The use of titanium non-penetrating clips to close the spinal dura

Endoscopic intradural extramedullary lesion excision: Results of augmented duroplasty with artificial dura

Objectives

Prevailing techniques of dural closure in endoscopic spine surgery (ESS) for intradural extramedullary (IDEM) tumor excision increase the steep learning curve and operative time. We aimed to assess the efficacy of augmented duroplasty with artificial dura and share our initial experience of ESS for IDEM excision.

Materials and Methods

We retrospectively analyzed 18 (n = 18) consecutive patients of IDEM tumors operated by ESS using Destandau's endoscopic system. The pre-operative, post-operative, and at the latest follow-up clinical status were recorded in terms of Nurick's grades and the Oswestry Disability Index. Immediate post-operative complications and intraoperative findings were noted from hospital information system and patient records.

Results

The mean (± SD) age of patients was 40.3 ± 14.9 (range 19-64) years, with M: F ratio of 2:1. All the lesions were intradural and present at lumber (n = 6), thoracic (n = 9), and cervical (n = 3) regions. The average duration of surgery, blood loss, hospital stay, and duration of follow-up were 157 ± 45.3 (90-240) min, 168.8 ± 78.8 (30-300) mL, 4.29 ± 1.4 (2-7) days, and 19.3 ± 7.2 (7-36) months, respectively. There were no CSF leaks, wound-related complications, or material-induced adverse events.

Conclusion

In endoscopic IDEM excision, dural closure with artificial dura is efficient in preventing CSF leak. It shortens the steep learning curve and improves the surgical outcome due to technical ease.

The current status and surgical outcome of the minimally invasive techniques for lumbar interbody fusion in India: A systematic review and meta-analysis

Objective

The global shift of trends to minimally invasive spine (MIS) surgery for lumbar degenerative diseases has become prominent in India for few decades. We aimed to assess the current status of MIS techniques for lumbar interbody fusion and their surgical outcomes in the Indian population.

Materials and Methods:

A systematic review (following Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines) was performed using PubMed and Google Scholar till November 2020. The primary (visual analog scale [VAS] and oswestry disability index [ODI] scores; intraoperative blood loss; duration of surgery; duration of hospital stay, and fusion rate) and secondary (wound-associated complications and dural tear/cerebrospinal fluid (CSF) leak) outcomes were analyzed using Review Manager 5.4 software.

Results:

A total of 15 studies comprising a total of 1318 patients were included for analysis. The pooled mean of follow-up duration was 26.64 ± 8.43 months (range 5.7–36.5 months). Degenerative spondylolisthesis of Myerding grade I/II was the most common indication, followed by lytic listhesis, herniated prolapsed disc, and lumbar canal stenosis. The calculated pooled standard mean difference (SMD) suggested a significant decrease in postoperative ODI scores (SMD = 5.53, 95% confidence interval [CI] = 3.77–7.29; P < 0.01) and VAS scores (SMD = 6.50, 95% CI = 4.6–8.4; P < 0.01). The pooled mean blood loss, duration of postoperative hospital stay, duration of surgery, and fusion rate were 127.75 ± 52.79 mL, 4.78 ± 3.88 days, 178.59 ± 38.69 min, and 97.53% ± 2.69%, respectively. A total of 334 adverse events were recorded in 1318 patients, giving a complication rate of 25.34%.

Conclusions:

Minimally invasive transforaminal lumbar interbody fusion (TLIF) is the most common minimally invasive technique employed for lumbar interbody fusion in India, while oblique lumbar interbody fusion is in the initial stages. The surgical and outcome-related factors improved significantly after MIS LIF in the Indian population.

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.

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.

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.

Management of intended durotomy in minimally invasive intradural spine surgery

Object

Minimally invasive surgery (MIS) has been increasingly used for the treatment of various intradural spinal pathologies in recent years. Although MIS techniques allow for successful treatment of intradural pathology, primary dural closure in MIS can be technically challenging due to a limited surgical corridor through the tubular retractor system. The authors describe their experience with 23 consecutive patients from a single institution who underwent MIS for intradural pathologies, along with a review of pertinent literature.

