Endoscopic repair of cerebrospinal fluid leaks after neurosurgical procedures

OBJECTIVES: Endoscopic repair of cerebrospinal fluid (CSF) leaks has proven to be effective and safe. CSF rhinorrhea is a well-known complication of neurosurgical procedures in the anterior cranial fossa. We present a series of endoscopic repairs of CSF rhinorrhea secondary to neurosurgical procedures. STUDY DESIGN: Retrospective review of 13 cases. METHODS: Thirteen patients are included in the study. Eleven had CSF leaks after hypophysectomy, one after clipping of an anterior circle of Willis aneurysm, and one after posttraumatic frontal lobe debridement. Leaks were identified intraoperatively during the neurosurgical procedure (n = 8) or with intrathecal fluorescein injection during a separate procedure (n = 5). Repair was performed by exposing the skull base defect, debriding the defect margins, and sealing the defect with a free mucosal graft or abdominal fat. RESULTS: Leaks were identified in the sphenoid (n = 12) and posterior ethmoid (n = 1) sinuses. Nine patients had lumbar drains placed. One patient had recurrence of CSF rhinorrhea 2 months after initial repair requiring a revision procedure. No other recurrences were noted. One patient developed postoperative meningitis requiring intravenous antibiotics and a prolonged hospital stay. No other postoperative complications were observed. CONCLUSIONS: Endoscopic repair is a safe and effective treatment for CSF rhinorrhea encountered as a neurosurgical complication.     

Arachnoid granulation cerebrospinal fluid otorrhea

A case report and review of the temporal bone (TB) collection in the Department of Otolaryngology at SUNY Health Science Center in Syracuse demonstrated the occurrence of arachnoid granulations (AGs) in the posterior fossa surface of the TB and their role in cerebrospinal fluid (CSF) otorrhea. A large AG responsible for CSF otorrhea in a 64-year-old man was excised with soft tissue repair of the dural defect. Sixteen of 188 TBs (8.5%) in the collection contained 24 AGs ranging in size from 0.07 to 80.65 mm3. Nine AGs (37%) were small (less than 1 mm3) and did not demonstrate enlargement. Twelve (50%) were of intermediate size (2.50 to 9.32 mm3), and three (13%) were large (49.82 to 80.65 mm3). The intermediate and large AGs were associated with bone erosion and a high incidence of communication with a pneumatized mastoid complex (serous otitis media or meningitis). These findings suggest that AGs of sufficient size to produce bone erosion are the primary responsible lesions in adult-onset spontaneous CSF otorrhea.     

Frontobasal fractures in children

In 1987, four children between 5 and 13 years of age with severe frontobasal trauma and dural tears were treated operatively. A CSF rhinorrhea was manifest clinically in only two cases. In addition high-resolution computerised tomography was essential in diagnosis and planning of the operation. In each of the cases an intracranial pneumatocele indicating dural laceration was shown. The fractures were confirmed during surgery in: Case 1. The roof of the ethmoid sinus and the roof of the orbit. Case 2. Both the sphenoid sinuses. Case 3. The roof of the ethmoid sinus and the posterior wall of the frontal sinus. Case 4. The roof of the ethmoidal sinus and the posterior wall of the frontal sinus. The ontogenetically oldest part of the paranasal sinuses in the floor of the anterior cranial fossa forming the anterior part of the roof of the ethmoid bone is the site of predilection for fractures, even in children. The anterior cranial fossa was exposed in each case through a paranasal subfrontal access, in the first case combined with a frontal craniotomy by a neurosurgeon, because of the fracture of the roof of the orbit. In the second case the dural injury had to be closed at a second neurosurgical operation, because of a recurrence of the CSF leak. The third and fourth cases were treated by nasal surgery alone.     

Management of cerebrospinal fluid rhinorrhea: the Medical College of Wisconsin experience

