Reconstruction of Dural Defects in Endoscopic Transnasal Approaches for Intradural Lesions Using Multilayered Fascia with a Pressure-Control Spinal Drainage System

Endoscopic Endonasal Approach Is Superior to Transcranial Approach for Small to Medium Tuberculum Sellae Meningiomas in Terms of Visual Outcome and Complications: A Retrospective Study in a Single Center

OBJECTIVE

This study compared the effectiveness of the endoscopic endonasal approach (EEA) with the conventional transcranial approach (TCA) for treating tuberculum sellae meningiomas (TSMs), aiming to identify the superior surgical method and the risk factors affecting outcomes.

METHODS

Patients treated for TSM from 1998 to 2023 at our institution were retrospectively analyzed, evaluating patient characteristics, tumor features, outcomes, and complications. A novel grading system for preoperative evaluation of TSMs was proposed.

RESULTS

Among 49 patients, 26 underwent EEA and 23 underwent TCA. The maximum diameters were comparable between the groups (mean 22 mm vs. 23 mm). Gross total resection rates were 62% for EEA and 70% for TCA, showing no significant difference. However, postsurgical visual improvement was significantly higher in the EEA group compared with the TCA group (77% vs. 44%; P = 0.020), with fewer complications in the EEA group (8% vs. 35%; P = 0.032).

CONCLUSIONS

EEA is a safe and effective treatment approach for small to medium TSMs, with outcomes comparable to TCA in terms of resection but superior in visual improvement and fewer complications. Selection of surgical approach should consider patient and tumor characteristics as well as surgeon experience.

Profiles of central nervous system surgical site infections in endoscopic transnasal surgery exposing the intradural space

OBJECTIVE

Despite its efficacy and minimal invasiveness, the clean-contaminated nature of endoscopic transnasal surgery (ETS) may be susceptible to central nervous system surgical site infections (CNS-SSIs), especially when involving intradural exposure. However, the profiles of ETS-associated CNS-SSIs are not fully elucidated.

METHODS

The institutional ETS cases performed between May 2017 and March 2023 were retrospectively analysed. The incidences of CNS-SSIs were calculated, and their risk factors examined.

RESULTS

The incidence of CNS-SSIs was 2.3% (7/305) in the entire cohort and 5.0% (7/140) in ETSs with intradural exposure. All the CNS-SSIs were meningitis and developed following ETS with intradural exposure. The incidences were 0%, 5.6% and 5.8% in ETSs with Esposito grade 1, 2 and 3 intraoperative cerebrospinal fluid leakage, respectively. Among the pre- and intra-operative factors, body mass index (unit odds ratio (OR), 0.62; 95% confidence interval (CI), 0.44-0.89; P<0.01), serum albumin (unit OR, 0.03; 95% CI, 0.0007-0.92; P=0.02), and American Society of Anesthesiologists physical status score (unit OR, 20.7; 95% CI, 1.65-259; P<0.01) were significantly associated with CNS-SSIs. Moreover, postoperative cerebrospinal fluid leakage was also significantly associated with CNS-SSIs (OR, 18.4; 95% CI, 3.55-95.0; P<0.01).

CONCLUSIONS

The incidence of ETS-associated CNS-SSIs is acceptably low. Intradural exposure was a prerequisite for CNS-SSIs. Malnutrition and poor comorbidity status should be recognized as important risks for CNS-SSIs in ETS.

[Endoscopic transnasal resection of clival meningiomas]

BACKGROUND

Surgical treatment of ventral and ventrolateral meningiomas of posterior cranial fossa is difficult in modern neurosurgery. This is due to peculiarities of approach to these areas and concentration of critical structures (cranial nerves and great vessels). Currently, endoscopic transnasal approach to these meningiomas allows partial, and in some cases, total resection. However, this technique is not widespread.

OBJECTIVE

To analyze the world literature data on postoperative outcomes in patients with clival and petroclival meningiomas after endoscopic transnasal resection.

MATERIAL AND METHODS

We analyzed 22 articles representing treatment of 61 patients with clival and petroclival meningiomas.

RESULTS

Total or near-total resection was achieved in 22.9% of cases, subtotal resection - 40.9%, partial resection - 26.2% (data were not provided in other cases). Even partial and subtotal resection leads to significant regression of symptoms.

