The dural repair using the combination of polyglycolic acid mesh and fibrin glue and postoperative management in spine surgery

Modification to the placement of the navigation reference frame in posterior corrective fusion of spinal deformity with myelomeningocele: a series of 6 cases

To show a modified placement of the navigation reference frame in posterior corrective fusion of spinal deformity with myelomeningocele. This was a retrospective, single-surgeon case series, and IRB-approved study. Six consecutive patients (one male and five females) who were diagnosed with spinal deformity with myelomeningocele underwent posterior corrective fusion surgery from the upper thoracic spine to the pelvis with preoperative computed tomography navigation (pCTN). At the level of the spina bifida, where posterior elements such as the spinous process were missing, the reference frame of the pCTN was placed on the flipped lamina or pedicles, and a pedicle screw (PS) or iliac screw (IS) was inserted. Screw deviation was investigated by using postoperative CT. A total of 55 screws were placed at the spina bifida level and pelvis. Of these, 12 ISs were placed on each side in each case. The screws placed using the pCTN were not reinserted or removed intraoperatively or postoperatively. However, only one PS was found to have perforated the spinal canal on postoperative CT but was left in place because it caused no neurological problem. By modifying the placement of the reference frame, such as placing it on the flipped lamina or pedicles, pCTN could be used even at the levels of the spina bifida, where the posterior elements are missing, to accurately place PSs and various types of ISs.

Postoperative neurological complications in intradural extramedullary tumors: A 10-year experience of a single center

BACKGROUND

Intradural extramedullary spinal cord tumors (IDEMs) cause neurological symptoms due to compression of the spinal cord and caudal nerves. The purpose of this study was to investigate the incidence of postoperative neurological complications after surgical resection of IDEM and to identify factors associated with such postoperative neurological complications.

METHODS

We retrospectively analyzed 85 patients who underwent tumor resection for IDEM between 2010 and 2020. We investigated the postoperative worsening of neurological disorders. The patients were divided into two groups: those with and without postoperative neurological complications. Patient demographic characteristics, tumor level, histological type, and surgery-related factors were also compared.

RESULTS

The mean age at the time of surgery was 57.4 years, and histological analysis revealed 45 cases of schwannoma, 34 cases of meningioma, three cases of myxopapillary ependymoma, one case of ependymoma, one case of hemangioblastoma and one case of lipoma. There were five cases (5.8%) of postoperative neurological complications, and four patients improved within 6 months after surgery, and one patient had residual worsening. There were no statistically significant differences in age, sex, tumor location, preoperative modified McCormick Scale grade, histology, tumor occupancy, or whether fixation was performed in the presence or absence of postoperative neurological complications. All four cases of meningioma with postoperative neurological complications had preoperative neuropathy and meningiomas were located in the anterior or lateral thoracic spine.

CONCLUSIONS

Neurological complications after surgical resection for IDEM occurred in 5.8% of patients. Meningiomas with postoperative neurological complications located anteriorly or laterally in the thoracic spine.

Clinical management of dural defects: A review

Dural defects are common in spinal and cranial neurosurgery. A series of complications, such as cerebrospinal fluid leakage, occur after rupture of the dura. Therefore, treatment strategies are necessary to reduce or avoid complications. This review comprehensively summarizes the common causes, risk factors, clinical complications, and repair methods of dural defects. The latest research progress on dural repair methods and materials is summarized, including direct sutures, grafts, biomaterials, non-biomaterial materials, and composites formed by different materials. The characteristics and efficacy of these dural substitutes are reviewed, and these materials and methods are systematically evaluated. Finally, the best methods for dural repair and the challenges and future prospects of new dural repair materials are discussed.

