Long-term outcome following radical temporal bone resection for lateral skull base malignancies: a neurosurgical perspective

Risk Factors for Complications in Patients Undergoing Temporal Bone Resection and Neck Dissection: Insights From a National Database

BACKGROUND

Temporal bone resection (TBR) with or without neck dissection (ND) is performed for otologic malignancies with occult or clinical cervical lymph node metastases. To date, characterization of post-operative complications in single institution case series may be non-representative of real-world outcomes. Here, we used data from the National Inpatient Sample (NIS) to comprehensively assess the complications encountered, their frequencies, and to identify underlying risk factors to improve future outcomes.

METHODS

The population was patients undergoing TBR and ND derived from the NIS between the years of 2017 and 2019. We utilized ICD-10 diagnosis codes to identify patients with post-operative complications, those discharged to non-home facilities (DNHF), and those with increased length of stay (LOS). Multivariable regression was performed to identify significant variables related to the above outcomes.

RESULTS

Ninety of 277 patients that underwent LTBR with ND had postoperative complications. Wound complications were the most frequent complication, occurring in 11 (4%) of patients, followed by CSF leak (n = 6; 2.2%), with acute respiratory failure being the most common medical complication (n = 4; 1.4%). Sixteen percent (45/277) were discharged to a facility besides home. Dementia (OR = 7.96; CI95 3.62-17.48), anemia (OR = 2.39; CI95 1.15-4.99), congestive heart failure (OR = 5.31; CI95 1.82-15.45), COPD (OR = 3.70; CI95 1.35-10.16), and history of prior stroke (OR = 8.50; CI95 1.55-46.68) increased the odds of DNHF. When evaluating LOS (median = 5 days, IQR = 1, 9), anemia (OR = 5.49; CI95 2.86-10.52), and Medicaid insurance (OR = 3.07; CI95 1.06-10.52) were found to increase the LOS.

CONCLUSIONS

The vast majority of patients undergoing LTBR with ND have no complications and are discharged within a week. Liver disease is a risk factor for medical complications and increased charges. Patients with dementia or a prior stroke are at risk for DNHF, and those with prior anemia are at risk for a wound complication.

LAY SUMMARY

This study identified factors related to worse post-operative outcomes in patients undergoing temporal bone resection and neck dissection. Although safe for most patients, an existing diagnosis of liver disease, stroke, dementia, and anemia specifically are at risk for developing negative outcomes.

LEVEL OF EVIDENCE

3.

A Combined Exoscopic and Endoscopic Approach for Radical Temporal Bone Resection and Usefulness of the Endoscopic Approach to the Medial Aspect of the Temporal Bone

Radical temporal bone resection (TBR) for lateral skull base malignancies is technically challenging because of the vital anatomical structures located at the medial part of the temporal bone and their limited exposure. A possible solution is to adopt an additional endoscopic approach for medial osteotomy to reduce blind spots. The authors aimed to describe a combined exoscopic and endoscopic approach (CEEA) for cranial dissection in radical TBR and to determine the usefulness of the endoscopic approach to the medial aspect of the temporal bone. Having utilized the CEEA in for cranial dissection in radical TBR since 2021, the authors included 5 consecutive patients who underwent the procedure between 2021 and 2022. All surgeries were successful and resulted in no significant complications. The additional use of an endoscope improved visualization of the middle ear in 4 patients and that of the inner ear and carotid canal in 1 patient, enabling precise and safe cranial dissection. Furthermore, surgeons experienced reduced intraoperative postural stress with CEEA than with a microscopic approach. The main advantage of CEEA in radical TBR was the extension of the viewing angles of the endoscope, which allowed observation of the medial aspect of the temporal bone and limited tumor exposure and injury to vital structures. Given the other benefits of exoscopes and endoscopes, including compact size, ergonomics, and surgical field accessibility, CEEA proved to be an efficient treatment option for cranial dissection in radical TBR.

