Eur Arch Otorhinolaryngol DOI 10.1007/s00405-014-3127-y
Otology
Facial and lower cranial nerve function preservation in lateral approach for craniocervical schwannomas ZhaoYan Wang · HongSai Chen · Qi Huang · ZhiHua Zhang · Jun Yang · Hao Wu
Received: 23 March 2014 / Accepted: 23 May 2014 © Springer-Verlag Berlin Heidelberg 2014
Abstract The purpose of this study was to discuss surgical approach selection, surgical procedures, and treatment strategy for preservation of the facial and lower cranial nerve function in craniocervical schwannomas surgery. Between 2002 and 2011, 44 craniocervical schwannomas were operated in Xinhua hospital of Shanghai, China by the same surgical team. The records were reviewed retrospectively regarding clinical presentation, radiographic assessment, surgical approaches selection, surgical procedures and facial and lower cranial nerve follow-up outcomes. Headache or neck pain was present in 30 patients (68.2 %) and cervical mass in 9 patients (20.5 %). Cranial nerve impairments, mainly involving the vagus nerve, were present in 19 patients (43.2 %) and hypoglossal nerve in five patients (11.4 %). 22 tumors were intra- and extracranial, 10 were intra-cranial and 12 were extra-cranial. According to the tumor region, infratemporal fossa type A approach, petrous occipital transsigmoid approach and transcervial approach were selected for tumor removal. Gross-total resection was achieved in 40 patients (90.9 %). Adjunctive radiosurgery was used in the management of residual tumor in two patients; tumor control was ultimately obtained in all cases. During follow-up period, good Z. Wang · H. Chen · Q. Huang · Z. Zhang · J. Yang · H. Wu (*) Department of Otolaryngology Head and Neck Surgery, Xinhua Hospital, School of Medicine, Shanghai Jiaotong University, 1665 Kongjiang Road, Shanghai 200092, China e-mail: [email protected] Z. Wang e-mail: [email protected] Z. Wang · H. Chen · Q. Huang · Z. Zhang · J. Yang · H. Wu Ear Institute, School of Medicine, Shanghai Jiaotong University, 1665 Kongjiang Road, Shanghai 200092, China
facial function was obtained in 42 patients (95.5 %) and complete compensation of lower cranial nerve function was achieved in all patients. The preoperative estimation of tumor in nature is of great importance in the determination of proper surgical planning of craniaocervical schwannomas. Facial nerve and lower cranial nerve function can be preserved in maximal degree by proper surgical approaches and careful operative manipulation. Initial surgical resection followed by radiosurgery may be an effective option for some special patients. Keywords Crainiaocervical schwannoma · Facial nerve · Lower cranial nerve · Surgical management · Classification
Introduction Craniaocervical schwannomas are rare benign tumors. These tumors are most often arising from cranial nerve X and XII [1, 2]. The ideal primary treatment for these schwannomas is total surgical removal. However, the location of these tumors and their relationship to neurovascular structures around the upper cervical and skull base make complete surgical resection a challenge. New postoperative cranial nerve deficits are the main complications. Although different surgical approaches have been proposed, new postoperative cranial nerve deficits are reported in 12–90 % of the involved cranial nerves [3–5]. We report the cases of 44 patients diagnosed with craniocervical schwannomas who underwent surgery in the Department of Otolaryngology Head and Neck Surgery, Xinhua Hospital affiliated to Shanghai Jiaotong University, School of Medicine, and discuss the tumor control rates and the function of facial nerve and lower cranial nerve during a long-term follow-up period after surgery.
13
Eur Arch Otorhinolaryngol
Fig. 1 Magnetic resonance imaging (MRI) for patients with craniaocervical schwannoma. Left column axial views. Right column coronal views. a Intracranial, b intra- and extracranial, and c extracranial
Patients and methods Subjects comprised 44 patients (20 men, 24 women) with craniocervical schwannomas treated surgically at Xinhua Hospital between December 2002 and May 2011. All data were collected retrospectively from patient medical records. Clinical presentation, radiographic assessment, cranial nerve involvement, surgical procedures, and follow-up outcomes were reviewed. All patients underwent gadolinium-enhanced magnetic resonance imaging
13
(MRI). Tumors were divided into three types, intracranial, intra- and extracranial, and extracranial, according to the tumor position (Fig. 1). Tumor size was defined as the largest diameter of the intracranial and the extracranial lesion on MRI. Patients were followed by interviews, otoneurological examination, and MRI every 6 months for 1 year at the outpatient clinic. Thereafter, followup imaging was performed every 1 or 2 years. Median follow-up after tumor resection was 62.3 months (range 26–124 months).
