Hydrostatic comparison of nonpenetrating titanium clips versus conventional suture for repair of spinal durotomies

The Use of Cranial Aneurysm Clips for Repair of Incidental Lumbar Durotomy: Operative Technique and Case Series

BACKGROUND

Incidental durotomy is a common complication of posterior lumbar spine surgery; however, effective and durable methods for primary repair remain elusive. Multiple existing techniques have previously been reported and extensively described, including sutured repair and the use of nonpenetrating titanium clips. The use of cranial aneurysm clips for primary repair of lumbar durotomy serves as a safe and effective alternative to obtain watertight closure of a dural tear.

METHODS

We performed a retrospective review of patients at a single institution who underwent primary repair of an incidental lumbar durotomy with the use of an aneurysm clip during open posterior lumbar surgery between 2012 and 2023. Patient demographics, operative details, and postoperative metrics were collected and examined to evaluate the safety and efficacy of the novel technique.

RESULTS

A total of 51 patients were included for analysis. Four patients underwent durotomy repair with an aneurysm clip alone, 27 patients were repaired with an aneurysm clip and fibrin glue, and 20 patients underwent repair with an aneurysm clip, fibrin glue, and a collagen dural substitute. Three patients (5.9%) reported headaches: 2 (3.9%) with pseudomeningocele and 1 (2%) with wound leakage. Two patients (3.9%) had treatment failure with a return to the operating room for repair of a cerebrospinal fluid leak.

CONCLUSIONS

To the best of our knowledge, we report the largest series of patients undergoing primary repair of incidental durotomy with the use of an aneurysm clip. Use of an aneurysm clip is noted to be a safe, quick, and effective method of primary repair compared with existing repair techniques such as sutured repair or nonpenetrating titanium clips.

Application of nonpenetrating titanium clips for primary spinal dural closure following intradural tethered cord release in pediatric tethered cord syndrome: Profile of safety, efficacy, efficiency, and complications

Introduction

Surgical treatment for tethered cord syndrome (TCS) involves a laminotomy for intradural lysis of filum terminale (LFT), with the goal of releasing excess tension on the conus medullaris by dividing the filum terminale. While LFT alleviates clinical symptoms, it is associated with risks and complications, including cerebrospinal fluid (CSF) leak and infection, either superficial or deep. Some risks and complications of LFT relate to efficiency and quality of primary dural closure and its downstream effects. We sought to assess the utility of nonpenetrating titanium clips (TC) for primary dural closure with a particular focus on operative duration, associated costs, and complication profiles in a series of pediatric patients undergoing LFT, hypothesizing that TC utilization leads to more efficient closure and therefore potentially lower costs and potentially associated anesthetic length and risks.

Methods

A 4-surgeon, single institution series of 28 pediatric patients underwent LFT with subsequent dural closure performed with either the AnastoClip® nonpenetrating titanium clips or traditional suture technique between July 2022 and May 2023. In order to compare the safety, efficacy, and cost-effectiveness between the two dural closure techniques, relevant data were collected including patient demographics and rates of CSF leak, infection at three-month follow-up, and reoperation. Operative durations and times from beginning to end of dural closure were recorded.

Results

A total of 28 pediatric patients (mean age: 5.9 years, 43% female, range: 0.71-17 years) with TCS underwent LFT. All patients underwent procedures involving intradural surgery of the lumbar region. Dural closure was performed using traditional suturing in 19 patients (67.9%) and TC in 9 (32.1%). With respect to duration of dural closure, the average time to closure using traditional suturing techniques was 1271 s (or 21 min and 11 s), while the average time for TC was 265 s (or 4 min and 25 s). At three-month follow-up, one case of cerebrospinal fluid (CSF) leak or infection was observed in the suture cohort and required reoperation.

Conclusion

Clinical outcomes in the TC group were excellent, consistent with previous reports; our findings further suggest that TCs result in more efficient dural closure than traditional suturing techniques. Our findings suggest that TC may be a safe, efficacious, and more efficient alternative to traditional suture for achieving dural closure in pediatric patients with TCS undergoing LFT surgery.

Efficacy of patch technique for dural tear repair using hydrogel sealant: a pilot study

BACKGROUND CONTEXT

Dural tear is one of the common complications of lumbar spine surgery. Suture repair is often difficult due to the requirement of meticulous suture technique in limited space. Dural tear repair is particularly challenging in minimally invasive spine surgery. The patch technique, applying patch material and glue without suture, is an alternative method for dural tear repair.

