The effect of autologous fibrin tissue adhesive on postoperative cerebrospinal fluid leak in spinal cord surgery: a randomized controlled trial

Safety and effectiveness of Evicel® fibrin sealant as an adjunct to sutured dural repair in children undergoing cranial neurosurgery

PURPOSE

Cerebrospinal fluid (CSF) leakage is a challenging complication of intradural cranial surgery, and children are particularly at risk. The use of dural sealants confers protection in adults, but pediatric studies are scarce. We evaluated the safety and efficacy of Evicel® fibrin sealant as an adjunct to primary dural suturing in children undergoing cranial surgery.

METHODS

A multicenter trial prospectively enrolled pediatric subjects (< 18 years) undergoing cranial neurosurgery who, upon completion of primary sutured dural repair, experienced CSF leakage. As agreed by the EMA Evicel® Pediatric Investigation Plan, 40 subjects were intra-operatively randomized 2:1 to Evicel® or additional sutures ('Sutures'). Data analysis was descriptive. The efficacy endpoint was treatment success rate, with success defined as intra-operative watertight closure after provocative Valsalva maneuver (primary endpoint). Safety endpoints were postoperative CSF leakage (incisional CSF leakage, pseudomeningocele or both) and surgical site complications (secondary endpoints).

RESULTS

Forty subjects (0.6-17 years) were randomized to Evicel® (N = 25) or Sutures (N = 15) (intention-to-treat). Intracranial tumor was the most common indication and procedures were mostly supratentorial craniotomies. Success rates were 92.0% for Evicel® and 33.3% for Sutures, with a 2.76 estimated ratio of success rates (Farrington-Manning 95% CI [1.53, 6.16]). Sensitivity analyses in per-protocol and safety sets showed similar results. Despite a higher rescue treatment rate, the frequencies of postoperative CSF leakage and wound complications were higher for Sutures than for Evicel®.

CONCLUSION

This small-scale prospective study shows Evicel® treatment to be safe and effective as an adjunct to primary sutured dura mater closure in a pediatric population. Compared to additional sutures, Evicel® was associated with reduced postoperative CSF leakage and surgical site complications. (Trial registration: The trial was registered as NCT02309645 and EudraCT 2013-003558-26).

Predictors of Cerebrospinal Fluid Leak Following Dural Repair in Spinal Intradural Surgery

OBJECTIVE

We aim to compare the effectiveness of dural closure techniques in preventing cerebrospinal fluid (CSF) leaks following surgery for intradural lesions and seek to identify additional factors associated with CSF leaks. Surgical management of spinal intradural lesions involves durotomy which requires a robust repair to prevent postoperative CSF leakage. The ideal method of dural closure and the efficacy of sealants has not been established in literature.

METHODS

We performed a retrospective analysis of all intradural spinal cases performed at a tertiary spine centre from 1 April 2015 to 29 January 2020 and collected data on patient bio-profile, dural repair technique, and CSF leak rates. Multivariate analysis was performed to identify predictors for postoperative CSF leak.

RESULTS

A total of 169 cases were reported during the study period. There were 15 cases in which postoperative CSF leak was reported (8.87%). Multivariate analysis demonstrated that patient age (odds ratio [OR], 0.942; 95% confidence interval [CI], 0.891-0.996), surgical indication listed in the "others" category (OR, 44.608; 95% CI, 1.706-166.290) and dural closure with suture, sealant and patch (OR, 22.235; 95% CI, 2.578-191.798) were factors associated with CSF leak. Postoperative CSF leak was associated with the risk of surgical site infection with a likelihood ratio of 8.704 (χ² (1) = 14.633, p < 0.001).

CONCLUSION

Identifying predictors for CSF leaks can assist in the counselling of patients with regard to surgical risk and expected postoperative recovery.

Complication Avoidance in Spine Surgery

The outcomes of spine surgery are closely related to postoperative morbidity. Therefore, an experienced surgeon must be aware of various complications and should apply all necessary preventive measures to avoid them. It is widely considered that complications of spine surgery are underreported and that their real incidence is much higher than expected. This review highlights methods to prevent various types of morbidity that may be encountered during different spinal procedures, considering general complications, approach-related complications, fusion- and implant-related complications, and systemic complications.

Clinical Feasibility of Completely Autologous Fibrin Glue in Spine Surgery

Introduction

Fibrin glue is widely used in spine surgery. Nevertheless, no report has demonstrated the feasibility of completely autologous fibrin glue (CAFG) in spine surgery. This study aims to investigate the safety, efficacy, and effect of bone fusion of CAFG on spine surgery.

Methods

We retrospectively extracted data of patients who underwent primary spine surgery with preoperatively prepared CAFG. Primary outcomes were the incidence of wound-related unplanned reoperations within 90 days following primary surgery and the occurrence of reoperation for the management of cerebrospinal fluid (CSF) leakage in patients who had been treated with CAFG used as dural sealants. The effect of CAFG on bone fusion was also assessed by detecting implant failure at one year postoperatively in patients aged 25 years or less undergoing primary fusion for idiopathic scoliosis.

Results

We identified 131 eligible patients (47 males and 84 females) with a mean age of 32.3 years. CAFG was used most frequently as an adhesive for fixation of graft bone (110 patients), followed by as a dural sealant for CSF leakage in 17 patients, and as a local hemostatic agent in four patients. Wound-related reoperations were identified in four patients (3.1%), which included three for surgical site infection, and one for postoperative epidural hematoma. There was no reoperation required for the management of CSF leakage among 17 patients with dural incision or incidental durotomy. Compared with the control cohort, the use of CAFG was not associated with early wound-related reoperations or implant failure in patients with spinal deformity.

Conclusions

We demonstrated the clinical feasibility of CAFG in spine surgery. The use of CAFG was not associated with the incidence of reoperations for wound-related complications. CAFG worked effectively as a dural sealant for preventing CSF leakage. CAFG had no beneficial or adverse effect on spinal bone fusion.

Open epidural blood patch to augment durotomy repair in lumbar spine surgery: surgical technique and cohort study

BACKGROUND CONTEXT

Incidental durotomy during elective spine surgery is relatively common. While usually benign and self-limited, it can be associated with morbidity, increased cost, and medicolegal ramifications. Dural repair typically involves performing a primary closure using a suture or dural staple; repairs are then frequently augmented with a sealant, patch, or fat/fascial graft. Although primary repair of an incidental durotomy is standard practice, the ideal secondary sealant or augment choice remains unclear. A wide variety of commercially available dural sealant options exist, and while none have demonstrated consistent superiority, all are associated with single-use costs in the hundreds to thousands of dollars and have concerns regarding swelling, local inflammation, or short-lived dural adherence.

PURPOSE

The goal of this study is to compare the results of dural repair augmentation using an open intraoperative epidural blood patch to a hydrogel technique.

STUDY DESIGN/SETTING

Retrospective comparative cohort study at an academic referral center PATIENT SAMPLE: Adult patients undergoing lumbar spine surgery from March 2017 to January 2021 who sustained an incidental durotomy. Patients undergoing surgery for infection were excluded.

OUTCOME MEASURES

The primary outcome was failure of the repair as determined by a return to the operating room for re-exploration of a persistent cerebrospinal fluid (CSF) leak within 30 days of the index procedure. A secondary outcome was the incidence of a postoperative positional headache, and if present, the method used to obtain resolution. The primary predictor was use of a suture and hydrogel technique ("hydrogel" group), or the use of an epidural blood patch ("EBP" group).

