Surgery in patients with spinal metastases can improve quality of life by decreasing pain, improving or preserving neurological function, and by maintaining some degree of mobility. However, a major pitfall of surgery in this group of patients is wound complications.
D Greg Anderson, Thomas Jefferson Hospitals, the Rothman Institute, Philadelphia, USA, said: “If you operate on someone who has only 12 months left to live and they subsequently have a large wound infection, they might then have to spend the next six weeks in and out of hospital on antibiotics as a result. With those six weeks, you have taken away a significant percentage of the remainder of their life.”
Radiation treatment is a major risk factor for post-surgery infection. A study by Ghogawala et al (Spine 2001; 26: 818-24) found that for patients who received radiation therapy prior to surgery, the risk of infection was three times higher than for patients who had not received radiation therapy (32% v. 12%). “So when we are dealing with patients who are post radiation, the risk of infection is always a challenge. Therefore, it would be good if we could see a patient before they have radiation therapy. But, often, we do not have that luxury. In many cases by the time the individual has come to us, they have already undergone radiation therapy and have been referred to us because they have developed a neurological deficit,” Anderson, who was giving a talk on the role of minimally invasive surgery in spinal metastases at IMAST 2011, said.
He added that the use of minimally invasive surgery has been shown “very definitively” to reduce the risk of infection, and described a retrospective review of patients with degenerative disk disease who had undergone minimally invasive surgery (O’Toole et al, J Neurosurg Spine 2009; 11: 471–76). This review found that the procedural rate of surgical site infection for simple decompression was 0.10% and 0.74% for minimally invasive fusion/fixation. Overall, the total surgical infection rate was 0.22 for the whole group. “The rate of infection with minimally invasive surgery is about 10 times less than that with historical controls. This study was done in the degenerative population, but I think it illustrates the point.”
Anderson outlined several cases in which he successfully treated patients with spinal metastases using minimally invasive surgery. One case was a 52-year-old woman with small cell carcinoma of the lung. Initially treated with chemotherapy, she presented with a fracture. She had very severe back pain and was bedridden despite receiving optimum painkillers. “In a case such as this, just a simple percutaneous stabilisation procedure can be done and can be done within an hour. There is very minimal blood loss from the percutaneous incisions and even if radiation therapy is received beforehand, an infection does not usually occur because you will have used a tissue sparring approach.” He added that following surgery, the woman became mobile and was able to make the most of her remaining life.
Concluding his talk, Anderson said “Surgical treatment for metastatic disease must be customised to the patient, including the type of tumour and the type of tumour burden. Patients with metastatic disease generally have limited life expectancy and should be treated in a way that minimises risks and the time spent recovering from surgery. Therefore, percutaneous fixation does have a role in the treatment of selected cases of metastatic disease.”