PURPOSE

To verify the efficacy of patch technique for dural tear repair using polyethylene glycol hydrogel sealant and to compare patch materials.

STUDY DESIGN/SETTING

Basic research.

METHODS

There were three study groups: Group 1 (control group, n=4) had hydrogel sealant alone, Group 2 (n=8) had collagen sheet patch and hydrogel sealant, Group 3 (n=8) had mesh sheet patch and hydrogel sealant. A 4-mm durotomy was made in a piece of bovine dura using an arterial punch. Patch material (collagen or mesh sheet) was placed over the dural tear with 2 mm margin and then sprayed with hydrogel sealant. The pressure in the system was increased by 10 mm Hg and monitored. When the leakage occurred, the pressure threshold was measured.

RESULTS

The mean pressure threshold for leakage was 32.5 (Standard deviation=15.0), 66.3 (37.0), and 88.8 (27.5) mm Hg for Group 1, 2 and 3, respectively. The mean pressure threshold for leakage for Group 3 was significantly higher than that for Group 1 (p<.05). There was no significant difference in the mean pressure threshold for leakage between Groups 1 and 2, and Groups 2 and 3.

CONCLUSIONS

Patch technique using mesh sheet and hydrogel sealant demonstrated significantly higher mean pressure threshold for leakage compared with hydrogel sealant alone.

CLINICAL SIGNIFICANCE

Patch technique using mesh sheet and hydrogel sealant without suture is potentially a reasonable option for dural tear repair in lumbar spine surgery.

Novel use of nonpenetrating titanium clips for pediatric primary spinal dural closure: A technical note

BACKGROUND

Dural closure is an important part of any pediatric spinal procedure with intradural pathology to prevent post-operative cerebrospinal fluid (CSF) egress and associated complications. Utilization of nonpenetrating titanium clips is one closure option that may have technical advantages such as ease of use and amenability to a narrow surgical corridor. No data exist on the efficacy of these clips for pediatric spinal dural closure.

METHODS

A single surgeon case series of 152 pediatric patients underwent procedures involving lumbar durotomy with subsequent dural closure using the AnastoClip® nonpenetrating titanium clip closure system. Rates of infection and cerebrospinal fluid leak were measured during the follow-up period.

RESULTS

A total of 152 pediatric patients (mean age: 6.25 ± 5.85 years, 50.7 % female) underwent intradural surgery with clip closure. The mean follow-up time was 57.0 ± 28.5 months. All patients were initially indicated for procedures involving spinal durotomy, with a majority being isolated tethered cord release (84.2 %). Others required tethered cord release and excision of a lipomyelomeningocele, spinal meningioma or arachnoid cyst (15.8 %). Post operative CSF leak occurred in two (1.32 %) patients at 11 and 18 days. Only one (0.66 %) patient was diagnosed with an infection, which was in a separate patient from those that had CSF leaks.

CONCLUSION

The remarkably low incidence of post-operative CSF leak and infection with nonpenetrating titanium clips suggests a strong safety and efficacy profile for this form of dural closure in a pediatric cohort. Further research evaluating this technique is required to fully demonstrate its acceptability as a cost-effective alternative to traditional suture-based closure.

Tension pneumocephalus following endoscopic resection of a mediastinal thoracic spinal tumor: A case report

BACKGROUND

Pneumocephalus is a rare complication presenting in the postoperative period of a thoracoscopic operation. We report a case in which tension pneumocephalus occurred after thoracoscopic resection as well as the subsequent approach of surgical management.

CASE SUMMARY

A 66-year-old man who received thoracoscopic resection to remove an intrathoracic, posterior mediastinal, dumbbell-shaped, pathology-proven neurogenic tumor. The patient then reported experiencing progressively severe headaches, especially when in an upright position. A brain computed tomography scan at a local hospital disclosed extensive pneumocephalus. Revision surgery for resection of the pseudomeningocele and repair of the cerebrospinal fluid leakage was thus arranged for the patient. During the operation, we traced the cerebrospinal fluid leakage and found that it might have derived from incomplete endoscopic clipping around the tumor stump near the dural sac at the T3 level. After that, we wrapped and sealed all the possible origins of the leakage with autologous fat, tissue glue, gelfoam, and duraseal layer by layer. The patient recovered well, and the computed tomography images showed resolution of the pneumocephalus.