METHODS

The method for applying an open epidural blood patch is presented in detail and involves primarily repairing the durotomy followed by allowing whole blood to pool and clot in the operative field until the durotomy is completely covered. This was compared with a group of patients undergoing secondary augmentation with commercially available hydrogel. In both groups, mechanical resistance to CSF leakage was confirmed with direct visualization and a Valsalva maneuver, respectively. Patients were instructed to remain flat until the morning after surgery. Chart review was used for data abstraction on preoperative, demographic, perioperative, and postoperative clinical factors. To compare between the hydrogel and EBP group, Wilcoxon rank-sum testing was used to test for non-parametric comparisons of means, and chi-square testing between binomial data.

RESULTS

Of 732 patients during the study period, forty-eight patients met study criteria. Twenty-five patients were in the hydrogel group and 23 in the EBP group. Mean age was 69.3 years (standard error 1.3 years). Patients were predominantly female (n = 31, 64.6%) with a mean BMI of 29.5 (SE 0.8), with no significant baseline differences between the hydrogel and EBP groups. Two patients in the hydrogel group (8.0%) and two in the EBP group (8.7%) had mild positional headaches postoperatively that resolved without intervention within 24 hours. One (4.3%) patient in the EBP group had positional headaches following an initial headache-free period; this patient was returned to the operating room and no evidence of a persistent CSF leak was found despite meticulous exploration.

CONCLUSIONS

An open, intraoperatively placed epidural blood patch may be an efficacious and cost-effective way to manage an incidental durotomy. This method merits further study as an allergy-free, no swell, cost-neutral method of dural repair augmentation.

Efficacy and safety of polyethylene glycol dural sealant system in cranial and spinal neurosurgical procedures: Meta-analysis

Background:

We aimed to assess the efficacy of polyethylene glycol (PEG) dura sealant to achieve watertight closure, prevention of cerebrospinal fluid (CSF) leak and to investigate its possible side effects.

Methods:

We searched Medline (through PubMed), Scopus, and the Cochrane Library through December 2019. We included articles demonstrating cranial or spinal procedures with the use of PEG material as a dural sealant. Data on intraoperative watertight closure, CSF leak, and surgical complications were extracted and pooled in a meta-analysis model using RevMan version 5.3 and OpenMeta (Analyst).

Results:

Pooling the controlled trials showed that PEG resulted in significantly more intraoperative watertight closures than standard care (risk ratio [RR] = 1.44, 95% confidence interval [CI] [1.24, 1.66]). However, the combined effect estimate did not reveal any significant difference between both groups in terms of CSF leaks, the incidence of surgical site infections, and neurological deficits (P = 0.7, 0.45, and 0.92, respectively). On the other hand, pooling both controlled and noncontrolled trials showed significance in terms of leak and neurological complications (RR = 0.0238, 95% CI [0.0102, 0.0373] and RR = 0.035, 95% CI [0.018, 0.052]). Regarding intraoperative watertight closure, the overall effect estimate showed no significant results (RR=0.994, 95% CI [0.986, 1.002]).

Conclusion:

Dura seal material is an acceptable adjuvant for dural closure when the integrity of the dura is questionable. However, marketing it as a factor for the prevention of surgical site infection is not scientifically proved. We suggest that, for neurosurgeons, using the dural sealants are highly recommended for duraplasty, skull base approaches, and in keyhole approaches.

Effectiveness of Repair Techniques for Spinal Dural Tears: A Systematic Review

BACKGROUND

Incidental or intentional durotomy in spine surgery is associated with a risk of cerebrospinal fluid (CSF) leakage and reoperation. Several strategies have been introduced, but the incomplete closure is still relatively frequent and troublesome. In this study, we review current evidence on spinal dural repair strategies and evaluate their efficacy.

METHODS

PubMed, Web of Science, and Scopus were used to search primary studies about the repair of the spinal dura with different techniques. Of 265 articles found, 11 studies, which specified repair techniques and postoperative outcomes, were included for qualitative and quantitative analysis. The primary outcomes were CSF leakage and postoperative infection.

RESULTS

The outcomes of different dural repair techniques were available in 776 cases. Pooled analysis of 11 studies demonstrated that the most commonly used technique was a combination of primary closure, patch or graft, and sealant (22.7%, 176/776). A combination of primary closure and patch or graft resulted in the lowest rate of CSF leakage (5.5%, 7/128). In this study, sealants as an adjunct to primary closure (13.7%, 18/131) did not significantly reduce the rate of CSF leakage compared with primary closure alone (17.6%, 18/102). The rates of infection and postoperative neurologic deficit were similar regardless of the repair techniques.

CONCLUSIONS

Although the use of sealants has become prevalent, available sealants as an adjunct to primary closure did not reduce the rate of CSF leakage compared with primary closure. The combination of primary closure and patches or grafts could be effective in decreasing postoperative CSF leakage.

Economic burden of readmission due to postoperative cerebrospinal fluid leak in Chinese patients

Aim: This real-world data study investigated the economic burden and associated factors of readmissions for cerebrospinal fluid leakage (CSFL) post-cranial, transsphenoidal, or spinal index surgeries. Methods: Costs of CSFL readmissions and index hospitalizations during 2014-2018 were collected. Readmission cost was measured as absolute cost and as percentage of index hospitalization cost. Factors associated with readmission cost were explored using generalized linear models. Results: Readmission cost averaged US$2407-6106, 35-94% of index hospitalization cost. Pharmacy costs were the leading contributor. Generalized linear models showed transsphenoidal index surgery and surgical treatment for CSFL were associated with higher readmission costs. Conclusion: CSFL readmissions are a significant economic burden in China. Factors associated with higher readmission cost should be monitored.

Integrity of dural closure after autologous platelet rich fibrin augmentation: an in vitro study

Background

Watertight closure of the dura mater is fundamental in neurosurgery. Besides the classical suturing techniques, a variety of biomaterials have been proposed as sealants. Platelet rich fibrin (PRF) is an autologous biomaterial which can readily be obtained through low-speed centrifugation of patient’s own blood. It is rich in fibrin, growth factors, leucocytes and cytokines and has shown adhesive properties while promoting the physiological wound healing process. In this study, we investigated the effect of applying PRF in reinforcing the watertight dura mater closure.

Methods

We created an in vitro testing device, where the watertight dura mater closure could be hydrostatically assessed. On 26 fresh harvested bovine dura maters, a standardised 20-mm incision was closed with a running suture, and the leak pressure was measured first without (primary leak pressure) and then with PRF augmentation (secondary leak pressure). The two groups of measurements have been statistically analysed with the Student’s paired t test.

Results

The “running suture only group” had a leak pressure of 10.5 ± 1.2 cmH2O (mean ± SD) while the “PRF-augmented group” had a leak pressure of 47.2 ± 2.6 cm H2O. This difference was statistically significant (p < 0.001; paired t test).

Conclusions

Autologous platelet rich fibrin augmentation reliably reinforced watertight closure of the dura mater to a > 4-fold increased leak pressure after failure of the initial standard running suture technique.

Electronic supplementary material

The online version of this article (10.1007/s00701-020-04254-4) contains supplementary material, which is available to authorized users.