INTRODUCTION: The management of cerebrospinal fluid (CSF) rhinorrhea has evolved in recent years. The purpose of this comprehensive retrospective study is to assess issues related to the management of skull base defects associated with CSF rhinorrhea involving the nose and paranasal sinuses. METHODS: A retrospective review of CSF leak management was conducted. This study included patients with CSF rhinorrhea managed by the Department of Otolaryngology, Medical College of Wisconsin, Milwaukee, WI, from 1992 to 2002. Data collected included site of leak, surgical approach, and any recurrence of leak. RESULTS: Fifty-seven CSF leaks occurred in 53 patients with CSF rhinorrhea originating from the nose or paranasal sinuses. Twenty-eight of the 53 had iatrogenic injuries resulting in CSF rhinorrhea, 16 had leaks from trauma, and 13 developed spontaneous CSF leaks. Ten patients responded to nonoperative management with bed rest with or without lumbar drain placement. Forty-three patients with 47 leaks underwent surgical repair of CSF rhinorrhea, of which 38 resolved after initial repair. Five of these patients developed recurrent CSF leaks at the repair site but resolved with subsequent surgery. Of these, two initially presented with spontaneous CSF leaks, one patient had a gunshot wound with massive skull base injury, and two recurred after repair of an iatrogenic injury. Factors associated with failure included lateral sphenoid leaks and elevated body mass index (BMI). DISCUSSION: Multiple approaches to the management of CSF rhinorrhea can be successful. An endoscopic repair results in resolution of CSF rhinorrhea in the majority of cases. Patients with spontaneous CSF rhinorrhea, elevated BMI, lateral sphenoid leaks, and extensive skull base defects are at increased risk for recurrence. Alternative management options may need to be considered in these cases.     

Localization and infliction pattern of iatrogenic skull base defects following endoscopic sinus surgery at a teaching hospital

Objective

Aim of this study is to evaluate the incidence, infliction patterns and management of dural injuries with cerebrospinal fluid (CSF) rhinorrhea following endoscopic sinus surgery at a teaching hospital. We present our results of over 14 years of experience from endoscopic repair of CSF rhinorrhea with long-term follow-up.

Methods

A retrospective study was performed by screening 14 years of sinus surgeries for iatrogenically inflicted CSF leaks of the anterior skull base. Obtained data were analyzed to determine the infliction pattern and location of CSF leaks, surgical closure techniques and outcomes. All incidences were further evaluated with regards to the surgeons training status.

Results

144 patients out of 6908 sinus surgeries were diagnosed with CSF rhinorrhea and underwent subsequent surgical repair. 52 patients had iatrogenic CSF leaks with 32 of the defects inflicted by the department's physician personnel. Average follow-up was 62 months, with a range of 10–168 months. The side distribution was 56.3% to the patient's right side and in 40.6% to the patient's left side. 68.7% became apparent during the initial surgery whereas 31.3% only after surgery. The most common defect location was the anterior ethmoid at the attachment of the medial concha base with 43.7%, followed by the junction between the ethmoid and sphenoid sinus with 21.9%, the frontal sinus aditus with 18.7% and the medial ethmoid region with 9.4%. With increasing training status, surgeons were more prone to cause defects at the frontal sinus aditus whereas surgeons with lesser training status caused more defects at the anterior ethmoid at the medial concha base. The posterior ethmoid and sphenoid sinus was equally prone to defects over all stages of surgical training. Initial endoscopic repair was successful in 87.5% of patients and 95% after revision surgery.

Conclusion

The obtained data confirm the safety of the endonasal sinus surgery according to Wigand's technique. The incidence of iatrogenic CSF leaks at a teaching hospital is not higher than at specialized rhinology departments. We observed a distinct pattern of inflicted skull base defects with different hot-spot areas, prone to damage in various stages of the surgeon's status of expertise.     

Current Management of Cerebrospinal Fluid Rhinorrhea

Forty-two patients with cerebrospinal fluid (CSF) rhinorrhea presenting over a 5 year period were analyzed as.to age, sex, etiology, anatomical and clinical findings, and methods of investigation and treatment. Eighty-eight were traumatic in origin, with the most common anatomical sites being ethmoid, frontal and sphenoid sinuses, and the cribriform plate region. Meningitis and pneumocephalus were the most frequently associated clinical findings each present in 31% of the cases. Chemical analysis of the CSF for protein was positive in 88% of cases vs. 13% when the protein content was quantitatively analyzed. The demonstration and localization of CSF leaks were most effective using metrizamide and CAT scanning when they were active and by indium cisternography when they were small, intermittent, or questionable. The clinical management was divided into medical and surgical approaches with the advantages and disadvantages discussed.     

Evaluation and management of temporal bone arachnoid granulations.