Clinical Analysis of En Bloc Resection for Advanced Temporal Bone Squamous Cell Carcinoma

Objective En bloc and margin-negative surgical resection seems to offer the best prognosis for patients with temporal bone squamous cell carcinoma (TB-SCC). In this study, we summarize the outcomes of surgical cases of advanced TB-SCC (T3–T4) that were managed in two institutions, with an accompanying description of the surgical procedure that was utilized: modified subtotal temporal bone resection (STBR), which involves the en bloc removal of the temporal bone including or transecting the otic capsule.

Design This is a case series study with chart review.

Setting The study was conducted at two academic tertiary care medical centers.

Participants Chart information was collected for all patients who underwent surgical resection of advanced TB-SCC between July 1998 and February 2019. The resulting dataset contained 43 patients with advanced TB-SCC who underwent en bloc resection during the review period. Tumor staging followed the modified Pittsburgh classification. Disease-specific survival (DSS) rates were calculated according to the Kaplan–Meier method.

Main Outcome Measure This study shows disease-specific 5-year DSS rate.

Results The 5-year DSS rate of the cases who underwent en bloc resection was 79.7%. En bloc lateral temporal bone resection was employed in a total of 25 cases (DSS: 79.0%). En bloc modified STBR was utilized in 18 cases (DSS: 81.7%).

Conclusion En bloc margin-negative resection is a reliable treatment strategy for advanced TB-SCC. Modified STBR can be a treatment option for TB-SCC without marked posterior extension.

Combined Exoscopic and Endoscopic Technique for Craniofacial Resection

We determined the feasibility of the combined exoscopic-endoscopic technique (CEE) as an alternative to the microscope in craniofacial resection (CFR). This retrospective study was conducted at a single institution and included eight consecutive patients with head and neck tumors who underwent CFR between September 2019 and July 2021. During the transcranial approach, microsurgery was performed using an exoscope in the same manner as in traditional microscopic surgery, and an endoscope was used at the blind spot of the exoscope. The exoscope provided images of sufficient quality to perform microsurgery, while the sphenoid sinus lumen was the blind spot of the exoscope during anterior (n = 3) and anterolateral CFR (n = 2), and the medial aspect of the temporal bone was the blind spot of the exoscope during temporal bone resection (n = 2). These blind spots were visualized by the endoscope to facilitate accurate transection of the skull base. The advantages of the exoscope and endoscope include compact size, ergonomics, surgical field accessibility, and equal visual experience for neurosurgeons and head and neck surgeons, which enabled simultaneous transcranial and transfacial surgical procedures. All the surgeries were successful without any relevant complications. CEE is effective in transcranial skull base surgery, especially CFR involving simultaneous surgical procedures.

Prognostic Impact of Tumor Extension in Patients With Advanced Temporal Bone Squamous Cell Carcinoma

Objective: The extreme rarity of temporal bone squamous cell carcinoma (TB-SCC) has delayed the accumulation of high-quality clinical evidence. Our objective here was to explore anatomical factors associated with the prognosis of T4 TB-SCC cases.

Study Design: Case series with chart review.

Setting: Two academic tertiary care medical centers.

Subjects and Methods: The medical records of all TB-SCC cases were retrospectively reviewed in two institutions. The resulting data set contained 30 cases of primary T4 cancer eligible for initial definitive (curative) treatment. Disease-specific survival was calculated according to the Kaplan–Meier method. Cox proportional hazards model was used to identify anatomical prognosis factors.

