Subtotal Petrosectomy for Cochlear Implantation

Objectives:

The purpose of this study was to review the indications for subtotal petrosectomy for cochlear implantation, report our management of complications, as well as review those technical factors that are critical for successful implantation.

Methods:

Patients (n = 104) that underwent subtotal petrosectomy with closure of the external auditory canal and obliteration of the cavity with abdominal fat in combination with cochlear implantation were analyzed.

Results:

The most frequent indication for subtotal petrosectomy was the existence of a previous canal wall down technique. Postoperative complications occurred in 13 patients (11.83%). Extrusion of the device took place in 5 cases (4.55%).

Conclusions:

Subtotal petrosectomy in cochlear implantation permits obtaining a cavity isolated from the external environment, and when needed, it improves the access and visibility during the surgical procedure. Subtotal petrosectomy is a safe technique, with a low rate of complications.

Management of the cervico-petrous internal carotid artery in class C tympanojugular paragangliomas

BACKGROUND

Management of the cervical and petrous internal carotid artery (ICA) is frequently required in Fisch class C tympanojugular paragangliomas (TJPs). The purpose of this study was to discuss the perioperative intervention of the ICA in patients who underwent surgical resection of a TJP.

METHODS

A retrospective study of 237 patients surgically treated for Fisch class C TJPs was done to identify cases that required ICA management.

RESULTS

Management of the ICA was required in 176 patients (74.2%). Forty-two patients required just an ICA decompression, 88 underwent a subperiosteal dissection, 19 underwent subadventitial dissection without intraluminal stenting, 17 underwent subadventitial dissection with intraluminal stenting, and 12 underwent arterial resection after permanent balloon occlusion. There were no complications associated with the endovascular procedures. Gross total tumor resection was achieved in 91.5% of the cases.

CONCLUSION

Preoperative endovascular intervention, in selected cases, facilitates gross total tumor removal and significantly reduces the risk of an intraoperative ICA injury. © 2015 Wiley Periodicals, Inc. Head Neck 38: 899-905, 2016.

Strategies and long-term outcomes in the surgical management of tympanojugular paragangliomas

BACKGROUND

The purpose of this study was to share our review of surgical strategies and long-term outcomes in the management of tympanojugular paragangliomas.

METHODS

This was a retrospective study with a literature review. The records of 184 patients with 185 tympanojugular paragangliomas were analyzed for tumor class, surgical procedure, preoperative vascular management, and perioperative sequelae.

RESULTS

Of class C1, C2, C3, and C4 tumors, we found 46 (24.9%), 95 (51.3%), 41 (22.2%), and 3 (1.6%), respectively. One hundred four (56.2%) tumors had intracranial extensions and 8 (4.3%) involved the vertebral artery. A single-stage procedure was adopted in 158 (85.4%) tumors. The infratemporal fossa type A approach was used in all cases. In 17 patients (9.7%), an intra-arterial stenting of the internal carotid artery was performed. Gross-total tumor removal was achieved in 166 cases (89.7%) and 4 (2.4%) among them developed a recurrence.

CONCLUSION

A thorough understanding of skull base techniques and a logical decision-making process in the management of tympanojugular paragangliomas can achieve a high rate of success in terms of recurrences and complications. © 2015 Wiley Periodicals, Inc. Head Neck 38: 871-885, 2016.

Staged resection for vestibular schwannoma

CONCLUSION

Surgery remains the preferred option for large vestibular schwannoma (VS). The presence of unpredictable intraoperative difficulties may convince the operator to suspend the surgery to avoid risks to patient life. Additional surgeries may be mandatory and are better performed using a transcochlear approach. High rates of complications, poor facial nerve results, and a percentage of incomplete removals should be expected in such unfavorable cases.

OBJECTIVES

To review the results for nine cases of huge VS treated by staged resection.

METHOD

A retrospective case review was performed for all nine patients who underwent staged resection of VS at the Gruppo Otologico between 1984-2012. The decision to perform staged surgery was always made intra-operatively after encountering unpredicted difficulties.

RESULTS

The nine patients represented 0.3% of all patients who underwent VS surgery during the same period. Mean tumor size was 4.7 cm (range = 3.0-6.6 cm). Two cases required three surgeries, resulting in a total of 20 operations. In addition, two cases required pre-operative ventriculoperitoneal shunt and one required temporary tracheotomy. After the final stage of surgery, complete removal had been achieved in six of the nine patients. The facial nerve was never preserved anatomically.

