Surgical Management of Sphenoid Sinus Lateral Recess Cerebrospinal Fluid Leaks: A Single Neurosurgical Center Analysis of Endoscopic Endonasal Minimal Transpterygoid Approach

Sternberg’s canal: a rare site of CSF leak—our experience and management of a series of cases at a tertiary care hospital in South India

Background

The lateral craniopharyngeal canal or Sternberg’s canal is located in the postero-lateral part of the sphenoid sinus. It is the weakest area of the skull base, originating due to defective fusion during embryological development in a small proportion of individuals. Hence, it can give rise to CSF leaks from that region. Due to the proximity of this region to the internal carotid artery, optic nerve, and cavernous sinus, it proves to be challenging to repair these defects. The exact location, role in the causation of CSF leaks, and clinical presentation with arachnoid herniation are also subject to much controversy.

Results

In our case series, we describe 7 patients with the rare clinical entity of CSF leak from the Sternberg’s canal, who had a mean age of 38.4 years, 4 of whom also had an arachnoid herniation through the canal. One patient already underwent prior endoscopic surgery for the CSF leak. We highlight a trans-nasal trans-sphenoid approach with multi-layer closure, i.e., fat plug, fascia, and a naso-septal flap with the use of an additional layer of muscle in one of the cases, following which all had good outcomes. Since the primary concern with this rare clinical scenario is correct identification and adequate exposure of the leak for repair, we additionally undertook a trans-pterygoid approach in 2 of our patients.

Conclusions

The key to the successful repair of the Sternberg’s canal leak lies in its accurate identification and exposure. In our series, we achieved good exposure by drilling the pterygoids and lateral sphenoid walls along with the use of angled endoscopes for visualization. Our case series highlights the linear relation of elevated BMI with spontaneous CSF leaks in the absence of benign intracranial hypertension and the reinforcement of repair with the use of a harvested naso-septal flap. Our multi-layered closure ensured good results and no recurrence of a leak in any of our patients.

Endonasal Exposure of Lateral Recess of the Sphenoid Sinus: Significance of Pterygoid Process Pneumatization

Background

Caudal pneumatization of the pterygoid process may impact endonasal exposure of the lateral recess of sphenoid sinus (LRSS).

Objectives

This study aims to explore the implications of a pneumatized pterygoid process for an endonasal transpterygoid approach to the LRSS and to define strategies regarding the preservation or sacrifice of the vidian nerve.

Methods

Dissection of the LRSS (11 sides) was performed on 6 cadaveric specimens, preselected for the radiographic presence of an LRSS. In addition, the dimensions of the LRSS were measured on the deidentified CT images of 120 patients (240 sides). The sphenoid sinus was subdivided into 3 categories: Type 1 (no identifiable LRSS), Type 2 (lateral pneumatization of the greater wing above the vidian canal), and Type 3 (pneumatization of both the greater wing and the pterygoid process).

Results

On the cadaveric specimens, a Type 2 pneumatization often allowed access to the LRSS above the level of the vidian canal; thus, sparing the vidian neurovascular bundle. In Type 3 pneumatization, a frontal corridor through the pterygoid base could be created to reach the LRSS with preservation of the vidian nerve. Extreme Type 3 pneumatization, however, required the transposition or sacrifice of the vidian nerve to facilitate a full direct access to the superolateral LRSS. Measurements on CT images revealed that the extent of caudal pneumatization of the pterygoid process had no statistically significant correlation with the superolateral extension of the lateral recess in patients with Type 3 LRSS ( P > .05).

Conclusion

Pneumatization of the LRSS toward a caudal or superolateral direction may develop independent from each other. Caudal pneumatization of the pterygoid process seems to variably impact the endonasal exposure of the LRSS.

Comparison of two surgical approaches in the management of cerebrospinal fluid rhinorrhea in the lateral recess of sphenoid sinus: A retrospective study

BACKGROUND

Cerebrospinal fluid (CSF) leakage from the lateral recess of the sphenoid sinus (LRSS) is usually repaired using endoscopic endonasal approaches, which can be challenging. Various surgical techniques have been developed for the disease.

