Weichteilnavigation im Kopf-Hals-Bereich und navigierte Fremdkörperentfernung

Solitary Fibrous Tumours of the Orbit - Clinical Pathology, Therapy and Prognosis

BACKGROUND

Solitary fibrous tumours are rare. The aim of this study is to describe the clinical features, therapy and outcome of affected patients and to identify factors associated with recurrence.

METHODS

Retrospective study of a cohort of 20 patients who underwent surgery for orbital solitary fibrous tumour at the University Department of Oral and Maxillofacial Surgery between 2002 and 2023. Demographic, clinical, and therapeutic data as well as tumour follow-up results were collected. Tumour volume and molecular genetic mutations were retrospectively determined.

RESULTS

The median patient age was 49.5 years at initial surgery. The left orbit was affected in 65% of cases. The most common clinical symptom was proptosis (80%). This was reported with a mean lateral difference of 3.9 mm (range: 1 - 10 mm). The tumours were localised predominantly in the intra- and extraconal space, craniolateral quadrant and middle third. The median tumour volume was 7.66 cm³ (range 2.15 - 12.57 cm³). In all patients, the diagnosis was made by pathological examination. All tumours investigated showed a NAB2-STAT6 mutation. The most frequently detected mutation was the fusion NAB2 exon 4 - STAT6 exon 2. All patients were initially managed with frontolateral orbitotomy. Incomplete resection (R1-status) occurred in 35% (n = 7). The recurrence rate was 25% (n = 5), with a median disease-free interval of 45.5 months (range 23 - 130). 80% (n = 4) of recurrences were initially R1-resected.

CONCLUSION

Orbital solitary fibrous tumours are rare tumours and are clinically manifested by signs of displacement of orbital structures. Diagnosis is made by histology and immunohistochemistry and can be proven with the molecular genetic detection of the NAB2-STAT6 mutation. The therapy of choice is complete surgical resection. R1-resection is more likely in the intraconal location as well as in location in the posterior third of the orbit - due to difficult surgical accessibility. The greatest risk factor for the development of recurrence is incomplete surgical excision. Late recurrences are possible, which is why a long-term connection to a specialised clinic is necessary.

Implementation of a miniaturised navigation system in head and neck surgery for the detection and removal of foreign bodies

The removal of embedded blast-generated fragments from soft tissue is very difficult, especially in the head and neck regions. First, because many retained foreign materials are non-metallic and can, therefore, not be detected by fluoroscopy, and second, because a broad exploration of the soft tissue is not possible in the facial area for functional and cosmetic reasons. Intraoperative navigation computer-assisted surgery (CAS) may facilitate the retrieval of foreign bodies and reduce exploration trauma. In a blind trial, five test specimens of different materials (glass, metal, wood, plastic, and stone) were inserted on the left and right sides of the head and neck of ten body donors through an intraoral incision. A second physician then detected and removed the foreign bodies from one side of the body without and from the other side of the body with navigation. We measured the duration of surgery, the extent of tissue trauma caused during surgery, the time it took to remove the foreign bodies, and the subjective evaluation of the usefulness of navigation. With the aid of the navigation system, the various foreign bodies were detected after an average of 26.7 (±35.1) s (p < 0.0001) and removed after an average of 79.1 (±66.2) s (p = 0.0239), with an average incision length of 10.0 (±3.5) mm. Without the navigation system, the foreign bodies were located after an average of 86.5 (±77.7) s and removed after an average of 74.1 (±45.9) s, with an average incision length of 13.0 mm (±3.6) mm (=0.0007). Intraoperative navigation systems are a valuable tool for removing foreign bodies from the soft tissue of the face and neck. Both the duration of surgery and the incision length can be reduced using navigation systems. Depending on the material of the foreign bodies and the signal intensity in the CT/MRI scanner, however, the detection reliability varies. All in all, navigation is considered to be a useful tool.

Application of a computer-aided navigation technique in surgery for recurrent malignant infratemporal fossa tumors

BACKGROUND

Because of the complexity of the local anatomy, tumors in the infratemporal fossa present a great challenge to oral and maxillofacial surgeons. Recurrent malignant tumors in this area are particularly difficult and precarious to resect because scars from previous operations may dislocate some important structures.

METHODS

From August 2010 to December 2013, all recurrent cases of malignant infratemporal fossa tumors at Peking University Stomatological Hospital were enrolled in this study. The patients were divided into 2 groups: the navigation group and the nonnavigation group, with different managements. The following factors were evaluated: operation time, bleeding volume, tumor size, surgical approach and complications, follow-up survey, and outcomes.In addition, survival analyses were performed for all patients.

RESULTS

In total, 42 patients were investigated. The mean operation time for the navigation group was not significantly longer than that of the nonnavigation group (283.64 versus 252.10 min, respectively; P = 0.393); the group's mean intraoperative bleeding volumes were similar (536.36 versus 503.87 mL, respectively; P = 0.814). The surgical approach was determined and categorized as an inferior approach (transmandibular approach, with or without splitting of the mandible), anterior approach (transmaxillary approach), lateral approach (subtemporal-preauricular approach), or combined approach. The inferior approach was most frequently used in both groups (ie, 63.6% for the navigation group and 80.6% for the nonnavigation group). The tumors were completely resected in 4 patients from the navigation group and 24 patients from the nonnavigation group. Regarding complications in the navigation and nonnavigation groups, the incidence was not significantly different (27.2% versus 41.9%, respectively; P = 0.485). The 3-year survival for patients in the navigation group was 71.6% compared with 52.9% in the nonnavigation group, with no significant difference. In the survival analysis, no significant factor was determined.

CONCLUSIONS

A computer-aided navigation technique has been successfully introduced to resect infratemporal fossa tumors and was successfully applied to the resection of recurrent malignant tumors. This new technique alone does not determine the outcome of patients with recurrent malignant infratemporal fossa tumors. Although some improvements are necessary, the visible navigation during surgery could increase the accuracy and safety of the operations and enhance surgeon confidence.

[Diagnosis and treatment of injuries to the frontal skull base]

The role of ENT surgery in the management of anterior skull base defects has become increasingly important in recent years. Transnasal endoscopic surgical techniques and intraoperative navigation enable a minimally invasive approach in a large proportion of patients, thus helping to avoid morbidity typically associated with neurosurgical subfrontal approaches. Whereas traffic accidents and sport injuries are the main causes of anterior skull base trauma in the civilian setting, penetrating injuries caused by gunshots and improvised explosive devices (IEDs) play an increasing role in the military arena and terroristic attacks. Minor injuries to the anterior skull base are usually managed by ENT surgeons. Major injuries, involving the midface or neurocranium, require an interdisciplinary approach including maxillofacial surgeons and neurosurgeons. A centre for head and neck medicine and surgery is an ideal setting for such interdisciplinary teams to provide appropriate care for patients with complex skull base trauma in cooperation with ophthalmologists and interventional neuoradiologists. The present article describes concepts for the treatment of anterior skull base trauma established at the head, neck and skull base center at the Ulm military hospital in Germany.