Cochlear implantation in irradiated tympanojugular paraganglioma

OBJECTIVE

Indications for cochlear implantation have extended progressively over the years both from an audiological and clinical point of view, including the introduction of cochlear implants (CI) for hearing rehabilitation following skull base surgeries and neurotological procedures. In the past, cochlear implantation has been used for hearing rehabilitation in radiation-induced sensorineural hearing loss in nasopharyngeal and tonsillar carcinoma with successful outcomes. Here we describe a similar outcome following total deafness after tympanojugular paraganglioma irradiation, which is also the first such report in literature.

DESIGN

The irradiated ear of this patient was implanted with a CI through standard posterior tympanotomy.

STUDY SAMPLE

A 26 year old male with multiple paragangliomas with bilateral deafness, secondary to surgery on one ear and radiotherapy for the opposite ear.

RESULTS

After a follow-up of 48 months, no local complications have occurred and the hearing results have remained stable with 100% sentence recognition.

CONCLUSIONS

Bilateral and multiple paragangliomas are rare tumors. Despite the modality of treatment, the hearing is almost always compromised. In these patients, cochlear implantation offers a new perspective for hearing restoration. This report demonstrates that cochlear implantation can be effectively performed after tympanojugular paraganglioma irradiation with long-lasting, satisfactory results, even in the presence of residual tumor.

Long term surgical and hearing outcomes in the management of tympanomastoid paragangliomas

OBJECTIVE

To analyze the long term outcomes after surgery in tympanomastoid paragangliomas.

STUDY DESIGN

Retrospective study.

METHODS

The charts of 145 patients with tympanomastoid paragangliomas managed between 1988 and 2013 were reviewed. The clinical features, audiological data, pre- and postoperative notes were noted. The tumors were staged according to the modified Fish and Mattox classification. The surgical approaches for all patients were formulated according to the surgical algorithm developed at our center.

RESULTS

34 (23.5%), 46 (31.7%), 22 (15.2%), 18 (12.4%) and 25 (17.2%) patients were diagnosed to have TMP class A1, A2, B1, B2 and B3 tumors respectively. Gross tumor resection was achieved in 141 (97.2%) patients. The facial nerve was uncovered in four patients and infiltrated in three. The cochlea was found eroded in seven cases. The mean follow-up was 48.4 months. Recurrence was seen in one patient (0.7%). In the cases where the facial nerve was preserved (n=143), the nerve function was graded as HB grade 1 in 138 patients (97%). Postoperatively, the mean AC showed an improvement in all categories except in class B2 and B3, which corresponds to the classes that include patients who underwent subtotal petrosectomy.

CONCLUSION

We report the long term surgical outcomes in tympanomastoid paragangliomas in the largest series published till date. It is possible to completely eradicate all types of tympanomastoid paragangliomas with minimum sequelae by choosing the correct surgical approach to achieve adequate exposure for individual tumor classes as described in our classification and algorithm.

LEVEL OF EVIDENCE

IIb.

Impact of cholesterol lowering treatment on plasma kynurenine and tryptophan concentrations in chronic kidney disease: relationship with oxidative stress improvement

BACKGROUND AND AIM

Tryptophan (Trp) degradation via indoleamine (2,3)-dioxygenase (IDO), with consequent increased in kynurenine (Kyn) concentrations, has been proposed as marker of immune system activation. Oxidative stress (OS) might contribute to the pro-inflammatory state in chronic kidney disease (CKD) through the activation of NF-kB, with consequent activation and recruitment of immune cells.

METHODS AND RESULTS

Serum concentrations of Trp and Kyn, oxidative stress indices malondialdehyde (MDA) and allantoin/uric acid (All/UA) ratio and anti-oxidant amino acid taurine were measured in 30 CKD patients randomized to 40 mg/day simvastatin (group 1), ezetimibe/simvastatin 10/20 mg/day (group 2) or ezetimibe/simvastatin 10/40 mg/day (group 3) and treated for 12 months. Baseline Kyn and Kyn/Trp ratio were higher in CKD patients vs. healthy controls (1.67 ± 0.62 μmol/L vs 1.25 ± 0.40 μmol/L, p < 0.01 and 0.036 ± 0.016 vs 0.023 ± 0.010, p < 0.001 respectively). Both Kyn and Kyn/Trp ratio significantly decreased after cholesterol lowering treatment, to values comparable with healthy controls after one year treatment (1.67 ± 0.62 μmol/L vs 1.31 ± 0.51 μmol/L, p < 0.0001 and 0.036 ± 0.016 vs 0.028 ± 0.012 p < 0.0001, respectively). This was paralleled by a significant decrease in MDA (218 ± 143 nmol/L vs 176 ± 123 nmol/L, p < 0.01) and All/UA ratio (1.47 ± 0.72 vs 1.19 ± 0.51, p < 0.01) in CKD patients.