CONCLUSION

Endoscopic transnasal surgery is a full-fledged alternative to transcranial approaches in surgical treatment of clival meningiomas. It is also an additional option for patients with petroclival meningiomas after ineffective transcranial approaches. Transnasal tumor shrinkage and devascularization lead to brainstem decompression, regression of hydrocephalus and baseline clinical symptoms.

Long-term Outcomes of Non-vascularized Multilayer Fascial Closure Technique for Dural Repair in Endoscopic Transnasal Surgery: Efficacy, Durability, and Limitations

OBJECTIVE

Non-vascularized multilayer fascial closure technique (NMFCT) can be used instead of nasoseptal flap reconstruction for dural repair in endoscopic transnasal surgery (ETS); however, due to the lack of blood supply, its long-term durability and possible limitations need to be clarified.

METHODS

This was a retrospective study on patients who underwent ETS with intraoperative cerebrospinal fluid (CSF) leakage. We assessed the postoperative and delayed CSF leakage rates and the associated risk factors.

RESULTS

Among 200 ETSs with intraoperative CSF leakage, 148 (74.0%) ETSs were performed for skull base pathologies other than pituitary neuroendocrine tumor. The mean follow-up period was 34.4 months. Esposito grade 3 leakage was confirmed in 148 (74.0%) cases. NMFCT was used either with (67 [33.5%]) or without (133 [66.5%]) lumbar drainage. There were 10 cases (5.0%) of postoperative CSF leakage that necessitated reoperation. In 4 other cases (2.0%), CSF leakage was suspected but lumbar drainage alone successfully restored the condition. Multivariate logistic regression analyses revealed that posterior skull base location (P < 0.01, odds ratio 11.5, 95% CI 1.99-2.17 × 102) and craniopharyngioma pathology (P = 0.03, odds ratio 9.4, 95% CI 1.25-1.92 × 102) were significantly associated with postoperative CSF leakage. No delayed leakage occurred during the observation period except for 2 patients who underwent multiple radiotherapies.

CONCLUSIONS

NMFCT is a reasonable alternative with long-term durability, though vascularized flap may be a better choice for cases in which vascularity of the surrounding tissues is significantly impaired due to interventions including multiple radiotherapies.

Kashimé: A Novel Knotless Surgical Suture to Simplify Dural Stitches in Endoscopic Transnasal Surgery

BACKGROUND

Dural suturing is an effective adjunct to skull base dural repair in endoscopic transnasal surgery, although it is technically cumbersome. Here, we presented a novel surgical suture "Kashimé" (Kono Seisakusho) that can be tightened without tying.

OBJECTIVE

To examine the efficacy of Kashimé for skull base dural repair in endoscopic transnasal surgery.

METHODS

Kashimé was used in 8 patients with skull base dural defects during nonpedicled flap-based multilayered skull base reconstruction to close or approximate the gaps between the dural edges or secure a free fascial graft. The time required for each dural stitch (passing a needle through the dura, pulling out the thread, and tightening it) and the incidence of postoperative cerebrospinal fluid leakage were the study end points.

RESULTS

Based on our preliminary experiences with 12 stitches used, no postoperative cerebrospinal fluid leakage was observed. The learning curve was steep, and the mean (±SD) time was 127 (±44) seconds for a single stitching procedure, except for the first case. Regarding the metal artifact, although a beam hardening artifact was not observed on computed tomography, a 4- to 9-mm diameter image defect was observed on magnetic resonance imaging.

CONCLUSION

Kashimé can help surgeons to complete a single dural stitch in endoscopic transnasal surgery for approximately 2 minutes. It may be an optimal tool for skull base reconstruction, but the efficacy and safety need to be investigated.

Risk Factors for Postoperative Cerebrospinal Fluid Leak after Graded Multilayer Cranial Base Repair with Suturing via the Endoscopic Endonasal Approach

