Abstract

Background:Traditional stainless steel retractors can interfere with electromagnetic neuronavigation and intraoperative magnetic resonance imaging (ioMRI). In such cases, titanium instruments are frequently used; however, they often shift during the procedure. The authors describe a simple technique, illustrated with intraoperative photographs, for securing titanium cerebellar retractors into place to keep both the retractors and tissues in their desired locations throughout a craniotomy.

Methods:Titanium retractors were used by our institute's neurosurgical service during operations utilizing electromagnetic neuronavigation or ioMRI. Once the retractor was in the desired position, a 2-0 silk suture was placed around a retractor tong and tied outside the skin. Two sutures were placed on either side of the titanium retractor in the same fashion.

Results:Retractors were subsequently noted to remain in their desired position throughout the operative procedure.

Conclusions:The authors describe a technique for securing titanium cerebellar retractors into their desired position during a craniotomy to minimize their movement during the procedure. This simple technique can help to eliminate a potential frequent source of surgeon frustration, and has proven to be quick to perform, safe, and practicable.

Keywords: Cerebellar, intraoperative, magnetic resonance imaging, retractor, titanium

INTRODUCTION

The increasing use of intraoperative magnetic resonance imaging (ioMRI) and electromagnetic neuronavigation has necessitated the use of titanium instruments during craniotomies. ioMRI craniotomies are performed with an ioMRI magnet adjacent to the surgical field. This results in a magnetic pull on stainless steel instruments that can lead to retractor displacement during the procedure.[ 1 ] Furthermore, ferromagnetic instruments in the operative cavity result in significant distortion of the intraoperative scan.[ 2 ] Similarly, stainless steel instruments can cause ferromagnetic artifact, arresting an electromagnetic neuronavigation signal. Titanium cerebellar retractors are a safe alternative, although they prove lighter and less robust than their stainless steel counterparts. In our experience, titanium cerebellar retractors often shift or become displaced several times during a craniotomy, resulting in obscuration of the operative field, increased operative time, and surgeon frustration. The authors describe a simple technique for securing titanium retractors to maintain their positioning during surgery and avoid the difficulties typically associated with their use.

MATERIALS AND METHODS

Titanium retractors were used for skin and soft tissue retraction during craniotomies requiring ioMRI or electromagnetic neuronavigation. Once in the desired position, a 2-0 silk suture was placed through the skin and between the retractor tongs, to be secured outside the skin on top of the retractor [Figures 1 and 2 ]. This process was repeated on each side of the retractor until each retractor was secured into place [ Figure 3 ]. The titanium cerebellar retractors were thus coupled to the subcutaneous tissue, preventing the elevation and displacement that typically occurs with their use. This technique can be applied with any brand of retractor. This was easily performed in less than a minute in most cases. The sutures were cut just before retractor removal. Figure 1

A 2-0 silk suture is placed through the skin and between the tongs of the retractor

ACKNOWLEDGMENTS

The authors thank Paul H. Dressel BFA for preparation of the illustrations and Debra J Zimmer for editorial assistance.

References

1. Johnston T, Moser R, Moeller K, Moriarty TM. Intraoperative MRI: Safety. Neurosurg Clin N Am. 2009. 20: 147-53

2. Shellock FG.editors. Magnetic Resonance Procedures: Health Effects and Safety. Boca Raton, FL: CRC Press, LLC; 2001. p. 959-