Tensile properties of human spinal dura mater and pericranium

Autologous pericranium is a promising dural graft material. An optimal graft should exhibit similar mechanical properties to the native dura, but the mechanical properties of human pericranium have not been characterized, and studies of the biomechanical performance of human spinal dura are limited. The primary aim of this study was to measure the tensile structural and material properties of the pericranium, in the longitudinal and circumferential directions, and of the dura in each spinal region (cervical, thoracic and lumbar) and in three directions (longitudinal anterior and posterior, and circumferential). The secondary aim was to determine corresponding constitutive stress-strain equations using a one-term Ogden model. A total of 146 specimens were tested from 7 cadavers. Linear regression models assessed the effect of tissue type, region, and orientation on the structural and material properties. Pericranium was isotropic, while spinal dura was anisotropic with higher stiffness and strength in the longitudinal than the circumferential direction. Pericranium had lower strength and modulus than spinal dura across all regions in the longitudinal direction but was stronger and stiffer than dura in the circumferential direction. Spinal dura and pericranium had similar strain at peak force, toe, and yield, across all regions and directions. Human pericranium exhibits isotropic mechanical behavior that lies between that of the longitudinal and circumferential spinal dura. Further studies are required to determine if pericranium grafts behave like native dura under in vivo loading conditions. The Ogden parameters reported may be used for computational modeling of the central nervous system. Graphical abstract.

Comparative Study of Circumferential Decompression and Posterior Decompression in Palliative Surgery for Metastatic Thoracic Spinal Tumors

STUDY DESIGN

This was a case-control study.

OBJECTIVE

The present study aimed to evaluate the significance of circumferential tumor resection around the spinal cord in palliative decompression surgery for patients with metastatic spinal cord compression (MSCC) in the thoracic spine.

SUMMARY OF BACKGROUND DATA

Although the benefits of palliative surgery for MSCC are well known, the significance of circumferential tumor resection with cord compression has not yet been clarified.

MATERIALS AND METHODS

We retrospectively compared the outcomes of 45 and 34 patients with incomplete paralysis of modified Frankel grade B-D caused by MSCC with anterior cord compression (epidural spinal cord compression grade ≥2) treated at 2 different university hospitals (H1 and H2, respectively). All patients in H1 hospital underwent posterior decompression only, while all patients in H2 hospital underwent full circumferential decompression. We analyzed factors that affect the postoperative ambulatory status. evaluated by the modified Frankel classification.

RESULTS

No significant differences were observed in the epidural spinal cord compression grade, spinal instability neoplastic score, new Katagiri score, revised Tokuhashi score, or postoperative survival between patients in H1 and H2 hospitals. A multivariable logistic regression analysis identified preoperative radiotherapy [odds ratio (OR): 0.23, 95% confidential interval (CI): 0.056-0.94] as a negative risk factor and postoperative chemotherapy (OR: 5.9, 95% CI: 1.3-27.0) as a positive risk factor for an improved ambulatory status. Five and 6 patients in H1 and H2 hospitals, respectively, showed deterioration in the ambulatory status. An older age (OR: 1.1, 95% CI: 1.0-1.2) and preoperative radiotherapy (OR: 10.3, 95% CI: 1.9-55.4) were extracted as significant independent risk factors for deterioration in the ambulatory status. Circumferential decompression did not improve the clinical results of patients regardless of the degree of paralysis.

CONCLUSIONS

Preoperative radiotherapy interfered with the recovery of paralysis, and postoperative chemotherapy improved the ambulatory status. Clinical outcomes did not significantly differ between total circumferential decompression and posterior decompression, although further validation in a small number of cases is needed, such as patients with Frankel grade D.

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.

Perioperative lumbar subarachnoid drainage could not prevent postoperative CSF leakage after spinal cord tumor resection using an artificial dura mater

BACKGROUND

Cerebrospinal fluid (CSF) leakage occurs in patients who undergo dural repair using artificial dura mater. This study aimed to determine if perioperative lumbar subarachnoid drainage could reduce the incidence of postoperative CSF leakage in cases of dural repair using artificial dura mater.

METHODS

We retrospectively analyzed 84 patients (41 men, 43 women; mean age, 52.2 ± 20.1 years) who underwent intradural spinal cord tumor resection and dural repair using artificial dura mater. These patients were divided according to whether they underwent perioperative lumbar subarachnoid drainage (39 patients: D group) or had no drainage (45 patients: ND group). The incidence of radiographic and symptomatic CSF leakage as well as baseline characteristics and operative data were compared between the two groups.

RESULTS

Radiographic CSF leakage was observed in 21 patients (25.0%), including 10 (25.6%) in the D group and 11 (24.4%) in the ND group. Symptomatic CSF leakage was observed in 12 patients (14.2%), including six (15,4%) in the D group and 11 (13.3%) in the ND group. There were no significant differences in the incidence of subcutaneous CSF accumulation and symptomatic CSF leakage between the two groups. In cases with symptomatic CSF leakage, the onset time of CSF leakage tended to be earlier (5.7 days vs 15.7 days), and the treatment period tended to be longer (5.8 weeks vs 2.8 weeks) in the ND group than in the D group.

