Reconstruction of the mandible for osteoradionecrosis Purpose of review To describe current standard of care for osteoradionecrosis (ORN) of the mandible and report possible future trends. Recent findings Cutting guides may be used to reduce surgical time and possibly improve outcomes. There has also been recent investigation into the use of pentoxifylline and tocopherol or pentoxifylline, tocopherol and clodronate (a well known conservative medial regime) as a prevention for development of ORN after dental extractions and the first randomized controlled study is upcoming. Augmented reality has shown promise as a comparable and inexpensive possible alternative to cutting guides. Summary Current standard of care involves conservative/supportive therapy with antioxidants, antibiotics, steroids, and pain control for low-grade ORN with surgery reserved for high-grade/progressive ORN with refractory to conservative therapy and with significant oral dysfunction. Correspondence to Orly M. Coblens, MD, Assistant Professor, Department of Otolaryngology – Head and Neck Surgery, University of Texas Medical Branch, Galveston, Texas, USA. Tel: +1 409 772 2701; e-mail: orcoblen@utmb.edu Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

Use of multiple free flaps in head and neck reconstruction Purpose of review To review the recent literature on the use of multiple flaps in head and neck reconstruction with attention to form, function, outcomes, and complications. Recent findings Multiple free flap reconstructions are technically feasible with high flap survival rates, tolerable complication rates, and overall adequate functional and aesthetic outcomes, given the large extent of the defects and the high surgical complexity of these cases. Summary Multiple free flap reconstructions should be considered in cases of large defects involving multiple functional regions and tissue types, which most often arises following resection of advanced malignancies. As there is mortality benefit with clear surgical margins and eradication of malignant lymph nodes, larger resections should be pursued if necessary, followed by a multiple flap reconstruction. Correspondence to Arnaud Bewley, MD, Department of Otolaryngology-Head and Neck Surgery, UC Davis Medical Center, 2521 Stockton Blvd., Suite 7200, Sacramento, CA 95817, USA. E-mail: abewley@ucdavis.edu Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

Postoperative management of patients with spontaneous cerebrospinal fluid leak Purpose of review To explore key management principles and outcomes following surgical intervention for spontaneous CSF leaks of the lateral skull base. Recent findings Outcomes following surgery for spontaneous CSF leaks of the lateral skull base depend on the surgical approach utilized. The approach reported most frequently in the literature is currently the middle fossa approach. Mean leak recurrence rates, regardless of approach, were approximately 6%. The lowest leak recurrence rates were associated with the combined middle cranial fossa-transmastoid approach. A multilayer closure was employed in all of the reviewed investigations, but the choice of reconstructive material did not significantly affect outcomes. Direct surgical complications rates, overall, were low at less than 2%. Meningitis, intracranial hemorrhage, and perioperative seizure activity were only rarely encountered. A concomitant diagnosis of idiopathic intracranial hypertension was found to be associated with increased rates of leak recurrence and sequential leak development at other skull base sites. Summary Postoperative management of patients with spontaneous CSF leaks of the lateral skull base has unique challenges. Observation of key treatment principles can lead to good outcomes and limit morbidity. A high index of suspicion should exist for concomitant idiopathic intracranial hypertension. Correspondence to Shawn M. Stevens, MD, Barrow Neurological Institute, 2222 E Highland Avenue, Ste 204, Phoenix, AZ 85016, USA. Tel: +1 602 264 4834; e-mail: sstevens@aocphysicians.com Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

Diagnosis and management of spontaneous cerebrospinal fluid fistula and encephaloceles Purpose of review To describe the current state in the diagnosis and management of spontaneous cerebrospinal fluid (sCSF) fistula and encephaloceles. Recent findings The increased incidence of obesity has resulted in more cases of sCSF fistula and encephaloceles. Obesity results in increased intracranial pressure and a greater chance of developing a sCSF fistula or encephalocele. Obstructive sleep apnea can also result in transient increase in intracranial pressure and has been shown to be common in patients with sCSF fistula. Treatment of CSF fistula is usually necessary because of the increased risk of meningitis. The use of hydroxyapatite bone cements to repair the temporal bone defects has been described with a high success rate of closing the fistula and a low complication rate. Concurrent superior semicircular canal dehiscent can be seen in up to 15% of cases and should be suspected during the surgical approach to avoid potential sensorineural hearing loss and chronic imbalance. Summary sCSF fistula and encephaloceles are an uncommon cause of hearing loss, middle ear effusion, and otorrhea, but should be recognized and repaired because of the risk of meningitis. Correspondence to Joe Walter Kutz Jr., MD, Associate Professor, Department of Otolaryngology, University of Texas Southwestern Medical Center, 2100 Inwood Dr., Dallas, TX 75390, USA. Tel: +1 214 648 3102; fax: +1 214 648 9122; e-mail: walter.kutz@utsouthwestern.edu Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

Trans-mastoid approach for cerebrospinal fluid leak repair Purpose of review To describe the technique and discuss the advantages and outcomes of the trans-mastoid approach (TMA) for temporal bone cerebrospinal fluid (CSF) leak. Recent findings TMA for CSF leak repair is an alternative to middle cranial fossa approach (MCFA) with less morbidity and good outcomes. Summary Persistent CSF leak in the temporal bone whether idiopathic, congenital or acquired, is an indication for surgery. TMA is a valid option for surgery, competing with MCFA in selected cases. Surgical technique consists of a standard mastoidectomy, exposure of the osteodural defect, and repairing it using multiple layers in an inlay and overlay fashion. Outcomes show low recurrence and complication rates with good hearing results. However, long-term follow-up should be made, as recurrences can be delayed. Correspondence to Alexandre Karkas, MD, PhD, Service ORL, Hopital Nord, Batiment B. 42055, Saint-Etienne, Cedex 2, France. Tel: +33 4 77 82 80 00; e-mail: Alexandre.Karkas@chu-st-etienne.fr Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