OBJECTIVE

To report our experience with repairing CSF leak from the LRSS via transethmoid sphenoidotomy approach (TESA) and transprelacrimal recess pterygoid root approach (TPLRA), to assess the efficiency of TPLRA by comparing it with TESA.

METHODS

This retrospective study included patients with LRSS CSF rhinorrhea who underwent TESA (n = 10) or TPLRA (n = 5) from January 2011 to December 2020. Demographic characteristics and operation-related parameters were recorded.

RESULTS

The mean operation time was 169.5 and 225.0 mins in the TESA and TPLRA groups, respectively, with a mean blood loss of 65 mL and 68 mL, respectively. Histopathological examinations confirmed encephalocele in 11 (73.33%) and 4 (26.67%) cases with meningocele, respectively. CSF rhinorrhea was successfully repaired in the first attempt in both groups during the mean follow-up time of 54 months. Postoperative permanent numbness of the cheek was observed in two patients in the TESA group. No cases of lacrimal overflow or subjective dry eye were observed.

CONCLUSIONS

The TPLRA, which could be an alternative procedure to treat CSF rhinorrhea in the LRSS, provides a straight-line trajectory and effective maneuverability. We also found that CSF rhinorrhea in the LRSS was accompanied by encephalocele or meningocele, with encephalocele presenting more commonly.

Endoscopic Repair of Spontaneous Cerebrospinal Fluid Leaks in the Lateral Recess of the Sphenoid Sinus

OBJECTIVE

This study aimed to assess the effectiveness of 3 endoscopic endonasal approaches for the management of cerebrospinal fluid (CSF) leaks and meningoencephaloceles in the lateral recess of the sphenoid sinus (LRSS).

STUDY DESIGN

Retrospective study.

SETTING

University hospital.

METHODS

This study retrospectively reviewed 49 patients with CSF leaks and meningoencephaloceles in the LRSS. Three endoscopic surgical repair approaches were indicated based on 5 different Rhoton's types of the LRSS. The postoperative symptoms, complications, and follow-up outcomes were investigated and evaluated.

RESULTS

The success rate of endoscopic surgical repair was 100% at a median follow-up of 75.06 (12-203.4) months. Endoscopic approaches to the LRSS included the prelacrimal recess (PLR) (18.37%), transsphenoidal (18.37%), and transpterygoid approaches (64.26%). All patients in the PLR approach (PLRA) group and most of the patients in the transpterygoid approach group had a full lateral type LRSS. Hypoesthesia and dry eyes were reported in 5 patients (55.56%) and 1 (11.12%) patient, respectively, from the PLRA group and in 6 (19.35%) and 5 (16.12%) patients, respectively, from the transpterygoid approach group.

CONCLUSIONS

Endoscopic closure is a safe and effective method for the treatment of CSF leaks and meningoencephaloceles in the LRSS. The transpterygoid approach and PLRA offer adequate exposure of the LRSS with extensive lateral pneumatization or a full LRSS. The endoscopic route of the PLRA is more direct than that of the transpterygoid approach. Careful preoperative imaging evaluation is crucial while selecting the optimal surgical approach for the repair of a skull base defect.

Cerebrospinal Fluid Leaks After Anterior Skull Base Trauma: A Systematic Review of the Literature

BACKGROUND

Anterior skull base (ASB) fractures are reported in 4% of head injuries and represent 21% of all skull fractures. Cerebrospinal fluid (CSF) leaks may follow, severely exacerbating outcomes. We systematically reviewed the literature to analyze and compare the roles of endoscopic surgery, open surgery, and combined approaches in the management of CSF leak repair after posttraumatic ASB fractures.

METHODS

PubMed, Web of Science, and Scopus databases were searched in accordance with the PRISMA guidelines. Studies reporting clinical data of patients with CSF leaks after ASB fracture were reviewed, focusing on management strategies and posttreatment outcomes.

RESULTS

We included 29 articles comprising 888 patients. The average age at diagnosis was 34 years (range, 18-91 years), with a male predominance (54%) and a male/female ratio of 2.9:1 (647:241). Clinical data were available for 888 patients with CSF leaks after ASB fracture, reporting a median follow-up time of 33.5 months (standard deviation, ±29; range, 0.5-330.0 months). Open surgical repair was the most common approach (67.9%), followed by endoscopic surgical repair (32.1%). The endoscopy cohort showed lower rates of complications (0.7% vs. 11.1%) and fistula recurrence (2.8% vs. 5.3%) compared with open surgery.