Cerebrospinal fluid leaks after spine tumor resection: avoidance, recognition and management

Post-operative CSF leaks are a known complication of spine surgery in general, and patients undergoing surgical intervention for spinal tumors may be particularly predisposed due to the presence of intradural tumor and a number of other factors. Post-operative CSF leaks increase morbidity, lengthen hospital stays, prolong immobilization and subject patients to a number of associated complications. Intraoperative identification of unintended durotomies and effective primary repair of dural defects is an important first step in the prevention of post-operative CSF leaks, but in patients who develop post-operative pseudomeningoceles, durocutaneous fistulae or other CSF-leak-related sequelae, early recognition and secondary intervention are paramount to preventing further CSF-leak-related complications and achieving the best patient outcomes possible. In this article, the incidence, risk factors and complications of CSF leaks after spine tumor surgery are reviewed, with an emphasis on avoidance of post-operative CSF leaks, early post-operative identification and effective secondary intervention.

Efficacy of Double Drug Impregnated Autologous Coagulum Patch versus Single Drug Impregnated Autologous Coagulum Patch in Postoperative Pain Management after Spinal Surgery

Background:

Postoperative pain and cerebrospinal fluid (CSF) leak are common known complications of spinal surgery, both having a synergistic effect on each other. Thus, both need to be dealt simultaneously. Double drug impregnated autologous coagulum patch (DDIAC) is a novel method which reduced both incidences of postoperative CSF leaks as well as pain.

Methodology:

Twenty-seven patients undergoing lumbar disc surgery without instrumentation were included and randomized into DDIAC and single drug impregnated autologous coagulum patch (SDIAC) group. The patients were assessed postoperatively with visual analog scale (VAS).

Results:

There were 21 males and 6 females in the study. Seventeen (63%) patients got randomized for DDIAC patch application and other 10 (37%) patients entered the control arm group (SDIAC) patch use. Preoperative VAS was 5 in both the groups. The average postoperative VAS was 3.01 in DDIAC arm and 4.29 in control arm. The average analgesic shot required in the DDIAC group was 0.41 in 24 h and SDIAC group was 4.1 in 24 h. In DDIAC group, none of these patients had CSF leak from the surgical wound till discharge from the hospital. In the SDIAC group, one (10%, n = 10) patient had CSF leak.

Conclusions:

DDIAC patch was effective in controlling pain in the postoperative period; however, few patients may require analgesic shots for pain management. SDIAC patch may control some pain in the immediate postoperative period; however, this was not sufficient for a longer postoperative period.

Cisterna magna arachnoid membrane suturing decreases incidence of pseudomeningocele formation and incisional CSF leakage

OBJECTIVE

A pseudomeningocele and an incisional cerebrospinal fluid leak are considered frequent complications following neurosurgical operations. The rate of these complications especially increases following neurosurgical procedures on the posterior cranial fossae. According to some publications, the rate of pseudomeningoceles has been reported as high as 40%, whereas that of incisional cerebrospinal fluid leaks is up to 17%. For the purposes of reducing the risk of these complications after a midline suboccipital craniotomy, we propose suturing the arachnoid membrane of the cisterna magna. In this paper, we present a retrospective analysis of arachnoid membrane suturing.

METHODS

Seventy patients underwent midline suboccipital craniotomy by the first author between 2012 and 2016 at Burdenko Neurosurgery Institute. In this group was included a consecutive group of patients with posterior fossae tumors where the approach was performed through the cisterna magna arachnoid membrane following midline suboccipital craniotomy and dural opening. The patients were divided into two groups. Group 1 included 38 patients to whom cisterna magna arachnoid membrane suturing was performed with monofilament nonabsorbable suture 7.0., and additionally, the suture was sealed with fibrin adhesive sealant TachoComb®. Group 2 included 32 patients without arachnoid membrane suturing. There was no other significant difference in terms of clinical signs and surgical procedures between these groups. In the postoperative period, the frequency of developing a pseudomeningocele and an incisional cerebrospinal fluid leak was assessed in these two groups. The results were evaluated on the basis of clinical, CT, and MRI data performed in the postoperative period.

RESULTS

In the patients who underwent arachnoid membrane suturing (group I), pseudomeningocele formation was observed in one (2.6%) and CSF leak in one (2.6%) of the 38 patients. In group II, in which patients had no arachnoid membrane suturing, we observed pseudomeningocele formation in 11 (34.4%) patients and a CSF leak in 7 (25.0%) out of 28 patients with known follow-up. Statistical analysis of the data indicates a significantly higher risk of postoperative pseudomeningocele formation and/or an incisional cerebrospinal fluid leak in a group of patients who did not undergo arachnoid membrane suturing (p < 0.05).

CONCLUSIONS

Suturing of the arachnoid membrane of the cisterna magna and its further sealing with fibrin adhesive sealant TachoComb® create an additional barrier for preventing cerebrospinal fluid collection in the extradural space. This technique significantly reduces the risk of postoperative pseudomeningocele formation and/or an incisional cerebrospinal fluid leak in patients with midline suboccipital craniotomy.

The use of fibrin sealant during non-emergency surgery: a systematic review of evidence of benefits and harms

BACKGROUND

Fibrin sealants are used in different types of surgery to prevent the accumulation of post-operative fluid (seroma) or blood (haematoma) or to arrest haemorrhage (bleeding). However, there is uncertainty around the benefits and harms of fibrin sealant use.

OBJECTIVES

To systematically review the evidence on the benefits and harms of fibrin sealants in non-emergency surgery in adults.

DATA SOURCES

Electronic databases [MEDLINE, EMBASE and The Cochrane Library (including the Cochrane Database of Systematic Reviews, the Database of Abstracts of Reviews of Effects, the Health Technology Assessment database and the Cochrane Central Register of Controlled Trials)] were searched from inception to May 2015. The websites of regulatory bodies (the Medicines and Healthcare products Regulatory Agency, the European Medicines Agency and the Food and Drug Administration) were also searched to identify evidence of harms.

REVIEW METHODS

This review included randomised controlled trials (RCTs) and observational studies using any type of fibrin sealant compared with standard care in non-emergency surgery in adults. The primary outcome was risk of developing seroma and haematoma. Only RCTs were used to inform clinical effectiveness and both RCTs and observational studies were used for the assessment of harms related to the use of fibrin sealant. Two reviewers independently screened all titles and abstracts to identify potentially relevant studies. Data extraction was undertaken by one reviewer and validated by a second. The quality of included studies was assessed independently by two reviewers using the Cochrane Collaboration risk-of-bias tool for RCTs and the Centre for Reviews and Dissemination guidance for adverse events for observational studies. A fixed-effects model was used for meta-analysis.

RESULTS

We included 186 RCTs and eight observational studies across 14 surgical specialties and five reports from the regulatory bodies. Most RCTs were judged to be at an unclear risk of bias. Adverse events were inappropriately reported in observational studies. Meta-analysis across non-emergency surgical specialties did not show a statistically significant difference in the risk of seroma for fibrin sealants versus standard care in 32 RCTs analysed [n = 3472, odds ratio (OR) 0.84, 95% confidence interval (CI) 0.68 to 1.04; p = 0.13; I² = 12.7%], but a statistically significant benefit was found on haematoma development in 24 RCTs (n = 2403, OR 0.62, 95% CI 0.44 to 0.86; p = 0.01; I² = 0%). Adverse events related to fibrin sealant use were reported in 10 RCTs and eight observational studies across surgical specialties, and 22 RCTs explicitly stated that there were no adverse events. One RCT reported a single death but no other study reported mortality or any serious adverse events. Five regulatory body reports noted death from air emboli associated with fibrin sprays.