CONCLUSIONS

Amelioration of both oxidative and inflammation status after cholesterol lowering treatment in CKD might be mediated by restoration of antioxidant taurine concentrations during therapy (from 51.1 ± 13.3 μmol/L at baseline to 63.1 ± 16.4 μmol/L, p < 0.001 by ANOVA), suggesting that improvement of both oxidative and inflammation status in CKD patients could be explained, at least partly, by the cholesterol lowering effects.

Profiling of somatic mutations in phaeochromocytoma and paraganglioma by targeted next generation sequencing analysis

At least 12 genes (FH, HIF2A, MAX, NF1, RET, SDHA, SDHB, SDHC, SDHD, SDHAF2, TMEM127, and VHL) have been implicated in inherited predisposition to phaeochromocytoma (PCC), paraganglioma (PGL), or head and neck paraganglioma (HNPGL) and a germline mutation may be detected in more than 30% of cases. Knowledge of somatic mutations contributing to PCC/PGL/HNPGL pathogenesis has received less attention though mutations in HRAS, HIF2A, NF1, RET, and VHL have been reported. To further elucidate the role of somatic mutation in PCC/PGL/HNPGL tumourigenesis, we employed a next generation sequencing strategy to analyse "mutation hotspots" in 50 human cancer genes. Mutations were identified for HRAS (c.37G>C; p.G13R and c.182A>G; p.Q61R) in 7.1% (6/85); for BRAF (c.1799T>A; p.V600E) in 1.2% (1/85) of tumours; and for TP53 (c.1010G>A; p.R337H) in 2.35% (2/85) of cases. Twenty-one tumours harboured mutations in inherited PCC/PGL/HNPGL genes and no HRAS, BRAF, or TP53 mutations occurred in this group. Combining our data with previous reports of HRAS mutations in PCC/PGL we find that the mean frequency of HRAS/BRAF mutations in sporadic PCC/PGL is 8.9% (24/269) and in PCC/PGL with an inherited gene mutation 0% (0/148) suggesting that HRAS/BRAF mutations and inherited PCC/PGL genes mutations might be mutually exclusive. We report the first evidence for BRAF mutations in the pathogenesis of PCC/PGL/HNPGL.

Ipsilateral cochlear implantation in patients with sporadic vestibular schwannoma in the only or best hearing ear and in patients with NF2

The aim of this study was to evaluate the cochlear implant (CI) performances in neurofibromatosis type 2 (NF2) patients with bilateral vestibular schwannoma (VS) and in patients with sporadic VS in the only or better hearing ear. All patients with bilateral VS or sporadic VS in the only or better hearing ear who underwent cochlear implantation, either simultaneous to VS surgery or staged after treatment for VS, in the tumor side were chosen for the study. Postimplantation audiometric scores (sound detection, closed-set and open-set discrimination scores) and device use patterns were the main outcome measures. 15 patients were implanted. Eight patients (53 %) were NF2 and seven patients had VS in the only or better hearing ear. One patient was explanted for cerebrospinal fluid leak. In the CI-only condition, the other 14 patients obtained sound detection, 64 % of them achieving open-set discrimination (mean 70 ± 38 %) and 85 % achieving closed-set discrimination (mean 41 ± 33 %). At the last follow-up 10 patients (67 %) were using the CI. Cochlear implantation provides hearing in particular cases of patients with bilateral VS or VS in the only or better hearing ear. As long as anatomic preservation of the cochlear nerve is achieved, cochlear implantation may offer improvement in communication skills for most patients.

The effects of tympanomastoid paragangliomas on hearing and the audiological outcomes after surgery over a long-term follow-up

The primary goals of surgery of tympanomastoid paragangliomas (TMPs) are tumor eradication and hearing preservation. Though the surgical management of TMPs has been dealt with widely in the literature, the effects of TMPs themselves on preoperative hearing and the audiological outcomes after surgery have not been analyzed in detail. This article comprehensively evaluates the preoperative hearing and the long-term hearing outcomes after surgery of TMPs. This study is based on a study population of 145 patients which is the largest reported in the literature. The surgical approaches for all patients with TMPs were formulated according to an algorithm developed by the authors. Complete tumor removal with excellent hearing results can be achieved by approaching the tumor classes by the right surgical technique. TMPs could possibly induce sensorineural hearing loss in higher frequencies, and future studies could be directed towards this.