CONCLUSIONS

ASB fractures are frequently treated as late surgery, 24 hours from injury or later, especially for endoscopic surgery. Overall, the endoscopic approach is preferred, mostly because of its safety and effectiveness, offering lower failure rates than does open surgery.

T2-weighted magnetic resonance imaging as a novel predictor of surgical remission in newly diagnosed pituitary macroadenomas presenting as acromegaly

BACKGROUND

Any preoperative diagnostic assessment that can predict the success of the operation in acromegaly will provide a positive impact on overall remission rates. The aim of this study is to reveal whether the signal intensity in T2-weighted Magnetic Resonance Imaging can predict postoperative results in acromegaly patients with macroadenoma.

METHODS

We analyzed our surgical results in regard to T2-weighted images in newly diagnosed consecutive 124 patients with acromegaly, operated between 2014 and 2019. The T2-intensity of the pure somatotroph macroadenomas was correlated with the clinical, radiological, surgical and histopathological characteristics of the acromegaly patients.

RESULTS

We found a predominance of T2-hyperintensity in our series (45%) and the T2-hypointense pure somatotroph adenomas were detected in only 34% of our patients. Total resection was performed in 72% of newly diagnosed acromegaly patients in this series. Accordingly, total resection was achieved in 69% of the T2-hyperintense group, 77% of the T2-hypointense group and 69% of the T2-isointense group. The surgical remission rates for the T2-hyper-, hypo- and isointense groups were 54.5%, 80.7%, and 68.7%, respectively. The surgical remission rate in the T2-hyperintense group was significantly lower than those of hypo- and isointense groups in newly diagnosed acromegaly patients.

CONCLUSIONS

This study demonstrates a close relationship between the T2 signal intensity and the surgical remission rates in acromegaly patients with macroadenoma. Preoperative T2-intensity images may predict the probability of post-surgical remission in patients with newly diagnosed acromegaly. Further support fort this idea comes from recent guidelines for acromegaly management in which the potential utility of using T2 intensity to optimize patient management has been emphasized.

Modified Transpterygoid Approach to Sphenoid Meningoencephaloceles: A Shorter Run for a Longer Slide

OBJECTIVES

Cerebrospinal fluid (CSF) leaks and meningoencephaloceles originating in the lateral recess of the sphenoid sinus can be challenging. The traditional transpterygoid approach through the pterygopalatine fossa (PPF) is time consuming and places important structures at risk, which can lead to significant morbidity. We report a multi-institutional experience using a simplified, endoscopic modified transpterygoid approach (MTPA), which spares the PPF contents in the management of lateral sphenoid sinus meningoencephaloceles and CSF leaks.

STUDY DESIGN

Multi-Institutional, Retrospective Case Series.

METHODS

Patients with lateral sphenoid recess CSF leaks and meningoencephaloceles between 2014 and 2020 who underwent the MTPA at two academic medical centers were identified. Repair techniques and outcomes were evaluated.

RESULTS

Thirty-three patients underwent the MTPA for management. Skull base reconstruction was performed using a free mucosal graft (24/33, 72.7%), nasoseptal flap (4/33, 12.1%), bone grafts (3/33, 9.1%), and abdominal fat grafts (2/33, 6.1%). Lumbar drains and perioperative intracranial pressure measurements were routinely employed. Postoperative complications were uncommon and included three patients (9.7%) with temporary V2 anesthesia, one patient (3.2%) with prolonged V2 anesthesia, and one patient (3.2%) with subjective dry eye, all of which resolved at 9 months postoperatively. There were no recurrent CSF leaks resulting in a 100% success rate. Average follow-up was 13 months.

CONCLUSION

The MTPA reduces morbidity and greatly simplifies access to the lateral sphenoid sinus for the management of CSF leaks and meningoencephaloceles, without compromising exposure. This technique avoids the need for extensive PPF dissection and should be considered for the management of benign lesions involving the lateral sphenoid sinus.