Results: The disease-specific 5-years survival rate of 30 cases of T4 TB-SCC was 53.9%. The tumor invasion to the pterygoid muscle, posterior fossa dura, and sigmoid sinus and destruction of the ossicles were associated with poor prognosis in univariate analysis. The multivariate analysis reveals that the invasion of the ossicles, posterior fossa dura, and sigmoid sinus is an independent prognostic factor [hazard ratio (HR): 4.528 (95% CI: 1.161–17.658), p = 0.030; HR: 5.135 (95% CI: 1.616–16.315), p = 0.006; HR: 4.292 (95% CI: 1.385–13.303), p = 0.012]. The invasion of the carotid canal, petrous apex, middle fossa dura, otic capsule, pterygoid muscle, and middle ear had a high HR (HR > 2). The more invaded anatomical factors present in patients resulted in a poorer patient disease-specific prognosis, with a statistically significant difference.

Conclusions: Assessing which anatomical structures are susceptible to invasion by tumors may be important for predicting TB-SCC patient prognosis and selecting appropriate treatment planning, especially surgical intervention. In addition to previously reported factors, the destruction of the ossicles in the middle ear cavity can be an anatomical prognosis factor.

Skull Base Invasion Patterns of Malignant Head and Neck Tumors: A Neurosurgical Perspective

Objective  Craniofacial resection (CFR) and temporal bone resection (TBR) on malignant head and neck tumors (MHNTs) invading skull base require accurate and precise determination of the tumor invasion. We investigated tumor skull base invasion patterns and surgical results in CFR and TBR cases. Methods  We performed either CFR or TBR for 75 selected patients with the possibility of en bloc resection over the period between 2011 and 2018. The medical charts of the selected patients were reviewed. Results  Primary tumor onset site (TOS) groups were: (1) nasal cavity/ethmoid sinus, 20 cases; (2) orbit, 10 cases; (3) maxillary sinus, 28 cases; and (4) external ear/temporomandibular joint, 17 cases. Grades for tumor invasion depth (TID) included: (I) extracranial invasion and skull base bone invasion; (II) extradural invasion; or (III) intradural invasion. Patients in groups 1 and 2 had a significantly higher frequency of grade II and III invasions than patients in groups 3 and 4. The main invasion site was nasal cavity superior wall and ethmoid sinus superior wall for group 1 tumors, orbit superior wall, and lateral skull base sphenoid bone for group 2 and 3 tumors, and lateral skull base temporal bone for group 4 tumors. Positive resection margins represented a significant negative prognostic factor. TID and TOS did not affect skull base margin status. Conclusion  Skull base invasion of MHNTs exhibits certain fixed patterns in sites susceptible to invasion based on the TOS. The frequencies of extradural and intradural invasions differed, indicating the importance for accurate preoperative tumor evaluation.

Impact of Surgical Margin in Skull Base Surgery for Head and Neck Sarcomas

Objective  This study aimed to determine the adequate resection margin in skull base surgery for head and neck sarcoma. Design  We retrospectively reviewed 22 sarcomas with skull base invasion. Induction chemotherapy, followed by surgery and postoperative radiotherapy and adjuvant chemotherapy, was performed in 18 patients with chemosensitive sarcomas, and surgery with or without postoperative radiotherapy was performed in four patients with chemoresistant sarcomas. Radical resection was performed in patients with chemosensitive sarcomas with a poor response to induction chemotherapy and in patients with chemoresistant sarcomas. Conservative resection with close surgical margin was performed in patients with chemosensitive sarcomas with a good response to induction chemotherapy. Setting and Participants  This single-centered retrospective study included patients from the National Cancer Center Hospital, Japan. Results  The response to induction chemotherapy was significantly associated with the 3-year local control rate (LCR; good response versus poor response: 100% versus 63%, p  = 0.048). Patients with a good response to chemotherapy had a favorable local prognosis even when the local therapy was conservative resection. In radical skull base surgery, patients whose surgical margins were classified as "wide margin positive" had significantly poorer 3-year LCR than did patients with "margin negative" or "micro margin positive" margins (25% versus 83%, p  = 0.014). Conclusion  Conservative resection with close surgical margins might be acceptable for chemosensitive sarcomas with a good response to chemotherapy. Resection margin status was an important predictive factor for local recurrence after radical skull base surgery. Microscopic microresidual tumor might be controlled by postoperative treatment.