Eur Arch Otorhinolaryngol
Results Patients characteristics Patients’ mean age at surgery was 45.3 ± 13.6 years (range 21–70 years). Tumor was located on the right side in 30 patients and on the left side in 14. The most common presenting sign was headache or neck pain (30 patients, 68.2 %), and cervical mass in nine patients (20.5 %). Cranial nerve impairments, mainly involving the vagus nerve, were present in 19 patients (43.2 %) and hypoglossal nerve in 5 patients (11.4 %), only 1 patient displayed two lower cranial nerve impairments, and 21 patients presented normal lower cranial nerve function. No severe swallowing problems were found in all patients. Facial paresthesia was not occurring in all the patients at the time of presentation. 9 patients presented with hearing loss. Radiological finding Twenty two tumors were intra- and extracranial, 10 were intracranial and 12 were extracranial. Mean intracranial tumor diameter was 12.3 ± 7.6 mm [range 0 (localized extracranially)–30 mm], and mean extracranial diameter was 13.9 ± 10.6 mm [range 0 (localized intra-cranially)–40 mm]. Tumor removal Lateral approaches were used for all the 44 patients. According to the tumor region, infratemporal fossa type A approach, petrous occipital trans-sigmoid approach and neck explosion were selected for tumor removal. Infratemporal fossa type A approach was used for 30 patients, among which anterior rerouting of facial nerve was used in 8 patients and facial nerve bridge technique used in 22 patients (Fig. 2); petrous occipital transsigmoid approach for 4 patients; and transcervical tumor removal was used for 10 patients with extracranial schwannomas. Gross-total resection was achieved in 40 patients (90.9 %), subtotal removal, defined as resection of >90 % of the preoperative tumor mass, was achieved in 4 patients, with complete removal of the intracranial portion. Intraoperatively, the nerve of origin was identified as the vagus nerve in 28 patients, the hypoglossal nerve in 9 patients, the glossopharyngeal nerve in 3 patients, and the accessory nerve in 2 patients. In the remaining two patients, tumor origin remained unknown. No CSF leakage and other neurovascular complications were found after surgery. Function of facial nerve No patient showed preoperative facial paralysis. In eight patients who received anterior rerouting of facial nerve via
Fig. 2 Infratemporal fossa type A approach for patients with craniaocervical schwannoma. a Infratemporal fossa type A approach with facial nerve partial rerouting. b Infratemporal fossa type A approach with facial nerve bridge technique
infratemporal fossa type A approach, immediately facial nerve paralysis was presented in all eight patients with House–Brackmann Grade III to Grade V, after 6 months rehabilitation training, House–Brackmann Grade I and II achieved in six of eight patients, Grade III in one patient, and remaining one patient got Grade V facial function without recovery. Good facial function was obtained in 42 patients (95.5 %). Function of lower cranial nerve Twenty three of 44 patients showed preoperative lower cranial nerve signs; only one patient presented two nerve impairment signs. All patients exhibited new or worsen lower cranial nerve signs immediately after surgery. Postoperatively, 31 patients only exhibited responsible nerve impairments. The dysfunction of non-responsible nerve was found in 13 patients (Table 1). For swallowing problems, postoperative status of IX and X nerves compared with preoperative status were unchanged in 20 patients, worse in 24 patients, and no patient showed better. However, with long-term follow-up, IX and X nerve dysfunction
13
Eur Arch Otorhinolaryngol
Table 1 Lower cranial nerves impairment before and after surgery Lower cranial nerves impairment
Preoperative
Postoperative
N 1 2
21
None
22 1
31 11
3
2
N normal nerve function, 1 one nerve impairment, 2 two nerves impairment, 3 three nerves impairment
Table 2 Long-term swallowing outcomes for 44 patients with craniaocervical schwannoma IX and X signs
Preoperative
Immediately after surgery
Final follow-up
None Mild dysfunction
40 4
20 18
37 7
Moderate or severe dysfunction
0
6
0
ameliorated compared with immediately after surgery in 21 of 24 patients (Table 2). No patients required postoperative nasogastric tube feeding or tracheotomy, and no patients needed vocal cord injections during follow-up. Tumor control Gross-total resection was achieved in 40 of 44 patients (90.9 %). An increase in residue tumor volume was observed in two of four patients during follow-up. They underwent gamma-knife surgery at 37 months and 60 months after surgery, respectively. No tumor regrowth was found during the furthermore MRI follow-up. The remaining two patients received no additional therapy because no signs or symptoms caused by tumor regrowth.