LEVEL OF EVIDENCE

IV Laryngoscope, 2021.

Plasma Ablation-Assisted Endoscopic Endonasal Transpterygoid Approach to Sphenoid Lateral Recess Cerebrospinal Fluid Leaks: Technique and Outcome

BACKGROUND

Management of sphenoid lateral recess (SLR) cerebrospinal fluid (CSF) leaks present a challenge because of the location and requiring complete visualization of the defect for a successful repair. The endoscopic endonasal transpterygoid approach (EETPA) is considered the gold standard in addressing these defects. We lay out our experience in implementing this approach with plasma ablation.

METHODS

This is a case series of 11 diagnosed patients of SLR CSF leaks who underwent plasma ablation-assisted EETPA repair by a single surgeon between 2011 and 2020 at our institution. Outcomes in terms of surgical field grade on the Wormald 11-point grading scale, postoperative complications, healing on nasal endoscopy and imaging, and surgical success rate were assessed.

RESULTS

The etiology was spontaneous leak in 10 (90.9%) patients and secondary to temporal lobe abscess and/or meningitis in one (9.09%). Three (27%) patients were previously operated elsewhere by the transsphenoidal route, which we reoperated by this technique. As per Wormald grading, grade 1 field in 3 (27.27%), grade 2 in 6 (54.5%), and grade 3 in 2 cases (18.18%) were noted. Complications occurred in 3 patients (27%) in the form of dry eye (9%), meningitis (9%), and transient CSF rhinorrhea in the immediate postoperative period (9%). Repair sites were well healed on follow-up nasal endoscopy and imaging. The surgical success rate was 100%.

CONCLUSIONS

Plasma ablation-assisted EETPA allows for a uninostril approach to the SLR, easy accessibility, and better visualization with a bloodless field, which allows appropriate repair, thus minimizing complications and preventing recurrence.

Management of Cerebrospinal Fluid Rhinorrhea in the Sphenoid Sinus Lateral Recess Through an Endoscopic Endonasal Transpterygoid Approach With Obliteration of the Lateral Recess

BACKGROUND

Cerebrospinal fluid rhinorrhea in the sphenoid sinus lateral recess is a rare occurrence and poses unique challenges due to limited surgical access for surgical repair.

OBJECTIVE

To report our experience of surgical repair of cerebrospinal fluid rhinorrhea in the sphenoid sinus lateral recess through an endoscopic endonasal transpterygoid approach with obliteration of the lateral recess. To evaluate the efficiency of this surgical procedure.

METHODS

A retrospective study. Twelve cases with cerebrospinal fluid rhinorrhea in the sphenoid sinus lateral recess were reviewed. Assisted by image-guided navigation, cerebrospinal fluid rhinorrhea was repaired through an endoscopic endonasal transpterygoid approach, with obliteration of the lateral recess. Complications and recurrence were recorded. Medical photographs were used.

RESULTS

This surgical approach provided a relatively spacious corridor to dissect the sphenoid sinus lateral recess and do postoperative surveillance. The repair area completely healed in 3 months after surgery. Cerebrospinal fluid rhinorrhea in the sphenoid sinus lateral recess was successfully repaired on the first attempt in all cases (100%). No main complications or recurrence was observed during a mean follow-up time of 40.3 months.

CONCLUSION

The endoscopic endonasal transpterygoid approach gives appropriate access for the treatment of spontaneous cerebrospinal fluid rhinorrhea in the sphenoid sinus lateral recess. Multilayer reconstruction of a skull base defect with obliteration of the lateral recess is a reliable and simple method.

Minimally Invasive Lateral Paraorbital Approach for Repairing Lateral Recess of the Sphenoid Sinus Spinal Fluid Leak

BACKGROUND

Cerebrospinal fluid (CSF) leaks in the lateral recess of the sphenoid sinus (LRSS) are typically spontaneous in nature and require surgical repair. Endoscopic endonasal approaches have become the mainstay of CSF leak repair in the LRSS, though they remain technically challenging and place the vidian nerve (VN) and sphenopalatine artery (SPA) at risk. Here we present a lateral paraorbital approach (LPOA) as a minimally invasive transcranial VN and SPA sparing alternative for LRSS CSF leak repairs.

