Safety Profiles for Balloon Kyphoplasty and Vertebroplasty 4 Independent Analysis

The consequences of vertebral compression fractures (VCFs) are well documented and include chronic pain, kyphosis, decreased pulmonary function, increased risk of subsequent fracture and increased mortality. Increased awareness of the deleterious affect multiple VCFs can have on patient quality of life has helped shift clinical attention to minimally invasive treatment options, i.e., Balloon Kyphoplasty (BK) and Vertebroplasty (VP) for management of symptomatic compression fractures.

A growing number of positive clinical outcomes reporting reduction/elimination of pain and a quick return to normal activity can be found in the literature. Evidence concerning safety and efficacy was examined in a meta-analysis of preoperative complication rates after BK and VP for osteoporotic and cancer-related VCFs, as reported in the published literature.(1)

Taylor et al. (Spine 2006) (2) published a health technology assessment of BK and VP. Thirteen BK case series studies (641 patients) and 57 case series VP studies (3029 patients) published between 1983 and March 2004 were compared for cement leakage and adverse events. A significantly higher cement leakage rate was reported with VP (40%) than with BK (8%) (p <0 .0001). No symptomatic cement leaks were reported with BK, while some 3% of VP symptomatic. In addition, adverse events per patient, such as pulmonary embolism, spinal cord compression and nerve root pain/radiculopathy, significantly less for BK.

A systematic review of 69 BK and VP studies by Hulme et al. (Spine 2006)(3) reported total cement leakages and overall complications. Vertebroplasty studies (47) showed the results of 2958 patients and 1288 BK patients were reported from 22 studies. Cement leaks occurred in 41% and 9% of the treated vertebrae for VP and BK, respectively. Most leaks were clinically asymptomatic; however, when clinical complications did occur, there were fewer complications reported with BK-treated patients (2.2%) than VP patients (3.9%).

Similar findings are reported in another systematic review of BK and VP studies published between 1983 and September 2004. Hadjipavlou et al. (JBJS Br 2005)(4) reports that cement leakage is rare with BK, but seems to be a common complication with VP. Cumulative data of treated vertebral bodies show BK had 8.4% cement extravasation compared to 29% for VP. When comparing the percentage for cement extravasation per location, BK showed a lower rate in all locations. (see table above)

Both vertebroplasty and balloon kyphoplasty are well tolerated and have been shown to be highly effective in reducing pain from compression fractures and osteolytic tumors. Both are also relatively safe percutaneous procedures. Balloon kyphoplasty has the added advantage of the balloon to potentially reduce the fracture and correct deformity by creation of a void in the vertebral body. Some believe BK has a lower risk because potential extravasation pathways may become closed as a result of bone compaction by the balloon during void creation.

This process creates a repository that permits deposition of a viscous cement. There is still a need for comparative blind randomized clinical trials before one procedure is determined to be safer than the other; however, these four relatively comprehensive independent analyses show the safety profile for kyphoplasty to be better than the safety profile for vertebroplasty.

References

1. Data on file Kyphon Inc. “Quantitative Analysis of Perioperative Complication Rates in Balloon Kyphoplasty and Vertebroplasty”
2. Taylor RS*, Taylor RJ, Fritzell P. Balloon Kyphoplasty and Vertebroplasty for Vertebral Compression Fractures: A Comparative Systematic Review of Efficacy and Safety. Spine 2006;31:2747–2755
3. Hulme PA, Krebs J, Ferguson SJ, Berlemann U*. Vertebroplasty and Kyphoplasty: A Systematic Review of 69 Clinical Studies. Spine 2006;31:1983–2001
4. Hadjipavlou AG**, Tzermiadianos MN, Katonis PG, Szpalski M. Percutaneous vertebroplasty and balloon kyphoplasty for the treatment of osteoporotic vertebral compression fractures and osteolytic tumours. J Bone Joint Surg Br. 2005 Dec;87(12):1595-1604

Note: An asterisk (*) denotes that some/all of the authors are paid Kyphon consultants. A cross (†) indicates that research cited may have been funded partially, or in whole, by Kyphon Inc.

Note: For a study to be included in the analysis, it needed to report on at least 10 patients with VCFs caused by either osteoporosis or cancer. Strict exclusion criteria included limiting the analyses to articles published in English; no duplicate cohorts; no case reports; exclusion of cadaveric or animal studies. The resulting 120 articles reported on a total of 1947 BK patients and over 6800 VP patients. Using a random effects logistic regression model, the rates of total procedure-related and cement-related complications were statistically lower in BK (0.7%) than in VP (2.9%). As expected, there was no statistical difference in either access-related or non-device-related complications. (see Table)

As with any surgery, there are potential risks. Although balloon kyphoplasty is designed to minimize these risks as much as possible, there is a chance that complications could occur. Serious adverse events can occur including: myocardial infarction (heart attack), cerebrovascular accident (stroke), pulmonary embolism (cement leakage that migrates to the lungs), cardiac arrest (heart stops beating), paralysis or muscle weakness, death. Patients should consult with their doctor for a full discussion of risks.