Antibiotic Could Thwart Costly Sarcoma Surgery Complication

— Benefit seen for adding "anaerobic coverage" to standard perioperative antibiotic prophylaxis

MedicalToday

BALTIMORE -- Including an antibiotic with strong activity against anaerobic bacteria to standard perioperative prophylaxis following soft-tissue sarcoma (STS) resection was associated with lower wound complication rates, a retrospective study suggested.

Overall, major wound complication rates dropped from 27.3% to 15.9% when an antibiotic such as metronidazole was incorporated into perioperative prophylaxis, a 42% relative reduction, Duncan Ramsey, MD, of Massachusetts General Hospital in Boston, reported at the .

Another study at the meeting, presented by Benjamin Wilke, MD, of the Mayo Clinic in Jacksonville, Florida, found that total healthcare costs were 21.3% higher for patients who developed these complications following STS resection.

Anaerobic Coverage

Considering the substantial rate of wound complications after resection of STS, "adding anaerobic coverage to the standard prophylactic regimen during STS resection should be considered," Ramsey said in his presentation.

Ramsey noted that the rates of such complications range from 10% to 35%, and recent studies have shown a high prevalence of anaerobic bacterial infections after STS resection.

The study analyzed outcomes of 579 patients who underwent STS resection from 2008 to 2021 -- 510 of whom received a first-generation cephalosporin, and the remaining 69 also received a second antibiotic with anaerobic coverage -- primarily metronidazole.

Wound complications were defined as any of the following within 120 days of initial resection:

  • Formal wound debridement in the operating room
  • Other procedural interventions such as percutaneous drain placement
  • Need for intravenous antibiotics
  • Wet-to-dry dressing changes at 120 days

The researchers found that the reduction in infection rates in patients treated with the second antibiotic with anaerobic coverage was driven by a decrease in anaerobic bacteria infection rates (2.9% vs 6.3%) and polymicrobial infection rates (7.2% vs 13.0%).

Factors predictive of major wound complications included body mass index, tumor size and location, neoadjuvant radiation, and chemotherapy, as well as anaerobic coverage at resection.

Based on the findings, Ramsey said the number needed to treat to prevent one major wound complication was 8.8.

"The standard fine print for retrospective -- especially clinical change -- studies applies here, and some sort of prospective testing and verification in a more well-defined and controlled study is necessary," he added.

He noted that while adding the second antibiotic with anaerobic activity substantially reduced the wound complication rate, "a 16% major wound complication rate is still significant, so we should still focus our efforts on other methods to keep these rates down."

Higher Costs After Wound Complications

Wilke presented findings of a retrospective review of patients who underwent STS resection at his institution from January 2013 to October 2019. The researchers calculated the number of clinic visits to the orthopedic and plastic surgery teams involved with patients in the first postoperative year, as well as the number of repeat hospitalizations and unplanned operations.

A total of 99 patients were included in the study, 42 of whom had wound complications. Of those, 76.2% required an average of 1.2 additional operations. The average duration of wound care was 5.7 months and required an average of eight outpatient visits during the first postoperative year, compared with five for patients without wound complications.

Other findings from the analysis:

  • Costs were 9.5% higher for former or active smokers than for nonsmokers
  • Total costs were 59.7% higher for patients who had undergone a free-flap closure and 29.1% higher for patients who had undergone a local flap closure than for patients who underwent primary closure during the index surgery
  • There was an increased cost 0f 13.2% for each additional operation due to a wound complication

Study limitations, Wilke noted, included its retrospective nature and that delays in patients' returning to work was not incorporated. "So our study really underestimates the true cost to both the patient and the provider," Wilke said.

"We believe this study helps to quantify the challenges in treating sarcoma patients, and this demonstrates how reducing complication rates will result in cost savings for the healthcare system and continues to remain an opportunity for improvement," he concluded.

  • author['full_name']

    Mike Bassett is a staff writer focusing on oncology and hematology. He is based in Massachusetts.

Disclosures

Ramsey reported no relevant disclosures.

Wilke reported no relevant disclosures.

Primary Source

Musculoskeletal Tumor Society

Ramsey D, et al "The addition of anaerobic coverage to perioperative antibiotic prophylaxis during soft tissue sarcoma resection decreases the rate of wound complications" MSTS 2021; Abstract 7.

Secondary Source

Musculoskeletal Tumor Society

Wilke B, et al "Cost variance in soft tissue sarcoma patients who develop postoperative wound complications" MSTS 2021; Abstract 9.