The use of dehydrated amniotic membrane allograft for augmentation of dural repair in transsphenoidal endoscopic endonasal resection of pituitary adenomas

Human Amniotic Membrane for Dural Repair and Duraplasty: A Systematic Review of Safety and Efficacy

The use of human amniotic membrane (HAM) has recently gained attention as a promising alternative option for duraplasty due to its superior tensile strength, elasticity, and anti-inflammatory and anti-fibrotic properties, offering greater durability and reliability compared to autologous grafts like the muscle fascia and pericranium. This systematic review aimed to evaluate the complications associated with duraplasty using HAM. We comprehensively searched the PubMed, Scopus, and Web of Science databases for studies on duraplasty with HAM. The eligibility criteria included studies on patients who underwent dural repair with duraplasty using HAM, with or without a control group. Duraplasty involves opening the dura mater, the protective covering of the brain and spinal cord, and using a graft to enlarge the space around the cerebellum. Dual repair, on the other hand, involves repairing the dura mater without opening it and then using a patch to enlarge the space around the cerebellum. Randomized controlled trials, observational studies, case series, and case reports were included, and quality assessment was conducted. Our search yielded 191 articles. Ten studies were included, with a total of 560 participants. The overall incidence of cerebrospinal fluid (CSF) leakage was three (0.63%) out of 478 in the HAM group and three (4.76%) out of 63 in the other methods group (pericranium, temporalis fascia, and biological dural substitutes). Regarding the incidence of postoperative complications, the overall incidence was eight (1.92%) out of 417 in the HAM group and two (8%) out of 25 in the other methods group. The overall incidence of meningitis was one (0.67%) out of 150 in the HAM group and three (10%) out of 30 in the other methods group. In conclusion, duraplasty using HAM may be a safe and effective alternative to traditional methods, with a low incidence of CSF leakage and postoperative complications.

Human amniotic membrane as a dural substitute in neurosurgery: A systematic review

Background:

Several studies have highlighted the use of human amniotic membrane (HAM) in neurosurgical procedures as an effective dural substitute. HAM has inherent antifibrotic and anti-inflammatory properties and exhibits immunomodulatory effect that makes it an ideal dural substitute. Other advantages including easy availability, low cost of procurement, and storage also render it a promising dural substitute especially in low- and middle-income countries.

Methods:

A systematic literature search was performed using PubMed, Scopus, and Google Scholar databases, using the search terms “human amniotic membrane,” “dural repair,” and “neurosurgery.” To be eligible for inclusion in our review, papers had to report primary data, be published in English language and report dural repair on humans with human amniotic membrane. Eligibility assessment was conducted by two independent reviewers with qualitative analysis on the basis of surgical utility, postoperative complications, and histological analysis.

Results:

Eight articles met the predefined inclusion criteria, including three randomized control trials and five cohort studies. We evaluated the use of HAM grafts in dural repair for elective cranial surgery (four studies), trauma surgery (three studies), and elective spine surgery (one study). Cases with postoperative cerebrospinal fluid (CSF) leak were reported by two studies. Other postoperative complications including meningitis, hydrocephalus, pseudomeningocele, CSF collection in subdural space, and subacute subdural hematoma were reported by one study each. Postsurgical histological analysis was reported by three studies highlighting the antiadhesive and integrative properties of HAM.

Conclusion:

The current review of evidence suggests that in terms of postsurgical outcomes, HAM is comparable with commercially available dural substitutes.

Conservative Management of Post-Operative Cerebrospinal Fluid Leak following Skull Base Surgery: A Pilot Study

Background/aims: Iatrogenic CSF leaks after endoscopic endonasal transsphenoidal surgery remain a challenging entity to manage, typically treated with CSF diversion via lumbar drainage. Objective: To assess the safety and efficacy of high-volume lumbar puncture (LP) and acetazolamide therapy to manage iatrogenic CSF leaks. Methods: We performed a prospective pilot study of four patients who developed iatrogenic postoperative CSF leaks after transsphenoidal surgery and analyzed their response to treatment with concomitant high-volume lumbar puncture followed by acetazolamide therapy for 10 days. Data collected included demographics, intra-operative findings, including methodology of skull base repair and type of CSF leak, time to presentation with CSF leak, complications associated with high-volume LP and acetazolamide treatment, and length of follow-up. Results: Mean patient age was 44.28 years, with an average BMI of 27.4. Mean time from surgery to onset of CSF leak was 7.71 days. All four patients had resolution of their CSF leak at two- and four-week follow-up. Mean overall follow-up time was 179 days, with a 100% CSF leak cure rate at the last clinic visit. No patient suffered perioperative complications or complications secondary to treatment. Conclusion: Although our pilot case series is small, we demonstrate that a high-volume LP, followed by acetazolamide therapy for 10 days, can be considered in the management of post-operative CSF leaks.

