Successful electrode insertion for spinal cord stimulation after balloon adhesiolysis in a patient with epidural adhesion - A case report -

Background: Spinal cord stimulation (SCS) can be successfully performed using highly developed implantation techniques. However, anatomical barriers, such as epidural adhesion, may impede placing the electrode for SCS in an adequate position.Case: A 60-year-old woman who had SCS with an electrode at the T9-10 level removed because she had a wound infection at the back incision site. After the wound infection was completely resolved, we tried to re-insert the SCS electrode. However, it was difficult to advance it up to the T11 level due to epidural adhesion. We performed a combined epidural adhesiolysis using balloon decompression with an inflatable balloon catheter. After that, the SCS lead was successfully placed up to the T11 level, and implantation of SCS was performed.Conclusions: When a patient has epidural adhesion, an epidural adhesiolysis with an inflatable balloon catheter may help the insertion of the SCS electrode in the epidural space.

Clinical Efficacy and Safety of Silicone Elastomer Sheet during Decompressive Craniectomy: Anti-Adhesive Role in Cranioplasty

(1) Background: Cranioplasty is a surgery to repair a skull bone defect after decompressive craniectomy (DC). If the process of dissection of the epidural adhesion tissue is not performed properly, it can cause many complications. We reviewed the effect of a silicone elastomer sheet designed to prevent adhesion. (2) Methods: We retrospectively reviewed 81 consecutive patients who underwent DC and subsequent cranioplasty at our institution between January 2015 and December 2019. We then divided the patients into two groups, one not using the silicone elastomer sheet (n = 50) and the other using the silicone elastomer sheet (n = 31), and compared the surgical outcomes. (3) Results: We found that the use of the sheet shortened the operation time by 24% and reduced the estimated blood loss (EBL) by 43% compared to the control group. Moreover, the complication rate of epidural fluid collection (EFC) in the group using the sheet was 16.7%, which was lower than that in the control group (41.7%, p < 0.023). Multivariate logistic regression analysis showed the sheet (OR 0.294, 95% CI 0.093–0.934, p = 0.039) to be significantly related to EFC. (4) Conclusions: The technique using the silicone elastomer sheet allows surgeons to easily dissect the surgical plane during cranioplasty, which shortens the operation time, reduces EBL, and minimizes complications of EFC.

Feasibility of Percutaneous Robot-Assisted Epiduroscopic System

Background: Endoscopy has replaced open surgery, especially in spinal surgery. Among them, image-guided epiduroscopy allows pain generators to be identified, including epidural adhesion, fibrotic tissues, root compression, and spinal stenosis. However, the heavy lead apron worn by pain physicians to avoid exposure to radiation can induce occupational hazards, such as orthopedic complications and radiation-induced cancer. Hence, we developed a robotic system to address these problems. Objective: The aim of the study was to evaluate the feasibility of a robot-controlled epiduroscopic system. Study Design: In vivo animal experiment. Setting: University in Republic of Korea. Methods: The robot-controlled epiduroscopic system was developed using the open architecture robot system (The Raven Surgical Robotic System, CITRIS, Berkley, CA, USA). The robotic system consists of a lab-made epiduroscope, steering section, robotic arm, and manipulator. For the in vivo study, 2 Yorkshire pigs were used to simulate an epiduroscopic procedure with the robotic system. Results: The insertion and steering of the catheter was performed safely, and epiduroscopic visualization was obtained without side effects. There were no device-related complications. Radiation exposure for the primary operator was 80% lower than the levels found during conventional epiduroscopic procedures. All live pigs showed normal behavior without any signs of pain. The mean time to reach the target region was less than 8 minutes. Limitations: The epiduroscopic procedure was performed on pigs and not on humans. The dimensions of the spinal canal of pigs cannot compare to those of humans. Conclusions: We demonstrated the feasibility of the robot-assisted epiduroscopic system. Key Words: Epiduroscopy, robotic system, spine, pig, animal model

Finite Element Analysis of the Effect of Epidural Adhesions

Background: It is well documented that epidural adhesion is associated with spinal pain. However, the underlying mechanism of spinal pain generation by epidural adhesion has not yet been elucidated. Objectives: To elucidate the underlying mechanism of spinal pain generation by epidural adhesion using a two-dimensional (2D) non-linear finite element (FE) analysis. Study design: A finite element analysis. Setting: A two-dimensional nonlinear FE model of the herniated lumbar disc on L4/5 with epidural adhesion. Methods: A two-dimensional nonlinear FE model of the lumbar spine was developed, consisting of intervertebral discs, dura, spinal nerve, and lamina. The annulus fibrosus and nucleus pulpous were modeled as hyperelastic using the Mooney-Rivlin equation. The FE mesh was generated and analyzed using Abaqus (ABAQUS 6.13.; Hibbitt, Karlsson & Sorenson, Inc., Providence, RI, USA). Epidural adhesion was simulated as rough contact, in which no slip occurred once two surfaces were in contact, between the dura mater and posterior annulus fibrosus. Results: The FE model of adhesion showed significant stress concentration in the spinal nerves, especially on the dorsal root ganglion (DRG). The stress concentration was caused by the lack of adaptive displacement between the dura mater and posterior annulus fibrosus. The peak von Mises stress was higher in the epidural adhesion model (Adhesion, 0.67 vs. Control, 0.46). In the control model, adaptive displacement was observed with decreased stress in the spinal nerve and DRG (with adhesion, 2.59 vs. without adhesion, 3.58, P < 0.00). Limitations: This study used a 2D non-linear FE model, which simplifies the 3D nature of the human intervertebral disc. In addition, this 2D non-linear FE model has not yet been validated. Conclusion: The current study clearly demonstrated that epidural adhesion causes significantly increased stress in the spinal nerves, especially at the DRG. We believe that the increased stress on the spinal nerve might elicit more pain under similar magnitudes of lumbar disc protrusion. Key words: Finite element, epidural adhesion, spinal pain, adhesiolysis