Radiographic Detectability of Retained Neuropatties in a Cadaver Model

Background

Counts are the commonest method used to ensure that all sponges and neuropatties are removed from a surgical site before closure. When the count is not reconciled, plain radiographs of the operative site are taken to determine whether the missing patty has been left in the wound. The purpose of this study was to describe the detectability of commonly used neuropatties in the clinical setting using digital technologies.

Methods

Neuropatties were implanted into the anterior and posterior cranial fossae and the thoracolumbar extradural space of a mature male cadaver. Four neuropatty sizes were used: 3 × 1 in, 2 × ½ in, ½ × ½ in, and ¼ × ¼ in. Neuropatties, with size and location chosen at random, were placed in the surgical sites and anteroposterior/posterior-anterior and lateral radiographs were taken using standard portable digital radiographic equipment. Six clinicians reviewed the digital images for the presence or absence of neuropatties. The readers were not aware of the number and size of the patties that were included in each image.

Results

The detectability of neuropatties is dependent on the size of the neuropatty's radiopaque marker and the operative site. Neuropatties measuring 2 × ½ in and 3 × 1 in were detected reliably regardless of the operative site. ¼ × ¼ in neuropatties were poorly detected by neurosurgeons and radiologists in all three operative sites. Readers of various experience and background were similar in their ability to detect neuropatties under these conditions.

Conclusions

Under simulated operating room conditions and using currently available neuropatties and plain radiograph imaging technology, small ¼-in and ½-in neuropatties are poorly visible/detectable on digital images.

Introduction

An unintentionally retained foreign body is a potential risk of any invasive procedure. Surgical sponges are the most common type of unintentionally retained foreign bodies (26). Retained surgical sponges (RSS) are chemically inert but induce an inflammatory response in situ. Patients may develop an acute exudative reaction or chronic fibroblastic encapsulation (23). Complications vary depending on the RSS location (13). Serious complications include formation of an abscess or fistula, perforation of a viscus, sepsis, and mortality 6, 18, 20, 26. The median time to discovery is 2.2 years (26), but RSS may remain undetected for ≥40 years 7, 25, 28.

RSS are theoretically preventable and are classified by the National Quality Forum and the Joint Commission as “never events.” In some jurisdictions, hospitals are financially penalized for never events (17). In malpractice suits, RSS are deemed indefensible. Documentation of correct surgical counts and adherence to standards of care does not indemnify the responsible surgeon or the team (12). The legal and compensation costs per RSS incident vary greatly, ranging from $37,000 to $2.3 million (8).

In neurosurgery, neuropatties are the commonest surgical sponges that pose a risk for RSS. When the final count does not agree with the “on-table count,” current standards require that plain radiographs of the operative site be taken before/after wound closure to exclude the possibility of a RSS. Commonly, RSS occur in patients in whom the counts were “correct” 4, 6.

Despite meeting industry testing standards for radiopacity, surgical sponges are not easily detected on plain films in clinical situations (23). The detectability of surgical sponges has been assessed using analogue plain film imaging, 5, 15, 22, 24, 27, but the detectability thresholds of neuropatties using digital imaging technology under clinical conditions is unknown.

The present study assessed the detectability of currently available neuropatties implanted in common neurosurgical sites in an adult cadaver model, using clinical radiographic digital imaging techniques and clinician readers.