Discussion Schwannomas of LCNs IX, X and XI represent 3–4 % of all cranial nerve schwannomas [1]. The natural incidence of these tumors is probably higher, but that small or asymptomatic tumors may go undiagnosed. We have seen a marked increase in the incidence of vestibular schwannomas after MRI became easily available [6, 7]. Despite advances in otoneruoimaging, microsurgical techniques, and modern skull base surgery, complete removal of craniocervical schwannomas with minimal cranial nerve impairments remains challenging. Bulsara et al. [6] reported 53 cases of jugular schwannomas. Total removal achieved in 48 patients (90.5 %), new postoperative paresis in a
13
previously normal cranial nerve was not seen, but worsening of IX and X cranial nerve function was frequently observed. Samii et al. [1] achieved total surgical removal in all of 16 patients and postoperative cranial nerve dysfunction was found in 6 patients. Sanna et al. [7] reported total tumor resection in 95 % of 23 cases and also got cranial nerve morbidity in 95 % patients. These series demonstrate that total tumor removal can be achieved in most cases. However, high cranial nerve morbidity rate is still a problem. Surgical approach The tumors frequently involve adjacent structures, such as the jugular bulb, carotid artery, petrous bone, infratemporal fossa, lower cranial nerves, and posterior fossa. Many reports have described various approaches to these regions. We mainly use three types of surgical approaches for these tumors according to their relationship with jugular bulb. In tumors occupied jugular bulb, infratemporal fossa approach with facial nerve bridge technique is used for tumor removal. Facial nerve should be skeletonized to permit tumor removal manipulate from anterior and posterior of facial bridge. In cases of vascularized tumors or tumors anterior growth adhere to temporal portion of carotid artery; partial anterior rerouting of facial nerve (from parotid segment to posterior geniculate) is important for better vision and secure tumor removal. In tumors located mainly in the lateral aspect of jugular bulb, petrous occipital trans-sigmoid approach can be used for removal of intra- and extracranial portion of tumor without hearing sacrifice. The selection of this approach should be restricted in the tumors without anterior or medial invasion. The advantage of upper neck trans-cervical approach is minimal invasive without mastoid dissection. The relationship between jugular bulb and tumor should be critically considered. The approach should be used in tumors located inferiorly to jugular bulb. If the tumors adhere to the inferior part of jugular bulb, cranial nerve injury cannot be avoided and bleeding from inferior petrous sinus and jugular bulb is hard to be controlled because the craniocervical area vision is restricted without mastoid exposure. Facial nerve and lower cranial nerve preservation Normally the tumors do not involve facial nerve. In tumors of intracranial growth, facial nerve may locate superior to the tumor in posterior fossa, and the tumor can be dissect and remove without nerve injury. The most common reason of facial injury is facial nerve anterior rerouting for better vision of anterior portion of tumor. To avoid this, we use facial bridge technique for tumors occupied the jugular bulb. For some patients with tumor anterior growth into Eustachian tube and adhere to carotid artery, facial nerve will obscure
Eur Arch Otorhinolaryngol
the tumor removal manipulate. Anterior rerouting of facial nerve is necessary for anterior portion tumor removal. Partial rerouting of facial nerve from parotid to posterior geniculate can provide adequate surgical vision with minimal nerve injury. Rerouting facial nerve with adjacent tissue and nourishing vessels can diminish the severity of nerve injury. Lower cranial nerve dysfunction is the most common and severe reason for postoperative morbidity. The common reason for no-responsible lower cranial injury is the manipulation of tumor removal at the cervical cranial joint and occlusion of inferior petrous sinus. The area is restricted by facial nerve, mastoid tip, transverse process of first cervical vertebra and jugular bulb. Removal of the mastoid tip and transverse process of first cervical vertebra and performing a facial bridge can get maximal surgical exposure. Dissection of tumor from jugular foramen and early identification of responsible cranial nerve, followed by total tumor removal and occlusion of inferior petrous sinus gently can gain maximal degree of preservation of other lower cranial nerve. Tumor control and radiosurgery Total surgical removal is still a reasonable goal for craniocervical schwannomas, but subtotal or near-total tumor resection is particularly used for elderly patients who cannot recover from severe swallowing problems or unfit patients who cannot tolerate prolonged surgery. In case of residue tumor, alternative strategies such as radiosurgery must also play a role in management [8]. The aim of radiosurgery is to achieve tumor control without causing additional cranial nerve deficits. Nishioka et al. [9] reported seven patients of nonacoustic schwannomas with radiotherapy. After a median follow-up of 59.5 months, tumor control was achieved in all of patients. Martin et al. [10] documented the largest series of schwannomas treated with gamma-knife surgery to date (35 patients total). 