CONCLUSION

This report and literature review indicated that the risk of developing a tension pneumocephalus cannot be ignored and should be monitored carefully after thoracoscopic tumor resection.

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.

Primary Repair of Posteriorly Located Anterior Skull Base Dural Defects Using Nonpenetrating Titanium Clips in Cranial Trauma

Objective Primary repair of posteriorly located anterior skull base (ASB) dural defects following cranial trauma is made difficult by narrow operative corridors and adherent dura mater. Inadequate closure may result in continued cerebrospinal fluid (CSF) leak and infectious sequelae. Here, we report surgical outcomes following the use of nonpenetrating titanium microclips as an adjunctive repair technique in traumatic anterior skull base dural defects extending from the olfactory groove to the tuberculum sellae.

Methods All trauma patients who underwent a bifrontal craniotomy from January 2013 to October 2019 were retrospectively reviewed. Patients with ASB defects located at posterior to the olfactory groove were analyzed. Patients with isolated frontal sinus fractures were excluded. All patients presented with CSF leak or radiographic signs of dural compromise. Patients were divided according to posterior extent of injury. Patient characteristics, imaging, surgical technique, and outcomes are reported.

Results A total of 19 patients who underwent a bifrontal craniotomy for repair of posteriorly located ASB dural defects using nonpenetrating titanium microclips were included. Defects were divided by location: olfactory groove (10/19), planum sphenoidale (6/19), and tuberculum sellae (3/19). No patients demonstrated a postoperative CSF leak. No complications related to the microclip technique was observed. Clip artifact did not compromise postoperative imaging interpretation.

Conclusion Primary repair of posteriorly located ASB dural defects is challenging due to narrow working angles and thin dura mater. Use of nonpenetrating titanium microclips for primary repair of posteriorly located dural defects is a reasonable adjunctive repair technique and was associated with no postoperative CSF leaks in this cohort.

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

Objective

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

Methods

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

Results

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

Conclusion

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

Watertightness of wound closure in lumbar spine-a comparison of different techniques

BACKGROUND

Since a primary watertight dural suture after incidental durotomies has a failure rate of 5-10%, a watertight closure technique of the overlying layers (fascia, subcutis and skin) is essential. The purpose of this cadaveric study was to find the most watertight closure technique for fascia, subcutis and skin.

METHODS

Different suturing techniques were tested for each layer in a sheep cadaveric model by measuring the leakage pressure. The specimens were mounted on a pressure chamber connected to a manometer and a water tube system. Subsequently, the leakage was over-sewed with a cross stitch and the experiment was repeated.

RESULTS

Cross stitch suturing [median =180 mbar (43; 660)] performed best compared to continuous [median =16 mbar (6; 52)] (P=0.003) but not to single knot [median =118 mbar (21; 387)] (P=1.0) or locking stitch suturing [median =109 mbar (3; 149)] (P=0.93) for fascia closure. Continuous suture [median =9 mbar (3; 14)] resulted in a higher leakage pressure than single knot [median =1 mbar (1; 6)] (P=0.017) for subcutaneous closure. No significant differences were found between intracutaneous, Donati-continuous, single knot and locking stitch for skin closures (P=0.075). However, the Donati-continuous stitch closure resulted in higher pressures in tendency. Over-sewing increased median leakage pressure from 8.0 to 11.0 mbar (P=0.068) and from 4.0 to 13.0 mbar (P=0.042) for single knot and for locking stitch skin closures, respectively.

CONCLUSIONS

Cross stitches for the fascia, continuous suturing technique for the subcutis and Donati-continuous stitch for the skin resulted in the most watertight closure within this experimental setting. If leakage occurs, over-sewing might relevantly improve the watertightness of the wound.

Prognostic impact of intra- and postoperative management of dural tear on postoperative complications in primary degenerative lumbar diseases

Aims

The aim of this study was to explore risk factors for complications associated with dural tear (DT), including the types of DT, and the intra- and postoperative management of DT.

Patients and Methods

Between 2012 and 2017, 12 171 patients with degenerative lumbar diseases underwent primary lumbar spine surgery. We investigated five categories of potential predictors: patient factors (sex, age, body mass index, and primary disease), surgical factors (surgical procedures, operative time, and estimated blood loss), types of DT (inaccessible for suturing/clipping and the presence of cauda equina/nerve root herniation), repair techniques (suturing, clipping, fibrin glue, polyethylene glycol (PEG) hydrogel, and polyglycolic acid sheet), and postoperative management (drainage duration). Postoperative complications were evaluated in terms of dural leak, prolonged bed rest, headache, nausea/vomiting, delayed wound healing, postoperative neurological deficit, surgical site infection (SSI), and reoperation for DT. We performed multivariable regression analyses to evaluate the predictors of postoperative complications associated with DT.