LIMITATIONS

It was not possible to provide a detailed evaluation of individual RCTs in their specific contexts because of the limited resources that were available for this research. In addition, the number of RCTs that were identified made it impractical to conduct independent data extraction by two reviewers in the time available.

CONCLUSIONS

The effectiveness of fibrin sealants does not appear to vary according to surgical procedures with regard to reducing the risk of seroma or haematoma. Surgeons should note the potential risk of gas embolism if spray application of fibrin sealants is used and not to exceed the recommended pressure and spraying distance. Future research should be carried out in surgery specialties for which only limited data were found, including neurological, gynaecological, oral and maxillofacial, urology, colorectal and orthopaedics surgery (for any outcome); breast surgery and upper gastrointestinal (development of haematoma); and cardiothoracic heart or lung surgery (reoperation rates). In addition, studies need to use adequate sample sizes, to blind participants and outcome assessors, and to follow reporting guidelines.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42015020710.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Watertight Sealing Without Lumbar Drainage for Incidental Ventral Dural Defect in Transthoracic Spine Surgery: A Retrospective Review of 53 Cases

STUDY DESIGN

A retrospective review.

OBJECTIVES

To evaluate the therapeutic efficacy of the triple layer closure technique to establish watertight sealing without diversion of lumbar drainage, in preventing persistent incidental subarachnoid-pleural fistula and other neurological complications related to excessive drainage of cerebrospinal fluid (CSF) after dural defect in transthoracic ossified posterior longitudinal ligament (OPLL) surgery.

SUMMARY OF BACKGROUND DATA

CSF leakage into the pleural cavity leads to unfavorable conditions for natural healing of incidental durotomy due to the negative pressure environment of the pleural space and lack of wound healing around the bony cavity near the decompressed spinal cord. This often leads to a persistent incidental subarachnoid-pleural fistula. In addition, diversion of lumbar drainage may lead to excessive CSF drainage resulting in intracranial hypotension. To avoid this, we studied the efficacy of a modified sealing method to establish a more watertight covering at the ventral dural defect without lumbar CSF drainage.

METHODS

Fifty-three patients who had CSF leakage from the ventral aspect of the spinal cord during transthoracic spine surgery for thoracic OPLL between 2004 and 2013 were retrospectively reviewed. Patients were divided into 2 groups: a conventional group (group A) and a triple layer closure group (group B). In group A (n=33 patients), the dural defect was covered with fibrin glue (Beriplast P) mixed with gelfoam (Spongostan Standard) with subsequent subarachnoid lumbar drainage. In group B (n=20 patients), the dural defect was sealed using the triple layer technique with 2 layers of fibrin glue and gelatin sponge plus a third layer of synthetic hydrogel (Duraseal, Dural Sealant System) without subsequent subarachnoid lumbar drainage. Both groups had chest tubes that drained through an underwater seal. Clinical data including duration and total amount of drainage (chest tube and lumbar drainage), related complications, and duration of hospital stay were compared between the 2 groups.

RESULTS

Compared with the patients in group A, group B had a significantly smaller total volume of drainage and shorter chest tube drainage time (P<0.05) during their hospital stay. In group A, complications occurred in 6 cases (18.2%), including 3 cases of intracranial hypotension combined with transient mental status alteration, postural headache, and dizziness, 1 case of regional atelectasis with pneumonia, and 2 cases of revision thoracotomy. Revision thoracotomy was performed to treat persistent subarachnoid-pleural fistula due to significant and prolonged CSF leakage. In group B, there were no complications and no revision thoracotomy was needed. The mean duration of hospital stay was shorter in group B (15.6 d) compared with group A (22.4 d).

CONCLUSIONS

The established watertight closure of the dural defect using the triple layer sealing method without lumbar drainage was more effective and safe.

Multiple uses of fibrin sealant for nervous system treatment following injury and disease

Lesions to the nervous system often produce hemorrhage and tissue loss that are difficult, if not impossible, to repair. Therefore, scar formation, inflammation and cavitation take place, expanding the lesion epicenter. This significantly worsens the patient conditions and impairment, increasing neuronal loss and glial reaction, which in turn further decreases the chances of a positive outcome. The possibility of using hemostatic substances that also function as a scaffold, such as the fibrin sealant, reduces surgical time and improve postoperative recovery. To date, several studies have demonstrated that human blood derived fibrin sealant produces positive effects in different interventions, becoming an efficient alternative to suturing. To provide an alternative to homologous fibrin sealants, the Center for the Study of Venoms and Venomous Animals (CEVAP, Brazil) has proposed a new bioproduct composed of certified animal components, including a thrombin-like enzyme obtained from snake venom and bubaline fibrinogen. Thus, the present review brings up to date literature assessment on the use of fibrin sealant for nervous system repair and positions the new heterologous bioproduct from CEVAP as an alternative to the commercial counterparts. In this way, clinical and pre-clinical data are discussed in different topics, ranging from central nervous system to peripheral nervous system applications, specifying positive results as well as future enhancements that are necessary for improving the use of fibrin sealant therapy.

Incidence, Management, and Outcome of Symptomatic Postoperative Posterior Fossa Pseudomeningocele: A Retrospective Single-Institution Experience

BACKGROUND

Pseudomeningocele is a source of considerable morbidity after posterior fossa surgery, but incidence and optimal management strategies are unclear.

OBJECTIVE

To define risk factors, evaluate management strategies, and identify predictors of resolution.

METHODS

A prospectively maintained database of 687 consecutive posterior fossa operations at a single institution was analyzed to identify cases of symptomatic postoperative pseudomeningocele. Retrospective analysis of treatment strategies and outcome was performed.

RESULTS

Overall rate of symptomatic postoperative pseudomeningocele was 14.1% (97 cases). The highest rate was for midline posterior fossa surgery (16.5%), and the lowest rate was for retrosigmoid surgery (11.9%). Multivariate logistic regression analysis revealed that the presence of increased ventricle size on postoperative imaging predicted significantly higher risk of failure of lumbar drainage (odds ratio, 6.57; 95% confidence interval [CI], 1.18-36.59; P < .05). Cox proportional hazards analysis revealed that time to clinical resolution was significantly associated only with use of temporary lumbar drainage (hazards ratio, 2.28; 95% CI, 1.04-5.00; P < .05), and time to radiographic resolution was associated only with placement of a ventricular shunt (hazards ratio, 2.84; 95% CI, 1.19-6.78; P < .05).

CONCLUSION

Pseudomeningocele is a common complication after posterior fossa surgery, but incidence is not related to age or medical comorbidity. Postoperative ventriculomegaly portends failure of temporary cerebrospinal fluid diversion, and early consideration of shunting might be appropriate in such cases. In the absence of ventriculomegaly, temporary use of a lumbar drain leads to earlier clinical resolution, but complete radiographic resolution is rare when a permanent shunt is not implanted. Further research should be performed to establish the most effective treatment strategy.

Fibrin Sealants in Dura Sealing: A Systematic Literature Review

Background

Fibrin sealants are widely used in neurosurgery to seal the suture line, provide watertight closure, and prevent cerebrospinal fluid leaks. The aim of this systematic review is to summarize the current efficacy and safety literature of fibrin sealants in dura sealing and the prevention/treatment of cerebrospinal fluid leaks.

