Electrical Diuretics: Lateral Epidural Stimulation of Dorsal Roots to Increase Diuresis.

BACKGROUND

Stimulating diuresis is crucial in heart failure (HF) treatment. Diuretic resistance develops in approximately 30% to 45% of patients with HF.

OBJECTIVE

We investigated the feasibility and safety of lateral epidural stimulation (LES) to enhance diuresis by stimulating renal afferent sensory nerves.

MATERIALS AND

METHODS

In 16 pigs, volume overload with elevated and stable pressures was induced. Diuresis was measured during cycles of up to two hours, and glomerular filtration rate (GFR) was assessed in 12 of 16 experiments. The most effective vertebrae stimulation level was established first. T11-T12 stimulation effectiveness was tested, using a high current (1.2 mA) in one animal and relatively low currents (0.1-0.3 mA) in 15 animals. In three animals, LES effects were assessed during furosemide infusion.

RESULTS

T11-T12 was the most effective vertebrae level for LES. Diuresis increased from 18 mL/20 min (SD = 4 mL/20 min) to 47 mL/20 min (SD = 32 mL/20 min) (n = 9, p < 0.0001), and GFR increased on average 44 [mL/min] (SD = 26, n = 6) (p < 0.001) during T11-T12 LES compared with baseline, excluding one experiment with high current and three lead misplacements. Negative effects in these excluded cases were, according to necroscopy, related to ventral root stimulation, causing shivering, muscle contractions, and elevated heart rate. LES enhanced diuresis during a continuous infusion of furosemide by 54% and 149% and GFR increased by 16 and 14 [mL/min] (two/three correct lead placement).

CONCLUSION

LES at T11-T12 could rival the effectiveness of long-term HF diuretics. Unlike furosemide, LES positively affected kidney function.