Navigation-guided resection with immediate functional reconstruction for high-grade malignant parotid tumour at skull base

Extended Complex Temporomandibular Joint Reconstructions Exploiting Virtual Surgical Planning, Navigation Assistance, and Custom-Made Prosthesis: A Comprehensive Protocol and Workflow

BACKGROUND

Alloplastic temporomandibular joint (TMJ) replacement is a well-established procedure in maxillo-facial surgery. However, the surgical management of large excision in this area requires complex reconstruction beyond the standard TMJ prosthesis.

OBJECTIVE

This study aims to describe the design and the consequential application of a protocol which involves the use of computer-assisted surgery tools to best face complex TMJ reconstruction (TMJR). Preoperative accurate study of every single case and intraoperative check of the surgical act are nowadays essential to perform such delicate surgical procedures.

MATERIALS AND METHODS

The study is a retrospective and single institution case series. The various processes of the management and planning of extended TMJ reconstruction (eTMJR) are extensively described, from the preoperative clinical evaluation, imaging acquisition protocols and virtual surgical planning (VSP), focusing also on the intraoperative transfer of VSP using navigation and surgical guides.

RESULTS

We included nine patients with different pathologies which were candidates for eTMJR. Overall, the application of our protocol and workflow permitted the reduction of complications and pain, and the improvement of the maximum interincisal opening (MIO) of the patients, restoring patients' masticatory function and esthetics.

CONCLUSIONS

The eTMJR should be considered as a safe and reliable surgical management modality in selected patients with large temporomandibular joint and skull base (TMJ-SB) lesions. An accurate preoperative protocol and workflow is essential to perform such insidious and complex reconstruction. However, more extensive studies on this type of device have to be conducted in order to validate its real usefulness and indications.

Surgical navigation system for temporomandibular joint ankylosis in a child: a case report

Background

Computer-assisted surgical navigation systems were initially introduced for use in neurosurgery and have been applied in craniomaxillofacial surgery for 20 years. The anatomy of the oral and maxillofacial region is relatively complicated and includes critical contiguous organs. A surgical navigation system makes it possible to achieve real-time positioning during surgery and to transfer the preoperative design to the actual operation. Temporomandibular joint ankylosis limits the mouth opening, deforms the face, and causes an increase in dental caries. Although early surgical treatment is recommended, there is controversy regarding the optimal surgical technique. In addition, pediatric treatment is difficult because in children the skull is not as wide as it is in adults. There are few reports of pediatric temporomandibular joint ankylosis surgery performed with a navigation system.

Case presentation

A 7-year-old Japanese girl presented severe restriction of the opening and lateral movement of her mouth due to a temporomandibular joint bruise experienced 2 years earlier. Computed tomography and magnetic resonance imaging demonstrated left condyle deformation, disappearance of the joint cavity, and a 0.7-mm skull width. We diagnosed left temporomandibular joint ankylosis and performed a temporomandibular joint ankylosis arthroplasty using a surgical navigation system in order to avoid damage to the patient's brain. A preauricular incision was applied, and interpositional gap arthroplasty with temporal muscle was performed. After the surgery, the maximum aperture was 38 mm, and the limitation of the lateral movement was eliminated.

Conclusions

A navigation system is helpful for confirming the exact target locations and ensuring safe surgery. In our patient's case, pediatric temporomandibular joint ankylosis surgery was performed using a navigation system without complications.

Role of Navigation in Oral and Maxillofacial Surgery: A Surgeon's Perspectives

Surgeries related to the maxillofacial area deal with an intricate network of anatomical structures. With the complexity of the vital structures, it necessitates a surgical team to respect each anatomical boundary. In the past, there was an exceptionally high number of cases with surgical errors. These errors were not because of flaws in the surgeon’s skills or techniques but owing to lack of resources. Visualisation is one of the key factors that determines the precision of any surgical outcome. Advances in surgical planning have led to the introduction of a “Navigation” system that helps surgeons to see more, know more and ultimately do more for their patients. The usefulness of the navigation system in oral surgeries has been indicated by its surgical applications in craniomaxillofacial trauma, orthognathic surgeries, head and neck pathological resections, complex skull base surgeries and surgery involving temporomandibular joint. A vast majority of research literature has suggested remarkable improvement in surgical outcomes under the guidance of 3d planning and navigation. However, with such an inordinate advancement, financial expenses and a gradual learning curve are always a constraining factor in surgical navigation. This article overviews indication of navigation in craniofacial surgeries with a focus on applied aspect, planning and solution to the future problem.

[Use of navigation in skull base surgery]

The review briefly presents the history of development of navigation systems in neurosurgery. The idea of the existing principles underlying the navigation systems used in neurosurgery is given. Currently, the basic principles of navigation are optical and electromagnetic. Studies are presented comparing the accuracy of various navigation systems. Optical navigation demonstrates greater accuracy compared to electromagnetic, but both methods demonstrate a submillimeter error in the experiment. The history of use of navigation in the surgery of the skull base is analyzed in detail, the most relevant areas of use of navigation within the surgery of the skull base are considered: craniofacial reconstruction, endoscopic endonasal surgery, surgery of common tumors of the skull base affecting the infratemporal, pterygopalatine fossa, temporomandibular joint. Indications for the use of navigation, limitations of the methodology are explained.