Skull base repair following endonasal pituitary and skull base tumour resection: a systematic review

PURPOSE

Postoperative cerebrospinal fluid rhinorrhoea (CSFR) remains a frequent complication of endonasal approaches to pituitary and skull base tumours. Watertight skull base reconstruction is important in preventing CSFR. We sought to systematically review the current literature of available skull base repair techniques.

METHODS

Pubmed and Embase databases were searched for studies (2000-2020) that (a) reported on the endonasal resection of pituitary and skull base tumours, (b) focussed on skull base repair techniques and/or postoperative CSFR risk factors, and (c) included CSFR data. Roles, advantages and disadvantages of each repair method were detailed. Random-effects meta-analyses were performed where possible.

RESULTS

193 studies were included. Repair methods were categorised based on function and anatomical level. There was absolute heterogeneity in repair methods used, with no independent studies sharing the same repair protocol. Techniques most commonly used for low CSFR risk cases were fat grafts, fascia lata grafts and synthetic grafts. For cases with higher CSFR risk, multilayer regimes were utilized with vascularized flaps, gasket sealing and lumbar drains. Lumbar drain use for high CSFR risk cases was supported by a randomised study (Oxford CEBM: Grade B recommendation), but otherwise there was limited high-level evidence. Pooled CSFR incidence by approach was 3.7% (CI 3-4.5%) for transsphenoidal, 9% (CI 7.2-11.3%) for expanded endonasal, and 5.3% (CI 3.4-7%) for studies describing both. Further meaningful meta-analyses of repair methods were not performed due to significant repair protocol heterogeneity.

CONCLUSIONS

Modern reconstructive protocols are heterogeneous and there is limited evidence to suggest the optimal repair technique after pituitary and skull base tumour resection. Further studies are needed to guide practice.

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.

Transethmoidal encephalocele endoscopically treated in a newborn: a case report

Congenital encephalocele is a very rare entity, with herniation of normal brain or gliotic tissue through a defect in the skull. The objective is to present a newborn child diagnosed with transethmoidal encephaloceles at birth. She developed respiratory problems, feeding difficulties, and failure to thrive since the first days of life and so required early surgery at her 33th day of life, through an endoscopic nasal approach. Technical difficulties encountered, complications, and management are discussed. To the best of our knowledge, this is the first report of endoscopic treatment of transethmoidal encephalocele in a newborn. Further studies are needed to understand the best way to repair the dural defect in this rare condition.

Reconstruction strategies for intraoperative CSF leak in endoscopic endonasal skull base surgery: systematic review and meta-analysis

BACKGROUND

Endoscopic endonasal surgery (EES) is one of the preferred options for skull base pathologies. Cerebrospinal fluid (CSF) leak is a significant complication of EES and neurosurgeons have proposed various reconstructive strategies to decrease this morbidity. We describe and compare the efficacy of these strategies.

METHODS

We searched PubMed, Cochrane Library, and Web of Science for publications between 1990 and November 2019. We defined a reconstruction hierarchy of seven levels from inside to outside: fat graft, intracranial intradural layer (inlay), intracranial extradural layer (onlay), buttress, mucosal flap, nasal packing and lumbar drainage. A single-arm analysis was performed for the primary outcome of CSF leak rate.

RESULTS

Of 3641 records identified, 48 studies met the inclusion criteria. Pituitary tumors had lower postoperative CSF leak rate than other diseases (1.8% vs. 6.5%, RD = -4.7% [-7.1%, -2.1%]). In high CSF flow group, the post-operative leak rate was reduced by application of mucosal flap (4.3% vs. without mucosal flap at 12.8%, RD = -8.5% [-15.1%, -1.9%]). The use of inlay showed potential of decreasing the post-operative leak rate (5.0% vs. 7.2%, RD = -2.2% [-7.7%, 3.3%]). In low CSF flow group, tampon was better than balloon for nasal packing (1.0% vs. 10.5%, RD = -9.5% [-16.5%, -2.4%]).

CONCLUSIONS

Mucosal flap and inlay for high-flow intraoperative CSF leak and tampon (compared with balloon) for low-flow intraoperative CSF leak, improved the postoperative CSF leak rate. Further studies are required to establish more robust evidence.