Results

In total, 429/12 171 patients (3.5%) had a DT. Multivariable analysis revealed that PEG hydrogel significantly reduced the incidence of dural leak and prolonged bed rest, and that patients treated with sealants (fibrin glue and PEG hydrogel) significantly less frequently suffered from headache. A longer drainage duration significantly increased the incidence of headache, nausea/vomiting, and delayed wound healing. Headache and nausea/vomiting were significantly more prevalent in younger female patients. Postoperative neurological deficit and reoperation for DT significantly depended on the presence of cauda equina/nerve root herniation. A longer operative time was the sole independent risk factor for SSI and was also a risk factor for dural leak, prolonged bed rest, and nausea/vomiting.

Conclusion

Sealants, particularly PEG hydrogel, may be useful in reducing symptoms related to cerebrospinal fluid leakage, whereas prolonged drainage may be unnecessary. Younger female patients should be carefully treated when DT occurs. Cite this article: Bone Joint J 2019;101-B:1115–1121.

Spinal dural closure without suture: Minimizing the risk of CSF leakage with a flat non-penetrating titanium U-clip

BACKGROUND

The classic surgical spinal dural closure technique in surgery on intradural lesions is performed with continuous suture or loose stitches using 4-0 to 6-0 polypropylene monofilament or nylon suture. Dural closure with suture causes irritant damage to the dural/arachnoid interface. The penetrating suture causes new dural holes. Even the needle of the suture can cause harm to the patient and the surgeon. For these reasons, other non-penetrating techniques for dural closure have been sought.

OBJECTIVE

The purpose of this review was to show the efficacy of using the titanium clip (U-clip) (Ligaclip-MCA of Ethicon Endo-Surgery, LLC, Medical GmbH, Norderstedt, Germany) with a flat internal surface in spinal neurosurgical procedures, and to evaluate the effects of its use on post-operative magnetic resonance imaging (MRI).

METHODS

We performed a retrospective analysis of a cohort of 50 consecutive patients who underwent intradural spinal surgeries for intradural spinal lesions in the neurosurgery department of our institution between 2013 and 2018.

RESULTS

The mean follow-up period was 27 months. No patient developed a post-operative cerebrospinal fluid (CSF) dural-cutaneous fistula. CSF leakage was not observed in the control MRIs at 6 weeks.

CONCLUSIONS

We describe, for the first time, the use of this type of U-clip with a flat inner side. The non-penetrating titanium U-clip facilitates effective and rapid dural closure at all spinal levels due to its flat internal face when closed. The U-clips did not cause significant artefacts or distortions on the magnetic resonance imaging.

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.

Simulation of Dural Repair in Minimally Invasive Spine Surgery With the Use of a Perfusion-Based Cadaveric Model

BACKGROUND AND IMPORTANCE

In an era of curtailed work hours and concerns over achieving technical proficiency in the repertoire of procedures necessary for independent practice, many residencies have turned to model simulation as an educational adjunct. Cerebrospinal fluid (CSF) leak repair after inadvertent durotomy in spine surgery is a fundamental skillset for any spine surgeon. While primary closure with suture is not always necessary for small durotomies, larger defects, on the other hand, must be repaired. However, the dire consequences of inadequate repair dictate that it is generally performed by the most experienced surgeon. Few intraoperative opportunities, therefore, exist for CSF leak repair by trainees.

OBJECTIVE

To simulate dural repair in spine surgery using minimal-access techniques.

METHODS

A cohort of 8 neurosurgery residents was evaluated on their durotomy repair efforts in a perfusion-based cadaveric model.

RESULTS

Study participants demonstrated consistent improvement across trials, with a significant reduction in closure times between their initial (12 min, 7 sec ± 4 min, 43 sec) and final attempts (7 min, 4 sec ± 2 min, 6 sec; P = .02). Moreover, all trainees—irrespective of postgraduate year—were able to accomplish robust dural closures resistant to simulated Valsalva maneuvers. Participants reported high degrees of model realism and exhibited significant increases in postprocedure confidence scores.

CONCLUSION

Our results support use of perfusion-based simulation models as a complement to neurosurgery training, as it affords unrestricted opportunities for honing psychomotor skillsets when resident learning is increasingly being challenged by work-hour limitations and stricter oversight in the context of value-based healthcare.