This study analyzed risk factors for postoperative cerebrospinal fluid (CSF) leak after graded multilayer cranial base repair method with dural suturing. We performed surgery via the endoscopic endonasal approach (EEA) from 2012.6 to 2018.4, and those consecutive clinical data were prospectively accumulated and retrospectively analyzed. We tailored the repair method according to the intraoperative CSF leak grade. Among 388 surgeries via the EEA, there were 10 (2.6%) cases of postoperative CSF leak after graded repair with suturing. Postoperative CSF leak occurred in two of the 150 cases without intraoperative CSF leak (grade 0), one of the 104 cases with small (grade 1) intraoperative CSF leak, two of the 60 cases with moderate (grade 2) leak, and five of the 74 cases with large (grade 3) leak. Univariate analysis indicated that chordoma (P = 0.023), estimated tumor volume ≥ 7400 mm³ (P = 0.003), and maximum tumor diameter ≥ 32.5 mm (P = 0.001) were significant risk factors for postoperative CSF leak. Additionally, among cases with intraoperative grade 3 CSF leak, chordoma (P = 0.021), estimated tumor volume ≥ 23000 mm³ (P = 0.003), and maximum tumor diameter ≥ 45.5 mm (P = 0.001) were significant risk factors for postoperative CSF leak. Maximum tumor diameter, estimated tumor volume, and chordoma tumor pathology are related to a higher risk of postoperative CSF leak.

Clinical Impact of Hydroxyapatite on the Outcome of Skull Base Reconstruction for Intraoperative High-Flow CSF Leak: A Propensity Score Matching Analysis

Background

Despite recent advances in skull base reconstructive techniques, including the multilayer technique during the last decade, complete reconstruction of grade 3 intraoperative high-flow cerebrospinal fluid (CSF) leak remains challenging. This study was designed to investigate the role of injectable hydroxyapatite (HXA) used in the multilayer technique on the clinical outcome of skull base reconstruction for intraoperative high-flow CSF leak.

Materials and Methods

This study enrolled 187 patients who experienced intraoperative high-flow CSF leak after endoscopic endonasal surgery for anterior skull base or suprasellar pathologies between January 2014 and July 2021. All skull base defects were reconstructed using the conventional multilayer technique including a vascularized naso-septal flap (NSF, n = 141) and the combined use of HXA with the conventional multilayer technique (HXA group, n = 46). We retrospectively evaluated the efficacy of the HXA group by 1:2 propensity score matching analysis.

Results

Overall, 17 of 187 patients (9.1%) showed postoperative CSF leaks, resulting in second reconstruction surgery. There were no statistical differences in patient age, sex, body mass index, tumor location, tumor type, and degree of resection, except for the follow-up period between the two groups. The HXA group showed a significantly lower incidence of postoperative CSF leak than the control group (0% vs. 12.1%, p < 0.05). Postoperative lumbar drain (LD) was performed in 8.7% of the HXA group compared to 46.1% of the control group (p < 0.01). CSF leak-related infection rates showed a decreasing tendency in the HXA group compared to the control group (0 vs. 7.1%, p = 0.06). A total of 46 patients in the HXA group were well matched with the control group (92 patients) at a 1:2 ratio. In the propensity score-matched control group, there were higher rates of postoperative CSF leaks than in the HXA group.

Conclusion

The use of HXA combined with the conventional multilayer technique completely reduced postoperative CSF leaks in this study. This technique resulted in reduced CSF leakage, even without postoperative LD, and decreased infection rates. Further randomized comparative studies are required to confirm our findings.

Endoscopic endonasal transpetroclival approach for recurrent bilateral petroclival meningioma

The authors performed an endoscopic endonasal transpetroclival approach for recurrent bilateral petroclival meningioma, with the aim of sufficient tumor resection with cranial nerve functional preservation. The tumor was sufficiently removed with excellent postoperative course. Petroclival meningioma, especially located in the medial region with dural attachment of the clivus, is considered a good indication for this approach. Recurrent tumors after radiotherapy often have strong adhesion to the brainstem and basilar artery; therefore, careful assessment of whether or not tumor detachment is possible is essential. The endoscopic endonasal transpetroclival approach is an acceptable, less-invasive treatment for petroclival tumors.

The video can be found here: https://stream.cadmore.media/r10.3171/2022.1.FOCVID21229

Endoscopic Transsphenoidal Resection of Suprasellar Histiocytosis in a Patient with Erdheim-Chester Disease: A Case Report

Erdheim–Chester disease (ECD) is a rare systemic disease characterized by non-Langerhans histiocytosis. Pituitary involvement, often manifesting as diabetes insipidus, is the most common central nervous system (CNS) lesion. However, significant mass formation compressing the optic apparatus is rarely reported. We present a case of ECD-related suprasellar mass treated with an endoscopic transnasal approach, with emphasis on the surgical strategy and the intraoperative findings. The mass was fibrous, significantly hard, and strongly adhered to the optic nerves, causing visual impairment. A subtotal resection was performed with preserving the adhesion between the mass and the optic nerves, and her visual symptoms improved remarkably after surgery. We highlight the surgical procedure of ECD-related suprasellar mass, from an endoscopic point of view. Due to strong adhesion of the mass to the surrounding optic apparatus and perforators, complete resection may be harmful; judicious mass reduction with preserving such adhesion would contribute to better visual outcomes.

