OBJECTIVES: The effect of hydrostatic infiltrations for subperichondrial dissection is controversial. Classical textbooks promote it as the "key step in elevating the flaps" or consider its practicability "a mere fable". Moreover, case reports describe fatal side effects. Up to now, experimental tests are missing. DESIGN: Experimental study. MATERIALS AND METHODS: Three surgeons simulated subperichondrial hydrodissection with 20 mineral salt fixed human cadaver heads. One ml lidocaine 5% with 1:105 adrenaline and India ink was infiltrated. Each septum was examined histologically using serial 3 microm sections in 150 microm intervals. Tissue cleavage containing the ink deposits with minimal distance to the proposed subperichondrial zone, intravasal spread and tissue deposition were analyzed. RESULTS: Every injection produced a physical dissection (n = 20). However, dissected planes were localized mostly in the supra-perichondrial connective tissue (n = 8) or within the perichondrium (n = 4). Only five cases showed the propagated correct dissection in a subperichondrial zone. Three anomalous septa were excluded from quantitative analysis. Infiltrated matter did not only accumulate within the dissection plane but also penetrated the surrounding vessels of the septal intumescentia (n = 8). CONCLUSION: Hydrostatic infiltrations represent an unreliable surgical technique for dissection of an anatomical correct subperichondrial plane but can be useful for anesthesia and hemostasis, however, using high pressure and high volume infiltrations might foster serious side effects.
OBJECTIVES: The effect of hydrostatic infiltrations for subperichondrial dissection is controversial. Classical textbooks promote it as the "key step in elevating the flaps" or consider its practicability "a mere fable". Moreover, case reports describe fatal side effects. Up to now, experimental tests are missing. DESIGN: Experimental study. MATERIALS AND METHODS: Three surgeons simulated subperichondrial hydrodissection with 20 mineral salt fixed human cadaver heads. One ml lidocaine 5% with 1:105 adrenaline and India ink was infiltrated. Each septum was examined histologically using serial 3 microm sections in 150 microm intervals. Tissue cleavage containing the ink deposits with minimal distance to the proposed subperichondrial zone, intravasal spread and tissue deposition were analyzed. RESULTS: Every injection produced a physical dissection (n = 20). However, dissected planes were localized mostly in the supra-perichondrial connective tissue (n = 8) or within the perichondrium (n = 4). Only five cases showed the propagated correct dissection in a subperichondrial zone. Three anomalous septa were excluded from quantitative analysis. Infiltrated matter did not only accumulate within the dissection plane but also penetrated the surrounding vessels of the septal intumescentia (n = 8). CONCLUSION: Hydrostatic infiltrations represent an unreliable surgical technique for dissection of an anatomical correct subperichondrial plane but can be useful for anesthesia and hemostasis, however, using high pressure and high volume infiltrations might foster serious side effects.