Methods

A retrospective review of a prospectively collected surgical database was performed to identify patients who underwent MIS for intradural spinal pathologies between November 2006 and July 2013. Patient demographics, preoperative records, operative notes, and postoperative records were reviewed. Primary outcomes include operative duration, estimated blood loss, length of bed rest, length of hospital stay, and postoperative complications, which were recorded prospectively.

Results

Twenty-three patients who had undergone MIS for intradural spinal pathologies during the study period were identified. Fifteen patients (65.2%) were female and 8 (34.8%) were male. The mean age at surgery was 54.4 years (range 30–74 years). Surgical pathologies included neoplastic (17 patients), congenital (3 patients), vascular (2 patients), and degenerative (1 patient). The most common spinal region treated was lumbar (11 patients), followed by thoracic (9 patients), cervical (2 patients), and sacral (1 patient). The mean operative time was 161.1 minutes, and the mean estimated blood loss was 107.2 ml. All patients were allowed full activity less than 24 hours after surgery. The median length of stay was 78.2 hours. Primary sutured dural closure was achieved using specialized MIS instruments with adjuvant fibrin sealant in all cases. The rate of postoperative headache, nausea, vomiting, and diplopia was 0%. No case of cutaneous CSF fistula or symptomatic pseudomeningocele was identified at follow-up, and no patient required revision surgery.

Conclusions

Primary dural closure with early mobilization is an effective strategy with excellent clinical outcomes in the use of MIS techniques for intradural spinal pathology. Prolonged bed rest after successful primary dural closure appears unnecessary, and the need for watertight dural closure should not prevent the use of MIS techniques in this specific patient population.

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

STUDY DESIGN

Biomechanics.

OBJECTIVE

To compare the hydrostatic strength of suture and nonpenetrating titanium clip repairs of standard spinal durotomies.

SUMMARY OF BACKGROUND DATA

Dural tears are a frequent complication of spine surgery and can be associated with significant morbidity. Primary repair of durotomies with suture typically is attempted, but a true watertight closure can be difficult to obtain because of leakage through suture tracts. Nonpenetrating titanium clips have been developed for vascular anastomoses and provide a close apposition of the tissues without the creation of a suture tract.

METHODS

Twenty-four calf spines were prepared with laminectomies and the spinal cord was evacuated leaving an intact dura. After Foley catheters were inserted from each end and inflated adjacent to a planned dural defect, the basal flow rate was measured and a 1-cm longitudinal durotomy was made with a scalpel. Eight repairs were performed for each material, which included monofilament suture, braided suture, and nonpenetrating titanium clips. The flow rate at 30, 60, and 90 cm of water and the time needed for each closure were measured.

RESULTS

There was no statistically significant difference in the baseline leak rate for all 3 groups. There was no difference in the leakage rate of durotomies repaired with clips and intact specimens at any pressure. Monofilament and braided suture repairs allowed significantly more leakage than both intact and clip-repaired specimens at all pressures. The difference in leak rate increased as the pressure increased. Closing the durotomy with clips took less than half the time of closure with suture.

CONCLUSION

Nonpenetrating titanium clips provide a durotomy closure with immediate hydrostatic strength similar to intact dura whereas suture repair with either suture was significantly less robust. The use of titanium clips was more rapid than that of suture repair.

Safety and efficacy of intradural extramedullary spinal tumor removal using a minimally invasive approach

BACKGROUND

Although minimally invasive surgery for intradural tumors offers the potential benefits of less postoperative pain, a quicker recovery, and the avoidance of long-term instability from multilevel laminectomy, there are concerns over whether one can safely and effectively remove intradural extramedullary tumors in a fashion comparable to open techniques and whether the advantages of minimally invasive surgery are clinically significant.

OBJECTIVE

To review our early experience with minimally invasive techniques for intradural extramedullary tumors of the spine.

METHODS

Thirteen intradural tumors (1 cervical, 6 thoracic, 6 lumbar) in 11 patients were operated on using a muscle-splitting, tube-assisted paramedian oblique approach with hemilaminectomy to access the spinal canal while preserving the spinous process and ligaments. Fluoroscopy and navigation were used to determine the surgical level in all thoracic and lumbar cases.