Combined endoscopic endonasal transtubercular and transclival approaches for large neurenteric cyst in posterior cranial fossa: A case report and literature review

Background:

Intracranial neurenteric cysts (NCs) are extremely rare tumors that more commonly involve the posterior fossa than any other cranial part. While transcranial skull base surgery has been the mainstay of treatment, the utility of endoscopic transnasal surgery (ETS) remains to be established.

Case Description:

We report a case of a large posterior fossa NC extensively involving the suprasellar region, cerebellopontine angle, and prepontine cistern, which we successfully resected with ETS through a combination of transtubercular and transclival routes. Before surgery, the patient presented with abducens nerve and pseudobulbar palsies, which resolved within 2 weeks postoperatively. The patient remained free from recurrence for 3 years postoperatively.

Conclusion:

Extended ETS may offer a minimally invasive option for the posterior fossa NC, extensively occupying the ventral space of the brainstem.

Graded Reconstruction Strategy Using a Multilayer Technique Without Lumbar Drainage After Endoscopic Endonasal Surgery

OBJECTIVE

Sellar reconstruction following endoscopic endonasal surgery (EES) requires modification based on the degree of cerebrospinal fluid (CSF) leak. For high-flow (grade II or III according to Esposito et al. 2007) intraoperative CSF leak, lumbar drainage (LD), in addition to the multilayer closing technique, is generally recommended. However, LD occasionally has complications including postpuncture headache, overdrainage symptoms, and increased length of stay. We retrospectively evaluated the outcome of our graded reconstruction strategy using a multilayer technique with a novel material, without LD, after EES.

METHODS

Ninety-seven patients who underwent EES with grade II or III intraoperative CSF leak between June 2020 and March 2021 were retrospectively reviewed. For grade II CSF leak, fibrin sealant and a nasoseptal flap were placed; for grade III CSF leak, a multilayer technique was used in combination with collagen matrix, an acellular dermal graft, injectable hydroxyapatite (HXA), and a nasoseptal flap. Postoperatively, routine LD was not performed.

RESULTS

This study included 48 (49.5%) grade II and 49 (50.5%) grade III CSF leaks. At follow-up (mean, 8.7 months), no patient showed postoperative CSF leak in either group. No HXA-associated complications occurred.

CONCLUSIONS

A graded surgical repair strategy after EES could avoid postoperative CSF leak. Combined use of injectable HXA and acellular dermal grafts for high-flow CSF leak can limit LD requirement without significant risks.

Heterogeneity in Outcome Reporting in Endoscopic Endonasal Skull Base Reconstruction: A Systematic Review

Objective  Presently, there are no standards for reporting outcomes of endoscopic endonasal skull base reconstruction (ESBR). This is problematic as a lack of consistent reporting makes synthesizing findings in systematic reviews and meta-analysis challenging. Thus, the aim of this study was to systematically review and describe the patterns of reporting outcomes in ESBR as a foundation for developing reporting guidelines. Study Design  Present study is a systematic review. Methods  Embase, PubMed, CINAHL, Cochrane Library, and Web of Science were searched for all publications with ≥25 patients and a focus on ESBR. The reporting patterns of each study's variables and outcomes were assessed. Results  A total of 112 studies were included in the review. The most commonly reported demographic variables were the number of included patients ( n  = 112, 100%) and types of pathologies treated ( n  = 104, 92.9%). Meanwhile, the most routinely described preoperative variable was history of prior treatment ( n  = 48, 42.9%). Type of reconstruction was a commonly reported intraoperative variable ( n  = 110, 98.2%), though the rate of intraoperative cerebrospinal fluid (CSF) leak was noted in only 76 studies (67.9%). With regard to postoperative outcomes, postoperative CSF leak rate was routinely provided ( n  = 101, 90.2%), but reporting of other surgical complications was more inconsistent. Ultimately, of the 43 variables and outcomes reviewed, a median of 12 (range: 4-22) was reported in each study. Conclusion  There is significant heterogeneity in the outcomes reported in studies relating to ESBR. This highlights the need for the development of standard reporting guidelines to minimize bias and improve interstudy comparability.

