A Retained Surgical Item (RSI) is an object unintentionally left inside a patient’s body following a surgical or invasive procedure. An RSI is universally categorized as a “never event.” This preventable error should not occur under standard surgical protocols, making its elimination a primary goal for patient safety.
Statistical Frequency of Retained Surgical Items
While the problem of RSIs is serious, the incidence rate is relatively low compared to the millions of procedures performed annually. Current estimates place the overall rate of occurrence at approximately 1.3 cases per 10,000 surgical procedures across various settings.
The risk of an RSI is not uniform across all types of surgery, showing a strong correlation with procedural complexity and urgency. Operations performed under emergency circumstances are up to nine times more likely to result in a retained item than elective procedures. In some high-risk situations, such as emergency abdominal surgery, the rate can be as high as one case per 700 operations. Recent data from 2016 to 2023 suggest a slow but steady decline in the national incidence of RSIs, indicating that safety efforts are having a positive effect.
Classification of Retained Objects and Contributing Factors
Retained surgical items fall into two main categories: soft goods and hard goods, with soft goods being the most frequent culprits. Surgical sponges and towels are the most commonly reported items, accounting for between 48% and 69% of all documented RSI cases. Hard goods include surgical instruments, such as retractors and clamps, as well as small miscellaneous items like needle fragments, screws, or broken device components.
These errors often involve a breakdown of systemic processes rather than a single individual’s mistake. Human factors, such as staff fatigue, poor communication, and unexpected personnel changes during a procedure, significantly increase risk. For instance, in over 80% of retained sponge cases, the surgical team incorrectly completed the final item count.
Certain patient and procedural characteristics also contribute to the risk of an item being missed. Patients with a high Body Mass Index (BMI) are at greater risk because increased tissue depth can make it more difficult to visualize or palpate items within the surgical cavity. Unexpected events, complications that disrupt workflow, and the sheer length of the operation also make item tracking more challenging.
Medical Consequences and Patient Discovery
The consequences of an RSI for a patient can range from chronic pain and discomfort to severe, life-threatening complications. A retained item can trigger a foreign body reaction, leading to chronic inflammation, the formation of an abscess, or a mass that mimics a tumor. If the object causes perforation or obstruction of an organ, the resulting infection or sepsis can lead to organ damage and be fatal if not quickly addressed.
The timeline for discovering an RSI is highly variable, with some items found immediately post-procedure while others remain latent for months or even years. Many patients are diagnosed only after presenting with persistent symptoms like unexplained fever, chronic localized pain, or digestive issues that prompt a follow-up investigation.
Diagnosis is typically achieved through medical imaging. X-rays can detect radiopaque markers on sponges or hard metal instruments. Non-metallic items are often revealed through detailed imaging, like CT scans or MRIs, which can show the characteristic “spongiform” appearance of a retained textile mass.
Protocols and Technology for Preventing Errors
The primary defense against RSIs involves the consistent application of standardized safety protocols by the entire surgical team. This begins with mandatory safety checks, such as the surgical time-out, a pause before the incision to confirm the procedure, patient, and site. Throughout the operation, teams follow a system of structured closing counts, performed at the beginning, during, and before the final closure of the surgical site.
Manual counting remains an important safety layer, but technology now provides an essential adjunct to this human process. Radiofrequency (RF) detection systems are increasingly used to scan the patient before closure, confirming the absence of sponges that have been tagged with a tiny microchip. Instrument tracking systems, which use barcoding or RFID technology, help monitor the hundreds of hard items used during complex procedures.