The use of stereotactic navigation guidance in minimally invasive transnasal nasopharyngectomy: a comparison with the conventional open transfacial approach

Skull-Base Surgery—A Narrative Review on Current Approaches and Future Developments in Surgical Navigation

Surgical navigation technology combines patient imaging studies with intraoperative real-time data to improve surgical precision and patient outcomes. The navigation workflow can also include preoperative planning, which can reliably simulate the intended resection and reconstruction. The advantage of this approach in skull-base surgery is that it guides access into a complex three-dimensional area and orients tumors intraoperatively with regard to critical structures, such as the orbit, carotid artery and brain. This enhances a surgeon’s capabilities to preserve normal anatomy while resecting tumors with adequate margins. The aim of this narrative review is to outline the state of the art and the future directions of surgical navigation in the skull base, focusing on the advantages and pitfalls of this technique. We will also present our group experience in this field, within the frame of the current research trends.

Comparing endoscopic surgeries with open surgeries in terms of effectiveness and safety in salvaging residual or recurrent nasopharyngeal cancer: Systematic review and meta-analysis

Consensus has yet to be reached on the optimal operation for patients with residual or recurrent nasopharyngeal carcinoma (NPC). To compare effectiveness and safety of open surgery and endoscopic surgery for patients with residual or recurrent NPC. Pubmed, Embase, and Cochrane were searched for relevant publications from January 1, 2000 to May 1, 2017. Included studies reported specific residual or local recurrent nasopharyngeal cancer survival data. Proportional meta-analysis was performed on both outcomes with a random-effects model, and the 95% confidential intervals were calculated by Stata 12.0 software. For patients with different tumor classification, a downward trend of 2-year overall survival (OS) was observed for both surgical populations. Endoscopic surgeries achieved bigger rates than open surgeries in patients with recurrent tumor (rT) 1, rT2, and rT3 (93% vs 87%, 77% vs 63%, 67% vs 53%). As for patients with rT4, 2-year OS was similar (35% vs 35%).In addition, the former is less severe complications, lower local recurrence rates (27% vs 32%). Our study found that, compared to open surgery, endoscopic surgery was a safer and more effective treatment modality in managing patients with recurrent or residual NPC.

Navigation-guided osteotomies improve margin delineation in tumors involving the sinonasal area: A preclinical study

OBJECTIVES

To demonstrate and quantify, in a preclinical setting, the benefit of three-dimensional (3D) navigation guidance for margin delineation during ablative open surgery for advanced sinonasal cancer.

MATERIALS AND METHODS

Seven tumor models were created. 3D images were acquired with cone beam computed tomography, and 3D tumor segmentations were contoured. Eight surgeons with variable experience were recruited for the simulation of osteotomies. Three simulations were performed: 1) Unguided, 2) Guided using real-time tool tracking with 3D tumor segmentation (tumor-guided), and 3) Guided by 3D visualization of both the tumor and 1-cm margin segmentations (margin-guided). Analysis of cutting planes was performed and distance from the tumor surface was classified as follows: "intratumoral" when 0 mm or negative, "close" when greater than 0 mm and less than or equal to 5 mm, "adequate" when greater than 5 mm and less than or equal to 15 mm, and "excessive" over 15 mm. The three techniques (unguided, tumor-guided, margin-guided) were statistically compared.

RESULTS

The use of 3D navigation for margin delineation significantly improved control of margins: unguided cuts had 18.1% intratumoral cuts compared to 0% intratumoral cuts with 3D navigation (p < 0.0001).

CONCLUSION

This preclinical study has demonstrated the significant benefit of navigation-guided osteotomies for sinonasal tumors. Translation into the clinical setting - with rigorous assessment of oncological outcomes - would be the proposed next step.

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.

Volumetric Analysis of Endoscopic and Maxillary Swing Surgical Approaches for Nasopharyngectomy

Objectives/Hypothesis  The endoscopic endonasal approach (EEA) for nasopharyngectomy is an alternative to the maxillary swing approach (MSA) for selected recurrent nasopharyngeal carcinomas (NPC). We compare the access between these approaches. Methods  Three cadaver specimens were used to compare access volumes of the EEA and MSA. Exposure volumes were calculated using image guidance registration to cone beam computed tomography and tracking of accessible tissue with volumetric quantification. The area of exposure to the carotid artery was measured. Results  The MSA provided higher volumes for access volume compared with the EEA (66.6 vs 39.1 cm ³ , p  = 0.009). The working area was larger in the MSA (80.2 vs 56.9 cm ² , p  = 0.06). The exposure to the carotid artery was higher in the MSA (1.88 vs 1.62 cm ² , p  = 0.04). The MSA provided larger volume of exposure for tumors of the parapharyngeal space with exposure below the palate. Conclusions  This study suggests that the MSA for nasopharyngectomy provides a larger volume of exposure. However, much of the increased exposure relates to exposure of the parapharyngeal space below the palate. The EEA provides adequate access to superior anatomical structures.

