Horizontal lateral lamella as a risk factor for iatrogenic cerebrospinal fluid leak. Clinical retrospective evaluation of 24 cases

Indirect Fistula: A New Terminology for Cerebrospinal Fluid Fistula With Different 'Apparent Origin' and 'Real Origin'

Fistulas are abnormal communications between body cavities. They can occur between the CNS and the extracranial space, presenting clinically as CSF leaks. Due to the variety of features, multiple classifications have been implemented to better study this pathology. A systematic review was conducted using the Scopus, Medline, and Web of Science databases. Observational studies such as cohort studies, case reports, case series, cross-sectional studies, systematic reviews, and publications that assess the classification of CSF leaks were included. The systematic review identified 29 publications that met the required criteria for inclusion. Although the primary focus of most of these publications was not on classification, they briefly mentioned it. The included publications describe classifications according to etiology, exiting flow pressure, anatomic site, and some new classification proposals. Of the 29 included studies, 11 referred to the appearance of CSF rhinorrhea or otorrhea with no relationship between the cause or site of origin and the site of the CSF leak. However, none of these publications names this situation. These results clearly indicate that a term for this circumstance needs to be established; none of the previously listed publications provide a name for this condition. This systematic review aims to demonstrate the necessity of implementing a new term to describe CSF leaks where the 'apparent origin' does not correspond to the 'real origin.' The results show no existing term that considers such cases; therefore, we propose the term 'Indirect Fistula' to designate these cases.

Examination of ethmoidal roof regarding Keros and Yenigun classifications in a Turkish population: a computerized tomography study

PURPOSE

Understanding ethmoid roof morphology is crucial to prevent complications in endoscopic sinus surgery. This study aimed to evaluate the morphological properties of the ethmoidal roof regarding gender and age differences using Keros and Yenigun classifications on high-resolution computed tomography images.

METHODS

We retrospectively analyzed 891 high-resolution computed tomography paranasal sinus study images and measured the depth of the cribriform plate in coronal sections and the anterior-posterior length in axial planes. The study retrospectively examined CT images of paranasal sinuses of patients living in the eastern Anatolian region of Turkey.

RESULTS

In both Keros and Yenigun Classifications, the most common class was type 2, and the least common class was type 3. According to Keros et al.'s method, no significant difference was observed between men and women (p = 0.698). However, according to Yenigun et al., the average values of women in terms of the anterior-posterior distance of the ethmoid roof were significantly higher than men (p = 0.001). When examined according to age, a very low, negative correlation was revealed regarding Keros and Yenigun classifications (p = 0.047 and p < 0.001 retrospectively). According to Keros and Yenigun's classification, there was no significant difference between the left and right sides (p = 0.488 and p = 0.919, respectively).

CONCLUSION

The morphological properties of the ethmoidal roof have importance to be considered for preoperative planning. Studying larger patient groups and meta-analyses that gather various research results about this subject might help better understand the ethmoidal roof morphology among populations.

Comprehensive access strategies to the frontal sinus

PURPOSE OF REVIEW

Despite the impressive evolutions in endoscopic endonasal approaches and instrumentations, the frontal sinus remains a challenging area. Different surgical options have been described over the years, but the main criticism lies in choosing the most suitable approach for a given case, based on the anatomy of each patient and the disease to treat. The purpose of this study is to provide a comprehensive review of surgical access strategies currently available to address the frontal sinus, including both endonasal and traditional external procedures, analysing indications, contraindications, complications and outcomes.

RECENT FINDINGS

Frontal sinus surgery includes minimally invasive endonasal approaches (balloon dilatation, Draf type I); extended endonasal approaches (Draf type IIA-IIB-IIC, Draf type III and their modifications via orbital transposition and contralateral pyriform aperture resection); external procedures (superior eyelid incision, frontal osteoplastic flap, Riedel procedure, Riedel-Mosher operation); and combined approaches.

SUMMARY

Recent advances in endoscopic endonasal techniques have deeply reshaped the surgical options to manage frontal sinus diseases, in an attempt to minimize the invasiveness of the procedures and maximize their outcomes. Traditional external procedures should be used in selected cases nonamenable for endonasal surgery. The appropriate selection of cases appears to be of paramount importance to obtain successful outcomes.

Management of Traumatic and Non-Traumatic Cerebrospinal Fluid Rhinorrhea-Experience from Three Southeast Asian Countries

BACKGROUND

Cerebrospinal fluid (CSF) rhinorrhea requires proper management to avoid disastrous consequences. The objectives of this study were to ascertain the patient characteristics, etiologies, sites of defect, skull base configurations, methods of investigation, and management outcomes of CSF rhinorrhea.

METHODS

A retrospective study was performed over 4 years involving three surgeons from Malaysia, Singapore, and Thailand. Hospital records were reviewed to determine the patients' characteristics, the causes and sites of leaks, methods of investigation, skull base configurations, choices of treatment, and outcomes.

RESULTS

A total of 15 cases (7 traumatic and 8 non-traumatic) were included. Imaging was performed in all cases. The most common site of leakage was the cribriform plate (9/15 cases). The mean ± SD of the Keros heights were 4.43 ± 1.66 (right) and 4.21 ± 1.76 mm (left). Type II Keros was the most common (60%). The mean ± SD angles of the cribriform plate slope were 51.91 ± 13.43 degrees (right) and 63.54 ± 12.64 degrees (left). A class II Gera configuration was the most common (80%). All except two patients were treated with endonasal endoscopic surgical repair, with a success rate of 92.3%. A multilayered repair technique was used in all patients except one. The mean ± SD postoperative hospital stay was 9.07 ± 6.17 days.

