The posterior nasoseptal flap: A novel technique for closure after endoscopic transsphenoidal resection of pituitary adenomas

Vomer-Rostrum Mucosal Flap for Exposed Bone Coverage After Sphenoid Sinusotomy

The vomer-rostrum mucosal flap is a useful technique utilizing vascularized mucosa of the rostrum and posterior septum to cover exposed hyperostotic bone following wide sphenoidotomy surgery. Laryngoscope, 133:552-556, 2023.

Fibrin-coated collagen fleece versus absorbable dural sealant for sellar closure after transsphenoidal pituitary surgery: a comparative study

Various surgical methods to prevent postoperative cerebrospinal fluid (CSF) leaks during transsphenoidal surgery have been reported. However, comparative studies are scarce. We aimed to compare the efficacy of a fibrin-coated collagen fleece (TachoSil) versus a dural sealant (DuraSeal) to prevent postoperative CSF leakage. We perform a retrospective study comparing two methods of sellar closure during endoscopic endonasal transsphenoidal surgery (EETS) for pituitary adenoma resection: TachoSil patching versus DuraSeal packing. Data concerning diagnosis, reconstruction technique, and surgical outcomes were analyzed. The primary endpoint was postoperative CSF leak rate. We reviewed 198 consecutive patients who underwent 219 EETS for pituitary adenoma from February 2007 and July 2018. Intraoperative CSF leak occurred in 47 cases (21.5%). A total of 33 postoperative CSF leaks were observed (15.1%). A reduction of postoperative CSF leaks in the TachoSil application group compared to the conventional technique using Duraseal was observed (7.7% and 18.2%, respectively; p = 0.062; Pearson exact test) although non-statistically significant. Two patients required lumbar drainage, and no revision repair was necessary to treat postoperative CSF rhinorrhea in Tachosil group. Fibrin-coated collagen fleece patching may be a valuable method to prevent postoperative cerebrospinal fluid (CSF) leaks during EETS for pituitary adenoma resection.

Heterogeneity in Outcome Reporting in Endoscopic Endonasal Skull Base Reconstruction: A Systematic Review

Objective  Presently, there are no standards for reporting outcomes of endoscopic endonasal skull base reconstruction (ESBR). This is problematic as a lack of consistent reporting makes synthesizing findings in systematic reviews and meta-analysis challenging. Thus, the aim of this study was to systematically review and describe the patterns of reporting outcomes in ESBR as a foundation for developing reporting guidelines. Study Design  Present study is a systematic review. Methods  Embase, PubMed, CINAHL, Cochrane Library, and Web of Science were searched for all publications with ≥25 patients and a focus on ESBR. The reporting patterns of each study's variables and outcomes were assessed. Results  A total of 112 studies were included in the review. The most commonly reported demographic variables were the number of included patients ( n  = 112, 100%) and types of pathologies treated ( n  = 104, 92.9%). Meanwhile, the most routinely described preoperative variable was history of prior treatment ( n  = 48, 42.9%). Type of reconstruction was a commonly reported intraoperative variable ( n  = 110, 98.2%), though the rate of intraoperative cerebrospinal fluid (CSF) leak was noted in only 76 studies (67.9%). With regard to postoperative outcomes, postoperative CSF leak rate was routinely provided ( n  = 101, 90.2%), but reporting of other surgical complications was more inconsistent. Ultimately, of the 43 variables and outcomes reviewed, a median of 12 (range: 4-22) was reported in each study. Conclusion  There is significant heterogeneity in the outcomes reported in studies relating to ESBR. This highlights the need for the development of standard reporting guidelines to minimize bias and improve interstudy comparability.

Cerebrospinal Fluid Leak after Transsphenoidal Surgery: A Systematic Review and Meta-analysis

Background Cerebrospinal fluid (CSF) leak is widely recognized as a challenging and commonly occurring postoperative complication of transsphenoidal surgery (TSS).

The primary objective of this study is to benchmark the current prevalence of CSF leak after TSS in the adult population.

Methods The authors followed the PRISMA guidelines. The PubMed, Embase, and Cochrane Library databases were searched for articles reporting CSF leak after TSS in the adult population. Meta-analysis was performed using the Untransformed Proportion metric in OpenMetaAnalyst. For two between-group comparisons a generalized linear mixed model was applied.

Results We identified 2,408 articles through the database search, of which 70, published since 2015, were included in this systematic review. These studies yielded 24,979 patients who underwent a total of 25,034 transsphenoidal surgeries. The overall prevalence of postoperative CSF leak was 3.4% (95% confidence interval or CI 2.8–4.0%). The prevalence of CSF leak found in patients undergoing pituitary adenoma resection was 3.2% (95% CI 2.5–4.2%), whereas patients who underwent TSS for another indication had a CSF leak prevalence rate of 7.1% (95% CI 3.0–15.7%) (odds ratio [OR] 2.3, 95% CI 0.9–5.7). Patients with cavernous sinus invasion (OR 3.0, 95% CI 1.1–8.7) and intraoperative CSF leak (OR 5.9, 95% CI 3.8–9.0) have increased risk of postoperative CSF leak. Previous TSS and microscopic surgery are not significantly associated with postoperative CSF leak.