Multi-Layer Onlay Graft Using Hydroxyapatite Cement Placement without Cerebrospinal Fluid Diversion for Endoscopic Skull Base Reconstruction

Objective

The skull base reconstruction step, which prevents cerebrospinal fluid (CSF) leakage, is one of the most challenging steps in endoscopic skull base surgery (ESS). The purpose of this study was to assess the outcomes and complications of a reconstruction technique for immediate CSF leakage repair using multiple onlay grafts following ESS.

Methods

A total of 230 consecutive patients who underwent skull base reconstruction using multiple onlay grafts with fibrin sealant patch (FSP), hydroxyapatite cement (HAC), and pedicled nasoseptal flap (PNF) for high-flow CSF leakage following ESS at three institutions were enrolled. We retrospectively reviewed the medical and radiological records to analyze the preoperative features and postoperative results.

Results

The diagnoses included craniopharyngioma (46.8%), meningioma (34.0%), pituitary adenoma (5.3%), chordoma (1.6%), Rathke’s cleft cyst (1.1%) and others (n=21, 11.2%). The trans-planum/tuberculum approach (94.3%) was the most commonly adapted surgical method, followed by the trans-sellar and transclival approaches. The third ventricle was opened in 78 patients (41.5%). Lumbar CSF drainage was not performed postoperatively in any of the patients. Postoperative CSF leakage occurred in four patients (1.7%) due to technical mistakes and were repaired with the same technique. However, postoperative meningitis occurred in 13.5% (n=31) of the patients, but no microorganisms were identified. The median latency to the diagnosis of meningitis was 8 days (range, 2–38). CSF leakage was the unique risk factor for postoperative meningitis (p<0.001).

Conclusion

The use of multiple onlay grafts with FSP, HAC, and PNF is a reliable reconstruction technique that provides immediate and complete CSF leakage repair and mucosal grafting on the skull base without the need to harvest autologous tissue or perform postoperative CSF diversion. However, postoperative meningitis should be monitored carefully.

The Rostral Mucosa: The Door to Open and Close for Targeted Endoscopic Endonasal Approaches to the Clivus

BACKGROUND

Extended endoscopic endonasal approaches (EEAs) have progressively widened the armamentarium of skull base surgeons. In order to reduce approach-related morbidity of EEAs and closure techniques, the development of alternative strategies that minimize the resection of normal tissue and alleviate the use of naso-septal flap (NSF) is needed. We report on a novel targeted approach to the clivus, with incision and closure of the mucosa of the rostrum, as the initial and final step of the approach.

OBJECTIVE

To present an alternative minimally invasive approach and reconstruction technique for selected clival chordomas.

METHODS

Three cases of clival chordomas illustrating this technique are provided, together with an operative video.

RESULTS

The mucosa of the rostrum is incised and elevated from the underlying bone, as first step of surgery. Following tumor resection with angled scope and instruments, the mucosa of the sphenoid sinus (SS) is removed and the tumor cavity and SS are filled with abdominal fat. The mucosal incision of the rostrum is then sutured. A hangman knot is prepared outside the nasal cavity and tightened after the first stitch and a running suture is performed.

CONCLUSION

We propose, in this preliminary report, a new targeted approach and reconstruction strategy, applying to EEAs the classic concept of skin incision and closure for transcranial approaches. With further development in the instrumentations and visualization tools, this technique may become a valuable minimally invasive endonasal approach for selected lesions.

Characteristics and clinical outcomes in pituitary incidentalomas and non-incidental pituitary tumors treated with endoscopic transsphenoidal surgery

PURPOSE

In this retrospective study, we investigated the status and validity of endoscopic transsphenoidal surgery (eTSS) for pituitary incidentalomas (PIs) as well as the value of basing the indication for surgery on the PI guidelines.

METHODS

Patients who underwent eTSS at Fukuoka University Chikushi Hospital between 2012 and 2018 were divided into the PI group and the non-PI group in accordance with the PI guideline of the Endocrine Society and their clinicopathological characteristics and outcomes were compared and analyzed.