The diagnosis and evaluation of temporal bone arachnoid granulations (AGs) is based on characteristic bone defects in the posterior or middle fossa surfaces of the temporal bone in adult patients with persistent serous otitis media or septic meningitis following acute otitis media. The cerebrospinal communication caused by AGs should be repaired by a middle fossa craniotomy (middle fossa AGs) or an intact canal wall mastoidectomy (posterior fossa AGs) to preserve normal sound transmission. In adult patients with chronic mastoiditis, the dural defect of an AG may permit intracranial extension of the chronic inflammatory process. This rare extension of disease should be considered in patients who have chronic ear inflammation and severe pain or signs of intracranial disease.     

Spontaneous CSF otorrhea from tegmen and posterior fossa defects

Spontaneous cerebrospinal otorrhea (SCSFO) from tegmen or posterior fossa defects is uncommon. Twenty-nine cases have been detailed in the literature to date. We report an additional four cases from three patients. This group of 33 cases of SCSFO from tegmen or posterior fossa defects is characterized by certain clinical features. These patients are usually older adults (mean age 48 years, range 8 months to 80 years). Aural fullness with a serous appearing middle ear effusion, or clear otorrhea, often subsequent to tube myringotomy, are the usual initial symptoms. Meningitis was the initial manifestation in eight patients (24%), and ultimately occurred in an additional four patients (12%). The pathophysiologic basis for SCSFO from tegmen defects is discussed. Methods for diagnosing and treating CSF otorrhea from tegmen defects are reviewed.     

颅脑外伤后顽固性脑脊液耳漏的手术策略和技巧研究

目的 探讨颅脑外伤后顽固性脑脊液耳漏手术治疗的技巧和策略.方法 采用颞下中颅底-乳突后联合入路,对11例颅脑外伤后中颅窝底缺损所致脑脊液耳漏且保守治疗无效的患者施行手术修补.结果 ①无需行乳突探查5例.因乳突为粉碎性骨折,在取下骨瓣前先行钛板固定2例.另外4例乳突粉碎骨折严重,术中将事先收集的颅骨碎屑回植到乳突缺损内,取头最长肌加生物胶加固;②术中发现有颅底广泛骨质缺损6例,脑组织疝入缺损中或乳突黏膜暴露广泛;③修补探查过程发现听骨链完整者3例,缺失2例,部分听小骨(锤骨)缺失2例,术中未探查听骨链者4例.术后随访2~11年,无复发.结论 ①当合并复杂性骨折时,通过幕上幕下联合,经颞下中颅底-乳突后联合入路,无疑是明智的选择,尤其是不稳定骨折累及乳突的患者;②对颅底骨折复杂而听力完全丧失的脑脊液耳漏患者,除了封闭外耳道外,尚需进行鼓室及咽鼓管填塞封闭,以防止假鼻漏的情况发生;③颈内动脉岩段与鼓室及咽鼓管关系密切,脑脊液耳漏修补手术中应避免手术误伤或骨折片意外伤及颈内动脉.     

Sphenoid sinus mucoceles

Mucoceles of the sphenoid or posterior ethmoid sinuses usually behave in a similar manner. Because of the thinness of surrounding bone and the proximity of vital structures, these lesions can expand aggressively at a clinically alarming rate. Presenting symptoms vary but characteristically include headache and ocular disturbance. Careful radiologic evaluation helps in the correct assessment of these lesions. The authors feel that the rhinologic approach to the sphenoid cavity, via an external ethmoidotomy, affords the best visualization possible of the diseased area without entailing possibly serious central nervous system complications. Six cases are discussed from the standpoint of presenting signs and symptoms, radiologic assessment, therapy and outcome.     

Cranial bone grafts in cerebrospinal fluid leak and encephalocele repair: a preliminary report

BACKGROUND: With the introduction and subsequent widespread acceptance of endoscopic surgery, otolaryngologists are increasingly being called on to care for patients with cerebrospinal fluid rhinorrhea and meningoencephaloceles. Patients with large encephaloceles and skull base defects present a special challenge. We present our experience with cranial bone grafts in treating this important entity. METHODS: Our clinical experience was reviewed from 1998 to 2001. Review parameters included defect size, cranial bone graft harvest site and size, and graft appearance on postoperative follow-up. RESULTS: Results revealed that 20 patients underwent defect repair with cranial bone graft. The average defect was approximately 0.92 x 0.7 cm; nine defects were located in the ethmoid roof, eight defects were in the sphenoid, and three defects were in the posterior table of the frontal sinus. Donor sites included 2 parietal, 3 frontal, and 15 temporal (mastoid). Grafts healed well and all defects remained closed on endoscopic and computerized tomographic follow-up. All donor sites healed well. CONCLUSION: Our experience indicates that cranial bone graft is an excellent material for endoscopic reconstruction of skull base defects. It confers special advantages in large defects, in defects with complex three-dimensional characteristics, and in patients with cerebrospinal fluid leaks associated with an elevated intracranial pressure.     