Conclusion The overall recent prevalence of CSF leak after TSS in adults is 3.4%. Intraoperative CSF leak and cavernous sinus invasion appear to be significant risk factors for postoperative CSF leak.

Special MRI Techniques to Suss out Spontaneous Cerebrospinal Fluid Leaks

Anterior skull base cerebrospinal fluid (CSF) fistulas result from skull base osteodural defects, allowing subarachnoid space CSF to escape into pneumatized cavities such as the paranasal sinuses and nasal fossa. Precise localization, characterization, and effective treatment of CSF leaks is essential to prevent meningitis, treatment failure, or recurrence. Advances in magnetic resonance imaging have improved radiologists' ability to localize and characterize anterior skull base CSF fistulas. This article reviews new imaging techniques enabling diagnostic location of CSF fistulas, with an emphasis on magnetic resonance imaging-based techniques.

Early Experience of Endoscopic Endonasal Transphenoidal Surgery for Pituitary Adenoma: Preliminary Report of 56 Cases Operated in a West African Institution

BACKGROUND

Although endoscopic endonasal approach (EEA) has been popularized worldwide for pituitary adenoma surgery, in sub-Saharan Africa, neurosurgeons are still only starting their experience with it. This study was designed to assess the early results of EEA for pituitary adenoma from an under-equipped environment, namely, the Department of Neurosurgery of the Teaching Hospital of Yopougon Abidjan and Bouaké in Ivory Coast.

METHODS

The data of 56 cases of EEA for pituitary adenoma surgery performed between 2016 and March 2019 at the Teaching Hospital of Yopougon-Abidjan and Bouaké were retrospectively assessed. Pre- and postoperative neuro-ophthalmologic and hormonal status were analyzed. Moreover, the quality of tumor removal, and pre- and postoperative complications were also evaluated.

RESULTS

In this study, there were nonfunctional adenomas (20), prolactinoma (18), Cushing disease (9), and acromegaly (3). A reduced visual acuity and/or visual field defect was observed in 49 cases. The mean operation time was 225 ± 94.7 minutes. The tumor removals were complete in 57.14%, subtotal in 35.71%, and partial in 7.14%. These led to a visual improvement in 69.64%. Postoperative complications were cerebrospinal fluid leaks (19.64%), diabetes insipidus (12.50%), visual worsening (7.14%), meningitis (3.57%), and carotid injury (3.57%) that led to death.

CONCLUSIONS

This study represents the early surgical experience using EEA for treating pituitary adenoma in an under-equipped environment. Although the postoperative complication rate was relatively high, refinements of local surgeons' technique would lead to a better patient outcome.

Correlation of spontaneous and traumatic anterior skull base CSF leak flow rates with fluid pattern on early, delayed, and subtraction volumetric extended echo train T2-weighted MRI

OBJECTIVE

CSF leakage is a potentially fatal condition that may result when a skull base dural defect permits CSF communication between the cranial vault and sinonasal cavities. Flow rate is an important property of CSF leaks that can contribute to surgical decision-making and predispose patients to complications and inferior outcomes. Noninvasive preoperative prediction of the leak rate is challenging with traditional diagnostic tools. The present study compares fluid configurations on early and late volumetric extended echo train T2-weighted MRI by using image tracings and sequence subtraction as a novel method of quantifying CSF flow rate, and it correlates radiological results with intraoperative findings and clinical outcomes.

METHODS

A total of 45 patients met inclusion criteria for this study and underwent 3-T MRI. Imaging sequences included two identical CUBE T2 (vendor trade name for volumetric extended echo train T2) acquisitions at the beginning and end of the scanning session, approximately 45 minutes apart. Twenty-five patients were confirmed to have definitive spontaneous or traumatic anterior skull base CSF leaks. Semiautomated volumetric segmentation of CSF intensity was performed on both CUBE data sets by using 3D-Slicer software, and volumes were subtracted to obtain accumulated CSF volume. These imaging-derived fluid accumulations were correlated with high- or low-flow states, as well as ultimate treatment outcomes including recurrences.