Methods

A comprehensive electronic literature search was run in the following databases: Cochrane Database of Systematic Reviews, Cochrane Central Resister of Controlled Trials, clinicaltrials.gov, MEDLINE/PubMed, and EMBASE. Titles and abstracts of potential articles of interest were reviewed independently by 3 of the authors.

Results

A total of 1006 database records and additional records were identified. After screening for duplicates and relevance, a total of 78 articles were assessed by the investigators for eligibility. Thirty-eight were excluded and the full-text of 40 articles were included in the qualitative synthesis. Seven of these included only safety data and were included in the safety assessment. The remaining 33 articles included findings from 32 studies that enrolled a total of 2935 patients who were exposed to fibrin sealant. Among these 33 studies there were only 3 randomized controlled trials, with the remaining being prospective cohort analysis, case controlled studies, prospective or retrospective case series. One randomized controlled trial, with 89 patients exposed to fibrin sealant, found a greater rate of intraoperative watertight dura closure in the fibrin sealant group than the control group (92.1% versus 38.0%, p<0.001); however, post-operative cerebrospinal fluid leakage occurred in more fibrin sealant than control patients (6.7% versus 2.0%, p>0.05). Other clinical trials evaluated the effect of fibrin sealant in the postoperative prevention of cerebrospinal fluid leaks. These were generally lower level evidence studies (ie, not prospective, randomized, controlled trials) that were not designed or powered to demonstrate a significant advantage to fibrin sealant use. Two small case series studies evaluated the effect of fibrin sealants in persistent cerebrospinal fluid leak treatment, but did not establish firm efficacy conclusions. Specific adverse reports where fibrin sealants were used for dura sealing were limited, with only 8 cases reported in neurosurgical procedures since 1987 and most reporting only a speculative relationship/association with fibrin sealant exposure.

Conclusions

A major finding of this systematic literature review is that there is a paucity of randomized studies that have evaluated the effectiveness and safety of fibrin sealants in providing intraoperative watertight dura closure and post-operative cerebrospinal fluid leakage. Among the limited studies available, evidence from a single randomized, controlled trial indicates that fibrin sealants provide a higher rate of intraoperative watertight closure of the dura suture line than control, albeit with a higher rate of postoperative cerebrospinal fluid leakage. Evidence from non-randomized, controlled trials suggests that fibrin sealants may be effective in preventing cerebrospinal fluid leaks with an acceptable safety profile. There is a substantial need for randomized, controlled clinical trials or well-designed prospective observational trials where the conduct of a randomized trial is not feasible to fully assess the impact of fibrin sealant utilization on the rates of intraoperative dura closure, postoperative cerebrospinal leakage, and safety.

The Use Fibrin Sealant after Spinal Intradural Tumor Surgery: Is It Necessary?

OBJECTIVE

A fibrin sealant is commonly applied after closure of an incidental or intended durotomy to reduce the complications associated with the leakage of cerebrospinal fluid. Routine usage might not be essential after closure of an intended durotomy, which has clear cut-margins. We investigated the efficacy of fibrin sealants for primary intradural spinal cord tumor surgery.

METHODS

A retrospective review was performed for 231 consecutive surgically treated patients with primary intradural spinal cord tumors without extradural extension. Fibrin sealants were not used for 47 patients (group I: age, 51.57±16.75 years) and were applied to 184 patients (group II: age, 48.8±14.7 years). The surgical procedures were identical except for the use of a fibrin sealant after closure of the durotomy. The primary outcome was the occurrence of complications (wound problems, hematoma collection, infection, and neurological deterioration). The covariates were age, sex, body mass index, operation time, pre-/postoperative ambulation, number of laminectomies, and type of tumor.

RESULTS

Schwannoma was the most common pathology (n=134), followed by meningioma (n=35) and ependymoma (n=31). Complications occurred in 13 patients (3 in group I and 10 in group II, p=0.73). The postoperative ambulation status (p<0.01; odds ratio, 28.8; 95% confidence interval, 6.9-120.0) and operation time (p=0.04; cutoff, 229 minutes; sensitivity, 62%; specificity, 72%) were significant factors, whereas the use of a fibrin glue was not (p=0.47).

CONCLUSION

The use of a fibrin sealant might not be essential to reduce complications after surgery for primary spinal intradural tumor.

Histological analysis of the repair of dural lesions with silicone mesh in rats subjected to experimental lesions

Objective

To evaluate inflammatory reaction, fibrosis and neovascularization in dural repairs in Wistar rats using four techniques: simple suture, bovine collagen membrane, silicon mesh and silicon mesh with suture.

Methods

Thirty Wistar rats were randomized in five groups: the first was the control group, submitted to dural tear only. The others underwent durotomy and simple suture, bovine collagen membrane, silicon mesh and silicon mesh with suture. Animals were euthanized and the spine was submitted to histological evaluation with a score system (ranging from zero to 3) for inflammation, neovascularization and fibrosis.

Results

Fibrosis was significantly different between simple suture and silicon mesh (p=0.005) and between simple suture and mesh with suture (p=0.015), showing that fibrosis is more intense when a foreign body is used in the repair. Bovine membrane was significantly different from mesh plus suture (p=0.011) regarding vascularization. Inflammation was significantly different between simple suture and bovine collagen membrane.

Conclusion

Silicon mesh, compared to other commercial products available, is a possible alternative for dural repair. More studies are necessary to confirm these findings.

Comparison of dural repair techniques

BACKGROUND CONTEXT

Incidental durotomy occurs in 1% to 17% of lumbar spine surgery. This is treated with watertight suture repair, often combined with a sealant.

PURPOSE

To compare the hydrostatic strength of dural repair using various suture sizes, closure techniques, and adhesives.

STUDY DESIGN

A novel in vitro hydrostatic calf spine model.

OUTCOME MEASURES

Dural leakage as a function of hydrostatic pressure and leak area.

METHODS

We compared surgical repair between 5-0 surgilon and 6-0 prolene suture, continuous locked versus interrupted suture, and the effectiveness of three adhesives hydrogel, cyanoacrylate, and fibrin glue. The leakage flow rate was compared among suture groups using analysis of variance (ANOVA). The percent reduction of leak area was determined for the sealants and compared using ANOVA. The study was funded from an intramural departmental grant.

RESULTS

6-0 Prolene was found to have significantly decreased leakage flow rate than 5-0 surgilon. We found no significant differences in the flow rate between the interrupted and continuous locked sutures. In most cases, leakage occurred from the needle holes around sutures. There was an 80% reduction in leak area with the hydrogel and cyanoacrylic sealants compared with only a 38% reduction with fibrin glue; however, there was no statistical difference between the leak rates using any of the sealants.

CONCLUSION

6-0 Prolene using either interrupted or locked techniques was the best at creating watertight closure of an incidental durotomy. If a watertight seal cannot be obtained, a hydrogel or a fibrin sealant will immediately improve the strength of repair. Newer sutures that have a larger diameter of suture relative to needle should be developed for use in dural repair.