Exploration of endonasal endoscopic repair of pediatric cerebrospinal fluid rhinorrhea

Objectives

To summarize the clinical manifestations of pediatric cerebrospinal fluid rhinorrhea (CSFR), discuss the localization of CSFR, and the surgical approaches, the graft material selection and the prognoses of endoscopic repair of CSFR.

Methods

The case data, surgical techniques and graft materials of endonasal endoscopic approach of 43 patients with CSFR who have been treated at the Second Xiangya Hospital, Central South University in the last 13 years were retrospectively analyzed. Among them, leaks in 34 cases were from the roof of the ethmoid sinuses. Other sites included frontal sinus (1), sphenoid sinus (6), and the conjunction of ethmoid and frontal sinuses (2). 37 patients were with unilateral CSF leaks, 6 were with bilateral CSF leaks. The dimensions of the defects ranged between 8 and 22 mm. For 25 cases, the procedure was as follows: first, the wound surrounding the perimeter of the defect was freshened and the leaks were plugged by myoplasm and overlaid with iliac fascia, and followed by the use of fibrin glue and nasal packing; for 5 cases, the procedure was as follows: at first, the wound was curetted and the leaks were intracranially plugged by autologous cartilage and muscle, overlaid with iliac fascia, followed by the use of fibrin glue and nasal packing; for 6 cases, the leaks were overlaid with iliac fascia only, and then fibrin and packing were used. For the rest of 7 cases, the frontal and sphenoid sinuses were filled with muscle.

Results

Of the total 43 cases, 31 had successful closure of the leaks by endonasal endoscopic repair on first attempt; 8 had successful closure of the leaks on second attempt, 3 was cured on third attempt; while, leaks in 2 patients failed to close after three attempts. Therefore, they underwent combined intracranial and transnasal endoscopic repair, one patient was cured and another one died postoperatively because of recurrent intracranial infection. At 12 month to 24 month follow-up 42 children remained leak free.

Conclusion

Endoscopic repair of CSF leaks is the optimum approach to the treatment of pediatric CSFR, featuring minor trauma, high successful rate, fewer complications and advantage of being able to carry out a revision surgery or more if needed. For children who have a large CSF leak in size and have failed to be treated successfully via endonasal endoscopic repair, combined intracranial and endoscopic repair could be performed to close the leak.     

Endonasal endoscopic repair of cerebrospinal fluid leaks of the sphenoid sinus

BACKGROUND: Multiple reports have demonstrated the efficacy of the transnasal endoscopic repair of cerebrospinal fluid (CSF) leaks of the anterior cranial base. The literature, however, lacks a comprehensive clinical study specifically addressing the transnasal endoscopic repair of CSF leaks of the sphenoid sinus. OBJECTIVE: To ascertain the factors that significantly affect the surgical outcome after transnasal endoscopic repair of CSF leaks of the sphenoid sinus. METHODS: We retrospectively reviewed the medical records of all patients who underwent an endoscopic transnasal repair of CSF leaks of the sphenoid sinus at our teaching hospitals. RESULTS: Twenty-four patients with CSF leaks of the sphenoid sinuses that were repaired by the transnasal endoscopic approach were included in our study. Causes of the CSF leaks included trauma, surgery, neoplasms, and idiopathic causes. Obliteration was the most common technique used to repair the CSF fistulas (used in 15 [58%] of 26 procedures). Grafting materials included banked pericardium, mucosa, turbinate bone, and mucoperichondrium placed by underlay or onlay grafting or abdominal fat used to obliterate the sphenoid sinus. Twenty-two patients were successfully treated on the first attempt. A persistent leak in 2 patients with previously unrecognized high-pressure hydrocephalus was repaired during a second endoscopic surgery, quickly followed by ventriculoperitoneal shunting. CONCLUSIONS: Assuming an adequate repair, other factors such as the cause, the size of the defect, the technique and material used to repair the defect, and perioperative management do not affect the surgical outcome significantly. Untreated high-pressure hydrocephalus can lead to a recurrence or persistence of the leaks and should be suspected in patients with posttraumatic, idiopathic, or recurrent CSF leaks.     