Dural Closure in Confined Spaces of the Skull Base with Nonpenetrating Titanium Clips

BACKGROUND

Dural repair in areas with limited operative maneuverability has long been a challenge in skull base surgery. Without adequate dural closure, postoperative complications, including cerebrospinal fluid (CSF) leak and infection, can occur.

OBJECTIVE

To show a novel method by which nonpenetrating, nonmagnetic titanium microclips can be used to repair dural defects in areas with limited operative access along the skull base.

METHODS

We reviewed 53 consecutive surgical patients in whom a dural repair technique utilizing titanium microclips was performed from 2013 to 2016 at our institution. The repairs primarily involved difficult-to-reach dural defects in which primary suturing was difficult or impractical. A detailed surgical technique is described in 3 selected cases involving the anterior, middle, and posterior fossae, respectively. An additional 5 cases are provided in more limited detail to demonstrate clip artifact on postoperative imaging. Rates of postoperative CSF leak and other complications are reported.

RESULTS

The microclip technique was performed successfully in 53 patients. The most common pathology in this cohort was skull base meningioma (32/53). Additional surgical indications included traumatic dural lacerations (9/53), nonmeningioma tumors (8/53), and other pathologies (4/53). The clip artifact present on postoperative imaging was minor and did not interfere with imaging interpretation. CSF leak occurred postoperatively in 3 (6%) patients. No obvious complications attributable to microclip usage were encountered.

CONCLUSION

In our experience, intracranial dural closure with nonpenetrating, nonmagnetic titanium microclips is a feasible adjunct to traditional methods of dural repair.

Spinal dura mater: biophysical characteristics relevant to medical device development

Understanding the relevant biophysical properties of the spinal dura mater is essential to the design of medical devices that will directly interact with this membrane or influence the contents of the intradural space. We searched the literature and reviewed the pertinent characteristics for the design, construction, testing, and imaging of novel devices intended to perforate, integrate, adhere or reside within or outside of the spinal dura mater. The spinal dura mater is a thin tubular membrane composed of collagen and elastin fibres that varies in circumference along its length. Its mechanical properties have been well-described, with the longitudinal tensile strength exceeding the transverse strength. Data on the bioelectric, biomagnetic, optical and thermal characteristics of the spinal dura are limited and sometimes taken to be similar to those of water. While various modalities are available to visualise the spinal dura, magnetic resonance remains the best modality to segment its structure. The reaction of the spinal dura to imposition of a foreign body or other manipulations of it may compromise its biomechanical and immune-protective benefits. Therefore, dural sealants and replacements are of particular clinical, research and commercial interest. In conclusion, existing devices that are in clinical use for spinal cord stimulation, intrathecal access or intradural implantation largely adhere to traditional designs and their attendant limitations. However, if future devices are built with an understanding of the dura's properties incorporated more fully into the designs, there is potential for improved performance.

The use of a novel perfusion-based cadaveric simulation model with cerebrospinal fluid reconstitution comparing dural repair techniques: a pilot study

BACKGROUND CONTEXT

Watertight dural repair is crucial for both incidental durotomy and closure after intradural surgery.

PURPOSE

The study aimed to describe a perfusion-based cadaveric simulation model with cerebrospinal fluid (CSF) reconstitution and to compare spine dural repair techniques.

STUDY DESIGN/SETTING

The study is set in a fresh tissue dissection laboratory.

SAMPLE SIZE

The sample includes eight fresh human cadavers.

OUTCOME MEASURES

A watertight closure was achieved when pressurized saline up to 40 mm Hg did not cause further CSF leakage beyond the suture lines.

METHODS

Fresh human cadaveric specimens underwent cannulation of the intradural cervical spine for intrathecal reconstitution of the CSF system. The cervicothoracic dura was then exposed from C7-T12 via laminectomy. The entire dura was then opened in six cadavers (ALLSPINE) and closed with 6-0 Prolene (n=3) or 4-0 Nurolon (n=3), and pressurized with saline via a perfusion system to 60 mm Hg to check for leakage. In two cadavers (INCISION), six separate 2-cm incisions were made and closed with either 6-0 Prolene or 4-0 Nurolon, and then pressurized. A hydrogel sealant was then added and the closure was pressurized again to check for further leakage.

