Fig. 1.1
MRI with contrast in the axial a, sagittal b, and coronal plane c shows a tumour mass with contrast enhancement in the right pterygopalatine fossa that was suspected to be a neuroma of the second branch of the trigeminal nerve
After an interdisciplinary conference with colleagues from ENT surgery, a surgical procedure with direct approach to the tumour through the maxillary sinus was planned (◘ Fig. 1.2). The planning included an intraoral incision by maxillofacial surgeons and was conducted with the help of a BrainLab navigation system (BrainLab, München, Germany) which was also used for intraoperative orientation (◘ Fig. 1.3).
Fig. 1.2
Demonstration of the planned surgical approach with a trajectory through the maxillary sinus a. Designated opening of the anterior wall of the maxillary sinus directly below the foramen of the right infraorbital nerve b
Fig. 1.3
Intraoperative planning of the approach by using neuronavigation. The pointer is positioned at the lower edge of the maxillary sinus after lifting the upper lip a. Intraoperative planning of the trajectory and simulation of the surgical approach through the maxillary sinus with virtual elongation of the pointer (red) until the posterior edge of the tumour into the direction of the foramen rotundum b. Surgical field of the transoral transmaxillary approach during tumour resection while the tip of the pointer is located at the temporal skull base close to the upper posterior edge of the right maxillary sinus c. View into the resection cavity through the maxillary sinus after total resection of the neuroma. The posterior wall of the maxillary sinus was reconstructed with TachoSil d
As planned, the intraoral incision and the skull base approach through the maxillary sinus were performed by maxillofacial surgeons. After dissection of the oral mucosa, the anterior wall of the maxillary sinus was cut out with a piezo-driven ultrasonic saw just below the foramen of the infraorbital nerve and, thus, the nerve could be preserved. Under microscopic view after the removal of the mucosa inside the maxillary sinus, the posterior wall of the maxillary sinus was resected with a 3-mm diamond drill which enabled a direct view onto the tumour. The lesion was then reduced in size by using an ultrasonic surgical aspirator (CUSA), a bipolar forceps and tumour forceps as it can be seen in the accompanying surgical video. Afterwards the tumour was microsurgically dissected from the maxillary nerve and removed from the pterygopalatine fossa . Intraoperative histological analysis confirmed the diagnosis of a benign neuroma (schwannoma).
Maxillary nerve and infraorbital nerve, respectively, could be preserved in their course at the roof of the maxillary sinus. Postoperatively the patient’s facial pain disappeared within 2 days with preserved sensory function in the V2 dermatome. The only postoperative deficits were a mild hypaesthesia and dysaesthesia at the right upper lip.
1.3.2 Partially Thrombosed Giant Aneurysm of the Left Vertebral Artery
Interdisciplinary treatment planning by oncology, neuroradiology and neurosurgery
A 57-year-old female patient had previous surgery for a tonsillar carcinoma (staging: T2N2M0-G3). Due to a slight gait ataxia and persisting dysphagia, our oncologic colleagues initiated a cranial MRI to rule out cerebral metastases. MRI showed a partially thrombosed giant aneurysm of the left vertebral artery with compression of the lower cranial nerves and the brainstem (◘ Figs. 1.4, 1.5, 1.6, and 1.7). Cerebral digital subtraction angiography confirmed the relatively small part of the aneurysm neck with blood flow and showed the origin of the posterior inferior cerebellar artery (PICA) right beside the aneurysm neck as well as irregularities of the tunica intima of the left vertebral artery. This case with slight clinical symptoms of brainstem compression and slowly developing dysfunction of lower cranial nerves is a classical example for an indication for microsurgical management of a giant aneurysm in the posterior fossa.