Complications of hydroxyapatite use for transnasal closure of cerebrospinal fluid leaks

BACKGROUND: Hydroxyapatite cement (HAC) was first introduced in the 1980s as a new method for bone replacement. However, it has not been recommended for use in areas exposed to air. Despite this, surgeries have been performed using HAC to close nasal/sinus cerebrospinal fluid (CSF) leaks or in the treatment of encephaloceles. METHODS: This study retrospectively documented four patients in whom HAC was used for closure of ethmoid and sphenoid sinus CSF leaks. RESULTS: This study showed that exposed hydroxyapatite could be extremely problematic resulting in scarring, chronic granulation, infection, and prolonged healing. Oftentimes, revision surgery was necessary to help control the reaction to hydroxyapatite. CONCLUSION: Because of the frequent complications occurring with use of hydroxyapatite in the paranasal sinuses, its use should be limited to selected individuals in whom difficulty in achieving closure of the CFS leak could be anticipated and in whom adequate tissue coverage could be provided.     

Endoscopic management of sphenoid sinus cerebrospinal fluid leaks

OBJECTIVES: Cerebrospinal fluid (CSF) leaks that originate within the sphenoid sinus pose a unique surgical challenge due to difficulties with access and visualization The objective of this report is to illustrate concepts for the successful management of sphenoid sinus CSF leaks. METHODS: Retrospective data analysis was performed on 9 patients who presented to a tertiary care medical center for endoscopic repair of a sphenoid sinus CSF leak from January 2002 to January 2006. RESULTS: The patient cohort included 7 women and 2 men with a mean age of 51.7 years. In 5 cases the CSF leak was caused by a previous neurosurgical procedure; the other 4 cases were idiopathic. An endoscopic pterygomaxillary fossa approach was required in 4 cases. A layered reconstruction of the sphenoid sinus wall with collagen allografts (cadaveric acellular dermal allograft, 8 patients; bovine collagen membrane, 1 patient) and mucosa under endoscopic visualization with intraoperative surgical navigation was performed in all cases. The reconstruction was buttressed with autologous bone in 2 cases and with cartilage in 2 cases. Fibrin sealant was used in 7 cases. Two patients developed transient diabetes insipidus after the repair. Two patients developed a recurrent CSF leak necessitating revision repair 2 and 15 months, respectively, after the initial repair procedure. The average hospital stay was 6.5 days. The mean length of follow-up was 21.1 months. CONCLUSIONS: This series demonstrates that minimally invasive endoscopic repair of sphenoid sinus CSF leaks may be accomplished with an acceptable rate of morbidity and excellent outcomes. Extended endoscopic approaches, including the pterygomaxillary fossa approach, may be useful in selected instances.     

Endoscopic repair of traumatic CSF rhinorrhea in a pediatric patient

Cerebrospinal fluid (CSF) rhinorrhea typically results from trauma to the skull base, producing leaks through either the cribiform plate region or the sphenoid bone. Traditional approaches to the repair of such leaks include a frontal craniotomy or external ethmoidectomy. An endoscopic approach through the nose has also proven to be successful. A 7-year-old male suffered traumatic CSF rhinorrhea and development of a meningocele in the region of the cribiform plate. After demonstrating the site of the leak with fluorescein dye, the defect was repaired via a transnasal endoscopic approach. The evaluation of the child with CSF rhinorrhea, including the presenting symptoms and signs and the radiographic assessment, is presented. The variety of approaches, types of repair and post-operative care are also discussed.     

Surgical policy in patients with basally advanced form of juvenile nasopharyngeal angiofibroma

The authors has modified surgical policy in a basicranially extending form of juvenile nasopharyngeal angiofibroma (JNA) which is classified into tumors of stage I, II and III. Basally advanced tumors were diagnosed in 28 of 40 JNA patients: basicranially extended tumor (n=12, 30%), stage I tumor invading nasopharynx, nasal cavity, sphenoid sinus (n=4, 14.3%), stage II tumor invading nasopharynx, nasal cavity, sphenoid sinus, pterygopalatine fossa, ethmoid sinuses (n=9, 32.1%), stage III tumor invading nasopharynx, nasal cavity, sphenoid sinus, pterygopalatine fossa, ethmoid sinuses, infratemporal fossa, orbit, maxillary sinus and parapharyngeal space (n=15, 53.6%). Differential surgical treatment according to Owens (stage I tumors), Denker (stage II tumors), Moure (stage III tumors) provides radical removal of the tumor in the majority of the patients (87.7%) and therefore is an effective therapy of surgical treatment of the above patients.     

