ALTERATIONS OF THE 3-PHASE BONE-SCAN AFTER SYMPATHECTOMY

Objective: To evaluate alterations of the three-phase bone scan (TPBS) in patients with the clinical diagnosis of reflex sympathetic dystrophy (RSD) before and after surgical or chemical sympathectomy. Design: The TPBS was done after i.v. administration of technetium-99 dimethylphosphonate. Scans were read by one blinded and one nonblinded reviewer (as to site of symptoms and procedure), using a visual grading system devised in our institution. Since there were no statistically significant differences between the two examiners' scores for blood flow, pool, and delayed phases, all scores were averaged and used for comparison before and after sympathectomy. Subjects: Ten women and four men with RSD were observed with 17 TPBSs before and 30 TPBSs after surgical (n = 6) or chemical (n = 8) sympathectomy. Results: All three phases of TPBS were significantly enhanced after sympathectomy in 11 of 14 patients in a pattern indistinguishable from that very commonly reported in florid RSD. The increased uptake occurred within 24 h after the procedure, normalized as early as 3 months in some scans, and remained abnormal in some patients in the 12-month follow-up period. In total, only 33% of all sympathectomies performed led to long-term symptom relief. Conclusions: The data demonstrated that alterations in TPBS after sympathectomy are identical to those reported in early RSD and these alterations bear no relationship to the success of sympathectomy regarding pain relief. The mechanisms underlying alterations of TPBS as well as the potential mechanisms of sympathectomy failures are discussed.