Sacral Hiatus Epiduroscopic Approach

Paulo Pereira and Pedro Monteiro

9.1 Introduction

In the same way as for lumbar epidural steroid injections, different surgical approaches are possible for epiduroscopy, namely, caudal, transforaminal, and interlaminar. However, since the description of the sacral hiatus epiduroscopic access to the lumbar spinal canal by Saberski and Kitahata,1 this has been the approach widely preferred by most surgeons, given the lower risk of dural puncture.²

9.2 Step 1: Position and Preoperative Setup

• The procedure is performed in the operating room or intervention room under sterile conditions.3,4,5

• Appropriate prophylactic antibiotics may be used (e.g., 1 g of intravenous cefazolin 30 minutes before the procedure).

• Intraoperative monitoring, including electrocardiogram, noninvasive blood pressure, and pulse oximetry, is recommended.

• The procedure is performed under conscious sedation with midazolam (initial dose of 0.04 mg/kg intravenously followed, if necessary, by titration doses of 1 mg, with a maximum of 6 mg). Systemic analgesia with intravenous fentanyl is used throughout the procedure, as needed. The patient must be able to provide feedback throughout the procedure.

• The patient is positioned prone on a radiolucent table. A radiolucent soft pillow is placed under the abdomen to reduce the lumbar lordosis and the lumbosacral angle ( Fig. 9.1). Additional pads are used under the ankles, and, if necessary, under pressure zones, to improve patient comfort.

• Skin preparation is performed at the lumbosacral, coccygeal, and buttocks regions, and a gauze compress is placed in the perianal area to prevent irritation of the mucosa by the antiseptic solution. After drying, sterile drapes are placed using a transparent film in the area of the sacral hiatus ( Fig. 9.2).

9.3 Step 2: Preoperative Planning and Anesthesia

• After sterile draping of the C-arm, lateral fluoroscopic images are obtained to localize the sacral hiatus.2

• Local anesthesia of the skin and subcutaneous tissue over the sacral hiatus is performed with 2% lidocaine using a 23-gauge subcutaneous needle ( Fig. 9.3). The same local anesthetic is injected through the sacral hiatus to the distal region of the sacral canal using a 22-gauge Quincke type spinal needle, for a total of 10 mL ( Fig. 9.4).

Fig. 9.1 Positioning of the patient.

Fig. 9.2 Surgical field after draping.

Fig. 9.3 Local anesthesia of the skin and subcutaneous tissue of the region over the sacral hiatus.

9.4 Step 3: Needle Insertion Technique and Epidurography

• An 18-gauge Tuohy needle is inserted into the sacral canal through the sacral hiatus under fluoroscopic control in lateral view ( Fig. 9.5). The skin entry point is chosen, assuring that a shallow angle is achieved between the needle and the sacral canal (typically 2–4 cm caudal to the sacral hiatus; Fig. 9.6).¹

• The needle position may be confirmed by injecting nonionic contrast (e.g., Ultravist 240, Bayer Schering Pharma A.G.).

9.5 Step 4: Setting the Approach for the Epiduroscope

• The stylet of the Tuohy needle is withdrawn and a “J-tip” flexible guidewire is introduced through the lumen into the sacral canal up to the level of S3 ( Fig. 9.7).⁶

• A 4-mm-length skin incision is made with a no. 11 scalpel blade, centered on the entry point, and the Tuohy needle is gently removed, ensuring that the guidewire is kept in place ( Fig. 9.8 and Fig. 9.9).