CONCLUSIONS

Non-traumatic CSF rhinorrhea outnumbered traumatic CSF rhinorrhea, with the most common site of leak at the cribriform plate. Imaging plays an important role in investigation, and Gera classification appears to be better than Keros classification for evaluating risk. Both conservative and surgical repairs are practiced with successful outcomes. Endonasal endoscopic CSF leak repair is the mainstay treatment.

CBCT Assessment of Ethmoid Roof Variations through Keros, Gera, and TMS Classifications

Background

This study is designed to assess the variations of the ethmoid roof through the Keros, Gera, and Thailand-Malaysia-Singapore (TMS) classifications by means of Cone-Beam Computed Tomography (CBCT).

Materials and Methods

372 CBCT scans were reviewed. The depth of the olfactory fossa (OF) was defined by the height of the lateral lamella (LL). The degree of the angle formed by the LL and the continuation of the horizontal plane passing through the cribriform plate was calculated. The risk of injury to the skull base was assessed by TMS classification.

Results

The distribution of Keros types 1, 2, and 3 was 20.43%, 66.26%, and 13.31%, respectively. No significant difference was seen in the Keros classification among males and females, and asymmetry in the depth of the cribriform plate was seen in 33.3% of patients. 29.57% of the cases had type I, 61.42% had type II, and 9.01% had type III of Gera classification. 33.9% of the patients had asymmetry in the Gera classification. There was not significant difference in the Gera classification among males and females. 95.43%, 4.17%, and 0.40% of patients were of types 1, 2, and 3 of TMS classification, respectively.

Conclusion

The most prevalent variations of the ethmoid roof were Keros type II, Gera type II, and TMS type 1. Although the prevalence of the dangerous types (Keros type 3, Gera type III, and TMS type 3) was low, preoperative assessment is essential in reducing surgical complications. CBCT is beneficial in evaluating these variations due to its low radiation dose.

Ethmoid roof morphometric measurements of a pediatric population using computed tomography

OBJECTIVE

To reveal the anatomical relationships of the ethmoid roof on CT in pediatric case group.

METHODS

We measured the depth of olfactory fossa (DOF), the width of olfactory fossa (WOF), the angle between lateral lamella and cribriform plate (LLCPA), the width of the olfactory cleft (WOC), the length of lateral lamella (LLL), orbital roof fovea to ethmoidal distance (ORFED) and orbital roof to cribriform plate distance (ORCPD) and we determined Keros and LLCPA types from paranasal sinus CT of subjects under 16 years of age retrospectively.

RESULTS

The incidence of Keros type I was higher in females and Keros Type II in males. The ORCPD, DOF and LLL values were found to be higher in 13-16 years age group and WOF and LLCPA in 4-6 years age group. The prevalence of Keros type II was higher in the 13-16 age group, and Keros type I was higher in other age groups. LLCPA type A was the most frequent in all age groups and in both sexes. There was a positive correlation between age and ORCPD, DOF, LLL, and a negative correlation with ORFED, WOF, LLCPA. Olfactory fossa width and depth had a negative correlation. LLCPA had a positive correlation with WOF and a negative correlation with DOF. There was a positive correlation between LLCPA and LLL. DOF and LLL had a positive correlation too.

CONCLUSIONS

Paranasal sinus CT provides useful information about frontal skull base anatomic relations before sinus surgery in pediatric cases.

[Analysis of risk factors for delayed iatrogenic cerebrospinal fluid otorrhinorrhea]

Objective:To explore the common causes of iatrogenic cerebrospinal fluid（CSF） otorrhinorrhea, and further analyze the risk factors for delayed iatrogenic CSF otorrhinorrhea. Methods:The clinical data of 35 iatrogenic CSF otorrhinorrhea patients in department of Otorhinolaryngology Head and Neck Surgery from January 2010 to January 2020 were retrospectively analyzed. Patients were divided into delayed and non-delayed iatrogenic CSF leak groups, according to the time intervals from medical intervention to CSF leak occurrence. The differences of baseline data, complications and success rate between the two groups were analyzed, and the risk factors of delayed iatrogenic cerebrospinal fluid otorrhinorrhea were further analyzed. Results:Endoscopic sinus surgery （n=11）, transsphenoidal pituitary surgery（n=8）, craniotomy（n=12）, and radiotherapy（n=4） all contribute to iatrogenic CSF otorrhinorrhea. Compared with the non-delayed group, the incidence of meningitis in the delayed group was significantly higher（20% vs 60%, P=0.041）. There were no significant differences in gender, radiation, hypertension, diabetes, and success rate between the two groups. Additionally, binary logistic regression analysis showed that sex, age, history of radiation, hypertension and diabetes, as well as causes of CSF otorrhinorrhea had no association with delayed iatrogenic CSF leakage. Conclusion:Patients with delayed iatrogenic CSF otorrhinorrhea have an increased risk of meningitis. Timely diagnose and intervention with appropriate surgical approach and reconstruction method ensures good clinical outcomes.

Adult and Pediatric Lateral Lamella Cribriform Plate Height: In Need for a Comparative Study

Surgery for sinuses has evolved with the advancement of instruments and modification in techniques. Endoscopes have expanded the surgical roles for lesions in the nose and para-nasal sinuses with reduced rate of complications and cosmetic side effects. Nevertheless sinus surgery in pediatrics patients has its own challenges. Pre-operative imaging is of paramount important especially when embarking on skull base procedures. The differences between adult and pediatric anatomy need to be further studied.