RESULTS

Spinal laminectomy with repair of intentional durotomy was successfully performed in eight cadavers. The operative microscope was used in all cases, and the model provided a realistic experience of spinal durotomy repair. For ALLSPINE cadavers (mean: 240 mm dura/cadaver repaired), the mean pressure threshold for CSF leakage was observed at 66.7 (±2.9) mm Hg in the 6-0 Prolene group and at 43.3 (±14.4) mm Hg in the 4-0 Nurolon group (p>.05). For INCISION cadavers, the mean pressure threshold for CSF leakage without hydrogel sealant was significantly higher in 6-0 Prolene group than in the 4-0 Nurolon group (6-0 Prolene: 80.0±4.5 mm Hg vs. 4-0 Nurolon: 32.5±2.7 mm Hg; p<.01). The mean pressure threshold for CSF leakage with the hydrogel sealants was not significantly different (6-0 Prolene: 100.0±0.0 mm Hg vs. 4-0 Nurolon: 70.0±33.1 mm Hg). The use of a hydrogel sealant significantly increased the pressure thresholds for possible CSF leakage in both the 6-0 Prolene group (p=.01) and the 4-0 Nurolon group (p<.01) when compared with mean pressures without the hydrogel sealant.

CONCLUSIONS

We described the feasibility of using a novel cadaveric model for both the study and training of watertight dural closure techniques. 6-0 Prolene was observed to be superior to 4-0 Nurolon for watertight dural closure without a hydrogel sealant. The use of a hydrogel sealant significantly improved watertight dural closures for both 6-0 Prolene and 4-0 Nurolon groups in the cadaveric model.

Mediastinal micro-vessels clipping during lymph node dissection may contribute to reduce postoperative pleural drainage

BACKGROUND

Postoperative pleural drainage markedly influences the length of postoperative stay and financial costs of medical care. The aim of this study is to retrospectively investigate potentially predisposing factors related to pleural drainage after curative thoracic surgery and to explore the impact of mediastinal micro-vessels clipping on pleural drainage control after lymph node dissection.

METHODS

From February 2012 to November 2013, 322 consecutive cases of operable non-small cell lung cancers (NSCLC) undergoing lobectomy and mediastinal lymph node dissection with or without application of clipping were collected. Total and daily postoperative pleural drainage were recorded. Propensity score matching (1:2) was applied to balance variables potentially impacting pleural drainage between group clip and group control. Analyses were performed to compare drainage volume, duration of chest tube and postoperative hospital stay between the two groups. Variables linked with pleural drainage in whole cohort were assessed using multivariable logistic regression analysis.

RESULTS

Propensity score matching resulted in 197 patients (matched cohort). Baseline patient characteristics were matched between two groups. Group clip showed less cumulative drainage volume (P=0.020), shorter duration of chest tube (P=0.031) and postoperative hospital stay (P=0.022) compared with group control. Risk factors significantly associated with high-output drainage in multivariable logistic regression analysis were being male, age >60 years, bilobectomy/sleeve lobectomy, pleural adhesion, the application of clip applier, duration of operation ≥220 minutes and chylothorax (P<0.05).

CONCLUSIONS

This study suggests that mediastinal micro-vessels clipping during lymph node dissection may reduce postoperative pleural drainage and thus shorten hospital stay.

Durotomy repair in minimally invasive transforaminal lumbar interbody fusion by nonpenetrating clips

Background:

Closure of the dura defect may be easy to perform in open lumbar surgery but could be difficult in minimally invasive transforaminal lumbar interbody fusions (MIS-TLIF) since MIS-TLIF was done through a small tube, which limited the use of standard dural repair instruments. We used nonpenetrating titanium clips that were originally designed for the vascular anastomoses to repair the dura defect, which is never described in the literature.

Methods:

We presented a case of spinal stenosis with incidental durotomy while performing MIS-TLIF. We closed the dura laceration with three medium-sized nonpenetrating titanium clips (AnastoClip Vessel Closure System, LeMaitre Vascular, Inc., Burlington, MA).

Results:

Nonpenetrating titanium clips have the benefits of being technically easy to use, reduced durotomy repair time, decreased bed rest due to related medical complications, superior postoperation with immediate hydrostatic strength, and better reapproximation if it fails to clip successfully. As for the postoperation follow up, clips are tiny and reveal no obvious artifact, especially in cases where the pedicle screws are already causing much artifact.

Conclusion:

Primary dural closure during MIS-TLIF with clips is an effective way in cases that involve limited tubular space.