Surgical Navigation: A Systematic Review of Indications, Treatments, and Outcomes in Oral and Maxillofacial Surgery

PURPOSE

This systematic review investigates the most common indications, treatments, and outcomes of surgical navigation (SN) published from 2010 to 2015. The evolution of SN and its application in oral and maxillofacial surgery have rapidly developed over recent years, and therapeutic indications are discussed.

MATERIALS AND METHODS

A systematic search in relevant electronic databases, journals, and bibliographies of the included articles was carried out. Clinical studies with 5 or more patients published between 2010 and 2015 were included. Traumatology, orthognathic surgery, cancer and reconstruction surgery, skull-base surgery, and foreign body removal were the areas of interests.

RESULTS

The search generated 13 articles dealing with traumatology; 5, 6, 2, and 0 studies were found that dealt with the topics of orthognathic surgery, cancer and reconstruction surgery, skull-base surgery, and foreign body removal, respectively. The average technical system accuracy and intraoperative precision reported were less than 1 mm and 1 to 2 mm, respectively. In general, SN is reported to be a useful tool for surgical planning, execution, evaluation, and research. The largest numbers of studies and patients were identified in the field of traumatology. Treatment of complex orbital fractures was considerably improved by the use of SN compared with traditionally treated control groups.

CONCLUSIONS

SN seems to be a very promising addition to the surgical toolkit. Planning details of the surgical procedure in a 3-dimensional virtual environment and execution with real-time guidance can significantly improve precision. Among factors to be considered are the financial investments necessary and the learning curve.

Salvage surgery for nasopharyngeal cancer

Nasopharyngeal carcinoma (NPC) is a special type of head and neck cancer with a widely variable geographical variation in incidence. The central location of the tumor inside the head coupled with the radiosensitivity of the tumor to radiation made radiation therapy the first choice in primary treatment of NPC. Advances in radiotherapy and chemotherapy have markedly improved the local control of NPC. Unfortunately, a small but significant number of patients still suffered from loco-regional failures that would be amenable to re-treatment. Traditional form of retreatment was to employ a second course of radiation. The efficacy of re-irradiation to treat local of regional recurrent NPC has been suboptimal. Moreover, the local tissue had already received a high dose of radiation and the second radiation could result in radiation toxicities to the local tissue, leading to significant complications.

Surgical salvage, on the other hand, could spare the patients from complications of re-treatment. Due to the difficult access of the nasopharynx, various surgical approaches had been devised for nasopharyngectomy. The maxillary swing approach had the largest published experience with over 300 cases from various centers. In the recent decade, the endoscopic approach with or without robotic assistance had gained popularity for resecting small, centrally located recurrences. This minimally invasive approach further reduced the morbidity for treating locally recurrent NPC.

Nodal recurrences had been a rare entity after the introduction of modern radiotherapy technique and concurrent chemotherapy. Treatment of nodal failure with second radiation has dismal results. Surgical removal of the lymph node harboring the recurrence should be in the form of a formal radical neck dissection. In cases of extensive nodal recurrence where microscopic disease may be present after a formal neck dissection, additional radiotherapy can be delivered with after-loading brachytherapy.

Surgical treatment played a definitive role in salvage of loco-regional failures of nasopharyngeal carcinoma.

[The role of surgical treatment for nasopharyngeal carcinoma]

AIM

Presentation of experiences and results of surgical treatment of nasopharyngeal carcinoma.

MATERIAL AND METHODS

4 patients with nasopharyngeal carcinoma operated in Department of Otolaryngology and Laryngological Oncology of Poznan University of Medical Sciences between 2006 and 2011. In one case operation was performed via transpalatal approach and in other three cases via transfacial approach (via lateral rhinotomy). In all cases operation was supported by endoscopy and in advanced tumors (T4) also by navigation.

RESULTS

We have not observed any important intraoperation and postoperation complications. Two patients with T2 tumor are disease free (observation time 5 years and 1 year). One patient with T4 tumor developed local recurrence and after few months died. Second patient with T4 tumor refused further control.

CONCLUSIONS

1. Instead of that nasopharyngeal carcinoma is typically treated by radiotherapy or in advanced stages by radio-chemotherapy, in some cases surgical treatment should be used. 2. The main indication to surgical treatment are residual and recurrent tumors after radiotherapy or radio-chemotherapy--both in nasopharynx and in cervical lymph nodes. It can be also used in primary, limited, radio-resistant tumors. 3. Appropriate surgical approach and using of endoscopy and navigations are important factors which influence the radical and safe excision of tumor. 4. The results of treatment of residual and recurrent tumors of nasopharynx depend on stage of disease and complexity of excision of the tumor and the worst prognostic factor is intracranial extension of tumor.