Axon growth inhibition by RhoA/ROCK in the central nervous system

Rho kinase (ROCK) is a serine/threonine kinase and a downstream target of the small GTPase Rho. The RhoA/ROCK pathway is associated with various neuronal functions such as migration, dendrite development, and axonal extension. Evidence from animal studies reveals that RhoA/ROCK signaling is involved in various central nervous system (CNS) diseases, including optic nerve and spinal cord injuries, stroke, and neurodegenerative diseases. Given that RhoA/ROCK plays a critical role in the pathophysiology of CNS diseases, the development of therapeutic agents targeting this pathway is expected to contribute to the treatment of CNS diseases. The RhoA/ROCK pathway mediates the effects of myelin-associated axon growth inhibitors—Nogo, myelin-associated glycoprotein (MAG), oligodendrocyte-myelin glycoprotein (OMgp), and repulsive guidance molecule (RGM). Blocking RhoA/ROCK signaling can reverse the inhibitory effects of these molecules on axon outgrowth, and promotes axonal sprouting and functional recovery in animal models of CNS injury. To date, several RhoA/ROCK inhibitors have been under development or in clinical trials as therapeutic agents for neurological disorders. In this review, we focus on the RhoA/ROCK signaling pathway in neurological disorders. We also discuss the potential therapeutic approaches of RhoA/ROCK inhibitors for various neurological disorders.

Management of CSF leak following spinal surgery

PURPOSE

Postoperative CSF leak is a known complication of spinal surgery especially after surgery for neural tube defects (NTD). The problem can metamorphose into a severe infection. This article hopes to shed some light on the management of these problems and suggests precautions so as to reduce their occurrence.

MATERIALS AND METHODS

A retrospective analysis of 102 children, between the ages of 1 day and 12 years, operated for various spinal pathologies, over the past 2.5 years by the same surgeon (CB) was done. The various methods of dural closure were noted. The methods of management of postoperative CSF leaks were analysed, and the patients were followed till discharge.

RESULTS

The incidence of CSF leak was found to be 12.7%. The methods of management included lumbar drain only (n = 7), lumbar drain with re-exploration (n = 3), lumbar drain followed by lumboperitoneal shunt (n = 2) and only lumboperitoneal shunt (n = 1). The use of fibrin glue did not seem to significantly prevent the incidence of CSF leak in cases.

CONCLUSIONS

Primary and meticulous dural closure is sine qua non in preventing postoperative CSF leak. A lumbar drain is a convenient and economical method of managing the problem initially failing which more invasive methods like re-exploration may be employed.

The use of surgical sealants in the repair of dural tears during non-instrumented spinal surgery

PURPOSE

To compare the success in repair of dural tears (DTs) using two different surgical sealants in non-instrumented lumbar spinal surgery and evaluate the incidence of associated short- and long-term complications.

METHODS

Twenty-three patients undergoing non-instrumented spinal surgery with intraoperative DTs were included both retrospectively and prospectively in this study. External signs of CSF leakage, neurological deficits, and infection-related complications were investigated postoperatively. The persistence of low-back pain was also evaluated and postoperative MRI was performed in all patients. DTs were repaired intraoperatively using suture with or without a dural patch. Eleven patients received an application of fibrin glue (Tissucol(®); Baxter, Inc., IL, USA) and 12 patients received an application of bovine serum albumin glutaraldehyde surgical adhesive (BioGlue(®) Surgical Adhesive; CryoLife, GA, USA). These patients were followed up at 3 months and 1 year postoperatively.

RESULTS

Successful intraoperative DT repair was obtained in all cases. Three patients in the Tissucol group presented with CSF leakage in the early postoperative period. There were no complications observed in the patients treated with BioGlue. At 3-month follow-up, no incidences of neurological or infection-related complications were observed in either group. There was no statistically significant difference in VAS between the two treatment groups.

CONCLUSIONS

Intraoperative DTs can be easily repaired by many effective techniques. However, in our experience, the use of BioGlue is an effective adjunct to immediate dural repair, being comparable in terms of efficacy and safety to the use of fibrin glue, potentially decreasing the incidence of associated short- and long-term complications.

CSF complications following intradural spinal surgeries in children

BACKGROUND

Cerebrospinal fluid (CSF) leakage is a complication of intradural spinal surgery and is associated with poor wound healing and infection. The incidence of CSF leak is reported at ∼16% in adults, but little information is available in children.

PURPOSE

The aim of this study is to determine the CSF leak rate and predisposing factors after intradural pediatric spinal surgeries.

METHODS

This study was a retrospective chart review of 638 intradural spinal operations at BC Children's Hospital. CSF leak was defined as pseudomeningocele or CSF leak through incision. Primary operations to untether lipomyelomeningoceles, myelomeningocele/meningocele closure, and Chiari decompressions were excluded.

RESULTS

CSF leaks occurred in 7.1%, with 3% having overt CSF leaks through skin (OCSF leak). CSF leaks, specifically OCSF leaks, were associated with postoperative wound infection (P = 0.0016). Sixteen of 45 cases of CSF leak required reoperation. The type of dural suture used, site of operation, or use of fibrin glue did not affect CSF leak rates. Previous spinal surgery (P < 0.0001), use of dural graft (P = 0.0043), method of dural suturing (P = 0.0023), and procedure performed (P < 0.001) were associated with postoperative CSF leakage. Patients with CSF leak were older than those without leak (98 vs. 72 months, P = 0.002).

CONCLUSIONS

Our results provide evidence on intraoperative factors that may predispose to CSF leaks after spinal intradural surgery and may help guide surgical practice. This study confirms that the pediatric population shares many of the same risk factors for CSF leak as in adult populations. Further research is needed to explain how specific factors are associated with CSF leaks.

Rho-ROCK inhibition in the treatment of spinal cord injury

BACKGROUND

The Rho pathway has been shown to have a role in the pathophysiology of spinal cord injury (SCI). Upregulation of the Rho signaling pathway occurs as a result of SCI. Activation of Rho and its downstream effector kinases triggers growth cone collapse and represents a significant barrier to axon regeneration. Furthermore, there is evidence that Rho-ROCK signaling mediates the inhibitory effects of chondroitin sulfate proteoglycans on neurons, and that inhibition of Rho and ROCK can reverse chondroitin sulfate proteoglycan-mediated inhibition of neurite outgrowth. Work building on these findings suggests that inhibition of this pathway may boost neuroprotection and axonal regeneration after SCI.

METHODS

A narrative review.

RESULTS

Investigators have identified a C3 transferase, which selectively inhibits Rho without affecting other guanine triphosphatases. This has been shown to promote axonal sprouting and recovery of locomotor function after hemisection of the thoracic spinal cord in a mouse model of SCI. The neuroprotective properties of Rho inhibitors in animal models of SCI have been reinforced by studies carried out in vitro using retinal ganglion cells. In light of this, a Rho inhibitor known as Cethrin has been evaluated as a therapeutic intervention for SCI in a phase I/IIa clinical trial with promising results.

CONCLUSIONS

The Rho pathway has been shown to have a role in the pathophysiology of SCI and preclinical and clinical work and is currently a promising target for the treatment of patients with SCI.