The behavior of residual tumors and facial nerve outcomes after incomplete excision of vestibular schwannomas

OBJECT

The authors evaluated the behavior of residual tumors and facial nerve outcomes after incomplete excision of vestibular schwannomas (VSs).

METHODS

The case records of all patients who underwent surgical treatment of VSs were analyzed. All patients in whom an incomplete excision had been performed were analyzed. Incomplete excision was defined as near-total resection (NTR), subtotal resection (STR), and partial resection (PR). Tumors in the NTR and STR categories were followed up with a wait-and-rescan approach, whereas the tumors in the PR category were subjected to a second-stage surgery and were excluded from this series. All patients included in the study underwent baseline MRI at the 3rd and 12th postoperative months, and repeat imaging was subsequently performed every year for 7-10 years postoperatively or as indicated clinically. Preoperative and postoperative facial function was noted.

RESULTS

Of the 2368 patients who underwent surgery for VS, 111 patients who had incomplete excisions of VSs were included in the study. Of these patients, 73 (65.77%) had undergone NTR and 38 (34.23%) had undergone STR. Of the VSs, 62 (55.86%) were cystic and 44 (70.97%) of these cystic VSs underwent NTR. The residual tumor was left behind on the facial nerve alone in 62 patients (55.86%), on the facial nerve and vessels in 2 patients (1.80%), on the facial nerve and brainstem in 15 patients (13.51%), and on the brainstem alone in 25 patients (22.52%). In the 105 patients with normal preoperative facial nerve function, postoperative facial nerve function was House-Brackmann (HB) Grades I and II in 51 patients (48.57%), HB Grade III in 34 patients (32.38%), and HB Grades IV-VI in 20 patients (19.05%). Seven patients (6.3%) showed evidence of tumor regrowth on follow-up MRI. All 7 patients (100%) who showed evidence of tumor regrowth had undergone STR. No patient in the NTR group exhibited regrowth. The Kaplan-Meier plot demonstrated a 5-year tumor regrowth-free survival of 92%, with a mean disease-free interval of 140 months (95% CI 127-151 months). The follow-up period ranged from 12 to 156 months (mean 45.4 months).

CONCLUSIONS

The authors' report and review of the literature show that there is undoubtedly merit for NTR and STR for preservation of the facial nerve. On the basis of this they propose an algorithm for the management of incomplete VS excisions. Patients who undergo incomplete excisions must be subjected to follow-up MRI for a period of at least 7-10 years. When compared with STR, NTR via an enlarged translabyrinthine approach has shown to have a lower rate of regrowth of residual tumor, while having almost the same result in terms of facial nerve function.

Skull base chondrosarcomas: surgical treatment and results

OBJECTIVES

We describe our experience in the management of patients with skull base chondrosarcoma, an uncommon neoplasm of the skull base.

METHODS

Thirteen cases of surgically treated skull base chondrosarcomas were identified. The patients' follow-ups ranged from 7 to 86 months (mean, 47 months).

RESULTS

The most common tumor locations were the jugular foramen (5 cases), the petrous apex (3 cases), and the petroclival region (3 cases). An infratemporal fossa type A approach was performed in 2 cases, and 2 patients underwent an infratemporal fossa type B approach. Two patients underwent a transotic approach, 1 patient underwent a petro-occipital transsigmoid approach, and a petro-occipital transsigmoid approach combined with a transotic approach was chosen in 1 case. One patient underwent an infratemporal fossa type C approach combined with a transotic approach, and 2 patients underwent an infratemporal fossa type B approach combined with a transotic approach. One patient underwent an infratemporal fossa type B approach combined with a transzygomatic approach, and the last patient underwent a transmastoid approach. Gross total tumor removal was achieved in all patients. Postoperative radiotherapy was performed in 7 cases. The most common complications were lower cranial nerve deficits. Two patients experienced recurrences, 36 months and 6 years after surgical removal.