RESULTS

A total of 59 patients were enrolled, with 35 patients in the PI group and 24 patients in the non-PI group. The diagnoses in the PI group were of non-functioning pituitary adenoma (NFPA) (n = 12, 34%), gonadotropin-producing pituitary adenoma (n = 8, 23%), Rathke cleft cyst (n = 7, 20%), meningioma (n = 4, 11%), and growth hormone-producing pituitary adenoma (n = 3, 9%); those in the non-PI group were of NFPA (n = 6, 25%), gonadotropin-producing pituitary adenoma (n = 3, 13%), Rathke cleft cyst (n = 3, 13%), growth hormone-producing pituitary adenoma (n = 3, 13%), and prolactin producing pituitary adenoma (n = 3, 13%). Regarding the preoperative factors, 1 patient in the PI group with panhypopituitarism was diagnosed with pituitary apoplexy (pure infarction) of an NFPA. The rates of postoperative anterior pituitary hormonal deficiencies (14% vs 46%, P = .015), residual tumor size (2 ± 5 vs 6 ± 7 mm, P = .008), and reoperation (n = 0, 0% vs n = 5, 21%, P = .005) were significantly different between the PI and non-PI groups.

CONCLUSIONS

This study showed that, postoperatively, the incidence of anterior pituitary hormonal deficiencies was lower in the PI than in the non-PI group, although it was comparable between the 2 groups before the operation. The patients in the PI group also had smaller residual tumors and a lower risk of reoperation than those in non-PI group. PIs could have a better postoperative clinical outcome than non-PIs when the indication for eTSS is based on preoperative scrutiny according to the PI guidelines and eTSS is performed by an experienced pituitary surgeon. Hence, more aggressive scrutiny and treatment for PIs might be desirable.

Stent-Assisted Coil Embolization of a Basilar Artery Dissecting Aneurysm Involved in Skull Base Chordoma Before Endoscopic Transsphenoidal Transclival Resection

BACKGROUND

Skull base chordomas will occasionally penetrate the clival dura mater and extend into the prepontine cistern, involving the basilar artery. Few reports have described cases of skull base chordoma accompanying a dissecting aneurysm of the basilar artery, and the treatment strategies have remained largely unknown.

CASE DESCRIPTION

A 28-year-old man was referred to our hospital with a complaint of severe headache. A skull base chordoma involving a basilar artery dissecting aneurysm was diagnosed. We initially performed endovascular surgery for the dissecting aneurysm after dual antiplatelet therapy before surgical resection of the tumor, which was successfully achieved without complications. Follow-up angiography 3 months after endovascular surgery disclosed obliteration of the dissecting aneurysm. We then stopped the dual antiplatelet therapy, and performed judicious resection using an endoscopic transclival approach. The residual tumor was treated with radiosurgery. At the last follow-up examination, the patient was stable, and the tumor remained sufficiently controlled.

CONCLUSIONS

We have reported a case of a dissecting aneurysm of the basilar artery with clival chordoma. Our findings suggest that chordoma with intradural vascular encasement has the potential to invade the vessel wall. To avoid rupture of those critical vascular structures, treatment strategies that minimize stress on the involved arteries and offer safe and sufficient surgical resection should be considered.

Endoscopic transnasal resection of the CP angle schwannoma

Cerebellopontine (CP) angle tumors are often resected via retrosigmoid craniotomy; however, sometimes cranial nerves (CNs) make their resection more complex. In such cases, the endoscopic transnasal approach can avoid such manipulations as delivering surgical instruments over CNs or peeling off CNs from the tumor, minimizing the risk of postoperative deficits. A 35-year-old man presented with a 37-mm cystic tumor in the right CP angle, and preoperative 3D fusion images revealed that multiple CNs (VII, VIII, and lower CNs) were running on the tumor posteriorly. The endoscopic transnasal approach enabled safe subtotal resection without causing neurological deficits, and the patient underwent stereotactic radiosurgery for the residual schwannoma.

The video can be found here: https://youtu.be/xKLwdDsLpWA.

Endoscopic transmastoid posterior petrosal approach for locally aggressive tumors in the petrous part of the temporal bone involving the internal auditory canal, jugular foramen, and hypoglossal canal

OBJECTIVE

The posterior petrosal approach is an established surgical method offering wide access to skull base lesions through mastoid air cells. The authors describe their experience with the endoscopic transmastoid "posterior petrosal" approach (EPPAP) for skull base tumors involving the internal auditory canal (IAC), jugular foramen, and hypoglossal canal.