10 year tumor control rate was 94 %. In our cases, two patients with regrowth tumor received the radiosurgery and gained good tumor control outcome. For special cases, initial surgical resection followed by radiosurgery on any residue tumor may be an effective option [11]. Treatment strategy We established our treatment strategy for craniaocervical schwannoma according to the patient age, tumor size and location, and preoperative lower cranial nerve function (Fig. 3). For aged patients, complete swallowing compensation recovery is hard achieved especially in those with normal IX and X cranial nerve function. Observation and scan policy are advocated for aged patients. Near-total removal and scheduled radiosurgery are performed for
Craniaocervical Schwannoma
Aged
Younger
rapid growth small
Observation & Scan
life threaten
NTR & RS
Total Removal JB free
ITF & POTS
JB involved
Transcervical
Fig. 3 Treatment strategy of craniaocervical schwannoma. NTR neartotal removal, RS radiosurgery, JB jugular bulb, ITF infratemporal fossa approach, POTS petrous occipital transsigmoid approach
life-threaten or rapid growth tumor. Staged tumor removal is not considered in our group because schwannoma is a no-vascularized tumor and one stage total tumor removal of intra- and extra-dural portion can be achieved. CSF leakage is not often happened by closure and obligation of the surgical cavity. The surgical approaches selection should be alternative on the jugular bulb involvement and dural invasion. Normally, there will be no severe postoperative swallowing problems in those patients with preoperative lower cranial nerve dysfunction. Surgery until complete nerve paralysis is also a treatable option.
Conclusion The preoperative estimation of tumor in nature is of great importance in the determination of proper surgical planning of craniocervical schwannomas. Facial nerve and lower cranial nerve function can be preserved in maximal degree by proper surgical approaches and careful operative manipulation. The key to diminish the lower cranial nerve injury is to identify the responsible nerve and preserve the non-responsible nerves. Initial surgical resection followed by radiosurgery may be an effective option for some special patients.
References 1. Samii M, Babu R, Tatagiba M, Sepehrnia A (1995) Surgical treatment of jugular foramen schwannomas. J Neurosurg 82:924–932 2. Fukuda M, Oishi M, Saito A, Fujii Y (2009) Long-term outcomes after surgical treatment of jugular foramen schwannomas. Skull Base 19:401–408
13
3. Carvalho GA, Tatagiba M, Samii M (2000) Cystic schwannomas of the jugular foramen: clinical and surgical remrks. Neurosurgery 46:560–566 4. Ramina R, Maniglia JJ, Fernandes YB, Paschoal JR, Pfeilsticker LN, Neto MC (2005) Tumor of the jugular foramen: diagnosis and management. Neurosurg 57(Suppl 1):59–68 5. Wilson MA, Hillman TA, Wiggins RH, Shelton C (2005) Jugular foramen schwannomas: diagnosis, management, and outcomes. Laryngoscope 115:1486–1492 6. Bulsara KR, Sameshima T, Friedman AH, Fukushima T (2008) Microsurgical management of 53 jugular foramen shwannomas: lessons learned incorporated into a modified grading system. J Neurosurg 109:794–803 7. Sanna M, Bacciu A, Falcioni M, Taibah A (2006) Surgical management of jugular foramen schwannomas with hearing and facial nerve function preservation: a series of 23 cases and review of the literature. Laryngoscope 116:2191–2204
13
Eur Arch Otorhinolaryngol 8. Peker S, Sengoz M, Kilic T, Pamir MN (2012) Gamma knife radiosurgery for jugular foramen schwannomas. Neurosurg Rev 35:549–553 9. Nishioka K, Abo D, Aoyama H, Furuta Y, Onimaru R, Onodera S et al (2009) Stereotactic radiotherapy for intracranial nonacoustic schwannomas including facial nerve schwannoma. Int J Radiat Oncol Biol Phys 75:1415–1419 10. Martin JJ, Kondziolka D, Flickinger JC, Mathieu D, Niranjan A, Lunsford LD (2007) Cranial nerve preservation and outcomes after stereotactic radiosurgery for jugular foramen schwannomas. Neurosurg 61:76–81 11. Cavalcanti DD, Martirosyan NL, Verma K, Safavi-Abbasi S, Porter RW, Theodore N et al (2011) Surgical management and outcome of schwannomas in the craniocervical region. J Neurosurg 114(5):1257–1267
Otology