CONCLUSIONS

Perioperative lumbar subarachnoid drainage did not reduce the incidence of either radiographic or symptomatic CSF leakage. However, it might shorten the treatment period and reduce refractory CSF leakage, which requires multiple treatments over a long period.

Hydrogel-mesh composite for wound closure

During operations, surgical mesh is commonly fixed on tissues through fasteners such as sutures and staples. Attributes of surgical mesh include biocompatibility, flexibility, strength, and permeability, but sutures and staples may cause stress concentration and tissue damage. Here, we show that the functions of surgical mesh can be significantly broadened by developing a family of materials called hydrogel-mesh composites (HMCs). The HMCs retain all the attributes of surgical mesh and add one more: adhesion to tissues. We fabricate an HMC by soaking a surgical mesh with a precursor, and upon cure, the precursor forms a polymer network of a hydrogel, in macrotopological entanglement with the fibers of the surgical mesh. In a surgery, the HMC is pressed onto a tissue, and the polymers in the hydrogel form covalent bonds with the tissue. To demonstrate the concept, we use a poly(N-isopropylacrylamide) (PNIPAAm)/chitosan hydrogel and a polyethylene terephthalate (PET) surgical mesh. In the presence a bioconjugation agent, the chitosan and the tissue form covalent bonds, and the adhesion energy reaches above 100 J⋅m^-2 At body temperature, PNIPAAm becomes hydrophobic, so that the hydrogel does not swell and the adhesion is stable. Compared with sutured surgical mesh, the HMC distributes force over a large area. In vitro experiments are conducted to study the application of HMCs to wound closure, especially on tissues under high mechanical stress. The performance of HMCs on dynamic living tissues is further investigated in the surgery of a sheep.

Osteogenic response under the periosteum by magnesium implantation in rat tibia

This study was designed to examine osteoconductive effects of Mg in rats tibia. The animals were sacrificed after 1, 2, and 8 weeks. The elemental analysis was performed using SEM/EDX at week 1. Following X-ray micrography at weeks 2 and 8, samples were embedded in paraffin. The expression of osteocalcin was observed by immunohistochemical staining. The element concentrations of fibrous capsules around the specimens were also measured by ICP-MS. The concentrations of Ca and P on the surface of the Mg specimen increased in SEM/EDX. The tissue specimen showed new bone formation on the bone surface near the implanted area. The concentrations of Mg, Ca, and P were high in the fibrous capsules surrounding Mg. Implantation induced differentiation of osteoblasts, and this process was considered to be associated with new bone formation. Induction of cell differentiation may be influenced by corrosion products in addition to corroding magnesium.

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.

Effect of polyglycolic acid mesh for prevention of pancreatic fistula after pancreatectomy: A systematic review and meta-analysis

Postoperative pancreatic fistula (POPF) is the most common and intractable complication after partial pancreatectomy, with an incidence of 13% to 64%. Polyglycolic acid (PGA) mesh is a new technique that is designed to prevent POPF, and its effect has been evaluated in several randomized controlled trials and some retrospective cohort studies. In this study, we systematically and comprehensively analyzed the efficacy of PGA mesh based on reported studies.We searched Medline, Embase, and Cochrane Library databases in English between January 2010 and October 2019. Analysis was performed by using Review Manger 5.3 software.Three RCTs and 8 nonrandomized studies were eligible with a total of 1598 patients including 884 PGA group patients and 714 control group patients. For pancreatoduodenectomy (PD), distal pancreatectomy (DP), and the 2 partial pancreatectomy (PD or DP), we found significant statistical differences in overall POPF (relative risk [RR] = 0.75, 95% confidence interval [CI] = 0.61-0.91, P = .004; RR = 0.74, 95% CI = 0.57-0.96, P = .02; RR = 0.76, 95% CI = 0.64-0.89, P = .0009, respectively) and clinical pancreatic fistula (PF) (RR = 0.5, 95% CI = 0.37-0.68, P < .00001; RR = 0.31, 95% CI = 0.21-0.46, P < .00001; RR = 0.41, 95% CI = 0.32-0.52, P < .00001, respectively) in favor of PGA. For partial pancreatectomy, significant statistical differences were found in overall complications (RR = 0.77, 95% CI: 0.67-0.88, P = .0002) and estimated blood loss (weighted mean difference [WMD] = -53.58; 95% CI: -101.20 to -5.97, P = .03) in favor of PGA. We did not find significant differences regarding operative time (WMD = -8.86; 95% CI: -27.59 to 9.87, P = .35) and hospital stay (WMD = -2.73; 95% CI: -7.53 to 2.06, P = .26).This meta-analysis shows the benefits of the PGA mesh technique regarding POPF, clinical PF, and postoperative complications. This still needs to be verified by more randomized control trials.

