1. 2022;25;E969-E975Comparison of Intravascular Uptake and Technical Ease Between Anteroposterior and Oblique Views During Lumbar Medial Branch Block
   Randomized Trial
   Ji Hee Hong, MD, PhD, Ji Hoon Park, MD, PhD, Seung Hoon Shin, MD, and Jae Yoon Lee, MD.

BACKGROUND: Inadvertent intravascular injection of local anesthetics can lead to false-negative results following lumbar medial branch block (MBB) performed to diagnose facet joint origin pain. A previous study demonstrated that the type of approach method could affect the incidence of intravascular injections and technical ease of the procedure.

OBJECTIVES: The primary objective of our study was to compare the incidence of inadvertent intravascular injection and technical ease of the MBB between anteroposterior (AP) and oblique (OB) views.

STUDY DESIGN: Prospective randomized trial.

SETTING: An interventional pain management practice in South Korea.

METHODS: The incidence of intravascular uptake of contrast medium was compared using AP and OB fluoroscopic views during lumbar MBB. Injection time, radiation dose, and patient discomfort during lumbar MBB were also compared. Risk factors associated with a longer procedure time and a higher radiation dose were analyzed.

RESULTS: The incidence of intravascular injection was 22.5% (23/102) in the AP group and 17.6% (18/102) in the OB group (P = 0.382). A significantly longer injection time and a higher dose of radiation were required to complete 3 levels of MBB in the OB group than in the AP group (45.9 seconds vs 61.9 seconds, P = 0.001; 27.4 centigray [cGy]/cm2 vs 42.2 cGy/cm2, I = 0.004). The OB approach and left side injection were the risk factors associated with a longer total procedure time (odds ratio [OR] = 6.64, 95% CI, 1.99-22.17, P = 0.002; OR = 0.20, 95% CI, 0.06-0.67, P = 0.009, OB and AP, respectively).

LIMITATIONS: The physician performing the MBB could recognize the AP or OB fluoroscopic view during procedure.

CONCLUSION: The overall incidence rate of intravascular injection during lumbar MBB showed nearly 20% in both approach methods groups. The OB approach and left side MBBs were associated with a longer total procedure time and a higher radiation dose.

KEY WORDS: Anteroposterior, intravascular injection, medial branch block, oblique, procedure time, radiation dose