Assessment of preprocedure difference in the supine and dependent transcutaneous tissue oxygenation to prognosticate pain relief, following chemical lumbar sympathectomy for critical limb ischemia in thromboangiitis obliterans

Context: Chemical lumbar sympathectomy (CLS) is performed in thromboangiitis obliterans (TAO) for relief of rest pain. Interruption of sympathetic innervation causes improvement in tissue oxygenation and is reflected in transcutaneous partial pressure of oxygen (TcPo2). There is very little data available to guide patient selection for CLS. Aims: The primary objective was to assess if preprocedure difference in TcPo2measured in supine and dependent positions on the foot correlated with relief of rest pain. The secondary objectives were to measure postprocedure TcPo2on the foot and assess preprocedure predictors of rest pain relief following sympathectomy. Settings and Design: Prospective observational study in patients undergoing CLS for TAO carried out from October 2009 to August 2014 in the Vascular Surgery Unit at Christian Medical College, Vellore. Subjects and Methods: Patients diagnosed to have TAO based on Shionoya's criteria, who were planned for a sympathectomy for rest pain, were included in the study. Statistical Analysis Used: Outcomes were compared using Mann—Whitney U-test and Wilcoxon signed-rank test. Data were entered and analyzed using SPSS 16.0 software. Results: There was a significant reduction of pain after sympathectomy (P < 0.001). There was a significant increase in TcPo2, supine to dependent position, independently before and after sympathectomy (P < 0.001). However, preprocedure difference in supine and dependent TcPo2did not correlate with the change in pain scores following sympathectomy. Conclusions: CLS provides relief of rest pain in TAO by improving tissue oxygenation. Preprocedure difference in the supine and dependent TcPo2did not correlate with pain relief