Facial and lower cranial nerve function preservation in lateral approach for craniocervical schwannomas ZhaoYan Wang · HongSai Chen · Qi Huang · ZhiHua Zhang · Jun Yang · Hao Wu
Received: 23 March 2014 / Accepted: 23 May 2014 © Springer-Verlag Berlin Heidelberg 2014
Abstract The purpose of this study was to discuss surgical approach selection, surgical procedures, and treatment strategy for preservation of the facial and lower cranial nerve function in craniocervical schwannomas surgery. Between 2002 and 2011, 44 craniocervical schwannomas were operated in Xinhua hospital of Shanghai, China by the same surgical team. The records were reviewed retrospectively regarding clinical presentation, radiographic assessment, surgical approaches selection, surgical procedures and facial and lower cranial nerve follow-up outcomes. Headache or neck pain was present in 30 patients (68.2 %) and cervical mass in 9 patients (20.5 %). Cranial nerve impairments, mainly involving the vagus nerve, were present in 19 patients (43.2 %) and hypoglossal nerve in five patients (11.4 %). 22 tumors were intra- and extracranial, 10 were intra-cranial and 12 were extra-cranial. According to the tumor region, infratemporal fossa type A approach, petrous occipital transsigmoid approach and transcervial approach were selected for tumor removal. Gross-total resection was achieved in 40 patients (90.9 %). Adjunctive radiosurgery was used in the management of residual tumor in two patients; tumor control was ultimately obtained in all cases. During follow-up period, good Z. Wang · H. Chen · Q. Huang · Z. Zhang · J. Yang · H. Wu (*) Department of Otolaryngology Head and Neck Surgery, Xinhua Hospital, School of Medicine, Shanghai Jiaotong University, 1665 Kongjiang Road, Shanghai 200092, China e-mail: [email protected] Z. Wang e-mail: [email protected] Z. Wang · H. Chen · Q. Huang · Z. Zhang · J. Yang · H. Wu Ear Institute, School of Medicine, Shanghai Jiaotong University, 1665 Kongjiang Road, Shanghai 200092, China
facial function was obtained in 42 patients (95.5 %) and complete compensation of lower cranial nerve function was achieved in all patients. The preoperative estimation of tumor in nature is of great importance in the determination of proper surgical planning of craniaocervical schwannomas. Facial nerve and lower cranial nerve function can be preserved in maximal degree by proper surgical approaches and careful operative manipulation. Initial surgical resection followed by radiosurgery may be an effective option for some special patients. Keywords Crainiaocervical schwannoma · Facial nerve · Lower cranial nerve · Surgical management · Classification
Introduction Craniaocervical schwannomas are rare benign tumors. These tumors are most often arising from cranial nerve X and XII [1, 2]. The ideal primary treatment for these schwannomas is total surgical removal. However, the location of these tumors and their relationship to neurovascular structures around the upper cervical and skull base make complete surgical resection a challenge. New postoperative cranial nerve deficits are the main complications. Although different surgical approaches have been proposed, new postoperative cranial nerve deficits are reported in 12–90 % of the involved cranial nerves [3–5]. We report the cases of 44 patients diagnosed with craniocervical schwannomas who underwent surgery in the Department of Otolaryngology Head and Neck Surgery, Xinhua Hospital affiliated to Shanghai Jiaotong University, School of Medicine, and discuss the tumor control rates and the function of facial nerve and lower cranial nerve during a long-term follow-up period after surgery.
13
Eur Arch Otorhinolaryngol
Fig. 1 Magnetic resonance imaging (MRI) for patients with craniaocervical schwannoma. Left column axial views. Right column coronal views. a Intracranial, b intra- and extracranial, and c extracranial
Patients and methods Subjects comprised 44 patients (20 men, 24 women) with craniocervical schwannomas treated surgically at Xinhua Hospital between December 2002 and May 2011. All data were collected retrospectively from patient medical records. Clinical presentation, radiographic assessment, cranial nerve involvement, surgical procedures, and follow-up outcomes were reviewed. All patients underwent gadolinium-enhanced magnetic resonance imaging
13
(MRI). Tumors were divided into three types, intracranial, intra- and extracranial, and extracranial, according to the tumor position (Fig. 1). Tumor size was defined as the largest diameter of the intracranial and the extracranial lesion on MRI. Patients were followed by interviews, otoneurological examination, and MRI every 6 months for 1 year at the outpatient clinic. Thereafter, followup imaging was performed every 1 or 2 years. Median follow-up after tumor resection was 62.3 months (range 26–124 months).
