Letters to the Editor: Letters & Announcements
To the Editor
Spinal anesthesia was selected for a parturient for repeat cesarean delivery. She weighed 112 kg, and was 173 cm tall. After multiple failed attempts with multiple needles at various spinal levels, using a combined spinal-epidural needle set, a 27-gauge, 11.5-cm Whitacre spinal needle was inserted through a 17-gauge Tuohy needle seated in the interspinous ligament. The stylet was withdrawn from the spinal needle, and the two needles advanced together while watching for cerebrospinal fluid (CSF) from the Whitacre. The Whitacre met with slight increased resistance, thought to be dura, at a depth of 8 cm. The Whitacre and Tuohy were advanced together through the resistance, with no flow of CSF noted. The Whitacre was withdrawn from the Tuohy without perceived difficulty. When the Whitacre was out of the Tuohy, a 1-cm portion of the Whitacre tip was missing. Spinal anesthesia was abandoned, and the cesarean delivery proceeded uneventfully under general anesthesia. Postoperatively, the patient remained neurologically intact, even denied back pain. No retained tip was found on radiographs. It may have remained inside the shaft of the Tuohy needle, which was not kept for subsequent examination.
Subsequent microscopic examination of the broken spinal needle revealed a residual bend at the fracture, with cracking observed nearby. The latter may have originated during the compressive nature of bending during attempted insertion, and widening of these cracks may have occurred with restraightening during withdrawal of the spinal needle through the Tuohy.
There are two reports of fractured spinal needles and two reports of fractured epidural needles in the literature.1–4 In each report, the needles were presumably bent during insertion attempts and fractured upon withdrawal, and each of the patients recovered without sequelae. Two evaluations of factors involved with needle failure4,5 documented that longer, thinner needles were more likely to bend and fracture upon restraightening, especially with movement.
In our case, the increased resistance perceived during the last insertion likely represented bone contact that caused the distal end of the 27-gauge Whitacre to pivot around the tip of the Tuohy as the two needles were advanced together. When the Whitacre was withdrawn, while leaving the Tuohy in place, the distal 1-cm tip probably sheared off against the tip of the Tuohy.
From our case experience, it seems prudent that practitioners limit the number of passes with any single spinal needle, and in the case of combined spinal-epidural technique, withdraw both the protruding spinal and introducer needle together if any difficulty occurs with lumbar puncture.
Adam L. Wendling, MD
Matthew T. Wendling, ME
Dietrich Gravenstein, MD
Tammy Y. Euliano, MD
University of Florida College of Medicine
Energizer Battery Manufacturing
1. Thomsen AF, Nilsson CG. Broken small-gauge spinal needle. Anesth Analg 1997;85:230
2. Abou-Shameh MA, Lyons G, Roa A, Mushtaque S. Broken needle complicating spinal anaesthesia. Int J Obstet Anesth 2006;15:178–9
3. Hershan DB, Rosner HL. An unusual complication of epidural analgesia in a morbidly obese parturient. Anesth Analg 1996;82:217–8
4. Dunn SM, Steinberg RB, O'Sullivan PS, Goolishian WT, Villa EA. A fractured epidural needle: case report and study. Anesth Analg 1992;75:1050–2
5. Hoff SJ, Sundberg P. Breakage and deformation characteristics of hypodermic devices under static and dynamic loading. Am J Vet Res 1999;60:292–8