Endoscopic nasopharyngectomy and its role in managing locally recurrent nasopharyngeal carcinoma

Local recurrence after primary radiation of nasopharyngeal carcinoma (NPC) remains an important cause of morbidity and mortality. Salvage treatment using reirradiation or surgery has been shown to improve survival over nontreatment. Surgery is traditionally performed using an open approach. Advances in endoscopic approaches for resection of paranasal sinus tumors have been extended to NPC. This article reviews the treatment options, in particular the role of endoscopic nasopharyngectomy in the management of recurrent NPC. The endoscopic anatomy, surgical principles, and published results on endoscopic nasopharyngectomy are presented. Short-term outcomes for early-stage recurrences are promising but long-term follow-up is needed.

Surgical salvage nasopharyngectomy for recurrent nasopharyngeal carcinoma: a multivariate analysis of prognostic factors

BACKGROUND

The purpose of this study was to identify independent prognostic factors that influenced local relapse-free survival (LRFS) and overall survival (OS) of patients who underwent salvage surgery for residual or recurrent nasopharyngeal carcinoma (NPC).

METHODS

Ninety-seven patients who had been treated with radiotherapy or chemoradiotherapy for NPC underwent a nasopharyngectomy for a residual or recurrent local tumor between November 1987 and June 2007. The subsequent minimum follow-up was 2 years. Univariate and multivariate analyses were performed to identify prognostic factors for LRFS and OS.

RESULTS

The 5-year LRFS and OS was 46.7% and 51.9%, respectively. On multivariate analysis for LRFS and OS, respectively, recurrent regional disease (hazard ratio [HR], 3.245; p = .008) and (HR, 4.990; p = .001), and positive surgical margins (HR, 5.963; p = .000), and (HR, 4.912; p = .000) were independent prognostic factors.

CONCLUSION

In patients undergoing surgical salvage nasopharyngectomy for residual or recurrent NPC, positive surgical margins have an independent negative influence on LRFS and OS.

Computer planning and intraoperative navigation in cranio-maxillofacial surgery

Preoperative computer design and stereolithographic modeling combined with intraoperative navigation provide a useful guide for and possibly more accurate reconstruction of a variety of complex cranio-maxillofacial deformities. Although probably not necessary for routine use, the author's early experience confirms that of other surgeons with more than a decade of experience: computer-assisted surgery is indicated for complex posttraumatic or postablative reconstruction of the orbits, cranium, maxilla, and mandible; total temporomandibular joint replacement; orthognathic surgery; and complex dental/craniofacial implantology. Further study is needed to provide outcomes data and cost-benefit analyses for each of these indications.

Anterior skull base surgery

The basic principle of anterior skull base surgery is to provide adequate exposure to enable three dimensional resection of skull base tumors. Negative surgical margins, which is within the control of surgeon, is the principle prognostic factor in anterior skull base tumors. Open skull base approaches is the standard of care for malignant anterior skull base tumors. Benign lesions may be resected by alternate minimally invasive approaches. Advances in anterior skull base surgery, in particular the facial translocation approaches allows wide exposure of the tumors with minimal retraction of the brain. The outcome of anterior skull base tumors have steadily increased over the years with disease free survival comparable to other malignant neoplasm of the head and neck region. This review described various surgical approaches and pertaining anatomy and pathology of anterior skull base tumors.

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

The authors report a case of navigation-guided tumour ablation of a high-grade epithelial-myoepithelial carcinoma of the right parotid gland extending to the skull base. Immediate functional reconstruction of the mandible with a prosthetic temporomandibular joint and facial nerve was performed. Postoperative follow-up showed no evidence of local tumour recurrence or distant metastasis with satisfactory temporomandibular and facial nerve function.

Endoscopic nasopharyngectomy for locally recurrent nasopharyngeal carcinoma

OBJECTIVES

Nasopharyngectomy is the primary treatment for locally recurrent nasopharyngeal carcinoma (rNPC). However, oncological nasopharyngectomy is difficult to achieve, even using extranasal surgical approaches, with potential risks of severe functional disabilities and serious complications. This report introduces an innovative, minimally invasive, oncological, endoscopic nasopharyngectomy.

METHODS

Between October 2004 and January 2008, 37 rNPC patients received endoscopic nasopharyngectomy, with 17, 4, 14, and 2 cases of rT1N0M0, rT2aN0M0, rT2bN0M0, and rT3N0M0, respectively. Tumors in all patients were confined to the nasopharyngeal cavity, postnaris, nasal septum, superficial parapharyngeal space, or the base of the sphenoid sinus. Nasopharyngeal malignancies and adequate surgical margin (>0.5-1.0 cm) were required for continuous en bloc resection.