Eur Arch Otorhinolaryngol
Results Patients characteristics Patients’ mean age at surgery was 45.3 ± 13.6 years (range 21–70 years). Tumor was located on the right side in 30 patients and on the left side in 14. The most common presenting sign was headache or neck pain (30 patients, 68.2 %), and cervical mass in nine patients (20.5 %). Cranial nerve impairments, mainly involving the vagus nerve, were present in 19 patients (43.2 %) and hypoglossal nerve in 5 patients (11.4 %), only 1 patient displayed two lower cranial nerve impairments, and 21 patients presented normal lower cranial nerve function. No severe swallowing problems were found in all patients. Facial paresthesia was not occurring in all the patients at the time of presentation. 9 patients presented with hearing loss. Radiological finding Twenty two tumors were intra- and extracranial, 10 were intracranial and 12 were extracranial. Mean intracranial tumor diameter was 12.3 ± 7.6 mm [range 0 (localized extracranially)–30 mm], and mean extracranial diameter was 13.9 ± 10.6 mm [range 0 (localized intra-cranially)–40 mm]. Tumor removal Lateral approaches were used for all the 44 patients. According to the tumor region, infratemporal fossa type A approach, petrous occipital trans-sigmoid approach and neck explosion were selected for tumor removal. Infratemporal fossa type A approach was used for 30 patients, among which anterior rerouting of facial nerve was used in 8 patients and facial nerve bridge technique used in 22 patients (Fig. 2); petrous occipital transsigmoid approach for 4 patients; and transcervical tumor removal was used for 10 patients with extracranial schwannomas. Gross-total resection was achieved in 40 patients (90.9 %), subtotal removal, defined as resection of >90 % of the preoperative tumor mass, was achieved in 4 patients, with complete removal of the intracranial portion. Intraoperatively, the nerve of origin was identified as the vagus nerve in 28 patients, the hypoglossal nerve in 9 patients, the glossopharyngeal nerve in 3 patients, and the accessory nerve in 2 patients. In the remaining two patients, tumor origin remained unknown. No CSF leakage and other neurovascular complications were found after surgery. Function of facial nerve No patient showed preoperative facial paralysis. In eight patients who received anterior rerouting of facial nerve via
Fig. 2 Infratemporal fossa type A approach for patients with craniaocervical schwannoma. a Infratemporal fossa type A approach with facial nerve partial rerouting. b Infratemporal fossa type A approach with facial nerve bridge technique
infratemporal fossa type A approach, immediately facial nerve paralysis was presented in all eight patients with House–Brackmann Grade III to Grade V, after 6 months rehabilitation training, House–Brackmann Grade I and II achieved in six of eight patients, Grade III in one patient, and remaining one patient got Grade V facial function without recovery. Good facial function was obtained in 42 patients (95.5 %). Function of lower cranial nerve Twenty three of 44 patients showed preoperative lower cranial nerve signs; only one patient presented two nerve impairment signs. All patients exhibited new or worsen lower cranial nerve signs immediately after surgery. Postoperatively, 31 patients only exhibited responsible nerve impairments. The dysfunction of non-responsible nerve was found in 13 patients (Table 1). For swallowing problems, postoperative status of IX and X nerves compared with preoperative status were unchanged in 20 patients, worse in 24 patients, and no patient showed better. However, with long-term follow-up, IX and X nerve dysfunction
13
Eur Arch Otorhinolaryngol
Table 1 Lower cranial nerves impairment before and after surgery Lower cranial nerves impairment
Preoperative
Postoperative
N 1 2
21
None
22 1
31 11
3
2
N normal nerve function, 1 one nerve impairment, 2 two nerves impairment, 3 three nerves impairment
Table 2 Long-term swallowing outcomes for 44 patients with craniaocervical schwannoma IX and X signs
Preoperative
Immediately after surgery
Final follow-up
None Mild dysfunction
40 4
20 18
37 7
Moderate or severe dysfunction
0
6
0
ameliorated compared with immediately after surgery in 21 of 24 patients (Table 2). No patients required postoperative nasogastric tube feeding or tracheotomy, and no patients needed vocal cord injections during follow-up. Tumor control Gross-total resection was achieved in 40 of 44 patients (90.9 %). An increase in residue tumor volume was observed in two of four patients during follow-up. They underwent gamma-knife surgery at 37 months and 60 months after surgery, respectively. No tumor regrowth was found during the furthermore MRI follow-up. The remaining two patients received no additional therapy because no signs or symptoms caused by tumor regrowth.