CASE DESCRIPTION

A 41-year-old African American woman presented with headaches and was found to have a spontaneous CSF leak in the LRSS. A LPOA was used to repair the CSF leak. An incision was made along the frontal process of zygoma (FPZ). Removal of the overhanging portion of the FPZ while sparing the lateral orbital rim and retraction of the temporalis muscle allowed for a tangential approach to the LRSS. A small encephalocele was seen and resected; the defect was identified and repaired with onlay DuraGen (Integra LifeSciences, Princeton, NJ) and Dura Repair (J&J Medical Devices, New Brunswick, NJ). There were no postoperative complications or recurrence of CSF leak.

CONCLUSIONS

The LPOA can be a useful alternative approach to the LRSS for CSF leak repair. The lateral-to-medial approach to defects in this area provides a shorter working distance while avoiding critical neurovascular structures.

Modified Ipsilateral Endonasal Endoscopic Trans-Sphenoidal Approach to Sphenoid Sinus Lateral Recess Cerebrospinal Fluid Leak Management in Two Cases: A Technical Note

Background  Cerebrospinal fluid (CSF) leak from the sphenoid sinus lateral recess (SSLR) is very rare. Majority prefer transpterygoid approach which is extensive and time consuming. Two such cases were managed with least possible dissection/destruction of paranasal sinus. Methods  Two cases of SSLR were accessed through the ipsilateral nostril from the side of CSF leak. Wide ipsilateral anterior sphenoidotomy was done preserving intersinus septum of sphenoid sinus. Middle turbinate was lateralized and remaining paranasal structures were preserved. Two handed single nostril approach was done in both the cases by 45- and 70-degree endoscope along with angled instruments. SSLR defects were visualized and packed with autologous fat graft and glue. Results  SSLR defects could be visualized and packed with fat graft in both the cases from ipsilateral side. Both cases had uneventful outcome with no leak with mean -follow-up of 11.5 months. Conclusion  Modified ipsilateral endonasal endoscopy trans-sphenoidal approach is least invasive technique for SSLR leak. Use of angled scope and instruments help in defect visualization, avoiding extensive paranasal sinus dissection and bony removal. Tedious time-consuming reconstructive procedures can be avoided with simple fat graft with good outcome.

Morbidities Associated with the Endoscopic Transnasal Transpterygoid Approach: Focusing on Postoperative Sequelae

OBJECTIVE

Although the endoscopic transpterygoid approach has been popularized, there are no studies about anatomy-specific morbidities of this approach. The objective of this study is to investigate the surgical morbidities associated with the endoscopic transpterygoid approach for resection of anatomic structures.

METHODS

A retrospective analysis was carried out of prospectively collected data of patients who underwent the endoscopic transpterygoid approach for skull base tumor by a single ear nose and throat surgeon in a tertiary-care center from November 2013 to January 2019. Postoperative patient symptom prevalence associated with surgical findings and SNOT-22 (Sino-Nasal Outcome Test-22) score were included in the analysis.

RESULTS

Thirty-seven consecutive patients were enrolled. The mean follow-up period was 12.4 months (range, 1-39 months). Twenty-six (70.3%) vidian nerves were sacrificed, but only 38.5% of those patients (10/26) reported mild dry eye symptoms. Fourteen nasolacrimal ducts (37.8%) were resected, with only 1 patient (7.1%) who had undergone previous radiation therapy reporting transient epiphora. SNOT-22 scores before and after surgery did not present statistical difference in inferior turbinate sacrifice group and preservation group.

CONCLUSIONS

Sacrifice of sinonasal structures such as the inferior turbinate or vidian nerve is sometimes inevitable for safe tumor resection with the endoscopic transpterygoid approach. Subjective symptoms were not apparent in most patients, despite the structural sacrifice.

Cranial nerve V2 and Vidian nerve trauma secondary to lateral pterygoid recess encephalocele repair

BACKGROUND

The incidence of adverse sequelae related to trauma of cranial nerve V₂ (V2) and the Vidian nerve (VN) during endoscopic pterygoid recess repair (PRR) of lateral sphenoid encephalocele is insufficiently reported in the medical literature. As part of our quality assessment and improvement program we sought to analyze the incidence and severity of V2 and VN injury during a 9-year experience (2010-2018) with PRR.

