence of disease was observed in 10 patients after a mean follow-up of 90.1 months (range, 14-189 months). One patient was alive with persistence of disease, although asymptomatic.

CONCLUSION

The endoscopic endonasal approach is a valid alternative for the vast majority of sinonasal schwannomas with minimal morbidity for the patient. © 2016 Wiley Periodicals, Inc. Head Neck 38: E2074-E2082, 2016.

The place of the osteoplastic flap in the endoscopic era: indications and pitfalls

OBJECTIVES/HYPOTHESIS

To evaluate the osteoplastic flap (OPF) procedure for frontal sinus pathology at our institution, including indications, revisions, obliteration vs. nonobliteration, and obliteration materials.

STUDY DESIGN

Single-institution retrospective review from 1998 to 2013.

METHODS

Current Procedural Terminology codes identified all OPF procedures. Demographic data, diagnoses, previous frontal procedures, obliteration materials, and outcomes were evaluated. Diagnoses were divided into two groups: inflammatory (refractory sinusitis, mucoceles, surgical material infections) and noninflammatory (tumors, cerebrospinal fluid leaks).

RESULTS

Fifty-seven patients underwent 73 OPF procedures: 36 obliterative and 37 nonobliterative/unobliterative. Inflammatory indications accounted for 76% of obliterated patients, but only 38% of nonobliterative procedures. Ten patients (17.5%) required revision, 90% of whom had an OPF for inflammatory indications. Only one patient who underwent an OPF procedure for noninflammatory pathology required revision. Twenty-four percent of patients obliterated with bone cement ultimately required complete removal to resolve infection.

CONCLUSIONS

The OPF approach is still valuable for pathology refractory to or inaccessible to endoscopic approaches. Infectious etiologies have a much higher revision rate. Careful selection of pathologies can reduce revision rates, but in some cases a repeated OPF procedure is the only viable alternative. When bone cement becomes infected the only resolution is complete removal.

Electromagnetic tracking in medicine--a review of technology, validation, and applications

Object tracking is a key enabling technology in the context of computer-assisted medical interventions. Allowing the continuous localization of medical instruments and patient anatomy, it is a prerequisite for providing instrument guidance to subsurface anatomical structures. The only widely used technique that enables real-time tracking of small objects without line-of-sight restrictions is electromagnetic (EM) tracking. While EM tracking has been the subject of many research efforts, clinical applications have been slow to emerge. The aim of this review paper is therefore to provide insight into the future potential and limitations of EM tracking for medical use. We describe the basic working principles of EM tracking systems, list the main sources of error, and summarize the published studies on tracking accuracy, precision and robustness along with the corresponding validation protocols proposed. State-of-the-art approaches to error compensation are also reviewed in depth. Finally, an overview of the clinical applications addressed with EM tracking is given. Throughout the paper, we report not only on scientific progress, but also provide a review on commercial systems. Given the continuous debate on the applicability of EM tracking in medicine, this paper provides a timely overview of the state-of-the-art in the field.