The appearance of dural sealants under MR imaging

Dural sealants are an adjunct to obtain watertight closure after intradural procedures. This study aims to characterize the appearance on MR imaging of 3 commonly employed dural sealants: fibrin glue, PEGH, and BSAG. To this end, patients who underwent spinal intradural procedures that included the use of dural sealant during closure were identified retrospectively. Post-operative data on 15 patients, including complications such as pseudomeningocele formation and infection, were gathered. The appearance of dural sealants on follow-up MR imaging scans within 3 days of surgery was analyzed. Fifteen patients were identified (5 with fibrin glue, 5 with PEGH, and 5 with BSAG applied during closure) with appropriately timed post-operative MR imaging scans. All 3 substances were identifiable based on anatomic location and imaging characteristics on post-operative MR imaging in standard T1, T1 PGFS, and T2 FSE. Definite differentiation between CSF and fibrin glue or PEGH was not possible with the T1 or T1 PGFS, or with the T2 FSE. Differences in intensity between CSF and BSAG were also not significant on either T1 sequence, but they were statistically significant on the T2 FSE. All patients had an uneventful post-operative course, and no patients developed post-operative pseudomeningocele at 30 days. This study concludes that water-based dural sealants such as fibrin glue and PEGH are difficult to differentiate from CSF on standard T1, T1 PGFS and T2 FSE, while BSAG is easily recognized on the T2 FSE. Recognition of water-based sealants therefore requires communication between the neurosurgeon and the neuroradiologist to avoid post-operative misidentification.

The ATA and its surgical importance: a newly described ligament lying between the dural sac and the ligamentum flavum at the L5 level

STUDY DESIGN

The anatomy of a new ligament in the human spine the ATA is described.

OBJECTIVE

To describe a new ligament; the ATA, which lies between the dural sac and the ligamentum flavum at the L5 level and to discuss it's surgical importance.

SUMMARY OF BACKGROUND DATA

Postoperative cerebrospinal fluid (CSF) leakage translates into longer hospital stays with significant implications for the patient, the health care system, and society as a whole. To avoid injury to the dural sac during lumbar surgery, it is crucial to know the surgical anatomy and its variations.

METHODS

The length and the number of ATAs were examined in 14 consecutive patients, which underwent an L5 laminoflavectomy in our department. The ATA and its anatomic landmarks are described here for the first time in the literature. We named this ligament the ATA; reminding us to pay attention to the Terminal Attachment.

RESULTS

The presence of the ATA is demonstrated in 10 patients (71%). There was a double ATA in four patients (40%). The mean length of the ATA was 7.7 ± 1.8 mm. The ATA originates from the dorsal surface of the dura mater at the level of the superior border of the superior facet of the S1 vertebra and projects toward the ligamentum flavum. Histologic examination of the ATA revealed fibrous connective tissue.

CONCLUSION

In this preliminary study, we have described a new ligament, the ATA, between the dural sac and the ligamentum flavum at the L5 level. The ATA is an important structure that creates a potential risk for inadvertent dural lacerations during flavectomy. Dissecting the ATA before the flavectomy may be an important step in reducing postoperative cerebrospinal fluid leaks, which may result in significant benefits for patients and health care organizations.

Evaluation of Fibrin Sealants for Central Nervous System Sealing in the Mongrel Dog Durotomy Model

BACKGROUND:

Watertight repair of the dura is imperative after neurosurgical procedures involving the brain or spinal cord because inadequately treated leakage of cerebrospinal fluid (CSF) from punctured dura can have serious consequences such as meningitis, arachnoiditis, or epidural abscess.

OBJECTIVE:

To assess the efficacy of Evicel Fibrin Sealant (Human) to prevent CSF leakage using a 2.0-cm durotomy mongrel dog repair model and to compare the tissue response with Tisseel (a fibrin sealant) and Duraseal (a synthetic polyethylene glycol [PEG] hydrogel sealant).

METHODS:

The canine durotomy repair model was used. This well-characterized model assesses the ability of sealants to achieve intraoperative watertight seals of the dura mater, as well as long-term safety and efficacy. This study included 27 mongrel dogs and had a 28-day duration.

RESULTS:

The 3 sealants were 100% effective in preventing CSF leakage intraoperatively at 15 mm Hg. The 2 fibrin sealants were 100% effective in postoperative sealing; the PEG hydrogel was not. Microscopically, the tissue changes induced by Evicel at the durotomy site were similar in nature except for foamy macrophages seen only with the PEG hydrogel. The extent and severity of adhesions at 28 days were less with the fibrin sealants than with the PEG hydrogel.

CONCLUSION:

Evicel, a fibrin sealant, was safe and effective in achieving and maintaining a watertight seal of the dura. The performance of the fibrin sealants was similar to that of the synthetic PEG hydrogel sealant with the exception of a Duraseal seal, which leaked.

Dural tears in spine surgery

Dural tears are among the most commonly seen complications in spine surgery. Most studies in the literature indicate that long-term outcomes are not negatively affected, provided that the tears are diagnosed early and managed appropriately. Direct suture repair remains the preferred method for the management of durotomy caused by or found during surgery. However, recent literature reports encouraging results with sutureless repair. Understanding dural anatomy, dural healing, and cerebrospinal fluid dynamics is helpful in choosing among the available management options for dural tear.

Use of autologous fibrin sealants to treat ganglion cysts: a report of two cases

Two patients underwent arthroscopy-guided injections of autologous fibrin sealants to treat ganglion cysts causing suprascapular nerve palsies. After at least 2 years of follow-up, both patients had no suprascapular nerve symptoms and their external rotation strength had returned to normal. Magnetic resonance imaging revealed no evidence of ganglion cyst recurrence.

A pilot study of fat allograft transplantation in immunocompetent rabbits for potential neurosurgical applications

OBJECT

The authors investigated the feasibility of using fat allografts (chemically treated to reduce the host immune response) for neurosurgical applications.

METHODS

Subcutaneous fat specimens collected from New Zealand White rabbits were treated with DNAse I and sodium deoxycholate to reduce immunogenicity before subcutaneous, midscapular implantation in immunocompetent recipient rabbits. Allograft incorporation and the host-allograft response were examined at 1, 6, and 11 weeks by histopathological analysis. Control specimens of autograft and untreated fat allograft implants were examined for comparison.

RESULTS

The host immune response was markedly reduced in the region around the chemically treated fat allografts when compared with untreated allografts, and was similar to the tolerant host response to autografts.

CONCLUSIONS

Based on their results, the authors suggest that fat allografts processed for reduced immunogenicity may be a convenient, viable alternative for neurosurgical applications.

The role of fibrin sealants in orthopaedic surgery

Blood conservation, specifically the avoidance of allogeneic blood transfusion, is becoming an important aspect of preoperative planning and intraoperative decision making in orthopaedic surgery. Knee and hip arthroplasty, as well as certain spine procedures, place patients at risk of significant blood loss. Fibrin sealants are topically applied hemostatic agents that reduce the time required to achieve hemostasis as well as the volume of blood loss. Fibrin sealants may provide additional benefits beyond hemostasis, such as improvements in wound healing and postoperative range of motion as well as lower rates of wound infections.

A new fibrin sealant from Crotalus durissus terrificus venom: applications in medicine

Fibrin sealant, a widely available tissue adhesive, has been used since 1940 in a variety of clinical applications. Commercially available fibrin sealant products are synthesized from bovine thrombin and human fibrinogen, which may transmit infectious diseases, and recipients may also develop antibodies against bovine thrombin. Bearing these disadvantages in mind, a new fibrin sealant was developed in 1989 by a group of researchers from the Center for the Study of Venoms and Venomous Animals, in Sao Paulo State, Brazil. The main purpose was to produce an adhesive fibrin without using human blood, to avoid transmitting infectious diseases. The components of this novel sealant were extracted from large animals and a serine proteinase extracted from Crotalus durissus terrificus snake venom. The applicability of this sealant was tested in animals and humans with beneficial results. The new fibrin sealant can be a useful tool clinically due to its flexibility and diversity of applications. This sealant is a biological and biodegradable product that (1) does not produce adverse reactions, (1) contains no human blood, (3) has a good adhesive capacity, (4) gives no transmission of infectious diseases, and (5) may be used as an adjuvant in conventional suture procedures. The effectiveness of this new fibrin sealant is reviewed and its development and employment are described.