Discussion Schwannomas of LCNs IX, X and XI represent 3–4 % of all cranial nerve schwannomas [1]. The natural incidence of these tumors is probably higher, but that small or asymptomatic tumors may go undiagnosed. We have seen a marked increase in the incidence of vestibular schwannomas after MRI became easily available [6, 7]. Despite advances in otoneruoimaging, microsurgical techniques, and modern skull base surgery, complete removal of craniocervical schwannomas with minimal cranial nerve impairments remains challenging. Bulsara et al. [6] reported 53 cases of jugular schwannomas. Total removal achieved in 48 patients (90.5 %), new postoperative paresis in a
13
previously normal cranial nerve was not seen, but worsening of IX and X cranial nerve function was frequently observed. Samii et al. [1] achieved total surgical removal in all of 16 patients and postoperative cranial nerve dysfunction was found in 6 patients. Sanna et al. [7] reported total tumor resection in 95 % of 23 cases and also got cranial nerve morbidity in 95 % patients. These series demonstrate that total tumor removal can be achieved in most cases. However, high cranial nerve morbidity rate is still a problem. Surgical approach The tumors frequently involve adjacent structures, such as the jugular bulb, carotid artery, petrous bone, infratemporal fossa, lower cranial nerves, and posterior fossa. Many reports have described various approaches to these regions. We mainly use three types of surgical approaches for these tumors according to their relationship with jugular bulb. In tumors occupied jugular bulb, infratemporal fossa approach with facial nerve bridge technique is used for tumor removal. Facial nerve should be skeletonized to permit tumor removal manipulate from anterior and posterior of facial bridge. In cases of vascularized tumors or tumors anterior growth adhere to temporal portion of carotid artery; partial anterior rerouting of facial nerve (from parotid segment to posterior geniculate) is important for better vision and secure tumor removal. In tumors located mainly in the lateral aspect of jugular bulb, petrous occipital trans-sigmoid approach can be used for removal of intra- and extracranial portion of tumor without hearing sacrifice. The selection of this approach should be restricted in the tumors without anterior or medial invasion. The advantage of upper neck trans-cervical approach is minimal invasive without mastoid dissection. The relationship between jugular bulb and tumor should be critically considered. The approach should be used in tumors located inferiorly to jugular bulb. If the tumors adhere to the inferior part of jugular bulb, cranial nerve injury cannot be avoided and bleeding from inferior petrous sinus and jugular bulb is hard to be controlled because the craniocervical area vision is restricted without mastoid exposure. Facial nerve and lower cranial nerve preservation Normally the tumors do not involve facial nerve. In tumors of intracranial growth, facial nerve may locate superior to the tumor in posterior fossa, and the tumor can be dissect and remove without nerve injury. The most common reason of facial injury is facial nerve anterior rerouting for better vision of anterior portion of tumor. To avoid this, we use facial bridge technique for tumors occupied the jugular bulb. For some patients with tumor anterior growth into Eustachian tube and adhere to carotid artery, facial nerve will obscure
Eur Arch Otorhinolaryngol
the tumor removal manipulate. Anterior rerouting of facial nerve is necessary for anterior portion tumor removal. Partial rerouting of facial nerve from parotid to posterior geniculate can provide adequate surgical vision with minimal nerve injury. Rerouting facial nerve with adjacent tissue and nourishing vessels can diminish the severity of nerve injury. Lower cranial nerve dysfunction is the most common and severe reason for postoperative morbidity. The common reason for no-responsible lower cranial injury is the manipulation of tumor removal at the cervical cranial joint and occlusion of inferior petrous sinus. The area is restricted by facial nerve, mastoid tip, transverse process of first cervical vertebra and jugular bulb. Removal of the mastoid tip and transverse process of first cervical vertebra and performing a facial bridge can get maximal surgical exposure. Dissection of tumor from jugular foramen and early identification of responsible cranial nerve, followed by total tumor removal and occlusion of inferior petrous sinus gently can gain maximal degree of preservation of other lower cranial nerve. Tumor control and radiosurgery Total surgical removal is still a reasonable goal for craniocervical schwannomas, but subtotal or near-total tumor resection is particularly used for elderly patients who cannot recover from severe swallowing problems or unfit patients who cannot tolerate prolonged surgery. In case of residue tumor, alternative strategies such as radiosurgery must also play a role in management [8]. The aim of radiosurgery is to achieve tumor control without causing additional cranial nerve deficits. Nishioka et al. [9] reported seven patients of nonacoustic schwannomas with radiotherapy. After a median follow-up of 59.5 months, tumor control was achieved in all of patients. Martin et al. [10] documented the largest series of schwannomas treated with gamma-knife surgery to date (35 patients total). 