CONCLUSIONS

We believe that the primary treatment for chondrosarcomas of the skull base is gross total surgical resection. We usually do not recommend radiotherapy as the primary treatment for patients with skull base chondrosarcomas; however, radiotherapy may be considered as an alternative primary treatment in selected cases in which there are serious medical contraindications to surgery, as well as in elderly patients. We reserve postoperative radiotherapy for patients with histologically aggressive tumors (grade II or III), as well as for cases of subtotal resection or recurrent tumors.

Intraoperatively diagnosed cerebellopontine angle facial nerve schwannoma: how to deal with it

OBJECTIVE

This study aimed to report our experience in the management of patients with intraoperatively diagnosed intracranial facial nerve schwannomas (FNSs) and propose a decision-making strategy.

METHODS

Twenty-three patients with FNS of the internal auditory canal and/or cerebellopontine angle operated on between 1992 and 2012 were identified.

RESULTS

Preoperatively, all cases have been radiographically diagnosed as vestibular schwannomas. Operative procedures consisted of total tumor resection with grafting in 43.4% of patients, near-total resection leaving behind the tumor capsule overlying the facial nerve in 21.7%, total tumor resection with preservation of anatomic continuity of the facial nerve in 13%, and subtotal resection in 4.3%. Four patients (17.4%) underwent bony decompression with no tumor removal.

CONCLUSION

Management of FNS diagnosed at surgery represents a significant clinical challenge. We considered total tumor resection with grafting when patients presented with preoperative facial nerve palsy (≥ grade III). Both subtotal and near-total tumor removal can be performed in patients with preoperative good facial function and/or large tumors with brainstem compression. Patients with small tumors who were selected for hearing preservation surgery can be considered for bony decompression. Fascicle preservation surgery may be an option when a clear cleavage plane between the tumor and the facial nerve is found.

Lipomas of the Internal Auditory Canal and Cerebellopontine Angle

Objectives:

Lipomas of the internal auditory canal (IAC) and cerebellopontine angle (CPA) are exceedingly rare lesions. The purpose of this report was to describe our experience with lipomas of the IAC and CPA and perform a review of the literature.

Methods:

We report 8 cases of lipomas involving the IAC and/or the CPA that were managed at Gruppo Otologico between April 1987 and October 2012.

Results:

Four cases of entirely intracanalicular lipomas were radiologically misinterpreted as vestibular schwannomas and underwent tumor removal by a translabyrinthine approach. Two of these patients experienced postoperative facial nerve palsy. Lipomas were suspected in 4 patients on the basis of imaging findings and were managed conservatively. Of these 4 cases, 3 did not show any growth after an average period of 28 months, and 1 case demonstrated tumor growth on follow-up imaging.

Conclusions:

Neuroimaging represents an extremely important tool for this diagnosis. Attempts to achieve complete resection may result in severe neurologic sequelae, especially in large lesions. Observation with repeated imaging in order to detect growth of the lesion is usually recommended. Debulking of the tumor, mainly aimed at brain stem and cranial nerve decompression, should be considered in cases of disabling and uncontrolled neurologic symptoms and signs.

Lower cranial nerves function after surgical treatment of Fisch Class C and D tympanojugular paragangliomas

The aim of this study was to report the postoperative lower cranial nerves (LCNs) function in patients undergoing surgery for tympanojugular paraganglioma (TJP) and to evaluate risk factors for postoperative LCN dysfunction. A retrospective case review of 122 patients having Fisch class C or D TJP, surgically treated from 1988 to 2012, was performed. The follow-up of the series ranged from 12 to 156 months (mean, 39.4 ± 32.6 months). The infratemporal type A approach was the most common surgical procedure. Gross total tumor removal was achieved in 86% of cases. Seventy-two percent of the 54 patients with preoperative LCN deficit had intracranial tumor extension. Intraoperatively, LCNs had to be sacrificed in 63 cases (51.6%) due to tumor infiltration. Sixty-six patients (54.09%) developed a new deficit of one or more of the LCNs. Of those patients who developed new LCN deficits, 23 of them had intradural extension. Postoperative follow-up of at least 1 year showed that the LCN most commonly affected was the CN IX (50%). Logistic regression analysis showed that intracranial transdural tumor extension was correlated with the higher risk of LCN sacrifice (p < 0.05). Despite the advances in skull base surgery, new postoperative LCN deficits still represent a challenge. The morbidity associated with resection of the LCNs is dependent on the tumor's size and intradural tumor extension. Though no recovery of LCN deficits may be expected, on long-term follow-up, patients usually compensate well for their LCNs loss.