Surgery is a complex process that requires extreme precision and care from surgeons and operating room staff. Despite high standards and safety protocols, mistakes can and do happen in the operating room. One of the most dreaded surgical errors is when a foreign object is accidentally left inside a patient’s body after surgery.
What is Retained Surgical Equipment (RSE)?
Retained surgical equipment (RSE), also called retained foreign objects (RFOs), refers to surgical tools, supplies, or other items that are unintentionally left inside a patient’s body after an operation. Some examples of retained objects include:
- Sponges
- Needles
- Scalpel blades
- Instruments like clamps or retractors
- Surgical towels
- Part of a broken instrument
Any item inadvertently left after surgery, no matter how small, is considered a retained object. Even tiny things like the tips of instruments, if left behind, can cause serious complications.
How Often Does This Happen?
Various studies and patient safety organizations have aimed to quantify how often retained surgical items occur. However, getting exact statistics is challenging because these events often go unreported.
That said, research indicates it is an infrequent event, happening after about 1 in every 1,000 to 1,500 abdominal operations. Some sources estimate the incidence is between 1 in 100 to 1 in 5000 for all surgical procedures.
According to the National Center for Health Statistics, there are over 50 million inpatient surgeries performed in the United States each year. Based on those figures, retained object cases may happen:
- 50,000 times a year
- 4,200 times a month
- 1,000 times a week
- 145 times a day
However, the actual annual occurrence is likely higher due to underreporting.
Which Procedures Have the Highest Risk?
While retained items can occur after any operation, certain types of surgeries have been associated with higher incidence rates:
| Type of Surgery | Estimated Frequency of Retained Objects |
|---|---|
| General surgery procedures (abdominal, bariatric) | 1 in 1,000 to 1 in 1,500 cases |
| Gynecologic surgery | 1 in 1,500 cases |
| Orthopedic surgery | 1 in 8,500 cases |
Factors that increase risk for retained objects during surgery include:
- Emergency surgeries with unexpected changes
- Operations involving obese patients
- Procedures with unexpected bleeding
- Surgeries involving multiple surgical teams
- Operations where more items are used (like towels and sponges)
Why Does This Happen?
Although human error is often blamed, most retained object cases are due to multiple contributing factors including:
- Communication breakdowns – not verbally confirming item counts during surgery
- Emergencies – unexpected bleeding or other crisis distracting the team
- Fatigue – tired staff near the end of long operations
- Time pressures – rushing through standard safety protocols
- Inadequate tracking – not carefully documenting use of small items like sponges
- Complex procedures – longer operations involving multiple item usage
While checklists and counts are utilized to prevent retention, human factors can result in steps being missed or miscommunication between team members.
What Are the Consequences?
A retained object left inside after surgery can lead to numerous adverse effects including:
- Infection – a serious complication as the item can act as a focus for germs
- Abscess formation – pocket of pus caused by infection
- Bowel obstruction – object blocks or perforates the intestines
- Perforation – sharp items piercing internal organs
- Pain/discomfort – from inflammatory reactions to item
- Adhesions – internal scar tissue wrapping around item
- Fistula – abnormal connection between organs
- Sepsis – body-wide inflammation from infection
- Death – if serious complication goes untreated
In many cases, additional surgery is required to find and remove the retained object once discovered. This not only puts the patient through another operation but adds time, cost and risk of complications.
How Are Retained Objects Discovered?
Unfortunately, retained surgical items often go undetected for weeks, months or even years after the initial procedure. Patients may experience vague or non-specific symptoms that could indicate a retained object, like:
- Ongoing pain near the surgical site
- Feeling of lump or foreign body
- Abscess, fever, drainage from incision
- Gastrointestinal symptoms if object is in abdomen
Or, they may not notice any warning signs at all. Objects like sponges can encase themselves in scar tissue and remain unseen by the body’s immune defenses.
Most retained items are discovered incidentally when the patient has imaging tests (like x-rays, CT scans, or MRIs) done for an unrelated reason. The object then shows up on the scan. Purposefully looking for retained objects via x-ray or scanner before the patient leaves the hospital after surgery can also detect some items.
Count discrepancies in the operating room may reveal a missing item Intra-operatively as well. Good communication between surgeons and nurses during counts is key.
Can This Be Prevented?
Patient safety experts emphasize that retained surgical items are preventable medical errors if proper protocols are followed.
Recommended safeguards include:
- Performing manual sponge/instrument counts at the beginning, multiple times during, and before closing the operation.
- Having a standardized counting process for small miscellaneous items.
- Using x-ray detectable sponges.
- Routinely doing x-rays after surgery to look for retained objects.
- Considering use of adjunct technologies like RFID tags to help track surgical items.
- Following a meticulous wound closing protocol, with multiple visual inspections.
- Confirming instrument, sponge, and needle counts verbally with the whole team before finishing surgery.
Additional strategies to improve quality and safety in the OR include:
- Adhering to established time-outs, checklists, and guidelines during surgery.
- Creating redundancy by having 2 staff members separately count and document surgical items.
- Limiting operating room disruptions and distractions.
- Tracking which staff were present for each surgical case.
- Using technologies to help automate counts and better visualize the surgical field.
The Bottom Line
The inadvertent retention of surgical items is an uncommon but still prevalent and preventable medical error that can cause patients harm. While exact data is difficult to ascertain due to underreporting, estimates indicate retained objects may occur in anywhere from 1 in 100 to 1 in 5000 surgeries.
Retained sponges, instruments and other items can trigger serious complications if left undiscovered in a patient’s body. Close adherence to safety protocols in the OR, good communication between staff, and technologies to help track instruments and sponges can all reduce the risk.
Increased awareness around this patient safety issue, transparency in reporting events, and continuously improving standards of care can help drive incidence rates even lower in the future.