10 year tumor control rate was 94 %. In our cases, two patients with regrowth tumor received the radiosurgery and gained good tumor control outcome. For special cases, initial surgical resection followed by radiosurgery on any residue tumor may be an effective option [11]. Treatment strategy We established our treatment strategy for craniaocervical schwannoma according to the patient age, tumor size and location, and preoperative lower cranial nerve function (Fig. 3). For aged patients, complete swallowing compensation recovery is hard achieved especially in those with normal IX and X cranial nerve function. Observation and scan policy are advocated for aged patients. Near-total removal and scheduled radiosurgery are performed for
Craniaocervical Schwannoma
Aged
Younger
rapid growth small
Observation & Scan
life threaten
NTR & RS
Total Removal JB free
ITF & POTS
JB involved
Transcervical
Fig. 3 Treatment strategy of craniaocervical schwannoma. NTR neartotal removal, RS radiosurgery, JB jugular bulb, ITF infratemporal fossa approach, POTS petrous occipital transsigmoid approach
life-threaten or rapid growth tumor. Staged tumor removal is not considered in our group because schwannoma is a no-vascularized tumor and one stage total tumor removal of intra- and extra-dural portion can be achieved. CSF leakage is not often happened by closure and obligation of the surgical cavity. The surgical approaches selection should be alternative on the jugular bulb involvement and dural invasion. Normally, there will be no severe postoperative swallowing problems in those patients with preoperative lower cranial nerve dysfunction. Surgery until complete nerve paralysis is also a treatable option.
Conclusion The preoperative estimation of tumor in nature is of great importance in the determination of proper surgical planning of craniocervical schwannomas. Facial nerve and lower cranial nerve function can be preserved in maximal degree by proper surgical approaches and careful operative manipulation. The key to diminish the lower cranial nerve injury is to identify the responsible nerve and preserve the non-responsible nerves. Initial surgical resection followed by radiosurgery may be an effective option for some special patients.
References 1. Samii M, Babu R, Tatagiba M, Sepehrnia A (1995) Surgical treatment of jugular foramen schwannomas. J Neurosurg 82:924–932 2. Fukuda M, Oishi M, Saito A, Fujii Y (2009) Long-term outcomes after surgical treatment of jugular foramen schwannomas. Skull Base 19:401–408
13
3. Carvalho GA, Tatagiba M, Samii M (2000) Cystic schwannomas of the jugular foramen: clinical and surgical remrks. Neurosurgery 46:560–566 4. Ramina R, Maniglia JJ, Fernandes YB, Paschoal JR, Pfeilsticker LN, Neto MC (2005) Tumor of the jugular foramen: diagnosis and management. Neurosurg 57(Suppl 1):59–68 5. Wilson MA, Hillman TA, Wiggins RH, Shelton C (2005) Jugular foramen schwannomas: diagnosis, management, and outcomes. Laryngoscope 115:1486–1492 6. Bulsara KR, Sameshima T, Friedman AH, Fukushima T (2008) Microsurgical management of 53 jugular foramen shwannomas: lessons learned incorporated into a modified grading system. J Neurosurg 109:794–803 7. Sanna M, Bacciu A, Falcioni M, Taibah A (2006) Surgical management of jugular foramen schwannomas with hearing and facial nerve function preservation: a series of 23 cases and review of the literature. Laryngoscope 116:2191–2204
13
Eur Arch Otorhinolaryngol 8. Peker S, Sengoz M, Kilic T, Pamir MN (2012) Gamma knife radiosurgery for jugular foramen schwannomas. Neurosurg Rev 35:549–553 9. Nishioka K, Abo D, Aoyama H, Furuta Y, Onimaru R, Onodera S et al (2009) Stereotactic radiotherapy for intracranial nonacoustic schwannomas including facial nerve schwannoma. Int J Radiat Oncol Biol Phys 75:1415–1419 10. Martin JJ, Kondziolka D, Flickinger JC, Mathieu D, Niranjan A, Lunsford LD (2007) Cranial nerve preservation and outcomes after stereotactic radiosurgery for jugular foramen schwannomas. Neurosurg 61:76–81 11. Cavalcanti DD, Martirosyan NL, Verma K, Safavi-Abbasi S, Porter RW, Theodore N et al (2011) Surgical management and outcome of schwannomas in the craniocervical region. J Neurosurg 114(5):1257–1267
