Surgeons do everything they can to prevent and/or reduce patients’ risk of complications. One of those complications is infection at the surgical site (called surgical site infection or SSI). Recovery can be challenging enough without adding delayed wound healing because of infection.
In this study, surgeons from Johns Hopkins University look into the risk and risk factors associated with removal of sacral tumors. Although tumors in this region are rare, they come with a host of problems. First of all, they don’t respond to radiation therapy. That means they have to be removed to ensure patient survival.
This type of surgery is called a radical resection procedure. The tumor and surrounding tissue are removed until the pathology report shows there are clear margins. Clear margins means there is a rim of normal tissue completely surrounding the tumor. The most common tumors in the sacral region are chondrosarcomas and chordomas.
Besides local infection, other possible complications of this surgery include nerve damage and injury of the blood vessels in the area. The removal of large areas of soft tissue can also leave the patient with impairments requiring extensive plastic surgery.
Looking back over five years’ worth of patients, the authors identified 46 patients with sacral tumors requiring radical resection. They reviewed a wide range of possible factors that could contribute to postoperative infection. Some of these risk factors included age, body mass index (obesity), tobacco use, history of diabetes, and previous history of lumbosacral surgery. Other potential factors studied included number of spinal levels exposed, size and type of tumor, blood loss, need for reconstructive surgery, and number of surgeons involved in the procedure.
The infections were also categorized carefully. Information was gathered and analyzed about the type of organism causing the infection (e.g., staphylococcus, e. coli), how soon the infection developed after surgery, how it was treated, and the final outcome.
The degree of amputation was also charted. About one-third of the patients had a low sacral amputation. Almost 10 per cent had the mid-portion of the sacrum removed. One-fourth had a high sacral amputation. The rest had either a hemisacrectomy (one side of the sacrum resected) or total sacrectomy (entire sacrum removed).
There were various complications such as breakage, misplacement, or pull-out of screws and/or rods. A small number of patients developed leaks of the cerebrospinal fluid (fluid inside spinal canal to protect spinal cord). And, of course, there were cases of postoperative infections, which was the focus of this study.
The treatment for surgical site infection was débridement and long-term antibiotics (four weeks or longer). The two main factors that seemed linked with postoperative infection after sacral tumor resection were a history of previous lumbosacral surgery and the number of surgeons involved in the operation.
Several other factors didn’t reach statistical significance but were described as a trend toward increased risk of surgical site infection. These included older age, complex soft-tissue reconstruction, and bowel and bladder problems.
The authors suggested that patients with sacral lesions are at increased risk for infection because of how close the open wound is to the rectum. There is the potential for cross contamination from feces (stool or bowel movement). And the surgeon often has to remove a large portion of the soft tissue, which also increases the risk of infection.
No matter what the reasons, the trauma of an infection that requires additional surgery (at additional cost) can be great. Identifying these predictive risk factors ahead of time can help surgeons screen patients carefully and plan the surgery accordingly. The high rate of infection (reported as high as 46 per cent) warrants studies of this kind.
Reducing the number of surgeons in the operating room may not be possible. Sacral tumor resection is a complex procedure requiring spine surgeons, general surgeons, plastic surgeons, and urologists. In large teaching hospitals, interns may also scrub and observe the operation. This (and other studies) support the idea that the more scrubbed members of the surgical team present in the operating room, the greater the risk of wound contamination with infection developing after surgery.
Controlling other factors such as patient age, history of previous lumbosacral surgery, and the removal of large amounts of soft tissues in the sacral area are less modifiable (or not modifiable at all). Other studies have shown that poor nutrition (represented by low albumin levels) can contribute to wound infection. It may be possible to prevent infections with better pre- and postoperative nutrition.
The authors report changes they have made in operative technique to reduce and/or prevent infection in sacral tumor resection. These include: 1) surgeons must be aware of the potential risk factors cited, 2) multiple hands in the wound may be needed but minimize this as much as possible, and 3) reduce the risk of contamination from bowel and bladder problems. This last suggestion can be done using glue to close the wounds and covering the wound for four to five days to create a barrier of protection.