RESULTS

Among the 37 endoscopic nasopharyngectomies, 35 achieved en bloc tumor resection with negative surgical margins. In the remaining two cases, the tumors were dissected into small blocks, and one had positive surgical margins. No patient received postoperative radiotherapy and no severe complication was observed. During the 6-45 months of follow-up (median, 24 months), five patients experienced in situ residual or recurrence with 1 submaxillary lymphatic metastasis. One patient developed distant metastases and died, one died of intracranial infection, and one died of another cancer. The 2-year overall survival rate, local relapse-free survival rate, and progression-free survival rate were 84.2%, 86.3%, and 82.6%, respectively.

CONCLUSIONS

Appropriate endoscopic nasopharyngectomy is a minimally invasive, safe, and promising surgical modality for the en bloc excision of rNPCs with encouraging short-term outcome. Long-term patient follow-up is ongoing.

Surgical practice in Hong Kong

Surgery in Hong Kong has undergone a significant evolution over the past century. The quality of surgical care, medical education, surgical training and academic research has improved significantly through the joint efforts of the two universities, the government and the surgical colleges over these years. Surgical practice in Hong Kong continues to change also with the development of specialties/subspecialties, the changing pattern of disease and the development of new and effective treatments. Areas of clinical excellence in oesophageal cancer, hepatocellular carcinoma (HCC) and nasopharyngeal cancer (NPC) have gradually developed in these areas in Hong Kong. With the ongoing Westernisation and continued economic development in Hong Kong, some previously uncommon diseases will become more common. The surgical service in Hong Kong will need to continue to change to meet the new challenges in the future

Anterior skull base surgery

This article focuses on selected key anatomic considerations in anterior skull base surgery, briefly reviews common pathologies of the paranasal sinuses, and provides an overview of surgical approaches, complications, and results.

Nasopharyngectomy for recurrent nasopharyngeal carcinoma: a review of 31 patients and prognostic factors

OBJECTIVES/HYPOTHESIS

Nasopharyngectomy is a well-established treatment option for recurrent nasopharyngeal carcinoma. Over a period of 4 years and 3 months, in a total of 43 patients, 45 nasopharyngectomies were performed. Thirty-one patients with follow-up ranging from 12 to 58 months were studied. Twenty-two patients (58%) survived; of these, 18 patients (82%) remained disease free. All patients who developed repeat recurrence or died (n = 12) had a high recurrent T-stage tumor, skull base involvement, multiple recurrences, positive surgical margins, or concurrent neck node metastasis. These factors are poor prognostic parameters and might mitigate the indications for aggressive salvage surgery. However, low recurrent T-stage tumor without neck metastasis carries a good prognosis. Modern minimally invasive surgery carries minimal morbidity. STUDY DESIGN A retrospective study was made to determine prognostic indicators in patients treated with salvage surgery for recurrent nasopharyngeal carcinoma.

METHODS

Medical records were analyzed for all patients who had received nasopharyngectomy for recurrent nasopharyngeal carcinoma from March 1997 to June 2001. They were followed up from March 1997 to January 2002. Recurrent T stage, nodal metastasis, surgical approach, surgical margins, and pathological nodal status, together with surgical mortality, morbidity, and the delivery of postoperative irradiation, were compared with survival.

RESULTS

In all, 43 patients underwent 45 nasopharyngectomies over a period of 4 years and 3 months. Patients with less than 1 year of follow-up were excluded. Four patients with residual disease, who represent a more favorable group, and five patients with planned debulking, nasopharyngectomy, and postoperative stereotactic irradiation were also excluded. The study group comprised 25 men and 6 women (ratio of 4:1) with age ranging from 26 to 69 years (mean age, 49.5 y). In 28 patients (90.3%), the recurrence of nasopharyngeal carcinoma was their first recurrence; in 3 patients (9.7%), the recurrences were second recurrences. Twenty-two patients (71%) survived, achieving a mean survival of 28.5 months. Nine patients died with a mean interval of 7.8 months (range, 1-14 mo). Of the nine patients who died, six (67%) had T3 or T4 tumor, four (44.4%) had concurrent recurrent neck disease, and five (55.5%) had positive surgical margins. Two patients died of perioperative meningitis. Fifteen (83.3%) of the 18 disease-free survivors had a low recurrent T-stage tumor. Mean intervals for development of repeat recurrence or distant metastasis were 16 and 7.9 months, respectively.

CONCLUSIONS

High recurrent T stage, skull base involvement, repeated recurrence before surgery, nodal metastasis, and positive surgical margins carry a poor prognosis. This is particularly evident with high T stage and concurrent nodal metastasis. However, patients with low T stage have a survival advantage and benefit most from surgical treatment.