Update on treatment options for blast-induced hearing loss Purpose of review The incidence of blast injuries has increased, and the ear is the highest risk organ. Ear injury induced by blast exposure is important in both military and civilian conditions. The permanent hearing loss caused by blast exposure is associated with a decline in the quality of life. In this review, I describe recent therapeutic strategies for each of the ear pathologies caused by blast exposure. Recent findings For tympanic membrane perforation after blast exposure, basic fibroblast growth factor (bFGF) has been used as a less invasive treatment to repair the tympanic membrane. The closure rates of tympanic membrane perforations treated with bFGF were reported to be comparable to those following conventional tympanoplasty. For sensorineural hearing loss after blast exposure, treatment with neurotrophic factors, such as nerve growth factor (NGF) or neurotrophin-3, antioxidants, and Atoh1 induction have recently been applied, and some of them were considered for clinical application. Summary Recent advances of therapeutics for blast-induced hearing loss, based on their pathologies, have been outlined. There are several promising therapeutic approaches for both middle and inner ear disorders after blast exposure; however, further research is needed to establish new treatments for blast-induced hearing dysfunction. Correspondence to Kunio Mizutari, MD, PhD, Department of Otolaryngology, Head and Neck Surgery, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama 359-8513, Japan. Tel: +81 4 2995 1511; fax: +81 4 2996 5212; e-mail: tari@mbf.ocn.ne.jp Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

Middle fossa approach for spontaneous cerebrospinal fluid fistula and encephaloceles Purpose of review The aim of this article is to describe the middle fossa craniotomy (MFC) approach for the repair of cerebrospinal (CSF) fistula and encephaloceles. Recent findings The MFC approach has a greater than 93% success rate for managing CSF fistula and encephaloceles located along the tegmen tympani and tegmen mastoideum. Posterior fossa defects cannot be managed by an MFC approach. Multilayer repair with the combination of soft tissue and durable substances is preferred. Hydroxyapatite bone cement provides a durable repair of thinned or absent areas of bone with a low risk of infection. Concurrent management of symptomatic superior semicircular canal dehiscence may be readily performed. Small keyhole craniotomies with the utilization of the endoscope are possible as a means to minimize temporal lobe retraction. Summary MFC repair of CSF fistula and encephaloceles is a highly effective approach for the repair of tegmen mastoideum and tegmen tympani defects. Correspondence to Joe Walter Kutz, Jr., MD, Department of Otolaryngology, Southwestern Medical Center, University of Texas, 2001 Inwood Road, Dallas, TX 75390, USA. Tel.: +1 214 648 2964;. fax: +1 214 648 9122; e-mail: walter.kutz@utsouthwestern.edu Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

The role of obesity, sleep apnea, and elevated intracranial pressure in spontaneous cerebrospinal fluid leaks Purpose of review Spontaneous cerebrospinal fluid (sCSF) leaks often occurs in middle age, obese females. Here we investigate the role of obesity, idiopathic intracranial hypertension (IIH), and obstructive sleep apnea (OSA) in the pathophysiology of sCSF leaks. Recent findings The association of obesity and sCSF leaks has been well established in many studies. It has now been revealed that sCSF leak patients have thinner calvariums along with the skull base. An intracranial process likely leads to calvarium and skull base thinning in sCSF leaks patients since this occurs independent of extracranial bone thinning and independent of obesity. OSA, which is known to cause spikes in intracranial pressure (ICP), has been found to be significantly prevalent in the sCSF population and has been shown to lead to both calvarial and skull base thinning. Chronically elevated ICP (IIH) has also been shown to impact calvarial and skull base thicknesses. Summary The incidence of sCSF leaks has increased in recent decades along with an increasing rate of obesity. OSA and IIH, which are obesity-related factors and cause transient and chronic elevations in ICP, have now been implicated as critical factors leading to calvarial and skull base thinning and resultant sCSF leaks. Correspondence to Rick F. Nelson, MD, PhD, Indiana University College of Medicine, 355 W. 16th St. Suite 3200, Indianapolis, IN 46202, USA. Tel: +1 317 963 7073; fax: +1 317 963 7085; e-mail: ricnelso@iupui.edu Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

The evolution of presenting signs and symptoms of lateral skull base cerebrospinal fluid leaks Purpose of review To review the presenting signs and symptoms of spontaneous cerebrospinal fluid (CSF) leaks of the lateral skull base. Recent findings Research continues to demonstrate that CSF leaks from the lateral skull base are insidious, and present with subtle signs and symptoms. Patients commonly present with symptoms of aural fullness, middle ear effusion, and otorrhea following tympanostomy tube insertion that can be confused for chronic otitis media. More recently headache, pulsatile tinnitus, and dizziness/vertigo are being recorded as symptoms at presentation, which is likely a reflection of the association of spontaneous CSF leak with obesity, intracranial hypertension, and superior canal dehiscence. The presence of these less common symptoms in the setting of middle ear effusion should raise suspicion for CSF leak. The rate of meningitis in spontaneous CSF leak is not negligible, and patients should be counseled on this life-threatening risk. Summary Spontaneous CSF leak from the lateral skull base presents with subtle signs and symptoms and remains a diagnostic challenge. Less common symptoms may represent associations with underlying comorbidities, and awareness of the increasing coincidence of diseases that accompany spontaneous CSF leak is essential to prompt diagnosis and management. Correspondence to James G. Naples, MD, Division of Otolaryngology, Beth Israel Deaconess Medical Center, 110 Francis St, Suite 6E, Boston, MA 02215, USA. Tel: +1 617 632 7500; e-mail: jnaples513@gmail.com Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.