Fibrin: a versatile scaffold for tissue engineering applications

Tissue engineering combines cell and molecular biology with materials and mechanical engineering to replace damaged or diseased organs and tissues. Fibrin is a critical blood component responsible for hemostasis, which has been used extensively as a biopolymer scaffold in tissue engineering. In this review we summarize the latest developments in organ and tissue regeneration using fibrin as the scaffold material. Commercially available fibrinogen and thrombin are combined to form a fibrin hydrogel. The incorporation of bioactive peptides and growth factors via a heparin-binding delivery system improves the functionality of fibrin as a scaffold. New technologies such as inkjet printing and magnetically influenced self-assembly can alter the geometry of the fibrin structure into appropriate and predictable forms. Fibrin can be prepared from autologous plasma, and is available as glue or as engineered microbeads. Fibrin alone or in combination with other materials has been used as a biological scaffold for stem or primary cells to regenerate adipose tissue, bone, cardiac tissue, cartilage, liver, nervous tissue, ocular tissue, skin, tendons, and ligaments. Thus, fibrin is a versatile biopolymer, which shows a great potential in tissue regeneration and wound healing.

The contribution of RCTs to quality management and their feasibility in practice

The randomized controlled trial (RCT) is generally accepted as the most reliable method of conducting clinical research. To obtain an unbiased evaluation of the effectiveness of spine surgery, patients should be randomly assigned to either new or standard treatment. The aim of the present article is to provide a short overview of the advantages and challenges of RCTs and to present a summary of the conclusions of the Cochrane Reviews in spine surgery and later published trials in order to evaluate their contribution to quality management and feasibility in practice. From the searches, 130 RCTs were included, 95 from Cochrane Reviews and systematic reviews, and 35 from additional search. No study comparing surgery with sham surgery was identified. The first RCT in spine surgery was published in 1974 and compared debridement and ambulatory treatment in tuberculosis of the spine. The contribution of RCTs in spinal surgery has markedly increased over the last 10 years, which indicates that RCTs are feasible in this field. The results demonstrate missing quality specifications. Despite the number of published trials there is conflicting or limited evidence to support various techniques of instrumentation. The only intervention that receives strong evidence is discectomy for faster relief in carefully selected patients due to lumbar disc prolapse with sciatica. For future trials, authors, referees, and editors are recommended to follow the CONSORT statement. RCTs provide evidence to support clinical opinions before implementation of new techniques, but the individual clinical experience is still important for the doctor who has to face the patient.

The use of fibrin glue to stop venous bleeding in the epidural space, vertebral venous plexus, and anterior cavernous sinus: technical note

OBJECTIVE

Various techniques have been used to stop venous bleeding from the epidural space, vertebral venous plexus, and cavernous sinus. Here, we describe our experience with the use of fibrin glue to stop venous bleeding in these areas.

METHODS

During the last 8 years, the senior author (LNS) has used injection of Tisseel fibrin glue (Baxter Healthcare Corp., Deerfield, IL) into the epidural space (n = 200 patients), anterior cavernous sinus (n = 46 patients), vertebral venous plexus (n = 20 patients), and superior petrosal sinus (n = 20 patients) to assist in hemostasis. The technical nuances are illustrated in three videos.

RESULTS

Injection of fibrin glue in the epidural space, anterior cavernous sinus, and vertebral venous plexus yielded good results in assisting with hemostasis. Two patients experienced complications caused by occlusion of veins draining the brainstem after fibrin glue was injected into the superior petrosal sinus.

CONCLUSION

Fibrin glue injection is an excellent option for hemostasis in the epidural space, anterior cavernous sinus, and vertebral venous plexus. However, based on our experience, fibrin glue injection into the superior petrosal sinus is not recommended.

Taming the Cavernous Sinus: Technique of Hemostasis Using Fibrin Glue

Objective:

Improved understanding of the microsurgical anatomy of the cranial base region has made surgery in and through the cavernous sinus safer. However, continuous venous oozing that occurs during cavernous sinus surgery can cause significant blood loss and poor visualization. We describe a technique that will help minimize cavernous sinus bleeding and improve the safety of the surgical steps.

Methods:

The lateral wall of the cavernous sinus is exposed. Cavernous sinus access windows between the V1 and V2 branches of the trigeminal nerve and posterior to the clinoidal internal carotid artery are used to inject fibrin glue into the different cavernous sinus compartments. Postoperative follow-up cerebral angiography in basilar apex aneurysms clipped using the transcavernous approach were evaluated for cavernous sinus patency during the venous phase.

Results:

Fibrin glue injection between V1 and V2 obliterated the lateral cavernous sinus compartment. Fibrin glue injection posterior to the clinoidal segment of the internal carotid artery obliterated the medial compartment of the cavernous sinus. These steps were used in 217 surgical procedures (95 benign and 9 malignant neoplastic lesions; 113 aneurysms). There were no significant clinical side effects. Follow-up angiographic controls of basilar aneurysms operated on via the transcavernous approach consistently showed the reestablishment of flow within the cavernous sinus as early as 2 to 3 months postoperatively.

Conclusion:

Presently, the use of hemostatic agents and the better understanding of the microsurgical anatomy of the cranial base and cavernous sinus enable us to tame the cavernous sinus and operate in and around it with a high degree of safety.

Cerebrospinal fluid (CSF) leak and pseudomeningocele formation after posterior fossa tumor resection in children: a retrospective analysis

OBJECTIVE

The purpose of this study was to determine the incidence of pseudomeningocele and cerebrospinal fluid (CSF) leak after posterior fossa tumor surgery and to analyze factors that may be associated with these conditions. In particular, we wished to determine if there was evidence to support the hypothesis that the use of tissue glue, dural grafts, or external ventricular drainage (EVD) prevented CSF from leaking outside the closed dura.

MATERIALS AND METHODS

A retrospective chart review was carried out of posterior fossa tumor resections at British Columbia's Children's Hospital. Information was collected regarding tumor location, surgical approach, CSF diversion, dural grafting, and use of tissue glue. Multiple univariate analyses and step-wise logistic regression were performed to identify factors associated with pseudomeningocele formation or CSF leak. A pseudomeningocele was said to be present if it was noted in the clinical records or if a fluid collection was present superficial to the craniotomy flap on a postoperative CT or MR scan.

RESULTS

Out of 174 posterior fossa operations, 53 pseudomeningoceles with or without CSF leak were identified along with five CSF leaks in the absence of pseudomeningocele (33%). None of the factors examined reached statistical significance, although there was a trend towards higher rates in patients with external CSF drainage (P=0.06631), dural graft usage (p=0.06492), and patients in whom tissue glue was used (p=0.06181). On logistic regression, only tissue glue use and external CSF drainage were associated with increased incidence of pseudomeningocele and/or CSF leak.

CONCLUSION

In this retrospective study, the use of tissue glue, dural grafts, and external ventricular drainage was not associated with a reduced rate of clinically or radiologically diagnosed pseudomeningocele formation or postoperative CSF leak. The results of this study provide a basis for planning a randomized controlled trial to determine the effectiveness of tissue glue and/or dural grafting in preventing these complications.