Microsurgical anatomy of subtotal temporal bone resection en bloc with the parotid gland and temporomandibular joint

BACKGROUND

Subtotal temporal bone resection (STBR) has been used for half a century to remove temporal bone malignancies. However, there are few reports on the detailed anatomy involved in the resection.

OBJECTIVE

To describe the microsurgical anatomy of STBR combined en bloc with the resection of the parotid gland and temporomandibular joint (TMJ).

METHODS

Cadaveric specimens were dissected in a stepwise manner using 3× to 40× magnification.

RESULTS

STBR can be combined with the total parotidectomy and the resection of the TMJ if the tumor extends into the parotid gland, TMJ, or facial nerve. In this study, we describe the step-by-step microsurgical anatomy of STBR en bloc with the parotid gland and TMJ. The surgical technique described combines 3 approaches: the high cervical, subtemporal-infratemporal fossa, and retromastoid-paracondylar approaches. Combining these 3 approaches aided in efficiently completing this modified approach.

CONCLUSION

STBR is a complicated and technically challenging procedure. This study highlights the importance of understanding the surgical anatomy of STBR and will serve as a catalyst for improvement of the surgical technique for temporal bone resection.

Osteomalacia caused by skull base tumors: report of 2 cases

BACKGROUND AND IMPORTANCE

Tumor-induced osteomalacia (TIO) is an uncommon paraneoplastic syndrome rarely encountered in neurosurgical practice. We report on 2 cases of TIO caused by skull base tumors. Although the diagnosis of TIO is difficult to make and often is delayed because of the insidious nature of the symptoms, mostly systemic pain and weakness, it is curable once it is diagnosed and properly treated.

CLINICAL PRESENTATION

Both patients presented with severe pain developing in the lower extremities and moving out to the entire body, as well as difficulty moving. They were diagnosed with TIO several years after onset. A high level of serum FGF23 was confirmed, and whole-body imaging studies demonstrated tumors in the middle and anterior cranial base, respectively. The patient with the anterior cranial base tumor had a history of hemorrhage into the frontal lobe and partial resection. En bloc resection of tumor with surrounding skull bone was performed. The histological diagnosis for both cases was phosphaturic mesenchymal tumor, mixed connective tissue variant.

CONCLUSION

The level of FGF23 normalized immediately after surgery. Both patients experienced a dramatic relief of pain and recovery of muscle power. Although reports of osteomalacia caused by tumors in the neurosurgical field are extremely rare in the literature, its true incidence is unknown. We emphasize the importance of recognition of this syndrome and recommend total resection of tumors when possible.

Predictors of survival and recurrence after temporal bone resection for cancer

BACKGROUND

The purpose of this study was to identify factors predictive of outcome in patients undergoing temporal bone resection (TBR) for head and neck cancer.

METHODS

This was a retrospective study of 72 patients undergoing TBR. Factors associated with survival and recurrence were identified on multivariable regression.

RESULTS

Most tumors were epithelial (81%), commonly (69%) involving critical structures. Cervical metastases were uncommon (6%). Squamous cell carcinoma (SCC) of the external auditory canal carried a high rate of parotid invasion (25%) and parotid nodal metastases (43%). The 5-year rate of overall survival (OS) was 62%; disease-specific survival (DSS), 70%; recurrence-free survival (RFS), 46%. Factors independently associated with outcome on multivariable analysis were margin status and extratemporal spread of disease to the parotid, mandible, or regional nodes. Recurrence was common (72%) in cT3-4 tumors.

CONCLUSIONS

Margin status and extratemporal disease spread are the strongest independent predictors of survival and recurrence. In SCC of the external auditory canal, high rates of parotid involvement support adjunctive parotidectomy. Risk of recurrence in T3-T4 tumors may support a role for adjuvant therapy.