Cerebrospinal fluid leaks of temporal bone origin: etiology and management

BACKGROUND: Cerebrospinal fluid (CSF) leaks of the temporal bone region require surgical treatment as they pose life-threatening risks such as meningitis. AIM: The aim of the study was to determine the surgical outcome depending on different operation techniques and grafts. METHOD: We performed a retrospective review of 28 cases of CSF leaks, operated in our department from 1983 to 2002. After a mean follow-up of 8 years, patients were interviewed concerning otorrhea or rhinorrhea and meningitis. In this context, our management of CSF leaks is presented. RESULTS: The CSF leak had arisen spontaneously (n = 3), traumatically (n = 6) or postoperatively (n = 19). The surgical CSF leak repairs were performed via a transmastoid (n = 13), a middle fossa (n = 11) or a combined (n = 4) approach. Surgical outcome was independent on the used graft. CSF leak could be sealed in 25 of 28 cases. Only 3 patients suffered from recurrences. Meningitis or other complications did not occur. CONCLUSIONS: Comparing different techniques and grafts, there were no differences in the surgical outcome.     

Management of Spontaneous Cerebrospinal Fluid Otorrhea

Objectives/Hypothesis: To describe the surgical approaches and materials used to repair spontaneous cerebrospinal fluid (CSF) otorrhea of temporal bone origin. Study Design: Retrospective case review at a tertiary academic medical center. Methods: All patients presenting with spontaneous CSF otorrhea or rhinorrhea over a consecutive 8‐year period were included. Clinic charts and operative reports were reviewed to obtain the clinical presentation, examination findings, diagnostic test results, intraoperative findings, operative technique, and postoperative follow‐up. Surgical approach and materials used for repair were determined by the location of the defect(s) and surgeon preference. Results: Seventeen patients underwent 19 operations for repair of spontaneous CSF otorrhea or rhinorrhea. The mean age was 61 years and the male to female ratio was 5:12. All female patients had a body mass index (BMI) greater than 30 mg/kg². The most common presenting symptom was otorrhea after a myringotomy or placement of a tympanostomy tube. A middle fossa craniotomy was used in 17 approaches. The most common defect sites were located over the tegmen mastoideum and tegmen tympani. Multiple materials were used in most repairs including allogenic bone cement and autologous materials. One patient had persistent otorrhea after a transmastoid approach and required a middle fossa craniotomy to repair a tegmen mastoideum defect. Conclusions: Spontaneous CSF otorrhea is uncommon and often not diagnosed until a myringotomy or tympanostomy tube is placed. The middle fossa craniotomy provides the best exposure for defects involving the middle fossa floor. Both alloplastic and autologous materials are highly successful in repairing the defect(s) responsible for CSF otorrhea. No infections of the alloplastic bone cement occurred in our series.     

Sphenoethmoid cerebrospinal fluid leak repair with hydroxyapatite cement

Despite advances in neurological, reconstructive, and endoscopic sinus surgery, sphenoethmoid cerebrospinal fluid (CSF) fistulae continually pose difficult management problems. Standard surgical techniques for fistulae closure succeed approximately 78% to 90% of the time. To improve this success rate, hydroxyapatite cement (HAC), a Food and Drug Administration-approved substance for cranial defect repair, was applied to this problem in a clinical setting. Twenty-one patients with spontaneous, posttraumatic, or postoperative CSF leaks of the sphenoid sinus, cribriform plate, or ethmoid region were treated with HAC. Study participants were prospectively accrued at 5 tertiary care medical centers in the eastern United States. The CSF leaks of all 21 patients treated with HAC were successfully sealed by its initial application. The sites of CSF leakage included the nasal cavity (n = 2) and sphenoid sinus (n = 19). Fifteen of the patients had previously undergone a failed repair by standard methods. There have been no recurrent CSF leaks with a maximum follow-up of 72 months, and an average follow-up of 36 months. All patients have survived to date. The only HAC-related morbidity was the extrusion of the HAC when placed in the nasal cavity. Hydroxyapatite cement is an effective method of repair for postoperative, posttraumatic, and spontaneous sphenoid CSF leaks. The efficacy of HAC in sealing the CSF leak was unaffected by previous attempts at leak closure by standard methods or by its origin. Hydroxyapatite cement should not be applied transnasally for the treatment of an ethmoid region fistula owing to its high probability of extrusion. Correct patient selection and technical familiarity with HAC are necessary for successful application.