Application of computer-assisted navigation systems in oral and maxillofacial surgery

The oral and maxillofacial region has a complicated anatomy with critical contiguous organs, including the brain, eyes, vital teeth, and complex networks of nerves and blood vessels. Therefore, advances in basic scientific research within the field of intraoperative oral and maxillofacial surgery have enabled the introduction of the features of these techniques into routine clinical practice to ensure safe and reliable surgery. A navigation system provides a useful guide for safer and more accurate complex in oral and maxillofacial surgery. The effectiveness of a navigation system for oral and maxillofacial surgery has been indicated by clinical applications in maxillofacial trauma surgery including complex midfacial fractures and orbital trauma reconstruction, foreign body removal, complex dentoalveolar surgery, skull base surgery including surgery of the temporomandibular joint (TMJ), and orthognathic surgery. However, some fundamental issues remain involving the mobility of the mandible and difficulty in updating images intraoperatively. This report presents an overview and feasible applications of available navigation systems with a focus on the clinical feasibility of the application of navigation systems in the field of oral and maxillofacial surgery and solutions to current problems.

The Safety and Accuracy of Surgical Navigation Technology in the Treatment of Lesions Involving the Skull Base

OBJECTIVE

As compared with the normal anatomy, structures of the skull base and its surroundings have been dramatically altered of the lesion near the skull base. How to remove the lesion at the skull base was mainly depending on surgeon's personal experience during past years. In this study, the authors explored the safety and accuracy of the surgical navigation system in resecting lesions near the skull base.

METHODS

The surgical cases consisted of 15 patients who underwent surgery involving the skull base with the using of surgical navigation technology. Five patients had adenoid cystic carcinoma at minor salivary glands of the palate extending to the skull base and 10 patients were suffered from bony ankylosis of temporomandibular joint. After the system converted patient's computed tomography scans into three-dimensional reconstructive images, preoperative planning and simulation of the operation process could be made by surgeons. During the operation, the virtual images were matched with the patient through individual registration. The system provided surgeon with feedback about the operation on the screen instantly with moving the navigated pointer.

RESULTS

The application of surgical navigation system was safe and reliable for resecting the ankylotic bone and identifying the extent of tumors resection near the skull base. No complications including cerebrospinal fluid leak, cranial nerve injuries, severe bleeding happened to those patients.

CONCLUSIONS

Given the safety and accuracy of the surgical navigation system, surgery near the skull base appeared to be an ideal field for using with its complex anatomy.

Reoperation following the use of non-standardized procedures for malignant parotid tumors

Non-standardized or conservative procedures are employed when parotid tumors involving the facial nerve or parotid carcinoma are misdiagnosed as benign parotid tumors prior to or during surgery. Remedial measures are usually required when the pathological diagnosis of a malignant parotid tumor is confirmed following surgery. The aim of the present study was to systematically evaluate reoperation subsequent to treatment with non-standardized procedures for malignant parotid tumors, and to explore the preoperative diagnoses, the primary procedure selection and the necessity of reoperation following non-standardized procedures in malignant parotid tumors. A total of 30 patients who met the inclusion criteria, were diagnosed with a malignant parotid tumor and underwent reoperation following the use of a non-standardized procedure were included in the present study. Surgical conditions and clinical data were analyzed. Among the patients with a malignant parotid tumor who underwent reoperation subsequent to a non-standardized procedure, the incidence of residual tumor, as confirmed by pathological examination, was 63.3% (19/30). The intact facial nerve preservation rate was 83.3% (25/30), the facial nerve branch resection rate was 6.7% (2/30), the facial partial nerve resection rate was 6.7% (2/30) and the facial nerve resection rate was 3.3% (1/30). In total, 3 patients underwent facial nerve reconstruction, 3 patients underwent a local flap repair of skin defects in the parotid region and 3 patients underwent pectoralis major muscle flap repair. The current findings indicate that the qualitative diagnosis of malignant parotid tumors prior to surgery is difficult, there is a high incidence of residual tumor following non-standardized procedures, and that reoperation in a timely manner is required in such cases.

Outcomes of temporal bone resection for locally advanced parotid cancer

This study was conducted to report outcomes and identify factors predictive of survival and recurrence in patients undergoing lateral temporal bone resection (LTBR) as part of an extended radical parotidectomy for parotid cancer. This is a retrospective cohort study which includes all patients undergoing LTBR for parotid cancer between 1994 and 2010 at two affiliated academic centers. Survival and recurrence rates were analyzed using the Kaplan-Meier method and Cox multivariate regression. A total of 12 patients with median follow-up duration of 30.6 months were included: 6 de novo cases and 6 patients referred after local recurrence. Actuarial locoregional control at 2 years was 73%. Most patients (11; 92%) developed disease recurrence with distant metastases the most common site of first failure (83%). Overall and disease-specific survival rates were 80% at 2 years and 22.5% at 5 years. Recurrence-free survival (RFS) was 67% at 2 years and 8.3% at 5 years. On multivariate analysis, surgical margin status was an independent predictor of RFS (hazard ratio = 3.85, p = 0.045). In advanced parotid cancer, LTBR with a goal of gross total resection offers good locoregional control with an acceptable complication rate. The benefits of this surgery must be balanced with the morbidity and low likelihood of long-term survival, with most patients ultimately experiencing disease recurrence and death.