METHODS

The EPPAP was performed for 7 tumors (3 chordomas, 2 chondrosarcomas, 1 schwannoma, and 1 solitary fibrous tumor). All surgical procedures were performed under endoscopic visualization with mastoidectomy. The compact bone of the mastoid air cells and posterior surface of the petrous bone are carefully removed behind the semicircular canals. When removal of cancellous bone is extended superomedially through the infralabyrinthine space, the surgeon can expose the IAC and petrous portion of the internal carotid artery to reach the petrous apex (infralabyrinthine route). When removal of cancellous bone is extended inferomedially along the sigmoid sinus, the surgeon can safely reach the jugular foramen (transjugular route). Drilling of the inferior surface of petrous bone is extended further inferoposteriorly behind the jugular bulb to approach the hypoglossal canal and parapharyngeal space through the lateral aspect of the occipital condyle (infrajugular route).

RESULTS

Of the 7 tumors, gross-total resection was achieved in 4 (57.1%), subtotal resection (> 95% removal) in 2 (28.6%), and partial resection (90% removal) in 1 (14.2%). Postoperatively, 2 of 3 patients with exudative otitis media showed improvement of hearing deterioration, as did 2 patients with tinnitus. Hypoglossal nerve palsy and swallowing difficulty were improved after surgery in 2 patients and 1 patient, respectively. In 1 patient with severe cranial nerve deficits before surgery, symptoms did not show any improvement.

CONCLUSIONS

The authors present their preliminary experience with EPPAP for skull base tumors in the petrous part of the temporal bone and the lateral part of the occipital condyle involving the cranial nerves and internal carotid arteries. The microscope showed a higher-quality image and illumination in the low-power field. However, the endoscope could offer wider visualization of the surgical field and contribute to minimizing the size of the surgical pathways, necessity of brain retraction, and eventually the invasiveness of surgery. Thus, the EPPAP may be safe and effective for skull base tumors in the petrous region, achieving balance between the radicality and invasiveness of the skull base surgery.

Treatment experience for full-thickness wound dehiscence with cerebrospinal fluid leakage following posterior primary spine surgery: Three case reports

RATIONALE

Full-thickness wound dehiscence with cerebrospinal fluid (CSF) leakage following posterior spine surgery is a rare but troublesome complication. In the present study, 3 clinical cases associated with this entity are reported.

PATIENT CONCERNS

The first case developed incision effusion 5 days after posterior decompression and internal fixation for lumbar spinal stenosis. The second case has the same diagnosis and treatment with the first case. She developed intraoperative CSF leak and incision effusion 7 days after the surgery. The third case developed incision effusion 6 days after posterior single door laminoplasty for cervical spondylosis.

DIAGNOSIS

All cases developed CSF leak, incision effusion and finally full-thickness wound dehiscence on the postoperative period.

INTERVENTIONS

Bed rest, drainage, vacuum sealing drainage (VSD), and reoperations were applied in all of the patients. Trapezius flap transfer was applied to the third case. One lumbar patient developed deep infection and meningitis; thus, the internal fixation and bone graft were removed.

OUTCOMES

All of the patients received wound healing finally and were followed up for >6 months. No incision complications reoccurred, and preoperative symptoms significantly relieved.

LESSONS

Several techniques can be adopted to minimize the incidence of complications and proper surgical repair is the most important. Lumbar cistern drainage and VSD are recommended. Some other available options of management will also help.

Endoscopic Transnasal Resection of Solitary Fibrous Tumor in the Optic Canal

BACKGROUND

Tumors extending into the optic canal can cause progressive visual impairment because of optic nerve compression. Prompt surgical resection is often necessary. When the tumor is located medially in the optic canal, endoscopic transnasal surgery provides a safer, less invasive alternative to a transcranial approach.

CASE DESCRIPTION

We recently encountered a case of small solitary fibrous tumor in the optic canal causing rapid visual deterioration. The radiographic findings of preoperative imaging studies were compatible with those of meningioma; however, unlike meningioma, bleeding from the tumor was profuse during the operation. The endoscopic transnasal approach was effective for handling the highly vascularized tumor in this delicate region, and gross total removal was achieved with postoperative gradual improvement in his visual function. Nevertheless, the tumor recurred after 6 months, and re-resection was performed using the same surgical corridor, followed by adjuvant radiotherapy.

CONCLUSIONS

Endoscopic transnasal surgery is a valuable option for aggressive lesions in the optic canal. Although the efficacy of radiotherapy for solitary fibrous tumor remains controversial, it should be considered when the tumor shows progressive features.