METHODS

Hypoesthesia, paresthesia, and dry eye and their impact on patient quality of life were sought through chart review and a self-reported 0 to 5 Likert scale for each symptom.

RESULTS

Thirty-five patients underwent repair of spontaneous cerebrospinal-fluid (CSF) rhinorrhea, with 11 consecutive patients undergoing endoscopic PRR. Mean follow-up for PRR was 32.5 months (range, 2.4 to 103.3 months). Although definitive management resulted in 100% success, 1 required secondary treatment. Eight patients were available for long-term follow-up (72.7%) and completed a symptom severity questionnaire using a Likert-scale. All patients observed either hypoesthesia, paresthesia, or dry eye of varying gradation (scale, 0 to 5). None described disabling symptoms, and some reported gradual improvement. Numbness, paresthesia, and dry eye were reported by 6 of 8 (75%), 5 of 8 (62.5%), and 4 of 8 (50%) patients, respectively. The mean Likert score among the 8 patients who completed this questionnaire noticing hypoesthesia, paresthesia, and dry eye was 2.6, 1.3, and 1.8, respectively.

CONCLUSION

Meticulous surgical technique is paramount for successful PRR and minimizing nerve injury, yet the anatomic variation of the lateral pterygoid recess can be challenging, and neural injury is a real risk. Preoperatively, patients should be counseled that although V2 or VN injury is common, most patients describe resulting symptoms to be rarely bothersome.

Endoscopic Endonasal Transpterygoid Approach to Sphenoid Sinus Lateral Recess Defects

Background  Lesions affecting sphenoid sinus lateral recess (SSLR) are difficult to visualize and manipulate through the transnasal routes, especially when the sinus is highly pneumatized. External approaches to this area involve extensive surgery and are associated with significant morbidity. The aims of this study are to present our experience with the endoscopic transpterygoid approach as a method for approaching lesions of the SSLR and to evaluate the outcomes of this procedure. Methods  Clinical charts of patients who had lesions in the SSLR and who were treated at our institution from September 1998 to June 2018 were retrospectively reviewed. All these patients were managed by the endoscopic endonasal transpterygoid approach. Results  Thirty-nine patients were identified. No cerebrospinal fluid leak recurrences were observed during follow-up (range: 1-19.7 years; median: 2.3 years). Hypoesthesia (temporary, 1; persistent, 4) in the region innervated by the maxillary branch of the trigeminal nerve was detected in five (12.8%) patients, while symptoms due to the Vidian nerve damage (dry eye, 3; dry nasal mucosa, 1) were present in four (10%) patients. Conclusions  Although the endoscopic endonasal transpterygoid approach is an excellent corridor for dealing with lesions of the SSLR, limited rate of neurologic and lacrimal complications was observed. Potential morbidity of the intervention should be discussed during preoperative counselling.

Management of sphenoid lateral recess encephalocoeles

PURPOSE OF REVIEW

Sphenoid sinus lateral recess encephalocoeles (SSLRE) are rare occurrences and pose unique challenges due to limited surgical access for endoscopic endonasal repair and also the lack of consensus on optimal perioperative managements specifically in the spontaneous cases, which are also believed to be a variant of idiopathic intracranial hypertension (IIH). Endoscopic endonasal approaches have largely replaced the transcranial route and the techniques are continuously being refined to reduce the neurovascular morbidity and improve outcome.

RECENT FINDINGS

Transpetrygoid is the most utilized approach with modifications suggested to limit bone removal, exposure and preservation of the neurovascular structures as dictated by the extent of the lateral recess. As more experience is gained, extended transphenoidal techniques were also successfully used for access. Lateral transorbital is a new approach to the lateral recess investigated in cadavers. IIH treatment is still controversial in the setting of SSLRE, but it appears rationale to evaluate, monitor and treat if necessary.

SUMMARY

SSLRE management should be tailored to the specific anatomical variances and cause. Modifications of techniques have been described giving different options to access the lateral recess. Successful repair for spontaneous SSLRE may require treatment of IIH if present, but the long-term outcome is still unclear.