RESULTS

Of the 45 patients, 25 (55.6%) had definitive evidence of CSF leakage, and 22 (88%) of these underwent surgical repair. Patients with high-flow CSF leaks had higher early (4.058 cm3 vs 0.982 cm3, p = 0.04), late (4.58 cm3 vs 1.096 cm3, p = 0.04), and accumulated (0.53 cm3 vs 0.11 cm3, p = 0.01) fluid volume measurements than patients with low-flow leaks. The 5 (22.7%) patients who exhibited postoperative CSF leak recurrence had significantly greater early (6.30 cm3 vs 1.23 cm3, p = 0.008) and late (6.87 cm3 vs 1.45 cm3, p = 0.008) volumes. Accumulated volume was not significantly greater in patients with leak recurrence (0.58 cm3 vs 0.22 cm3, p = 0.07). Early, late, and accumulated volumes were significantly correlated with postoperative hospital stay as well as duration of postoperative lumbar drain placement (p < 0.05 for all measures).

CONCLUSIONS

High-resolution CUBE T2 MRI, coupled with precise volumetric segmentation and subtraction of sinonasal hyperintensity, not only demonstrated predictive value in differentiating low- and high-flow CSF leaks, but also correlated with postoperative complications such as leak recurrence. These findings may be useful in the clinical workup and neurosurgical management of patients with skull base CSF leaks.

Vascular pedicled flaps for skull base defect reconstruction

OBJECTIVE

Techniques for reconstruction of skull base defects have advanced greatly since the introduction of the vascular pedicled nasoseptal flap in 2006. The objective of this review is to assess the current state of the field by examining both intranasal and extranasal techniques of vascular pedicled skull base defect repair, their indications and success rates, and novel techniques that are currently under investigation.

METHODS

A review of the literature describing the use of vascular pedicled flaps in skull base defect reconstruction was conducted using PubMed and Google Scholar.

RESULTS

The nasoseptal flap remains the most widely used vascular pedicled flap for endoscopic repair of skull base defects. Its ease of harvest, wide arch of rotation, and high success rates make it a popular choice among surgeons. Several variations including a "rescue" nasopseptal flap have been developed. Other less commonly used pedicled intranasal flaps include the middle turbinate flap and the posterior pedicled inferior turbinate flap. Additionally, several novel vascular pedicled flaps have been developed and tested in small cohorts of patients. Extranasal flaps such as the pericranial flap and the temporoparietal fascia flap are used less frequently than intranasal flaps. However, they remain valuable options for reconstruction in certain situations.

CONCLUSION

Advancements continue to be made in the field of skull base defect reconstruction using vascular pedicled flaps. Though the nasoseptal flap remains the most widely utilized option, additional intranasal techniques continue to be developed and tested to optimize surgical outcomes and patient care.

LEVEL OF EVIDENCE

NA.

Failure Pressures of Dural Repairs in a Porcine Ex Vivo Model: Novel Use of Titanium Clips Versus Tissue Glue

Objective

Endoscopic skull base surgery is advancing, and it is important to have reliable methods to repair the resulting defect. The objective of this study was to determine the failure pressures of 2 commonly used methods to repair large dural defects: collagen matrix underlay with fibrin glue and collagen matrix underlay with polyethylene glue, as well as a novel repair method: fascia lata with nonpenetrating titanium vascular clips.

Methods

The failure pressure of the 3 dural repairs was determined in a closed testing apparatus. Defects in porcine dura were created and collagen matrix grafts were used as an underlay followed by either fibrin glue (FG/CMG) or polyethylene glycol glue (PEG/CMG). A third condition using a segment of fascia lata was positioned flush with the edges of the dural defect and secured with titanium clips (TC/FL). Saline was infused to simulate increasing intracranial pressure (ICP) applied to the undersurface of the grafts until the repairs failed.

Results

The mean failure pressure of the PEG/CMG repair was 34.506 ± 14.822 cm H₂O, FG/CMG was 12.413 ± 5.114 cm H₂O, and TC/FL was 8.330 ± 3.483 cm H₂O. There were statistically significant differences in mean failure pressures among the 3 repair methods.

Conclusion

In this ex vivo model comparing skull base repairs’ ability to withstand cerebrospinal fluid leak, the repairs that utilized PEG/CMG tolerated the greatest amount of pressure and was the only repair that exceeded normal physiologic ICP’s. Repair methods utilizing glues generally tolerated higher pressures compared to the novel repair using clips alone.

Update on anterior skull base reconstruction

PURPOSE OF REVIEW

Anterior skull base reconstruction has rapidly evolved over the past few years as endoscopic approaches to resect tumors in this region have become more established. The present review evaluates the robust amount of new literature on this topic over the past year with particular attention to minimally invasive methods for reconstruction.

RECENT FINDINGS

Although vascularized local flaps remain the mainstay reconstructive choice when available for the anterior skull base, innovative techniques for all types of reconstruction, ranging from free grafts to free flaps continue to emerge.

SUMMARY

Because of the unique challenges and wide variety of options available to repair the anterior skull base with the goal to prevent or treat cerebrospinal fluid leaks, surgical expertise and experience in this field is of utmost importance.