RESULTS

Satisfactory tumor resection using standard microsurgical techniques was achieved in all but 1 case using a minimally invasive approach. Surgical time and intraoperative blood loss were favorable compared with our open technique cases. There was no postoperative morbidity with the minimally invasive approach, although in 2 patients with tumors in the mid- and upper thoracic spine, the surgical incision was inaccurately placed by 1 level. In 1 case, the approach was converted to open when the tumor could not be found, and postoperatively there was a cerebrospinal fluid leak with infection that required readmission.

CONCLUSION

Intradural extramedullary tumors can be safely and effectively removed using minimally invasive techniques. The pros and cons of minimally invasive vs open surgery are discussed.

Spinal dural closure with nonpenetrating titanium clips in pediatric neurosurgery

OBJECT

The authors report a retrospective review of their experience using nonpenetrating titanium anastomotic clips for dural closure in 27 pediatric cases (26 patients) of spinal surgery for a variety of diagnoses. The goal of this review was to define the utility of these clips in pediatric neurosurgical spinal procedures, identify complications of their use, and assess the effects on postoperative imaging because of their use.

METHODS

Institutional review board approval was obtained for a retrospective chart review of all patients in whom titanium dural clips had been utilized. Patients were identified over a 2-year period using hospital and clinic records, and data were collected on the patient demographics, surgical diagnosis and procedure, durotomy location and length, and adjunctive closure methods. Postoperative complications were assessed. When available, postoperative imaging data were reviewed.

RESULTS

Twenty-six patients underwent 27 operations over a 20-month period. They ranged in age from 2.5 months to 18.5 years, with a median age of 3.2 years and an average age of 5.8 years. The operative diagnosis was some form of spinal dysraphism in 19 patients, with a syrinx or dural tear in 2 patients each, and an arachnoid cyst in 3 cases; 1 patient had a tumor resected. Operative levels included lumbosacral (19), thoracic (7), and cervical (1). Dural exposure was limited to 1 laminar level in 16 cases, 2 levels in 8, and 3 levels in 1; 2 cases involved focal dural tears. A combination of additional hemostatic and tissue sealant materials was applied over the clips in 16 cases. One patient required reoperation 13 months after clip placement. Prior clip use did not make subsequent exposure and opening more complicated. No significant complications were identified in the follow-up period ranging from 1 to 24 months. There were no documented CSF leaks. The clips are not easily seen on plain radiographs and did not cause artifacts or distortion on either CT or MR imaging.

CONCLUSIONS

Nonpenetrating titanium anastomotic clips afford an effective means of closure while limiting the exposure needed, and thus allowing more minimally invasive approaches. In tight spaces, dural closure is accomplished more easily and faster with the clips as compared with conventional suturing. No significant complications were seen from clip use, and the clips did not interfere with postoperative imaging.

Aneurysm clips for durotomy repair: technical note

BACKGROUND

Dural injury is a common complication of lumbar spine surgery. Primary closure is the "gold standard."

OBJECTIVE

This technical note describes a failed primary closure of a durotomy revised using an aneurysm clip.

METHODS

From 2005 to 2009, 5 patients underwent repair of a durotomy with the use of aneurysm clips. Resolution of the cerebrospinal fluid leak was seen in all patients. An 84-year-old woman underwent a laminectomy with an inadvertent dural tear that was primarily repaired with suture. On postoperative day 8, the patient presented with new incisional drainage. The wound was explored, and the dura had torn around the previous sutured closure. A curved aneurysm clip was used to obtain dural closure. Postoperatively, the patient's incision remained dry.

RESULTS

Microsurgical closure with suture is the primary modality in durotomy repair. Difficulty arises when the dura is friable and multiple small tears are present. Suturing worsens the durotomy. Also, the durotomy is often caused along a bony edge with limited visualization, requiring additional bone removal to suture, therefore risking destabilization of the spine.

CONCLUSION

We describe the application of an aneurysm clip to treat a recurrent durotomy where the standard practice of sutured closure failed. Aneurysm clips offer a quick, safe, and secure manner to close dura without risking spinal destabilization. They offer significant benefit to already torn, friable dura. Postoperatively, patients have no limitations and are therefore prevented from being exposed to additional risks associated with bed rest. Aneurysm clips are cost and clinically effective in the management of dural injuries.