Applications of materials for dural reconstruction in pre-clinical and clinical studies: Advantages and drawbacks, efficacy, and selections

The dura mater provides a barrier to protect the tissue underneath and cerebrospinal fluid. However, dural defects normally cause cerebrospinal fluid leakage and other complications, such as wound infections, meningitis, etc. Therefore, the reconstruction of dura mater has important clinical significance. Current dural reconstruction materials include: homologous, acellular, natural, synthetic, and composite materials. This review comprehensively summarizes the characteristics and efficacy of these dural substitutes, especially in clinical applications, including the advantages and drawbacks of those from different sources, the host tissue response in pre-clinical studies and clinical practice, and the comparison of these materials across different surgical procedures. Furthermore, the selections of materials for different surgical procedures are highlighted. Finally, the challenges and future perspectives in the development of ideal dural repair materials are discussed.

Repair of giant lumbosacral pseudomeningocele with fast-resorbing polymer mesh in a pediatric patient operated for posterior dysraphism

Lumbar pseudomeningocele is a common complication of spinal surgery. It is caused by dural defect, and it consists of extradural collection of cerebrospinal fluid communicating with subarachnoid space. Usually it is small, asymptomatic, and self-limiting. In case of persistence, common treatments include bedrest, puncture and compressive dressing, subcutaneous or subarachnoid lumbar drainage, surgical re-exploration for durotomy closure, and blood patch. Fast-resorbing polymer mesh has been recently used for closure osseous gap in adult patients who developed giant pseudomeningocele following laminectomy. We report the case of a 16-year-old girl, affected by spinal dysraphism, who developed a persistent giant lumbar pseudomeningocele after repeated surgery for detethering of the spinal cord and removing of spinal lipomyelomeningocele. She was finally treated with fast-resorbing polymer mesh, to fill the gap of the posterior osseous defect and to provide support for the thecal sac. For our best knowledge, this is the first pediatric case reported in literature on this kind of reconstruction. In complex cases of pseudomeningocele, implant of fast-resorbing polymer mesh may represent an option also in pediatric patients.

Spinal Dural Repair: A Canadian Questionnaire

STUDY DESIGN

Questionnaire.

OBJECTIVES

Iatrogenic dural tear is a complication of spinal surgery with significant morbidity and cost to the health care system. The optimal management is unclear, and therefore we aimed to survey current practices among Canadian practitioners.

METHODS

A questionnaire was administered to members of the Canadian Neurological Surgical Society designed to explore methods of closure of iatrogenic durotomy.

RESULTS

Spinal surgeons were surveyed anonymously with a 55% response rate (n = 91). For pinhole-sized tears, there is no agreement in the methods of closure, with a trend toward sealant fixation (36.7%). Medium- and large-sized tears are predominantly closed with sutures and sealant (67% and 80%, respectively). Anterior tears are managed without primary closure (40.2%), or using sealant alone (48%). Posterior tears are treated with a combination of sutures and sealant (73.8%). Nerve root tears are treated with either sealant alone (50%), or sutures and sealant (37.8%). Tisseal is the preferred sealant (79.7%) over alternatives. With the exception of pin-hole sized tears (39.5%) most respondents recommended bed rest for at least 24 hours in the setting of medium (73.2%) and large (89.1%) dural tears.

CONCLUSIONS

This study elucidates the areas of uncertainty with regard to iatrogenic dural tear management. There is disagreement regarding management of anterior and nerve root tears, pinhole-sized tears in any location of the spine, and whether patients should be admitted to hospital or should be on bed rest following a pinhole-sized dural tear. There is a need for a robust comparative research study of dural repair strategies.